MATERIALS AND METHODS
First, we objectively compared the pre- and postoperative quadriceps strength and power of both patient groups using the Keiser A420 leg press. We also analyzed the data obtained from validated functional tests, such as the six-minute walk test and timed get up & go test, and from patient-reported outcomes, including the Knee Injury and Osteoarthritis Outcome Score (KOOS) and the Forgotten Joint Score 12 (FJS12). Additionally, we investigated the benefits of ischemic preconditioning performed on the affected leg before implementing one of both arthroplasty techniques. Some studies have suggested that preconditioning is beneficial, but its potential benefits have not yet been fully proven. In our study, we thus tried to answer this question regarding limb preconditioning in knee arthroplasty.
Preoperative analysis revealed a better muscular capacity of the affected legs in patients of the UKA group as compared to those of the TKA group. No difference was found in the healthy contralateral legs between both groups. Postoperative analysis showed a significant difference in strength between the healthy legs of the UKA and TKA groups, with the strength increasing from 1,162±86 N to 1419± 158N on average in the UKA group while decreasing from 1018±98 N to 961±141 N in the TKA group. Preoperative ischemic preconditioning of the quadriceps muscle did not show any significant impact.
Prior to treatment, patients eligible for UKA have on average a more powerful quadriceps muscle than patients eligible for TKA. This difference between patient groups increases after surgery, and the TKA technique seems to have an unexpected harmful impact on the non-operated contralateral quadriceps muscle. Finally, our study was not able to confirm any benefit of limb preconditioning in knee arthroplasty surgery.