Supination-external rotation (SER) injuries make up 80% of all ankle fractures. SER stage 2 injuries (AITFL and Weber B) are considered stable. SER stage 3 injury includes disruption of the posterior malleolus (or PITFL). In SER stage 4 there is either medial malleolus fracture or deltoid injury too. SER 4 injuries have been considered unstable, requiring surgery. The deltoid ligament is a key component of ankle stability, but clinical tests to assess deltoid injury have low specificity. This study specifically investigates the role of the components of the deep deltoid ligament in SER ankle fractures. To investigate the effect of deep deltoid ligament injury on SER ankle fracture stability.Background
Aim
Osteoporosis is a disease when bone mass and tissue is lost, with a consequent increase in bone fragility and increase susceptibility to develop fracture. The osteoporosis prevalence increases markedly with age, from 2% at 50 years to more than 25% at 80 years1 in women. The vast majority of distal radius fractures (DRFs) can be considered fragility fractures. The DRF is usually the first medical presentation of these fractures. With an aging population, all fracture clinics should have embedded screening for bone health and falls risk. DRF is the commonest type of fracture in perimenopausal women and is associated with an increased risk of later non-wrist fracture of up to one in five in the subsequent decade2. According to the national guidelines in managing the fragility fractures of distal radius with regards the bone health review, we, as orthopedic surgeons, are responsible to detect the risky patients, refer them to the responsible team to perform the required investigations and offer the treatment. We reviewed our local database (E-trauma) all cases of fracture distal radius retrospectively during the period from 01/08/2019 to 29/09/2019. We included total of 45 patients who have been managed conservatively and followed up in fracture clinic. Our inclusion criteria was: women aged 65 years and over, men aged 75 years and over with risk factors, patients who are more than 50 years old and sustained low energy trauma whatever the sex is or any patient who has major risk factor (current or frequent recent use of oral or systemic glucocorticoids, untreated premature menopause or previous fragility fracture). We found that 96% of patients were 50 years old or more and 84% of the patients were females. 71% of patients were not referred to Osteoporosis clinic and 11% were already under the orthogeriatric care and 18% only were referred. Out of the 8 referred patients, 3 were referred on 1st appointment, 1 on the 3rd appointment, 1 on discharge from fracture clinic to GP again and 3 were without clear documentation of the time of referral. We concluded that we as trust are not compliant to the national guidelines with regards the osteoporosis review for the DRF as one of the first common presentations of fragility fractures. We also found that the reason for that is that there is no definitive clear pathway for the referral in our local guidelines. We recommended that the Osteoporosis clinic referral form needs to be available in the fracture clinic in an accessible place and needs to be filled by the doctor reviewing the patient in the fracture clinic in the 1st appointment. A liaison nurse also needs to ensure these forms have been filled and sent to the orthogeriatric team. Alternatively, we added a portal on our online database (e-trauma), therefore the patient who fulfils the criteria for bone health review should be referred to the orthogeriatric team to review.
Congenital talipes equinovarus (CTEV), also known as club foot or talipes is a common congenital disorder. Parents are using the Internet more and more as a source of information about health care. Unfortunately, the quality of health care information on the Internet varies. This study looked at information available to parents using two instruments for judging the equality of information on the internet. The top five search engines were searched on Google. Three of these were also included in the top 50 sites in Ireland so these 3 sites were used. The phrases CTEV and club foot were searched from all 3 platforms. Websites were then scrutinized using the HON code and the DISCERN tool. 54 organic sites were found for the 3 search engines using the key word club foot. For the key word CTEV 55 matches were returned for the three search engines. 4 websites displayed the HON code. Using the discern tool CTEV websites had a mean score of 60 with a standard deviation of 17. While club foot had a mean score of 56.8 with a standard deviation of 13. Max score 80. Large volumes of information are available to parents on the Internet. Often parents find comfort in sharing experiences and feel empowered by learning about their children's illnesses. However, information provided on the interned can also be ambiguous and disingenuous. Practitioners should be aware of a number of key websites that parents can be directed towards.
Innominate Osteotomy first described by Salter is one of the commonest procedures performed for treatment of Developmental Dysplasia of the Hip (DDH) in children. We recently described a less invasive technique for Innominate Osteotomy, which significantly reduces the operation time without compromising outcome (J Pediatr Orthop B. 2010 Jul;19(4):318–22). As part of the evolution of this procedure we now routinely use bioabsorbable pins (INION OTPS PIN, made from co-polymers of L-lactic acid, D-lactic acid and trimethylene carbonate) instead of K-wires to secure the graft. We prospectively followed-up 120 consecutive cases done using bioabsorbale pins over a 2 year period. The surgical technique was as described in our less invasive innominate osteotomy paper. Average age at surgery was 24 months (18–52) with mean follow-up period of 15 months (6–24 months). The mean preoperative acetabular index was 36.2o. Our results show a mean acetabular index of 18.7o (P< 0.0001) at latest follow-up with no loss of correction. We recorded three superficial wound infections (one MRSA), all resolved uneventfully. There was no foreign body reaction. The use of bioabsorbable pins eliminates the need for a second anaesthetic to remove the pins with significant cost benefit without compromising outcome.
Trauma is the leading cause of death and disability in children. Pelvic fractures although rare, with a reported incidence of one per 100,000 children per year are 2nd only to skull fractures with respect to morbidity. The objectives of this study were to improve understanding of paediatric pelvic fractures through a concise review of all aspects of these fractures and associated injuries. Understanding the patterns in which paediatric pelvic fractures and their associated injuries occur and the outcome of treatment is vital to the establishment of effective preventative, diagnostic and therapeutic interventions. All children admitted to our unit with a pelvic fracture over the 14-year period from January 1995 to December 2008 were identified. The complete medical records and radiographs of all patients were obtained and reviewed. Data recorded included, age, sex, mechanism of injury, Glasgow Coma Score, Injury Severity Score, fracture type, radiological investigation, length of in-patient stay, length of intensive care unit stay, blood transfusion requirement, associated injuries, management (both orthopaedic and non-orthopaedic), length of follow-up, and outcomeIntroduction
Patients and Methods
Athletes significantly alter their lumbar spinal motion when performing squat lifting at heavy weights. This altered motion effects a change in pressure in the posterior annulus of lumbar discs.
