Risk Factors for Persistent Shoulder Pain After Cervical Spine Surgery

Objective To define risk factors of having persistent shoulder pain following cervical spine surgery. Methods From April 1995 to May 2012, 862 patients underwent cervical spine surgery in a tertiary referral university hospital. Ninety-six patients were referred to a shoulder surgeon for persistent shoulder pain over 3 months after cervical spine surgery. Thirty-five were excluded from the study due to failure to follow-up or lack of radiographic data. We analyzed a total of 61 patients as patient group (PG) compared to age, sex, and surgeon matched control group (CG) with no shoulder pain after surgery. Medical records were reviewed for age, sex, level of cervical surgery, approach of cervical surgery, underlying medical problems, final diagnosis of the shoulder pathology, and shoulder visual analog scale (VAS) score. The pre- and post-operative variables for level of cervical surgery, approach of cervical surgery, underlying medical history, and shoulder VAS were compared and analyzed in this study. Results The number of patients with lower cervical level surgery was significantly higher (91 patients, 74.6%) compared to upper cervical level surgery (31 patients, 25.4%) (P = 0.005). Anterior approach was more frequently used (70 patients, 57.3%) compared to posterior approach (52 patients, 42.7%) (P < 0.001). The final diagnosis of shoulder pathology in PG were rotator cuff disease in 31 patients, adhesive capsulitis in 18 patients, and calcific tendinitis in 10 patients respectively. No significant difference for preoperative shoulder VAS score was found in both groups. A lower level of cervical spine pathology in patients (C-4-T-1 level) and posterior approach surgery were factors that significantly presented with more shoulder pain. Subgroup analysis revealed no statistical difference for level of cervical surgery and approach of cervical surgery among groups with different shoulder pathology. Conclusions The current study includes patients with persistent shoulder pain following cervical surgery without having evidence of concurrent preexisting shoulder pathology documented previously. We suggest that posterior approach and lower level of cervical surgery patients could be clinically relevant risk factors for persistent shoulder pain following cervical spine surgery.