Analysis of prevertebral soft-tissue swelling and dysphagia in multilevel anterior cervical discectomy and fusion with recombinant human bone morphogenetic protein-2 in patients at risk for pseudarthrosis.

Object: The goal of this study was to demonstrate the incidence of fusion and soft-tissue swelling in multilevel anterior cervical discectomies and fusions (ACDFs) using polyetheretherketone (PEEK) spacers with recombinant human bone morphogenetic protein-2 (rhBMP-2) impregnated in a Type I collagen sponge and titanium plates.

Methods: A single surgeon performed 30 multilevel ACDFs using PEEK spacers with an rhBMP-2 impregnated collagen sponge (0.4 ml, or the equivalent of 0.6 mg rhBMP-2). Soft-tissue swelling was assessed using cervical spine radiographs on postoperative Day 1 and at 2, 6, and 10 weeks and 6 months after surgery. Incidence of dysphagia was assessed with the Cervical Spine Research Society Swallowing-Quality of Life tool. Clinical success was evaluated with the Neck Disability Index, neck pain scores, and arm pain scores. Final fusion was assessed with CT by an independent neuroradiologist.

Results: Patients were followed for 6 months unless they had an incomplete fusion; those patients were reassessed at 9 months. Twenty-four patients underwent 2-level ACDFs and 6 underwent 3-level ACDFs were performed on patients with the following risk factors for pseudarthrosis: smoking (33%), diabetes (13%), and obesity (body mass index ≥ 30 [43%]). Seventeen percent of the patients had multiple risk factors. Soft-tissue swelling peaked at 2 weeks regardless of level of surgery or number of levels treated surgically and decreased to near preoperative levels by 6 months. At 2 weeks, Swallowing-Quality of Life evaluation showed 19% of patients frequently choking on food, 4.8% frequently choking when drinking, and 47.6% with frequent food sticking in the throat. Scores continued to improve, and at 6 months, 0% had frequent choking on food, 6.7% had frequent difficulty drinking, and 6.7% had frequent food sticking in the throat. The Neck Disability Index, neck pain, and arm pain scores all improved progressively over 6 months. Incidence of fusion was 95% at 6 months and 100% at 9 months. There were no rehospitalizations or reoperations for soft-tissue swelling or dysphagia.

Conclusions: Multilevel ACDF procedures using PEEK grafts and rhBMP-2 can be performed safely in patients with multiple risk factors for pseudarthrosis with excellent fusion outcomes.