48 athletes performed 6 lifts at 40% maximum, 4 lifts at 60% maximum and 2 lifts at 80% maximum. Zebris 3-D motion analysis system used to measure lumbar spine motion. Exercise then repeated with weight lifting support belt. 4 cadaveric sheep spinal motion segments fixed to tension/compression loading frame, allowing compression replicating the forces seen in in vivo study. Pressure measurement achieved using a Flexiforce single element force sensor strip, positioned at posterior annulus. Posterior annulus pressure measured during axial compression and on compression with specimen fixed at 3° of extension.Hypothesis
Methods
Determine the minimum inhibitory concentration (MIC) of Povidone-iodine. Investigate the effect of Povidone-iodine on icaADBC operon encoded staphylococcal biofilm formation. Investigate wether any observed changes on biofilm by Povidone-iodine is mediated through a change in icaADBC operon.
A step-wise reduction of biofilm was observed at increasing sub-inhibitory doses of povidone-iodine (p<
0.0001). IcaA expression correlated with biofilm formation in staphylococcal organisms. Decrease in icaA expression was strongly associated with an increase in expression in the biofilm repressor gene, icaR. The repressive effect of povidone-iodine on biofilm formation by Staphylococcal bacteria is by a separate mechanism from its bacteriostatic mechanism of action.
Current intervention strategy is focussed on prevention of initial device colonisation and inhibition of genes encoding biofilm formation.
Determine the minimum inhibitory concentration (MIC) of betadine. Investigate the effect of betadine on icaADBC operon encoded staphylococcal biofilm formation. Investigate wether betadine can prevent bacterial adherence and biofilm formation by inhibition of the encoding genes.
Total RNA for cDNA synthesis was isolated from bacterial at different twofold dilutions of betadine concentrations. Real time polymerase chain reaction was used to quantify effects of betadine on gene expression pattern of the icaADBC operon using the constitutively expressed gyrB gene as internal control. Bacterial was cultivated on polystyrene plates coated with different sub-inhibitory and clinical in-use doses of betadine to assess surface adherence.
A step-wise reduction of biofilm was observed at increasing sub-inhibitory doses of betadine (p<
0.0001). IcaA expression correlated with biofilm formation in staphylococcal organisms. Decrease in icaA expression was strongly associated with an increase in expression in the biofilm repressor gene, icaR. The repressive effect of betadine on biofilm formation by Staphylococcal bacteria is by a separate mechanism from its bacteriostatic mechanism of action.
Prevention of bacterial surface attachment as demonstrated by this study is suggestive that these compounds could be developed as a surface coating agents for orthopaedic implants.
3-D motion analysis of lumbar spinal motion in athletes, during squat weight lifting. Pressure measurement of the posterior annulus following the motion analysis study.
4 cadaveric sheep spinal motion segments mounted in purpose built jig, replicating angulation seen in the in vivo motion study. These samples were then fixed to a tension/compression loading frame, replicating the forces seen in the in vivo study. Pressure measurement was achieved using a Flexiforce single element force sensor strip, positioned at the posterior annulus. Posterior annulus pressure was measured during axial compression and on compression with the specimen fixed at 3° of extension.
Significant decrease (p<
0.05) in flexion in all groups when lifting at 40% max was compared with lifting at 60% and 80% of max. Flexion from calibrated zero point ranged from 24.7° (40% group), to 6.8° (80% group). A progressively significant increase (p<
0.05) seen in extension in groups studied when lifting at 40% max was compared with lifting at 60% and 80% max lift. Extension from a calibrated zero point ranged from − 1.5° (40% group), to − 20.3° (80% group). No statistically significant difference found between motion seen when performing the exercise as a ‘free’ squat or when lifting using a support belt in any group studied. Initial uniform rise in measured pressure readings to a pressure of 350–400N, in the axially loaded and extension loaded specimens. Pressure experienced by the axially loaded group then gradually dropped below the pressure exerted by the loading frame, while the pressure experienced in the posterior annulus of the extension loaded specimens progressively increased. Comparing axially loaded specimens with specimens loaded in extension, there was an average increase in pressure of 36.4% in the posterior annulus, when the spine was loaded in 3° of extension at a pressure equivalent to the 80% lift in the in vivo motion study, in comparison to axial loading.
The cervical spine exhibits the greatest range of motion amongst the spinal segments due to its tri-planar components of movement. As a result, measurement of movements has proved difficult. A variety of methods have been used in an attempt to measure these movements but none have provided satisfactory triplanar data. This paper uses the Zebris ultrasonic 3-D motion analysis system to measure flexion, extension, range of lateral bending and range of axial rotation in five similar male and five similar female subjects with no history of neck injuries. The subjects were tested unrestrained and in soft and hard collars, as well as in Philadelphia, Miami J and Minerva orthoses. Results show that the Minerva is the most stable construct for restriction of movement in all planes in both groups (p<
0.001 vs. all groups (p=0.01 vs. Philadelphia in female extension), ANOVA). In the male group, the standard hard collar provides the second best resistance to flexion, lateral bending and axial rotation. The female group showed no one orthosis in second place overall. Looking at these results allows ranking of the measured orthoses in order of their three-dimensional stability. Furthermore, they validate the Zebris as a reliable and safe method of measurement of the complex movements of the cervical spine with low intersubject variability. In conclusion, this paper, for the first time presents reproducible data incorporating the composite triplanar movements of the cervical spine thus allowing comparative analysis of the three-dimensional construct stability of the studied orthoses. In addition, these results validate the use of the Zebris system for measurement of cervical spine motion.
