Analgesic Efficacy of Saphenous Nerve Block in Total Knee Replacement
Condition: Post Operative Pain
MeSH terms: Pain, Postoperative
Study type: Interventional
Phase: Phase 4

Summary: 
      We hypothesize that preoperative saphenous nerve block (SNB) in combination with
      periarticular local infiltration provides better post operative pain relief (POPR) profile as
      compared to local infiltration alone
    

Detailed description: 
      Introduction:

      Local infiltration analgesia (LIA) is considered acceptable after total knee replacements
      (TKR) in terms of analgesia, ease of performance, early mobilization and early hospital
      discharge . Continuous femoral nerve block has been used to enhance post op pain relief
      (POPR) for TKR but at the expense of motor blockade . A Sub sartorial approach to saphenous
      nerve block (SNB) spares the motor block . To date the role of saphenous nerve block for POPR
      in TKR has not been evaluated.

      Methodology:

      In order to test this hypothesis, we proposed to carry out a prospective randomized
      controlled double blinded (surgeon and assessor) trial study. With institutional ethics
      approval and having obtained written informed consent from each patient, 20 ASA 1 - 3
      patients scheduled to undergo TKR under spinal anesthesia +/- sedation were allocated to one
      of two groups i.e. Group (SNB): patients receiving SNB sub sartorial approach and Group
      (NSNB): patients not receiving SNB.

      Group allocation was determined using computer generated random number tables. Sealed
      envelopes were opened on the day of the surgery by the attending anesthetist responsible for
      the care of the recruited patient.

      Postoperative period:

      Patients were then assessed for pain at rest and on movement on arrival in recovery and then
      at 6 , 12 and 24 hrs. Visual analogue scale on a 10 cm straight line was used to assess
      postoperative pain scores as predictive value of post operative analgesia on rest and
      movement i.e passive flexion of knee to 30 degree . Patients were assessed for any motor
      block by using maximum tolerable range of active knee flexion (MKF) and maximum range of
      straight leg raise(MSLR) on arrival in recovery and at 6, 12 and 24 hrs. All patients
      received regular paracetamol 1g 6 hourly, diclofenac 75 mg 12 hourly, oxycontin 10-20 mg (
      depending on age) 12 hourly and oxynorm 10 mg as rescue analgesia.
    

Intervention name(s): SNB Saphenous Nerve Block; NSNB Non Saphenous Nerve Block
Intervention type(s): Procedure; Procedure
Intervention description(s): Patients in group SNB received an ultrasound guided SNB (a sub sartorial approach) by a single operator with 10 mls 0.5% bupivacaine. At the end of surgery periarticular knee infiltration of 30 mls 0.5% levobupivacaine + 70 mls 0.9% saline + 0.5 mg adrenaline was performed in a staged fashion by the surgeon, beginning with infiltration of the deep structures on tibial surface at 1mm depth around all exposed tissues, medial and lateral collateral ligament origin, all cut surfaces of extensor mechanism, all cut surface of skin and subcutaneous tissue; All patients at the end of surgery received periarticular knee infiltration of 30 mls 0.5% levobupivacaine + 70 mls 0.9% saline + 0.5 mg adrenaline, in a staged fashion by the surgeon, beginning with infiltration of the deep structures on tibial surface at 1mm depth around all exposed tissues, medial and lateral collateral ligament origin, all cut surfaces of extensor mechanism, all cut surface of skin and subcutaneous tissue
Other intervention name(s): Bupivacaine; Levobupivacaine; Adrenaline; 0.9% NaCl; Levobupivacaine; Adrenaline; 0.9% NaCl
Intervention MeSH terms: Epinephrine; Racepinephrine; Bupivacaine; Levobupivacaine; Epinephryl borate
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Double (Investigator, Outcomes Assessor)
Primary purpose: Treatment
Keywords: Total Knee Replacement; Bupivacaine; Levobupivacaine; Saphenous Nerve Block; Local Infiltration Analgesia