DEFINITION

A plantarflexion contracture is defined as the inability to passively dorsiflex the ankle at least 5 degrees past neutral, with a neutral hindfoot, and suggests contracture of the gastrocsoleus complex (FIG 1).

Plantarflexion contracture may be secondary to contracture of the gastrocnemius, soleus, or both components of the complex.

Plantarflexion contractures are commonly associated with a variety of foot/ankle conditions. Up to 65% patients presenting with foot and ankle pathology may have some degree of contracture of the gastrocsoleus complex.2

 

 

ANATOMY

 

The superficial posterior compartment contains the gastrocnemius, soleus, and plantaris muscles.

 

The gastrocnemius muscle has two heads (medial and lateral) and originates above the knee from the posterior distal femur, which makes the gastrocnemius a three-joint muscle.

 

The soleus originates from the posterior aspect of the proximal fibula, interosseous membrane, and the posterior aspect of the middle third of the tibia, which makes the soleus a two-joint muscle.

 

 

 

FIG 1 • The gastrocsoleus complex, as viewed from a posterolateral angle, including the location of the sural nerve.

 

 

The gastrocnemius tendon is longer than that of the soleus and they blend together to form the Achilles tendon approximately 5 cm from the calcaneal tuberosity, which has a broad enthesis.

 

As the Achilles tendon shifts from its origin to insertion, it spirals 90 degrees so that the medial border of the proximal tendon rests posterolaterally.

 

The gastrocsoleus complex can be considered in three zones4 (FIG 2):

 

Zone 1 is from the femoral origins of the gastrocnemius muscle to the distal extent of the bluntly separable interval between the gastrocnemius and soleus, which is usually at the level of the medial gastrocnemius muscle belly.

 

 

Zone 2 is from the distal aspect of the medial gastrocnemius muscle belly to the distal end of the soleus muscle. Zone 3 is the Achilles tendon from the distal end of the soleus muscle to the insertion on the calcaneus.

 

The gastrocnemius and soleus muscles can be differentially lengthened in zones 1 and 2 (ie, separate fascial releases can be performed for each of these muscles).

 

 

 

FIG 2 • Three zones of gastrocsoleus lengthening.

 

 

 

PATHOGENESIS

40

 

The etiology of gastrocsoleus contractures is broad and includes metabolic/endocrine (eg, diabetes mellitus), posttraumatic, congenital, neurologic, and idiopathic origins. The natural history of the contracture is dependent on the etiology.

 

Gastrocsoleus contractures have implications for coronal and sagittal plane pathologies.

 

Sagittal plane pathologies include forefoot overloading and its sequelae including metatarsalgia, plantar plate pathology, or bunions.

 

Coronal plane pathologies include flatfoot and hallux valgus deformities.

 

Contracture may also be associated with midfoot pain/arthritis, planar fasciitis, or Achilles tendinopathy.

 

In patients with peripheral vascular disease and/or neuropathy, contracture may predispose to Charcot midfoot breakdown or serious foot ulcerations; treatment may require a gastrocsoleus complex lengthening.

NATURAL HISTORY

 

In general, conditions caused by a gastrocsoleus complex contracture will fail to completely resolve without some form of gastrocsoleus stretching/lengthening. This concept can be critical in diabetic forefoot ulcers.

PATIENT HISTORY AND PHYSICAL FINDINGS

 

The patient history should be used to determine if there is a specific etiology of the contracture (eg, posttraumatic, diabetes,

cerebral palsy, stroke).

 

Associated medical conditions should be ascertained on history (eg, diabetes, neuropathy).

 

Physical examination should assess the overall lower extremity alignment, including hindfoot, midfoot, and forefoot alignment.

 

Look for any signs of forefoot overloading, such as metatarsophalangeal (MTP) joint tenderness, prominent metatarsal calluses, or ulcerations.

 

Special attention should be paid to ankle range of motion with the knee extended and flexed, with the hindfoot held in a neutral position as is described with the Silfverskiöld test (see Exam Table at end of volume), which may help distinguish an isolated gasctocnemius contracture from a tight gastrocsoleus complex.

