A survey of the McKenzie Classification System in the Extremities: prevalence of mechanical syndromes and preferred loading strategies

Mechanical diagnosis and therapy in musculoskeletal pain of individuals with spinal cord injury

CONTEXT/OBJECTIVE

Musculoskeletal pain (MSKP) has high prevalence in individuals with spinal cord injury (SCI). Mechanical Diagnosis and Therapy (MDT) is a method focused on identifying the pain source in the musculoskeletal system and presents good results in pain relief in people without neurological impairment. However, no studies have investigated the use of MDT in SCI population. The objective was to evaluate the applicability and outcomes of MDT treatment in pain relief and independence improvement in daily activities of individuals with SCI presenting MSKP.

DESIGN

Single-arm trial.

SETTING

Rehabilitation Hospital.

PARTICIPANTS

Twenty-four individuals with SCI who presented MSKP.

INTERVENTION

MDT-certified physical therapist conducted assessments and treatments of pain according to the MDT approach.

OUTCOMES MEASURES

Numeric rating scale (NRS) was used to measure pain and Pain Disability Index (PDI) and Patient-Specific Functional Scale (PSFS) to evaluate daily activities.

RESULTS

Significant median decreases were found for NRS (from 7 to 2) and PDI (from 27 to 8) after MDT, whereas PSFS score presented a significant mean increase (from 3.2-7.7). The average decrease in pain after MDT treatment was 70.9% (5.36 on the NRS).

CONCLUSION

MDT can reduce pain and enhance independence in daily activities in individuals with SCI and MSKP.

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.

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.

Diagnosing acetabular labral tears with hip traction sonography: a case series

PURPOSE

Three cases of acetabular labral tear (ALT) diagnosed with sonography (US) are reported. We aim to show utility for US with the addition of manual hip traction as an adjunctive modality to the current diagnostic imaging of choice, magnetic resonance arthrography (MRA), for diagnosing ALT.

METHODS

Three cases of young athletic patients with similar clinical presentations are reported. All received US examination of the hip with attention to the labrum that included a novel long-axis hip traction technique which assisted in diagnosing ALT.

RESULTS

In the first and second cases, MRA and orthopedic consult were obtained for confirmation of the diagnosis. Arthroscopy was performed to correct the ALT. The third patient declined an MRA. Conservative management consisted of McKenzie method active care, resulting in return to sport in the third case.

CONCLUSION

These three cases demonstrate the clinical and sonographic presentation of ALT. The dynamic long-axis hip traction protocol facilitated the use of US as an adjunctive modality for diagnosing ALT by increasing the visualization of the defect.

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.

A prospective study of patients with shoulder pain and Mechanical Diagnosis and Therapy (MDT)

Objectives: A prospective observational cohort study was conducted to (1) determine the prevalence of Mechanical Diagnosis and Therapy (MDT) syndromes for patients with shoulder 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 by 115 patients. A two-way mixed model analysis of variance with subsequent pairwise comparisons was done to examine differences in clinical outcomes between the following MDT classifications: Shoulder Derangement, Shoulder Dysfunction, and Other.Results: The primary findings were that (1) 44.3 (35.3, 53.4), 40.0 (31.0, 48.9), and 15.6 (9.0, 22.3) percent of patients' conditions were classified as Shoulder Derangement, Shoulder Dysfunction, and Other, respectively, (2) all groups managed via MDT methods made clinically significant improvements in disability and pain intensity at discharge, (3) a statistically significant difference in pain intensity at discharge was observed between the Shoulder Derangement and the Shoulder Dysfunction classifications (p = 0.01), and (4) patients with the Shoulder Derangement classification were discharged, on average, 35.3 days earlier than the Shoulder Dysfunction classification and 28.3 days earlier than the Other classification.Discussion: This study confirms previous reports that the Shoulder Derangement and Shoulder Dysfunction classifications are common and represent distinct clinical trajectories when assessed and managed via MDT methods.

An international survey of the comprehensiveness of the McKenzie classification system and the proportions of classifications and directional preferences in patients with spinal pain

BACKGROUND

Classification of spinal pain has been a key goal identified in the research. However it is not clear if existing classification systems are comprehensive.

OBJECTIVE

To examine the comprehensiveness and distribution of classifications within the McKenzie classification system (MDT), and the directional preference in consecutive patients with spine pain.

STUDY DESIGN

Prospective, observational study.

METHODS

Clinicians with a Diploma in MDT provided data on patients that they had assessed, classified, managed, and then confirmed their classification at discharge. They provided data on the spinal area, the MDT classification, and the loading strategy used in management.

