Posterior Spinal Fusion of Scoliosis in Osteogenesis Imperfecta Patients

Background:
The surgical treatment of scoliosis in osteogenesis imperfecta (OI) patients is challenging due to impaired bone integrity which potentially increases the risks of mechanical failure. Several methods to overcome this risk have been described, including bisphosphonate therapy, halo gravity traction (HGT) and cement screw augmentation. The purpose of this study is to publish the outcomes and experience from a series of 11 OI patients who undergone posterior spinal fusion (PSF) to treat scoliosis in a single institution where specific pre, intra and post-operative methods have been established.

Methods:
All patients with OI who underwent PSF in our institution since the establishment of a pediatric scoliosis unit have been included in this study. Data collected included demographics, operative and follow up records, OI type, additional medical history, bisphosphonate therapy, fusion length, HGT protocol when implemented, scoliosis and kyphosis curves pre and postoperatively and post HGT when implemented, hospitalization length, complications and reoperations. General treatment strategies were bisphosphonate therapy protocol, HGT protocol, Titanium rods and cementless screw technique.

Results:
Eleven patients with OI underwent operative treatment for scoliosis in our institution between 2003-2020. Mean age at surgery was 15.6 (SD=2.3). Mean follow up period (FUP) was 7.3±6.5 years and minimal FUP was 1.3 years. Mean preoperative, post HGT and postoperative scoliosis curves were 85.4°±19.3°, 65.2°±12.8° and 43.1°±12.5° respectively. Mean fused vertebrae was 15.5±2.1 and mean postoperative hospitalization length was 5.9±1.6. One case of postoperative deep infection which resolved following treatment by a single operative debridement procedure followed by antibiotic treatment was recorded, and no other complications were observed.

Conclusion:
This case series presents a safe and effective strategy for operative correction of scoliosis in OI patients. More studies including comparison of different techniques are required in order to improve the operative treatment of this patient population.