Minimal Clinically Important Differences for Patient-Reported Outcomes After TKA Depend on Central Sensitization

Restoration of anatomical knee phenotype is associated with improved postoperative clinical outcomes after total knee arthroplasty

BACKGROUND

A comprehensive assessment of knee phenotypes is crucial for optimizing surgical realignment strategies in total knee arthroplasty (TKA). This study aimed to investigate the relationship between the restoration of preoperative phenotypes, such as joint line orientation (JLO) and alignment, and clinical outcomes following TKA.

METHODS

A retrospective review was performed on the records of 1052 primary osteoarthritic knees that underwent mechanically aligned (MA) TKA between March 2016 and October 2021. Patient-reported outcome measures (PROMs) were assessed preoperatively and at 2 years postoperatively. Patients were categorized according to the coronal plane alignment of the knee (CPAK) classification system, which incorporates the arithmetic hip-knee-ankle angle (aHKA) as an indicator of constitutional alignment and JLO. Clinical outcomes were compared between patients whose knee phenotype was maintained and those in whom it was not restored.

RESULTS

Among osteoarthritic knees, the majority (59.4%) were classified as CPAK type I (varus aHKA, apex distal JLO) preoperatively. Using mechanical axis techniques, the native phenotype was restored in 127 (12.1%) of the 1052 cases. These patients demonstrated significantly better postoperative clinical outcomes, as measured by WOMAC function and Forgotten Joint Scores (FJS), compared with the non-restored group (P < 0.05). When alignment was adjusted through detailed analyses of patients with maintained alignment between preoperative and latest follow up assessments, the significant differences in WOMAC function and FJS outcomes between restored JLO and non-restored JLO groups persisted (all P < 0.05). No significant association was observed between the restoration of aHKA and clinical outcomes.

CONCLUSION

The restoration of the anatomical knee phenotype, particularly JLO, is associated with improved postoperative PROMs, notably in functional outcomes, following TKA. These findings underscore the clinical importance of prioritizing preoperative JLO for optimizing surgical outcomes, rather than focusing exclusively on overall limb alignment.

Preoperative Central Sensitization Worsens Pain and Dissatisfaction Following Unicompartmental Knee Arthroplasty

Background and Objectives: Central sensitization (CS) has been identified as a significant factor influencing persistent pain and dissatisfaction following total knee arthroplasty (TKA). However, its effect on unicompartmental knee arthroplasty (UKA) remains largely unexplored. Unlike TKA, UKA preserves most native knee structures, with less bone cut, leading to different postoperative pain mechanisms. Nevertheless, the revision rate for unexplained pain following UKA is higher than after TKA. This study investigates the influence of preoperative CS on pain and dissatisfaction after UKA. Materials and Methods: This retrospective cohort study included 121 patients who underwent primary UKA for medial compartment osteoarthritis of the knee. Patients were screened for CS preoperatively using the Central Sensitization Inventory (CSI) and categorized into a CS group (CSI ≥ 40; n = 26) and a non-CS group (CSI < 40; n = 95). Clinical outcomes, including the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), Forgotten Joint Score (FJS), and patient satisfaction, were assessed at the 2-year postoperative follow-up visit. A multivariate regression analysis was used to determine the risk factors for postoperative dissatisfaction. Results: The CS group reported significantly worse postoperative WOMAC pain, function, and total scores than the non-CS group (all p < 0.05). FJS was also significantly worse in the CS group than in the non-CS group (64.4 vs. 72.7, respectively, p = 0.005). Patient satisfaction was significantly lower in the CS group than in the non-CS group (65.4% vs. 95.8%, respectively, p < 0.001). The multivariate logistic regression analysis demonstrated that patients with a CSI score ≥ 40 had an 11.349-fold increased likelihood of dissatisfaction after UKA (95% CI: 2.315-55.626, p = 0.003). Conclusions: This study underscores the importance of recognizing CS as a critical determinant of postoperative pain and functional recovery following UKA. Patients with high CSI scores experience greater pain, increased joint awareness, and overall poorer satisfaction despite technically successful surgeries.

The impact of central sensitization on perioperative pain in TKA: a retrospective cohort study

BACKGROUND

Total knee arthroplasty (TKA) is an established surgical procedure for severe knee osteoarthritis (KOA) that has provided excellent outcomes. While several studies have reported that patients with preoperative central sensitization (CS) experienced worse pre- and post-operative pain and outcomes, the evidence is limited. We conducted this study to determine the impact of CS on perioperative knee pain in TKA for severe KOA.

