Concomitant low back pain impairs outcomes after primary total knee arthroplasty in patients over 65 years: a prospective, matched cohort study

Multiple Joint Arthroplasty in Hip and Knee Osteoarthritis Patients: A National Longitudinal Cohort Study

BACKGROUND

Many patients suffer from osteoarthritis (OA) in multiple joints, possibly resulting in multiple joint arthroplasties (MJAs). Primarily, we determined the cumulative incidence (Cin) of MJA in hip and knee joints up to 10 years. Secondly, we calculated the mean time between the first and subsequent joint arthroplasty, and evaluated the different MJA trajectories. Lastly, we compared patient characteristics and outcomes (functionality and pain) after surgery between MJA patients and single hip arthroplasty or knee arthroplasty (HA and KA) patients.

METHODS

Primary index (first) HA or KA for OA were extracted from the Dutch Arthroplasty Register. The 1, 2, 5, and 10-year Cin (including competing risk death) of MJA, mean time intervals, and MJA-trajectories were calculated and stratified for primary index HA or KA. Sex, preoperative age, and body mass index were compared using ordinal logistic regression. Outcomes, measured preoperatively, 3, 6, and 12 months postoperatively (function: Hip Disability or Knee Injury and OA Outcome Score; Pain: Numerical Rating Scale), were compared using linear regression.

RESULTS

A total of 140,406 HA-patients and 140,268 KA-patients were included. One, 2, 5, and 10-year Cin for a second arthroplasty were respectively 8.9% [95% confidence interval (CI): 8.7 to 9.0], 14.3% [95% CI: 14.1 to 14.5], 24.0% [95% CI: 23.7 to 24.2], and 32.7% [95% CI: 32.2 to 33.1] after index HA, and 9.5% [95% CI: 9.4 to 9.7], 16.0% [95% CI: 15.9 to 16.2], 26.4% [95% CI: 26.1 to 26.6], and 35.8% [95% CI: 35.4 to 36.3] after index KA. The 10-year Cin for > 2 arthroplasties were small in both the index HA and KA groups. Time-intervals from first to second, third, and fourth arthroplasty were 26 [95% CI: 26.1 to 26.7], 47 [95% CI: 46.4 to 48.4], and 58 [95% CI: 55.4 to 61.1] months after index HA, and 26 [95% CI: 25.9 to 26.3], 52 [95% CI: 50.8 to 52.7], and 61 [95% CI: 58.3 to 63.4] months after index KA. There were 83% of the second arthroplasties placed in the contralateral cognate joint (ie, knee or hip). Differences in postoperative functionality and pain between MJAs and single HAs and KAs were small.

CONCLUSIONS

The 10-year Cin showed that about one-third of patients received a second arthroplasty after approximately 2 years, with the majority in the contralateral cognate joint. Few patients received > 2 arthroplasties within 10 years. Being a women, having a higher body mass index, and being younger increased the odds of MJA. Postoperative outcomes were slightly negatively affected by MJA.

Functional somatic syndromes are associated with inferior outcomes and increased complications after hip and knee arthroplasty: a systematic review

BACKGROUND

Functional somatic syndromes (FSSs), defined as chronic physical symptoms with no identifiable organic cause, may impact results after hip and knee arthroplasty. The purpose of this study was to perform a systematic review assessing the relationship between FSSs and clinical outcomes after primary total hip arthroplasty (THA), total knee arthroplasty (TKA), and unicompartmental knee arthroplasty (UKA).

METHODS

The PubMed and Web of Science databases were queried from January 1955 through December 2021 for studies investigating the impact of at least one FSS (fibromyalgia, irritable bowel syndrome (IBS), chronic headaches, and chronic low back pain) on outcomes after primary THA/TKA/UKA. Outcomes of interest included patient-reported outcome measures (PROMs), postoperative opioid use, complications, revisions, and costs of care.

