Prognostic factors for neurological outcome after anterior decompression and fusion for proximal-type cervical spondylotic amyotrophy - A retrospective analysis of 77 cases

Comparison of anterior spinal fusion and posterior cervical foraminotomy for cervical spondylotic radiculopathy in terms of postoperative recovery of upper-limb motor deficits

This study compared postoperative motor recovery between anterior spinal fusion (ASF) and posterior cervical foraminotomy (PCF) in patients with cervical spondylotic radiculopathy (CSR) who had motor deficits. From a database maintained by surgeons across 27 institutions, 227 patients undergoing primary ASF or PCF for CSR without myelopathy were evaluated. Among these, 106 patients with upper-limb motor deficits (manual muscle testing [MMT] grade 0-3) were observed for at least 12 months post-surgery. Data on preoperative and postoperative MMT grades were collected at 3, 6, and 12 months after surgery and at the final follow-up. The recovery of motor function was compared between the ASF and PCF groups using Kaplan-Meier curves and Cox regression analysis. While the overall excellent recovery rates (MMT grade ≥ 2) at the final follow-up were similar between the ASF and PCF group (74 % vs. 86 %, p = 0.15), the PCF group showed significantly faster motor recovery at 3, 6, and 12 months postoperatively, with recovery rates of 43 %, 63 %, and 82 %, respectively, compared to 18 %, 46 %, and 54 % in the ASF group (HR = 1.62, p = 0.031). These findings suggest that PCF may offer a quicker recovery of motor function and could be a more suitable surgical procedure than ASF for patients with CSR and motor deficits.

Increased Cervical Spinal Instability is Associated With the Development of Proximal-type Cervical Spondylotic Amyotrophy

STUDY DESIGN

Retrospective cohort study.

OBJECTIVES

We aimed to clarify the clinical relationship between the etiology of proximal-type cervical spondylotic amyotrophy (CSA) and cervical sagittal alignment and instability.

SUMMARY OF BACKGROUND DATA

Although several researchers have discussed hypotheses regarding the etiology of CSA, the trigger and mechanism underlying the onset remain unclear.

METHODS

We retrospectively analyzed 52 proximal-type CSA patients (CSA group) and 60 control patients (Control group). The following data were collected: age; sex; cervical lordosis (CL); T1 slope (TS); TS-CL; C2-7 sagittal vertical axis (SVA) on x-ray in the neutral position; flexion angle; extension angle and range of motion (ROM) of C3/4, C4/5 and C5/6; and C3/4, C4/5 and C5/6 instability (translation of >3 mm for adjacent segmental segments) on dynamic x-ray.

RESULTS

Compared with the Control group, the CSA group was associated with an older age (mean age, 67.6 vs. 61.1 years' old, P= 0.029) and male sex (78.8% vs. 50.0%, P= 0.002). In the CSA group, the radiographic parameters showed smaller C4/5 and C5/6 extension angles and C5/6 ROM values and a greater C3/4 flexion angle than the Control group. Furthermore, compared with the Control group, the CSA group was associated with C3/4 instability (13.5% vs. 3.3%, P= 0.049) and C4/5 (21.2% vs. 3.3%, P = 0.003). A logistic regression analysis, with adjusting for the age and sex, showed that the C3/4 flexion angle (odds ratio [OR], 1.2; 95% confidence interval [CI], 1.08- 1.40, P =0.002), C3/4 instability (OR, 7.3; 95% CI 1.25-42.96, P =0.027) and C4/5 instability (OR, 8.1; 95% CI, 1.56-42.19, P = 0.012) were independent risk factors of CSA.

CONCLUSION

This study suggested that a wide C3/4 flexion angle and high C3/4 or C4/5 spinal instability were closely associated with the etiology of proximal-type CSA.