Utilizing a Novel Combinatorial Physical Performance Test-Based Clinical Assessment Tool to Screen for Radiologically Severe Degenerative Cervical Myelopathy

Abstract

<h3>Study design</h3><p>Prospective cross-sectional observational study.</p><h3>Objective</h3><p>This study aimed to develop a novel Physical Performance Test (PPT)-based scoring system by linking PPTs with the radiological severity of Degenerative Cervical Myelopathy (DCM).</p><h3>Methods</h3><p>The severity of spinal cord compression in DCM patients was assessed using the cross-sectional area (CSA) at the maximal stenosis, as determined by magnetic resonance imaging (MRI). Functional performance was evaluated with the modified JOA scoring system (mJOA) and PPTs: 10-second-Grip-and-Release-Test (GR), Simple-Foot-Tapping-Test (FTT), 10-second-Step-Test (SST), Nine-hole-Peg-Test (HPT), and 30-meter-Walking-Test (30MWT). Validity was determined by examining correlations between CSA and these metrics, using Pearson’s correlation. The Hong Kong Myelopathy Criteria (HKMC) were developed through Principal Component Analysis and K-means clustering to combine PPTs with the highest correlation with CSA.</p><h3>Results</h3><p>269 DCM patients (57% female, mean age 63 ± 9) were studied. 55% had CSA less than 70 mm² (mean CSA 55.92 ± 7.37 mm²), symptoms for 19 ± 6 months, and mJOA of 14.4 ± 2.0. PPTs showed significant correlations with CSA (r = −0.473 to 0.837, <em>p</em> < 0.001), but not with mJOA. The HKMC, combining GR, FTT, and SST (loadings >0.87), with a four-tier scoring system (0-3), showed a strong correlation (r = 0.896, <em>p</em> < 0.001). A cutoff of 4.5 effectively indicates significant cervical stenosis, with 90% sensitivity and 94% specificity.</p><h3>Conclusion</h3><p>This study is the first to demonstrate a strong association between spinal cord compression and physical performance in DCM. As a novel DCM-specific assessment tool, the HKMC demonstrates bedside utility and superior validity compared to individual PPTs and mJOA to identify individuals with radiologically severe DCM.</p>