[Correction of maltracking of patellofemoral joints in total knee arthroplasty].

OBJECTIVE

To summarize the strategies and treatment methods in correcting the maltracking of patellofemoral joints in the total knee arthroplasty (TKA).

METHODS

From January 2000 to May 2007, the methods of releasing lateral retinaculum and tightening medial retinaculum of patellar, adjusting the position of the tibial prothesis properly and shifting the lateral 1/2 insertion inward to the medial side of patellar tendon, and reconstructing the patellar tendon insertion were used in correcting the maltracking of patellofemoral joints when the TKA was conducted for 49 knee joints of 48 cases. All the cases were females, aged 53-76 years old (66.8 on average). The course of disease was 6-23 years (16.2 years on average). Among all the cases, 37 with 38 knee joints were osteoarthritis, and 11 with 11 knee joints were arthritis pauperum. Different degrees of genu valgum and external rotation of knee joints were found in all cases. The genu valgum angle was 23-42 degrees with an average of 33 degrees. The Q angle was 16-23 degrees with an average of 19 degrees. Flexion deformity of knee joints with 8-35 degrees (22 degrees on average) was found in 23 cases. The preoperative KSS knee joint score was 21-51 points (32 points on average), and the function score was 29-45 points (33 points on average).

RESULTS

All incisions obtained healing by first intension. All the patients were followed up for 7-82 months (52 months on average). Genu valgum deformity of knee joints was corrected in all cases. Residual flexion deformity with 5 degrees of knee joints was found in 3 cases. The running track of patellofemoral joints returned to normal in all cases. Laceration or fragmentation was not found in reconstructed patellar ligaments. The postoperative KSS knee joint score was 76-89 points (82 points on average), and the function score was 81-90 points (85 points on average). The X-ray films from the very beginning of post-operation to the end of follow-up showed the prosthesis was normal.

CONCLUSION

In correcting the maltracking of patellofemoral joints in TKA, releasing lateral retinaculum and tightening medial retinaculum of patellar, adjusting the position of the tibial prothesis properly, shifting the lateral 1/2 insertion inward to the medial side of patellar tendon and reconstructing the patellar tendon insertion were efficient methods, without any adverse effect on the early rehabilitation training of knee joins.