IMAGING AND OTHER DIAGNOSTIC STUDIES

 

Standard radiographic workup should include a weightbearing foot and ankle series.

 

Radiographs should be assessed for foot alignment and any structural causes for decreased ankle dorsiflexion (eg, talar neck/anterior tibial osteophytes, malunion, inflammatory ankle arthritis; FIG 3).

 

Targeted imaging should be performed for the symptoms the patient is experiencing (eg, magnetic resonance imaging [MRI] for Achilles tendinopathy).

 

DIFFERENTIAL DIAGNOSIS

Ankle arthritis

Anterior ankle impingement (bony or soft tissue) Posttraumatic malunion of the tibia Syndesmotic malreduction

Neglected drop foot Spasticity

 

FIG 3 • Lateral radiograph demonstrating an osseous etiology for a plantarflexion contracture; note the large talar neck osteophytes.

 

 

 

NONOPERATIVE MANAGEMENT

 

Calf stretching is indicated in patients with a gastrocsoleus contracture and foot symptoms/pathology that can be attributed to or

exacerbated by this contracture.

 

 

Static calf stretching may provide small increases in ankle dorsiflexion.7

 

Eccentric calf stretching exercises may be helpful in managing Achilles tendinopathy.1

 

Night splints may be indicated in the treatment of plantar fasciitis, but the effectiveness of night splints in treating other conditions is unknown.

SURGICAL MANAGEMENT

 

Failure of nonoperative management of the pathology associated with a tight gastrocsoleus complex is an indication for surgery.

 

Lengthening of the gastrocsoleus complex can be a critical component of a more extensive surgical plan (eg, Achilles tendon lengthening in addition to a flatfoot reconstruction) or it may be the sole treatment (eg, gastrocnemius recession in patients with noninsertional Achilles tendinopathy). Accordingly, surgical decision making is individualized for each patient.

 

Different techniques for gastrocsoleus lengthenings and their relative characteristics are shown in Table 1.

 

Preoperative Planning

 

 

The patient should be medically optimized for surgery; this is of particular importance in patients with diabetes mellitus. Deformities of the lower extremity should be examined, and joint ranges of motion should be measured.

 

Preoperative performance of a Silfverskiöld test is of critical importance to determine if the plantarflexion contracture is secondary to an isolated gastrocnemius contracture or a combined gastrocsoleus contracture.

 

If gastrocsoleus lengthening is indicated as part of a larger surgical plan, it is controversial if the lengthening should be performed at the beginning or the end of the case.

 

Positioning

 

Although positioning is determined by the specific surgical case, supine positioning is generally sufficient to perform most gastrocsoleus lengthenings.

 

An assistant can elevate the leg to facilitate lengthenings, such as the Hoke or Vulpius lengthening (FIG 4).

 

 

Prone positioning is preferred for an Achilles Z-lengthening. Occasionally, concomitant procedures may require repositioning.

 

 

Table 1 Different Techniques for Gastrocsoleus Lengthenings and Their Relative Characteristics

 

 

 

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			Possibility for
			Differential
			Lengthening of
			the
			Gastrocnemius	Capacity for	Mechanical	Postoperative
Lengthening	Indication	Zone	and Soleus	Lengthening	Stability	Protection

 

Baumann	Gastrocnemius or gastrocsoleus contracture	Proximal 1	Yes		Stable	WBAT
Strayer	Gastrocnemius or gastrocsoleus contracture	Distal 1	Yes		Stable	WBAT

Vulpius/Baker Gastrocsoleus

2

No

Stable

WBAT

                              contracture                                                                                                                 

Hoke

Gastrocsoleus

contracture

3

No

Unstable

Protected

Z-lengthening

Gastrocsoleus

contracture

3

No

Unstable

Protected

WBAT, weight bearing as tolerated. From Firth GB, McMullan M, Chin T, et al. Lengthening of the gastrocnemius-soleus

complex: an anatomical and biomechanical study in human cadavers. J Bone Joint Surg Am 2013;95(16):1489-1496.

 

 

 

 

 

FIG 4 • If the patient is in a supine position, elevation of the leg enables access to perform some two or three lengthenings.

