The aim of this study was to ascertain if a correlation exists between the indication for revision and the clinical outcome in revision total knee replacement.

Methods: We analysed the data of 81 revision knee arthroplasty patients performed at Wrightington Hospital with an average follow-up of 31 months (1yr – 6yrs). All patients had semi-constrained prosthesis implanted (PS-PFC or TC3, Depuy). The indications for revising the total knee arthroplasty in each patient were noted and the clinical outcome was determined using a patient satisfaction questionnaire.

Results: Of the 81 patients, 18 were enthusiastic with the clinical outcome, 38 were satisfied, eight were non-committal and 17 were disappointed. Indications for revision in our series were aseptic loosening (31 patients), implant failure (21 patients), instability (14 patients), pain (eight patients) and infection (seven patients). Correlation between the indication for revision and the clinical outcome are detailed in the table below.

Sixteen per cent of patients revised for aseptic loosening were non-committal or disappointed with the outcome in comparison with 33.3% revised for implant failure, 21.4% revised for instability, 62.5% revised for pain and 71.4% revised for infection.

Conclusion: The indication for revision does affect the clinical outcome in revision knee arthroplasty. Patients undergoing revision knee arthroplasty for infection and pain are less likely to be satisfied with the clinical outcome of revision surgery.

It is usually assumed that there is a correlation between the number of previous operations and the clinical outcome of revision knee arthroplasty though it has not been studied and published. We reviewed our series of 81 revision knee arthroplasty patients to ascertain if a correlation exists. All patients had a semi-constrained prosthesis implanted.

Methods: We analysed the data of 81 revision knee arthroplasty patients performed at Wrightington Hospital with an average follow-up of 31 months (1yr – 6yrs). The number of previous operations on each knee were noted and the clinical outcome was determined using a patient satisfaction questionnaire.

Results: Of the 81 patients; 18 were enthusiastic with the clinical outcome; 38 were satisfied; eight were non-committal; 17 were disappointed. Seventy four per cent of patients with one previous operation were enthusiastic or satisfied with the revision surgery outcome in comparison to 55.5% and 0% of patients with two and three previous surgery respectively.

Conclusion: The trend from the above figures suggests that as the number of previous operations increases the likelihood of satisfactory clinical outcome decreases, in revision total knee replacement using semi-constrained prosthesis.

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.