The purpose of this study was to review the early results of a consecutive series of patients undergoing periac-etabular osteotomy (PAO) at Cappagh National Orthopaedic Hospital. The procedure was first carried out in 1998, and a total of 85 PAOs have been performed in 79 patients. The mean follow-up was 42 months (range 6-84 months). There were 72 females and 7 males with a mean age at the time of the operation of 22.9 years (range, 14-41 years). The preoperative diagnosis was developmental hip dysplasia in 80 hips, Legg-Calve-Perthes disease in one hip, congenital coxa vara in three hips, and slipped capital femoral epiphysis in one hip. The average Merle d’Aubigne score increased from 12.4 points preoperatively to 16 points at latest followup. The lateral center edge angle of Wiberg was between – 20 and +28 before surgery and was improved from 12 to 48 (average 30 degrees) following PAO. While, the anterior center edge angle of Lequesne and de Seze was between – 22 and +35 preoperatively and was improved by an average of 28 degrees (range, 17 – 40) postoperatively. The acetabular index angle decreased from an average of 24.8 preoperatively to 8.4 postoperatively. Clinical follow-up revealed that 77% of patients had no or mild pain, 33% of patients had a limp and 64% of patients were unlimited in physical activity, representing a markedly improved clinical outcome. Four patients underwent subsequent total hip arthroplasty. The short term results in this group of patients treated with PAO show reliable radiographic correction of deformity and improved clinical scores. The study reflects the learning curve associated with performing this procedure and the results that can be expected with a smaller clinical case-load than described in previous studies. We suggest that PAO may safely be carried out at a non-super-specialized institution provided the surgeons have sufficient experience and patients are selected appropriately.
Many pedicle screw instrumentation systems are currently available to the spine surgeon. Each system has its unique characteristics. It is important for the surgeon to understand the differences in these pedicle screw systems1 Following the introduction of a new spinal instrumentation set to our clinical practice we encountered two cases of pedicle screw breakage. We thus decided to investigate the mechanism of this screw failure (screw A) in these particular cases and to compare the biomechanical properties, through independent analysis, of a variety of pedicle screws from different manufacturers. Samples of the broken pedicle screws were retrieved at surgery. Surface analysis of the fracture area using the electron microscope, demonstrated features consistent with fatigue fracture. Pedicle screws of comparable size from a variety of manufacturers were gathered for independent analysis. Shadowgraph analysis was performed of each screw allowing multiple measurements to be taken of the screw’s geometry. Using this data stress concentration factors were determined demonstrating screw A to have larger values than all the other screws ranging from 2 – 3.6 times the nominal stress. The smaller teeth of screw A, spaced further apart than in the other screws, means that the large proportion of the load which would be carried by the threads is distributed over a smaller area resulting in higher stresses in the threads. The sharp corner at the root of the thread, acting as a stress concentrator, would become the focal point of these high stresses, and magnify them by 2 to 3.6 times. These increased stresses most likely account for an increased susceptibility to fatigue fracture seen in screw A. In conclusion it is important to be careful with the introduction and use of new pedicle screw materials and designs, that all the standard biomechanical testing has been performed to a satisfactory standard. Knowing the physical characteristics of the available pedicle screw instrumentation systems may allow the choice of pedicle screw best suited for a given clinical situation.
Slipped upper femoral epiphysis (SUFE) is a condition, which affects the immature hip joint. Many theories have been postulated as to its underlying aetiology however; its exact cause is, as yet unknown. The final common pathway appears to be failure of the of the growth plate to resist shearing forces, giving rise to displacement of the femoral head. We hypothesized that the lubricating ability of the synovial fluid in hip joints of children with SUFE was defective, thereby allowing increasing shear forces on the physis to occur, so that when the joint is loaded it will fail at its weakest point, namely the capital epiphysis.
Nine patients had additional acetabular bone grafting with autologous femoral head, two patients had subtrochanteric osteotomy, and another patient had an adductor tenotomy performed at the time of their surgery. Follow-up ranged from 6 to 44 (mean 19.6) months.
The mean age of diagnosis was 14.6 months (range 4–72). Many of the late referrals had risk factors for DDH.
Recent work has identified environmental stimuli which induce biofilm formation in Staphylococci. These include stressors such as high temperature, high osmolarity, anaerobiosis, nutrient depletion, salt, ethanol and subinhibitory concentrations of certain antimicrobial drugs. Given the ability of these bacteria to survive the “respiratory burst” from the cells of the mononuclear-macrophage system, we hypothesised that oxidative stress may be one such promoter of biofilm formation by Staphylococci.
Bacteria were incubated for 24 hours at 37°C in Brain-Heart Infusion (BHI, Oxoid) containing progressively weaker concentrations of H2O2 to determine a Minimal Inhibitory Concentration (M.I.C.) for the representative strains. Bacterial viability was assessed by measuring the optical density of the incubated culture using a cell density meter (Ultraspec 10, Amersham Biosciences). The bacteria were then grown as a biofilm on a 96 well microtitre plate (Nunc) in the presence of subinhibitory concentrations of H2O2, using pure BHI as a control. Semiquantative determination of biofilm formation was performed by washing the plates, staining the adherent cells with crystal violet, and measuring the light absorbance of the adherent stained cells at 492 nm using a Multiskan plate reader (Flow Laboratories).
There was no difference in biofilm formation by
The aim of this study is to evaluate the effectiveness of the application of vibration, during the femoral cementation, as a cementing technique. It has been demonstrated that when vibration of a constant frequency was utilised, flow of low viscosity cement increased with vibration of increasing amplitude up to a particular acceleration. Above this acceleration there was little additional benefit. It has also been shown that when constant amplitude was used the flow increase was uniform over a wide frequency range, eventually falling off over a particular frequency. These results prove that the flow of orthopaedic bone cement is significantly affected by mechanical vibration of the receiving structure. It is our hypothesis that vibration promotes the ingress of bone cement into cancellous bone. The effect of mechanical vibration in the frequency range 0–500 Hz on the cadaveric human femur has been assessed in the past. It was found that when the bone was fixed at both ends, its resonant frequency was markedly affected by end loading and damping. If the conditions of the experiment were designed to simulate the condition of the femur when prepared for a total hip replacement, it was found that the bone did not resonate but behaved in a mass-like mode. The significance of this observation is that in the event of vibration being applied to enhance the penetration of orthopaedic bone cement, the movement induced in the bone will be proportional to the force applied regardless of frequency.
