Discussion
(see also: role of ankle and subtalar joint in gait)
- normally, during the transition from foot flat to heel off, the foot dorsiflexes as the body moves forward;
- gait consequences of equinus contracture:
- patient may adopt a toe to toe gait pattern or a toe to heel gait pattern (premature forefoot loading)
- reduced propulsion
- excessive knee hyperextension
- excessive foot pronation which allows more dorsiflexion to occur at the subtalar joint;
- reduced stride length of the opposite limb
- reduced gait velocity
- external rotation
diff dx
- anterior ankle impingement
- leg length descrepancy
- hyperpronation of the foot
- clubfoot
- ankle equinus in CP
- immobilization after trauma
Exam
Silfverskiold test
- normal ankle dorsiflexion:
- ankle dorsiflexion with knee extended (= 10 degrees of DF)
- with flexion of the knee there will be an additional 10 deg of DF (= 20 deg of DF);
- isolated gastroc contracture: (usually seen in CP)
- equinus contracture with knee extended (20 degrees of plantarflexion);
- when the knee is flexed to 90 degrees, ankle dorsiflexion significantly improves (10 degrees of dorsiflexion).
Heel Cord Stretching
- patient should be standing and facing wall w/ the feet internally rotated (which keeps heel flat on floor during stretch and which locks the subtalar joint);
- this ensures that dorsiflexion motion occurs only at ankle joint;
- care must be take to invert subtalar joint and forefoot before applying dorsiflexion stress;
- this locks calcaneus under talus, ensuring that dorsiflexion occurs only at the ankle joint rather than dorsiflexion does not occur at the midfoot;
Orthotics
- with a fixed equinus deformity, patients may do well with a heel-lift shoe insert;
Operative Treatment
Baumann procedure
- consists of intramuscular lengthening (recession) of the gastrocnemius muscle in the deep interval between the soleus and gastrocnemius muscles;
- goal of the procedure is to increase ankle dorsiflexion when ankle movement is restricted by a contracted gastrocnemius muscle;
- truly isolates the lengthening to the gastrocnemius muscle
- procedure is indicated when the results of the Silfverskiold test are positive.
Vulpius procedure
- superficial gastrocnemius-soleus recession includes an intramuscular lengthening of the soleus muscle
Strayer
- distal gastrocnemius tenotomy, 3 cm proximal to the gastrocnemius-soleus aponeurosis;
- gastroc and soleus are separated to allow the gastrocnemius tendon to retract proximally, which is then sutured to soleus
References
- Biomechanics and Orthotics of the Foot in Athletes. Graves SC, Badwey TH, Graves KO. Oper Tech Sports Med. 1994;2(1):2-8.
- Isolated Recession of the Gastrocnemius Muscle: The Baumann Procedure
- Helical Cutting as a New Method for Tendon-Lengthening in Continuity
- Lengthening of the Gastrocnemius-Soleus Complex: An Anatomical and Biomechanical Study in Human Cadavers