Abstract. Objectives. Total hip replacement (THR) is one of the most successful and cost-effective interventions in orthopaedic surgery. Dislocation is a debilitating complication of THR and managing an unstable THR constitutes a significant clinical challenge. Stability in THR is multifactorial and is influenced by surgical, patient and implant related factors. It is established that larger diameter femoral heads have a wider impingement-free range of movement and an increase in jump distance, both of which are relevant in reducing the risk of dislocation. However, they can generate higher frictional torque which has led to concerns related to increased wear and loosening. Furthermore, the potential for taper corrosion or trunnionosis is also a potential concern with larger femoral heads, particularly those made from cobalt-chrome. These concerns have meant there is hesitancy among surgeons to use larger sized heads. This study presents the comparison of clinical outcomes for different head sizes (28mm, 32mm and 36mm) in primary THR for 10,104 hips in a single centre. Methods. A retrospective study of all consecutive patients who underwent primary THR at our institution between 1st April 2003 and 31st Dec 2019 was undertaken. Institutional approval for this study was obtained. Demographic and surgical data were collected. The primary outcome measures were all-cause revision, revision for dislocation, and all-cause revision excluding dislocation. Continuous descriptive statistics used means, median values, ranges, and 95% confidence intervals where appropriate. Kaplan-Meier survival curves were used to estimate time to revision. Cox proportional hazard regression analysis was used to compare revision rates between the femoral head size groups. Adjustments were made for age at surgery, gender, primary diagnosis, ASA score, articulation type, and fixation method. Results. 10,104 primary THRs were included; median age 68.6 years with 61.5% females. A posterior approach was performed in 71.6%. There were 3,295 hips with 28 mm heads (32.6%), 4,858 (48.1%) with 32 mm heads and 1,951 (19.3%) with 36 mm heads. Overall rate of revision was 1.7% with the lowest rate recorded for the 36mm group (2.7% vs. 1.3% vs. 1.1%). Cox regression analysis showed a decreased risk of all-cause revision for 32mm & 36mm head sizes as compared to 28mm; this was statistically significant for the 32mm group (p = 0.01). Risk of revision for dislocation was significantly reduced in both 32mm (p = 0.03) and 36mm (p = 0.03) head sizes. Analysis of all cause revision excluding dislocation showed no significant differences between head sizes. Conclusion. There was a significantly reduced risk of revision for all causes, but particularly revision for dislocation with larger head sizes (36mm & 32mm vs. 28mm). Concerns regarding increased risk of early revision for aseptic loosening, polyethylene wear or taper corrosion with larger heads appear to be unfounded in this cohort of 10,104 patients with a mean of 6.0-year follow-up. Declaration of Interest. (b) declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research reported:I declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project

Acute post-operative urinary retention (POUR) is a recognized complication following lower limb arthroplasty. Its occurrence may have patient and ultimately medico-legal implications. Identifying high-risk patients and the associated risk factors pre-operatively, is vital to tackle this issue and reduce its occurrence, which ultimately, may enhance the overall success of our operations. Our aim was to assess the incidence of POUR following elective lower limb arthroplasty and analyze the related factors that could potentially predict the likelihood of developing POUR in our patient cohort. A prospective audit of 158 patients was conducted in our department. POUR was defined as inability to pass urine voluntarily within the first 24 hours following elective lower limb arthroplasty leading to the insertion of a urinary catheter. Surgical-related factors including intra-operative fluid use, type of spinal anesthetic, duration of surgery, time from surgery till insertion of a urinary catheter as well as patient-related factors including medication, urological history and Body Mass index (BMI) was collected and analyzed. 21 (13.3%) patients developed post-operative urinary retention, 11 (52%) and 10 (48%) following knee and hip replacements respectively. Of which, 19 (90.5%) were male and 2 (9.5%) were female with an average age of 66 yrs. 13 (62%) had a previous urological history and 10 (48%) were on retention associated medication. Bupivacaine as a spinal anesthetic was associated with an increased risk of developing post-operative urinary retention. The average time till catheter insertion was 14 hrs. Only 2 (10%) had an unsuccessful TWOC on discharge. Bupivacaine as a spinal anesthetic and a previous urological history can be considered as risk factors for the development of POUR. Pre-operative urinary catheterization should be considered in this high-risk group of patients

