Patient-Reported Outcomes following Single- and Multiple-Radius Total Knee Replacement: A Randomized, Controlled Trial.

Although single-radius (SR) designs of total knee replacement (TKR) have theoretical benefits, the clinical advantage conferred by such designs is unknown. The aim of this randomized, controlled study was to compare the short-term clinical outcomes of the two design rationales. A total of 105 knees were randomized to receive either a single radius (Scorpio, Stryker; SR Group) or multiple radius (AGC, Zimmer Biomet; MR group) TKR. Patient-reported outcomes (Oxford Knee Score [OKS] and Knee Society Score [KSS]) were collected at 6 weeks, 6 months, and 1 year following surgery. No knees were revised. There was no difference in primary outcomes: OKS was 39.5 (95% confidence interval [CI]: 36.9-42.1) in the SR group and 38.1 (95% CI: 36.0-40.3) in the MR group (p = 0.40). KSS was 168.4 (95% CI: 159.8-177.0) in the SR group; 159.5 (95% CI 150.5-168.5) in the MR group (p = 0.16). There was a small but statistically significant difference in the degree of change of the objective subscale of the KSS, favoring the SR design (p = 0.04), but this is of uncertain clinical relevance. The reported benefits of SR designs do not provide demonstrable functional advantages in the short term.

Accelerated rehabilitation after total knee replacement.

This study records the length of hospital stay of 50 total knee arthroplasty patients involved in an accelerated postoperative rehabilitation protocol, and a control group of patients undergoing routine rehabilitation. This protocol involved modifications to normal knee replacement procedure, including infiltration of bupivacaine and adrenaline to the divided tissue layers at the time of surgery, spinal anaesthesia, and mobilisation on the day of surgery. These modifications were combined with an organised multidisciplinary approach anticipating issues that may delay discharge. In addition, patients and hospital staff were encouraged to expect an earlier discharge from the hospital. The mean length of hospital stay after surgery was reduced to 3.6 (S.D. 1.0) days, from a previous departmental average of 10.5 days. The control group inpatient stay was 6.6 (S.D. 2.6) days. Plasma bupivacaine levels were found to be well within safe levels, and pain records indicated that the protocol did not cause increased levels of discomfort. American Knee Society and Oxford knee scores demonstrated good levels of knee function at 6 weeks post surgery. In addition, it was noted that no postoperative blood transfusions were required. This is regarded as a significant further benefit.