## Clinical Scenario

A newborn presents with the left arm held in shoulder adduction, elbow extension, forearm pronation, and wrist flexion following difficult delivery with shoulder dystocia. Which nerve roots are most likely injured?

## Answer Options

Select all statements that are **TRUE**. This is an X-Type question where each option is independently True or False.

A C8-T1

B C5-C6

C C7-T1

D C5-T1

E C6-C7

Reveal Answer Pattern

**Correct Pattern:** `FTFFF` | Option | Answer | |:------:|:------:| | A | FALSE | | B | TRUE | | C | FALSE | | D | FALSE | | E | FALSE |

## Detailed Explanations ### Option A: FALSE ✗

FALSE "C8-T1"

**Why this is INCORRECT:** Understanding lower trunk injury patterns: 1. **C8-T1 injury pattern**: - **Klumpke palsy** - Hand and wrist involvement - Intrinsic muscle paralysis - Different presentation - Much less common 2. **Classic Klumpke presentation**: - Claw hand deformity - Weak wrist flexors - Weak finger flexors - Intrinsic muscle weakness - NOT this case 3. **Position described**: - **Shoulder adduction** - **Elbow extension** - **Forearm pronation** - **Wrist flexion** - Upper trunk pattern 4. **Waiter's tip position**: - Classic Erb's palsy - Upper trunk injury - C5-C6 roots - NOT lower trunk - Pathognomonic 5. **Horner's syndrome**: - May accompany C8-T1 - Ptosis, miosis, anhidrosis - Indicates root avulsion - NOT described here - Poor prognostic sign 6. **Incidence**: - C8-T1 only: less than 1% - Very rare - C5-C6: 50-60% - Opposite frequency - Wrong level **Clinical Pearl**: Isolated lower trunk injuries (Klumpke palsy) are extremely rare in birth palsy, accounting for less than 1% of cases. When present, they suggest severe traction injury and often indicate root avulsion. The classic "waiter's tip" position described in this case is pathognomonic for upper trunk (C5-C6) injury.

### Option B: TRUE ✓

TRUE "C5-C6"

**Why this is CORRECT:** Understanding Erb's palsy (C5-C6 injury): 1. **Classic presentation**: - **Waiter's tip position** - **Shoulder adduction** - **Elbow extension** - **Forearm pronation** - **Wrist flexion** 2. **Pathophysiology**: - Upper trunk injury - C5-C6 nerve roots - Lateral traction injury - Shoulder dystocia - Most common pattern 3. **Muscles affected**: - **Deltoid** (shoulder abduction) - **Biceps** (elbow flexion, supination) - **Brachialis** (elbow flexion) - **Supraspinatus/infraspinatus** (shoulder rotation) - **Supinator** (forearm supination) 4. **Muscles preserved**: - Hand muscles intact - Wrist extensors work - Triceps functions - Finger movement present - Lower trunk spared 5. **Incidence**: - **50-60% of all BPBP** - Most common type - Narakas Type I - Best prognosis - Recognizable pattern 6. **Prognosis**: - 80-90% recovery - If spontaneous early - By 3 months - Better than extended - Good outcomes **Clinical Pearl**: The "waiter's tip" position results from paralysis of shoulder abductors and external rotators (C5) plus elbow flexors and forearm supinators (C6), while the muscles opposing these actions (shoulder adductors/internal rotators, elbow extensors, forearm pronators) remain active and pull the arm into the characteristic position.

### Option C: FALSE ✗

FALSE "C7-T1"

**Why this is INCORRECT:** Understanding middle-lower trunk patterns: 1. **C7-T1 pattern**: - Not a classic pattern - Unusual combination - Would affect hand primarily - Wrist extensors weak - NOT this presentation 2. **C7 involvement**: - Triceps weakness - Wrist extensor weakness - Finger extensor weakness - NOT described here - Different pattern 3. **Lower trunk addition**: - Hand intrinsic weakness - Finger flexor weakness - Klumpke component - NOT waiter's tip - Wrong presentation 4. **Shoulder function**: - Would be preserved - With C7-T1 only - Shoulder abduction intact - Opposite to case - Key distinction 5. **Elbow function**: - Biceps preserved - Would flex elbow - NOT extended position - Contradicts stem - Wrong level 6. **Actual presentation**: - **Shoulder adducted** - **Elbow extended** - **Upper trunk pattern** - C5-C6 injury - NOT C7-T1 **Clinical Pearl**: If C7 is significantly involved (C5-C7, also called "extended Erb's palsy" or Narakas Type II), you would see additional findings including weak wrist extension, weak finger extension, and weak triceps. The prognosis is worse than isolated C5-C6 injury, with only 40-60% recovering fully.

### Option D: FALSE ✗

FALSE "C5-T1"

**Why this is INCORRECT:** Understanding total plexus palsy: 1. **C5-T1 injury**: - **Total plexus palsy** - All roots involved - Complete paralysis - Narakas Type IV - Worst prognosis 2. **Expected presentation**: - **Flail upper extremity** - No movement shoulder - No movement elbow - No movement wrist - No movement hand 3. **Hand involvement**: - Would be paralyzed - If C5-T1 injured - Intrinsics paralyzed - Fingers paralyzed - NOT described 4. **Case description**: - **Specific position held** - Muscle imbalance pattern - Some muscles working - Not flail limb - Partial injury 5. **Horner's syndrome**: - Common with total - Ptosis, miosis, anhidrosis - Indicates T1 avulsion - NOT mentioned here - Poor prognostic sign 6. **Incidence**: - Total palsy: 10-15% - Less common - Severe injury - Worse outcomes - NOT this case **Clinical Pearl**: Total plexus palsy (C5-T1) presents as a completely flail upper extremity with no voluntary movement from shoulder to fingertips. The presence of Horner's syndrome indicates T1 nerve root avulsion (preganglionic injury) with no potential for spontaneous recovery. These children require early nerve surgery and have much poorer functional outcomes than upper trunk injuries.

### Option E: FALSE ✗

FALSE "C6-C7"

**Why this is INCORRECT:** Understanding C6-C7 pattern: 1. **C6-C7 involvement**: - Not a classic pattern - Unusual combination - Middle trunk emphasis - Different presentation - NOT waiter's tip 2. **Expected findings**: - **Weak elbow flexion** (C6) - **Weak wrist extension** (C6-C7) - **Weak elbow extension** (C7) - **Weak finger extension** (C7) - Different from case 3. **Shoulder function**: - Would be relatively preserved - Deltoid less affected - Supraspinatus less affected - Abduction possible - NOT adducted position 4. **Forearm position**: - Supination less affected - Without strong C5 - Not pure pronation - Different pattern - Wrong presentation 5. **Classic waiter's tip**: - **Requires C5 involvement** - Shoulder positioned - Arm internally rotated - Must have C5 - NOT C6-C7 alone 6. **Actual case**: - **C5-C6 pattern** - Erb's palsy - Upper trunk - Narakas Type I - Most common **Clinical Pearl**: The "waiter's tip" position specifically requires C5 and C6 involvement because the shoulder internal rotation and adduction result from unopposed action of the subscapularis, pectoralis major, and latissimus dorsi after paralysis of the C5-innervated shoulder abductors and external rotators (deltoid, supraspinatus, infraspinatus).

