Spinal Fusion in Patients With Classic Amyoplasia and General Arthrogryposis

Background: Arthrogryposis multiplex congenita is a group of conditions characterized by joint contractures affecting 2 or more joints. This study describes results of spinal fusion in patients with classic amyoplasia and general arthrogryposis. Methods: IRB approved retrospective review of patients with a diagnosis of classic amyoplasia and general arthrogryposis who had a primary definitive posterior spinal fusion between 1990 and 2017 at a single pediatric institution. Patients with distal and syndromic arthrogryposis were excluded as well as patients treated with growth-sparing spinal instrumentation. The Modified Clavien-Dindo-sink (MCDS) classification system was used to describe postoperative complications. Results: Over the 28-year period, 342 patients were diagnosed with amyoplasia and general arthrogryposis. Among the 342 patients, 60 (18%) had scoliosis, and 22 (6% of the cohort and 37% of those with scoliosis) were treated surgically. Six patients had growth-sparing techniques, initial fusion elsewhere, or 1 year of follow-up, leaving 15 patients. Of the 15, 9 (60%) had a posterior spinal fusion (PSF) and 6 (40%) had a combined anterior spinal fusion (ASF)/PSF. The ASF/PSF group was significantly younger at surgery, had a greater American Society of Anesthesiologists status, longer surgery duration, and lower implant density. The average preoperative major coronal deformity in ASF/PSF patients (108 degrees) was greater than patients treated with PSF alone (88 deg). There were 11 complications in 7 patients, with the most common being deep infection requiring reoperation (5/11, 45%). There was 1 instance (1/11, 9%) of each: prolonged intensive care unit admission (>72 h), superficial wound dehiscence, symptomatic implants requiring removal/revision, coronal plane progression requiring extension of fusion, recurrent pneumothorax requiring return to OR, and pseudoarthrosis leading to implant failure (without revision). Complications occurred in 1/9 (11%) PSF-only patients and 6/6 (100%) ASF/PSF patients with all 6 ASF/PSF patients requiring at least 1 reoperation. The average coronal correction was 48% in the PSF-only group and 28% in the ASF/PSF group. Conclusion: Complication rates after spinal fusion for scoliosis in arthrogryposis multiplex congenita patients are high, especially in patients undergoing ASF/PSF, deep infection is common, and major coronal plane curve correction is modest.