Surgical Anatomy of the Gastrocnemius Recession (Strayer Procedure)

INTRODUCTION

The gastrocnemius recession was first described in 1913. ¹¹ The procedure is often named after Strayer, who reviewed the procedure in 1950. ¹⁰ Gastrocneius recession is a treatment option for patients with clinically relevant gastrocnemius equinus contracture. Initially the procedure was largely used within the pediatric population. ^{1 –4,7,8} In recent years, the procedure has been presented as an important component of the surgical treatment of a number of chronic foot problems. ^5,6 The purpose of this study was to review the surgical anatomy of the Strayer procedure with specific reference to 1) the location of the sural nerve and 2) the gastrocnemius tendon release point. A detailed understanding of the surgical anatomy should improve cosmesis and decrease the incidence of sural nerve injury.

MATERIALS AND METHODS

Forty consecutive gastrocnemius recessions in 33 patients (15 males, 18 females) formed the study group. The average age was 49.9 years (range, 12–79 years). The indication for surgery was a chronic foot problem with an associated gastrocnemius equinus contracture with the knee straight which subsequently corrected with the knee bent. All patients had a preoperative diagnosis of either acquired adult flatfoot deformity, hallux valgus, or plantar fasciitis. The gastrocnemius recession was performed through a posteromedial lower leg incision approximately 7 cm in length (Fig. 1). The dissection was carried through the skin and subcutaneous tissue to the deep fascia. The deep fascia was excised in line with the skin incision. The areolar tissue overlying the gastrocnemius tendon was incised to expose the tendon. An elevator was used to clear the areolar tissue off the gastrocnemius tendon. The sural nerve was identified (Fig. 2). The nerve was then protected throughout the operation with a right angle retractor. The interval between the gastrocnemius and soleus was developed from medial to lateral using manual dissection. Adhesions between the gastrocnemius and soleus were cleared manually. A right-angled snap was passed through the gastrocsoleus interval to allow the distal extent of the gastrocnemius tendon to be cut with a scalpel under direct vision (Fig. 3). Closure was performed in layers. The cut tendinous end of the gastrocnemius was sutured to the underlying soleus fascia with 3–0 absorbable suture. The gap between the cut ends of the gastrocnemius tendon was typically about 3 cm. The increase in ankle dorsiflexion achieved was equivalent to maximal preoperative ankle dorsiflexion with the knee bent, typically about 20°. ⁹ The deep fascia was closed with running 3–0 absorbable suture. If necessary, interrupted 3–0 absorbable sutures were used to close the subcutaneous layer. The skin was closed with 4–0 or 5–0 nylon suture.

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Fig. 1:

Posteromedial lower leg incision.

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Fig. 2:

Identification of the sural nerve deep to the fascia.

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Fig. 3:

Right-angled snap is positioned in the gastrocsoleus interval to allow the distal extent of the gastrocnemius tendon to be incised under direct vision.

In each patient, standard measurements were recorded. The visible gastrocnemius indent was defined as the angled indent seen tangentially as the distal extent of the gastrocnemius muscle belly merges into the gastrocnemius tendon (Fig. 4). The distance from this visible indent to the actual gastrocnemius tendon insertion (the insertion point) was recorded. In one patient, the visible indent could not be accurately determined due to excess adipose tissue. The distance from the Achilles insertion point to the gastrocnemius tendon insertion into the Achilles (Y) was recorded (Fig. 4). This was standardized as a fraction of the length of the lower leg (X) (Fig. 4).

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Fig. 4:

Gastrocnemius indentation due to the muscle belly merging into the tendon (arrow). Gastrocnemius tendon insertion site/release point (star). Gastrocnemius tendon insertion into the Achilles to Achilles insertion in the calcaneus (Y). Length of the lower leg (X).

The location of the sural nerve was recorded as either superficial or deep to the fascia. In some patients, the sural nerve was found directly adherent to the gastrocnemius tendon and this was recorded. In addition, the distance from the medial border of the gastrocnemius tendon to the sural nerve was measured in millimeters (mm).