--- ### Exam Tip

**High-Yield Points for Brachial Plexus Birth Palsy Classification:** - **Narakas Classification**: - Type I: C5-C6 (Erb's) - 50-60%, "waiter's tip" - Type II: C5-C7 (extended Erb's) - 30%, wrist drop added - Type III: C5-T1 (total) - 10-15%, flail limb - Type IV: C5-T1 + Horner's - worst, root avulsion - **Waiter's Tip Position**: Pathognomonic for C5-C6 - Shoulder: adducted, internally rotated - Elbow: extended - Forearm: pronated - Wrist: flexed - **Klumpke Palsy**: C8-T1, less than 1%, claw hand - **Horner's Syndrome**: T1 avulsion, no recovery - **Prognosis**: Upper trunk better than total (80-90% vs 20-40%) - **Key Teaching**: "Waiter's tip = C5-C6 = upper trunk = Erb's palsy"

--- ### Related Topic

📚 **Learn more**: [Brachial Plexus Birth Palsy - Full Topic Review](/topics/pediatrics/brachial-plexus-birth-palsy)

--- ### References

- Narakas AO. Obstetrical brachial plexus injuries. In: Lamb DW, editor. The Paralysed Hand. Edinburgh: Churchill Livingstone; 1987. p. 116-135. - Shenaq SM, et al. Brachial plexus birth injuries and current management. Clin Plast Surg. 1998;25(4):527-536. PMID: 9863881 - Gilbert A, Tassin JL. Surgical repair of the brachial plexus in obstetric paralysis. Chirurgie. 1984;110(1):70-75. PMID: 6723138 - Waters PM. Comparison of the natural history, the outcome of microsurgical repair, and the outcome of operative reconstruction in brachial plexus birth palsy. J Bone Joint Surg Am. 1999;81(5):649-659. PMID: 10360693

## Clinical Scenario

A 3-month-old infant with Narakas Type I brachial plexus birth palsy has no antigravity biceps function. According to the Gilbert criteria, what is the recommended management?

## Answer Options

Select all statements that are **TRUE**. This is an X-Type question where each option is independently True or False.

A Continue observation as most will recover by 12 months

B Immediate nerve exploration and grafting

C Refer to a brachial plexus specialist for consideration of nerve surgery

D Botulinum toxin injection to antagonist muscles

E Shoulder tendon transfer surgery

Reveal Answer Pattern

**Correct Pattern:** `FFTFF` | Option | Answer | |:------:|:------:| | A | FALSE | | B | FALSE | | C | TRUE | | D | FALSE | | E | FALSE |

## Detailed Explanations ### Option A: FALSE ✗

FALSE "Continue observation as most will recover by 12 months"

**Why this is INCORRECT:** Understanding prognostic indicators: 1. **No antigravity biceps at 3 months**: - **Poor prognostic sign** - Gilbert criteria threshold - Indicates severe injury - Unlikely spontaneous recovery - Action needed 2. **Recovery timeline**: - Most recovery by 3-6 months - If going to recover - Early recovery better - Late recovery incomplete - 3 months critical 3. **Gilbert criteria**: - **No biceps at 3 months = surgery** - Strong predictor - Evidence-based threshold - Validated internationally - Standard of care 4. **Waiting until 12 months**: - **Missed opportunity** - Nerve surgery window closes - Best at 3-9 months - Muscle atrophy worsens - Poorer outcomes 5. **Natural history without recovery**: - 20% spontaneous improvement - Incomplete recovery - Persistent weakness - Secondary deformities - NOT acceptable 6. **Window for nerve surgery**: - **Optimal: 3-9 months** - Adequate: up to 12 months - Muscles still viable - Can reinnervate - Time-sensitive **Clinical Pearl**: The Gilbert criteria state that absence of antigravity biceps function (M2 or less) at 3 months of age is an indication for surgical exploration and nerve reconstruction. Waiting beyond 9 months significantly reduces the success rate of nerve surgery because motor endplates degenerate without innervation.

### Option B: FALSE ✗

FALSE "Immediate nerve exploration and grafting"

**Why this is INCORRECT:** Understanding timing of nerve surgery: 1. **"Immediate" is wrong**: - Not at 3 months - Too early decision - Some still recovering - Need specialist evaluation - Premature intervention 2. **Standard timeline**: - **Identify at 3 months** - **Refer for evaluation** - **Surgery at 6-9 months** - Not immediate - Planned approach 3. **Why delay to 6-9 months**: - Some late recovery - Allows planning - Optimal surgical window - Muscle still viable - Better outcomes 4. **Specialist evaluation needed**: - **Complex decision** - Multiple factors - MRI sometimes needed - Nerve conduction studies - NOT immediate surgery 5. **Surgical complexity**: - Requires expertise - Brachial plexus center - Microsurgical skills - Nerve grafting/transfers - NOT emergency 6. **Correct approach**: - **Identify poor prognosis** - **Refer to specialist** - **Plan surgery 6-9 months** - Coordinated care - Best outcomes **Clinical Pearl**: Nerve surgery for brachial plexus birth palsy is typically performed between 6-9 months of age, not immediately upon identifying poor prognostic signs at 3 months. This allows time for specialist evaluation, advanced imaging if needed, surgical planning, and for some children who will have late recovery to avoid unnecessary surgery.

### Option C: TRUE ✓

TRUE "Refer to a brachial plexus specialist for consideration of nerve surgery"

**Why this is CORRECT:** Understanding appropriate management pathway: 1. **Poor prognostic indicator**: - **No antigravity biceps at 3 months** - Gilbert criteria met - Surgery likely needed - Specialist evaluation required - Time-sensitive referral 2. **Specialist centers**: - **Brachial plexus expertise** - Multidisciplinary team - Microsurgical capability - Experience with outcomes - Best practice 3. **Evaluation components**: - Detailed examination - Serial assessments - Consider advanced imaging - Nerve conduction studies - Surgical planning 4. **Surgical options**: - **Neurolysis** (if neuroma) - **Nerve grafting** (if gap) - **Nerve transfers** (if avulsion) - Multiple techniques - Individualized approach 5. **Timing considerations**: - Refer at 3 months - Evaluate 3-6 months - Surgery 6-9 months - Optimal window - Better outcomes 6. **Additional management**: - Physical therapy continues - Serial imaging if needed - Family education - Realistic expectations - Long-term follow-up **Clinical Pearl**: The management pathway for BPBP with poor prognostic signs is: (1) Identify at 3 months using Gilbert criteria, (2) Refer to brachial plexus specialist, (3) Detailed evaluation and planning, (4) Nerve surgery at 6-9 months if indicated. This coordinated approach optimizes timing and surgical outcomes.

