122P A retrospective review of changes in upper limb function following spinal surgery in spinal muscular atrophy

In recent years, disease-modifying treatments (DMT) for Spinal Muscular Atrophy (SMA) have become readily available on the National Health Service in the UK. Although phenotypes are changing, progressive scoliosis remains common and can affect individuals' quality of life causing a negative impact on mobility, increased pain and worsened respiratory function. Corrective spinal surgery aims to reduce the curvature of the spine with the purpose to improve sitting posture and lung function. Limited data is available on the effects of scoliosis surgery on upper limb function in SMA patients. The revised upper limb module (RULM) is used to monitor changes in the arm function in the SMA cohort assessing both proximal and distal activities. The aim of this study is to review changes in upper limb function of SMA children following spinal surgery identifying possible contributing factors. A single-centre retrospective review has been completed of the current SMA cohort at Great Ormond Street Hospital (GOSH) that underwent corrective spinal surgery (posterior spinal fusion or growth rod insertion). Forty-two patients were identified; 20 were excluded due to insufficient data. Of the remaining 22 patients, 14 were female and 8 male. Nine were classified as type 3, 12 as type 2 and 1 as type 1;12/22 had started on DMT prior to surgery. Scores from 2 RULM assessments taken prior to surgery at least 6 months apart were compared with RULM results post-surgery at two 6-month intervals. Other factors were recorded including age, Cobb angle and time on DMT prior to surgery. Patients receiving DMT post-surgery were used as a control group. At the initial follow-up, 64% showed a decline in RULM score with an average change in score of-2.18. At the second follow-up, 78% had improved or maintained their score with an average score change of 0.09. Comparing the treated and untreated group, there was no significant difference in scores at the initial follow-up, while at the second follow up a significant difference was observed (p=0.018) with an average change of +1 in the DMT group compared to -1 in the untreated group. Our study shows that children with SMA treated with a DMT prior to surgery declined initially however 87% regained or maintained some upper limb function at their second follow-up. We aim to further analyse the data and present the full scope of this study including a larger group across the UK.