Review of the Reasons in Cases Requiring Varus/Valgus Constrained Prosthesis in Primary Total Knee Arthroplasty / 대한정형외과학회잡지

Purpose@#The least constrained prosthesis is generally recommended in primary total knee arthroplasty (TKA). Nevertheless, a varus/valgus constrained (VVC) prosthesis should be implanted when a semi-constrained prosthesis is not good for adequate stability, especially in the coronal plane. In domestic situations, however, the VVC prosthesis could not always be prepared for every primary TKA case. Therefore, it is sometimes impractical to use a VVC prosthesis for unsual unstable situations. This study provides information for preparing VVC prostheses in the preoperative planning of primary TKA through an analysis of primary VVC TKA cases. @*Materials and Methods@#This study reviewed 1,797 primary TKAs, performed between May 2003 and February 2016. The reasons for requiring VVC prosthesis and the preoperative conditions in 29 TKAs that underwent primary TKA with a VVC prosthesis were analyzed retrospectively. @*Results@#In primary TKA, 29 cases (1.6%) in 27 patients (6 male and 21 female) used VVC prosthesis. Two patients underwent a VVC prosthesis on both knees. The mean age of the patients was 63.4 years old (34–79 years). The mean flexion contracture was 16.2° (-20°–90°), and the mean angle of great flexion was 111.7° (35°–145°). The situations requiring a VVC prosthesis were severe valgus deformity in 10 knees, knee stiffness requiring extensive soft tissue release in 10 knees, previously injured collateral ligaments in five knees, and distal femoral bone defect due to avascular necrosis in four knees. The mean tibiofemoral angle was 25.7° (21°–43°) in 10 cases with a valgus deformity. The mean flexion contracture was 37.5° (20°–90°), and the mean range of motion was 48.5° (10°–70°) in 10 cases with knee stiffness. @*Conclusion@#The preparation of VVC prosthesis is recommended, even for primary TKA in cases of severe valgus deformity (tibiofemoral angle>20°), stiff knee (the range of motion: less than 70° with more than 20° flexion contracture), and the cases with a previous collateral ligament injury. This information will help in the preparation of adequate TKA prostheses for unusual unstable situations.

Mid-Term Results of Fixed Bearing Unicompartmental Knee Arthroplasty: Minimum 5-Year Follow-Up / 대한정형외과학회잡지

PURPOSE: To evaluate the clinical and radiological outcomes, and the complications of unicompartmental knee arthroplasty (UKA) using a fixed bearing prosthesis after 5-year follow-up. MATERIALS AND METHODS: Twenty-six knees (25 patients) that underwent fixed bearing UKA between May 2003 and August 2011 were included. The subjects were 3 males (3 knees) and 22 females (23 knees), and the average age was 63.5 years. The preoperative diagnosis was osteoarthritis (23 knees) and osteonecrosis (3 knees). The mean follow-up duration was 67 months (from 60 to 149 months). The clinical evaluation included pre- and postoperative American knee society knee and function score, and range of motion. The radiology evaluation included standing antero-posterior, lateral view, and fluoroscopic film to analyze the postoperative alignment and osteolysis. RESULTS: The mean American Knee Society knee score and function score were improved from 42.0 and 57.5 to 87.9 and 85.0, respectively (p < 0.001). The mean preoperative and postoperative range of motion was 132.9° and 132.5°, respectively. The mean femorotibial angle were varus 0.5° preoperatively and valgus 2.2° postoperatively. A radiolucent line was observed in 2 knees; one knee had a stable implant, while in the other knee, patellofemoral arthritis was identified during UKA. Diffuse pain of the knee joint with tenderness of the medial joint line was identified at the follow-up, so conversion to total knee arthroplasty was recommended. No other complications, such as osteolysis, infections, postoperative stiffness, and dislocation, were encountered. CONCLUSION: The midterm results of fixed bearing UKA were clinically and radiologically satisfactory.

Traumatic Anterolateral Fracture-Dislocation of the Lumbosacral Spine by Horizontal Shear Force / 대한정형외과학회잡지

Lumbosacral fracture-dislocation is very rare because of the characteristic anatomical features, and various displacements by injury mechanisms have been reported. Most of the reports were displaced by flexion, distraction, compression and rotation. Complete reduction and appropriate treatment can be difficult or impossible in the case of delayed diagnosis. We report a case of lumbosacral fracture & dislocation that occured in horizontal shear and flexion, which was correctly diagnosed and treated successfully with partial corpectomy, open reduction, posterior interbody fusion and transpedicular fixation with posterolateral fusion by posterior approach only.

The Effect of Zoledronic Acid on the Volume of the Fusion-Mass in Lumbar Spinal Fusion

BACKGROUND: Few studies have explored the effects of bisphosphonates on bony healing in patients undergoing spinal fusion surgery. Most previous studies used animal models and found that bisphosphonate shows negative effects on spinal fusion consolidation. We intended to evaluate the effect of a single-dose of zoledronic acid on the volume of the fusion-mass in lumbar spinal fusion. METHODS: A retrospective review was carried out on 44 patients with symptomatic degenerative lumbar spinal stenosis who underwent one or two-level posterolateral fusion from January 2008 and January 2011. They were divided into 4 groups: group 1, autograft and zoledronic acid; group 2, allograft and zoledronic acid; group 3, autograft alone; and group 4, allograft alone. Functional radiography and three-dimensional computed tomography scans were used to evaluate and quantify the volume of the fusion-mass. The visual analog scale (VAS), the Oswestry disability index (ODI), and the short form 36 (SF-36) were used to evaluate the clinical outcomes. RESULTS: The mean volume of the fusion-mass per level was 8,814 mm3, 8,035 mm3, 8,383 mm3, and 7,550 mm3 in groups 1, 2, 3, and 4, respectively, but there were no significant differences between the groups (p = 0.829). There were no significant decreases in the volume of the fusion-mass (p = 0.533) in the zoledronic acid groups (groups 1 and 2). The VAS, the ODI, and the SF-36 at the 6-month follow-up after surgery were not significantly different (p > 0.05) among the 4 groups. The VAS, the ODI, and the SF-36 were not correlated with the volume of the fusion-mass (p = 0.120, 0.609, 0.642). CONCLUSIONS: A single dose of zoledronic acid does not decrease the volume of the fusion-mass in patients undergoing spinal fusion with osteoporosis. Therefore, we recommend that zoledronic acid may be used after spinal fusion in osteoporotic patients.