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. The aim of this study was to evaluate the diagnostic accuracy of the absolute synovial polymorphonuclear neutrophil cell (PMN) count for the diagnosis or exclusion of periprosthetic joint infection (PJI) after total hip (THA) or knee arthroplasty (TKA). Methods. In this retrospective cohort study, 147 consecutive patients with acute or chronic complaints following THA and TKA were included. Diagnosis of PJI was established based on the 2018 International Consensus Meeting criteria. A total of 39 patients diagnosed with PJI (32 chronic and seven acute) and 108 patients with aseptic complications were surgically revised. Results. Using receiver operating characteristic curves and calculating the area under the curve (AUC), an optimal synovial cut-off value of 2,000 PMN/µl was determined (AUC 0.978 (95% confidence interval (CI) 0.946 to 1)). Using this cut-off, sensitivity and specificity of absolute synovial PMN count for PJI were 97.4% (95% CI 91.2 to 100) and 93.5% (95% CI 88.9 to 98.1), respectively. Positive and negative predictive value were 84.4% (95% CI 72.7 to 93.9) and 99.0% (95% CI 96.7 to 100), respectively. Exclusion of 20 patients with acute complications improved specificity to 97.9% (95% CI 94.6 to 100). Different cut-off values for THA (< 3,600 PMN/µl) and TKA (< 2,000 PMN/µl) were identified. Absolute synovial PMN count correlated strongly with synovial alpha-defensin (AD) (r = 0.759; p < 0.001). With a positive AD result, no additional PJI could be identified in any case. Conclusion. Absolute synovial PMN count is a widely available, rapid, cost-effective, and accurate marker in PJI diagnostics, whereas synovial AD appears to be a surrogate parameter of absolute synovial PMN count. Despite limitations in the early postoperative phase, wear, and rheumatic diseases in confirming PJI, an absolute synovial PMN count below 2,000/µl is highly suitable for ruling out PJI, with specific cut-off values for THA and TKA. Cite this article: Bone Joint J 2023;105-B(4):373–381

Aims. In countries with social healthcare systems, such as Canada, patients may experience long wait times and a decline in their health status prior to their operation. The aim of this study is to explore the association between long preoperative wait times (WT) and acute hospital length of stay (LoS) for primary arthroplasty of the knee and hip. Methods. The study population was obtained from the provincial Patient Access Registry Nova Scotia (PARNS) and the Canadian national hospital Discharge Access Database (DAD). We included primary total knee and hip arthroplasties (TKA, THA) between 2011 and 2017. Patients waiting longer than the recommended 180 days Canadian national standard were compared to patients waiting equal or less than the standard WT. The primary outcome measure was acute LoS postoperatively. Secondarily, patient demographics, comorbidities, and perioperative parameters were correlated with LoS with multivariate regression. Results. A total of 11,833 TKAs and 6,627 THAs were included in the study. Mean WT for TKA was 348 days (1 to 3,605) with mean LoS of 3.6 days (1 to 98). Mean WT for THA was 267 days (1 to 2,015) with mean LoS of 4.0 days (1 to 143). There was a significant increase in mean LoS for TKA waiting longer than 180 days (2.5% (SE 1.1); p = 0.028). There was no significant association for THA. Age, sex, surgical year, admittance from home, rural residence, household income, hospital facility, the need for blood transfusion, and comorbidities were all found to influence LoS. Conclusion. Surgical WT longer than 180 days resulted in increased acute LoS for primary TKA. Meeting a shorter WT target may be cost-saving in a social healthcare system by having shorter LoS. Cite this article: Bone Jt Open 2021;2(8):679–684

