Biomedical subjects

Michael A Tonkin

Publications and source records attributed to Michael A Tonkin.

5 recordsLinked to original sources

PubMed2005

Adhesion formation after flexor tendon repair: comparison of two- and four-strand repair without epitendinous suture.

Increased handling, increased bulk at the repair site and an increase in external suture material may affect adhesion formation and gliding after tendon repair. A previous study(1) showed no significant difference in biomechanical or histopathological measurement of adhesion formation in two- and four-strand repairs combined with an epitendinous suture in the chicken model. In the present study, the flexor digitorum profundus tendon of the middle toe of 47 broiler chickens was cut and repaired with either a single (two-strand) or double (four-strand) modified Kessler core suture without epitendinous suture and immobilised for four weeks. Adhesion formation was measured by biomechanical testing or quantitative and qualitative histopathology. Biomechanical and histological data showed no differences between two- and four-strand repairs. Results did not differ from the previous study which used an epitendinous suture. Adhesion formation is not necessarily increased when multi-strand techniques are used, nor by the placement of an epitendinous suture if care is taken with surgical technique. Individual healing response introduces more variability than an increase in tendon handling by an experienced surgeon.

Animals↗

PubMed2004

Adhesion formation after flexor tendon repair: a histologic and biomechanical comparison of 2- and 4-strand repairs in a chicken model.

PURPOSE: Both increased handling and increased bulk at the repair site have been hypothesized as affecting adhesion formation and gliding after tendon repair. Tendons repaired with 2- and 4-strand techniques were compared using both biomechanical and histopathologic measurements to determine the influence of increasing strand number on adhesion formation and gliding. METHODS: The flexor digitorum profundus tendon of the right middle toe of 80 broiler chickens was cut and then repaired with either a single (2-strand) or double (4-strand) modified Kessler core suture, followed by a running epitendinous suture. The limb was immobilized after surgery. Birds were killed at either 3 days or 4 weeks after tendon repair and adhesion formation measured using either biomechanical testing or quantitative and qualitative histology. For biomechanical testing, the tendon was pulled free of the sheath and a force versus displacement curve was generated. Comparisons of peak force and work to peak were made. Histologic specimens were examined by a pathologist blinded to the treatment group who scored the length and density of adhesions and made qualitative observations. RESULTS: Both biomechanical and histologic data showed expected differences in adhesion formation for early (3 days) and late (4 weeks) healing but no significant differences between 2- and 4-strand repairs. Biomechanical testing of 4-week specimens showed a nonsignificant tendency toward greater work required to break adhesions in 4-strand repairs. CONCLUSIONS: Adhesion formation and gliding resistance of tendons after 2- or 4-strand modified Kessler core suture were not significantly different, which suggests that simply increasing the number of strands crossing a repair does not necessarily result in more adhesions or resistance in this model.

Animals↗

PubMed2003

Surgical management of the thumb in cerebral palsy.

Surgical treatment of the thumb in cerebral palsy is complex and treatment must be directed toward the specific deformities. Thumb-in-palm deformity can be treated successfully in patients with spastic CP, but caution is required in patients with other varieties of CP. The main deforming force is contracture and spasticity of the intrinsic thumb muscles. Treatment involves release of the deforming muscles and other soft tissue, augmentation of opposing muscles, and stabilization of appropriate joints.

Cerebral Palsy↗

PubMed2003

Thumb deformity in the spastic hand: classification and surgical techniques.

Surgery based on an accurate determination of deforming forces, muscle weakness, and joint instability achieves reasonably predictable results in patients with cerebral palsy. Thumb deformities can be classified into those of mainly intrinsic nature, extrinsic nature, and those of a combined nature. This allows identification of which muscles are released most appropriately and which muscle function requires augmentation. Joint instability needs to be taken into consideration because tendon transfers across unstable joints will be ineffective. The various surgical procedures are outlined in the text. In 32 patients, application of these principles and techniques allowed removal of the thumb from the palm in 29 patients during fist formation. Lateral pinch was established in 26 thumbs, and functional assessment revealed improvement in one functional grade. Functional benefit may be determined by other factors beyond the control of the surgeon. Therefore, the decision to proceed to surgery may be undertaken only after detailed and repeated clinical examinations are conducted that are coordinated with the assessments of parents, caregivers, physicians, occupational and physical therapists, and social counselors.

Journal Article↗

PubMed2002

Ulnar-sided cleft hand.

Three cases of ulnar-sided cleft hand are presented in which clefting was accompanied by ring finger absence in 2 and by small finger abduction, supination, shortening, and camptodactyly in all 3. An approach to surgical reconstruction is described with marked improvement in appearance.

Child, Preschool↗