Surgery of the Foot

 

Principles of foot and ankle‌‌		Interdigital neuroma	408
arthrodesis‌	385	Lesser toe deformities	409
Hallux valgus correction	388	Lesser metatarsal (Weil’s) osteotomy	414
First metatarsophalangeal joint cheilectomy‌	401	Fifth toe soft tissue correction (Butler’s procedure)	416
First metatarsophalangeal joint‌		Hindfoot arthrodesis	417
arthrodesis	404	Calcaneal osteotomy	421
Ingrowing toenail surgery	406	Viva questions	424

 

Joint/Movement	Range of motion
Subtalar joint inversion	10°
Subtalar joint eversion	5°
Transverse tarsal joint adduction	20°
Transverse tarsal joint abduction	10°
Combined foot supination	30°
Combined foot pronation	15°
First metatarsophalangeal joint flexion	30°
First metatarsophalangeal joint extension	60°

 

 

Position of arthrodesis

• The positions of arthrodesis are covered in the relevant sections.

 

 

 

 

 

Principles of foot and ankle arthrodesis

Preoperative planning

Arthrodesis is a commonly used technique throughout the foot and ankle. Although the approach, position and fixation used are specific to each joint fused, the principles and techniques are common throughout the region and should be well understood. Individual arthrodeses will be dealt with in the relevant sections.

 

Indications

• Painful arthropathy of a joint: Given the large number of adjacent joints in the foot, it can be useful to localise the source of pain with a radiologically guided injection of the proposed joint preoperatively.

• Deformity of a joint affecting the position of the remaining foot: Often associated with congenital or acquired tendon or neuromuscular conditions.

  Contraindications

• Active infection

• Critical ischaemia

• Multiple adjacent arthrodeses (relative contraindication)

   

  Consent and risks

  • Prolonged postoperative treatment: The joint must be immobilised until union and unprotected weightbearing avoided, which may take about 3 months in the hindfoot or ankle.

  • Infection and wound healing problems: Dependent on surgical technique and soft tissue

    handling as well as patient factors.

  • Cutaneous nerve damage: Given the subcutaneous and variable location of cutaneous nerves in the foot, inadvertent damage and subsequent painful neuroma formation can occur.

  • Non-union: Absolute risk is dependent on technical and patient factors. Most patients

    have a 5%–10% risk of non-union and ongoing pain for most procedures. This is increased dramatically in smokers (up to sevenfold), those with poor perfusion, active infection or diabetes.

  • Malunion: Technique dependent. Malunions may be symptomatic, requiring footwear

    adaptations or revision surgery, or may be asymptomatic and tolerated.

  • Development of arthropathy in neighbouring joints: Common over time, but may represent the progression of unrecognised early joint disease.

  • Alteration of gait: Dependent on number and location of arthrodeses.

   

  Anaesthesia and positioning

  General anaesthesia is usually required. A thigh tourniquet is required to allow exposure of the limb to above the knee. This allows accurate assessment of alignment. A supportive bolster under the calf is useful to allow free access to the foot.

   

  Surgical principles

  The principles for achieving successful arthrodesis are: (1) complete removal of cartilage and soft tissue that may prevent adequate fusion, (2) adequate compression across the fusion site, (3) optimal position of the joint and (4) adequate bone apposition until fusion is achieved. The general principles are to mobilise the joint to allow correction of any deformity and complete access to the joint surfaces. The surfaces are prepared, maintaining the joint

   

  shape and congruity while exposing bleeding cancellous bone. The joint is then held rigidly in the required position of arthrodesis.

  Careful placement of incisions of adequate length is vital to prevent undue soft tissue damage and tension. Most joints are relatively superficial, so adequate soft tissue cover is vital.

  The capsule and surrounding soft tissues need to be released to allow full access to the joint and to correct any deformity. Most deformities can be corrected with adequate mobilisation, but occasionally bone resection is required.

  The joint surfaces need to be carefully prepared. First, any peripheral osteophytes should be removed to expose the true joint. Second, the cartilage and subchondral plate must be removed, maintaining the contour of the joint. This is best achieved with a variety of sharp chisels working in a methodical manner from superficial to deep. Power tools generate unwanted heat and should be avoided. As the joint is prepared, a laminar spreader is gradually advanced into the joint to open it up. Pituitary rongeurs and Kerrison laminectomy rongeurs are useful to access the deep recesses of the joint safely. Once all joint surfaces are removed, the surface area of bleeding bone should be increased by various methods. Using a chisel to cross-cut the surface and applying a slight twist on removal can produce bone ‘petals’ to good effect.

  The joint should be positioned in the desired position and, if needed, provisionally held with a K-wire. A careful confirmation of the position with respect to the limb alignment and the rest of the foot must be undertaken to ensure a satisfactory outcome. It is unusual, unless bony destruction has occurred, to require a supplementary bone graft. If required, sufficient quantities can usually be harvested locally from the calcaneus, medial malleolus or proximal tibia without need to prepare the iliac crest.

  Rigid fixation and compression of the joint must be achieved. This is usually done with some form of compression screw or screws. However, in certain situations other forms of fixation, such as staples, intramedullary devices or external fixations may be appropriate. Satisfactory compression can be tested by carefully inserting a fine chisel into the joint and twisting – there should be no give.

  Careful, tension-free wound closure is critical. A soft tissue layer should be closed over the joint prior to skin closure. The joint is immobilised in a back slab to protect the fusion and soft tissues.

  Postoperative care and instructions

  The leg should be elevated until swelling has subsided. Mobilisation should avoid weightbearing on the joint. In the forefoot, a wedge-type shoe may be sufficient but may require a non-weightbearing cast. Unprotected weightbearing should be avoided until there is clinical and radiological evidence of union.

  Recommended references

  Glissan DJ. The indications for inducing fusion at the ankle by operation with description of two successful techniques. Aust N Z J Surg. 1949;19:64–71.

  Hardy MA, Logan DB. Principles of arthrodesis and advances in fixation for the adult acquired flatfoot.

  Clin Podiatr Med Surg. 2007;24:789–813.

   

  Hallux valgus correction‌

  Preoperative planning

  There are a multitude of procedures described for the correction of hallux valgus deformity, some considered historical and others in current use. In order to select the correct procedure for a specific patient, an understanding of the spectrum of hallux valgus deformities must exist.

   

  Indications and choice of procedure

  The presence of a bunion is not an indication for surgery.

   

   

  The strongest indication for operative intervention in hallux valgus is pain. This pain is located over the bunion and usually only felt with shod feet. Pain present when barefoot or under the metatarsal head suggests another source of the pain should be sought. Footwear problems due to extreme deformities are a relative indication. Operating solely for cosmetic or fashion reasons is generally not recommended.

  On examining the patient, the neurovascular status of the patient must be examined along with the overall hindfoot and foot alignment. Joint mobility is assessed: hypermobility of the first tarsometatarsal joint (TMTJ) is associated with an increased risk of postsurgical recurrence.

   

  Contraindications

  Patients with significant pre-existing degenerative change in the metatarsophalangeal joint (MTPJ) will usually not benefit from realignment surgery and should be offered arthrodesis (see ‘First metatarsophalangeal joint arthrodesis’, p. 404).

  Patients with hypermobility or instability of the first TMTJ are likely to have a recurrence after a simple osteotomy. These deformities might be best treated with a first TMTJ arthrodesis combined with a lateral release (see ‘Lapidus procedure’, p. 399).

   

  Consent and risks

  There is considerable variation, depending on the specific procedure: details of operation-specific risks are detailed within the operative techniques discussed later. General complications are listed here:

   

  • Foot sNape: Most procedures will result in a narrower forefoot with a straighter hallux. However, this may still preclude the wearing of many fashionable shoes.

  • 3tiffness: Most procedures which violate the MTPJ are associated with varying degrees

  of postoperative stiffness. This can be particularly troublesome with the Scarf osteotomy due to the degree of soft tissue mobilisation.

   

   

  • Recurrence of deformity: Usually associated with poor technique, attempting to push the indications of a procedure too far or not recognising complicating factors (laxity, increased distal metatarsal articular angle [DMAA], congruent joint, etc.).

  • Overcorrection and Nallux varus: Usually occur due to overenthusiastic soft tissue

    correction or excessive displacement of the capital fragment. Excessive medial eminence excision or the excision of the fibular sesamoid in a McBride release also predispose to hallux varus.

  • Nerve damage and neuroma formation: Damage to the dorsomedial or plantar nerves is

    possible with most procedures and can cause painful neuroma formation.

  • Transfer metatarsalgia: Anything that alters the relationship between the first and lesser metatarsals in the sagittal plane can lead to painful overloading of the lesser metatarsals, usually the second. This can occur in techniques that result in excessive shortening or elevation of the metatarsal head. It can also occur with defunctioning of the hallux, as occurs with a Keller procedure.

   

   

  Operative planning

  Radiology

  All patients presenting with hallux valgus should have weigNtbearing anteroposterior (AP) and lateral radiographs of both feet obtained. Various radiographic angles and measurements are frequently used to define the anatomical location and magnitude of the hallux deformity which can aid surgical planning (Figure 14.1a through d). These include:

   

  

   

   

  Figure 14.1 Radiographic assessment of hallux valgus. (a) Intermetatarsal angle (IMA). (b) Hallux valgus angle (HVA). (c) Distal metatarsal articular angle (DMAA). (d) Hallux valgus interphalangeus angle (HVI).

