Introduction. Hip dysplasia is the most common congenital deformity of the musculoskeletal system. This is a pathology that brings the hip joint from subluxation to dislocation. Frequency of hip dysplasia − 16 children per 1000 newborns. Materials and Methods. Diagnostic methods of research are X-ray inspection which is necessarily carried out at internal rotation (rotation) of an extremity as lateral rotation of a hip on the radiograph always increases an angle of a valgus deviation of a neck. Surgical treatment is performed in the subclavian area of the femur. An external fixation device is applied and a corrective corticotomy is performed, and valgus deformity and anteversion are eliminated. The duration of treatment is 2.5–3 months. Results. Frequency of hip dysplasia − 16 children per 1000 newborns. We perform about 30 operations a year, including 60% girls and 40% boys. In addition, valgus deformity can be traced -. - in cerebral palsy. - after polio. - at progressing muscular dystrophies. - tumor in the area of the epiphyseal cartilage. At insufficient stability in a hip joint at insufficiently expressed roof of an acetabulum of rotational deformation of a neck of a hip, for prevention of a coxarthrosis and normalization of a ratio of articular ends operation detorsion-varying subvertebral corticotomy of a femur is shown. Conclusions. The operation is minimally invasive, with accesses of 5–6 mm, anatomical and topographical features are taken into account, which will eliminate damage to tissues, nerve trunks and the circulatory system

Developmental Dysplasia of the Hip (DDH) is the most common orthopaedic disorder in newborns. Whilst the Pavlik harness is one of the most frequently used treatments for DDH, there is immense variability in treatment parameters reported in the literature and in clinical practice, leading to difficulties in standardising teaching and comparing outcomes. In the absence of definitive quantitative evidence for the optimal Pavlik harness management strategy in DDH, we addressed this problem by scientifically obtaining international expert-based consensus on the same. An initial list of items relevant to Pavlik harness treatment was derived by systematic review of the literature according to PRISMA criteria and reviewed by two expert clinicians in DDH management. Delphi methodology was used to guide serial rounds of surveying and feedback to content matter experts from the International Hip Dysplasia Institute (IHDI), a collaborative group of paediatric orthopaedic surgeons with expertise in the management of DDH. Rounds of surveying continued in the same manner until consensus was reached. Importance ratings were derived from each round of surveying by calculating median score responses on the 5-point Likert scale for each item. Items requiring clarification or those with a median score of below 4 (“agree”) were modified as needed prior to each subsequent round. Consensus was considered reached when 90% or more of the items had an interquartile range (IQR) of ≤ 1. This value indicates low sample deviation and is accepted as having achieved consensus. This was followed by a corroboration of face validity to derive the final set of management principles. The literature search and expert review identified an initial list of 66 items in 8 categories relevant to Pavlik harness management. Four rounds of structured surveying were required to reach consensus. Following a final round of face validity, a definitive list of 33 items in 8 categories met consensus by the experts. These items were tabulated and presented as “General Principles of Pavlik Harness Treatment for DDH” and “Pavlik Harness Treatment by Severity of Hip Dysplasia”. Furthermore, highly contentious items were identified as important future areas of study and will be discussed. We have developed a comprehensive set of principles derived by expert consensus to assist clinicians, and for use as a teaching resource, in the non-operative management of DDH using the Pavlik harness. We have gained consensus on both the general principles of Pavlik harness treatment as well as the detailed treatment of hip subtypes seen across the spectrum of pathology of DDH. Furthermore, this study has also served to generate a list of the most controversial areas in the non-operative management of DDH which should be considered high priority for future study to further refine and optimise the outcomes of children with developmental hip dysplasia

