Aims. Total hip arthroplasty (THA) and total knee arthroplasty (TKA) are common orthopaedic procedures requiring postoperative radiographs to confirm implant positioning and identify complications. Artificial intelligence (AI)-based image analysis has the potential to automate this postoperative surveillance. The aim of this study was to prepare a scoping review to investigate how AI is being used in the analysis of radiographs following THA and TKA, and how accurate these tools are. Methods. The Embase, MEDLINE, and PubMed libraries were systematically searched to identify relevant articles. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for scoping reviews and Arksey and O’Malley framework were followed. Study quality was assessed using a modified Methodological Index for Non-Randomized Studies tool. AI performance was reported using either the area under the curve (AUC) or accuracy. Results. Of the 455 studies identified, only 12 were suitable for inclusion. Nine reported implant identification and three described predicting risk of implant failure. Of the 12, three studies compared AI performance with orthopaedic surgeons. AI-based implant identification achieved AUC 0.992 to 1, and most algorithms reported an accuracy > 90%, using 550 to 320,000 training radiographs. AI prediction of dislocation risk post-THA, determined after five-year follow-up, was satisfactory (AUC 76.67; 8,500 training radiographs). Diagnosis of hip implant loosening was good (accuracy 88.3%; 420 training radiographs) and measurement of postoperative acetabular angles was comparable to humans (mean absolute difference 1.35° to 1.39°). However, 11 of the 12 studies had several methodological limitations introducing a high risk of bias. None of the studies were externally validated. Conclusion. These studies show that AI is promising. While it already has the ability to analyze images with significant precision, there is currently insufficient high-level evidence to support its widespread clinical use. Further research to design robust studies that follow standard reporting guidelines should be encouraged to develop AI models that could be easily translated into real-world conditions. Cite this article: Bone Joint J 2022;104-B(8):929–937

Aims. Increasing demand for total hip and knee arthroplasty (THA/TKA) and associated follow-up has placed huge demands on orthopaedic services. Feasible follow-up mechanisms are therefore essential. . Methods. We conducted an audit of clinical follow-up decision-making for THA/TKA based on questionnaire/radiograph review compared with local practice of Arthroplasty Care Practitioner (ACP)-led outpatient follow-up. In all 599 patients attending an ACP-led THA/TKA follow-up clinic had a pelvic/knee radiograph, completed a pain/function questionnaire and were reviewed by an ACP. An experienced orthopaedic surgeon reviewed the same radiographs and questionnaires, without patient contact or knowledge of the ACP’s decision. Each pathway classified patients into: urgent review, annual monitoring, routine follow-up or discharge. . Results. In total, 401 hip and 198 knee patients were included. There was substantial agreement between the ACP and surgeon for both hip (kappa = 0.69, 95% confidence interval (CI) 0.62 to 0.76) and knee (kappa = 0.81, 95% CI 0.74 to 0.88). Positive agreement was very high for discharge and routine follow-up; however the ACP was more likely to select annual monitoring and the surgeon urgent review. . Discussion. Review of the questionnaire/radiograph together identified all patients in need of increased surveillance, with good agreement for on-going patient management. However, review of the radiograph or questionnaire alone missed some patients with potential problems. A radiograph in conjunction with a questionnaire as a review may represent a cost effective THA/TKA follow-up mechanism. Take home message: A questionnaire and radiograph-based remote review may represent a cost-effective total joint arthroplasty follow-up mechanism; thereby reducing the considerable burden that follow-up currently places on the NHS. Cite this article: Bone Joint J 2016;98-B:201–8

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Gram-negative periprosthetic joint infection (PJI) has been poorly studied despite its rapidly increasing incidence. Treatment with one-stage revision using intra-articular (IA) infusion of antibiotics may offer a reasonable alternative with a distinct advantage of providing a means of delivering the drug in high concentrations. Carbapenems are regarded as the last line of defense against severe Gram-negative or polymicrobial infection. This study presents the results of one-stage revision using intra-articular carbapenem infusion for treating Gram-negative PJI, and analyzes the characteristics of bacteria distribution and drug sensitivity.

We wished to estimate the incidence of surgical-site infection (SSI) after total hip replacement (THR) and hemiarthroplasty and its strength of association with major risk factors. The SSI surveillance service prospectively gathered clinical, operative and infection data on inpatients from 102 hospitals in England during a four-year period. The overall incidence of SSI was 2.23% for 16 291 THRs, 4.97% for 5769 hemiarthroplasty procedures, 3.68% for 2550 revision THRs and 7.6% for 198 revision hemiarthroplasties. Staphylococcus aureus was identified in 50% of SSIs; 59% of these isolates were methicillin-resistant (MRSA). In the single variable analysis of THRs, age, female gender, American Society of Anesthesiologists (ASA) score, body mass index, trauma, duration of operation and pre-operative stay were significantly associated with the risk of SSI (p < 0.05). For hemiarthroplasty, the ASA score and age were significant factors. In revision THRs male gender, ASA score, trauma, wound class, duration of operation and pre-operative stay were significant risk factors. The median time to detection of SSI was eight days for superficial incisional, 11 days for deep incisional and 11 days for joint/bone infections. For each procedure the mean length of stay doubled for patients with SSI. The multivariate analysis identified age group, trauma, duration of operation and ASA score as significant, independent risk factors for SSI. There was significant interhospital variation in the rates of SSI. MRSA was the most common pathogen to cause SSI in hip arthroplasty, especially in patients undergoing hemiarthroplasty, but coagulase-negative Staph. aureus may be more important in deep infections involving the joint

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To investigate whether chronic kidney disease (CKD) is associated with the risk of all-cause revision or revision due to a periprosthetic joint infection (PJI) after primary hip or knee arthroplasty.