METHODS

A retrospective cohort study of 66 patients who underwent bilateral TKA for bilateral severe KOA was conducted. Multiple linear regression models that included covariates and scaled estimated regression coefficients were used to examine the impact of CS on the patients' pre- and post-operative pain subscale values on the Knee Injury and Osteoarthritis Outcome Score (KOOS) and the improvement of KOOS pain. Postoperative KOOS pain was assessed at 3 months postoperatively, while other evaluation items including preoperative KOOS pain, CS, and pain self-efficacy were assessed on admission.

RESULTS

CS had a negative impact on pre- and post-operative KOOS pain (preoperative, β: -0.28, 95% confidence interval [CI] -18.53, -0.92; postoperative, β: -0.26, 95%CI -14.09, -0.44; p < 0.05). High pain self-efficacy had a positive impact on preoperative KOOS pain (β: 0.25, 95%CI 0.32, 18.08; p < 0.05). However, CS did not influence the improvement of KOOS pain.

CONCLUSIONS

These results demonstrate that CS had a negative impact on pre- and post-TKA knee pain in patients but did not affect the improvement of knee pain. TKA provides sufficient pain relief for severe KOA, with or without CS. Further research is required to improve pre- and post-operative knee pain in KOA patients with CS.

Influence of Central Sensitization on Surgical Outcomes of Patients With Degenerative Cervical Myelopathy After Posterior Decompression Surgery: A Multicenter Prospective Study

STUDY DESIGN

Multicenter prospective study.

OBJECTIVE

The influence of central sensitization (CS) on neurological symptoms and surgical outcomes in patients with degenerative cervical myelopathy (DCM) remains unknown. This study aimed to investigate the effects of preoperative CS on surgical outcomes of patients with DCM following posterior decompression surgery.

METHODS

77 consecutive patients with DCM (mean age 67.1) who received posterior decompression surgery were included in this study. The participants completed CS inventory (CSI) scores and the following patient-reported outcome measures (PROMs) preoperatively and 12 months postoperatively: the Japanese Orthopaedic Association (JOA) score for cervical myelopathy and JOA cervical myelopathy evaluation questionnaire (JOACMEQ) for cervical spinal diseases. The association of preoperative CSI scores with preoperative and postoperative PROMs was analyzed, and their changes were statistically evaluated.

RESULTS

The preoperative CSI score was significantly decreased at 12 months postoperatively, and it was significantly associated with the JOA score and JOACMEQ preoperatively and at 12 months postoperatively. However, no significant association was observed between preoperative CSI and the postoperative change of any PROMs at 12 months. The posterior decompression surgery significantly improved the JOA scores and 'lower extremity function' and 'quality of life (QOL)' domains of the JOACMEQ, independent of the severity of preoperative CSI score. Multiple regression analysis demonstrated that preoperative CSI was significantly associated with the 'QOL' domain of JOACMEQ and original JOA score at 12 months postoperatively.

CONCLUSION

The CSI score can be an auxiliary indicator of surgical outcomes of patients with DCM following posterior decompression surgery.

What are the common factors that lead to the failure to achieve minimal clinically important difference after shoulder surgery? A scoping review

INTRODUCTION

The goal of this research is to identify the factors that negatively impact the achievement of the minimum clinically significant change (MCID) for the American Shoulder and Elbow Surgeons (ASES) score within the realm of various orthopedic shoulder procedures.

METHODS

We conducted a comprehensive review of studies published from 2002 to 2023, utilizing OvidMedline and PubMed databases. Our search criteria included terms such as "minimal clinically important difference" or "MCID" along with associated MeSH terms, in addition to "American shoulder and elbow surgeon" or "ASES." We selectively included primary investigations that assessed factors linked to the failure to achieve MCID for the ASES score subsequent to orthopedic shoulder procedures, while excluding papers addressing anatomical, surgical, or injury-related aspects.

RESULTS

Our analysis identified 149 full-text articles, leading to the inclusion of 12 studies for detailed analysis. The selected studies investigated outcomes following various orthopedic shoulder procedures, encompassing biceps tenodesis, total shoulder arthroplasty, and rotator cuff repair. Notably, factors, such as gender, body mass index, diabetes, smoking habits, opioid usage, depression, anxiety, workers' compensation, occupational satisfaction, and the preoperative ASES score, were all associated with the inability to attain MCID.

