Overall – guest speaker Dr. V. Rod Hentz (San Francisco?) presented some interesting perspectives on current management of complex peripheral nerve injury. New perspectives were discussed as well as current evidence reviewed.
Nerve Transfers for distal UL injuries (rather than nerve repair or tendon transfers)
- AIN to distal median nerve
- AIN to distal ulnar nerve
- 1/2 motor branch to Pron. Teres – radial nerve
- others were discussed, but overall the limits of nerve transfer are patient anatomy and imagination.
Questions / Comments
- imaging more helpful in decision making than NCS/EMG
- important to follow clinical recovery
- differentiate between low-energy (old person with shoulder dislocation) and high energy (motorcyclist with vascular injury and other injuries)
- at 1 yr follow-up reasonable results obtained.
Age limit?
- not a full contrainidication.
Direct Transfer vs. transfer + graft?
- difference described in literature
identification of motor branch
- dissection
- sunderland mapping
- microstimulator with awake patient — sounds good but not very reliable
- can stimulate distally early-on
Nerve Injury impact
Changes in
- distal receptors
- nerve itself
- cortical mapping (especially in musicians, blind patients, increases with purposeful movement)
Significant Differences between Pediatric and Adult patients
Early motion is key.
Electrical Stimulation
- no evidence to support that this changes rate of degeneration of NMJ….therefore no point to use in denervated muscle.
nerve transfer
- donor must be synergistic
- better to have volitional control
- NB Retrain to minimize antagonistic muscle contraction and maximize synergists
- e.g. intercostal transfers –>co-contraction of Abs improves recruitment
Questions / Comments
- Dissociate donor from recipient muscle for fine function, co-contraction for power
- nerve transfer vs tendon transfer (paradigm shift)
Q. USe of Botox into co-contracting muscle?
Q. Nerve transfers in lower extremity?
- look for study from Mayo clinic (referenced)
- lose the drop foot, but no volitional control
OBPP (Obstetrical Brachial Plexus Palsy)
- Even the name is controversial (“obstetrical”)
- lower palsy (C8/T1) is uncommon in kids, common in adult trauma
Risk factors
- increased birth weight
- dystonia
- maternal d.m.
- obesity
Injuries are predominantly supraclavicular, very proximal
most babies with a weak arm at birth recover early
Decision making value of EMG and MRI limited, Ct myelography is considered too high risk in babies (understated consensus seemed to be that MRI is equivalent or better as an imaging technique and CT myelogram is only the gold standard for historical reasons…literature is behind practice)
Treatment Decisions based on clinical course
- global palsy – surgery at 3rd to 4th month unless recovery is rapid
- upper palsy – poor hand / no reinnervation of biceps by 3rd month –> surgery
Priorities
- shoulder control
- elbow control
- hand function
SEcondary Procedures
- limited shoulder ROM esp. ABDuction, IR contracture –> leads to humeral head and glenoid deformity (NB early Dx…Rx priniciples similar to DDH)
- limited pronation
- limited wrist and finger extension
Early Diagnosis is Key
Clinical Signs
- apparent shortening
- skin fold asymetry
- deep axilla
- palpable click
- posterior shoulder fullness
- sudden loss of ER is a key sign for intervention.
Q. Botox?
- Underwhelming
- needs to be done in conjunction with casting
Imaging
- U/S or CT scan to look at relation of ossific nucleus to humerus to detect posterior shoulder dislocation
Nerve Conduits (side conversation, not actual presentation)
- small gaps (2-3 cm)
- well vascularized beds
- use for sensory nerves established
- no donor morbidity
- added cost (saves OR time)
Ulnar nerve — Rx of failed cubital tunnel syndrome
- no good evidence between surgical treatment types.
- 20% of patients will have ongoing problems
Q. incomplete release vs. iatorgenic injury?
MABC neuroma
Current preference = simple decompression (especially for patients with multiple comorbidities)
- watch nerve with elbow flexion…if subluxes ?transpose or just watch?
- revision surgery — intramuscular…identify cutaneous neuromas and transpose
- release fascia over muscle for revision surgery rather than proximal release
exceptions — skinny young athlete – do submuscular transposition?
Gelberman
- intramuscular? complication rate
- less dissection
- quicker recovery
- Same recovery (increased complication rate vs . transposition)
traction and compressive components of neuropathy
Comment — if nerve subluxes/ dislocates may not be symptomatic…dogma may be incorrect.
Recurrent carpal tunnel
- incomplete release vs. recurrence
- vein wrapping — vein 3X size of nerve
Delayed Diagnosis
Epineural scarring — ?distinctive patter…worse with traction signs.
separate incision more ulnarly to previous incision (Dillon)
Comments:
- can recur but unusual
- symptoms different (pain vs. paresthesias)
- problem outside or inside nerve?
