Spinal deformations are posture dependent. Official data from the Netherlands show that youth are encountering increasing problems with the musculoskeletal system (>40% back pain, and sport injury proneness). Prolonged sloth and slumped sitting postures are causative factors. Dutch youth are “champion sitting” in Europe. The effects of sitting on the development of posture and function of locomotion (stiffness) during growth have only been reported clearly in classic textbooks (in German) of practical anatomy and orthopaedics. Research with relevant clinical examinations is being done to understand epidemiological data on the increasing posture-dependent problems. A cohort of adolescents (15–18 years) in secondary school was assessed for sagittal postural deviations while bending. 248 children completed a questionnaire, and tests were done on neuromuscular tightness. The femorotibial angle was used to measure hamstring tightness. Measurement of the dorsiflexion of the foot was used to assess the tightness of calf muscles and Achilles tendons. All adolescents were photographed laterally while performing the finger–floor test (used to test flexibility), assessed as a knockout test: “Can you reach the floor or not?” The spinal profiles while bending were classified as abnormal arcuate or angular kyphosis. Hamstring tightness was present in 62.1% of the cohort in both legs, and in 18.2% unilaterally. Achilles tendon tightness was present bilaterally in 59.3%, and unilaterally in 19.4%. Activities with presence of stiffness (finger–floor distance), in descending order, were football, running, no sports, field hockey, tennis, dance, and gymnastics. 93.5% of the soccer players had tight hamstrings in both legs compared with none of those performing gymnastics. The correlation of the finger–floor test with tight hamstrings was 73.2%. For sagittal bending deformities, the correlation between form and function deficits cannot be made yet. 80 of 248 spines were rated by the examiners as having deformed flexion. Since Andry (1741) and at the zenith of continental orthopaedics and anatomy around 1900, the prolonged flexed positions of a young spine were indicated as being the main cause of deformity by overload and shear loads on immature discs and cartilage, preventing normal development of the discs. Nachemson proved that the intradiscal pressure in sitting adults was extremely high, so it follows that children must also be at risk. Evidence suggests that youth, generally because of their sedentary and “screenful lifestyle”, will encounter serious problems in growth, manifesting as incongruent neuro-osseous growth (Roth), serious neuromuscular tightness (being prone to injury), and spinal deformations, leading to pain

The purpose of this retrospective study, is to demonstrate the survivorship and clinical effectiveness of the Wallis implant, against low back pain and functional disability in patients with degenerative lumbar spine disease. The Wallis Interspinous implant, was developed as a minimally invasive and anatomically conserving procedure, without recourse to rigid fusion procedures. The initial finite element analysis and cadaver biomechanical studies showed that the Wallis ligament improves stability in the degenerate lumbar motion segment. Unloading the disc and facet joints reduces intradiscal pressures at same and adjacent levels allowing for the potential of the disc to repair itself. A total of 157 patients who had wallis ligament insertion between 2003 and 2009 were reviewed, with a mean age of 54 and were followed for 48 months on average. Patients were assessed pre-operatively and post-operatively every 6 months by VAS pain score, Oswestry Disability Index and SF-36. 90% of patients improved, to show a minimal clinical difference, compared to the pre-operative evaluation. There is overall 75-80% good clinical outcome. Low infection rate of 1.1%. Two cases of prolapsed discs at the same level requiring further discectomy, 7 required fusion. No fractures or expulsions. The Wallis implant represents a safe non-fusion stabilisation device in the treatment of degenerative lumbar spine disease with canal stenosis. There is less soft tissue damage, quick rehabilitation, less morbidity and associated low complication rate

