Cerebral Palsy (CP) is a group of disorders that affect movement and posture caused by injury to the developing brain. While prematurity and low birth weight are common causes in developed countries, birth asphyxia, kernicterus, and infections have been identified as predominant aetiologies in Africa. There is, however, very little information on the aetiology of CP in South Africa. The purpose of this study was to determine the aetiology, severity, and topographical distribution of CP in children undergoing orthopaedic surgery at our tertiary paediatric unit. A retrospective folder review was performed for patients with CP that underwent orthopaedic surgery from July 2018 to June 2022. Data was collected on perinatal circumstances, aetiology or risk factors for developing CP, severity of disability as classified by the Gross Motor Function Classification Scale (GMFCS) and topographical distribution. Descriptive analysis was performed. Two-hundred-and-thirty-four patients were included in the analysis. No specific aetiology could be identified in 51 (21.9%) patients. Hypoxic ischaemic encephalopathy (HIE) accounted for 23.6% of patients and was the most common aetiology across the different categories except for patients graded as GMFCS 2, in whom prematurity was the most common aetiology. Congenital brain malformations (10.5%) and cerebral infections, including HIV encephalopathy (11.4%) were the next most frequent aetiologies, followed by prematurity (7.6%), ischaemic stroke (6.8%) and intraventricular haemorrhage (6.3%). Fifty-two percent of patients were classified as GMFCS 4 or 5. There was a predominance of quadriplegic patients (37%) compared to hemiplegics (29%), diplegics (30%) and monoplegics (4%). Most patients undergoing orthopaedic surgery for musculoskeletal sequelae of CP were severely disabled quadriplegic patients in whom HIE was the predominant cause of CP. This emphasises the need for intervention at a primary care level to decrease the incidence of this frequently preventable condition

Purpose. Fracture-related infection (FRI) is an important complication related to orthopaedic trauma. Although the scientific interest with respect to the diagnosis and treatment of FRI is increasing, data on the microbiological epidemiology remains limited. Therefore, the primary aim of this study was to evaluate the microbiological epidemiology related to FRI, including the association with clinical symptoms and antimicrobial susceptibility data. The secondary aim was to analyze whether there was a relationship between the time to onset of infection and the microbiological etiology of FRI. Methods. Over a five-year period, FRI patients treated at the University Hospitals of Leuven, Belgium, were retrospectively included. The microbiological etiology and antimicrobial susceptibility data were analyzed. Patients were classified as having an early (<2 weeks after implantation), delayed (2–10 weeks) or late-onset (> 10 weeks) FRI. Results. One hundred ninety-one patients with 194 FRIs, mainly involving the tibia (23.7%) and femur (18.6%), were included. Staphylococcus aureus was the most frequently isolated pathogen, regardless of time to onset (n=61; 31.4%), followed by S. epidermidis (n=50; 25.8%) and non-epidermidis coagulase-negative staphylococci (n=35; 18.0%). Polymicrobial infections (n=49; 25.3%), mainly involving Gram-negative bacilli (n=32; 65.3%), were less common than monomicrobial infections (n=138; 71.1%). Virulent pathogens in monomicrobial FRIs were more likely to cause pus or purulent discharge (n=45;54.9%; p=0.002) and fistulas (n=21;25.6%; p=0.030). Susceptibility to piperacillin/tazobactam for GNB was 75.9%. Vancomycin covered 100% of Gram-positive cocci. Conclusion. The high frequency of polymicrobial infections, including Enterobacterales and enterococci, should be considered when choosing an empirical regimen, especially for early FRI. However, since antibiotic stewardship is the cornerstone of good antibiotic practice, overuse and misuse of broad-spectrum empiric therapy should be avoided at all costs. Large multicenter prospective studies are necessary to gain more insight into the added value of (broad) empirical antibiotic therapy

