Central Sensitization Is Associated with Inferior Patient-Reported Outcomes and Increased Osteotomy Site Pain in Patients Undergoing Medial Opening-Wedge High Tibial Osteotomy

Abstract

Background and Objectives: Studies have shown that centrally sensitized patients have worse clinical outcomes following total knee arthroplasty (TKA) than non-centrally sensitized patients. It is unclear whether central sensitization (CS) affects patient-reported outcomes (PROs) and/or level of osteotomy site pain in patients undergoing medial opening-wedge high tibial osteotomy (MOWHTO). The purpose of this study was to determine whether CS is associated with PROs and osteotomy site pain following MOWHTO. Materials and Methods: A retrospective evaluation was conducted on 140 patients with varus knee osteoarthritis (OA) who were treated with MOWHTO and monitored for two years. Before surgery, the Central Sensitization Inventory (CSI) was used to assess CS status, and a CSI of 40 or higher was considered indicative of CS. The Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) and pain visual analogue scale (VAS) were used to assess PROs. The minimal clinically important difference (MCID) for the WOMAC was set as 4.2 for the pain subscore, 1.9 for the stiffness subscore, 10.1 for the function subscore, and 16.1 for the total based on the results of a previous study. The WOMAC score, pain VAS score of the osteotomy site, and the achievement rates of WOMAC MCID were compared between the CS and non-CS groups. Results: Thirty-seven patients were assigned to the CS group, whereas 84 were assigned to the non-CS group. Before surgery, the CS group showed a higher WOMAC score than the non-CS group (58.7 vs. 49.4, p < 0.05). While there was a statistically significant improvement in WOMAC subscores (pain, stiffness, function, and total) for both groups at two years after surgery (all p < 0.05), the CS group had a higher WOMAC score than the non-CS group (37.1 vs. 21.8, p < 0.05). The CS group showed significantly inferior results in pre- and postoperative changes of WOMAC subscores (pain, function, and total) relative to the non-CS group (all p < 0.05). In addition, pain at the osteotomy site was more severe in the CS group than in the non-CS group at two years after surgery (4.8 vs. 2.2, p < 0.05). Patients with CS had worse MCID achievement rates across the board for WOMAC pain, function, and total scores (all p < 0.05) compared to the non-CS group. Conclusions: Centrally sensitized patients following MOWHTO had worse PROs and more severe osteotomy site pain compared to non-centrally sensitized patients. Furthermore, the WOMAC MCID achievement rate of patients with CS was lower than that of patients without CS. Therefore, appropriate preoperative counseling and perioperative pain management are necessary for patients with CS undergoing MOWHTO. Level of Evidence: Level III, case-control study.

Low central sensitisation inventory score is associated with better post‐operative outcomes of osteotomy around the knee

“…The primary outcome of this study is concordant with previous studies [15, 16, 19, 29] indicating that a high CSI score is correlated with unfavourable outcomes following surgeries for KOA treatment, even after adjusting for confounding factors. While the majority of similar studies focus on TKA [16, 19, 29], there is only one existing study by Kim et al that addresses OWHTO.…”

“…While the majority of similar studies focus on TKA [16, 19, 29], there is only one existing study by Kim et al that addresses OWHTO. In their study, Kim et al [15] reported that patients with a high pre‐operative CSI score (≥ 40) experienced poorer patient‐reported outcomes and higher levels of pain two years after the surgery. However, it should be noted that there is a discrepancy in the cut‐off scores between Kim et al and this present study.…”

“…In previous studies [15, 19, 29] with a similar nature, the patient groups were commonly divided based on a CSI cut‐off score of 40. However, this cut‐off was derived from studying CSS patients and healthy university students, with no consideration of osteoarthritis as a potential comorbidity [26].…”

“…Earlier studies established an optimum CSI cut-off score of 40 for identifying CSSs [26]. A recent study conducted by Kim et al [15] highlighted that a pre-operative CSI score of 40 or higher is associated with an inferior outcome following medial open-wedge high tibial osteotomy (OWHTO) compared to patients with lower scores. On the other hand, Mibu et al [25] proposed that of 17 would be an optimal CSI cut-off value for KOA patients and that the optimal CSI cut-off value would be disease-specific.…”

Association of the Degree of Varus Thrust during Gait Assessed by an Inertial Measurement Unit with Patient-Reported Outcome Measures in Knee Osteoarthritis

“…Thus, considering these confounding factors is essential to rigorously examine the association between these two. Additionally, central sensitization (CS) has also received attention recently as a factor that strongly influences PROMs [ 25 , 26 , 27 , 28 ]. CS is defined as the increased responsiveness of nociceptive neurons in the central nervous system to normal or subthreshold afferent input by the International Association for the Study of Pain [ 29 ].…”