Abstract
Background: Opinions about hinged knee prostheses vary a lot in different studies. We wanted to examine our series to ascertain their continued need in treating severely unstable knee joints and look at the early results.
Methods: 30 rotating hinged knee prostheses were implanted in Wrightington Hospital by the senior author. 4 patients deceased and the remaining knees were retrospectively followed up for an average of 16 months and examined for clinical or radiological factors indicating the overall outcome.
Results: Preoperative diagnosis: Gross instability associated with 12 – aseptic loosening; 18 – infection (15 pseudarthrosis, 1 failed arthrodesis) 19
Preoperatively, 16 patients were wheelchair bound and using a frame as a walking aid and 10 used two crutches for ambulation. 5 patients needed plastic surgical input and 5 needed a whiteside’s osteotomy for exposure. Previous surgery on the knee:
2 patients – 1 surgery
13 patients – 2 surgeries
8 patients – 3 surgeries
5 patients – 4 surgeries
2 patients – more than 4 surgeries
In the latest review, excluding the deceased patients, there were 24 patients (89%) regarded as having satisfactory and 3 patients (11%) unsatisfactory results. 89% of the patients were subjectively satisfied with the operation, mostly because of a stable, mobile knee with minimal pain, in comparison to their pre-operative debilitating condition.
Conclusions: Apart from clinical and radiological examination, preoperative diagnosis, pain, mobility, the number of previous surgeries and need for plastic surgery can be used as factors to assess the preoperative severity/morbidity of the case. Taking into account the very poor initial status of these patients, we recommend the rotating hinged prostheses still to be used in severely unstable knees.
The abstracts were prepared by Mr R. B. Smith. Correspondence should be addressed to him at the British Orthopaedic Association, Royal College of Surgeons, 35-43 Lincoln’s Inn Fields, London WC2A 3PN.
