Aims. The hip’s capsular ligaments passively restrain extreme range of movement (ROM) by wrapping around the native femoral head/neck. We determined the effect of hip resurfacing arthroplasty (HRA), dual-mobility total hip arthroplasty (DM-THA), conventional THA, and surgical approach on ligament function. Materials and Methods. Eight paired cadaveric hip joints were skeletonized but retained the hip capsule. Capsular ROM restraint during controlled internal rotation (IR) and external rotation (ER) was measured before and after HRA, DM-THA, and conventional THA, with a posterior (right hips) and anterior capsulotomy (left hips). Results. Hip resurfacing provided a near-native ROM with between 5° to 17° increase in IR/ER ROM compared with the native hip for the different positions tested, which was a 9% to 33% increase. DM-THA generated a 9° to 61° (18% to 121%) increase in ROM. Conventional THA generated a 52° to 100° (94% to 199%) increase in ROM. Thus, for conventional THA, the capsule function that exerts a limit on ROM is lost. It is restored to some extent by DM-THA, and almost fully restored by hip resurfacing. In positions of low flexion/extension, the posterior capsulotomy provided more normal function than the anterior, possibly because the capsule was shortened during posterior repair. However, in deep flexion positions, the anterior capsulotomy functioned better. Conclusion. Native head-size and capsular repair preserves capsular function after arthroplasty. The anterior and posterior approach differentially affect postoperative biomechanical function of the capsular ligaments. Cite this article: Bone Joint J 2019;101-B:426–434

Obesity is a global epidemic of 2.1 billion people and a well known cause of osteoarthritis. Joint replacement in the obese attracts more complications, poorer outcomes and higher revision rates. It is a reversible condition and the fundamental principles of dealing with reversible medical conditions prior to elective total joint replacement should apply to obesity. The dilemma for orthopaedic surgeons is when to offer surgery in the face of a reversible condition, which if treated may obviate joint replacement and reduce the risk and severity of obesity related disease in both the medical arena and the field of orthopaedics

Although patients with a history of venous thromboembolism (VTE) who undergo lower limb joint replacement are thought to be at high risk of further VTE, the actual rate of recurrence has not been reported. The purpose of this study was to identify the recurrence rate of VTE in patients who had undergone lower limb joint replacement, and to compare it with that of patients who had undergone a joint replacement without a history of VTE. . From a pool of 6646 arthroplasty procedures (3344 TKR, 2907 THR, 243 revision THR, 152 revision TKR) in 5967 patients (68% female, mean age 67.7; 21 to 96) carried out between 2009 and 2011, we retrospectively identified 118 consecutive treatment episodes in 106 patients (65% female, mean age 70; 51 to 88,) who had suffered a previous VTE. Despite mechanical prophylaxis and anticoagulation with warfarin, we had four recurrences by three months (3.4% of 118) and six by one year (5.1% of 118). In comparison, in all our other joint replacements the rate of VTE was 0.54% (35/6528). The relative risk of a VTE by 90 days in patients who had undergone a joint replacement with a history of VTE compared with those with a joint replacement and no history of VTE was 6.3 (95% confidence interval, 2.3 to 17.5). There were five complications in the previous VTE group related to bleeding or over-anticoagulation. Cite this article: Bone Joint J 2014;96-B:1515–19

Aims. Natural Language Processing (NLP) offers an automated method to extract data from unstructured free text fields for arthroplasty registry participation. Our objective was to investigate how accurately NLP can be used to extract structured clinical data from unstructured clinical notes when compared with manual data extraction. Methods. A group of 1,000 randomly selected clinical and hospital notes from eight different surgeons were collected for patients undergoing primary arthroplasty between 2012 and 2018. In all, 19 preoperative, 17 operative, and two postoperative variables of interest were manually extracted from these notes. A NLP algorithm was created to automatically extract these variables from a training sample of these notes, and the algorithm was tested on a random test sample of notes. Performance of the NLP algorithm was measured in Statistical Analysis System (SAS) by calculating the accuracy of the variables collected, the ability of the algorithm to collect the correct information when it was indeed in the note (sensitivity), and the ability of the algorithm to not collect a certain data element when it was not in the note (specificity). Results. The NLP algorithm performed well at extracting variables from unstructured data in our random test dataset (accuracy = 96.3%, sensitivity = 95.2%, and specificity = 97.4%). It performed better at extracting data that were in a structured, templated format such as range of movement (ROM) (accuracy = 98%) and implant brand (accuracy = 98%) than data that were entered with variation depending on the author of the note such as the presence of deep-vein thrombosis (DVT) (accuracy = 90%). Conclusion. The NLP algorithm used in this study was able to identify a subset of variables from randomly selected unstructured notes in arthroplasty with an accuracy above 90%. For some variables, such as objective exam data, the accuracy was very high. Our findings suggest that automated algorithms using NLP can help orthopaedic practices retrospectively collect information for registries and quality improvement (QI) efforts. Cite this article: Bone Joint J 2020;102-B(7 Supple B):99–104

