Shin Woo Nam

Rupture of Posterior Cruciate Ligament: Diagnosis and Treatment Principles

Posterior cruciate ligament (PCL) injuries associated with multiple ligament injuries can be easily diagnosed, but isolated PCL tears are less symptomatic, very difficult to diagnose, and frequently misdiagnosed. If a detailed investigation of the history of illness suggests a PCL injury, careful physical examinations including the posterior drawer test, dial test, varus and valgus test should be done especially if the patient complains of severe posterior knee pain in >90° of flexion. Vascular assessment and treatment should be done to avoid critical complications. An individualized treatment plan should be established after consideration of the type of tear, time after injury, associated collateral ligament injuries, bony alignment, and status of remnant. The rehabilitation should be carried out slower than that after anterior cruciate ligament reconstruction.

Comparative Analysis of Femoral Tunnels Between Outside-In and Transtibial Double-Bundle Anterior Cruciate Ligament Reconstruction: A 3-Dimensional Computed Tomography Study

PURPOSE The objectives of this study were (1) to compare locations of the femoral tunnels created by outside-in and transtibial techniques and the reference data and (2) to compare the diameter of the tunnel entrance based on the real reaming size. METHODS A comparative study was performed with 20 outside-in and 22 transtibial double-bundle anterior cruciate ligament reconstruction patients. Computed tomography scans of the operated knees of the outside-in and transtibial groups were performed at 1.25 days (range, 1 to 3 days) and 2.7 weeks (range, 3 days to 4 weeks), respectively. Three-dimensional surface models were then produced. For all 3 plane data sets, the positions of the femoral tunnels were measured by an anatomic coordinate axis method. For comparison of the tunnel diameter at the entrance of tunnel, the difference between the real reaming and measured diameter was determined first on computed tomography images. Subsequently, the differences in the outside-in and transtibial techniques were compared. RESULTS In the comparison between outside-in and reference data, the posterior-anterior direction of the posterolateral (PL) tunnel showed an anterior position compared with reference data, even though it was positioned more posteriorly compared with that of the transtibial technique (P = .003). In the comparison between transtibial and reference data, the posterior-anterior direction of the anteromedial (AM) and PL tunnels showed an anterior position compared with reference data (P = .019 and P = .005, respectively). The transtibial technique showed significantly larger diameters in both AM and PL tunnels (P < .001 and P < .001, respectively). CONCLUSIONS The outside-in technique showed more accurate replication of the femoral tunnels than the transtibial technique, particularly the AM tunnel of the femur. The transtibial technique showed an ellipsoidal tunnel configuration at the entrance of the tunnel, which suggests that eccentric reaming is unavoidable because the reaming angle is determined by the tibial tunnel. LEVEL OF EVIDENCE Level III, retrospective comparative study.

A Comparison of the Clinical and Radiographic Results of Press Fit Condylar Rotating-Platform High-Flexion and Low Contact Stress Mobile Bearing Prosthesis in Total Knee Arthroplasty: Short term Results.

Purpose This study compared the results of rotating-platform high-flexion (RP-F) total knee arthroplasty with low contact stress (LCS) for clinical and radiographical assessment after a short-term period. Materials and Methods 68 total knee arthroplasties using a RP-F and LCS system were analyzed retrospectively. Thirty-five of the 68 were osteoarthritic knees and were followed-up for more than 2 years. The clinical evaluation included range of motion (ROM), Knee Society Knee Score and Function Score (KSKS and KSFS), tailor position and kneeling. The radiographic evaluation included femorotibial angle, position of implants, radiolucent line and position of patella. Results The postoperative ROM, KSKS, and KSFS improved statistically in both implants. Comparing RP-F with LCS there were statistically no differences in ROM (p=0.863), KSKS (p=0.835), KSFS (p=0.535) and tailor position (p=0.489). There were no significant radiographic differences. Conclusions Total knee arthroplasty with RP-F and LCS showed similar clinical and radiographic results; it also showed excellent and predictable results at the short-term follow up. However, in RP-F there was 1 case of early osteolysis, 1 case of patella clunk syndrome and 1 case of painful patella crepitus; therefore, further case studies and follow-up are needed.

Comparison of anatomic ACL reconstruction between selective bundle reconstruction and double-bundle reconstruction

AbstractPurpose The objective of this study was to compare the clinical and radiologic results of preserved ligament remnants in the selective bundle anterior cruciate ligament (ACL) reconstruction and totally sacrificed ligament remnant in the double-bundle ACL reconstruction in order to confirm the evidence of selective bundle reconstruction.MethodsThis retrospective comparative study was conducted for comparison between preserved ligament remnants in the selective bundle ACL reconstruction and totally sacrificed ligament remnant in the double-bundle ACL reconstruction. From 2008 to 2010, 16 patients (group I) underwent selective bundle ACL reconstruction and 30 patients (group II) underwent double-bundle ACL reconstruction. Clinical, stability and radiologic results (tunnel locations of femoral tunnels using 3-D computed tomography and graft signal intensity using magnetic resonance imaging) were compared.ResultsIn comparison with functional results, no statistical differences in the Lysholm, Tegner and International Knee Documentation Committee scores were observed between the two groups (n.s.). In comparison with stability results between the two groups, no statistical differences were observed in the Lachman, pivot shift and anterior drawer stress tests using a Telos® device at 30° and 90° flexed positions (n.s.). In evaluation of the femoral tunnel location, no statistical significant differences in the tunnel position were observed between the groups (n.s.). No statistically significant differences in signal intensity were observed between the two groups (n.s.).ConclusionsCompared to the double-bundle ACL reconstruction, selective bundle ACL reconstruction produced comparable clinical and radiologic results. Selective bundle ACL reconstruction could be performed instead of double-bundle ACL reconstruction if some intact bundle exists.Level of evidenceComparative study, Level III.

