Efficacy of exercise intervention as determined by the McKenzie System of Mechanical Diagnosis and Therapy for knee osteoarthritis: a randomized controlled trial

Research Priorities in the Mechanical Diagnosis and Therapy Among Diploma Therapists: An International Delphi Study

Introduction Mechanical diagnosis and therapy (MDT) is the most researched approach in musculoskeletal physical therapy and involves classifying patients into sub-groups based on their response to loading strategies. MDT diploma therapists (Dip-MDTs) fully recognize the value of MDT in musculoskeletal physical therapy. MDT is updating its system based on the latest research, but the system has not yet been fully established. Therefore, more research is required to increase the comprehensibility of the system. Thus, we aimed to identify future research priorities of MDT. Methods We conducted a modified Delphi study with three rounds. The Research Advisory Committee (RAC) members (n=7) of the McKenzie Institute International were invited to participate in the initial idea generation round. In the subsequent two consensus rounds, Dip-MDTs (n=299) were asked to indicate their level of agreement with the results of the idea generation round using a five-point Likert scale. The criteria for consensus were mean score ≥4.0, coefficient of variation ≤30%, percent agreement ≥75%, and quartile deviation ≤1. A post-hoc analysis of the consensus was conducted when the number of participants from a certain country exceeded one-third of the total number of participants. Results The participation rates for each round were 57.1%, 52.2%, and 49.8%. The USA accounted for 43.6% and 44.3% of all participants at the two consensus rounds, respectively. Finally, nine items reached consensus in the second consensus round. After the post-hoc analysis, eight items reached consensus: (1) cost-effectiveness, (2) cervical and thoracic spine, (3) extremity classifications, (4) filtered randomized controlled trials (RCTs), (5) spinal source classification, (6) centralization and directional preferences, (7) predictive factors for recurrence, and (8) patient education. Conclusion In this study, we identified the research priorities of MDT that would enhance the completion of the MDT system.

The influence of directional preference on lateral patellar dislocation: a case report

BACKGROUND

There is little consensus on the conservative management of lateral patellar dislocations (LPD). Mechanical diagnosis and therapy (MDT) is an established classification system in the spinal and extremity population. This case report describes the use of MDT in the management and classification of a patient with LPD.

CASE DESCRIPTION

The patient was a 20-year-old female with a 3-month history of left knee pain precipitated by a lateral patellar dislocation. The patient described pain and a feeling of instability with standing and walking and limitations in work and recreational activities which involve lifting, squatting, and running. Based on the patient's response to repeated end range knee movements, the patient was found to have a directional preference (DP) for knee extension and instruction in performance of knee extension DP exercises was provided.

OUTCOMES

The patient's knee examination and subsequent intervention included her responses to repeated end range knee movements. Her knee pain was abolished, and strength, function, and motion were fully restored in five visits. A minimal clinically important difference (MCID) was achieved on the Lower Extremity Functional Scale (LEFS). At discharge, the patient was able to independently manage symptoms and perform all work and recreational activities at a pre-injury level and these improvements were maintained at a 9-month follow-up.

DISCUSSION

There are various management strategies for lateral patellar dislocation. This case demonstrated the use of classifying, subgrouping, and treating a patient with lateral patellar dislocation using the principle of DP.

CONCLUSION

The patient's outcomes suggest that MDT may be used in the nonoperative management of people with LPD who present with a DP.

The impact of waiting time for orthopaedic consultation on pain levels in individuals with osteoarthritis: a systematic review and meta-analysis

OBJECTIVE

Time spent waiting for access to orthopaedic specialist health services has been suggested to result in increased pain in individuals with osteoarthritis (OA). We assessed whether time spent on an orthopaedic waiting list resulted in a detrimental effect on pain levels in patients with knee or hip OA.

METHODS

We searched Ovid MEDLINE, EMBASE and EBSCOhost databases from inception until September 2021. Eligible articles included individuals with OA on an orthopaedic waitlist and not receiving active treatment, and reported pain measures at two or more time points. Random-effects meta-analysis was used to estimate the pooled effect of waiting time on pain levels. Meta-regression was used to determine predictors of effect size.

RESULTS

Thirty-three articles were included (n = 2,490 participants, 67 ± 3 years and 62% female). The range of waiting time was 2 weeks to 2 years (20.8 ± 18.8 weeks). There was no significant change in pain over time (effect size = 0.082, 95% CI = -0.009, 0.172), nor was the length of time associated with longitudinal changes in pain over time (β = 0.004, 95% CI = -0.005, 0.012). Body mass index was a significant predictor of pain (β = -0.043, 95% CI = -0.079, 0.006), whereas age and sex were not.

CONCLUSIONS

Pain remained stable for up to 1 year in patients with OA on an orthopaedic waitlist. Future research is required to understand whether pain increases in patients waiting longer than 1 year.

Hip abductor versus adductor strengthening for clinical outcomes in knee symptomatic osteoarthritis: A randomized controlled trial

BACKGROUND

Hip adductors and abductors are weak in patients with knee osteoarthritis (KOA). However, most studies have not investigated selective adductor strengthening.

OBJECTIVE

To compare the effects of adding selective hip abductors versus adductors strengthening to lower limb multimodal exercise program for pain, self-reported function, knee-related quality of life, medication ingested and performance-based tests in patients with symptomatic KOA.

DESING

Randomized controlled trial.

METHODS

Sixty-six patients with KOA were randomly assigned to two treatment groups: hip abductor group (HABG) or hip adductor group (HADG). Both groups performed a lower limb multimodal exercise program. HABG and HADG groups added three hip abduction and three hip adduction exercises, respectively. Intensity of pain through numeric pain scale, Knee Injury and Osteoarthritis Outcome Score (KOOS) subscales, Lequesne questionnaire, global perceived effect scale, medication ingested, performance-based tests were assessed at baseline, after 6 weeks, and 6 months.

RESULTS

No significant between-group differences were found in primary outcomes: pain intensity (mean difference = -1.15, 95%CI -2.44 - 0.12, P = 0.07), KOOS-pain (mean difference = 1.64, 95%CI -6.79 - 10.07, P = 0.70) and KOOS-function in daily living (mean difference = -0.12, 95%CI, -8.78 - 8.54, P = 0.97) in 6 weeks. Groups did not differ in any secondary outcome after 6 weeks or after 6 months (P > 0.05).

CONCLUSIONS

There is no difference between adding hip abductors or adductors strengthening to lower limb multimodal exercise program in improving pain, self-reported function, quality of life, medication ingested and performance-based tests in patients with KOA.