There is a growing requirement by governmental and other funders of research, that investigators pay attention to and integrate considerations of sex and gender in their health research studies. Doing so, the argument goes, will reduce data waste, lead to the generation of more complete and accurate evidence to apply to the delivery of health care, and hopefully improve outcomes for both male and female patients. Yet, it is not always clear what sex and gender mean and how best to apply these to the study of diverse health conditions and health service delivery. In this presentation sex, gender and other related factors will be considered in the context of fractures, fracture repair, and post-operative management. Examples of sex and gender bias, sex and gender differences, and the integration of sex and gender in research on fracture and fracture repair will be presented

Ceramic-on-ceramic (CoC) total hip arthroplasty (THA) can produce articular noise during the normal activities, generating discomfort to the patient. THA noise has to be investigated also as a potential predictor and a clinical sign of prosthetic failure. An observational study has been carried out to characterize the noise in CoC cementless THA, and to analyze the related factors. A total of 46 patients with noisy hip have been enrolled in 38 months, within the follow-up protocol normally applied for the early diagnosis of ceramic liner fracture [1]. Noise recording was based on a high-quality audible recorder (mod. LS 3, Olympus, Japan) and a portable ultrasonic transducer (mod USB AE 1ch, PAC, USA). The sensors for noise recording were applied to the hip of the patient during a sequence of repeatable motorial activities (forward and backward walking, squat, sit in a chair, flexion and extension of the leg). Sessions were also video-recorded to associate the noise emission to the specific movements. Each noise event was initially identified by the operator and therefore classified by comparison to the spectral characteristics (duration, intensity and frequency) of the main noise types. Number and spectral characteristics of noise events were obtained and correlated to the factors describing the clinical status of the patient, the surgical approach, the prosthetic device implanted. The study investigated also the noise as a sign of implant failure, by comparison with the total number of implants failed in the cohort during the study. We observed three types of noise with the main spectral characteristics in agreement to the literature: clicking, squeaking and popping. Among the identified types of noise, squeaking showed the longest duration and the highest amplitude. The 63% of hip presented the emission of just one type of noise, while the remaining a mix of types. The movement with the highest presence of noise was walking, followed by squat. Correlation was found between the noise type and the dimension of the ceramic head (p<0.001), with the sizes of 32 mm more affected by squeaking that the smaller one. Squeaking appeared before during the follow-up than the other types of noise. The 35% (16/46) of the noisy hips were revised during the study. Among the revised hips, the 81% (13/16) were affected by impingement and/or severe damage of the prosthetic components. The antiversion of the cup (p=0.008), the presence of debris in the synovial fluid (p=0.021) and the average frequency of squeaking (p=0.006) were significant predictors for the revision, but it has to be mentioned that the squeaking data was obtained on a small subset of revised patients. Ultrasonic analysis did not show significant correlations. The study presented and validated an experimental procedure to analyze noisy hips in clinical trials. Noise is confirmed to be a significant parameter in the follow-up evaluation of ceramic THA

There is a critical need for safe innovation in total joint replacements to address the demands of an ageing yet increasingly active population. The development of robust implant designs requires consideration of uncertainties including patient related factors such as bone morphology but also activity related loads and the variability in the surgical procedure itself. Here we present an integrated framework considering these sources of variability and its application to assess the performance of the femoral component of a total hip replacement (THR). The framework offers four key features. To consider variability in bone properties, an automated workflow for establishing statistical shape and intensity models (SSIM) was developed. Here, the inherent relationship between shape and bone density is captured and new meshes of the target bone structures are generated with specific morphology and density distributions. The second key feature is a virtual implantation capability including implant positioning, and bone resection. Implant positioning is performed using automatically identified bone features and flexibly defined rules reflecting surgical variability. Bone resection is performed according to manufacturer guidelines. Virtual implantation then occurs through Boolean operations to remove bone elements contained within the implant's volume. The third feature is the automatic application of loads at muscle attachment points or on the joint contact surfaces defined on the SSIM. The magnitude and orientation of the forces are derived from models of similar morphology for a range of activities from a database of musculoskeletal (MS) loads. The connection to this MS loading model allows the intricate link between morphology and muscle forces to be captured. Importantly, this model of the internal forces provides access to the spectrum of loading conditions across a patient population rather than just typical or average values. The final feature is an environment that allows finite element simulations to be run to assess the mechanics of the bone-implant construct and extract results for e.g. bone strains, interface mechanics and implant stresses. Results are automatically processed and mapped in an anatomically consistent manner and can be further exploited to establish surrogate models for efficient subsequent design optimization. To demonstrate the capability of the framework, it has been applied to the femoral component of a THR. An SSIM was created from 102 segmented femurs capturing the heterogeneous bone density distributions. Cementless femoral stems were positioned such that for the optimal implantation the proximal shaft axis of the femurs coincided with the distal stem axis and the position of the native femoral head centre was restored. Here, the resection did not affect the greater trochanter and the implantations were clinically acceptable for 10000 virtual implantations performed to simulate variability in patient morphology and surgical variation. The MS database was established from musculoskeletal analyses run for a cohort of 17 THR subjects obtaining over 100,000 individual samples of 3D muscle and joint forces. An initial analysis of the mechanical performance in 7 bone-implant constructs showed levels of bone strains and implant stresses in general agreement with the literature

