We reviewed the long-term clinical and radiological
results of 63 uncemented Low Contact Stress (LCS) total knee replacements
(TKRs) in 47 patients with rheumatoid arthritis. The mean age of
the patients at the time of surgery was 69 years (53 to 81). At
a mean follow-up of 22 years (20 to 25), 12 patients were alive
(17 TKRs), 27 had died (36 TKRs), and eight (ten TKRs) were lost
to follow-up. Revision was necessary in seven patients (seven TKRs, 11.1%)
at a mean of 12.1 years (0 to 19) after surgery. In the surviving
ten patients who had not undergone revision (15 TKRs), the mean
Oxford knee score was 30.2 (16 to 41) at a mean follow-up of 19.5
years (15 to 24.7) and mean active flexion was 105° (90° to 150°).
The survival rate was 88.9% at 20 years (56 of 63) and the Kaplan–Meier
survival estimate, without revision, was 80.2% (95% confidence interval
37 to 100) at 25 years. Cite this article:
The management of the patella during total knee replacement is controversial. In some studies the absence of patellar resurfacing results in residual anterior knee pain in over 10% of patients. One form of treatment which may be used in an endeavour to reduce this is circumferential patellar rim electrocautery. This is believed to partially denervate the patella. However, there is no evidence of the efficacy of this procedure, nor do we know if it results in harm. A retrospective comparative cohort study was performed of 192 patients who had undergone a primary total knee replacement with the porous coated Low Contact Stress rotating platform prosthesis without patellar resurfacing between 2003 and 2007. In 98 patients circumferential electrocautery of the patellar rim was performed and in 94 patients it was not. The two groups were matched for gender and age. The general Oxford Knee Score and the more specific patellar score for anterior knee pain were used to assess patient outcomes a minimum of two years post-operatively. No statistically significant differences were noted between the groups for either scoring system (p = 0.41 and p = 0.87, respectively). Electrocautery of the patella rim did not improve the outcome scores after primary total knee replacement in our patients.
We analysed the long-term clinical and radiological results of 63 uncemented Low Contact Stress total knee replacements in 47 patients with rheumatoid arthritis. At a mean follow-up of 12.9 years (10 to 16), 36 patients (49 knees) were still alive; three patients (five knees) were lost to follow-up. Revision was necessary in three knees (4.8%) and the rate of infection was 3.2%. The mean clinical and functional Knee Society scores were 90 (30 to 98) and 59 (25 to 90), respectively, at final follow-up and the mean active range of movement was 104° (55° to 120°). The survival rate was 94% at 16 years but 85.5% of patients lost to follow-up were considered as failures. Radiological evidence of impending failure was noted in one knee.
We have studied prospectively the outcome of wound discharge in patients after arthroplasty of the hip and knee. Over a period of 3.5 years 530 primary arthroplasties were carried out in one hospital. Postoperative wound infections developed in 82. At a mean follow-up of two years a comparison was made between these patients and 82 with healthy wounds, in terms of symptoms and signs of deep infection. There was an incidence of 1.1% of early deep infection, within six weeks in all cases. The rate of ‘superficial’ infection was 17.3% in the hips, 10.5% in the knees and 14.3% in total. At a mean follow-up of 26 months, there were no significant differences between the patients with infected wounds and a matched group of patients with healthy wounds in terms of the ESR, level of C-reactive protein, white cell count and radiological scores, but clinical scores were significantly worse in the patients with infected knees (p <
0.05). The length of stay was also significantly longer in this group (mean 14.6 days in the healthy wound group, 19 days in the problem group; p <
0.005). There was, however, no convincing evidence that these wound infections led to deep infection and early revision in the early to medium follow-up period. A larger and longer prospective trial would be necessary to shed more light on this potential problem.
