High Yield Overview

FIBULAR HEMIMELIA

Most Common Long Bone Deficiency | Achterman-Kalamchi Classification | Syme vs Reconstruction | Foot Preservability Key

1:40,000Incidence

Achterman I-IIClassification

Foot raysTreatment decision

30-40cmLLD threshold for amputation

ACHTERMAN-KALAMCHI CLASSIFICATION

Type IA

PatternFibula present, hypoplastic (under 50% short), foot normal

TreatmentReconstruction possible

Type IB

PatternFibula present (over 50% short), foot 3-4 rays

TreatmentReconstruction or Syme

Type II

PatternComplete fibular absence, foot 0-3 rays

TreatmentSyme amputation (usually)

Critical Must-Knows

Treatment based on foot preservability, NOT fibula length - key principle: assess foot rays (under 3 = Type 2 = amputation usually)
Achterman-Kalamchi classification: Type IA (mild), IB (moderate), II (severe) - guides treatment approach
Birch classification: Type 1 (foot preservable, 4-5 rays) vs Type 2 (foot not preservable, under 3 rays)
Syme amputation: Indicated for predicted LLD over 30-40cm, under 3 foot rays, severe ankle valgus over 30 degrees
Reconstruction: Multiple lengthenings, foot centralization, ankle stabilization - long treatment course (10-15 years)

Examiner's Pearls

"
Treatment decision based on FOOT (not fibula) - under 3 rays = Type 2 = usually amputation
"
Syme amputation preserves plantar heel pad for end weight-bearing - better function than BKA
"
LLD percentage is constant throughout growth - predict final LLD using multiplier method
"
Reconstruction requires 2-4 lengthenings, each 4-8cm, starting age 6-8 years

Clinical Imaging

Imaging Gallery

Radiographic presentation of a 6 years old patient with fibular hemimelia type II. Patient's (case 6) radiographs on first examination in the age of 6 years old showing a complete absence of the fibul — Radiographic presentation of a 6 years old patient with fibular hemimelia type II. Patient's (case 6) radiographs on first examination in the age of 6Credit: Alaseirlis DA et al. via J Orthop Surg Res via Open-i (NIH) (Open Access (CC BY))

Radiographic presentation of the same patient two years after lengthening procedure. Severe valgus deformity of 85° of the distal tibia in the age of nine y.o., and two years after completing a length — Radiographic presentation of the same patient two years after lengthening procedure. Severe valgus deformity of 85° of the distal tibia in the age of Credit: Alaseirlis DA et al. via J Orthop Surg Res via Open-i (NIH) (Open Access (CC BY))

Radiographic presentation of the same patient two years after new surgical intervention. Radiograph of the same patient in the age of eleven years old and two years after new surgical intervention. Th — Radiographic presentation of the same patient two years after new surgical intervention. Radiograph of the same patient in the age of eleven years oldCredit: Alaseirlis DA et al. via J Orthop Surg Res via Open-i (NIH) (Open Access (CC BY))

Clinical presentation of the same patient in the age of thirteen years old. Four years after completion of the second surgical procedure. Although there is an acceptable mechanical axis, there is a qu — Clinical presentation of the same patient in the age of thirteen years old. Four years after completion of the second surgical procedure. Although theCredit: Alaseirlis DA et al. via J Orthop Surg Res via Open-i (NIH) (Open Access (CC BY))

Critical Fibular Hemimelia Exam Points

Foot Preservability Determines Treatment

Treatment based on FOOT, not fibula length - assess foot rays: 4-5 rays (Type 1) = reconstruction possible, under 3 rays (Type 2) = usually Syme amputation. This is the most important decision point.

Syme vs Reconstruction Decision

Syme amputation: Predicted LLD over 30-40cm, under 3 foot rays, ankle valgus over 30 degrees, family acceptance. Reconstruction: LLD under 30cm, 4-5 foot rays, moderate valgus (correctable), motivated family. Syme often has better function in severe cases.

LLD is Main Problem

Limb length discrepancy is the primary issue - predict final LLD using multiplier method. LLD percentage is constant throughout growth. Severe LLD (over 30-40cm predicted) favors amputation over reconstruction.

Associated Anomalies Common

Common associations: Anteromedial tibial bowing, tarsal coalition, equinovalgus foot, cruciate deficiency, PFFD (50%), coxa vara, acetabular dysplasia. Always assess entire limb and other systems (cardiac, renal).

