Surgery of the Ankle

Ankle arthrodesis ‌ ‌	367	Surgery for Achilles tendinopathy	377
Ankle arthroplasty ‌	371	Surgery for peroneal tendinopathy	381
Ankle arthroscopy	374	Viva questions	383

Movement	Range of motion
Dorsiflexion	0°-20°
Plantarflexion	0°-45°

Position of arthrodesis

• Neutral flexion

• 0°-5° valgus

• 5°-10° external rotation

Ankle arthrodesis ‌

Preoperative planning

Indications

• Arthropathy failing conservative management

• Failed arthroplasty

• Tumour reconstruction

• Sequelae of infection, particularly tuberculosis

• Avascular necrosis of talus

• Neuropathic joint

• Neurological conditions (resulting in instability)

  Contraindications

• Infection

• Degeneration of subtalar and midfoot joints

  Consent and risks

  • Failure of fusion: Less than 2%

  • Malpositioning (poorly tolerated, particularly equinus, varus and internal rotation)

  • Metalwork prominence: May require further surgery

  • Nerve injury is rare

  • Progression of arthritis of surrounding joints

  The patient must understand that walking will not return to normal. There is a significant reduction in walking speed and increase in energy expenditure compared with normal.

  Operative planning

  Planning of the position of fusion is vital. The position is:

• 0° dorsiflexion

• 0°-5° valgus hindfoot (varus positioning restricts midtarsal mobility)

• 5°-10° external rotation (Note: Observe contralateral limb)

  Posterior displacement of the talus allows for greater ease of 'rollover' at the end of the stance phase. Avoid residual anterior displacement.

  Anaesthesia and positioning

  These are performed as for ankle replacement.

  Surgical technique

  Arthrodesis can be performed arthroscopically (see 'Ankle arthroscopy' p. 374) or open. Arthroscopic ankle arthrodesis has been shown to have equivalent union rates with shorter hospital stay; however, it is more difficult to correct deformity. Open ankle arthrodesis is usually via an anterior approach (see 'Ankle arthroplasty' p. 371). The lateral transmalleolar approach may be used if soft tissues determine it, or if the subtalar joint is also to be arthrodesed (tibio-talo-calcaneal arthrodesis). Where possible the fibula is preserved for an isolated ankle arthrodesis to provide increased surface and vascularity for fusion and to enable potential conversion to arthroplasty in the future. Internal fixation is with crossed or parallel screws and/or plates for isolated ankle arthrodesis. Screws, plates or intramedullary nails are used for tibio-talo-calcaneal fusion. It is essential to obtain good hold and adequate compression ( Figure 13.1). Thorough preparation of all joint surfaces is vital. This is achieved by removal of remaining articular cartilage and exposure of subchondral bleeding cancellous bone to aid biological union.

  For surgical principles of joint surface preparation, see Chapter 14.

  Ankle fusion

  Figure 13.1 Arthrodesis with screw fixation.

  Lateral transmalleolar approach

  Landmarks

• Tip, anterior and posterior border of fibula

• Base of fourth metatarsal

• Anterior to sural nerve

  Dissection

  A longitudinal incision is made directly over the lateral aspect of the fibula, of sufficient length to avoid tension on the soft tissue flap. Distally the incision is angled toward the base of the fourth metatarsal to allow greater access to the ankle joint (and subtalar joint if required).

  Procedure

  Structures at risk

  • Peroneal tendons

  • Sural nerve

  Subperiosteal dissection of the fibula is carried out, protecting the peroneal tendons posteriorly and distally at all times. This also serves to protect the sural nerve. The joint line is identified, using an image intensifier, and is marked on the skin. The fibula is cut obliquely with a saw (superolateral to inferomedial ending at the level of the tibial plafond) and finished with an osteotome. The free distal end of the fibula is then reflected inferiorly and freed of soft tissues and ligamentous attachments, and it is excised. Care is taken not to divide the peroneal tendons at the tip of the distal fibula during excision. Capsulotomy then allows access to the tibiotalar surface. Continued dissection distally will expose

  the subtalar joint if required. The bone of the distal fibula can then be used to harvest cancellous bone graft and the surgeon's choice of fixation is performed. For an isolated ankle fusion, with good quality bone, cannulated screws can be used. For poorer quality bone, or if the subtalar joint is to be included, a retrograde tibio-talo-calcaneal nail is a better choice ( Figure 13.2).

