Unicompartmental Knee Arthroplasty: A Current Review
Unicompartmental Knee Arthroplasty: A Current Review
There are several documented advantages to utilizing unicompartmental knee arthroplasty over total knee arthroplasty in properly selected patients. Studies have demonstrated a lower perioperative morbidity and mortality rate in patients undergoing UKA when compared with TKA. Also, patients who have had UKA have been shown to be able to walk farther while hospitalized, have a shorter length of hospital stay, have better early range of motion, and higher Knee Society scores than patients after TKA.
Another advantage of unicompartmental knee arthroplasty is preservation of the normal ligamentous structures in the knee that drive normal knee kinematics. Recent data suggest that the status of the anterior cruciate ligament (ACL) is important to postoperative functional and satisfaction scores in TKA. The data showed that patients with an intact ACL at the time of TKA had lower postoperative functional and clinical scores, less improvement, and lower range of motion than TKA patients with preexisting ACL deficiency. This may suggest that properly selected patients would do better with UKA as opposed to TKA (Berend et al. Does the status of the ACL at the time of primary total knee arthroplasty predict early outcomes? Poster presentation at the American Association of Hip and Knee Surgeons 24th Annual Meeting, November 2014, Dallas, TX).
A heavily quoted disadvantage of UKA is the higher rate of revision surgery. The New Zealand Joint Registry reports a three-fold higher revision rate when comparing UKA to TKA despite the fact that the 6mo average Oxford Knee Score was higher in patients with UKA. These increased revision rates could be attributed to the fact that converting a UKA to a TKA is a less complex surgery to perform than revising a TKA (Dodd, et al. Medial unicompartmental knee arthroplasty is an efficacious procedure despite Registry Data, Poster presentation at the Knee Society Meeting, March 2013, Chicago, IL)
UKA Versus TKA
There are several documented advantages to utilizing unicompartmental knee arthroplasty over total knee arthroplasty in properly selected patients. Studies have demonstrated a lower perioperative morbidity and mortality rate in patients undergoing UKA when compared with TKA. Also, patients who have had UKA have been shown to be able to walk farther while hospitalized, have a shorter length of hospital stay, have better early range of motion, and higher Knee Society scores than patients after TKA.
Another advantage of unicompartmental knee arthroplasty is preservation of the normal ligamentous structures in the knee that drive normal knee kinematics. Recent data suggest that the status of the anterior cruciate ligament (ACL) is important to postoperative functional and satisfaction scores in TKA. The data showed that patients with an intact ACL at the time of TKA had lower postoperative functional and clinical scores, less improvement, and lower range of motion than TKA patients with preexisting ACL deficiency. This may suggest that properly selected patients would do better with UKA as opposed to TKA (Berend et al. Does the status of the ACL at the time of primary total knee arthroplasty predict early outcomes? Poster presentation at the American Association of Hip and Knee Surgeons 24th Annual Meeting, November 2014, Dallas, TX).
A heavily quoted disadvantage of UKA is the higher rate of revision surgery. The New Zealand Joint Registry reports a three-fold higher revision rate when comparing UKA to TKA despite the fact that the 6mo average Oxford Knee Score was higher in patients with UKA. These increased revision rates could be attributed to the fact that converting a UKA to a TKA is a less complex surgery to perform than revising a TKA (Dodd, et al. Medial unicompartmental knee arthroplasty is an efficacious procedure despite Registry Data, Poster presentation at the Knee Society Meeting, March 2013, Chicago, IL)
