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Ten patients who had undergone primary intraarticular proximal tibial replacement between April 1985 and December 1994, and had a minimum of 2 years of followup, were available for stride analysis. Mean age, time since intraarticular proximal tibial replacement, height, and weight were 23.8 years, 6.5 years, 167 cm, and 63 kg, respectively. A volunteer control group of five male patients who had undergone above knee amputation was obtained from the local community. The mean age, time since above knee amputation, height, and weight were 43.6 years, 24.1 years, 165 cm, and 70 kg, respectively. Stride analysis was performed over the central 6-m portion of a 10-m walkway at a self selected, comfortable pace. Gait velocity, stride length, cadence, and stance time symmetry were measured. Velocity after intraarticular proximal tibial replacement versus above knee amputation was 79.2 +/- 7.6 m per minute versus 71.4 +/- 5.4 m per minute. Cadence after intraarticular proximal tibial replacement versus above knee amputation was 112.4 +/- 10.6 steps per minute versus 110.1 +/- 2.4 steps per minute. There were no significant differences between stride length (1.41 +/- 0.13 m versus 1.43 +/- 0.12 m) and stance time symmetry (0.90 +/- 0.07 versus 0.87 +/- 0.11) for intraarticular proximal tibial replacement versus above knee amputation. The results suggest that endoprosthetic reconstruction resulted in a gait comparable with that after above knee amputation with an external prosthesis.

Published reports describe the clinical efficacy of modified Brostrom anatomic repairs, surgical procedures that involve repair and fortification of the lateral capsuloligamentous complex of the ankle for patients suffering from chronic lateral instability of this joint. A cadaveric serial sectioning study of the anterior talofibular ligament, the calcaneofibular ligament, and the remainder of the anterolateral joint capsule was completed to quantitate the contribution of the superior portion of the anterolateral joint capsule, independent of the other two structures, to the overall mechanical stability of the lateral ankle. Using 20 fresh frozen specimens, talar tilt and anterior drawer stress radiographs were taken before and after sectioning these anatomic structures in an order established by one of two protocols. Sectioning of the superior anterolateral joint capsule caused 17% to 18% of the total displacement in a Grade II sprain simulation and 29% to 33% of the total displacement in a Grade III sprain simulation. This work suggests that disruption of the segment of ankle joint capsule superior to the anterior talofibular ligament creates approximately 30% of the overall laxity encountered in a Grade III inversion sprain, substantiating the principle of restoring the integrity of the entire anterolateral joint capsule when operating on a chronically unstable ankle.