Aims. Breast cancer survivors have known risk factors that might influence the results of total hip arthroplasty (THA) or total knee arthroplasty (TKA). This study evaluated clinical outcomes of patients with breast cancer history after primary THA and TKA. Methods. Our total joint registry identified patients with breast cancer history undergoing primary THA (n = 423) and TKA (n = 540). Patients were matched 1:1 based upon age, sex, BMI, procedure (hip or knee), and surgical year to non-breast cancer controls. Mortality, implant survival, and complications were assessed via Kaplan-Meier methods. Clinical outcomes were evaluated via Harris Hip Scores (HHSs) or Knee Society Scores (KSSs). Mean follow-up was six years (2 to 15). Results. Breast cancer patient survival at five years was 92% (95% confidence interval (CI) 89% to 95%) after THA and 94% (95% CI 92% to 97%) after TKA. Breast and non-breast cancer patients had similar five-year implant survival free of any reoperation or revision after THA (p ≥ 0.412) and TKA (p ≥ 0.271). Breast cancer patients demonstrated significantly lower survival free of any complications after THA (91% vs 96%, respectively; hazard ratio = 2 (95% CI 1.1 to 3.4); p = 0.017). Specifically, the rate of intraoperative fracture was 2.4% vs 1.4%, and venous thromboembolism (VTE) was 1.4% and 0.5% for breast cancer and controls, respectively, after THA. No significant difference was noted in any complications after TKA (p ≥ 0.323). Both breast and non-breast cancer patients experienced similar improvements in HHSs (p = 0.514) and KSSs (p = 0.132). Conclusion. Breast cancer survivors did not have a significantly increased risk of mortality or reoperation after primary THA and TKA. However, there was a two-fold increased risk of complications after THA, including intraoperative fracture and VTE. Cite this article: Bone Joint J 2024;106-B(4):365–371

Aims. Waiting times for arthroplasty surgery in Northern Ireland are among the longest in the NHS, which have been further lengthened by the onset of the COVID-19 global pandemic in March 2020. The Department of Health in Northern Ireland has announced a new Elective Care Framework (ECF), with the framework proposing that by March 2026 no patient will wait more than 52 weeks for inpatient/day case treatment. We aimed to assess the feasibility of achieving this with reference to total hip arthroplasty (THA) and total knee arthroplasty (TKA). Methods. Mathematical modelling was undertaken to calculate when the ECF targets will be achieved for THA and TKA, as well as the time when waiting lists for THA and TKA will be cleared. The number of patients currently on the waiting list and percentage operating capacity relative to pre-COVID-19 capacity was used to determine future projections. Results. As of May 2021, there were 3,757 patients awaiting primary THA and 4,469 patients awaiting primary TKA in Northern Ireland. Prior to April 2020, there were a mean 2,346 (2,085 to 2,610) patients per annum boarded for primary THA, a mean 2,514 (2,494 to 2,514) patients per annum boarded for primary TKA, and there were a mean 1,554 primary THAs and 1,518 primary TKAs performed per annum. The ECF targets for THA will only be achieved in 2030 if operating capacity is 200% of pre COVID-19 pandemic capacity and in 2042 if capacity is 170%. For TKA, the targets will be met in 2034 if capacity is 200% of pre-COVID-19 pandemic capacity. Conclusion. This modelling demonstrates that, in the absence of major funding and reorganization of elective orthopaedic care, the targets set out in the ECF will not be achieved with regard to THA and TKA. Waiting times for THA and TKA surgery in Northern Ireland are likely to remain greater than 52 weeks for most of this decade. Cite this article: Bone Jt Open 2022;3(4):302–306

Aims

Elective orthopaedic surgery was cancelled early in the COVID-19 pandemic and is currently running at significantly reduced capacity in most institutions. This has resulted in a significant backlog to treatment, with some hospitals projecting that waiting times for arthroplasty is three times the pre-COVID-19 duration. There is concern that the patient group requiring arthroplasty are often older and have more medical comorbidities—the same group of patients advised they are at higher risk of mortality from catching COVID-19. The aim of this study is to investigate the morbidity and mortality in elective patients operated on during the COVID-19 pandemic and compare this to a pre-pandemic cohort. Primary outcome was 30-day mortality. Secondary outcomes were perioperative complications, including nosocomial COVID-19 infection. These operations were performed in a district general hospital, with COVID-19 acute admissions in the same building.

