Kang Il Kim

Causes and Patterns of Aborting a Robot-Assisted Arthroplasty

For a successful robot-assisted arthroplasty, every step should be executed harmoniously. However, when we encounter serious obstacles during surgery, it is sometimes better to abort the procedure in a timely manner. This study investigated the possible causes and patterns of aborted robot-assisted arthroplasties. Of 100 consecutively planned robot-assisted arthroplasties, 22 cases were aborted. Most involved total knee arthroplasty (21/22 cases). We classified the causes according to the stage at which they occurred and the type of error. Abortions after starting the milling procedure and abortions due to an interactive factor were the most common. We believe that this study can guide surgeons to effective decision making during robot-assisted arthroplasty.

Sonographic Evaluation of Anterosuperior Hip Labral Tears With Magnetic Resonance Arthrographic and Surgical Correlation

The purpose of this study was to retrospectively evaluate the sonographic findings compared with magnetic resonance (MR) arthrographic and arthroscopic findings in diagnosis of anterosuperior labral tears of the hip.

Does Osteoporosis Increase Early Subsidence of Cementless Double-Tapered Femoral Stem in Hip Arthroplasty?

Among 320 hip arthroplasties performed between January 2007 and March 2008, patients younger than 50 years old and patients older than 70 with a T-score at the proximal femur less than -2.5 made up the control and study group, respectively. There were 40 patients in each group. We measured stem subsidence, both digital and manual methods. Measurements were made from radiographs taken serially from 2 weeks to 1 year after surgery. The amount of mean subsidence for each group was not different, and all stems showed stable fixation in the final radiographs. Our study suggests that even in osteoporotic proximal femurs, press-fit fixation of double-tapered stems for hip arthroplasty can be safe and effective without excessive early subsidence.

Effects of the pro-inflammatory milieu on the dedifferentiation of cultured fibroblast-like synoviocytes

The aim of this study was to determine whether the inflammatory milieu and/or hypoxia induces the dedifferentiation of synovial cells into mesenchymal stem-like cells, which may contribute to the tumor-like growth of synovial cells. Expression of mesenchymal stem cell markers (CD24, CD44, CD90, CD106, CD146 and Stro-1) was compared among cultured fibroblast-like synoviocytes (FLSs) from patients with rheumatoid arthritis (RA) or osteoarthritis (OA), bone marrow mesenchymal stem cells (BM MSCs) and normal dermal fibroblasts. After the cells were stimulated with pro-inflammatory cytokines for 3 days under hypoxia or normoxia, the stem cell markers were analyzed by FACS. CD44 and CD90 were expressed constitutively in all four cell types. Only the BM MSCs strongly expressed CD146. The expression of stem cell markers was similar between FLSs from RA and those from OA patients. In addition, the expression levels in FLSs were similar to those in normal dermal fibroblasts. The stimulation of FLSs and dermal fibroblasts with IL-1β or a mixture of cytokines under hypoxia did not induce a marked change in the expression of stem cell markers. These results indirectly suggest that the pro-inflammatory milieu may be not sufficient to induce the dedifferentiation of FLSs in arthritic joints.

Cementless Total Hip Arthroplasty with Medial Wall Osteotomy for the Sequelae of Septic Arthritis of the Hip

Background We performed a retrospective study to evaluate the results of acetabular circumferential medial wall osteotomy, a procedure designed to provide secure fixation of a cementless hemispherical acetabular cup for the sequelae of septic arthritis of the hip. Methods We assessed 38 total hip arthroplasties (THAs) with circumferential acetabular medial wall osteotomies performed on patients with sequelae of septic arthritis of the hip between 1993 and 2000, who were followed up for ≥ 3 years. The average follow-up period was 8.3 years (range, 3 to 12 years). The indication for this technique was poor acetabular cup coverage of ≤ 70% on preoperative templating. In all cases, cementless hemispherical acetabular cups were fixed to the true acetabulum. Additional procedures included soft tissue release in 16 hips and femoral derotational and shortening osteotomies in 12 hips. We evaluated both clinical and radiological results. Results The Harris hip scores improved from 57 points preoperatively to 91 points postoperatively. Radiological analysis revealed no aseptic loosening or radiolucent lines around the acetabular cup. Stable bony fixation of the acetabular cup in the true acetabulum was seen in all cases. Acetabular osteolysis was demonstrated in 12 hips. Revision surgery was performed in 6 hips, but there were no complications related to acetabular circumferential medial wall osteotomy. Conclusions Circumferential acetabular medial wall osteotomy can provide appropriate positioning and sufficient coverage of the acetabular cup and thus preserve the medial wall thickness in cementless THA without the need for additional bone grafting for the sequelae of septic arthritis of the hip.

