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Biomedical subjects

R S Adelaar

Publications and source records attributed to R S Adelaar.

16 recordsLinked to original sources
PubMed1991

Effect of isolated talocalcaneal fusion on contact in the ankle and talonavicular joints.

A cadaveric model was developed to establish the articular contact area and load distribution in the ankle joint, posterior facet of the talocalcaneal joint, and talonavicular joint using pressure sensitive film. Positions of dorsiflexion, neutral, and plantarflexion were evaluated. This model was further used to determine the effect of talocalcaneal fusion on the articular contact area in the talonavicular and ankle joints. Alteration of articular contact was most pronounced in the talonavicular joint. There, a statistically significant reduction in contact area postfusion was noted when the foot was in the plantarflexed position. Reductions in ankle joint articular contact area were observed in the dorsiflexed and plantarflexed positions in the majority of specimens. Lateral displacement of the region of articular contact was noted in some specimens. A pressure-weighted centroid calculation was performed to provide a quantitative measure of the shift of the contact region.

Ankle Joint↗
PubMed1990

A comparison of the Brooker-Wills and Russell-Taylor nails for treatment of patients who have fractures of the femoral shaft.

Seventy-three fractures of the femoral shaft (seventy patients) were randomized to treatment with interlocked nailing with either the Brooker-Wills femoral nail (thirty-nine fractures) or the Russell-Taylor femoral nail (thirty-four fractures). Sixty-one patients (sixty-four fractures) were prospectively followed from admission until healing of the fracture. Specific attention was paid to recording operative details, including technical difficulties associated with insertion of the nails. Technical difficulties were encountered in insertion of the proximal screw, distal screw, and nail, and in deployment of the fins. Insertion of the Russell-Taylor nail was associated with less technical difficulty, operative time, and estimated loss of blood. The two nails differ in their biomechanical properties, methods of fixation, and instrumentation. These differences did not affect the clinical outcome; the fractures in both groups of patients healed with excellent functional results.

Biomechanical Phenomena↗
PubMed1989

Nerve sheath myxoma of digital nerve.

A case of a dermal nerve sheath myxoma arising in a digital nerve is reported. Similar tumors and its variants have been termed neurothekeoma, pacinian neurofibroma, bizarre cutaneous neurofibroma, and plexiform neurofibroma. The perineural sheath or the Schwann cell have been presumed to be the cell of origin by several investigators. The positive reaction with antibody to S-100 would appear to favor the Schwann cell as the progenitor of this tumor.

Adult↗
PubMed1989

The treatment of complex fractures of the talus.

The treatment of complex talar injuries entails an intricate knowledge of the anatomy and blood supply to the talus. The approach used should not violate any vascular structure, and the fixation used should be biomechanically stable to allow fracture healing. The three classes of talar fractures are discussed as well as avascular necrosis, talar salvage problems, and talar body fractures.

Fracture Fixation, Internal↗
PubMed1985

Lumbosacral dislocation.

We describe a patient with dislocation of the lumbosacral junction. No previous report of this rare injury has included a normal lateral radiograph without displacement in an anteroposterior direction. The radiologist should be aware that marked lumbosacral abnormality may be present despite the innocent appearance of a lateral radiograph.

Accidents, Traffic↗
PubMed1984

The treatment of the cubital tunnel syndrome.

Treatment by in situ release, submuscular transposition, and anterior subcutaneous transposition have all been reported to produce satisfactory results for ulnar neuropathy secondary to the cubital tunnel syndrome. A prospective study was done to determine which preoperative clinical and electrical factors and surgical approaches in patients with ulnar nerve palsy at the elbow had the best results. The 32 patients had an average age of 50 years, had symptoms for an average of 15 months before surgery, and underwent postoperative follow-up for an average of 13 months. All patients with good results had no atrophy or preoperative fibrillations in the intrinsic muscles and had an obtainable evoked sensory potential. The change in motor conduction velocity did not correlate with good results. There was no significant difference in the results of the three surgical procedures. Eight of the 37 operations yielded good results, 19 patients showed an improvement, but 10 of the operations yielded poor results. Our results also indicated that surgical results could be predicted by proper patient selection through the assessment of the preoperative physical examination and electromyogram.

Adult↗
PubMed1983

Sarcoidosis of the upper extremity: case presentation and literature review.

