Selection of surgical strategy for patients with multilevel cervical spondylosis and concomitant developmental cervical spinal stenosis.

Abstract

To investigate the clinical efficacy of different surgical approaches for patients with multilevel cervical spondylosis and varying degrees of cervical canal stenosis, and to explore factors associated with poorer prognosis. This retrospective study included 168 patients with multilevel cervical spondylosis and concomitant developmental cervical spinal stenosis who underwent surgery in our department between December 2018 and December 2020. Diagnosis was made by spinal surgeons with over 15 years of experience. Patient data collected included age, gender, symptom duration, preoperative and postoperative modified Japanese Orthopaedic Association (mJOA) scores, smoking history, and pre- and postoperative radiographs. All included patients exhibited typical signs and symptoms of cervical spondylosis, confirmed by imaging demonstrating multilevel compression and varying degrees of developmental cervical canal stenosis (canal-to-body ratio <0.75 on lateral cervical radiographs). The Pavlov ratio was defined as the sagittal diameter of the cervical canal divided by the sagittal diameter of the corresponding vertebral body. All patients underwent either anterior cervical discectomy and fusion (ACDF) or posterior open-door laminoplasty. Neurological function was assessed using the mJOA score, minimal clinically important difference (MCID) achievement rate, and mJOA improvement rate. Radiographic parameters evaluated via cervical X-rays included the Pavlov ratio, cervical curvature (C2-7 Cobb angle), and sagittal vertical axis (SVA). Cervical MRI was used to assess the degree of spinal cord compression. Patients were divided into three groups based on preoperative Pavlov ratio (Severe stenosis: Pavlov ratio <0.65; Moderate stenosis: Pavlov ratio 0.66-0.70; Mild stenosis: Pavlov ratio 0.71-0.75). Each group was further subdivided into anterior and posterior surgery subgroups for comparison of clinical and radiographic outcomes. Binomial logistic regression was used to identify independent risk factors for poor prognosis. At final follow-up, all patients showed significant neurological improvement, with marked increases in mJOA scores and improvement rates. In the severe stenosis group, posterior surgery had higher postoperative mJOA scores, RR, and MCID achievement rate (90.6 % vs. 58.3 % in anterior, P < 0.05). In the moderate stenosis group, no significant differences in mJOA or RR were observed between approaches, but both achieved high MCID rates (anterior:79.2 %; posterior:82.1 %). In the mild stenosis group, anterior surgery yielded higher postoperative mJOA scores, RR, and MCID rate (56.0 % vs. 31.8 % in posterior, P < 0.05). Among all patients undergoing anterior surgery, the mild stenosis group had the highest preoperative mJOA scores, while the moderate stenosis group exhibited the highest postoperative mJOA scores and improvement rates. Among all patients undergoing posterior surgery, the mild stenosis group had the highest preoperative mJOA scores, while the severe stenosis group showed the highest mJOA improvement rate. Furthermore, the subgroup with an mJOA improvement rate ≥50 % had significantly higher postoperative mJOA scores and lower postoperative VAS scores compared to the subgroup with an improvement rate <50 %. Logistic regression identified preoperative mJOA, postoperative VAS, average Pavlov ratio, and CR as independent risk factors for poor recovery (P < 0.05). For patients with multilevel cervical spondylosis and mild canal stenosis, the anterior approach provides superior improvement in postoperative mJOA scores and higher improvement rates. Similarly, among patients undergoing anterior surgery, those with mild to moderate stenosis achieve higher postoperative mJOA scores and improvement rates. For patients with severe stenosis, the posterior approach significantly improves postoperative mJOA scores and improvement rates. Among posterior surgery patients, those with severe stenosis exhibit the highest mJOA improvement rate. Posterior surgery may be preferred for severe stenosis.