RESULTS

There were twenty-eight studies, including 768,909 patients, of which 378,384 had an FSS. Five studies reported preoperative PROMs prior to THA/TKA, all of which showed worse PROMs among patients with at least 1 FSS diagnosis. Thirteen studies reported postoperative PROMs after THA/TKA, all of which demonstrated worse PROMs among patients with at least 1 FSS diagnosis. Patients with FSS diagnoses were more likely to continue using opioids at 3, 6, and 12 months following TKA, THA, and UKA. Medical and surgical complications, as well as revision rates, were higher among patients with FSSs.

CONCLUSION

Patients with FSSs have inferior PROMs and are at increased risk for prolonged postoperative opioid use, medical and surgical complications, and revision after hip and knee arthroplasty. Improved understanding of the factors influencing the success of hip and knee arthroplasty is critical. Future studies should address the biopsychosocial determinants of health that can impact outcomes after total joint arthroplasty.

Spondylolisthesis and mismatch deformity affect outcomes after total knee arthroplasty

BACKGROUND

Little published data currently exist regarding the potential relationships between spondylolisthesis, mismatch deformity, and clinical outcomes following total knee arthroplasty (TKA). We hypothesize that preexisting spondylolisthesis will result in decreased functional outcomes after TKA.

METHODS

This retrospective cohort comparison of 933 TKAs was performed between January 2017 and 2020. TKAs were excluded if they were not performed for primary osteoarthritis (OA) or if preoperative lumbar radiographs were unavailable/inadequate to measure the degree of spondylolisthesis. Ninety-five TKAs were subsequently available for inclusion and divided into two groups: those with spondylolisthesis and those without. Within the spondylolisthesis cohort, pelvic incidence (PI) and lumbar lordosis (LL) were calculated on lateral radiographs to determine the difference (PI-LL). Radiographs with PI-LL > 10° were then categorized as having mismatch deformity (MD). The following clinical outcomes were compared between the groups: need for manipulation under anesthesia (MUA), total postoperative arc of motion (AOM) both pre-MUA or post-MUA/revision, incidence of flexion contracture, and a need for later revision.

RESULTS

Forty-nine TKAs met the spondylolisthesis criteria, while 44 did not have spondylolisthesis. There were no significant differences in gender, body mass index, preoperative knee range of motion (ROM), preoperative AOM, or opiate use between the groups. TKAs with spondylolisthesis and concomitant MD were more likely to have MUA (p = 0.016), ROM < 0-120 (p < 0.014), and a decreased AOM (p < 0.02) without interventions.

CONCLUSION

Preexisting spondylolisthesis by itself may not have adverse effect clinical results following TKA. However, spondylolisthesis increases the likelihood of developing MD. In those with both spondylolisthesis and concomitant mismatch deformities, patients had statistically and clinically significantly decreased in postoperative ROM/AOM and increased need for MUA. Surgeons should consider clinical/radiographic assessments of patients with chronic back pain who present for total joint arthroplasty.

LEVEL OF EVIDENCE

Level 3.

Is inpatient rehabilitation a predictor of a lower incidence of persistent knee pain 3-months following total knee replacement? A retrospective, observational study

Background

Moderate to severe levels of persistent knee pain have been estimated to affect up to 25% of people 3-months or more after a total knee replacement. It is unknown whether the type of rehabilitation pathway is associated with persistent high pain after surgery. Using a prospectively followed Australian cohort who underwent total knee replacement for knee osteoarthritis, this study aimed to i) report the incidence of high-intensity knee pain (defined as a score ≤ 15 on the Oxford Knee Score pain subscale) across time and ii) identify whether referral to inpatient rehabilitation was one of the predictors of persistent pain at 3-months post-surgery.

Methods

A retrospective analysis of a large prospective study was conducted using the Oxford Knee Score pain subscale to determine if participants had high pain at 3-months, 12-months and 36-months post-surgery. Relative risks for high pain at 3-, 12- and 36-months between the type of rehabilitation pathway were determined using Poisson multivariable regression with robust standard errors. The same technique was also employed to determine potential predictors, including rehabilitation pathway, of high pain at 3 months.

