Biomedical subjects

M I Boyer

Publications and source records attributed to M I Boyer.

At least 19 recordsLinked to original sources

PubMed1999

Complications of the operative treatment of Dupuytren's disease.

Complications of surgery for Dupuytren's disease occur intra-operatively as well as during the early and late postoperative periods. Digital nerve injury, vascular injury, skin flap "button holes," hematoma, swelling, infection, flare, wound dehiscence, recurrence, pseudoaneurysm, and inclusion cysts are discussed and their treatment reviewed. Recognition of the complication is necessary for motion therapy to proceed in a timely fashion in order to avoid postoperative digital stiffness.

Dupuytren Contracture↗

PubMed1998

An ultrastructural study of the intimal hyperplasia in healing microarterial anastomoses.

The purpose of the study was to investigate the ultrastructure of intimal hyperplastic cells. End-to-end microarterial anastomoses were studied in a rabbit free-tissue-transfer model. There were five experimental groups, with 1, 3, 7, 14, or 28 days follow-up. At sacrifice the anastomoses were tested for patency and then examined by light and electron microscopy. At days 1 and 3 the repaired intima was covered with macrophages and extravasated erythrocytes. At day 7 spindle-shaped fibroblasts with copious rough endoplasmic reticulum were seen. Some of these cells also contained pinocytotic vesicles, filaments with focal densities, and subplasmalemmal attachment sites, the features of smooth muscle cells. At day 14, more cells contained smooth muscle features and these features were also more pronounced. These young myofibroblasts were plumper than adjacent fibroblasts. At day 28 mature myofibroblasts with a full complement of organelles were present. The results, therefore, supported the hypothesis that myofibroblasts are present in the intimal hyperplasia of healing microarterial anastomoses.

Anastomosis, Surgical↗

PubMed1998

Scaphoid nonunion with avascular necrosis of the proximal pole. Treatment with a vascularized bone graft from the dorsum of the distal radius.

Scaphoid nonunion with avascular necrosis of the proximal pole remains a difficult problem. We have endeavoured to heal the fracture, restore scaphoid height and revascularize the proximal pole of the scaphoid by means of a vascularized dorsal interposition graft from the distal radius. The procedure has resulted in union of six of ten fractures. Fractures that healed had not been treated by a previous bone grafting procedure. Dissatisfaction was due to loss of motion in patients who had healed fractures, and pain in those patients with persistent non-unions.

Adolescent↗

PubMed1998

Flexor digitorum profundus tendon-to-bone repair: an ex vivo biomechanical analysis of 3 pullout suture techniques.

Avulsions or distal transsections of the flexor digitorum profundus tendon are typically repaired by direct suture of tendon to the distal phalanx. The tensile properties of tendon-tobone repairs performed in cadaver fingers using 3 common suture patterns, the Bunnell, the Kessler, and the Kleinert techniques, were compared; 3-0 Prolene (monofilament) suture was used. Repairs done using the Kessler pattern had an average yield force of 30 N, compared to 39 N for the Bunnell and Kleinert patterns. Although these average yield forces were greater than that required for active digital flexion, considerable elongation (average, 8 mm) was measured at a force of 20 N. Data indicated that the safety factor achieved with these repair methods is lower than that achieved with modern tendon-to-tendon repair methods. The authors conclude that the common tendon-to-bone repair techniques are insufficient to withstand the higher forces associated with controlled passive and active motion rehabilitation methods that are currently advocated.

Aged↗

PubMed1998

The effects of multiple-strand suture techniques on the tensile properties of repair of the flexor digitorum profundus tendon to bone.

We examined the effects of multiple-strand suture techniques on the tensile properties of flexor digitorum profundus tendon-to-bone repairs in a human cadaver finger model. Forty-four fingers were obtained from the cadavera of fifteen donors who had been an average of seventy-four years old (range, fifty-four to eighty-nine years old) at the time of death. Four or eight-strand proximal grasping sutures were secured to the distal phalanx of each finger with use of either a suture anchor or a dorsally placed button. There were four subgroups of eleven fingers each. We found that repairs performed with use of a dorsally placed button had greater yield force, ultimate force, and rigidity than those performed with use of an anchor and that repairs performed with eight strands had greater ultimate force than those performed with four strands. These differences were significant (p < 0.05). We could detect no differences among the four types of repairs with regard to the amount of relative tendon-bone elongation at twenty newtons of force. The repairs performed with eight strands and a dorsally placed button had an average yield force (and 95 per cent confidence interval) of 50.0 +/- 14.1 newtons, an average ultimate force of 68.5 +/- 14.6 newtons, an average rigidity of 744 +/- 327 newton/(millimeter/millimeter), and an average tendon-bone elongation of 3.4 +/- 0.7 millimeters at twenty newtons of force. Multiple-comparison testing showed that the eight-strand repairs performed with a dorsally placed button had greater ultimate force than the other three types of repairs as well as greater yield force and rigidity than the four and eight-strand repairs performed with a suture anchor.