Summary. Biomechanically, a 2° screw deviation from the nominal axis in the PFLCP leads to significantly earlier implant failure. Screw deviation relies on a technical error on insertion, but in our opinion cannot be controlled intraoperatively with the existing instrumentation devices. Background. Several cases of clinical failure have been reported for the Proximal Femoral Locking Compression Plate (PFLCP). The current study was designed to investigate the failure mode and to explore biomechanically the underlying mechanism. Specifically, the study sought to determine if the observed failure was due to technical error on insertion or due to implant design. Methods. To exclude patient and fracture type related factors, an abstract foam block model simulating an unstable pertrochanteric fracture was created for three study groups with six specimens each (n=6). Group 1 was properly instrumented according to the manufacturer's guidelines. In Group 2 and 3, the first or second screw was placed in a posterior or anterior off-axis orientation by 2° measured in the transversal plane, respectively. Each construct was tested cyclically until failure using a test setup and protocol simulating complex axial and torsional loading. Radiographs were taken prior to and after the tests. Force, number of cycles and failure mode were compared. Results. The 2° screw deviation from the nominal axis led to significantly earlier construct failure in Group 2 and 3. The failure mode consisted of loosening of the off-axis screw due to disengagement with the plate, resulting in loss of construct stiffness and varus collapse of the fracture. Conclusions. In our biomechanical test setup, a screw deviation of only 2° from the nominal axis consistently led to the failure mode observed clinically. In our opinion, screw deviation mostly relies on technical error on insertion. But, proper screw insertion may be difficult or impossible with the existing instrumentation devices, especially as it cannot be controlled or guaranteed intraoperatively

The surgical treatment options for patients who have sustained an intra-capsular hip fracture can vary depending on a number of patient and fracture related factors. Currently most national guidelines support the use of cemented prostheses for patient undergoing hemi-arthroplasty surgery. Uncemented prostheses are commonly used for a variety of indications including those patients who have significant medical co-morbidities. To determine whether cemented hemi-arthroplasty is associated with a higher post operative mortality when compared to uncemented procedures. Data was extracted from the Scottish SMR01 database from 01/04/1997 from all patients who were admitted to hospital after sustaining a hip fracture. We investigated mortality at day 1, 2, 4, 7, 30, 120 and 1 year from surgery vs. that on day 0. In order to control for the effects of confounding variables between patients cohorts, 12 case-mix variable were used to construct a multivariable logistic regression analysis model to determine the independent effect of prosthesis fixation method. There were 64,979 patients were included in the study. Mortality for osteosynthesis of extra-capsular fractures was consistently lower when compared to that for surgical procedures for intra-capsular fractures. At day 0, uncemented hemi-arthroplasty operations had a lower associated mortality (p<0.001) when compared to cemented implant designs. Unadjusted figures showed an increased mortality equal to 1 extra death per 424 procedures. By day 1 this had become 1 extra death per 338 procedures. By day 7 cumulative mortality was less for cemented than for uncemented procedures though this did not reach significance until day 120. When compared to uncemented fixation techniques, cemented hemiarthroplasty is associated with a higher mortality in the immediate postoperative period. However, by day 120 and beyond the trend is reversed

