Historically, the clinical performance of novel implants was usually reported by designer surgeons who were the first to acquire clinical data. Regional and national registries now provide rapid access to survival data on new implants and drive ODEP ratings. To assess implant performance, clinical and radiological data is required in addition to implant survival. Prospective, multi-surgeon, multi-centre assessments have been advocated as the most meaningful. We report the preliminary results of such a study for the MiniHip™femoral component and Trinity™ acetabular component (Corin Ltd, UK). As part of a non-designer, multi-surgeon, multi-centre prospective surveillance study to assess the MiniHip™stem and Trinity™ cup, 535 operations on 490 patients were undertaken. At surgery, the average age and BMI of the study group was 58.2 years (range 21 to 76 years) and 27.9 (range 16.3 to 43.4) respectively. Clinical (Harris Hip Score, HHS) and radiological review have been obtained at 6 months, 3 and 5 years. Postal Oxford Hip Score (OHS) and EuroQol- 5D (EQ5D) score have been obtained at 6 months and annually thereafter. To date, 23 study subjects have withdrawn or lost contact, 11 have died, and 9 have undergone revision surgery. By the end of March 2018, 6 month, 1, 2, 3, 4, and 5 year data had been obtained for 511, 445, 427, 376, 296 and 198 subjects respectively.INTRODUCTION
METHODS
Total Hip Replacement (THR) is widely assumed to resolve sleep disturbance commonly experienced by individuals with hip osteoarthritis (OA). We report a study of 329 THRs with mean age of 71.9 years comparing pre-operative and one and two year post-operative patient reported outcomes for sleep disturbance to determine the veracity of this expectation. Data was collected from the validated Oxford Hip Patient Reported Questionnaire. Specifically, Question 12: “During the past four weeks, have you been troubled by pain from your hip in bed at night?” Answers to the question were multiple choice: No nights (4 points), Only 1 or 2 nights (3 points), Some nights (2 points), Most nights (1 point) and Every Night (0 points) Pre-operatively, the mean score for patients with hip OA was 1.2/4. This increased to 3.5 at one year and was also maintained at two years. The pre- to post-operative improvement was significant at both one and two years for THR with p <0.00001. Pre-operatively, only 6% of patients with arthritic hips reported that they were never woken from sleep because of their painful hip. One year after THR 72% always enjoyed pain free sleeping and at two years this had risen to 75%. When patients who only experienced disturbance one or two nights per month were included, the three figures increased from 13% to 83% and 83% respectively. The study confirms that sleep disturbance affects over 90% of patients with arthritic hip joints. Over 80% of THR patients will enjoy sleep that is seldom or never disturbed by their artificial hip. The improvement achieved by THR occurs within a year of surgery and is preserved at two years. In this regard, hip replacement is a highly effective intervention.
