Retention of Spinal Mobility and Growth after Correction of Lordo-Scoliosis; Preliminary Assessment of a Novel Implant Device

Abstract

forces to its adjacent modules. The cumulative effect was the application of de-rotational forces to the deformed spine. For a "proof of concept" investigation, a right thoracic lordo-scoliosis was formed in lambs using an implanted cable as a tether secured on the left side between pedicle screws. After tether removal, 15 lambs with stable scoliotic curves underwent implantation of the modules at each of the segments along the abnormal curve. Animals were euthanased at skeletal maturity. RESULTS: Serial radiographic measurements over two years, revealed an average of 76% coronal plane correction in 12 of the 15 lambs. Specimens demonstrated independent segmental mobility though three animals had adjacent segmental fusion at two levels. Longitudinal spinal growth over the instrumented region averaged 3.9 cm. CONCLUSION: The novel implant dynamically corrected an induced lordo-scoliosis in 12 lambs whilst permitting continued spinal growth and preserving spinal mobility.