Objectives

Wound complications are reported in up to 10% hip and knee arthroplasties and there is a proven association between wound complications and deep prosthetic infections. In this randomised controlled trial (RCT) we explore the potential benefits of a portable, single use, incisional negative pressure wound therapy dressing (iNPWTd) on wound exudate, length of stay (LOS), wound complications, dressing changes and cost-effectiveness following total hip and knee arthroplasties.

During the last ten years, greater attention has been given to the management of peri-operative blood loss after total knee arthroplasty (TKA), as it is a modifiable outcome that has a significant effect on the rate of complications, the recovery, and the economic burden. Blood loss after TKA has been greatly reduced during this time, thereby dramatically reducing the rates of allogeneic transfusion. This has significantly reduced the complications associated with transfusion, such as fluid overload, infection, and increased length of stay. . The greatest advent in lowering peri-operative blood loss after TKA has been the introduction of tranexamic acid, which reduces blood loss without increasing the risk of thromboembolic events. . This paper discusses the ways of reducing blood loss after TKA, for which a multimodal algorithm, with pre-, intra- and post-operative measures, has been adopted at our institution. Cite this article: Bone Joint J 2016;98-B(1 Suppl A):98–100

Collateral ligament release is advocated in total knee arthroplasty (TKA) to deal with significant coronal plane deformities, but is also associated with significant disadvantages. We describe steps to avoid release of the collateral (superficial medial and lateral collateral) ligaments during TKA in severely deformed knees, while correcting deformity and balancing the knee. . Cite this article: Bone Joint J 2016;98-B(1 Suppl A):101–4

Objectives. Unicompartmental knee arthroplasty (UKA) is a potential treatment for isolated bone on bone osteoarthritis when limited to a single compartment. The risk for revision of UKA is three times higher than for total knee arthroplasty (TKA). The aim of this review was to discuss the different revision options after UKA failure. Materials and Methods. A search was performed for English language articles published between 2006 and 2016. After reviewing titles and abstracts, 105 papers were selected for further analysis. Of these, 39 papers were deemed to contain clinically relevant data to be included in this review. Results. The most common reasons for failure are liner dislocation, aseptic loosening, disease progression of another compartment and unexplained pain. . UKA can be revised to or with another UKA if the failure mode allows reconstruction of the joint with UKA components. In case of disease progression another UKA can be added, either at the patellofemoral joint or at the remaining tibiofemoral joint. Often the accompanying damage to the knee joint doesn’t allow these two former techniques resulting in a primary TKA. In a third of cases, revision TKA components are necessary. This is usually on the tibial side where augments and stems might be required. Conclusions. In case of failure of UKA, several less invasive revision techniques remain available to obtain primary results. Revision in a late stage of failure or because of surgical mistakes might ask for the use of revision components limiting the clinical outcome for the patients. Cite this article: Bone Joint J 2017;99-B(1 Supple A):65–9

