Targeting care: tailoring nonsurgical management according to clinical presentation

Pain and functional trajectories in symptomatic knee osteoarthritis over up to 12 weeks of exercise exposure

OBJECTIVE

Exercise is the recommended treatment for knee osteoarthritis (OA). However, heterogeneous patterns in treatment response are poorly understood. Our purpose was to identify pain and functional trajectories from exercise interventions in knee OA, and to determine their association with baseline factors.

METHODS

Prospective cohort of 171 participants (mean age 61 years; BMI 32 kg/m², 71% female; 57% white) with symptomatic knee OA from a randomized trial comparing 12-week Tai Chi and Physical Therapy. We analyzed weekly Western Ontario and McMaster Osteoarthritis Index (WOMAC) pain (0-500) and function (0-1700) scores using group-based trajectory models. Associations between baseline factors and trajectories were examined using multinomial logistic regression.

RESULTS

We identified four pain trajectories: Lower-Early Improvement (43%), Moderate-Early Improvement (32%), Higher-Delayed Improvement (15%), and Higher-No Improvement (10%). We found similar trajectories for function, except that the lower function trajectories diverged into gradual (12%) or delayed-improvement (15%). Compared with the Lower-Early Improvement pain trajectory, moderate and higher trajectories were associated with poorer physical and psychosocial health. A similar pattern of associations were found among the function trajectories.

CONCLUSIONS

We found four distinct trajectories for pain and function over up to 12-weeks of exercise interventions. While most participants experienced improvements over a short-term exposure, subgroups with greater baseline pain/physical disability had either gradual, delayed, or no improvements. These findings help disentangle the heterogeneity of treatment response and may advance patient-centered care in knee OA.

Dose-Response Effects of Tai Chi and Physical Therapy Exercise Interventions in Symptomatic Knee Osteoarthritis

BACKGROUND

Therapeutic exercise is a currently recommended nonpharmacological treatment for knee osteoarthritis (KOA). The optimal treatment dose (frequency or duration) has not been determined.

OBJECTIVE

To examine dose-response relationships, minimal effective dose, and baseline factors associated with the timing of response from 2 exercise interventions in KOA.

DESIGN

Secondary analysis of a single-blind, randomized trial comparing 12-week Tai Chi and physical therapy exercise programs (Trial Registry #NCT01258985).

SETTING

Urban tertiary care academic hospital PARTICIPANTS: A total of 182 participants with symptomatic KOA (mean age 61 years; BMI 32 kg/m², 70% female; 55% white).

METHODS

We defined dose as cumulative attendance-weeks of intervention, and treatment response as ≥20% and ≥50% improvement in pain and function. Using log-rank tests, we compared time-to-response between interventions, and used Cox regression to examine baseline factors associated with timing of response, including physical and psychosocial health, physical performance, outcome expectations, self-efficacy, and biomechanical factors.

MAIN OUTCOME MEASURES

Weekly Western Ontario and McMasters Osteoarthritis Index (WOMAC) pain (0-500) and function (0-1700) scores.

RESULTS

Both interventions had an approximately linear dose-response effect resulting in a 9- to 11-point reduction in WOMAC pain and a 32- to 41-point improvement in function per attendance-week. There was no significant difference in overall time-to-response for pain and function between treatment groups. Median time-to-response for ≥20% improvement in pain and function was 2 attendance-weeks and for ≥50% improvement was 4-5 attendance-weeks. On multivariable models, outcome expectations were independently associated with incident function response (hazard ratio = 1.47, 95% confidence interval 1.004-2.14).

CONCLUSIONS

Both interventions have approximately linear dose-dependent effects on pain and function; their minimum effective doses range from 2-5 weeks; and patient perceived benefits of exercise influence the timing of response in KOA. These results may help clinicians to optimize patient-centered exercise treatments and better manage patient expectations.

LEVEL OF EVIDENCE

II.

Mindfulness Is Associated With Treatment Response From Nonpharmacologic Exercise Interventions in Knee Osteoarthritis

OBJECTIVE

To examine the association between baseline mindfulness and response from exercise interventions in knee osteoarthritis (OA).

