Spine: Affiliated Society Meeting Abstracts:
Podium Presentation Abstracts
Summary: We examine a novel use of spinal hooks on ribs in a study with 2 years of follow‐up. Hybrid growing rods where proximal anchors are spinal hooks on ribs may avoid fusion of the thoracic spine, while allowing distractive forces to minimize spinal deformity and encourage growth. This technique compares favorably to traditional growing rods in terms of complication rate, T1‐S1 growth, and SAL and Cobb angle correction, with the potential pulmonary benefit of avoiding fusion of the thoracic spine.
Introduction: Fusion of the upper thoracic spine in children severely limits pulmonary development. Traditional growing rods typically include a fusion of the upper thoracic spine. Hybrid growing rods in which the proximal anchors are spinal hooks placed on ribs may avoid fusion of the proximal thoracic spine, while allowing distractive forces to minimize spinal deformity and encourage growth. The purpose was to evaluate this novel use of spinal hooks on ribs as proximal anchors.
Methods: A retrospective multi‐center study of 28 patients with growing spine instrumentation using spinal hooks on ribs treated at 6 institutions was performed. Mean follow up was 37 months (24‐74 mos). Mean age at index surgery was 44 months (5‐111 mos). 24 patients have congenital scoliosis.
Results: 23 patients had single rod constructs on the concave side only, and 5 patients had dual rods. Mean primary Cobb angle at the time of index surgery was 69o. Mean Cobb angle correction achieved at the time of the index surgery was 19 o, which was maintained through latest follow up. Mean increase in T1‐S1 length on the AP radiograph at latest follow up was 49 mm, with a mean increase of 13 mm per lengthening procedure. On average, space available for the lung (SAL) improved by on 25 mm on both the concave side and convex side at latest follow up.
Complications occurred in 7 (24%) patients, all with congenital scoliosis. There is a non‐significant trend that complications are associated with younger age (p=0.12) and larger Cobb angle at index surgery (p=0.12). Complications included 2 wound issues, 9 losses of fixation of rib anchors, and 1 rod breakage. There were no neurologic complications. There was no loss of fixation in any construct that had a proximal foundation of at least 4 up‐going hooks on ribs, and there were no complications in dual‐sided constructs.
Conclusion: We describe a novel technique that compares favorably to traditional growing rods in terms of complication rate, T1‐S1 growth, and improvement in SAL and Cobb angle correction, with the potential long‐term pulmonary benefit of avoiding fusion or instrumentation of the upper thoracic spine.
Significance: Use of spinal hooks on ribs may be included in our armamentarium for growing spine constructs.
The FDA has not cleared the drug and/or medical device for the use described in this presentation (i.e., the drug or medical device is being discussed for an ‘off label’ use).