De Bastiani et al. introduce callotasis: limb lengthening by slow distraction of callus at a proximal submetaphyseal corticotomy, using a dynamic axial fixator. The study reports outcomes across 100 lengthened segments (56 femora, 41 tibiae, 3 humeri) in 73 patients with limb length discrepancy or achondroplasia. It answers whether physiological callus regeneration can replace bone grafting and reduce the catastrophic complication rates seen with prior methods.
The complication history of limb lengthening before this paper was enough to make most surgeons abandon the field entirely. The Wagner technique — then the Western standard. Carried a 44.8% complication rate in its originator's hands, and the Verona group's own prior experience required 89 revision operations to lengthen just 27 segments.
This paper is why modern limb lengthening targets the proximal submetaphyseal zone, waits for callus before distracting, and uses dynamic loading to finish corticalization. When you plan a lengthening case, the healing index of ~38 days/cm is what you use to counsel the patient on total frame time. It comes directly from this dataset.
The protocol described here (corticotomy, 10–15 day latency, 1 mm/day distraction in 4 increments, then dynamic axial loading) remains the conceptual backbone of every modern lengthening system, from circular Ilizarov frames to intramedullary lengthening nails.
For board purposes: callotasis = distraction of corticotomy callus (not osteotomy gap), latency period = 10–15 days, rate = 0.25 mm q6h, and all 100 segments healed without graft.
De Bastiani et al. introduce callotasis: limb lengthening by slow distraction of callus at a proximal submetaphyseal corticotomy, using a dynamic axial fixator. The study reports outcomes across 100 lengthened segments (56 femora, 41 tibiae, 3 humeri) in 73 patients with limb length discrepancy or achondroplasia. It answers whether physiological callus regeneration can replace bone grafting and reduce the catastrophic complication rates seen with prior methods.
The complication history of limb lengthening before this paper was enough to make most surgeons abandon the field entirely. The Wagner technique — then the Western standard. Carried a 44.8% complication rate in its originator's hands, and the Verona group's own prior experience required 89 revision operations to lengthen just 27 segments.
This paper is why modern limb lengthening targets the proximal submetaphyseal zone, waits for callus before distracting, and uses dynamic loading to finish corticalization. When you plan a lengthening case, the healing index of ~38 days/cm is what you use to counsel the patient on total frame time. It comes directly from this dataset.
The protocol described here (corticotomy, 10–15 day latency, 1 mm/day distraction in 4 increments, then dynamic axial loading) remains the conceptual backbone of every modern lengthening system, from circular Ilizarov frames to intramedullary lengthening nails.
For board purposes: callotasis = distraction of corticotomy callus (not osteotomy gap), latency period = 10–15 days, rate = 0.25 mm q6h, and all 100 segments healed without graft.