Computed tomography based evaluation of the bone mineral density around the fixation area during knee ligament reconstructions: Clinical relevance in the choice of fixation method

INTRODUCTION This study examined the bone density around the fixation area during knee ligament reconstructions and assessed how this clinical relevance can be applied to a firm construction for a reconstructed ligament. MATERIALS AND METHODS Fifty consecutive patients (25 healthy men and 25 healthy women) were enrolled in this study. A quantitative computed tomography was used to determine the trabecular bone density at the 7 clinically relevant areas (anteromedial area of proximal tibia, anterolateral area of proximal tibia, posteromedial area of the proximal tibia, posterocentral area of the proximal tibia, posterolateral area of the proximal tibia, near femoral tunnel entrance of the ACL, near the femoral funnel entrance of the PCL). The means and standard deviations of the areas of interest were measured using a 10mm diameter circle and the bone density was compared. RESULTS A comparison of the fixation areas in the proximal tibia, anteromedial area of proximal tibia showed the highest bone density and posterocentral area showed the lowest bone density. A comparison of the PCL tibial fixation with interference screws or trans-condylar fixation revealed the posterocentral area to have the lowest bone density. A comparison of the femoral fixation areas in the ACL and PCL reconstruction revealed no differences in bone density. CONCLUSION The anteromedial area of the proximal tibia was most acceptable in the interference screw fixation and the posterocentral area had the lowest bone density in the proximal tibia. There were no differences in the femoral fixation areas in the ACL and PCL reconstruction.

Mycobacterium wolinskyi infection after total knee arthroplasty in a healthy woman

Rapidly growing mycobacteria (RGM) are grouped together based on their ability to grow within seven days of subculture to solid media [1]. Among them, Mycobacterium fortuitum, Mycobacterium chelonae, and Mycobacterium abscessus account for the majority of human diseases caused by RGM [2, 3]. Mycobacterium wolinskyi is a kind of RGB and only approximately 10 clinical cases have been reported in the English-written literature [1]. Despite the high volume of arthroplasty performed, very few cases of peri-prosthetic RGB infections have been reported [2]. Only one English-written case report [4] of peri-prosthetic infection due to Mycobacterium wolinskyi could be found in the literature; however, a few cases of RGB peri-prosthetic infections have been reported in the literature [2, 4–14]. Because there are no standardized treatment protocols, management of this kind of infection could be challenging. In the only previous report of peri-prosthetic infection after total hip arthroplasty due to Mycobacterium wolinskyi, acetabular components and cement were removed and antibiotic treatment was performed. In contrast, we achieved a successful eradication of this infection with a prolonged antibiotics treatment and debridement with prosthesis retention (only liner change) [4]. In the periprosthetic infection, retention of the prosthesis is important because re-plantation is time-consuming and requires significant expense and causes health-related problem. Herein, we describe the clinical course and outcome of peri-prosthetic Mycobacterium wolinskyi infection after total knee arthroplasty in a healthy female patient.

Relationship between Tibial Bone Defect and Extent of Medial Release in Total Knee Arthroplasty

Purpose To understand the relationship between tibial bone defect and extent of medial release in total knee arthroplasty. Materials and Methods We evaluated 32 knees in 22 patients with variable degrees of tibial bone defect on medial plateau has undergone total knee arthroplasty. In this study, 31 cases had been diagnosed as degenerative osteoarthritis and 1 case was osteonecrosis. We excluded cases with infection, traumatic arthritis, or neuropathic joints. With regard to gender, 29 cases were female and 3 cases were male. The following relationships were analyzed: preoperative degrees of tibial bone defect and varus deformity; the femorotibial angle of both weight-bearing whole extremity radiogram, distractive stress radiogram, and the extent of medial release. Results Average tibial bone defect was 9.8±4.1 mm. Average femorotibial angle on weight-bearing whole extremity radiograph was varus 10.0°±6.2°. Average femorotibial angle on distractive stress radiograph was varus 0.7°±4.6°. Statistically the extent of medial release showed no significant relationship with the degree of tibial bone defect and femoro-tibial angle of whole extremity radiogram. However, it revealed a statistically significant relationship with the femorotibial angle on distractive radiogram (r=0.465, p=0.007). Conclusions Preoperative distractive stress radiograph might be a useful method to predict the extent of intraoperative medial release during total knee arthroplasty.

Delayed Knee Locking after Complicated Anterior Cruciate Ligament Reconstruction Despite Good Stability Using A Bio-Transfix

We describe a case of delayed cyst formation that presented as intermittent knee locking after complicated anterior cruciate ligament (ACL) reconstruction using a Bio-TransFix implant in a 21-year-old male patient. During femoral fixation, we could not pull out the guide wire that was temporarily used for the femoral fixation. However, stability was good, and the guide wire was not removed. This was shown to be a wrong type of fixation in a later study. During follow-up, the patient was satisfied and stability was relatively good until 18 months post-operatively. From the 2nd post-operative year, he experienced intermittent knee swelling and locking and pain around the lateral femoral condyle. Follow-up magnetic resonance imaging showed a large cyst around the broken wire tip, but the reconstructed ACL was fine.