### Option D: FALSE ✗

FALSE "Botulinum toxin injection to antagonist muscles"

**Why this is INCORRECT:** Understanding role of botulinum toxin: 1. **Wrong timing**: - Not at 3 months - Not for severe palsy - Not primary treatment - Wrong indication - Different role 2. **Botulinum toxin indications**: - **Muscle imbalance later** - Internal rotation contracture - After some recovery - Adjunctive treatment - NOT for paralysis 3. **Typical use**: - Age 1-3 years - Developing contracture - Strong antagonists - Weak agonists - Secondary prevention 4. **Example scenario**: - Recovered biceps - Weak external rotators - Strong internal rotators - Inject subscapularis - Prevent contracture 5. **Cannot help paralysis**: - **No antigravity biceps** - Muscle paralyzed - Weakening antagonists won't help - Need nerve function - Wrong approach 6. **Current case needs**: - **Nerve surgery evaluation** - Restore innervation - Not muscle balancing - Primary problem - Fundamental treatment **Clinical Pearl**: Botulinum toxin injection has a role in BPBP but only after partial recovery has occurred to address muscle imbalance. For example, injecting the subscapularis and pectoralis major in children aged 1-3 years who have recovered some shoulder function but are developing internal rotation contracture due to stronger internal rotators than external rotators.

### Option E: FALSE ✗

FALSE "Shoulder tendon transfer surgery"

**Why this is INCORRECT:** Understanding staged reconstruction: 1. **Wrong timing**: - Not at 3 months - Way too early - Wrong stage - Different indication - Later intervention 2. **Tendon transfer indications**: - **After nerve surgery failed** - **Or nerve surgery not done** - Age 3-5 years typically - Persistent weakness - Secondary reconstruction 3. **Common tendon transfers**: - Latissimus dorsi transfer - For external rotation - Trapezius transfer - For shoulder abduction - Later procedures 4. **Prerequisites for transfer**: - Stable skeleton - Donor muscle available - Adequate strength - Passive ROM achieved - NOT at 3 months 5. **Current priority**: - **Primary nerve reconstruction** - Restore native function - Better outcomes - First-line treatment - Age-appropriate 6. **Surgical sequence**: - **Nerve surgery 6-9 months** - Assess recovery 2-3 years - Soft tissue procedures 3-5 years - Bony procedures 5-8 years - Staged approach **Clinical Pearl**: Secondary reconstruction procedures in BPBP follow a temporal sequence: (1) Primary nerve surgery at 6-9 months, (2) Soft tissue releases/transfers at 3-5 years (subscapularis release, latissimus transfer), (3) Bony procedures at 5-8 years or later (humeral osteotomy, glenoid osteotomy). At 3 months with no biceps function, the focus is on primary nerve reconstruction.

--- ### Exam Tip

**High-Yield Points for BPBP Management:** - **Gilbert Criteria** (indications for surgery at 3 months): - No antigravity biceps function (M2 or less) - No elbow flexion against gravity - No antigravity shoulder abduction - **Surgical Timing**: - Identify at 3 months - Refer immediately - Surgery at 6-9 months (optimal window) - After 12 months: outcomes decline - **Nerve Surgery Options**: - Neurolysis (neuroma in continuity) - Nerve grafting (rupture with gap) - Nerve transfers (root avulsion) - **Staged Reconstruction**: - Primary nerve surgery: 6-9 months - Soft tissue procedures: 3-5 years - Bony procedures: 5-8 years+ - **Botulinum Toxin**: For muscle imbalance after partial recovery (age 1-3) - **Key Teaching**: "No biceps at 3 months = refer for surgery at 6-9 months"

--- ### Related Topic

📚 **Learn more**: [Brachial Plexus Birth Palsy - Full Topic Review](/topics/pediatrics/brachial-plexus-birth-palsy)

--- ### References

- Gilbert A, Tassin JL. Surgical repair of the brachial plexus in obstetric paralysis. Chirurgie. 1984;110(1):70-75. PMID: 6723138 - Waters PM. Comparison of the natural history, the outcome of microsurgical repair, and the outcome of operative reconstruction in brachial plexus birth palsy. J Bone Joint Surg Am. 1999;81(5):649-659. PMID: 10360693 - Michelow BJ, et al. The natural history of obstetrical brachial plexus palsy. Plast Reconstr Surg. 1994;93(4):675-680. PMID: 8134423 - Tse R, et al. Surgical treatment of obstetrical brachial plexus palsy. Semin Perinatol. 2014;38(4):222-234. PMID: 24863028

## Clinical Scenario

A newborn with total brachial plexus palsy (C5-T1) is noted to have ipsilateral ptosis, miosis, and anhidrosis. What does this finding indicate about prognosis?

## Answer Options

Select all statements that are **TRUE**. This is an X-Type question where each option is independently True or False.

A Improved prognosis due to preserved sympathetic function

B Poor prognosis indicating T1 nerve root avulsion with no spontaneous recovery expected

C Intermediate prognosis similar to extended Erb's palsy

D The finding is unrelated to the brachial plexus injury

E Good prognosis as the injury is at the trunk level

Reveal Answer Pattern

**Correct Pattern:** `FTFFF` | Option | Answer | |:------:|:------:| | A | FALSE | | B | TRUE | | C | FALSE | | D | FALSE | | E | FALSE |

## Detailed Explanations ### Option A: FALSE ✗

FALSE "Improved prognosis due to preserved sympathetic function"

**Why this is INCORRECT:** Understanding Horner's syndrome significance: 1. **Horner's syndrome present**: - **Ptosis, miosis, anhidrosis** - Described in stem - Sympathetic disruption - NOT preserved - Opposite claim 2. **Indicates disruption**: - **Sympathetic chain involved** - Preganglionic injury - Root level damage - NOT preservation - Severe injury 3. **Anatomical pathway**: - Sympathetic fibers T1 - Travel with C8-T1 - Join via white rami - Cervical sympathetic chain - Innervate face 4. **Horner's indicates avulsion**: - **Root pulled from spinal cord** - Preganglionic injury - Cannot repair - No spontaneous recovery - Worst prognosis 5. **Actual prognosis**: - **Very poor** - NOT improved - T1 avulsion confirmed - No recovery expected - Opposite of statement 6. **Clinical significance**: - Warrants early surgery - Nerve transfers needed - Cannot graft avulsions - Poor functional outcome - Critical finding **Clinical Pearl**: Horner's syndrome (ptosis, miosis, anhidrosis) in BPBP is pathognomonic for T1 nerve root avulsion, a preganglionic injury where the nerve root is torn from the spinal cord. This indicates the worst possible prognosis as avulsed roots cannot spontaneously recover and cannot be repaired with nerve grafts—only nerve transfers can bypass the injury.

### Option B: TRUE ✓

TRUE "Poor prognosis indicating T1 nerve root avulsion with no spontaneous recovery expected"

**Why this is CORRECT:** Understanding Horner's syndrome and prognosis: 1. **Horner's syndrome triad**: - **Ptosis** (eyelid drooping) - **Miosis** (small pupil) - **Anhidrosis** (no sweating) - Ipsilateral to injury - Sympathetic disruption 2. **Anatomical basis**: - **Sympathetic fibers from T1** - Travel preganglionic - Cervical sympathetic chain - Stellate ganglion - Superior cervical ganglion 3. **Injury level indicated**: - **Preganglionic injury** - Root avulsion - Torn from spinal cord - NOT trunk/cord level - Worst injury type 4. **Avulsion characteristics**: - **Cannot spontaneously recover** - No nerve continuity - Cell bodies lost - Permanent denervation - No regeneration 5. **Prognosis implications**: - **Very poor prognosis** - Total palsy already severe - Plus T1 avulsion - Narakas Type IV - Worst combination 6. **Surgical implications**: - Nerve grafts cannot work - Avulsed roots unrepairable - **Nerve transfers needed** - Intercostal to musculocutaneous - Spinal accessory to suprascapular - Limited functional recovery **Clinical Pearl**: The presence of Horner's syndrome in total brachial plexus palsy (Narakas Type IV) confirms T1 root avulsion and indicates the worst possible prognosis. These children require early nerve transfer surgery (not nerve grafting) and will likely need multiple secondary reconstructive procedures. Expected outcomes are much poorer than upper trunk injuries—goal is a functional helper arm, not normal function.

