Search PubMed⌕ Search

Biomedical subjects

L S Levin

Publications and source records attributed to L S Levin.

At least 55 records · Page 3Linked to original sources

Treatment of segmental defects of the radius with use of the vascularized osteoseptocutaneous fibular autogenous graft.

Nine patients who had a complex, combined skeletal and soft-tissue defect involving the radius were managed with operative reconstruction with use of a vascularized osteoseptocutaneous fibular autogenous graft. All of the patients were male, and the average age was thirty-two years (range, twenty-one to forty-two years). Three patients sustained the injury as the result of a gunshot wound and two each, as the result of a motor-vehicle accident, a fall from a height, or a machinery-related accident. Five patients had a concomitant fracture of the ulna. The average length of the radial defect was seven centimeters. Six patients had a deep osseous infection. The average length of the fibular autogenous graft was 7.9 centimeters, and the average size of the associated fasciocutaneous component was 11.8 by 5.9 centimeters. Two patients had a concomitant arthrodesis of the wrist. A split-thickness skin graft was used to close the donor site in six patients. Two patients had postoperative vascular complications that necessitated revision with an autogenous vein graft. One patient had a second operation six months postoperatively to correct an angular deformity that had developed secondary to a non-union at the graft-host bone junction. After an average duration of follow-up of twenty-four months, all but one of the patients had radiographic evidence of osseous union at both the proximal and the distal graft-host bone junction. No patient had evidence of resorption of the graft or symptoms referable to the donor leg at the time of the most recent examination. Six patients had returned to their preinjury occupation.

Adult↗

Free composite serratus anterior and rib flaps for tibial composite bone and soft-tissue defect.

Open fracture in the lower extremity often involves composite bone and soft-tissue defects. For patients with extensive segmental bone defects, vascularized fibular transfers can be utilized and are generally accepted as one of the best options for reconstruction of intercalary defects. In some cases, either bilateral tibias and fibulas are fractured or the contralateral fibula is traumatically damaged or absent, precluding free fibular transfer. If an osteocutaneous fibular flap cannot be used to manage such a defect, a composite serratus anterior and rib flap may be considered. Nine composite serratus anterior and rib flaps, with or without latissimus dorsi transfers, were performed in eight patients between August of 1993 and March of 1994. One patient sustained a left knee disarticulation and underwent reconstruction for a right tibial defect. He failed to achieve lower extremity function within 2 years and was considered a failure. One flap failed, and the patient underwent a below-knee amputation. The remaining six patients received seven composite flaps for tibial and calcaneal defects and could ambulate without assistance. Based on this review, we conclude that the composite serratus anterior and rib flap with optional latissimus dorsi muscle can be used for (1) bilateral tibial fibular fractures, (2) contralateral lower limb amputation with fillet of the amputated leg if the leg is present for harvest, (3) contralateral middle-third fracture of the fibula, (4) patients in whom iliac bone is not suitable because of either a bone defect greater than 10 to 12 cm or previous harvest of bone graft, and (5) extensive composite bone and soft-tissue defects.

Adolescent↗

Free flap expansion using balloon-assisted endoscopic technique.

Pre-expansion of free flaps augments flap size dimensions and provides delay of tissue by opening "choke" vessels, thus augmenting the territories of adjacent angiosomes. Pre-expansion of free tissue transfers has been used for reconstruction of large soft tissue defects. A secondary benefit is that the donor site, traditionally treated by skin graft, can be closed primarily. Using conventional techniques for free flap pre-expansion, blunt dissection may risk injury to the pedicle. Using balloon dissectors a large optical cavity can be created quickly through an avascular fascial cleft. This allows endoscopic exploration of the optical cavity and confirmation of placement of the tissue expander. In addition, balloon-assisted endoscopic tissue expander placement optimizes the hysteresis effect of skin stretching and offers the possibility of immediate fluid inflation, which ultimately shortens the time for free flap expansion prior to microsurgical transfer.

