Background. Some studies report greater repositioning error in LBP patients compared to healthy subjects with other studies showing no differences. This conflicting evidence may be due to different methodologies. A new tool, the Flexchair¯Back Balance Trainer measures consistency of lumbo-pelvic movement during visual tracking tasks which challenge the lumbo-pelvic region. This study aimed to establish the within day (WD) and between day (BD) reliability of a lumbo-pelvic tracking task using the Flexchair in healthy subjects,. Method. 22 subjects gave informed consent (10 females, 12 males (age 38.40(±9.29) Height 171.35cms (±8.07) weight 76.21kg (±18.55) Subjects completed six different tracking tasks on the Flexchair, 3 times in the first day with 2 hour of intervals between each test and once on a second and third visit with 2 days in between. Tests 1-6 are of increasing difficulty. Results. Test1 WD ICC.200, SEM ±3.65, BD ICC .565, SEM± 1.06. Test 2WD ICC .471, SEM ±4.24, BD ICC.475, SEM ±5.46. Test 3 WD ICC .366, SEM± 5.20, BD ICC .405, SEM± 5.46. Test 4 WD ICC .522 SEM ±3.06, BD ICC.483, SEM± 4.49. Test 5 WD ICC .567, SEM± 4.66, BD ICC .718, SEM± 4.47. Test 6 WD ICC .630 SEM ± 3.47, BD ICC .474 SEM± 5.60. Discussion. A substantial degree of variation exists in healthy subjects when performing a lumbo-pelvic tracking task, with poor to moderate reliability for all tasks apart from between day scores for Task 5. Further studies should be conducted on patients with LBP

Background. Stem cell therapy has been suggested as a potential regenerative strategy to treat IVD degeneration and GDF6 has been shown to differentiate adipose-derived stem cells (ASCs) into an NP-like phenotype. However, for clinical translation, a delivery system is required to ensure controlled and sustained GDF6 release. This study aimed to investigate the encapsulation of GDF6 inside novel microparticles (MPs) to control delivery and assess the effect of the released GDF6 on NP-like differentiation of human ASCs. Methods. GDF6 release from PLGA-PEG-PLGA MPs over 14 days was determined using BCA and ELISA. The effect of MP loading density on collagen gel formation was assessed through SEM and histological staining. ASCs were cultured in collagen hydrogels for 14 days with GDF6 delivered exogenously or via microspheres. ASC differentiation was assessed by qPCR for NP markers, glycosaminoglycan production (DMMB) and immunohistochemistry. Results. GDF6 release from MPs was controlled over 14 days equivalently to exogenous addition. SEM and histology confirmed that MPs were distributed throughout gels and that gel formation was not disrupted. In 3D cultures, GDF6 release from microspheres elicited equivalent ASC differentiation and NP-like matrix formation compared to exogenous delivery in media, indicating activity was not affected by MP encapsulation. Conclusions. This study demonstrates the effective encapsulation and controlled delivery of GDF6, which was able to maintain its activity and induce ASC differentiation into an NP-like phenotype and production of an NP-like ECM. Delivery of GDF6 microspheres in combination with ASCs is a promising strategy for IVD regeneration and treatment of back pain. Conflicts of interest. No conflicts of interest. Sources of funding. We would like to acknowledge UKRMP Acellular Hub, MRC, NIHR Musculoskeletal BRU and The Rosetrees Trust for funding this research

Introduction. Injectable hydrogels via minimally invasive surgery reduce the risk of infection, scar formation and the cost of treatment. Degradation of the intervertebral disc (IVD) currently has no preventative treatment. An injectable hydrogel material could restore disc height, reinforce local mechanical properties, and promote tissue regeneration. We present a hydrogel material Laponite. ®. associated poly(N-isopropylacrylamide)-co-poly(dimethylacrylamide) (NPGel). Understanding how the components of this hydrogel system influence material properties, is crucial for tailoring treatment strategies for the IVD and other tissues. Methods & Results. The effect of hydrogel wt./wt., clay and co-monomer percentages were assessed using a box-Behnken design. Rheometry, SEM, FTIR and swelling was used to measure changes in material properties in simulated physiological conditions. Rheometry revealed gelation temperature of hydrogel materials could be modified with dimethyl-acrylamide co-monomer; however, final maximum mechanical properties remained unaffected. Increasing the weight % and clay % increased resultant mechanical properties from ∼500–2500 G' (Pa), increased viscosity, but retained the ability to flow through a 26G needle at 39°C. Discussion & Conclusions. By increasing the weight and clay percentage of the material we can attain greater mechanical properties, this could be beneficial for orthopaedic or even dental applications. By modifying the co-monomer percentage, we can control gelation temperature important for ensuring the material is fully set at 37°C, this could also be utilised to locally deliver drugs from the implanted material. Our current work is focused on comparing our NPGel material formulation with human IVD tissue. Acknowledgements. We would like to thank Arthritis Research UK grant number 21497 for supporting this research. No conflicts of interest. Sources of Funding: Funded by Arthritis Research UK grant number 21497

