The Effect of Combined IPACK Block with ACB Versus ACB Alone on Pain Management and Early Mobility After Total Knee Arthroplasty

This trial was established to assess efficiency of IPACK block in combination with ACB in relieving postoperative pain , particularly posterior knee pain and providing early rehabilitation after TKA in comparison with ACB alone .All patients were subjected to full history taking including current medications and thorough physical examination.

Age, sex, BMI and ASA physical status were recorded and Preoperative investigations were done to all patients including laboratory investigations as (complete blood picture, bleeding time, prothrombin time and activated partial thromboplastin time) and other investigations according to the patient's medical condition. The patients were fasting for 2 to 8 hours preoperatively. All patients were consented with a written consent for the spinal anesthesia and either of the peripheral regional blocks that were held after explaining the procedure. Intraoperatively, All patients were monitored by pulse oximeter, non-invasive blood pressure cuff and electrocardiogram for heart rate and rhythm. IV Access was applied. All patients received 0.03 mg/kg midazolam iv, granisetron 1mg iv and dexamethasone 10 mg iv as a prophylaxis against nausea and vomiting.Sign IN and Time OUT checklist were revised before starting the anesthetic procedure and the surgical procedure, respectively.All patients received spinal anesthesia using 15 mg 0.5% hyperbaric bupivacaine in the sitting position at L3-4 or L4-5 intervertebral space.All patients received Intraoperative fluids and sedation with intravenous dexmedetomidine if needed.Checking on the availability of intralipid (lipid emulsion 20%) nearby and preparation of the ultrasound device (investigators used in the recent study the Sonosite M-Turbo C Portable Ultrasound). After patients' stabilization, Patients were divided into 2 group.

Group A: received ultrasound guided adductor canal block (ACB) alone using 22 Gag spinal needle with injection of 15ml 0.25% bupivacaine with addition of 2mg dexamethasone and 2.5mcg /ml epinephrine as an adjuvant to prolong its action.

Group B: received ultrasound guided adductor canal block (ACB) as group A, in addition to ultrasound guided infiltration of the interspace between popliteal artery and the capsule of posterior knee (IPACK) block with either of the two previously mentioned approaches, using 22Gag spinal needle injecting 20ml 0.25%bupivacaine with addition of 2mg dexamethasone and 2.5mcg /ml epinephrine as an adjuvant to prolong its action. Postoperatively,All patients were transferred to the post anesthesia care unit (PACU).

All patients were monitored at (PACU) for oxygen saturation, heart rate and blood pressure for 2hours observational period.The two groups of patients were evaluated and compared as regard:

Degree of postoperative pain using Numerical Rating Scale (NRS) at the first 48 hrs. The first need for analgesic rescue (NRS score ≥ 4 [0: no pain 10: very severe pain]) at 2, 4, 6, 8, 12, 24, and 48 hr. and the total amount of analgesic rescues was determined. Analgesic rescue was provided using 1 gram paracetamol IV and 30mg ketorolac IV, while in a few cases titration of pethidine was used after failure of the determined analgesic rescue with paracetamol and ketorolac to provide pain relief.

The recovery of spinal motor blockade and early motor ability using Bromage score and the incidence of peroneal motor weakness (dorsiflexion of the ankle and toes).

Length of hospital stays (defined as the days from the end of surgery until discharge).

The first mobilization time recorded in hours. The Timed Up and Go (TUG)test (measured in seconds).This test was performed on the 1st and 2nd postoperative days.Postoperative 1st and 2nd-day Rang of Movement (ROM) measurements.

Inclusion criteria

• Sex: Patients of either sex
• Age: between 45 and 75 years.
• Physical status: ASA I- III.
• Weight: BMI between 28-40 kg/m2.
• Lesion: any patient with knee pathology requiring total knee arthroplasty (TKA)

Exclusion criteria

• o Body mass index >40 kg/m2.

• ASA>III.
• Patient's refusal.
• Revision knee arthroplasty
• Bilateral knee arthroplasty.
• Lack of mental ability to provide informed consent.
• Neuropathic pain or sensory disorders of the surgical limb.
• Contraindication to regional anesthesia (intolerance to the study drugs, bleeding diathesis, coagulopathy, malignancy or infection at the site of block).