DESIGN

Cohort study; responder analysis of a clinical trial subset.

SETTING

Urban tertiary care academic hospital.

PARTICIPANTS

Participants with symptomatic, radiographic knee OA (N=86; mean age, 60y; 74% female; 48% white).

INTERVENTIONS

Twelve weeks (twice per week) of Tai Chi or physical therapy exercise.

MAIN OUTCOME MEASURES

Treatment response was defined using Osteoarthritis Research Society International criteria indicating meaningful improvements in the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) pain, WOMAC function, or Patient Global Assessment scores. At baseline, participants completed the Five Facet Mindfulness Questionnaire (mean total score, 142±17) and were grouped into 3 categories of total mindfulness: higher, medium, or lower. Relative risk (RR) ratios were used to compare treatment response across groups.

RESULTS

Participants with higher total mindfulness were 38% (95% confidence interval [CI], 1.05-1.83) more likely to meet responder criteria than those with lower mindfulness. We found no significant difference between medium and lower mindfulness groups (RR=1.0; 95% CI, 0.69-1.44). Among the 5 mindfulness facets, medium acting-with-awareness was 46% (95% CI, 1.09-1.96) more likely to respond than lower acting-with-awareness, and higher acting-with-awareness was 34% more likely to respond, but this did not reach significance (95% CI, 0.97-1.86).

CONCLUSIONS

In this study, higher mindfulness, primarily driven by its acting-with-awareness facet, was significantly associated with a greater likelihood of response to nonpharmacologic exercise interventions in knee OA. This suggests that mindfulness-cultivating interventions may increase the likelihood of response from exercise.

Incidence, prevalence, natural course and prognosis of patellofemoral osteoarthritis: the Cohort Hip and Cohort Knee study

OBJECTIVE

To examine the proportion of isolated patellofemoral osteoarthritis (PFOA) compared to tibiofemoral osteoarthritis (TFOA) in middle-aged participants with early osteoarthritis (OA) symptoms of the knee; to describe the natural course of PFOA compared with that of TFOA and to identify whether patients with PFOA have a different phenotype compared to patients with TFOA, or with combined PFOA and TFOA (combined osteoarthritis (COA)).

DESIGN

Participants with early OA symptoms of the knee were selected, completed questionnaires, underwent physical examination, and had knee radiographs at baseline, and at 2 and 5 years follow-up. Based on radiographs, participants were classified as having isolated TFOA, isolated PFOA, COA, or no radiographic OA. Multivariate logistic regression was used to identify participant characteristics associated with a specific group of OA at 2 years follow-up.

RESULTS

The cohort comprised 845 participants (mean age 55.9 years). At baseline, 116 had PFOA, none had TFOA or COA. Of these 116 participants, 66.3% had developed COA at 5 years follow-up. At 2 years follow-up, PFOA, TFOA and COA were present in 77 (10.8%), 39 (5.5%) and 83 (11.6%) participants, respectively. Multivariate regression analyses at 2 years follow-up showed that participants with radiographic PFOA or TFOA were not significantly different from each other with respect to signs and symptoms.

CONCLUSIONS

These results suggest that OA is more likely to start in the patellofemoral joint and then progress to COA in individuals with symptoms of early knee OA. No differences in TFOA and PFOA phenotypes were determined with respect to signs and symptoms.

Can We Predict Those With Osteoarthritis Who Will Worsen Following a Chronic Disease Management Program?

OBJECTIVE

To identify predictors of worsening symptoms and overall health of the treated hip or knee joint following 26 weeks of a nonsurgical chronic disease management program for hip and knee osteoarthritis (OA) and to examine the consistency of these predictors across 3 definitions of worsening.

METHODS

This prospective cohort study followed 539 participants of the program for 26 weeks. The 3 definitions of worsening included symptomatic worsening based on change in the Western Ontario and McMaster Universities Osteoarthritis Index Global score (WOMAC-G) measuring pain, stiffness, and function; a transition scale that asked about overall health of the treated hip or knee joint; and a composite outcome including both. Multivariate logistic regression models were constructed for the 3 definitions of worsening.