### Option C: FALSE ✗

FALSE "Intermediate prognosis similar to extended Erb's palsy"

**Why this is INCORRECT:** Understanding prognostic stratification: 1. **Extended Erb's palsy**: - C5-C7 injury - Narakas Type II - Intermediate prognosis - 40-60% good recovery - Better than total 2. **This case is worse**: - **Total palsy C5-T1** - **Plus Horner's syndrome** - **T1 avulsion confirmed** - Narakas Type IV - Worst prognosis 3. **Prognosis comparison**: - Extended Erb's: intermediate - Total without Horner's: poor - **Total with Horner's: very poor** - Different categories - NOT similar 4. **Recovery expectations**: - Extended Erb's: 40-60% good - Total palsy: 20-40% good - **Total + Horner's: less than 20%** - Significant difference - NOT intermediate 5. **Surgical complexity**: - Extended Erb's: nerve grafts - Total + Horner's: nerve transfers - Multiple procedures needed - More complex reconstruction - Worse outcomes 6. **Functional outcomes**: - Extended Erb's: active use - **Total + Horner's: helper arm** - Lower expectations - More disability - NOT similar **Clinical Pearl**: Prognostic stratification in BPBP: (1) Upper trunk (C5-C6): 80-90% good recovery, (2) Extended Erb's (C5-C7): 40-60% good recovery, (3) Total palsy (C5-T1): 20-40% good recovery, (4) Total palsy with Horner's syndrome (C5-T1 + T1 avulsion): less than 20% good recovery. These are distinct prognostic categories.

### Option D: FALSE ✗

FALSE "The finding is unrelated to the brachial plexus injury"

**Why this is INCORRECT:** Understanding the anatomical relationship: 1. **Horner's is directly related**: - **Part of injury complex** - Sympathetic involvement - T1 level injury - NOT coincidental - Diagnostic finding 2. **Anatomical connection**: - **T1 nerve root** - White rami communicantes - Preganglionic sympathetic - Stellate ganglion - Cervical chain 3. **Injury mechanism**: - Same traction force - Avulses T1 root - Disrupts sympathetic - Single event - Related pathology 4. **Diagnostic value**: - **Confirms root avulsion** - Localizes injury level - Prognostic information - Guides surgery - Critical finding 5. **Other causes excluded**: - Birth trauma specific - Ipsilateral to palsy - Temporal relationship - Clinical correlation - NOT separate 6. **Pathognomonic significance**: - **Specific for preganglionic** - Cannot occur with trunk injury - Anatomically impossible - Definitive relationship - Key diagnostic sign **Clinical Pearl**: Horner's syndrome in the setting of BPBP is pathognomonic for preganglionic (root avulsion) injury involving T1. This is not a coincidental finding but direct evidence of the injury level and severity. The sympathetic fibers traveling with T1 are disrupted when the root is avulsed from the spinal cord, making Horner's syndrome a definitive diagnostic and prognostic sign.

### Option E: FALSE ✗

FALSE "Good prognosis as the injury is at the trunk level"

**Why this is INCORRECT:** Understanding injury levels and prognosis: 1. **Injury is NOT at trunk level**: - **Horner's indicates root avulsion** - Preganglionic injury - Most proximal possible - Worse than trunk - Opposite location 2. **Injury level hierarchy**: - **Root avulsion: worst** - Root level: very poor - Trunk level: poor to intermediate - Cord/branch: better - More distal = better 3. **Prognosis by level**: - **Avulsion: no spontaneous recovery** - Root rupture: poor - Trunk injury: intermediate - Distal injury: good - Level matters 4. **Trunk injury would mean**: - Postganglionic - Could have spontaneous recovery - Better surgical options - Nerve grafts work - NOT this case 5. **Horner's rules out trunk**: - **Can only occur with root avulsion** - Anatomically impossible at trunk - Sympathetics already separate - Definitive localization - Confirms worst level 6. **Actual prognosis**: - **Very poor** - NOT good - Root avulsion proven - No spontaneous recovery - Opposite claim **Clinical Pearl**: The level of brachial plexus injury determines prognosis and surgical options. Preganglionic injuries (root avulsions, proven by Horner's syndrome) have the worst prognosis because they cannot spontaneously recover and cannot be repaired with nerve grafts. Postganglionic injuries (trunk/cord/branch level) may spontaneously recover and can be repaired with nerve grafts if needed.

--- ### Exam Tip

**High-Yield Points for Horner's Syndrome in BPBP:** - **Horner's Syndrome Triad**: - Ptosis (eyelid droop) - Miosis (small pupil) - Anhidrosis (no facial sweating) - **Anatomical Basis**: - Sympathetic fibers from T1 - Travel preganglionic with C8-T1 - Via stellate and cervical ganglia - Innervate face - **Indicates**: T1 nerve root avulsion (preganglionic) - **Prognosis**: Very poor, no spontaneous recovery - **Narakas**: Type IV (total palsy + Horner's) - **Surgical**: Nerve transfers only (grafts cannot work for avulsions) - **Recovery**: Less than 20% achieve good function - **Injury Level Hierarchy**: - Avulsion (Horner's+) worse than root worse than trunk worse than cord/branch - **Key Teaching**: "Horner's = avulsion = no recovery = nerve transfers = poor outcome"

--- ### Related Topic

📚 **Learn more**: [Brachial Plexus Birth Palsy - Full Topic Review](/topics/pediatrics/brachial-plexus-birth-palsy)

--- ### References

- Narakas AO. Obstetrical brachial plexus injuries. In: Lamb DW, editor. The Paralysed Hand. Edinburgh: Churchill Livingstone; 1987. p. 116-135. - Clarke HM, Curtis CG. An approach to obstetrical brachial plexus injuries. Hand Clin. 1995;11(4):563-580. PMID: 8567740 - Terzis JK, Kokkalis ZT. Outcomes of secondary reconstruction after obstetrical brachial plexus injury. Plast Reconstr Surg. 2008;122(6):1791-1801. PMID: 19050531 - Brown SH, et al. The association of Horner syndrome with neurological outcome in children with obstetric brachial plexus palsy. J Hand Surg Am. 2012;37(11):2299-2305. PMID: 23101533

## Clinical Scenario

A 4-year-old child with recovered Erb's palsy has 30 degrees of internal rotation contracture at the shoulder (cannot externally rotate past neutral) and difficulty with hand-to-mouth activities. Ultrasound shows a concentrically located humeral head without posterior subluxation. What is the most appropriate surgical intervention?