First described in 1910, Legg Calve Perthes disease is considered to be a complication of osteonecrosis of the femoral head-affecting children between the ages of 2 and 12. Treatment has centred on containment, surgical and non-surgical in the hope that keeping the femoral head covered by acetabulum that it will remodel and maintain congruency with the acetabulum. We know from previous studies that deformities of the femoral head increase the risk of development of arthritis in later life and that the shape of the femoral head is the only alterable parameter in the development of this early onset arthritis. During the natural history of the disease, once the central part of the femoral head collapses the integrity of the femoral head is reliant on the support of the lateral and medial columns. These columns then collapse altering the shape of the femoral head. We induced LCPD in the femoral heads of twenty skeletally immature rabbits and buttressed the central column of the femoral head in twelve. These treated rabbits had cement, bone graft or bone paste inserted through a drill hole that extended into the centre of the femoral head. The rabbits were then recovered and x-rayed at six weeks. All the rabbits had evidence of varying degrees of head collapse radiologically. Once the rabbits reach skeletal maturity in March, they will be euthanised and their femoral heads examined histologically and radiologically to determine the effects of central column enhancement by each of the three substances.
Management of symptomatic residual acetabular dysplasia in adolescence and early adulthood remains a major therapeutic challenge. At our unit the two senior authors review all patients preoperatively and simultaneously perform each procedure. In the four years from 1998 forty-three Bernese osteotomies were performed in 40 patients with residual acetabular dysplasia. The mean average age at surgery was 21 years (range 12 – 43 years) and there were 34 female patients. The indication for surgery was symptomatic hip dysplasia (all idiopathic but for one male with a history of slipped capital femoral epiphysis) presenting with pain and restricted ambulation. 4 patients had previous surgery on the affected hip (2 Salter’s osteotomy, one Shelf procedure and one proximal femoral osteotomy). 27.5% of patients had symptomatic bilateral disease. 42% of patients had Severin class IV or V dysplasia at presentation. 100% of patients had preservation of the hip joint at last follow-up evaluation (mean 2.4 years), with excellent results in 82%, an average post-operative Harris hip score of 96, and an average d’Aubigne hip score of 16.1. The mean post-operative improvements in radiographic measures were as follows: Anterior centre edge angle +19.4°, Lateral centre angle +25.8°, Acetabular Index – 10.7°. Head to Ischial distance – 7.3mm. Surgical operative time decreased from 128 minutes to 43 minutes from the first to the most recent case. Average blood loss has reduced from 1850mls to 420mls over the four years experience. Predonation of 2 units of blood requested from all patients with baseline hemoglobin of >
12g/dl. When combined with intraopera-tive cell salvage the need for transfusion of homologous blood has been eliminated. All complications occurred in the first 9 patients: (one major – iliac vein injury requiring no further treatment; four moderate – lateral cutaneous nerve injuries; four minor – asymptomatic heterotopic ossification). Our experience confirms that the Ganz periacetabular osteotomy is an efficacious procedure for the treatment of the residually dysplastic hip, providing excellent clinical results, where early intervention is the key to improved outcome. It is a technically demanding procedure with a significant early learning curve and we believe that a two
In contrast, the coronal femoral osteotomies had a worse healing response. The alignment of the fracture line perpendicular to the plane of motion of the joint exposes the repair tissue within it to increased shear and tensile stresses. This may play a negative role in the repair of these coronal defects when compared to sagittal osteotomies, which are relatively protected from the high transarticular pressures and showed a greater tendency to remodel their articular surface.
A marked reduction in osteomyelitis was noted over the twenty-four year incidence of the study. In addition, a shift in the causative organism was noted from an incidence of H Influenzae in the 70’s of up to 30%, to less than 5% in the 90’s. The treatment regime changed markedly over the course of the study period, with a significantly reduced duration of hospital stay reflecting the move away from protracted periods of hospitalisation.
Management of symptomatic residual acetabular dysplasia in adolescence and early adulthood remains a major therapeutic challenge. At our unit the two senior authors review all patients preoperatively and simultaneously perform each procedure. In the four years from 1998 forty-three Bernese osteotomies were performed in 40 patients with residual acetabular dysplasia. The mean average age at surgery was 21 years (range 12 – 43 years) and there were 34 female patients. The indication for surgery was symptomatic hip dysplasia (all idiopathic but for one male with a history of slipped capital femoral epiphysis) presenting with pain and restricted ambulation. 4 patients had previous surgery on the affected hip (2 Salter’s osteotomy, one Shelf procedure and one proximal femoral osteotomy). 27.5% of patients had symptomatic bilateral disease. 42% of patients had Severin class IV or V dysplasia at presentation. 100% of patients had preservation of the hip joint at last follow-up evaluation (mean 2.4 years), with excellent results in 82%, an average post-operative Harris hip score of 96, and an average d’Aubigne hip score of 16.1. The mean post-operative improvements in radiographic measures were as follows: Anterior centre edge angle +19.4°, Lateral centre angle +25.8°, Acetabular Index – 10.7°. Head to Ischial distance – 7.3mm. Surgical operative time decreased from 128 minutes to 43 minutes from the first to the most recent case. Average blood loss has reduced from 1850mls to 420mls over the four years experience. Predonation of 2 units of blood requested from all patients with baseline hemoglobin of >
12g/dl. When combined with intraoperative cell salvage the need for transfusion of homologous blood has been eliminated. All complications occurred in the first 9 patients: (one major – iliac vein injury requiring no further treatment; four moderate – lateral cutaneous nerve injuries; four minor – asymptomatic heterotopic ossification). Our experience confirms that the Ganz peri-acetabular osteotomy is an efficacious procedure for the treatment of the residually dysplastic hip, providing excellent clinical results, where early intervention is the key to improved outcome. It is a technically demanding procedure with a significant early learning curve and we believe that a two-surgeon approach is invaluable to the management of these difficult cases.