RESULTS

Complete data were available for 386 participants: mean age was 66.3 years, 69% were female, 85% reported knee joint pain as primary symptom (signal joint), 46% were waitlisted for total joint arthroplasty (TJA). TJA waitlist status, signal joint, 6-Minute Walk Test (6MWT), depressive symptoms, pain, and age were independently associated with at least 1 definition of worsening. TJA waitlist status and 6MWT remained in the multivariate models for the transition and composite definitions of worsening.

CONCLUSION

Participants reporting worsening on the transition scale did not consistently meet the WOMAC-G definition of worsening symptoms. TJA waitlist status was predictive of the composite definition of worsening, a trend apparent for the transition definition. However, variables that predict worsening remain largely unknown. Further research is required to direct comprehensive and targeted management of patients with hip and knee OA.

Ultrasound of knee osteoarthritis: interobserver agreement and correlation with Western Ontario and McMaster Universities Osteoarthritis

The aim of this work was to assess the reproducibility of ultrasound findings of knee osteoarthritis and to correlate ultrasound findings with Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC). Prospective study was conducted upon 80 patients (56 F, 24 M; mean age 57 years) with primary osteoarthritis of knee joint. All patients underwent clinical assessment with calculation of WOMAC and high-resolution ultrasound of the knee joint. The ultrasound images were analyzed for cartilage thinning, osteophytes, synovial effusion, synovial proliferation, popliteal cyst, and meniscal protrusion. Image analysis was performed by two readers and linear regression analysis was used to determine association of ultrasound findings with WOMAC. There was excellent inter-observer agreement of both readers for cartilage thinning (k = 0.99, P = 0.001), osteophytes (k = 0.94, P = 0.001), synovial effusion (k = 0.98, P = 0.001), synovial thickening (k = 0.96, P = 0.001), popliteal cyst (k = 1.00, P = 0.001), and meniscal protrusion (k = 0.86, P = 0.001). There was significant association of WOMAC with cartilage changes (t = 3.406, 3.302, P = 0.001), osteophytes (t = 3.841, 3.006, P = 0.001), and synovial effusion (t = 4.140 and 2.787, P = 0.05) of both readers. We concluded that ultrasound is a reproducible method for assessment of knee osteoarthritis and well correlated with WOMAC.

Does clinical presentation predict response to a nonsurgical chronic disease management program for endstage hip and knee osteoarthritis?

OBJECTIVE

To identify baseline characteristics of participants who will respond favorably following 6 months of participation in a chronic disease management program for hip and knee osteoarthritis (OA).

METHODS

This prospective cohort study assessed 559 participants at baseline and following 6 months of participation in the Osteoarthritis Chronic Care Program. Response was defined as the minimal clinically important difference of an 18% and 9-point absolute improvement in the Western Ontario and McMaster Universities Arthritis Index global score. Multivariate logistic regression modeling was used to identify predictors of response.

RESULTS

Complete data were available for 308 participants. Those who withdrew within the study period were imputed as nonresponders. Three variables were independently associated with response: signal joint (knee vs hip), sex, and high level of comorbidity. Index joint and sex were significant in the multivariate model, but the model was not a sensitive predictor of response.

CONCLUSION

Strong predictors of response to a chronic disease management program for hip and knee OA were not identified. The significant predictors that were found should be considered in future studies.

Patellofemoral joint osteoarthritis: an individualised pathomechanical approach to management

Patellofemoral joint integrity is maintained by an optimal interaction of passive, dynamic and structural restraints. Disruption of these mechanics can lead to structural joint damage and subsequent patellofemoral osteoarthritis, which is a prevalent and disabling condition with few effective conservative management strategies. Due to the influential role of biomechanics in this disease, targeting the specific pathomechanics exhibited by an individual is logical to improve their likelihood of a positive treatment outcome. This review summarises the effect of different pathomechanical factors on the presence and progression of patellofemoral osteoarthritis. It then presents a synthesis of mechanical effect of treatment strategies specifically addressing these pathomechanics. Identifying the pathomechanics and clinical characteristics of individuals with patellofemoral osteoarthritis that respond to treatment may assist in the development of individualised treatment strategies that alleviate symptoms and slow structural damage.