## Answer Options

Select all statements that are **TRUE**. This is an X-Type question where each option is independently True or False.

A Humeral derotation osteotomy

B Subscapularis release with or without latissimus dorsi transfer

C Glenoid osteotomy

D Arthroscopic capsular release

E Shoulder fusion

Reveal Answer Pattern

**Correct Pattern:** `FTFFF` | Option | Answer | |:------:|:------:| | A | FALSE | | B | TRUE | | C | FALSE | | D | FALSE | | E | FALSE |

## Detailed Explanations ### Option A: FALSE ✗

FALSE "Humeral derotation osteotomy"

**Why this is INCORRECT:** Understanding indications for humeral osteotomy: 1. **Wrong for this scenario**: - **Humeral head centered** - No posterior subluxation - Soft tissue problem - NOT bony deformity - Wrong indication 2. **Humeral osteotomy indicated for**: - **Glenohumeral dysplasia** - **Posterior subluxation** - Abnormal version - Bony deformity - NOT this case 3. **Problem in this case**: - **Muscle imbalance** - Strong internal rotators - Weak external rotators - Contracture developed - Soft tissue issue 4. **Why osteotomy wrong**: - Doesn't address imbalance - Doesn't release contracture - May worsen with growth - Not treating cause - Symptomatic only 5. **Age considerations**: - 4 years old - Still growing - Joint congruent - Fix muscle balance first - Osteotomy later if needed 6. **Correct approach**: - **Soft tissue procedure** - Release contracture - Balance forces - Allow normal development - Prevent deformity **Clinical Pearl**: Humeral derotation osteotomy in BPBP is reserved for children with established glenohumeral dysplasia and posterior subluxation, typically age 5-8 years. When the humeral head is concentrically located (as in this case), the priority is soft tissue rebalancing to prevent future bony deformity, not treating bony deformity that hasn't yet occurred.

### Option B: TRUE ✓

TRUE "Subscapularis release with or without latissimus dorsi transfer"

**Why this is CORRECT:** Understanding soft tissue rebalancing surgery: 1. **Pathophysiology**: - **Strong internal rotators** - Subscapularis, pectoralis, latissimus - **Weak external rotators** - Infraspinatus, teres minor - Muscle imbalance 2. **Internal rotation contracture**: - **Cannot externally rotate past neutral** - 30-degree contracture - Limits hand-to-mouth - Functional impairment - Surgical threshold 3. **Subscapularis release**: - **Remove deforming force** - Z-lengthening technique - Preserves some function - Improves passive ROM - Essential component 4. **Latissimus dorsi transfer**: - **Converts internal to external rotator** - Transfer to greater tuberosity - Active external rotation - Teres major also released - Powerful rebalancing 5. **Indications matched**: - **Age 3-5 years typical** - Internal rotation contracture - Concentric humeral head - Functional limitation - Perfect fit 6. **Expected outcomes**: - Improved passive ROM - Improved active external rotation - Better hand-to-mouth - Prevent future dysplasia - High satisfaction **Clinical Pearl**: The subscapularis release with latissimus dorsi transfer (also called the "modified Hoffer procedure" or "triangle tilt" surgery) is the gold-standard soft tissue operation for internal rotation contracture in BPBP. It addresses both components: releases the deforming force (subscapularis, teres major) and augments the weak external rotators (transfers latissimus to become external rotator).

### Option C: FALSE ✗

FALSE "Glenoid osteotomy"

**Why this is INCORRECT:** Understanding indications for glenoid osteotomy: 1. **Too advanced for this case**: - **Humeral head centered** - No subluxation - No dysplasia yet - Preventable stage - Too aggressive 2. **Glenoid osteotomy indicated for**: - **Severe glenohumeral dysplasia** - Posterior glenoid deficiency - Posterior humeral subluxation - Failed soft tissue surgery - Older children 3. **Problem identified wrong**: - This is soft tissue - Not bony deformity - Muscle imbalance - Early stage - Reversible 4. **Age consideration**: - 4 years old - Too young for osteotomy - Usually 7-10 years - After growth affects bone - Wrong timing 5. **Procedure complexity**: - Major surgery - Complex technical - Significant morbidity - Reserved for severe - NOT first-line 6. **Natural history**: - Soft tissue surgery now - May prevent dysplasia - May avoid osteotomy - Early intervention better - Preserve normal anatomy **Clinical Pearl**: Glenoid osteotomy (posterior opening wedge to reorient the glenoid version) is reserved for children age 7-10+ years with established glenohumeral dysplasia, posterior glenoid deficiency greater than 30 degrees, and posterior humeral head subluxation despite previous soft tissue surgery. It's a salvage procedure, not first-line treatment for muscle imbalance.

### Option D: FALSE ✗

FALSE "Arthroscopic capsular release"

**Why this is INCORRECT:** Understanding role of capsular release: 1. **Wrong pathology**: - **Muscle contracture** - Not capsular contracture - Subscapularis shortened - Active deforming force - NOT passive stiffness 2. **Capsular release indicated for**: - True capsular adhesions - Post-traumatic stiffness - Adhesive capsulitis - Frozen shoulder - NOT BPBP 3. **BPBP contracture is dynamic**: - **Muscle imbalance** - Active pulling force - Ongoing deformity - Need muscle release - Not just stretching 4. **Why capsular release insufficient**: - Doesn't address muscle - Subscapularis still tight - Latissimus still pulling - Recurrence likely - Incomplete treatment 5. **Arthroscopic approach**: - Cannot release subscapularis - Cannot transfer latissimus - Cannot rebalance muscles - Wrong technique - Wrong indication 6. **Standard approach**: - **Open anterior approach** - Direct muscle visualization - Subscapularis lengthening - Latissimus transfer - Proper surgery **Clinical Pearl**: Internal rotation contracture in BPBP is due to muscle imbalance and muscle contracture, not capsular contracture. The subscapularis muscle is shortened and fibrotic from constant unopposed contraction. Simply releasing the capsule arthroscopically would not address the underlying muscle pathology and would result in recurrence.

### Option E: FALSE ✗

FALSE "Shoulder fusion"

**Why this is INCORRECT:** Understanding indications for arthrodesis: 1. **Completely inappropriate**: - 4 years old - Growing child - Functional recovery - Motion present - Absolutely wrong 2. **Arthrodesis reserved for**: - **Complete flail shoulder** - No motor function - Failed all reconstruction - Older patients - Last resort 3. **This child has function**: - **Recovered Erb's palsy** - Active motion present - Contracture only - Treatable problem - Good prognosis 4. **Age contraindication**: - **Never in 4-year-old** - Growth concerns - Limb length issues - Psychological impact - Unacceptable 5. **Functional impact**: - Eliminates shoulder motion - Permanent disability - Affects ADLs severely - Irreversible - Devastating 6. **Appropriate treatment**: - **Soft tissue rebalancing** - Preserve motion - Improve function - Allow growth - Excellent outcomes **Clinical Pearl**: Shoulder arthrodesis is NEVER indicated in pediatric BPBP except in the most extreme cases of complete flail shoulder unresponsive to all other reconstructions in older adolescents approaching skeletal maturity. For internal rotation contracture with preserved motion in a 4-year-old, soft tissue rebalancing provides excellent functional outcomes without sacrificing motion.

