A Study on clinical and functional outcome of cemented/uncemented total hip replacements in patients with avascular necrosis of femoral head

Background: Avascular necrosis (also osteonecrosis, bone infarction, aseptic necrosis, ischemic bone necrosis, and AVN) is a disease where there is cellular death (necrosis) of bone components due to interruption of the blood supply. The current well accepted treatment for arthritis secondary to AVN in hip joint is total hip replacement.Methodology: A prospective study was carried out on 30 patients who underwent cemented/uncemented Total Hip Replacement in Department of Orthopaedics, Vydehi Institute of Medical Sciences and Research Centre, Whitefield, Bangalore.Results: This study has shown that, the mean age of patients in the study group was 42.30±11.43 years. About 43.3% of the avascular necrosis patients in the study group belonged to 31-40 years age group. The sex distribution of the study group has shown that, about 76.7% of the patients were Males and 23.3% were females. The analysis of patients for the etiology of AVN showed that 70.0% of the patient developed AVN of hip joint without any known cause (idiopathic), 16.7% of patients developed AVN secondary to corticosteroid, and secondary to post trauma. 13.3% patients developed AVN of the hip joint. The analysis of patients for the side which they have undergone total hip replacement has shown that, most (50.0%) of the patients had left hip replacement, 26.7% had undergone right total hip replacement and 23.3% had undergone bilateral total hip replacement. Majority of the patients (86.7%) had uncemented type of arthroplasty and 13.3% had undergone hybrid type of arthroplasty. The mean pain score during preoperative period was 10.13±1.96 and during postoperative stage was 42.13±2.03. The mean functional gait score during preoperative stage was 10.53±6.96and during postoperative stage was 30.33±2.31. The mean functional activity score during preoperative stage was 5.17±1.62 and during postoperative stage was 11.40±1.07.There was a statistically significant difference between the pre and postoperative scores in the study group. The mean total score (Harris hip score) during preoperative stage was 32.27±8.11 and during postoperative stage was 92.60±3.16. The difference between pre and postoperative scores was statistically significant. The mean ROM score of study group during preoperative stage was 2.40±1.25 and postoperative stage was 4.63±0.49. The difference between the ROM scores during pre and postoperative stage was statistically significant. The type of implant used in eth study group. Stryker implant was used in 73.3% and Link implant was used in 26.7% of the study group.Conclusion: This study suggests that the current generation of uncemented implants used in total hip replacement for arthritis of the hip joint secondary to AVN, provides satisfactory clinical and radiographic outcomes after an intermediate duration follow up. Even though the procedure is not free of complications, the overall functional and clinical outcome had shown good to excellent result