Introduction: Subject to recent literature citing a reduction in ankle range of motion predisposing to ankle fractures in children, we decided prospectively to analyse the passive range of motion in children presenting to our fracture clinic with simple distal radial metaphyseal fractures treated conservatively in cast. The range of motion was assessed by two observers, and measured using a goniometer in 80 patients. (42 radial fractures and 38 controls) The controls were recruited from children presenting with lower limb injuries and with no prior history of an upper limb injury or neuromuscular condition. The fractures were as a result of simple falls onto the outstretched hand with definite radiological and clinical findings. The range of motion in the contralateral limb was assessed. Both groups showed an equal distribution of dominant and non-dominant limbs. Results: Both groups were well matched with an average age of 10 and 10.3 years fracture group and control group respectively, and gender 55% male fracture group and 52.5% control group. The m injured group showed a passive range of motion of 1680, whereas the control group showed a higher range of motion of 1820, a difference of 140 (p<
. 005 student t-test). A third blinded independent observer of 20 children assessed Intra and interobserver error, and no observer was noted to have higher or lower readings. Conclusion: Children with radial fractures have a lower passive range of motion of their wrists than Controls. This may contribute to the aetiology of wrist fractures in a paediatric population. An possible explanation may be as cited in original work that children who sustain fractures have less mobility around their joints due to reduced elasticity in their musculoskeletal framework. Simple passive stretching of fracture prone joints should therefore be advised.
Background: Developmental dysplasia of the hip (DDH) is a common paediatric orthopaedic problem. Open reduction and debridement of the hip joint in neonates is necessary to ensure a congruent reduction in some patients. Despite advances in the treatment of DDH, the various surgical approaches are not without limitations and risks. The development of hip arthroscopy is a new science, which we believe could be applied to the treatment of DDH. Aims: To date there have been no reports in the literature of the use of hip arthroscopy in either the neonatal hip or in infantile hips with DDH. The purpose of this study was: (a) to design a suitable animal model of DDH for the purpose of designing and evaluating hip arthroscopy, (b) to document the pathoanatomy of the dysplastic hip arthroscopically and (c) to define the methodology of performing hip arthroscopy in neonates with DDH. Method: A novel model of producing hip dysplasia in large white cross piglets has been created. 4-week-old piglets undergo surgical fixation of the knee by retrograde passage of a 3.5mm diameter steinmann pin. After free ambulation, progressive hip dysplasia is produced. We have monitored the development of hip dysplasia at 4 and 6 weeks post fixation by plain radiographs, MRI and Hip Arthroscopy using a 2.7mm diameter arthro-scope. Results: We have successfully produced hip dysplasia in an animal model of comparable size and anatomy to that seen in infants. Hip arthroscopy was performed in 20 animals. Documentation of a lax capsule, elongated ligamentum teres and pulvinar has been made. In addition arthroscopic debridement of the joint has been performed. We believe that arthroscopic debridement of the impediments to reduction in DDH is possible using the techniques learned from this model.
Introduction: Elucidation of the exact cause of adolescent idiopathic scoliosis (AIS) remains an elusive goal. The intervertebral disc is one of the many areas that have been investigated in an effort to find a cause for this condition. We hypothesize that a qualitative change in the orientation of collagen fibers in the annular layers of the disc could cause the deformity seen in AIS. This paper presents a mathematical model of such a change and how it could produce appropriate deforming forces. Hypothesis: In the normal disc the collagen fibers are obliquely orientated. Fibers in adjacent lamellae are orientated in opposing directions. This means that as forces are transmitted from a compressed nucleus to the annular fibers there is no net force tending to rotate one vertebra with respect to its neighbour. If there is a preponderance of fibers running in one direction as the nucleus is compressed there will be a net resultant force perpendicular to the long axis of the spine tending to produce an intervertebral rotation. This intervertebral rotation, applied to successive spinal segments will cause a scoliotic deformity. Model: The highly oriented structure of the AF suggests the utility of an explicit representation of the collagen fibres and their mechanical contribution to disc function. In our study we have considered two groups of fibres, representing the clockwise and counter clockwise fibres in the disc. The AF is considered as a continuum containing two populations of fibres assumes to be of equal density and uniform distribution within an isotropic material as originally described by Spencer. Nuclear compression as a result of growth was modelled as a tendency to produce increased intervertebral separation of spinal segments and examined whether the resultant transformation that leads to a scoliotic pattern of deformity. Based on anatomical data from literature the positions of the 12 nodes that represent the thoracic vertebrae are applied to the model. The three-dimensional location of each vertebral body is defined. We store the coordinates of thoracic vertebrae in a three-dimensional matrix. In the present study in order to involve the translation operation in our transformation, we have used the homogeneous transformation matrix or Denavit &
Hartenberg matrix. In the present model for the initial set of transformations the reference axis is chosen to be the lowest vertebral axis (T-12) and remains unchanged throughout the transformation. All elements of the spine above the reference axis are transformed (translated and rotated). After completion of this iteration and storing the values for the origin coordinate and vector values in the next level of the matrix, the next reference axis is chosen. For the second axis everything above the axis will be transformed in the same way with the current axis and the one preceding it remaining unchanged. Therefore for each transformation a new reference axis is taken and the transformations are applied to all vectors and origins above it leaving all elements preceding it unchanged by the transformation. Results: The first part of the model shows that rotational displacement increases linearly with changes in the fibre ratio. Rotational displacement on the other hand occurs independently of distraction of the vertebral bodies. When the rotational displacement is applied to a series of segments it produces alterations of curvature in the three planes. Specifically it produces a lateral curvature in the coronal plane and a hypokyphotic curvature in the saggital plane. The magnitude of these displacements varies with the imbalance in fibre ratio. Discussion: The proposed changes in annular fiber orientation have been modeled using accepted mathematical methods. These changes will produce an intervertebral rotation whose magnitude depends on the degree of fiber imbalance akin to that seen in AIS. When the displacements produced by this rotation being applied to a series of segments is modeled, it will produce a three dimensional deformity similar to that seen in AIS. Ongoing histological studies are being performed to see if the proposed imbalance can be identified in patients with AIS. Such a fiber orientation anomaly may be genetically determined by some fashion of directional sense gene and may be the aetiological basis for AIS.
