Effect of Serious Adverse Events on Health-Related Quality of Life Measures Following Surgery for Adult Symptomatic Lumbar Scoliosis

STUDY DESIGN: Secondary analysis of prospective multicenter cohort. OBJECTIVE: To assess effect of serious adverse events (SAEs) on 2- and 4-year patient-reported outcomes measures (PROMs) in patients surgically treated for adult symptomatic lumbar scoliosis (ASLS). SUMMARY OF BACKGROUND DATA: Operative treatment for ASLS can improve health-related quality of life, but has high rates of SAEs. How these SAEs effect health-related quality of life remain unclear. METHODS: The ASLS study assessed operative versus nonoperative ASLS treatment, with randomized and observational arms. Patients were 40- to 80-years-old with ASLS, defined as lumbar coronal Cobb ≥30° and Oswestry Disability Index (ODI) ≥20 or Scoliosis Research Society-22 (SRS-22) ≤4.0 in pain, function, and/or self-image domains. SRS-22 subscore and ODI were compared between operative patients with and without a related SAE and nonoperative patients using an as-treated analysis combining randomized and observational cohorts. RESULTS: Two hundred eighty-six patients were enrolled, and 2- and 4-year follow-up rates were 90% and 81%, respectively, although at the time of data extraction not all patients were eligible for 4-year follow-up. A total of 97 SAEs were reported among 173 operatively treated patients. The most common were implant failure/pseudarthrosis (n = 25), proximal junctional kyphosis/failure (n = 10), and minor motor deficit (n = 8). At 2 years patients with an SAE improved less than those without an SAE based on SRS-22 (0.52 vs. 0.79, P = 0.004) and ODI (-11.59 vs. -17.34, P = 0.021). These differences were maintained at 4-years for both SRS-22 (0.51 vs. 0.86, P = 0.001) and ODI (-10.73 vs. -16.69, P = 0.012). Despite this effect, patients sustaining an operative SAE had greater PROM improvement than nonoperative patients (P<0.001). CONCLUSION: Patients affected by SAEs following surgery for ASLS had significantly less improvement of PROMs at 2- and 4-year follow-ups versus those without an SAE. Regardless of SAE occurrence, operatively treated patients had significantly greater improvement in PROMs than those treated nonoperatively. LEVEL OF EVIDENCE: 2.