One of the known mechanisms which could contribute to the failure of total hip replacements (THR) is edge contact. Failures associated with edge contact include rim damage and lysis due to altered loading and torques. Recent study on four THR patients showed that the inclusion of pelvic motions in a contact model increased the risk of edge contact in some patients. The aim of current study was to determine whether pelvic motions have the same effect on contact location for a larger patient cohort and determine the contribution of each of the pelvic rotations to this effect. Gait data was acquired from five male and five female unilateral THR patients using a ten camera Vicon system (Oxford Metrics, UK) interfaced with twin force plates (AMTI) and using a CAST marker set. All patients had good surgical outcomes, confirmed by patient-reported outcomes and were considered well-functioning, based on elective walking speed. Joint contact forces and pelvic motions were obtained from the AnyBody modelling system (AnyBody Technologies, DK). Only gait cycle regions with available force plate data were considered. A finite element model of a 32mm head on a featureless hemispherical polyethylene cup, 0.5mm radial clearance, was used to obtain the contact area from the contact force. A bespoke computational tool was used to analyse patients' gait profiles with and without pelvic motions. The risk of edge contact was measured as a “centre proximity angle” between the cup pole and centre of the contact area, and “edge proximity angle” between the cup pole and the furthest contact area point away from the pole. Pelvic tilt, drop and internal-external rotation were considered one at a time and in combinations.Introduction
Methods
Decellularised extracellular matrix scaffolds show great promise for the regeneration of damaged musculoskeletal tissues (cartilage, ligament, meniscus), however, adequate fixation into the joint remains a challenge. Here, we assess the osseo-integration of decellularised porcine bone in a sheep model. This proof-of-concept study supports the overall objective to create composite decellularised tissue scaffolds with bony attachment sites to enable superior fixation and regeneration. Porcine trabecular bone plugs (6mm diameter, 10mm long) were decellularised using a novel bioprocess incorporating low-concentration sodium dodecyl sulphate with protease inhibitors. Decellularised bone scaffolds (n=6) and ovine allograft controls (n=6) were implanted into the condyle of skeletally mature sheep for 4 and 12 weeks. New bone growth was visualised by oxytetracycline fluorescence and standard resin semi-quantitative histopathology. Scaffolds were found to be fully decellularised and maintained the native microarchitecture. Following 4-week implantation in sheep, both scaffold and allograft appeared well integrated. The trabecular spaces of the scaffold were filled with a fibro-mesenchymal infiltrate, but some areas showed a marked focal lymphocytic response, associated with reduced bone deposition. A lesser lymphocytic response was observed in the allograft control. After 12-weeks the lymphocytic reaction was minimised in the scaffold and absent in allografts. The scaffold showed a higher density of new mineralized bone deposition compared to allograft. New marrow had formed in both the scaffold and allografts. Following the demonstration of osteointegration this bioprocess can now be transferred to develop decellularised composite musculoskeletal tissue scaffolds and decellularised bone scaffolds for clinical regeneration of musculoskeletal tissues.
Between 15% and 20% of patients remain dissatisfied following total knee arthroplasty (TKA). The SAIPH knee system (MatOrtho, Surrey, United Kingdom) is a medial ball and socket TKA that has been designed to replicate native knee kinematics in order to maximize the range of movement, stability, and function. This system is being progressively introduced in a stepwise fashion, with this study reporting the mid-term clinical and radiological outcomes. A retrospective review was undertaken of the first 100 consecutive patients with five-year follow-up following SAIPH TKA performed by the senior authors. The data that were collected included the demographics of the patients, clinical findings, the rate of intraoperative ligamentous release, patient-reported outcome measures (PROMS), radiological assessment, complications, and all-cause revision. Revision data were cross-checked with a national registry.Aims
Patients and Methods
Acetabular tissue damage is implicated in osteoarthritis (OA) and investigation of in situ acetabular soft tissues behaviour will improve understanding of tissue properties and interconnections. The study aim was to visualise acetabular soft tissues under load and to quantify displacements using computed tomography (CT) scans (XtremeCT, Scano Medical). A CT scan (resolution 82 μm) was performed on the disarticulated, unloaded porcine acetabulum. The femoral head was soaked in Sodium Iodide (NaI) solution and cling film wrapped to prevent transfer to the acetabular side. The joint was realigned, compressed using cable ties and re-scanned. The two images were down-sampled to 0.3 mm. Acetabular bone and soft tissues were segmented. Bony features were used to register the two background images, using Simpleware ScanIP 7.0 (Synopsys), to the same position and orientation (volume difference < 5%). Acetabular soft tissues displacements were measured by tracking the same points at the tissue edges on the two acetabular masks, along with difference in bone position as an additional error assessment. The use of radiopaque solution provided a clear contrast allowing separation of the femoral and acetabular soft tissues in the loaded image. The image registration process resulted in a difference in bone position in the areas of interest equivalent to image resolution (0.3 mm, a mean of 3 repeats by same user). A labral tip displacement of 1.7 mm and a cartilage thickness change from 1.5 mm unloaded to 0.9 mm loaded, were recorded. The combination of contrast enhancement, registration and focused local measurement was precise enough to reduce bone alignment error to that of image resolution and reveal local soft tissue displacements. These measurement methods can be used to develop models of soft tissues properties and behaviour, and therapy for hip tissue damage at early stage may be reviewed and optimised.
