Introduction. Differing levels of tendon retraction are found in full-thickness rotator cuff tears. The pathophysiology of tendon degeneration and retraction is unclear. Neoangiogenesis in tendon parenchyma indicates degeneration. Hypoxia inducible factor 1(HIF) and vascular endothelial growth factor (VEGF) are important inducers of neoangiogenesis. Rotator cuff tendons rupture leads to fatty muscle infiltration (FI) and muscle atrophy (MA). The aim of this study is to clarify the relationship between HIF and VEGF expression, neoangiogenesis, FI, and MA in tendon retraction found in full-thickness rotator cuff tears. Methods. Rotator cuff tendon samples of 33 patients with full-thickness medium-sized rotator cuff tears were harvested during reconstructive surgery. The samples were dehydrated and paraffin embedded. For immunohistological determination of VEGF and HIF expression, sample slices were strained with VEGF and HIF antibody dilution. Vessel density and vessel size were determined after Masson-Goldner staining of sample slices. The extent of tendon retraction was determined intraoperatively according to Patte's classification. Patients were assigned to 4 categories based upon Patte tendon retraction grade, including one control group. FI and MA were measured on standardized preoperative shoulder MRI. Results. HIF and VEGF expression, FI, and MA were significantly higher in torn cuff samples compared with healthy tissue (p<0.05). HIF and VEGF expression, and vessel density significantly increased with extent of tendon retraction (p<0.04). A correlation between HIF/VEGF expression and FI and MA could be found (p<0.04). There was no significant correlation between HIF/VEGF expression and neovascularity (p>0.05). Conclusion. Tendon retraction in full-thickness medium-sized rotator cuff tears is characterized by neovascularity, increased VEGF/HIF expression, FI, and MA. VEGF expression and neovascularity may be effective monitoring tools to assess tendon degeneration

The aim is to evaluate the effectiveness of pericardium patch as a tendon augmentation graft in the repair of massive rotator cuff tear. This is prospective study analysis of a consecutive series of 60 patients who underwent open repair of a massive rotator cuff tear with patch between 1999 and 2007. The inclusion criteria were: symptomatic with pain, deficit of elevation, not responsive to the physiotherapy, tear size (massive: 2 or more tendons), minimum follow-up of 2 years since surgery, active and motivated patients. All were assessed preoperatively with plain radiographs (anteroposterior and axillary views), ultrasound and NMR of the shoulder. The study group consistent of 60 patients (39 men and 21 women) with the mean age of was 66 years (range, 46–81). The mean duration of symptoms before repair was 18 months (range 3–48). Patients were assessed with UCLA score, visual analog scale (Vas scale) and ultrasound preoperatively, at 1 year, and at 3 years. The change in UCLA scores, Vas scale were analyzed with the paired Student's test, assuming a normal distribution of the total score. Satisfactory results were achieved in 49 patients: mean preoperative UCLA score improved from 9.3 to 16.9 at final follow-up. For pain, the mean preoperative value of Vas scale was 9,1, postoperative mean value was 4.9. Range of motion and abduction power improved not significantly after surgery, although patients satisfaction levels were high. Imaging studies identified intact patch in 15 patients and patch detachment in 45. No adverse side effects (infection, rejection, allergy) were reported during the study period. The results of our study suggest that patients (appropriately selected) with a massive full-thickness rotator cuff tear can be expected to have a pain relief after repair, but not a significantly improved of functional outcome