CONCLUSION

In summary, numerous factors exert a negative influence on the attainment of MCID following shoulder procedures, and these factors appear to be irrespective of the specific surgical technique employed. Patients presenting with these factors may perceive their surgical outcomes as less successful when compared to those without these factors. Identifying these factors can enable healthcare providers to provide more effective counseling to patients regarding their expected outcomes and rehabilitation course. Furthermore, these findings can aid in the development of a screening tool to better identify these risk factors and optimize them before surgery.

Does central sensitization correlate with two-year postoperative functional outcome scores following hip arthroscopy?

Background

Central sensitization (CS) involves amplified central nervous system (CNS) signaling and several biochemical changes which lead to pain hypersensitivity. Data on the effects of CS are limited in orthopaedics and has been associated with reported levels of postoperative pain after hip arthroscopy.

Methods

Patients over the age of 18 who underwent hip arthroscopy with preoperative as well as 2-year postoperative functional outcome scores were identified through the Multicenter Arthroscopic Study of the Hip (MASH) database. Patient demographics, procedure information, as well as patient reported outcome measures (PROMs) were collected along with CS index scores.

Results

34 patients met inclusion criteria for our study. Preop MCS and iHOT as well as Postop MCS, showed moderate to strong negative correlations with CSI scores (-0.607, -0.573, and -0.756, respectively). VAS, PCS and MSC scores were significantly different preoperatively to postoperatively, ensuring alleviation of pain after hip arthroscopy. Subgroup analysis by stratifying CSI scores into 1 SD below the mean, within 1 SD of the mean, and above 1 SD showed significant differences across all 3 groups for preoperative MCS (p < 0.001), postoperative MCS (p = 0.001), and PSEQ2 (p = 0.015). Postoperative VAS pain approached significance but did not meet criteria of p < 0.05 (p = 0.062).

Conclusion

Increased postoperative CSI scores directly correlated with decreased preoperative and postoperative MCS scores and worse preoperative resilience. Recognizing the influence of CS on pain perception and resilience on coping with adversity in the recovery period may guide orthopaedic surgeons in developing comprehensive treatment plans to continue to improve surgical outcomes in hip arthroscopy.

Level of evidence

IV.

Central Sensitization and Neuropathic Pain Cumulatively Affect Patients Reporting Inferior Outcomes Following Total Knee Arthroplasty

UPDATE

This article was updated on November 17, 2023, because of previous errors, which were discovered after the preliminary version of the article was posted online. On page 102, the text that had read "In a post hoc analysis of the preoperative results, Group 1 showed significantly inferior WOMAC pain, function, and total scores compared with Group 4 (p < 0.05 for all). Groups 2 and 3 showed worse preoperative WOMAC pain, function, and total subscores compared with Group 4 (p < 0.05 for all). These results remained the same at 2 years after surgery." now reads "In a post hoc analysis of the preoperative results, Groups 1, 2, and 3 showed significantly inferior WOMAC pain, function, and total scores compared with Group 4 (p < 0.05 for all). At 2 years postoperatively, Group 1 showed inferior WOMAC pain, function, and total scores compared with the other groups (p < 0.05 for all). Also, Groups 2 and 3 had worse WOMAC pain, function and total scores compared with Group 4 (p < 0.05 for all)." Also, on page 106, the title of Table IV, which had previously read "Inter-Group Comparison of Preoperative Scores (Post Hoc Analysis)" now reads "Inter-Group Comparison of Postoperative Scores (Post Hoc Analysis)."

Cross-cultural adaptation and validation for central sensitization inventory: based on Chinese patients undergoing total knee arthroplasty for knee osteoarthritis

BACKGROUND

This study was conducted to develop a simplified Chinese version of the central sensitization inventory (CSI-CV) and to evaluate its reliability and validity.

METHODS

The CSI-CV was developed through a process involving the translation and back translation of the original CSI. Subsequently, experts reviewed and revised the content of the items to ensure their appropriateness. A total of 325 patients with knee osteoarthritis (KOA), who were scheduled to undergo total knee arthroplasty (TKA), completed the CSI-CV at a prominent orthopedic center in Xi'an, China. Afterward, a random selection of 100 participants was chosen for retesting after one week. The reliability and validity of the inventory were evaluated through exploratory factor analysis, correlation coefficient calculation and other methods.