RESULTS

Fifty-four clinicians from at least 15 different countries provided data on 750 patients: lumbar 64.8%, cervical 29.6%, thoracic 5.6%. The distribution of classifications was as follows: Derangement 75.4%, OTHER 22.8%, Dysfunction 1.7%, Postural syndrome 0.1%. In Derangements 82.5% had a directional preference for extension, 12.9% for lateral forces, and 4.6% for flexion. Those patients classified as one of the OTHER subgroups were given specific classifications.

CONCLUSION

Derangement was the most common classification and extension was by far the most common directional preference. A substantial proportion were classified as OTHER subgroups, for whom management is less straightforward.

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 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.

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.

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.

Application of the McKenzie system of Mechanical Diagnosis and Therapy (MDT) in patients with shoulder pain; a prospective longitudinal study

Objectives

The primary objective was to determine if the pain and function response to the McKenzie system of Mechanical Diagnosis and Therapy (MDT) differs by MDT classification category at two and four weeks following the start of MDT treatment for shoulder complaints. The secondary objective was to describe the frequency of discharge over time by MDT classification.

Methods

International, MDT-trained study collaborators recruited 93 patients attending physiotherapy for rehabilitation of a shoulder problem. The Numeric Pain Rating Scale (NPRS) and the Upper Extremity Functional Index (UEFI) were collected at the initial assessment and two and four weeks after treatment commenced. A two-way mixed model analysis of variance with planned pairwise comparisons was performed to identify where the differences between MDT classification groups actually existed.

Results

The Derangement and Spinal classifications had significantly lower NPRS scores than the Dysfunction group at week 2 and week 4 (p < 0.05). The Derangement and Spinal classifications had significantly higher UEFI scores than the Dysfunction group at week 2 and week 4 (p < 0.05). The frequency of discharge at week 2 was 37% for both Derangement and Spinal classifications, with no discharges for the Dysfunction classification at this time point. The frequency of discharge at week 4 was 83, 82 and 15% for the Derangement, Spinal and Dysfunction classifications, respectively.

Discussion

Classifying patients with shoulder pain using the MDT system can impact treatment outcomes and the frequency of discharge. When MDT-trained clinicians are allowed to match the intervention to a specific MDT classification, the outcome is aligned with the response expectation of the classification.Level of Evidence: 2b.

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.

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.

Attitude Towards the Use of Mechanical Diagnosis and Therapy and Reliability of Classification Extremity Problems by Credentialed Therapists

OBJECTIVE

The purpose of this study was to investigate attitudes towards Mechanical Diagnosis and Therapy (MDT) for extremity problems and inter-examiner reliability of classifying extremity problems into MDT subgroups by credentialed practitioners in MDT (Cred.MDT) in Japan.

METHODS

A cross-sectional survey was used and all 120 Cred.MDT practitioners registered in the McKenzie Institute International Japan branch were asked about their attitude towards MDT for extremity problems and were asked to select the most appropriate MDT subgroup for each of the 25 extremity patient vignettes. Model classifications were used to investigate accuracy of classification. Percent agreement and Kappa analyses were examined.

RESULTS

Sixty practitioners (50%) participated in this study. For the management of patients with extremity problems, the majority did not use MDT most of the time (53%) due to a lack of confidence in using MDT in the extremities (78%). The overall accuracy for their MDT classification for extremity problems was 87% (Fleiss's κ = 0.78).

CONCLUSIONS

The majority of the Cred.MDT practitioners in Japan did not use MDT frequently and were not confident to use MDT with extremity patients. However, accuracy and inter-examiner agreement of their MDT classification from the information on the assessment sheet was good.

Inter-examiner reliability of diplomats in the mechanical diagnosis and therapy system in assessing patients with shoulder pain

OBJECTIVE

To investigate the inter-examiner reliability of Mechanical Diagnosis and Therapy (MDT)-trained diplomats in classifying patients with shoulder disorders. The MDT system has demonstrated acceptable reliability when used in patients with spinal disorders; however, little is known about its utility when used for appendicular conditions.

METHODS

Fifty-four clinical scenarios were created by a group of 11 MDT diploma holders based on their clinical experience with patients with shoulder pain. The vignettes were made anonymous, and their clinical diagnoses sections were left blank. The vignettes were sent to a second group of six international McKenzie Institute diploma holders who were asked to classify each vignette according to the MDT categories for upper extremity. Inter-examiner agreement was evaluated with kappa statistics.