Fibular Hemimelia Treatment Decision - Quick Reference

Foot Rays	Predicted LLD	Ankle Valgus	Treatment
4-5 rays	Under 30cm	Under 30 degrees	Reconstruction
3-4 rays	30-40cm	30-40 degrees	Reconstruction or Syme
Under 3 rays	Over 30-40cm	Over 30 degrees	Syme amputation

Mnemonic

FOOTFibular Hemimelia Treatment Decision

Foot rays count

Under 3 rays = Type 2 = usually amputation

Over 30cm LLD

Predicted LLD over 30-40cm favors amputation

Over 30° valgus

Severe ankle valgus (over 30 degrees) favors amputation

Treatment decision

Based on foot (not fibula) - key principle

Memory Hook:FOOT determines treatment: Foot rays count, Over 30cm LLD, Over 30° valgus, and Treatment decision based on foot!

Mnemonic

TALUSFibular Hemimelia Associated Findings

Tibial bowing

Anteromedial tibial bowing (characteristic)

Ankle valgus

Equinovalgus foot deformity (common)

Limb length discrepancy

LLD is main problem

Ulnar hemimelia

May be associated (upper limb)

Syndactyly/tarsal coalition

Foot anomalies common

Memory Hook:TALUS findings: Tibial bowing, Ankle valgus, Limb length discrepancy, Ulnar hemimelia, and Syndactyly/tarsal coalition!

Mnemonic

SALVAGESyme Amputation Indications

Severe LLD

Predicted LLD over 30-40cm at maturity

Ankle valgus over 30°

Severe uncorrectable ankle deformity

Less than 3 rays

Foot with under 3 functional rays (Type 2)

Valgus uncorrectable

Severe ankle valgus not correctable

Acceptance by family

Family counseling and acceptance essential

Greater function expected

Syme often has better function than reconstruction

End weight-bearing

Syme preserves heel pad for end weight-bearing

Memory Hook:SALVAGE decision: Severe LLD, Ankle valgus over 30°, Less than 3 rays, Valgus uncorrectable, Acceptance needed, Greater function, End weight-bearing capability!

Overview and Epidemiology

Fibular hemimelia is the most common congenital long bone deficiency, characterized by partial or complete absence of the fibula. It represents a spectrum from mild hypoplasia to complete absence, with associated limb length discrepancy and foot deformities.

Clinical photograph showing right-sided fibular hemimelia with limb length discrepancy — Right-sided fibular hemimelia demonstrating significant limb length discrepancy - the primary clinical finding that determines treatment. Assessment of foot rays (number of functional toes/metatarsals) is crucial for deciding between reconstruction and Syme amputation.Credit: Wikimedia Commons. CC BY-SA 4.0

Epidemiology:

Incidence: 1 in 40,000 live births
Male to female ratio: 1.5:1
Bilateral involvement: 9-52% of cases
Right side slightly more common
Most common long bone deficiency

Pathophysiology: Fibular hemimelia results from failure of normal fibular development during embryogenesis. The exact cause is unknown but may involve:

Vascular insult during development
Genetic factors (rare familial cases)
Teratogenic exposure
Failure of mesenchymal condensation

The condition represents a spectrum, with Achterman-Kalamchi classification describing severity based on fibular presence and foot status.

Pathophysiology and Mechanisms

Normal Fibular Anatomy: The fibula is the lateral bone of the lower leg. It provides:

Lateral stability to the ankle
Muscle attachments (peroneals, flexor hallucis longus)
Contributes to ankle mortise
Minimal weight-bearing (10-15%)

Fibular Hemimelia Pathology: In fibular hemimelia, there is:

Partial or complete absence of fibula
Anteromedial tibial bowing (characteristic)
Limb length discrepancy (main problem)
Foot deformities (equinovalgus, absent rays, tarsal coalition)
Ankle valgus (lateral tether absent)
Knee problems (valgus, cruciate deficiency)

Pathophysiology: The absence of fibula causes:

Loss of lateral support → ankle valgus
Anteromedial tibial bowing (compensatory)
Limb length discrepancy (fibula contributes to length)
Foot deformities (lateral column affected)

Associated Musculoskeletal Findings:

Anteromedial tibial bowing (characteristic)
Tarsal coalition (common)
Equinovalgus foot (most common)
Absent lateral rays (common)
Cruciate ligament deficiency
Genu valgum
Lateral femoral condyle hypoplasia
PFFD (50% association)
Coxa vara
Acetabular dysplasia

Understanding the anatomy helps determine treatment - foot status is key, not fibula length.

