Han Jun Lee

Remnant Posterior Cruciate Ligament–Augmenting Stent Procedure for Injuries in the Acute or Subacute Stage

PURPOSE To evaluate the results of a remnant posterior cruciate ligament (PCL)-augmenting stent procedure for acute- or subacute-stage PCL injuries in terms of stability and clinical results. METHODS Between September 2003 and March 2006, 32 patients with a PCL tear underwent a reconstructive stent procedure with an autogenous hamstring tendon graft to augment the remains of the injured PCL. Of these patients, 20 who satisfied our inclusion criteria and could be followed up for a minimum duration of 24 months were enrolled in our study. The remnant PCL and synovium were preserved, and augmentation was performed by use of the transtibial technique. A femoral tunnel was created near the footprint of the anterolateral bundle. Stability was measured on posterior stress radiographs and by use of a maximum manual displacement test performed with a KT-1000 arthrometer (MEDmetric, San Diego, CA). The International Knee Documentation Committee (IKDC) and Orthopädische Arbeitsgruppe Knie scoring systems were used for clinical evaluation. RESULTS Stress radiographs showed that the mean side-to-side differences in displacement were reduced from 9.9 +/- 4.0 mm preoperatively to 3.0 +/- 2.6 mm at the last follow-up, whereas KT-1000 tests showed that these differences were reduced from 6.9 +/- 2.1 mm preoperatively to 2.7 +/- 1.5 mm. The final IKDC score was A in 7 patients (35%), B in 10 (50%), C in 2 (10%), and D in 1 (5%). The mean Orthopädische Arbeitsgruppe Knie score improved from 61.6 +/- 13.1 to 88.2 +/- 9.5. CONCLUSIONS Of the patients, 90% showed satisfactory posterior stability and 85% had a normal or nearly normal rating based on the IKDC score at a mean of 3 years after the remnant PCL-augmenting stent procedure in the acute or subacute stage of PCL injuries.

Characterization of spontaneous healing of chronic posterior cruciate ligament injury: Analysis of instability and magnetic resonance imaging.

To explore the healing process of the injured posterior cruciate ligament (PCL) by evaluating instability measurements and magnetic resonance imaging (MRI) findings.

Analysis of the Orientation of Lumbar Isthmic Defect

Purpose: We analyzed angles of defect planes of spondylolysis from coronal plane using axial computed tomography to identify the problem of oblique plain radiograph by which we routinely has used and to suggest an appropriate radiological diagnostic tool for spondylolysis. Materials and Methods: From January 2001 to July 2002, 84 cases of spondylolysis from 44 patients were studied. The diagnosis of spondylolysis was confirmed with axial computed tomography in all cases and angles of isthmic defect from coronal plane were measured. We intended to assess the distribution of angles of isthmic defect and analyzed the result of plain radiographs which were obtained in the direction parallel to the angle of the mean value. Results: Although angles of lumbar isthmic defects have a wide distribution, the mean value was 20.9 which was nearer to coronal plane than oblique plane. Fifty eight cases were distributed within from coronal plane. A diagnostic sensitivities were 88.1% in lateral view, 78.6% in oblique view and 100% in oblique view, so a oblique view seemed to be more sensitive in diagnosis of lumbar isthmic defect. Conclusion: Because the mean angle of lumbar isthmic defects from coronal plane was about , oblique view with was more appropriate and sensitive diagnostic tool for spondylolysis than oblique view with which have been used routinely.

Expression of MMP-2 in the Healing Process of Acute Tear of the Rotator Cuff Tendon in Rats

Purpose : Rotator cuff diseases combined with cuff tear are the most common causes of pain and disability of the upper extremity. Most rotator cuff tears are of partial thickness and respond well to conservative treatment. Many authors have addressed the capacity of cuff tendon healing, but little is known of the precise healing process. The MMPs (matrix metalloproteinases) are synthesized and secreted from connective tissue cells and are known to participate in the degradation and remodeling of organs in both normal and pathologic states. Using a rat model, we studied the healing process of rotator cuff tendon tear with reference to the expression of MMP-2. Materials and Methods : Forty Mature Sprague-Dawley rats were used in this anima study. Twenty rats were assigned to the experimental group, the other twenty to the control group. In the experimental group, a partial thickness tear of the rotator cufft tendon was made and rats were examined 4 weeks after surgery. Results : On gross inspection, the defects were covered with granulation tissue, and on microscopic evaluation, proliferation of fibroblasts and vessels at the defect demonstrated the healing capacity of rotator cuff tendon. The expression of MMP-2 was determined by immunohistochemistry and RT-PCR. Immunohistochemistry demonstrated MMP-2 positively stained cells at the defect site. Also, RTPCR demonstrated MMP-2 expression. Conclusion : These results suggest that the remodeling and healing processes of injured rotator cuff tendon are associated with the expression of MMP-2.