ABSTRACT
BACKGROUND: Few reports have evaluated the use of hydroxyapatite (HA) coating in SL-MIA-type stems in total hip arthroplasty (THA). Here, we compared early femoral bone remodeling after total hip arthroplasty using the SL-PLUS MIA stem with and without hydroxyapatite coating. METHODS: From February 2012 to March 2017, 132 patients (150 hips) (HA group: 48 patients [52 hips], non-HA group: 84 patients [98 hips]) underwent THA with an SL-PLUS MIA stem. The mean follow-up duration was 3.7 years (standard deviation 1.2, range: 1.0-6.1). The Harris Hip Score (HHS), postoperative bleeding volume measurements and plain radiographs were used for clinical and radiological follow-up evaluations. Peri-prosthetic bone mineral density changes were measured by dual-energy X-ray absorptiometry. RESULTS: At 1 year, the HHS improved from 44.4 points preoperatively to 89.2 points postoperatively and from 44.5 points to 89.7 points in the HA and non-HA groups, respectively. At 1 year postoperatively, subsidence (⧠3 mm) occurred in 0% and 8.2% of the HA and non-HA groups, respectively. Stress shielding (⧠Grade 3) occurred in 0% and 6% of the HA and non-HA groups, respectively. The radiolucent line was significantly smaller in the HA than in the non-HA group. There was no significant difference in the bone mineral density distribution in the two groups. CONCLUSION: Addition of HA to the SL-MIA stem can help enhance the initial fixation and early osseointegration. Further studies are required on the long-term effects of adding HA to reduce stress shielding of the proximal area of the stem.
Subject(s)
Arthroplasty, Replacement, Hip , Biocompatible Materials , Bone Remodeling/physiology , Durapatite , Femur/physiology , Hip Prosthesis , Absorptiometry, Photon , Aged , Bone Density , Female , Femur/diagnostic imaging , Follow-Up Studies , Humans , Male , Osseointegration/physiology , Outcome Assessment, Health Care , Postoperative Hemorrhage/diagnosis , Prospective Studies , Retrospective Studies , Time FactorsABSTRACT
PURPOSE: The aim of this study was to evaluate clinical and radiographic findings of stage 3 or lower osteonecrosis of the femoral head (ONFH) with intact acetabular cartilage in patients treated with bipolar hemiarthroplasty (BHA). METHODS: A total of 79 hips that underwent BHA for ONFH were included in this study. The average observation period was 7.6 years. Clinical results were evaluated using the Harris hip score. We performed radiographic analysis to assess the migration of the outer cup, the permanent image around the outer cup, and loosening of the stem. RESULTS: The total Harris hip score improved from 50 points before surgery to 92 points at final follow-up, while pain improved from 14 points to 36 points. Flexion improved from 94° to 120° and abduction from 27° to 37°. One patient on dialysis showed progress in terms of inward migration, and revision surgery was performed on the patient 14 years after the original surgery. CONCLUSIONS: Midterm performance of BHA for stage 3 or lower ONFH at our hospital was good.
