[Analysis of factors relating to clinical outcomes after total knee replacement]

To analyze the outcomes and complications after total knee replacement (TKR) with posterior stabilized prosthesis (PS) and to investigate the influencing factors relating to outcomes.

From January 1998 to August 2004, 60 cases (74 knees) of osteoarthritis underwent TKR with PS. The outcomes were evaluated according to the HSS (hospital for special surgery) scoring. The difference in outcomes between patients with post-operative complications and without complications were compared. Pearson correlation was used to analyze postoperative outcomes and the pre-operative factors relating to patients.

All 74 knees were followed up 42.5 months (24 to 94 months). The scores for HSS, pain, function, ROM muscle strength, flexion deformity and stability of knees after operation were 84.2 +/- 14.2, 25.7 +/- 6.9, 17.9 +/- 4.3, 13.1 +/- 2.0, 9.2 +/- 0.8, 8.1 +/- 0.4 and 9.3 +/- 0.1 respectively. They were improved to some extents, especially pain alleviation was remarkable. The excellent and good rate for outcome assessment was 90.5%. Among 74 knees, 10 cases suffered from post-operative complications, including 1 case of common peroneal nerve paralysis, two cases of wound faulty union, one case of wound infection, one case of joint infection, one case of stiff knee, two cases of deep vein thrombosis and 2 cases of patellofemoral joint complications. The excellent and good rate of outcome in patients with complications (60%) was much lower than that in patients without complication (95.3%),and there was significant difference between them (P < 0.05). Analysis for correlation showed that postoperative HSS score was positively correlative with the postoperative HSS score, pain and function score of knees. The correlation value was 0.523, 0.431 and 0.418 respectively (P < 0.01). Whereas, postoperative HSS score was not correlative with ROM, muscle strength, flexion deformity, stability of knee, age, weight and body mass index (P > 0.05).

TKR with PS is an effective method for severe osteoarthritis. The outcomes after TKR have a positive correlation with the HSS score, pain and function score of knees before surgery. Complications associating with surgery have a negative influence on outcomes.