The December 2024 Arthroplasty Roundup³⁶⁰ looks at: Aspirin for hip and knee arthroplasty?; VTE prophylaxis; VTE prophylaxis part II.

Aims. Venous thromboembolism (VTE) is a potential complication of foot and ankle surgery. There is a lack of agreement on contributing risk factors and chemical prophylaxis requirements. The primary outcome of this study was to analyze the 90-day incidence of symptomatic VTE and VTE-related mortality in patients undergoing foot and ankle surgery and Achilles tendon (TA) rupture. Secondary aims were to assess the variation in the provision of chemical prophylaxis and risk factors for VTE. Methods. This was a multicentre, prospective national collaborative audit with data collection over nine months for all patients undergoing foot and ankle surgery in an operating theatre or TA rupture treatment, within participating UK hospitals. The association between VTE and thromboprophylaxis was assessed with a univariable logistic regression model. A multivariable logistic regression model was used to identify key predictors for the risk of VTE. Results. A total of 13,569 patients were included from 68 sites. Overall, 11,363 patients were available for analysis: 44.79% were elective (n = 5,090), 42.16% were trauma excluding TA ruptures (n = 4,791), 3.50% were acute diabetic procedures (n = 398), 2.44% were TA ruptures undergoing surgery (n = 277), and 7.10% were TA ruptures treated nonoperatively (n = 807). In total, 11 chemical anticoagulants were recorded, with the most common agent being low-molecular-weight heparin (n = 6,303; 56.79%). A total of 32.71% received no chemical prophylaxis. There were 99 cases of VTE (incidence 0.87% (95% CI 0.71 to 1.06)). VTE-related mortality was 0.03% (95% CI 0.005 to 0.080). Univariable analysis showed that increased age and American Society of Anesthesiologists (ASA) grade had higher odds of VTE, as did having previous cancer, stroke, or history of VTE. On multivariable analysis, the strongest predictors for VTE were the type of foot and ankle procedure and ASA grade. Conclusion. The 90-day incidence of symptomatic VTE and mortality related to VTE is low in foot and ankle surgery and TA management. There was notable variability in the chemical prophylaxis used. The significant risk factors associated with 90-day symptomatic VTE were TA rupture and high ASA grade. Cite this article: Bone Joint J 2024;106-B(11):1249–1256

The October 2024 Knee Roundup³⁶⁰ looks at: Managing the unexpected: treatment of intraoperative medial collateral ligament injuries; Identifying subgroups of patients that may benefit from robotic arm-assisted total knee arthroplasty: secondary analysis of data from a randomized controlled trial; Cost-effectiveness of enoxaparin versus aspirin in the prevention of venous thromboembolism after total hip or knee arthroplasty: an analysis from the CRISTAL cluster-randomized trial; Cartilage regeneration and long-term survival in medial knee osteoarthritis patients treated with high tibial osteotomy and osteochondral autologous transfer system; Treatment of chronic and complex meniscal tears with arthroscopic meniscus repair augmented with collagen matrix wrapping: failure rate and functional outcomes; Long-term outcomes of multiligament knee injuries in American football players.

Aims

We investigated the efficacy and safety profile of commonly used venous thromboembolism (VTE) prophylaxis agents following hip and knee arthroplasty.

Introduction. VTE is a possible complication of foot and ankle surgery, however there is an absence of agreement on contributing risk factors in the development of VTE. The primary outcome of this study was to analyse the 90-day incidence of symptomatic VTE following foot and ankle surgery and to determine which factors may increase the risk of VTE. Methods. This was a national, multi-centre prospective audit spanning a collection duration of 9 months (2022/2023). Primary outcomes included incidence of symptomatic VTE and VTE related mortality up to 90 days following foot and ankle surgery and Achilles tendon rupture, and analysis of risk factors. Results. In total 11,363 patients were available for analysis. 5,090 patients (44.79%) were elective procedures, 4,791 patients (42.16%) were trauma procedures (excluding Achilles ruptures), 398 patients (3.50%) were acute diabetic procedures, 277 patients (2.44%) were Achilles ruptures undergoing surgery and 807 patients (7.10%) were Achilles ruptures treated non-operatively. There were 99 cases of VTE within 90 days of admission across the whole group (Total incidence = 0.87%), with 3 cases of VTE related mortality (0.03%). On univariate analysis, increased age and ASA grade showedhigher odds of 90-day VTE, as did previous cancer, stroke, history of VTE, and type of foot and ankle procedure / injury (p<0.05). However, on multivariate analysis, the only independent predictors for 90-day VTE were found to be the type of foot and ankle procedure (Achilles tendon rupture = Odd's Ratio 11.62, operative to 14.41, non-operative) and ASA grade (grade III/IV = Odd's Ratio 3.64). Conclusion. The incidence of 90-day post procedure VTE in foot and ankle surgery in this national audit was low. Significant, independent risk factors associated with the development of 90-day symptomatic VTE were Achilles tendon rupture management and high ASA grade

