Longitudinal comparison of direct medical cost, radiological and health-related quality of life treatment outcomes between traditional growing rods and magnetically controlled growing rods from preoperative to maturity

BACKGROUND: Magnetically controlled growing rods (MCGR) have replaced traditional growing rods (TGR) in the past decade, however, a comparison of their direct costs and treatment outcomes based on real longitudinal data is lacking. This study aims to compare the direct cost and treatment outcomes between TGR and MCGR, whilst incorporating complications, reoperations and changes in health-related quality of life (HRQoL) throughout the entire treatment course. METHODS: Patients with early onset scoliosis (EOS) who underwent initial growing rod surgery between 2003 and 2016 at a tertiary scoliosis clinic were studied with longitudinal data. Accumulated direct medical costs were calculated based on the unit cost of surgeries of each TGR and MCGR, costs incurred for any rod exchange or remedial surgery for post-operative complication. Treatment outcomes were evaluated via: Patient’s HRQoL using SRS-22r questionnaire, and radiological parameters (including major curve correction, spine length gains, spinal balance) throughout the treatment until maturity. RESULTS: A total of 27 EOS patients (16 MCGR, 11 TGR) were studied. Total direct cost of index surgery for MCGR was HKD$223,108 versus lower cost of HKD$135,184 for TGR (p < 0.001). At 2–3 years post-index surgery, accumulative total direct medical cost of MCGR and TGR became most comparable (TGR:MCGR ratio = 1.010) and had reached neutrality between the two groups since. Radiological parameters had no intergroup differences at maturity. For HRQoL, TGR group had shown the trend of less pain (domain score mean difference: 0.53, p = 0.024) post-index surgery and better self-appearance (domain score mean difference: 1.08, p = 0.017) before fusion. Higher satisfaction with treatment (domain score mean difference: 0.76, p = 0.029) was demonstrated by TGR patients at fusion/maturity. MCGR had negative (r(s) = -0.693) versus TGR’s positive (r(s) = 0.989) correlations (p < 0.05) of cost and SRS-22r total scores at 2–3 years post-index surgery. CONCLUSIONS: From index surgery to maturity, TGR demonstrated better satisfaction with treatment by patients and comparable overall HRQoL with MCGR during the treatment course, as MCGR did not show apparent benefit despite less surgeries and cost neutrality between the two groups at 2–3 years post-index surgery.