Adjacent segment disease following anterior cervical fusion and the presence of surgery for lumbar disc herniation and surgery at the musculoskeletal joints: are they related?

BACKGROUND CONTEXT: A potential correlation between surgery for symptomatic adjacent segment degeneration (sASD) and the development of degenerative disease of the lumbar spine or osteoarthritis of the musculoskeletal joints remains to be determined.

PURPOSE: To assess the rate of sASD following anterior cervical discectomy and fusion (ACDF), the rate of lumbar discectomy (LD), and rate of surgery performed for osteoarthritis at the joints of the musculoskeletal in a long term follow-up.

STUDY DESIGN/

SETTING

Cohort study OUTCOME MEASURES: Repeat procedure for sASD, microsurgical LD (MSD), and/or the musculoskeletal joints (shoulder, knee, hip).

PATIENT SAMPLE: Retrospectively, a total of 833 consecutive patients who underwent ACDF for degenerative disorders ≥20 years ago were identified. Charts were reviewed for preoperative neurological status, smoking status, physical labor, and repeat procedures. Missing data lead to exclusion from follow-up assessment.

METHODS

At final follow-up the need for pain medication, Neck disability index (NDI), and Odoms criteria were evaluated. An MRI was performed to assess the grade of degeneration of the cervical spine via the segmental degeneration index (SDI). Patients without (group 1) and with (group 2) repeat procedure for sASD were compared.

RESULTS

Collectively, 313 patients met inclusion criteria and 136 patients were evaluated. The mean follow-up was 26 years. Clinical success rate according to Odoms was 85.3%, mean NDI was 14.4%, the rate of regular intake of pain medication was 14.7%, the rate of repeated procedure for sASD was 10.3%. MSD was performed in 23.5%, surgery for osteoarthritis of the shoulder, the hip, and the knee were performed in 11.8%, 6.9%, and 27.7%, respectively. The rate of MSD (p=.018) was significantly higher in group 2 compared to group 1. Gender, smoking status, surgery of the musculoskeletal joints, and the grade of degeneration of the cranial and caudal adjacent segments were similar between group 1 and group 2.

CONCLUSION

The overall clinical success following ACDF was 85.3%. The rate of repeat procedure for sASD was 10.3% within 26 years. Patients with sASD had a significantly higher rate of MSD and poorer clinical outcome compared to patients without sASD.