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Biomedical subjects

R A Mann

Publications and source records attributed to R A Mann.

At least 73 records · Page 4Linked to original sources
PubMed1990

Hallux rigidus.

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Foot Deformities, Acquired↗
PubMed1989

Relationship of metatarsophalangeal joint fusion on the intermetatarsal angle.

To evaluate the effect of fusion of the first metatarsophalangeal joint on the first intermetatarsal angle, a series of 62 consecutive first metatarsophalangeal fusions was reviewed. Of these, 47 had sufficient data to be included in this study. The results of this study showed that the change in the first intermetatarsal angle following a first metatarsophalangeal joint arthrodesis is directly proportional to the preoperative first intermetatarsal angle. Therefore, when a first metatarsophalangeal joint arthrodesis is performed on a patient with a wide intermetatarsal angle, a concomitant proximal first metatarsal osteotomy is usually not indicated.

Adult↗
PubMed1989

The great toe.

The biomechanics of the great toe and the pathologic anatomy of a hallux valgus deformity are presented. Patient evaluation is discussed. The section on decision making includes explanations of the Akin, chevron, and Mitchell procedures and instances for which the use of each is recommended.

Biomechanical Phenomena↗
PubMed1988

Murine interstitial nephritis. VIII. Characterization of Igh-V restriction determinants in the development of anti-idiotypic immunity using blocking antibodies.

We have prepared antisera specific for Igh-V-linked determinants (alpha Igh-V) in order to study Igh-V restriction during the development of protective, T cell-mediated anti-idiotypic immunity in autoimmune interstitial nephritis. Suppressor T cells in this network use an antigen-binding (RE-Id+) factor (TsF1) secreted by first-order suppressor cells (Ts-1) to induce an anti-idiotypic (RE-alpha Id+) soluble factor (TsF1) released by effector-phase, Ts-2 suppressor cells. Each of these soluble suppressor factors requires homology in the Igh-V region to complete its regulatory functions. Our alpha Igh-V antisera, adsorbed against network idiotypes, can interfere with the Igh-V restriction used in the induction of Ts-2 suppression by TsF1. The antisera bind both TsF1 and TsF2 in an allele-specific manner and are cytotoxic to induced Ts-2 cells, but not their precursors. These Igh-V determinants appear to behave like activation molecules. They lie outside of the ligand-binding site, do not map with the serologic binding of idiotype, and thus act as distinct associative-recognition elements in the maturation of anti-idiotypic immunity.

Animals↗
PubMed1988

Hallux rigidus: treatment by cheilectomy.

Cheilectomy, the excision of an irregular osseous rim that interferes with motion of a joint, was performed on the distal part of the first metatarsal of twenty-five patients who had hallux rigidus. Relief of pain was achieved in all but three patients, whose cases were considered as failures. Joint motion improved by an average of 20 degrees, and it was in an acceptable range in twenty-three patients. There were no complications other than persistence of swelling in six patients. No patient required additional operative intervention during an average follow-up of fifty-six months. We concluded that cheilectomy is a better method of treatment for hallux rigidus than arthrodesis, resection arthroplasty, or arthroplasty with the use of a flexible implant.

Adult↗
PubMed1988

Amputation of the great toe. A clinical and biomechanical study.

Clinical and biomechanical observations were made on otherwise normal feet in ten patients, who had had amputations for pollicization of the great toe. Measureable changes were demonstrated in the patients' gait pattern and in force plate data. The center of pressure was noted to shift from beneath the second metatarsal head on the normal side to beneath the third metatarsal head on the amputated side. The velocity of movement of the center of pressure slowed significantly in the metatarsal head region of the operated side, which secondarily resulted in an increased loading of the metatarsal region. The progression of the center of pressure was noted to be beneath the third metatarsal head region on the involved side, instead of progressing medially and distally toward the first web space. Clinically, the operated foot demonstrated slight thickening beneath the second and third metatarsal heads but no significant abnormal callus formation developed. The patients' shoes all showed increased lateral wear on the amputated side. From a functional standpoint, the patients had little or no disability from loss of the hallux.

