Cruciate-Retaining Total Knee Arthroplasty versus Unicompartmental Knee Arthroplasty in Medial Compartmental Osteoarthritis: A Propensity Score-Matched Analysis of Early Postoperative Recovery

Artit Laoruengthana,1 Kongpob Reosanguanwong,1 Piti Rattanaprichavej,1 Kamonnop Sahasoonthorn,1 Nopparat Santisathaporn,1 Krit Pongpirul2,3 1Department of Orthopaedics, Faculty of Medicine, Naresuan University, Phitsanulok, Thailand; 2Department of Preventive and Social Medicine, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand; 3Department of International Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USACorrespondence: Kongpob Reosanguanwong, Department of Orthopaedics, Faculty of Medicine, Naresuan University, Phitsanulok, Thailand, Email reosanguanwongk@gmail.comBackground: Cruciate-retaining (CR) total knee arthroplasty (TKA) may provide better physiological knee kinematics, proprioception, and quadricep recovery than posterior-stabilized (PS) TKA. Therefore, we hypothesized that CR TKA with multimodal pain control may provide comparable postoperative pain and recovery as unicompartmental knee arthroplasty (UKA).Methods: This study included patients with isolated medial compartment knee osteoarthritis who underwent CR TKA and UKA. TKA and UKA patients were propensity score-matched with age and body mass index (BMI) and compared using visual analog scales (VAS) for pain scores, total amount of morphine use (TMU), knee flexion angle, straight leg raise (SLR), independent ambulation, length of hospital stay (LOS), and costs during hospitalization.Results: After propensity score matching, 46 patients were included in the TKA and UKA groups, respectively, with no differences in demographic data. VAS at 6– 72 h and TMU at 48 h after surgery were comparable between the groups. The knee flexion angle in the UKA group was significantly higher at 24 h (60.0° vs 46.6°; p< 0.001) and 48 h (76.9° vs 69.1°; p = 0.021) than that in the TKA group. The SLR in the UKA group was significantly higher than that in the TKA group at 24– 72 h. The UKA group ambulated significantly earlier (1.56 vs 2.13 days; p< 0.001), had shorte