Aims. Advances in surgical technique and implant design may influence the incidence and mechanism of failure resulting in revision total hip arthroplasty (rTHA). The purpose of the current study was to characterize aetiologies requiring rTHA, and to determine whether temporal changes existed in these aetiologies over a ten-year period. Methods. All rTHAs performed at a single institution from 2009 to 2019 were identified. Demographic information and mode of implant failure was obtained for all patients. Data for rTHA were stratified into two time periods to assess for temporal changes: 2009 to 2013, and 2014 to 2019. Operative reports, radiological imaging, and current procedural terminology (CPT) codes were cross-checked to ensure the accurate classification of revision aetiology for each patient. Results. In all, 2,924 patients with a mean age of 64.6 years (17 to 96) were identified. There were 1,563 (53.5%) female patients, and the majority of patients were Caucasian (n = 2,362, 80.8%). The three most frequent rTHA aetiologies were infection (27.2%), aseptic loosening (25.2%), and wear (15.2%). The frequency of rTHA for adverse local tissue reaction (ALTR) was significantly greater from 2014 to 2019 (4.7% vs 10.0%; p < 0.001), while the frequency of aseptic loosening was significantly greater from 2009 to 2013 (28.6% vs 21.9%; p < 0.001). Conclusion. Periprosthetic joint infection was the most common cause for rTHA in the current cohort of patients. Complications associated with ALTR necessitating rTHA was more frequent between 2014 to 2019, while aseptic loosening necessitating rTHA was significantly more frequent between 2009 to 2013. Optimizing protocols for prevention and management of infection and ALTR after THA may help to avoid additional financial burden to institutions and healthcare systems. Cite this article: Bone Joint Open 2020;2(1):16–21

Flat-top talus (FTT) is a complication well-known to those treating clubfoot. Despite varying anecdotal opinions, its association with different treatments, especially the Ponseti method, remains uncertain. This systematic review aimed to establish the aetiology and prevalence of FTT, as well as detailing management strategies and their efficacy. A systematic review was conducted according to PRISMA guidelines to search for articles using MEDLINE, EMBASE and Web of Science until November 2021. Studies with original data relevant to one of three questions were included: 1) Possible aetiology 2) Prevalence following different treatments 3) Management strategies and their outcomes. 32 original studies were included, with a total of 1473 clubfeet. FTT may be a pre-existing feature of the pathoanatomy of some clubfeet as well as a sequela of treatment. It can be a radiological artefact due to positioning or other residual deformity. The Ponseti method is associated with a higher percentage of radiologically normal tali (57%) than both surgical methods (52%) and non-Ponseti casting (29%). Only one study was identified that reported outcomes after surgical treatment for FTT (anterior distal tibial hemiepiphysiodesis). The cause of FTT remains unclear. It is seen after all treatment methods but the rate is lowest following Ponseti casting. Guided growth may be an effective treatment. Key words:. Clubfoot, Flat-top talus, Ponseti method, guided growth. Disclosures: The authors have no relevant disclosures

Objectives. A successful outcome following treatment of nonunion requires the correct identification of all of the underlying cause(s) and addressing them appropriately. The aim of this study was to assess the distribution and frequency of causative factors in a consecutive cohort of nonunion patients in order to optimise the management strategy for individual patients presenting with nonunion. Methods. Causes of the nonunion were divided into four categories: mechanical; infection; dead bone with a gap; and host. Prospective and retrospective data of 100 consecutive patients who had undergone surgery for long bone fracture nonunion were analysed. Results. A total of 31% of patients had a single attributable cause, 55% had two causes, 14% had three causes and 1% had all four. Of those (31%) with only a single attributable cause, half were due to a mechanical factor and a quarter had dead bone with a gap. Mechanical causation was found in 59% of all patients, dead bone and a gap was present in 47%, host factors in 43% and infection was a causative factor in 38% of patients. In all, three of 58 patients (5%) thought to be aseptic and two of nine (22%) suspected of possible infection were found to be infected. A total of 100% of previously treated patients no longer considered to have ongoing infection, had multiple positive microbiology results. Conclusion. Two thirds of patients had multiple contributing factors for their nonunion and 5% had entirely unexpected infection. This study highlights the importance of identifying all of the aetiological factors and routinely testing tissue for infection in treating nonunion. It raises key points regarding the inadequacy of a purely radiographic nonunion classification system and the variety of different definitions for atrophic nonunion in the current mainstream classifications used for nonunion. Cite this article: L. Mills, J. Tsang, G. Hopper, G. Keenan, A. H. R. W. Simpson. The multifactorial aetiology of fracture nonunion and the importance of searching for latent infection. Bone Joint Res 2016;5:512–519. DOI: 10.1302/2046-3758.510.BJR-2016-0138