 

 

 

FIG 5 • Commonly used gastrocsoleus lengthenings and their position along the gastrosoleus complex. For Zone 1, the left figure represents the anterior gastrocnemius recession as seen from an anterior view and the right one represents the posterior soleal fascia lengthening.

 

Approach

 

The particular surgical approach is determined by the lengthening that will be performed.

 

More proximal lengthenings (eg, Baumann or Strayer lengthening) are more mechanically stable, are able to differentially lengthen the gastrocnemius and soleus, provide smaller corrections, and may require less postoperative protection.4

 

More distal lengthenings (eg, Hoke or Z-lengthening) are less mechanically stable, lengthen the gastrocsoleus complex as a unit, and elicit larger corrections but may require more postoperative protection.4

 

In general, the location of the sural nerve needs to be considered for each approach. The sural nerve has an inconsistent course and may be superficial to the deep fascia of the leg (42.5%), deep to the deep fascia of the leg (57.5%), or deep and

adherent to the gastrocnemius tendon (12.5%).6

 

Plantarflexion contracture secondary to isolated gastrocnemius contracture is typically treated with a more proximal lengthening such as a Baumann or Strayer procedure (FIG 5).

 

42

 

Plantarflexion contracture secondary to combined gastrocsoleus contracture is generally treated with a more distal procedure, such as a Vulpius, Hoke, or Z-lengthening procedure.

 

More complex plantarflexion contractures secondary to posttraumatic cases may require a Z-lengthening with posterior

ankle/subtalar joint capsular releases and may require external fixation to facilitate a safe and gradual correction.

TECHNIQUES

• Baumann Lengthening

The patient is placed supine and the surgeon stands on the contralateral side.

A 5-cm incision is made two fingerbreadths posterior to the posteromedial tibial crest at junction of the proximal and middle third of the leg.

Bluntly develop the plane to the superficial fascia of the leg (crural fascia) and retract the saphenous neurovascular bundle if encountered.

Longitudinally incise the crural fascia at the interval between the gastrocnemius and soleus muscle bellies.

Use finger dissection to bluntly develop the plane between the gastrocnemius and soleus from their palpable medial to

 

 

lateral borders. It is critical to identify the lateral most margin of the gastrocnemius muscle. Identify the plantaris tendon and transect.

 

 

TECH FIG 1 • View of the proximal gastrocsoleus interval for a Baumann recession and recessions of the anterior gastrocnemius fascia and posterior soleal fascia. (The gastrocnemius muscle has been removed from the posterior view for the purpose of the illustration.)

 

Once the anterior gastrocnemius and posterior soleal fascial are identified, place the ankle in dorsiflexion and use a long-handled knife to incise the anterior gastrocnemius fascia from medial to lateral. Take care not to incise the underlying muscle belly. Repeat the Silfverskiöld test. Up to three fascial incisions of the gastrocnemius can be performed, each about

1.5 cm apart (TECH FIG 1).

 

If the ankle still requires more dorsiflexion, the surgeon can perform a posterior soleal recession distal to the gastrocnemius recessions. Place the soleal recession about 1.5 cm distal to the gastrocnemius recessions to avoid postoperative adhesions between the gastrocnemius and soleus.

 

Close the crural fascia with an absorbable suture and close the skin.

 

The Baumann procedure has the benefit of being relatively more cosmetic because the distal gastrocnemius confluence with soleus tendon is preserved.

• Strayer Lengthening

   

  The patient is placed in the supine position and the distal aspect of the medial gastrocnemius muscle belly is identified visually and by palpation. In legs with a larger subcutaneous fat layer, dorsiflexing and plantarflexing the ankle can assist in defining this landmark.

   

  An incision is made from this muscle belly extending 3 cm distally two fingerbreadths posterior to the posteromedial tibial crest (TECH FIG 2A).

   

  Bluntly develop the plane of dissection to the superficial fascia of the leg (crural fascia), and retract the saphenous neurovascular bundle if encountered.

   

  Longitudinally incise the crural fascia over the visible gastrocnemius tendon where it meets the soleus muscle. This interval is visible through the crural fascia (TECH FIG 2B,C).

