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The purpose of this study was to determine whether distraction osteogenesis can be used to treat hypertrophic nonunion associated with angular deformity and shortening after Coventry style high tibial osteotomy. Five consecutive patients were retrospectively reviewed. In all patients the alignment had collapsed into excessive varus or valgus and leg length discrepancy was present. The leg length discrepancy, malalignment, and nonunion were treated simultaneously with distraction. Union was achieved by the time of fixator removal, which averaged 4.4 months. The Hospital for Special Surgery knee score significantly improved from 42 to 89. The mechanical axis deviation significantly improved by 5 cm. The coronal plane deformity significantly improved by 13 degrees, and leg length discrepancy improved significantly from 2.3 to 0.5 cm. Metaphyseal bone stock increased by 43%, and the Insall-Salvati ratio increased from 1.1 to 1.2 and remained within normal limits. All patients were satisfied with the procedure, and none have had or need a total knee replacement at an average followup of 4 years. Distraction osteogenesis of nonunion after high tibial osteotomy is a minimally invasive and successful procedure. It leads to bony union with correction of deformity and leg length discrepancy and prevents the need for total knee replacement at intermediate-term followup. The increase in metaphyseal bone stock may make total knee replacement technically easier.

Debridement of chronic osteomyelitis can be technically demanding and difficult. The surgical principles that govern treatment of osteomyelitis involve an atraumatic approach and complete removal of all devitalized tissue and foreign material. Despite recent advances in medical science, the quality of surgical debridement remains the most critical factor in the successful management of chronic orthopaedic infections. Important areas discussed include thorough preoperative evaluation, the surgical philosophy, soft tissue aspects, bone considerations, and dead space management.

Gradual mechanical distraction with the Ilizarov external fixator was used on 28 limbs in 23 patients to correct complex lower-extremity deformities of diverse causes. To determine the accuracy of realignment and deformity correction, the charts and radiographs were reviewed retrospectively. Preoperative long-standing anteroposterior radiographs of the entire lower extremity were compared with those obtained at the most recent follow-up visit. The parameters used to assess accuracy of correction were joint alignment and joint orientation. Alignment was determined by mechanical axis deviation (MAD) and mechanical tibiofemoral angle (mTFA). The preoperative MAD averaged 48 mm and the postoperative MAD 8.6 mm. The preoperative mTFA averaged 16 degrees and the postoperative mTFA 3 degrees. The result of deformity correction from early cases was compared with the result obtained from recent cases. Residual MAD averaged 13.2 mm in the early group and 6.4 mm in the recent group. Residual mTFA averaged 4.7 degrees in the early group and 2.2 degrees in the recent group. Gradual correction by dynamic external fixation can restore alignment and correct complex deformities with great accuracy. These results suggest the accuracy of correction increases with surgical experience.

Multiapical deformities complicate the process of preoperative planning. It is necessary to determine the level of each apex of deformity to plan accurate correction. The basic principles of mechanical axis realignment and joint orientation need to be preserved. Using the joint reference lines and mechanical axis of each bone segment, one can accurately determine the apex of each deformity. Bowing deformities are multiapical angular deformities. There are two types of bowing deformities: compensated and noncompensated. Typical examples of compensated bowing are the anterolateral and posteromedial bows of the tibia. A noncompensated bow is typical of the deformity seen in rickets.

Angular deformities of the tibia or femur in the frontal plane lead to mechanical axis deviation of the lower limb and malorientation of the joints above and below the level of deformity. Accurate correction of the malalignment and of the joint orientation is important for function and to prevent joint degeneration. An accurate yet simple method to determine the apex of deformity and the type of correction required is based on the joint reference lines of the hip, knee, and ankle, and the individual mechanical axis lines of each bone segment. If the osteotomy is performed at the level of the apex of the deformity, then the only correction needed is angulation. If the osteotomy is performed at a level proximal or distal to the apex, then translation in addition to angulation is necessary to accurately correct the deformity.