The purpose of this study was to evaluate the role of high tibial osteotomy (HTO) [Lateral closed wedge v/s medial open wedge] in varus aligned knees with ligament instability. (ACL, PCL, PLRl). We treated 14 patients with knee instability and varus alignment with HTO with or without ligament reconstruction. 5 patients with varus angulated ACL deficiency (double varus) were treated with single stage closed wedge HTO and ACL reconstruction. Of the remaining nine patients with PCL + PLRI injuries with varus angulation (Triple varus), six were treated with LARS ligament reconstruction with HTO, and the remaining were treated with HTO without ligament reconstruction. Four of these patients with triple varus had a open wedge HTO and the remaining five patients had a closed wedge HTO. The mean time interval between injury and index surgery was 8.3 years. At a mean follow-up of 2.8 years 12 knees (86%) were stable and eliminated of giving way. In one patient the result was compromised with severe infection. Five patients (35%) continued to have varying degree of pain. According to the Cincinnati knee scoring system there were eight good, four fair and two poor results. In patients with triple varus, open wedge HTO had better scores than closed wedge HTO. The results of this series are encouraging and we recommend HTO with ligament reconstruction in these complex cases.
The purpose of this study was to evaluate the reasons for patellar instability in modular rotating hinge TKR, with regards to design of the prosthesis offering unlimited rotation, component positioning and the role of compromised soft tissues. We reviewed six patients with rotating hinge TKR operated over the past 3½ years for either ligamentous instability, bone loss or both. The problem of patellar instability was identified in all patients. Five patients had realignment of extensor mechanism for patellar maltracking, while the remaining one patient with patellar instability was asymptomatic. Post-realignment the HSS scores revealed good results in 3 knees, fair in 2 and poor in 1 patient. All patients had a well aligned knee with satisfactory component positioning. The unlimited rotation offered by the modular rotating hinge TKR because of the absence of a rotational stop causes excessive demands on the soft tissue and is a reason for patellar instability in patients with compromised medial soft tissue integrity. The high incidence of patellar instability compromises the results of TKR and is a cause of concern and this implant should be reserved for patients with severe ligamentous instability and bone loss not amenable to ligament balancing.