Recently there has been considerable interest in the role of inflammatory mediator production by herniated degenerate discs. Modic has described MR endplate changes which have an inflammatory appearance and have been linked with discogenic back pain. To date there has been no biomechanical investigation of discs with associated Modic changes. The aim of this study is to determine if degenerate discs with associated Modic changes have higher levels of pro-inflammatory mediator production than those without Modic changes. Intervertebral disc tissue was obtained from 52 patients undergoing spinal surgery for sciatica [40] and discogram proven discogenic low back pain [12]. The tissue was cultured and the medium analysed for interleukin-6, interleukin-8 and prostaglandin E2 using an enzyme linked immunoabsorbetn assay method. Preoperative MR images of the patients were examined by a double blinded radiologist to determine the Modic status of the cultured disc level. Forty percent of patients undergoing surgery for discogenic low back pain had a Modic 1 change compared to only 12.5% of patients undergoing surgery for sciatica [p<
.05] There was a statistically significant difference between levels of IL-6, IL-8 and PGE2 production by both the Modic1 [M1] and Modic2 [M2] groups compared to the Modic negative [NEG] group. IL-6:NEGvM1 p<
.001, NEG v M2 p<
.05, IL-8: NEG v M1 p<
.01, NEG v M2 p>
.05, PGE2: NEG v M1 p<
01, NEG v M2 p<
.05. Modic changes have been associated with positive provocative discography by a number of authors. Pain generation requires the presence of nerves and hyperalgsia inducing mediators. Both IL-8 and PGE2 are known to induce hyperalgesia. The fact that Modic changes are associated with high levels of production of these mediators supports their role as an objective marker of discogenic low back pain.
Cement is still in common usage in primary and revision arthroplasty surgery. Infection rates in cemented arthroplasties ranges from 1–4% and poses a huge problem for the revision arthroplasty surgeon. Infection in septic implants is biofilm based and almost completely resistant to conventional anti-microbial therapy. Recent papers have questioned the efficacy of using gentamicin-loaded cement in arthroplasty as staphylococcus aureus biofilms will develop on same. The focus of this study was to investigate the efficacy of antibiotic loaded cement in preventing initial bacterial adhesion and subsequent development of a bacterial biofilm in vitro. Three cements Simplex unloaded, Simplex with erythromycin and Simplex with tobramycin were mixed in a conventional manner, ie vacuum hand mixing in sterile conditions and then injected into pre-moulded PTFE coated cylinder moulds yielding 8 cylinders in each group. The cement cylinders were then removed and exposed to a known pathogenic strain of staphylococcus aureus ATCC—29213-NCTC 12973 in solution 3x106 Colony forming units CFH/ml) for 15 minutes. The cylinders were then removed and cultured for 24 hours at 37°C in RPMI with Glutamine. Cylinders were then removed and subjected to rinsing in PBS to remove any non-adherent bacteria. Cylinders were then sonicated at 50 Hz in Ringer’s solution and adherent biofilms were serially log diluted and plated on Columbia blood agar. Colonies were counted manually. Control cylinders of unloaded cement showed 120,000 CFU/cm2 of adherent bacteria whereas loaded cement erythromycin and tobramycin showed 500 and 80 CFU/cm2 respectively (p<
.0005 Student t-test). This study shows that loaded cement does not prevent biofilm adhesion in its initial reversible stages whereas unloaded cement does not. This is important since most infected implants are infected at time of primary operation and cements anti-bacterial role beyond the first 48 hours remains questionable, when inflammatory encapsulation of the implant begins. We would therefore question the usage of unloaded cement in primary arthroplasty surgery.
Metallic implants are used frequently in the operative repair of joints and fractures in orthopaedic surgery. Orthopaedic implant infection is chronic and biofilm based. Present treatment focuses on removing the infective substratum and implant surgically as well as prolonged anti-microbial therapy. Biofilms are up to 500 times more resistant than planktonic strains of bacterial flora to antibiotics. Silver coatings on polymers and nylon (catheters, heart valve cuffs, burn dressings) have shown inhibition of this biofilm formation in its adhesion stage. Our aim was to deposit effective, minute, antibacterial layers of silver on orthopaedic stainless steel and titanium K-wires and to investigate the effect of these coatings when exposed to Staphylococcus Aureus biofilms in an in vitro and in vivo environment. Combining magnetron sputtering with a neutral atom beam (Saddle Field) plasma source at 10−4 mbar in argon gas at temperatures of 60°C, a silver coating of 99.9% purity was deposited onto stainless steel and titanium orthopaedic K-wires. Coating thickness measurements were obtained using glancing angle x-ray diffraction of glass slides coated adjacent to wires. Magnetron parameters were modified to produce varying thickness of silver. Adhesiveness was examined using Rockwell punch tests. Silver leaching experiments were carried out in phosphate buffered saline at 37°C for 48 hours and using inductive coupled plasma spectrometry to assess leached silver ions. Surface microscopy visualised physical changes in the coatings. Biofilm adhesion was determined by exposing wires to Staphylococcus Aureus ATCC 29213 – NCTC 12973 for 15 minutes to allow biofilm initiation and adhesion. Wires were then culturing for 24 hours at 37°C in RPMI. Subsequently, wires were sonicated at 50Hz in ringer’s solution and gently vortexed to dislodge biofilm. Sonicate was plated out by log dilution method on Columbia blood agar plates. Bacterial colonies were then counted and changes expressed in log factors. K-wires were coated with 1 to 50 nm of silver by running the magnetron sputtering at low currents. These coatings showed excellent adhesive properties within the 48 hours exposed with only 3.7% of silver leaching in buffered saline. The silver coated stainless steel wires showed a log 2.31 fold reduction in biofilm formation as compared to control wires (p<
.001), Student t-test), the silver coated titanium wires showed a log reduction of 2.06, (p<
.001, Student t-test). Animal studies demonstrated enormous difficulty in reproducing biofilm formation and showed a 0.49 log fold reduction in the titanium group when exposed to Staph Aureus (p<
.01, Student t-test), the other groups showed no statistically significant reduction. We have perfected a method of depositing tiny layers of anti-bacterial silver onto stainless steel and titanium, which is anti-infective in vitro but not in vivo. Further studies involving other metal coatings such as platinum and copper are warranted.