Introduction. The standard plane imaging of Graf and the dynamic methods of Harcke are well established methods in assessing hip dysplasia but give limited information in the flexed-abducted treatment position used in the Pavlik harness. The femoral head may sit on the edge of the acetabulum in a flexed position and only reduce when the hips are abducted. This may mean that hips, which reduce when abducted in the Pavlik harness, appear subluxed when scanned in neutral abduction. Harness treatment may thereby be abandoned prematurely due to the failure to confirm reduction. This study identifies ultrasound landmarks on an anterior hip scan which could be used to confirm reduction of the hip in Pavlik Harness. Materials and method. Hips of a newborn piglet were scanned, imaged with magnetic resonance and x-rayed both before and after anatomical dissection. Radiographic markers delineated the position of the tri-radiate cartilage and potential ultrasound landmarks identified to help confirm hip reduction in the flexed-abducted position. Porcine imaging was then compared with that of a human newborn. Results. The porcine model corresponded well to human imaging and we were able to establish a landmark, the ‘Ischial Limb’, which corresponds to the ossification front delineating the posterior ischial edge of the tri-radiate cartilage. This could clearly be seen on anterior hip ultrasound of both the porcine and human hip. This landmark can be used to confirm the hip is reduced by reference to the centre of the femoral head. Discussion and conclusion. We would recommend anterior hip scanning using the ‘Ischial Limb’ as a reference point to confirm hip reduction in Pavlik harness. This simple method is a useful adjunct to conventional ultrasound scanning in the harness treatment of hip instability

Introduction. Total hip replacement with metal-on-polymer (MoP) hip prostheses is a successful treatment for late-stage osteoarthritis. However, the wear debris generated from the polymer acetabular liners remains a problem as it can be associated with osteolysis and aseptic loosening of the implant. This has led to the investigation of more wear resistant polymers in orthopaedics. Cross-linked polyethylene (XLPE) is now the gold-standard acetabular liner material. However, we asked if carbon fibre reinforced polyether ether ketone (CFR-PEEK) might be a lower wear material. In addition, we sought to understand the influence of contact stress on the wear of both XLPE and CFR-PEEK as this has not previously been reported. Materials and Methods. A 50-station circularly translating pin-on-disc (SuperCTPOD) machine was used to wear test both XLPE and CFR-PEEK pins against cobalt chromium (CoCr) discs to investigate the influence of contact stress on their wear rates. Fifty XLPE and 50 CFR-PEEK pins were articulated against CoCr discs. The pins, 9 mm in outer diameter and 12 mm in height, were drilled with different diameter holes to generate different sized annuli and thus, different contact areas. The pins were tested at 1.10, 1.38, 1.61, 2.00 and 5.30 MPa, which are typical contact stresses observed in the natural hip joint. An additional pin for every test group was used as a control to track the lubricant uptake. The discs were polished to 0.015 μm Sa prior to testing. The test stations contained 16 ml of diluted newborn calf serum (protein concentration: 22 g/L). Wear was measured gravimetrically with a balance (resolution: 10 μm) every 500,000 cycles. A standardised cleaning and weighing protocol was followed. Results and Discussion. The wear rates for the XLPE pins were calculated as 1.05, 0.90, 0.77, 0.48 and 0.28 mg/million cycles for the different pin stress groups respectively. The wear rates decreased with increasing contact stress, which was similar to what was observed for ultra-high molecular weight polyethylene (UHMWPE). The change in weight of the discs was insignificant (p-value:0.85). For the CFR-PEEK pin groups, the wear rates were calculated as 0.56, 0.65, 0.61, 0.58 and 0.65 mg/million cycles respectively. The difference between the wear rates was insignificant (p-value: 0.92). However, the weight of the discs decreased significantly (p-value: 0.00). At 1.11 MPa and taking data for UHMWPE tested in the same way, comparison of the three polymers showed that CFR-PEEK produced the lowest wear against CoCr. Although the wear rates for CFR-PEEK were found to be the lowest, the decrease in weight of the CoCr discs articulated against CFR-PEEK was indicative of metallic wear. Conclusion. CFR-PEEK should not be used against orthopaedic metals. XLPE articulating against CoCr was found to be the optimum combination, producing low wear without causing weight change from the counterface, under varying contact stresses