Classification Systems

Achterman-Kalamchi Classification (1979)

Based on fibular presence and foot status:

Achterman-Kalamchi Classification Summary

Type	Fibula	Foot	Treatment
Type IA	Present, hypoplastic (under 50% short)	Normal (5 rays)	Reconstruction
Type IB	Present (over 50% short)	3-4 rays	Reconstruction or Syme
Type II	Complete absence	0-3 rays	Syme amputation (usually)

Type IA: Mildest form. Fibula present but hypoplastic (under 50% of normal length). Foot normal with 5 rays. Treatment: Reconstruction with lengthening, epiphysiodesis if needed.

Type IB: Moderate severity. Fibula present but significantly shortened (over 50% of normal length). Foot has 3-4 rays. Treatment: Reconstruction possible but complex, or Syme amputation depending on LLD and family preference.

Type II: Most severe. Complete absence of fibula. Foot has 0-3 rays. Treatment: Usually Syme amputation (better function than reconstruction in severe cases).

The classification guides treatment approach but foot status is the key decision factor.

Clinical Assessment

History:

Shortened lower limb noted at birth
May have foot deformity noted
Family history (rare but may be present)
Difficulty with walking or activities
Previous treatment (if established case)

Physical Examination:

Inspection:

Shortened lower limb
Anteromedial tibial bowing (characteristic)
Foot deformity (equinovalgus most common)
Assess number of foot rays (toes)
Assess for bilateral involvement
Look for associated deformities (hip, knee, upper limb)

Palpation:

Fibula may be absent or hypoplastic
Anteromedial tibial bowing palpable
Assess ankle stability
Assess foot structure

Range of Motion:

Ankle: May have limited motion, valgus deformity
Knee: May have valgus, assess cruciate function
Hip: Assess for PFFD, coxa vara
Assess for contractures

Measurements:

True leg length: ASIS to medial malleolus
Apparent leg length: umbilicus to medial malleolus
Tibial length: knee joint line to ankle
Predict final LLD using multiplier method

Foot Assessment:

Count functional rays (toes)
Assess foot position (equinovalgus, equinovarus)
Assess for tarsal coalition
Assess ankle valgus angle

Associated Examination:

Hips: Assess for PFFD (50% association)
Knees: Assess for valgus, cruciate deficiency
Upper limbs: Assess for ulnar hemimelia
Other systems: Cardiac, renal (rare associations)

Investigations

Radiographs:

AP and Lateral Lower Limb:

Assess fibular presence/absence
Evaluate anteromedial tibial bowing
Measure limb length discrepancy
Assess ankle valgus angle
Evaluate foot structure (ray count, tarsal coalition)

Full-Length Standing Radiographs (Scanogram):

Accurate LLD measurement
Assess alignment
Evaluate tibia-femur ratio
Plan treatment

Foot Radiographs:

Count functional rays
Assess for tarsal coalition
Evaluate foot structure
Assess ankle valgus

CT Scan (if reconstruction considered):

Detailed foot anatomy
Assess tarsal coalition
Plan foot centralization
Evaluate ankle structure

Other Imaging:

MRI: May assess soft tissue structures
Ultrasound: Usually not needed

LLD Prediction:

Multiplier method: Current LLD × multiplier = predicted final LLD
Growth remaining method: More complex, accounts for growth
LLD percentage is constant throughout growth

Management Algorithm

Fibular Hemimelia Treatment Algorithm - Illustrated medical sketchnote style — Treatment decision flowchart for fibular hemimelia showing Syme vs reconstruction pathway based on foot rays and predicted LLD.Credit: OrthoVellum

Treatment Philosophy

Key principle: Treatment based on foot preservability, NOT fibula length.

Decision factors:

Foot rays: Under 3 rays (Type 2) = usually amputation, 4-5 rays (Type 1) = reconstruction possible
Predicted LLD: Over 30-40cm = favors amputation, under 30cm = reconstruction possible
Ankle valgus: Over 30 degrees = favors amputation, under 30 degrees = may be correctable
Family preference: After counseling about both options

Treatment options:

Syme amputation: For severe cases (Type 2, LLD over 30-40cm, severe valgus)
Reconstruction: For milder cases (Type 1, LLD under 30cm, correctable valgus)

No "wrong" choice - shared decision making essential.

Surgical Techniques

Syme Amputation

Indication: Type 2 (under 3 foot rays), predicted LLD over 30-40cm, severe ankle valgus.

Technique:

Incision:
- Transverse across anterior ankle (just above joint line)
- Plantar extension in racquet fashion
- Encompass plantar heel pad
Dissection:
- Divide nerves high (prevent neuroma): sural, saphenous, deep peroneal, tibial
- Ligate vessels: posterior tibial, anterior tibial
- Divide tendons
Disarticulation:
- Disarticulate ankle joint
- Remove foot
- Resect medial malleolus flush
- Smooth tibial end
Heel pad preservation:
- Preserve heel pad with posterior tibial artery branches
- Fix centrally to tibia with sutures through drill holes
Closure:
- Close without tension
- End weight-bearing stump

Postoperative: Cast 2-3 weeks, then prosthetic fitting.

