Systemic Ropivacaine Concentrations Following Local Infiltration Analgesia and Femoral Nerve Block in Older Patients Undergoing Total Knee Arthroplasty.

Purpose: The study examined the pharmacokinetic profile of fixed formulation mixtures comprising 225 mg of ropivacaine for local infiltration analgesia with or without epinephrine, and femoral nerve block in older patients presenting for orthopedic surgery and explored potential influences of block type, age, and body weight on this profile. Patients and Methods: Twenty four patients scheduled for total knee arthroplasty were randomly assigned to three groups: femoral nerve block, local infiltration analgesia with epinephrine and local infiltration analgesia without epinephrine. Blood samples were collected at 10, 30, 60, and 120 min following the block and total plasma concentrations of ropivacaine were quantified by high performance liquid chromatography. Results: The mean individual peak total plasma concentrations of ropivacaine in local infiltration analgesia with and without epinephrine, and femoral nerve block group were 0.334, 0.490 and 0.545 µg mL-1 (p = 0.16). Local infiltration with epinephrine group had significantly lower plasma ropivacaine concentrations at 30, 60 and 120 minutes. The plasma ropivacaine concentrations exceeded 2.2 µg mL-1 in one patient. Age, but not body weight, had a moderate correlation with peak plasma ropivacaine concentration (r = 0.37, p = 0.08). Conclusion: Administration of a fixed 225 mg dose of ropivacaine for local infiltration analgesia with epinephrine and femoral nerve block results in plasma ropivacaine concentrations below the toxicity threshold, indicating their safety. The use of local infiltration analgesia with epinephrine provides a greater safety margin, as local infiltration analgesia without epinephrine may lead to ropivacaine concentrations associated with symptoms of local anesthetic toxicity.

Resection Arthroplasty Treatment Possibility for a Patient with Fibrous Dysplasia, Chronic Osteomyelitis, and Recurrent Periprosthetic Hip Joint Infection: A Case Report.

INTRODUCTION: Fibrous dysplasia (FD) is a rare congenital abnormality, in which parts of bone are replaced with fibrous stroma and woven bone, making it susceptible to pathological fractures. Osteomyelitis following intramedullary nailing of such fractures of the femur and periprosthetic joint infection (PJI) after hip arthroplasty is one of the most devastating complications and a true challenge for the orthopedic surgeon. To the best of our knowledge, this is the 1st time, such complications are reported in a patient with monostotic FD. CASE REPORT: We present a 30-year-old male patient with FD of the left femur, chronic osteomyelitis, recurrent periprosthetic hip joint infection after multiple revision arthroplasties, and two episodes of axillary vein thrombosis. Due to the severe structural changes and a large medial wall defect in the proximal femur with impairment of a large soft tissue zone, it was decided during operation not to put any other implants in the hip joint and perform only a resection hip arthroplasty procedure. CONCLUSION: Managing a recurrent PJI in a patient with poor bone quality, severe bone defects, soft tissue compromise, and thromboembolic events is challenging even for the most experienced orthopedic surgeon. Resection arthroplasty is a salvage treatment option that should be considered in such complex cases.