| Background and objectives: Rotator cuff tear(RCT)is one of the most common diseases in orthopedics,and the most common cause leading to shoulder pain,reduced shoulder function and weakness.Despite the advances in the arthroscopy and rotator cuff repair techniques,the rotator cuff still has a high rate of re-tearing after surgery.In many cases,the rotator cuff is not able to achieve good tendon bone healing,which affects the efficacy of surgery.For this reason,finding new ways to change the process of tendon bone healing and promote the appearance of fibrocartilage at the tendon bone interface has become the key to promote healing of rotator cuff and improve the effect of rotator cuff repair.In this study,we investigated the effect of hydroxyapatite with TGFβ1 on the healing of tendon bone interface after rotator cuff repair in a rat model and assessed changes in bone and cartilage regeneration on tendon bone interface and morphology and mechanical strength of the tendon bone interface.This study also investigated the relationship between the hemodynamic changes in arterial blood flow to the rotator cuff and shoulder function in patients with rotator cuff tear using Doppler ultrasonography.Methods: 1.117 Sprague-Dawlay rats underwent unilateral detachment of the supraspinatus tendon following by acute repair using transosseous suture fixation.Animals were divided into 3 groups:(1)repair only(control);(2)repair with interposition of hydroxyapatite bioceramic(HA);(3)repair with interposition of HA-TGFβ1 ceramic powder(HATGFβ1).Animals were sacrificed in 2,4,8 weeks after surgery.Micro-CT was used to evaluate the new bone formation.Histomorphometric analysis were used to quantify the fibrocartilage formation and collagen organization.Biomechnical tests were used to asses the suprspinatus tendon-bone complex.2.Patients with rotator cuff tears including supraspinatus and infraspinatus tendon tears,with or without subscapularis or teres minor tendon tears,were considered for enrollment in this study.They were evaluated with ultrasound prior to arthroscopy.The peak systolic velocity(PSV)and resistance index(RI)of the arteria brachialis,anterior humeral circumflex artery(AHCA),posterior humeral circumflex artery(PHCA)and arteria suprascapularis(AS)were evaluated and recorded.The PSV and RI were compared between affected and unaffected sides in individual patients.Shoulder function was evaluated according to the American Shoulder and Elbow Surgeons(ASES)standardized scoring method.Results: 1.the micro-CT revealed remarkable new bone formation in the group with HA and HA-TGFβ1 when HA-TGFβ1 showed better outcome(P<0.05).Histomorphometric analysis revealed improved fibrocartilage formation and collagen organization at the tendon-bone-interface in experiment group(P<0.05).The HA-TGFβ1 can significantly improve the area of fibrocartilage especially in the early time point compared with control and HA group(P<0.05).there was significantly greater load to failure of the tendon-bone-interface in HA-TGFβ1 group compared with control and HA group at 4 and 8 weeks(P<0.05).2.Forty-two patients were eligible for our study and were divided into two groups according to their ASES scores.The PSV and RI value of the AHCA differed significantly between the affected and unaffected sides in the group with low ASES scores(P<0.01).The PSV of the AS and the RI of the PHCA also differed significantly between the affected and unaffected sides in the group with lower ASES scores(P<0.01).There were no significant differences among the other groups.Conclusions: 1.augmentation of hydroxyapatite-TGFβ1 ceramic powder in the tendon-bone interface was found to strengthen the healing enthesis,increase the bone and fibrocartilage formation and improve collagen organization compared with repair alone.2.In patients with rotator cuff tears and low ASES scores,there is a US-detected alteration in blood flow around the shoulder,most noticeable in the AHCA. |
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