   

• Hallux valgus angle (HVA): The angle between the anatomical axes of the first metatarsal and the proximal phalanx.

   

• First–second intermetatarsal angle (IMA): The angle between the anatomical axes of the first and second metatarsals.

• DMM: The angle between a line drawn from the medial and lateral borders of the articular surface of the distal metatarsal and the anatomical axis of the metatarsal.

• InterpNalangeal angle: The angle between the proximal and distal articular surfaces of the proximal phalanx of the hallux.

• Hallux valgus interpNalangeal angle (HVI): The angle formed between the long axis of the distal phalanx and the proximal phalanx and is usually less than 10°.

• Joint congruity: The medial and lateral borders of the joint surface of the metatarsal and phalanx are identified. The first MTPJ is said to be congruent if the lateral and medial borders of the two joint surfaces align. If they do not, the joint is incongruent (Figure 14.2).

   

   

  

  Figure 14.2 Assessment of first metatarsophalangeal joint congruity.

   

• Presence of degenerative cNanges in tNe first MTPJ.

• 3igns of first TMTJ instability: These include opening up of the first TMTJ on the lateral view and widening of the gap between the first/second metatarsal bases.

• Congruent deformities require an osteotomy that incorporates rotation to correct the relationship of the articular surface to the axis of the metatarsal.

• Mild deformities can be corrected with a single metatarsal osteotomy (e.g. biplanar Chevron or modified Scarf – see later) with or without the addition of a phalangeal osteotomy (Akin osteotomy – see later).

• Severe deformities occasionally require a combined proximal and distal metatarsal osteotomy (see ‘Proximal (basal) metatarsal osteotomy’, p. 400).

• Most authors categorise incongruent hallux valgus based on broad categories of severity. Such categories are not absolute but act as general guidelines to help define the limits of certain procedures and to help in the selection of the correct treatment. Table 14.1 shows typical figures.

  Anaesthesia and positioning

  All hallux valgus surgery can be performed under a regional (ankle) block or general anaesthesia. A bloodless field is provided by a thigh or ankle tourniquet. The patient is positioned supine and the whole foot and ankle prepared.

   

  Table 14.1 Categorisation of hallux valgus severity

   

  Angle measured	Normal	Mild	Moderate	Severe
  HVA	<15°	15°–20°	20°–40°	>40°
  IMMA	<9°	9°–11°	11°–16°	>16°
  DMAA	<6°

  Source: After Coughlin MJ, Saltzamn CL, Anderson RB. Mann’s Surgery of the Foot and Ankle. 9th ed.

  Philadelphia, PA: Mosby, 2007.

   

  Surgical techniques

  Given the huge range of surgical procedures described for hallux valgus, it is not within the scope of this book to describe them all. We shall therefore concentrate on those procedures commonly performed. Each procedure is described individually, but in practice, several techniques, such as the metatarsal osteotomy, Akin osteotomy and lateral soft tissue release, may be performed in combination.

   

  First metatarsophalangeal joint sofi tissue release

  A soft tissue release attempts to balance out the soft tissues around the first MTPJ. With a valgus deformity, the medial tissues become attenuated and those on the lateral side contracted. The original McBride procedure was more extensive, including excision of the lateral sesamoid, and was associated with a high rate of hallux varus. The procedure has been altered so many times that the term ‘modified McBride’ is misleading and should be avoided.

   

   

  A soft tissue release is rarely performed in isolation. However, it is part of many procedures so a detailed understanding is important.

   

  Specific indications

• Incongruent, mild hallux valgus with normal, or near normal IMA

• In combination with another procedure (see later)

   

  Consent and risks

  • Overcorrection and Nallux varus: Caused by excessive soft tissue release and excessive medial plication

  • Excessive medial plication can also lead to joint stiffness

  • Nerve damage: The common digital nerve is deep to the intermetatarsal ligament and can be damaged

   

   

  Incision

  Starting on the medial side, a medial longitudinal incision is made, centred over the metatarsal head and extending from the shaft of the proximal phalanx to the distal shaft of the metatarsal.

   

  Dissection

   

  Structure at risk

  • Dorsomedial sensory nerve

   

  Dissection is continued down to capsule and then a dorsal flap is carefully elevated to identify the dorsal nerve adherent to the capsule on the dorsomedial aspect. This is repeated on the plantar side, dissecting around the capsule to create a small pocket. A longitudinal capsulotomy is performed and any adhesions released.

   

  Surgical technique

  Unless a distal metatarsal osteotomy is also to be performed, the prominent medial eminence of the head can now be removed. This is done with a fine oscillating saw, aiming to cut in line with the medial shaft starting 2–3 mm from the medial sulcus (Figure 14.3).

   

   

  

  Figure 14.3 Excision of medial eminence of first metatarsophalangeal joint.

   

  It is the authors’ practice to use a separate incision for lateral release, however many surgeons use the same medial approach for the soft tissue release. Attention is now turned

   

  to the first web space. A 3 cm incision is centred between the metatarsal heads in the first web space then bluntly dissected down to the level of the heads. Inserting a laminar spreader or self-retainer between the heads allows identification of the lateral sesamoid and insertion of adductor hallucis into its lateral edge. Using a size 15 blade, the capsule is released from the dorsal aspect of the sesamoid then the blade is advanced to the insertion of adductor hallucis into the phalanx. The insertion of adductor hallucis is released from the phalanx then, working proximally, the remaining tendon is released from the sesamoid. Deep to this is the intermetatarsal ligament which runs from the second metatarsal to the lateral sesamoid, not the first metatarsal itself. This is carefully divided from the sesamoid, taking care to preserve the neurovascular bundle which lies directly underneath. The lateral capsule (metatarso-sesamoid ligament) is then incised longitudinally, after which the articular surface of the lateral sesamoid can be inspected and should be reducible underneath the metatarsal head. The retractor is removed and confirmation that the toe can be passively overcorrected is sought.

  Returning to the medial side, the metatarsal head should be reducible onto the sesamoids. If too much resistance is encountered, a bony procedure is required to correct the deformity. Subsequent capsular plication is designed to take in excess capsule, not pull the sesamoid complex over.

  Using an absorbable suture, the excess capsule is ‘double-breasted’ while holding the MTPJ flexed. This is done by passing a stitch through the dorsal capsule from outside in, medial to the extensor tendon and avoiding the identified nerve. The needle is then passed from outside the plantar capsule, just medial to the sesamoid then reversed to come from inside out. It is finished by exiting through the dorsal capsule, near the earlier entry point. As the suture is tightened, the dorsal capsule should double-breast over the plantar capsule. Plication is checked to ensure that it is not too tight by flexing and extending the joint.

   

  Closure

  The rest of the capsule is then closed with absorbable sutures prior to skin closure.

   

  Scarf osteotomy

  The Scarf osteotomy is a powerful and versatile osteotomy allowing correction of all of the axes of the hallux valgus deformity; it is a tecNnically cNallenging procedure with a steep learning curve. It is named after a joiners’ technique, used to connect two beams.

   

  Specific indications

• Moderate or severe hallux valgus

• Hallux valgus with an increased DMAA

• Revision surgery

   

  Specific contraindications

• Poor bone stock or osteoporosis increasing the risk of fracture

 

Consent and risks

• Fracture: Given the length of the osteotomy, fracture, either intraoperatively or postoperatively can occur (3%–5%).

• MTPJ stiffness: Especially if the metatarsal is inadvertently lengthened.

• Malunion: Care must be taken to ensure all cuts are in the correct direction in all three planes.

• TrougNing: This occurs when the shaft cortex of one fragment collapses into the cancellous

bone of the other fragment (Figure 14.4). This results in elevation of the metatarsal head and rotation of the osteotomy. It is more common where there is poor bone stock. By ensuring the ends of the osteotomy are in dense metaphyseal bone, rather than the diaphysis, the risk can be reduced.

 

 

 

 

 

 

Incision

Figure 14.4 Troughing of Scarf osteotomy.

A medial approach, as described earlier, is performed. However, the incision continues proximally until approaching the TMTJ.

 

Dissection

 

Structures at risk

• Dorsomedial sensory nerve

• Blood supply to first metatarsal head

 

Dorsally, the capsule and dorsal periosteum are released from the distal half of the bone, exposing the dorsal surface. Plantarwards, great care is taken to not damage the vascular leash entering the head on the plantar surface of the neck (Figure 14.5).

 

Surgical technique

The periosteum is only elevated from the proximal third, dissecting away from the neck. A minimal excision of the medial eminence is performed in line with the shaft, aiming to just expose cancellous bone. At this point it is advisable to draw out the planned osteotomy, on the medial aspect of the bone (see Figure 14.5). The longitudinal arm begins at a point

 

 

 

Figure 14.5 Scarf osteotomy and plantar vascular supply of the metatarsal head.