--- ### Exam Tip

**High-Yield Points for Secondary Reconstruction in BPBP:** - **Internal Rotation Contracture** (most common secondary problem): - Age 3-5 years typical presentation - Indication: Cannot externally rotate past neutral - Treatment: Subscapularis release + latissimus transfer - Goal: Improve hand-to-mouth, prevent dysplasia - **Surgical Algorithm**: - Concentric humeral head: Soft tissue procedure - Posterior subluxation: Consider humeral osteotomy - Severe dysplasia: Glenoid osteotomy (age 7-10+) - **Modified Hoffer/Triangle Tilt**: - Release: Subscapularis, teres major, pectoralis minor - Transfer: Latissimus dorsi to greater tuberosity - Outcome: 80-90% improved external rotation - **Glenohumeral Dysplasia Prevention**: - Early soft tissue surgery prevents bony deformity - Monitor with serial ultrasound/MRI - Intervene before subluxation occurs - **Key Teaching**: "Centered humeral head = soft tissue surgery; Posterior subluxation = consider bony procedure"

--- ### Related Topic

📚 **Learn more**: [Brachial Plexus Birth Palsy - Full Topic Review](/topics/pediatrics/brachial-plexus-birth-palsy)

--- ### References

- Hoffer MM, et al. Tendon transfers and arthrodesis for reconstruction of the shoulder in obstetrical brachial plexus palsy. J Bone Joint Surg Am. 1978;60(5):691-695. PMID: 681392 - Pearl ML, et al. Comparison of arthroscopic findings with magnetic resonance imaging and arthrography in children with glenohumeral deformities secondary to brachial plexus birth palsy. J Bone Joint Surg Am. 2003;85(5):890-898. PMID: 12728041 - Waters PM, Bae DS. The effect of derotational humeral osteotomy on global shoulder function in brachial plexus birth palsy. J Bone Joint Surg Am. 2006;88(5):1035-1042. PMID: 16651578 - Birch R. Late sequelae of obstetric brachial plexus palsy. In: Tubiana R, editor. The Hand. Vol 4. Philadelphia: WB Saunders; 1993. p. 771-785.

## Clinical Scenario

What is the Oberlin procedure and when is it indicated in brachial plexus injury?

## Answer Options

Select all statements that are **TRUE**. This is an X-Type question where each option is independently True or False.

A Transfer of spinal accessory nerve to suprascapular nerve for shoulder abduction

B Transfer of a fascicle of the ulnar nerve to the musculocutaneous nerve for elbow flexion

C Transfer of intercostal nerves to the musculocutaneous nerve

D Transfer of the phrenic nerve to the axillary nerve

E Latissimus dorsi transfer to the humerus for shoulder function

Reveal Answer Pattern

**Correct Pattern:** `FTFFF` | Option | Answer | |:------:|:------:| | A | FALSE | | B | TRUE | | C | FALSE | | D | FALSE | | E | FALSE |

## Detailed Explanations ### Option A: FALSE ✗

FALSE "Transfer of spinal accessory nerve to suprascapular nerve for shoulder abduction"

**Why this is INCORRECT:** Understanding different nerve transfers: 1. **Wrong procedure name**: - This is NOT Oberlin - Different transfer - Different indication - Different surgeon - Wrong attribution 2. **Spinal accessory to suprascapular**: - Valid nerve transfer - For shoulder function - Restores external rotation - Helps abduction - NOT called Oberlin 3. **Historical attribution**: - Described by multiple surgeons - Bertelli, Narakas, others - Common transfer for C5-C6 - Shoulder reconstruction - Different name 4. **Target function**: - **Suprascapular nerve** - Supraspinatus (abduction) - Infraspinatus (external rotation) - Shoulder, not elbow - Different goal 5. **Oberlin procedure**: - **For elbow flexion** - Ulnar to musculocutaneous - NOT for shoulder - Different target - Wrong answer 6. **Clinical use**: - Both transfers used - Often combined - Same patient - Different procedures - Know distinction **Clinical Pearl**: The spinal accessory to suprascapular nerve transfer is a valuable procedure for restoring shoulder external rotation and abduction in brachial plexus injuries, but it is NOT the Oberlin procedure. The Oberlin transfer specifically refers to ulnar fascicle to musculocutaneous nerve transfer for elbow flexion restoration.

### Option B: TRUE ✓

TRUE "Transfer of a fascicle of the ulnar nerve to the musculocutaneous nerve for elbow flexion"

**Why this is CORRECT:** Understanding the Oberlin procedure: 1. **Oberlin procedure definition**: - **Ulnar nerve fascicle** - **To musculocutaneous nerve** - **For elbow flexion** - Described by Oberlin 1994 - Revolutionary technique 2. **Surgical technique**: - **One fascicle from ulnar** - Usually 20-30% of nerve - Identify motor fascicle - Coapt to musculocutaneous - Direct coaptation 3. **Donor nerve selection**: - **Ulnar nerve chosen** - Has redundant fascicles - Forearm/hand function preserved - Minimal donor deficit - Acceptable trade-off 4. **Target restoration**: - **Elbow flexion** - Reinnervate biceps - Reinnervate brachialis - Critical function - Hand-to-mouth 5. **Indications**: - **Upper trunk avulsion** - C5-C6 preganglionic - No biceps recovery - Lower plexus intact - Ulnar nerve functional 6. **Outcomes**: - **M3+ in 80-90%** - Excellent elbow flexion - Minimal donor deficit - Short reinnervation distance - High success rate **Clinical Pearl**: The Oberlin procedure (ulnar fascicle to musculocutaneous transfer) revolutionized brachial plexus surgery because it provides excellent elbow flexion recovery (M3+ in 80-90%) with minimal donor morbidity and short reinnervation time. The key is careful intraoperative identification of a motor fascicle to the flexor carpi ulnaris (FCU), which can be sacrificed without significant hand function loss.

### Option C: FALSE ✗

FALSE "Transfer of intercostal nerves to the musculocutaneous nerve"

**Why this is INCORRECT:** Understanding intercostal nerve transfers: 1. **Not Oberlin procedure**: - Different donor nerve - Different technique - Older procedure - Different surgeon - Wrong name 2. **Intercostal transfer**: - Valid nerve transfer - For elbow flexion - Historical significance - Still used sometimes - NOT called Oberlin 3. **Technical differences**: - **Multiple intercostals needed** - Usually 3-4 nerves - Longer distance - More dissection - More invasive 4. **Donor morbidity**: - **Chest wall numbness** - Respiratory effects - Intercostal muscle loss - Greater than Oberlin - Less acceptable 5. **Outcomes comparison**: - **Oberlin superior results** - Faster recovery - Better strength - Less morbidity - Preferred technique 6. **Current use**: - Largely replaced by Oberlin - Historical importance - Rarely used now - Oberlin preferred - Better option **Clinical Pearl**: Intercostal nerve transfer to musculocutaneous nerve was historically important (described by Nagano, Tsuyama, and others in the 1970s-1980s) but has been largely replaced by the Oberlin procedure. Oberlin transfer provides superior elbow flexion recovery (M3+ in 80-90% vs 60-70% with intercostals) with less donor morbidity and faster recovery.