The surgical treatment options for patients who have sustained an intra-capsular hip fracture can vary depending on a number of patient and fracture related factors. Currently most national guidelines support the use of cemented prostheses for patient undergoing hemiarthroplasty surgery. Uncemented prostheses are commonly used for a variety of indications including those patients who have significant medical co-morbidities. To determine whether cemented hemiarthroplasty is associated with a higher post operative mortality when compared to uncemented procedures. Data were extracted from the Scottish SMR01 database from 01/04/1997 from all patients who were admitted to hospital after sustaining a hip fracture. We investigated mortality at day 1,2,4,7,30, 120 and 1 year from surgery vs. that on day 0. In order to control for the effects of confounding variables between patients cohorts, 12 case-mix variable were used to construct a multivariable logistic regression analysis model to determine the independent effect of prosthesis design. There were 52283 patients included in the study. Mortality for osteosynthesis of extra-capsular fractures was consistently lower when compared to that for surgical procedures for intra-capsular fractures. At day 0, uncemented hemiarthroplasty had a lower associated mortality (p<0.001) when compared to cemented implant designs. However, this increased mortality was equal to 1 extra death per 2000 procedures. From day 1 onward mortality for cemented procedures was equal to or lower than that of uncemented. By day 4, cumulative mortality was less for cemented than for uncemented procedures. Complication and re-operation rate was significantly higher in the uncemented cohort. The use of uncemented hemiarthroplasty for the treatment of intra-capsular hip fractures cannot be justified in terms of early/late post-operative mortality

Summary Statement. Objectifying postoperative recovery of patients with comminuted tibial plateau fractures treated with a unilateral plate trough the use of a gait analysis system. Introduction. Gait analysis has been a proved method for assessing postoperative results in patients with different orthopedic afflictions of the lower limb such as hallux valgus, ankle instabilities, knee osteoarthritis and arthroplasties but it has rarely been used for postoperative assessment of proximal tibial fractures. The more traditional means of quantifying postoperative articular step-off and limb axis deviations such as conventional X Rays and CT scanning and the clinician and patient completed scores that subjectively assess the outcome are complemented by the analysis of gait patterns set to objectify the most important patient related factor - the gait. As controversy exists in literature regarding the optimal treatment for severe tibial plateau fractures we proposed a gait study to evaluate locked angle unilateral plate osteosynthesis. Patient & Method: A computerised motion analysis system and a sensor platform were used to gather gait data from 15 patients with unilateral tibial plateau fractures graded Shatzker V and VI treated with a angular stable locked lateral plate osteosynthesis. Gait analysis was performed postoperatively based on patient availability and as soon as ambulation was possible and permitted without auxiliary support (crutches) at 4 (mean of 4,6), 6 (mean of 6,2) and 12 (mean of 11,7) months respectively, at a naturally comfortable walking. All patients were evaluated using classic anteroposterior and lateral knee radiography and were asked to fill the KOOS score questionnaire at the time of the gait analysis session. Results. The spatial-temporal and angular parameters revealed the expected postoperative decrease in ROM in both flexion and extension of the knee. Step and stance time objectively decreased between measuring session with an increase in single support of 3,7% mean value. A constant increase in walking speed was noted from a mean of 42 cm/sec (cadence of 31 st/min) at 4 months to a speed of 90 cm/sec (mean of 49 st/min cadence). We also determined a asymmetrical and wider walking base, increased area of support during single leg standing, decreased stance and increased swing phases for the injured knee compared to contralateral. Discussion. All patients in the study were subjectively satisfied with the results of the treatment, however we were able to detect quantifiable differences of gait parameters such between the injured and the contralateral knee such as step, stance and swing time and in knee flexion and adduction, combined with a modified, wider walking base. Ground reaction forces were strongly related to score improvement and thus directly reflected the healing at the fracture site

Introduction. Transtrochanteric curved varus osteotomy is one of the effective joint-preserving operations for osteonecrosis (ON) of the femoral head. We correlated various factors with the radiological outcome of this procedure. Methods. We reviewed 74 hips in 63 patients who had a minimum follow-up of 5 years after transtrochanteric curved varus osteotomy for the treatment of ON. There were 28 men and 35 women who had a mean age of 33 years (range, 15 to 68 years) at the time of surgery. Clinical assessment was made based on the Harris hip score (HHS). Radiographically, we investigated various factors; affected lesion, stage and type (localization of the necrotic lesion) of ON, varus degree, post-operative intact ratio, progression of collapse, and joint-space narrowing. On the basis of postoperative radiographs, the hips were divided into 2 groups (Group I: either the progression of collapse or joint-space narrowing, Group II: neither progression of collapse or joint-space narrowing). The related factors with radiological outcome were analyzed by using multivariate analysis (Stepwise discriminant analysis). Results. Sixty-seven of 74 hips (90.5%) survived without conversion to total hip arthroplasty at final follow-up. The mean preoperative HHS was 60 points (range, 34 to 85 points), which improved to 85 points (range, 51 to 100 points) at final follow-up. Thirteen hips were categorized as Group I and 61 hips as Group II. Both the post-operative intact ratio and type of ON affected the radiological outcome. Regarding post-operative intact ratio, the cutoff point to prevent the progression of collapse was 32.1%, and to prevent both the progression of collapse and joint-space narrowing was 42.6%. Conclusion. The results of this study indicated that the post-operative intact ratio should be at least 32.1%. This critical ratio would be useful for surgical planning in transtrochanteric curved varus osteotomy for ON

