Abstract
Background
There are some critical points of Cruciate retaining (CR) TKA. We recognized that it is one of the most important issue how to manage for release of PCL contracture. PCL contracture would lead to poor ROM, stiff or painful knee after CR TKA. PCL release at insertion of femoral / tibial side or cut in PCL itself, “pie craft” were reported. However, for retaining of PCL function after TKA, peeling off PCL itself would be not desirable. Therefore, we proposed to perform V shape-osteotomy at PCL insertion of tibia with osteotome (Fig.1,2) and cancellous bone graft at osteotomy site to get bony union (V-shape osteotomy with cancellous bone graft: VOCG). We would present how to perform VOCG at CR TKA and clinical results.
Patients and Methods
188 knees in 126 patients were received NRG CR TKA (Stryker) at Nagano Matsushiro General Hospital between February 2008 and August 2009. Mean age at operation was 75.1±5.9 years old. The indications for VOCG were positive of POLO test positive, inadequate soft tissue balance because of PCL contracture, or poor pre-operative ROM et al. All patients were reviewed with clinical and radiographic assessments. Clinical evaluation was carried out using the Knee Society Score (knee score and functional score). The range of motion (ROM) was pre- and post-operatively. In order to evaluate the effect of VOCG, clinical outcomes were compared between two groups (with VOCG vs without VOCG).
Results
Of 126 patients (188 knees), 4 (6 knees) died in cardiac disease or malignant tumor within 1 year. 3 (5 knees) suffered from some comorbidities. Therefore, 177 knees in 119 patients available for review at a minimum 1 year (one to six). There were no revision cases. No patients had PCL dysfunction, infection or deep vein thrombosis in current study. 21 knees (11.8%) received VOCG. The reasons for VOCG: lift off positive:11 knees, inadequate soft tissue balance: 8 knees, flexion contracture: 1 knee There were no significant difference in FTA before TKA and KS between with VOCG and without VOCG cases. In pre-oprerative varus knee group (n=133), there was significant difference in pre-oprerative ROM between with VOCG group (94.4°±25.5°) and without VOCG group (106.0°±25.5°) (p<0.05). In addition, post operatively ROM of without VOCG group (125.6°±17.3°) was significantly better than with VOCG group(112.8°±13.5°)(p<0.05). However, there was no significant difference in improvement rate of ROM between two groups. In radiographic evaluation, no cases revealed non-union at osteotomy site.
Conclusions
In current series, no cases revealed PCL dysfunction after CR TKA in two groups. Our clinical results suggested that VOCG would provide reasonable PCL release and remain PCL function in CR TKA.