RESULTS

The location of the actual gastrocnemius tendon insertion point into the Achilles was found to be an average of 18 mm distal to the visible indent (range, 20 mm proximal to 57 mm distal). The gastrocnemius insertion point was an average of 159 mm (range, 107–209 mm) proximal to the Achilles insertion into the calcaneus. The average lower leg ratio (Y/X) was 0.43 (range, 0.33–0.60). The sural nerve was located an average of 46 mm (range, 27–69 mm) from the medial border of the gastrocnemius tendon. In 17 (42.5%) legs, the sural nerve was located superficial to the deep fascia at the gastrocnemius insertion point. In the remaining 23 legs (57.5%), the nerve was located deep to the fascia. In five legs (12.5%), the nerve was applied directly to the tendon and required gentle dissection of the gastrocnemius tendon prior to performing the recession.

DISCUSSION

The gastrocnemius recession was first described in 1913. ¹¹ It was reviewed in more detail by Strayer in 1950 and is therefore often referred to as the Strayer procedure. ¹⁰ The early reports of the procedure described long posterior incisions. Indications for surgery were largely confined to the pediatric populations in which conditions such as cerebral palsy predispose this patient population to develop clinically significant gastrocnemius equinus contractures. More recently, gastrocnemius equinus contracture has been presented as a predisposing factor to such common foot conditions such as hallux valgus, symptomatic adult flatfoot deformity, and plantar fasciitis. ^5,6 Treatment of these conditions often requires a gastrocnemius recession as a component of surgical management. Two potential complications that are of relevance to the gastrocnemius recession are poor cosmesis and sural nerve injury. The results of this article may serve to minimize these complications.

Poor cosmesis due to an excessively long incision or tethering of the skin to the underlying fascia can lead to patient dissatisfaction. The length of the incision can be minimized by preoperatively identifying the visible indent created by the distal extent of the gastrocnemius muscle belly. Dissection is only required proximal to the gastrocnemius tendon insertion into the Achilles. The results of this study demonstrate that this point is on average 18 mm distal to the visible indent. Therefore, the skin incision should be initiated 2 cm distal to the visible gastrocnemius indentation and extended proximally. Excess adipose tissue can make this anatomical landmark difficult to identify. There can be variability between the anatomical landmark and the actual tendon insertion site, as this study demonstrated. To accommodate for this variability, the incision can be extended proximally or distally as required. Cosmesis of the incision can also be compromised by tethering of the skin to the underlying tissue. This relatively frequent complication can be minimized by closing the deep fascia and ensuring that homeostasis has been obtained.

Sural nerve injury either by direct trauma or excessive stretch is another complication of particular relevance to the gastrocnemius recession. Because of the nearly direct posterior position of the nerve at the gastrocnemius insertion point, we recommend a posteromedial incision rather than a straight posterior incision. This will avoid inadvertently cutting the nerve during the surgical approach. We believe it is critical to identify the sural nerve. It should then be protected with a right-angled retractor throughout the operation. Results from this study show that the sural nerve is typically found 46 mm (range, 27–69 mm) from the medial border of the gastrocnemius tendon. In 42.5% of legs, the nerve was superficial to the fascia, and therefore unlikely to be injured except during a straight posterior approach. However, in the majority (57.5%) of legs, the nerve was deep to the fascia and at risk for direct injury if not identified and fully protected with a retractor. The most problematic sural nerve location was encountered when the nerve was directly applied to the gastrocnemius tendon. If not identified the sural nerve would be cut in the tendon release. Furthermore, even if identified and freed from the tendon, the nerve is still at high risk for a stretch injury after the gastrocnemius recession, presumably due to the tethering of the nerve proximally and distally to the recession site. In this instance, to minimize the risk of sural nerve injury, gentle dissection of the nerve off the tendon should occur in both a proximal and distal direction. The nerve should be palpated during the gastrocnemius recession to avoid excess tension.

CONCLUSION

Gastrocnemius recession (Strayer procedure) can be complicated by sural nerve injury and/or poor cosmesis. This study provides a review of the surgical anatomy of the gastrocnemius recession. The sural nerve should be protected to minimize the risk of injury. Employing a posteromedial approach instead of a straight posterior incision will help avoid direct injury. The nerve will be found deep to the fascia in the majority of patients and therefore should be identified prior to incising the gastrocnemius insertion. The length of the incision can be minimized by starting 2 cm distal to the gastrocnemius indentation and extending proximally.