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To determine the trajectories of patient reported pain and functional disability over five years following total hip arthroplasty (THA) or total knee arthroplasty (TKA).

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Preoperative nasal Staphylococcus aureus screening and eradication reduces surgical site infections (SSIs) but its impact on reducing early prosthetic joint infection (PJI) remains controversial. This study aims to assess the effect of preoperative nasal S. aureus screening and eradication on the incidence of early PJI in general and S. aureus-induced early PJI.

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The aim of this study was to give estimates of the incidence of component incompatibility in hip and knee arthroplasty and to test the effect of an online, real-time compatibility check.

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Surgical site infection (SSI) is a common complication of surgery with an incidence of about 1% in the United Kingdom. Sutures can lead to the development of a SSI, as micro-organisms can colonize the suture as it is implanted. Triclosan-coated sutures, being antimicrobical, were developed to reduce the rate of SSI. Our aim was to assess whether triclosan-coated sutures cause a reduction in SSIs following arthroplasty of the hip and knee.

Whether patients with asymptomatic bacteriuria should be investigated and treated before elective hip and knee replacement is controversial, although it is a widespread practice. We conducted a prospective observational cohort study with urine analyses before surgery and three days post-operatively. Patients with symptomatic urinary infections or an indwelling catheter were excluded. Post-discharge surveillance included questionnaires to patients and general practitioners at three months. Among 510 patients (309 women and 201 men), with a median age of 69 years (16 to 97) undergoing lower limb joint replacements (290 hips and 220 knees), 182 (36%) had pre-operative asymptomatic bacteriuria, mostly due to Escherichia coli, and 181 (35%) had white cells in the urine. Most patients (95%) received a single intravenous peri-operative dose (1.5 g) of cefuroxime as prophylaxis. On the third post-operative day urinary analysis identified white cells in 99 samples (19%) and bacteriuria in 208 (41%). Pathogens in the cultures on the third post-operative day were different from those in the pre-operative samples in 260 patients (51%). Only 25 patients (5%) developed a symptomatic urinary infection during their stay or in a subsequent three-month follow-up period, and two thirds of organisms identified were unrelated to those found during the admission. All symptomatic infections were successfully treated with oral antibiotics with no perceived effect on the joint replacement.

We conclude that testing and treating asymptomatic urinary tract colonisation before joint replacement is unnecessary.

Cite this article: Bone Joint J 2014;96-B:390–4.

Since the introduction of the National Institute for Health and Care Excellence (NICE) guidelines on thromboprophylaxis and the use of extended thromboprophylaxis with new oral agents, there have been reports of complications arising as a result of their use. We have looked at the incidence of wound complications after the introduction of dabigatran for thromboprophylaxis in our unit.

We investigated the rate of venous thromboembolism and wound leakage in 1728 patients undergoing primary joint replacement, both before and after the introduction of dabigatran, and following its subsequent withdrawal from our unit.

We found that the use of dabigatran led to a significant increase in post-operative wound leakage (20% with dabigatran, 5% with a multimodal regimen; p < 0.001), which also resulted in an increased duration of hospital stay. The rate of thromboembolism in patients receiving dabigatran was higher (1.3%) than in those receiving the multimodal thromboprophylaxis regimen, including low molecular weight heparin as an inpatient and the extended use of aspirin (0.3%, p = 0.047). We have ceased the use of dabigatran for thromboprophylaxis in these patients.

Cite this article: Bone Joint J 2014;96-B:122–6.

In our department we use an enhanced recovery protocol for joint replacement of the lower limb. This incorporates the use of intravenous tranexamic acid (IVTA; 15 mg/kg) at the induction of anaesthesia. Recently there was a national shortage of IVTA for 18 weeks; during this period all patients received an oral preparation of tranexamic acid (OTA; 25 mg/kg). This retrospective study compares the safety (surgical and medical complications) and efficacy (reduction of transfusion requirements) of OTA and IVTA. During the study period a total of 2698 patients received IVTA and 302 received OTA. After adjusting for a range of patient and surgical factors, the odds ratio (OR) of receiving a blood transfusion was significantly higher with IVTA than with OTA (OR 0.48 (95% confidence interval 0.26 to 0.89), p = 0.019), whereas the safety profile was similar, based on length of stay, rate of readmission, return to theatre, deep infection, stroke, gastrointestinal bleeding, myocardial infarction, pneumonia, deep-vein thrombosis and pulmonary embolism. The financial benefit of OTA is £2.04 for a 70 kg patient; this is amplified when the cost saving associated with significantly fewer blood transfusions is considered.

