Open-wedge osteotomy of the proximal tibia with hemicallotasis

Abstract

Conventional high tibial osteotomy for osteoarthritis of the medial compartment of the knee with closed-wedge or dome osteotomy (DMO) may produce shortening of the patellar tendon and loss of inclination of the proximal tibial plateau or of the offset of the tibial condyle relative to its bony axis. This can make subsequent total knee arthroplasty technically demanding. We undertook a prospective study comparing these changes after DMO with those after using open-wedge osteotomy hemicallotasis (HCO). A total of 50 knees with arthritis of the medial compartment in 46 consecutive patients was randomly allocated to either DMO or HCO. There were no significant differences between the groups with regard to age, gender, femorotibial angle before operation or the angle of correction. Radiological studies showed that HCO caused little change in the length of the patellar tendon or the inclination angle of the tibial plateau, while after DMO both gradually decreased. The degree of tibial condylar offset increased in both groups, but less so in the HCO group.

High tibial osteotomy with a dynamic axial fixator

“…The mean changes in the Insall-Salvati index and tibial slope were not statistically significant. 12 A typical good result is shown in Figure 3.…”

“…31,36 The tibial slope decreases after closed wedge and increases after open wedge osteotomy, 34,37,38 whereas it is relatively unaffected by hemicallostasis. 12 These changes are attributable to various factors, 34,37,38 including the triangular cross-sectional profile of the tibia with the apex pointing anteriorly, placement of the plate too anteriorly in open-wedge osteotomy, and less wedge resected posteriorly in closed-wedge osteotomy. Another possible cause for an increase in tibial slope after HTO can be premature weight-bearing, although this can affect both open-and closed-wedge procedures.…”

“…Variable rates of such pin tract infections with hemicallotasis, ranging from 8% to 60% have been reported. 12,13,29,42 Another concern has been the time required for the fixator to be in situ, which has been acknowledged previously as a cause of patient dissatisfaction. 42 Low pulse field ultrasound has been shown to accelerate healing 43 but was not applied in our series.…”

“…9,10 Preliminary reports of HTO using the hemicallostasis technique have been favourable. [11][12][13] Furthermore, concerns have been raised about alterations to the tibial slope and patellar dynamics, and subsequent conversion to total knee replacement after closed wedge ostetomy. 14,15 This study aimed to evaluate the functional results of HTO using a unilateral external fixator and the precision afforded in achieving the desired alignment.…”

What’s New in Limb Lengthening and Deformity Correction

“…In another study on eighty-four patients (ninety-nine knees) who had undergone opening-wedge high tibial osteotomy 80 , poor outcome was associated with an age of more than fifty-six years and postoperative flexion of <120°. Given the divergent findings of two recent studies 81,82 , the preservation of lower-limb alignment that is achieved following opening-wedge high tibial osteotomy needs further investigation. Despite complications, a singlestage total knee arthroplasty and high tibial osteotomy with use of rigid fixation for patients with extra-articular frontal-plane tibial deformity may be a viable option 83 .…”