### Option D: FALSE ✗

FALSE "Transfer of the phrenic nerve to the axillary nerve"

**Why this is INCORRECT:** Understanding phrenic nerve transfers: 1. **Wrong procedure**: - Not Oberlin transfer - Different donor - Different target - Different function - Wrong answer 2. **Phrenic nerve use**: - **Controversial donor** - Respiratory importance - Rarely used - High morbidity risk - Generally avoided 3. **Historical context**: - Used in past - For musculocutaneous - For shoulder function - Abandoned mostly - Better alternatives 4. **Respiratory concerns**: - **Hemidiaphragm paralysis** - Respiratory compromise - Exercise limitation - Unacceptable in children - Safety issue 5. **Target nerve wrong**: - **Axillary nerve** - Shoulder abduction - Deltoid function - NOT elbow - Different goal 6. **Oberlin is**: - **Ulnar to musculocutaneous** - For elbow flexion - Minimal morbidity - Excellent outcomes - Standard technique **Clinical Pearl**: Phrenic nerve transfer was historically used in brachial plexus surgery (to musculocutaneous for elbow flexion or to suprascapular for shoulder function) but has been largely abandoned due to the risk of hemidiaphragm paralysis. Modern nerve transfer techniques like Oberlin provide excellent functional outcomes without sacrificing vital respiratory function.

### Option E: FALSE ✗

FALSE "Latissimus dorsi transfer to the humerus for shoulder function"

**Why this is INCORRECT:** Understanding muscle vs nerve transfers: 1. **Wrong category**: - **Muscle transfer** - NOT nerve transfer - Different procedure type - Different timing - Wrong classification 2. **Latissimus transfer**: - Secondary reconstruction - For shoulder external rotation - After nerve recovery - Age 3-5 years - Different stage 3. **Oberlin is nerve transfer**: - **Primary reconstruction** - Nerve to nerve - Microsurgical - Age 6-12 months - Early intervention 4. **Target function**: - Latissimus: shoulder - **Oberlin: elbow flexion** - Different goals - Different joints - Wrong answer 5. **Timing difference**: - Nerve transfers: 6-12 months - Muscle transfers: 3-5 years - Sequential approach - Different phases - Key distinction 6. **Complementary not identical**: - Both used in BPBP - Different indications - Different timing - Not interchangeable - Know difference **Clinical Pearl**: It's critical to distinguish nerve transfers (performed at 6-12 months as primary nerve reconstruction, like Oberlin) from muscle transfers (performed at 3-5+ years as secondary reconstruction for residual deficits, like latissimus dorsi transfer). They are complementary procedures at different stages of BPBP management, not alternatives to each other.

--- ### Exam Tip

**High-Yield Points for Nerve Transfers in BPBP:** - **Oberlin Procedure**: - Donor: Ulnar nerve fascicle (to FCU) - Recipient: Musculocutaneous nerve - Function: Elbow flexion (biceps, brachialis) - Success: M3+ in 80-90% - Advantage: Short distance, minimal donor deficit - **Common Nerve Transfers in BPBP**: - Spinal accessory → suprascapular (shoulder ER, abduction) - Ulnar fascicle → musculocutaneous (Oberlin, elbow flexion) - Median fascicle → musculocutaneous (double fascicle) - Radial → axillary (shoulder abduction) - **Timing**: Primary nerve surgery at 6-9 months - **Indications**: Root avulsion (preganglionic injury) - **Advantage over grafts**: Can bypass avulsion, shorter distance - **Oberlin Variants**: - Double fascicle: Ulnar + median to MCN (stronger) - Modified Oberlin: For adult traumatic BPI - **Key Teaching**: "Oberlin = Ulnar fascicle to MCN = Best elbow flexion transfer"

--- ### Related Topic

📚 **Learn more**: [Brachial Plexus Birth Palsy - Full Topic Review](/topics/pediatrics/brachial-plexus-birth-palsy)

--- ### References

- Oberlin C, et al. Nerve transfer to biceps muscle using a part of ulnar nerve for C5-C6 avulsion of the brachial plexus: anatomical study and report of four cases. J Hand Surg Am. 1994;19(2):232-237. PMID: 8201186 - Mackinnon SE, Novak CB. Nerve transfers: new options for reconstruction following nerve injury. Hand Clin. 1999;15(4):643-666. PMID: 10560212 - Estrella EP, Montales TD. Nerve transfers in obstetric brachial plexus palsy. J Hand Surg Asian Pac Vol. 2016;21(3):288-295. PMID: 27595999 - Tung TH, Mackinnon SE. Nerve transfers: indications, techniques, and outcomes. J Hand Surg Am. 2010;35(2):332-341. PMID: 20141906

## Clinical Scenario

What is the major long-term orthopaedic complication in children with brachial plexus birth palsy even after nerve recovery?

## Answer Options

Select all statements that are **TRUE**. This is an X-Type question where each option is independently True or False.

A Elbow flexion contracture

B Wrist drop and finger contractures

C Glenohumeral dysplasia with posterior subluxation

D Radial head dislocation

E Forearm synostosis

Reveal Answer Pattern

**Correct Pattern:** `FFTFF` | Option | Answer | |:------:|:------:| | A | FALSE | | B | FALSE | | C | TRUE | | D | FALSE | | E | FALSE |

## Detailed Explanations ### Option A: FALSE ✗

FALSE "Elbow flexion contracture"

**Why this is INCORRECT:** Understanding elbow complications in BPBP: 1. **Elbow not major complication**: - **Shoulder is primary** - Elbow recovers better - Less frequent problem - NOT the major issue - Wrong joint 2. **Typical elbow pattern**: - **Good biceps recovery** - In most children - Full ROM common - Minimal contractures - Generally successful 3. **If contracture occurs**: - Usually mild - Responds to therapy - Rarely needs surgery - Secondary importance - Not long-term issue 4. **Elbow extension loss**: - Can occur - From overactive biceps - Less than 20% of cases - Usually less than 30 degrees - Not the major problem 5. **Actual major complication**: - **Glenohumeral dysplasia** - Progressive deformity - Affects 30-50% - Requires surgery - Long-term disability 6. **Clinical focus**: - Monitor shoulder closely - Elbow secondary concern - Serial shoulder imaging - Prevent dysplasia - Different priority **Clinical Pearl**: While mild elbow flexion contractures can occur in BPBP (usually less than 30 degrees), they are far less common and less clinically significant than shoulder complications. Most children with BPBP who recover biceps function achieve full or near-full elbow range of motion without surgical intervention.