Objectives. Nylon sutures and skin staples are used commonly in total knee arthroplasty (TKA) surgical wound closure. However, there is no study that compares the wound healing efficacy and patient satisfaction scores of both techniques in the same knee. Methods. We randomised 70 patients who underwent primary TKA into two groups. In one group of 34 patients, the skin at the upper half of the wound was closed with skin staples and the lower half of the wound was closed with simple interrupted nylon sutures. In the other group of 36 patients, the skin at the upper half of the wound was closed with nylon stitches and the lower half of the wound was closed with skin staples. We recorded the wound closure time, pain score at the time of stitch removal, wound complication rate, patient satisfaction score, and the Hollander wound evaluation score at the post-operative periods of five days, 14 days, six weeks, three months, and six months. Each half wound was analysed separately. Results. The mean patient body mass index was 26.8 kg/m. 2. (standard deviation 6.3). A total of 70 nylon stitched wounds and 70 skin stapled wounds were analysed. There were no significant differences in wound complication rates, patient satisfaction score, and the Hollander wound evaluation score between both types of wounds (p > 0.05). The wound closure time for skin stapled wounds was significantly lower than the nylon stitched wounds (p < 0.001). However, the skin stapled wounds had a significantly higher pain score at the time of stitch removal (p < 0.001). Conclusion. Skin staples and nylon stitches had comparable results with respect to wound healing and patient satisfaction in TKA wound closure in non-obese patients. The benefit of skin staples over nylon stitches was a decrease in operative time, but was more painful upon removal. Cite this article: V. Yuenyongviwat. A randomised controlled trial comparing skin closure in total knee arthroplasty in the same knee: nylon sutures versus skin staples. Bone Joint Res 2016;5:185–190. DOI: 10.1302/2046-3758.55.2000629

We randomised 102 knees suitable for a unicompartmental replacement to receive either a unicompartmental (UKR) or total knee replacement (TKR) after arthrotomy. Both groups were well matched with a predominance of females and a mean age of 69 years. Patients in the UKR group showed less perioperative morbidity, but regained knee movement more rapidly and were discharged from hospital sooner. At five years, two UKRs and one TKR had been revised; another TKR was radiologically loose. All other knees appeared to be clinically and radiologically sound. Pain relief was good in both groups but the number of knees able to flex ≥ 120° was significantly higher in the UKR group (p < 0.001) and there were more excellent results in this group. Our findings have shown that UKR gives better results than TKR and that this superiority is maintained for at least five years

The lateral subvastus approach combined with an osteotomy of the tibial tubercle is a recognised, but rarely used approach for total knee replacement (TKR). A total of 32 patients undergoing primary TKR was randomised into two groups, in one of which the lateral subvastus approach combined with a tibial tubercle osteotomy and in the other the medial parapatellar approach were used. The patients were assessed radiologically and clinically using measurement of the range of movement, a visual analogue patient satisfaction score, the Western Ontario McMasters University Osteoarthritis Index and the American Knee Society score. Four patients were lost to the complete follow-up at two years. At two years there were no significant differences between the groups in any of the parameters for clinical outcome. In the lateral approach group there was one complication due to displacement of the tibial tubercle osteotomy and two osteotomies took more than six months to unite. In the medial approach group, one patient had a partial tear of the quadriceps. There was a significantly greater incidence of lateral patellar subluxation in the medial approach group (3 of 12) compared with the lateral approach group (0 of 16) (p = 0.034), but without any apparent clinical detriment. We conclude that the lateral approach with tibial tubercle osteotomy is a safe technique with an outcome comparable with that of the medial parapatellar approach for TKR, but the increased surgical time and its specific complications do not support its routine use. It would seem to be more appropriate to reserve this technique for patients in whom problems with patellar tracking are anticipated

Objectives. Because posterior cruciate ligament (PCL) resection makes flexion gaps wider in total knee replacement (TKR), preserving or sacrificing a PCL affects the gap equivalence; however, there are no criteria for the PCL resection that consider gap situations of each knee. This study aims to investigate gap characteristics of knees and to consider the criteria for PCL resection. Methods. The extension and flexion gaps were measured, first with the PCL preserved and subsequently with the PCL removed (in cases in which posterior substitute components were selected). The PCL preservation or sacrifice was solely determined by the gap measurement results, without considering other functions of the PCL such as ‘roll back.’. Results. Wide variations were observed in the extension and flexion gaps. The flexion gaps were significantly larger than the extension gaps. Cases with 18 mm or more flexion gap and with larger flexion than extension gap were implanted with cruciate retaining component. A posterior substitute component was implanted with the other cases. Conclusions. In order to make adequate gaps, it is important to decide whether to preserve the PCL based on the intra-operative gap measurements made with the PCL intact. Cite this article: Bone Joint Res 2014;3:95–100

