Aims

Psychoeducative prehabilitation to optimize surgical outcomes is relatively novel in spinal fusion surgery and, like most rehabilitation treatments, they are rarely well specified. Spinal fusion patients experience anxieties perioperatively about pain and immobility, which might prolong hospital length of stay (LOS). The aim of this prospective cohort study was to determine if a Preoperative Spinal Education (POSE) programme, specified using the Rehabilitation Treatment Specification System (RTSS) and designed to normalize expectations and reduce anxieties, was safe and reduced LOS.

Background

Degenerative spondylolisthesis (DS) with stenosis is now typically treated by decompression and instrumented fusion. This treatment method does produce predictable results at the spondylolisthetic level, but later stenosis will occur commonly at the adjacent level due to the rigidity of the construct. Pedicle screw fusion may also be a significantly invasive procedure for an elderly patient.

To assess the effectiveness of unilateral sublaminar and concave rib tethering with convex rib resection through the period of peak growth in lambs.

Morphometric growth data from 10 experimental Scottish Blackface sheep were compared to those from 5 control animals (no intervention) over 12 months.

Standardized AP and Lateral radiographs were taken before and at monthly intervals after scoliosis creation. The Cobb angle was measured in the coronal and sagittal planes. Rotational mal-alignment was assessed by axial CT 7 months post surgery.

In the supine position the control animals had no coronal plane deformity and a mean 5° lordosis (T4-T12). These figures did not alter with growth (doubling of body weight). Tethering (at age 5 weeks) produced an immediate scoliosis of 22±11° and a lordosis of 24±8° (means(sd). The degree of scoliosis was maintained over 7 months (at 20°) but lordosis increased (to 59±11°, p<0.01). There was an associated change in vertebral rotation. Surgery had no influence on rate of growth or animal development.

Two animals died from Clostridium associated enterocolitis. There were no deaths associated with the surgical intervention.

This ovine model gives a progressive spinal deformity in the sheep but primarily in the sagittal plane. This fact should be considered in studies designed to evaluate the effectiveness of surgical implants.

To compare outcomes and costs of transforaminal endoscopic surgical discectomy (TES) with those of microdiscectomy (Micro)

48 patients with a primary lumbar disc prolapse were randomly allocated by computer to surgery.

Assessments were made of leg and back pain (VAS), Oswestry Disability index (ODI), and SF-36 as primary outcomes. Cost data was collated.

25 TES and 23 Micro patients are reported with similar age, sex, smoking status and affected disc levels (14 v.17 L5/S1). Three months following surgery leg pain scores had decreased by 55 and 65% in the two groups. Patient satisfaction ratings were equal. ODI had decreased 15 points in both groups by 1yr and this improvement was maintained to 2 years (final scores: 7±3 TES v.14±13 Micro - means ±SD; p<0.05). Similar changes were noted in SF36-P. Mean bed stay was lower in the TES group (16 v. 40 hours). Other post-operative costs were similar. There were no immediate complications. One revision was required at 12 months (TES) and one at 18 months (Micro). Two patients presented with a disc prolapse at a different level and side (both TES).

Results at up to two years follow-up are similar following the two interventions. Recovery was more rapid in those patients undergoing endoscopic surgery.

To investigate whether restoration of mechanical function and spinal load-sharing following vertebroplasty depends upon cement distribution.

Fifteen pairs of cadaver motion segments (51-91 yr) were loaded to induce fracture. One from each pair underwent vertebroplasty with PMMA, the other with a resin (Cortoss). Various mechanical parameters were measured before and after vertebroplasty. Micro-CT was used to determine volumetric cement fill, and plane radiographs (sagittal, frontal, and axial) to determine areal fill, for the whole vertebral body and for several specific regions. Correlations between volumetric fill and areal fill for the whole vertebral body, and between regional volumetric fill and changes in mechanical parameters following vertebroplasty, were assessed using linear regression.

For Cortoss, areal and volumetric fills were significantly correlated (R=0.58-0.84) but cement distribution had no significant effect on any mechanical parameters following vertebroplasty. For PMMA, areal fills showed no correlation with volumetric fill, suggesting a non-uniform distribution of cement that influenced mechanical outcome. Increased filling of the vertebral body adjacent to the disc was associated with increased intradiscal pressure (R=0.56, p<0.05) in flexed posture, and reduced neural arch load bearing (F_N) in extended posture (R=0.76, p<0.01). Increased filling of the anterior vertebral body was associated with increased bending stiffness (R=0.55, p<0.05).

Cortoss tends to spread evenly within the vertebral body, and its distribution has little influence on the mechanical outcome of vertebroplasty. PMMA spreads less evenly, and its mechanical benefits are increased when cement is concentrated in the anterior vertebral body and adjacent to the intervertebral disc.