Utility of the Modified Clavien-Dindo-Sink (mCDS) Grading System for Classifying Casting Complication Severity in Early Onset Scoliosis Patients.
BACKGROUND Serial casting can effectively treat early-onset scoliosis (EOS), thereby preventing or delaying the need for surgery. Reported complications range from pressure sores to cardiac arrest. The modified Clavien-Dindo-Sink (mCDS) system has high reliability for grading complications following EOS surgery, but has not previously been used to classify complications of casting. We aimed to assess the utility of the mCDS system for grading complications of EOS casting and hypothesized that, with modifications, it would be a valid system for assessing these complications. METHODS This was a multicenter retrospective study. Patients aged 10 years or younger who underwent ≥1 cast application for EOS treatment were included. Demographics, radiographic data, casting details, complications, and unplanned procedures were collected. Two authors (E.S. and M.H.) reviewed complications and assigned a mCDS grade to each. RESULTS One thousand twenty patients (5605 casts) were included. Two hundred forty-four casting-related complications in 159 patients were analyzed. 15.6% of patients (n=159) had a complication, and 47 patients (4.6%) had >1 complication. Fifteen complications were categorized as mCDS grade I (6.1%), 192 as grade II (78.7%), 5 as grade IIIa (2.0%), 28 as grade IIIb (11.5%), 4 as grade IVa (1.6%), and 0 as grade IVb or grade V (0%). The most common reason for a grade IIIb complication, which is an unplanned procedure, was early cast removal necessitating early cast re-application (25/28 patients). CONCLUSIONS Most casting complications in our cohort were grades II and IIIb. The mCDS system, in its current state, may not accurately describe the complications of casting. Although a grade IIIb complication after casting results in an additional procedure requiring anesthesia, an unplanned return to the operating room after surgery is likely associated with greater morbidity than an unplanned cast re-application. Using the mCDS system to compare casting with surgery risks overstating the severity of casting complications and may inadequately represent outcomes. We propose modifying the mCDS system for casting. LEVEL OF EVIDENCE Level III-therapeutic.