Objectives. Surgeons face a substantial risk of infection because of the occupational exposure to blood-borne pathogens (BBPs) from patients undergoing high-risk orthopaedic procedures. This study aimed to determine the seroprevalence of four BBPs among patients undergoing joint arthroplasty in Shanghai, China. In addition, we evaluated the significance of pre-operative screening by calculating a cost-to-benefit ratio. Methods. A retrospective observational study of pre-operative screening for BBPs, including hepatitis B and C viruses (HBV and HCV), human immunodeficiency virus (HIV) and Treponema pallidum (TP), was conducted for sequential patients in the orthopaedic department of a large urban teaching hospital between 01 January 2009 and 30 May 2016. Medical records were analysed to verify the seroprevalence of these BBPs among the patients stratified by age, gender, local origin, type of surgery, history of previous transfusion and marital status. Results. Of the subjects who underwent arthroplasty surgery in our institution, pre-operative screening tests were available for 96.1% (11 609 patients). The seroprevalence of HBV, HCV, HIV and TP was 5.47%, 0.45%, 0.08% and 3.6%, respectively. A total of 761 seropositive cases (68.4%) were previously undiagnosed. Pre-operative screening for HIV resulted in a low cost to benefit ratio, followed by HCV and HBV. Conclusion. Routine HCV and HIV screening prior to joint arthroplasty is not a cost-effective strategy. Considering the high rate of undiagnosed patients and the shortage of protective options, targeted pre-operative screening for HBV and syphilis should be considered for the protection of healthcare workers in China who have not been vaccinated. Cite this article: Bone Joint Res 2017;6:566–571

Aims. Prosthetic joint infections (PJIs) of the hip and knee are associated with significant morbidity and socioeconomic burden. We undertook a systematic review of the current literature with the aim of proposing criteria for the selection of patients for a single-stage exchange arthroplasty in the management of a PJI. Material and Methods. A comprehensive review of the current literature was performed using the OVID-MEDLINE, EMBASE, and Cochrane Library databases and the search terms: infection and knee arthroplasty OR knee revision OR hip arthroplasty OR hip revision, and one stage OR single stage OR direct exchange. All studies involving fewer than ten patients and follow-up of less than two years in the study group were excluded as also were systematic reviews, surgical techniques, and expert opinions. Results. The initial search revealed 875 potential articles of which 22 fulfilled the inclusion and exclusion criteria. There were 16 case series and six comparative studies; five were prospective and 14 were retrospective. The studies included 962 patients who underwent single stage revision arthroplasty of an infected hip or knee joint. The rate of recurrent infection ranged from 0% to 18%, at a minimum of two years’ follow-up. The rate was lower in patients who were selected on the basis of factors relating to the patient and the local soft-tissue and bony conditions. . Conclusion. We conclude that single-stage revision is an acceptable form of surgical treatment for the management of a PJI in selected patients. The indications for this approach include the absence of severe immunocompromise and significant soft-tissue or bony compromise and concurrent acute sepsis. We suggest that a two-stage approach should be used in patients with multidrug resistant or atypical organisms such as fungus

In Africa the amount of joint replacement surgery is increasing, but the indications for operation and the age of the patients are considerably different from those in the developed world. New centres with variable standards of care and training of the surgeons are performing these procedures and it is important that a proper audit of this work is undertaken. In Malawi, we have pioneered a Registry which includes all joint replacements that have been carried out in the country. The data gathered include the age, gender, indication for operation, the prosthesis used, the surgical approach, the use of bone graft, the type of cement, pressurising systems and the thromboprophylaxis used. All patients have their clinical scores recorded pre-operatively and then after three and six months and at one year. Before operation all patients are counselled and on consent their HIV status is established allowing analysis of the effect of HIV on successful joint replacement. To date, 73 total hip replacements (THRs) have been carried out in 58 patients by four surgeons in four different hospitals. The most common indications for THR were avascular necrosis (35 hips) and osteoarthritis (22 hips). The information concerning 20 total knee replacements has also been added to the Registry

Aims

We aimed to evaluate the utility of ⁶⁸Ga-citrate positron emission tomography (PET)/CT in the differentiation of periprosthetic joint infection (PJI) and aseptic loosening (AL), and compare it with ^99mTc-methylene bisphosphonates (^99mTc-MDP) bone scan.