Adult↗

A new approach to the closure of cloacal exstrophy.

Cloacal exstrophy patients are often difficult to reconstruct. Urinary continence is usually achievable only with a catheterizable stoma of some type. Since cloacal exstrophy is usually associated with omphalocele or gastroschisis, one-stage closure of the abdominal wall defect is frequently impossible. We prefer to incorporate the exstrophic large bowel, which separates the hemibladders, into the closed bladder as a sort of "natural" augmentation to maximize its volume for use as a continent reservoir. If a silastic "silo" or synthetic mesh is required to close the abdominal wall, excessive scarring occurs and later creation of a continent stoma is usually difficult and time-consuming. In all but those with the smallest abdominal wall defects we recommend that the omphalocele and upper abdominal wall be repaired first, replacing the evicted gut into the peritoneal cavity. During nutritional stabilization a tissue expander is placed under the superficial musculature of the chest wall. The flap is enlarged by gradual inflation of the tissue expander until it fills the abdominal wall defect left by subsequent closure of the cloacal exstrophy. The flap is then rotated inferiorly with blood supply intact at the time of bladder closure to make good the remaining abdominal wall defect. This flap improves the appearance of the abdominal wall and reduces scarring. Thus, this approach has the possibility of making subsequent operations to provide continence shorter, simpler, and more successful in most infants with cloacal exstrophy.

Abdomen↗

Long-term follow-up of 50 Duke silicone prosthetic fingers.

Thirty-three patients with single and multiple digital amputations were fitted with a total of 50 prosthetic silicone fingers over a mean period of 4 years. The prosthetic fingers were custom made using a special method which has been modified at our institution. This study provides a detailed analysis of patients' occupational and cosmetic usage of and satisfaction with their prostheses, as well as describing the fabrication technique.

Adult↗

A comparative mechanical analysis of plate fixation in a proximal phalangeal fracture model.

A biomechanical study compared the mechanical properties of hand and craniofacial plating systems commonly used in proximal phalangeal fractures. Two plates of each of the various systems were mounted dorsally on a yellow-birch-dowel model of a proximal phalanx after a transverse cut was made in the middle of the section of the dowel, modeling a midshaft transverse osteotomy or fracture. Torsional rigidity, as well as four-point bending rigidity in apex dorsal, lateral and volar directions, was achieved. Failure testing in apex palmar four-point bending was then examined. Between plating systems, torsion varied 1,600% and results of apex palmar testing varied 1,500%. Apex palmar moment-to-failure testing varied 1,000% and represented a 3.5%-38% range of intact proximal phalangeal strength. This also represented 12%-128% of the maximum calculated in vivo bending moments of the proximal phalanx. The wide variation in plate strengths and stiffness raises questions as to the suitability of certain plating systems with regard to early mobilization. Moreover, some plating systems tested were mechanically weaker than the reported strengths of certain Kirschner wire fixation techniques.

Biomechanical Phenomena↗

Periprosthetic infections due to Mycobacterium tuberculosis in patients with no prior history of tuberculosis.

Although uncommon, infection of prostheses with Mycobacterium tuberculosis can be managed successfully if it is diagnosed early and treated correctly. A case of M. tuberculosis infection of a prosthetic knee first diagnosed 4.5 years after initial arthroplasty is described. This case and a review of the literature led to the conclusion that there are two distinct patterns of M. tuberculosis infection following joint implant surgery in patients without a history of tuberculosis. (1) Mycobacterium tuberculosis infection may be an unexpected finding at the time of arthroplasty. These patients generally have favorable outcomes using standard antituberculous chemotherapy, without implant removal. (2) Late-onset M. tuberculosis joint infection may be identified in patients with painful, clinically infected, or malfunctioning prostheses. In these cases, medical treatment alone is usually unsuccessful; prosthesis removal is often required. With recent increases in the incidence of tuberculosis in the United States and the emergence of multidrug-resistant strains of M. tuberculosis, periprosthetic tuberculous infection is likely to become more common.

