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

目的：肩袖不完全厚度撕裂是40岁以上人群常见的疼痛症状，常被误认为是“肩周炎”。为了确定保守或手术治疗方案的理论依据，我们通过检测部分撕裂肌腱中前胶原* 1型mrna来检测不完全厚度撕裂的愈合能力。材料与方法术中获得10根冈上肌腱撕裂，其中法囊侧撕裂3根，腱内撕裂3根，关节侧撕裂4根。这些标本用10%的福尔马林缓冲液固定，石蜡包埋。我们的原位杂交方案使用地高辛标记的寡核苷酸探针（22 mer），该探针对人前胶原α 1型mRNA具有特异性。结果冈上肌腱残端及残端附近的腱细胞和未分化间充质细胞中检测到前胶原α 1型mRNA的表达，而在峰下法氏囊成纤维细胞中检测不到。在没有明显创伤的标本中几乎没有观察到它们。结论10例不完全厚度袖带撕裂中有8例检测到信号。即使在长期的眼泪中，信号也被检测到了。肌腱内撕裂被认为延伸到近端和远端。不完全厚度的袖带撕裂不太可能自发愈合。为了更加客观，一项额外的研究正在考虑定量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.