  

  Closure

  Figure 13.2 Arthrodesis with nail fixation.

  A layered closure is followed by the surgeon's choice of skin closure for open techniques. Nylon to skin is used to close arthroscopic fusion portals.

  Postoperative care and instructions

  Thromboembolism should be prevented by early mobilisation and the addition of chemical or mechanical measures in patients at increased risk.

  Early mobilisation is non-weightbearing, with the aid of crutches. Radiographic signs of union are sought before unprotected full weightbearing is allowed; this often takes around 3 months.

  Recommended references

  Buck P, Morrey BF, Chao EY. The optimum position of arthrodesis of the ankle. J Bone Joint Surg Am.

  1987;69:1052-1062.

  Hendrickx RP, StuRens SA, de Bruijn EE, Sierevelt IN, van Dijk CN, Kerkhoffs GM. Medium- to long-term outcome of ankle arthrodesis. Foot Ankle Int. 2011;32(10):940-947.

  Kitaoka HB, Patzer GL, Felix NA. Arthrodesis for the treatment of arthrosis of the ankle and osteonecrosis of the talus. J Bone Joint Surg Am. 1998;80:370-379.

  Mann RA. Arthrodesis of the foot and ankle. In RA Mann and MJ Coughlin, eds. Surgery of the Foot and Ankle. St. Louis, MO: Mosby Year Book, 1993.

  Mann R, Rongstad AM. Arthrodesis of the ankle: A critical analysis. Foot Ankle Int. 1998;19:3-9. Scranton PE. An overview of ankle arthrodesis. Clin Orthop Relat Res. 1991;268:268-296.

  Townshend D, Di Silvestro M, Krause F et al. Arthroscopic versus open ankle arthrodesis: A multicenter comparative case series. J Bone Joint Surg Am. 2013;95(2):98-102.

  Ankle arthroplasty ‌

  Preoperative planning

  Indications

  Total ankle arthroplasty is indicated in painful conditions that have failed conservative management. The most frequent indications are:

• Osteoarthritis (often post-traumatic)

• Inflammatory arthritis and other arthropathies

• Average age 68 years, from latest National Joint Registry

  Contraindications

• Ankle joint infection

• Avascular necrosis of a large part of the talar body

• Severe deformity that would not allow for good biomechanical function and cause early failure (traditionally felt to be greater than the 15° varus/valgus deformity, although experienced arthroplasty surgeons now sometimes exceeding this)

• Poor soft tissue envelope

• Heavy manual occupation

• Neurovascular compromise (e.g. Charcot neuroarthropathy)

  Consent and risks

  • Loosening: Failure rates variably reported usually between 1% and 2% per year.

  • Malpositioning.

  • Fracture: Most common is medial malleolus. Up to 10% though they fare well with appropriate identification and management.

  • Wound problems.

  • Pain and stiffness: 5%.

  • Deep vein thrombosis (DVT)/pulmonary embolism/infection: 1%.

  Operative planning

  Assessment of the soft tissues, as well as vascular and neurological examination, are mandatory on the day of surgery. Recent weightbearing radiographs must be available. These may include long leg alignment films if there is any proximal deformity that needs to be taken into consideration.

  Availability of the implants and operative sets must be checked by the surgeon. Prophylactic antibiotics are administered on induction (the antibiotic of choice depends on local policy).

  Anaesthesia and positioning

  Anaesthesia is usually general, regional or combined. A thigh tourniquet is used. The supine position is used with appropriate padding where necessary. Occasionally, a sandbag under the ipsilateral buttock allows for greater ease of surgery. The knee should always be exposed and prepared (with a germicidal solution) to allow for intraoperative orientation of the implant.

  The ankle should be sufficiently mobile for appropriate movement intraoperatively. Some rest the calf on a support to facilitate this. Waterproof drapes are used with adhesive edges to provide a seal to the skin.

  Surgical technique

  Landmarks

  These should be marked preoperatively:

• Tendons (tibialis anterior, extensor hallucis longus, extensor digitorum longus)

• Dorsalis pedis (Note: This is absent in 10% of the population.)

• Cutaneous branches of the superficial peroneal nerve (variable course)

  Incision

  The anterior approach to the ankle is used. The skin is incised in the midpoint between the medial and lateral malleoli - from 3 cm above, extending 5 cm below the palpable ankle joint and avoiding cutaneous nerves where encountered.