Results

The incidence of high pain in all participants was 73% pre-surgery and 10, 5 and 6% at 3-, 12- and 36-months respectively following knee replacement. There was a significant interaction between time and rehabilitation pathway, suggesting that the effect of the rehabilitation pathway varied across time. The incidence of high pain at 3-months did not significantly differ between those who attended inpatient rehabilitation (11.6%) and those discharged directly home (9.5%). Multivariable Poisson regression analysis identified the pre-surgical presence of high pain, co-morbid low back pain or other lower limb problem, younger age and having a major complication within 3-months following surgery as significant predictors of persistent pain whilst discharge to inpatient rehabilitation was not.

Conclusion

A small but clinically significant minority of people continued to have high pain levels at 3-, 12- and 36-months following a primary total knee replacement for osteoarthritis. Participation in an inpatient rehabilitation program does not appear to be an important predictor of ongoing knee pain.

Trial registration

The data were collected in the Evidence-based Processes and Outcomes of Care (EPOC) study, ClinicalTrials.gov Identifier: NCT01899443

Perioperative medicine role in painful knee prosthesis prevention

Total knee arthroplasty is one of the most frequently performed orthopaedic surgeries. However, up to 20% of patients develop persistent postoperative pain. Persistent postoperative pain may be an extension of acute postoperative pain, but can also occur after more than 3 months without symptoms. Risk factors associated with persistent postoperative pain after arthroplasty have now been characterised within the patient's perioperative context (preoperative, intraoperative and postoperative), and can be grouped under genetic, demographic, clinical, surgical, analgesic, inflammatory and psychological factors. Identification and prevention of persistent postoperative pain through a multimodal and biopsychosocial approach is essential in the context of perioperative medicine, and has been shown to prevent or ameliorate postoperative pain.

Severity and location of lumbar spine stenosis affects the outcome of total knee arthroplasty

Background

Recent studies have noted that patients with pre-existing lumbar spinal stenosis (LSS) have lower functional outcomes after total knee arthroplasty (TKA). Given that LSS manifests heterogeneously in location and severity, its influence on knee replacement merits a radiographically targeted analysis. We hypothesize that patients with more severe LSS will have diminished knee mobility before and after TKA.

Methods

This retrospective case series assessed all TKAs performed at our institution for primary osteoarthritis from 2017–2020. Preoperative lumbar magnetic resonance image (MRI) with no prior lumbar spine surgery was necessary for inclusion. Stenosis severity was demonstrated by (1) anterior–posterior (AP) diameter of the thecal sac and (2) morphological grade. TKA outcomes in 103 cases (94 patients) were assessed by measuring preoperative and postoperative arc of motion (AOM), postoperative flexion contracture, and need for manipulation under anesthesia.

Results

Patients with mild stenosis did significantly better in terms of postoperative knee AOM. As AP diameter decreased at levels L1–2, L2–3, L3–4, and L4–5, there was a significant reduction in preoperative-AOM (p < 0.001 for each), with a 16 degree decrease when using patients’ most stenotic level (p < 0.001). The same was noted with respect to increased morphological grade (p < 0.001), with a 5 degree decrease for patients’ most stenotic level (p < 0.001).

Conclusion

Severe LSS, which is readily demonstrated by a reduction in the AP diameter of the thecal sac or increased morphological grade on MRI, correlated with a significant reduction in preoperative AOM that was not improved after TKA. Persistent postoperative reductions in AOM may contribute to reduced patient satisfaction and recovery.

Level of evidence: Level 4

Multicenter study evaluating factors associated with treatment outcome for low back pain injections

BACKGROUND

There has been a worldwide surge in interventional procedures for low back pain (LBP), with studies yielding mixed results. These data support the need for identifying outcome predictors based on unique characteristics in a pragmatic setting.

