CLINICAL OUTCOME AND RADIOLOGICAL APPEARANCE 5 YEARS AFTER ANTERIOR CERVICAL DISCECTOMY WITHOUT FUSION

Abstract

Objective: To extend the follow up period of previous studies undertaken by the senior author, looking at the clinical outcome and radiological changes observed in patients with either myelopathy or radiculopathy, following anterior cervical discectomy without fusion.

Design: Prospective, observational cohort study of patients undergoing anterior cervical discectomy without fusion and followed up for five years, radiologically, with serial plain radiographs, and clinically, using validated outcome measures including SF36, neck disability index and analogue visual pain scores.

Subjects: 109 Patients undergoing anterior cervical dis-cectomy without fusion under the senior author’s care.

Outcome measures:

1. Radiological

   1. Occurrence of segmental cervical kyphosis

   2. Loss of overall cervical alignment

2. Clinical

   SF36, Neck disability index, Visual analogue neck and arm pain scores

Results: A total cohort of 109 patients, of mean age 56 years, were followed up after anterior cervical discectomy without fusion, for up to 5 years. Segmental kyphosis was demonstrated on 44%, and loss of overall cervical alignment on 60% of follow up plain radiographs during the third postoperative year. In the cohorts of patients with either loss of cervical alignment or segmental kyphosis at one year the mean clinical outcome scores (Wilcoxon’s matched pairs signed ranks test) continued to improve at the 5 year follow up. The annual rate of loss of cervical alignment in patients unaffected at the first post operative year was around 10% but there was no significant rate of progression of segmental kyphosis. Comparison of the relationship between these radiological changes and clinical outcome (Mann-Whitney U test) did not show any significant correlation.

Conclusions: This study assesses patients over the period during which the anticipated alignment changes associated with undertaking simple anterior cervical discectomy could be having progressive detrimental clinical effects. Where such radiological changes occur they most commonly occur during the first post operative year. However, clinical outcome measures in these patients all improve at one year follow up, and still continue to improve or plateau up to five years post operatively. As anticipated, the most significant clinical improvement, occurs during the first post operative year. During the longer follow up period there is no significant detrimental effect of the radiological changes discussed on clinical outcome.