OBJECTIVE: There is substantial heterogeneity in the number of screws used per level fused in adolescent idiopathic scoliosis (AIS) surgery. Assuming equivalent clinical outcomes, the potential cost savings of using fewer pedicle screws were estimated using a medical decision model with sensitivity analysis. METHODS: Descriptive analyses explored the annual costs for 5710 AIS inpatient stays using discharge data from the 2009 Kids' Inpatient Database (Healthcare Cost and Utilization Project, Agency for Healthcare Research and Quality), which is a national all-payer inpatient database. Patients between 10 and 17 years of age were identified using the ICD-9-CM code for idiopathic scoliosis (737.30). All inpatient stays were assumed to represent 10-level fusions with pedicle screws for AIS. High screw density was defined at 1.8 screws per level fused, and the standard screw density was defined as 1.48 screws per level fused. The surgical return for screw malposition was set at $23,762. A sensitivity analysis was performed by varying the cost per screw ($600-$1000) and the rate of surgical revisions for screw malposition (0.117%-0.483% of screws; 0.8%-4.3% of patients). The reported outcomes include estimated prevented malpositioned screws (set at 5.1%), averted revision surgeries, and annual cost savings in 2009 US dollars, assuming similar clinical outcomes (rates of complications, revision) using a standard- versus high-density pattern. RESULTS: The total annual costs for 5710 AIS hospital stays was $278 million ($48,900 per patient). Substituting a high for a standard screw density yields 3.2 fewer screws implanted per patient, with 932 malpositioned screws prevented and 21 to 88 revision surgeries for implant malposition averted, and a potential annual cost savings of $11 million to $20 million (4%-7% reduction in the total cost of AIS hospitalizations). CONCLUSIONS: Reducing the number of screws used in scoliosis surgery could potentially decrease national AIS hospitalization costs by up to 7%, which may improve the safety and efficiency of care. However, such a screw construct must first be proven safe and effective.
Bibliographical noteFunding Information:
This study was funded by the Scientific Forum/Spine Care grant from the Orthopaedic Research and Education Foundation and represents work by the Minimize Implants Maximize Outcomes Study Group. The authors report the following. Dr. Richards owns stock in Pfizer, receives non-study-related clinical or research support from Biomet, Medtronic, DePuy Synthes, and Stryker; receives travel expenses from Biomet, Medtronic, DePuy Synthes, and Stryker; receives a presidential stipend from the Scoliosis Research Society; and is involved in planning meetings for the Association of Collaborative Research. Dr. Shah is a consultant for DePuy Synthes Spine, received clinical or research support for the described study from the Setting Scoliosis Straight Foundation (aka Harms Study), and owns stock in Globus Medical. Dr. Ledonio has a financial relationship with Medtronic and receives non-study-related research support from Medtronic, SI-Bone, DOD, and OREF through the University of Minnesota. Dr. Lonner is an employee at Mount Sinai Beth Israel Medical Center; is a consultant for DePuy Synthes; owns stock in Paradigm Spine and Spine Search; receives non-study-related clinical or research support from the Setting Scoliosis Straight Foundation (with funding from DePuy Synthes), AOSpine, the John and Marcella Fox Fund, and OREF; serves on the scientific advisory board of DePuy Synthes; serves on the board of directors of Spine Search; is part of the speaker's bureau for DePuy Synthes and K2M; and receives royalties from DePuy Synthes. Dr. Ackerman is a consultant to the medical device industry through employment at Covance. Dr. Emams is a consultant for DePuy Synthes and Medtronic, and receives royalties for VEPTR II.
- Curve correction
- Implant density