  The superficial peroneal nerve is often encountered and should be freed and marked with a coloured loop. Care must be taken to avoid excess traction on this during the operation.

  Dissection

  Structures at risk

  • Dorsalis pedis artery

  • Deep peroneal nerve

  The extensor retinaculum is divided in the line of the incision. We tend to create medial and lateral flaps of the retinaculum as we are opening it, in order to facilitate closure and prevent bow stringing of the tibialis anterior tendon. Large skin flaps are avoided to reduce the risk of necrosis. The approach is then developed either between the extensor hallucis longs (EHL) and the extensor digitorum longus (EDL) or (more commonly) between the tibialis anterior and the EHL. The key is protecting the dorsalis pedis artery and deep peroneal nerve - identification (and protection) of these structures more proximally, before they cross at the ankle joint itself, may be required. A longitudinal capsulotomy is then performed.

  Procedure

  Several ankle prostheses are commercially available, and the individual operative technique should be referred to. Although the designs vary, the principles include minimal soft tissue handling and bone resection, correction of deformity at the ankle, press fit between bone and implant, ligament and tendon balancing and correction of any concomitant foot deformity. In general terms, an extramedullary guide is placed on the anterior surface of the tibia. Pins are used to fix the cutting guide to the tibia. The tibia is cut in the correct coronal, sagittal and rotational planes. The talar cut is then usually referenced from the tibial cut. This ensures parallel cuts in the distal tibia and talar dome, without altering the joint line height - approximately 2-3 mm is resected from each surface. Guides then size the tibial and talar components, and accurate anterior and posterior chamfer cuts are made to the talus. Trial components and a spacer (to assess stability and range of movement) are used prior to actual prosthesis placement.

  Pitfalls to avoid include:

• Varus/valgus positioning of tibial and talar cutting guides, which can also lead to abnormal sagittal plane tilting - early loosening

• Anterior/posterior placement of talar or tibial components - early loosening

• Notching of medial and lateral malleoli during tibial cuts - fracture

• Failure to balance the foot underneath the ankle replacement (e.g. a rigid flat foot under an ankle replacement will cause early failure)

  Newer-generation systems are uncemented with a predominance of fixed bearing implants. Commonly used prostheses include Infinity, Box, Zenith and STAR (Scandinavian Total Ankle Replacement).

  Postoperative care and instructions

  This usually includes non-weightbearing and immobilisation in a cast for 4-6 weeks. The patient is then transitioned into a removable boot and begins weightbearing and exercises. A return to work (and driving) would be expected after 3 months. Follow-up is recommended at 6 weeks, 6 months and 1 year after surgery. Continuation of follow-up is typically at 5 years, 10 years, 15 years and then at yearly intervals. The patient should be cautioned to return to the clinic if there is pain or functional deterioration.

  Recommended references

  Carachiolo B. Design features of current total ankle replacements: Implants and instruments. J Am Acad Orthop Surg. 2008;19:530-540.

  Hopgood P, Kumar R, Wood PL. Arthrodesis for failed ankle replacement. J Bone Joint Surg Br.

  2006;88:1032-1038.

  Saltzman CL, Mann RA, Ahrens JE et al. Prospective controlled trial of STAR total ankle replacement versus ankle fusion: Initial results. Foot Ankle Int. 2009;30(7):579-596.

  Spirt AA, Assal M, Hansen ST Jr. Complications and failure after total ankle arthroplasty. J Bone Joint Surg Am. 2004;86:1172-1178.

  Wood PL, Deakin S. Total ankle replacement: The results in 200 ankles. J Bone Joint Surg Br. 2003;85:334-341. Zaidi R, Cro S, Gurusamy K et al. The outcome of total ankle replacement: A systematic review and meta-

  analysis. Bone Joint J. 2013;95-B(11):1500-1507.

