The Usefulness of Three-dimensional Computed Tomography as an Assessment of Periacetabular Osteolysis in Revision Total Hip Arthroplasty / 대한고관절학회지

PURPOSE: This study was performed to determine the usefulness of three-dimensional computed tomography (3D-CT) in measuring periacetabular osteolysis by comparing the real volume of osteolysis in revision surgery. MATERIALS AND METHODS: Twnety-three patients who had undergone revision surgery due to periacetabular osteolysis but not included septic osteolysis and implant loosening. The mean age of patients at the time of surgery was 55.2 years. And the mean time interval between the primary total hip arthroplasty and revision surgery was 13.3 years. We measured the polyethylene wear in plain radiographs using computer assisted vector wear analysis program, the volume of acetabular osteolytic lesions in high-resolution spiral CT scans using Rapidia 3D software version 2.8 algorithms before the revision surgery were performed. Intraoperative real osteolytic volume was calculated as the sum of the volumetric increments of the acetabular cup and impacted allo-cancellous bone volume. RESULTS: Strong correlation was found between the volume of acetabular osteolytic lesions measured on 3D-CT and intraoperative real osteolytic volume which was calculated as the sum of the volumetric increments of the acetabular cup and impacted allo-cancellous bone volume. CONCLUSION: 3D-CT is considered a useful method for assessing and measuring the volume of periacetabular osteolysis before revision surgery.

Single Bundle Anterior Cruciate Ligament Reconstruction

Anterior cruciate ligament (ACL) reconstruction is generally accepted as the most reliable method of re-establishing knee kinematics so as to prevent various symptoms related to the instability and subsequent injuries to the knee. Double bundle ACL reconstruction has emerged as a potential solution for single bundle reconstruction, as the latter can restore anteroposterior stability, but it had limitations for improving the rotational stability. However, double bundle reconstruction is a more complex surgical procedure and it remain unclear whether double bundle reconstruction has better results than single bundle reconstruction on long term follow-up. Recent studies have demonstrated that a femoral tunnel could be created independently of the tibial tunnel and in a more anatomic position by using the anteromedial portal technique, so that that there is better restoration of the rotational stability as well as anterior stability than that with performing the transtibial technique.

Pseudarthrosis at L5-S1 after Posterolateral Lumbar Fusion

STUDY DESIGN: This is a retrospective study. OBJECTIVES: We wanted to investigate the rate of pseudarthrosis at L5-S1 after posterolateral fusion only for degenerative lumbar spinal disease, and to determine the radiological findings that help diagnose pseudarthrosis. SUMMARY OF THE LITERATURE REVIEW: The pseudarthrosis rate at L5-S1 is much higher than that at the other lumbar segments. However, there have been few studies for the rate and risk factors of pseudarthrosis at L5-S1. MATERIALS AND METHODS: A total of 88 patients who underwent pedicle screw instrumentation and posterolateral lumbar fusion were evaluated with a minimum of 1-year follow up. Bony union was evaluated by the bony fusion mass, the angulation on the flexion-extension radiographs and the radiolucent zone around the pedicle screws. The patients' age, bony mineral density, the number of fused segments and lumbar lordosis were evaluated for their association with pseudarthrosis at L5-S1. RESULTS: Pseudarthrosis developed in 22 patients at L5-S1 and in 8 patients at other levels. The change of angulation on the flexion-extension radiographs at the last follow-up was 5.2degrees in the pseudarthrosis group and 1.7degrees in the fusion group (P=0.3). A radiolucent zone of the sacral screws was noted in 10 patients; in 7 of the 22 patients in the pseudarthrosis group and in 3 of the 66 patients in the fusion group. The average age, the mean number of levels fused and the bone mineral density were similar in both groups. Lumbar lordosis was not associated with the development of pseudarthrosis at L5-S1. CONCLUSION: The pseudarthrosis rate was significantly higher at L5-S1 than that at the other lumbar segments following instrumented posterolateral fusion. Pseudarthrosis was closely related to hypermobile angulation (> or =5degrees) on the flexion-extension radiographs and a radiolucent zone around the sacral screws.

Degeneration of Acetabular Articular Cartilage to Bipolar Hemiarthroplasty

PURPOSE: This study examined the rate of degeneration of acetabular cartilage by the bipolar head according to time, and also which clinical factors are related to the degeneration of acetabular cartilage. MATERIALS AND METHODS: Among 192 patients (226 hip joints) who received bipolar hemiarthroplasty from August 1996 to August 2002, 61 patients (65 hip joints) were enrolled in this study, who were followed up for more than 2 years and showed no signs of dislocation, infection, or functional problems. A modified form of a computer assisted vector wear analysis program was used to measure the rate of degeneration of the acetabular cartilage. The factors that appeared to affect the rate of acetabular degeneration in the two groups was evaluated. RESULTS: The average linear degenerative change in the acetabular cartilage and the volumetric degenerative change were 0.23 +/- 0.107mm/year and 114 +/- 47.2mm3/year, respectively. The result showed significant differences in activity and HHS between the 2 groups. The HHS showed a reverse relationship with the linear degeneration and volumetric degeneration, and the activity showed a correlation with the linear and volumetric degeneration. CONCLUSION: The acetabular cartilage degenerates faster as the patient' activity increases, and slower with a higher HHS. When surgeons perform hip joint arthroplasty, it is strongly recommended that the life expectancy and the level of activity should be considered when deciding between a hemiarthroplasty and total hip arthroplasty.