Innervations of the Median Nerve Sieg & Adams, Illustrated Essentials of Musculoskeletal Anatomy; 1996 Etiology Majority of injuries are at the wrist level Trauma Compressive Other Laceration *Carpal Tunnel Syndrome Charcot-Marie-Tooth disease Gunshot Wound Synovitis (e.g. Rheumatoid Arthritis) Lipofibrohamartoma Fracture/Dislocation Tumor *Prolonged CTS most common Charcot-Marie-Tooth disease: neuronal or demyelinating disorder that leads to peripheral neuropathy Lipofibrohamartoma: rarely occurring, benign neoplasm consisting of fibroadipose tissue that affects peripheral nerves Kozin, S 2005; pg 213 Muscle Loss of the Thumb Opponens Pollicis (OP) Abductor Pollicis Brevis (APB) Superficial head of the Flexor Pollicis Brevis (FPB) www.meded.ucsd.edu Sensory Loss Thumb, Index, Middle, and radial ½ of Ring finger www.rch.org.au Functional Loss Thumb opposition and manipulation Pre-Operative Therapy Objectives • Prepare patient, physically and psychologically, for surgery • Enable patient to be as functional as possible prior to surgery Splinting for Function Objective: Position MP in palmer abduction to stabilize for opposition to digits Hand based: Ribbon splint Hand based thumb spica Splinting for Function Forearm based: high median nerve lesion need to stabilize the wrist Forearm based thumb spica Oval 8 to stabilize IP joints if Flexor Pollicis Longus (FPL) is not working Splinting to Prevent or Correct Deformity Objective: Maintain 1st web space, reduce pain, and maintain length of extrinsics C-bar splint in palmer abduction for night wear Forearm based thumb spica to support wrist Resting splint for night ncmedical.com Adaptations/Modifications Increase ability to complete tasks with weak pinch Built up foam for handles/utensils Use of adaptive equipment large pens Use of jump rings for zipper pulls Compensation with gross grasp Angled knives Travel mug with a handle Interventions Maintain full PROM for involved joints Electrical Stimulation Manual Muscle Testing Persistent pain management/education Patient Education regarding realistic expectations related to function, timing, and rehab needs Specific Transfers and Indications Goal to Regain Thumb Opposition and Abduction From: Donor Tendon (working) To: Recipient Tendon (deficient) Low Median Nerve Palsy Bunnell opponensplasty: base proximal FDS of ring phalanx or APB tendon (use FCU as pulley) APB (pulley around ulnar side of wrist) EIP High Median Nerve Palsy Thumb IP flexion Brachioradialis Flexor Pollicis Longus Index and long finger flexion FDP of index and middle (side-to-side transfer) www.orthobullets.com FDP of ring and small finger (ulnar nerve) Muscle Training for Transfer Flexor Digitorum Sublimis (FDS) of Ring Finger is primary choice to thumb MCP (at APB and/or EPB tendon) Use of differential tendon gliding of RF to isolate Post-Operative Therapy Tendon Transfer First 2-3 wks post-op Post-op brace with 30 degrees wrist flexion to relax transfer and thumb in full opposition Immediate AROM of fingers- especially RF if FDS used May need night finger extension gutter if RF positions in flexion s/p 3 wks post-op Splint in forearm based dorsal blocking splint with wrist in 10-20 degrees wrist flexion PROM to maintain joint mobility 4-6x/day AROM for tendon gliding and retraining Kozin, S, JHT (2005) Post-Operative Therapy Tendon Transfer Concomitant RF flexion with thumb opposition MP blocking of RF to isolate PIP flexion Use of opposite hand MP flexion blocking splint Use of Chopstick/pen to block MP flexion Visualization with place and hold exercises Use of Graded Motor Imagery Discharge splint at 6 weeks post-op Strengthening at 8 weeks post-op Kozin, S, JHT (2005) Cortical Re-Mapping Cortical Re-mapping Graded motor imaging Left/Right discrimination Explicit Motor Imagery Mirror Therapy Patient Education noigroup.com Joint blocking with a chopstick Joint Blocking with ICAM Median Nerve Transfer Critical for forearm pronation, wrist and finger flexion, and thumb opposition Options: Restoring pronation Branch to FCU to pronator teres