Attempting to Separate Placebo Effects from Exercise in Chronic Pain: A Systematic Review and Meta-analysis

BACKGROUND

Pain is the most disabling characteristic of musculoskeletal disorders, and while exercise is promoted as an important treatment modality for chronic musculoskeletal conditions, the relative contribution of the specific effects of exercise training, placebo effects and non-specific effects such as natural history are not clear. The aim of this systematic review and meta-analysis was to determine the relative contribution of these factors to better understand the true effect of exercise training for reducing pain in chronic primary musculoskeletal pain conditions.

DESIGN

Systematic review with meta-analysis DATA SOURCES: MEDLINE, CINAHL, SPORTDiscus, EMBASE and CENTRAL from inception to February 2021. Reference lists of prior systematic reviews.

ELIGIBILITY CRITERIA

Randomised controlled trials of interventions that used exercise training compared to placebo, true control or usual care in adults with chronic primary musculoskeletal pain. The review was registered prospectively with PROSPERO (CRD42019141096).

RESULTS

We identified 79 eligible trials for quantitative analysis. Pairwise meta-analysis showed very low-quality evidence (GRADE criteria) that exercise training was not more effective than placebo (g [95% CI]: 0.94 [- 0.17, 2.06], P = 0.098, I² = 92.46%, studies: n = 4). Exercise training was more effective than true, no intervention controls (g [95% CI]: 0.99 [0.66, 1.32], P < 0.001, I² = 92.43%, studies: n = 42), usual care controls (g [95% CI]: 0.64 [0.44, 0.83], P < 0.001, I² = 76.52%, studies: n = 33), and when all controls combined (g [95% CI]: 0.84 [0.64, 1.04], P < 0.001, I² = 90.02%, studies: n = 79).

CONCLUSIONS

There is very low-quality evidence that exercise training is not more effective than non-exercise placebo treatments in chronic pain. Exercise training and the associated clinical encounter are more effective than true control or standard medical care for reductions in pain for adults with chronic musculoskeletal pain, with very low quality of evidence based on GRADE criteria.

Arthroscopy Association of Canada Position Statement on Exercise for Knee Osteoarthritis: A Systematic Review of Guidelines

BACKGROUND

Exercise is widely regarded to improve pain and function in patients with knee osteoarthritis (OA) through building supportive muscle mass, facilitating weight loss, and through the other beneficial effects associated with it.

PURPOSE

To explore literature that presents clinical guidelines for the use of exercise in the treatment of knee OA to inform an evidence-based position statement for the Arthroscopy Association of Canada.

STUDY DESIGN

Position statement.

METHODS

PubMed, MEDLINE, Embase, and Cochrane databases were searched for guidelines commenting on the role of exercise for knee OA. The search was limited to guidelines published in the last 10 years. Articles were screened for relevance, focusing on recently published research with clinical guidelines. Inclusion criteria involved all articles providing clinical guidelines for exercise and knee OA.

RESULTS

Eight guidelines were identified. All eight recommended exercise as an important component of treatment for knee OA, with 6/8 strongly recommending it.

CONCLUSION

Exercise is an effective and important component of the non-pharmacological management of knee OA. The Arthroscopy Association of Canada strongly recommends the use of exercise in the management of knee OA.

Effectiveness of mechanical diagnosis and therapy in patients with non-specific chronic low back pain: a literature review with meta-analysis

OBJECTIVE

To determine the effectiveness of mechanical diagnosis and therapy (MDT) in patients with chronic low back pain (CLBP) compared to other traditional physical therapy interventions.

METHODS

Randomized controlled trials investigating the effect of MDT compared to other traditional physical therapy interventions in individuals with CLBP were considered eligible. For the purpose of this review, MDT was compared to active and passive physical therapy interventions. Independent reviewers assessed the eligibility of studies, extracted data, and assessed the risk of bias. The primary outcomes investigated were pain and disability.

RESULTS

Fourteen studies were included in the review. Of these, 11 provided data to be included in the meta-analyses. Our findings showed that MDT was no more effective in decreasing pain (standardized mean difference [SMD]=0.01, 95% confidence interval [CI]: -0.44, 0.46) and disability (SMD=0.08, 95% CI: -0.53, 0.68) than other active treatments. Similar results were found when comparing MDT to other passive treatments for pain (SMD=-0.39, 95% CI: -0.90, 0.11) and disability (SMD=-0.13, 95% CI: -0.29, 0.03).

CONCLUSION

There is low to moderate quality evidence that MDT is not superior than other traditional physical therapy interventions in improving pain and disability in people with CLBP.

A prospective study of patients with knee pain and mechanical diagnosis and therapy (MDT) classification

OBJECTIVES

A prospective observational cohort study was conducted to 1) determine the prevalence of Mechanical Diagnosis and Therapy (MDT) syndromes for patients with knee impairments, and 2) report the interaction between MDT classification and clinical outcomes, including pain intensity and disability, at discharge.

METHODS

Clinical outcome measures were completed at intake and discharge on 186 patients. A two-way mixed model analysis of variance with subsequent pairwise comparisons was done to examine differences between the following MDT classifications: Knee Derangement, Knee Dysfunction, and Other.

RESULTS

The primary findings were that: 1) 61.3% (54.3, 68.3), 9.7% (5.4, 13.9), and 29.0% (22.5, 35.5) of patients' conditions were classified as Knee Derangement, Knee Dysfunction, and Other, respectively; 2) all groups managed via MDT methods made clinically significant improvements in disability and pain intensity at discharge with the exception of the Other classification for pain intensity (NPRS difference score = 1.8); 3) a clinically significant difference was observed between the Knee Derangement and Other for pain and between the Knee Derangement and Other and the Knee Dysfunction and Other classifications for disability; and 4) the Knee Derangement classification was discharged, on average, 15.8 days earlier than the Knee Dysfunction classification.

DISCUSSION

This was the first prospective study of the application of MDT in patients with knee impairments. Results should be interpreted with caution as follow-up data were only completed on 58% of patients that started data collection. Assuming that none of the dropouts were Derangement, the overall prevalence of Derangement would be 32.2% and 79.7% if all dropouts were classified as Derangement. This study adds insight into understanding the unique clinical trajectories of these MDT classifications for the knee and offers recommendations for future work in this growing field of research.

Relative Efficacy of Different Exercises for Pain, Function, Performance and Quality of Life in Knee and Hip Osteoarthritis: Systematic Review and Network Meta-Analysis

Background

Guidelines recommend exercise as a core treatment for osteoarthritis (OA). However, it is unclear which type of exercise is most effective, leading to inconsistency between different recommendations.

