Biomedical subjects
Publications and source records attributed to Dipak V Patel.
In this review, an in-depth anatomic and molecular pathogenesis of diabetic neuropathy is provided. Classifications and clinical manifestations of diabetic neuropathy are discussed. The current modalities of treatment and clinical research on this disorder are summarized.
Although bone metastasis to the acetabulum can cause significant disability from pain and immobility, little has been written about the diagnosis and management of a pathologic acetabular fracture. We present three patients with metastatic acetabular fractures and discuss an approach to evaluation and management. When a high index of suspicion of fracture exists, further radiographic workup is warranted. Management requires a multidisciplinary approach. Factors such as age, associated comorbidities, natural history of the underlying primary cancer, general health status, prognosis, acetabular fracture characteristics, and quality of bone should be considered. We briefly discuss the options available to nonoperative candidates.
BACKGROUND: Displaced intra-articular calcaneal fractures may have a central cancellous bone defect area. We hypothesized that human demineralized bone matrix (DBM) calcium sulfate (CaSO(4)) might act as a reasonable alternative to autograft in calcaneal fractures. When combined with antibiotic powder, this bone graft substitute also may act as a local antibiotic delivery device. This is the first clinical study evaluating bone healing and complications associated with DBM-calcium sulfate bone graft substitute in the treatment of displaced intra-articular calcaneal fractures with a central cancellous bone defect. METHODS: Over a 29-month period, 33 displaced intra-articular calcaneal fractures with central cancellous defects were treated with open reduction and internal fixation (ORIF) and grafting with vancomycin/DBM-calcium sulfate bone graft substitute. Eleven fractures without bone defects were treated with ORIF only. Patient demographics, medical history, and CT fracture classification were recorded. Postoperatively, fractures were monitored every 2 weeks for healing and complications. RESULTS: The mean time to union was 8.2 weeks in the grafted, while the control group mean time to union was 10.4 weeks (p = 0.0117). Wound problems occurred in five (15%) of the 33 patients with grafting, all in type III fractures with severe soft-tissue swelling, and included two minor wound healing delays, and three serious wound problems. At a mean followup time of 22.4 months, no DBM-calcium sulfate grafted calcaneus demonstrated evidence of osteomyelitis. CONCLUSIONS: This is the first study examining human DBM-calcium sulfate bone graft substitute to treat displaced intra-articular calcaneal fractures. Based on these initial data, human DBM-calcium sulfate acted as an acceptable and safe autograft alternative in displaced intra-articular calcaneal fractures with moderate (5 cc to 10 cc) central cancellous bone defects.
For young people, osteonecrosis of the femoral head (OFH) is one of the most debilitating complications of sickle-cell hemoglobinopathies. Management of advanced (Ficat and Arlet stage III or IV) OFH remains a challenging clinical problem: There is no ideal treatment, and management by total hip arthroplasty has a high failure rate. Consequently, the search continues for procedures that preserve the femoral head--such as vascularized and nonvascularized bone grafting and osteotomy. Various osteotomies have been used to try to salvage hips with stage II or III OFH. The Sugioka transtrochanteric rotational osteotomy is a technically demanding procedure with a variable success rate. Failure rates have also been variable for varus and valgus osteotomies after short-term follow-up. In this report, we present the case of a 13-year-old girl with stage III OFH caused by sickle-cell disease that had been successfully treated with a valgus-flexion osteotomy of the proximal femur, with 42-month postoperative follow-up. We suggest that stage III OFH in a young patient with sickle-cell disease can be successfully treated with corrective proximal femoral osteotomy.
UNLABELLED: Feet are prone to bacterial contamination. We hypothesized that chlorhexidine scrub and isopropyl alcohol paint provide superior local flora reduction than povidone-iodine scrub and paint. Patients with intact, uninfected skin having clean elective foot and ankle surgery were prospectively enrolled and randomly assigned to skin preparation with povidone-iodine (Group 1) or chlorhexidine scrub and isopropyl alcohol paint (Group 2). Culture swabs (aerobic, anaerobic, acid fast, fungus, and routine antibiotic sensitivity) were taken from all web spaces, nail folds, toe surfaces, and proposed surgical incision sites. One-hundred twenty-seven patients were enrolled (mean age, 46 years; range, 16-85 years). Sixty-seven patients were assigned to Group 1; 60 patients were assigned to Group 2. In Group 1, 53 of 67 patients (79%) had positive cultures; in Group 2, 23 of 60 patients (38%) had positive cultures. These data indicate that chlorhexidine and alcohol provide better reduction in bacterial carriage than povidone-iodine. Based on these data, we recommended chlorhexidine as the surgical preparatory agent for the foot and ankle. LEVEL OF EVIDENCE: Therapeutic study, Level I-1a (significant difference). See the Guidelines for Authors for a complete description of levels of evidence.
