Incidence of Soft-Tissue Releases, Clinical and Radiological Outcomes of Lateral Parapatellar Approach for Valgus Arthritic Knees: A 4-year Follow-up Study with A Review of Literature.

Abstract

To analyse the incidence of additional soft tissue releases with the lateral parapatellar approach, and the clinical and radiological outcomes of total knee arthroplasties performed using the lateral parapatellar approach for valgus arthritic knees. A review of the existing literature on valgus arthritic knees undergoing knee replacement was performed and our results compared. This is a prospective cohort study of 50 patients operated by this approach. Operation and clinical records were assessed to determine the number and sequence of soft tissue releases. Functional outcome was measured using the Oxford Knee Score. Radiological assessment included measurement of alignment and implant positioning. 46 patients included. Mean follow-up of 4 years. Additional lateral releases were performed in 11 (24%) cases. Mean valgus alignment corrected from 13.1 degrees pre-operatively to 5.7 degrees post-operatively. Oxford Knee Score improved from a mean pre-operative score of 11.9 to a mean post-operative score of 38.3 at final follow-up. Radiographs revealed lateralisation of the tibial component in 4 patients. No immediate or late post-operative wound complications, late instabilities or revisions were observed. Lateral parapatellar approach is highly effective in correcting the valgus deformity with a low incidence of additional soft tissue releases. Medium-term results indicate an excellent functional outcome with no complications.