 

3 mm from the dorsal cortex, 5 mm proximal to the dorsal articular edge. This then extends proximally and plantarwards to a point 3 mm from the plantar surface and 10 mm from the TMTJ. Two horizontal 60° limbs are then added to the ends to exit the nearby cortices. The distal horizontal limb should be perpendicular to the second metatarsal shaft; we advise drawing a line connecting the medial point of origin of the distal first metatarsal cut running perpendicular to the second metatarsal shaft and on through the lateral rays. The metatarsal head that it passes through (usually the fourth) can be used as a reference for the cut. Palpating the fourth metatarsal head, another line is drawn on the dorsal surface, from the distal arm across the dorsal surface towards the fourth.

Once satisfied with the planned osteotomy, an oscillating saw is used to score the cortex for the longitudinal arm. After a starting point is made, the blade is angled plantarwards, in the plane of the shafts of the metatarsals. Maintaining this angle, the whole length of the longitudinal arm is cut, penetrating only the medial cortex; the lateral cortex is then softly cut in the same plane. Next, the distal arm is cut, maintaining the slight plantar angle and aiming for the fourth metatarsal head as planned. The proximal cut should now be cut parallel or slightly divergent to this – if the cuts converge, the osteotomy will not displace. The osteotomy should now be mobile. If not, all cuts are checked for completion and the two fragments gently freed with a MacDonald dissector, starting proximally.

The osteotomy is now displaced as required. This is facilitated by a ‘push-pull’ action, grasping the proximal fragment with a towel clip while pushing the distal fragment laterally. The osteotomy sNould displace laterally and plantarwards. The reduction is then held with a clamp. The reduction is checked by observing the position of the medial sesamoid: it should lie under the medial metatarsal head. Once the reduction is satisfactory, a K-wire is inserted along the lateral edge of the proximal fragment into the head and a stepped bone clamp will prevent displacement.

The osteotomy is secured with two screws – headless, variable pitch compression screws are ideal. The first screw should start from the dorsolateral aspect of the distal end of the proximal fragment and aim towards the medial sesamoid. This must be intraosseous to avoid sesamoid damage. A second screw can then be used in a dorsoplantar direction to secure the proximal extent of the osteotomy. The proximal screw should be bicortical.

After fixation, the prominent medial cortex of the proximal fragment can be bevelled flush with the shaft.

 

Closure

Closure of the capsule should be performed as described previously.

 

Akin osteotomy

Specific indications

• Hallux interphalangeus deformity, where the deformity occurs distal to the MTPJ

• In combination with a metatarsal osteotomy to correct residual phalangeal deformity

  Specific contraindications

  Akin osteotomy in isolation will not correct joint incongruity or an increased IMA so should not be used alone in these cases.

   

  Incision

  A medial longitudinal incision is performed, starting just proximal to the interphalangeal joint (IPJ) and extended past the medial eminence of the metatarsal. This can be incorporated into the incision for a metatarsal osteotomy if required.

   

  Dissection

  A longitudinal capsular incision is made and extended proximally to incise the periosteum of the phalanx. This is then carefully elevated, allowing the placement of retractors superiorly and inferiorly.

   

  Surgical technique

   

  Structure at risk

  • Flexor hallucis longus tendon

   

   

  If required, the medial eminence of the metatarsal can be excised, as earlier. The osteotomy is a closing wedge osteotomy, performed with an oscillating saw from the medial side; the lateral cortex is left intact. Particular care should be taken to avoid damage to the long flexor inferiorly. It is easy to overcorrect the deformity, so it is wise to underestimate the size of the wedge and check the result. The alignment of the osteotomy depends on the planned means of fixation (Figure 14.6).

  If a staple is used, the first cut should be parallel to the proximal joint surface. The second cut is parallel to the base of the nail, aiming to converge before the lateral cortex, leaving it intact. The wedge is removed and the osteotomy closed. If there is resistance, the lateral cortex can be cautiously weakened with the saw, but should not be breached. Using the planned staple as a guide, entry holes are drilled using a fine K-wire and the staple inserted. After insertion the joint is inspected to ensure that it is not penetrated by the staple. Postoperative radiographs can be misleading in this regard because of the convex nature of the joint surface.

   

   

  

  Figure 14.6 Akin osteotomy.

  If a cannulated compression screw is to be used, the osteotomy will be angled to allow compression. A screw will be inserted over a guide wire passing from the medial edge of the proximal flair of the phalanx, exiting distally in the lateral cortex.

   

  Closure

  The capsule is closed with absorbable sutures prior to skin closure. A forefoot dressing is applied.

   

  Chevron osteotomy

  The chevron osteotomy is a relatively simple osteotomy for the correction of mild hallux valgus.

   

  Specific indications

• Mild (and moderate – see later) hallux valgus deformity

• Congruent hallux valgus deformity as the osteotomy does not disturb the balance of the joint – using a biplanar chevron (see later)

  Specific contraindications

  Due to technical limits of the procedure, it should be reserved for deformities with an IMA less than 12°, HVA less than 30° and DMMA less than 15°. Attempting to push the indications further increases the risk of avascular necrosis of the capital fragment.

   

  Consent and risks

  • Avascular necrosis of tNe capital fragment: Up to 20% in some series. Probably technique dependent with increased avascular necrosis seen with extensive soft tissue stripping and release and with excessive displacements attempted.

  • Malunion: If the osteotomy is angled too proximally, shortening of the first metatarsal

  will occur with translation. Similarly, if the osteotomy is angled dorsally the metatarsal head will be elevated. Both of these technical errors will alter the relationship of the first metatarsal head to that of the lesser metatarsals and may lead to transfer metatarsalgia.

   

   

  Incision and dissection

  A standard medial approach is made to the metatarsal head (see earlier).

   

  Surgical technique

  The medial eminence is resected in a plane parallel to the medial border of the foot, beginning at the sulcus. A lateral release is not routinely performed due to the increased risk of avascular necrosis. The chevron osteotomy is a V-shaped cut of approximately 60° witN tNe apex at tNe centre of tNe metatarsal Nead (Figure 14.7a). Because the plane of the cuts is crucial, it can be useful to place a K-wire in this central point, running parallel to the sole of the foot and the distal articular surface of the metatarsal. This wire can then be used as a cutting guide to position the limbs of the chevron. The most crucial cut is the plantar limb, which must exit the plantar surface of the metatarsal in an extra-articular position to avoid damage to the sesamoid articulation. Several authors advocate a more horizontal plantar limb (see Figure 14.7b) to attempt to preserve the plantar blood supply (see ‘Scarf osteotomy’, p. 393). The dorsal limb is then cut at approximately 60° to the first cut. After completion of the cuts, the capital fragment can be translated laterally by up to 30% of its width to correct the hallux valgus.

   

  
  

   

   

  Figure 14.7 Chevron osteotomy. (a) Classic chevron osteotomy, risking damage to plantar blood supply to metatarsal head. (b) Modified chevron osteotomy to preserve plantar blood supply to metatarsal head.

  If there is an increased DMMA, the joint can be reorientated by means of a biplanar chevron. By taking a small (1–2 mm) wedge from the superomedial and inferomedial aspect of the limbs, the fragment can be displaced laterally but rotated medially, correcting the DMMA as may be required in a congruent hallux valgus.

  Although inherently a stable osteotomy, most surgeons hold the osteotomy with a K-wire or screw inserted from a dorso-proximal to plantar-distal direction. Care must be taken not to leave any fixation proud of the joint to avoid damage to the sesamoid articulation.

   

  Closure

  Capsular closure is as presented earlier.

   

  Lapidus procedure

  Specific indications

• Hallux valgus deformity in the presence of instability of the first TMTJ

• Moderate to severe incongruent hallux valgus deformity

• Salvage procedure for previous failed hallux valgus surgery

• Arthritis of the first TMTJ

  Specific contraindications

  Given the shortening of the first ray that occurs with Lapidus, the procedure should not be performed on patients with short first metatarsals.

   

  Surgical technique

   

  Structure at risk

  • Tibialis anterior tendon

   

  The Lapidus procedure involves first TMTJ arthrodesis; this should be performed with the previously described lateral soft tissue release, excision of the medial eminence and plication of the medial capsule. The medial incision for the MTPJ can be continued proximally to the TMTJ. Alternatively, a separate medial incision can be made centred over the joint. The joint is usually deep to a vein, crossing from dorsal to plantar, and some authors advocate preserving it to reduce postoperative swelling. The joint can be identified with the aid of a needle and opened to mobilise the joint. Care must be taken to avoid damage to the tendon of tibialis anterior, which lies on the inferomedial aspect of the joint. Using traction on the toe, the joint can be opened and preparation of the joint performed as detailed in ‘Principles of foot and ankle arthrodesis’ (p. 385). Once the preparation has begun, there is enough room to insert a laminar spreader.

  Several authors describe a Lapidus procedure as a closing wedge arthrodesis. However, this is usually not required. By careful preservation of the joint shape, the base of the metatarsal can usually be displaced medially and slightly inferiorly with digital pressure, thereby reducing the IMA and overcoming the elevation of the metatarsal head caused by shortening of the joint. A good correction coincides with the appearance of a ‘step’ on the medial side. Once reduced, the joint is provisionally held with a K-wire before checking the position. If further correction is required, minimal resection of the inferolateral aspect of the metatarsal base is performed.