Instability continues to be a troublesome complication after total hip arthroplasty (THA). Patient-related risk factors associated with a higher dislocation risk include the preoperative diagnosis, an age of 75 years or older, high body mass index (BMI), a history of alcohol abuse, and neurodegenerative diseases. The goal of this study was to assess the dislocation rate, radiographic outcomes, and complications of patients stratified as high-risk for dislocation who received a dual mobility (DM) bearing in a primary THA at a minimum follow-up of two years. We performed a retrospective review of a consecutive series of DM THA performed between 2010 and 2014 at our institution (Hospital for Special Surgery, New York, New York) by a single, high-volume orthopaedic surgeon employing a single prosthesis design (Anatomic Dual Mobility (ADM) Stryker, Mahwah, New Jersey). Patient medical records and radiographs were reviewed to confirm the type of implant used, to identify any preoperative risk factors for dislocation, and any complications. Radiographic analysis was performed to assess for signs of osteolysis or remodelling of the acetabulum.Aims
Materials and Methods
Whilst home-based exercise rehabilitation plays a key role in determining patient outcomes following orthopaedic intervention (e.g. total knee replacement), it is very challenging for clinicians to objectively monitor patient progress, attribute functional improvement (or lack of) to adherence/non-adherence and ultimately prescribe personalised interventions. This research aimed to identify whether 4 knee rehabilitation exercises could be objectively distinguished from each other using lower body inertial measurement units (IMUs) and principle components analysis (PCA) in the hope to facilitate objective home monitoring of exercise rehabilitation. 5 healthy participants performed 4 repetitions of 4 exercises (knee flexion in sitting, knee extension, single leg step down and sit to stand) whilst wearing lower body IMU sensors (Xsens, Holland; sampling at 60 Hz). Anthropometric measurements and a static calibration were combined to create the biomechanical model, with 3D hip, knee and ankle angles computed using the Euler sequence ZXY. PCA was performed on time normalised (101 points) 3D joint angle data which reduced all joint angle waveforms into new uncorrelated PCs via an orthogonal transformation. Scatterplots of PC1 versus PC2 were used to visually inspect for clustering between the PC values for the 4 exercises. A one-way ANOVA was performed on the first 3 PC values for the 9 variables under analysis. Games-Howell post hoc tests identified variables that were significantly different between exercises. All exercises were clearly distinguishable using the PC scatterplot representing hip flexion-extension waveforms. ANOVA results revealed that PC1 for the knee flexion angle waveform was the only PC value statistically different across all exercises. Findings demonstrate clear potential to objectively distinguish between different knee rehabilitation exercises using IMU sensors and PCA. Flexion-extension angles at the hip and knee appear most suited for accurate separation, which will be further investigated on patient data and additional exercises.
The current ‘gold’ standard surgical intervention for critical size bone defect repair involves autologous bone grafting, that risks inadequate graft containment and soft tissue invasion. Here, a new regenerative strategy was explored, that uses a barrier membrane to contain bone graft. The membrane is designed to prevent soft tissue ingrowth, whilst supporting periosteal regrowth, an important component to bone regeneration. This study shows the development of a collagen-based barrier membrane supportive of periosteal-derived mesenchymal stem cell (P-MSC) growth. P-MSC-homing barrier membranes were successfully obtained with nonaligned fibres, via free-surface electrospinning using type I collagen and poly(E-caprolactone) in 1,1,1,3,3,3-Hexafluoro-2-propanol. Introduction of collagen in the electrospinning mixture was correlated with decreased mean fibre diameter (d: 319 nm) and pore size (p: 0.2–0.6 μm), with respect to collagen-free membrane controls (d: 372 nm; p: 1–2 μm). Consequently, as the average MSC diameter is 20 μm, this provides convincing evidence of the creation of a MSC containment membrane. SEM-EDX confirmed Nitrogen and therefore collagen fibre localisation. Quantification of collagen content, using Picro Sirius Red dye, showed a 50% reduction after 24 hours (PBS, 37 °C), followed by a drop to 25% at week 3. The collagen-based membrane has a significantly higher elastic modulus compared to collagen-free control membranes. P-MSCs attached and proliferated when grown onto collagen-based membranes, imaged using confocal microscopy over 3 weeks. A modified transwell cell migration assay was developed, using MINUSHEET® tissue carriers to assess barrier functionality. In line with the matrix architecture, the collagen-based membrane proved to prevent cell migration (via confocal microscopy) in comparison to the migration facilitating positive control. The aforementioned results obtained at molecular, cellular and macroscopic scales, highlight the applicability of this barrier membrane in a new ‘hybrid graft’ regenerative approach for the surgical treatment of critical size bone defects.
With increasing numbers of total joint arthroplasties being performed, peri-prosthetic fracture incidence is rising, and operative management remains the gold standard. Short-term survivorship up to 12 months has been well-documented but medium to long-term is almost unknown. We present survivorship review from a district general hospital, undertaking 800 primary hip and knee arthroplasties per year. Patients with peri-prosthetic fractures and background total knee replacements were identified using our computer database between 2006–2011. All patients were operated on our site; methods used include open reduction, internal fixation (ORIF) using Axsos (Stryker Newbury) locking plates (28), intra-medullary nailing (1) or complex revision (6) depending on fracture and patient factors and surgeon's preference. Mortality was assessed at 30 days, 12 months and 5 years. Thirty-four patients were identified with a 7:1 female to male ratio and mean age of 76. 75% of patients had their primary arthrodesis at our hospital. There was only 1 plate failure noted requiring revision plating. Mortality at 30 days, 12 months and 5 years were 3.2, 12.5% and 50% respectively. When compared to the literature our time interval from index surgery to fracture is considerably longer (115 vs 42 months). Further multi-centre reviews are required to further asses this unexpected finding. Overall mortality is better than our hip fracture cohort, suggesting that good results can be achieved in District Hospital. The longer-term results are encouraging and can act as a guide for patients with this injury. We recommend that patients are managed in consultant-led, multi-disciplinary teams.