Stiffness after TKR is a frustrating complication that has many possible causes. Though the definition of stiffness has changed over the years, most would agree that flexion > 75 degrees and a 15-degree lack of extension constitutes stiffness. This presentation will focus upon the potential causes of a stiff TKR, intra-operative tips, the post-operative evaluation and management, and the results of revision for a stiff TKR. The management of this potentially unsatisfying situation begins pre-operatively with guidance of the patient's expectations; it is well-known that pre-operative stiffness is strongly correlated with post-operative lack of motion. At the time of surgery, osteophytes must be removed and the components properly sised and aligned and rotated. Soft-tissue balancing must be attained in both the flexion/extension and varus/valgus planes. One must avoid overstuffing the tibio-femoral and/or patello-femoral compartments with an inadequate bone resection. Despite these surgical measures and adequate pain control and rehabilitation, certain patients will continue to frustrate our best efforts. These patients likely have a biological predisposition for formation of scar tissue. Other potential causes for the stiff TKR include complex regional pain syndrome or joint infection. Close followup of a patient's progress is crucial for the success in return of ROM. Should motion plateau early in the recovery phase, the patient should be evaluated for manipulation under anesthesia. At our institution, most manipulations are performed within 3 months post-operative under an epidural anesthetic; patients will stay overnight for continuous epidural pain relief and immediate aggressive PT. The results of re-operations for a stiff TKR are variable due to the multiple etiologies. A clear cause of stiffness such as component malposition, malrotation or overstuffing of the joint has a greater chance of regaining motion than arthrofibrosis without a clear cause. Although surgical treatment with open arthrolysis, isolated component or complete revision can be used to improve TKR motion, results have been variable and additional procedures are often necessary

Aims

Avascular femoral head necrosis in the context of gymnastics is a rare but serious complication, appearing similar to Perthes’ disease but occurring later during adolescence. Based on 3D CT animations, we propose repetitive impact between the main supplying vessels on the posterolateral femoral neck and the posterior acetabular wall in hyperextension and external rotation as a possible cause of direct vascular damage, and subsequent femoral head necrosis in three adolescent female gymnasts we are reporting on.

The aim of school screening is to identify most or all the individuals with unrecognized idiopathic scoliosis (IS) at an early stage when a less invasive treatment is more effective. The present study summarises the contribution of school screening in research of IS epidemiology, natural history and aetiology. In addition, school screening is a unique tool for research of IS in humans, as in most published articles, all aetiopathogenetic factors are studied in animals and not in humans. Such contribution is beyond the original aim of school screening but is very important to expand our knowledge and adequately understand the pathogenesis of IS. The role of biological factors such as the menarche, the lateralization of the brain, the handedness, the thoracic cage, the intervertebral disc, the melatonin secretion, as well as the role of environmental factors such as the light and the impact of the geographical latitude in IS prevalence were studied in children referred from school screening. The present study provides evidence to support that school screening programs should be continued not only for early detection of IS but also as a basis for epidemiological surveys until we learn much more about the aetiology of IS

