Innervations of the Ulnar Nerve

Sieg & Adams, Illustrated Essentials of Musculoskeletal Anatomy (1996)

Etiology

High Lesion: Proximal to elbow Recovery of intrinsic function rare due to long distance from site of injury

Trauma

Laceration

Compressive

Cubital Tunnel Syndrome

Other

Peripheral Neuropathy (i.e. Diabetes) Charcot-Marie-Tooth disease Gunshot/stab wound Fracture/dislocation Prolonged or repetative compression at Guyon’s Canal (i.e. bicycling, tennis) Tumor

Compression at Guyon’s Canal

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Muscle Loss

  Low: Intrinsic musculature         Palmar Interossei Dorsal interossei 3 rd and 4 th Lumbricals Adductor Pollicis Flexor Pollicis Brevis (deep head) Flexor Digiti Minimi Opponens Digiti Minimi Abductor Digiti Minimi High: Intrinsic + Extrinsic musculature  Flexor Digitorum Profundus of Ring and Small  Flexor Carpi Ulnaris

Muscle Loss: Presentation

  Claw hand  low nerve palsy only Froment’s Sign    Jeanne’s Sign Swan Neck Boutonniere Deformity

Functional Loss

 Decreased grip strength often as much as 60-80%  Key Pinch   as much as 70-80% Relies on the adductor pollicis, 1 interossei, and flexor pollicis brevis for stability and strength st dorsal Froment’s Sign  Hyperflexion of the thumb IP joint during pinch  Jeanne’s Sign  Hyperextension of the thumb MP joint during pinch Dell, P et al, JHT (2005)

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Froment’s Sign

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Jeanne’s Sign

Boutonniere and Swan Neck

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Sensory Loss

 Ulnar ½ of Ring Finger, Small finger, hypothenar eminence, and similar on dorsum of hand  Dorsal sensory branch of the ulnar nerve originates approximately 7 cm proximal to ulnar styloid www.rch.org.au

Pre-Operative Therapy

Objectives  Prepare patient, physically & psychologically, for surgery  Enable patient to be as functional as possible prior to surgery

Splinting for Function

 Objectives:  Reduce MP joint hyperextension due to normal function of the EDC unopposed by the intrinsic flexors  Stability of thumb for key pinch  Hand Based:   Dorsal Knuckle Bender Figure 8 or Lumbrical Bar   Hand based thumb spica for pinch Thumb MP stabilizer for Jeanne’s sign  Oval 8 for Froment’s sign

Dorsal Knuckle Bender

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Figure 8 or Lumbrical bar

Hand based thumb spica

MP blocking fingers & thumb

Thumb MP stabilizer

Oval 8 for IP stabilization

Splint for function

 Forearm Based: if high ulnar nerve lesion may need to stabilize forearm  Ulnar gutter allegromedical.com

Splinting to Prevent or Correct Deformity

 Objective:  Prevent or reduce PIP joint contractures of ring and small fingers  Prevent or reduce Boutonniere & Swan Neck deformities  Reduce pain in thumb due to imbalance in pinch

Serial Casting

To reduce PIP contractures prior to surgery www.msdlatinamerica.com

Silver Ring Splint

For Boutonniere and Swan Neck

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Functional Adaptations/Modifications

Increase ability to complete tasks with weak pinch  Use of adaptive equipment  Elastic shoelaces Adaptive light switch Compensation  Modified writing position  Adaptive key pinch for car

Interventions

 Maintain full PROM for involved joints  Manual Muscle Testing  Electrical Stimulation  Persistent pain management/education  Patient Education regarding realistic expectations related to function, timing, and rehab needs

Specific Transfers and Indications

Goal to Regain From: Donor Tendon (working) To: Recipient Tendon (deficient)

Thumb Adduction Finger Abduction (index most important) FDS, ECRB or ECRL, EIP, or Brachioradialis APL, ECRL, or EIP Adductor pollicis 1 st dorsal interossei Reverse Clawing effect FDS, ECRL (must pass volar to transverse metacarpal ligament to flex proximal phalanx) Lateral bands of ulnar digits www.orthobullets.com

Tendon Transfers: Thumb Adduction

 Use of ECRB or ECRL w/ free tendon graft (usually Palmaris Longus) to restore Adductor Pollicis function  Advantage:  Strong motor component and avoids sacrificing finger flexor  Good excursion  Disadvantage:  Doesn’t reproduce same line of pull Dell, P. JHT (2005); http://www.msdlatinamerica.com/ebooks/HandSurgery/sid731790.html