The Kinematic Stabilizer is a posterior-cruciate-substituting design of total knee replacement. We have reviewed 109 primary total knee replacements in 95 patients at a mean follow-up time of 12.7 years (10 to 14). We used survival analysis with failure defined as revision of the implant. This gave a cumulative survival rate of 95% (95% CI± 5%) at ten years and 87% (± 10%) at 13 years. These results from an independent centre confirm the value of an established design of cemented total knee replacement and question the wisdom of the introduction of modifications and new designs without properly controlled trials

Decreasing proprioception of the knee is multifactorial and is a function of age and degenerative joint disease. Soft-tissue release during total knee replacement may have an influence. We have quantified soft-tissue imbalance at the time of knee replacement and attempted to eliminate it at full extension, using established methods. We studied the influence of residual soft-tissue imbalance on postoperative proprioception, assessing this in 38 patients before total knee replacement and at three and six months postoperatively. We found that proprioception improved in varus knees at three and six months after soft-tissue balancing procedures. Knees balanced in full extension and in flexion (< ±2°) showed a significant improvement in proprioception (p < 0.0005) whereas those which were not balanced in flexion but fully balanced in extension had no significant improvement. We conclude that soft-tissue balance in both flexion and extension is important to allow satisfactory postoperative proprioception of the knee

Chemical prophylaxis is known to reduce the venographic prevalence of deep-vein thrombosis (DVT) after total knee replacement (TKR), but it is uncertain whether this affects the incidence of symptoms. Further analysis depends on the basic epidemiology of thromboembolic symptoms. We therefore studied the pattern of such symptoms in a consecutive series of 1000 patients with primary TKR, with particular reference to risk factors and prophylaxis. We reviewed all the clinical records and contacted all the patients individually, noting risk factors, prophylaxis, symptomatic pulmonary embolus (PE) or DVT and its timing, death and its causes, and all complications. All the patients wore antiembolism stockings, 83% had regional anaesthesia and 33.9% had chemical prophylaxis. One patient died from PE on the day of surgery, having had no prophylaxis giving a rate of 0.1% (95% CI 0.003% to 0.56%). Symptomatic, radiologically confirmed thromboembolism (VTE) was common with a rate of 10.6% (95% CI 8.7% to 12.5%). There was a similar incidence of VTE in those with and without chemical prophylaxis (10.1% v 10.5%, RR 0.96, NS). VTE was more common in patients with risk factors (15.1% v 9.5%, RR 1.59, p = 0.02) and tended to occur earlier in this group (median day of onset 5 v 7, p = 0.01). Chemical prophylaxis did not reduce the frequency of symptomatic thromboembolism in either those with risk factors (RR 0.81, p = 0.5) or those without them (RR 0.94, p = 0.8). Haematoma or wound dehiscence was more common in those having chemical prophylaxis (11.9% v 6.9%; RR 1.73 95% CI 1.16 to 2.60). Readmission for symptomatic, radio-logically confirmed thromboembolism involved 1.1% of patients (95% CI 0.55% to 2.1%). Four patients were readmitted with proven non-fatal PE and six with proven DVT (the latest on day 40). Our results show that the main risk factor for thromboembolism was TKR itself; chemical prophylaxis did not reduce the incidence of symptomatic thromboembolism but gave an increased perception of side-effects. New prophylactic methods or combinations of methods are needed, with their efficacy compared by randomised controlled studies of both the clinical and the radiological effect