  The arthrodesis can be secured by means of screws or a custom plate. To use screws, a

  3.5 mm glide hole is drilled from the dorsum of the metatarsal, starting 15–20 mm from the joint and slightly laterally, aiming for the cuneiform. It is important to avoid aiming

   

  too plantarwards, which results in a poor hold on the cuneiform. The cuneiform is then drilled, using a 2.5 mm drill in standard AO fashion. Prior to inserting the screw, an oval groove in the transverse plane should be created (using a small burr or countersink) to accommodate the head of the screw and avoid breaking the dorsal cortical bridge. Once tightened, a second screw can be inserted from the cuneiform to the metatarsal, in a parallel sagittal plane to the first screw.

   

  Closure

  The soft tissues are closed over the fusion prior to skin closure.

   

  Specific postoperative instructions

  If satisfactory fixation is achieved and the patient is compliant, they may mobilise postoperatively in a forefoot-offloading wedge shoe for 12 weeks.

  Otherwise a non-weightbearing cast can be used to protect the arthrodesis.

   

  Proximal (basal) metatarsal osteotomy

  The proximal metatarsal osteotomy is usually performed in combination with a lateral soft tissue release, excision of medial eminence and medial capsule closure, as described earlier.

   

  Specific indications

  Correction of moderate to severe Nallux valgus is an indication, especially when associated with a large IMA. By making an osteotomy at the base of the metatarsal, larger corrections of IMA can be made than by operating more distally.

   

  Specific contraindications

  Congruent deformities (if used in isolation) – as the osteotomy does not alter the relationship between the anatomical axis of the metatarsal and the distal articular surface, it will not alter the DMMA. However, it may be of use when combined with a distal osteotomy to correct a congruent deformity with increased IMA (a double osteotomy).

   

  Consent and risks

  • Malunion: Any misorientation of the plane of the osteotomy can result in significant accidental misplacement of the metatarsal head.

  • Overcorrection: Given the power of this osteotomy to realign the shaft, overcorrection

  and hallux varus can be troublesome, especially when combined with an aggressive lateral release.

   

  Incision

  A dorsal incision is made over the base of the metatarsal, avoiding any superficial cutaneous nerves.

   

  Surgical technique

  The osteotomy is ideally placed about 1 cm from the TMTJ in metaphyseal bone to provide a broad area for union. A dome osteotomy or closing or opening wedge osteotomies can be performed.

  The lateral closing wedge will tend to shorten the metatarsal. There are various plates designed to fix the opening wedge osteotomies.

  The coronal plane of tNe osteotomy is vital – It should be perpendicular to the plane of the metatarsal. If the blade is directed too medially, the head will be elevated; if directed too laterally, it will be depressed. In the sagittal plane, the blade should be positioned perpendicular to the sole then angled slightly proximally. Once cut, the osteotomy can provisionally be reduced and the position checked. If satisfactory the osteotomy is fixed with two screws or a screw and wire.

   

  Keller procedure

  This involves excision of the medial prominence of the metatarsal and the proximal third of the phalanx to relax the lateral structures and allow correction of the toe, which is then held with a temporary K-wire. Although once commonly performed, its generally unsatisfactory results have caused it to fall out of favour. The patient is left with a floppy great toe and, by defunctioning the hallux, is prone to overload their lesser rays with resultant pain. However, it can be considered in the older, minimally ambulatory patient who has footwear problems or in those patients whose soft tissues or general fitness precludes a more aggressive procedure.

   

  General postoperative care and instructions

• The foot is dressed with a standard forefoot dressing, extending above the ankle.

• The foot is elevated for 72 hours to reduce swelling.

• The patient may mobilise, fully weightbearing, in a forefoot-offloading wedge shoe for 6 weeks.

• After skin wounds have healed, the patient is taught passive mobilisation of the MTPJ to reduce stiffness.

  Recommended references

  Barouk LS. Scarf osteotomy for hallux valgus correction. Local anatomy, surgical technique, and combination with other forefoot procedures. Foot Ankle Clin. 2000;5:525–558.

  Barouk LS. Forefoot Reconstruction. Paris, France: Springer-Verlag, 2005.

  Weil LS. Scarf osteotomy for correction of hallux valgus. Historical perspective, surgical technique, and results. Foot Ankle Clin. 2000;5:559–580.

   

  First metatarsophalangeal joint cheilectomy‌

  Preoperative planning

  Hallux rigidus, or degenerative arthritis of the first MTPJ, is a common condition. Although in its early stages it can be managed with conservative measures, such as footwear and

   

  activity modifications, patients often require operative intervention. Cheilectomy, from the Greek for lip, cNeilos, addresses both the pain and stiffness found in this condition.

   

  Indications

• Mild to moderate degenerative changes in the first MTPJ with pain and stiffness, failing to respond to conservative management

• More advanced degenerative changes in a patient unwilling to lose joint movement (patient must be counselled that there may be improvement in movement but only limited improvement in pain)

• Prominent dorsal osteophytes causing footwear problems

   

  Contraindications

  Contraindications include advanced degenerative changes with loss of joint space.

   

  Consent and risks

  • Failure or recurrence of symptoms: Especially if the degenerative changes are more extensive than appreciated preoperatively or if insufficient resection is performed

  • Instability of first MTPJ: Especially if resection exceeds 35% of joint surface

  • Damage to dorsal cutaneous nerve and neuroma formation

   

   

  Anaesthesia and positioning

• Regional or general anaesthesia

• Ankle or thigh tourniquet

• Supine on operating table

   

  Surgical technique

  Landmarks

• The MTPJ of the great toe is easily palpable

• Extensor hallucis longus (EHL) tendon

   

  Incision

  A 5 cm dorsal incision is made along the medial border of EHL centred over the first MTPJ.

   

  Dissection

  The underlying extensor hood is incised in line with the incision but leaving a cuff of tissue on the medial side of the tendon to avoid violating the tendon sheath and reducing the risk of adhesions.

  The joint capsule is incised and the joint exposed by dissection medially and laterally. Alternatively, a medial approach, as described in first MTPJ arthrodesis, may be used.

   

  Procedure

  A full synovectomy is performed and any loose bodies removed. Flexing the joint fully allows inspection of the joint surface. In mild and moderate disease, the damage is usually limited to the dorsal aspect. Ideally, the resection should extend from just dorsal of the edge of the viable cartilage to just proximal of the dorsal prominence of the head. However, care should be taken to ensure that this resects 20%–30% of the joint (Figure 14.8).

   

   

   

  

   

   

  Figure 14.8 First metatarsophalangeal joint cheilectomy – minimum and maximum resection levels.

   

   

  Note on resection level (Figure 14.8): A common cause for failure of cheilectomy is insufficient resection. A minimum of 20% of tNe articular surface must be removed, even if this includes normal joint surface, to ensure adequate movement. Exceeding 35% is likely to destabilise the joint.

  The dorsal prominence is resected with a saw or osteotome and satisfactory dorsiflexion (ideally 60°) is confirmed. Any prominent osteophytes are removed from the dorsal phalanx and the medial and lateral aspect of the head, and the joint is irrigated to thoroughly wash out. Bone wax can be used sparingly to reduce bleeding and adhesions. Moberg osteotomy – proximal phalanx osteotomy. Once cheilectomy is carried out, the range of movement should then be assessed. If the cheilectomy fails to achieve between 30° and 40° of motion, then one can consider a proximal phalanx osteotomy. This is a dorsal closing wedge osteotomy popularized by Moberg in the adult population.

   

  Closure

  Careful closure of the capsule with interrupted Vicryl precedes skin closure. A forefoot dressing is applied to above the ankle.

   

  Postoperative instructions

  The foot is elevated for 48 hours. The patient fully weightbears on a postoperative shoe and aggressive active and passive mobilisation begins once skin healing has occurred.

   

  Recommended reference

  Coughlin MJ, Shurnas PS. Hallux rigidus. Grading and long-term results of operative treatment. J Bone Joint Surg Am. 2003;85:2072–2088.

   

  First metatarsophalangeal joint arthrodesis‌

  Preoperative planning

  Once a patient has developed severe hallux rigidus, a cheilectomy is unlikely to address the problem. Although various arthroplasties are available, most either have limited long-term results or are associated with high failure rates. Arthrodesis of the joint provides a reliable solution to the pain of advanced arthritis of the joint.

   

  Indications

• Painful arthropathy of first MTPJ not responding to conservative treatment and not suitable for less invasive treatment (e.g. cheilectomy)

• Severe first MTPJ deformity in the presence of degenerative changes

• Salvage of failed first ray surgery

  Absolute contraindications

• Active infection

• Limb ischaemia or poor perfusion

  Relative contraindication

  This includes previous IPJ arthrodesis or pre-existing IPJ degenerative changes.

   

  Consent and risks

  (See also ‘Principles of foot and ankle arthrodesis’, p. 385.)

  • Malunion: Excessive extension can cause defunctioning of hallux and transfer metatarsalgia. Excessive flexion can cause increased wear and pain in the IPJ. Excessive valgus can cause pressure on the second toe.

  • Damage to dorsal cutaneous nerve and neuroma formation.

  • Unable to wear NigN Neels after surgery: This must be stressed to women considering operation.

  • Minimum of 6 weeks protected weightbearing.

