Hyung-Bin Park

Comparison of internal bone transport and vascularized fibular grafting for femoral bone defects.

Objective To compare results between vascularized fibular grafting and internal bone transport for large bone defects of the femur. Design Retrospective review of patients. Setting University teaching hospitals. Patients This study included 37 patients with femoral bone loss: 20 patients were treated with internal bone transport and seventeen patients were treated with vascularized fibular grafting. Main Outcome Measurements The outcomes investigated were external fixation time, external fixation index, bone results (union, infection, deformity, leg length discrepancy), and functional results. Results The mean amount of filled defect was 8.4 cm with internal bone transport and 8.9 cm with vascularized fibular grafting. The external fixation index was 1.4 months/cm with internal bone transport and 1 month/cm with vascularized fibular grafting. The bone results and functional results of the internal bone transport were excellent in 65% and 0%, good in 5% and 45%, fair in 5% and 40%, poor in 25% and 15%, respectively, whereas those of the vascularized fibular grafting were excellent in 35% and 0%, good in 25% and 47%, fair in 5% and 35%, and poor in 35% and 18%. Conclusion With vascularized fibular grafting, careful monitoring of circulation and early intervention surgery is necessary to avoid vascular failure. With internal bone transport, repeated radical debridement until control of infection is achieved, bone grafting at the docking site for early union, and avoiding stress fracture are recommended to improve bone results.

Revision Total Knee Arthroplasty with a Cemented Posterior Stabilized, Condylar Constrained or Fully Constrained Prosthesis: A Minimum 2-year Follow-up Analysis

Background The clinical and radiological outcomes of revision total knee arthroplasty with a cemented posterior stabilized (PS), condylar constrained knee (CCK) or a fully constrained rotating hinge knee (RHK) prosthesis were evaluated. Methods This study reviewed the clinical and radiological results of 36 revision total knee arthroplasties with a cemented PS, CCK, and RHK prosthesis in 8, 25, and 13 cases, respectively, performed between 1998 and 2006. The mean follow-up period was 30 months (range, 24 to 100 months). The reason for the revision was aseptic loosening of one or both components in 15, an infected total knee in 18 and a periprosthetic fracture in 3 knees. The average age of the patients at the time of the revision was 65 years (range, 58 to 83 years). The original diagnosis for all primary total knee arthroplasties was osteoarthritis except for one case of a Charcot joint. All revision prostheses were fixed with cement. The bone deficiencies were grafted with a cancellous allograft in the contained defect and cortical allograft fixed with a plate and screws in the noncontained defect. A medial gastrocnemius flap was needed to cover the wound dehiscence in 6 of the 18 infected cases. Results The mean Knee Society knee score improved from 28 (range, 5 to 43) to 83 (range, 55 to 94), (p < 0.001) and the mean Knee Society function score improved from 42 (range, 10 to 66) to 82 (range, 60 to 95), (p < 0.001) at the final follow-up. Good or excellent outcomes were obtained in 82% of knees. There were 5 complications (an extensor mechanism rupture in 3 and recurrence of infection in 2 cases). Three cases of an extensor mechanism defect (two ruptures of ligamentum patellae and one patellectomy) were managed by the RHK prosthesis to provide locking stability in the heel strike and push off phases, and two cases of recurrent infection used an antibiotic impregnated cement spacer. The radiological tibiofemoral alignment improved from 1.7° varus to 3.0° valgus in average. Radiolucent lines were observed in 18% of the knees without progressive osteolysis. Conclusions Revision total knee requires a more constrained prosthesis than primary total knee arthroplasty because of the ligamentous instability and bony defect. This short to midterm follow-up analysis demonstrated that a well planned and precisely executed revision can reduce pain and improve the knee function significantly. Infected cases showed as good a result as those with aseptic loosening through the use of antibiotics-impregnated cement beads and proper soft tissue coverage with a medial gastrocnemius flap.

