The reasons for failure of a hemirthroplasty (HA) when used to
treat a proximal humeral fracture include displaced or necrotic
tuberosities, insufficient metaphyseal bone-stock, and rotator cuff
tears. Reverse total shoulder arthroplasty (rTSA) is often the only
remaining form of treatment in these patients. The aim of this study
was to evaluate the clinical outcome after conversions from a failed
HA to rTSA. A total of 35 patients, in whom a HA, as treatment for a fracture
of the proximal humerus, had failed, underwent conversion to a rTSA.
A total of 28 were available for follow-up at a mean of 61 months
(37 to 91), having been initially reviewed at a mean of 20 months
(12 to 36) postoperatively. Having a convertible design, the humeral
stem could be preserved in nine patients. The stem was removed in
the other 19 patients and a conventional rTSA was implanted. At
final follow-up, patients were assessed using the American Shoulder
and Elbow Surgeons (ASES) score, the Constant Score, and plain radiographs.Aims
Material and Methods
Despite widespread use of radiofrequency (RF) shrinkage, there have been no animal studies on the effects of post-operative immobilisation on the histological properties of the shrunken tissue. We have therefore examined the role of post-operative immobilisation after RF shrinkage with special emphasis on the histological properties of collagenous tissue. One patellar tendon of 66 New Zealand White rabbits was shrunk. Six rabbits were killed immediately after the operation. Twenty rabbits were not immobilised, 20 were immobilised for three weeks and 20 for six weeks. Fibroblasts, collagen and vascular quality and density were evaluated on sections, stained by haematoxylin and eosin. Nine weeks after operation the histological properties were inferior to those of the contralateral control tendons. Shrunk tendons did not return to normal at any time after operation irrespective of whether the animals had been immobilised or not. All the parameters improved significantly between zero and three weeks after operation. Immobilised tendons tended to have a better and faster recovery. Careful rehabilitation is imperative after RF shrinkage. Immobilisation aids recovery of the histological properties. Our findings in this animal model support a period of immobilisation of more than three weeks.
