138. Cervical radiographic parameters and patient reported outcomes following Harrington instrumentation: a minimum 35-year follow-up

BACKGROUND CONTEXT As patients who underwent Harrington instrumentation for AIS approach older age, identifying the cervical spine deformity in the setting of preexisting Harrington instrumentation is important. There are few studies that have evaluated this topic. PURPOSE To evaluate cervical radiographic parameters and patient-reported outcomes in patients undergoing Harrington instrumentation for AIS. STUDY DESIGN/SETTING Observational. PATIENT SAMPLE Patients undergoing Harrington Instrumentation from 1962 to 1984. OUTCOME MEASURES Radiographic parameters, Neck Disability Index METHODS AIS patients undergoing Harrington instrumentation from 1962 to 1984 were identified. Inclusion criteria were completion of the patient-reported outcomes and recent cervical/scoliosis radiographs. Recent cervical and scoliosis radiographs were used to measure cervical deformity parameters (C2-C7 SVA, T1 slope, C2 SVA, C7 SCA). Neck Disability Index (NDI) was used to assess patient-reported outcomes. Using multivariate analysis, radiographic measurements and NDI scores were assessed. RESULTS A total of 32 patients met our inclusion criteria. The mean follow-up was 48 years (35-57). The mean age was 63.5± (51-82) years; 29 were females and 3 were males. The average age at which surgeries were performed was 15.4 (11-47) years with the average number of levels fused 9.7±1.7. Radiographic measurements resulted in C2-C7 SVA (mean, 24.7±11.1), T1 slope (mean, 26.1±10.7), C2 SVA (mean, 60.0±38.1) and C7 SVA (40.7±30.6). The mean NDI was 11.5 (0-48). Higher radiographic measurements of C2-C7 SVA (p=0.004) and C7 SVA (p=0.003) were strongly correlated with worse NDI scores, indicating decreased patient satisfaction with increased level of angulation. The T1 slope did not yield a statistically significant correlation (p=0.90). CONCLUSIONS Higher C2-C7 SVA and C7 SVA angles are correlated with worse patient reported outcomes in patients with minimum of 35 years follow-up after Harrington instrumentation for AIS. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.