Ankle sprains are common athletic injuries, with a peak lifetime incidence between the ages of 15 and 19 years, especially in young males. However, an unclear history, an imprecise physical exam, and unhelpful radiographies lead to frequent misdiagnosis of paediatric ankle traumas, and subsequently, inappropriate treatment. Improper management may lead to residual pain, instability, slower return to physical activity, and long-term degenerative changes. The purpose of this study was to evaluate the initial management and treatment of acute paediatric ankle sprains at our center, a tertiary care paediatric hospital. Our hypothesis was that the initial diagnosis is often incorrect, and treatment varies considerably amongst orthopaedic surgeons. We conducted a retrospective study of all cases of ankle sprains and Salter-Harris one (SH1) fractures referred to our orthopaedic surgery service between May and August 2014. Exclusion criteria included ankle fractures other than SH1 types, and cases where treatment was initially undertaken elsewhere before referral to our service. Patients were evaluated on a clinical and radiographic basis. Primary outcome was the difference between initial and final diagnosis. Secondary outcome was variation in immobilisation duration for each diagnosis. The main variables we considered were age, sex, mechanism of trauma, referral delay, patient symptoms, physical exam findings, radiographic findings, type and duration of immobilisation, prescription of any medication, and referral to physical therapy. A total of 3047 patients were reviewed and 31 cases matched our inclusion criteria, comprised of 17 girls and 14 boys, with a mean age of 10.4 years. Patients were seen at a mean of 10.3 days after injury. Initial diagnosis was SH1 fracture in 20 cases, acute ankle sprain in 8 cases, and uncertain in 3 cases. Final diagnosis was SH1 fracture in 11 cases, acute ankle sprain in 13 cases, uncertain in 5 cases, and other in 3 cases. During follow up, 48.5% of cases saw a change in diagnosis. Forty five percent (9/20) of cases initially diagnosed as SH1 fractures proved to be incorrect, with 55.5% (5/9) of these being ultimately diagnosed as acute ankle sprains. Amongst cases initially diagnosed as acute ankle sprains, 37.5% (3/8) received a different final diagnosis. Duration of immobilisation was significantly different between acute ankle sprain and SH1 fracture groups, with an average of 17.3 days and 26.1 days, respectively. Physical therapy was prescribed to 33.3% of acute ankle sprains and 9.1% of SH1 fractures. Initial distinction between acute ankle sprains and SH1 fractures can be difficult in paediatric ankle trauma. Case management and specific treatments vary considerably, as there is neither an evaluation algorithm nor consensus on treatment of these paediatric pathologies. This study reinforces the need to develop a systematic diagnostic and treatment protocol for paediatric ankle sprains.
Anterior lumbar inter-body fusion (ALIF) is a surgical procedure that is available to chronic lower back pain patients who fail to respond to conservative treatments. Failure to achieve fusion may result in persistence of pain. Fusion of the lumber vertebral segment is more accurately assessed using fine-cut helical Computed tomography (CT) scans (0.25 mm thickness slices). Unfortunately this technique exposes the body to high radiation dose with hazard of increase risk of late malignancy. An alternative imaging tool is radiostereometry (RSA) which developed as a means to determine the magnitude of relative motion between two rigid bodies. In this study we used RSA to detect movement at the fused lumbar segment (ALIF site) during flexion and extension and compare the results obtained with fine-cut helical CT scan using histopathology as final gold standard assessment tool. ALIF of three levels of lumbar spine (L1-L2, L3-L4, and L5-L6) was done in 9 sheep. The sheep divided into three groups (3sheep each). The first group had RSA assessment immediately, 3, and 6 months after surgery. The second group had RSA immediately, 3, 6, 9 months after surgery. The third group had an RSA immediately, 3, 6, 9, 12 months after surgery All the animals were humanly killed immediately after having the last scheduled RSA (group1, group2, and group 3 sheep were killed 6 month, 9month and 12 months after surgery respectively). This followed by in vitro fine cut CT and histopathology after the animals are scarified. Micro CT scan has been also used to identify the area where histopathology slide should be made to pick up fusion. Fine cut CT scan assessment for all sheep were done. The CT scan has been reported by two independent radiologists. Histopathology has been started and will finish in 2 weeks RSA showed there was significant increasing stiffness of the spine though the fused segments as the time pass on compare to immediate postoperative assessment. CT scan were done and showed variable fusion though out the spinal segments. Histopathology of all sheep has been started and the results will be available in 2 weeks which will be followed by statistical assessment to decide how accurate RSA compare to CT scan in assessment of fusion.
the mid-sagittal plane of 10 male and 10 female discs aged 13–79 years; 7 parasagittal slices through a single disc; discs showing various types of tears.
