Perioperative intravenous antibiotics were administered: 2 g cefazolin 30 minutes before incision and 1 g every 8 hours for 24 hours after surgery. A pneumatic tourniquet was placed on the proximal thigh, and the entire leg was prepared and draped in a sterile fashion. The limb was elevated and exsanguinated with an Esmark bandage and the tourniquet raised to 250 mm Hg. With fluoroscopy, the site of the tibial deformity was identified. Generally, an incision was made centered over the apex of the deformity and one fingerbreadth lateral to the palpable tibial crest. In most cases, the anterolateral aspect of the tibia was exposed while minimizing soft-tissue and periosteal stripping. The plane of the maximum deformity was identified with both direct visualization and fluoroscopy. The osteotomy was performed with an oscillating saw, and in each case a fibular osteotomy was also performed. Malalignment was corrected using a combination of manual manipulation and femoral distractor.25,26 Intraoperative biplanar radiographs were compared with our preoperative plan and with reversed images of the contralateral tibia to assess correction of the deformity. If lengthening was required, in addition to the tibial osteotomy, a corticotomy was created, and a circular external fixator applied and distraction osteogenesis performed.
We maintained the limbs in a short-leg splint for about 10 days after surgery and then initiated active-assisted range of motion of neighboring joints. Patients were maintained on toe-touch weight-bearing for the initial 6 weeks and were then advanced to partial weight-bearing (23 kg). Physical therapy for lower extremity strengthening and gait training was started 6 weeks after surgery. Three months after surgery, patients were advanced to weight-bearing as tolerated and were allowed to return to their activities of daily living without restrictions if radiographs and clinical examination were consistent with healing of the osteotomy.
Each patient was examined and radiographs obtained at regular intervals (2, 6, and 12 weeks and then about every 3 months) after surgery until healing. Bone union was determined by history and physical examination with pain-free weight-bearing without use of assistive devices and by return of functional use of the extremity. Radiographic union was considered to have occurred when bridging trabeculae were present across the osteotomy and there was no loosening or failure of the implants. Occasionally, if there were questions regarding healing, a musculoskeletal radiologist was consulted. Acceptable tibia alignment was defined as alignment of less than 5° varus or less than 10° valgus in the coronal plane and less than 15° procurvatum or recurvatum in the sagittal plane. Immediate postoperative radiographs and most recent radiographs were used to determine the final amount of angular correction.27
Two patients subsequently required secondary operative procedures. One had varus collapse through the regenerate, and the other developed a nonunion of the osteotomy site and required exchange intramedullary nailing. In each case, the final assessment was done after the patient had healed after the second surgery and had fully recovered.
Perceived Functional Assessment
The MFA is a 100-item self-administered QOL questionnaire designed to assess self-perception of physical, psychological, and social well-being in patients with a musculoskeletal injury or condition. The MFA provides a summary score and separate score for each of 10 functional domains. The lower the score, the better the patient’s perception of function. Validated and published norms are available.20,28-30
Perceived Health Status
The Short Form-36 is a 36-item multipurpose self-administered health survey questionnaire. The SF-36, which assesses overall health status, provides a Physical Component Score (PCS) and a Mental Component Score (MCS). The higher the score, the better the patient’s perception of function. Validated and published norms are available.31
Gait Analysis
Video data from a 6-camera high-resolution system (Motion Analysis, Santa Rosa, California) were used to assess gait. A set of 3 reflective surface markers was placed on each of 4 areas: trunk, thighs, legs, and feet.18,19 The patient walked barefoot along a 9-meter walkway, and video data were collected during the middle 2 meters. For each patient, data from 4 to 7 trials were collected. Computerized software produced data describing the averaged joint angle as a function of the gait cycle for each of the 3 principal planes of the body. Specific points in the gait cycle were analyzed. Variables included maximum knee varus in stance phase; maximum knee valgus in swing; maximum knee flexion in stance and swing; minimum knee flexion in stance; maximum ankle inversion in terminal stance; maximum ankle eversion in stance; maximum ankle dorsiflexion in stance and swing; and maximum ankle plantarflexion at takeoff. In addition to the lower extremity joint kinematics, angular measurements, basic gait measurements of step length, stride length, cadence, and speed were also recorded.