Analysis of acetabular cup positioning and functional outcome in total hip replacement

INTRODUCTION: Total hip replacement, nowadays have become commonly performed reconstructive hip procedure for various hip disorders. In total hip replacement, the position of acetabular cup version is one of the important factor which influence the functional outcome of Total hip replacement. The dislocation rate and good availability of hip movements are majorly depends on acetabular cup version. AIM: The aim of this study is an analysis of acetabular cup positioning and functional outcome in total hip replacement. MATERIALS AND METHODS: This retrospective study was conducted at Govt. Royapettah hospital, to analyse acetabular cup placement and functional outcome in THR, the period between 2013 to 2015. Study Population: 20 HIPS. Method of selection: 20 patients selected randomly from MRD department who complied with our study without any drop out. METHOD: 1. CT examination of acetabular cup 2. Analysis of functional outcome according to Harris hip score This study was conducted during my training period. All these patients were called over phone to attend the ortho OPD. This study had been done to assess the post oprative acetabular cup positioning and functional outcome of total hip replacement done for various indications. All patients were assessed post operatively with CT scan of pelvis for cup version. These patients were also examined clinically to analyze the functional outcome based on Harris hip score at the latest follow up. The results were compared and analysed in these randomly selected patients. RESULTS AND CONCLUSIONS: All patients were assessed clinically using the HARRIS HIP SCORE SYSTEM [modified] for hip function in our study. 1. We had one case of dislocation with associated sciatic nerve palsy due to retroverted acetabular cup which was corrected by revision THR. Now the patient had recovered from nerve palsy and had good functional outcome 2. Limb length discrepancy: we had significant LLD of >3.2 cm in one case, other 5 cases had around 1 cm shortening on operated limb. 3. None of our patients had infection in our study. 4. In our study, 90% of patients had excellent functional outcome, 5% of patients had good functional outcome and 5% of patients had fair functional outcome. 5. In our study, 90% of acetabular cup positions were in acceptable range. Only 10% of acetabular cups were in excessive anteversion, 6. The cases with excessive anteversion were not associated with dislocation of joint. But had no internal rotation. 7. CT scan based acetabular cup measurement has given good predication of our intra operative free hand assessment of acetabular cup positioning