METHODS

We prospectively evaluated the association between over two dozen demographic, clinical and technical factors on treatment outcomes for three procedures: epidural steroid injections (ESIs) for sciatica, and sacroiliac joint (SIJ) injections and facet interventions for axial LBP. The primary outcome was change in patient-reported average pain intensity on a numerical rating scale (average NRS-PI) using linear regression. For SIJ injections and facet radiofrequency ablation, this was average LBP score at 1 and 3 months postprocedure, respectively. For ESI, it was average leg pain 1- month postinjection. Secondary outcomes included a binary indicator of treatment response (success).

RESULTS

346 patients were enrolled at seven hospitals. All groups experienced a decrease in average NRS-PI (p<0.0001; mean 1.8±2.6). There were no differences in change in average NRS-PI among procedural groups (p=0.50). Lower baseline pain score (adjusted coefficient -0.32, 95% CI -0.48 to -0.16, p<0.0001), depressive symptomatology (adjusted coefficient 0.076, 95% CI 0.039 to 0.113, p<0.0001) and obesity (adjusted coefficient 0.62, 95% CI 0.038 to 1.21, p=0.037) were associated with smaller pain reductions. For procedural outcome, depression (adjusted OR 0.94, 95% CI 0.91, 0.97, p<0.0001) and poorer baseline function (adjusted OR 0.59, 95% CI 0.36, 0.96, p=0.034) were associated with failure. Smoking, sleep dysfunction and non-organic signs were associated with negative outcomes in univariate but not multivariate analyses.

CONCLUSIONS

Identifying treatment responders is a critical endeavor for the viability of procedures in LBP. Patients with greater disease burden, depression and obesity are more likely to fail interventions. Steps to address these should be considered before or concurrent with procedures as considerations dictate.

TRIAL REGISTRATION NUMBER

NCT02329951.

Impact of Preoperative and Incident Musculoskeletal Problematic Areas on Postoperative Outcomes after Total Knee Replacement

OBJECTIVE

To examine impact of pre-existing and incident problematic musculoskeletal (MSK) areas after total knee replacement (TKR) on postoperative 60-month Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) pain/function scores.

METHODS

Using data from a randomized controlled trial of subjects undergoing TKR for osteoarthritis, we assessed problematic MSK areas in six body regions before TKR and 12, 24, 36, and 48 months after TKR. We defined the following two variables: 1) density count (number of problematic MSK areas occurring after TKR; range 0-24) and 2) cumulative density count (problematic MSK areas both before and after TKR, categorized into four levels: no preoperative areas and density count of 0-1 [reference group]; no preoperative areas and density count of 2 or more; one or more preoperative areas and density count of 0-1; and one or more preoperative areas and density count of 2 or greater). We evaluated the associations between categorized 60-month WOMAC and cumulative density count by ordinal logistic regression.

RESULTS

Among 230 subjects, 24% reported one or more preoperative problematic MSK area. After TKR, 75% reported a density count of 0 to 1; 25% reported a density count of 2 or more. Compared with the reference group, each cumulative density count category was associated with an increased odds of having a higher category of 60-month WOMAC pain score, as follows: 2.97 (95% confidence interval [CI], 1.48-5.98) for no preoperative problematic areas and density count of 2 or greater, 3.31 (95% CI, 1.64-6.66) for one or more preoperative problematic areas and density count of 0 to 1, and 2.85 (95% CI, 0.97-8.39) for one or more preoperative problematic areas and density count of 2 or greater. Similar associations were observed with 60-month WOMAC function score.

CONCLUSION

In TKR recipients, the presence of problematic musculoskeletal areas beyond the index knee-preoperatively and/or postoperatively-was associated with worse 60-month WOMAC pain/function score.

Perioperative medicine role in painful knee prosthesis prevention

Total knee arthroplasty is one of the most frequently performed orthopaedic surgeries. However, up to 20% of patients develop persistent postoperative pain. Persistent postoperative pain may be an extension of acute postoperative pain, but can also occur after more than 3 months without symptoms. Risk factors associated with persistent postoperative pain after arthroplasty have now been characterised within the patient's perioperative context (preoperative, intraoperative and postoperative), and can be grouped under genetic, demographic, clinical, surgical, analgesic, inflammatory and psychological factors. Identification and prevention of persistent postoperative pain through a multimodal and biopsychosocial approach is essential in the context of perioperative medicine, and has been shown to prevent or ameliorate postoperative pain.