Objectives

The aim of this systematic review and network meta-analysis was to investigate the relative efficacy of different exercises (aerobic, mind–body, strengthening, flexibility/skill, or mixed) for improving pain, function, performance and quality of life (QoL) for knee and hip OA at, or nearest to, 8 weeks.

Methods

We searched nine electronic databases up until December 2017 for randomised controlled trials that compared exercise with usual care or with another exercise type. Bayesian network meta-analysis was used to estimate the relative effect size (ES) and corresponding 95% credibility interval (CrI) (PROSPERO registration: CRD42016033865).

Findings

We identified and analysed 103 trials (9134 participants). Aerobic exercise was most beneficial for pain (ES 1.11; 95% CrI 0.69, 1.54) and performance (1.05; 0.63, 1.48). Mind–body exercise, which had pain benefit equivalent to that of aerobic exercise (1.11; 0.63, 1.59), was the best for function (0.81; 0.27, 1.36). Strengthening and flexibility/skill exercises improved multiple outcomes at a moderate level. Mixed exercise was the least effective for all outcomes and had significantly less pain relief than aerobic and mind–body exercises. The trend was significant for pain (p = 0.01), but not for function (p = 0.07), performance (p = 0.06) or QoL (p = 0.65).

Conclusion

The effect of exercise varies according to the type of exercise and target outcome. Aerobic or mind–body exercise may be the best for pain and function improvements. Strengthening and flexibility/skill exercises may be used for multiple outcomes. Mixed exercise is the least effective and the reason for this merits further investigation.

Electronic supplementary material

The online version of this article (10.1007/s40279-019-01082-0) contains supplementary material, which is available to authorized users.

Mechanical diagnosis and therapy and Morton's neuroma: a case-series

Objectives: Morton's neuroma (MN) is a neuralgia involving the common plantar digital nerves of the metatarsal region. Evidence-based treatment options for MN are sparse, and utility of physical therapy (PT) is unknown. Mechanical Diagnosis and Therapy (MDT) is a classification system utilizing direction-specific treatment for orthopedic conditions based on mechanical and symptomatic response to repeated end range movements. The purpose of this case series is to describe the management of three patients with a medical diagnosis of MN using the MDT classification system.Methods: Three female patients aged 54-75 years with unilateral plantar forefoot pain for 6 weeks to 8 years were referred by a podiatrist following positive clinically accepted diagnostic criteria for MN including radiological imaging and provocation testing. Patients were evaluated and treated utilizing MDT assessment and treatment principles. The intervention consisted of repeated movements matched to the patient's directional preference at either the lumbar spine (1 patient) or distal extremity (2 patients).Results: Immediate and one-year outcomes were excellent, demonstrating rapid and lasting improvement. Following discharge, the patients have been asymptomatic or able to self-manage without seeking additional medical intervention for this condition. Total visit frequency per patient averaged 2-3 visits total across 8-16 days.Discussion: Responses to repeated end range movements testing allowed for classification and prescription of exercise to rapidly improve symptoms and function in three patients referred to PT services with medically diagnosed MN. This series provides preliminary evidence that MDT may be effective in classifying and treating patients with MN.

Innovative treatment of clinically diagnosed meniscal tears: a randomized sham-controlled trial of the Mulligan concept 'squeeze' technique

Objective: The purpose of this study was to assess the effects of the Mulligan Concept (MC) 'squeeze' technique compared to a sham technique in participants with a clinically diagnosed meniscal tear.

Methods: A multi-site randomized sham-controlled trial of participants (n = 23), aged 24.91 ± 12.09 years, with a clinically diagnosed meniscal tear were equally and randomly divided into two groups. Groups received a maximum of six treatments over 14 days. Patient outcomes included the numeric pain rating scale (NRS), patient-specific functional scale (PSFS), the disablement in the physically active (DPA) scale and the knee injury osteoarthritis outcome score. Data were analysed using univariate ANOVA, univariate ANCOVA, and descriptive statistics.

Results: All participants in the MC 'squeeze' group met the discharge criteria of ≤2 points on the NRS, ≥9 points on the PSFS, and ≤34 points or ≤23 on the DPA Scale for chronic or acute injuries, respectively within the treatment intervention timeframe. A significant difference was found in favor of the MC 'squeeze' technique in PSFS scores (F(1, 21) = 4.40, p = .048, partial eta squared = .17, observed power = .52) and in DPA Scale scores (F(1, 21) = 7.46, p = .013, partial eta squared = .27, observed power = .74).

Discussion: The results indicate the MC 'squeeze' technique had positive effects on patient function and health-related quality of life over a period of 14 days and was clinically and statistically superior to the sham treatment. Further investigation of the MC 'squeeze' technique is warranted.

The most common classification in the mechanical diagnosis and therapy for patients with a primary complaint of non-acute knee pain was Spinal Derangement: a retrospective chart review

Objectives: To preliminarily investigate in patients with a primary complaint of non-acute knee pain for ≥ 1 month: 1) the proportion of patients with non-acute knee pain classified by Mechanical Diagnosis and Therapy (MDT) as Spinal Derangements, 2) the number of sessions taken to identify the concluding classification, and 3) the ability of MDT classifications, demographics, and symptomatic baselines to predict pain reduction at 1-month follow-up.Methods: This study reviewed data from outpatients managed with MDT. For modeling knee pain reduction at the 1-month follow-up, 3 MDT provisional or concluding classifications (Spinal Derangement, Knee Derangement, and Non-Derangement) and the following variables were included: 1) gender, 2) symptom duration, 3) presence of low back pain (LBP), 4) the Japanese Knee Osteoarthritis Measure, 5) average pain intensity at the initial session using a 0-10 numerical rating scale, and 6) the Kellgren-Lawrence grade.Results: Data from 101 patients were extracted. The percentage of patients with the concluding classification of Spinal Derangement was 44.6%. This was greater in those patient's reporting concomitant LBP (p = .002) and without radiographic findings of knee osteoarthritis (p < .001). A concluding classification was determined by the fourth session in 80% of patients. Multiple regression modeling demonstrated that only the concluding classification significantly predicted the knee pain reduction at the 1-month follow-up.Discussion: These findings suggest the importance of careful screening assessments of the lumbar spine and the importance of detecting Derangements throughout the follow-up sessions for patients with a primary complaint of knee pain.

