Aykin Simsek

Venous thromboembolism prophylaxis in major orthopaedic surgery: A multicenter, prospective, observational study

OBJECTIVES We investigated risk factors for venous thromboembolism (VTE), prophylaxis measures employed, and incidence of symptomatic deep venous thrombosis (DVT) and pulmonary embolism (PE) in patients undergoing major orthopaedic surgery (MOS). METHODS An open, multicenter, prospective, observational study was conducted in 21 medical centers, comprising 899 patients. Of these, 316 patients (35.2%) underwent total hip arthroplasty (THA), 328 patients (36.5%) underwent total knee arthroplasty (TKA), and 255 patients (28.4%) underwent surgery for hip fractures (HF). Pharmacologic prophylaxis was employed in all the patients. RESULTS Risk factors for VTE were seen in 73.2% of the patients, the most common being obesity (72%) and prolonged immobilization (36.3%). Low-molecular-weight heparin (91.1%) and fondaparinux (8.9%) were used for prophylaxis, which was short-term in 273 patients (30.4%) and long-term in 626 patients (69.6%). Mechanical prophylaxis was performed with compression stockings in 610 patients (67.9%) and by intermittent pneumatic compression in 67 patients (7.5%). During three-months of follow-up, symptomatic DVT and PE were seen in eight (0.9%) and four patients (0.4%), respectively. Mortality occurred in 10 patients (1.1%). Complications of major and minor bleeding were seen in eight (0.9%) and 40 (4.5%) patients, respectively. CONCLUSION Effective VTE prophylaxis is associated with low risk of clinically apparent DVT and PE in MOS.

Interaction of Cultured Chondrocytes with Chitosan Scaffold

Chitosan scaffolds with sponge-like structures were prepared by a wet spinning technique. Glutaraldehyde was used to control the swellability (water uptake) of the scaffolds. It was possible to reach a swelling ratio about 56.8% in aqueous medium. These wet scaffolds were soft and easily shaped by hand. The cartilage specimen was obtained from the knee joints of a New Zealand white rabbit. Chondrocyte cells were isolated and cultured in vitro for about 10 days to reach a usable population. The cells were then incubated with the chitosan scaffolds and interactions were examined by microscopy. Chondrocyte cells showed junctional complexes consisting of plaques and filaments at the interface. Cell membranes were strongly attached on the chitosan surface.

The Relationship of the Heel Pad Compressibility and Plantar Pressure Distribution

Loss of heel pad elasticity has been suggested as one of the possible explanations of heel pain. This study aimed to determine the effect of heel pad thickness and its compressibility to heel pressure distribution, in 47 (94 feet) normal subjects and 59 (94 feet) patients with heel pain, using radiological measurements and EMED-SF (Novel, Munich) plantar pressure distribution measurement system. Both heels of the patients and control group were radiographed with and without weight bearing. The ratio of the heel pad thickness in loading to unloading position was defined as “the heel pad compressibility index.” The plantar peak pressure of the heel was measured at heel strike phase of the gait cycle. The compressibility index for control and patient groups were found to be 0.60 and 0.69, respectively. The peak pressure under the heel pad was recorded to be 28.4 N/cm2 for patients and 31.7 N/cm2 for control group. No significant difference was found for heel pad compressibility index and heel pad pressures between patient and control groups (p>0.05). This study revealed that there is no relationship between heel pad compressibility and pressure distribution of the heel pad both in control and patient group. We feel the flexibility of the heel pad does not have any influence on heel pain syndromes.

Clear cell chondrosarcoma of the proximal femur with intrapelvic extension

Clear cell chondrosarcoma is a rare tumor that can be easily confused with benign tumors. The aim of this report is to present a case that is rare, initially diagnosed as aneurysmal bone cyst and then chondroblastoma, and has an interesting extension pattern. A 41-year-old male patient was treated for an apparently benign cystic lesion of the right proximal femur by intralesional excision and bone grafting. The pathological diagnosis was aneurysmal bone cyst. Two years later, the patient presented with a pathological fracture at the same site and a total hip arthroplasty was performed. The pathological specimen was diagnosed as chondroblastoma. Three years later, clinical and radiological examination of the patient revealed a large mass located on the intrapelvic side of the acetabulum. There was no evidence of distant metastases. Both tumors were resected with a wide margin on the femoral side and a marginal margin on the intrapelvic side. The extremity was reconstructed with a resection-type total hip prosthesis. Again, the pathological diagnosis was chondroblastoma. The patient developed a deep infection that was treated by antibiotic therapy and surgical debridement. One year later, there was recurrence of the femoral and intrapelvic masses and right hemipelvectomy was performed; the specimen was reported as clear cell chondrosarcoma. Since then, the patient has been leading an active life, and there is no evidence of local recurrence or distant metastasis. Clinically and pathologically, clear cell chondrosarcoma may be confused with benign bone tumors. This caused a delay in the final diagnosis of this patient and he received inadequate surgical treatment, leading to a hemipelvectomy. We also found that the intrapelvic mass seemed to have developed independently on the intrapelvic side of the acetabulum. We were unable to find an exact explanation for this finding and postulated that tumor cells might have been seeded into the inner wall of the acetabulum during acetabular preparation of the total hip prosthesis.