A NOVEL OPERATIVE TECHNIQUE, FUNCTIONAL, OUTCOME AND GENE EXPRESSION STUDY IN PATIENTS WITH RUPTURED DISTAL BICEPS TENDONS

Abstract

Aim: To evaluate the functional outcome of patients following intra-osseous suturing for repair of distal biceps tendon ruptures, using the Mayo scoring system. Subsequent analysis of mRNA expression; in the ruptured biceps tendons was performed.

Methods: We operated on 8 patients who had ruptured their biceps tendon. The average ages of the patients were 36 (Range 22–50). The technique involved using intrasosseous suturing via a single anterior skin crease incision. The functional outcome of these patients was scored by using the Mayo elbow performance score. The average follow-up was 7 months. (Range 5–8 months). The tendons were processed for RNA isolation and reverse -transcription – polymerase chain reaction (RT-PCR).

Results: The average subjective assessment (pain and function) of these patients was 63/70 (Range 57–68). The average objective assessment (motion and stability) was 24/30 (Range 22–27). The overall average was 87/100. None of the patients had any complications postoperatively. Our results showed that in the samples of ruptured biceps tendon there was mRNA expression of ECM structural components, especially aggrecan and the small proteoglycans biglycan and decorin. Interestingly, these samples also showed a high expression for the enzymes commonly involved in articular cartilage degradation and turnover, the aggrecanases (ADAMTS-4 and ADAMTS-5) and the matrix metalloproteinases (MMP-3 and MMP-13).

Conclusion: We demonstrated that intrasosseous suturing via a single anterior incision, in-patients with ruptured biceps tendons could provide a good functional outcome. This technique should therefore be considered as one of the surgical options in the management of this condition. We know clinically that patients can rupture their biceps tendon either due to trauma if not due to degenerative conditions. In our study we wanted to know if the subset of patients how ruptured their tendons traumatically had any pre-existing degenerative conditions leading on to the rupture compared to the normal subjects. Interestingly our study has shown that there is mRNA expression of degradative enzymes (aggrecanases and MMPs) in the samples of ruptured biceps tendon. Furthermore, our samples also showed mRNA expression for factors involved in the inflammatory response. In conclusion, mRNA expression of the factors involved in degradation and inflammation may suggest a phenotype that predisposes the biceps tendon to rupture, although further studies are required in order to investigate this.