Directional preference of the extremity: a preliminary investigation

Background: Mechanical diagnosis and therapy (MDT) is a specific classification-based musculoskeletal examination and intervention system that uses repeated end range and sustained movement to classify patients into mechanical syndromes. Research has recently demonstrated increased prevalence, reliability, and efficacy of MDT syndromes in varied peripheral musculoskeletal populations. There is currently no research analyzing if predictive variables exist for establishing directional preference in peripheral joints, other than the wrist. The aim of this study was to examine the clinical application of predictive variables for establishing directional preference and spinal referral in patients with isolated peripheral joint pain. Case Description: Thirty-seven consecutive patients with isolated peripheral pain were evaluated and classified using MDT assessment. Secondary analysis of predetermined variables was performed for association with directional preference and identification of spinal referral in Derangement syndrome. Results: All 37 patients were classified using MDT assessment. Thirty-three (89.2%) were classified as Derangement syndrome: 17 as spinal Derangement (45.9%) and 16 as peripheral Derangement (43.2%). One peripheral derangement also had an underlying Articular Dysfunction. Additionally, there were four patients classified as Other (10.8%). Discussion: Historical and physical examination findings were analyzed to determine if there were associated variables of directional preference or spinal referral. Mechanical stress was found to be the most associated factor in predicting directional preference. No peripheral movement loss, paresthesia, and constant pain were more associated with spinal referral. These findings may lead to a greater understanding of peripheral MDT assessment, which may lead to increased identification of directional preference and improved patient outcomes. Level of Evidence: 4.

Provider reliability with interventions for knee impairments: a preliminary investigation to facilitate development of an MDT-based knee intervention taxonomy

Objectives: The lack of a standardized intervention taxonomy in comparative effectiveness research trials has led to uncertainty regarding the management of individuals with knee impairments. Inconsistently and poorly defined interventions affect frontline-care providers' abilities to understand and assimilate research findings into practice. An intervention taxonomy could help overcome the lack of treatment specificity commonly found in research trials. Methods: In the present study, we aimed to develop a Mechanical Diagnosis and Therapy (MDT)-based taxonomy and test the levels of reliability between providers who currently manage individuals with knee impairments in a rehabilitation setting. A total of 182 participants accessed the study during the study period, in which 180 consented to participate and 59 completed the survey (98.9% participation rate; 32.7% completion rate). Results: A total of 89.8% of the participants who completed the survey were physical therapists. Fleiss kappa values for the primary, secondary, and tertiary categories were 0.90, 0.89, and 0.71, respectively. The results of our investigation suggest substantial to almost perfect levels of reliability for identifying diverse MDT-based knee interventions displayed in video and vignette format within a sample population primarily of physical therapists who currently manage individuals with knee impairments in a rehabilitation setting. Discussion: Our findings show acceptable levels of reliability and provide support for using this standardized MDT-based intervention taxonomy as a way to improve intervention specificity and generalizability in comparative effectiveness research. Level of Evidence: 5.

The application of Mechanical Diagnosis and Therapy to the ankle-foot complex: a case series

Background

Pain at the ankle-foot complex is a common musculoskeletal condition that can lead to dysfunction. Mechanical Diagnosis and Therapy (MDT) is an orthopedic classification and treatment system based on mechanical and symptomatic response to repeated and sustained movement. There has been no investigation of the association between MDT and patients diagnosed with ankle-foot complex pain.

Case description

This report presents four patients with a primary complaint of pain in the ankle-foot complex. Three patients had a medical diagnosis while the other was self-referred through direct access. All received classification and treatment by clinicians trained in MDT solely utilizing MDT principles.

Outcomes

Short- and long-term (4-12 months) outcomes were excellent, demonstrating rapid abolishment of symptoms and return to prior levels of function in an average of six visits over 21 days (4-8 visits over 14-33 days) without the use of modalities, strength, or proprioceptive training. The patients demonstrated the ability to prevent and manage re-occurrence of symptoms independently without seeking further health care at long-term follow-up.

Discussion

The rapid speed of recovery and return to functional activities demonstrated in this case series, raises questions about whether or not the pathologies traditionally associated with the etiology of ankle-foot injuries are actually at fault or understood. Moreover, it demonstrates that specific movements can rapidly worsen or improve symptoms challenging the current generalized rehabilitation protocols. This report provides preliminary evidence that MDT may be capable of providing more effective short-term outcomes in the management of ankle-foot complex injuries.

Level of Evidence

4.

McKenzie mechanical syndromes coincide with biopsychosocial influences, including central sensitization: a descriptive study of individuals with chronic neck pain

BACKGROUND

Mechanical diagnosis and therapy (MDT) aims to assess and classify patients into theoretically mutually exclusive subgroups, in order to direct treatment. However, the latest evidence for biopsychosocial influence-central sensitization (CS) and psychological distress-have not been assessed in conjunction with MDT.

OBJECTIVES

(1) Determine the percentage of patients categorized into the MDT subgroups; (2) characterize the biopsychosocial clinical profile (presence of CS and psychological distress); and (3) identify associations between pain, disability, and biopsychosocial influences among this cohort.

METHODS

Eighty four patients with chronic neck pain were recruited by 10 certified MDT therapists using a convenience (consecutive) sampling method. Patients were evaluated using MDT principles and also completed an online survey to measure CS (using the Central Sensitization Inventory [CSI]), pain catastrophizing and kinesiophobia.

RESULTS

The proportions of the subgroups derangement (DER), dysfunction, postural and 'other' were 74.4, 2.4, 1.2, 20.7%, respectively. CS was observed in 62% of our sample (CSI score ≥ 40). CS was also observed in 64.7% of patients of the DER subgroup. Almost half of our sample (47.8%) demonstrated the co-occurrence of CS and DER, while 38% presented with DER syndrome, CS, and kinesiophobia.

CONCLUSION

The majority of our patients were classified as DER; they also presented with high levels of CS and/or psychological distress. This suggests that MDT mechanical subgroups, particularly DER, can present with co-occurring biopsychosocial influences. Without assessing CS and psychological distress, MDT therapists may miss crucial information. Further research is required to determine the optimal management of patients presenting with mechanical and non-mechanical drivers of pain.

The application of mechanical diagnosis and therapy on hip osteoarthritis: A case report

Background: The prevalence and cost of hip osteoarthritis (OA) is rising. Mechanical diagnosis and therapy (MDT) is an orthopedic classification and treatment system based on mechanical and symptomatic response to repeated and sustained end-range movements. There has been no investigation of the association between MDT and patients diagnosed with hip OA. Case Description: This case report presents a 71-year-old female diagnosed with hip OA and matching the currently accepted clinical prediction rule (CPR) for symptomatic hip OA. The patient was classified and treated by a Diplomat of MDT and co-examiner using MDT. Outcomes: Short- and long-term (13 months) outcomes were excellent, demonstrating rapid abolishment of symptoms and improvement in function in 5 visits over 21 days. The patient demonstrated the ability to prevent and manage reoccurrence of symptoms independently; nevertheless, she received a total hip replacement which was not in accordance with current guidelines and recommendations. Conclusion: This case report raises questions about whether or not pathologies traditionally associated with the etiology of hip OA are actually at fault. Moreover, it raises questions about the utility of special tests and CPRs typically utilized to identify those structures. The case report provides preliminary evidence from one patient that MDT may be capable of providing effective short- and long-term outcomes in the management of hip OA.