Introduction. Total contact casting (TCC) is one of the most commonly utilized modalities in the management of diabetic feet. We undertook a retrospective review to determine the prevalence of symptomatic VTE events in patients treated in a weight bearing TCC in our diabetic foot unit, and to formulate guidelines for VTE prophylaxis. Methods. Electronic records were reviewed to identify all patients treated in a TCC between 2014 and 2021. Data collection included patient demographics, comorbidities, period of immobilization in TCC, the incidence of VTE events, and any VTE prophylaxis prescribed during their period in TCC. Results. 549 patients were identified who had at least one episode of TCC. Mean age was 67 years (range 28 to 94 years) and the mean duration in cast was 10.2 weeks (range 0.3–46 weeks). Only 6 patients (1.1%) were prescribed chemical thrombo-prophylaxis during their period in TCC. Mean body mass index (BMI) for these patients was 32.3 (Range 18.4–58.9). Other significant comorbidities: 81% (n-444) of patients had associated cardio-vascular comorbidities; 54 % (n-296) had renal comorbidities including 22% (n-121) having had dialysis and 4.2% (n-23) with renal transplants. Eight of the 549 patients (1.5%) had suffered a VTE event of which only 2 (0.36%) were during the period of immobilization in TCC. One was a symptomatic DVT (0.18%) and the another was an asymptomatic (incidental) finding of pulmonary embolism (PE). There was no mortality related to the VTE episodes. Conclusion. NICE guidelines state that one should “Consider pharmacological VTE prophylaxis for patients with lower limb immobilization”. Our study finds that patients treated in a weight bearing TCC do not require routine pharmacological VTE prophylaxis, in spite of an extended period of lower limb immobilization and significant medical comorbidities

Aims. The aim of this study was to evaluate the healthcare costs and benefits of enoxaparin compared to aspirin in the prevention of symptomatic venous thromboembolism (VTE) after total hip arthroplasty (THA) or total knee arthroplasty (TKA) using data from the CRISTAL trial. Methods. This trial-based economic analysis reports value for money as incremental cost per quality-adjusted life-year (QALY) gained in 2022 Australian dollars, compared to a single threshold value of AUD$70,000 per QALY. Event costs were estimated based on occurrence of VTEs and bleeds, and on published guidelines for treatment. Unit costs were taken from Australian sources. QALYs were estimated using CRISTAL six-month follow-up data. Sensitivity analyses are presented that vary the cost of VTE treatment, and extend the analyses to two years. Results. The CRISTAL trial found that enoxaparin was more effective than aspirin in preventing symptomatic VTE within 90 days of THA or TKA (risk difference 1.97% (95% confidence interval (CI) 0.54% to 3.41%; p = 0.007)). The additional cost after a THA or TKA was AUD$83 (95% CI 68 to 97) for enoxaparin, and enoxaparin resulted in an additional 0.002 QALYs (95% CI -0.002 to 0.005). Incremental cost per QALY gained was AUD$50,567 (95% CI 15,513, dominated) for enoxaparin. We can be 60% confident that the incremental cost per QALY does not exceed the willingness-to-pay threshold of AUD$70,000. Increasing the cost of VTE treatment and extension of costs and consequences to two years suggested greater confidence that enoxaparin is good value for money (70% and 63% confidence, respectively). Conclusion. This analysis provides strong evidence that enoxaparin thromboprophylaxis following THA or TKA reduced VTEs, but weak evidence of net economic benefits over aspirin. If the value of avoiding VTEs is high, and there is a strong likelihood of VTE-related health impairments, we can be more confident that enoxaparin is cost-effective compared to aspirin. Cite this article: Bone Joint J 2024;106-B(6):589–595

