Bilateral Pars Fractures Complicating Long Fusion to L5 in a Patient with Rheumatoid Arthritis

In Brief Study Design. Case report. Objective. To report bilateral pars fractures at L5 complicating a long fusion for adult idiopathic scoliosis in a patient with rheumatoid arthritis. Summary of Background Data. To our knowledge, there are no reports in the literature regarding bilateral pars fractures at the end instrumented vertebrae of a long fusion at the lumbosacral junction, nor reports that have evaluated long spinal deformity corrections in patients with rheumatoid arthritis. The question of ending a long fusion at L5 or S1 is controversial, and a review is presented. Methods. We present the patient's history, physical examination, and radiographic findings; describe the surgical treatment and long-term follow-up; and provide a literature review. Results. Bilateral pars fractures at the end instrumented vertebrae of a long construct (T4-L5) that we discovered were subsequently revised by extension of the fusion to the sacrum. Anterior structural support at L5-S1 was also provided. At the latest follow-up (46 months), the patient has had no recurrence of her symptoms. Her radiographs showed a stable construct without loss of alignment in the sagittal or coronal planes. Her rheumatoid arthritis continues to be treated with biologic, disease-modifying antirheumatic drugs. Conclusion. To our knowledge, this is the first report of the treatment and long-term outcome of a patient with rheumatoid arthritis and bilateral pars fractures at the end instrumented vertebrae (L5) of a long deformity correction construct. Crossing the lumbosacral junction for adult spinal deformity in the presence of a healthy L5 disc is controversial. The outcomes of spinal deformity correction in adult patients with rheumatoid arthritis are not known. We present a patient with rheumatoid arthritis with T4-L5 fusion and subsequent bilateral L5 pars fractures requiring fusion to the sacrum