Effectiveness of the McKenzie Method of Mechanical Diagnosis and Therapy for Treating Low Back Pain: Literature Review With Meta-analysis

Study Design Literature review with meta-analysis. Background The McKenzie Method of Mechanical Diagnosis and Therapy (MDT), a classification-based system, was designed to classify patients into homogeneous subgroups to direct treatment. Objectives To examine the effectiveness of MDT for improving pain and disability in patients with either acute (less than 12 weeks in duration) or chronic (greater than 12 weeks in duration) low back pain (LBP). Methods Randomized controlled trials examining MDT in patients with LBP were identified from 6 databases. Independent investigators assessed the studies for exclusion, extracted data, and assessed risk of bias. The standardized mean difference (SMD) and 95% confidence interval were calculated to compare the effects of MDT to those of other interventions in patients with acute or chronic LBP. Results Of the 17 studies that met the inclusion criteria, 11 yielded valid data for analysis. In patients with acute LBP, there was no significant difference in pain resolution (P = .11) and disability (P = .61) between MDT and other interventions. In patients with chronic LBP, there was a significant difference in disability (SMD, -0.45), with results favoring MDT compared to exercise alone. There were no significant differences between MDT and manual therapy plus exercise (P>.05) for pain and disability outcomes. Conclusion There is moderate- to high-quality evidence that MDT is not superior to other rehabilitation interventions for reducing pain and disability in patients with acute LBP. In patients with chronic LBP, there is moderate- to high-quality evidence that MDT is superior to other rehabilitation interventions for reducing pain and disability; however, this depends on the type of intervention being compared to MDT. Level of Evidence Therapy, level 1a. J Orthop Sports Phys Ther 2018;48(6):476-490. Epub 30 Mar 2018. doi:10.2519/jospt.2018.7562.

Directional preference of the wrist: a preliminary investigation

Background

Directional preference is a phenomenon that occurs in musculoskeletal disorders. It is associated with improved symptomatic and functional outcomes. Research has shown a 90% increase in the identification of directional preference in the peripheral joints between 2006 and 2012. There is currently no research analyzing if predictive variables exist for establishing directional preference.

Case Description

This report presents 19 consecutive patients with wrist pain. These patients were evaluated using a mechanical diagnosis and therapy (MDT)-based assessment. Patients were classified into the mechanical syndromes Derangement, Dysfunction, Postural, and Other. Patients classified with wrist Derangement were assessed for the presence of directional preference. Secondary analysis of predetermined variables was performed for association with directional preference. One case description was included to demonstrate MDT assessment, treatment, and clinical reasoning.

Results

Of the 19 patients evaluated, 15 (79%) were classified as having wrist Derangement. All patients with wrist Derangement demonstrated directional preference. Eight movements were found to establish directional preference. Each was unique with varying degrees of direction, load, and force.

Discussion

This report found directional preference to be higher (79%) than previously reported values. Historical and physical examination findings were analyzed to determine if there were associated variables of directional preference. Excessive mechanical stress was found to be the most associated factor in predicting directional preference. These findings may lead to a greater understanding of peripheral MDT assessment, which may lead to increased identification of directional preference and improved patient outcomes.

Level of Evidence

4.

Consistency of commonly used orthopedic special tests of the shoulder when used with the McKenzie system of mechanical diagnosis and therapy

BACKGROUND

Shoulder Orthopedic Special Tests (OSTs) are used to assist with diagnosis in shoulder disorders. Issues with reliability and validity exist, making their interpretation challenging. Exploring OST results on repeated testing within Mechanical Diagnosis and Therapy (MDT) shoulder classifications may offer insight into the poor performance of these tests.

OBJECTIVES

To investigate in patients with shoulder complaints, whether MDT classifications affect the agreement of OST results over the course of treatment.

METHODS

An international group of MDT clinicians recruited 105 patients with shoulder problems. Three commonly used OSTs (Empty Can, Hawkins-Kennedy, and Speed's tests) were utilized. Results of the OSTs were collected at sessions 1, 3, 5 and 8, or at discharge from an MDT classification-based treatment. The Kappa statistic was utilized to determine the agreement of the OST results over time for each of the MDT classifications.

RESULTS

The overall Kappa values for Empty Can, Hawkins-Kennedy and Speed's tests were 0.28 (SE = 0.07), 0.28 (SE = 0.07) and 0.29 (SE = 0.07), respectively. The highest level of agreement was for Articular Dysfunction for the Empty Can test (0.84, SE = 0.19). For shoulder Derangements, there was no agreement for any of the OSTs (P values > 0.05).

CONCLUSION

The lack of agreement when the OSTs were consecutively tested in the presence of the MDT Derangement classification contrasted with the other MDT classifications. The presence of Derangement was responsible for reducing the overall agreement of commonly used OSTs and may explain the poor consistency for OSTs.

Conservative Management of Possible Meniscal Derangement Using the Mulligan Concept: A Case Report

Objective

The purpose of this case study was to report on the immediate effects of the combined use of mobilizations with movement and the "squeeze" technique on a patient with knee stiffness, popping, and swelling.

Clinical Features

The patient presented with right knee stiffness, swelling, and a popping sensation of insidious onset. Clinical examination revealed pain with terminal knee extension and flexion, joint line tenderness, a positive Apley's compression test, and a positive Thessaly's test at 20° of knee flexion. A working diagnosis was established of a meniscal pathology with the differential diagnoses of meniscal derangement and synovial plica.

Intervention and Outcome

The patient received 3 total treatments using the Mulligan concept over the course of 11 days. The treatments included the application of a tibia internal rotation mobilization with movement and the "squeeze" technique to the affected knee. Patient outcomes, including the Disablement in the Physically Active Scale, the Patient-Specific Functional Scale, and the Numeric Rating Scale for pain, were collected throughout the course of treatment. The patient reported a minimal clinically important difference on the Numeric Rating Scale for pain after each treatment and on all outcomes after the third treatment. The patient reported improvement on her follow-up visit 4 days after the third treatment; the results of a clinical exam and patient outcomes supported a complete discharge after 3 treatments.