Introduction. Ion analysis has been used as one of the key indicators to assess the performance of MoM devices in patients. Modular devices, in particular having larger overall surface area (the stem and sleeve), and locking interfaces (head – bore, sleeve- taper and sleeve-bore, stem-taper surfaces) than other MoM devices are expected to release greater number of ions. Concerns have been expressed that the ion release at the taper junction might be a potential cause leading to the failure of the implant [Garbuz et al, 2010]. The aim of this study was to look into the wear and the associated ion release from the taper junction and the articulating surface of modular devices. Method. For the first time a novel design has been used to isolate the taper junction on modular devices on the hip simulators in order to compare the wear at the taper junction and articulating surface. The taper junction has been isolated in a small gaiter, while the head and cup were contained in a large gaiter. CoCrMo sleeves having an offset of +8 mm have been used on 50 mm modular heads along with Ti6Al4V stems. The acetabular components were standard BHR cups. Three devices (Smith & Nephew, UK) have been tested with newborn calf serum as a lubricant (in the large gaiter) and also as the medium containing the taper junction (in the small gaiter). The serum samples from the articulating surface and taper junction were analysed using HR-ICPMS. The locking interfaces at the taper junction have been left intact throughout the duration of the test. Both the head and the cup have been tested under anatomical conditions using the standard implant development centre's (IDC) profile for 2 million cycles (Mc). The lubricant was newborn calf serum with 0.2% sodium azide diluted with de-ionised water to achieve protein concentration of 20 mg/ml. The flexion/extension was 30°/15° and the internal/external rotation was ±10°. The force was Paul-type stance phase loading with a maximum load of 3 kN and a standard ISO swing phase load of 0.3 kN. The frequency was 1 Hz, with an 8 hour stop after every 16 hours of testing. Results and discussion. The ion analysis results from the articulating surface expressed in cumulative volume showed a biphasic wear trend at 0.96 ± 0.15 mm. 3. (0.5 Mc) and 1.05 ± 0.13 mm. 3. (2 Mc). The ion analysis results obtained for the samples from the small gaiter are (1.83 ± 0.35) x 10. −3. mm. 3. at 0.5 Mc and (4.52 ±0.83) x 10. −3. mm. 3. (2 Mc). On comparison, the ion release from the taper junction is 100 fold lower than that from the articulating surface. It should be noted that the ion release from the taper junction can be influenced by the material, tolerance, surface finish and design of the taper joint. Conclusion. The ion release associated with the taper junction is extremely low when compared with the ion release from the articulating surface

Vancomycin -impregnated bonechips from a human morselized femoral head allograft (BCs) are used in orthopaedic surgery to treat infections. Literature suggests that bonechips can be efficient vancomycin carriers, but due to the diversity in the type of bonechips, of impregnation and of method used to evaluate AB release, there are no uniform guidelines. We performed an in vitro study to examine the release of vancomycin from solution-impregnated deepfrozen processed bonechips. Quantification was performed using a fully validated chromatographic method. Results were compared with the elution-profile from Osteomycin®, a commercially available lyophilised processed bonegraft. Different vancomycine impregnation-concentrations and impregnation-durations of frozen processed bonechips were investigated. After impregnation, bonechips were rinsed with saline in order to determine only the absorbed vancomycin. Elution was performed in newborn calf serum at 37°C. Eluted vancomycin concentrations were determined using Ultra Performance Liquid Chromatography – Diode Array Detection (UPLC-DAD). In addition an elution study was performed on the commercially available Osteomycin®, bone chips containing vancomycine. Using processed frozen bonechips, an impregnation-concentration of minimum 100 mg/mL during 10 minutes delivers the desired local concentration (therapeutic window 25 – 1000 mg/L) for 3 days. Longer impregnation time at this concentration had no effect. Osteomycin®: delivers the desired local concentration for 8 days in our experimental setting. Literature suggests that freshfrozen BCs can be used as carrier for vancomycin through solution-impregnation [1,3]. There is however much less information on the carrier-capacities of frozen processed bonechips, a type used in our hospital. Our impregnation-protocol was based on that of Mathyssen et al., but with direct quantification of elution concentrations. Impregnation with vancomycine 100 mg/mL during 10 minutes results in a release above the desired concentration for 3 days, which seems too short when treating bone-infections. Osteomycin®, shows a substantially longer elution [2]. Vancomycin-solution impregnation of frozen processed bonechips may not be sufficient to obtain the desired release-characteristics for the treatment of bone-infections

