Long-term Outcomes of Cemented Total Hip Arthroplasty in Patients with Ankylosing Spondylitis at a Minimum Follow-up of 10 Years / 대한고관절학회지

PURPOSE: This study was performed to evaluate long-term clinical and radiologic outcomes of cemented total hip arthroplasty in patients with ankylosing spondylitis. MATERIALS AND METHODS: A retrospective study of 12 patients (16 cases) diagnosed with ankylosing spondylitis undergoing total hip arthroplasty with cemented femoral stem from November 2002 to January 2006 with a minimum follow up of 10 years. Clinical outcomes were assessed using Harris Hip Scores and measures of pain and range of motion. Radiologic outcomes were assessed with serial plain X-ray. Fixation and stability of implant, enthesopathy of ischium and development of heterotopic ossification were also evaluated. RESULTS: Mean Harris Hip Scores significantly improved from pre-operative levels (58 points; range, 39–81 points) to post-operative (92 points; range, 68–100 points). Mean flexion contracture levels decreased from preoperative (13°) to post-operative (5°), and mean post-operative range of motion improved 106° compared to preoperative levels. No newly developed osteolysis lesions or implant loosening were observed in last follow up X-rays. One heterotopic ossification and one greater trochanter fracture were observed. Greater trochanter fracture was treated conservatively, and was resulted in bony union. No patients underwent revisions. CONCLUSION: This study revealed positive long-term clinical and radiologic outcomes following total hip arthroplasty with cemented femoral stems in patients with ankylosing spondylitis patients.

The Usefulness of Intraoperative Radiography for Prevention of Malalignment of the Cemented Femoral Stem / 대한고관절학회지

PURPOSE: The purpose of this study was to evaluate the usefulness of our method, which estimated femoral stem alignment using a c-arm when the broach was inserted, for prevention of femoral stem malalignment. MATERIALS AND METHODS: A total of 103 hips were enrolled in this study. All patients underwentprimary hip arthroplasty from October 2011 to February 2013. The study was conductedretrospectively. Intraoperative estimated femoral stem alignments and final femoral stem alignments were classified into three groups. Multinomial logistic regression analysis was performed for analysis of factors (age, sex, diagnosis, body mass index, femoral stem size, osteoporosis, and proximal demur geometry) thatmight affect intraoperatively estimated femoral stem alignment. RESULTS: The distribution of intraoperative estimated femoral stem alignment was 80(78%) in the neutral group, 18(17%) in the varus group, and 5(5%) in the valgus group. The distribution of final femoral stem alignment was 100(97%) in the neutral group, 2(2%) in the varus group, and 1(1%) in the valgus group. There was no statistically significant factor affecting the intraoperatively estimated femoral stem alignment. CONCLUSION: Intraoperative estimated femoral stem alignment using a c-arm is an effective method for prevention of femoral stem malalignment.

Ceramic-on-Ceramic Bearing Total Hip Arthroplasty: Five-Year Midterm Follow-up Results

PURPOSE: We believe that cemented femoral stems will relieve the stiffness of ceramic-based bearings, resulting in reduced complication of ceramic-on-ceramic bearing total hip arthroplasty (THA). The purpose of this study was to evaluate the midterm effect of ceramic-on-ceramic bearing THA using cemented femoral stems. MATERIALS AND METHODS: We studied 32cases (30 patients) of THA using ceramic-on-ceramic bearing cemented femoral stems and 33 cases (31 patients) of THA using ceramic-on-ceramic bearing cementless femoral stems. All total hip arthroplasties were performed between January 2004 and December 2005 and were followed up for more than 5 years. The clinical results and radiographic results were evaluated. RESULTS: The mean HHS improved from points pre-operatively to points at the last follow-up in both the cemented and cementless stem groups (P<0.05). The mean WOMAC score also improved from points pre-operatively to points at the last follow-up in both the cemented and cementless stem groups (P<0.05). But no statistically significant difference was noted between the cemented and cementless stem groups in HHS and WOMAC scores (P=0.304, P=0.769). There were 3 patients with a sense of discomfort on ambulation and 5 patients with thigh pain in the cementless stem group and no cases in the cemented stem group. There was no instance of acetabular loosening in either group. Subsidenc of the cemented femoral stem was less than 1mm in 30 cases and less than 2 mm in 2 cases. All cementless femoral stems acquired firm bony union. CONCLUSION: Midterm results showed no statistical links between ceramicon-ceramic-bearing THA using cemented femoral stems or cementless femoral stems.