A consecutive series of 235 total knee arthroplasties using the PFC system was followed prospectively for at least ten years in 186 patients. The operation was for osteoarthritis in 150 knees, for rheumatoid arthritis in 83, and for Paget’s disease and femoral osteonecrosis in one knee each. At the latest review 56 patients had died, fi ve were too ill to assess and three could not be traced. The PFC knee replacement utilised was a nonconforming posterior-cruciate-retaining prosthesis with a polyethylene insert which is fl at in the sagittal plane. The patella was resurfaced using a metal-backed component in 170 cases, but later in the series we used an all-polyethylene component in 22 knees; 43 patellae were not resurfaced. The survival without need for reoperation for any reason was 90% at ten years. Nineteen revisions were component-related due to failure of nine metal-backed patellae, nine polyethylene inserts, and one unresurfaced patella; two reoperations were for synovectomy (one for recurrent haemarthrosis and one for recurrent rheumatoid synovitis) and three were for metastatic joint infection. There were no revisions for aseptic loosening of femoral or tibial components, or the all-polyethylene patellar replacement. The PFC system provides good and predictable results in tricompartmental arthritis of the knee. Loosening appeared to be negligible, but there were wear-related problems in 8%. The change from a metal-backed patella and an increase in the contact area of the tibial insert should provide further improvement by minimising wear

Aims. For the increasing number of working-age patients undergoing total hip or total knee arthroplasty (THA/TKA), return to work (RTW) after surgery is crucial. We investigated the association between occupational class and time to RTW after THA or TKA. Methods. Data from the prospective multicentre Longitudinal Leiden Orthopaedics Outcomes of Osteoarthritis Study were used. Questionnaires were completed preoperatively and six and 12 months postoperatively. Time to RTW was defined as days from surgery until RTW (full or partial). Occupational class was preoperatively assessed and categorized into four categories according to the International Standard Classification of Occupations 2008 (blue-/white-collar, high-/low-skilled). Cox regression analyses were conducted separately for THA and TKA patients. Low-skilled blue-collar work was used as the reference category. Results. A total of 360 THA and 276 TKA patients, preoperatively employed, were included. Patients were mainly high-skilled (THA 57%; TKA 41%) or low-skilled (THA 24%; TKA 38%) white-collar workers. Six months post-THA, RTW rates were 78% of low-skilled blue-collar workers compared to 83% to 86% within other occupational classes, increasing after 12 months to 87% to 90% in all occupational classes. Six months post-TKA, RTW rates were 58% of low-skilled and 64% of high-skilled blue-collar workers compared to 80% to 89% of white-collar workers, and after 12 months 79% of low-skilled blue-collar workers compared to 87% to 92% within other occupational classes. High-skilled white-collar workers (THA: hazard ratio (HR) 2.12 (95% confidence interval (CI) 1.32 to 3.40); TKA: HR 2.31 (95% CI 1.34 to 4.00)) and low-skilled white-collar workers (TKA: HR 1.82 (95% CI 1.04 to 3.18)) had a higher hazard to RTW within six months postoperatively. Conclusion. Clear differences existed in time to RTW among both THA and TKA patients in each of the groups studied. These findings may help guide tailored patient-specific information during preoperative consultation and advice postoperatively, as well as to create awareness among workers and their employers. Cite this article: Bone Joint J 2023;105-B(9):977–984

We measured the pressure distribution across the tibiofemoral and patellofemoral joints during total knee arthroplasty (TKA) using Fuji pressure-sensitive film (Prescale) in 51 patients (63 joints) comparing the results with those in 21 patients in whom Prescale was not used. We classified the stress-distribution patterns in the tibiofemoral joints into four types: normal, varus-valgus instability, rotational malalignment, and a combination of instability and malrotation. The medial ligaments were then released according to the information obtained from these patterns. The conformity ratio of the contact area between repeated trials was 87.0%. Pressure distribution across the patellofemoral joints was also considered. There was a significant decrease in the mean valgus stress angle in the Prescale group compared with the control group (p < 0.01). Release of the lateral retinaculum according to the results showed no significant differences in subluxation of the patella between the released group and the group which did not appear to need this procedure