Tendon Transfer: Finger Abduction

 Objective: provide more stability to index during pinch than strength  Transfers typically provide 25 50% of normal pinch strength Dell, P. JHT (2005); http://www.msdlatinamerica.com/ebooks/HandSurgery/sid731790.html

Tendon Transfer: Reduce clawing effect

Procedure Concept

Bunnell Release of A1 & A2 pulleys to allow flexors to bowstring, often combined with tightening of volar capsule Zancolli Volar plate advanced proximally to produce flexion contracture of MP Stiles-Bunnell Splits FDS (usually MF) and transfers to radial lateral bands of RF/SF Zancolli lasso Fowler Brand FDS of MF, passed through A1 pulley and sutured onto self Active tenodesis w/ 2 tendon grafts sutured to lateral bands Must have active wrist flexion to elicit tightening for MP flexion and IP extension ECRB or ECRL to radial lateral bands Dell, P. JHT (2005)

Tendon Transfer: Reduce clawing effect

Flexor digitorum superficialis (FDS) tendon transfers for correction of clawing. The FDS can be sewn to the lateral band (A), to bone (B), or on itself in the Zancolli lasso (C).

http://www.msdlatinamerica.com/ebooks/HandSurgery/sid731790.html

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Post Op Protocol

For Brand procedure:  3 ½ weeks post-op  Splint:  Volar routing: Dorsal Blocking splint with wrist in 30 degrees flexion, MP 60 degrees flexion, and IP neutral  Dorsal routing: Dorsal Blocking splint with wrist in 30 degrees of extension, MP blocked in 60 degrees of flexion, and IP extended    ROM  AROM w/ in splint 10 minutes every hour   Passive extension to PIP and DIP Passive flexion-only if tendon inserted into bone; for insertion into lateral bands: no passive flexion until 6 wks due to risk of stretching out transfer NMES to facilitate excursion Scar Management Indiana Hand Protocol (2001)

Post Op Protocol

 6 weeks post-op  Splint  Reduced to MP block with palmar bar in 45 degrees of flexion to be worn at all times  If PIP extensor lag-continue with dorsal blocking splint  ROM   PROM to MPs, PIPs, and DIP joints All completed within the restrains of the MP block Indiana Hand Protocol (2001)

Post Op Protocol

 7-8 weeks post-op  Dynamic flexion initiated prn  Monitor for PIP extensor lags  10-12 weeks post-op  MP blocking splint discontinued if hyperextension not present and minimal (<15 degrees) PIP extensor lag Indiana Hand Protocol (2001)

Post Op Protocol

To ensure good excursion of long flexors, concentration on blocking exercises and use of NMES to restore flexion of FDS and FDP can be helpful Indiana Hand Protocol (2001)

Ulnar nerve Transfers

 Objective: Restore intrinsic muscle function for pinch strength, power grip, and dexterity  Options  Terminal branch of AIN to deep motor branch of ulnar nerve  Not synergistic but increases pinch/grip strength and decreases clawing  Branches of Posterior Interosseous Nerve (PIN), EDM and ECU branch, to ulnar nerve

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 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

Cortical Re-Mapping

 Cortical Re-mapping  Graded motor imaging   Left/Right discrimination Explicit Motor Imagery   Mirror Therapy Patient Education

Sensory Re-education

Vibration Clapping Stereognosis Contact particles

Sensory Re-Education

Light to deep Touch blog.physiotek.com

Exercise

   ROM    PROM Place and Hold with visualization 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

Exercise

Strengthening

Putty Exercises for grip and pinch

Bibliography

     Cannon, N, et al. Diagnosis and Treatment manual for Physician and Therapists. Upper Extremity Rehabilitation, 4 th edition. Indianapolis. 2001.

Davis KD, Taylor KS, Anastakis DJ. Nerve Injury Triggers Changes in the Brain. Neuroscientist. 2011; 17 (4).

Dell PC, Sforzo CR. Ulnar Intrinsic Anatomy and Dysfunction. Journal of Hand Therapy. April-June 2005; 2:198-207.

Hoard AS, Bell-Krotoskie JA, Mathews R. Application of Biomechanics to Tendon Transfers. Journal of Hand Therapy. April June 1995; 115-123.

Moore AM, Novak CB. Advances in nerve transfer surgery. Journal of Hand Therapy. April-June 2014; 27: 96-105.

Bibliography

    Moseley GL, Butler DS, Beames TB, Giles TJ. The Graded Motor Imagery Handbook. Adelaide, Australia. Noigroup Publications. 2012.

Sieg & Adams. Illustrated Essentials of Musculoskeletal Anatomy, 3 rd 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.