The purpose of this study was to identify aetiological that may determine prognosis in ulnar nerve lesions and to evaluate the role of non-operative treatment. 148 consecutive patients (100 male) with 170 electrophysiologically proven (by nerve conduction and electromyography) ulnar nerve lesions were identified from the departmental records. Patient details, symptoms, known aetiology and treatment profile were recorded. Each patient was then contacted by telephone and/or questionnaire 1–6 (median 3. 8) years following electrodiagnosis to determine clinical progress and outcome. In patients with sensory symptoms alone or non-progressive painless motor symptoms, non-operative treatment was commenced. This involved advice on activity modifications and protection with a tubipad bandage or night spin. 12. 9% and 8. 8% of lesions were due to injury and intra-operative pressure respectively. Other causes included deformity and/or synovitis from arthritis of the elbow, repeated pressure, medial epicondylitis and benign space occupying lesions. 58. 2% were idiopathic with no clinical aetiological factor. 22 patients had expected bilateral lesions whereas 15 had contralateral lesions that were not symptomatic. 89. 4% and 4. 7% of lesions occurred at the elbow and wrist respectively. 83% of patients received non-operative first line treatment. 21% of these required operative intervention following further clinical and electrophysiological assessment. Partial or complete recovery occurred in 80%, 67% and 52% of the intra-operative, idiopathic and injury cases respectively (P< 0. 05). We conclude lesions of the ulnar nerve predominate in males and can be treated non-operatively providing clinical and electrophysiological monitoring is possible. Bilaterality is not uncommon and should be excluded. Lesions due to injury have a worse prognosis than those caused by direct continuous or repeated pressure or where no aetiological factor exists

Introduction: Femoroacetabular impingement (FAI) causes pain in young adults and osteoarthritis. Genetic factors are important in the aetiology of osteoarthritis. We aimed to investigate the extent to which FAI has an underlying genetic basis, by studying the siblings of patients undergoing surgery for FAI and comparing them with controls. Methods: 66 patients (probands, 29 male, 37 female, mean age 39.1 years) treated surgically for FAI provided siblings for the study. Probands were classified as having cam, pincer or mixed FAI. 101 siblings (55 male, 56 female, mean age 38.2 years) were recruited. The control group consisted of their 77 partners and was age and gender-matched. All subjects were assessed clinically and radiologically (standardised AP Pelvic and cross-table lateral radiographs of each hip). Radiographs were scored for the presence of osteoarthritis, and morphological abnormalities. Participants were classified as:. Normal morphology, no clinical features. Abnormal morphology, no clinical features. Abnormal morphology, clinical signs but no symptoms. Abnormal morphology with symptoms and signs. Osteoarthritis. Results: The sibling relative risks were significant for groups b, c, and d (ranging between 2–5, p< 0.01). Pro-bands and siblings shared the same pattern of abnormal morphology. Gender specificity was apparent: pincer abnormalities common in sisters but not in brothers. The brothers of probands with cam deformities almost universally demonstrated the same deformity, but only 50% of sisters did. Discussion: Genetic influences are important in the aetiology of FAI. Whether the morphological abnormality is determined at conception or by an inherited predisposition to an acquired event during development warrants further study. Symptoms are variable, indicating a spectrum of disease progression. These cohorts present an opportunity to prospectively study the natural history of the condition, improve understanding of the mechanisms and pathology, and potentially to be recruited into clinical trials

Introduction: Femoroacetabular impingement (FAI) is an important cause of hip pain in young adults and a precursor to osteoarthritis. Genetic factors are important in the aetiology of osteoarthritis of the hip. From a research perspective, FAI is an example of how subtle morphological abnormality results in a predictable pattern of cartilage damage, and thereby offers great potential as a model to study early degenerative disease. Although many causes of FAI are described, the vast majority of patients give no history of previous hip disease. The purpose of this study was to investigate the extent to which FAI has an underlying genetic basis, by studying the siblings of patients undergoing surgery for FAI and comparing them with controls. Methods: 66 patients (probands, 29 male, 37 female, mean age 39.1 years) treated surgically for FAI provided siblings for the study. These patients were classified as having cam, pincer or mixed FAI. 101 siblings (55 male, 56 female, mean age 38.2 years) were recruited. The control group consisted of the 77 partners of those siblings (40 male, 37 female, mean age 41.9 years). All subjects underwent clinical (interview, examination, and hip scores) and radiological assessment (standardised AP Pelvic and cross-table lateral radiographs of each hip). Radiographs were scored for the presence of osteoarthritis, and cam- and pincer-type abnormalities. Results: Participants were classified as a) Normal morphology with no clinical features, b) Abnormal morphology but no clinical features c) Abnormal morphology with clinical signs but no symptoms, and d) Abnormal morphology with symptoms and signs. The sibling relative risks were significant for groups b, c, and d, supporting the hypothesis of an underlying genetic predisposition to FAI. Siblings usually demonstrated the same type of abnormal morphology as the proband. Gender specificity was apparent however, with pincer abnormalities which were usually apparent in female probands being common in sisters but less common in brothers. The brothers of probands with cam deformities almost universally demonstrated the same deformity, although only 50% of sisters did so. Discussion: Genetic influences are important in the aetiology of FAI. Whether the morphological abnormality is determined at conception or by an inherited predisposition to an acquired event during maturity warrants further study. We have identified a spectrum of disease with a proportion of siblings with abnormal morphology currently asymptomatic. These cohorts present an opportunity to prospectively study the natural history of the condition, improve our understanding of the mechanisms and pathology in early degenerative disease, and potentially to be recruited into clinical trials of surgical and adjuvant treatments