Adolescent↗
PubMed1988

Subtalar fusion for isolated subtalar disorders. Preliminary report.

Retrospective observations on subtalar fusions performed for isolated subtalar disorders in 11 feet were performed to determine whether a satisfactory result could be obtained without significant changes to the talonavicular and calcaneocuboid joints. Preoperative diagnoses included five feet with degenerative arthritis secondary to a calcaneal fracture, four feet with a talocalcaneal bar, one foot with a degenerative subtalar arthropathy of unknown cause, and one foot with an unstable subtalar joint secondary to a peroneal tendon rupture. The average follow-up period was 41.5 months (range, 23-103 months). The hindfoot was fused in a average of 6 degrees of valgus. The feet maintained approximately 50% of their transverse tarsal motion, compared with the contralateral side. No foot developed hypermobility of any tarsal joint. Three feet fused for degenerative joint disease developed very mild talar beaking, and two feet fused for a tarsal coalition developed a mild progression or increase in talar beaking. Three feet demonstrated very minimal osteophyte formation at the calcaneocuboid joint. Functional and pain ratings for patients who had fusions for talocalcaneal bars or degenerative joint disease were good to excellent. Minimal radiographic changes at the talonavicular and calcaneocuboid joints secondary to increased stress brought about by the fusion did not seem to be clinically significant. Isolated subtalar fusion for lesions limited to the subtalar joint, which includes talocalcaneal bars, is a satisfactory method of treatment.

Adult↗
PubMed1988

Pathophysiology of Charcot-Marie-Tooth disease.

The etiology of the foot deformity in patients with Charcot-Marie-Tooth disease has not previously been discussed in relation to the extrinsic muscle function around the foot and ankle. Eight adult patients with a strong familial history were evaluated, and their foot findings were remarkably similar. All demonstrated a marked cavus deformity that was secondary to a forefoot equinus associated with contracture of the plantar fascia and a varus deformity of the calcaneus. The muscle function demonstrated marked weakness of the tibialis anterior and peroneus brevis muscles, whereas the peroneus longus and posterior calf muscles were rated as good to normal. Based on the relative strengths of these muscles and the progression of weakness, the authors hypothesize that the deformity observed in patients with Charcot-Marie-Tooth disease is secondary to the weakness of the tibialis anterior, peroneus brevis, and the intrinsic muscles, with their natural antagonists, the peroneus longus and the tibialis posterior muscles causing most of the deformity noted in these adult patients.

Adolescent↗
PubMed1987

Pain in the foot. 2. Causes of pain in the hindfoot, midfoot, and forefoot.

Pain in the foot has many causes. A careful history and physical examination, radiographs, and laboratory data usually yield the correct diagnosis so that specific treatment can be directed toward the problem to help relieve the patient's pain. Rarely is surgery necessary. Good conservative management usually produces a satisfactory clinical response.

Achilles Tendon↗
PubMed1987

The pathophysiology of the juvenile bunion.

While the surgeon may tend to use one procedure in the repair of a hallux valgus deformity, versatility is most important when treating the juvenile bunion. Using a distal soft-tissue repair when subluxation is solely at the metatarsophalangeal joint is an acceptable approach. A metatarsal or cuneiform osteotomy is necessary if the intermetatarsal angle is abnormally large. It is important not to stretch the indications for a bunion technique in order to correct the hallux valgus deformity. If a more severe deformity is present, a more aggressive technique must be used to correct the abnormality. That varying success rates are reported with different techniques testifies to the fact that the juvenile bunion is not suited for a standard hallux valgus repair. The surgical technique used to repair a specific juvenile bunion depends upon the anatomic and physiologic abnormalities present in each patient.

Adolescent↗