Periprosthetic joinTt infection (PJI) remains an uncommon, yet devastating complication of total hip arthroplasty (THA) and total knee arthroplasty (TKA). Debridement with antibiotics and implant retention (DAIR) provides an alternative to staged revision. Chronic infection is considered to be a contraindication to DAIR, however, outcomes stratified by chronicity have not been documented. We performed a retrospective review of all DAIR cases performed at our institution between 2008–2015. Timeframe to treatment was categorized as acute (< 6 weeks since surgery), chronic (>6 weeks since surgery) or acute hematogenous (previously well-functioning prosthesis). Treatment failure was defined as reoperation during the first 90-days following DAIR. Univariate analysis (Mann-Whitney U and Chi-square; p<0.05) and generalized estimating equations (GEE) were used with multiple comparison adjustment by Tukey-Kramer method (α = 0.05).Introduction
Methods
Custom flanged acetabular components (CFAC) have been shown to be effective in treating complex acetabular reconstructions in revision total hip arthroplasty (THA). However, the specific patient factors and CFAC design characteristics that affect the overall survivorship remain unclear. Once the surgeon opts to follow this treatment pathway, numerous decisions need to be made during the pre-operative design phase and during implantation, which may influence the ultimate success of CFAC. The goal of this study was to retrospectively review the entire cohort of CFAC cases performed at a large volume institution and to identify any patient, surgeon, or design factors that may be related to the long-term survival of these prostheses. We reviewed 96 CFAC cases performed in 91 patients between 2004 and 2017, from which 36 variables were collected spanning patient demographics, pre-operative clinical and radiographic features, intraoperative information, and implant design characteristics. Patient demographics and relevant clinical features were collected from individual medical records. Radiographic review included analysis of pre-operative radiographs, computer tomographic (CT) scans, and serial post-operative radiographs. Radiographic failure was defined as loosening or gross migration as determined by a board-certified orthopedic surgeon. CFAC implant design characteristics and intra-operative features were collected from the design record, surgical record and post-operative radiograph for each case respectively. Two sets of statistical analyses were performed with this dataset. First, univariate analyses were performed for each variable, comprising of a Pearson chi-square test for categorical variables and an independent t-test for continuous variables. Second, a random forest supervised machine learning method was applied to identify the most influential variables within the dataset, which were then used to perform a bivariable logistic regression to generate odds ratios. Statistical significance for this study was set at p < 0.05.Introduction
Methods
The aim of this study was to determine the stability of a new
short femoral stem compared with a conventional femoral stem in
patients undergoing cementless total hip arthroplasty (THA), in
a prospective randomized controlled trial using radiostereometric
analysis (RSA). A total of 53 patients were randomized to receive cementless
THA with either a short femoral stem (MiniHip, 26 patients, mean
age: 52 years, nine male) or a conventional length femoral stem
(MetaFix, 23 patients, mean age: 53 years, 11 male). All patients
received the same cementless acetabular component. Two-year follow-up
was available on 38 patients. Stability was assessed through migration
and dynamically inducible micromotion. Radiographs for RSA were
taken postoperatively and at three, six, 12, 18, and 24 months.Aims
Patients and Methods
The aim of this study was to investigate the structural integrity of torn and non-torn human acetabular labral tissue. A total of 47 human labral specimens were obtained from a biobank. These included 22 torn specimens and 25 control specimens from patients undergoing total hip arthroplasty with macroscopically normal labra. The specimens underwent dynamic shear analysis using a rheometer to measure storage modulus, as an indicator of structural integrity.Objectives
Methods
The development of more wear resistant biomaterials and better locking mechanisms for the polyethylene into the tibial base has significantly reduced polyethylene wear as a reason for revision TKA. Aseptic loosening is now the primary cause for revision TKA. Loosening can be caused by multifactorial operative issues: 1] patient selection, 2] implant alignment, 3] cementing technique. Furthermore, aseptic loosening occurs at a consistent rate over time. Increased cement penetration is important to counter bone resorption. Increasing penetration also improves cement mantle toughness leading to better mechanical integrity of the bone-cement interface and reduces bone-cement interface stress. It is important to recognise that a cleaner and drier interface does improve bone-cement penetration. Techniques to improve the process include better cement formulations, drilling sclerotic bone, devices and implant features to increase pressurization, using negative pressure suction ports in the tibia. We have extensive experience with CarboJet, a method of CO2 gas jet cleaning and drying. This experience was developed during 20 years of performing TKA with NO tourniquet. Schnetler et al found that the “use of a tourniquet in TKA causes a paradoxical increase in total blood loss”. So, NO tourniquet TKA is becoming the new paradigm for knee arthroplasty in reconstructive orthopaedics. Goldstein reported that pressurised carbon dioxide jet lavage resulted in a 35% increase in cement penetration depth when used versus use of pulsatile saline lavage alone. Another important factor in increasing the cement interdigitation is the influence of lipids which significantly weakens the bond at the interfaces. If motion is allowed during cementation there is additional loss of penetration and therefore fixation. The pressurised carbon dioxide delivered by the CarboJet system actually pushes the lipid, fatty marrow up and out of the bone allowing it to be suctioned or lap dried from the interface surface. The NO tourniquet technique and the use of carbon dioxide jet gas delivery to improve the bone-cement interface in TKA will be demonstrated.
Total knee arthroplasty (TKA) is one of the most common orthopaedic operations performed worldwide and it is largely successful in pain relief and functional recovery. However, when pain persists post-operatively the thorough evaluation must be instituted. Extra-articular causes of knee pain include; hip pathology, lumbar spine degenerative disease or radicular symptoms, focal neuropathy, vascular disease, and chronic regional pain syndrome. Intra-articular causes of knee pain: infection, crepitation/clunk, patella osteonecrosis, patella mal-tracking, soft tissue imbalance, malalignment, arthrofibrosis, component loosening, implant wear, ilio-tibial band irritation, and bursitis. Other causes of pain to rule out are component overhang with soft tissue irritation, recurrent hemarthrosis secondary to synovial impingement or entrapment, non-resurfaced patella, and metal sensitivity. A careful history may reveal previous knee surgeries with delayed healing or prolonged drainage, chronology of sign and symptoms, co-morbid medical conditions, jewel or metal sensitivity. Physical exam should help with specific signs in the operated knee. Targeted local anesthetic blocks are helpful and response to lumbar sympathetic blocks determines presence of CRPS. Lab tests are important: ESR, CRP, WBC, aspiration with manual cell count and diff, leucocyte esterase dipstick, RA titers, metal derm patch testing, nuclear scans, CT best for rotational malalignment, and MARS MRI. More recently patient satisfaction as an outcome measure has shown TKA results not satisfactory in 11- 18% of patients. A discordance of patient vs. surgeon satisfaction exists so the following factors may help improve this: correct patient selection, establishing and correlating surgeon-patient expectations, peri-operative optimization of patient co-morbidities to help avoid preventable complications, use of pre-operative and post-operative pathways. Satisfaction rates can best be improved by addressing the previous points with patients prior to TKA surgery.