Aged↗

Microsurgical composite tissue transplantation at difficult recipient sites facilitated by preliminary installation of vein grafts as arteriovenous loops.

In microvascular surgery when local recipient vessels are inadequate, vein grafting is required. There are several potential inherent disadvantages of immediate vein grafting, including the development of graft thrombosis or leakage, an increased opportunity for technical errors, and an increased number of anastomoses in series. All of these may contribute to a higher failure rate for composite-tissue transplantation requiring vein grafts. The authors hypothesized that in cases where vein grafting is obviously required, the creation of a temporary, looped, arteriovenous fistula (AVF) would reduce the morbidity of vein grafting, by allowing the detection of thrombosis or technical errors predisposing to thrombosis prior to free-tissue transplantation. Since delaying the division of an AVF for 5 or more days may allow time for healing of the endothelium at the AVF anastomotic site, the hypothesis was that composite-tissue transplantation whose vein grafts were installed as an AVF divided in a delayed manner, might have better patency than those in which vein grafts were installed at the time of reconstruction. This study reviews the results of 16 patients (8 females, 8 males) who underwent 17 microvascular reconstructions using AVFs. Patient courses and outcomes were compared between those undergoing immediate (8 patients) and delayed (7 patients) AVF construction, division, and free-tissue transplantation. There was a low patency rate for AVFs which were divided in a delayed fashion (2 of 7 patients, 29 percent), compared with those which were immediately divided (10 of 10, 100 percent). These results suggest that, in spite of a strong theoretical basis for delayed division of the AVF, delayed harvesting of the AVF is empirically associated with a higher thrombosis rate (p = 0.0048, Fishers exact test).

Adolescent↗

The histological effect of barrier vein wrapping of peripheral nerves.

Twenty-four Sprague-Dawley rats underwent exploration and exposure of the sciatic nerve, followed by sham isolation, irrigation, and subsequent wound closure (Group 1); barrier vein wrapping of the nerve using glutaraldehyde-preserved allograft inferior vena cava (Group 2); or barrier vein wrapping of the nerve with femoral vein autograft from the contralateral extremity (Group 3). Four months later, the rats were sacrificed and the nerves fixed in situ in buffered glutaraldehyde. Sections proximal, mid-portion, and distal to the barrier and vein wrap were fixed with osmium tetroxide, epon embedded, stained with toluidine blue, and studied under x200 and x400 light microscopy. Epineural scar formation increased 10 times in Group 2, compared to Group 3 (p < 0.0001). Epineural thickness and the number of degenerating axons did not differ significantly among all groups. Inflammatory cells in Group 2 increased 100 times, compared to Group 3 (p < 0.0001). Continuing with the underlying epineural layer was apparent grossly and microscopically with all allografts, but with no autografts. Thus, glutaraldehyde-preserved allograft vein wraps appear to incite a marked inflammatory response, with epineural scarring and adherence to the underlying nerve, while autograft vein wraps do not.

Animals↗

Combined injuries--soft tissue management.

The combination of severe bone and soft tissue injuries challenges all hand surgeons. Immediate restoration of all damaged structures is the goal whenever possible, integrating soft tissue techniques with principles of internal fixation. Debridement must be radical and resulting defects in bone, vessel, nerve, tendon and skin must be reconstituted with the combination of free and vascularized grafts. Rigid internal fixation is mandatory to allow functional restoration of the hand to begin with a stable platform against which motor tendon units and gliding structures to move. The timing of subsequent reconstruction is based on the prerequisites of adequate vascularity and soft tissue coverage. Understanding the reconstructive ladder and the nuances of techniques regarding skin grafting, local and distant flaps and microsurgical reconstruction is necessary to complete reconstruction in a timely and appropriate fashion. Various soft tissue techniques are described; from simple skin grafting to the use of toe to hand transfers. The decision to amputate versus reconstruct is also important, particularly in today's cost conscious health care environment. Finally, a well thought out and directed rehabilitation program will allow patients to ultimately return to functional status after mutilating injuries of the hand. This article provides a comprehensive review of the combined injury.