Conclusion

This patient responded favorably to use of the Mulligan concept as a manual therapy technique for the treatment of symptoms related to possible meniscal derangement.

Mechanical diagnosis and therapy enhances attitude toward self-management in people with musculoskeletal disorders: A preliminary evidence with a before-after design

Objectives:

Mechanical diagnosis and therapy is one of the most common approaches for the management of low back pain. In mechanical diagnosis and therapy, a great emphasis is placed on patient education so that patients can manage their problems by themselves. However, there has been no evidence that mechanical diagnosis and therapy actually enhances patient’s self-management skills. This study aimed to preliminarily investigate whether self-reported skills of self-management for musculoskeletal problems are enhanced through the course of mechanical diagnosis and therapy.

Method:

Outpatients with musculoskeletal disorders in a local orthopedic clinic were included. The primary outcome measures were the “Self-monitoring and Insight” and “Skill and Technique Acquisition” scores of the Health Education Impact Questionnaire, where higher scores indicate greater self-management skills. Mechanical diagnosis and therapy was undertaken up to a maximum of twice per week for 1 month. The Self-monitoring and Insight and Skill and Technique Acquisition scores before and 1 month after the mechanical diagnosis and therapy interventions were compared. Proportions of patients who exceed the threshold for “reliable change” in the Health Education Impact Questionnaire scores (% >positive “reliable change”) and proportions of patients with the net positive “reliable change” (% net positive “reliable change”) were investigated.

Results:

Forty-five patients participated and 97.8% completed the 1-month follow-up. The Self-monitoring and Insight and Skill and Technique Acquisition scores significantly increased at the follow-up (Self-monitoring and Insight, p = 0.002; Skill and Technique Acquisition, p < 0.001. The % >positive “reliable change” (Self-monitoring and Insight = 22.2%, Skill and Technique Acquisition = 48.9%) and % net positive “reliable change” (Self-monitoring and Insight = 13.3%, Skill and Technique Acquisition = 46.7%) in this study were comparative to or greater than self-management programs in previous studies (%> positive “reliable change’: Self-monitoring and Insight = 20.5%, Skill and Technique Acquisition = 30.7%; % net positive “reliable change”: Self-monitoring and Insight = 14.1%, Skill and Technique Acquisition = 23.0%).

Conclusion:

This study provides a preliminary evidence that mechanical diagnosis and therapy enhances patient’s self-management skills, particularly in the self-monitoring skills for symptoms/functions and the self-management skill for symptoms/problems.

Task-Specific Training for Adults With Chronic Knee Pain: A Case Series

Study Design Case series. Background Recent evidence suggests that traditional impairment-based rehabilitation approaches for patients with knee pain may not result in improved function or reduced disability. This case series describes a novel task-specific training approach to exercise therapy for patients with chronic knee pain and reports changes in measures of clinical outcome (pain and physical function) following participation in the training program. Case Description Seven patients with chronic knee pain aged 40 years or older were included. Each reported at least "moderate" difficulty with sit-to-stand transfers, floor transfers, and/or stair negotiation at baseline. Experienced physical therapists provided between 8 and 16 treatment sessions focusing on improving performance of difficult or painful tasks. Outcomes A majority of patients demonstrated clinically important improvements in both patient-rated outcomes (Knee injury and Osteoarthritis Outcome Score, numeric pain-rating scale, modified Arthritis Self-Efficacy Scale) and performance-based outcomes (30-second chair-rise test, timed stair-climb test, floor transfer test, Performance Assessment of Self-Care Skills). Discussion A task-specific training approach for patients with chronic knee pain was described and yielded considerable improvement in pain and function for most of the individuals in this case series. Larger studies are needed to determine how task-specific training compares with more traditional impairment-based exercise approaches for chronic knee pain. Level of Evidence Therapy, level 5. J Orthop Sports Phys Ther 2017;47(8):548-556. doi:10.2519/jospt.2017.7349.

Inter-rater reliability of the McKenzie System of Mechanical Diagnosis and Therapy in the examination of the knee

OBJECTIVE

The McKenzie System of Mechanical Diagnosis and Therapy (MDT) is a widely used method of classification and management of musculoskeletal problems. Although MDT has been investigated for its reliability and efficacy in the management of spinal pain, few studies have evaluated the system when applying it to musculoskeletal problems in the extremities, in particular the knee. The purpose of this study was to investigate the inter-rater reliability of MDT when classifying clinical vignettes describing patients with musculoskeletal knee pain.

METHODS

This study was divided into two phases. First, 10 clinicians experienced in the use of MDT were recruited to write a total of 60 clinical vignettes based upon the initial assessment of their past patients with knee pain. Second, six different MDT raters were recruited to rate 53 selected vignettes and reliability was determined using Fleiss Kappa.

RESULTS

There was 'substantial agreement' among six MDT raters classifying the clinical vignettes into one of four categories (κ = 0.72). There was no statistically significant difference between therapists with different levels of training.

DISCUSSION

MDT demonstrated acceptable reliability among trained raters to classify clinical vignettes describing patients with musculoskeletal knee pain. To generalize the use of the system to more users, future research should continue to investigate the reliability of MDT using raters with lower levels of training and experience and assess reliability in real patients.

LEVEL OF EVIDENCE

5.

The Ottawa panel clinical practice guidelines for the management of knee osteoarthritis. Part one: introduction, and mind-body exercise programs

OBJECTIVE

To identify effective mind-body exercise programs and provide clinicians and patients with updated, high-quality recommendations concerning non-traditional land-based exercises for knee osteoarthritis.

METHODS

A systematic search and adapted selection criteria included comparative controlled trials with mind-body exercise programs for patients with knee osteoarthritis. A panel of experts reached consensus on the recommendations using a Delphi survey. A hierarchical alphabetical grading system (A, B, C+, C, D, D+, D-) was used, based on statistical significance ( P < 0.5) and clinical importance (⩾15% improvement).

RESULTS

The four high-quality studies identified demonstrated that various mind-body exercise programs are promising for improving the management of knee osteoarthritis. Hatha Yoga demonstrated significant improvement for pain relief (Grade B) and physical function (Grade C+). Tai Chi Qigong demonstrated significant improvement for quality of life (Grade B), pain relief (Grade C+) and physical function (Grade C+). Sun style Tai Chi gave significant improvement for pain relief (Grade B) and physical function (Grade B).

CONCLUSION

Mind-body exercises are promising approaches to reduce pain, as well as to improve physical function and quality of life for individuals with knee osteoarthritis.