Background. Auxetic materials have a negative poisons ratio, and a number of native biological tissues are proposed to possess auxetic properties. One such tissue is annulus fibrosus (AF), the fibrous outer layers of the intervertebral disc (IVD). However, few studies to date have investigated the potential of these materials as tissue engineering scaffolds. Here we describe the potential of manually converted polyurethane (PU) foams as three dimensional cellular scaffolds for AF repair. Methods. Rat MSCs were seeded onto fibronectin coated auxetic foams at a cell density of 6.4 × 10. 3. cells/mm. 3. , and cultured for up to 3 weeks. Cell viability was assessed throughout culture and following culture scanning electron microscopy (SEM) was used to assess morphological characteristics. Histological assessment was performed to assess production of matrix proteins. Results. Cells adhered to the surface auxetic foams and remained viable for the 3 weeks investigated. Histology and SEM demonstrated cells within the full thickness of the auxetic foams, where extracellular matrix was starting to be produced following 3 weeks, including collagens suggesting differentiation of the MSCs. Conclusion. Auxetic PU foams have a significant potential for use in tissue engineering applications, potentially mimicking the multiaxial strains of annulus fibrous tissue. MSCs were shown to adhere, survive and produce matrix within the foams after 3 weeks, future work will focus on longer term studies and in depth analysis of the phenotype of the cells. No conflicts of interest. Funding provided by a grant from Sheffield Children's Hospital NHS trust

Aim:. The aim of this study was test the amount of corrosion occurring at the (Ti) /cobalt chrome (CoCr) interface comparing this with Ti and Ti interfaces. This was compared with retrieved metal work visualised under a scanning electron microscope (SEM). Methods:. The interface of interest is the interface between rod and the screw. We investigated corrosion seen at that interface with a CoCr rod coupled to a Ti screw versus a Ti rod coupled to a Ti screw (6 screws were used) Implants were loaded according to the ASTM F2193 – 02 Standard Specifications and Test Methods for Components Used in the Surgical Fixation of the Spinal Skeletal System. Pitting potentials were monitored using cyclic potentiodynamic polarization tests (ASTM F2129 – 08 Standard Test Method for Conducting Cyclic Potentiodynamic Polarisation Measurements) to determine corrosion susceptibility. Retrieved implants were visualised under (SEM) to confirm corrosion. Results:. Mean fretting current for titanium and cobalt chrome was 7.94 (μA) and for titanium on titanium 5.89 (μA). The results of SEM showed evidence of fretting and galvanic corrosion. Discussion:. Cobalt chrome ions in hip implants have raised concern amongst the orthopaedic community. This study showed that metal ion production occurs due to fretting and galvanic corrosion. This corrosion is increased in cobalt chrome and titanium constructs but statistically more tests are required to confirm this. Further research is required to understand this interface as cobalt chrome ions pose a potential hazard to patients with their reproductive years ahead. Conflict Of Interest Statement: No conflict of interest

Introduction. Lumbar spinal pain can be a consequence of discogenic pain. After failure of conservative management, lumbar fusions are popular and considered the gold standard. However, these techniques are associated with significant morbidity. A percutaneous trans-sacral technique may address these for L4/L5 and/or L5/S1 alone spinal fusions. Our unit has adopted this technique and presents our initial experience of 51 patients and preliminary results. Method. Patients with a confirmed clinical and radiological evidence of degenerate intervertebral disc with or without prior surgical intervention were selected. Patients with a history of pelvic surgery/radiotherapy were excluded. Data was collected prospectively using the Global Patient Outcome Scoring System and Oswestry Disability Index (ODI) scores at clinical follow-up. Results. 51 patients received the procedure and 30 achieving a minimum of 6 months follow-up. Patients had a median age of 46(range 20-78) and included 19 male and 32 females with on average 40 months of pain. The mean ODI score improved after surgery from pre-operative levels 52.9(SEM 3.0) to 6 month scores of 38.4(SEM 3.9), t(29)=4.2, p<0.0002 . This difference remained statistically significant at 12 month follow-up with a mean ODI scores 34.3 (SEM 5.2), t(18)=4.37, P<0.0004 (Mean difference of 21.1 SEM 4.8). A sub-analysis of confounding factors identified patients with previous surgery, claiming state benefits, pursuing litigation, mainly leg pain and requiring pedicular fusion failed to achieve statistical significance. Patients receiving a 360 degree fusion with facet screws alone improved sooner and achieving a mean difference in ODI score of 27.6(SEM 8.2). Conclusion. Our initial results confirm this to be an effective alternative treatment modality for lumbar spine fusion in the management of primary discogenic back pain. Patients receiving 360 degree fusion and not claiming state benefits or pursuing litigation appear to have a better outcome