branch Branch to FDS to pronator teres branch *Branch to ECRB to pronator teres branch Preferred due to synergistic movements of wrist extension and pronation Restoring thumb opposition Isolated low median nerve injury-use of a short interpositional graft: proximal branch of the median nerve, specifically the terminal AIN supplying the pronator quadratus muscle Moore et al, JHT (2014) Median Nerve Transfer Restoring finger and thumb flexion Anterior Interosseous Nerve (AIN)- motor nerve that supplies the FPL and FDP to to the index and middle fingers, and pronator quadratus Branches from musculocutaneous, radial, or ulnar nerves to reinnervate the AIN Brachialis branch of musculocutaneous to AIN Supinator branch of the radial nerve to AIN Brachioradialis branch to AIN Radial nerve branch of ECRB and supinator to AIN Moore et al, JHT (2014); www.neurosurgery.med.nyu.edu Post-Operative Therapy Nerve Transfer Immobilization Elbow/Forearm: 7-10 days Post-op dressing May change to splint as early as s/p 2-3 days No further protection after 10 days due to no tension on nerve transfer If tendon transfer at same time, protocol paradigm shift related to tendon Shoulder: up to 4 wks Allow intermittent ROM for elbow and hand Shoulder A/PROM resumes at s/p 4 wks Moore et al, JHT, (2014) Precautions Post Operative Tendon Transfer Same as for Tendon repair Nerve Transfer Risk of increased tension on nerve repair site Post Operative Therapy Tendon and/or Nerve Transfer Edema control Scar management Pain management Range of Motion Sensory Re-Education Strengthening Restore Function Motor Re-education Objective: To correct recruitment and restoration of muscle balance and decrease compensatory patterns Motor Re-education Challenges: Alterations in motor cortex mapping (i.e. neuro tag smudging) Muscle imbalances due to weakness associated with dennervation May persist due to compensatory movement patterns and persistent weakness of reinnervated muscles Method: Contract muscle from donor nerve/muscle with new muscle until motor pattern established The more synergistic the action and based on original motor pattern, the more recruitment and establishment of muscle balance Moore et al, JHT (2014) Sensory Re-education Vibration: Tapping fingers Stereognosis: Carry 3-4 small items in pocket - throughout the day try to reach in and identify Sensory Re-Education Light to deep Touch danmicglobal.com Exercise ROM PROM Place and Hold with visualization and use of RF flexion initially AROM through full range Opposition exercises Light object pick-up Marble cup 3 poker chips Strengthening Graded putty exercises Button find Pushing golf tees in putty Tearing paper Dexterity/Opposition Strengthening Bibliography Davis KD, Taylor KS, Anastakis DJ. Nerve Injury Triggers Changes in the Brain. Neuroscientist. 2011; 17 (4). Hoard AS, Bell-Krotoskie JA, Mathews R. Application of Biomechanics to Tendon Transfers. Journal of Hand Therapy. AprilJune 1995; 115-123. Kozin SH. Tendon transfers for radial and median nerve palsies. Journal of Hand Therapy. April-June 2005; 2: 208-215. Moore AM, Novak CB. Advances in nerve transfer surgery. Journal of Hand Therapy. April-June 2014; 27: 96-105. Moseley GL, Butler DS, Beames TB, Giles TJ. The Graded Motor Imagery Handbook. Adelaide, Australia. Noigroup Publications. 2012. Bibliography Murphy RKJ, Wilson ZR, Mackinnon SE. Repair of median nerve transection injury using multiple nerve transfers, with long-term functional recovery. Journal of Neurosurgery. Nov 2012; 117: 886889. Sieg & Adams. Illustrated Essentials of Musculoskeletal Anatomy, 3rd Edition. Gainesville, Megabooks, Inc. 1996. Sultana SS, MacDermid JC, Grewal R, Rath S. The effectiveness of early mobilization after tendon transfers in the hand: A systematic review. Journal of Hand Therapy. October 2013; 26: 1-21. Wang JHC, Guo Q. Tendon Biomechanics and Mechanobiology-A minireview of basic concepts and recent advancements. Journal of Hand Therapy. April-June 2012; 7: 133-140. Thank you to my family for their never ending support and encouragement