Aged↗

PubMed1998

Microvascular surgery in the reconstruction of congenital hand anomalies.

Several congenital upper extremity anomalies may be treated using micro-surgical techniques. Long-term studies have shown the usefulness of microvascular toe transfer in the treatment of adactyly with the incorporation of the transferred digit into grasp-and-pinch function. The use of free fibular transfer for long bone deformities of the forearm has been shown to provide bony union as well as growth. Factors that must be considered include patient age, vessel availability, and lack of other possible reconstructive options.

Adolescent↗

PubMed1997

Atrophic nonunion of the clavicle: treatment by compression plate, lag-screw fixation and bone graft.

We describe a new surgical treatment of atrophic nonunion of the clavicle. The nonunion is excised by cuts at 45 degrees to the long axis and repair uses 3.5 mm pelvic reconstruction or dynamic compression plates, with a lag screw to provide interfragmentary compression. The site is grafted with cancellous bone. We have been successful in all seven patients, with early return to normal function. The consequent narrowing of the shoulder girdle is fully acceptable for appearance and function.

Adolescent↗

PubMed1997

Complex injuries of the forearm. Coverage considerations.

Complex forearm injuries involve damage to the skin and underlying tissues. The best results are obtained when a multidisciplinary approach is taken to their management. Management of the acute injury should be done in a manner that takes into consideration late reconstructive procedures and best possible final function outcome. This article reviews initial management and options for soft-tissue coverage. Advantages and disadvantages of a wide variety of procedures are discussed and in addition the authors review some of the more controversial areas and give personal preferences.

Debridement↗

PubMed1996

Small versus large diameter closed-section femoral nails for the treatment of femoral shaft fractures: is there a difference?

UNLABELLED: A retrospective series of 99 femoral shaft fractures treated by small diameter (10 and 11 mm) and large diameter (> 11 mm) closed section femoral nails from November 1989 to September 1993 was analyzed. No significant differences in the parameters of bony union and time to full weight bearing were seen between the two groups nor were there significant differences between the rate of secondary procedures. There were no broken nails in either group and there was no difference in the overall respiratory complication rate. CONCLUSION: No statistically significant differences existed between the small and large diameter groups except for the mean age and mean follow-up period. Small diameter nails can be used safely without the risk of nail breakage.

Adult↗

PubMed1995

Restriction fragment-length polymorphism analysis of the major histocompatibility complex in New Zealand white rabbits.

As a model system, rabbits are particularly useful in transplantation studies because of their size and accessibility. However, inbred rabbits of known MHC haplotype are not commercially available, and there are few monoclonal antibody reagents available to permit serological typing of experimental animals prior to transplant. Here we present a rapid and reliable method to distinguish rabbits that differ at their MHC class I and class II loci, and present 34 class I and 16 class II haplotypes determined by restriction fragment-length polymorphism analysis of outbred heterozygous rabbits. The applicability of this molecular typing system to transplantation experiments in the New Zealand White rabbit is discussed.

Animals↗

PubMed1995

Can quantitative 99mTc-MDP bone scans be used to predict longitudinal growth of epiphyseal plate allografts after microvascular transplantation? An experimental study.

Allograft and autograft microvascular proximal tibial epiphyseal plate transplants were performed in female New Zealand White (NZW) rabbits to quantify the growth rate and total growth potential of immunosuppressed and nonimmunosuppressed rabbits. The purpose of this experiment is to examine whether the 99mTc-MDP radionuclide uptake of the transplanted epiphyseal plate at 1 week postoperatively, done to assess anastomotic patency of the transplant, could also serve as a predictor of eventual longitudinal growth of the transplant or replant. All transplants and replants demonstrating positive 99mTc-MDP uptake in the proximal tibial epiphyseal plate at 1 week showed continued longitudinal growth. The precise amount of 99mTc-MDP uptake, however, did not correlate with the amount of growth at 3 and 5 weeks follow-up.

Animals↗

PubMed1995

Wrist arthrodesis using a dynamic compression plate.

We performed 45 wrist arthrodeses in 43 patients by a modification of the AO technique using the dynamic compression plate. Radiological follow-up was obtained in 41 wrists; all had united at a mean of ten weeks. Clinical follow-up was obtained in 32 wrists. Subjectively, the surgical outcome was satisfactory in 26, marginally satisfactory in two and unsatisfactory in four. This method is safe and reliable. The plate can be contoured to allow a variety of positions of fusion, and gives rigid immobilisation. The rate of union is higher than that for other techniques.

Adult↗

PubMed1995

Microvascular transplantation of physeal allografts.