Inter-examiner classification reliability of Mechanical Diagnosis and Therapy for extremity problems - Systematic review

BACKGROUND

Mechanical Diagnosis and Therapy (MDT) is used in the treatment of extremity problems. Classifying clinical problems is one method of providing effective treatment to a target population. Classification reliability is a key factor to determine the precise clinical problem and to direct an appropriate intervention.

OBJECTIVES

To explore inter-examiner reliability of the MDT classification for extremity problems in three reliability designs: 1) vignette reliability using surveys with patient vignettes, 2) concurrent reliability, where multiple assessors decide a classification by observing someone's assessment, 3) successive reliability, where multiple assessors independently assess the same patient at different times.

DESIGN

Systematic review with data synthesis in a quantitative format.

METHOD

Agreement of MDT subgroups was examined using the Kappa value, with the operational definition of acceptable reliability set at ≥ 0.6. The level of evidence was determined considering the methodological quality of the studies.

RESULTS/FINDINGS

Six studies were included and all studies met the criteria for high quality. Kappa values for the vignette reliability design (five studies) were ≥ 0.7. There was data from two cohorts in one study for the concurrent reliability design and the Kappa values ranged from 0.45 to 1.0. Kappa values for the successive reliability design (data from three cohorts in one study) were < 0.6.

CONCLUSION

The current review found strong evidence of acceptable inter-examiner reliability of MDT classification for extremity problems in the vignette reliability design, limited evidence of acceptable reliability in the concurrent reliability design and unacceptable reliability in the successive reliability design.

The Ottawa panel clinical practice guidelines for the management of knee osteoarthritis. Part two: strengthening exercise programs

OBJECTIVE

To identify effective strengthening exercise programs and provide rehabilitation teams and patients with updated, high-quality recommendations concerning traditional land-based exercises for knee osteoarthritis.

METHODS

A systematic search and adapted selection criteria included comparative controlled trials with strengthening exercise programs for patients with knee osteoarthritis. A panel of experts reached consensus on the recommendations using a Delphi survey. A hierarchical alphabetical grading system (A, B, C+, C, D, D+ or D-) was based on statistical significance ( p < 0.5) and clinical importance (⩾15% improvement).

RESULTS

The 26 high-quality studies identified demonstrated that various strengthening exercise programs with/without other types of therapeutic exercises are generally effective for improving knee osteoarthritis management within a six-month period. Strengthening exercise programs demonstrated a significant improvement for pain relief (four Grade A, ten Grade B, two Grade C+), physical function (four Grade A, eight Grade B) and quality of life (three Grade B). Strengthening in combination with other types of exercises (coordination, balance, functional) showed a significant improvement in pain relief (three Grade A, 11 Grade B, eight Grade C+), physical function (two Grade A, four Grade B, three Grade C+) and quality of life (one Grade A, one Grade C+).

CONCLUSION

There are a variety of choices for strengthening exercise programs with positive recommendations for healthcare professionals and knee osteoarthritis patients. There is a need to develop combined behavioral and muscle-strengthening strategies to improve long-term maintenance of regular strengthening exercise programs.

February 2017 Letter to the Editor-in-Chief

Letter to the Editor-in-Chief of JOSPT as follows: "Regarding the Complexity of Low Back Pain" with Authors' Response J Orthop Sports Phys Ther 2017;47(2):126-129. doi:10.2519/jospt.2017.0201.

Agreement of Mechanical Diagnosis and Therapy Classification in People With Extremity Conditions

BACKGROUND

In the McKenzie system of mechanical diagnosis and therapy (MDT), a reliable system for the management of spinal problems, classifications are used to guide management strategies. For the classification of extremity disorders, interexaminer agreement has not been investigated with patients.

OBJECTIVE

The study objective was to investigate interexaminer agreement for provisional MDT extremity classification with patients.

DESIGN

This was a reliability study with examiner masking.

METHODS

A therapist with an MDT credential observed the assessments made by 2 therapists with MDT diplomas, who successively performed MDT assessments for 33 patients with extremity pain on the same day. Immediately after each evaluation, all 3 therapists assigned the most appropriate MDT classification from 15 categories; they were unaware of each other's selection. The observed agreement and the Cohen kappa were calculated for the MDT classifications.

RESULTS

The observed agreement for the 15 MDT categories of classification between the therapist with an MDT credential and the first therapist with an MDT diploma was 78.8%. The Cohen kappa was .72 (95% confidence interval=.54, .89), indicating good agreement. However, the observed agreement between the 2 therapists with MDT diplomas when the patient was assessed separately was 42.4%. The Cohen kappa was .21 (95% confidence interval=.01, .41), indicating poor agreement.

LIMITATIONS

Study limitations included convenience sampling of patients, the small number of examiners, and the limited extremity experience of the therapists with MDT diplomas.

CONCLUSIONS

Interexaminer agreement for provisional MDT extremity classification was good when the examiners were seeing the same patient concurrently but poor when the patient was seen successively. Further studies are needed to establish which factors, including study method, are responsible for the divergent results of the MDT assessments of extremity disorders.

Effect of Adding McKenzie Syndrome, Centralization, Directional Preference, and Psychosocial Classification Variables to a Risk-Adjusted Model Predicting Functional Status Outcomes for Patients With Lumbar Impairments

Study Design Retrospective cohort. Background Patient-classification subgroupings may be important prognostic factors explaining outcomes. Objectives To determine effects of adding classification variables (McKenzie syndrome and pain patterns, including centralization and directional preference; Symptom Checklist Back Pain Prediction Model [SCL BPPM]; and the Fear-Avoidance Beliefs Questionnaire subscales of work and physical activity) to a baseline risk-adjusted model predicting functional status (FS) outcomes. Methods Consecutive patients completed a battery of questionnaires that gathered information on 11 risk-adjustment variables. Physical therapists trained in Mechanical Diagnosis and Therapy methods classified each patient by McKenzie syndromes and pain pattern. Functional status was assessed at discharge by patient-reported outcomes. Only patients with complete data were included. Risk of selection bias was assessed. Prediction of discharge FS was assessed using linear stepwise regression models, allowing 13 variables to enter the model. Significant variables were retained in subsequent models. Model power (R(2)) and beta coefficients for model variables were estimated. Results Two thousand sixty-six patients with lumbar impairments were evaluated. Of those, 994 (48%), 10 (<1%), and 601 (29%) were excluded due to incomplete psychosocial data, McKenzie classification data, and missing FS at discharge, respectively. The final sample for analyses was 723 (35%). Overall R(2) for the baseline prediction FS model was 0.40. Adding classification variables to the baseline model did not result in significant increases in R(2). McKenzie syndrome or pain pattern explained 2.8% and 3.0% of the variance, respectively. When pain pattern and SCL BPPM were added simultaneously, overall model R(2) increased to 0.44. Although none of these increases in R(2) were significant, some classification variables were stronger predictors compared with some other variables included in the baseline model. Conclusion The small added prognostic capabilities identified when combining McKenzie or pain-pattern classifications with the SCL BPPM classification did not significantly improve prediction of FS outcomes in this study. Additional research is warranted to investigate the importance of classification variables compared with those used in the baseline model to maximize predictive power. Level of Evidence Prognosis, level 4. J Orthop Sports Phys Ther 2016;46(9):726-741. Epub 31 Jul 2016. doi:10.2519/jospt.2016.6266.