   

  Anaesthesia and positioning

• Regional or general anaesthesia

• Ankle or thigh tourniquet

• Supine on operating table

  Surgical technique

  Landmarks

  The MTPJ of the great toe is easily palpable.

   

  Incision

  A straight medial midline incision is made, centred over the MTPJ.

   

  Dissection

  This is continued straight down to the joint capsule, without developing flaps. The capsule is incised in line with the skin incision and freed dorsally over the metatarsal head and sufficiently around the phalangeal base to allow its surface to be delivered. Alternatively, the approach described for cheilectomy may be used.

   

  Procedure

  The surfaces are prepared in a manner outlined in ‘Principles of foot and ankle arthrodesis’ (p. 385). Given the joint’s small size, it is not possible, or really necessary, to use a laminar spreader. Furthermore, the concave surface of the phalanx makes the use of chisels difficult; a curette or bone nibbler may be more useful. Various dome-shaped reamers may also be used, but care should be taken to avoid removal of excessive bone, which will lead to shortening.

  Note about sagittal position of artNrodesis (Figure 14.9): several textbooks state a fixed value for the position of first MTPJ arthrodesis, e.g. 25°–30° extension. This can be confusing as it may be unclear if this refers to the angle relating to the floor or the metatarsal shaft. Furthermore, the angle to the metatarsal depends on the pitch of the metatarsal, i.e. whether the foot is planus or cavus. It is therefore preferred to arthrodese the joint in a relative position to a simulated floor. Using a flat surface to push up against the sole of the foot, assess the position of the pulp of the hallux with regard to the surface. If a finger can be pushed under the pulp, the toe is too extended. If there is no space for any flexion of the

   

  
  

   

   

  Figure 14.9 Coronal position of arthrodesis of the first metatarsophalangeal joint. Note that the phalanges are parallel to floor, allowing clearance of toe pulp.

   

  IPJ, the position is too flexed. An ideal position allows a small amount of movement with downward pressure on the distal phalanx.

  The joint is positioned as required and provisionally held with a K-wire. The sagittal position of the toe is then assessed with regard to a flat surface as outlined earlier. The coronal position should be of sufficient valgus to avoid the medial border of the toe rubbing upon the toe box of a shoe but not so much that there is impingement of the hallux against the second toe; 10°–15° HVA is usually appropriate. There should be no rotational deformity.

  In primary surgery with good bone stock, the arthrodesis can be secured in various ways. A single-axial compression screw combined with a dorsal neutralising or compression plate or crossed screw techniques are commonly used. Our preferred method is the crossed screw technique using two crossed screws. The first is inserted with a lag technique to compress the joint; the second provides a de-rotational function. Alternatively, a custom-made plate may be used.

   

  Closure

• Careful closure of the capsule with interrupted Vicryl precedes skin closure.

• A forefoot dressing is applied to above the ankle.

  Postoperative instructions

  The foot is elevated for 72 hours. A reliable patient can mobilise in a wedge shoe to offload the forefoot until evidence of clinical and radiological union. If there is concern about the compliance of the patient, a cast may be used.

   

  Recommended references

  Coughlin MJ, Saltzamn CL, Anderson RB. Mann’s Surgery of the Foot and Ankle. 9th ed. Philadelphia, PA: Mosby, 2007.

  Coughlin MJ, Shurnas PS. Hallux rigidus. J Bone Joint Surg Am. 2004;86(Suppl 1):119–130.

   

  Ingrowing toenail surgery‌

  Preoperative planning

  A multitude of operations exist to deal with ingrowing toenails, or onychocryptosis. Chemical ablation with phenol of either part or all of the nail matrix is associated with lower recurrence rates than surgical ablation in most series.

   

  Indications

  Indications include painful onychocryptosis or recurrent infections.

   

  Contraindications

• Severe digital vascular compromise is an absolute contraindication.

• Active infection is a relative contraindication.

   

  Recurrence may be better treated with total matrix ablation.

   

  Consent and risks

  • Recurrence: Less than 5%

  • Infection: Superficial infection commonly dependent on postoperative care

  • PNenol burns: Rare

   

  Anaesthesia and positioning

  Toenail surgery can be effectively performed under digital block with or without additional sedation. A bloodless field is established with the use of a digital tourniquet secured with an artery forceps.

   

  Surgical technique

  The affected nail border is elevated from the nail bed and surrounding skin by blunt dissection with forceps. The nail border is then cut using a blade or scissors underneath the ungual fold (Figure 14.10). Grasping the fragment with an artery forceps and using a rotating movement, the nail border is carefully avulsed in its entirety, complete with the widened germinal base. The nail groove is then carefully curetted.

   

   

  Figure 14.10 Partial matrix ablation – line of excision for nail border.

   

  All blood is carefully cleared from the field and all exposed skin protected with petroleum jelly. A cotton bud is soaked in phenol and inserted along the exposed nail bed, under the ungual fold, and left for 60 seconds. This process is repeated once more then the whole area irrigated with copious amounts of saline. The tourniquet is released and a toe dressing applied.

   

  Postoperative care and instructions

  The foot is elevated for 48 hours then the dressings are reduced. The wound is then washed in tepid boiled salted water twice a day using a baby toothbrush, sweeping in a proximal to distal direction. When showering the patient is instructed to aim the spray directly over the wound.

   

  Recommended references

  Herold N, Houshian S, Riegels-Nielsen P. A prospective comparison of wedge matrix resection with nail matrix phenolization for the treatment of ingrown toenail. J Foot Ankle Surg. 2001;40:390–395.

  Park DH, Singh D. The management of ingrowing toenails. BMJ. 2012;344:e2089.

   

  Interdigital neuroma‌

  Preoperative planning

  Indications

  Proven, symptomatic interdigital (Morton’s) neuroma in the third (80%–90%) or second (10%–20%) web space failing to respond to conservative treatment.

   

  Contraindications (relative)

• Vague symptoms or unusual location

• Other causes of metatarsalgia

• Lack of response to accurate injection of lesion

   

  Consent and risks

  • Failure or recurrence: Up to 20%, dependent on technique and diagnosis and closely related to short incision surgery

  • 3car pain (especially with plantar incision)

  • Interdigital numbness: Common but rarely troublesome

  • Vascular damage and digital iscNaemia: Risk if multiple web space explorations are undertaken

   

   

  Anaesthesia and positioning

  May be performed under general or regional anaesthesia. The patient is positioned supine with an ankle or thigh tourniquet to provide a bloodless field.

   

  Surgical technique

  Landmarks

  The dorsal aspect of the affected web space is the landmark.

   

  Incision

  A longitudinal incision is placed over the dorsum of the foot, starting in the web space and extending 3–4 cm proximally. (An insufficient incision is commonly found in recurrent cases and is to be avoided.)

   

  Dissection

   

  Structure at risk

  • Dorsal digital nerves

   

   

  Taking care to avoid the dorsal digital nerves, dissection is carried down to the metatarsal heads and a laminar spreader is used between the metatarsal heads to place the transverse metatarsal ligament under tension. A Macdonald dissector is placed under the ligament which is then divided under direct vision. The laminar spreader is then advanced into the wound to open up the intermetatarsal space.

   

  Procedure

   

  Structure at risk

  • Common digital artery

   

  Plantar pressure will usually deliver the neuroma into the wound. Sometimes it will be obscured by a bursa which requires excision. Taking care to protect the common digital artery, the neuroma is retracted proximally and the two true digital nerves are divided. The nerve is then traced as proximally as possible and then divided under traction such that the cut end is proximal to the weightbearing area of the foot. The specimen should be sent for histology for confirmation of the diagnosis.

   

  Closure

  After release of the tourniquet, haemostasis is obtained. Skin is closed in a single layer and a forefoot bandage is applied.

   

  Postoperative care and instructions

  The patient should elevate the foot for 48 hours. They may mobilise, weightbearing as tolerated, in a postoperative flat shoe.

   

  Recommended reference

  Mann RA, Reynolds JD. Interdigital neuroma: A critical clinical analysis. Foot Ankle. 1983;3:238–243.

  Lesser toe deformities‌

  Preoperative planning

  The decision-making process for correction of lesser toe deformities must take into account the type of deformity and whether it is fixed or flexible. A detailed examination of

   

  the deformity must be made in the awake patient prior to surgery. The position of the toe in the standing and lying position must be noted and any deformity assessed for a fixed component. Any subluxation or dislocation of the MTPJ must be identified. There is some confusion in the literature regarding toe deformity nomenclature. For the purposes of this book we have used the following terms:

   

• Mallet toe: A flexion deformity of the distal IPJ (DIPJ), often resulting in a callosity on the tip of the toe.

• Hammer toe: A flexion deformity of the proximal IPJ (PIPJ), often associated with hyperextension of the DIPJ and an accommodative hyperextension of the MTPJ.

• Claw toe: A term usually reserved for multiple toes and often associated with an underlying neurological condition. The primary deformity is one of hyperextension of the MTPJ with secondary flexion of the PIPJ.

   

  Indications

• Painful lesser toe deformity not responding to conservative treatment

• Severe lesser toe deformity causing footwear problems and not responding to footwear modification

   

  Contraindications

• Vascular insufficiency

• Local infection

• Undiagnosed underlying neurological condition (relative)

   

  Consent and risks

  • Infection: Less than 1%

  • Neurovascular damage: Less than 1%.