We compared growth in vascularised allograft transplants, autografts and in non-operated physes in rabbits immunosuppressed with cyclosporin A and in non-immunosuppressed animals. Molecular haplotyping was undertaken before operation to ensure allogenicity. Postoperative bone scans and fluorochrome labelling were used to confirm physeal vascularity. The animals were killed at three or five weeks. Proximal tibial physeal autografts, with or without cyclosporin A, or allografts with cyclosporin A, grew at similar rates to the physes of non-operated rabbits. All the operated physes grew at rates significantly greater than their contralateral controls. 99mTc-MDP bone scans accurately predicted the viability of the epiphyseal plate. Quantitative histomorphological analysis of the heights of the physeal proliferative and hypertrophic zones showed that successful physeal transplants have a normal appearance, but when unsuccessful have thickened hypertrophic zones compatible with physeal ischaemia. We discuss the significance of these results in relation to the transplantation of physes in children.

Analysis of Variance↗

PubMed1995

Tarsal tunnel syndrome: an unusual case resulting from an intraneural degenerative cyst.

Multiple local and systemic entities have been implicated as causes of tarsal tunnel syndrome. In this report, a 31-year-old man presented with medial plantar nerve compression caused by an intraneural degenerative cyst of the posterior tibial nerve. Removal of the cyst and decompression of the nerve relieved his symptoms. This is the first time that such an entity has been reported as a cause of tarsal tunnel syndrome.

Adult↗

PubMed1995

Ruptured deep femoral artery aneurysm simulating a soft-tissue sarcoma: a case report.

False aneurysms of the deep femoral artery are uncommon. The presentation in the 80-year-old woman described in this case report was unique in that the pseudoaneurysm was subacute; after an initial hemorrhage, compression of the pseudoaneurysm by the deep femoral artery resulted in a large hematoma suggestive of a soft-tissue sarcoma. The recommended management was angiography, computed tomography and magnetic resonance imaging to differentiate between a false aneurysm and a tumour followed by treatment for the vascular lesion. Such an approach will prevent tumour spread and uncontrollable hemorrhage.

Aged↗

PubMed1994

Short-term response of epiphyseal plate cell populations following selective devascularization and microsurgical revascularization.

The distal femoral epiphyseal plates of 21 8-week-old New Zealand white rabbits were totally or partially (nutrient artery only) devascularized, or devascularized and then microsurgically revascularized. Sacrifice was at 24, 48 or 72 hours postoperatively. The heights of the proliferative and hypertrophic zones of the epiphyseal plates operated upon were compared with the contralateral control epiphyseal plates for both the central and the peripheral regions of the epiphyseal plate. Neither extent of devascularization nor revascularization had a significant effect on the height of the proliferative zone of chondrocytes at any of the follow-up intervals. Selective devascularization of the nutrient artery led to a significant increase in height of the central region of the hypertrophic zone of chondrocytes at 48 and 72 hours. Microsurgical revascularization did not lead to a significant change in the height of either the central or the peripheral regions of the hypertrophic zone of chondrocytes at any of the follow-up intervals. This study is another 'building block' experiment toward vascularized epiphyseal plate transplantation in humans.

Animals↗

PubMed1994

Epiphyseal plate transplantation: an historical review.

Non-vascularized and vascularized transplantation of epiphyseal plate autografts have been performed both clinically and experimentally for over 100 years. However, the ultimate clinical goal of vascularized transplantation of epiphyseal plate allografts for paediatric extremity reconstruction remains elusive, due primarily to the lack of suitably nontoxic techniques to prevent graft rejection. We have summarized the published clinical and experimental investigations of vascularized epiphyseal plate transplantation, and organized the experiments and clinical operations into four main groups: (1) local vascular studies on unmanipulated epiphyseal plates, (2) studies of epiphyseal plate behaviour after orthotopic replantation, (3) studies of epiphyseal plate behaviour after heterotopic transplantation, and (4) studies of epiphyseal plate behaviour after allograft transplantation. Prior investigations into the non-vascularized transplantation of epiphyseal plate autografts and allografts are presented as background. These groups of studies serve as the building blocks for the more clinically applicable experimental investigations outlined in the final section of this review.

Animals↗

PubMed1994

Reconstruction of a severe grinding injury to the medial malleolus and the deltoid ligament of the ankle using a free plantaris tendon graft and vascularized gracilis free muscle transfer: case report.

Whether or not to reconstruct deltoid ligament injuries of the ankle remains controversial. We present a case of deltoid ligament loss and an extensive overlying soft tissue defect from a grinding injury. The resultant gross medial ankle instability and soft tissue defect necessitated deltoid ligament reconstruction using a free plantaris tendon graft and soft tissue coverage using a free muscle transfer.

Adolescent↗