Gastrocnemius Recession (Strayer / Vulpius)

The gatekeeper test. Gastrocnemius recession is only appropriate when the contracture is isolated to the gastrocnemius. The Silfverskiöld test decides this: assess ankle dorsiflexion with the knee extended, then flexed to 90 degrees. If dorsiflexion improves by at least 5 degrees with the knee flexed, the soleus has been slackened and the contracture is isolated to the gastrocnemius (a positive test) — recession is the correct operation. If dorsiflexion does not change, the contracture involves the soleus or the entire tendo-Achilles (a negative test) and a recession will under-correct; a formal tendo-Achilles lengthening is required instead. Normal ankle dorsiflexion is at least 10 degrees beyond neutral with the knee extended. Absolute indications — an isolated gastrocnemius contracture (positive Silfverskiöld test) demonstrated as a biomechanical contributor to:

• Forefoot or midfoot pathology (metatarsalgia, midfoot overload) that has failed non-operative treatment
• Recurrent or recalcitrant plantar fasciitis after at least 6 to 12 months of structured non-operative care (stretching programme, orthotics, physiotherapy, night splint, at least one corticosteroid injection)
• Diabetic forefoot ulceration refractory to offloading and wound-care optimisation Relative indications:
• Non-insertional Achilles tendinopathy with isolated gastrocnemius contracture, failed non-operative treatment
• Flatfoot deformity where gastrocnemius contracture contributes to hindfoot valgus — recession as an adjunct to flatfoot reconstruction
• Paediatric equinus — cerebral palsy or idiopathic toe-walking (Baumann or Strayer)
• Chronic ankle stiffness / anterior impingement where gastrocnemius tightness limits dorsiflexion Contraindications. Absolute: a negative Silfverskiöld test (recession under-corrects; TAL required); active infection at the surgical site or ipsilateral limb; severe peripheral vascular disease unlikely to heal (ABI less than 0.4, rest pain, or unoptimised tissue loss). Relative: previous ipsilateral calf surgery or trauma (distorted anatomy, higher sural nerve risk); marked obesity (BMI greater than 40); active Charcot neuroarthropathy (wait until stabilised); calf weakness from neuromuscular disease (polio, stroke, Charcot-Marie-Tooth) — further weakening is poorly tolerated. The one decision that matters — which lengthening. The contracture having been confirmed as isolated, the choice is which technique lengthens the gastrocnemius without sacrificing soleus push-off:

Special situation — diabetes. In diabetics, isolated gastrocnemius contracture raises forefoot plantar pressure by roughly 20 to 30 percent, driving recalcitrant plantar ulceration. Recession (Strayer) is strongly preferred over percutaneous TAL: it uses a proximal calf incision in better-vascularised tissue, does not violate the Achilles tendon, and avoids the 20 to 50 percent wound-breakdown rate reported with percutaneous TAL in this group. A randomised trial (Holzer, JBJS 2014) showed recession plus wound care improved ulcer healing and reduced recurrence versus wound care alone. Consent specifically for sural nerve neurapraxia (5 to 10 percent transient, less than 1 percent permanent), over-lengthening (push-off weakness, calcaneal gait), under-correction (residual equinus), wound infection (less than 2 percent) and dehiscence, DVT/PE, and the possibility of conversion to a tendo-Achilles lengthening if the recession is found intra-operatively to be insufficient.

The goal: expose the gastrocnemius aponeurosis through a short posteromedial calf incision, identify and protect the sural nerve before any release, divide the aponeurosis from the soleus fascia incrementally while checking dorsiflexion, and stop at 5 to 10 degrees beyond neutral — lengthening the gastrocnemius while preserving the soleus. The exposure and the step-by-step release are laid out below.

