Arthroscopic Bankart reconstruction using different absorbable tacks. The clinical results, radiographic findings and effect on calcaneal bone mineral

Sammanfattning: ABSTRACT The aim of the thesis was to explore the clinical and radiographic results after post- traumatic anterior shoulder instability treated with arthroscopic Bankart surgery using absorbable tacks with different compositions. Further aims were to explore possible effects on bone mineral in the heel bone and health-related quality of life after a shoulder-stabilising surgical procedure. Study I was a clinical long-term study of 81 patients (84 shoulders) operated on using tacks made of PGA (polygluconate B polymer). The majority of patients had good functional results after eight years, although 18% had recurrent instability. Study II was a randomised, controlled study (RCT) using two different tacks, PGA and PLLA (poly-L-lactate acid polymer), with a clinical and radiographic evaluation after seven years. The drill holes after implanting PLLA tacks (18 patients) had healed to a lesser extent (55% unhealed) than those after implanting PGA tacks (17 patients), (0% unhealed), seven years after the operation. There were no differences between the groups regarding radiographic degenerative findings or functional results. Study III (32 patients, 34 shoulders) was a clinical and radiographic two- and eight-year follow-up after reconstruction using PGA implants. As in Study II, the radiographs were classified with regard to the drill-hole appearance and degenerative changes. In Study III, the radiological degenerative changes increased from no changes preoperatively to 24% mild and 18% moderate degenerative changes eight years postoperatively. In Study IV (23 patients), bone mineral was evaluated using Dual-Energy X-ray Absorptiometry (DEXA) combined with laser measurement in the heel bone preoperatively and until five years postoperatively. Activity level was classified according to Tegner activity level and health-related quality of life was classified with the Euroqol 5-dimension (EQ-5D) instrument. The bone mineral had decreased by 6% in the calcaneus five years after the operation. The activity level did not increase, but the EQ-5D increased after the operation.