Assessment of two novel surgical positions for the reduction of scoliotic deformities: lateral leg displacement and hip torsion

Cobb angles and apical vertebral rotations (AVR) are two of the main scoliosis deformity parameters which spinal instrumentation and fusion techniques aim to reduce. Despite this importance, current surgical positioning techniques do not allow the reduction of these parameters. Two new surgical frame accessory prototypes have been developed: (1) a lateral leg displacer (LLD) allows lateral bending of a patient’s legs up to 75° in either direction and (2) a pelvic torsion device (PTD) which allows transverse plane twisting of a patient’s pelvis at 30° in either direction while raising the thoracic cushion, opposite to the raised side of the pelvis, by 5 cm. The objective of this study was to evaluate the ability of the LLD and PTD to reduce Cobb angles and AVR. Experimental testing was performed pre-operatively on 12 surgical scoliosis patients prone on an experimental surgical frame. Postero-anterior radiographs of their spines were taken in the neutral prone position on a surgical frame, and then again for 6 with their legs bent towards the convexity of their lowest structural curve, 4 with their pelvis raised on the convex side of their lowest structural curve and one each in opposite LLD and PTD intended use. Use of the LLD allowed for an average supplementary reduction of 16° (39%) for Cobb angle and 9° (33%) for AVR in the lowest structural curve. Use of the PTD allowed for an average supplementary reduction of 9° (19%) for Cobb angle and 17° (48%) for AVR in the lowest structural curve. Both devices were most efficient on thoraco-lumbar/lumbar curves. Opposite of intended use resulted in an increase in both Cobb angle and AVR. The LLD and PTD provide interesting novel methods to reduce Cobb angles and AVR through surgical positioning which can be used to facilitate instrumentation procedures by offering an improved intra-operative geometry of the spine

Effectiveness of posterior tension band fixation in the thoracolumbar seat-belt type injuries of the young population

We report results in the surgical treatment of thoracolumbar flexion–distraction fractures, both associated or not with neurological impairment. Items in the present study include function, pain (back pain rating scale) and neurological recovery (Asia Score). A prospective series of 19 consecutive flexion–extension thoracolumbar injuries (T11–L2), occurred in young patients (20–33 years) due to motor vehicle crashes wearing the 3-point safety belts, includes 2 Chance and 17 seat-belt fractures, with different amount of vertebral dislocation and neurological impairment. Fractures have been evaluated according to the Magerl’s classification. All patients were operated via posterior approach using hybrid instrumentation or short pedicular fixation to reduce dislocation and to obtain spinal fusion. Posterior decompression was performed in all patients with neurological deficit. Posterior instrumented arthodesis was performed by wide constructs that preferably include 2 levels above and below the dislocated vertebra. Most of them were instrumented using thoracic hooks and lumbar pedicular screws. One postoperative vascular complication was successfully treated by selective embolization. All neurological patients were submitted to a postoperative rehabilitation program. Posterior procedure allows proper reduction and realignment. In our experience, the use of laminar hooks one level above the dislocation seems to reduce the potential risk of neurological and /or vascular damage during the intraoperative maneuvers on the dislocated pedicles. At follow-up, fusion was achieved in all patients. The clinical condition was totally satisfactory due to the absence of significant pain, confirming mechanical stability of the implants. In terms of neurological outcomes, patients presenting as ASIA A-B or ASIA E, maintained their preoperative neurological condition. Surgical treatment, together with an early postoperative rehabilitation program, can be of paramount importance in neurological patients’ quality of life