Over the long term, the results of the insertion of a Grammont inverted shoulder prothesis are unknown. The present study reports survivorship curves and the role of the initial aetiology in patients re-examined after 5 to 10 years. Patients and methods Eighty prostheses (for 77 patients) were implanted between 1992 and 1998: 66 cases of massive cuff tear arthropathy (MCTA) and 24 cases for another aetiology (mainly rheumatoid arthritis and revision). At the time of follow-up, 18 patients had died and 2 could not be traced. The remaining patients (57 representing 60 prostheses) were seen by an independent examiner. The minimum follow-up was 5 years. The average follow-up was 69,6 months. Kaplan-Meir survivorship curves for the 60 prostheses were established in order to show the probability of failure as defined by: revision of the prothesis, glenoid loosening, and a functional level< 30 points according to the Constant score. Results The survivorship curves were as follow:. - for non revision of the prosthesis at 10 years: 91% overall; after 9 years: 95% for MCTA, and 77 % for the others aetiologies. This difference was statistically significant (p< 0,01) ; 6 implants were revised: 3 for MCTA and 3 for other aetiologies. - for non glenoid loosening at 10 years: 84 % overall ; after 7 years: 91% for MCTA and 77% for other aetiologies. This difference was statistically significant (p< 0,05). In addition to the cases of replaced implants mentioned above there was a case of glenoid loosening after 8 years follow-up in a patient aged 92. -for Constant score < 30 at 10 years: 58 % overall. The punctual survivorship rate was significantly different in function of the aetiology, at 6 years ; but this was no longer the case after 7 years. Discussion. According to revision of the prosthesis, there is a clear rupture in the survivorship curve about 3 years after insertion in aetiologies other than MCTA. This suggests that Grammont inverted total shoulder arthroplasty is not appropriate in these aetiologies (particularly in cases of rheumatoid arthritis). According to Constant score < 30, there is a clear rupture in the survivorship curve about 7 years after insertion specially in MCTA cases. This suggests that inverted protheses should be used only in cases with severe handicap and only in patients aged over 75

The purpose of this study was to identify aetiological factors that may determine prognosis in ulnar nerve lesions at the elbow and to evaluate the role of non-operative treatment. One hundred and thirty consecutive patients (92 male) with 152 electrophysiologically proven (by nerve conduction and electromyography) ulnar nerve lesions at the elbow were identified from the departmental records. Patient details, symptoms, known aetiology and treatment profile were recorded. Each patient was then contacted by telephone and / or questionnaire between one and six years after electrodiagnosis to determine clinical progress and outcome. In patients with sensory symptoms alone or non-progressive painless motor symptoms, non-operative treatment was commenced. This involved advice on activity modification and protection with a tubipad bandage or night splint with continued clinical and electrophysiological surveillance. Sixty-one percent of lesions were idiopathic with no clinical aetiological factor. Defined causes included deformity and/or synovitis from arthritis of the elbow (11.2%), injudicious intra-operative pressure (9.2%), injury/trauma (8.5%) repeated pressure (4.1%), medial epicondylitis (2.9%) and benign space occupying lesions (2.9%). Twenty-two patients had expected bilateral lesions whereas 15 had contralateral lesions that were not symptomatic. Eighty-three percent of patients received non-operative first line treatment. Twenty-one percent of these required operative intervention (simple decompression) following further clinical and electrophysiological assessment. Partial or complete recovery occurred in 88%, 80%, 67% and 52% of the arthritis, intra-operative, idiopathic and injury cases respectively (P< 0.05). We conclude lesions of the ulnar nerve at the elbow predominate in males and the majority can be treated non-operatively providing clinical and electrophysiological monitoring is possible. Bilaterality is not uncommon and should be excluded. Lesions due to injury have a worse prognosis than those caused by arthritis of the elbow, direct continuous or repeated pressure or where no aetiological factor exists