INTRODUCTION. Wear, aseptic loosening, dislocation, corrosion and prosthetic joint infection (PJI) are major factors leading to revision of THA. The effect of using ceramic components to address these issues was investigated to determine their behaviour and potential benefit. METHODS. a) Wear determination in off-normal conditions. A series of CoC articulations (32mm) was evaluated using a hip simulator (ISO 14242) up to 4 million cycles in presence of fine alumina particles (48mg/ml). Wear was measured gravimetrically. b) Friction moment determination. Friction moments were measured in a hip simulator with 25% newborn calf serum as lubricant. CoC, CoPE, MoPE, MoXLPE and CoXLPE with articulating diameters ranging between 28 and 40mm were used. The cup was inclined to a constant angle of 33° and rotated ±20° sinusoidally around a horizontal axis at 1Hz. Peak friction moments were measured around the cup rotation axis during a constant joint force period of 1700N between 200 and 210 seconds. c) Infections. Four databases were analysed and additionally data from registers and literature were reviewed to determine the risk of revision for prosthetic joint infection (PJI) dependence on the bearing. Only data for cementless THA were used. Several studies also included analysis of several confounding factors like age at surgery, BMI, pathology, etc. using Cox multivariate analysis. RESULTS. a) Wear determination in off-normal conditions. Loading the test medium with alumina particles didn't produces detectable wear. Opaque areas appeared only after 3 million load cycles, but the wear-rate remained within the gravimetric measurement detection limit (about 0.1–0.2mg) indicating the still extremely low wear-rate of the tested couplings. b) Friction moment determination. The highest moments were measured for metal heads; the lowest for CoC bearings. 40mm CoC bearing showed a similar friction moment like 28mm bearings when coupled with a XLPE liner. c) Infections. The rate of revisions for PJI for 500'749 patients from various studies was in the range of 0.2 to 1.1%. Age at surgery and BMI did not influence septic loosening, while the bearing did; sometimes significant. The trend was identical for all seven sources and ceramic components resulted in a lower incidence of revisions for up to 60%. CONCLUSION. The wear of CoC articulations is extremely low even in a heavily contaminated environment with fine hard particles. Such high scratch resistance makes CoC the preferable revision solution in THA. Friction moments with CoC are the lowest, even with large diameter bearings. The low friction moments of ceramics lower the stresses at the modular and also bone interface and can affect the outcome of THA. Revisions due to infection seem to be also dependent on the bearing couple with a positive influence of ceramic components. Although due to the complex reasons for infections only a trend, CoP and CoC has been identified to mitigate the risk of PJI

