Mehta's 1972 landmark study of 138 infants asks whether progressive and resolving infantile scoliosis can be distinguished on a radiograph — before months of watchful waiting. It introduces the rib-vertebra angle difference (RVAD) and a two-phase rib-head classification as the first objective, radiograph-based prognostic tools for this decision.
Until this paper, the only way to distinguish a self-resolving infantile curve from a progressive one was to watch and wait — Lloyd-Roberts and Pilcher were still doing exactly this with 100 untreated babies as late as 1965.
Mehta gave clinicians two tools applicable at the first visit: measure the RVAD and assess rib-head phase. A curve with Phase 2 overlap requires no further deliberation. It is progressive and needs treatment now. A curve with RVAD ≥20 degrees in Phase 1 is indeterminate: bring the child back in 3 months. If the RVAD falls at follow-up, even with a rising Cobb angle, you are watching resolution. Observe. If the RVAD holds or rises, the curve is progressive. Intervene regardless of curve size or age.
This framework is the foundation on which Mehta casting and modern early-intervention protocols are built: the earlier you control a progressive curve, the lower the adolescent peak. Because the infantile rise sets the ceiling for final deformity.
Mehta's 1972 landmark study of 138 infants asks whether progressive and resolving infantile scoliosis can be distinguished on a radiograph — before months of watchful waiting. It introduces the rib-vertebra angle difference (RVAD) and a two-phase rib-head classification as the first objective, radiograph-based prognostic tools for this decision.
Until this paper, the only way to distinguish a self-resolving infantile curve from a progressive one was to watch and wait — Lloyd-Roberts and Pilcher were still doing exactly this with 100 untreated babies as late as 1965.
Mehta gave clinicians two tools applicable at the first visit: measure the RVAD and assess rib-head phase. A curve with Phase 2 overlap requires no further deliberation. It is progressive and needs treatment now. A curve with RVAD ≥20 degrees in Phase 1 is indeterminate: bring the child back in 3 months. If the RVAD falls at follow-up, even with a rising Cobb angle, you are watching resolution. Observe. If the RVAD holds or rises, the curve is progressive. Intervene regardless of curve size or age.
This framework is the foundation on which Mehta casting and modern early-intervention protocols are built: the earlier you control a progressive curve, the lower the adolescent peak. Because the infantile rise sets the ceiling for final deformity.