Prolonged bedrest in hospitalized patients is a major risk factor for venous thromboembolism (VTE), especially in high risk patients with hip fracture. Thrombelastography (TEG) is a whole blood viscoelastic hemostatic assay with evidence that an elevated maximal amplitude (MA), a measure of clot strength, is predictive of VTE in orthopaedic trauma patients. The objective of this study was to compare the TEG MA parameter between patients with hip fracture who were more mobile post-operatively and discharged from hospital early to patients with hip fracture with reduced mobility and prolonged hospitalizations post-operatively. In this prospective cohort study, TEG analysis was performed in patients with hip fracture every 24-hours from admission until post-operative day (POD) 5, then at 2- and 6-weeks post-operatively. Hypercoagulability was defined by MA > 65. Patients were divided into an early (within 5-day) and late (after 5-day) discharge group, inpatient at 2-weeks group, and discharge to MSK rehabilitation (MSK rehab), and long term care (LTC) groups. Two-sample t-test was used to analyze differences in MA between the early discharge and less mobile groups. All statistical tests were two-sided, and p-values < 0.05 were considered statistically significant. In total, 121 patients with a median age of 81.0 were included. Patients in the early discharge group (n=15) were younger (median age 64.0) and more likely to ambulate without gait aids pre-injury (86.7%) compared to patients in the late discharge group (n=105), inpatients at 2-weeks (n=48), discharged to MSK rehab (n=30), and LTC (n=20). At two weeks post-operative, the early discharge group was significantly less hypercoagulable (MA=68.9, SD 3.0) compared to patients in the other four groups. At 6-weeks post-operative, the early discharge group was the only group to demonstrate a trend towards mean MA below the MA > 65 hypercoagulable threshold (MA=64.4, p=0.45). Symptomatic VTE events were detected in three patients (2.5%) post-operatively. All three patients had hospitalizations longer than five days after surgery. In conclusion, our analysis of hypercoagulability secondary to reduced post-operative mobility demonstrates that patients with hip fracture who were able to mobilize independently sooner after hip fracture surgery, have a reduced peak hypercoagulable state. In addition, there is a trend towards earlier return to normal coagulation status as determined by the TEG MA parameter. Post-operative mobility status may play a role in determining individualized duration of thromboprophylaxis following hip fracture surgery. Future studies comparing TEG to clinically validated mobility tools may more closely evaluate the contribution of venous stasis due to reduced mobility on hypercoagulation following hip fracture surgery

Prolonged bedrest in hospitalized patients is a major risk factor for venous thromboembolism (VTE), especially in high risk patients with hip fracture. Thrombelastography (TEG) is a whole blood viscoelastic hemostatic assay with evidence that an elevated maximal amplitude (MA), a measure of clot strength, is predictive of VTE in orthopaedic trauma patients. The objective of this study was to compare the TEG MA parameter between patients with hip fracture who were more mobile post-operatively and discharged from hospital early to patients with hip fracture with reduced mobility and prolonged hospitalizations post-operatively. In this prospective cohort study, TEG analysis was performed in patients with hip fracture every 24-hours from admission until post-operative day (POD) 5, then at 2- and 6-weeks post-operatively. Hypercoagulability was defined by MA > 65. Patients were divided into an early (within 5-day) and late (after 5-day) discharge group, inpatient at 2-weeks group, and discharge to MSK rehabilitation (MSK rehab), and long term care (LTC) groups. Two-sample t-test was used to analyze differences in MA between the early discharge and less mobile groups. All statistical tests were two-sided, and p-values < 0.05 were considered statistically significant. In total, 121 patients with a median age of 81.0 were included. Patients in the early discharge group (n=15) were younger (median age 64.0) and more likely to ambulate without gait aids pre-injury (86.7%) compared to patients in the late discharge group (n=105), inpatients at 2-weeks (n=48), discharged to MSK rehab (n=30), and LTC (n=20). At two weeks post-operative, the early discharge group was significantly less hypercoagulable (MA=68.9, SD 3.0) compared to patients in the other four groups. At 6-weeks post-operative, the early discharge group was the only group to demonstrate a trend towards mean MA below the MA > 65 hypercoagulable threshold (MA=64.4, p=0.45). Symptomatic VTE events were detected in three patients (2.5%) post-operatively. All three patients had hospitalizations longer than five days after surgery. In conclusion, our analysis of hypercoagulability secondary to reduced post-operative mobility demonstrates that patients with hip fracture who were able to mobilize independently sooner after hip fracture surgery, have a reduced peak hypercoagulable state. In addition, there is a trend towards earlier return to normal coagulation status as determined by the TEG MA parameter. Post-operative mobility status may play a role in determining individualized duration of thromboprophylaxis following hip fracture surgery. Future studies comparing TEG to clinically validated mobility tools may more closely evaluate the contribution of venous stasis due to reduced mobility on hypercoagulation following hip fracture surgery

