Harrington described an implanted rod‑and‑hook system that corrects scoliosis through distraction and compression and holds the correction by skeletal fixation, and he reported his preliminary results.
Developmental series of 129 patients treated in three successive groups as the device was redesigned, 1949 to 1960.
Methods
Indication
Scoliosis
Harrington factor of 5 or more plus curve progression (children), increasing pain or fatigue (adults) or progressive cardiopulmonary decompensation
Approach
Implanted metal rods and hooks
Distraction and compression forces applied to the curve
Groups I and II: instrumentation without cast immobilization
Group III: fusion with instrumentation and prolonged plaster‑jacket immobilization
Outcomes
Clinical result
Curve correction
Instrument breakage
Complications and deaths
Key Findings
Results were better in Group III, treated with fusion, instrumentation and prolonged plaster‑jacket immobilization, than in Groups I and II, which had no cast and no immobilization.
Bar breakage fell with each redesign, from 11 of the first 19 patients to 4 of 46 in the second series and 2 of the last 59 with the current bars.
In Group I, where the main instrument development took place, no casts were used and nearly every patient eventually needed fusion to reach a reasonable result.
Patients usually lost 5 to 15 degrees of correction after surgery because of bone erosion at the hooks.
In the illustrated case, a 75‑degree thoracic curve was corrected to 12 degrees, and the uninstrumented 55‑degree lumbar curve improved to 18 degrees, which the author believed came from changing the geometry of the whole spine.
Two of the 129 patients died: one from obstructive bronchial edema 4 hours after intubation, and one 6 days after operation from cardiac failure with cor pulmonale present for 9 months.
Board pearl
The Harrington factor is the Cobb angle divided by the number of vertebrae in the curve, and Harrington usually considered surgery indicated when it reached 5 or more.
Authors' conclusion
The axial skeleton can be stabilized by a prestressed metallic system in direct contact with it, especially if spine fusion is performed within the span of the instrumentation.
Harrington described an implanted rod‑and‑hook system that corrects scoliosis through distraction and compression and holds the correction by skeletal fixation, and he reported his preliminary results.
Developmental series of 129 patients treated in three successive groups as the device was redesigned, 1949 to 1960.
Methods
Indication
Scoliosis
Harrington factor of 5 or more plus curve progression (children), increasing pain or fatigue (adults) or progressive cardiopulmonary decompensation
Approach
Implanted metal rods and hooks
Distraction and compression forces applied to the curve
Groups I and II: instrumentation without cast immobilization
Group III: fusion with instrumentation and prolonged plaster‑jacket immobilization
Outcomes
Clinical result
Curve correction
Instrument breakage
Complications and deaths
Key Findings
Results were better in Group III, treated with fusion, instrumentation and prolonged plaster‑jacket immobilization, than in Groups I and II, which had no cast and no immobilization.
Bar breakage fell with each redesign, from 11 of the first 19 patients to 4 of 46 in the second series and 2 of the last 59 with the current bars.
In Group I, where the main instrument development took place, no casts were used and nearly every patient eventually needed fusion to reach a reasonable result.
Patients usually lost 5 to 15 degrees of correction after surgery because of bone erosion at the hooks.
In the illustrated case, a 75‑degree thoracic curve was corrected to 12 degrees, and the uninstrumented 55‑degree lumbar curve improved to 18 degrees, which the author believed came from changing the geometry of the whole spine.
Two of the 129 patients died: one from obstructive bronchial edema 4 hours after intubation, and one 6 days after operation from cardiac failure with cor pulmonale present for 9 months.
Board pearl
The Harrington factor is the Cobb angle divided by the number of vertebrae in the curve, and Harrington usually considered surgery indicated when it reached 5 or more.
Authors' conclusion
The axial skeleton can be stabilized by a prestressed metallic system in direct contact with it, especially if spine fusion is performed within the span of the instrumentation.