Introduction. Stress shielding and wear induced aseptic loosening cause failure in total joint arthroplasty. To improve long-term outcomes in total knee arthroplasty (TKA), the use of a low modulus, low wearing biomaterial may be a suitable alternative to cobalt chromium (CoCr) femoral components. Based on its favorable mechanical properties and observed clinical success especially in spinal surgery, polyetheretherketone (PEEK) is investigated as a candidate material for a metal free TKA. An all polymer TKA has several theoretical advantages, these include a more physiological stress in the distal femur, elimination of biological reaction to metal, better radiographic visualisation of the bone implant interface especially with CT and MRI. In addition, polymers afford a cheaper option for the manufacture of prostheses. Aims and Hypothesis. This study investigated the wear performance of PEEK and carbon reinforced PEEK (CFR-PEEK) as bearing materials in an all polymer TKA using a unidirectional pin on plate test. Our hypothesis was that reduced wear is generated from PEEK or CFR-PEEK bearings when compared with metal on polyethylene (MoP) bearings and that this combination may provide a suitable alternative in TKA. Methods. A validated modification of ASTM F7321 was used as test protocol. Twenty millimeter diameter spherically ended pins with a radius of 25mm were articulated against 40mm diameter plates. A load of 1000N was applied to generate an initial contact stress of ∼70MPa similar to high contact stresses previously reported in non congruent knee designs2. Ten material combinations were tested as shown in Table 1. Table 1: Tribological couples tested (Pin vs. Plate) UHMWPE – ultrahigh molecular weight polyethylene, XLPE – highly cross-linked polyethylene). The lubricant used was 25% newborn calf serum containing 0.3% sodium azide to retard bacteria growth and 20mM EDTA to prevent calcium deposition. Three repeats of pin on plate combinations (including 2 passive soak controls) were tested for 2 million cycles at a cycle frequency of 1Hz and a cycle length of 20 mm. Gravimetric wear was analysed every 250,000 cycles and results converted to volumetric wear using material density. Results. All CFR-PEEK articulations were stopped due to excessive wear of the counter-surfaces. Results showed a linear wear rate of UHMWPE and XLPE plates over the test period. PEEK vs. XLPE showed similar wear rates to metal on polyethylene (MoP)bearings (Fig 1). Conclusion. At high stresses representative of non conforming knee designs, PEEK pins articulated against XLPE plates generated volumetric wear similar to that noted in MoP bearings. From these results, it may be possible to replace CoCr in TKR with PEEK which may be beneficial because of the low elastic modulus and elimination of biological activity to metal alloy

Background. The optimal management of idiopathic clubfoot has changed over three decades. Recently there has been an enthusiastic embracing of the Ponseti technique. The purpose of this 14-year comparative prospective longitudinal study was to directly assess the differences in results between these two treatment methods. Methods. Over the period of this study there were 52,514 births in the local population and all newborns with clubfoot were referred directly to the Pediatric Orthopedic Surgeon. Patient demographics, the Harrold & Walker Classification, and associated risk factors for clubfoot were collected prospectively and analyzed. If conservative treatment failed to correct the deformity adequately, a radical subtalar release (RSR) was undertaken (the primary outcome measure of the study). Results. There were 114 feet (80 patients): 64 feet treated ‘traditionally’ and 50 feet with the Ponseti technique. Idiopathic clubfoot was present in 76.25% of patients. Mean time to RSR was 33.3 and 44.1 weeks for the traditional and Ponseti groups respectively. In the traditional group 65.6% (CI: 53.4 to 76.1%) of feet underwent RSR surgery compared to 25.5% (CI: 15.8 to 38.3%) in the Ponseti group. When idiopathic clubfoot alone was analysed, these rates reduce to 56.5% (CI: 42.3 to 69.8%) and 15.8% (CI: 7.4 to 30.4%) respectively. The Relative Risk of requiring RSR in traditional compared to Ponseti groups was 2.58 (CI: 1.59 to 4.19) for all patients and 3.58 (CI: 1.65 to 7.78) for idiopathic clubfoot. Conclusions. Introduction of the Ponseti technique into our institution significantly reduced the need for RSR in fixed clubfoot

