Application of constrained polyethylene insert to primary total knee arthroplasty in older patients / 中国组织工程研究

ABSTRACT

BACKGROUND:Valgus-varus constrained polyethylene insert is selected in strict accordance with the principle of“to obtain reliable stability using minimum restriction”. The stability of the prosthesis is elevated, but the restriction is not increased. OBJECTIVE:To retrospectively analyze the application experience of constrained polyethylene insert in valgus and varus instability of primary total knee arthroplasty for older patients and to summarize the indications and clinical effects of this kind of implements. METHODS:From March 2010 to March 2012, a total of 70 patients combined valgus and varus malfomation who accepted primary total knee arthroplasty were enrol ed in this study, including 56 varus patients (averagely 15°-30°) and 14 valgus patients (averagely 10°-20°). Constrained polyethylene insert was performed in 23 patients (25 knees) who stil had remaining unilateral valgus or varus RESULTS AND CONCLUSION:Patients were fol owed up for 2 years on average (18-42 mouths). The knee pain symptoms of al cases disappeared. The joint stability was obviously improved. The lower limb power lines were correct. The Knee Society Score scores were improved from an average of 39.4 points preoperation to an average of 88.5 points postoperation. Al cases did not need the protection of knee braces. The maximum degree of flexion was 110°(96°-130°). The satisfaction degree of 36-Item Short Form Health Survey was 98%. No dislocation or infection happened. Results indicated that constrained polyethylene insert could be applied in the cases of less than 6 mm valgus and varus instability when finished operation of standard osteotomy and soft tissue balancing in total knee arthroplasty for older patients. This kind of implements can preserve bone mass, simplify operational process and have good clinical outcome in a short period.