Instrumentation failure following pediatric spine deformity growth-sparing surgery using traditional growing rods or vertical expandable prosthetic titanium ribs.

BACKGROUND: Instrumentation failure (IF) is a major complication associated with growth-sparing surgery for pediatric spinal deformities; however, studies focusing on IF following each surgical procedure are lacking. We aimed to evaluate the incidence, timing, and rates of unplanned return to the operating room (UPROR) associated with IF following each surgical procedure in growth-sparing surgeries using traditional growing rods (TGRs) and vertical expandable prosthetic titanium ribs (VEPTRs). METHODS: We reviewed 1,139 surgical procedures documented in a Japanese multicenter database from 2015 to 2017. Of these, 544 TGR and 455 VEPTR procedures were included for evaluation on a per-surgery basis. IF was defined as the occurrence of an implant-related complication requiring revision surgery. RESULTS: The surgery-based incidences of IF requiring revision surgery in the TGR and VEPTR groups were 4.3% and 4.0%, respectively, with no significant intergroup difference. Remarkably, there was a negative correlation between IF incidence per surgical procedure and the number of lengthening surgeries in both groups. In addition, rod breakage in the TGR group and anchor-related complications in the VEPTR group tended to occur relatively early in the treatment course. The surgery-based rates of UPROR due to IF in the TGR and VEPTR groups were 2.0% and 1.5%, respectively, showing no statistically significant difference. CONCLUSIONS: We found that IF, such as anchor related-complications and rod breakage, occurs more frequently earlier in the course of lengthening surgeries. This finding may help in patient counseling and highlights the importance of close postoperative follow-up to detect IF and improve outcomes.

Incidence and causes of instrument-related complications after primary definitive fusion for pediatric spine deformity.

OBJECTIVE: Various complications have been reported in the treatment of pediatric spinal deformities. Among these, instrument-related complications could be critical concerns and risks of reoperation. This study aimed to identify the incidence and causes of complications after primary definitive fusion for pediatric spine deformities. METHODS: The authors retrospectively collected data from 14 institutions about patients who underwent primary definitive fusion between 2015 and 2017. There were 1490 eligible patients (1184 female and 306 male), with a mean age of 13.9 years. The incidence, causes, and reoperation rates were analyzed according to 4 etiologies of pediatric spine deformity (congenital, neuromuscular, syndromic, idiopathic). The complications were also categorized as screw-, hook-, or rod-related complications, implant loosening or backout, and junctional problems. RESULTS: The incidence of overall instrument-related complications was 5.6% (84 cases). Regarding etiology, the incidence rates were 4.3% (idiopathic), 6.8% (syndromic), 7.9% (congenital), and 10.4% (neuromuscular) (p < 0.05). The most common causes were pedicle screw malposition (60.7%), followed by implant backout or loosening (15.4%), junctional problems (13.1%), rod breakage (4.8%), and other complications (6.0%). Univariate analysis showed that etiology, type of deformity (kyphosis), surgical procedure, operation time, and estimated blood loss were significant factors. Multivariate analysis revealed that etiology (neuromuscular), surgical procedure (combined approach), and operation time (> 5 hours) remained as significant risk factors. Among all patients with instrument-related complications, 45% (38/84) required revision surgery. Of these cases, > 50% were related to pedicle screw malposition. Medial breach was the most common complication regardless of location, from upper thoracic to lumbar spine. CONCLUSIONS: Pedicle screw malposition was the primary cause of overall complications and subsequent reoperation. In addition to more precise screw insertion techniques, meticulous confirmation of pedicle screw placement, especially of medial breach, may reduce the overall instrument-related complications and revision rates.