Genome-wide association scans for idiopathic osteonecrosis of the femoral head in a Korean population

Osteonecrosis of the femoral head (ONFH) is a multifactorial disease and is associated with genetic predisposition, and exposure to certain risk factors. In particular, idiopathic ONFH in twins and the clustering of cases in families have indicated that genetic factors are involved. However, the majority of cases of ONFH are sporadic and various studies have demonstrated that differences in the study design and/or the ethnic groups analyzed leads to different results. The present study performed one of the first genome-wide association studies to identify genetic loci that may increase the risk of idiopathic ONFH. In total, 217 patients with idiopathic ONFH and 217 control samples, without ONFH, were genotyped using Axiom™ chips. Following quality control, 509,886 single-nucleotide polymorphisms (SNPs) were included in the association analysis to identify genetic variants that may influence susceptibility to idiopathic ONFH. The lowest P-value identified by the current study was for an association with rs220324 (P=3.57×10-7), an SNP that is located near to the uromodulin-like 1 gene region on chromosome 21q22.3, although none of the SNPs reached the traditional genome-wide significance level of 5×10–8. However, the DnaJ heat shock protein family (Hsp40) member C6 (DNAJC6) locus, a region between 65.37 and 65.67 Mb located on chromosome 1p31.3, harbored a cluster of SNPs that were associated with idiopathic ONFH at a significance level of P<1×10–5. Four variants, rs10493374, rs12032616, rs17127529 and rs6679032, with marginal associations were located in and around the DNAJC6 locus and were in strong linkage disequilibrium with each other. In conclusion, the current study did not identify any SNPs that were associated with idiopathic ONFH at a genome-wide significance level, however, the results suggest that future studies should investigate the effects of SNPs in the DNAJC6 gene on the idiopathic ONFH risk.

Arthroscopic Findings of Dysplastic Hip & Usefulness of Preoperative Labral Test

Purpose : To report the arthroscopic findings in symptomatic dysplastic hips and to clarify the efficacy of a labral test. Materials and Methods : Between July 2001 and Nov 2004, arthroscopy was performed on 37 dysplastic hips. There were 7 males and 30 females and the average age was 38.8 years. The average center-edge angle was 6.54˚. Radiographically, 28 hips were prearthritic and 9 hips showed arthritic changes. The arthroscopic findings of the labrum and cartilage and the efficacy of labral test were compared. Results : Labral lesions were found in 25 cases, and cartilage lesions were found in 16 cases of 28 prearthritic hips. All patients with radiographic evidence of osteoarthritis had both labral and cartilage lesions. Labral lesions were found in 30 out of 33 cases with a positive labral test. Conclusion : This study identified the pathologic processes of acetabular labrum and cartilage in most cases, even though there was no radiographic evidence of osteoarthritis. Preoperative labral test is a useful physical examination in those suspected of having labral lesions.

Cementless Acetabular Component Fixation with Circumferential Medial Wall Osteotomy in Severely Hypoplastic Acetabulum

Purpose : To evaluate the results of the acetabular circumferential medial wall osteotomy in obtaining secure fixation of cementless hemispherical acetabular cup to the hypoplastic acetabulum. Materials and Methods : Seventy-nine THAs with a circumferential acetabular medial wall osteotomy in the dysplastic acetabulum performed between 1987 to 1997 and followed up for more than 6 years were assessed. The indication of this technique was acetabular coverage that could not achieve more than 70% after cup fixation. In all cases, a cementless hemispherical acetabular cup was fixed in the true acetabulum. Additional procedures included soft tissue releases in 23 hips, a derotational femoral osteotomy in 10 hips, a structural bone graft in 7 hips and femoral shortening in 8 hips. Both clinical and radiographic parameters were evaluated. Results : The Harris hip scores were improved from 68.4 to 92.2 postoperatively. Radiographic analysis revealed no aseptic loosening or radioluacent line, and showed stable bony fixation at the true acetabulum in all cases. 7 hips showed acetabular osteolysis. Two acetabular components were revised due to dissociation of the polyethylene liner and 4 polyethylene liners were exchanged because of severe wear or osteolysis. Conclusion : The circumferential acetabular medial wall osteotomy can provide appropriate positioning, sufficient coverage of the acetabular cup with a preservation of the medial wall thickness in cementless THA without additional bone grafting in the dysplastic acetabulum.

Revision Total Hip Arthroplasty Using Cementless Long Stem

Purpose: This study evaluated the clinical and radiographic results of patients who received revision total hip arthroplasty (THA) using an anatomic BR and BIAS cementless long stem. Materials and Methods: This study was based on 46 cases involving 42 patients who received revision THA using a cementless long stem between October 1988 and August 1998. The average follow-up period was 8 years and 6 months. The Harris hip score and thigh pain were analyzed to evaluate the postoperative result and the changes around the femoral stem were observed radiologically. Results: The Harris hip score improved from an average of 60.7 to 90.8 at the last follow up with no significant difference between the Anatomic BR stem and the BIAS stem. There were 12 cases of osteolysis, 9 cases of calcar resorption, 8 cases of pedestal formation, and 5 cases of vertical subsidence. An obvious spot weld around the stem was observed in 11 cases who received an anatomic BR stem and 7 cases who received a BIAS stem but there was no significant difference between the two. Five cases who received a BIAS stem developed vertical subsidence>5 mm. The complications encountered included 12 cases of femoral cracks intraoperatively and 2 cases of aseptic loosening. Conclusion: The cementless long stem, which has a circumferential and widely proximal porous coating, showed accelerated bony ingrowth and eventual stable fixation. This indicated that a cementless long stem would be better when the stem has a wider and circumferentially porous coated surface.