Endoscopic Gastrocnemius Recession

Saul G. Trevino

Santaram Vallurupalli

David Flood

INTRODUCTION

Progressive deformities of the foot and ankle have been associated with contracture of the triceps surae. Historically, these contractures were addressed by distal release of the Achilles tendon.¹^, ²^, ³ Complications of this approach include calcaneal gait, plantar flexion weakness, and wound-healing problems. Isolated contracture of the gastrocnemius was first identified in the early 20th century. The first open procedure to release primarily the gastrocnemius contracture was described in 1913 by Vulpius⁴ and modified in 1950 by Strayer.⁵ Unfortunately, open procedures can be complicated by over-lengthening, poor cosmesis, sural nerve damage, skin contractures, and wound-healing problems. Endoscopic gastrocnemius recession (EGR) has been developed to address these concerns.

The EGR has several advantages over open procedures. It can be done under local anesthetic without use of a tourniquet. The short surgical time (usually 10 to 15 minutes) allows ample time to perform associated reconstructions under the same anesthetic. The procedure has a small learning curve and can be mastered by the general orthopedic surgeon.⁶^, ⁷ It can also be performed in pediatric patients. The short incisions are excellent from a cosmetic perspective.

INDICATIONS

EGR is indicated in cases of demonstrable gastrocnemius contracture. Isolated gastrocnemius contracture must be distinguished from contracture associated with tightness of the gastrocsoleus unit, as well as contracture associated with anatomic bone or joint pathology such as posttraumatic arthrosis.⁷^, ⁸^, ⁹^, ¹⁰^, ¹¹ Anatomical equinus may be defined as an ankle with less than 0 degrees of dorsiflexion. Functional ankle equinus has been defined as a limitation of ankle dorsiflexion of less than 10 degrees. Most authors agree that normal gait after toe off requires at least 10 degrees of dorsiflexion. Barrett described passive dorsiflexion less than 10 degrees with the leg extended as pathologic.¹⁰ DiGiovanni et al.¹² proposed that passive dorsiflexion less than 5 degrees to be considered as an equinus contracture. We feel that any dorsiflexion with full knee extension less than 10 degrees is possibly pathologic and that dorsiflexion less than 5 degrees is definitely pathologic.

The Silfverskiold test¹³ remains the primary method of distinguishing isolated contractures of the gastrocnemius from contractures of the gastrocsoleus complex (Fig. 2-1). The distinction relies on the anatomical fact that the gastrocnemius originates on the distal femur and spans the knee joint, compared to the soleus muscle, which originates on the tibia and only spans the ankle joint. To perform the Silfverskiold test, the ankle is dorsiflexed with the knee in both extension and in 20 to 40 degrees of flexion. The test is considered positive for isolated gastrocnemius contracture if dorsiflexion normalizes with knee flexion but is limited in knee extension (Fig. 2-1). It is important to position the hindfoot in subtalar neutral to slight inversion. This neutral position locks transverse tarsal joint, thus controlling the eversion and abduction that may give a false sense of greater dorsiflexion than is actually present.

While the gastrocnemius contracture release was initially performed primarily in patients with a neurologic disorder such as cerebral palsy, various authors including Hansen, expanded its use to the treatment of conditions not necessarily associated with neurologic disorders.¹⁴^, ¹⁵^, ¹⁶ These authors and others postulated that the contracted gastrocnemius muscle limits dorsiflexion, which in turn alters normal gait biomechanics. This contracture causes excessive pronation and may evolve into actual peritalar subluxation over time.⁸^, ⁹

In 2002, DiGiovanni et al.¹² published a prospective study with a control group that supported the association of gastrocnemius contracture with other common foot disorders like plantar fasciitis, bunions, and midfoot pathology. In addition, Adelman et al.¹⁷ reported in 2008 the use of gastrocnemius recession combined with subtalar arthrodesis and flexor tendon transfer in the successful treatment of Stage II posterior tibialis tendon in dysfunction in 10 patients. EGR is indicated whenever gastrocnemius contracture is impairing normal gait or contributes to other pathologic states (Fig. 2-6).

Endoscopic Gastrocnemius Recession Procedure Setup

The patient can either be placed in a supine or prone position. In general, the supine position is preferred as it allows for performing additional related procedures without intraoperative repositioning. Elevation of the contralateral hip and a small bump under the operative
ankle allows for easy manipulation of the endoscope. The medial portal site is located 15 to 17 cm proximal to the insertion of the Achilles tendon.¹⁰ The incisional site is 3 to 4 cm distal to the most distal extent of the gastrocnemius bellies. There is some variance in the distal extension of the muscle bellies beyond the center attachment point of the aponeurosis. In pediatric or small-statured people, the physical examination will determine the ideal location. The muscle bellies of the gastrocnemius muscle are identified and help to determine a point approximately 4 to 6 cm distal to these structures (Fig. 2-2). In obese patients, an ultrasound can help to identify the precise location of the distal extent of these muscles. EGR can be performed using both medial and lateral portals; however, this two-portal technique is not necessary since the medial portal allows for visualization of both the medial and lateral borders of the aponeurosis. A lateral portal is more likely to damage the sural nerve. The approximate location of the sural nerve can be estimated by drawing a line from the center of the popliteal fossa to an area 1 cm behind the lateral malleolus at the level of the ankle.¹⁸

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