While gentamycin, erythromycin, cefotaxime and vanomycin have a proven record as effective thermostatic antibiotics, newer antibiotics teicoplanin (although used in clinical practice) are as yet untested.
Heat alone did not affect the growth of the bacteria. None of the antibiotic impregnated cement batches had any effect on an established growth of Staph Aureus indicating the effect of antibiotic impregnated cement may be bacteriostatic rather than bacteriocidal. Teicoplanin is thermosable and is effective in the short term at least at halting the growth of Staph Aureus. Addition of antibiotics to cement may change the biomechanical properties of the cement. It was noted that it took on average twice as long for the teicoplanin-impregnated cement to harden. Further investigations into this are ongoing.
The role of nucleus pulposus (NP) biology in the genesis of sciatica is being increasingly investigated. The aim of this study was to examine the ability of control and degenerate human nucleus pulposus to respond to an exogenous pro-inflammatory stimulus. Control disc material was obtained from surgical procedures for scoliosis and degenerate disc tissue from surgical procedures for sciatica and low back pain. Disc specimens were cultured using a serumless technique under basal and lipopolysaccharride (LPS) stimulated conditions and the media harvested, aliquoted and stored at –80°C for subsequent analysis. Levels of IL-1β,TNFα, LTB4, GM-CSF, IL-6, IL-8, MCP-1, PGE2, bFGF and TGFβ-1 in the media were estimated using commercially available enzyme linked immunoabsorbent assay kits. Neither basal nor LPS stimulated control or degenerate NP produced detectable levels of IL-1β, TNFα, LTB4 or GM-CSF. Control disc IL-8 secretion increased significantly with LPS stimulation, p<
.018. Degenerate disc IL-6, IL-8 and PGE2 production increased significantly with LPS stimulation, p<
.01, p<
.001 and p<
.005 respectively. LPS stimulated degenerate NP secreted significantly more IL-6, IL-8 and PGE2 than LPS stimulated control NP, p <
0.05, 0.02 and 0.003 respectively. LPS induces an increase in both control and degenerate NP mediator production demonstrating the ability of human NP to react to a noxious stimulus by producing pro-inflammatory mediators. The difference in levels of basal and LPS stimulated mediator production between control and degenerate discs show that as a disc degenerates it increases both its level of inflammatory mediator production and its ability to react to a pro-inflammatory stimulus. The increased sensitivity of degenerating human NP to noxious stimuli and increased ability to respond with inflammatory mediator production support the role of NP as an active participant in the genesis of lumbar radiculopathy and discogenic back pain.
The K wires were added to either the culture media alone or the culture media containing platinum and incubated at 37 degrees for 24 hours. The wires were then removed from the media and rinsed in PBS. Samples were subjected to sonication, to fragment biofilms thereby releasing the bacteria, which were then quantified by serial log dilution technique and manual counting. The presence of platinum reduced the adhesion of both Staph Aureus and Staph Epidermidis to stainless steel. This reduction was statistically significant using paired t-test (SPSS version 6.0). There was a significant reduction of adhesion with platinum in the Staph Aureus and titanium group while the reduction in the Staph Epidermidis and titanium group did not reach statistical significance.
Metallic implants are used frequently in the operative repair of joints and fractures in orthopaedic surgery. Metal infection is a catastrophic complication of the surgery with patients loosing their newfound mobility and independence, associated morbidity and mortality is high. Orthopaedic implant infection is chronic and biofilm based. Present treatment focuses on removing the infective substratum and implant surgically as well as prolonged anti-microbial therapy. Biofilms are 500 times more resistant than planktonic strains of bacterial flora to antibiotics, and with evolving resistant strains this form of therapy is loosing ground. Silver coatings on polymers and nylon (catheters, heart valve cuffs, burn dressings) have shown inhibition of this biofilm formation in its adhesion stage. Our aim was to deposit effective, minute, biocompatible, anti-bacterial layers of silver on orthopaedic stainless steel K-wires. Combining magnetron sputtering with a neutral atom beam (Saddle Field) plasma source at 10−4 mbar in argon gas at temperatures of 60°C, a silver coating of 99.9% purity was deposited onto stainless steel orthopaedic K-wires. Coating thickness measurements were obtained using glancing angle x-ray diffraction of glass slides coated adjacent to wires. Magnetron parameters were modified to produce varying thickness of silver. Adhesiveness was examined using Rockwell punch tests and tape tests. Silver leaching experiments were carried out in phosphate buffered saline at 37°C for 48hrs and using inductive coupled plasma spectrometry to assess leached silver ions. Surface microscopy visualised physical changes in the coatings. Biofilm adhesion was determined by exposing wires to K-wires were coated with 5 to 50 nm of silver by running the magnetron sputtering at low currents. These coatings showed excellent adhesive properties within the 48hr exposed with only 5% of silver leaching in buffered saline. The silver coated wires showed a log 3–4 fold reduction in biofilm formation as compared to control wires. The coatings showed no cytotoxic effects. Silver coating of medical implants has been shown in urological catheters to reduce biofilm infection. We have perfected a method of depositing thin layers of anti-bacterial silver onto stainless steel, which is both anti-infective and biocompatible. This coating could potentially add to the armourary of anti-infective agents in the elimination of infection related orthopaedic implant failure.