RESULTS

The CSI-CV consists of 25 items in five dimensions (emotional distress, headache and jaw symptoms, physical symptoms, urological symptoms, and fatigue and sleep problems). The cumulative variance contribution rate was 75.3%, the Cronbach's α coefficient was 0.83, the Guttman split-half reliability coefficient was 0.88 and the intraclass correlation coefficient was 0.965. The CSI-CV scores correlated moderately with the total scores of the brief pain inventory (r = 0.506), Western Ontario and McMaster Universities Osteoarthritis Index (r = 0.466) and EuroQoL Group's five-dimension questionnaire (r = 0.576).

CONCLUSIONS

The findings demonstrate that the CSI was successfully trans-culturally adapted into a simplified Chinese version (CSI-CV) that was reliable and valid for Chinese-speaking patients who awaiting TKA for KOA.

Central sensitization as a predictive factor for the surgical outcome in patients with lumbar spinal stenosis: a multicenter prospective study

PURPOSE

The impact of central sensitization (CS) on neurological symptoms and surgical outcomes in patients with lumbar spinal stenosis (LSS) remains unknown. This study aimed to investigate the influence of preoperative CS on the surgical outcomes of patients with LSS.

METHODS

A total of 197 consecutive patients with LSS (mean age 69.3) who underwent posterior decompression surgery with or without fusion were included in this study. The participants completed the CS inventory (CSI) scores and the following clinical outcome assessments (COAs) preoperatively and 12 months postoperatively: the Japanese Orthopaedic Association (JOA) score for back pain, JOA back pain evaluation questionnaire, and Oswestry Disability Index (ODI). The association between preoperative CSI scores and preoperative and postoperative COAs was analyzed, and postoperative changes were statistically evaluated.

RESULTS

The preoperative CSI score significantly decreased at 12 months postoperatively and was significantly correlated with all COAs preoperatively and 12 months postoperatively. Higher preoperative CSI showed worse postoperative COAs and inferior postoperative improvement rates in the JOA score, VAS score for neurological symptoms, and ODI. Multiple regression analysis demonstrated that preoperative CSI was significantly associated with postoperative low back pain (LBP), mental health, quality of life (QOL), and neurological symptoms at 12 months postoperatively.

CONCLUSIONS

Preoperative CS evaluated by CSI had a significantly worse impact on surgical outcomes, including neurological symptoms, disability, and QOL, especially related to LBP and psychological factors. CSI can be used clinically as a patient-reported measure for predicting postoperative outcomes in patients with LSS.

Discordance Abounds in Minimum Clinically Important Differences in THA: A Systematic Review

BACKGROUND

The minimum clinically important difference (MCID) is intended to detect a change in a patient-reported outcome measure (PROM) large enough for a patient to appreciate. Their growing use in orthopaedic research stems from the necessity to identify a metric, other than the p value, to better assess the effect size of an outcome. Yet, given that MCIDs are population-specific and that there are multiple calculation methods, there is concern about inconsistencies. Given the increasing use of MCIDs in total hip arthroplasty (THA) research, a systematic review of calculated MCID values and their respective ranges, as well as an assessment of their applications, is important to guide and encourage their use as a critical measure of effect size in THA outcomes research.

QUESTIONS/PURPOSES

We systematically reviewed MCID calculations and reporting in current THA research to answer the following: (1) What are the most-reported PROM MCIDs in THA, and what is their range of values? (2) What proportion of studies report anchor-based versus distribution-based MCID values? (3) What are the most common methods by which anchor-based MCID values are derived? (4) What are the most common derivation methods for distribution-based MCID values? (5) How do the reported medians and corresponding ranges compare between calculation methods for each PROM?

