Role of the Triradiate Cartilage in Predicting Curve Progression in Adolescent Idiopathic Scoliosis

Abstract

Braces are commonly used to treat progressive adolescent idiopathic scoliosis. Several previous studies have reported a correlation between the success of brace treatment and skeletal maturity markers. These studies have not focused on the status of the triradiate cartilage (TRC) as it relates to successful brace treatment for adolescent idiopathic scoliosis. The authors retrospectively evaluated all patients at their institution from 1990 to 1997 with a diagnosis of adolescent idiopathic scoliosis who were treated in a Boston brace. Sixty-two patients met inclusion criteria. At presentation, the average age was 12.87 years, the average Risser sign was 0.56, and 45% of patients had an open TRC. The average follow-up was 2.92 years. Greater than 5 degrees of progression at discontinuation of bracing was considered a failure. Curves with a closed TRC failed bracing 21% of the time, whereas those with an open TRC failed 54% of the time (P = 0.0069). Those curves with a closed TRC progressed 3.12 degrees on average, whereas curves with an open TRC progressed 6.86 degrees. Curves associated with a closed TRC at initiation of bracing progressed less frequently and to a lesser degree than those associated with an open TRC (P = 0.027). Although the TRC is not an independent predictor of curve stability, it is an additional indicator of skeletal maturity and may prove most useful in patients with otherwise borderline indications for brace treatment.

Recommendations for research studies on treatment of idiopathic scoliosis: Consensus 2014 between SOSORT and SRS non–operative management committee

“…The Risser + staging was an idea that came out during discussion when the importance of other radiographic signs like the tri-radiate cartilage was considered [ 30 , 42 , 43 ]. Many researchers in the SOSORT community use the so-called European Risser sign [ 28 - 30 ] that is born from a reported by Stagnara, a variation of the original Risser sign (here called US Risser sign).…”

Imaging in the Diagnosis and Monitoring of Children with Idiopathic Scoliosis

“…Prognostically, patients with Risser 0- 2 are regarded as skeletally immature [ 34 ] and at high risk of progression. A recent study attempted to determine the influence of Risser sign on the need for surgery in children wearing orthoses for the treatment of AIS [ 35 ].…”

“…Interestingly, Ryan et al (2007) compared the curve progression rates of two groups of patients at Risser 0, one with tri-radiate cartilage open and another with the cartilage fused [ 34 ]. They found that the incidence of curve progression is higher in patients with open tri-radiate cartilage as opposed to those with closed tri-radiate cartilages [ 34 ].…”

“…Interestingly, Ryan et al (2007) compared the curve progression rates of two groups of patients at Risser 0, one with tri-radiate cartilage open and another with the cartilage fused [ 34 ]. They found that the incidence of curve progression is higher in patients with open tri-radiate cartilage as opposed to those with closed tri-radiate cartilages [ 34 ]. Despite bracing, patients with an open tri-radiate cartilage progressed a mean of 3.12 o and those with a closed or fused tri-radiate cartilage progressed a mean of 6.86 o [ 34 ].…”

Pediatric scoliosis

“…This can be done clinically with serial measurements of overall standing and seated trunk height measurements with each office visit, Tanner staging, and recording the timing of menarche for female patients. Radiographic methods include obtaining a left hand radiographs for comparison with a Greulich and Pyle atlas, open or closed status of the triradiate cartilage, or with use of Risser staging of the iliac apophysis [12][13][14]. Of these three, the most commonly used clinically the Risser sign described in 1958 [15].…”