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Biomedical subjects

J F Connolly

Publications and source records attributed to J F Connolly.

At least 145 records · Page 8Linked to original sources
PubMed1981

A multicenter study of the treatment of non-union with constant direct current.

A clinical study was initiated at the University of Pennsylvania in 1970 to evaluate the use of constant direct current in treating acquired non-union. In 1977 the study was expanded to include twelve participating investigators throughout the United States. The results indicate that, given proper electrical parameters and proper cast immobilization, a rate of bone union comparable to that seen with bone-graft surgery was achieved. Experience dictated that four cathodes, each delivering twenty microamperes of constant direct current for twelve weeks, were required to heal a non-union of a long bone. Of 178 non-union in 175 patients treated with adequate electricity in the University of Pennsylvania series, 149 (83.7 per cent) achieved solid bone union. Patients with a history of osteomyelitis had a healing rate of 74.4 per cent. The presence of previously inserted metallic fixation devices did not affect the end-result healing rate. Of eighty non-unions in seventy-nine patients treated with electricity in the participating investigators' series, fifty-eight (72.5 per cent) achieved solid bone union. Review of the non-unions treated unsuccessfully with constant direct current suggested that inadequate electricity, the presence of synovial pseudarthrosis or infection, and dislodgment of the electrodes are causes for failure with the procedure. Complications of the electrical treatment were minor and there was no deep infection resulting from this procedure in patients without previous osteomyelitis. We concluded that the practicing orthopaedic surgeon utilizing constant direct current to treat non-union should, by adhering to proper fracture management and by following the biophysical principles described herein, be able to achieve a rate of union comparable to that of bone-graft surgery, with a lower associated risk.

Adolescent↗
PubMed1980

Torsional fractures and the third dimension of fracture management.

Torsional strength is the weakest structural property of bone. Fractures produced by common indirect mechanisms are likely to have significant rotational components that bear on their management. The characteristics of torsional fracture lines in bone specimens are completely predictable and reproducible. The physician who is aware of these biomechanical consistencies can use them for fracture reduction and can anticipate and treat fracture deformities accentuated by torsional loading.

Adolescent↗
PubMed1980

Assessment of healing of long-bone fractures by intraosseous venography.

Intraosseous venography with compression of the soft tissue was performed following fracture of the radius in 13 dogs to assess the repair process. Two angiographic criteria were analyzed: (a) intraosseous venous crossing of the fracture ("medullary crossing") and (b) capillary blush of the proximal osseous fragment ("proximal blush"). The bone strength of the fractured and intact radii was compared. Venograms obtained immediately after fracture showed contrast material reaching but not crossing the fracture line, indicating that the entire intramedullary venous network had been disrupted. When Parafilm was interposed between the bone fragments to prevent healing, proximal blush was seen at 4 weeks and medullary crossing at 6-7 weeks; bone strength was 13-14% of normal. With no barrier, proximal blush appeared at 5 weeks and medullary crossing at 10-11 weeks; bone strength was 30-40% of normal. The authors conclude that medullary crossing can be seen in the presence of decreased bone strength if the healing process is uneven across the fracture line, as occurred with Parafilm. If the animal model reproduces the clinical situation, this finding challenges the predictive value of intraosseous venography.

Animals↗
PubMed1979

Malignant hyperthermia. A potentially fatal syndrome in orthopaedic patients.

Malignant hyperthermia is an inherited muscular disorder and a cause of sudden death in afflicted patients. Stress arising from tramuma, surgery, and other causes can initiate the syndrome. We studied the types of orthopaedic problems commonly seen in patients with this condition as well as the clinical manifestations and pathophysiology of the syndrome. Recognition, management, and understanding of the pathophysiology of malignant hyperthermia can be aided by a study of its similarities to porcine stress syndrome. We performed experimental studies of muscle and prophylaxis in swine. We also demonstrated the extension of the prophylactic use of dantrolene sodium in a management protocol in eighty surgical procedures in humans.

Adult↗
PubMed1978

A multiwire proportional gamma camera for imaging 99Tcm radionuclide distributions.

A gamma camera made of multiple multiwire proportional chambers with thin converter foils has been evaluated for clinical application. Results are presented from a small prototype (10 cm x 10 cm)showing good imaging of 99Tcm radionuclide distributions and comfirming the predictions of the theory regarding quantum efficiency and spatial resolution. The technique is especially aimed at creating a gamma camera with an active area greater than or approximately equal to 1 m2, a quantum efficiency of 15% and a spatial resolution approximately 3 mm, to be applied in whole body scanning and tomographic applications. The results generated by the current prototype indicate that the above requirements can be met using relatively cheap mass production techniques from the electronic industry. This apparatus is covered by patent applcation number 26595/77.

Gamma Rays↗
PubMed1978

Fracture healing in weight-bearing and nonweight-bearing bones.

Animal models demonstrated the differences in the process of fracture healing in weight-bearing and nonweight-bearing bones. Canine rib fractures regained strength properties rapidly; in canine radial fractures the return to normal stiffness levels was primary. The structural differences in fracture healing are probably functional and due more to biologic reorganization than to any measurable change in the biochemical components of the callus.

Animals↗