Long constructs in the thoracic and lumbar spine with a minimally invasive technique.

BACKGROUND: Literature about long implants used together with a minimally invasive spine surgery (MISS) technique is scarce. Our objective is to contribute our surgical experience in this field and to specifically focus on several technical details. PATIENTS AND METHODS: A digitally-dissected canal along the paravertebral muscles was created linking the stab wounds on each side in relation with the pedicles to be cannulated. Screws were inserted following the percutaneous technique. Long rods were modelled, threaded through the extender sleeves along the paravertebral canal and pushed into the screw heads with the reduction forceps. When fusion was needed, the facet complex was decorticated with a drill. To insert a cross-link, a canal between the 2 rods was digitally created and the spinous process was drilled. RESULTS: 8 patients underwent surgery (age range: 25-77 years). Indications were postosteomyelitis kyphosis in 3 patients, bone tumor in 3, and spine fracture in 2. No blood transfusions were necessary during or after surgery. A cross-link was inserted in 2 patients. Posterolateral bone fusion was attempted in 4, but radiologically identifiable in none. In one patient a cantilever manoeuvre was done to correct kyphosis. Mean duration of surgery was 4 h. There were no clinical complications related to the operation or the hardware (mean follow-up of 7.14 months, range: 1-15 months). CONCLUSION: The application of MISS techniques can be broadened to long spinal constructs to assess fractures, tumors or deformity, especially in elderly or debilitated patients. Nevertheless, posterolateral fusion is still a challenge through these limited exposures.

[Intraoperative neurophysiological monitoring of the spinal cord: our experience]. / Monitorización neurofisiológica intraoperatoria de la médula espinal: nuestra experiencia.

INTRODUCTION: The main objective of intraoperative monitoring of the spinal cord is to detect any neurological damage that may occur (and which would otherwise go unnoticed) while it is still reversible. AIM: To retrospectively evaluate the effectiveness of neurophysiological monitoring in spine and spinal cord surgery since the time such procedures were first implemented within our centre. PATIENTS AND METHODS: The patients were divided into three groups, according to their pathologies. They were clinically evaluated with the McCormick scale before surgery, on discharge from hospital and at six months after the operation. Neurophysiological monitoring was performed with motor evoked potentials, somatosensory potentials and screw stimulation, when appropriate. RESULTS: The sample finally consisted of 49 subjects, with a mean age of 51 +/- 19.4 years. Distribution by groups was 53.1% spinal cord tumours, 22.4% traumatic injuries to the spinal cord and 24.5% bone/disc pathologies. During surgery potentials improved in 4.08% of patients, in 63.26% they remained intact, 20.41% were alerted by the neurophysiologist with intact potentials, 10.2% suffered a transitory decline and in one case there was permanent loss. All the patients who were submitted to a follow-up at six months displayed a clinical status that was the same or better than the one before their operation. CONCLUSIONS: Neurophysiological monitoring is a valuable tool that prevented, in 30.61% of our patients, damage that could otherwise have occurred. From the clinical point of view, its high predictive value is also worth highlighting.