Dupuytren’s contracture is characterised by abnormal fibroblast proliferation and extracellular matrix deposition in the palmar fascia. Fibroblast proliferation and matrix deposition in connective tissues are regulated by cytokines. A number of cytokines including transforming growth factor beta (TGFβ), basic fibroblast growth factor (bFGF), platelet derived growth factor (PDGF) and epidermal growth factor (EGF) are known to have potent anabolic effects on connective tissue. The aim of this study was to investigate the role played by anabolic cytokines in the pathogenesis of Dupuytren’s disease. Twelve specimens of Dupuytren’s contracture and six control specimens of palmar fascia obtained from patients undergoing carpal tunnel release were cultured using a serumless method under standard conditions for 72 h. Levels of TGFβ-1, bFGF, PDGF and EGF in the medium were estimated using an enzyme linked immunoabsorbent assay technique. Neither Dupuytren’s tissue nor control palmar fascia produced any EGF. The mean (±S.D.)levels of bFGF, PDGF and TGFβ-1 produced by cultured palmar fascia were: 1270 ± 832, 74 ± 24, <
7, and for Dupuytren’s tissue were 722 ± 237, 139 ± 76.6, 645 ± 332, respectively. The levels of PDGF and TGFβ-1 were significantly higher in Dupuytren’s tissue. PDGF is produced in increased amounts by Dupuytren’s tissue. This may contribute to the fibroblast proliferation and increased ECM deposition observed in this condition. TGFβ-1 is not produced by normal palmar fascia but is produced in large amounts by Dupuytren’s tissue. The major physiologic role of TGFβ-1 is to stimulate formation of fibrous tissue. It plays a major role in wound healing and also in pathological conditions where fibrosis is a prominent feature. Inappropriate production of TGFβ-1 in the palmar fascia in Dupuytren’s disease may play a central role in initiating and stimulating the abnormal fibroblast proliferation and collagen synthesis seen in this condition.
The pathophysiology of discogenic low back pain is poorly understood. The morphological changes occurring in disc degeneration are well documented but unhelpful in determining if a particular degenerate disc will be painful or not. Herniated intervertebral disc tisssue has been shown to produce a number of pro-inflammatory mediators and cytokines. No similar studies have to date been done utilising disc material from patients with discogenic low back pain. The aim of this study was to compare levels of production of interleukin-6 (IL-6), interleukin-8 (IL-8) and Prostaglandin E2 (PGE2) in disc tissue from patients undergoing discectomy for sciatica with that from patients undergoing fusion for discogenic low back pain. Tissue from 50 patients undergoing discectomy for sciatica and 20 patients undergoing fusion for discogenic low back pain was cultured and the medium harvested for subsequent analysis using an enzyme linked immunoabsorbent assay method. Statistical analysis of the results was performed using the Mann-Whitney test. Disc specimens from both experimental groups produced measurable levels of all three mediators. Mean production of IL-6, IL-8 and PGE2 in the sciatica group was 26.2±75.7, 247±573 and 2255±3974 respectively. Mean production of IL-6, IL-8 and PGE2 in the low back pain group was 92±154, 776±987 and 3221±3350 respectively (data = mean production pg/ml ± 1 standard deviation). There was a statistically significant difference between the levels of IL-6 and IL-8 production in the sciatica and low back pain groups (p<
0.006 and p<
0.003 respectively). The high levels of pro-inflammatory mediator production found in disc tissue from patients undergoing fusion for discogenic LBP may indicate that nucleus pulposis pro-inflammatory mediator production is a major factor in the genesis of a painful lumbar disc. This could explain why some degenerate discs cause LBP while other morphologically similar discs do not.
Infection around implanted biomaterials in humans is a major healthcare issue and current ability to effectively prevent and treat such infections using antibiotics is limited. The hypothesis of the study was that surface charge could be manipulated to a positive state and thus moderate bacterial adhesion to the implant. The surface charge was manipulated by creating a galvanic cell using a zinc strip in a standard suction drain. Adhesion of In this experiment we have shown that alteration of the electrochemical environment around an implant influences bacterial adhesion. While our technique is not therapeutically viable, further manipulation of surface charge of an implant is possible using other electroactive materials. This may be explored in the prophylactic treatment of implant infection
Cervical orthoses are currently used in the pre-hospital stabilization of trauma patients and also as part of the definitive non-operative treatment of injuries of the cervical spine. The construct stability of orthoses is compromised by virtue of the fact that the cervical spine exhibits the greatest range of movement amongst the spinal segments and also because of the complex composite nature of neck movements. To date, data has been difficult to attain comparing the various orthoses, in the various planes of movement of the cervical spine. Various methods including the use of inclinometers, goniometers, radiography, computerized tomography and cineroentgenography have been used in an attempt to measure these movements but none have provided satisfactory triplanar data. This paper uses the Zebris ultrasonic 3-D motion analysis system to measure flexion, extension, range of lateral bending and range of axial rotation in five similar male and five similar female subjects with no history of neck injuries. The subjects were tested in a soft and hard collar, Philadelphia, Miami J and Minerva. Results show that the Minerva is significantly the most stable construct for restriction of movement in all planes in both groups (p<
0.002 vs. all groups, Student’s t-test), but more impressively in the female group. In the male group, the standard hard collar performs second best in flexion, lateral bending and axial rotation. In the female group, the second most stable orthosis is the Philadelphia in flexion/extension and the hard collar in lateral bending and axial rotation (p<
0.05 vs. next most stable in all cases, Student’s t-test). The soft collar in both groups offered only minimal resistance to movement in any plane, Looking at these results together allows the ranking of the measured orthoses in order of the three-dimensional stability they offer. Furthermore, they validate the Zebris as a reliable and safe method of measurement of the complex movements of the cervical spine with low intersubject variability. In conclusion, this paper, for the first time presents reproducible data incorporating the composite triplanar movements of the cervical spine thus allowing comparative analysis of the three-dimensional construct stability of the studied orthoses.
Herniated intervertebral disc tissue has been shown to produce a number of proinflammatory mediators and cytokines, but there have been no similar studies using discs from patients with discogenic low back pain. We have compared the levels of production of interleukin-6 (IL-6), interleukin-8 (IL-8) and prostaglandin E2 (PGE2) in disc tissue from patients undergoing discectomy for sciatica (63) with that from patients undergoing fusion for discogenic low back pain (20) using an enzyme-linked immunoabsorbent assay. There was a statistically significant difference between levels of production of IL-6 and IL-8 in the sciatica and low back pain groups (p <
0.006 and p <
0.003, respectively). The high levels of proinflammatory mediator found in disc tissue from patients undergoing fusion suggest that production of proinflammatory mediators within the nucleus pulposus may be a major factor in the genesis of a painful lumbar disc.