Squeaking sound in total hip arthroplasty using ceramic-on-ceramic bearing surfaces.

PURPOSE: To evaluate the causes and frequency of the squeaking sound in ceramic-on-ceramic THA. MATERIALS AND METHODS: This study included 61 hips of 50 patients who underwent ceramic-on-ceramic THA in our hospital from March 1999 to April 2005. The average age at the time of operation was 57.6 years. The average duration of follow-up was 69.5 months. Three different acetabular components were used: Osteonics (Stryker, USA: 24 cases), Bicontact (Aesculap, Germany: 27 cases) and ABG (Howmedica, UK: 10 cases). RESULTS: Fourteen (22.9%) of the 61 cases had a squeaking sound, and this sound started a mean of 47.57 months after the operation. Except in one case, the squeaking sound remained until the last follow-up. There was no difference in acetabular component position between the squeaking and nonsqueaking groups. The squeaking sound was found to be related to the BMI (body mass index) and cup design. It occurred frequently in patients with high BMI who had received a total hip arthroplasty using an Osteonics cup. Among 11 of the patients, squeaking occurred while squatting, and in 3 patients while walking. Six patients suffered from mild restrictions on their activities of daily living, and 8 had more than moderate restrictions with squeaking sounds. CONCLUSION: A squeaking sound in THA using ceramic-on-ceramic surfaces is not a rare complication, and often affects the patient's behavior.

High revision rate of hydroxyapatite-coated ABG-I prosthesis.

BACKGROUND: The aim of this study was to investigate the causes of the high revision rate of the hydroxyapatite-coated Anatomique Benoist Girard (ABG-I) prosthesis. METHODS: We performed 204 total hip arthroplasties (THAs) at our hospital between March 1992 and December 1996. Of the 204 THA patients, 129 were followed up; the mean duration of follow-up was 12.2 years (range 10.0-14.5 years). There were 113 male patients and 16 female patients, with an average age of 53 years (30-83 years) at the time of surgery. The reasons for THA were avascular necrosis in 119 hips, acetabular dysplasia in 8 hips, and traumatic arthritis in 2 hips. RESULTS: The Harris hip score was 47.3 preoperatively and 86.4 at the last follow-up. The linear polyethylene wear was an average of 0.29 mm/year. Acetabular osteolysis was seen in 113 cases (88%). Altogether, 61 (47.2%) acetabular cups were revised for aseptic loosening in 38 hips, polyethylene wear and osteolysis in 20 hips, recurrent dislocation in 2 hips, and deep infection in 1 hip. Femoral osteolysis was observed in 100 cases (77.5%). The femoral stem was revised in 4 hips (3.1%). CONCLUSION: We observed that the fatal detriment to ABG-I acetabular cup survival in long-term follow-up was periacetabular osteolysis followed by aseptic loosening.

Total hip arthroplasty using two-incision technique.

BACKGROUND: To evaluate the effectiveness of minimally invasive surgery total hip arthroplasty (THA) using the two-incision technique as described by Mears. METHODS: From January 2003 to December 2006, sixty-four patients underwent total hip arthroplasty using the one-incision (group I) and two-incision (group II) technique by one surgeon. There were 34 hips in group I and 30 hips in group II. There was no difference in age, gender, and causes of THA between the two groups. We evaluated the operation time, bleeding amount, incision length, ambulation, hospital stay, and complications between the two groups. RESULTS: There was no difference in the bleeding amount between the two groups. Operation time was longer in the two-incision group than in the one-incision group. Operation time of the two-incision technique could be reduced after 15 cases. Patients started ambulation after surgery earlier in group II than group I, and the hospital stay was shorter in group II than in group I. There was no difference in clinical results between the two groups. There was no difference in component position of the acetabular cup and femoral stem between the two groups. Intraoperative periprosthetic fracture occurred in four cases (13.3%) in group II. CONCLUSIONS: Two-incision THA has the advantage of rapid recovery and shorter hospital stay. However, longer operation time and a high complication rate compared to one-incision are problems that need to be solved in the two-incision technique.

Electron Microprobe Analysis and Tissue Reaction around Titanium Alloy Spinal Implants.

STUDY DESIGN: A retrospective study of tissue surrounding titanium alloy spinal implants was performed using histological and electron microprobe analysis. PURPOSE: To identify the metal debris generated by spinal implants, and then to evaluate the electron microprobe analysis results and the histological response of soft tissue surrounding the spinal implants. OVERVIEW OF LITERATURE: Microscopic metal particles from the soft tissue surrounding joint arthroplasty have been shown to activate a macrophage response that leads to bone resorption and increased inflammation. The effect of unintended wear particles in spinal instrumentation remains a clinical concern. METHODS: Ten patients (average age, 51.3 years), 6 men and 4 women, who had undergone previous lumbar fusions using pedicle screw instrumentation and who were now undergoing revision surgery were included in the study. The tissues obtained from the adjacent area of these implants were analyzed by light microscopy, immunohistochemistry and scanning electron microscope. After the removing the spinal implants, the changes of back pain and the spinal fusion were assessed. RESULTS: There were metal particles in the soft tissue in 7 cases. Histological finding observed mild chronic inflammation surrounding the deposition of the metal particles and the anti Cotrel-Dubousset 68 positive macrophages were observed at tissue adjacent to the metal particles in 5 patients. Scanning electron microscopy of the specimens showed metallic debris within the tissue and mapping of the metallic particles revealed the distribution of titanium in the tissue in 5 cases. Nine patients had successful relief of back pain after removing the spinal implants. Improvement of the back pain may be an association macrophage response rather than the metal particle. CONCLUSIONS: The presence of metallic particles generated from spinal implants may serve as the impetus for a late-onset inflammatory response and late operative site pain.