SLR - February 2018 - Jeffrey M. Demian

Suture Button Fixation Versus Syndesmotic Screws in Supination-External Rotation Type 4 Injuries: A Cost-Effectiveness Analysis

Reference: Kaitlin C. Neary, MD, Matthew A. Mormino,y MD, and Hongmei Wang,y PhD. Suture Button Fixation Versus Syndesmotic Screws in Supination-External Rotation Type 4 Injuries: A Cost-Effectiveness Analysis. The American Journal of Sports Medicine, Sept  2016.

Scientific Literature Review

Reviewed By: Jeffrey M. Demian, DPM
Residency Program: Chino Valley Medical Center, Chino Valley, CA

Podiatric Relevance: In unstable supination-external rotation type 4 (SER4) ankle fractures, the selection of implant for fixation has been debated. The routinely used forms of fixation are metallic screws and suture buttons. The key factors for fixation are anatomic reduction and strength of the fixation, but the cost of the implant also requires consideration. This study was performed to examine the cost-effectiveness of the suture button in comparison to a 3.5 mm syndesmotic screws for fixation of SER type 4 fractures.

Methods: The study design is an economic and decision analysis study, following the recommendations made by the panel on cost effectiveness in health and medicine. Level 1 and 2 studies were reviewed to estimate the amount of hardware removal and failure of the “gold standard” two 3.5 mm syndesmotic screws, versus suture button fixation. A decision analysis model was used to compare the different methods, with a follow-up period of eight years. The costs of the fixation methods were determined by examining average costs for patients who underwent surgical fixation for unstable SER4 ankle fractures. Patients were divided into two treatment groups based on screw fixation or suture button fixation, with patients allocated to one of three potential outcome groups consisting of well, symptomatic needing hardware removal or failure with end-stage arthritis.

Subjects were allocated to groups using the Markov cohort analysis model. Exclusion criteria included infections, other minor complications or revisional surgery and were assumed to be equivalent between both groups. The average cost for operative fixation of a unstable SER4 injury was estimated based on data obtained from a level 1 trauma institution, which included fees for surgeon, hospital, anesthesia, implants and radiology. Surgical costs without fixation were averaged to be $17,726.00. Average cost of the screw was $64.00, and the suture button was $880.00. Indirect costs, such as physical therapy, loss of work time and medical equipment, were assumed to be the same for both groups.

Results: The total cost for two syndesmotic screws totaled $20,836.00, and the total effectiveness of the screws was 5.816 with total cost per quality-adjusted life yearly (QALY) to be at $3,564.00 over an eight-year period. The total cost for suture button was $19,354.00, and the total effectiveness was 5.874 resulting in a cost per quality-adjusted year to be at $3,294.00 over the same period of time. The above was determined based on using a 20 percent hardware removal rate and a 4 percent suture button hardware removal rate. Fixation with a single-suture button was the dominant treatment strategy compared with two suture buttons, one screw and two screws for syndesmotic fixation.

Conclusions: For unstable SER type 4 ankle fractures, the cost effectiveness analysis suggests that suture button fixation is more cost effective spending $1,482.00 less than syndesmotic screws not removed on a routine basis and had a higher QALY by 0.058. Screw fixation only became more cost effective when the screw removal rate was below 10 percent and suture button costs would be greater than $2,000.00 with the difference in cost effectiveness becoming less significant. 

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