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

Highlights

• Chronic low back pain (CLBP) is a primary cause of pain and disability.

• Mechanical diagnosis and therapy (MDT) is a suitable approach for CLBP.

• Improvements with MDT in CLBP are similar to other physical therapy approaches.

Abstract

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.

Introduction

Chronic low back pain (CLBP) is a primary cause of pain, functional limitations, and disability worldwide.1, 2 Prevalence estimates for CLBP vary considerably between studies, accounting for 11.9% as current prevalence, 38% as 1-year prevalence, and 38.9% as lifetime prevalence.3, 4 Consequently, CLBP poses a substantial economic burden on healthcare, social, and welfare systems.5, 6, 7

The diagnosis and treatment of CLBP are well discussed topic in recent decades.8, 9 A range of intervention strategies have been investigated, including active and passive strategies provided in isolation or in combination.¹⁰ A common reason for the lack of effectiveness for conventional treatments is that non-specific CLBP is broadly defined and rarely has a confirmed diagnosis.¹¹ In addition, there is still no established classification system for patients with CLBP, because most classifications lack solid evidence of validity and reliability.12, 13

In this context, some authors have suggested that the McKenzie method, also known as mechanical diagnosis and therapy (MDT) method, may be a suitable approach to treat CLBP.14, 15 Although MDT has been commonly referred to as a treatment based on extension exercises, it actually consists of a treatment method based on a comprehensive diagnosis classification system, which includes three mechanical syndromes (Derangement, Dysfunction, and Postural) and an “Others” subgroup. Among those, derangement is by far the most common syndrome in patients with CLBP.¹⁶ This syndrome is characterized by quick mechanical and symptomatic changes secondary to performance of a directional-preference exercise. This directional preference is defined as the direction of a repeated movement and/or sustained position that induces mechanical and symptomatic improvement. Symptomatic improvements may include centralization,17, 18, 19, 20 in which symptoms are progressively and permanently abolished in a distal-to-proximal direction, suggesting a good prognosis. Therefore, with the MDT approach, individuals with CLBP can be classified in one of the four groups, based on which specific treatment may be implemented.

Numerous authors have appraised the effects of MDT in individuals with CLBP.15, 21, 22, 23, 24 A previous systematic review, published in 2006, concluded that the effectiveness of MDT could not be estimated.²⁵ More recently, another systematic review concluded that there is moderate-to-high-quality evidence that MDT is superior to other rehabilitation interventions in reducing pain and disability.²⁶ However, the favorable results favoring MDT reported in this review, may have been due to the type of comparator used in the meta-analysis. To our knowledge, comparing the MDT approach to other active or passive physical therapy treatment approaches has not previously been done. Therefore, this systematic review with meta-analysis investigated the effectiveness of MDT compared to other active or passive physical therapy interventions in individuals with CLBP.