Tomoyuki Kamenaga1,2, Takafumi Hiranaka3, Yuichi Hida1, Naoki Nakano2, Yuichi Kuroda2, Masanori Tsubosaka2, Shinya Hayashi2, Ryosuke Kuroda2, Tomoyuki Matsumoto2. 1. Department of Orthopedic Surgery and Joint Surgery Centre, Takatsuki General Hospital, 1-3-13, Kosobe-cho, Takatsuki, Osaka, 569-1192, Japan. 2. Department of Orthopaedic Surgery, Kobe University Graduate School of Medicine, 7-5-1, Kusunoki-cho, Chuo-ku, Kobe, 650-0017, Japan. 3. Department of Orthopedic Surgery and Joint Surgery Centre, Takatsuki General Hospital, 1-3-13, Kosobe-cho, Takatsuki, Osaka, 569-1192, Japan. takafumi.hiranaka@gmail.com.
Abstract
PURPOSE: Lateral compartment osteoarthritis progression (LOP) is a major complication after Oxford mobile-bearing unicompartmental knee arthroplasty (OUKA). This study aimed to identify the association between tibiofemoral subluxation (TFS) and LOP after OUKA. Patients whose TFS was uncorrectable according to preoperative stress radiographs were hypothesised to develop residual TFS even after surgery, and thought to be more likely to develop LOP. METHODS: The study included 201 patients who underwent medial OUKA. Fifteen patients showed increases in LOP of at least two Kellgren-Lawrence grades after surgery [progression (P) group], while the others had no progression (N group, n = 186). TFS was measured on preoperative full leg weight-bearing radiographs, valgus stress radiographs and postoperative plain radiographs. Valgus stress radiographs were obtained using a firm manual valgus force with the knee flexed at 20°. Leg alignment, Oxford knee score (OKS), and revision rates were assessed. RESULTS: The P group had significantly higher TFS values on preoperative valgus stress (6.8° ± 2.2° vs. 4.5° ± 2.0°; P < 0.001) and postoperative radiographs (6.6° ± 2.3° vs. 4.6° ± 2.9°; P < 0.001) than the N group. Patients with postoperative residual TFS and postoperative valgus alignment were more likely to have LOP, but 9 of the 15 LOP patients did not show postoperative valgus alignment. The P group had significantly poorer postoperative OKS (33.0 ± 10.2 vs. 37.4 ± 6.5, P = 0.017) and a higher rate of revision (6/15 vs 6/186; odds ratio = 19.16; 95% CI = 4.98-76.05, P < 0.001). CONCLUSION: OA progression in the lateral compartment after medial OUKA might be associated with postoperative residual TFS, but does not always coexist with postoperative valgus alignment. Preoperative assessment of TFS with valgus stress could be a potential predictor of postoperative residual TFS and LOP. LEVEL OF EVIDENCE: Level III.
PURPOSE: Lateral compartment osteoarthritis progression (LOP) is a major complication after Oxford mobile-bearing unicompartmental knee arthroplasty (OUKA). This study aimed to identify the association between tibiofemoral subluxation (TFS) and LOP after OUKA. Patients whose TFS was uncorrectable according to preoperative stress radiographs were hypothesised to develop residual TFS even after surgery, and thought to be more likely to develop LOP. METHODS: The study included 201 patients who underwent medial OUKA. Fifteen patients showed increases in LOP of at least two Kellgren-Lawrence grades after surgery [progression (P) group], while the others had no progression (N group, n = 186). TFS was measured on preoperative full leg weight-bearing radiographs, valgus stress radiographs and postoperative plain radiographs. Valgus stress radiographs were obtained using a firm manual valgus force with the knee flexed at 20°. Leg alignment, Oxford knee score (OKS), and revision rates were assessed. RESULTS: The P group had significantly higher TFS values on preoperative valgus stress (6.8° ± 2.2° vs. 4.5° ± 2.0°; P < 0.001) and postoperative radiographs (6.6° ± 2.3° vs. 4.6° ± 2.9°; P < 0.001) than the N group. Patients with postoperative residual TFS and postoperative valgus alignment were more likely to have LOP, but 9 of the 15 LOP patients did not show postoperative valgus alignment. The P group had significantly poorer postoperative OKS (33.0 ± 10.2 vs. 37.4 ± 6.5, P = 0.017) and a higher rate of revision (6/15 vs 6/186; odds ratio = 19.16; 95% CI = 4.98-76.05, P < 0.001). CONCLUSION: OA progression in the lateral compartment after medial OUKA might be associated with postoperative residual TFS, but does not always coexist with postoperative valgus alignment. Preoperative assessment of TFS with valgus stress could be a potential predictor of postoperative residual TFS and LOP. LEVEL OF EVIDENCE: Level III.
Authors: Hasan Raza Mohammad; Stephen Mellon; Andrew Judge; Christopher Dodd; David Murray Journal: Knee Surg Sports Traumatol Arthrosc Date: 2021-04-17 Impact factor: 4.342
Authors: Priyanka Ghosh; Hasan R Mohammad; Benjamin Martin; Stefano Campi; David W Murray; Stephen J Mellon Journal: Knee Surg Sports Traumatol Arthrosc Date: 2020-09-17 Impact factor: 4.342
Authors: D M Moore; G A Sheridan; A Welch-Phillips; J M O'Byrne; P Kenny Journal: Knee Surg Sports Traumatol Arthrosc Date: 2021-07-12 Impact factor: 4.114