  Ankle arthroscopy ‌

  Preoperative planning

  Indications

• Osteochondral defect

• Undiagnosed ankle pain in the young

• Osteoarthritis

• Removal of loose bodies

• Synovectomy or synovial biopsy

• Impingement syndromes (bony and soft tissue, anterior and posterior)

• Arthrofibrosis (e.g. post-traumatic)

• Fracture

• Meniscoidal lesions

• Septic arthritis

  Contraindications

• Infection of overlying skin

• Lack of proper instrumentation

• Gross osteoarthritis is a relative contraindication

• Severe oedema

  Consent and risks

  • Nerve injury: Less than 1%

  • Vascular injury: Less than 1%

  • Infection: Less than 1%; risk is very low, so prophylactic antibiotics are not recommended

  Operative planning

  It is vital that the patient is examined before transfer to theatre. This allows for identification and marking of structures vulnerable to damage during portal insertion intraoperatively. These include:

• Tibialis anterior and EHL tendons

• Dorsalis pedis artery and associated deep peroneal nerve

• Traction on second and fourth toes usually demonstrates medial and lateral branches of the superficial peroneal nerve

• Saphenous vein and nerve

• Medial and lateral malleoli

  Recent radiographs and, where taken, magnetic resonance (MR) images should be available.

  The equipment must be available; this should be checked by the surgeon. Usually, a 2.7 mm 30° arthroscope and 3.5 mm shavers are used; however, a 4 mm scope may be used in some

  circumstances (e.g. arthroscopic arthrodesis) to increase field of view. Water pressure is set at 50 mm Hg.

  Anaesthesia and positioning

  Anaesthesia is usually general with intraoperative local anaesthetic infiltration into the joint at the end of the procedure. A variety of techniques of patient positioning and joint distraction are available. For anterior arthroscopy, the authors' preferred technique involves the supine position, with the hip flexed and a well-padded support under the thigh. An ankle distractor is applied with the knee at 90° of flexion and the ankle in a neutral position. Adequate padding avoids damage to skin and neurological structures. Too much traction (>15 kg) and excessive time can lead to irreversible nerve damage.

  The surgical field is prepared with a germicidal solution. Waterproof drapes are used with adhesive edges to provide a seal to the skin.

  Surgical technique

  The ankle joint is filled with 20 mL of saline to aid access and avoid chondral surface damage. Small longitudinal skin incisions are made, then blunt dissection (with a clip) is used to breech the ankle joint, thereby avoiding damage to the superficial nerves - unlike knee arthroscopy where a blade is passed directly into the joint.

  Creation of portals

  Structures at risk

  • Nerves: Deep peroneal, superficial peroneal branches, sural, tibial

  • Arteries: Dorsalis pedis, posterior tibial artery

  A number of portal sites are described ( Figure 13.3). The central anterior portal is best avoided because of a high risk of neurovascular damage.

• Anteromedial portal: This lies medial to tibialis anterior. The joint line is initially identified by palpation and then a white needle is inserted into the joint to confirm the level. It is helpful to mark out the tip of the medial and lateral malleoli in order to identify the ankle joint more proximal to these. The needle is directed slightly

  superiorly to pass over the talar dome. The arthroscope and introducing trochar should be able to be swept across the joint from medial to lateral.

• Anterolateral portal: This lies lateral to extensor peroneus tertius and the neurovascular bundle (dorsalis pedis and deep peroneal nerve), avoiding the superficial nerves marked out preoperatively. The light source within the joint can be used as a guide;

  this will also help to identify the dorsal lateral branch of the superficial peroneal nerve which is at risk. A white needle is inserted as outlined earlier. This helps ensure your instruments will come in from a suitable trajectory.

  Anteromedial portal Anterocentral

  portal

  Anterolateral portal Tibialis ant.

  

  Figure 13.3 Typical portal positioning (anterior on top and posterior on bottom).

• Posterolateral portal: This is located lateral to the Achilles tendon 1 cm above the tip of fibula. The tip of the fibula is at the level of the subtalar joint. Insert prior to posteromedial portal - risk of sural nerve damage.

• Posteromedial portal: This is just medial to the Achilles tendon at the level of the posterolateral portal. Flexor hallucis longus is used to protect the tibial nerve and posterior tibial artery - the main structures at risk.

  Posterior portals are not as frequently used (because of the increased risk of neurovascular damage) but are helpful in visualising the posterior ankle and subtalar joints.

  Procedure

  A systematic approach is essential if pathology is not to be missed. Initially the whole of the talar dome is inspected - ankle plantar flexion aids visualisation of the posterior dome. The talar neck is then examined. Pathology on the corresponding articulating surface of the tibia is also documented, as well as the anatomy of the anterior aspect of tibia. The medial and lateral gutters are then inspected. Key features to identify include:

• Medial malleolus

• Deltoid ligament

• Talar dome

• Tibial plafond

• Anterior inferior tibio-fibular ligament

• Posterior inferior tibio-fibular ligament

• Syndesmosis

• Lateral malleolus

• Anterior talofibular ligament

  Closure

  Non-absorbable suture is used to close the skin incisions.