Short bone-conserving femoral stem implants were developed to achieve more physiological, proximal bone loading than conventional femoral stems. Concerns have arisen, however, that improved loading may be offset by lower primary stability because of the reduced potential area for bony contact. The aim of this study was to determine the primary stability of a novel short femoral stem compared with a conventional femoral stem following cementless total hip arthroplasty (THA), in a prospective, blinded, randomised, controlled trial using radiostereometric analysis.Background
Aims
Registry data from around the world demonstrates instability following primary THA is a leading indication for revision. However, the burden of THA dislocation is poorly documented and is not routinely recorded or reported at a national level. Our aim was to determine the rate of dislocation following primary THA in contemporary practice and in doing so determining the burden of THA dislocation to the NHS in Wales. We considered all Welsh residents who underwent primary THA from 2011–2016. Via clinical coding linkage using Patient Episode Database for Wales (PEDW), the equivalent of HES data in England, we were able determine re-admission for dislocation, revision THA following dislocation and all cause revision at 1 to 5 years follow-up.Introduction
Method
A patient in his thirties developed synovitis with grade 4 chondrolysis and a stiff knee with a fixed flexion deformity between three and six years following PLC and PCL reconstruction using LARS (Ligament Augmentation and Reconstruction System, Corin). There was histologic evidence of foreign body reaction, the knee was painful, swollen and stiff. We did not use any further LARS ligaments for soft tissue reconstructions of the kneein our practice. We commenced a recall programme for all 83 patients patients who underwent a soft tissue knee reconstruction using LARS. Of those contacted, 41 replied (49%) and 16 patients had symptoms (19%) and were investigated further with XRay, MRI and arthroscopy as indicated. We discovered a total of five patients had histologically proven synovitis with foreign body reactions (6%), three of whom had life-changing symptomatic pain, swelling and stiffness with degenerate changes (3.6%). These patients had undergone various reconstructions, including a) PLC only, b) ACL and PCL, c) PCL and PLC and d) ACL, PCL and PLC. A further single case of massive bone cyst formation was noted, following PCL reconstruction using LARS (1.2%).
Up to 60% of total hip arthroplasties (THA) in Asian populations arise from avascular necrosis (AVN), a bone disease that can lead to femoral head collapse. Current diagnostic methods to classify AVN have poor reproducibility and are not reliable in assessing the fracture risk. Femoral heads with an immediate fracture risk should be treated with a THA, conservative treatments are only successful in some cases and cause unnecessary patient suffering if used inappropriately. There is potential to improve the assessment of the fracture risk by using a combination of density-calibrated computed tomographic (QCT) imaging and engineering beam theory. The aim of this study was to validate the novel fracture prediction method against Six femoral heads from six subjects were tested, a subset (n=3) included a hole drilled into the subchondral area of the femoral head via the femoral neck (University of Leeds, ethical approval MEEC13-002). The simulated lesions provided a method to validate the fracture prediction model with respect of AVN. The femoral heads were then modelled by a beam loaded with a single joint contact load. Material properties were assigned to the beam model from QCT-scans by using a density-modulus relationship. The maximum joint loading at which each bone cross-section was likely to fracture was calculated using a strain based failure criterion. Based on the predicted fracture loads, all six femoral heads (validation set) were classified into two groups, high fracture risk and low fracture risk (Figure 1). Beam theory did not allow for an accurate fracture load to be found because of the geometry of the femoral head. Therefore the predicted fracture loads of each of the six femoral heads was compared to the mean fracture load from twelve previously analysed human femoral heads (reference set) without lesions. The six cemented femurs were compression tested until failure. The subjects with a higher fracture risk were identified using both the experimental and beam tool outputs.Introduction
Methods
There are many surgical, implant design and patient factors that should be considered in preclinical testing of hip replacement which are not being considered in current standards. The aim of this study was to develop a preclinical testing method that consider surgical positioning, implant design and patient factors and predict the occurrence and severity of edge loading under the combination of such conditions. Then, assess the safety and reliability of the implant by predicting the wear, deformation and damage of the implant bearings under worst case conditions. Ceramic-on-ceramic (CoC, 36mm, BIOLOX® delta, Pinnacle®, DePuy Synthes, UK) and metal-on polyethylene (MoP, 36mm, Marathon®, Pinnacle®, DePuy Synthes, UK) bearings were used for this study on multi-station multi-axis hip joint simulators. Two factors were varied, cup inclination angles (45° and 65°) and translational mismatch between the femoral head and acetabular cup (0, 2, 3 and 4 (mm)). Under each condition for both CoC and MoP bearings, three million cycles of gait cycle testing were completed with wear, deformation and/or damage measurements completed at one million cycle intervals. Other outputs of the study were the level of dynamic separation between the femoral head and acetabular cup during gait, the maximum force at the rim during edge loading when the head was sliding back to the cup confinement. Means and 95% confidence limits were determined and statistical analysis were done using one way ANOVA with significance taken at p<0.05.Introduction and Aims
Methods
Geometric variations of the hip joint can give rise to repeated abnormal contact between the femur and acetabular rim, resulting in cartilage and labrum damage. Population-based geometric parameterisation can facilitate the flexible and automated Parametric geometries can be developed into finite element models to assess the potential effects of morphological variations in bone on soft tissue strains. The aim of this study was to demonstrate the capabilities of our parameterisation research tool by assessing impingement severity resulting from a range of parametrically varied femoral and acetabular geometries. Custom made MATLAB (MathWorks) and Python codes[1] were used to generate bone surfaces, which were developed into finite element models in Abaqus (SIMULIA). Parametric femoral surfaces were defined by a spherical proximal head and ellipse sections through the neck/cam region. This method produced surfaces that were well fitted to bone geometry segmented from CT scans of cam patients and capable of producing trends in results similar to those found using segmented models. A simplified spherical geometry, including the labrum and acetabular cartilage, represented the acetabulum. Femoral parameters were adjusted to define relevant variations in cam size and position. Two radii (small and large cams) and two positions (anterior and superior cams) were defined resulting in four models. Alpha angles of these parametric femurs were measured in an anterior-posterior view and a cross-table lateral view using ImageJ (NIH). A further model was developed using a femur with a medium cam size and position, and the level of acetabular coverage and labrum length were varied. Bones were modelled as rigid bodies and soft tissues were modelled as transversely isotropic linearly elastic materials. With the acetabulum fully constrained in all cases, the femurs were constrained in translation and rotated to simulate flexion followed by internal rotation to cause impingement against the labrum.Introduction