Sarcoidosis of the skeletal system is not rare but problems related to it are unusual. Two cases of sarcoidosis, with involvement of the upper extremity, are presented to point out problems that may occur in its treatment. Osteolytic sarcoid involvement of the phalanges leads to resorption and collapse, with a poor response to bone grafting or splinting. The phalangeal collapse could be treated with intramedullary cement or Kirschner wire fixation. Sarcoid involvement of fractures can lead to a nonunion and they should be treated with excision when appropriate, rather than attempting osteosynthesis. Arteriograms of sarcoid lesions show them to have a very poor blood supply. A bone scan can be used to demonstrate areas of sarcoid involvement before the characteristic lesion becomes evident on a radiography.

Adult↗
PubMed1983

Dynamic musculotendinous transfer to replace the anterior cruciate ligament in the dog.

Dynamic muscle-tendon substitution for acute anterior cruciate deficiency in the dog was studied using the semimembranosus muscle-tendon. Nineteen mongrel dogs each had a semimembranosus transfer in one knee; as a control, the anterior cruciate ligament and the semimembranosus were released in the opposite knee. No postoperative immobilisation was used. The anterior drawer sign was assessed before and after operation and when the dogs were killed five months later. Dogs were excluded from the study if they developed infections or contractures of the hind legs. At five months, 11 dogs were available for study. The operated knees were examined histologically and evaluated using a reproducible index of arthritis based on: the macroscopic discoloration of the articular cartilage, the cellularity of the cartilage, the microscopic appearance of the articular surface, the loss of proteoglycans, the formation of osteophytes and the degree of subchondral osteosclerosis. There was no significant difference in the anterior drawer sign or the degree of arthritic changes between knees with a semimembranous transfer and the controls. Examination showed that a muscle-tendon transfer into the tibia was equivalent to transferring the muscle into the posterior capsule--the intra-articular tendon being weak but histologically viable. The transfer did not prevent the anterior drawer sign becoming positive nor the development of osteoarthritis. A second control group, in which three dogs had an arthrotomy and semimembranosus release in both their hind legs, showed that a semimembranosus release alone did not cause osteoarthritis.

Animals↗
PubMed1980

Congenital convex pes valgus: results of an early comprehensive release and a review of congenital vertical talus at Richmond Crippled Children's Hospital and the University of Alabama in Birmingham.

Nineteen patients with 28 feet with congenital vertical talus were reviewed. The male to female ratio was equal, and associated congenital abnormalities were found in 15 of the 19 patients. No genetic pattern was established. Fifteen of the 16 surgically corrected feet were reevaluated, with an average follow-up of 60 months. Ten of the 15 feet were found to be in the good to excellent category, and five were rated poor. Twelve of 12 feet treated by cast correction were poor. Poor prognostic signs include late age of surgical correction, associated arthrogryposis and cerebral palsy, and an increased space between the calcaneus and cuboid. Best results occurred in those patients who had early surgical correction, after 4 to 6 months of serial casting, using magnification. Surgical technique which yielded the best results involved total release of the talus from the posterior, medial, and lateral approach, with reduction of the talocalcaneal as well as the talonavicular joints with multiple pin fixation. Lengthening of the Achilles tendon, extensor tendons, and peroneal tendons and transfer of the anterior tibialis to the navicular are recommended. Navicular excision was not found to be necessary. Surgical results in those patients over 3 1/2 years of age were found to be poor, and these individuals were considered for salvage procedures using a subtalar extra articular arthrodesis, excision of the navicular, or triple arthrodesis, depending on age.

Casts, Surgical↗
PubMed1977

Experimental evaluation of microsurgical techniques in small artery anastomoses.

A number of factors that influence the success of microvascular anastomosis have been studied, including adventitial stripping, choice of suture material and needles, suturing technique, and perfusion of the distal lumen. It is apparent that only minimal stripping of the adventitia is indicated in order to prevent increased necrosis of the vessel ends at the anastomosis site. The use of 10-0 monofilament nylon suture material with needles 75 microns or less in diameter achieves the best results in small vessel anastomoses. Optimal anastomosis of 1 mm. vessels requires interrupted full thickness sutures with minimal adventitial stripping and the use of the smallest number of sutures possible. We do not advocate routine perfusion of small arteries unless there are specific indications. An experienced team of microsurgeons utilizing these principles along with proper patient selection and a sound postoperative regimen should be able to achieve more than a 70 per cent success rate in replantation of completely amputated digits and hands.

Amputation, Traumatic↗
PubMedDate not supplied

The practical biomechanics of running.

The foot and ankle is a complex structure made of many small bones with capsular and ligamentous constraints. The physiology, kinematics, and muscle interaction of the walking, jogging, and running cycles will be discussed and the current biomechanical literature reviewed. To analyze the pathologic state, one must be aware of the normal stresses and functions of the running cycle. This knowledge establishes a rational basis for the interpretation of problems in providing medical and orthotic treatment.

Ankle↗