· complications uncommon
· overall < 1%
· neurological complications rare
· incidence 0.1%
Direct injury
· from incorrect placement of portals
· risk reduced by
· correct placement
· use of blunt trocar
Compartment syndrome
· from extravasation of fluid for distension of joint
· risk reduced by
· minimisation of pressure used
· minimisation of duration of procedure
· use of readily absorbed physiological solution
· minimisation of number of capsular punctures
· palpation of extremity at end of procedure
Neuropraxia
Tourniquet
· risk reduced by
· minimisation of duration (<90 min in upper limb and <120 min in lower limb)
· minimisation of pressure (< 250 mm Hg in upper limb and <350 mm Hg in lower limb)
· adequate cuff width
Positioning
· direct pressure on nerve from inappropriate positioning
Reflex sympathetic dystrophy
· uncommon
· should be considered with
· prolonged pain
· vasomotor disturbance
· delayed functional recovery
· trophic changes
Infrapatellar branch
· may be injured by direct puncture for anteromedial portal
Saphenous nerve
· may be injured by
· direct puncture for posteromedial portal
· passage of needles during arthroscopic meniscal repair
· retraction during open meniscal repair
Common peroneal nerve
· may be injured by
· direct puncture for posterolateral portal
· passage of needles for arthroscopic meniscal repair
· entrapment by sutures of meniscal repair
Tibial nerve
· may be injured by posterior penetration
· fluid may enter through rupture of synovial pouch
· into knee through suprapatellar pouch
· into calf through semimembranosus bursa
· should check circumference of thigh and tension of tissue at end of procedure
· usually from tourniquet
Saphenous nerve
· most commonly injured
· usually from portal
· sometimes from meniscal suture
· can be avoided by
· direct dissection and identification
· use of retractor to deflect needles
Common peroneal nerve
· next most common
· usually from meniscal suture
· can be avoided by
· flexion of knee
· direct dissection and identification
· use of retractor to deflect needles