  Postoperative care and instructions

  The patient is fully weightbearing - as tolerated - unless the patient has had a micro-fracture of an osteochondral defect, where range of movement is encouraged in a non-loading manner so as to protect the developing fibrocartilage plug.

  Specific precautions are rarely required.

  Recommended references

  van Dijk CN, de Leeuw PA, Scholten PE. Hindfoot endoscopy for posterior ankle impingement. Surgical technique. J Bone Joint Surg Am. 2009;91(Suppl 2):287-298.

  Ferkel RD, Karzel RP, Del Pizzo W et al. Arthroscopic treatment of anterolateral impingement of the ankle. Am J Sports Med. 1991;19:440-446.

  Ferkel RD, Zanotti RM, Komenda GA et al. Arthroscopic treatment of osteochondral lesions of the talus: Long-term results. Am J Sports Med. 2008;36:1750-1762.

  Niek van Dijk C, van Bergen CJ. Advancements in ankle arthroscopy. J Am Acad Orthop Surg.

  2008;16:635-646.

  Tryfonidis M, Whitfield CG, Charalambous CP et al. Posterior ankle arthroscopy portal safety regarding proximity to the tibial and sural nerves. Acta Orthop Belgica. 2008;74:370-373.

  Surgery for Achilles tendinopathy ‌

  Preoperative planning

  There is an ever-increasing incidence of tendon problems, most commonly seen in recreational runners (racquet sports, track and field, volleyball and football) and competitive runners, who are 10 times more affected than age-matched controls.

  Despite preventive measures, 7%-8% of top-level athletes experience the problem at some stage in their career.

  Indications

  There are three common patterns of Achilles tendon pathology:

• Partial and complete ruptures: There is a sudden onset of severe pain and marked disability. These ruptures are 10 times more common in males, with peak incidence in the 30s and 40s. Patients often describe hearing a 'pop' and feel an impact in the back of the leg or heel.

• Non-insertional (mid-substance) tendinopathy: This often has a gradual onset, classically with morning pain and stiffness that eases with activity and reoccurs at rest later. Associated with a sudden increase in activity, change of surface or change of footwear/poor footwear.

• Insertional tendinopathy: Degeneration and inflammation at the insertion of the Achilles tendon onto the calcaneus. This can be accompanied by a number of pathologies including retrocalcaneal bursitis, Haglund's disease (painful

  retrocalcaneal bursitis and a bony prominence), Achilles bursitis and enthesopathy.

  Be aware of the systemic enthesopathies/rheumatoid arthritis and spondyloarthropathies. This is an area where misdiagnosis is common and the differential diagnoses include:

• Posterior ankle impingement syndrome

• Accessory soleus

• Deep posterior compartment syndrome

• Sever's disease

• Stress fracture

• Inflammatory arthropathy

• Neurogenic referred pain

  Contraindications

  Active infection is a contraindication.

  Consent and risks

  • 12% complications (54% wound related)

  • 88% return to function after a 6- to 12-month treatment programme

  Operative planning

  Non-operative management

  Once the diagnosis has been made, consideration is given to whether operative treatment is the best option for the patient. These factors include:

• Age and activity level of patient.

• Ability to tolerate a rehabilitation regimen.

• Gap size: There have been reports of using the gap between tendon ends on dynamic ultrasound to help guide management. Some have used a gap of 5 or 10 mm in neutral or full equinus to drive surgical treatment, although there is no clear consensus on this.

• Traditionally the re-rupture rate was considerably greater with non-operative treatment; however, with the use of improved methods of non-operative treatment, the difference has narrowed.

  Non-operative treatment of Achilles tendon rupture

  Traditional techniques involved sequential non-weightbearing plasters, with lessening degrees of equinus. This had a high re-rupture rate. Recent studies support functional/

  dynamic rehabilitation. This involves early weightbearing with a dynamic controlled range of motion.

  Operative management

  Anaesthesia and positioning

• General anaesthesia with local infiltration

• Thigh tourniquet

• Prone position with ankles resting on pillow

  Surgical technique

  There is much debate about open versus percutaneous repair. The open technique is described here, as an example. However, there is an increasing movement towards percutaneous repair techniques that reduce incidence of wound complications with little difference in strength of repair.

