Objective: Fast track concepts are used to reduce the risk of perioperative and postoperative complications after total knee arthroplasty.
Indications: The described concepts are used for patients with indications for the implantation of a total knee prosthesis.
Contraindications: Contraindications for fast track concepts are aged patients, dementia, American Society of Anesthesiologists (ASA) grade IV and implantation of large revision or tumor prostheses. Contraindications for tranexamic acid are bleeding in the urinary tract, caution in cases of known epilepsy, individual risk assessment in existing thromboses or increased thrombosis risk, fresh myocardial infarction, conditions following fresh pulmonary embolism, percutaneous transluminal coronary angioplasty (PTCA) and stent implantation. Contraindications for ropivacaine are hypersensitivity (allergy) to ropivacaine and other amide type topical anesthetics and hypovolemia.
Surgical technique: Preoperative administration of 1 g tranexamic acid and intraoperative local infiltration anesthesia are carried out. After femoral and tibial bone resection and before cementing the femoral and tibial components, approximately 40 ml of ropivacaine (2%) is injected into the posterior capsule. This is followed by injection of the medial and lateral collateral ligaments with approximately 20 ml each and infiltration of Hoffa's fat pad and the extensor apparatus also with approximately 20 ml local anesthetic. After cementing, the subcutaneous tissue is infiltrated with approximately 50 ml ropivacaine solution.
Postoperative management: On the same day as the operation the patient is mobilized with the help of a physiotherapist. The patient should, if possible, walk a few steps on crutches. Systemic analgesic treatment is carried out according to the World Health Organization (WHO) staged scheme II with a weak opioid and first stage non-opioid analgesic (nonsteroidal anti-inflammatory drug, NSAID and/or metamizole). Gabapentin can be used as an adjuvant comedication. Medicinal thrombosis prophylaxis is carried out with a low molecular weight heparin for 2 weeks postoperatively.
Results: In 100 patients who preoperatively received 1 g tranexamic acid and intra-articular infiltration anesthesia, in the evening of the day of the operation the pain was on average 2.1 (±1.8) on the numeric pain rating scale (NPRS). In one patient, there was a sensitive deficit of the lower leg and foot. A motor deficit was not observed. A total of 90 patients were able to raise and straighten leg. On the day of surgery 68 patients were able to walk more than 10 steps and 22 patients could be mobilized to a standing position. The mean length of hospital stay was 6.6 days (5-11 days). No infections, thromboses or pulmonary embolisms occurred.
Keywords: Anesthesia, conduction; Length of stay; Local anesthesia; Ropivacaine; Tranexamic acid.