   

  Use finger dissection to bluntly develop the plane between the gastrocnemius and soleus to the point where they converge distally (approximately 2 cm distal to the most distal aspect of the medial gastrocnemius muscle belly).

   

  43

   

   

   

  TECH FIG 2 • A. Skin incision for a Strayer recession. B. Superficial dissection to the crural fascia at the medial gastrocnemius myotendinous junction demonstrating the visible interval between the underlying soleus (S) and gastrocnemius (G). C. Dissection through the crural fascia at the visible interval with proximal retraction of the mobile skin window demonstrating the soleus and distal extent to the medial gastrocnemius muscle (arrow). D. The plantaris (P) is identified in the interval between the soleus and gastrocnemius and brought into the surgical field with a snap for easy transection. E. The distal extent of the medial gastrocnemius muscle is identified, and a Kocher clamp is used to retract the gastrocnemius tendon anteriorly to allow for inspection of the sural nerve, which may be adherent to the posterior gastrocnemius tendon in some cases. F. The sural nerve (arrow) is identified posterior to the gastrocnemius tendon on most cases and must be identified for safe gastrocnemius recession at this level. G. A vaginal speculum can be used for safe anterior and posterior retraction of the gastrocnemius tendon at the level of the myotendinous junction (open arrow). The sural nerve can be identified (closed arrow) and retracted with the posterior tine of the speculum. H. The gastrocnemius tendon is sharply divided with a long-handled knife. Often, a secondary inspection will reveal that the lateral most margin of the gastrocnemius tendon is still intact and a second pass with the knife is required to complete the recession. Using a long-handled clamp to deliver the lateral margin of the tendon into the surgical field may provide easier access to the lateral tendon. A finger should be used to palpate the tendon and verify that the recession is complete. I. Once the recession is complete, the sural nerve can be identified in the interval where the recession occurred.

   

  It is critical to develop this plane from the medial border to the lateral border. A small blunt elevator can help palpate the lateral margin.

   

  Identify the plantaris tendon and transect (TECH FIG 2D).

   

  Identify the distal extent of the medial gastrocnemius muscle and identify the sural nerve posterior to the gastrocnemius myotendinous junction, being mindful of the variations in location of the sural nerve (TECH FIG 2E,F).

   

  Dorsiflex the ankle and place the gastrocnemius tendon on tension. A vaginal speculum will function as an excellent retractor if placed on the anterior and posterior sides of the gastrocnemius tendon (TECH FIG 2G).

   

  If just proximal to the myotendinous junction, the medial belly of the gastrocnemius can be swept off of the distal aspect of

  the posterior gastrocnemius tendon with a blunt soft tissue elevator. Use a long-handled knife or scissors to incise the gastrocnemius tendon (TECH FIG 2H,I).

   

  Ensure there are no fibers of the tendon intact laterally.

   

  The Silfverskiöld test is repeated, and if there is still an equinus contracture, the underlying soleal fascial may be recessed as well.

   

   

  We do not suture the gastrocnemius fascial to the soleal fascia following the recession. The gastrocnemius-to-soleus recession occurs in an approximate 2:1 ratio.4

   

  The crural fascia is closed with an absorbable suture.

   

   

  44

• Vulpius and Baker Lengthenings

   

  The Vulpius and Baker procedures lengthen at the same level (through the conjoined tendon of the gastrocnemius aponeurosis and soleus fascia) and only differ in the geometry of the cut (see FIG 5).

   

  If this is an isolated procedure, prone positioning allows for better visualization of the cut. However, if associated

  procedures are performed, these lengthenings can be performed with an assistant elevating the leg and the surgeon positioned at the end of the bed (see FIG 4).

   

  A midline 2 cm incision is made at the junction between the distal and middle thirds of the leg.

   

   

   

  TECH FIG 3 • A. The conjoint gastrocsoleus tendon, exposed for a Vulpius or Baker lengthening. Median soleal raphe exposed after recession of the overlying gastrocsoleus conjoint tendon before (B) and after (C) transection.