METHODS

The EMBASE, MEDLINE, and PubMed databases were systematically reviewed from inception through March 2022 for THA studies reporting an MCID value for any PROMs. Two independent authors reviewed articles for inclusion. All articles calculating new PROM MCID scores after primary THA were included for data extraction and analysis. MCID values for each PROM, MCID calculation method, number of patients, and study demographics were extracted from each article. In total, 30 articles were included. There were 45 unique PROMs for which 242 MCIDs were reported. These studies had a total of 1,000,874 patients with a median age of 64 years and median BMI of 28.7 kg/m 2 . Women made up 55% of patients in the total study population, and the median follow-up period was 12 months (range 0 to 77 months). The overall risk of bias was assessed as moderate using the modified Methodological Index for Nonrandomized Studies criteria for comparative studies (the mean score for comparative papers in this review was 18 of 24, with higher scores representing better study quality) and noncomparative studies (for these, the mean score was 10 of a possible 16 points, with higher scores representing higher study quality). Calculated values were classified as anchor-based, distribution-based, or not reported. MCID values for each PROM, MCID calculation method, number of patients, and study demographics were extracted from each study. Anchor-based and distribution-based MCIDs were compared for each unique PROM using a Wilcoxon rank sum test, given the non-normal distribution of values.

RESULTS

The Oxford Hip Score (OHS) and the Hip Injury and Osteoarthritis Score (HOOS) Pain and Quality of Life subscore MCIDs were the most frequently reported, comprising 12% (29 of 242), 8% (20 of 242), and 8% (20 of 242), respectively. The EuroQol VAS (EQ-VAS) was the next-most frequently reported (7% [17 of 242]) followed by the EuroQol 5D (EQ-5D) (7% [16 of 242]). The median anchor-based value for the OHS was 9 (IQR 8 to 11), while the median distribution-based value was 6 (IQR 5 to 6). The median anchor-based MCID values for HOOS Pain and Quality of Life were 33 (IQR 28 to 35) and 25 (14 to 27), respectively; the median distribution-based values were 10 (IQR 9 to 10) and 13 (IQR 10 to 14), respectively. Thirty percent (nine of 30) of studies used an anchor-based method to calculate a new MCID, while 40% (12 of 30) used a distribution-based technique. Thirty percent of studies (nine of 30) calculated MCID values using both methods. For studies reporting an anchor-based calculation method, a question assessing pain relief, satisfaction, or quality of life on a five-point Likert scale was the most commonly used anchor (30% [eight of 27]), followed by a receiver operating characteristic curve estimation (22% [six of 27]). For studies using distribution-based calculations, the most common method was one-half the standard deviation of the difference between preoperative and postoperative PROM scores (46% [12 of 26]). Most reported median MCID values (nine of 14) did not differ by calculation method for each unique PROM (p > 0.05). The OHS, HOOS JR, and HOOS Function, Symptoms, and Activities of Daily Living subscores all varied by calculation method, because each anchor-based value was larger than its respective distribution-based value.

CONCLUSION

We found that MCIDs do not vary very much by calculation method across most outcome measurement tools. Additionally, there are consistencies in MCID calculation methods, because most authors used an anchor question with a Likert scale for the anchor-based approach or used one-half the standard deviation of preoperative and postoperative PROM score differences for the distribution-based approach. For some of the most frequently reported MCIDs, however, anchor-based values tend to be larger than distribution-based values for their respective PROMs.

CLINICAL RELEVANCE

We recommend using a 9-point increase as the MCID for the OHS, consistent with the median reported anchor-based value derived from several high-quality studies with large patient groups that used anchor-based approaches for MCID calculations, which we believe are most appropriate for most applications in clinical research. Likewise, we recommend using the anchor-based 33-point and 25-point MCIDs for the HOOS Pain and Quality of Life subscores, respectively. We encourage using anchor-based MCID values of WOMAC Pain, Function, and Stiffness subscores, which were 29, 26, and 30, respectively.

Neuropathic-like symptoms and central sensitization related signs and symptoms negatively affect the functional performance of patients with knee osteoarthritis – a cross-sectional study

Objective

This study aimed to compare the functional performance among participants with a neuropathic-like symptoms (NS) and central sensitization related signs and symptoms (CS), and their knee osteoarthritis (OA) counterparts.

Methods

A cross-sectional observational study was conducted with 125 participants with knee OA (94 females, mean age 63.1 ​± ​7.4 years). Participants completed a self-reported questionnaire with personal and clinical features and musculoskeletal pain characteristics, including NS (PainDETECT), CS (Central Sensitization Inventory, CSI), and conditioned pain modulation. Self-reported functional disability (Western Ontario and McMaster Universities Osteoarthritis Index, WOMAC) and functional mobility (Timed Up and Go, TUG) were compared among patients with NS, CS, and their knee OA counterparts using the one-way analysis of variance (ANOVA).