Methods
This review aims to explore the methodologies used for estimating the direct and indirect costs attributed to back pain in developed countries. Six databases were searched to uncover studies about the direct and indirect costs of back pain published in English upto November 2016. Data extracted included study characteristics, cost categories and analysis methods. Results were synthesised descriptively.Purpose
Methods
To investigate whether the duration of pain has an influence on the clinical outcomes of patients with low back pain (LBP) managed through the North East of England Regional Back Pain and Radicular Pain Pathway (NERBPP). The NERBPP is a clinical pathway based upon NICE guidelines (2009) for LBP. Patients with LBP referred onto the NERBPP by their General Practitioner (GP) between May 2015 and January 2017 were included in this evaluation. Data from 635 patients, who provided pre and post data for pain (Numerical rating scale [NRS]), function (Oswestry Disability Index [ODI]) and quality-of-life (EuroQol [EQ5D]), were analysed using a series of covariate adjusted models in SPSS. Patients were categorised into four groups based upon pain duration: <3months, ≥3 to <6months, ≥6months to <12months, ≥12months.Aims
Patients and Methods
The study sought to determine the results of labral restoration among patients over age 60 compared to a cohort of younger adults. 21 consecutive patients over age 60 undergoing labral repair with minimum one-year follow-up were compared to a contemporaneous group of 21 patients age 18–55 matched for gender, degree of chondral damage, and associated FAI or dysplasia. Follow-up averaged 18.9 months (12 to 24 months). The study group averaged 63.2 years (61 to 71); with 20 FAI and one dysplasia. 19 had acetabular articular damage (2 grade IV, 11 grade III, 5 grade II, 1 grade I) and 6 had femoral changes (1 grade IV, 5 grade 3). The control group averaged 35.8 years (20 to 54). Average improvement among the study group was 28.1 points modified Harris Hip Score (mHHS) and 37.5 points iHOT; and among the control group, 21.2 points mHHS and 37.1 points iHOT. There was no statistically significant difference between the two groups in the amount of improvement, with statistically and clinically significant improvement noted in both. Two study group patients underwent total hip arthroplasty (THA) at average 10 months with one control group THA at 11 months. All three converted to THA had combined grade IV acetabular and grade III femoral damage. There were no repeat arthroscopies and no complications in either group. We conclude that patients over age 60 can benefit from arthroscopic labral repair with improved outcomes, modest rates of conversion to THA, and small risk of complication. Results are comparable to younger adults. Combined bipolar grade IV or grade III articular damage is a harbinger of conversion to THA, regardless of age.
The aim of this study was to describe the epidemiology of closed
isolated fractures of the femoral shaft in children, and to compare
the treatment and length of stay (LOS) between major trauma centres
(MTCs) and trauma units (TUs) in England. National data were obtained from the Trauma and Audit Research
Network for all isolated, closed fractures of the femoral shaft
in children from birth to 15 years of age, between 2012 and 2015.
Age, gender, the season in which the fracture occurred, non-accidental
injury, the mechanism of injury, hospital trauma status, LOS and
type of treatment were recorded.Aims
Patients and Methods
The pelvis is known to undergo significant movement during Total Hip Replacement (THR). We developed a 4D-tracking device employing an inertial measurement unit (IMU) to track changes in pelvic orientation during THR. The IMU was mounted on the iliac crest in 39 cases with tracking initiated at the commencement of surgery and digital logging of significant intra-operative milestones (i.e. acetabular impaction). The system was validated by videoing a select number of cases and the 4D model linked in real-time. Data were processed using a custom Java-based infrastructure to calculate roll (left/right) and tilt (flexion/extension). 19 patients underwent direct anterior approach (DAA) and 20 posterior approach (PA). Comparing DAA to PA, at acetabular impaction there was mean pelvic roll seen of 3.7°(range 0.5–10.1°) in the DAA group, and 5.6°(range 0.1–16.2°) in the PA group. Mean tilt in the DAA group was 3.7°(range: 0.2–7.1°) and in the PA group was 1.7°(range: 0.2–4.3°). Mean BMI in the DAA group was 25.2(range: 18.4–34.2) and 29.1(range: 21.5–42.4). There was no direct correlation between BMI and the amount of roll or tilt recorded for individual patients. The IMU tracking device provided a useful and real-time method of assessing pelvic orientation during THR via both the DAA and posterior approach. Specific variations in tilt and roll are consistent with previous literature. Significant variation in the pattern of pelvic movement was noted to be dependent on the approach and the position of the patient on the operating table.
The aim of this study was to determine whether patients with
metal-on-metal (MoM) arthroplasties of the hip have an increased
risk of cardiac failure compared with those with alternative types
of arthroplasties (non-MoM). A linkage study between the National Joint Registry, Hospital
Episodes Statistics and records of the Office for National Statistics
on deaths was undertaken. Patients who underwent elective total
hip arthroplasty between January 2003 and December 2014 with no
past history of cardiac failure were included and stratified as
having either a MoM (n = 53 529) or a non-MoM (n = 482 247) arthroplasty.
The primary outcome measure was the time to an admission to hospital
for cardiac failure or death. Analysis was carried out using data
from all patients and from those matched by propensity score.Aims
Patients and Methods
We present a retrospective review of patients treated with extracorporeally
irradiated allografts for primary and secondary bone tumours with
the mid- and long-term survivorship and the functional and radiographic
outcomes. A total of 113 of 116 (97.4%) patients who were treated with
extracorporeally irradiated allografts between 1996 and 2014 were
followed up. Forms of treatment included reconstructions, prostheses
and composite reconstructions, both with and without vascularised
grafts. Survivorship was determined by the Kaplan-Meier method.
