Retrospective matched cohort of 52 AIS patients (26 per group) comparing segmental pedicle screw vs. hook posterior spinal fusion. Groups were matched on age, Lenke curve type, number of fused vertebrae, and operative method. Outcomes at 2 years include radiographic correction, pulmonary function, fusion length, operative parameters, implant cost, and SRS-24 scores.
The case for pedicle screws in AIS rests on three concrete advantages over hooks: better coronal correction (76% vs. 50%), shorter fusion constructs (0.8 levels saved distally), and preservation of percent-predicted pulmonary function at 2 years.
When planning posterior AIS fusion, screws let you stop shorter distally than hooks because stronger 3-column fixation provides adequate distal anchoring without extending to the next stable vertebra. This matters because every motion segment fused unnecessarily accelerates adjacent segment degeneration.
The pulmonary data deserve a careful read: percent-predicted FVC and FEV-1 favor screws significantly, but absolute FVC and FEV-1 changes are not statistically different. The authors caution that the percent-predicted differences are statistically significant but may not yet be clinically significant at 2 years, though they argue preserving maximal pulmonary reserve matters given inevitable age-related decline.
The cost premium is real (roughly double the implant cost), and SRS-24 scores are identical at 2 years. The clinical argument for screws is radiographic correction and fusion length, not patient-reported satisfaction in the short term.
Retrospective matched cohort of 52 AIS patients (26 per group) comparing segmental pedicle screw vs. hook posterior spinal fusion. Groups were matched on age, Lenke curve type, number of fused vertebrae, and operative method. Outcomes at 2 years include radiographic correction, pulmonary function, fusion length, operative parameters, implant cost, and SRS-24 scores.
The case for pedicle screws in AIS rests on three concrete advantages over hooks: better coronal correction (76% vs. 50%), shorter fusion constructs (0.8 levels saved distally), and preservation of percent-predicted pulmonary function at 2 years.
When planning posterior AIS fusion, screws let you stop shorter distally than hooks because stronger 3-column fixation provides adequate distal anchoring without extending to the next stable vertebra. This matters because every motion segment fused unnecessarily accelerates adjacent segment degeneration.
The pulmonary data deserve a careful read: percent-predicted FVC and FEV-1 favor screws significantly, but absolute FVC and FEV-1 changes are not statistically different. The authors caution that the percent-predicted differences are statistically significant but may not yet be clinically significant at 2 years, though they argue preserving maximal pulmonary reserve matters given inevitable age-related decline.
The cost premium is real (roughly double the implant cost), and SRS-24 scores are identical at 2 years. The clinical argument for screws is radiographic correction and fusion length, not patient-reported satisfaction in the short term.