Results

Thirty-three (26.4%) participants had NS and CS, eighteen (14.4%) had NS, twenty-seven (21.6%) participants had CS, and 47 (37.6%) had knee OA with no NS or CS. A one-way ANOVA revealed greater functional limitation in the group with NS and CS (mean ​= ​67.5 ​± ​12.0) or NS (mean ​= ​56.7 ​± ​17.5) than the group without these symptoms (mean ​= ​32.0 ​± ​20.7) with a statistical significance difference [F(3, 121) ​= ​29.434, p ​< ​0.001] in the WOMAC Total score. The group with NS and CS (mean ​= ​19.2 ​± ​7.4) or NS (mean ​= ​16.3 ​± ​6.3) had slower velocity than the group without these symptoms (mean ​= ​11.6 ​± ​3.5) with a statistical significance difference [F(3,121) ​= ​10.045, p ​< ​0.001] in the TUG test.

Conclusion

Participants with knee osteoarthritis and NS or CS pain phenotype have greater functional limitations than their counterparts.

A Prospective Clinical Trial Comparing Denervation With Suspension Arthroplasty for Treatment of Carpometacarpal Arthritis of the Thumb

PURPOSE

Trapeziectomy with suspensionplasty is the most popular treatment for thumb carpometacarpal arthritis. However, carpometacarpal denervation has recently shown promise as an alternative treatment option. This study was designed to compare functional outcomes, pain reduction, and quality of life between denervation and suspension arthroplasty in patients treated for thumb carpometacarpal osteoarthritis.

METHODS

We conducted a prospective clinical trial between June 2020 and December 2021. Preoperative and postoperative evaluations were conducted on patients, including the evaluation of functional outcomes via the Michigan Hand Outcomes Questionnaire, pain with the visual analog score, quality of life with the EuroQol-5D, and the evaluation of time to return to function. Outcomes and complications were compared between patients undergoing denervation versus arthroplasty.

RESULTS

Forty-eight patients were included in the study, 34 of whom underwent denervation and 14 underwent suspension arthroplasty of the thumb carpometacarpal joint. Patients in the denervation group were younger, with an average age of 59 years compared with 67 years in the arthroplasty group. All other patient characteristics were similar. Pain reduction, functional outcomes, and quality of life scores showed equal improvement in both groups. Denervation patients had a reduced time to return to function (3.3 weeks vs 4.5 months in the arthroplasty group).

CONCLUSIONS

Carpometacarpal denervation appears to provide similar short-term outcomes as suspension arthroplasty for the treatment of thumb carpometacarpal arthritis. Treatment with denervation may offer a quicker return to function. The long-term outcomes of denervation remain unknown.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic IV.

There are Considerable Inconsistencies Among Minimum Clinically Important Differences in TKA: A Systematic Review

BACKGROUND

Patient-reported outcome measures (PROMs) are frequently used to assess the impact of total knee arthroplasty (TKA) on patients. However, mere statistical comparison of PROMs is not sufficient to assess the value of TKA to the patient, especially given the risk profile of arthroplasty. Evaluation of treatment effect sizes is important to support the use of an intervention; this is often quantified with the minimum clinically important difference (MCID). MCIDs are unique to specific PROMs, as they vary by calculation methodology and study population. Therefore, a systematic review of calculated MCID values, their respective ranges, and assessment of their applications is important to guide and encourage their use as a critical measure of effect size in TKA outcomes research.

QUESTIONS/PURPOSES

In this systematic review of MCID calculations and reporting in primary TKA, we asked: (1) What are the most frequently reported PROM MCIDs and their reported ranges in TKA? (2) What proportion of studies report distribution- versus anchor-based MCID values? (3) What are the most common methods by which these MCID values are derived for anchor-based values? (4) What are the most common derivation methods for distribution-based values? (5) How do the reported medians and corresponding interquartile ranges (IQR) compare between calculation methods for each PROM?