Clinical outcomes were assessed using the Musculoskeletal Tumor
Society (MSTS) scoring system, the Toronto Extremity Salvage Score
(TESS) and Quality of Life-C30 (QLQ-30) measures. Radiographic outcomes
were assessed using the International Society of Limb Salvage (ISOLS)
radiographic scoring system.Aims
Patients and Methods
The number of patients undergoing arthroscopic surgery of the
hip has increased significantly during the past decade. It has now
become an established technique for the treatment of many intra-
and extra-articular conditions affecting the hip. However, it has
a steep learning curve and is not without the risk of complications.
The purpose of this systematic review was to determine the prevalence
of complications during and following this procedure. Preferred Reporting Items for Systematic Reviews and Meta-Analyses
guidelines were used in designing this study. Two reviewers systematically
searched the literature for complications related to arthroscopy
of the hip. The research question and eligibility criteria were
established Aims
Materials and Methods
Osteosynthesis to conserve femoral head following neck of femur (NOF) fractures has reported failure rates of 36 to 47% at 2 years. However, the long-term outcomes of THAs performed for failed osteosynthesis is yet to be elucidated. This study aims to report on long term outcome of primary THAs post failed osteosynthesis for NOF fracture. Consecutive patients with THA for failed NOF osteosynthesis managed by a single unit between January 1974 and December 2009 were included. Clinical and radiological outcomes of all 72 patients were analysed. Patients with minimum follow-up of 5 years were included. Those with less than 5 years of follow-up were reviewed for failures.Introduction
Methods
The ideal operative treatment of displaced sub capital femoral fractures in the elderly is controversial. Recently, randomised controlled trials have suggested a better outcome with the use of total hip arthroplasty (THA) to treat displaced intra capsular fractures of the femur for elderly patients in good health. More recently the concept of dual mobility cups is being promoted to avoid dislocations in this cohort of patients. However, overall there is limited evidence to support the choice between different types of arthroplasty. Dislocation remains a main concern with THA, especially when a posterior approach is used. We analysed the outcome of 115 primary THR (112 cements and 3 uncemented) THR using a posterior approach with soft tissue repair in active elderly patients presenting with displaced intra capsular femoral neck fractures. Size 28 mm head was used in 108 and a size 32 mm head in the rest. All surgery was performed by specialist hip surgeons. Satisfactory results were noted in terms of pain control, return to pre-morbid activity and radiological evidence of bone implant osteo-integration. The 30-day mortality was nil. There were two dislocations and only one needed revision surgery due to recurrent dislocation. In conclusion, with optimal patient selection, THA seems to provide a good functional outcome and pain relief in the management of displaced intracapsular femoral neck fractures. Excellent outcome can be achieved when done well using the standard cemented THR and with 28mm head. A good soft tissue repair and a specialist hip surgeon is preferable.
Prosthetic joint infection continues to remain a diagnostic challenge for unhappy primary arthroplasty of hip and knees. There is increasing dependence upon alpha-defensin test to make key decisions like whether to revise or not & to decide between one-stage versus two-stage. This study aims to assess diagnostic accuracy of alpha-defensin test in determining prosthetic hip & knee infection and to provide guidance for appropriate use of this novel but expensive investigation. Retrospective review of all alpha-defensin investigated patients in an orthopaedic institute between February 2015 & March 2017 was performed. Clinical and radiological outcomes including re-infections, re-operations were analysed and alpha-defensin outcomes were compared with that of other available investigations.Aim
Methods
Conservative treatment of acute AT ruptures with functional rehabilitation has demonstrated superior results with equal reported re-rupture rates but without the added complications of surgical treatment. There is no consensus on the duration and method of treatment using functional rehabilitation regimes. The purpose of this paper is to define our treatment regime, the Leicester Achilles Management Protocol (LAMP), supported with patient reported outcomes and objective measures of assessment. All patients with an acute achilles tendon rupture were treated with the same non-operative LAMP functional rehabilitation regime in a VACOped boot for 8 weeks. 12 months post rupture ATRS scores and objective measures of calf muscle girth and heel raise height were obtained and analysed. Venous thromboembolic rates and rates of re-rupture were recorded.Background
Methods
One of the major concerns of hinge knees have been reported in literature is mechanical failure. Failure in the form of component fracture (2–10%) and hinge dislocation/ failure are worrisome. In addition, higher risk of aseptic loosening with hinge knee prosthesis has been attributed to stress transfer at bone cement interface. Retrospective review of clinical and radiological results of 71 consecutive patients operated at single centre using Smiles hinge knee (Stanmore implants) between 2010 and 2014. Data was collected till the latest follow up. Mechanical failure due to any reason was considered as primary end point. Radiological evidence of aseptic loosening was considered to be one of the surrogate end points.Background
Methods
This study reports on a secondary exploratory analysis of the early clinical outcomes of a randomised clinical trial comparing robotic arm-assisted unicompartmental knee arthroplasty (UKA) for medial compartment osteoarthritis of the knee with manual UKA performed using traditional surgical jigs. This follows reporting of the primary outcomes of implant accuracy and gait analysis that showed significant advantages in the robotic arm-assisted group. A total of 139 patients were recruited from a single centre. Patients were randomised to receive either a manual UKA implanted with the aid of traditional surgical jigs, or a UKA implanted with the aid of a tactile guided robotic arm-assisted system. Outcome measures included the American Knee Society Score (AKSS), Oxford Knee Score (OKS), Forgotten Joint Score, Hospital Anxiety Depression Scale, University of California at Los Angeles (UCLA) activity scale, Short Form-12, Pain Catastrophising Scale, somatic disease (Primary Care Evaluation of Mental Disorders Score), Pain visual analogue scale, analgesic use, patient satisfaction, complications relating to surgery, 90-day pain diaries and the requirement for revision surgery.Objectives