  Landmarks

• Midpoint of the calcaneal tuberosity posteriorly where tendo-Achilles inserts

• Medial and lateral aspects of tendon traced proximally to bellies of gastrocnemius to identify aponeurosis

  Incision

  Structure at risk

  • Sural nerve

  A 5-10 cm incision is created (at the level of the defect) along the medial border of the Achilles tendon. This avoids the sural nerve and allows access to plantaris.

  Dissection

• Directly deepen to paratenon

• Open paratenon and debride tendon

• Thick flaps are vital for healing

  Procedure

  It is necessary to address peritendinous adhesions and excise intratendinous lesions. A modified Kessler box suture is recommended. This consists of two standard Kessler sutures, at 90° to each other, ensuring the ends are tied inside not outside. It is best to use 1/0 PDS: this ensures good strength and slides easily. The repair is completed with a continuous epitendinous suture (3/0 Vicryl). A number of techniques are described where there is a large defect. This is usually for chronic ruptures with retraction. These include:

• Turndown flaps: This involves a centrally based fascial flap developed from the proximal segment and turned distally through 180° before suturing.

• V-Y advancement : A V-shaped incision is made in the aponeurosis. The limbs of the 'V' should be 1.5 cm longer than the gap to be filled. The intermediate segment is advanced distally, and the proximal segment is closed as a 'Y' in the lengthened position ( Figure 13.4).

  Figure 13.4 V-Y advancement for repairs with defect.

  If the repair or augment is too compromised the flexor hallucis longus, the peroneus brevis or an allograft made of polyglycol or carbon fibre can be used.

  Closure

  Closure is performed in thick layers with a non-absorbable suture for the tendon repair. Absorbable suture is used for the paratenon and skin closure.

  Postoperative care and instructions

  Increasingly, functional regimens are also being used postoperatively. This involves early weightbearing and controlled range of motion.

  Recommended references

  Hufner TM, Brandes DB, Thermann H et al. Long-term results after functional nonoperative treatment of Achilles tendon rupture. Foot Ankle Int. 2006;27:167-171.

  Kadakia AR, Dekker RG 2nd, Ho BS. Acute Achilles tendon ruptures: An update on treatment. J Am Acad Orthop Surg. 2017;25(1):23-31.

  Manoli A, Graham B. The subtle cavus foot. Foot Ankle Int. 2005;26:256-263.

  Oyedele O, Maseko C, Mkasi N et al. High incidence of Os peroneum in cadavers. Clin Anat.

  2005;19:605-610.

  Soroceanu A, Sidhwa F, Aarabi S, Kaufman A, Glazebrook M. Surgical versus nonsurgical treatment of acute Achilles tendon rupture: A meta-analysis of randomized trials. J Bone Joint Surg Am. 2012;94(23):2136-2143.

  Surgery for peroneal tendinopathy ‌

  Preoperative planning

  The peroneus longus originates from the lateral tibial condyle and head of fibula to insert on the first metatarsal base and medial cuneiform. The peroneus brevis originates from the middle one-third of the fibula and tibia to insert on the base of the fifth metatarsal. Remember, at the ankle the peroneus brevis is sandwiched between the bone and the peroneus longus - 'brevis to bone'.

  Indications

  A history of sprains is common. Other causes include trauma, inflammatory arthritides, fibula anatomy (shallow fibular groove, sharp lateral ridge), hypertrophied peroneal tubercle, lateral ankle instability and peroneus quartus (overcrowding). Developmental varus hindfoot alignment is associated with increased incidence of peroneal disorders:

• Tenosynovitis (a static mass on examination).

• Tendinosis (a mass moving with the tendon, through sheath).

• Tears (present with pain and weakness).

• Subluxation (palpation along the length of the tendons noting any deviation of their course).

• Os peroneum syndrome: Ossified in 20% population. Articulates with inferior margin of cuboid. May be degenerative/osteochondritis or fractured, leading to pain in the plantar/lateral aspect of the foot.

• Eventually pain-related functional weakness will lead to deformity.

  Contraindications

  Varus deformity related to underlying peroneal weakness rather than tendinopathy.

