Predictors for Deformity Progression in a Spinal Muscular Atrophy Cohort After Scoliosis Correction Surgery

Abstract

Study Design: This was a single-center, retrospective study. Objective: The objective of this study was to assess the risk factors for deformity progression after scoliosis correction surgery in spinal muscular atrophy (SMA) patients. Summary of Background Data: Moderate residual postoperative scoliosis curve is common in SMA populations; however, the acceptable postoperative scoliosis curve for preventing deformity progression remains uncertain. Materials and Methods: Twenty-nine SMA patients undergoing scoliosis correction surgery were included. Scoliosis progression was defined as an increase of 10 degrees in the major curve of Cobb angle (MCCA); pelvic obliquity (PO) or concave-side hip progression was arbitrarily defined as an increase of ≥1 grade after surgery. Risk factors for deformity progression were examined using Cox proportional hazard models. The cumulative incidence rate of deformity progression was performed by the Kaplan-Meier survival analysis Results: The mean age at surgery was 13.3 years (range: 8–25 y) and the mean follow-up time was 7 years (range: 2–22.9 y). The mean MCCA was corrected from 69 to 34.6 degrees at initial follow-up and 42.2 degrees at the final follow-up. Postoperative MCCA ( P =0.002) and PO ( P =0.004) at initial follow-up were the risk factors for scoliosis progression. Postoperative MCCA at initial follow-up ( P =0.007) and age at the time of surgery ( P =0.017) were the risk factors for PO progression. Different cutoff points of postoperative MCCA at initial follow-up were compared for predicting deformity progression. We found the patient with postoperative MCCA of <30 degrees at initial follow-up had a significantly less cumulative incidence rate of progression than their counterparts for scoliosis ( P =0.005), PO ( P =0.023), and concave-side hip progressions ( P =0.008). Conclusions: We recommended that MCCA should be corrected to <30 degrees to prevent postoperative scoliosis, PO, and concave-side femoral head coverage percentage progressions. Patients receiving surgery earlier had less postoperative MCCA at initial follow-up but with no increase in the risk of postoperative scoliosis progression.

Influence of Paraspinal Growth-Friendly Spinal Implants in Children with Spinal Muscular Atrophy on Parasol Deformity, Rib-Vertebral Angles, Thoracic, and Lung Volumes

“…Most children with SMA type I or II develop spinal deformity in early childhood, which may require early surgical intervention [18]. In the past years, implantation of GFSI with bilateral paraspinal rib-to-pelvis fixation was postulated [7] and deformity control in SMA children was shown both in short and long-term follow-up using this surgical technique [19, 20].…”

Anaesthetic considerations in posterior instrumentation of scoliosis due to spinal muscular atrophy: Case series of 56 operated patients

“…For example, the pa- (n = 10), just to mention a few recent ones. [11][12][13] Additionally, such work is rarely alluding to the anaesthetic technique but rather to medical and surgical aspects, e.g. the natural history of scoliosis and lifetime risk of instrumentation, 11 postoperative wound healing 14 or postoperative pulmonary function.…”

“…Altogether, the literature is sparse but in some publications, there were more female than male (F:M) SMA patients undergoing scoliosis surgery: F:M 23:13, 16:13 and 8:4. 11,12,27 The present analysis does not contain any data as regards newer innovative remedies for SMA, for example nusinersen (Spinraza ® , Biogen, USA), which has been tried in Scandinavia. With these, the demand for scoliosis surgery and anaesthesia in SMA patients might shrink considerably in the time ahead.…”

Scoliosis Orthopedic Surgery Combined With Nusinersen Intrathecal Injection Significantly Improved the Outcome of Spinal Muscular Atrophy Patient: A Case Report

“…The more severely the child is affected, the higher the probability of developing scoliosis at an earlier age and also the greater anticipated curve progression ( 1 ). Spinal fusion is recommended in the presence of documented scoliosis progression and curves between 40° and 60° in children, ideally at 10 years of age or older ( 10 ), especially, if there is a recorded deterioration in their motor function or pulmonary capacities. However, intrathecal injection treatment is very difficult for the patients who have received orthopedic surgery because of the lack of anatomical landmarks on the vertebral laminae and deficient flexion of the lumbar spine after scoliosis orthopedic surgery and there were few experiences in China up to date.…”