Most chondrocytes were unicellular but bicellular and multicellular chondrons were common in the margins of large tears and the nucleus in degenerate discs. Cellularity was highest in the right posterior quadrant, lowest in the left anterior quadrant, about equal in the left posterior and right anterior quadrants, and substantially higher in the right half of the nucleus. The correlation of increasing age with declining cell density was much stronger for the nucleus than for the annulus. Nucleus cellularity continued to decline throughout life whereas the annulus ceased its decline after the age of 50. Cell density was low in the vicinity of tears but elsewhere the disc was unaffected. Extensive inferior and superior end-plate separations reduced cellularity throughout the disc. Increased thickness of the cartilage end-plate was associated with higher cellularity in the nucleus.
For an antibiotic to be effective against the infecting organism it must diffuse through the disc matrix. Blood vessels that surround the disc facilitate the diffusion process, but with age this vascularity decreases and may impede diffusion. The aims of the pilot study were to assess the effectiveness of antibiotic in treating infection in both normal and degenerate sheep discs and to measure the concentration of antibiotic in non-operated discs at varying ages.
INTRODUCTION: The development of laboratory techniques in the last ten years has enabled the successful harvest, in vitro selection, culture and transplant of chondrocytes. The study proposes that transplantation of autologous chondrocytes prevents degeneration of the intervertebral disc following outer annular injury in an ovine model. METHODS: Eight sheep were anaesthetised and five contiguous lumbar discs were exposed via a left-sided posterolateral approach. Four of the animals were given full thickness annular incisions in three alternate discs. No annular incisions were made in the other four sheep. Costal cartilage was harvested from the left twelfth rib of all animals. Tissue was cultured and the chondrocytes were labelled in vitro with CFSE for verification following transplantation. Six weeks later autologous cultured chondrocytes were injected into the lower two alternate discs of all animals, leaving the uppermost discs and those untouched in between as internal controls. Animals were sacrificed after three, six, twelve and twenty-four weeks. Results were based on X-rays, histological, and immunocytochemical assessments. RESULTS: Preliminary histological results up to three months showed viability of cultured chondrocytes and matrix production post transplantation. Serial X-rays suggested that progressive disc degeneration was arrested in the treated discs. DISCUSSION: In this pilot study we have shown that cultured autologous chondrocytes can remain viable long term in vivo. These preliminary results suggest that these transplanted chondrocytes have the ability to retard and possibly prevent disc degeneration following annular incision. Previous similar studies have reported the use of chondrocytes cultured from disc, whilst this study showed that chondrocytes from a source foreign to the disc can exert positive effects. The encouraging result from this pilot study needs to be further validated to realise its potential as a treatment for degenerative disc disease.
INTRODUCTION: Intradiscal electrothermal therapy (IDET) is being used increasingly as a minimally-invasive treatment for chronic discogenic low back pain, with success reported in up to 70% of cases. The mechanism of action however is poorly understood. Proposed mechanisms include the contraction of collagen and the coagulation of annular nociceptors. An ovine model was used to assess the innervation of peripheral posterolateral annular lesions and the potential for IDET to denervate this region. METHODS: Posterolateral annular incisions were made in 36 lumbar discs of 18 sheep. After twelve weeks the sheep underwent IDET at one level and a sham treatment at the other level. IDET was performed using a modified intradiscal catheter (SpineCATHTM, Oratec Interventions Inc., Menlo Park, CA). Temperatures were recorded in the nucleus and the posterior annulus. The spines were harvested at intervals of up to eighteen months. Histological sections of the discs were stained with haematoxylin and eosin and an antibody to the general neuronal marker PGP 9.5. RESULTS: The target temperature of 90°C at the catheter tip was reached in all cases. The mean maximum TPa was 63.6°C and the mean maximum TN was 67.8°C. Vascular granulation tissue consistent with a healing response was observed in the region of the posterior annulus tear of all incised discs from 12 weeks. PGP 9.5 positive nerve fibres were clearly identified in the adjacent periannular tissue, but were scarce within the outer few lamellae of the annulus. There were no fewer nerve fibres identified in those specimens that had undergone IDET. From six weeks after IDET there was evidence of thermal necrosis in the inner annulus, sparing the periphery of the disc. DISCUSSION: IDET delivered at 90°C in the sheep consistently heats the posterior annulus and the nucleus to a temperature associated with coagulation of nociceptors and collagen contraction. Thermal necrosis was observed within the inner annulus from six weeks after IDET. In this model IDET did not appear to produce denervation of the posterior annular lesion.