  Consent and risks

  • Sural nerve injury during dissection and skin closure

  • Painful scar

  • Late re-rupture/subluxation

  • Fracture to tip of fibula/disruption of retinaculum

  • Tendinous adhesions

  Operative planning

  Radiographs are helpful; however, magnetic resonance imaging and ultrasound show brevis flattening, thickening, nodules, tears, fluid in the peroneal sheath, dislocation and the retro-fibular groove anatomy in good detail (18% have a shallow or convex surface). The presence of fluid around a normal tendon on imaging indicates tenosynovitis.

  Depending on the quality of proximal and distal tendon, orthoses (lateral posting) and physiotherapy are usually successful. Conservative management of peroneal subluxation has less than 50% success.

  Anaesthesia and positioning

  General anaesthesia with local infiltration, or spinal/epidural, can be used. The patient is positioned supine with a thigh tourniquet and a sandbag under the ipsilateral buttock or, more usually, the lateral position is used, with adequate supports and protection between leg pressure points.

  Surgical technique

  Landmarks

  Landmarks are the tip of the fibula to the base of the fifth metatarsal.

  Incision

  A longitudinal incision is made parallel to the posterior border of the fibula. Distally, the incision is curved towards the base of the fifth metatarsal.

  Dissection

  Dissection is straight down, directly to the tendon sheath. Thick tissue flaps are reflected under minimal tension. The sheath is divided longitudinally and as posteriorly as possible, to aid repair and reduce scar tissue irritation when the tendons are mobilised under stress. Tendon hooks are used to isolate, deliver and clear individual tendons of adhesions.

  Procedure

  Surgical management for tendinopathy includes soft tissue procedures such as synovectomy, debridement or tubularization of tears. If greater than 50% of the tendon is intact, repair is advocated; if it is less than 50% tenodesis is recommended. Tendon transfer of flexor digitorum longus to peroneus brevis or an autograft using gracilis can maintain function.

  Bony procedures include:

• Deepening of the peroneal groove: Using a 4.5 mm drill, a longitudinal hole is made in the posterior third of the tip of fibula, then the posterior cortex is 'stoved in' to deepen the peroneal groove. Some are now advocating this procedure to be done

  arthroscopically. The retinaculum is then repaired, and a calcaneal osteotomy can be performed if required. The tendons can also be rerouted behind the calcaneofibular ligament as an alternative to the deepening procedure.

• Partial-thickness distal fibular osteotomy: This is rotated posteriorly (Kelly procedure).

• Distal fibular sliding graft (Duvries modification): This can also be carried out ( Figure 13.5).

Postoperative care and instructions

Tubularization of tears/bony procedures (4 weeks plaster of Paris, 4 weeks brace).

Figure 13.5 Bone block procedures.

Recommended references

Dombek MF, Catanzariti AR. Peroneal tendon tears: A retrospective review. J Foot Ankle Surg.

2003;42:250-258.

Manoli A, Graham B. The subtle cavus foot. Foot Ankle Int. 2005;26:256-263.

Oyedele O, Maseko C, Mkasi N et al. High incidence of Os peroneum in cadavers. Clin Anat.

2005;19:605-610.

Porter D, Torma J. Peroneal subluxation in athletes. Foot Ankle Int. 2005;26:436-441.

Viva questions ‌

1. What are the indications for ankle arthrodesis?

2. What is the optimum position for ankle arthrodesis?

3. What are the treatment options for a 40-year-old man with symptomatic osteoarthritis of the ankle?

4. What are the pros and cons of ankle replacement versus ankle arthrodesis?

5. Describe the anatomy of the anterior approach to the ankle.

6. What complications do you warn the patient about prior to ankle replacement? What are their incidences?

1. What are the contraindications to ankle replacement?

2. Describe the portals used in anterior ankle arthroscopy.

3. How do you perform an ankle arthroscopy?

4. What are the complications of ankle arthroscopy, and how can they be minimised?

5. How would you fuse an ankle?

6. Describe the follow-up and complications you might expect following ankle arthrodesis.

7. What types of ankle arthroplasty are you aware of?

8. Describe the technique of ankle arthroplasty.

9. What are the two types of Achilles tendinopathy, and how do they differ?

10. What is meant by functional Achilles rehabilitation?

11. Describe the techniques for direct repair of the Achilles tendon.

12. How might you augment a tendo-Achilles repair, e.g. in a patient with tendon loss/shortening?

13. Describe an approach to the peroneal tendons.

14. How might you address peroneal tendon subluxation?