Key point: Preserves plantar heel pad for end weight-bearing (better than BKA).

Complications

Reconstruction Complications:

Early:

Infection (20-30% with external fixators)
Wound healing problems
Neurovascular injury
Inadequate correction

Late:

Persistent LLD (may need additional lengthenings)
Ankle problems (instability, stiffness, arthritis)
Knee problems (valgus, cruciate deficiency)
Foot problems (deformity recurrence, tarsal coalition)
Contractures (ankle, knee)
Hardware problems

Lengthening Complications:

Pin site infection (common)
Stiffness (ankle, knee)
Contractures
Delayed union
Premature consolidation
Nerve injury (peroneal most common)
Refracture

Syme Amputation Complications:

Early:

Wound healing problems (5-10%)
Heel pad migration (if not properly fixed)
Infection (rare)

Late:

Heel pad migration (may need revision)
Bony overgrowth (may need revision)
Prosthetic fitting problems (rare)

Prevention:

Careful patient selection
Meticulous surgical technique
Aggressive physical therapy (reconstruction)
Long-term bracing (reconstruction)
Realistic expectations

Postoperative Care

Syme Amputation:

Immediate:

Pain management
Wound care
Cast 2-3 weeks

After Healing:

Prosthetic fitting (6-8 weeks)
Gait training
Return to activities

Long-term:

Prosthetic adjustments as child grows
Monitor for heel pad migration
Monitor for bony overgrowth

Reconstruction:

Immediate:

Pain management
Wound care
Cast or external fixator care

Lengthening Phase:

Pin site care (daily cleaning)
Distraction protocol (1mm/day)
Physical therapy (critical)
Regular radiographs

After Union:

Protected weight-bearing
AFO long-term
Physical therapy
Gradual return to activities

Long-term Follow-up:

Annual assessment until skeletal maturity
Monitor LLD progression
Assess function
Address complications

Outcomes and Prognosis

Functional Outcomes:

Syme Amputation:

Excellent function in 80-90%
Running, sports possible with prosthesis
Minimal restrictions
High patient satisfaction
Single surgery, short treatment

Reconstruction:

Variable function (60-70% good outcomes)
Often residual LLD (2-5cm)
Ankle problems common (instability, stiffness)
May need AFO long-term
Multiple surgeries (2-4 lengthenings)
Long treatment course (10-15 years)

Quality of Life:

Syme: Excellent quality of life, high satisfaction
Reconstruction: Variable, depends on outcome
Both groups function well overall
Psychosocial support important

Predictors of Success:

Appropriate patient selection
Syme: Proper technique, heel pad preservation
Reconstruction: Motivated family, adequate rays, manageable LLD

Long-term:

Syme: Prosthetic adjustments as child grows, otherwise stable
Reconstruction: May need additional procedures, ankle problems may worsen
Both: Most function independently

Evidence Base

Achterman-Kalamchi Classification

Achterman C, Kalamchi A • J Bone Joint Surg Am (1979)

Key Findings:

Classification based on fibular presence and foot status
Type IA: Mild, reconstruction possible
Type IB: Moderate, reconstruction or amputation
Type II: Severe, usually amputation

Clinical Implication: Achterman-Kalamchi classification provides framework for treatment planning, though foot preservability (Birch classification) is the key decision factor, not fibula length alone.

Birch Classification and Treatment

Birch JG, Lincoln TL, Mack PW • J Bone Joint Surg Am (2011)

Key Findings:

Treatment based on foot preservability, NOT fibula length
Type 1 (4-5 rays): Reconstruction possible
Type 2 (under 3 rays): Usually amputation
LLD percentage constant throughout growth

Clinical Implication: Birch classification emphasizes that treatment decision is based on foot rays (preservability), not fibula length - this is the key principle for fibular hemimelia management.

Syme vs Reconstruction Outcomes

Paley D, Herzenberg JE • J Pediatr Orthop (2002)

Key Findings:

Syme amputation: Better function in severe cases
Single surgery vs multiple for reconstruction
Lower complication rate with Syme
Higher patient satisfaction with Syme in severe cases

Clinical Implication: Syme amputation provides superior functional outcomes compared to complex reconstruction in severe fibular hemimelia cases (Type 2, LLD over 30-40cm) - single surgery, lower complications, better function.