Aims

The aim of this study was to determine whether the sequential application of povidone iodine-alcohol (PVI) followed by chlorhexidine gluconate-alcohol (CHG) would reduce surgical wound contamination to a greater extent than PVI applied twice in patients undergoing spinal surgery.

Objectives

In order to elucidate the influence of sympathetic nerves on lumbar radiculopathy, we investigated whether sympathectomy attenuated pain behaviour and altered the electrical properties of the dorsal root ganglion (DRG) neurons in a rat model of lumbar root constriction.

We investigated the pre-operative and one-year post-operative health-related quality of life (HRQOL) outcome by using a Euroqol (EQ-5D) questionnaire in 263 patients who had undergone surgery for herniation of a lumbar disc. Data from the National Swedish Register for lumbar spinal surgery between 2001 and 2002 were used and, in addition, a comparison between our cohort and a Swedish EQ-5D population survey was performed. We analysed the pre- and post-operative quality of life data, age, gender, smoking habits, pain and walking capacity.

The mean age of the patients was 42 years (20 to 66); 155 (59%) were men and 69 (26%) smoked. Pre-operatively, 72 (17%) could walk at least 1 km compared with 200 (76%) postoperatively.

The mean EQ-5D score improved from 0.29 to 0.70, and the HRQOL improved in 195 (74%) of the patients. The pre-operative score did not influence the post-operative score. In most patients, all five EQ-5D dimensions improved, but did not reach the level reported by an age- and gender-matched population sample (mean difference 0.17). Predictors for poor outcome were smoking, a short pre-operative walking distance, and a long history of back pain.

The belief that an intervertebral disc must degenerate before it can herniate has clinical and medicolegal significance, but lacks scientific validity. We hypothesised that tissue changes in herniated discs differ from those in discs that degenerate without herniation. Tissues were obtained at surgery from 21 herniated discs and 11 non-herniated discs of similar degeneration as assessed by the Pfirrmann grade. Thin sections were graded histologically, and certain features were quantified using immunofluorescence combined with confocal microscopy and image analysis. Herniated and degenerated tissues were compared separately for each tissue type: nucleus, inner annulus and outer annulus.

Herniated tissues showed significantly greater proteoglycan loss (outer annulus), neovascularisation (annulus), innervation (annulus), cellularity/inflammation (annulus) and expression of matrix-degrading enzymes (inner annulus) than degenerated discs. No significant differences were seen in the nucleus tissue from herniated and degenerated discs. Degenerative changes start in the nucleus, so it seems unlikely that advanced degeneration caused herniation in 21 of these 32 discs. On the contrary, specific changes in the annulus can be interpreted as the consequences of herniation, when disruption allows local swelling, proteoglycan loss, and the ingrowth of blood vessels, nerves and inflammatory cells.

In conclusion, it should not be assumed that degenerative changes always precede disc herniation.

Cite this article: Bone Joint J 2013;95-B:1127–33.

We have reviewed 1858 patients who had undergone a cervical laminoplasty and identified 43 (2.3%) who had developed a C5 palsy with a MMT (MRC) grade of 0 to 2 in the deltoid, with or without involvement of the biceps, but with no loss of muscular strength in any other muscles. The clinical features and radiological findings of patients with (group P; 43 patients) and without (group C; 100 patients) C5 palsy were compared. CT scanning of group P revealed a significant narrowing of the intervertebral foramen of C5 (p < 0.005) and a larger superior articular process (p < 0.05). On MRI, the posterior shift of the spinal cord at C4–5 was significantly greater in group P, than in group C (p < 0.01).

This study is the first to correlate impairment of the C5 nerve root with a C5 palsy. It may be that early foraminotomy in susceptible individuals and the avoidance of tethering of the cord by excessive laminoplasty may prevent a post-operative palsy of the C5 nerve root.