INTRODUCTION: Although it is well recognised that the outer annulus is innervated, the relative densities of innervation of different regions of the disc have not been quantitated. We present here the first comparative analysis of the innervation of the innervation of different regions of the lumbar intervertebral disc. METHODS: A sheep model was used allowing evaluation of the whole motion segment. Four sheep spines were used. One was processed for PGP 9.5 immunofluorescence and three were processed for PGP 9.5 immunoperoxidase histochemistry. Serial sagittal sections were obtained and a count was made of the densities of innervation of different regions of the endplate and annulus. These were compared to identify which areas of the disc and endplate are most innervated. RESULTS: The endplate innervation is concentrated centrally adjoining the nucleus. The mean density of innervation of the central endplate was 0.44 (SEM 0.07) nerves/mm2 while the mean density of the peripheral endplate was 0.10 (SEM 0.03) nerves/ mm2 (p= 0.0001). There was no significant difference between the overall endplate and annulus innervation densities 0.52 (SEM 0.1) v 0.37 (SEM 0.07) p=0.2. But the peri-annular connective tissue, external to the outer annulus contained the densest innervation of any region in the motion segment 1.05 (SEM 0.16). DISCUSSION: The lumbar intervertebral disc has a meagre innervation. This is concentrated in the peri-annular connective tissue and the central endplate. While receptor threshold is more closely related to noci-ceptive function than innervation density, these findings have important implications for any treatment of discogenic pain.
INTRODUCTION: Infection can occur after any spinal procedure that involves entry into the disc and although it is not common, the potential consequences are serious. Treatment usually requires identification of the bacteria followed by a course of antibiotics. This treatment remains controversial since it is not clear whether antibiotics actually penetrate the disc and if so, whether they are effective, or even if the outcome would be the same without antibiotics. For an antibiotic to be effective against the infecting organism it must diffuse through the disc matrix. Blood vessels that surround the disc facilitate the diffusion process, but with age this vascularity decreases and may impede diffusion. The aims of the pilot study were to assess the effectiveness of antibiotic in treating infection in both normal and degenerate sheep discs and to measure the concentration of antibiotic in non-operated discs at varying ages. METHODS: In each of six Merino wethers aged 12 weeks (n=3) and 24 months (n=3), two lumbar discs were “degenerated” by incising the posterolateral annulus with a scalpel blade. After four weeks all animals had discography with radiographic contrast that contained Staphylococcus aureus at the incised levels and at two non-incised levels. Seven days after infection four animals began IV antibiotic treatment with cephazolin sodium (David Bull Laboratories, Australia) for 21 days at a dose of 50 mg/kg/day. The antibiotic was chosen for effectiveness against S. aureus. One control animal from each age group did not receive any antibiotics, to follow the natural progression of infection. Lateral radiographs of the lumbar spine were taken at two, six and 12 weeks. At 12 weeks all sheep were given a single intravenous dose of cephazolin sodium as either a 1, 2 or 3 g dose. The sheep were then killed after 30 minutes. The spines were removed and prepared for light microscopy to assess pathology of the discs and for biochemical analysis of antibiotic concentration. Success of treatment was judged using histologic and radiographic features. RESULTS: Discitis was evident radiologically as early as two weeks after inoculation in all animals. Histology at 12 weeks confirmed discitis in all discs regardless of treatment. Biochemistry results confirmed that antibiotic diffused throughout the disc but was more concentrated in the annulus than the nucleus. At all doses disc concentration of antibiotic was higher in lambs than sheep. DISCUSSION: Treatment with cephazolin sodium at a dose of 50 mg/kg/day for 21 days administered from seven days after inoculation, did not prevent discitis. This does not appear to be due to inability of antibiotic diffusion into the disc.