METHODS

Following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, a systematic review was conducted using the PubMed, EMBASE, and MEDLINE databases from inception through March 2022 for TKA articles reporting an MCID value for any PROMs. Two independent reviewers screened articles for eligibility, including any article that calculated new MCID values for PROMs after primary TKA, and extracted these data for analysis. Overall, 576 articles were identified, 38 of which were included in the final analysis. These studies had a total of 710,128 patients with a median age of 67.7 years and median BMI of 30.9 kg/m 2 . Women made up more than 50% of patients in most studies, and the median follow-up period was 17 months (range 0.25 to 72 months). The overall risk of bias was assessed as moderate using the Jadad criteria for one randomized controlled trial (3 of 5 ideal global score) and the modified Methodological Index for Non-randomized Studies criteria for comparative studies (mean 17.2 ± 1.8) and noncomparative studies (mean 9.6 ± 1.3). There were 49 unique PROMs for which 233 MCIDs were reported. Calculated values were classified as anchor-based, distribution-based, or not reported. MCID values for each PROM, MCID calculation method, number of patients, and study demographics were extracted from each study. Anchor-based and distribution-based MCIDs were compared for each unique PROM using a Wilcoxon rank sum test given non-normal distribution of values.

RESULTS

The WOMAC Function and Pain subscores were the most frequently reported MCID value, comprising 9% (22 of 233) and 9% (22 of 233), respectively. The composite Oxford Knee Score (OKS) was the next most frequently reported (9% [21 of 233]), followed by the WOMAC composite score (6% [13 of 233]). The median anchor-based values for WOMAC Function and Pain subscores were 23 (IQR 16 to 33) and 25 (IQR 14 to 31), while the median distribution-based values were 11 (IQR 10.8 to 11) and 22 (IQR 17 to 23), respectively. The median anchor-based MCID value for the OKS was 6 (IQR 4 to 7), while the distribution-based value was 7 (IQR 5 to 10). Thirty-nine percent (15 of 38) used an anchor-based method to calculate a new MCID, while 32% (12 of 38) used a distribution-based technique. Twenty-nine percent of studies (11 of 38) calculated MCID values using both methods. For studies reporting an anchor-based calculation method, a question assessing patient satisfaction, pain relief, or quality of life along a five-point Likert scale was the most commonly used anchor (40% [16 of 40]), followed by a receiver operating characteristic curve estimation (25% [10 of 40]). For studies using distribution-based calculations, all articles used a measure of study population variance in their derivation of the MCID, with the most common method reported as one-half the standard deviation of the difference between preoperative and postoperative PROM scores (45% [14 of 31]). Most reported median MCID values (15 of 19) did not differ by calculation method for each unique PROM (p > 0.05) apart from the WOMAC Function component score and the Knee Injury and Osteoarthritis Outcome Score Pain and Activities of Daily Living subscores.

CONCLUSION

Despite variability of MCIDs for each PROM, there is consistency in the methodology by which MCID values have been derived in published studies. Additionally, there is a consensus about MCID values regardless of calculation method across most of the PROMs we evaluated.

CLINICAL RELEVANCE

Given their importance to treatment selection and patient safety, authors and journals should report MCID values with greater consistency. We recommend using a 7-point increase as the MCID for the OKS, consistent with the median reported anchor-based value derived from several high-quality studies with large patient groups that used anchor-based approaches for MCID calculation, which we believe are most appropriate for most applications in clinical research. Likewise, we recommend using a 10-point to 15-point increase for the MCID of composite WOMAC, as the median value was 12 (IQR 10 to 17) with no difference between calculation methods. We recommend use of median reported values for WOMAC function and pain subscores: 21 (IQR 15 to 33) and 23 (IQR 13 to 29), respectively.

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

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.

Cross-Sectional Comparative Study on Central Sensitization-Psychosocial Associated Comorbidities and Psychological Characteristics in Breast Cancer Survivors with Nociceptive Pain and Pain with Neuropathic Features and without Pain

Simple Summary

Persistent pain after breast cancer treatment is still under research due to its complex and multifactorial underlying pathogenesis, including phycological factors. Further research is needed to elucidate more information about the factors that cause and perpetuate this pain. Thus, this study defined the influence of psychosocial and psychological factors on breast cancer survivors who report pain and those who do not. The psychosocial factors assessed were those that are associated with a central sensitization process, and the psychological factors were pain catastrophizing, fear of movement, anxiety and depression. Hence, the psychosocial symptom clusters were identified related to the clinical features of pain or to not reporting pain, which may encourage health clinicians to establish a customized biopsychosocial model focused on the management of pain-catastrophizing thoughts and fear of movement. Furthermore, anxiety and depression should be detected early by health professionals and referred to psychologists to be managed.

