Controversial issues in knee arthroplasty

A prospective randomized clinical trial comparing tibial baseplate fixation with or without screws in total knee arthroplasty: a radiographic evaluation

In a randomized prospective study, we compared the use of tibial screws with screwless tibial baseplate fixation in uncemented total knee arthroplasty and report the results of 154 prostheses at a mean follow-up of 5 years. Patients were mobilized within 24 hours and continued with partial weight-bearing for up to 6 weeks postoperatively. There were no significant differences in radiologic results and revision rates. Radiographic outcomes do not seem to be influenced by the use of screws in tibial baseplate fixation of this prosthesis. The prosthesis studied has a large tibial keel and 4 adjunctive pegs that seem to provide adequate stability and allow bony ingrowth to take place. Longer follow-up will determine whether in this implant design, the use of tibial screws for cementless tibial baseplate fixation can be justified.

Results of total knee replacement with/without resurfacing of the patella

OBJECTIVE

To study the difference of post-op patellofemoral pain, clunk and crepitus in patients with/without resurfacing at 5 years who had pre-op patellofemoral pain. To study the incidence of post-operative patellofemoral pain, clunk and crepitus following patelloplasty in both the groups.

METHODS

Retrospective review of 765 patients who had total knee replacement with/without resurfacing.Patients were asked about both pre-operative pain and also post-operative pain 5 years after the operation. Patients were examined by a specialist nurse at 5 years post-operatively to check for any patellofemoral clunk/crepitus.

CONCLUSION

In patients with pre-op PF pain, there is significant (p<0.005) higher incidence of post-op clunk in the R group. In patients without pre-op PF pain, there is significantly (p<0.005) higher incidence of post-op crepitus in the R group. In patients with/without pre-op PF pain, the incidence of post-op PF pain, clunk and crepitus is lower than in patients who underwent patelloplasty when compared to the other members of the NR group (statistically significant p<0.005).

LEVEL OF EVIDENCE

Type 4, Case series .

Failure to resurface the patella during total knee arthroplasty may result in more knee pain and secondary surgery

Resurfacing the patella during primary total knee arthroplasty is controversial. The objective of this meta-analysis was to evaluate the outcome of total knee arthroplasty with or without resurfacing of the patella with particular attention to patient satisfaction, incidence of anterior knee pain, patellar complications, and the need for secondary operations. Computerized databases were searched for citations and published randomized clinical trials relevant to patellar resurfacing from 1966-2003. Of 158 citations identified as related to patellar resurfacing during total knee arthroplasty, 14 articles met all inclusion criteria for this study. The incidence of anterior knee pain was greater in knees with nonresurfaced patellas. Secondary resurfacings for anterior knee pain was needed in 8.7% of nonresurfaced knees. No difference in reported complications existed. Total knee arthroplasty resulted in improvement of functional outcome regardless of whether the patella was resurfaced. Based on the results of this meta-analysis, nonresurfacing of the patella during primary total knee arthroplasty is likely to result in a greater incidence of anterior knee pain, the need for secondary resurfacing in almost one in 10 patients, and possibly less patient satisfaction.

LEVEL OF EVIDENCE

Therapeutic study, Level IV (case series). See the Guidelines for Authors for a complete description of levels of evidence.

Computer-assisted decision analysis in orthopedics: resurfacing the patella in total knee arthroplasty as an example

The purpose of the present study was to illustrate the use of computer-assisted decision analysis in making decisions in the field of orthopaedic surgery, using the choice between resurfacing and not resurfacing the patella in total knee arthroplasty as an example. We used a decision analysis technique based on probability theory and on Bayesian logic, with the help of an especially developed computer software. The process involves building a decision tree, searching for probabilities and utilities in the literature, folding back the tree to compute the baseline result, and running sensitivity analyses. Our literature search provided 26 useful articles, only 3 of which were randomized controlled trials. In the baseline analysis, both options were rated similarly, with resurfacing the patella faring slightly better. Sensitivity analyses revealed that not resurfacing becomes the procedure of choice if the probability of postoperative anterior knee pain with an unresurfaced patella falls below 14%, or if the probability of having pain with a resurfaced patella rises above 8% or if the utility of patellar implant failure falls below 80% of the utility of a perfect health state. Computer-assisted decision analysis is a promising, evidence-based tool to assist clinical decision making in orthopaedic surgery. However, its validity is limited by the poor quality of data found in the orthopaedic literature, especially the scarcity of randomized controlled trials.