Sun Chul Hwang

Two-Stage Total Knee Arthroplasty for Prosthetic Joint Infection

Purpose This retrospective review was conducted to identify prognostic factors for two-stage reimplantation for infected total knee arthroplasty (TKA) and the rate of reinfection following revision TKA. Materials and Methods Out of 88 patients diagnosed with post-TKA infection between 1998 and 2011, 76 underwent two-stage reimplantation and were reviewed in this study. The 76 patients were divided into two groups-those who experienced reinfection and those who did not. Comorbidities, culture results, and inflammation indices were analyzed and compared between the two groups. Results Of the 76 patients who underwent a two-stage reimplantation, 18 (23.7%) experienced reinfection. Patients with more than three comorbidities had significantly higher reinfection rates than those with less than three comorbidities (47.1% vs. 4.8%, p=0.032). The reinfection rate between the culture positive prosthetic joint infection group and the culture negative prosthetic joint infection group was not significantly different (p=0.056). Inflammation indices (erythrocyte sedimentation rate [ESR] and C-reactive protein [CRP]) showed a statistically significant difference between patients with reinfection and those without reinfection at 4 weeks after the first-stage surgery. Conclusions Reimplantation must be carefully performed when the risk of reinfection is high, particularly in patients with more than three systemic or local comorbidities and higher inflammation indices (ESR and CRP) prior to revision TKA.

Effect of Anteromedial Portal Entrance Drilling Angle during Anterior Cruciate Ligament Reconstruction: A Three-Dimensional Computer Simulation

Purpose The object of this study was to evaluate entrance angle effects on femoral tunnel length and cartilage damage during anteromedial portal drilling using three-dimensional computer simulation. Materials and Methods Data was obtained from an anatomic study performed using 16 cadaveric knees. The anterior cruciate ligament femoral insertion was dissected and the knees were scanned by computer tomography. Tunnels with different of three-dimensional entrance angles were identified using a computer simulation. The effects of different entrance angles on the femoral tunnel length and medial femoral cartilage damage were evaluated. Specifically, tunnel length and distance from the medial femoral condyle to a virtual cylinder of the femoral tunnel were measured. Results In tunnels drilled at a coronal angle of 45°, an axial angle of 45°, and a sagittal angle of 45°, the mean femoral tunnel length was 39.5±3.7 mm and the distance between the virtual cylinder of the femoral tunnel and the medial femoral condyle was 9.4±2.6 mm. The tunnel length at a coronal angle of 30°, an axial angle of 60°, and a sagittal angle of 45°, was 34.0±2.9 mm and the distance between the virtual cylinder of the tunnel and the medial femoral condyle was 0.7±1.3 mm, which was significantly shorter than the standard angle (p<0.001). Conclusion Extremely low and high entrance angles in both of axial plane and coronal plane produced inappropriate tunnel angles, lengths and higher incidence of cartilage damage. We recommend that angles in proximity to standard angles be chosen during femoral tunnel drilling through the anteromedial portal.

Systematic Review of Cadaveric Studies on Anatomic Posterior Cruciate Ligament Reconstruction: The Landmarks in Anatomic Posterior Cruciate Ligament Reconstruction

Recently, several new techniques for anatomic posterior cruciate ligament reconstruction (PCLR) have emerged and are believed to restore the normal anatomy of the posterior cruciate ligament more accurately. Despite the latest trend, the optimal methods for anatomic PCLR remain controversial. The purpose of this research is to review surgical techniques for PCLR in cadaver studies and suggest consistent and reproducible technical criteria. For the review of the literature, MEDLINE and EMBASE were screened for articles on anatomic PCLR. Only basic science studies on PCLR performed on human cadavers and written in English were included. Seventeen studies were included in this systematic review. Only the tunnel positions, graft types, and surgical techniques were reported in the majority of the studies. There were many variations of the reported tunnel positions, graft types, and surgical techniques among the studies. In most studies, surgical techniques for consistent and reproducible anatomic PCLR were not explained clearly. Therefore, high level medical research should be encouraged in order to establish standard surgical techniques for anatomic PCLR.