Surfing is a popular UK water-sport. Recommendations for protective gear are based on studies abroad from trauma from large waves and reef breaks which may not be relevant in the UK. This study assesses the aetiology of UK surfing injuries in order to assist treatment and provide formative recommendations on protective equipment. Data was collected from UK surf clubs via an online survey. 130 individuals reported 335 injuries. M:F ratio 85:45, median age 28 (range 17–65). Head injuries were the most common (24%) followed by foot and ankle (19%). Surfers collided most often with their own boards (31%) followed by rocks/coral (15%), the sea (11%) and other surf boards (10%). Lacerations were the commonest injury (31%); followed by bruises/ black-eyes (24%) and joint/ligament sprains (15%). Concussions (5%), fractures (3%) and teeth injuries (1%) were rare. Less than 1/3 of all injuries required professional medical attention, 2 required operative intervention. Surfing injuries in the UK are common but usually minor. Serious head injuries (fractures and concussions) are rare. There is insufficient evidence to warrant the routine use of protective helmets whilst surfing in the UK, although protective head and foot gear may be considered when surfing the rarer reef/ rock breaks

Introduction: This is a prospective study of a series of consecutive cases of Os Odontoideum focussing on CT and MRI data. Both congenital and post-traumatic aetiologies have been proposed in the literature. This can lead to confusion in a medico-legal and clinical setting. Methods: Radiological, CT and MRI data from 26 consecutive cases of cranio-cervical anomalies were collected prospectively. Demographic details, the presence of any recent or remote traumatic aetiology and the clinical presentation were obtained from the medical record. A reconstructed mid-sagittal CT was examined for the thickness of the arch of C1, the size and location of the Os and the morphology of the atlantodens joint. The presence of any cord impression or signal change was obtained from the MRI. Results: 18 cases of Os Odontoideum were identified. Only one had a history of significant trauma remote from presentation. All adults had an abnormal archdens joint configuration (the ‘Jigsaw’ sign) with one exception. The atlantodens ratio was significantly greater in all cases of Os odontoideum indicating a relatively thickened anterior arch of the atlas. One case of non-union of a dens fracture presenting five or more years after the injury was identified in this series. Neither in this case nor two cases of transverse ligament rupture and two cases of Ossiculum terminale, was a thickened arch or an abnormal atlantodens joint observed. 12 of the cases presented after traumatic injury to the neck. In only three of these was there any abnormal neurological signs. Conclusions: Os Odontoideum has a characteristic appearance of the anterior C1 arch and the atlantodens joint as viewed on CT. These radiological signs are not observed after dens fractures. They may be taken to indicate a congenital aetiology for the condition. Patients with Os odontoideum are able to tolerate moderate to severe levels of injury without sustaining significant acute cord damage

Aims

Despite numerous studies on periprosthetic joint infections (PJI), there are no robust data on the risk factors and timing of metachronous infections. This study was performed to answer the following questions: 1) Is there any difference of manifestation time of metachronous PJIs between different localizations of multiple artificial joints? 2) Can we identify any specific risk factor for metachronous PJIs for different localizations of multiple artificial joints?