Physical Therapist Management of Total Knee Arthroplasty

A clinical practice guideline on total knee arthroplasty was developed by an American Physical Therapy (APTA) volunteer guideline development group that consisted of physical therapists, an orthopedic surgeon, a nurse, and a consumer. The guideline was based on systematic reviews of current scientific and clinical information and accepted approaches to management of total knee arthroplasty.

Musculoskeletal Symptomatic Areas After Total Knee Replacement for Osteoarthritis

OBJECTIVE

The objective of this study was to measure cumulative incidence and incidence rate and identify factors associated with new musculoskeletal (MSK) symptomatic areas after total knee replacement (TKR) for osteoarthritis (OA).

METHODS

Using data from a randomized controlled trial of patients undergoing elective TKR for OA, we assessed for MSK symptomatic areas by region (neck, hands/wrists/arms/shoulders, back, hips, nonindex knee, and ankles/feet) at baseline (pre-TKR), and at 3, 6, 12, 24, 36, and 48 months post-TKR. Cumulative incidence and incidence rates were calculated for each region. Factors associated with incident MSK symptomatic areas were identified using generalized linear mixed models. Time to incident symptomatic area was assessed using Cox proportional hazards regression.

RESULTS

Among 293 subjects, the cumulative incidence of any new MSK symptomatic area over 4 years was 45%; the incidence rate was 19.2 per 100 person-years. Body site-specific cumulative incidence and incidence rates were highest for nonindex knee and back. Predictors of incident MSK symptomatic areas included female sex (relative risk [RR] 1.64; 95% confidence interval [CI] 1.15-2.34), body mass index of 35 or higher (RR 1.27; 95% CI 0.88-1.85), Charlson Comorbidity Index 2 or more (RR 1.28; 95% CI 0.92-1.78), baseline index knee Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) pain score greater than 40 (RR 1.39; 95% CI 0.99-1.95), and anxiety/depression (measured by the five-item Mental Health Index) (RR 1.70; 95% CI 1.20-2.40).

CONCLUSION

Incident MSK symptomatic areas occurred in roughly half of recipients of TKR in the 4 years after the operation. Further study is needed to examine the long-term impact of MSK symptomatic areas on postoperative pain, function, and quality of life.

Predictive Factors for Developing Chronic Pain After Total Knee Arthroplasty

Total knee arthroplasty offers substantial improvements for patients as measured by functional status and quality of life; however, 8% to 34% of patients experience chronic postsurgical pain following surgery (CPSP). In addition to disruption in daily activities of life caused by the pain itself, CPSP has been associated with an overall reduction in quality of life following surgery. Risk factors for CPSP can be broadly defined as potentially modifiable or unlikely modifiable. Unlikely modifiable risks include gender, age, medical comorbidities, and socioeconomic status. Potentially modifiable risks include perioperative pain, physical function, psychological state, surgical factors, and possibly genomics. Understanding risks and the magnitude of their effect on outcomes such as CPSP is desirable because interventions designed to affect these factors may be able to dramatically improve outcomes.

Efficiency and predictive parameters of outcome of a multimodal pain management concept with spinal injections in patients with low back pain: a retrospective study of 445 patients

Low back pain is one of the most common diseases of modern civilization. Multimodal pain management (MPM) represents a central approach to avoiding surgery. Short-term results are published rarely and often incomparable because of different treatment concepts. This study compared the subjective and objective parameters as well as the anamnestic and clinical parameters of 445 patients with low back pain before and after inpatient MPM to investigate the influence of this type of therapy on short-term outcome. The majority of patients were very satisfied (39%) or satisfied (58%) with the treatment outcome. The median pain reduction for back pain was 3.0 (IQR 2.88) (numeric rating scale, NRS), thus 66% and 2.75 (IQR 3.38, 62%) for leg pain. The main pain reduction occurred within the first 10 days of treatment and was clinically significant from day 5 onwards. The outcome for patients with hospitalization of more than 10 days was significantly worse. The parameters female sex, BMI of > 30, local pain, and pain duration of 3-24 months had a significantly better outcome. In contrast, age, treatment cause, depression, anxiety, and other diseases had no statistically significant influence on outcome. MPM therapy for more than 5 days seems to be an efficient short-term approach to treating low back pain. Knowledge of some of the outcome predictors helps to early identify patients who require more intensive individual care. In the case of no clear indication for surgery, MPM can be an appropriate treatment option.

