Collagenase in the treatment of Dupuytren's disease: an in vitro study.

The effects of clostridial collagenase on the tensile strength of Dupuytren's cords was studied in vitro to assess its potential efficacy as an agent for clinical enzymatic fasciotomy. Collagenase was injected into Dupuytren's cords from patients undergoing fascioctomy. Following a pilot experiment, in which a 3,600-unit dose of collagenase induced a 93% decrease in tensile modulus as compared with control cords, groups of five cords each were injected with 150, 300, and 600 units. These cords and a control group of five cords were tested by loading to failure in tension. The ultimate stress and strain to failure were recorded by a video capture technique. All specimens were stained for histologic examination with hematoxylin and eosin for collagen typing with sirrius red. Comparison of the ultimate stress values obtained with published values of extensor forces obtainable by the individual fingers of 40 normal hands indicated that a 300-unit dose of collagenase was sufficient for cord rupture within the average maximum force limits of the extensors of the index, long, ring, and small fingers (p < .02). All samples were in the residual disease stage histologically and contained type I collagen by sirrius red staining. These results indicate that collagenase may be effective in enzymatic fasciotomy of residual-stage Dupuytren's disease.

A neural network approach for bone fracture healing assessment.

An approach based on auscultatory percussion, a technique used by some orthopedists both for bone fracture detection and bone fracture healing assessment, is described. Low-frequency, low-intensity mechanical power, very much like the finger tap of orthopedists, is used to evaluate the vibrational response of the bone. The novel element is the data processing, which incorporates specialized preprocessing and a neural network for estimating fractured bone strength. In addition, a new mathematical model for the vibrational response of a fractured limb, which provides data to design and test the neural network processing scheme, is presented. An experimental procedure is described for acquiring real data from animal and human fractures in a form necessary for neural network input.