Introduction

Controlling post-operative pain and reducing opioid requirements after total knee arthroplasty (TKA) remains a challenge, particularly in an era stressing rapid recovery protocols and early discharge. A single shot adductor canal block (ACB) has been shown to be effective in decreasing post-operative pain. This requires a specialty-trained Anesthesiologist skilled in ultrasound techniques, which imposes cost, time and skill barriers. Cadaveric studies and magnetic resonance imaging data have shown that access to the adductor canal is possible from within the joint, and thus the potential for intraoperative, intra-articular, surgeon administered ACB through a standard surgical approach is a feasible alternative to ultrasound guided ACB at the time of TKA. The purpose of the present study is to compare the efficacy of surgeon administered intraoperative ACB to anesthesiologist administered ACB.

Introduction: Osteonecrosis of the hip is a devastating disease that often results in the collapse of the femoral head and secondary osteoarthritis of the hip. Although total hip arthroplasty is considered the main therapeutic option in cases of advanced osteonecrosis (Ficat stage III or IV), historically high failure rates have been reported for this treatment. Variables such as, whether or not the prosthesis was cemented, year of implantation, age, various medical comorbidities, and risk factors such as alcohol abuse, corticosteroids usage, autoimmune disease, or sickle cell anemia may lead to better or worse outcomes. The purpose of this study was to determine which factors were associated with risk for failure concerning total hip arthroplasty (THA) for osteonecrosis of the femoral head from a complete meta-analysis of the literature.

Methods: A systematic review utilizing the Medline bibliographic database found 35 studies meeting our inclusion criteria that were related to osteonecrosis encompassing 557 hips in 443 patients. These reports were published between the years 1989 to 2007. The mean follow-up was 6.7 years (range, 3 – 10). The study population comprised of 60% men who had a mean age of 47 years (range, 17 to 90). The most frequent associated risk factors for osteonecrosis were corticosteroid usage (26.2%) and alcohol abuse (30.1%). The final outcome parameters were number and percentage of patients who underwent revision surgery, who had impending radiographic failure, such as osteolytic lesions in close proximity to the implant, or who were clinical failures. Clinical failure was defined as a value less than 70% of the maximum score of the relevant hip scoring system used.

All reviewed studies were divided into cemented, cementless, or hybrid fixation, as well as year of implantation (before and after 1990). In addition, patients were stratified according to comorbidities, age, gender, and various diagnostic and other risk factors (e.g. systemic lupus erythematosus, sickle cell disease, use of corticosteroids, alcohol abuse).

Results: Overall, there were 131 poor outcomes out of 557 hips (23.5%). Seventy-six revision surgeries were performed, with another 55 hips showing either radiographic signs of loosening or clinical failures. Cemented THA had a failure rate of 17.9%, while the cementless THA had a failure rate of 24.5%.

Overall outcomes were different for various risk factors; intake of corticosteroids led to a failure rate of 42.3%, alcohol abuse; 38.1%, posttraumatic disorders; 39%, and sickle cell anemia; 45.5%. Patients without known adverse risk factors had only 17% failures.

Discussion: Our findings further emphasize the poor results of total hip arthroplasty in patients with various risk factors such as alcohol abuse, use of corticosteroids, lupus, and sickle cell anemia. It also appears that patients without these adverse risk factors have a better survival rate. The importance of this study is that it may help the surgeon understand the risk of total hip arthroplasty in various stratified groups in patients with osteonecrosis.

Introduction and Aims: While clinical variables are considered important risk factors for post-arthroplasty VTE, the role of common genetic thrombophilic factors is less clear. The aims of this study were to determine if common thrombophilic genetic polymorphisms are independent risk factors for VTE post-arthroplasty; and if clinical variables are equally or more important.

Method: A prospective study of consecutive patients undergoing elective total hip or knee arthroplasty at a single institution, involving two surgeons. Patients were interviewed to assess clinical risks. Pre-operative blood samples were taken for Factor V Leiden (FVL), Pro-thrombin G20210A (PTH) and Methylenetetrahydrofolate reductase C677T (MTHFR) testing. All patients received routine enoxaparin prophylaxis and compression stockings. Intermittent pneumatic calf compression was also used by one surgeon. Presence of DVT was assessed using bilateral lower limb duplex ultrasonography (seven ± two days post-operatively) in all patients and performed in a vascular laboratory. Symptoms suggestive of pulmonary embolism were investigated by ventilation/perfusion lung scanning.

Results: A total of 569 patients were recruited with a median age of 67 years (range 20–90). Osteoarthritis was the main surgical indication. The overall incidence of post-operative venous thromboembolism (VTE) was 26%. Of thromboembolic events, 15% VTE were proximal DVT; 84% VTE were distal DVT and only one percent were pulmonary emboli. Prevalence of the thrombophilic genotypes was: 4.6% (heterozygous FVL mutation); 2.1% (heterozygous PTH); and 10.4% (homozygous C677T MTHFR mutation). Using univariate analysis, older age (p < 0.0005), total knee arthroplasty (p < 0.0005), recent surgery (p = 0.002), general anaesthesia (p = 0.013), operation time in minutes (p < 0.0005) and use of blood transfusions (p < 0.0005) were significantly associated with post-operative DVT. None of the thrombophilic genotypes were found to be significantly associated with post-operative DVT, however the frequency of FVL and PTH was highest in patients with proximal DVT and total hip arthroplasty patients with DVT. In multivariate analysis of both genetic and clinical thrombophilic factors, only age (p=0.02) and total knee arthroplasty (p< 0.0005) were found to be significant independent risk factors for post-operative VTE.

Conclusion: We conclude that clinical factors such as age and type of surgery (total knee arthroplasty) are independent risks for post-operative VTE in patients undergoing lower limb arthroplasty. FVL, PTH and MTHFR are not significant risk factors for post-operative VTE and screening for these mutations is not indicated.