Normalized gait analysis parameters are closely related to patient-reported outcome measures after total knee arthroplasty

Up till now, only a weak connection could be shown between patient-related outcome measures (PROMs) and measurements obtained by gait analysis (e.g. speed, step length, cadence, ground reaction force, joint moments and ranges of motion) after total knee arthroplasty (TKA). This may result from the methodical problem that regression analyses are performed using data that are not normalized against a healthy population. It does appear reasonable to assume that patients presenting a physiological gait pattern are content with their joint. The more the gait parameters differ from a normal gait pattern the worse the clinical outcome measured by PROMs should be expected to be. In this retrospective study, 40 patients were enrolled who had received a gait analysis after TKA, and whose PROMs had been evaluated. A gender- and age-matched control group was formed out of a group of test persons who had already undergone gait analysis. Gait analysis was undertaken using the motion analysis system 3D Vicon with ten infrared cameras and three strength measuring force plates. The physiological gait analysis parameters were deduced from arithmetic mean values taken from all control patients. The deviances of the operated patients' gait analysis parameters from the arithmetic mean values were squared. From these values, the Pearson correlation coefficients for different PROMs were then calculated, and regression analyses were performed to elucidate the correlation between the different PROMs and gait parameters. In the regression analysis, the normalized cadence, relative gait speed of the non-operated side, and range of the relative knee moment of the operated side could be identified as factors which influence the Forgotten Joint Score (FJS-12). The explanation model showed an increase of the FJS-12 with minimisation of these normalized values corresponding to an approximation of the gait pattern seen in the healthy control group. The connection was strong, having a correlation coefficient of 0.708. A physiological gait pattern after TKA results in better PROMs, especially the FJS-12, than a non-physiological gait pattern does.

Total knee arthroplasty with unexplained pain: new insights from kinematics

INTRODUCTION

Up to 20% of total knee arthroplasty patients remain unsatisfied post-surgery, and a large proportion of them report anterior knee pain. This study aims to verify whether patients who experience anterior knee pain after total knee arthroplasty (TKA) will exhibit kinematic characteristics similar to those associated with patellofemoral syndrome, including in the frontal and transverse planes.

MATERIALS AND METHODS

Using four different assessment methods [radiological, patient-reported outcome, musculoskeletal assessment with functional performance testing, and a 3D kinematic assessment during gait], the clinical and 3D knee kinematic profiles of three groups were compared: a painful and an asymptomatic TKA group and a healthy control group. All three groups underwent a three-dimensional kinematic knee assessment while walking on a treadmill. Prosthetic component rotation was assessed through a CT scan measurement performed by one experienced radiologist. Flexion/extension, ab/adduction, and tibial internal rotation curves were compared, and significant differences were highlighted through ANCOVA analysis performed on SPSS.

RESULTS

A total of 62 knees were evaluated, 24 asymptomatic, 21 painful, and 17 control. A dynamic flexion contracture during gait was observed in the painful group, which was associated with a lack of flexibility of the thigh muscles. Moreover, painful TKA cases exhibited a valgus alignment (- 1.5°) during stance, which increases the Q angle and lateralizes the patella. Finally, CT scan evaluation of painful total knee arthroplasty patients revealed that their combined components rotation was in slight internal rotation (- 1.4°, SD 7.0°).

CONCLUSIONS

Painful TKA patients presented three well-known characteristics that tend to increase patellofemoral forces and that could be the cause of the unexplained pain: a stiff knee gait, a valgus alignment when walking, and combined TKA components slightly internally rotated.

