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

ABSTRACT

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.

KEYWORDS:

• Knee pain
• directional preference
• mechanical diagnosis and therapy
• Mckenzie
• practice-based evidence
• orthopedic
• musculoskeletal

Declaration of interest

The author declares no conflict of interest.