Eight to Eighteen Years Follow Up Study of Primary Hybrid Total Hip Arthroplasty Using a Precoat Femoral Stem / 대한정형외과학회잡지

PURPOSE: The purpose of this study was to evaluate the 15.5 year long term survival rate of the Precoat femoral stem. MATERIALS AND METHODS: We reviewed the results of 105 primary hybrid total hip replacements (98 patients) that were performed by one surgeon between October 1990 and August 1995 using a cemented polymethyl-methacrylate coated femoral prosthesis (Precoat) and contemporary cementing techniques. Thirty four patients (34 hips) died and seventeen patients (17 hips) were lost to follow-up. Forty seven patients (54 hips) were available for clinical follow-up, with an average follow-up period of 15.5 years (range: 8.4 to 18.3 years). The average age of the patients at the time of the index operation was 46 years (range: 22 to 67 years). There were 32 male patients (37 hips) and 15 female patients (17 hips). RESULTS: For the acetabular component, 15 hips (27.8%) were revised for cup loosening and isolated liner exchange was performed in 12 hips (22.2%) for liner wear and osteolysis. For the femoral component, 12 hips (22.2%) were revised due to aseptic loosening. Of these twelve hips, 3 hips had Grade B cement mantles and 9 had Grade C cement mantles. The clinical results of the 54 retained hips were good or excellent in 52 hips (96.3%) with the average Harris hip score being 88 points (range: 72 to 96 points). CONCLUSION: The mean 15.5 years' survival rate of the Precoat cemented femoral stem was 78%. We think that there were several factors for the failure of femoral stem fixation, including age, physical activity and the body weight, as well as the stem design and the surgical technique had an influence on the stem's survival.

Measurement of the Cement Thicknessaround the Femoral Stemin THRA: CAD Data Analysis Obtained from 3D Scanner / 대한정형외과학회잡지

PURPOSE: To measure the cement mantle thickness that developed from a rotation of the femoral stem in virtual space made by the broach. MATERIALS AND METHODS: The C stem and Versys stem of the subjects enrolled in this study were examined. A C250/400VZ(Steinbichler Co. Germany) and S/W: Geomagic & CATIA V5 was used to examine the three-dimensional configurations. The axial images were acquired after neutral placement of the femoral stem, horizontal rotation, coronal tilting, and a combination of both. The thickness was measured from the distance between the outer surface of the femoral stem and the closest vertex in the outer contour of the broach in cross-sectional images. RESULTS: The distance was <1 mm at the horizontal rotation of 3 degrees in the C stem, and at 5 degrees in the Versys stem. The distance was <1 mm at varus of 0.25 degrees in the C stem, and touched at 0.8 degrees. In the case of the Versys stem, the femoral stem touched at a varus of 1 degree. A combination of both horizontal and pivot rotation made the distance <1 mm at rotation of all angles. CONCLUSION: It might be necessary to develop a new instrument for the accurate insertion of the femoral stem along the broached space or to modify the stem design to stand against the change in the femoral stem position in the broached space.

Postmortem Retrieval of Bipolar Cemented Femoral Stem: A Case Report / 대한정형외과학회잡지

The purpose of this postmortem retrieval study of the femoral stem was to measure, analyse and compare the femoral stem taken from the patient who died after hip arthroplasty morphologically and radiologically. In this case we analysed the femoral stem from a patient who underwent bipolar endoprosthesis 4 months previously, which had never been reported previously in Korea. From radiologic and stereomicroscopic studies, we found that the cement around the femoral stem was inserted uniformly, and the cement thickness was shown the same uniform pattern. A cross sectional study showed small voids and defects that was not seen on the radiographs. Postmortem retrieval of hip arthroplasties can help in studies of operation methods, voids, cement, stemcement interfaces, and cement-bone interfaces.