Soft Tissue Balancing of Varus Arthritic Knee in Minimally Invasive Surgery Total Knee Arthroplasty: Comparison between Posterior Oblique Ligament Release and Superficial MCL Release

PURPOSE: To assess proper soft tissue balancing of the varus arthritic knee between posterior oblique ligament (POL) release group and superficial medial collateral ligament (SMCL) release group. MATERIALS AND METHODS: This retrospective study was performed on 186 patients who underwent minimally invasive surgery (MIS) total knee arthroplasty (TKA) from January 2011 to December 2011. Eighty-three patients were in the group of SMCL release and 103 patients were in the POL release group. We intended to use a 10 mm polyethylene insert (PE) during TKA, and retrospectively compared the actual thickness of PE between POL release group and SMCL release group. RESULTS: The mean PE thickness was 10.59+/-1.3 mm (range, 8 to 15 mm) in POL group and 11.88+/-1.8 mm (range, 10 to 18 mm) in SMCL group (p=0.001). We found a significant difference in the mean PE thickness between POL release group and SMCL release group. CONCLUSIONS: POL and deep MCL releases in MIS-TKA would be beneficial for varus deformity correction in the osteoarthritic knee.

Easy Identification of Mechanical Axis during Total Knee Arthroplasty

PURPOSE: We devised an intraoperatively identifiable mechanical axis (IIMA) as a reference of alignment in total knee arthroplasty (TKA). MATERIALS AND METHODS: Between February 2010 and January 2011, primary TKAs were consecutively performed on 672 patients (1007 knees) using an IIMA as a reference in the coronal plane. RESULTS: The alignment of the lower extremity improved from a mean of 11.4+/-6.7degrees (-10.3-34.4degrees) of varus preop. to 0.7+/-3.5degrees (-5.2-8.6degrees) immediately after surgery. Mean alignment of the femoral component in the coronal plane was 89.3+/-2.3degrees (83.4-97.2degrees) postop. and mean alignment of the tibial component was 90.4+/-2.2degrees (85.1-94.2degrees) postop. CONCLUSION: This study showed that IIMA could be of considerable value as a new guider of alignment that is easily accessible and highly effective during total knee arthroplasty.

Results of Hook Plate Fixation of Unstable Distal Clavicle Fractures

PURPOSE: This study evaluated the clinical and radiological outcomes of unstable distal clavicular fractures treated with an AO Hook plate. MATERIALS AND METHODS: From March 2009 to October 2010, sixteen patients with distal clavicular fractures underwent open plating using an AO Hook plate. The clinical outcomes were assessed by measuring the UCLA scores and KSS sores, and the radiological outcomes were evaluated using simple radiographs at the final follow-up. RESULTS: Fracture union was obtained in all patients at an average of 13.9 weeks (range, 9~20 weeks). The UCLA scoring system showed excellent results in 9 cases and good results in 7. The average KSS scores of distal clavicular fractures were 95.5. At the final follow-up, subacromial osteolysis developed in 11 cases (68.7%) of whom 3 suffered from pain around the acromion. Other complications occurred in 4 patients: one had a fracture adjacent to the plate proximally, two had a stiff shoulder with subacromial impingement, and one had hypoesthesia around the surgical wound. CONCLUSION: Unstable distal clavicular fractures treated with a Hook plate provided rigid fixation and satisfactory outcomes considering the high union rate. Nevertheless, potential postoperative complications related to morphometric properties of the plate should be considered.