To compare the efficacy and safety of balloon kyphoplasty (BKP) to non-surgical management (NSM) over 24 months in patients with acute painful fractures by clinical outcomes and vertebral body kyphosis correction and surgical parameters. Three hundred Adult patients with one to three VCF's were randomised within 3 months of the acute fracture; 149 to Balloon Kyphoplasty and 151 to Non-surgical management. Subjective QOL assessments and objective functional (Timed up and go [TUG]) and vertebral body kyphotic angulation (KA), were assessed over 24 months; we also report surgical parameters and adverse events temporally related to surgery (within 30-days).Purpose
Material and Methods
Balloon kyphoplasty (BKP) is a minimally invasive treatment for vertebral fractures (VCF) aiming to correct deformity using balloon tamps and bone cement to stabilize the body. Patients with 1 - 3 non-traumatic acute VCF were enrolled within three months of diagnosis and randomly assigned to receive either BKP (N=149) or nonsurgical care (N=151). Follow-up was 2 years. The mean SF-36 physical component summary (PCS) score improved 5.1 points (95%CI, 2.8-7.4; p<0.0001) more in the kyphoplasty than the nonsurgical group at one month, the primary endpoint of the study. Kyphoplasty improved the PCS score by an average of 3.0 points (95%CI, 1.6-5.4; p=0.002) during the two-year follow-up. There was a significant interaction between treatment and follow-up time (p=0.003), indicating that the treatment effect over the year is not uniform across follow-up; a result from early improvement that persists in the kyphoplasty group whereas the nonsurgical group shows more incremental improvement over time. Overall, patients assigned to kyphoplasty also had statistically significant improvements over the two years compared to the control group in global quality of life (EQ-5D), pain relief (VAS), back disability (RMDQ) and days of limited activity (within a two-week period). There was no statistical significant difference between groups in the number of patients with adverse events or new VCF's over 24 months. Compared to the control, BKP improved quality of life and reduced back pain and disability and did not increase adverse events including the risk of new vertebral fractures over 2 years.
Vertebral body compression fractures (VCFs) impair quality of life (QOL) and increase patient morbidity and mortality. The international, multicentre, randomised, controlled Fracture Reduction Evaluation (FREE) trial was initiated to compare effectiveness and safety of Balloon kyphoplasty (BKP) to non-surgical management (NSM) for the treatment of acute painful VCFs. We describe the primary endpoint of the ongoing 2-year study. Patients with 1-3 non-traumatic VCFs (< 3 months old) were randomised to either BKP or NSM. The primary endpoint was the change in QOL as measured by the SF-36 Health Survey Physical Component Summary (PCS) at one month, and device/procedure-related safety. Secondary endpoints included SF-36 subscales, the EQ-5D, self-reported back pain and function using the Roland Morris Disability Questionnaire (RMDQ). All patients were given osteoporosis medical therapy.Background
Methods
The biomechanical effects on facet joints after posterior fusion remain unclear and seem to be responsible for accelerated degeneration. The following biomechanical study was performed to investigate the effects on the pressure and mobility of neighbouring unfused segments after double level T12-L2 posterior stabilization. The experimental study was performed on eighteen fresh, human, cadaveric thoracolumbal spine specimens. The specimens were cleaned and dissected from muscles and fat with care to preserve bone-ligament units intact. In a specially constructed testing machine the data of the segmental pressure and mobility of adjacent segments above and below the fusion were measured before and after double level T12-L2 posterior stabilization with an internal fixator (Universal Spine System) in flexion, extension, lateral bending, and rotation. For measuring the mobility a motion tracker (3Space Fastrak) and for direct evaluation of the pressure a quartz miniature force transducer was used. Also the bone mineral density of the specimens were measured and showed normal values. In flexion and extension Range of Motion (ROM) of the segment above the double level T12-L2 posterior fusion was significantly increased (p<
0,05). In the adjacent segment below the fusion there was no significant increased mobility after fusion for each moment was applied. The pressure did not show any significant difference, but after posterior fusion in flexion and extension the pressure below the posterior fusion (L2/L3) was decreased and above the fusion (T11/T12) increased. There is evidence that the adjacent segment above a double-level T12-L2 posterior fusion becomes more mobile and leads possibly to an accelerated degeneration in the facet joints due to increased stress at this point. Also the posterior fusion seems to change the load distribution in the facets of adjacent segments. These results could be responsible for symptoms like low back pain after spinal surgery.
The new distractable titanium implant (Synex) is designated for replacement of the vertebral body following fracture, posttraumatic kyphosis or tumor. Synex was compared with the “Harms” cage (MOSS, 22x28 mm, stabilising ring) in two test series.
In test series B the bisegmental motion (T12-L2) of 12 spinal specimens were tested in a 3D loading simulator with moments of 0–7.5 Nm for the six directions. After testing the intact spine, we replaced L1 and stabilised with Fixateur interne (USS) or Ventrofix (VFix). Analysis of the range of motion (ROM), elastic zone (EZ) and neutral zone (NZ) for five conditions: 1) Intact specimen, 2) USS+Synex, 3) USS+MOSS, 4) VFix+Synex, 5) VFix+MOSS (randomized order).
Significantly higher stability was noted with USS+Synex for extension, lateral bending, and axial rotation. No differences between Synex and MOSS were observed in combination with VFix. The combined instrumentation (USS) was superior to the anterior one (VFix). The possibility of secondary dislocation, loss of correction, or posttraumatic kyphosis can be decreased using Synex for replacement of the vertebral body, compared with MOSS. A combined anterior-posterior stabilisation provides higher biomechanical stability compared with an anterior construct.