Gorham's disease is a rare disorder characterized by proliferation of vascular channels that results in destruction and resorption of osseous matrix. Since the initial description of the disease by Gorham and colleagues (1954) and by Gorham and Stout (1955), fifty years have elapsed but still the precise etiology of Gorham's disease remains poorly understood and largely unknown. There is no evidence of a malignant, neuropathic, or infectious component involved in the causation of this disorder. The mechanism of bone resorption is unclear. The clinical presentation of Gorham's disease is variable and depends on the site of involvement. It often takes many months or years before the offending lesion is correctly diagnosed. A high index of clinical suspicion is needed to arrive at an early, accurate diagnosis. Patients with Gorham's disease may complain of dull aching pain or insidious onset of progressive weakness. In some cases, pathologic fracture often leads to its discovery. Gorham's disease is progressive in most patients; however, in some cases, the disease process is self-limiting. The clinical course is generally protracted but rarely fatal, with eventual stabilization of the affected bone being the most common sequelae. Chylous pericardial and pleural effusions may occur due to mediastinal extension of the disease process from the involved vertebra, scapula, rib or sternum, and can be life threatening. A high morbidity and mortality is seen in patients with spinal and/or visceral involvement. The medical treatment for Gorham's disease includes radiation therapy, anti-osteoclastic medications (bisphosphonates), and alpha-2b interferon. Surgical treatment options include resection of the lesion and reconstruction using bone grafts and/or prostheses. In most cases, bone grafts tend to undergo resorption and are not helpful. Surgical reconstruction and/or radiation therapy are used for management of patients who have large, symptomatic lesions with long-standing, disabling functional instability. Surgical stabilization may be required for unstable spinal lesions. Various treatment options, including pleurectomy, pleurodesis, thoracic duct ligation, radiation therapy, interferon therapy, and bleomycin, have been used for management of patients with Gorham's disease presenting with chylothorax. In general, no single treatment modality has proven effective in arresting the disease.
Ankle injuries are common in the general and athletic populations. These injuries constitute 21% of all sports-related injuries. The wide spectrum of sports-related ankle injuries includes ligamentous injuries, soft-tissue and osseous impingement, osteochondral lesions of the talus, tendon injuries, and fractures. Occult lesions (eg, fractures of the lateral process of the talus, fractures of the anterior process of the calcaneus, fractures of the base of the fifth metatarsal, os trigonum, stress fractures) may be missed on initial physical examination, and patients with such injuries often present to a sports clinic with persistent pain around the ankle. Because of increasing participation in sporting events, health care professionals involved in the care of athletes at all levels must have a thorough understanding of the anatomy, pathophysiology, and initial management of ankle injuries. In this review, we describe the pertinent anatomy, pathology, diagnosis, and treatment of sports-related injuries of the ankle.
The records of 47 consecutive patients with metastatic pathologic fractures of the lower extremity were analyzed with respect to thromboembolic complications. All patients were unable to receive pharmacologic deep venous thrombosis prophylaxis, and were stratified into two groups, based on use of an inferior vena cava filter. Group I (n = 24) consisted of patients who had an inferior vena cava filter plus mechanical deep venous thrombosis prophylaxis (compression stockings and sequential compression boots); Group II (n = 23) consisted of a group of patients receiving only mechanical deep venous thrombosis prophylaxis. All patients had routine lower extremity venous duplex imaging preoperatively, postoperatively, and before hospital discharge. At final followup, patients were examined for deep venous thrombosis and reviewed for thromboembolic events. At a mean followup of 11.5 months, Group I had two detectable deep venous thromboses and no pulmonary emboli; Group II had one detectable deep venous thrombosis and five pulmonary embolisms. In Group II, 40% (two of five) of pulmonary embolisms were fatal, yielding an 8.7% (two of 23) group mortality rate. Overall, the entire group had an approximately 17% deep venous thrombosis rate. Only 6.4% (three of 47) of deep venous thromboses were detectable by standard duplex imaging. The majority of deep venous thromboses (five of eight, 62.5%) were nondetectable by duplex imaging. Overall, a 4.3% (two of 47) death rate was attributable to pulmonary embolism. In contrast, an 8.6% (four of 47) mortality rate occurred in Group II alone. All pulmonary embolisms occurred in patients who did not receive an inferior vena cava filter. The majority of venous thromboses (62.5%) were not detectable on duplex scanning, therefore were thought to arise from the pelvic venous system. Complications related to inferior vena cava filter insertion were minimal. For patients with metastatic pathologic fractures of the lower extremities who are unable to receive pharmacologic deep venous thrombosis prophylaxis, the use of inferior vena cava filters, in conjunction with standard mechanical deep venous thrombosis prophylaxis, is a procedure that has a low risk and is useful adjunct to prevent fatal pulmonary embolisms.
