ABSTRACT
BACKGROUND: Total hip arthroplasty (THA) is one of the most commonly performed and successful orthopaedic surgeries. While the long-term success of THA is well documented, there is still significant room for improving patient speed of recovery and return to activities. The surgical technique used during THA has the potential to affect these early outcomes. METHODS: The described design is a single center, prospective, randomized, controlled study. Subjects will be randomized to receive THA using either the supercapsular percutaneously-assisted total hip (SuperPath) or traditional posterior surgical techniques. Subjects will be evaluated using Timed Up and Go (TUG), Timed Stair Climb (TSC), Hip Dysfunction and Osteoarthritis Outcome Score (HOOS), and Visual Analog Scale (VAS) for pain level estimation preoperatively, during the hospital stay, and at 2, 6 weeks, and 100 days post-discharge. Other endpoints to be evaluated include: length of stay (LOS); discharge status; transfusion rates; readmission rates; complication rates; operative time; date returned to work; and acetabular component anteversion and inclination angles. DISCUSSION: The described study will determine the effect of a tissue-sparing surgical technique on short term subject recovery following THA in comparison to the most commonly used technique in clinical practice.
ABSTRACT
BACKGROUND: In a prospective 2-year study we have used dual-energy X-ray absorptiometry to measure periprosthetic bone mineral density (BMD) following implantation of a novel, "physiological", acetabular component designed using composite materials. METHOD: The acetabular components were implanted in hydroxyapatite (HA) and HA-removed options. They were implanted in conjunction with a cemented femoral component in 50 female patients who presented with displaced, subcapital, fractures of the neck of the femur. Regions of interest (ROI) were defined according to De Lee and Charnley. BMD during follow-up was compared with immediate postoperative values for the affected limb. RESULTS: The mean precision error (CV%) was 1.01%, 2.26% and 1.12%, for ROI I, II and III respectively. The mean change in BMD, for both cups, was analyzed. There was no significant difference between the BMD changes induced with the HA- and non-HA-coated cups. INTERPRETATION: After an initial fall in BMD in all 3 ROI at 6 months, ROI I and ROI II showed return to baseline BMD by 2 years. ROI III showed no significant decrease in BMD beyond 6 months, but did not return to baseline levels. Statistical analysis revealed no significant decrease in BMD in ROI I and ROI II at 2 years, compared with immediate postoperative values. The changes in BMD reflect a pattern of maximally reduced stress in the non-weight-bearing zone (ROI III), with preservation of bone density in weight bearing zones ROI I and ROI II. These results support the design principles of the Cambridge cup.
