Malunion in the lower limb

Abstract

Nomograms derived from mathematical analysis indicate that the level of malunion is the most important determinant of changes in the moment arm of the knee, the plane of the ankle and alterations in limb length. Testing in five patients undergoing reconstruction showed a mean error of postoperative limb length of 2.2 mm (SD 0.8 mm), knee moment arm of 4.7 mm (SD 3.3 mm) and ankle angle of 2.6° (SD 2.3°). These nomograms provide the information required when assessing whether a particular degree of angulation may be accepted. Patients and MethodsMathematical analysis. We used a Cartesian co-ordinate system to represent the lower limb. The nomograms were derived from this analysis. 12Patients. We studied five patients undergoing correction of malalignment (Table I). All had full-length anteroposterior radiographs to assess the mechanical axis and the degree of deformity in the coronal plane, and lateral radiographs to assess deformity in the sagittal plane. CT scanograms allowed for more accurate assessment of the length of the unaffected limb. Nomograms generated using the calculations above were used in preoperative planning to determine the predicted changes in length, knee moment and ankle axis. After correction the actual changes achieved were measured, taking into account errors due to magnification on the plain radiographs, the additional changes in length after osteotomy and any callotasis following correction of angulation. The accuracy of the system was assessed by comparing the predicted and actual changes for all three measurements in both planes. Figure 1 shows the steps involved in preoperative planning and postoperative measurement. A radiograph of the whole limb allows the length to be measured and the level of the deformity calculated as a percentage of the distance from the centre of the femoral head to the ankle mortice. The deformity in both planes is measured on the radio-

Tibial uniapikal deformitelerde tedavi

“…Bu nedenle uzatma gerektiren deformitelerde uygulanması uygun değildir (Şekil 3). [14] Açık Kama Osteotomisi Deformitede düzelme sağlaması ve tekniğin uygulanma biçiminden (osteotomi hattının distraksiyonu) dolayı tibiada uzunluk kazanımını sağlar. Bu nedenle deformitenin sebep olduğu kısalığın da mevcut olduğu hastalar için avantajlıdır.…”