Although the number of patients in the study is modest, this work supports the use of OTA, and we recommend that a randomised trial be undertaken to compare the different methods of administering tranexamic acid.

Cite this article: Bone Joint J 2013;95-B:1556–61.

Using general practitioner records and hospital notes and through direct telephone conversation with patients, we investigated the accuracy of nine patient-reported complications gathered from a self-completed questionnaire after elective joint replacement surgery of the hip and knee. A total of 402 post-discharge complications were reported after 8546 elective operations that were undertaken within a three-year period. These were reported by 136 men and 240 women with a mean age of 71.8 years (34 to 93). A total of 319 reported complications (79.4%; 95% confidence interval 75.4 to 83.3) were confirmed to be correct. High rates of correct reporting were demonstrated for infection (94.5%) and the need for further surgery (100%), whereas the rates of reporting deep-vein thrombosis (DVT), pulmonary embolism, myocardial infarction and stroke were lower (75% to 84.2%). Dislocation, peri-prosthetic fractures and nerve palsy had modest rates of correct reporting (36% to 57.1%). More patients who had knee surgery delivered incorrect reports of dislocation (p = 0.001) and DVT (p = 0.013).

Despite these variations, it appears that post-operative complications may form part of a larger patient-reported outcome programme after elective joint replacement surgery.

In order to compare the effect of oral apixaban (a factor Xa inhibitor) with subcutaneous enoxaparin on major venous thromboembolism and major and non-major clinically relevant bleeding after total knee and hip replacement, we conducted a pooled analysis of two previously reported double-blind randomised studies involving 8464 patients. One group received apixaban 2.5 mg twice daily (plus placebo injection) starting 12 to 24 hours after operation, and the other received enoxaparin subcutaneously once daily (and placebo tablets) starting 12 hours (± 3) pre-operatively. Each regimen was continued for 12 days (± 2) after knee and 35 days (± 3) after hip arthroplasty. All outcomes were centrally adjudicated. Major venous thromboembolism occurred in 23 of 3394 (0.7%) evaluable apixaban patients and in 51 of 3394 (1.5%) evaluable enoxaparin patients (risk difference, apixaban minus enoxaparin, -0.8% (95% confidence interval (CI) -1.2 to -0.3); two-sided p = 0.001 for superiority). Major bleeding occurred in 31 of 4174 (0.7%) apixaban patients and 32 of 4167 (0.8%) enoxaparin patients (risk difference -0.02% (95% CI -0.4 to 0.4)). Combined major and clinically relevant non-major bleeding occurred in 182 (4.4%) apixaban patients and 206 (4.9%) enoxaparin patients (risk difference -0.6% (95% CI -1.5 to 0.3)).

Apixaban 2.5 mg twice daily is more effective than enoxaparin 40 mg once daily without increased bleeding.

Infection remains a significant and common complication after joint replacement and there is debate about which contributing factors are important. Few studies have investigated the effect of the operating time on infection.

We collected data prospectively from 5277 hip and knee replacements which included the type of procedure, the operating time, the use of drains, the operating theatre, surgeon, age and gender. In a subgroup of 3449 knee replacements further analysis was carried out using the tourniquet time in place of the operating time. These variables were assessed by the use of generalised linear modelling against superficial, deep or joint-space post-operative infection as defined by the Australian Surgical-Site Infection criteria.

The overall infection rate was 0.98%. In the replacement data set both male gender (z = 3.097, p = 0.00195) and prolonged operating time (z = 4.325, p < 0.001) were predictive of infection. In the knee subgroup male gender (z = 2.250, p = 0.02447), a longer tourniquet time (z = 2.867, p = 0.00414) and total knee replacement (versus unicompartmental knee replacement) (z = −2.052, p = 0.0420) were predictive of infection.

These findings support the view that a prolonged operating time and male gender are associated with an increased incidence of infection. Steps to minimise intra-operative delay should be instigated, and care should be exercised when introducing measures which prolong the duration of joint replacement.

We analysed data from the Oxford hip and knee questionnaires collected by the New Zealand Joint Registry at six months and five years after joint replacement, to determine if there was any relationship between the scores and the risk of early revision. Logistic regression of the six-month scores indicated that for every one-unit decrease in the Oxford score, the risk of revision within two years increased by 9.7% for total hip replacement (THR), 9.9% for total knee replacement (TKR) and 12.0% for unicompartmental knee replacement (UKR). Our findings showed that 70% of the revisions within two years for TKR and 67% for THR and UKR would have been captured by monitoring the lowest 22%, 28% and 28%, respectively, of the Oxford scores. When analysed using the Kalairajah classification a score of < 27 (poor) was associated with a risk of revision within two years of 7.6% for THR, 7.0% for TKR and 24.3% for UKR, compared with risks of 0.7%, 0.7% and 1.8%, respectively, for scores > 34 (good or excellent).

Our study confirms that the Oxford hip and knee scores at six months are useful predictors of early revision after THR and TKR and we recommend their use for the monitoring of the outcome and potential failure in these patients.