  • Vascular insufficiency of the digit following correction of a severe or long-standing deformity: may require further shortening or accepting a slightly flexed position

  • Recurrence of deformity

  • Swelling

  • Non-union of artNrodesis: 20%–50% of PIPJ arthrodeses in some series formed a fibrous union, but this does not correlate with postoperative dissatisfaction

  • Malunion of artNrodesis: Hyperextension of the joint or varus/valgus deformity often

    poorly tolerated

  • Loss of movement or function of the toe, depending on procedure performed

   

   

  Anaesthesia and positioning

  Anaesthesia can be regional or general. If surgery is limited to the interphalangeal joints, a digital block can be used. A supine position is used, with the foot at the end of the table.

   

  Surgical techniques

  Percutaneous flexor digitorum longus tenotomy

  Indication

  Flexible mallet deformity.

   

  Incision

  Holding the toe to put the flexor tendon under tension, a size 15 blade (or tenotomy blade if available) is used to make a 2–3 mm incision over the DIPJ flexor crease.

   

  Procedure

   

  Structure at risk

  • Neurovascular bundles

   

   

  With the blade facing away from the neurovascular bundle, the tightened tendon is palpated with the blade and divided. The toe is then released to check the degree of correction.

   

  Closure

  Formal closure of the wound is not required.

   

  Distal interphalangeal joint arthrodesis

  Indication

  A fixed mallet deformity is an indication.

   

  Incision

  An elliptical incision is made over the DIPJ and carried down to bone, excising the extensor tendon. Care is taken to avoid damage to the nail matrix distally.

   

  Procedure

   

  Structure at risk

  • Neurovascular bundles

   

   

  Facing the blade away from the neurovascular bundles, the collateral ligaments are divided, allowing deliverance of the condyles of the middle phalanx into the wound. Using a bone cutter, the condyles are excised at the metaphyseal flair. The articular surface of the distal phalanx is then decorticated. Under direct vision, the flexor digitorum longus tendon in the base of the wound is divided and the degree of correction is assessed. A double-ended K-wire is advanced in an antegrade direction through the distal phalanx, aiming to come out just below the nail bed. The joint is then reduced and the wire advanced into the middle phalanx to secure the joint.

   

  Closure

  The wound is best closed with non-absorbable mattress sutures to secure the skin and extensor tendon en masse.

   

  Flexor tendon transfer (Girdlestone procedure)

  The principle of this procedure is to recreate the action of the intrinsic muscles in flexing the MTPJ and extending the IPJs.

   

  Indications

• Flexible hammer deformity

• Flexible claw toe deformity

  Incision

  A 5 mm transverse incision is made over the proximal flexor crease.

   

  Procedure

   

  Structure at risk

  • Neurovascular bundles

   

   

  Following blunt dissection down to the flexor sheath, the sheath is incised in a longitudinal manner. Of the three tendons seen, the flexor digitorum longus (FDL) is the central one. A percutaneous FDL tenotomy is performed at the level of the DIPJ (see earlier), and the FDL is delivered out of the proximal wound. The tendon is split into two halves along its length. On the dorsum of the toe, a longitudinal incision is made over the proximal phalanx. A small artery forceps is used to bluntly dissect down one side of the phalanx, remaining close to the extensor expansion, and exiting the toe through the plantar wound. The forceps are used to grasp one-half of the divided FDL tendon and deliver it to the dorsum, repeating the manoeuvre on the other side. Holding the MTPJ in about 20° flexion, both ends of the tendon are sutured to the extensor tendon, using an absorbable suture. The toe is released to ensure that the correction is being held. If there is judged to be some residual tightness in the MTPJ, a dorsal release may be performed (see later). A K-wire may be used to protect the repair.

   

  Closure

  Skin wounds are closed with appropriate sutures, usually non-absorbable suture material.

   

  Proximal interphalangeal joint arthrodesis

  Indication

  Fixed hammer deformity or claw toe deformity is an indication.

   

  Incision

  An elliptical or a longitudinal incision is made over the PIPJ and carried down to bone excising the extensor tendon.

   

  Procedure

   

  Structure at risk

  • Neurovascular bundles

   

   

  Facing the blade away from the neurovascular bundles, the collateral ligaments are divided, allowing deliverance of the condyles of the proximal phalanx into the wound. Using a bone cutter, the condyles are excised at the metaphyseal flair. Sufficient bone must be removed to allow the toe to be straightened without undue tension on the tissues, especially the neurovascular bundles. The plantar plate is released from the middle phalanx allowing its base to be delivered. The articular surface is then decorticated using a nibbler. A double-ended K-wire is advanced in an antegrade direction through the middle and distal phalanges, aiming to come out just below the nail bed. The joint is then reduced and the wire advanced into the proximal phalanx to secure the joint.

   

  Closure

  The wound is closed with non-absorbable mattress sutures to secure skin and extensor tendon en masse. If the MTPJ remains extended, a dorsal release (see later) should be included to avoid a ‘cock-up’ deformity.

   

  Metatarsophalangeal joint release

  Indication

  Hyperextension of the MTPJ with or without subluxation is an indication.

   

  Incision

   

  Structures at risk

  • Dorsal veins

  • Dorsal sensory nerve branches

   

   

  A 3 cm incision is made in line with the metatarsal, centred over the MTPJ. If two adjacent joints are being addressed, the incision should be made in the web space. An attempt should be made to protect the dorsal veins and sensory nerves.

   

  Procedure

  Release of the joint should occur in a stepwise manner and stop when satisfactory release is achieved. The extensor digitorum longus (EDL) and extensor digitorum brevis (EDB) to the toe (EDL lies medial to EDB) are identified and their tightness assessed. If tight, the EDB may be divided but the EDL should be Z-lengthened. A dorsal capsulotomy is performed then, with the blade facing away from the neurovascular bundles, progressive capsular and

   

  collateral releases are performed both medially and laterally. In long-standing deformities, adhesions may exist between the plantar capsule and the metatarsal head which should be released. Once satisfactory release is achieved, the EDL should be repaired with absorbable suture and the wound closed. If, despite maximal release of the MTPJ, the joint cannot be reduced, a metatarsal osteotomy sNould be considered. (See ‘Lesser metatarsal [Weil’s] osteotomy’, p. 414.)

   

  Postoperative care and instructions

  After all lesser toe surgery, the tourniquet should be released prior to waking the patient and the toe observed. If reperfusion is slow, releasing excessively tight dressings and hanging the foot over the side of the table usually allows the toe to reperfuse. If the toe remains white and a K-wire has been inserted, gently bending the arthrodesed joint will relieve excess tension on the blood vessels.

  All patients can fully weightbear on a flat postoperative shoe. K-wires, if used, should be removed at 4–6 weeks.

   

  Recommended reference

  Coughlin MJ. Lesser-toe abnormalities. J Bone Joint Surg Am. 2002;84:1446–1469.

  Lesser metatarsal (Weil’s) osteotomy‌

  Preoperative planning

  Historically, the Helal osteotomy was a popular treatment for lesser metatarsal overload and subluxed lesser MTPJs. This has largely been replaced by the Weil osteotomy, as popularised by Barouk.

   

  Indications

• Overload of a metatarsal head secondary to a relatively long metatarsal

• Reduction of a chronically subluxed or dislocated MTPJ

  Contraindications

• Gross deformity of the joint

• Vascular insufficiency or infection

   

  Consent and risks

  • Ongoing forefoot pain: Often related to the use of an excessively long screw

  • MTPJ stiffness: Some degree is very common

  • ‘Floating toe’: Stiff hyperextension of the MTPJ preventing the toe from touching the floor

  • Infection: Less than 1%

  • Avascular necrosis and non-union: Rare

  • Neurovascular damage: Rare

   

   

  Anaesthesia and positioning

  See ‘Lesser toe deformities’ (p. 409).

   

  Surgical technique

  Incision

  A 4 cm incision is made over the metatarsal, or in the interspace if two adjacent osteotomies are to be performed.

   

  Dissection

   

  Structure at risk

  • Neurovascular bundles

   

  The extensor tendons are retracted out of the way and the dorsal capsule of the MTPJ released. Protecting the neurovascular bundles, the collaterals are released to allow the proximal phalanx to be displaced plantarwards.

   

  Procedure

  A Macdonald dissector or custom-made head elevator is inserted under the metatarsal head. Using a fine saw blade, an osteotomy is made, starting 2 mm below the dorsal surface of the head and continuing proximally, parallel to the sole of the foot (Figure 14.11). Using a fine osteotome or McDonald, the head fragment is freed up to allow it to retract proximally the desired amount. The fragment can then be fixed with a small screw, the length of which usually decreases from 14 mm in the second metatarsal to 11 mm in the fifth. The excess dorsal bone overhanging the head can then be trimmed to ensure that the proximal phalanx can freely dorsiflex.

  

   

   

  Figure 14.11 Orientation of Weil osteotomy of the lesser metatarsal and screw placement.

  Postoperative care and instructions

  The patient is asked to mobilise in a heel weightbearing shoe. Once wounds have healed, passive and active range-of-motion exercises can begin and the toe can be strapped down to prevent hyperextension.