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Rehabilitation | Phase | Timing | Immobilisation & weight-bearing | Therapy | |-------|--------|--------------------------------|---------| | 1 | 0–2 weeks | Below-knee walker boot (or posterior splint) in neutral; touch-down to partial weight-bearing | Elevation above the heart for 48 hours; paracetamol ± NSAIDs; DVT prophylaxis per protocol | | 2 | 2–4 weeks | Boot; sutures/clips out at 10–14 days | Gentle active dorsiflexion out of the boot; passive dorsiflexion within the surgical range | | 3 | 4–8 weeks | Wean the boot by 4–6 weeks into a stiff-soled shoe | Calf stretching within the corrected range; gait retraining; progressive calf strengthening | | 4 | 8–12 weeks+ | Normal footwear | Eccentric calf strengthening; sport-specific rehabilitation | Return to function: sedentary work 2–4 weeks; standing or manual work 6–8 weeks; driving 4–6 weeks (right foot; earlier for the left in an automatic); light sport at 8 weeks and full sport by 12 weeks. Maximum medical improvement — full calf strength and final dorsiflexion range — takes 6 to 12 months. Complications

Pathoanatomy. The triceps surae has three heads. The gastrocnemius is bi-articular: its medial head arises from the posterior medial femoral condyle and the posterior knee capsule, its lateral head from the lateral condyle and the supracondylar line — so it crosses both the knee and the ankle and is tightened by knee extension. The soleus is uni-articular, arising from the posterior tibia (soleal line) and the fibular head and proximal fibula, crossing only the ankle and unaffected by knee position. The two merge into a common aponeurosis in the distal calf to form the tendo-Achilles, inserting on the posterior calcaneal tuberosity. The gastrocnemius bellies converge on a thick, glistening, white, transversely-fibred aponeurosis at the junction of the proximal and middle thirds of the calf, which sits on — and can be separated from — the thinner soleus fascia beneath; that interval is the plane of the Strayer release. The gastrocnemius musculotendinous junction lies in the proximal third of the calf, roughly 5 to 8 cm distal to the popliteal crease, marking the level of the incision. Structures at risk. The sural nerve — formed from the medial sural cutaneous nerve (tibial) and the sural communicating branch (common peroneal) — descends in the subcutaneous tissue of the posterolateral calf about 1 to 2 cm posterior to the lateral fibular border, then passes behind the lateral malleolus to supply the lateral foot and fifth toe; it is the most commonly injured structure and the reason identification before deep dissection is mandatory. The posterior tibial neurovascular bundle (tibial nerve, posterior tibial artery and vein) lies deep to the soleus between flexor digitorum longus and flexor hallucis longus — safe as long as the dissection stays superficial to the soleus fascia. The common peroneal nerve at the fibular neck is at risk only in the Baumann proximal release. The Silfverskiöld test — biomechanics. Because the gastrocnemius crosses both joints and the soleus only the ankle, a contracted gastrocnemius limits dorsiflexion with the knee extended (gastrocnemius at maximum length). Flexing the knee slackens the gastrocnemius: if dorsiflexion then improves, the gastrocnemius is the tight structure (positive); if it does not, the soleus or tendo-Achilles is tight (negative). Stabilise the hindfoot in subtalar neutral, measure dorsiflexion with the knee extended and then flexed to 90 degrees, and compare.

Key evidence. The evidence supports recession when an isolated gastrocnemius contracture is confirmed. DiGiovanni (2002) established that isolated gastrocnemius tightness is significantly more common in patients with plantar fasciitis, metatarsalgia and forefoot overload than in controls — the biomechanical rationale. Maskill (2010) reported 93 percent satisfaction in 29 patients with isolated foot pain and a positive Silfverskiöld test. Kiewiet (2013) showed improved pain and function after recession for chronic non-insertional Achilles tendinopathy. The highest-level support is Molund (2018), a Level I randomised controlled trial in which proximal medial gastrocnemius recession plus stretching outperformed stretching alone for chronic plantar heel pain, with benefit sustained at 6 years. In diabetics with recalcitrant forefoot ulceration, Holzer's randomised trial showed recession plus wound care improved healing and reduced recurrence versus wound care alone.