Adult↗

Suprascapular neuropathy after distal clavicle excision.

Two cases of suprascapular neuropathy after excision of the distal clavicle are reported. Both patients were treated successfully with neurolysis of the suprascapular nerve starting at the upper trunk of the brachial plexus. Anatomic dissections revealed that the suprascapular nerve is quite close (<1.4 cm) to the posterior aspect of the distal clavicle, within 2 to 3 cm of the acromioclavicular joint. To avoid the complication of suprascapular neuropathy that could be associated with this close relationship, it is recommended that no more than 1 cm of the distal clavicle be removed posteriorly. It is also recommended that minimal periosteal elevation should be performed on the posteroinferior border of the distal clavicle.

Adult↗

Use of the expanded thoracoepigastric myocutaneous flap in the closure of cloacal exstrophy.

We describe the first reported use of an expanded thoracoepigastric myocutaneous flap in the closure of cloacal exstrophy. This approach offers several distinct advantages. The expander increases the available cutaneous surface area of the thoracoepigastric region, improves vascularity, induces a fibrous capsule that augments the abdominal wall, permits primary closure, and avoids prosthetic adjuncts that increase scarring and hinder delayed urinary tract reconstruction. Osteotomy and spica casting may be obviated by using this flap, but mesh may be required eventually. We anticipate its use in all future cases in which the abdomen cannot be closed safely at the primary procedure at this institution. This technique also should be considered for classic bladder exstrophy or any other large congenital or acquired defect of the lower abdomen.

Abdominal Muscles↗

Sternal plating for the treatment of sternal nonunion.

BACKGROUND: Sternal nonunion, defined as sternal pain with clicking, instability, or both for more than 6 months in the absence of infection, is an uncommon complication of median sternotomy. Nonunion is frequently complicated by the presence of multiple transverse fractures, which make simple rewiring inadequate. METHODS: Six patients with debilitating pain secondary to sternal nonunion were treated with the technique of sternal plating between 1989 and 1995. RESULTS: Sternal plating corrected sternal instability and provided excellent pain relief in all 6 patients. All patients reported an improved quality of life and were able to resume recreational activities. Two patients have had plate removal for late bursa formation. Sternal healing was complete in both instances. CONCLUSIONS: Sternal plating, which is based on the tension-band principle, is an effective treatment of sternal nonunion. The technique is applicable to both simple and complex nonunions. The stainless steel plates resist bending stresses, and the cortical bone resists compressive forces. The technique requires minimal dissection of the posterior sternal border, is not circumferential, and provides secure sternal approximation.

Aged↗

Compartment syndrome of the hand. Etiology, diagnosis, and treatment.

Isolated acute compartment syndrome of the hand is relatively rare phenomenon, Acute compartment syndrome occurs when the tissue pressure within an enclosed space is elevated to the extent that there is decreased blood flow within the space, decreasing tissue oxygenation and impairing metabolic function. In this review, compartment syndrome of the forearm and wrist involving the hand will not be included because the clinical presentation of these patients can be quite different compared with compartment syndrome within the hand.

Compartment Syndromes↗

Restoration of sensation in paraplegia by a sensory innervated plantar fillet free flap. Case report.

Sensory denervation most likely is the key factor to the multiple physiological derangements that predispose paraplegic patients to recurrent decubitus ulceration. A sensory innervated plantar free flap offers the ability to provide soft tissue coverage and to regain sensory innervation of the ulcer prone area in patients with recurrent ulceration. We present a patient in which an innervated plantar free flap was used to restore sensation to the sacral area in a patient with recurrent ulceration.

Humans↗