The use of robotics in arthroplasty surgery is expanding rapidly as improvements in the technology evolve. This article examines current evidence to justify the usage of robotics, as well as the future potential in this emerging field

Between May 1998 and May 2007 we carried out 50 Avon patellofemoral joint replacements in 32 patients with isolated patellofemoral osteoarthritis. There were no revisions in the first five years, giving a cumulative survival of 100% for those with a minimum follow-up of five years. The mean follow-up was 5.3 years (2.1 to 10.2). The median Oxford knee score was 30.5 (interquartile range 22.25 to 42.25). In patients with bilateral replacements the median Euroqol General health score was 50 which was significantly lower than that of 75 in those with a unilateral replacement (p = 0.047). The main complication was progression of disease, which was identified radiologically in 11 knees (22%). This highlights the need for accurate selection of patients. Our findings suggest that the Avon prosthesis survives well and gives a satisfactory functional outcome in the medium term

We assessed the outcome of patients who were lost to follow-up after arthroplasty by a single surgeon. The aim was to validate the surgeon’s data set with the Australian Orthopaedic Association National Joint Replacement Registry and determine the outcome of those patients lost to follow-up. Prospective data on patient demographics, operative details and outcomes of the surgeon’s 1192 primary unicompartmental knee arthroplasty (UKA) procedures were analysed. There were 69 knees in patients who were lost to follow-up, among whom the Registry identified 31 deaths and eight revisions. The cumulative percentage revision (CPR) at seven years using the additional Registry data was 8.8% (95% confidence interval (CI) 7 to 11). Using the surgeon’s data, the CPR at seven years was 8% (95% CI 6.3 to 10.1) for the best-case scenario where loss to follow-up was excluded, and 16% (95% CI 13.8 to 19.4) for the worst-case scenario, where all patients lost to follow-up were deemed to have been revised. There was a significantly higher mortality rate in those patients lost to follow-up. This study demonstrates that a national joint registry can be used by individual surgeons to establish more accurate revision rates in their arthroplasty patients. This is expected to facilitate a more rigorous audit of surgical outcomes by surgeons and lead to more accurate and uniform reporting of the results of arthroplasty in general

Aims. In the initial development of total shoulder arthroplasty (TSA), the humeral component was usually fixed with cement. Cementless components were subsequently introduced. The aim of this study was to compare the long-term outcome of cemented and cementless humeral components in arthroplasty of the shoulder. Patients and Methods. All patients who underwent primary arthroplasty of the shoulder at our institution between 1970 and 2012 were included in the study. There were 4636 patients with 1167 cemented humeral components and 3469 cementless components. Patients with the two types of fixation were matched for nine different covariates using a propensity score analysis. A total of 551 well-balanced pairs of patients with cemented and cementless components were available after matching for comparison of the outcomes. The clinical outcomes which were analysed included loosening of the humeral component determined at revision surgery, periprosthetic fractures, post-operative infection and operating time. Results. The overall five-, ten-, 15- and 20-year rates of survival were 98.9%, 97.2%, 95.5%, and 94.4%, respectively. Survival without loosening at 20 years was 98% for cemented components and 92.4% for cementless components. After propensity score matching including fixation as determined by the design of the component, humeral loosening was also found to be significantly higher in the cementless group. Survival without humeral loosening at 20 years was 98.7% for cemented components and 91.0% for cementless components. There was no significant difference in the risk of intra- or post-operative fracture. The rate of survival without deep infection and the mean operating time were significantly higher in the cemented group. Conclusion. Both types of fixation give rates of long-term survival of > 90%. Cemented components have better rates of survival without loosening but this should be weighed against increased operating time and the risk of bony destruction of the proximal humerus at the time of revision of a cemented humeral component. Cite this article: Bone Joint J 2017;99-B:666–73

The low contact stress patellofemoral replacement consists of a trochlear component and a modular patellar component which has a metal-backed mobile polyethylene bearing. We present the early results of the use of this prosthesis for established isolated patellofemoral arthritis in 51 consecutive patellofemoral replacements in 35 patients. The mean follow-up was 25 months (5 to 60). The estimated survival rate at three years was 63% (95% confidence interval 47 to 80) with revision as the endpoint and 46% (95% confidence interval 30 to 63) with revision and ongoing moderate or severe pain as the endpoint. The early results of the use of the low contact stress patellofemoral replacement are disappointing with a high rate of revision. We cannot therefore recommend its use

Arthroscopy of the native hip is an established diagnostic and therapeutic procedure. Its application in the symptomatic replaced hip is still being explored. We describe the use of arthroscopy of the hip in 24 symptomatic patients following total hip replacement, resurfacing arthroplasty of the hip and partial resurfacing (study group), and compared it with arthroscopy of the native hip in 24 patients (control group). A diagnosis was made or confirmed at arthroscopy in 23 of the study group and a therapeutic arthroscopic intervention resulted in relief of symptoms in ten of these. In a further seven patients it led to revision hip replacement. In contrast, arthroscopy in the control group was diagnostic in all 24 patients and the resulting arthroscopic therapeutic intervention provided symptomatic relief in 21. The mean operative time in the study group (59.7 minutes (35 to 93)) was less than in the control group (71 minutes (40 to 100), p = 0.04) but the arthroscopic approach was more difficult in the arthroplasty group. We suggest that arthroscopy has a role in the management of patients with a symptomatic arthroplasty when other investigations have failed to provide a diagnosis