Developmental dysplasia of the hip (DDH) is the commonest musculoskeletal condition diagnosed in neonates. Two previous studies showed no statistical advantage with the addition of ultrasound to clinical screening. In the UK, the Standing Medical Advisory Committee (SMAC) (1969) recommended clinical examination at birth and at 6 weeks. The Newborn Infant Physical Examination (NIPE) (2008) guidelines in addition advised ultrasound scanning for clinically unstable hips or for those with risk factors (breech presentation or family history). We compared SMAC and NIPE in the two main hospitals of the East Lancashire Hospitals NHS Trust: Burnley General Hospital (BGH) and the Royal Blackburn Hospital (RBH), respectively. Our outcome measure was the number of irreducible hip dislocations over a two year period (2007–2008). The records of the lead Paediatric Orthopaedic Surgeon were used to identify all cases of irreducible hip dislocations born in 2007 and 2008. Maternity records provided information on birth statistics. Syndromal cases were excluded from further analysis. BGH had 5382 live births and 7 irreducible hip dislocations (incidence 1.3/1000 births). 4/7 met SMAC recommendations and 6/7 met NIPE guidelines. 2/7 had equivocal clinical examinations at birth. 13 children were referred to the clinic with unstable hips (2.42/1000 births). RBH had 7899 total births and 3 irreducible hip dislocations (incidence 0.38/1000 births). 2/3 met NIPE guidance and 1/3 met SMAC recommendations. 33 were referred to the clinic with unstable hips (4.18/1000 births). The difference in the numbers of irreducible hips did not reach statistical significance (p=0.12). This study found no statistically significant advantage with the addition of selective ‘at risk’ ultrasound screening to clinical screening alone. Confounding factors in this study included the age of referral of cases to clinic and the numbers of cases referred as primary instability. These findings are in keeping with two previous studies in Norway

Construction of a functional skeleton is accomplished through co-ordination of the developmental processes of chondrogenesis, osteogenesis, and synovial joint formation. Infants whose movement in utero is reduced or restricted and who subsequently suffer from joint dysplasia (including joint contractures) and thin hypo-mineralised bones, demonstrate that embryonic movement is crucial for appropriate skeletogenesis. This has been confirmed in mouse, chick, and zebrafish animal models, where reduced or eliminated movement consistently yields similar malformations and which provide the possibility of experimentation to uncover the precise disturbances and the mechanisms by which movement impacts molecular regulation. Molecular genetic studies have shown the important roles played by cell communication signalling pathways, namely Wnt, Hedgehog, and transforming growth factor-beta/bone morphogenetic protein. These pathways regulate cell behaviours such as proliferation and differentiation to control maturation of the skeletal elements, and are affected when movement is altered. Cell contacts to the extra-cellular matrix as well as the cytoskeleton offer a means of mechanotransduction which could integrate mechanical cues with genetic regulation. Indeed, expression of cytoskeletal genes has been shown to be affected by immobilisation. In addition to furthering our understanding of a fundamental aspect of cell control and differentiation during development, research in this area is applicable to the engineering of stable skeletal tissues from stem cells, which relies on an understanding of developmental mechanisms including genetic and physical criteria. A deeper understanding of how movement affects skeletogenesis therefore has broader implications for regenerative therapeutics for injury or disease, as well as for optimisation of physical therapy regimes for individuals affected by skeletal abnormalities.

Cite this article: Bone Joint Res 2015;4:105–116

Adult presentation of neglected congenital muscular torticollis is rare. We report 12 patients with this condition who underwent a modified Ferkel’s release comprising a bipolar release of sternocleidomastoid with Z-lengthening. They had a mean age of 24 years (17 to 31) and were followed up for a minimum of two years. Post-operatively a cervical collar was applied for three weeks with intermittent supervised active assisted exercises for six weeks. Outcome was assessed using a modified Lee score and a Cheng and Tang score. The mean pre-operative rotational deficit was 8.25° (0° to 15°) and mean lateral flexion deficit was 20.42° (15° to 30°), which improved after treatment to a mean of 1.67° (0° to 5°) and 7.0° (4° to 14°) after treatment, respectively. According to the modified Lee scoring system, six patients had excellent results, two had good results and four had fair results, and using the Cheng and Tang score, eight patients had excellent results and four had good results.

Surgical management of adult patients with neglected congenital muscular torticollis using a modified Ferkel’s bipolar release gives excellent results. The range of neck movement and head tilt improved in all 12 patients and cosmesis improved in 11, despite the long-standing nature of the deformity.