Abstract
The Nottingham Hood is a polyester soft tissue reinforcement device for the treatment of weakened or torn rotator cuff tendons (RCTs). The device was introduced in 1987 and has undergone a number of modifications from a close weave polyester modified aortic vascular graft (Mark 1) to an embroidered trefoil shape (Mark 4 – Pearsall’s Ltd) which has now been available since 2000. While this device has been under development it has been used on a named patient basis for 10 years on humanitarian grounds as an alternative treatment option for patients with massive RCTs. Approximately 30 Nottingham Hoods have been inserted over the past 10 years. This study investigates the histological changes and ingrowth associated with this device.
Four patients who have had the Nottingham Hood inserted for massive RCTs have had re-operations for various reasons on five occasions. Excised material from the rotator cuff has been subjected to histological investigation. Excised biopsy material has been obtained 6 weeks, 6, 9 & 12 months and 14 years following implantation. Transmitted and polarised light microscopy has been used in all cases.
At 6 weeks birefringent clear material similar to suture material was identified, invested by fibrin and occasional red cells i.e. old thrombus. The fibrin was partly calcified and insinuated between bundles of the meshwork material. No true ingrowth of material was seen at this stage. At 6 months the material was seen macroscopically to be covered with collagenous material, rather like fascia which interdigitated closely with the embedded polyester material. At 14 years the mesh appeared to be invested, sandwich-like into a collagenous fascia-like structure with dense hyaline bands of collagen. Some fibrin was also present between the fibrils and a low grade foreign body giant cell response with light chronic inflammation. The local synovium showed detritic synovitis.
The histological features show that there is an early organisational response to the insertion of the new tissue, which is then accompanied by long-term incorporation into host tissues by fibrosis and scarring. A small fibrin and foreign body response lingers on.
This long-term follow-up assessment provides evidence that long-term implantation of polyester as reinforcement for the rotator cuff tendons is not associated with serious biological problems. However the problem of stretching of the repaired rotator cuff muscles does occur and needs to be considered in more depth.
These abstracts were prepared by Mr Cormac Kelly. Correspondence should be addressed to him c/o British Orthopaedic Association, Royal College of Surgeons, 35-43 Lincoln’s Inn Fields, London WC2A 3PN.