Methods
Dislocation and instability remain leading cause of failure following THA. We present a single-surgeon 10-year experience with use of Dual Mobility (DM) bearings in Primary and Revision THA using posterior approach. 127 DM bearings were implanted between September 2006 – September 2016; 102 in high-risk primary THA's and 25 revision THA's for either treatment or prevention of instability. Selection for DM bearing followed individual patient risk assessment. Criteria for use of DM bearing were presence of multiple risk factors. Mean age was 72.9 years. 100 Mono-block DM implants, 22 Modular DM implants and 5 custom-made DM devices were implanted. Revision cohort included those used in conjunction with a cage or porous metal augments. 2 dislocations (1.6%) were observed, both in the Revision group, 1 was recurrent requiring revision to constrained liner. Primary group had 2 revisions; 1 peri-prosthetic fracture and 1 deep infection. No DM bearing specific complications were observed. A constructed life table calculated survival function with endpoint set as revision for any reason demonstrated a cumulative survival of 94% at 7.4 years. In high-risk patients, DM bearings are successful at preventing and treating dislocation in THA. Primary cohort in this study all had multiple risk factors for instability but no dislocations or bearing specific complications were observed. Dislocations observed in Revision group were associated with major soft tissue deficiency. This study adds to the promising results already reported with DM THA articulations and should be considered for patients at risk of dislocation or instability. Runner Up – Best Paper Award
Our aim in this study was to describe a continuing review of
11 total hip arthroplasties using 22.225 mm Alumina ceramic femoral
heads on a Charnley flanged femoral component, articulating against
a silane crosslinked polyethylene. Nine patients (11 THAs) were reviewed at a mean of 27.5 years
(26 to 28) post-operatively. Outcome was assessed using the d’Aubigne
and Postel, and Charnley scores and penetration was recorded on
radiographs. In addition, the oxidation of a 29-year-old shelf-aged
acetabular component was analysed.Aims
Patients and Methods
Non-traumatic osteonecrosis of the femoral head
is a potentially devastating condition, the prevalence of which
is increasing. Many joint-preserving forms of treatment, both medical
and surgical, have been developed in an attempt to slow or reverse
its progression, as it usually affects young patients. However, it is important to evaluate the best evidence that is
available for the many forms of treatment considering the variation
in the demographics of the patients, the methodology and the outcomes
in the studies that have been published, so that it can be used
effectively. The purpose of this review, therefore, was to provide an up-to-date,
evidence-based guide to the management, both non-operative and operative,
of non-traumatic osteonecrosis of the femoral head. Cite this article:
The US obesity epidemic has transcended into the arthroplasty patient population and surgeons must assess whether obesity is a risk factor for poor outcomes in total joint arthroplasty (TJA) and determine how it should be managed in order to insure good clinical outcomes. In the United States, 34.9% of adults are currently obese (BMI > 30). In a recent study, 54.5% of patients reporting to arthroplasty clinics in the US were obese. We performed a recent literature review to determine how obesity impacts outcomes in total hip and knee arthroplasty and what must be done to improve outcomes in the obese arthroplasty patient. We know that obesity and its associated comorbid conditions do have worse outcomes and increased complications in TJA patients. We also know that complications proportionately increase with increasing severity of obesity. The super-obese population is at the greatest risk of complication following TJA and pre-operative screening and management is essential in reducing complications. Although weight loss is important, our bariatric data has shown that it does not solve the problem of obesity in itself and the patient's metabolic state is likely a more important issue. Implant selection is important and strong consideration should be given to avoiding direct anterior approach in the THA obese patient. Understanding of obesity specific complications and treatment options is crucial for patient counseling and optimisation to ensure successful treatment in obese TJA patients.
TKA is one of the most common orthopaedic operations performed worldwide and it is largely successful in pain relief and functional recovery. However, when pain persists post-operatively the thorough evaluation must be instituted. Extra-articular causes of knee pain include; hip pathology, lumbar spine degenerative disease or radicular symptoms, focal neuropathy, vascular disease, and chronic regional pain syndrome. Intra-articular causes of knee pain: infection, crepitation/ clunk, patella osteonecrosis, patella mal-tracking, soft tissue imbalance, malalignment, arthrofibrosis, component loosening, implant wear, ilio-tibial band irritation, and bursitis. Other causes of pain to rule out are component overhang with soft tissue irritation, recurrent hemarthrosis secondary to synovial impingement or entrapment, non-resurfaced patella, and metal sensitivity. A careful history may reveal previous knee surgeries with delayed healing or prolonged drainage, chronology of sign and symptoms, co-morbid medical conditions, jewel or metal sensitivity. Physical exam should help with specific signs in the operated knee. Targeted local anesthetic blocks are helpful and response to lumbar sympathetic blocks determines presence of CRPS. Lab tests are important: ESR, CRP, WBC, aspiration with manual cell count and diff, leukocyte esterase dipstick, RA titers, metal derm patch testing, nuclear scans, CT best for rotational malalignment,, and MARS MRI. More recently patient satisfaction as an outcome measure has shown TKA results not satisfactory in 11 – 18% of patients. A discordance of patient vs. surgeon satisfaction exists so the following factors may help improve this: correct patient selection, establishing and correlating surgeon-patient expectations, peri-operative optimisation of patient comorbidities to help avoid preventable complications, use of pre- and post-operative pathways. Satisfaction rates can best be improved by addressing the previous points with patients prior to TKA surgery.
