Popliteal Fossa Sarcomas

PURPOSE OF THE STUDY Soft tissue sarcomas of the popliteal fossa are extremely rare tumors of mesenchymal origin accounting for 3%-5% of all extremity sarcomas. However, data regarding the tumor type, neurovascular involvement, and administration of radiation therapy before or after resection are limited. This study aimed to report on popliteal fossa sarcomas analyzing data from two institutions based on a relatively large patient sample. MATERIAL AND METHODS Twenty-four patients (80%; 9 men and 15 women) with a popliteal fossa soft tissue sarcoma were included in this study. The reviewed patient data included sex, age, duration of complaints, interval to diagnosis, radiology, pre- and postoperative biopsy, tumor histology, surgery type, complications, and pre- and postoperative oncologic and functional outcomes. The minimum follow-up was 24 months. RESULTS The mean age of the patients was 48 ± 21.23 (range 3-72) years at the time of diagnosis. The mean follow-up was 41.79 ± 16.97 (range 24-120) months. The most common histological diagnoses were synovial sarcoma (6 patients), hemangiopericytoma (2 patients), soft tissue osteosarcoma (2 patients), unidentified fusiform cell sarcoma (2 patients), and myxofibrosarcoma (2 patients). Local recurrence after limb salvage was observed in six patients (26%). At the latest followup, 2 patients died of the disease, 2 patients were still alive with progressive lung disease and soft tissue metastasis, and the remaining 20 patients were free from the disease. CONCLUSIONS Microscopically positive margins may not be an absolute indication for amputation. Also, negative margins do not provide a guarantee that local recurrence will not occur. Lymph node or distant metastasis may be predictive factors for local recurrence rather than positive margins. Key words: fossa poplitea, sarcoma.

Biomechanical comparison of dynamic hip screw, proximal femoral nail, cannulated screw, and monoaxial external fixation in the treatment of basicervical femoral neck fractures

PURPOSE OF THE STUDY The objective of this study was to establish relative fixation strengths of proximal femoral nail (PFN), dynamic hip screw (DHS), monolateral external fixator (EF), and cannulated screw (CS) in basicervical hip fracture model. MATERIAL AND METHODS The study involved four groups of implanted composite proximal femoral synthetic bones of eight specimens per group; nailing with PFN, DHS, fixation with three cannulated screws, and EF. 70˚ osteotomy was performed to simulate a Pauwels Type 3 basicervical fracture. Minimum preload of 100 N was applied before loading to failure. The constructs were subjected to cyclic loading with 16˚ to midline from 100 N to 1,000 N for 10,000 cycles at 3Hz. Axial loading was applied at 10 mm/min until failure. Failure load, failure mode, and displacement were documented. RESULTS Mean failure load was 2182.5 ± 377.9 N in PFN group, 2008.75 ± 278.4 N in DHS group, 1941.25 ± 171.6 N in EF group, and 1551.6 ± 236.2 N in CS group. Average displacement was 15.6 ± 4.5 mm, 15.5 ± 6.7 mm, 11.7 ± 1.9 mm, and 15 ± 1.7 mm, respectively. No significant difference was noted among groups for fixation strength except CS group. All CS constructs failed during cyclic loading. CONCLUSION Our findings suggest that PFN, DHS and EF achieved higher fixation strengths than CS in basicervical fracture. PFN has higher failure loads and possesses biomechanical benefits for fixation of unstable basicervical fractures compared with DHS and EF. Key words: basicervical fracture, internal fixation, biomechanics.

Long-term results of conservative treatment of Sanders type 4 fractures of the calcaneum

A high rate of complications is associated with open reduction and internal fixation of Sanders type 4 fractures of the calcaneum. We assessed the long-term outcome of 83 Sanders type 4 comminuted intra-articular fractures of the calcaneum in 64 patients who underwent non-operative treatment between 1999 and 2005. Each fracture was treated by closed reduction and immobilisation in a long leg cast. Patients were reviewed every three months in the first year, and every six months thereafter. At each visit, the involved ankles were assessed by the American Orthopaedic Foot and Ankle Society (AOFAS) criteria. The degree of fracture healing and the presence of osteoarthritis were assessed.

At a mean follow-up of 51 months (24 to 70) the mean AOFAS score was 72 (52 to 92). Osteoarthritis was scored radiologically using Graves’ classification and was evident in the subtalar joints of 75 ankles (90%) on x-ray and in all ankles on CT scans, of which 20 were grade 0 or 1, 39 grade 2, and 24 grade 3.

A non-operative approach to treating these fractures may be simpler, less expensive, easier to administer with fewer complications, and may be better tolerated than surgery, by many patients.