Introduction Both congenital and acquired aetiologies for Os Odontoideum have been proposed leading to confusion in a medico-legal setting. No large series with CT and MRI features has been reported. Methods Clinical, radiological, CT and MRI data from 25 cases of cranio-cervical anomalies (including 18 with Os Odontoideum) was collected prospectively. The hypothesis that Os Odontoideum is associated with signs of dysplasia such as arch hypertrophy (as quantified by the arch-peg ratio) and a ‘jigsaw’ like atlanto-dens joint configuration was tested. Results Only one of 18 cases with Os Odontoideum gave a history of remote trauma. None of the cases with other post traumatic conditions showed arch hypertrophy or dysplasia of the joint. Os Odontoideum was associated with two distinctive features on mid-sagittal CT reconstruction: arch hypertrophy and the presence of a ‘jigsaw sign’. A quantitative definition of arch hypertrophy (an arch/ peg ratio greater than 0.5) provided a sensitive and specific test for Os Odontoideum. This was further enhanced in combination with the jigsaw sign to give a test accuracy of 97%. Motor changes with MRI signs of cord damage were observed in one of 12 cases associated with trauma. Conclusions The lack of a history of remote trauma and the dyplastic atlanto-dens joint seen on CT are more suggestive of a congenital than a post-traumatic aetiology for Os Odontoideum. Patients with Os odontoideum are able to tolerate moderate to severe levels of injury without sustaining significant acute cord damage

A sibling risk study that shows a statistically significant increase in risk for anteromedial osteoarthritis of the knee. Anteromedial osteoarthritis is a distinct phenotype of osteoarthritis. Previous studies have shown a genetic aetiology to both hip and knee osteoarthritis. The aim of this study was to determine the sibling risk of antero-medial osteoarthritis of the knee. We conducted a retrospective cohort study of 132 probands with primary anteromedial osteoarthritis, who had undergone unicompartmental arthroplasty. Sibling were identified as having symptomatic knee problems by postal Oxford Knee Score (OKS). A positive OKS was defined as an OKS+/− 2SD of the mean of the proband group. Sibling spouses were used as controls. Those siblings & spouses that were symptomatic from the OKS were invited to undergo Knee X-rays, to look for radiological signs of osteoarthritis. Osteoarthritis was diagnosed as greater than Grade II on the Kell-gren Lawrence classification. The pattern of disease was noted and it was considered if the sibling were suitable for a unicompartmental knee arthroplasty. The prevalence and sibling risk of anteromedial osteoarthritis was determined using a randomly selected single sibling per proband family. The prevalence was determined in the 103 single proband sibling pairs. There was a statistically significant risk within the sibling group P= 0.024 using the Chi square test. The relative risk of anteromedial osteoarthritis was. 3.21(95% CI 1.08 to 9.17). Genetic factors play a major role in the development of anteromedial osteoarthritis

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. Aim: The aim of this study was to establish a biomechanical porcine cadaveric model to study SUFE and use this model to determine how defective joint lubrication may increase the probability of SUFE. Methods: Using immature porcine femurs and a custom-made rig, a torsional load was applied about an axis perpendicular to the growth plate in order to cause the femur to fail along the growth plate. The Hounsefield testing machine applied a tensile load and recorded the associated elongation. From these figures the torque applied to the femoral head and the associated angular rotation could be computed. Using Weibel analysis we were able to determine the probability of SUFE occurring for a range of synovial fluid coefficients of friction, a range of joint reaction forces and neck-shaft angles. Results: We found that it is possible to induce a SUFE in an immature porcine loaded hip joint and that there was an increased probability of slip with increased coefficient of friction of synovial fluid, increased percentage body weight and increased neck-shaft angle. Conclusion: Defective lubrication may be a key underlying aetiological factor responsible for SUFE

Aims: The study aimed at analyzing the outcome of femoral components in patients with total hip replacement following osteonecrosis of the femoral head with regard to the associated factor of the osteonecrosis. Methods: We reviewed 41 patients with 55 cementless total hip replacements operated for advanced osteonecrosis. According to etiology of the osteonecrosis patients were divided into two groups. The first group included 17 cases with osteonecrosis without a systemic disease and the second group 38 cases with osteonecrosis associated with a systemic disease (alcohol abuse, corticosteroid medication, sickle-cell-disease). Results: The follow-up was on average 6.4 years (range, 2 to 12.8). Eight stem revisions had to be performed, all of them were in the patients with a systemic disease. Ten-year survival rates with femoral revision as the endpoint were in the first group 100%, and in the systemic disease group 68% (p=0.03). Conclusion: The data of this retrospective study supports the notion that the aetiology of osteonecrosis might has an influence on the survival of the femoral component