The application of mechanical diagnosis and therapy in lateral epicondylalgia

BACKGROUND

lateral epicondylalgia (LE) is a musculoskeletal diagnosis that causes pain and dysfunction in the lateral aspect of the elbow. Mechanical diagnosis and therapy (MDT) is an orthopaedic classification and treatment system based on mechanical and symptomatic response to repeated and sustained end-range movement. There has been no investigation of the association between MDT and patients diagnosed with LE.

CASE DESCRIPTION

this report presents three patients matching the currently accepted diagnostic criteria for LE, two with a diagnosis of lateral epicondylitis (tennis elbow) from a medical doctor. These patients were classified and treated by a diplomat of MDT and two third-year doctoral students of physical therapy using MDT.

OUTCOMES

short- and long-term (one year) outcomes were excellent, demonstrating rapid abolishment of symptoms and return to prior levels of function in 3-6 visits between 11-59 days. Patients demonstrated the ability to prevent and manage reoccurrence of symptoms independently without seeking further health care.

DISCUSSION

this case series raises questions about whether or not the pathologies traditionally associated with the aetiology of LE are actually at fault. Moreover, it raises questions about the utility of special tests typically utilized to identify those structures. The series provides preliminary evidence that MDT may be capable of providing effective short- and long-term outcomes in the management of LE.

LEVEL OF EVIDENCE

4.

Rehabilitation Strategies for the Athletic Individual with Early Knee Osteoarthritis

Knee osteoarthritis (OA) is a major cause of disability in the United States. The condition has most commonly been associated with elderly sedentary individuals; however, it also can affect those who participate in regular athletic activities. The diagnosis and management of these individuals can be challenging because of both their higher level of physical activity and their overall athletic goals. Treatment requires an appropriate exercise regimen, rehabilitation program, and education of both the athlete and the coach. The focus of our article is to provide an up-to-date overview of the evaluation and management of the athletic individual who presents with symptomatic early knee OA, in particular, the nonsurgical rehabilitation treatment options available to the practitioner and the evidence to support these recommendations.

Physical therapists' level of McKenzie education, functional outcomes, and utilization in patients with low back pain

STUDY DESIGN

Longitudinal, prospective, observational cohort.

OBJECTIVE

To examine associations between McKenzie training, functional status (FS) at discharge, and number of physical therapy visits (utilization) in patients receiving physical therapy for low back pain.

BACKGROUND

The McKenzie method is commonly used in treating patients with low back pain.

METHODS

A McKenzie postgraduate educational program was initiated in a large outpatient physical therapy service. Functional status data were collected at intake and at discharge. Separate hierarchical linear mixed models were used to examine associations between physical therapists' McKenzie training level (none; Parts A, B, C, and D; and credentialed), FS score at discharge, and utilization, controlling for patient risk factors.

RESULTS

The final data set included 20 882 patients (mean ± SD age, 51 ± 16 years; 57% women) who completed FS surveys at both admission and discharge. Patients treated by physical therapists with any McKenzie training had better outcomes (additional 0.7 to 1.3 FS points; P<.05 to <.001) and fewer visits (0.6 to 0.9, P<.001) compared to patients treated by physical therapists with no training. For patients treated by therapists with no versus some McKenzie education, 65% versus 70% achieved at least the minimal clinically important improvement, respectively. There were no significant differences in outcomes or utilization by level of McKenzie training.

CONCLUSION

There was a slightly greater improvement of 0.7 to 1.3 points in FS at discharge in patients receiving physical therapy for low back pain by physical therapists who underwent McKenzie training. This difference was clinically important for an additional 5% of patients who achieved the minimal clinically important improvement when treated by therapists with some McKenzie training. Reduction in physical therapy utilization was 0.6 to 0.9 visits, with the fewest visits utilized by patients of physical therapists at the McKenzie Part D and credentialed levels. Together, these findings suggest improved cost-effectiveness at advanced McKenzie training levels. Ways to improve ongoing education and patient outcomes were proposed.

Comparison of measurement properties of the P4 pain scale and disease specific pain measures in patients with knee osteoarthritis

OBJECTIVE

To compare measurement properties of the P4 pain scale, Western Ontario and McMaster Universities Arthritis Index pain subscale (WOMAC-pain), and Intermittent and Constant Osteoarthritis Pain (ICOAP) measure in patients with knee osteoarthritis (OA).

DESIGN

A secondary analysis from a randomized controlled trial included participants (n = 156) with knee OA that were consulting with a surgeon regarding knee arthroplasty. They completed pain measures (P4, WOMAC-pain, ICOAP) and WOMAC-function subscale (WOMAC-function) at baseline and 2 weeks. Measurement properties assessed in various subgroups included floor/ceiling effects, test-retest reliability using intraclass correlation coefficients (ICC2,1), internal consistency using Cronbach's ɑ, factorial structure of each pain measure combined with WOMAC-function using principal component analysis, and responsiveness using standardized response mean (SRM).

RESULTS

P4 had low floor and ceiling effects (<1%). P4 test-retest reliability (ICC2,1 = 0.72), internal consistency (Chronbach's ɑ = 0.91), and responsiveness (SRM = 0.56) were similar to the values for WOMAC-pain and ICOAP. Factorial structure of P4 and ICOAP were separate from WOMAC-function items. WOMAC-pain and WOMAC-function items loaded on similar factors. ICOAP-constant subscale had a large floor effect (33%).

CONCLUSIONS

P4 should be used to measure pain in patients with knee OA. It had acceptable measurement properties which is comparable to more widely used pain measures. WOMAC-pain shared a factorial structure with WOMAC-function indicating these measures might be capturing the same construct, questioning its validity to measure pain separately from function. ICOAP had acceptable properties. More work should compare pain measures in less severely affected OA populations.