To assess the potential for IDET to ablate nerve fibres in an experimentally induced peripheral annular lesion. Intradiscal electrothermal therapy (IDET) is being increasingly used as a minimally-invasive treatment for discogenic low back pain, with success reported in up to 70% of cases. One proposed mechanism of IDET is ablation reported in up to 70% of cases. One proposed mechanism of IDET is ablation of nerve fibres in the peripheral annulus. An ovine model was used to assess the innervation of peripheral annular lesions and the potential for IDET to denervate this region of the disc. Postero-lateral annular incisions were made in 32 lumbar discs of 16 sheep. At twelve weeks the sheep underwent IDET at one level and a sham treatment at the other level. IDET was performed using a modified Intradiscal Catheter (SpineCath, Oratec Interventions Inc., Menlo Park, CA). The spines were harvested at intervals up to six months. Histological sections of the discs were stained with H&
E and an antibody to the general neuronal marker PGP 9.5. Vascular granulation tissue consistent with a healing posterior annular tear was observed in all incised discs from 12 weeks, extending to an average depth of 850 μm at 0 weeks to 690 μm at 6 months. PGP 9.5 positive nerve fibres were clearly identified outside the discs but were scarce within the discs. Nerves were identified up to 300 μm inside the annulus, from the earliest time point, and there was a trend towards less innervation with time. There were no fewer nerve fibres identified in those specimens that had undergone IDET. Specimens obtained six weeks after IDET showed evidence of thermal necrosis in the inner annulus, sparing the periphery of the disc. The reported benefit from IDET appears to be related to factors other than denervation. Thermal necrosis within the annulus six weeks after IDET.
Are peak posterior annular and nuclear temperatures obtained during IDET within the temperature range normally associated with nociceptor destruction and contraction of collagen? Pain relief following intradiscal electrothermal therapy (IDET) has been reported to result from coagulation of annular nociceptors and contraction of collagen. This requires temperatures respectfully of 45°C and 60°C. A cadaveric study using an intradiscal catheter (Spinecath, Oratec Interventions Inc., CA) reported sufficient temperatures for these events to occur. However a human study reported temperatures sufficient only to coagulate nociceptors. This study reports peak posterior annular and nuclear temperatures attained in-vivo with an intradiscal catheter in sheep. Twenty sheep were anaesthetised and the lumbar spine exposed. In two non-adjacent discs a stab incision was made in the left postero-lateral annulus and the wound closed. Twelve weeks later the animals returned for a second operation. The spine was approached from the right. Under fluoroscopic control the intradiscal catheter was placed into a previously operated disc. One thermocouple sensor needle was placed 2mm posterior to the catheter to record the posterior annular temperature and a second was inserted 2mm anterior to record the nuclear temperature. The process was repeated for a non-operated control disc. Electrothermal energy was delivered according to the recommended heating protocol. The target temperature of 90°C at the catheter tip was reached in all cases. Data were tabulated with the mean and standard deviation calculated for each site. There was no significant difference between temperatures reached in the ‘degenerate’ discs and those in the control discs. The mean maximum posterior annular temperature was 63.6°C (range 46.8 to 77.7) and the mean maximum nuclear temperature was 67.8°C (Range 51.1 to 81.2). Intradiscal electrothermal therapy delivered at 90°C in the sheep consistently heats the posterior annulus and the nucleus to a temperature associated both with coagulation of nociceptors and collagen contraction. These findings may contribute to understanding the mechanism of pain relief following IDET.
Primary disc space infections are thought to occur in children because of the abundant vascularity of the disc prior to skeletal maturity, and while they generally resolve with treatment, little is known about the long-term consequences on the spine. An ovine model of discitis was used to investigate the effects of discitis on spinal development in the growing sheep. Six-week-old lambs underwent lumbar discography at multiple spinal levels using either radiographic contrast inoculated with Staphylococcus epidermidis (inoculated group) or radiographic contrast only (control group). Plain x-rays of the spines were taken at intervals up to 18 months before the animals were killed and the spines removed for histologic and morphometric analysis. Discs from animals in the control group were radiologically and histologically normal at all time points, and as expected there was a steady increase in vertebral body and disc dimensions. Although not all inoculated animals showed histologic evidence of discitis, disc abnormalities were evident from an early stage. In particular disc height was significantly reduced from 2 weeks after inoculation and vertebral body dimensions were significantly reduced from one year. Infection of discs at a young age, whether or not it progresses to discitis, has a significant effect on spinal development.
We studied 135 lumbar discs from 27 spines removed post-mortem from subjects of an average age of 31.5 years. Defects of the annulus fibrosus were classified as peripheral, circumferential or radiating; the nucleus pulposus as normal, moderately or severely degenerate. Peripheral tears were more frequent in the anterior annulus, except in the L5-S1 disc. Circumferential tears were equally distributed between the anterior and the posterior annulus. Almost all the radiating tears were in the posterior annulus, and closely related to the presence of severe nuclear degeneration. Histology suggested that peripheral tears were due to trauma rather than biochemical degradation, and that they developed independently of nuclear degeneration. The association of peripheral annular lesions with low back pain is uncertain but our study suggests that they may have a role in the pathogenesis of discogenic pain.