Aims. Our aim was to examine the Elixhauser and Charlson comorbidity indices, based on administrative data available before surgery, and to establish their predictive value for mortality for patients who underwent hip arthroplasty in the management of a femoral neck fracture. Patients and Methods. We analyzed data from 42 354 patients from the Swedish Hip Arthroplasty Register between 2005 and 2012. Only the first operated hip was included for patients with bilateral arthroplasty. We obtained comorbidity data by linkage from the Swedish National Patient Register, as well as death dates from the national population register. We used univariable Cox regression models to predict mortality based on the comorbidity indices, as well as multivariable regression with age and gender. Predictive power was evaluated by a concordance index, ranging from 0.5 to 1 (with the higher value being the better predictive power). A concordance index less than 0.7 was considered poor. We used bootstrapping for internal validation of the results. Results. The predictive power of mortality was poor for both the Elixhauser and Charlson comorbidity indices (concordance indices less than 0.7). The Charlson Comorbidity Index was superior to Elixhauser, and a model with age and gender was superior to both indices. Conclusion. Preoperative comorbidity from administrative data did not predict mortality for patients with a hip fracture treated by arthroplasty. This was true even if association on group level existed

The aim of this study was to review the early outcome of the Femoro-Patella Vialla (FPV) joint replacement. A total of 48 consecutive FPVs were implanted between December 2007 and June 2011. Case-note analysis was performed to evaluate the indications, operative histology, operative findings, post-operative complications and reasons for revision. The mean age of the patients was 63.3 years (48.2 to 81.0) and the mean follow-up was 25.0 months (6.1 to 48.9). Revision was performed in seven (14.6%) at a mean of 21.7 months, and there was one re-revision. Persistent pain was observed in three further patients who remain unrevised. The reasons for revision were pain due to progressive tibiofemoral disease in five, inflammatory arthritis in one, and patellar fracture following trauma in one. No failures were related to the implant or the technique. Trochlear dysplasia was associated with a significantly lower rate of revision (5.9% vs 35.7%, p = 0.017) and a lower incidence of revision or persistent pain (11.8% vs 42.9%, p = 0.045). . Focal patellofemoral osteoarthritis secondary to trochlear dysplasia should be considered the best indication for patellofemoral replacement. Standardised radiological imaging, with MRI to exclude overt tibiofemoral disease should be part of the pre-operative assessment, especially for the non-dysplastic knee. Cite this article: Bone Joint J 2013;95-B:793–7

We prospectively reviewed 14 patients with deficiency of the proximal pole of the scaphoid who were treated by rib osteochondral replacement arthroplasty. Improvement in wrist function occurred in all except one patient with enhanced grip strength, less pain and maintenance of wrist movement. In 13 patients wrist function was rated as good or excellent according to the modified wrist function score of Green and O’Brien. The mean pre-operative score of 54 (35 to 80) rose to 79 (50 to 90) at review at a mean of 64 months (27 to 103). Carpal alignment did not deteriorate in any patient and there were no cases of nonunion or significant complications. This procedure can restore the mechanical integrity of the proximal pole of the scaphoid satisfactorily and maintain wrist movement while avoiding the potential complications of alternative replacement arthroplasty techniques and problems associated with vascularised grafts and salvage techniques

We present a prospective review of the two-year functional outcome of 37 Avon patellofemoral joint replacements carried out in 29 patients with a mean age of 66 years (30 to 82) between October 2002 and March 2007. No patients were lost to follow-up. This is the first independent assessment of this prosthesis using both subjective and objective analysis of outcome. At two years the median Oxford knee score was 39 (interquartile range 32 to 44), the median American Knee Society objective score was 95 (interquartile range 90 to 100), the median American Knee Society functional score was 85 (interquartile range 60 to 100), and the median Melbourne Knee score was 28 (interquartile range 21 to 30). Two patients underwent further surgery. Only one patient reported an unsatisfactory outcome. We conclude that the promising early results observed by the designing centre are reproducible and provide further support for the role of patellofemoral joint replacement

There has been considerable discussion as to the influence of obesity on the indications for, and the outcome after, joint replacement. Attempts have been made to withhold funding for such procedures in those who are overweight. What is the justification for this? This editorial examines the current evidence concerning the influence of obesity on joint replacement and suggests that it is only in the morbidly obese, with a body mass index > 40 kg/m. 2. , that significant contraindications to operation are present