Osteoarthritis year in review 2017: clinical

This review is based on a systematic review of the literature relevant to clinical topics in osteoarthritis (OA) performed for the time period February 22, 2016 to April 1, 2017. A PubMed search using the terms "osteoarthritis" and "treatment or epidemiology" returned over 800 papers, of which 57 are reviewed here, with inclusion primarily based on relevance to clinical OA. Epidemiologic studies in this time frame focused on the incidence and prevalence of OA, comorbidities and mortality in relation to OA (particularly obesity and cardiovascular disease), and multiple joint involvement. Papers on therapeutic approaches to OA considered: non-pharmacologic options, a number of topical, oral, and intra-articular therapies, as well as the cost-effectiveness of some OA treatments. There an enormous need to identify novel strategies to reduce the impact of this highly prevalent and debilitating condition.

Influence of anxiety and pain catastrophizing on the course of pain within the first year after uncomplicated total knee replacement: a prospective study

PURPOSE

Prolonged postoperative pain is a frequent problem after uncomplicated total knee replacement (TKR). The purpose of this study was to evaluate the effect of anxiety and pain catastrophizing on postoperative pain after TKR.

METHODS

A total of 150 patients were enrolled in this prospective study. Preoperatively, anxiety was assessed using the State-Trait Anxiety Inventory (STAI) and pain catastrophizing was assessed using the Pain Catastrophizing Scale (PCS). The primary outcome measure was postoperative pain on a numerical rating scale (NRS). The secondary outcome parameters were the different Knee Osteoarthritis Outcome Score (KOOS) subscales and patient satisfaction. Intergroup differences were tested with an independent t test. The odds ratio was calculated to determine the probability of an unsatisfactory outcome.

RESULTS

Preoperatively and at 6 and 12 months postoperatively, patients with anxiety and particularly patients with pain catastrophizing usually had a higher NRS score, lower knee function before and after surgery, and higher dissatisfaction. These intergroup differences were significant preoperatively and at 6 months postoperatively.

CONCLUSIONS

Psychopathologic factors, particularly pain catastrophizing, have an impact on postoperative pain after TKR. Preoperative screening and concurrent treatment of the diagnosed psychological disorder may improve patient-perceived outcomes.

Pain catastrophizing as a predictor for postoperative pain and opiate consumption in total joint arthroplasty patients

BACKGROUND

Pain catastrophizing has been suggested as a prospective risk factor for poor postoperative pain outcomes in total joint arthroplasty (TJA). However, results from the previous studies have been mixed and have not controlled for postoperative opiate analgesic intake. This study investigates pain catastrophizing and postoperative pain intensity in TJA patients, adjusting for analgesic intake. We hypothesized that "pain catastrophizers" would exhibit higher pain scores and increased analgesic requirements postoperatively.

METHODS

In this prospective cohort study, patients were defined as catastrophizers (PCS > 30), or non-catastrophizers (PCS ≤ 30). The primary outcome was the visual analog scale (VAS) pain score at 3-month follow-up. Secondary outcomes included length of stay (LOS) for the index hospitalization, total daily opiate analgesic intake, and VAS pain scores on postoperative days 0, 1, 2, and 3 through discharge. Multivariable regression was used to control for total daily morphine equivalent dose consumed during the stay in addition to other clinical and demographic factors.

RESULTS

There were 87 patients in the "non-catastrophizing" and 36 in the "catastrophizing" groups. There was no clinically significant difference in VAS pain scores between groups at 3-month follow-up. Patients with a length of stay (LOS) ≥ 3 postoperative days differed in VAS pain scores ("non-catastrophizers" = 5.08 vs. "catastrophizers" = 7.13; p = 0.002) and were 2.4 times more likely to be catastrophizers than non-catastrophizers (p = 0.042). There were no differences in the remaining secondary outcomes.

CONCLUSION

The pain catastrophizing scale is a poor predictor of postoperative pain at 3-month follow-up. However, it may be a risk factor for increased LOS.