Outcome After Total Knee Arthroplasty Under General or Spinal Anesthesia

Outcome After Total Knee Arthroplasty Under General or Spinal Anesthesia, a Randomized Controlled Trial

Previous retrospective database studies suggest that total knee arthroplasty (TKA) surgery under spinal anesthesia has less complications than when performed under general anesthesia. In general, complications are rare and both anesthesia types are widely accepted. In Finland, total knee arthroplasty has typically been performed under spinal anesthesia.

In a recent prospective randomized controlled study, total knee arthroplasty under general anesthesia resulted in less acute postoperative pain (opioid-need measured by patient-controlled anesthesia), less nausea, and faster hospital discharge than that performed under spinal anesthesia. Also the use of surgical tourniquet can affect surgical outcome: it may reduce bleeding and surgery time, but it may also cause weakness of thigh muscles and thus hinder mobilization. In a recent study, both techniques with and without surgical tourniquet appeared equal.

The aims of this study are to compare total knee arthroplasty under spinal or general anesthesia, with or without surgical tourniquet, in relation to acute and chronic postoperative pain, nausea, knee function, patient reported quality of life and satisfaction on care, complications, length of stay, and need of surgical unit resources. This randomized controlled study includes 400 patients with informed consent, 18-75-years-of-age, standard primary total knee arthroplasty operation, American Society of Anesthesiologist (ASA) physical status classification I-III, body mass index under 40, and no contraindications for medications or treatments used.

The hypothesis of this study are used to reassess best practices of primary total knee arthroplasty operation to enhance quality of care, patient outcomes and satisfaction, and availability of surgery due to better patient flow at surgical unit.

Inclusion Criteria:

• Indication for total knee arthroplasty exists (patient has osteoarthritis, rheumatoid arthritis or other disease affecting knee joint that does not respond to conservative treatment)
• Patient understands the study information and is willing to participate
• Triathlon endoprosthesis is suitable for patient
• ASA Physical Status Classification 1-3
• Patient will be operated by a surgeon who has done at least 100 total knee arthroplasty procedures with Triathlon endoprosthesis before

Exclusion Criteria:

• BMI > 40 kg/m2
• ASA Physical Status Classification > 3
• Valgus or varus > 15° degrees in the knee that will be operated
• Extension deficit ≥ 20° or flexion ≤ 90° in the knee that will be operated
• Earlier major (open) surgery in the knee that will be operated
• Contraindication for drugs used in the study
• Contraindication for either spinal or general anesthesia
• Glomerular filtration rate < 60ml/min/1.73m2 (by Chronic Kidney DIsease Epidemiology Collaboration formula)
• Known or suspected disease affecting the function of liver
• Preoperative use of strong opioids
• Patient is pregnant, cognitively disabled, under guardianship, a prisoner or in compulsory military service
• Patient will be operated by a surgeon who has done less than 100 total knee arthroplasty procedures before or by a surgeon who does not operate with Triathlon endoprosthesis
• Day of the surgery is not suitable for study (no research personnel available for 24 hours postoperative evaluation)