   

  Recommended references

  Barouk LS. Forefoot Reconstruction. Berlin, Germany: Springer-Verlag, 2005.

  Helal B. Metatarsal osteotomy for metatarsalgia. J Bone Joint Surg Br. 1975;57:187–192.

  Trnka HJ, Mühlbauer M, Zettl R et al. Comparison of the results of the Weil and Helal osteotomies for the treatment of metatarsalgia secondary to dislocation of the lesser metatarsophalangeal joints. Foot Ankle Int. 1999;20:72–79.

  Fifth toe soft tissue correction (Butler’s procedure)‌

  Preoperative planning

  Indications

• Moderate or severe over-riding fifth toe with pain and callosity or footwear problems

• Failure of footwear adaptations and other conservative measures

  Contraindications

  Digital ischaemia or poor perfusion is a contraindication.

   

  Consent and risks

  • Neurovascular damage and risk of toe iscNaemia: Reduced by careful dissection and avoidance of traction or manipulation of the toe

  • Recurrence of deformity: Rare

   

  Anaesthesia and positioning

  Regional or general anaesthesia is required as digital anaesthesia is insufficient. The patient is positioned supine with an ankle or thigh tourniquet to ensure a bloodless field.

   

  Surgical technique

  Incision and dissection

   

  Structure at risk

  • Neurovascular bundles of the fifth toe

   

  A double-racquet incision is drawn to ensure correct placement. The dorsal limb of the incision should follow the line of tension along the extensor tendon. The plantar limb should be longer and heading laterally (Figure 14.12). The skin is incised with care and the neurovascular bundles identified and protected.

   

  Procedure

  The tight extensor tendons are divided and then the joint capsule exposed. The tight dorsal capsule and usually the collateral ligaments require release. Sometimes the plantar capsule is adherent and needs to be dissected off. The toe should now assume the required position.

   

  (a) (b)

   

  

   

   

  Figure 14.12 Butler procedure – position of skin incision. (a) Dorsal and (b) plantar views.

  Closure

  The skin is closed without tension. The dorsal incision assumes a V to Y position and the plantar incision a Y to V position. The tourniquet must be released to ensure adequate perfusion of the toe prior to the end of anaesthesia. No taping or splintage is required.

   

  Postoperative care and instructions

  The patient can mobilise fully weightbearing on a postoperative shoe.

   

  Recommended reference

  Cockin J. Butler’s operation for an over-riding fifth toe. J Bone Joint Surg Br. 1968;50:78–81.

  Hindfoot arthrodesis‌

  Preoperative planning

  The three joints of the hindfoot, the subtalar (ST), calcaneocuboid (CC) and talonavicular (TN) joints, can be arthrodesed individually or in combination, depending upon the indication. However, as all three joints work in unison, fusion of one will affect the others. As the normal hindfoot swings into varus during gait, Chopart’s joints (TN and CC) are locked in position to provide a firm platform. Therefore, a subtalar fusion must avoid varus to leave Chopart’s joints relatively mobile and avoid fixed supination of the foot. Similarly, fusion of the TN joint in isolation fixes the CC joint and greatly reduces the movement of the ST joint. Therefore, in arthrodesing one or more of these joints, attention to the position of all three must be taken.

  The ultimate aim of any hindfoot fusion is to provide a pain-free, stable hindfoot and a foot that can be placed flat on the floor for weightbearing.

   

  Indications

  (See also ‘Principles of foot and ankle arthrodesis’, p. 385.)

• Painful arthropathy of one or more hindfoot joints secondary to degenerative, inflammatory or traumatic causes not responding to conservative management. In such cases, isolated fusion of the affected joint can be considered.

   

• Fixed deformity of the hindfoot not amenable to soft tissue correction and/or osteotomy. Historically, this was primarily for paralytic conditions, especially poliomyelitis. Hindfoot fusions are now more commonly performed for tibialis posterior dysfunction, rheumatoid arthritis and congenital neuromuscular disorders. In such cases, a double fusion of the TN and CC joints, or a triple fusion of all three joints is indicated.

• Gross instability of the hindfoot with bony destruction, as seen in rheumatoid arthritis or Charcot’s joints in people with diabetes.

  Contraindications

• Active infection or ischaemia of the limb is an absolute contraindication.

• A more proximal uncorrected deformity is a relative contraindication. It is difficult to judge hindfoot alignment if there is a more proximal deformity. Furthermore,

  if a proximal deformity is subsequently corrected, the hindfoot alignment may be rendered incorrect. It is therefore prudent to address proximal deformities first.

• Ipsilateral ankle fusion is a relative contraindication – the patient must be counselled that a combined ankle and hindfoot fusion will result in a loss of normal gait and possibly the need for footwear adaptations to walk.

   

  Consent and risks

  (See also ‘Principles of foot and ankle arthrodesis’, p. 385.)

   

  • Non-union: The TN joint is especially prone to non-union. This is likely to be due to its curved surface and extensively cortical composition making adequate visualisation and preparation technically difficult. Obtaining adequate rigid fixation can also be difficult compared with the ST joint.

  • Malunion: Due to incorrect positioning or fixation failure. A malunion preventing the

  patient from placing the foot flat on the floor, often with overload of the lateral border, is very poorly tolerated by the patient and often requires revision.

   

   

  Anaesthesia and positioning

  (See also ‘Principles of foot and ankle arthrodesis’, p. 385.)

  For isolated subtalar fusion, a lateral decubitus position, with the operative side up, allows excellent access and visualisation. For TN or double/triple arthrodeses, a supine position is optimal. The use of a bolster under the calf allows free access around the foot.

   

  Surgical technique

  Landmarks

• Utility lateral approacN: Tip of fibula and base of fourth metatarsal

• Anterior approacN: EHL and tibialis anterior tendons

• Anteromedial approacN: Tibialis anterior and posterior tendons

 

Incision

 

Structures at risk

• Sural nerve (utility lateral approach)

• Superficial peroneal nerve (utility lateral approach)

• Saphenous nerve and vein (anteromedial approach)

 

The incision(s) used will depend upon the joints to be addressed. For isolated TN arthrodesis, an anterior approach allows excellent visualisation. For isolated ST and/or CC joint fusion, a utility lateral approach is used. For a triple fusion, the utility lateral in combination with an anteromedial approach to the TN joint allows wide skin bridges (Figure 14.13a and b).

 

Figure 14.13 (a) Approaches for hindfoot arthrodesis – utility lateral approach. (b) Approaches for hindfoot arthrodesis – anterior (A) and anteromedial (B) approach to talonavicular joint.

The utility lateral approach allows excellent visualisation of the ST and CC joints. It is preferable to the traditional Ollier incision as there is less risk to the branches of the superficial peroneal nerve. A straight incision is made from the tip of the fibula towards the base of the fourth metatarsal. This should lie between the sural and peroneal nerves but care must be taken, especially distally. The incision can be stopped at the CC joint if access to only the subtalar joint is required.

The anterior approach is an extension of the approach used to access the ankle. A straight incision between the tendons of extensor hallucis longus and tibialis anterior is made over the TN joint and the extensor retinaculum carefully incised. This gives excellent access to the medial and lateral extents of the surprisingly broad TN joint.

Alternatively, if performing a triple fusion, an anteromedial incision between the tendons of tibialis anterior and posterior allows a wider skin bridge. Care must be taken of the saphenous vein and nerve, which lie in this plane. It is harder to access the far lateral extent of the TN joint through this incision, and access through the lateral incision may be required.

 

Dissection

The utility lateral incision is deepened to pass above the peroneal tendons to the subtalar joint. By releasing the insertion of extensor digitorum brevis and elevating this with a

 

distally based flap, the sinus tarsi and CC joint can be visualised. In triple arthrodeses, after preparation of the CC and ST joints, the lateral aspect of the TN joint can be accessed from the lateral side.

 

Procedure

 

Structure at risk

• Tibial neurovascular bundle

 

Once exposed and mobilised, the selected joints should be meticulously prepared as detailed in ‘Principles of foot and ankle arthrodesis’ (p. 385). With regard to the TN joint, the full extent of the joint must be realised for successful fusion. It is easy not to prepare deep enough (one should see the spring ligament in the depth of the wound) or laterally enough. During subtalar preparation, the posterior facet is prepared first. When the tendon of FHL (identified by moving the toe) is visualised, preparation is deep enough. Great care should be taken, however, as deep to the FHL is the tibial neurovascular bundle. After preparation of the posterior facet, the medial facet can be prepared. Damage to the structures posterior to this, and the head of the talus superiorly, must be avoided. Once all of the required joints have been prepared, they need to be held in the required position of arthrodesis. For the ST joint, the optimum position is 5° of valgus. However, if there is rigidity of the midfoot from a long-standing deformity, 5° of valgus may not allow the foot to be placed flat on the floor. Therefore, the position of the weightbearing foot should be confirmed by using a flat surface prior to fixation of the ST joint. A varus position must be avoided.

The ideal position of arthrodesis of the TN joint is one of ‘talar neutral’ – that is, with the domed talar head central in the navicular. In this position, the long axis of the talus should pass through the long axis of the first metatarsal. Care must be taken not to extend or flex the TN joint, and the foot should be perpendicular to the tibia with the ankle in neutral. Again, the position of the foot flat on the floor must be checked and a suboptimal position may have to be accepted to achieve this. The CC joint position will be dictated by the other joints and therefore fixed last.