The aim of this study was to identify factors independently associated with symptomatic venous thromboembolism (VTE) following acute Achilles tendon rupture (ATR), and to suggest a clinical VTE risk assessment tool for patients with ATR. From 2010–2018, 984 consecutive adults (median age 47yrs, 73% male) sustaining an ATR were retrospectively identified. There were 95% managed non-operatively (below-knee cast 52%, n=507/984; walking boot 44%, n=432/984), with 5% (n=45/984) undergoing primary operative repair (<6wks). VTE was diagnosed using medical records and national imaging archives, reviewed at a mean of 5yrs (1–10) post-injury. Regression was performed to identify factors independently associated with VTE. Incidence of VTE within 90 days of ATR was 3.6% (n=35/984; deep vein thrombosis 2.1% [n=21/984], pulmonary embolism 1.9% [n=19/984]). Age ≥50yrs (adjusted OR [aOR] 2.3, p=0.027), personal history of VTE/thrombophilia (aOR 6.1, p=0.009) and family history of VTE (aOR 20.9, p<0.001) were independently associated with VTE. These non-modifiable risk factors were incorporated into a VTE risk assessment tool. 23% of patients developing VTE (n=8/35) had a relevant personal or family history, but incorporating age into the tool identified 69% of patients with VTE (n=24/35). Non weight-bearing ≥2wks after ATR was also independently associated with VTE (aOR 3.2, p=0.026). Age ≥50 years, personal history of VTE/thrombophilia and a positive family history were independently associated with VTE following ATR. Incorporating age into our suggested VTE risk assessment tool enhanced sensitivity in identifying at-risk patients. Early weight-bearing in an appropriate orthosis may be beneficial in VTE risk reduction

Aims

Many surgeons choose to perform total knee arthroplasty (TKA) surgery with the aid of a tourniquet. A tourniquet is a device that fits around the leg and restricts blood flow to the limb. There is a need to understand whether tourniquets are safe, and if they benefit, or harm, patients. The aim of this study was to determine the benefits and harms of tourniquet use in TKA surgery.

Aims

As the first wave of the COVID-19 pandemic began to dip, restarting elective orthopaedics became a challenge. Protocols including surgery at ‘green’ sites, self-isolation for 14 days, and COVID-19 testing were developed to minimize the risk of transmission. In this study, we look at risk effects of 14-day self-isolation on the incidence of venous thromboembolism (VTE) in our green site hospital among patients undergoing total joint replacement (TJR).

Aims

We studied the safety and efficacy of multimodal thromboprophylaxis in patients with a history of venous thromboembolism (VTE) who undergo total hip arthroplasty (THA) within the first 120 postoperative days, and the mortality during the first year. Multimodal prophylaxis includes discontinuation of procoagulant medications, VTE risk stratification, regional anaesthesia, an intravenous bolus of unfractionated heparin prior to femoral preparation, rapid mobilization, the use of pneumatic compression devices, and chemoprophylaxis tailored to the patient’s risk of VTE.