Abstract:
Background:
With an aging and active population, injuries at the tendon-bone interface are a leading cause of morbidity. Rotator cuff and hip abductor tendon tears are commonly encountered in orthopaedic practice. With the advent of novel tissue engineering techniques, there is scope for translational studies to improve the outcomes of tendon to bone repair.
Aims:
Firstly, this thesis aimed to clarify the clinical burden and pathology of hip abductor tendon tears, as well as summarise the current surgical treatment options for both hip abductor and rotator cuff tears. The second aim was to design a large animal model of hip abductor tendinopathy and tear and validate it against an acute repair model. Lastly, a novel collagen scaffold and growth factor combination were evaluated for their potential to improve tendon to bone healing using both in vitro and in vivo studies.
Methods:
A survey of New Zealand orthopaedic surgeons and a systematic review of the literature was conducted on the pathology and surgical treatment of hip abductor tendon tears. Pathological features of hip abductor tendon tears were examined using 36 cadaveric samples. A delayed repair model of the hip abductor tear was established using sheep by detaching the tendon, followed by evaluation of histological changes and delayed repair after 6 weeks, and finally comparing the results of repair to an acute model. A systemic approach was adopted for evaluation of both the scaffold and growth factor combination for improving healing at the tendon-bone interface using an improved rat supraspinatus model.
Results:
Hip abductor tendon tears are commonly encountered in orthopaedic practice and present a significant treatment challenge. It shares pathological features with rotator cuff tears and involves both the distal tendon and the tendon-bone interface. A large animal, delayed repair model was
successfully established in sheep and produces significantly different results to acute repair. The growth factor combination was able to significantly improve the quality of healing at the tendon-bone interface.
Conclusions:
Hip abductor and rotator cuff tears are analogous pathologies and common treatment strategies may improve outcomes following surgical repair. The growth factor combination demonstrates clinical promise, and further translational studies with our large animal, delayed repair model are needed.