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

Introduction. Disc degeneration is often scored using macroscopic and microscopic scoring systems. Although reproducible, these scores may not accurately reflect declining function in a degenerated disc. Accordingly, we compared macroscopic and microscopic degeneration scores with measurements of disc function. Methods. Thirteen cadaveric motion segments (62–93 yrs) were compressed to 1kN while a pressure-transducer was pulled across the mid-sagittal diameter of the disc. Resulting stress profiles indicated intradiscal pressure (IDP), and maximum stress in the anterior (MaxStress_Ant) and posterior (MaxStress_Post) annulus. Macroscopic grade (1–4) of disc degeneration was based on visual examination of mid-sagittal sections, using subscales that yielded a maximum score of 48. Microscopic grade (1–4) was based on histological sections of the disc + vertebral body taken from anterior annulus, nucleus pulposus and posterior annulus, using subscale scores that totalled 108. Cartilage endplate thickness (CEP_thickness) was measured histologically, and porosity of the bony endplates was measured using micro-CT. ANOVA was used to compare between grades, and regression was used to establish dependence on scores. Results. IDP and CEP_thickness both decreased with increasing macroscopic grade (1–4) of degeneration (P= 0.021 & 0.022 respectively). Also, IDP, CEP_thickness and MaxStress_Ant decreased with increasing macroscopic score (1–48) (R. 2. = 0.39, P = 0.022; R. 2. = 0.36, P = 0.03; R. 2. = 0.30, P = 0.04 respectively). IDP and MaxStress_Ant decreased with increasing microscopic grade (1–4) of degeneration (P=0.05 & 0.005 respectively) and increasing microscopic score (1–108) (R. 2. = 0.36, P = 0.02; R. 2. = 0.47, P = 0.009 respectively) whereas inferior endplate porosity increased with increasing microscopic grade (P = 0.05) and score (R. 2. = 0.36, P = 0.03). Conclusion. Macroscopic and microscopic ‘degeneration’ scores both reflect changes in disc function and endplate integrity

Introduction. Osteoporotic fracture reduces vertebral stiffness, and alters spinal load-sharing. Vertebroplasty partially reverses these changes at the fractured level, but is suspected to increase deformations and stress at adjacent levels. We examined this possibility. Methods. Twelve pairs of three-vertebra cadaver spine specimens (67-92 yr) were loaded to induce fracture. One of each pair underwent vertebroplasty with PMMA, the other with a resin (Cortoss). Specimens were then creep-loaded at 1.0kN for 1hr. In 15 specimens, either the uppermost or lowest vertebra was fractured, so that compressive stress distributions could be determined in the disc between adjacent non-fractured vertebrae. Stress was measured in flexion and extension, at each stage of the experiment, by pulling a pressure-transducer through the disc whilst under 1.0kN load. Stress profiles quantified intradiscal pressure (IDP), stress concentrations in the posterior annulus (SP. P. ), and compressive load-bearing by the neural arch (F. N. ). Elastic deformations in adjacent vertebrae were measured using a MacReflex tracking system during 1.0kN compressive ramp loading. Results. No differences were found between Cortoss and PMMA so data was pooled. Following fracture, IDP fell by 27% in extension (P=0.009), and SP. P. increased by 277% in flexion (P=0.016). F. N. increased from 17% to 30% of the applied load in flexion, and from 23% to 37% in extension (P<0.05). Vertebroplasty partially reversed these changes without inducing any increase in elastic deformation of the adjacent vertebrae. Conclusion. Vertebral fracture increases stress concentrations acting on the vertebral bodies and neural arches of adjacent (non-fractured) vertebrae, and these increases can be partially reversed by vertebroplasty

Aims

In order to evaluate the effectiveness of the Mobi-C implant in cervical disc degeneration, a randomised study was conducted, comparing the Mobi-C prosthesis arthroplasty with anterior cervical disc fusion (ACDF) in patients with single level cervical spondylosis.

Discogenic low back pain is a common cause of disability, but its pathogenesis is poorly understood. We collected 19 specimens of lumbar intervertebral discs from 17 patients with discogenic low back pain during posterior lumbar interbody fusion, 12 from physiologically ageing discs and ten from normal control discs. We investigated the histological features and assessed the immunoreactive activity of neurofilament (NF200) and neuropeptides such as substance P (SP) and vasoactive-intestinal peptide (VIP) in the nerve fibres.

The distinct histological characteristic of the painful disc was the formation of a zone of vascularised granulation tissue from the nucleus pulposus to the outer part of the annulus fibrosus along the edges of the fissures. SP-, NF- and VIP-immunoreactive nerve fibres in the painful discs were more extensive than in the control discs. Growth of nerves deep into the annulus fibrosus and nucleus pulposus was observed mainly along the zone of granulation tissue in the painful discs. This suggests that the zone of granulation tissue with extensive innervation along the tears in the posterior part of the painful disc may be responsible for causing the pain of discography and of discogenic low back pain.