Correlation between Femoral Guidewire Position and Tunnel Communication in Double Bundle Anterior Cruciate Ligament Reconstruction

Purpose The object of this study was to determine the shortest possible distances of antero-medial (AM) and postero-lateral (PL) guide wire tunnel positions required to prevent femoral bone tunnel communication in double-bundle anterior cruciate ligament (ACL) reconstruction using human cadaver knees. Materials and Methods The centers of femoral AM and PL bundles of 16 cadaveric knees were drilled with guide wires and the distances of guide wires, were measured upon entrance into the bone. Femoral tunnel drilling was performed using transportal technique. The diameters of AM and PL graft were 8 mm and 6 mm, respectively. CT scans were taken on each knee, and 3-dimensional models were constructed to identify the femoral tunnel position and to create AM and PL tunnel virtual cylinders. Thickness of the bone bridge between the two tunnels was measured. Results In four out of six specimens, in which the guide wires were placed at less than or equal to 9 mm, communication was noted. In specimens with guide wires placed at distances greater than or equal to 10 mm, communication was not noted. The two groups showed a statistically significant difference (p=0.008). In cases where the distance between the AM and PL femoral tunnel guide wires was 12 mm, the bone bridge thickness was greater than 2 mm along the tunnel. Conclusion The technique for double bundle-anterior cruciate ligament (DB-ACL) reconstruction that we show here can avoid bone tunnel communication when AM and PL femoral guide wires are placed at least 10 mm apart, and 12 mm should be kept to preserve 2 mm bone bridge thickness.

Common Upper Extremity Disorders and Function Affect Upper Extremity-Related Quality of Life: A Community-Based Sample from Rural Areas

Purpose Upper extremity musculoskeletal disorders (UEMDs), such as rotator cuff tear, epicondylitis, and hand osteoarthritis, have a negative impact on quality of life (QOL). In this study, we evaluated the prevalence of rotator cuff tear, lateral and medial epicondylitis, and hand osteoarthritis in the dominant side and the impact of these UEMDs on the disabilities of the arm, shoulder, and hand (DASH) outcome measure, which assesses upper extremity-related QOL. Materials and Methods In 2013–2015, 987 participants from rural areas completed a questionnaire and underwent physical examinations, laboratory tests, simple radiographic evaluations of bilateral upper extremities, and magnetic resonance imaging studies of bilateral shoulders. Based on data from these participants, researchers evaluated DASH and performed a functional assessment of each region of the dominant side and related UEMDs. Results The prevalences of epicondylitis, rotator cuff tear, and hand osteoarthritis were 33.7%, 53.4%, and 44.6%, respectively. Univariate regression analysis results revealed that epicondylitis, epicondylitis+rotator cuff tear, epicondylitis+hand osteoarthritis, and epicondylitis+rotator cuff tear+hand osteoarthritis were significantly associated with DASH score. Multiple regression analysis, including DASH, UEMD, and regional functional assessments, showed that only epicondylitis and epicondylitis+rotator cuff tear were associated with DASH score. Conclusion Epicondylitis significantly affected QOL, while other UEMDs, such as hand osteoarthritis and rotator cuff tear, had no significant impact. When a patients QOL is affected by a UEMD, there is an increased possibility of the simultaneous presence of other UEMDs.

Early surgical decompression within 8 hours for traumatic spinal cord injury: Is it beneficial? A meta-analysis

Introduction The aim of this study is to evaluate whether early (<8 h) surgical decompression is better in improving neurologic outcomes than late (≥8 h) surgical decompression for traumatic spinal cord injury (tSCI). Methods The various electronic databases were used to detect relevant articles published up until May 2016 that compared the outcomes of early versus late surgery for tSCI. Data searching, extraction, analysis, and quality assessment were performed according to Cochrane Collaboration guidelines. The results are presented as relative ratio (RR) for binary outcomes and mean difference (MD) for continuous outcomes with 95% confidence intervals (CIs). Results Seven studies were finally included in this meta-analysis. There were significant differences between the 2 groups in neurologic improvement (MD = 0.54, 95% CI = −18.52 to −7.02, P < 0.0001) and length of hospital stay (MD = −12.77, 95% CI = 0.34–0.74, P < 0.00001). However, no significant differences were found between the 2 groups in perioperative complications (OR = 0.95, 95% CI = 0.35–2.61, P = 0.92). Conclusions Early surgical decompression within 8 h after tSCI was beneficial in terms of neurologic improvement compared with late surgery. Early surgical decompression (within 8 h) is recommended for patients with tSCI. Level of evidence Level III, therapeutic study.