A Phase IV Study of Thromboembolic and Bleeding Events Following Hip and Knee Arthroplasty Using Oral Factor Xa Inhibitor.

BACKGROUND: Multiple randomized controlled trials have documented the effectiveness of rivaroxaban in the prevention of venous thromboembolism up to 1-month following total joint arthroplasty. However, the effectiveness and safety of rivaroxaban in the real-world setting, outside of the strict protocols used by randomized clinical trials, are unknown. METHODS: This was a prospective, observational, noninterventional, phase IV study of 3914 consecutive patients who underwent total joint arthroplasty from June 2010 to December 2012. Patients were treated with rivaroxaban 10 mg by mouth daily starting postoperative day 1 and continued for 15 days. Participants were followed up in clinic at 6 weeks and contacted by telephone at 12 weeks. The primary outcome of interest was symptomatic venous thromboembolism; secondary outcomes included bleeding events, transfusion requirements, and death. RESULTS: The incidence of symptomatic deep venous thrombosis at 3 months was 0.5% (n = 18). Only 1 deep venous thrombosis event occurred within 7 days of surgery. The incidence of symptomatic pulmonary embolism (PE) at 3 months was 0.7% (n = 28). Thirteen PEs (46%) occurred within 7 days of surgery. The rate of major bleeding while on prophylaxis was 0.1%. Only 5% of patients received a blood transfusion. No deaths were attributed to thromboembolic events. CONCLUSION: This prospective, observational, phase IV study demonstrates that rivaroxaban appears to protect patients against symptomatic PE and is not associated with major bleeding events when used in a real-world setting as described.

Patient-reported compliance with thromboprophylaxis using an oral factor Xa inhibitor (rivaroxaban) following total hip and total knee arthroplasty.

This prospective study examines patient non-compliance (NC) for an oral factor Xa inhibitor (Rivaroxaban) when used as venous thromboembolic (VTE) prophylaxis following lower limb arthroplasty. A total of 3145 patients underwent surgery from May 2010 to December 2011. At 6 weeks patients completed an anonymous self-administered questionnaire. Postoperatively 2947 (94%, 2947/3145) received Rivaroxaban. 2824 (96%, 2824/2947) completed all in-hospital doses. Seven percent (203/2824) of patients did not attend the 6-week follow-up. Two thousand one hundred sixty-three (83%, 2163/2621) completed all prescribed doses, 98 (4%, 98/2621) were NC and 360 (14%, 360/2621) had incomplete data. Gender, age, body mass index and preoperative hemoglobin all correlated with NC (p < 0.05). Type and side of surgery did not correlate with compliance (p > 0.05). Patient-reported NC for Rivaroxaban is 4% which compares favorably to other VTE prophylaxis modalities.

Bilateral rotational osteotomies of the proximal tibiae and tibial tuberosity distal transfers for the treatment of congenital lateral dislocations of patellae: a case report and literature review.

Congenital dislocation of patella (CDP) causes varying degree of disability. Patients may present as late walkers with asymmetric gait, habitual or recurrent dislocators or even non-walkers if the condition is bilateral. Patellar instability is often associated with soft tissue or bony pathology. Soft tissue anomalies include lateral soft tissue contractures, shortened quadriceps as well as vastus medialis dysplasia (abnormal origin and insertion). Bony anomalies include shallow trochlear groove and hypoplastic patella or lateral femoral condyle. Soft tissue etiologies result in an imbalance of the dynamic forces acting on the patella while in bony etiologies the static stabilizers to resist lateral dislocation are compromised. External tibial torsion is an additional etiology, often under diagnosed due to the difficulty in measuring the Q angle of dislocated patella. We report a case of bilateral congenital lateral dislocations of the patellae treated with bilateral tibial rotational osteotomies with an 8 year and a 4 year follow up.