   

  Carry the dissection bluntly down to the crural fascia and palpate the medial and lateral margins of the conjoint tendon with blunt soft tissue elevator (TECH FIG 3A).

   

  Incise the conjoint tendon from its medial to lateral margin, and do not incise the deep soleus muscle belly. Vulpius' original

  description indicated that cuts could be made “horizontally, diagonally, or, best of all, in the form of an upside-down ‘V’.”4 We prefer to make a simple transverse incision. The Baker lengthening describes an upside-down U cut, which forms a tongue- and groove-shaped defect.

   

   

  Identify the deep median soleal raphe and incise this (TECH FIG 3B,C). Close the crural fascia and skin.

• Hoke Achilles Triple Hemisection Lengthening

   

  This procedure can be performed in the supine position with an assistant elevating the leg.

   

  The proximal and distal margins of the Achilles tendon are palpated with the ankle in dorsiflexion.

   

  Mark the proximal, middle, and distal central points of the Achilles tendon (ie, a total of three marks; TECH FIG 4).

   

  Place the ankle in dorsiflexion and make a longitudinal percutaneous stab incision in the distal most mark with a no. 15 or

  no. 11 blade. Place the blade in the tendon just to the anterior aspect of the tendon; it is critical not to plunge with the blade, as there are vital structures nearby.

   

  Turn the blade 90 degrees medially; place a thumb on the medial border of the Achilles tendon adjacent to the blade. Complete the hemisection using the thumb to palpate when the blade completes the hemisection.

   

   

  Repeat the percutaneous hemisection, except for a lateral direction, at the middle mark. Repeat the percutaneous medial hemisection as described earlier for the proximal mark.

   

  Some surgeons prefer to perform proximal lateral/middle medial/distal lateral hemisections in patients with valgus hindfeet to theoretically decrease the lateral/valgus moment arm of the Achilles tendon pull. If this is the case, extra precautions need to be taken to avoid damaging the sural nerve, especially at the proximal most incision.

   

  Place Steri-Strips type dressings on the percutaneous stab incisions.

   

  Care must be take not to plunge the blade when performing the hemisections, as there are critical structures nearby; the FHL and tibial nerve are less than 1 cm from the proximal cut if directed medially and the sural nerve is less than 1 cm from

  the middle cut if directed laterally.8

   

   

   

  TECH FIG 4 • Skin markings demonstrating appropriate placement of the percutaneous stab incisions for a Hoke lengthening.

   

   

  45

• Z-Lengthening

 

This procedure needs to be performed in the prone position.

 

The proximal and distal aspects of the Achilles tendon are identified, and a longitudinal incision is made either in the midline of the Achilles tendon or on the medial border of the Achilles tendon, extending the length of the Achilles tendon.

 

The paratenon is identified and incised sharply in line with the length of the incision. Raise the paratendon flaps as a medial and lateral soft tissue layer for later closure over the Achilles tendon.

 

Perform a full-thickness incision of the Achilles tendon in the midline from its proximal to distal extent.

 

At the proximal margin of the tendon-splitting incision, turn the knife 90 degrees and come out of the tendon medially (exiting laterally proximally puts the sural nerve at higher risk of inadvertent laceration).

 

 

 

TECH FIG 5 • Z-lengthening demonstrating the overlying paratendon and Z cuts in the tendon before (A) and after (B) ankle dorsiflexion.

 

At the distal margin of the tendon-splitting incision, turn the knife 90 degrees to come out of the tendon laterally.

 

For more serious contractures, reflect the Z-lengthening and continue the dissection deep to the posterior ankle and subtalar joints. Perform capsular releases as necessary.

 

Dorsiflex the ankle to the desired tension and suture the Achilles tendon back to itself with a heavy nonabsorbable suture. Take care to ensure that the knot pillars are not prominent (TECH FIG 5).

 

Close the skin and paratenon with an absorbable suture.

 

PEARLS AND PITFALLS

Rule out other causes of decreased ankle range of

motion

• Bony impinging lesions and ankle arthritis are readily

apparent on weight-bearing radiographs.

