Roussouly Sagittal Spinopelvic Morphotypes in Patients with Lumbar Disc Herniation: Distribution, Herniation Level, and Interobserver Reliability

Creative Commons License

Gök H., Baymurat A. C.

Traumatology and Orthopaedics of Kazakhstan, cilt.77, sa.2, ss.1-3, 2026 (Hakemli Dergi)

Özet

Sagittal spinopelvic morphology has been implicated in the biomechanical environment of the lumbar spine and may influence susceptibility to lumbar disc pathology. However, data on the distribution of Roussouly morphotypes in patients with lumbar disc herniation (LDH) remain limited. Objective: To evaluate the distribution of sagittal spinopelvic morphotypes according to the Roussouly classification in patients with LDH, to investigate their relationship with herniation level, and to assess interobserver reliability of the classification. Methods. This retrospective cross-sectional single-center study included 256 patients with LDH. Age, sex, disc herniation level, pelvic incidence (PI), sacral slope (SS), and pelvic tilt (PT) were recorded. Herniation levels were classified as L2–3, L3–4, L4–5, and L5–S1; L2–3 and L3–4 were additionally grouped as upper lumbar for comparative analyses. Sagittal spinopelvic morphology was classified as Roussouly type 1, 2, 3, or 4 by two independent observers. Associations between Roussouly type and herniation level were analyzed using chi-square tests, and spinopelvic parameters were compared among morphotypes. Results. The most common herniation level was L4–5 (54.3%), followed by L5–S1 (32.4%). The most frequent morphotype was type 3 (42.6%), followed by type 2 (37.9%), type 1 (13.7%), and type 4 (5.9%). No significant association was found between Roussouly type and herniation level (p = 0.220). In contrast, PI and SS differed significantly among Roussouly types (both p < 0.001), whereas PT did not (p = 0.341). Interobserver agreement for Roussouly classification was excellent, with a Cohen’s kappa of 0.935 and a quadratic weighted kappa of 0.967. Conclusions. Sagittal spinopelvic morphotypes were not evenly distributed in patients with LDH. Although type 3 was the most common morphotype, this likely reflects its high prevalence in asymptomatic populations. The notable representation of type 1 and especially type 2 morphotypes suggests that flatter sagittal profiles may represent a potentially relevant morphologic pattern in LDH. No significant association was found between morphotype and herniation level. The Roussouly classification demonstrated excellent interobserver reliability in this cohort.