The accessory extensor tendon of the first metatarsophalangeal joint (1st MTPJ) was evaluated in 32 cadaver feet. Eighty-one percent of feet possessed an accessory tendon to the 1st MTPJ. Of those feet possessing an accessory tendon to the 1st MTPJ, approximately 92% originated from the extensor hallucis longus muscle-tendon unit, while approximately 8% originated from the tibialis anterior muscle-tendon unit. All accessory tendons inserted onto the dorsal/dorsomedial capsule of the 1st MTPJ. Accessory tendons were found to be bilateral in the majority (87.5%) of specimens. Differences in sex distribution of the accessory tendon of the 1st MTPJ were not statistically significant. The difference in distribution of an accessory tendon to the 1st MTPJ in those feet that demonstrated clinical hallux valgus versus those that did not demonstrate hallux valgus was not statistically significant (p = 1.0000, respectively, Fisher's exact test). This tendon is unique to the human foot (lacking in primates) and is a fairly constant structure (80%). The data presented do not lend support for the accessory tendon of the 1st MTPJ to play a role in the development of hallux valgus. At the present time, the role of this accessory tendon on the biomechanics of the 1st MTPJ remains unknown.
BACKGROUND: Appropriate suture selection is necessary in providing mechanical stability to soft tissue reconstructions. Caprolactone/glycolide (Panacryltrade mark) became a popular suture, possessing excellent handling properties; however, clinical observations questioned the knot security of caprolactone/glycolide. Caprolactone/glycolide is still available on many commercial suture anchor systems. This study compared the security of the knots and ultimate tensile strength of braided caprolactone/glycolide suture to that of a commonly used suture material, braided polyester (Ethibondtrade mark). MATERIALS: Suture knots of No. 2 braided polyester suture and No. 2 braided caprolactone/glycolide suture were submersed in a physiologic saline solution and stressed using a continuous (non-cyclic) load, simulating a single maximal loading event in a clinical setting. Continuous loading was done to achieve clinical suture knot failure (3-mm knot slippage), then continued until catastrophic suture failure (suture breakage) occurred. Ten trials of each suture were tested. RESULTS: Force required to cause knot slippage of 3 mm was greater for braided polyester than for braided caprolactone/glycolide (p <. 0001, unpaired Students' t-test). Forces resulting in catastrophic failure were greater for braided polyester than braided caprolactone/glycolide (p = .0284, unpaired Students' t-test). CONCLUSIONS: These data have important implications in the selection of suture materials for repair of soft tissue injuries. In the clinical setting, a single maximal loading event may result in suture failure. These data indicate that braided polyester possesses superior in-vitro mechanical properties and suggest that braided polyester may provide greater security in-vivo than braided caprolactone/glycolide suture.
Repeat episodes of musculoskeletal infarction coupled with immunosuppression predispose sickle cell patients to infectious complications throughout their lives. Osteomyelitis is a familiar complication of sickle cell disease, and it may result in significant morbidity, especially when occurring in multiple sites. Staphylococcus and Salmonella remain the most common causes of osteomyelitis in sickle cell patients. Vancomycin-resistant enterococcus (VRE) infections have been reported mainly in connection with bacteremias and infections outside of the musculoskeletal system. To our knowledge, only a few cases of VRE long bone osteomyelitis have been reported in the literature. A few antimicrobial agents are available to treat VRE infections. The occurrence of VRE osteomyelitis is a major clinical concern, especially in an immunocompromised host, such as a sickle cell patient. We present a case of multiple long bone vancomycin-resistant Enterococcus faecium (mixed organisms) osteomyelitis in a sickle cell patient, and we report on a new method of using quinupristin-dalfopristin as part of the management plan to treat a complicated VRE infection successfully. We discuss the mechanism of action of anti-VRE drugs and the future direction to combat VRE in orthopedic infections.
The skeletally immature athlete poses unique problems in diagnosis and treatment of injuries to the extensor mechanism of the knee. An accurate and detailed history and physical examination of the knee are essential for making a specific diagnosis and formulating an appropriate treatment plan. This article presents an overview of acute and chronic injuries of the extensor mechanism of the knee that are unique to skeletally immature athletes. The subjects of femoral trochlear dysplasia and medial subluxation of the patella are briefly discussed. The etiopathology, clinical evaluation, and management (non-operative and operative) of sleeve fractures of the patella and avulsion fractures of the tibial tubercle in children and adolescents are discussed. The pathoanatomy, clinical features, and management of synovial plica syndrome, Hoffa's syndrome, Osgood-Schlatter disease, and Sinding-Larsen-Johansson disease are presented.