For the past few decades, the repair of rotator cuff tears has evolved significantly with advances in arthroscopy techniques, suture anchors and instrumentation. From the biomechanical perspective, the focus in arthroscopic repair has been on increasing fixation strength and restoration of the footprint contact characteristics to provide early rehabilitation and improve healing. To accomplish these objectives, various repair strategies and construct configurations have been developed for rotator cuff repair with the understanding that many factors contribute to the structural integrity of the repaired construct. These include repaired rotator cuff tendon-footprint motion, increased tendon-footprint contact area and pressure, and tissue quality of tendon and bone. In addition, the healing response may be compromised by intrinsic factors such as decreased vascularity, hypoxia, and fibrocartilaginous changes or aforementioned extrinsic compression factors. Furthermore, it is well documented that torn rotator cuff muscles have a tendency to atrophy and become subject to fatty infiltration which may affect the longevity of the repair. Despite all the aforementioned factors, initial fixation strength is an essential consideration in optimizing rotator cuff repair. Therefore, numerous biomechanical studies have focused on elucidating the strongest devices, knots, and repair configurations to improve contact characteristics for rotator cuff repair. In this review, the biomechanical concepts behind current rotator cuff repair techniques will be reviewed and discussed.
Arthroscopy/*methods ; Biomechanical Phenomena ; Humans ; Models, Biological ; Rotator Cuff/injuries/*physiology/*surgery ; Weight-Bearing

OBJECTIVE: To explore clinical effect of arthroscopy-assisted rotator cuff tendon transfer in treating irreparable rotator cuff tears (IRCT). METHODS: From May 2015 to May 2018, 23 patients with unrepairable rotator cuff tears were treated with arthroscopy-assisted rotator cuff tendon transfer, and 21 patients were followed up finally, including 8 males and 13 females, aged from 48 to 82 years old with an average of(64.3±9.1) years old;the courses of disease ranged from 6 to 36 months with an average of (14.0±6.4) months. American Rotator and Elbow Surgeons Score(ASES) and Constant-Murley score were used to evaluate clinical efficacy before surgery and at the latest follow-up. RESULTS: All 21 patients were followed up for 36 to 54 months with an average of (39.4±4.4) months. Axillary incision of 1 patient was redness, swelling and exudation after surgery, which healed after 3 weeks of dressing change, and exudate culture was negative. At the latest follow-up, MRI showed partial tearing of the metastatic tendon in 2 patients, but pain and movement of the affected shoulder were still better than before surgery. ASES increased from preoperative (41.0±9.6) scores to the latest follow-up (75.6±14.0) scores, and had statistical difference (t=10.50, P<0.01). Constant-Murley score increased from (49.8±7.1) scores before operation to (67.5±11.6) scores at the latest follow-up (t=11.27, P<0.01). CONCLUSION Arthroscopic assisted latissimus dorsalis tendon transposition restores physiological and anatomical structure of glenohumeral joint by reconstructing balance of horizontal and vertical couples of shoulder joint, thus achieving the stability of the shoulder joint, relieving shoulder pain and improving shoulder joint function.
Male ; Female ; Humans ; Middle Aged ; Aged ; Aged, 80 and over ; Rotator Cuff Injuries/surgery* ; Superficial Back Muscles ; Rotator Cuff ; Treatment Outcome ; Shoulder Joint/surgery* ; Tendon Transfer ; Arthroscopy ; Range of Motion, Articular/physiology*

BACKGROUND: Arthroscopic rotator cuff repair generally has a good clinical outcome but shoulder stiffness after surgery due to subacromial adhesion is one of the most common and clinically important complications. Sodium hyaluronate (HA) has been reported to be an anti-adhesive agent in a range of surgical procedures. However, there are few reports of the outcomes of arthroscopic rotator cuff repair of the shoulder. This study examined whether a subacromial injection of HA/carboxymethylated cellulose (CMC) affected the postoperative shoulder stiffness and healing of rotator cuff repair, as well as the safety of an injection. METHODS: Between January 2008 and May 2008, 80 consecutive patients with arthroscopic rotator cuff repair were enrolled. The patients were assigned randomly to the HA/CMC injection group (n = 40) or control group (n = 40). All patients were evaluated using the visual analog scale (VAS) for pain, passive range of motion at 2, 6 weeks, 3, 6, 12 months after surgery, and the functional scores at 6, 12 months postoperatively. Cuff healing was also evaluated using CT arthrography or ultrasonography at 6 or 12 months after surgery. RESULTS: The HA/CMC injection group showed faster recovery of forward flexion at 2 weeks postoperatively than the control group but the difference was not statistically significant (p = 0.09). There were no significant difference in pain VAS, internal rotation, external rotation and functional scores between two groups at each follow-up period. The functional scores improved 6 months after surgery in both groups but there were no differences between the two groups. The incidence of unhealed rotator cuff was similar in the two groups. There were no complications related to an injection of anti-adhesive agents including wound problems or infections. CONCLUSIONS: A subacromial injection of an anti-adhesive agent after arthroscopic rotator cuff repair tended to produce faster recovery in forward flexion with no adverse effects on cuff healing. However, its anti-adhesive effects after rotator cuff repair should be considered carefully with further studies.
Adult ; Aged ; Arthroscopy/*adverse effects/*methods ; Carboxymethylcellulose Sodium ; Drug Carriers ; Female ; Humans ; Hyaluronic Acid/adverse effects/*therapeutic use ; Male ; Middle Aged ; Pain ; Prospective Studies ; Range of Motion, Articular ; Recovery of Function ; Rotator Cuff/injuries/*surgery ; Shoulder Joint/physiology ; Tissue Adhesions/*prevention & control ; Treatment Outcome ; Viscosupplements/adverse effects/*therapeutic use