RESULTS

There was 'very good' agreement among the six MDT diplomats for classifying the McKenzie syndromes in patients with shoulder pain (kappa = 0.90, SE = 0.018). The raw overall level of multi-rater agreement among the six clinicians in classifying the vignettes was 96%. After accounting for the actual MDT category for each vignette, kappa and the raw overall level of agreement decreased negligibly (0.89 and 95%, respectively).

DISCUSSION

Using clinical vignettes, the McKenzie system of MDT has very good reliability in classifying patients with shoulder pain. As an alternative, future reliability studies could use real patients instead of written vignettes.

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

STUDY DESIGN

Randomized controlled trial. Objectives To examine the efficacy of exercise intervention in patients with knee osteoarthritis (OA), as directed by Mechanical Diagnosis and Therapy (MDT) assessment, and, secondarily, to explore outcomes between MDT assessment-defined subgroups within the exercise group.

BACKGROUND

Due to the high physical and economic burden of knee OA, the effectiveness of conservative interventions and determining those patients who will respond to them should be investigated.

METHODS

Patients with knee OA (n = 180) were randomized to an exercise intervention group or a control group. The intervention group, in which patients classified as having knee derangements (MDT derangement) received MDT directional exercises and patients classified as nonresponders (MDT nonresponders) received evidence-based exercises, was compared to a control group that received no exercise intervention. Pain and function were assessed at baseline, 2 weeks, and 3 months, using the P4 pain scale and Knee injury and Osteoarthritis Outcome Score (KOOS) pain and function subscales. Two-way analysis of covariance was used to examine treatment and time effects. Multiple comparisons were examined, and mean differences with 95% confidence intervals (CIs) were reported.

RESULTS

The exercise intervention group had significantly improved P4 scores (mean difference, -6; 95% CI: -8, -3), KOOS pain scores (mean difference, 9; 95% CI: 5, 13), and KOOS function scores (mean difference, 11; 95% CI: 7, 15) compared to those of the control group at 2 weeks. At 3 months, the exercise intervention group had significantly improved KOOS pain scores (mean difference, 7; 95% CI: 3, 11) and KOOS function scores (mean difference, 5; 95% CI: 1, 9) compared to controls.

CONCLUSION

Patients with knee OA who were prescribed exercises based on an MDT assessment had superior outcomes compared to those of wait-list controls. The MDT subgroup of knee derangement may warrant further investigation in patients with knee OA. Protocol registered at ClinicalTrials.gov (NCT01641874).

LEVEL OF EVIDENCE

Therapy, level 1b-.

Rapid resolution of chronic shoulder pain classified as derangement using the McKenzie method: a case series

The McKenzie method, also known as Mechanical Diagnosis and Therapy (MDT), is primarily recognized as an evaluation and treatment method for the spine. However, McKenzie suggested that this method could also be applied to the extremities. Derangement is an MDT classification defined as an anatomical disturbance in the normal resting position of the joint, and McKenzie proposed that repeated movements could be applied to reduce internal joint displacement and rapidly reduce derangement symptoms. However, the current literature on MDT application to shoulder disorders is limited. Here, we present a case series involving four patients with chronic shoulder pain from a duration of 2-18 months classified as derangement and treated using MDT principles. Each patient underwent mechanical assessment and was treated with repeated movements based on their directional preference. All patients demonstrated rapid and clinically significant improvement in baseline measures and the disabilities of the arm, shoulder, and hand (QuickDASH) scores from an average of 38% at initial evaluation to 5% at discharge within 3-5 visits. Our findings suggest that MDT may be an effective treatment approach for shoulder pain.

Directional preference at the knee: a case report using mechanical diagnosis and therapy

Knee pain is common amongst the sporting and general population. Numerous examination procedures are used to apply diagnostic labels to knee symptoms, such as McMurray's test, which is used to diagnose a meniscal injury. However, previously in the literature the validity compared with a 'gold standard' and the reliability between examiners of such tests has been questioned. In this case study, we report on a sports woman, diagnosed by her general practitioner with a meniscal injury and demonstrating a positive McMurry's test, who was examined using repeated movements as in the McKenzie system of mechanical diagnosis and therapy. Following self-application of extension exercises and extension exercises with over-pressure the McMurry's test became negative, and she returned to full sporting activities. The case study indicates a further caution about the use of single orthopaedic test procedures. Not only is their validity and reliability questionable, but also following treatment using repeated movements if positive tests can be made negative, this provides an additional query to their validity.