Introduction. Osteonecrosis of the femoral head usually progresses to collapse in up to 70% to 80% of all cases. Previous studies have shown high failure rates with non-operative treatment, whereas, some surgical options including bone grafting, core decompression, osteotomy and arthroplasty have been recommended. Total hip arthroplasty and hemiarthroplasty, either cemented or cementless, are the last resort for improving the functional outcomes for the elderly. However, salvage of the femoral head in relatively young patients is widely advocated. Thus vascularized bone grafting has been recommended to salvage the collapsing femoral head. The purpose of this study was to evaluate the prognostic factors related to the outcome of the vascularized iliac bone grafting in the treatment of osteonecrosis of the femoral head. Methods. A retrospective case series review study is presented. Between April 1987 and April 2003, 47 patients (51 hips) in the authors' hospital underwent vascularized iliac bone grafting for the treatment of osteonecrosis of the femoral head. Three patients were lost to follow-up, thus, 44 patients (48 hips), 38 men and 4 women, were included in the study. All patients underwent operation by one experienced senior surgeon. Patients were grouped according to related risk factors, i.e., trauma, corticosteroid, alcohol, and an idiopathic group. A radiographic scale, the Ficat and Arlet classification system, was used for grading the osteonecrosis. We set the conversion to total hip arthroplasty as the end point for survival of vascularized iliac bone grafting in this study. Kaplan-Meier survivorship analysis was used to determine the significance with regard to the risk factors, age, Ficat and Arlet staging, gender, and side. Results. The Kaplan-Meier survivorship analysis showed that the 5-year overall rate of graft survival was 68.5% (95% confidence interval: 52.7% to 80.0%), 10-year overall rate of graft survival was 61.5% (95% confidence interval: 44.4% to 74.8%), and 61.5% (95% confidence interval: 44.4% to 74.8%) at 15 years. There was no significant difference between the groups regarding the prognostic factors of etiology, gender, side, and stage. The only significant parameter was the age that the patients older than 50 years had the worst 5-year survival rate of the femoral head (p<0.05). Conclusion. Vascularized bone grafting is a technically demanding procedure when compared to conventional core decompression or arthroplasty. However, this technique can preserve the femoral head from collapse and preclude the need for arthroplasty in young patients

Aim

Osteoarthritis (OA) is caused by complex interactions between genetic and environmental factors. Epigenetic mechanisms control the expression of genes and are likely to regulate the OA transcriptome. We performed integrative genomic analyses to define methylation-gene expression relationships in osteoarthritic cartilage.

Intermittently administered parathyroid hormone (PTH 1-34) has been shown to promote bone formation in both human and animal studies. The hormone and its analogues stimulate both bone formation and resorption, and as such at low doses are now in clinical use for the treatment of severe osteoporosis. By varying the duration of exposure, parathyroid hormone can modulate genes leading to increased bone formation within a so-called ‘anabolic window’. The osteogenic mechanisms involved are multiple, affecting the stimulation of osteoprogenitor cells, osteoblasts, osteocytes and the stem cell niche, and ultimately leading to increased osteoblast activation, reduced osteoblast apoptosis, upregulation of Wnt/β-catenin signalling, increased stem cell mobilisation, and mediation of the RANKL/OPG pathway. Ongoing investigation into their effect on bone formation through ‘coupled’ and ‘uncoupled’ mechanisms further underlines the impact of intermittent PTH on both cortical and cancellous bone. Given the principally catabolic actions of continuous PTH, this article reviews the skeletal actions of intermittent PTH 1-34 and the mechanisms underlying its effect.

Cite this article: L. Osagie-Clouard, A. Sanghani, M. Coathup, T. Briggs, M. Bostrom, G. Blunn. Parathyroid hormone 1-34 and skeletal anabolic action: The use of parathyroid hormone in bone formation. Bone Joint Res 2017;6:14–21. DOI: 10.1302/2046-3758.61.BJR-2016-0085.R1.

Objectives

To assess the sensitivity and specificity of self-reported osteoporosis compared with dual energy X-ray absorptiometry (DXA) defined osteoporosis, and to describe medication use among participants with the condition.