We used the National Joint Registry for England, Wales, Northern Ireland and the Isle of Man (NJR) to investigate the risk of revision due to prosthetic joint infection (PJI) for patients undergoing primary and revision hip arthroplasty, the changes in risk over time, and the overall burden created by PJI. We analysed revision total hip arthroplasties (THAs) performed due to a diagnosis of PJI and the linked index procedures recorded in the NJR between 2003 and 2014. The cohort analysed consisted of 623 253 index primary hip arthroplasties, 63 222 index revision hip arthroplasties and 7585 revision THAs performed due to a diagnosis of PJI. The prevalence, cumulative incidence functions and the burden of PJI (total procedures) were calculated. Overall linear trends were investigated with log-linear regression.Objectives
Methods
Synovasure has been designed and validated for use in the diagnosis of periprosthetic joint infection (PJI). It has a reported sensitivity of 97.4% (CI 86.1–99.6%) and specificity of 95.8% (CI 90.5–98.6%), higher than the variable results reported for aspiration by most units. At a cost of £500 per test, we aimed to establish cost-effectiveness and diagnostic accuracy, to determine its role in routine practice. We developed a protocol for pre-operative aspiration or intra-operative use. Prerequisites for entry were a high index of clinical suspicion for PJI and equivocal standard investigations. All cases were discussed at the lower limb arthroplasty MDT and approved only if use would change clinical management. Over 15 months, 36 tests were approved for 22 aspirations (5 hip, 17 knee) and 14 intra-operative cases (7 hip, 7 knee). 10/36 had undergone previous revision surgery. 35/36 cases complied with the protocol. All 22 Synovasure aspirations were negative, corresponding to the microbiology in all but one case; thought to be a contaminant. In the intra-operative group there was one true positive and 12 true negative tests, giving a sensitivity of 100% (95% CI 2.5–100%) and a specificity of 100% (95% CI 73.5–100%). Synovasure influenced decision making in 34/36 procedures. One test failed and in another there was evidence of frank infection. In 11 cases no surgery was performed versus a potential two-stage revision and in 21 cases a single rather than two-stage revision was performed. Resulting in estimated savings of £686,690, offset against a cost of £18,000. The Synovasure test was found to be sensitive and specific and can aid decision-making particularly in complex cases with an equivocal diagnosis of PJI. The use of this test through a robust protocol driven peer review MDT process not only reduces patient morbidity but drives significant efficiency savings.
Early intervention is advocated to prevent long-term work absence due to musculoskeletal (MSK) pain. The SWAP trial tested whether adding a vocational advice (VA) service to best current care led to fewer days work absence over 4 months. The SWAP trial was a cluster randomised controlled trial in 6 general practices, 3 randomised to best current care (control), 3 randomised to best current care and the VA service (intervention). Patients were ≥18 years, absent from work ≤6 months or struggling at work due to MSK pain. Primary outcome was number of days absent over 4 months. Exploratory subgroup analyses examined whether the effect was larger for patients with spinal pain compared to other MSK pain.Introduction
Methods
The stability of the elbow joint following an acute elbow dislocation is dependent on associated injuries. The ability to identify these concomitant injuries correctly directs management and improves the chances of a successful outcome. Interpretation of plain radiographs in the presence of either a dislocation or post-reduction films with plaster in-situ is difficult. This study aimed to assess the ability of orthopaedic registrars to accurately identify associated bony injuries on initial plain radiographs using CT as the gold standard for comparison. Patients over the age of 16 years undergoing an elbow CT scan within one week of a documented elbow dislocation between 1st June 2010 and 1st June 2014 were included in the study. Three orthopaedic registrars independently reviewed both the initial dislocation and immediate post reduction plain radiographs to identify any associated bony injuries. This radiograph review was repeated by each registrar after two weeks. The incidence of associated injuries as well as the inter- and intra-observer variability was calculated.Introduction
Methods
The aim of this study was to examine the real time A total of 50 patients (83 hips) underwent 4D dynamic CT scanning
of the hip, producing real time osseous models of the pelvis and
femur being moved through flexion, adduction, and internal rotation.
The location and size of the cam deformity and its relationship
to the angle of flexion of the hip and pelvic tilt, and the position
of impingement were recorded.Aims
Patients and Methods
Since 2011, the knee service at the Nuffield Orthopaedic Centre has been offering a neutralising medial opening wedge high tibial osteotomy (HTO) to a group of patients presenting with early medial osteoarthritis of the knee, varus alignment and symptoms for more than 2 years. During development of this practice an association was observed between this phenotype of osteoarthritis and the presence of CAM deformity at the hip. A retrospective cohort study. All patients who underwent HTO since 2011 were identified (n=30). Comparator groups were used in order to establish whether meaningful observations were being made: Control group: The spouses of a high-risk osteoarthritis cohort recruited for a different study at our unit (n=20) Pre-arthroplasty group: Patients who have undergone uni-compartmental arthroplasty (UKA) for antero-medial osteoarthritis (n=20)All patients had standing bilateral full-length radiographs available for analysis using in house developed Matlab-based software for hip measurements and MediCAD for lower limb alignment measurements.Background
Methods
Frequency of primary total hip (THA) and total knee (TKA) arthroplasty procedures is increasing, with a subsequent rise in revision procedures. This study aims to describe timing and excess surgical mortality associated with revision THA and TKA compared to those on the waiting list. All patients from 2003–2013 in a single institution who underwent revision THA and TKA, or added to the waiting list for the same procedure were recorded. Mortality rates were calculated at cutoffs of 30- and 90-days post-operation or addition to the waiting list.Background
Methods
Functional restoration of patella kinematics is an essential component of TKA, whether the patella is replaced or not. This goal is accomplished by a multifactorial approach: establish proper component position and alignment, especially rotation; avoid IR of the femoral and ER of the tibial components; maintain correct joint line position; achieve symmetrical soft tissue balance. Most modern TKA designs have an anatomic trochlear groove shape to enable midline tracking. Patella implants are better designed as well with three equilateral lugs for fixation and either dome or anatomic shape. The apex of the patella component should be aligned with the apex of the patella raphe which is more medial than lateral. This method leaves an island of exposed lateral patella facet which is managed with the “lateral slat technique” to be described. It is essentially an intraosseous lateral release. The early mobilization of modern TKA patients demands watertight closure to prevent soft tissue attenuation and late tracking issues. When confronted with a patient with a laterally dislocated patella, implementation of the “lateral slat technique” should be done at the approach to obtain midline tracking. Such patients require a median parapatellar (MPP) approach and may need distal-lateral vastus medialis advancement (Insall procedure). Adherence to the principles iterated herein will produce a happy patient with good patello-femoral kinematics and function.
