Introduction: Posterior percutaneous instrumentation may represent a challenge when multiple levels need to be instrumentated, especially when including the upper thoracic spine. The aim of the present study was to evaluate the technical feasibility and the long-term outcome of such long constructs in different surgical conditions. Materials and Methods: This investigation was a retrospective cohort study which included patients who underwent thoraco-lumbar percutaneous fixations. We collected clinical, surgical and radiological data, with a minimum follow-up of 24 months. Health-related quality-oflife, residual pain, instrumentation placement, and complications were studied. Results: A total of 18 procedures were enrolled, in which 182 screws were implanted, (170 positioned in thoracic and 12 in lumbar pedicles, respectively). No surgical complications or hardware failure occurred in our series, 6 out of 182 (3,2%) screws had a partial pedicle breach, without neurological impairment or need for surgical revision. Conclusion: According to our results, a fully posterior percutaneous approach for long thoraco-lumbar spine instrumentation can be considered safe and reproducible, although an adequate training is strictly required.

Disc herniation is one of most common causes of spine surgery. Because of the presence of posterior longitudinal ligaments, disc fragments often migrate into the ventral epidural space. A posterior epidural herniation of a disc fragment is a rare occurrence. We report two cases of posterior migrated disc fragments, with, radiological and clinical findings. Because of the rarity of a posterior migration of the intervertebral disc fragments, a differential diagnosis can be challenging. This painful syndrome associated with neurological lower limb deficits can be confused initially, with other posterior epidural spaceoccupying lesions such as tumours, abscess or hematomas. A gadolinium-enhanced MRI scan is the gold standard for a correct diagnosis. Early surgical decompression of the spine with a posterior approach remains the optimal technique in ensuring the best possible outcome for the patient.