Abstract
<title>Abstract</title> <p> <bold>Purpose</bold> To compare neurological recovery after conventional (lesion-level) and dome (adjacent-level) laminoplasty for degenerative cervical myelopathy using propensity score matching, and to determine whether any difference has a morphological correlate on magnetic resonance imaging (MRI). <bold>Methods</bold> Retrospective cohort of 215 consecutive patients undergoing French-door laminoplasty (2008–2025): Conventional LP (lesion levels only, n = 114) or Dome LP (plus dome undercutting of ≥1 adjacent level, n = 101). The primary outcome was the JOA recovery rate (RR). Propensity score matching on six covariates yielded 79 pairs, analysed with methods that respect the matched-pair structure. Exploratory endpoints were cord shift and canal morphometry on paired MRI at three level categories, and cervical alignment, extension reserve and complications. <bold>Results</bold> In the matched cohort the JOA RR favoured Dome LP by 10.7 percentage points (95% CI −0.6 to 21.9; <italic>p</italic> = 0.062), postoperative mJOA was higher (+0.77; <italic>p</italic> = 0.024) and the conditional odds ratio for good recovery was 2.10 (95% CI 0.99 to 4.46; <italic>p</italic> = 0.054). On multivariable regression with pair-clustered standard errors, Dome LP was independently associated with a higher JOA RR (β = +11.3; 95% CI 0.5 to 22.1; <italic>p</italic> = 0.040), the direction being consistent across all twelve specifications. On paired MRI (n = 141), decompression at the level of maximum compression was similar, whereas at the adjacent levels Dome LP produced greater posterior cord displacement (+0.46 mm; <italic>p</italic> = 0.004) and canal diameter (+0.92 mm; <italic>p</italic> = 0.002). Loss of cervical lordosis ( <italic>p</italic> = 0.418), extension reserve ( <italic>p</italic> = 0.897) and complications ( <italic>p</italic> = 0.839) did not differ. <bold>Conclusion</bold> Dome laminoplasty was consistently associated with greater neurological recovery, by about 10 percentage points of JOA recovery rate, reaching significance in adjusted but not unadjusted matched-pair analysis. MRI localised the difference to the adjacent levels, with no additional loss of cervical alignment or extension reserve and no observed difference in recorded complications. </p>