Preoperative Cervical Extension and Flexion Range of Motion Predict Postoperative Kyphotic Change without Affecting 2-Year Clinical Outcomes Postoperatively after Laminoplasty for Degenerative Cervical Myelopathy.

STUDY

DESIGN

Multi-center retrospective cohort study.

OBJECTIVE

To investigate whether preoperative cervical extension range of motion (eROM) and flexion range of motion (fROM) predict postoperative kyphotic change and affect clinical outcomes after laminoplasty for degenerative cervical myelopathy (DCM).

SUMMARY OF BACKGROUND DATA: Cervical laminoplasty is a standard procedure for DCM; however, postoperative kyphotic change due to loss of cervical lordosis (CL) is a major concern. Although small eROM and large fROM may predict postoperative CL loss, their impact on clinical outcomes is unclear.

METHODS

We analyzed 147 patients with DCM ≥60 years who underwent C3-C6 laminoplasty with ≥2 years of follow-up. Radiographic parameters (CL, eROM, and fROM) were measured pre- and postoperatively. Kyphotic change was defined as CL loss ≥10°. Clinical outcomes included Japanese Orthopaedic Association (JOA) score, visual analogue scale (VAS) for neck pain, EuroQol 5-dimension 5-level instrument (EQ-5D-5L), and Neck Disability Index (NDI). Logistic regression was used to identify predictors of kyphotic change, and clinical outcomes were compared between predictor-defined groups up to 2 years postoperatively.

RESULTS

Kyphotic change occurred in 35 patients (23.8%) at 2 years postoperatively. Logistic regression revealed that small eROM (≤9°) and large fROM (≥37°) independently predicted postoperative kyphotic change at 1 and 2 years postoperatively. Its incidence in the small eROM and large fROM groups was significantly higher than that in their respective counterpart groups. No significant group differences were found in JOA score, VAS for neck pain, EQ-5D-5L, or NDI changes.

CONCLUSION

Preoperative small eROM and large fROM independently predicted postoperative kyphotic change after laminoplasty for DCM. However, these factors did not negatively affect neurological recovery, neck pain, quality of life, or cervical function for up to 2 years postoperatively. Laminoplasty remains an effective option for patients with DCM with eROM ≤9° or fROM ≥37°, despite potential CL loss.

LEVEL OF EVIDENCE: III.