Search PubMed⌕ Search

Biomedical subjects

G R Mack

Publications and source records attributed to G R Mack.

24 records · Page 2Linked to original sources
PubMed1977

Kienböck's disease: the role of silicone replacement arthroplasty.

A review of thirty-eight patients with Kienböck's disease indicated that both delay in diagnosis and prolonged treatment by plaster immobilization led to progressive collapse of the lunate and an unsatisfactory result in most instances. Four clinical and roentgenographic stages were identified, and the results of silicone replacement arthroplasty were correlated with the preoperative stage after an average follow-up of twenty-seven months. The results were satisfactory in fourteen of twenty wrists in which the procedure was performed before collapse of the lunate had occurred. The importance of early diagnosis and early surgical treatment of this disorder was emphasized by the findings in this study.

Adolescent↗
PubMed1976

Skeletal uptake of 99mTc-diphosphonate in relation to local bone blood flow.

The right/left ratios of tibial uptake of 99mTc-diphosphonate (EHDP) and relative blood flow (based on microsphere distribution) were determined in control rats and rats with a ligated right femoral artery or a healing right tibial fracture. Correlation between 99mTc-EHDP uptake and relative blood flow was highly significant (r=0.917; P less than 0.0001) for relative flow ratios less than 1.7. When the ratio was greater than 1.7, there was little further increase in 99mTc-EHDP uptake. Ligation of the femoral artery in rats with healing fractures resulted in a more marked reduction of blood flow than of 99mTc-EHDP uptake. These results suggest that regional bone blood flow is a major determinant of 99mTc-EHDP uptake, though changes in regional tracer extraction efficiency are also important.

Animals↗
PubMedDate not supplied

Femoral neck stress fractures and metabolic bone disease.

OBJECTIVE: To determine whether metabolic bone disease plays a role in the cause of femoral neck stress fractures. STUDY DESIGN: Twenty-three patients with femoral neck stress fractures were enrolled prospectively in the study. Examination included computed tomography bone densitometry, trace mineral analysis, and histomorphometric analysis of the iliac crest in thirteen patients who underwent surgical treatment of their stress fractures. A control group of fifteen patients undergoing iliac crest bone grafting for scaphoid nonunions underwent similar examinations. SETTING: Tertiary military medical center. RESULTS: Patients with femoral neck stress fractures had lower bone mineral density than did control patients (p = 0.010), but no trace mineral deficiencies or consistent histomorphometric differences were noted. CONCLUSIONS: Bone mineral density is decreased in patients with femoral neck stress fractures. Despite observations of decreased bone mineral density in the stress fracture group, osteoporosis, as determined by histomorphometry, is not a consistent finding.

Absorptiometry, Photon↗
PubMedDate not supplied

Subacute scaphoid fractures. A closer look at closed treatment.

Twenty-three subacute scaphoid fractures were retrospectively reviewed to determine the efficacy of nonoperative treatment. All of the patients sought medical attention between 4 weeks and 6 months after injury, and their fractures were classified according to location and stability. Nineteen fractures were observed to radiographic union or until closed treatment was abandoned; four patients were lost to followup. Nine of 10 stable subacute middle-third scaphoid fractures healed with cast immobilization in an average of 19 weeks (range, 11 to 38), and these were compared with a randomly selected group of acute middle-third fractures that healed in an average of 10 weeks (range, 6 to 13). Five of six unstable subacute middle-third fractures healed in an average of 20 weeks. One of these had a symptomatic humpback deformity treated by cheilectomy. Of three subacute proximal-third fractures, only one healed after 29 weeks of closed treatment. This study demonstrates that stable subacute middle-third scaphoid fractures will heal with cast treatment but may take twice as long to do so as stable acute middle-third fractures. Unstable subacute middle-third scaphoid fractures and subacute proximal-third fractures appear less likely to heal with closed treatment.

Adolescent↗