Various methods of ST joint fixation have been described. Our preferred method is to place a large-diameter (8 mm) cannulated compression screw from the posterolateral aspect of the calcaneum into the talus to cross the posterior facet at 90°. This avoids possible impingement problems from a screw inserted from the talar neck. The entry point is in a line down from the lateral margin of the Achilles tendon, just above the plantar skin of the heel. Too plantarwards or central an entry point may cause painful prominence of the screw head. Usually, a single screw is sufficient. The TN joint can be fixed using a retrograde screw from the medial edge of the navicular into the talar neck. Care must be taken to ensure a good bite is obtained medially without intruding upon the NC joint. Further fixation can be obtained with a screw from the anterior surface of the navicular. Screw fixation of the CC joint, antegrade from the anterior process of the calcaneum or retrograde from the cuboid, can sometimes be difficult, in which case compression staples or a low-profile plate can be used.

 

Closure

All wounds should be carefully closed, ensuring a good soft tissue layer is closed over the joints prior to skin closure. If an anterior approach has been used, the retinaculum must be carefully repaired. The leg is then placed in a back slab.

 

Postoperative care and instructions

(See also ‘Principles of foot and ankle arthrodesis’, p. 385.)

The patient is kept in a non-weightbearing cast for 6 weeks or until early radiological signs of union are seen. They can then begin to gradually increase their weightbearing. A cast should be retained for 3 months or until there is solid radiographical and clinical evidence of union.

 

Recommended reference

Davies MB, Rosenfeld PF, Stavrou P et al. A comprehensive review of subtalar arthrodesis. Foot Ankle Int.

2007;28:295–297.

Calcaneal osteotomy‌

Preoperative planning

Indications

A calcaneal osteotomy is rarely indicated in isolation. It is usually performed as part of a soft tissue correction of a hindfoot deformity to protect the reconstruction and reconstitute the mechanical axis of the hindfoot. Commonly used examples are a medial displacement osteotomy as part of a tibialis posterior reconstruction and a closing wedge or lateralising osteotomy as part of a pes cavus correction. Occasionally, an osteotomy may be used to correct a post-traumatic deformity of the calcaneum, but this is often done in combination with a subtalar arthrodesis as there is usually associated joint disruption.

 

Contraindications

• Active infection or critical ischaemia of the limb is an absolute contraindication.

• A more proximal uncorrected deformity is a relative contraindication. It is difficult to judge hindfoot alignment if there is a more proximal deformity. Furthermore, if a proximal deformity is subsequently corrected, the hindfoot alignment may become incorrect. It is therefore advisable to address proximal deformities first.

   

   

  Consent and risks

  • Neurovascular damage: The sural nerve is in the zone of the incision and must be avoided. On the medial extent of any osteotomy, the neurovascular bundle is close by and can be injured with aggressive use of power tools.

  • Malunion: Usually due to technical errors in judging the degree of correction but also

  due to hardware failure.

   

   

  • Non-union: Rare due to large surface area of cancellous bone.

  • Recurrence of deformity: Especially if the deforming soft tissues are not correctly balanced or there is a progressive neuromuscular condition.

   

  Anaesthesia and positioning

• General or spinal anaesthesia with a thigh tourniquet allowing exposure to above the knee to judge alignment satisfactorily.

• Most soft tissue procedures require access to both the medial and lateral sides of the hindfoot. Therefore, position the patient supine, with a removable sandbag under the ipsilateral buttock.

  Surgical technique

  The calcaneal osteotomy is usually performed first as part of any soft tissue correction of the hindfoot to avoid accidental damage to the correction.

   

  Landmarks

• Anterior border of tendo-Achilles

• Junction of dorsal and plantar skin of heel

Incision

 

Structure at risk

• Sural nerve

 

Some authors advocate an oblique lateral incision over the line of the proposed osteotomy. Unfortunately, this coincides with the course of the sural nerve and puts it at risk. We therefore advise an extensile lateral incision, commonly used for calcaneal fixation, as the sural nerve is protected in the elevated flap. This also allows better visualisation of the calcaneum. The inferior limb of the incision runs along the junction of the plantar and dorsal skin. The superior limb extends superiorly in line with the anterior border of the tendo-Achilles (Figure 14.14).

 

 

 

 

 

Figure 14.14 Extensile lateral approach to os calcis.

 

The extent of the exposure required is less than for calcaneal fixation, but the insertion of tendo-Achilles superiorly and plantar fascia inferiorly should be visualised.

 

Dissection

The incision is carried straight down to bone and the flap elevated in the subperiosteal layer with minimal trauma to the soft tissues.

 

Procedure

 

Structures at risk

• Tendo-Achilles

• Plantar fascia

 

For both medial and lateral displacement and lateral closing wedge osteotomies, the angle of the osteotomy is the same, at about 45° to the plantar surface of the foot (Figure 14.15). It runs anterior to the insertion of tendo-Achilles to superior to the insertion of the plantar fascia. Trethowan bone levers are placed to protect these two structures and guide the osteotomy line. Using an oscillating saw, the lateral wall is cut and the saw advanced until it reaches the medial wall.

 

Tendoachilles

 

Plantar fascia

 

 

 

Figure 14.15 Alignment of calcaneal osteotomy.

The medial wall is cautiously weakened by bouncing the saw off the wall and the osteotomy completed using a broad osteotome witN care to avoid any pressure on tNe medial soft tissues. Once completed, the osteotome is carefully twisted to mobilise the fragment and a dissector used to free the medial periosteum. The tuberosity fragment can then be displaced, either medially or laterally; this is performed with the ankle in a plantarflexed position. Displacement will depend upon the degree of correction required, 1 cm is usually sufficient. The position can usually be provisionally ‘locked’ by holding the foot in a plantigrade position. Once the surgeon is confident with the correction, a guide wire from a cannulated screw system can be inserted, under fluoroscopic guidance, from the lateral aspect of the tuberosity into the anterior fragment. Care must be taken to ensure that the wire enters the anterior calcaneum and does not penetrate medially. Once satisfied with the position, a single cannulated screw is sufficient to hold the osteotomy. Alternatively, a stepped plate may be used.

 

A lateral closing wedge can be added to the lateral displacement osteotomy, if required, to allow increased correction; the thickness of the wedge will depend upon the correction desired. Using minimal force, an attempt is made to close the wedge prior to fixation.

 

Closure

Closure of the flap must be meticulous and without tension. Deep Vicryl sutures and interrupted nylon sutures are satisfactory. The leg should be immobilised once the soft tissue component is completed.

 

Postoperative care and instructions

The leg should be elevated for 72 hours until swelling has subsided. The leg is then placed in a non-weightbearing cast for a duration usually dictated by the soft tissue correction. The osteotomy usually heals within about 6 weeks.

 

Recommended references

Dwyer FC. Osteotomy of the calcaneum for pes cavus. J Bone Joint Surg Br. 1959;41:80–86. Evans D. Calcaneo-valgus deformity. J Bone Joint Surg Br. 1975;57:270–278.

Trnka HJ, Easley ME, Myerson MS. The role of calcaneal osteotomies for correction of adult flatfoot. Clin Orthop Relat Res. 1999;365:50–64.

 

 

Viva questions‌

1. Describe how you can maximise the union rate for a midfoot arthrodesis.

2. In the context of hallux valgus deformity, what is congruency, and how does it affect your decision-making process?

3. What radiographs do you use to assess hallux valgus deformity, what angles do you measure and how does this influence your choice of operation?

4. What surgical approach do you use for a first metatarsal osteotomy, and what are the important structures at risk?

5. Describe the blood supply to the first metatarsal head. How can your choice of hallux valgus procedure affect the blood supply?

6. What structures do you need to identify in performing a lateral release in a hallux valgus deformity?

7. In a Scarf osteotomy, what is ‘troughing’, and how does the design of your osteotomy influence occurrence?

8. Why is a Keller’s procedure generally poorly tolerated by patients, and when would you consider performing one?

9. What are the key differences between a Weil’s and a Helal’s osteotomy of the lesser metatarsals?

10. What is the difference between a claw toe, mallet toe and a hammer toe?

     

     

11. Describe the mechanics of a Girdlestone tendon transfer for the lesser toes and when you would perform this.

12. How do you assess the severity of hallux rigidus, and how does this influence your treatment options?

13. What is the optimum position of arthrodesis of the first metatarsophalangeal joint (MTPJ), and how would you assess this intraoperatively?

14. Describe the anatomy of a toenail. How does this knowledge help in the treatment of ingrowing nails?

15. What is a Morton’s neuroma, and where is it most commonly found?

16. How does movement of the subtalar joint in gait affect movement of the Chopart joints (talonavicular and calcaneocuboid)?

17. Describe your understanding of the concept of ‘talar neutral’, and why is this useful in assessing foot position?

18. What surgical approach do you use to reach the subtalar joint, what are the landmarks and what structures are at risk?

19. What structures are at risk during a calcaneal osteotomy?

20. When would you consider performing a lateralising calcaneal osteotomy?