Prediction Models to Improve the Diagnostic Value of Plain Radiographs in Children With Complete Discoid Lateral Meniscus.

PURPOSE: To develop prediction models to improve the diagnostic utility of plain radiographs for the diagnosis of complete discoid lateral meniscus by combining previously reported radiographic findings. METHODS: Patients ages 5 to 16 years with complete discoid lateral meniscus confirmed by arthroscopy or magnetic resonance imaging were included. Patients with insufficient radiographs were excluded. Normal control subjects were randomly sampled by age and sex matching. Subjects were divided into 2 groups considering skeletal maturation (5-9 and 10-16 years). Radiographic variables included were lateral joint space, height of the fibular head, height of the lateral tibial spine, obliquity and cupping of the lateral tibial plateau, condylar cutoff sign, and squaring and notching of the lateral femoral condyle. Prediction models were developed by regression analyses. The cutoff value (COV) for best accuracy was determined with its sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV). RESULTS: A total of 162 knees (126 patients) with complete discoid lateral meniscus and 151 age- and sex-matched knees (151 subjects) with normal meniscus were included. In subjects 5 to 9 years old, the prediction model was risk score = [-20.08 * height of the fibular head/femoral interepicondylar distance (FIED)] + [-42.26 * height of the lateral tibial spine/FIED]. The COV of -8.47 showed the best accuracy (74.4%), with sensitivity of 85.9%; specificity, 60.4%; PPV, 72.4%; and NPV, 78.0%. In subjects 10 to 16 years old, the prediction model was risk score = [77.04 * lateral joint space/FIED] + [-34.55 * height of the fibular head/FIED] + [-56.58 * height of the lateral tibial spine/FIED] + [-16.44 * condylar cutoff sign]. The COV of -18.03 showed the best accuracy (85.4%), with sensitivity of 79.6%; specificity, 90.4%; PPV, 87.6%; and NPV, 83.9%. CONCLUSIONS: The prediction models combining the plain radiographic findings showed higher diagnostic values than the diagnostic values of the individual radiographic findings. The results of this study provide improved diagnostic utility of plain radiography for the detection of completed discoid lateral meniscus in children. LEVEL OF EVIDENCE: Level III, diagnostic study.

The effect of electroacupuncture on osteotomy gap healing in a rat fibula model.

OBJECTIVE: To examine the effect of electroacupuncture (EA) on osteotomy gap healing in a rat fibula model. METHODS: A total of 40 12-week-old male Wistar rats underwent unilateral open osteotomy of the fibula to create a 2 mm gap. The rats were randomly assigned to an EA group (n=20) and a control group (n=20). In the EA group, a cathodal electrode was connected to an acupuncture needle percutaneously at the surgery site, while another acupuncture needle inserted 15 mm proximal to the surgery site was used as an anodal electrode. EA was performed 5 days a week for 6 weeks. The control group received no treatment. Some rats were killed at 3 days and 1 week after surgery and the cut end of the distal part of the fibula was surgically removed and histologically assessed. Haematoxylin and eosin (H&E) staining was used to measure total cell count and immunohistochemical staining to assess the increase in the bone morphogenetic protein 2 (BMP-2)-positive cells. The healing process was also assessed weekly after surgery via x-ray examinations. RESULTS: At each time point, total cell count showed a marked increase in the EA group (p<0.05), while BMP-2 expression showed a tendency to increase in the EA group. Radiological examination showed a marked reduction in the distance between the cut ends of the fibula in the EA group. CONCLUSIONS: There was a marked increase in cell count and expression of growth factor in the EA group. These results indicate direct current EA could be useful for promoting bone healing.

Stress-induced spiculated periosteal reaction appearing as a malignant bone tumor: a case report.

OBJECTIVE: The aim of this study was to describe the appearance of a rare occurrence of a spiculated periosteal reaction caused by stress injury and the subsequent diagnostic assessments. A proposed mechanism for the etiology of stress-induced periosteal reactions in this case is offered. CLINICAL FEATURES: A 54-year-old female had ankle pain for 1 year. Radiographs revealed a spiculated periosteal reaction of the distal fibula. In light of the clinical history of prior breast carcinoma, the possibility of metastatic disease was entertained. INTERVENTION AND OUTCOME: Scintigraphy and magnetic resonance imaging were used in the diagnostic evaluation of this patient. Malignancy was ruled out on the basis of the magnetic resonance imaging findings, and an etiology of a stress reaction was proposed based on the scintigraphic findings. CONCLUSION: Stress-induced spiculated periosteal reactions are a rare occurrence. This case illustrates the role that advanced imaging plays in the assessment of a suspicious periosteal reaction.

