Aims

To evaluate graft healing of decellularized porcine superflexor tendon (pSFT) xenograft in an ovine anterior cruciate ligament (ACL) reconstruction model using two femoral fixation devices. Also, to determine if pSFT allows functional recovery of gait as compared with the preoperative measurements.

Purpose: Massive rotator cuff defects are often associated with incapacitating pain and severe functional impairment and pose a difficult management problem. Introduction: Tears of the rotator cuff are a common orthopaedic condition. The surgical treatment for such defects is varied and include simple debridement, “balanced” repair, local musculotendinous transfers, and autograft or allograft tendon grafts. This study was designed to evaluate the mid-term results of porcine dermal xenograft tendon grafts in the treatment of chronic, massive rotator cuff defects. Method: Ten patients with a mean age of 64.9 years (46 – 80), 5 male, 5 female, with mean cuff defects of 4.5 cm, were selected from the waiting list to undergo an open subacromial decompression and grafting of the rotator cuff defect with a PDX patch. The patients were then subjected to the standard post-operative rehabilitation regime. All patients were assessed pre-operatively and at six weeks, three months, six months, and one year using the Constant score and Mini-DASH questionnaire. The study had the approval of the regional ethics committee. Results: All ten patients were followed up and demonstrated excellent pain relief from the procedure. Pain scores improved from 6.7 pre-operatively to 13.9 at 12 months. At the same time intervals function score improved from 12.1 to 15.7, range of movement from 13.6 to 21.4, power from 5.1 to 10.9, Constant score from 39.6 to 56.9 and finally the DASH score from 26 to 17.9. There were no major post-op complications and the graft did not cause any adverse reaction. Subjective and functional results improved to six months from pre-op values, but at one year, with the exception of pain, the results were slightly less good but still improved. Conclusion: This procedure offers an alternative method of managing massive rotator cuff tears. It simplifies the surgery with no tension on the repair and may reduce the requirement for prolonged splintage. Pain relief is excellent and there have been no reported adverse effects to the graft

The formation of postoperative adhesions poses a major complication in surgery, especially in the treatment of tendon, where adhesions can result in an alteration of the biomechanical and gliding properties, impeding a proper functioning of the tendon. Current treatments to prevent adhesions in the tendon are mainly based on the use of mechanical barriers which isolate the tendon and prevent fibrin deposition. Despite the positive results in preclinical models, these results have not been translated to clinics. Thus, in this study we propose a porcine peritoneum xenograft as an alternative antiadhesion barrier which integrates a basal membrane, since the presence of a basal membrane together with an epithelium or mesothelium layer prevents the formation of adhesions in vivo. First results have shown the suitability of the porcine peritoneum xenograft as an antiadhesion barrier due to its lower crosslinking ratio (p<0.05) and faster degradation by MMPs in vitro than a commercially available tendon product, which suggest a faster remodelling in vivo. On the other hand, the porcine peritoneum showed higher mechanical properties (p<0.01) and a lower coefficient of friction (p<0.01), characteristics that make the porcine peritoneum an appropriate material for tendon regeneration. Furthermore, the presence in the xenograft of a collagen type IV and laminin network after decellularisation was confirmed with immunohistochemistry, which poses the potential of the porcine peritoneum as antiadhesion device due to the presence of a basal membrane. Preliminary cell assessment experiments showed different morphology of adult dermal fibroblast (ADFs) on the different sides of the material (basal membrane and connective tissue) due to the differences in composition of both layers. Furthermore, the culture of ADFs during 7 days in media conditioned with the porcine peritoneum resulted in higher proliferation and metabolic activity (p<0.05) than those observed in the control and the media conditioned with the commercial product, suggesting the presence of growth factors in the porcine peritoneum which promote the growth of cells. Although positive results have been observed regarding the potential of porcine peritoneum as antiadhesion barrier for tendon regeneration, further studies which assess the influence of the basal membrane on cell behaviour and confirm the potential of the xenograft as antiadhesion barrier are being carried out