Localization of mRNA of procollagen type I in supraspinatus tendons of incomplete- thickness tears by in situ hybridization

肩袖不全厚撕裂是一种常见于40岁以上人群的痛性撕裂，常被误认为肩周炎。为了确定保守或手术治疗方案的理论依据，通过检测部分撕裂肌腱中I型前胶原的mRNAs来检测不完全撕裂的愈合能力。材料与方法术中获得10条冈上肌腱撕裂，其中法氏囊撕裂3侧，腱内撕裂3例，关节侧撕裂4例。这些标本固定在10%的缓冲福尔马林中，石蜡包埋。结果在棘上肌腱残端及其附近的腱细胞和未分化间充质细胞中检测到I型前胶原mRNA的表达，而在肩峰下囊成纤维细胞中检测不到。结论10例不完全厚度袖带撕裂中有8例可见信号。即使在长期存在的泪水中，也能检测到这些信号。腱内撕裂被认为是近端和远端的撕裂。肌腱自然愈合不太可能发生在不完全厚度的袖带撕裂中。为了更加客观，我们还打算进行一项额外的研究来定量检测mRNA.

ObjectiveIncomplete-thickness tears of the rotator cuff are painful conditions which are commonly seen in those aged over 40 and often mistaken for the 'frozen shoulder'. In order to determine the theoretical basis for treatment options, conservative or surgical, the healing capacity of incomplete-thickness tears was examined by detecting mRNAs of procollagen * 1 type I in the partially torn tendons.Materials and MethodsTen torn supraspinatus tendons were obtained during operation which were 3 bursal-side, 3 intratendinous and 4 joint-side tears. These specimens were fixed in 10% buffered formalin and embedded in paraffin. The digoxigenin-labeled oligonucleotide probe (22 mer), which was specific to human procollagen alpha 1 type I mRNA, was used in our in situ hybridization protocols.ResultsThe signals of procollagen alpha 1 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.ConclusionsSignals were detected in 8 cases out of 10 incomplete-thickness cuff tears. Even in the long-standing tears, the signals were detected. An intratendinous tearing is considered to exteed both proximally and distally. Spontaneous tendon healing is unlikely in incomplete-thickness cuff tears. An additinal study is contemplated to quantitate mRNA in order to be more objective.