Percutaneous intramedullary decompression, curettage, and grafting with medical-grade calcium sulfate pellets for unicameral bone cysts in children: a new minimally invasive technique.

Several treatment options exist for unicameral bone cysts (UBCs), including observation, steroid injection, bone marrow injection, and curettage and bone grafting. These are all associated with high recurrence rates, persistence, and occasional complications. Newer techniques have been described, most with variable success and only short follow-up reported. Because of these factors, a new minimally invasive percutaneous technique was developed for the treatment of UBCs in children. Twenty-eight children with UBCs who underwent percutaneous intramedullary decompression, curettage, and grafting with medical-grade calcium sulfate (MGCS) pellets by the senior author (J.P.D.) between April 2000 and April 2003 were analyzed as part of a pediatric musculoskeletal tumor registry at a large tertiary children's hospital. Four patients were lost to follow-up, and the remaining 24 patients had an average follow-up of 21.9 months (range 4-48 months). Twelve patients were followed for at least 24 months. Six of the 24 children had received previous treatment of their UBC, most often at an outside institution. Follow-up was performed through clinical evaluation and radiographic review. Postoperative radiographs at most recent follow-up showed complete healing, defined as more than 95% opacification, in 22 of 24 patients (91.7%). One patient (4.2%) demonstrated partial healing, defined as 80% to 95% opacification. One patient had less than 80% radiographic healing (4.2%). All 24 patients returned to full activities and were asymptomatic at most recent follow-up. The only complication noted was a superficial suture abscess that occurred in one patient; this resolved with local treatment measures. The new minimally invasive technique of percutaneous intramedullary decompression, curettage, and grafting with MGCS pellets demonstrates favorable results with low complication and recurrence rates compared with conventional techniques. The role of intramedullary decompression as a part of this percutaneous technique is discussed.

Effects of vitamin D analog, 22-oxa-1,25-dihydroxyvitamin D(3), on bone reconstruction by vascularized bone allograft.

We previously reported that vascularized bone allograft using immunosuppressants, such as cyclosporine A (CsA), is one approach for reconstruction of large bone defects in both experimental animals (Microsurgery 15:663; 1994) and clinically in humans (Lancet 347:970, 1996). Because immunosuppressive agents such as CsA induce significant side effects, including bone loss, other therapeutic agents supporting successful vascularized bone allografts have been sought after. We investigated the effects of 22-oxa-1,25-dihydroxyvitamin D(3) (OCT) on vascularized bone allograft, and compared its effects with CsA. Twelve-week-old DA rats with the major histocompatibility antigen (MHC) RT-1(a) were used as donors and age-matched Lewis rats with MHC RT-1(l) used as recipients. Allografted bones in rats treated with vehicle were rejected completely. Soft X-ray examination demonstrated that administration of OCT (0.5 microg/kg per day) for 12 weeks after bone graft induced bone union as effective as treatment for 12 weeks with CsA (10 mg/kg per day). Transplanted bones in OCT-treated rats showed higher bone mineral density than that in CsA-treated rats. Histologically, transplanted bones in OCT-treated rats at 12 weeks were nonvital, but these bones united with recipient vital bones. After cessation of 12 week treatment with OCT, new bone formation occurred around the grafted nonvital bones during a 9 month period. Transplanted bones in CsA-treated rats were vital and formed union with recipient bones, whereas cortical bones became thin when compared with nonvital bones in OCT-treated rats. Urinary deoxypyridinoline levels in rats treated with CsA were significantly higher than levels in rats treated with OCT, suggesting accelerated bone resorption in CsA-treated rats. These results suggest that OCT exerts an anabolic action on bone reconstruction by allogeneic bone transplantation.

Successful surgical treatment of haemophilic pseudotumour, filling the defect with hydroxyapatite.

A preliminary report is made on the use of hydroxyapatite for surgical procedure of pseudotumour, a rare but serious complication of the bleeding diathesis in patients with inherited bleeding disorders. Surgical or percutaneous treatment and refilling with fibrin sealant is shown to be a successful therapy in a 19-year-old male with severe haemophilia B. The pseudotumour, in the upper pad of the left leg, was filled with hydroxyapatite after surgery. We suggest that the use of hydroxyapatite is a new and useful option in the surgical treatment of haemophilic pseudotumour.