Inflammatory cytokines are overexpressed in the subacromial bursa of frozen shoulder

BACKGROUND Frozen shoulder is a debilitating condition characterized by gradual loss of glenohumeral motion with chronic inflammation and capsular fibrosis. Yet its pathogenesis remains largely unknown. We hypothesized that the subacromial bursa may be responsible for the pathogenesis of frozen shoulder by producing inflammatory cytokines. MATERIALS AND METHODS We obtained joint capsules and subacromial bursae from 14 patients with idiopathic frozen shoulder and from 7 control subjects to determine the expression levels of interleukin (IL) 1α, IL-1β, IL-6, tumor necrosis factor α (TNF-α), cyclooxygenase (COX) 1, and COX-2 by real-time reverse transcriptase-polymerase chain reaction, immunohistochemistry, and enzyme-linked immunosorbent assay. RESULTS IL-1α, IL-1β, TNF-α, COX-1, and COX-2 were expressed at significantly high levels in the joint capsules of the frozen shoulder group compared with those of the control group. Intriguingly, IL-1α, TNF-α, and COX-2 were also expressed at significantly high levels in the subacromial bursae of the frozen shoulder group compared with those of the control group. Immunohistochemical analysis showed increased expression of COX-2 in both the joint capsules and subacromial bursae of the frozen shoulder group. CONCLUSIONS These findings imply that elevated levels of inflammatory cytokines in the subacromial bursa may be associated with the pathogenesis of inflammation evolving into fibrosis.

Iliacus hematoma and femoral nerve palsy after revision hip arthroplasty: a case report.

Femoral nerve palsy occurred in a 65-year-old man after he had undergone a revision total hip arthroplasty using cementless components. The magnetic resonance imaging scan showed a mass in the iliacus muscle. The mass showed increased signal intensity on T1-weighted and T2-weighted spin-echo images and contained linear septa and a nodule. The gadolinium-enhanced T1-weighted image showed a rim of significant enhancement in the nodule. The findings of magnetic resonance images were suggestive of iliacus hematoma and of liposarcoma. The patient underwent surgery, and the mass was identified as an iliacus hematoma. The femoral nerve was stretched by the hematoma. After removal of the hematoma, the nerve palsy was improved completely. Iliacus hematoma may occur after total hip arthroplasty, even without anticoagulant therapy. The hematoma might appear to be a liposarcoma on magnetic resonance imaging scans.

Restoration of the Center of Rotation in Revision Total Hip Arthroplasty

We measured the change of the center of hip rotation after the revision of acetabular loosening using an acetabular reconstruction ring and an impaction allogenic bone grafting. Thirty-five revision total hip arthroplasties were performed. The average follow-up was 3.8 years. Horizontal distance was changed from 34.01±10 mm preoperatively to 41.07±6 mm at the latest follow-up. Vertical distance was changed from 32.06±9 mm preoperatively to 20.21±7 mm at the latest follow-up. The Harris hip score was improved from an average of 47 in the preoperative period to 86 at the final follow-up. The restoration of the anatomical hip center has shown to be favorable in terms of functional and radiologic evaluation in total hip revision.

Concomitant fractures of the femoral head and neck without hip dislocation.

This case report describes two patients who sustained ipsilateral fractures of the femoral head and femoral neck without dislocation of the hip. The fractures in the two patients resulted from vehicle accidents. The femoral head was fractured in the sagittal plane, and the femoral neck was fractured at the subcapital portion. However, the hip was not dislocated in either patient. Both patients were treated using cementless total hip arthroplasty. These unusual hip injuries have not been reported previously and are not categorized according to any known classification system of hip injuries.

Use of Intramedullary Nonvascularized Fibular Graft with External Fixation for Revisional Charcot Ankle Fusion: A Case Report

We describe a case of Charcot ankle arthropathy in a 43-year-old male patient who underwent revision surgery for tibiotalocalcaneal arthrodesis with a retrograde intramedullary nonvascularized fibular graft. After 3 months of postoperative stabilization with a ring external fixator, successful radiographic union was identified. The findings obtained at 33 months postoperatively showed maintenance of solid fusion and restoration of hindfoot alignment without any complications.