### Option B: FALSE ✗

FALSE "Wrist drop and finger contractures"

**Why this is INCORRECT:** Understanding hand/wrist complications: 1. **Wrong injury pattern**: - **Most BPBP is C5-C6** - Upper trunk injury - Hand spared - Wrist/fingers normal - NOT affected 2. **Wrist drop requires**: - **C7 involvement** - Radial nerve function - Extended Erb's palsy - Less common - Not most cases 3. **Finger contractures**: - **Require C8-T1 injury** - Klumpke palsy - Very rare (less than 1%) - NOT typical - Wrong complication 4. **Clinical reality**: - Hand function usually excellent - Even with shoulder problems - Lower plexus spared - Normal hand use - Major strength 5. **Focus of reconstruction**: - **Shoulder and elbow** - NOT hand/wrist - Proximal joints - Functional priorities - Different targets 6. **Major complication is**: - **Glenohumeral dysplasia** - Shoulder deformity - Progressive subluxation - Requires complex surgery - Long-term problem **Clinical Pearl**: The vast majority of BPBP cases involve C5-C6 (Erb's palsy) or C5-C7 (extended Erb's), both of which spare hand and finger function. Hand complications would only occur with very rare C8-T1 involvement (Klumpke palsy, less than 1%). The major long-term orthopedic complication is shoulder dysplasia, not distal upper extremity deformities.

### Option C: TRUE ✓

TRUE "Glenohumeral dysplasia with posterior subluxation"

**Why this is CORRECT:** Understanding glenohumeral dysplasia in BPBP: 1. **Most significant complication**: - **Affects 30-50% of BPBP** - Even after nerve recovery - Progressive deformity - Long-term disability - Major clinical problem 2. **Pathophysiology**: - **Muscle imbalance** - Strong internal rotators - Weak external rotators - Abnormal forces on growth plate - Progressive deformity 3. **Bony changes**: - **Glenoid retroversion** - Posterior glenoid deficiency - Flattened glenoid - Abnormal humeral head - Subluxation develops 4. **Natural history**: - **Begins age 1-2 years** - Progressive with growth - Can occur despite recovery - Muscle imbalance sufficient - May not self-correct 5. **Clinical significance**: - **Limited shoulder ROM** - Posterior humeral subluxation - Functional impairment - Pain in adolescence/adulthood - May require surgery 6. **Monitoring essential**: - **Serial ultrasound/MRI** - Every 6-12 months - Detect early changes - Intervene appropriately - Prevent progression **Clinical Pearl**: Glenohumeral dysplasia is the major long-term orthopedic complication in BPBP, occurring in 30-50% of children even after good nerve recovery. The muscle imbalance (strong internal rotators, weak external rotators) creates abnormal forces across the growing shoulder, leading to progressive glenoid retroversion, posterior glenoid deficiency, and posterior humeral head subluxation requiring complex reconstructive surgery.

### Option D: FALSE ✗

FALSE "Radial head dislocation"

**Why this is INCORRECT:** Understanding elbow complications in BPBP: 1. **Not associated with BPBP**: - **Different pathology** - Congenital radial head - NOT from nerve palsy - Wrong complication - Different etiology 2. **Radial head dislocation causes**: - Congenital anomaly - Monteggia fracture - Chronic forearm injury - NOT muscle imbalance - NOT from BPBP 3. **BPBP elbow complications**: - Usually minor - Mild flexion contracture - Good overall function - NOT structural deformity - Different pattern 4. **Muscle forces at elbow**: - Biceps may recover - Triceps usually intact - No significant imbalance - Unlike shoulder - No progressive deformity 5. **If radial head dislocated**: - Coincidental finding - Separate condition - NOT from BPBP - Different management - Unrelated 6. **Major complication is**: - **Glenohumeral dysplasia** - Shoulder joint - Progressive with growth - From muscle imbalance - Requires monitoring **Clinical Pearl**: Radial head dislocation is NOT a recognized complication of BPBP. If found in a child with BPBP, it represents either a congenital anomaly, a separate traumatic injury, or coincidental finding. The elbow joint does not develop progressive deformity from BPBP muscle imbalance the way the shoulder does.

### Option E: FALSE ✗

FALSE "Forearm synostosis"

**Why this is INCORRECT:** Understanding forearm complications: 1. **Not related to BPBP**: - **Different condition** - Congenital anomaly - OR post-traumatic - NOT from nerve palsy - Wrong complication 2. **Forearm synostosis**: - **Proximal radioulnar fusion** - Blocks pronation/supination - Congenital common - Post-fracture possible - NOT from BPBP 3. **BPBP forearm position**: - **Held in pronation** - Due to muscle imbalance - Biceps weak (supinator) - Pronators stronger - Positional only 4. **No bony fusion**: - Soft tissue contracture - NOT synostosis - Can improve with surgery - Reversible problem - Different pathology 5. **If synostosis present**: - Coincidental finding - Separate anomaly - NOT caused by BPBP - Different management - Unrelated condition 6. **Major complication is**: - **Glenohumeral dysplasia** - Progressive shoulder deformity - From muscle imbalance - Affects 30-50% - Requires complex surgery **Clinical Pearl**: Forearm positioning in BPBP (pronation deformity from weak biceps/supinator) is due to muscle imbalance and soft tissue contracture, NOT radioulnar synostosis. If radioulnar synostosis is found in a child with BPBP, it is a coincidental congenital anomaly, not a complication of the nerve injury. The shoulder is the major site of progressive bony deformity in BPBP.

--- ### Exam Tip

**High-Yield Points for Glenohumeral Dysplasia in BPBP:** - **Incidence**: 30-50% of BPBP patients - **Pathophysiology**: - Muscle imbalance (strong IR, weak ER) - Abnormal forces on growing physis - Progressive bony deformity - **Bony Changes**: - Glenoid retroversion (increased posterior angulation) - Posterior glenoid deficiency/flattening - Abnormal humeral head shape - Posterior subluxation of humeral head - **Natural History**: - Begins age 1-2 years - Progressive with growth - Can occur even with good nerve recovery - May cause pain in adolescence/adulthood - **Monitoring**: Serial ultrasound (age less than 1) or MRI (age greater than 1) - **Treatment Algorithm**: - Prevention: Early soft tissue balancing (age 3-5) - Mild dysplasia: Soft tissue procedures - Moderate: Humeral derotation osteotomy (age 5-8) - Severe: Glenoid osteotomy (age 7-10+) - **Key Teaching**: "BPBP's major long-term complication = shoulder dysplasia, NOT hand/elbow"

--- ### Related Topic

📚 **Learn more**: [Brachial Plexus Birth Palsy - Full Topic Review](/topics/pediatrics/brachial-plexus-birth-palsy)

--- ### References

- Pearl ML, Edgerton BW. Glenoid deformity secondary to brachial plexus birth palsy. J Bone Joint Surg Am. 1998;80(5):659-667. PMID: 9611026 - Kozin SH. Correlation between external rotation of the glenohumeral joint and deformity after brachial plexus birth palsy. J Pediatr Orthop. 2004;24(2):189-193. PMID: 15076606 - Waters PM, Bae DS. The early effects of tendon transfers and open capsulorrhaphy on glenohumeral deformity in brachial plexus birth palsy. J Bone Joint Surg Am. 2008;90(10):2171-2179. PMID: 18829915 - van der Sluijs JA, et al. Treatment of internal rotation contracture of the shoulder in obstetric brachial plexus lesions by subscapularis tendon lengthening and open reduction: early results and complications. J Pediatr Orthop B. 2004;13(3):218-224. PMID: 15083135

Brachial Plexus Birth Palsy MCQs

Brachial Plexus Birth Palsy MCQs