Abstract

The frequency of a high Central Sensitization Inventory (CSI) total score and the prevalence of pain have already been established among breast cancer survivors (BCS). However, the psychological factors’ influence based on the clinical features of pain is still unknown, as well as BCS characteristics with no pain. Thus, our main aim was to evaluate the presence of a high CSI total score in BCS with pain and compare it with BCS without pain and to evaluate the influence of psychosocial factors. A cross-sectional comparative study was designed to compare BCS with nociceptive pain (n = 19), pain with neuropathic features (n = 19) or no pain (n = 19), classified by the Leeds Assessment of Neuropathic Symptoms and Signs (LANSS). CSI, pain catastrophizing, fear of movement, anxiety and depression symptoms were analyzed and compared among the three groups. The CSI total score was higher in both BCS pain groups compared to BCS without pain, but there were no statistical differences between the pain groups. The same observation was made when comparing pain catastrophizing. The neuropathic feature group showed greater levels of fear of movement, anxiety and depression compared to the no pain group. Thus, CS-psychosocial associated comorbidities and pain-catastrophizing thoughts were more prevalent among BCS with pain, regardless of the clinical features of pain. BCS with neuropathic pain features showed greater psychological disturbances.

Diagnosis of Central Sensitization and Its Effects on Postoperative Outcomes following Total Knee Arthroplasty: A Systematic Review and Meta-Analysis

Central sensitization (CS) has been extensively researched as a cause of persistent pain after total knee arthroplasty (TKA). This systematic review study sought to investigate the diagnosis of CS in patients who underwent TKA for knee osteoarthritis (OA) and the effect of CS on clinical outcomes after TKA. Three comprehensive databases, including MEDLINE, EMBASE, and the Cochrane Library, were searched for studies that evaluated the outcomes of TKA in knee OA patients with CS. Data extraction, risk of bias assessment, and (where appropriate) meta-analysis were performed. The standardized mean difference (SMD) with a 95% confidence interval was used to assess the different scales of pain. A total of eight studies were selected, including two retrospective studies and five prospective observational studies. One study used additional randomized controlled trial data. Five studies were finally included in the meta-analysis. All studies had a minimum follow-up period of 3 months. The Central Sensitization Inventory (CSI), whole-body pain diagram, and quantitative sensory testing (QST) were used for measuring CS. The pooled analysis showed that patients with CS had more severe postoperative pain after TKA (SMD, 0.65; 95% CI, 0.40−0.90; p < 0.01) with moderate heterogeneity (I2 = 60%). In patients who underwent TKA with knee OA, CSI is most often used for the diagnosis of CS, and the QST and whole-body pain diagram are also used. CS is closely associated with more severe and persistent pain after TKA.

Scientific Knowledge Graph and Trend Analysis of Central Sensitization: A Bibliometric Analysis

BACKGROUND

Central sensitization refers to a state of hypersensitivity in the central nervous system and is associated with the development and maintenance of chronic pain. Central sensitization plays an essential role in various diseases. Nevertheless, there has been no bibliometric analysis before in this field. The purpose of this study was to provide critical themes and trends in the area of central sensitization, to build a network of knowledge, and to facilitate the future development of relevant basic and clinical research.

METHODS

Publications on central sensitization were extracted from the Science Citation Index-Expanded. We used R software to systematically analyze the countries, institutions, authors, journals, references, and keywords of the publications. Besides, conceptual structure, intellectual structure, and social structure were constructed.

RESULTS

A total of 4466 publications were included. Research in the field of central sensitization generally showed a steady upward trend. The three structural networks showed that the United States is the leading country in this field. Arendt-Nielsen L and Woolf CJ were the most productive and influential authors, respectively. "Pain" was the journal with the most studies. Most journals that published and cited articles about central sensitization were academically influential. Cluster analysis revealed that research in central sensitization contains three main conceptual clusters, and the themes of research evolve frequently. Current research focuses on the pathogenesis of central sensitization in neuropathic pain, the role of central sensitization in different diseases, and related clinical double-blind trials.

CONCLUSION

Central sensitization received widespread attention. The United States led the way in academic activity. In this field, the current situation of cooperation and communication between different countries and institutions is positive. The present research hotspots were the pathogenesis of central sensitization in neuropathic pain, the role of central sensitization in different diseases, and related clinical double-blind trials.