Mid-term results of an uncemented tapered femoral stem and various factors affecting survivorship

Abstract

ObjectiveCLS stem is commonly used today in primary hip arthroplasty, but only a few studies have evaluated their outcome in young high demanding patients. In Indian scenario, many patients require squatting and sitting cross-legged as part of their daily activities placing excessive load on the joint. We evaluated (I) Mid-long term functional and radiological results (II) Influence of age, gender, diagnosis, stem alignment, Canal fill index (CFI) on the outcome (III) Kaplan-Meier survivorship using revision for any reason or for aseptic loosening as an endpoint. MethodsRetrospective evaluation of 64 THA in 54 patients operated between July 2000 to July 2011 using CLS stem was done. Mean follow-up was 10.3 years (5–14.9 years) with 5 patients lost to follow-up and 4 patients died. Mean age at surgery was 46.8 years (18–78 years). ResultsMean Harris hip score was 89.4 (72–100). Thigh pain was present in 4 hips which were not associated with the sizing of the stem (p = .489). Stable fixation by bony ingrowth was seen in 53 hips (96.4%) and by fibrous ingrowth in 2 cases (3.6%) with no case of loosening seen. Stress shielding was seen as Grade II in 17 hips (30.9%), Grade III in 3 hips (5.4%). Pedestal formation was seen in 9 hips (16.4%) which were statistically associated with varus alignment and CFI < 80. No stem revision was performed with stem survivorship of 100%. ConclusionThe mid-term survival rates and good clinical-radiological outcomes of CLS stem in high demanding Indian population were excellent.