Radiologically documented adjacent-segment degeneration after cervical arthroplasty: characteristics and review of cases

Yi, Seong; Lee, Dong Yeob; Ahn, Poong Gee; Kim, Keung Nyun; Yoon, Do Heum; Shin, Hyun Chul

doi:10.1016/j.surneu.2009.02.013

« Previous Next »Surgical Neurology
Volume 72, Issue 4 , Pages 325-329, October 2009

Radiologically documented adjacent-segment degeneration after cervical arthroplasty: characteristics and review of cases

Seong Yi, MD
- Department of Neurosurgery, Spine and Spinal Cord Institute, Yonsei University, College of Medicine, Seoul 120-752, Korea
Dong Yeob Lee, MD
- Department of Neurosurgery, Spine and Spinal Cord Institute, Yonsei University, College of Medicine, Seoul 120-752, Korea
Poong Gee Ahn, MD
- Department of Neurosurgery, Spine and Spinal Cord Institute, Yonsei University, College of Medicine, Seoul 120-752, Korea
Keung Nyun Kim, MD, PhD
- Department of Neurosurgery, Spine and Spinal Cord Institute, Yonsei University, College of Medicine, Seoul 120-752, Korea
Do Heum Yoon, MD, PhD
- Department of Neurosurgery, Spine and Spinal Cord Institute, Yonsei University, College of Medicine, Seoul 120-752, Korea
Hyun Chul Shin, MD, PhD
- Department of Neurosurgery, Kangbuk Samsung Hospital, Sungkyunkwan University, Seoul 110-746, Korea
- Corresponding author. Tel.: +82 2 2001 2160; fax: +82 2 2001 2157.

Received 31 July 2008; accepted 16 February 2009. published online 10 August 2009.

Abstract

Background

The authors retrospectively studied the incidence and characteristics of radiologically documented adjacent-segment degeneration after single-level diskectomy and subsequent cervical arthroplasty using the Bryan (Medtronic Sofamor Danek; Memphis, TN) disk prosthesis.

Methods

Seventy-two patients with single-level arthroplasty using the Bryan cervical disk prosthesis were evaluated. Radiological evidence of adjacent-disk disease included new formation or enlargement of anterior osteophyte, new or increasing ALL calcification, or narrowing of disk space documented on serial plain radiographs. We reported the characteristics of adjacent-segment degeneration and reviewed all of the cases.

Results

Among the 72 patients, 9 patients (12.5%) showed radiological evidence of adjacent-segment degeneration. The mean age was 43.3 years old, with a male-female ratio 1:3. The mean follow-up period was 24.2 (12.1-35.9) months. The mean period of onset was 16.3 months. Upper-segment degeneration was documented in 4 cases (3 new osteophyte, 1 enlargement of osteophyte), whereas lower-segment degeneration was noted in 5 cases (1 new osteophyte, 3 enlargement of osteophyte, 1 decreased disk height). Among the degenerated cases, 4 cases (44.4%) also showed various degrees of HO.

Conclusions

The rate of adjacent-segment degeneration was higher than that observed in previous studies. Adjacent-segment degeneration documented a tendency toward HO. A longer follow-up period is necessary to investigate and document the different types of degeneration seen at levels adjacent to artificial Bryan cervical disk prostheses.

Abbreviations: ADR, artificial disk replacement, ALL, anterior longitudinal ligament, ASD, adjacent-segment disease, CT, computed tomography, HO, heterotopic ossification, MRI, magnetic resonance imaging, ROM, range of motion