ARTHROPLASTY VERSUS INTERBODY FUSION TECHNIQUES IN THE TREATMENT OF DEGENERATIVE DISC DISEASE IN THE CERVICAL SPINE

Abstract

Study Design/Objective: Prospective two-leg cohort study on anterior cervical fusion versus cervical arthroplasty with emphasis on clinical outcome measures.

Patients and Methods: Between August 2003 and May 2005 21 consecutive patients underwent anterior cervical fusion with or without anterior decompression with 26 levels fused. Between December 2004 and August 2006 24 patients had cervical arthroplasty with 30 levels replaced. The mean age at operation of the fusion group was 52 years and 5 months (46–69) and for the arthroplasty group 51 years and 2 months (42–62). To establish fusion the Cervios® cage (Synthes) with or without anterior plating was used. In the arthroplasty group the Prodisc C® disc prothesis (Synthes) was used. Contraindication for arthroplasty were osteoporosis, osteopathies, spinal canal stenosis, hypertrophic spondylarthrosis, spondylolisthesis, tumors and privious infection. Both groups were comparable with respect to age and gender, diagnosis, level distribution and preoperative clinical outcome measures (VAS for nack pain and arm pain, neck disability index and SF-36–sub-scores pain, function, vitality).

Results: Postoperatively all of the clinical outcome measures significantly improved in both groups. After three months postoperatively no significant further improvement was evident.

• VAS neck pain: Fusion group/arthroplasty group: Preoperatively 6.2/5.9 n.s., 6 weeks 3.5/3.1 n.s., 12 weeks 2.1/1.9 n.s, 1 year 2/2.1 n.s.

• VAS arm pain: Fusion group/arthroplasty group: Preoperatively 5.5/5.3 n.s., 6 weeks 2.6/2.4 n.s., 12 weeks 1.7/1.8 n.s, 1 year 2/1.9 n.s.

• Neck disability index: Fusion group/arthroplasty group: Preoperatively 43/40 n.s., 6 weeks 28/23 p< 0.05., 12 weeks 18/14 p< 0.05, 1 year 20/15 p< 0.05.

• SF-36 subscore pain: Fusion group/arthroplasty group: Preoperatively 36/37 n.s., 6 weeks 42/44 n.s., 12 weeks 52/58 p< 0.05, 1 year 52/60 p< 0.05.

• SF-36 subscore function: Fusion group/arthroplasty group: Preoperatively 52/54 n.s., 6 weeks 57/59 n.s., 12 weeks 60/62 n.s, 1 year 64/67 n.s.

• SF-36 subscore vitality: Fusion group/arthroplasty group: Preoperatively 42/44 n.s., 6 weeks 45/46 n.s., 12 weeks 50/52 n.s, 1 year 54/56 n.s.

In the fusion group we had 1 recurrent radiculopathy and 1 non union without the need of further intervention. In the arthroplasty group we faced 1 recurrent laryngeus recurrens nerve palsy and 3 spontaneus fusions within 1 year postoperatively, which might not be classified as complication.

Conclusion: Short term outcome after both procedures is excellent in terms of pain relief and function. 10% spontaneus fusion after disc replacement within the first year was evident. In our series we found better results after 3 months to 1 year postoperatively with respect to the neck disability index and SF-36 subscore pain within the arthroplasty group.