Determining if the contracture is isolated to the

gastrocnemius or combined gastrocsoleus will help indicate the proper lengthening procedure

• Preoperative and intraoperative Silfverskiöld testing,

with the hindfoot held in a neutral position, is an important physical examination maneuver.

It is important to obtain adequate ankle dorsiflexion

intraoperatively.

• The Baumann and Strayer procedures can be

supplemented with a release of the soleal fascia to

 

 

			improve ankle dorsiflexion.
		Good visualization is key. ▪ A vaginal or nasal speculum and headlamp can be very helpful.
		Avoid nerve injuries. ▪ Be mindful of the variable anatomy of the sural nerve; identifying it with the Strayer procedure may help decrease inadvertent injury.

 

 

46

POSTOPERATIVE CARE

 

All patients should be examined at about 2 weeks postoperatively for a wound check.

 

When performed in conjunction with larger surgical reconstructions, the postoperative care is determined by the reconstruction.

 

In the case of isolated gastrocsoleus lengthenings, all lengthenings described herein except Hoke and Z-lengthenings may be weight bearing as tolerated in a cam boot for 2 weeks followed by a gradual transition out of the boot and range of motion protocol.

 

The author's preferred method is to remove the cam boot on postoperative day 4 and mobilize in a sneaker to allow for range of motion. The patient should sleep with the boot for 4 to 6 weeks.

 

Hoke and Z-lengthenings should be maintained non-weight bearing in a boot for 2 to 4 weeks, followed by gradual progression of weight bearing to full weight bearing over 2 to 4 weeks. The patient should be maintained in a cam boot for 6 to 8 weeks.

 

OUTCOMES

Lengthening of part or the entire gastrocsoleus complex increases passive ankle range of motion and gains are maintained late in the postoperative period.

Lengthening causes a slight weakness in the gastrocsoleus complex, which improves with time to closely approximate the contralateral side.

Forefoot plantar pressure decreases following lengthening; this may be secondary to increased ankle range of motion or initial weakness in the gastrocsoleus complex.

Clinical outcomes are dependent on the pathology being treated; however, results for a variety of pathologies are encouraging.

Achilles tendon lengthening may significantly decrease the early and late risk of ulcer recurrence in patients with diabetes and neuropathic ulcers.5

Lengthening may improve clinical outcomes in patients with Achilles tendinopathy.3

 

 

COMPLICATIONS

Sural nerve injury

Poor cosmesis secondary to scar adhesions or proximal gastrocnemius muscle retraction Overlengthening and subsequent heel pain

Wound healing problems

 

 

REFERENCES

1. Alfredson H, Cook J. A treatment algorithm for managing Achilles tendinopathy: new treatment options. Br J Sports Med 2007;41:211-216.

    

    

2. DiGiovanni CW, Kuo R, Tejwani N, et al. Isolated gastrocnemius tightness. J Bone Joint Surg Am 2002;84-A(6):962-970.

    

    

3. Duthon VB, Lübbeke A, Duc SR, et al. Noninsertional Achilles tendinopathy treated with gastrocnemius lengthening. Foot Ankle Int 2011;32:375-379.

    

    

4. Firth GB, McMullan M, Chin T, et al. Lengthening of the gastrocnemius-soleus complex: an anatomical and biomechanical study in human cadavers. J Bone Joint Surg Am 2013;95(16):1489-1496.

    

    

5. Mueller MJ, Sinacore DR, Hastings MK, et al. Effect of Achilles tendon lengthening on neuropathic plantar ulcers: a randomized clinical trial. J Bone Joint Surg Am 2003;85-A(8):1436-1445.

    

    

6. Pinney SJ, Sangeorzan BJ, Hansen ST Jr. Surgical anatomy of the gastrocnemius recession (Strayer procedure). Foot Ankle Int 2004; 25:247-250.

    

    

7. Radford JA, Burns J, Buchbinder R, et al. Does stretching increase ankle dorsiflexion range of motion? A systematic review. Br J Sports Med 2006;40:870-875.

    

    

8. Salamon ML, Pinney SJ, Van Bergeyk A, et al. Surgical anatomy and accuracy of percutaneous Achilles tendon lengthening. Foot Ankle Int 2006;27:411-413.