Abstract
[Purpose]The purpose of this study was to evaluate the healing ability of incomplete-thickness cuff tears.
[Materials & methods]
Ten torn supraspinatus tendons were obtained during operations, which were 3 bursal-side,3 intratendinous and 4 joint-side cuff tears. These specimens were fixed in 10%buffered formalin and embedded in paraffin. The digoxigenin-labeled oligonucleotide probe (22mer), which was specific to human procollagen α1 type I mRNA, was used in our in situ hybridization protocols.
[Results]
The signals of procollagen α1 type I mRNA were detected in the tenocytes and undifferentiated mesenchymal cells of or in the vicinity of the stumps of the torn supraspinatus tendons, but not in the fibroblasts of the subacromial bursa. They were scarcely observed in the specimens without apparent trauma.
[Conclusion]
Signals were detected in 8 cases out of 10 incomplete-thickness tears. Even in the longstanding tears, the signals were detected. An intratendinous tearing is supposed to extend. Spontaneous tendon healing is considered unlikely in the incomplete-thickness cuff tears.
