Factors associated with degeneration of rotator cuff tendon : a histological study in patients with rotator cuff tear.

Factors associated with tendon degeneration have not been fully investigated. The purpose of this study was to identify factors associated with tendon degeneration in patients with rotator cuff tear. A total of 93 patients with a full-thickness rotator cuff tear (fRCT) were included in the study. A full-thickness supraspinatus tendon sample was harvested from the middle portion between the lateral edge and the musculotendinous junction, and assessed histologically. Association between the degree of tendon degeneration and factors in demographic, clinical, radiologic, and arthroscopic categories were investigated. The mean of the total degeneration score was significantly lower in patients with symptom duration of 6 months or less than longer than 6 months (13.1 ± 2.6 vs 14.4 ± 2.3, p = 0.010). This study showed that tendon degeneration significantly progressed 6 months after the onset of symptoms, and suggested early intervention to avoid further deterioration of tendon degeneration.

Intra-articular injection of mesenchymal stem cells for the treatment of osteoarthritis of the knee: a proof-of-concept clinical trial.

Mesenchymal stem cells (MSCs) are known to have a potential for articular cartilage regeneration. However, most studies focused on focal cartilage defect through surgical implantation. For the treatment of generalized cartilage loss in osteoarthritis, an alternative delivery strategy would be more appropriate. The purpose of this study was to assess the safety and efficacy of intra-articular injection of autologous adipose tissue derived MSCs (AD-MSCs) for knee osteoarthritis. We enrolled 18 patients with osteoarthritis of the knee and injected AD MSCs into the knee. The phase I study consists of three dose-escalation cohorts; the low-dose (1.0 × 10(7) cells), mid-dose (5.0 × 10(7)), and high-dose (1.0 × 10(8)) group with three patients each. The phase II included nine patients receiving the high-dose. The primary outcomes were the safety and the Western Ontario and McMaster Universities Osteoarthritis index (WOMAC) at 6 months. Secondary outcomes included clinical, radiological, arthroscopic, and histological evaluations. There was no treatment-related adverse event. The WOMAC score improved at 6 months after injection in the high-dose group. The size of cartilage defect decreased while the volume of cartilage increased in the medial femoral and tibial condyles of the high-dose group. Arthroscopy showed that the size of cartilage defect decreased in the medial femoral and medial tibial condyles of the high-dose group. Histology demonstrated thick, hyaline-like cartilage regeneration. These results showed that intra-articular injection of 1.0 × 10(8) AD MSCs into the osteoarthritic knee improved function and pain of the knee joint without causing adverse events, and reduced cartilage defects by regeneration of hyaline-like articular cartilage.

Platelet-rich plasma for arthroscopic repair of large to massive rotator cuff tears: a randomized, single-blind, parallel-group trial.

BACKGROUND: Platelet-rich plasma (PRP) is expected to have a biological augmentation potential in the healing of various diseases and injuries, including rotator cuff tears. However, few evaluations have been performed specifically for large to massive tears. PURPOSE: To assess the efficacy of PRP augmentation in patients undergoing arthroscopic repair for large to massive rotator cuff tears. STUDY DESIGN: Randomized controlled trial; Level of evidence, 1. METHODS: A total of 48 patients scheduled for arthroscopic repair of large to massive rotator cuff tears were randomly assigned to receive either PRP-augmented (PRP group) or conventional treatment (conventional group). In the PRP group, 3 PRP gels (3 × 3 mL) were applied to each patient between the torn end and the greater tuberosity. The primary outcome measure was the retear rate assessed by magnetic resonance imaging (MRI) or computed tomographic arthrography (CTA) at a minimum of 9 months after surgery. Secondary outcome measures included pain, range of motion, muscle strength, overall satisfaction, functional scores, and the change in cross-sectional area (CSA) of the supraspinatus. RESULTS: The retear rate of the PRP group (20.0%) was significantly lower than that of the conventional group (55.6%) (P = .023). Clinical outcomes showed no statistical difference between the 2 groups (all P > .05) except for the overall function (P = .043). The change in 1-year postoperative and immediately postoperative CSA was significantly different between the 2 groups: -15.54 ± 94.34 mm² in the PRP group versus -85.62 ± 103.57 mm² in the conventional group (P = .047). CONCLUSION: The application of PRP for large to massive rotator cuff repairs significantly improved structural outcomes, as evidenced by a decreased retear rate and increased CSA of the supraspinatus compared with repairs without PRP augmentation. While there was no significant difference in clinical outcomes except the overall shoulder function after 1-year follow-up, better structural outcomes in the PRP group might suggest improved clinical outcomes at longer term follow-up.