Bilateral Stress Fracture at the Inferior Pole of Patella in a Juvenile Athlete / 대한정형외과학회잡지

Patellar fractures in children occur rarely in approximately 1% of all pediatric fractures and 57% of these are osteochondral or cartilaginous avulsion fractures, a type of sleeve fracture. They may be missed in diagnosis due to small bony fragment on simple radiographs, and they always occur ipsilaterally; however, only a few cases of bilateral patellar fracture of the inferior pole have been reported. We experienced an 11 year-old patient an athlete, who suffered repetitive minor trauma, with a stress fracture, which occurred at the inferior pole of the patella bilaterally, and we report on this unusual case with a literature review.

The Result of Treatment of Femoral Periprosthetic Fractures after Total Knee Arthroplasty / 대한정형외과학회잡지

PURPOSE: We assessed and compared the clinical and radiologic outcomes of treatment in periprosthetic fractures of the femur after total knee arthroplasty. MATERIALS AND METHODS: We compared 22 knees, 22 patients of femoral periprosthetic fractures which had been fixed with absolute stabilization such as plate or screw fixation in 16 cases (group A), and with relative stabilization such as retrograde intramedullary nailing or Ender nailing in six cases (group B) from November 2004 to March 2013; the mean follow-up period was 51.9 months. RESULTS: The mean tibio femoral angle and the mean mechanical axis showed statistically significant change in group B, between before fracture and last follow-up. The mean bone union time and the mean hospital for special surgery score were not significantly different between group A and B. Nonunion was demonstrated in one case in each group, malunion was demonstrated in one case in group B. CONCLUSION: In the treatment of periprosthetic fractures of the femur after total knee arthroplasty, absolute stabilization had an advantage for regain of limb alignment. Among the complications, more cases of refracture and infection were observed in the absolute stabilization group, while more cases of nonunion and malunion were observed in the relative stabilization group.

Clinical Features and Treatments of Carpal Bone Cysts

PURPOSE: A total of 27 carpal bone cysts were analyzed for their sites, relations of other wrist soft tissue ganglions and their results of treatment were evaluated. METHODS: Twenty-seven carpal bone cysts in 20 patients (bilateral 5, multiple 2) from February 2002 to June 2013 were evaluated. Mean follow-up period was 16.6 months. We investigated etiological classification, the site of carpal bone cyst, and their relationship with soft tissue ganglion in same wrist. Pain, range of motion, radiographic changes, and their satisfaction after treatment were assessed postoperatively. RESULTS: The carpal bone cysts occurred mainly at the radial wrist axial ray on the lunate (12 cases), scaphoid (6 cases), and triquetrum (5 cases), trapezium (2 cases), and capitate (2 cases). Based on the magnetic resonance imaging (MRI) findings in 25 cases, we classified carpal bone cysts into 4 distinct types; type I with purely intraosseous lesion (16 cases), type II with bone cyst associated cortical perforations (6 cases), type III with coexisting soft tissue ganglion communicating with intra-osseous lesion (2 cases), and type IV with coexisting soft tissue ganglion non-communicating intraosseous lesions (1 case). CONCLUSION: The carpal bone cysts can be classified by MRI into 4 distinct types. The purely intraosseous type is most common, suggesting the intrinsic cause in the development of carpal bone cyst.

Results of Revision Surgery and Causes of Unstable Total Knee Arthroplasty

BACKGROUND: The aim of this study was to evaluate causes of unstable total knee arthroplasty and results of revision surgery. METHODS: We retrospectively reviewed 24 knees that underwent a revision arthroplasty for unstable total knee arthroplasty. The average follow-up period was 33.8 months. We classified the instability and analyzed the treatment results according to its cause. Stress radiographs, postoperative component position, and joint level were measured. Clinical outcomes were assessed using the Hospital for Special Surgery (HSS) score and range of motion. RESULTS: Causes of instability included coronal instability with posteromedial polyethylene wear and lateral laxity in 13 knees, coronal instability with posteromedial polyethylene wear in 6 knees and coronal and sagittal instability in 3 knees including post breakage in 1 knee, global instability in 1 knee and flexion instability in 1 knee. Mean preoperative/postoperative varus and valgus angles were 5.8degrees/3.2degrees (p = 0.713) and 22.5degrees/5.6degrees (p = 0.032). Mean postoperative alpha, beta, gamma, delta angle were 5.34degrees, 89.65degrees, 2.74degrees, 6.77degrees. Mean changes of joint levels were from 14.1 mm to 13.6 mm from fibular head (p = 0.82). The mean HSS score improved from 53.4 to 89.2 (p = 0.04). The average range of motion was changed from 123degrees to 122degrees (p = 0.82). CONCLUSIONS: Revision total knee arthroplasty with or without a more constrained prosthesis will be a definite solution for an unstable total knee arthroplasty. The solution according to cause is very important and seems to be helpful to avoid unnecessary over-constrained implant selection in revision surgery for total knee instability.

Pigmented Villonodular Synovitis in Forefoot (A Case Report) / 대한족부족관절학회지

Pigmented villonodular synovitis (PVNS) is a slowly, progressive, proliferative disorder of synovial tissue characterized by villous or nodular changes of synovial-lined joints, bursae, and tendon sheaths and most frequently affects the large joints, with the knee and hip. A few studies have been reported that occurred PVNS in small joint, but mainly in hands. It is a very rare condition that occurs in the small joints of the forefoot. We have experienced the case, which developed in small joint of the forefoot, and performed total synovectomy. After the operation, there was no recurrence. We report a case of PVNS in forefoot with a review of the literature.