Reconstruction Outcomes in Fibular Hemimelia

Catagni MA, Guerreschi F • J Pediatr Orthop (2001)

Key Findings:

Reconstruction requires 2-4 lengthenings
Each lengthening: 4-8cm
Treatment course: 10-15 years
60-70% good outcomes, but complications common

Clinical Implication: Reconstruction for fibular hemimelia is complex, requiring multiple lengthenings over 10-15 years with significant complication rates - appropriate patient selection and family counseling essential.

Associated Anomalies in Fibular Hemimelia

Stevenson DA, Carey JC • Am J Med Genet (2006)

Key Findings:

50% associated with PFFD
Tarsal coalition common
Anteromedial tibial bowing characteristic
Equinovalgus foot most common
Cardiac and renal associations rare

Clinical Implication: Fibular hemimelia has multiple associated anomalies - always assess for PFFD (50% association), tarsal coalition, tibial bowing, and foot deformities. Complete musculoskeletal and systemic assessment essential.

Exam Viva Scenarios

Practice these scenarios to excel in your viva examination

VIVA SCENARIOStandard

Scenario 1: Initial Assessment

EXAMINER

"A 1-year-old child presents with fibular hemimelia. On examination, the fibula is completely absent, there is anteromedial tibial bowing, the foot has 2 functional rays, and there is severe ankle valgus (40 degrees). How would you assess and manage this child?"

EXCEPTIONAL ANSWER

This is a case of fibular hemimelia, Achterman-Kalamchi Type II (complete fibular absence) with Birch Type 2 (under 3 foot rays). I would take a systematic approach: First, complete assessment including measurement of current limb length discrepancy, prediction of final LLD using multiplier method, evaluation of foot structure (2 rays confirmed), assessment of ankle valgus (40 degrees - severe), and evaluation for associated anomalies (PFFD in 50%, tarsal coalition, cruciate deficiency). Second, obtain full-length standing radiographs (scanogram) for accurate LLD measurement and to assess tibia-femur ratio. Third, based on the findings - under 3 foot rays (Type 2), predicted LLD likely over 30-40cm, severe ankle valgus (40 degrees), and complete fibular absence - I would recommend Syme amputation. I would counsel the parents that Syme amputation provides better function than complex reconstruction in this severe case, that it is a single surgery (vs multiple lengthenings over 10-15 years), that the child will have excellent function with a prosthesis, and that this is the standard treatment for Type 2 fibular hemimelia with these features.

KEY POINTS TO SCORE

Recognize Type II (complete fibular absence) and Type 2 (under 3 rays)

Assess predicted LLD (likely over 30-40cm)

Evaluate ankle valgus (40 degrees - severe)

Recommend Syme amputation for severe case

Counsel about better function than reconstruction in severe cases

COMMON TRAPS

✗Suggesting reconstruction for Type 2 with under 3 rays - amputation usually better

✗Not assessing predicted LLD - critical for decision

✗Not emphasizing foot-based decision - key principle

LIKELY FOLLOW-UPS

"What if the family prefers reconstruction despite Type 2?"

"How do you preserve the heel pad in Syme amputation?"

"What are the functional outcomes of Syme vs reconstruction?"

VIVA SCENARIOChallenging

Scenario 2: Type 1 Reconstruction

EXAMINER

"A 2-year-old child with fibular hemimelia has a hypoplastic fibula (Type IA), foot with 4 functional rays (Type 1), predicted LLD of 12cm, and moderate ankle valgus (20 degrees). The family prefers reconstruction over amputation. What is your treatment plan?"

EXCEPTIONAL ANSWER

This is Achterman-Kalamchi Type IA with Birch Type 1 (4 foot rays, preservable foot) - a candidate for reconstruction. I would develop a comprehensive, staged treatment plan: First stage (age 1-2 years): Foot centralization with supramalleolar osteotomy to correct the 20-degree ankle valgus, foot repositioning to centralize under tibia, and lateral column shortening (calcaneocuboid fusion) if needed. Second stage (age 6-8 years): Begin lengthening program with external fixator or lengthening nail, planning for 2-3 lengthenings of 4-6cm each to address the 12cm predicted LLD. Each lengthening requires 1mm/day distraction, aggressive physical therapy to prevent stiffness, and 2-3 months consolidation per cm. Third stage: Additional lengthenings as needed, with possible epiphysiodesis of contralateral leg if LLD still significant. Fourth stage: Ankle stabilization (fusion or ligament reconstruction) if instability develops. Long-term: AFO bracing for ankle support. I would counsel the family that this is a 10-15 year treatment course, that multiple surgeries are needed, that complications are common (infection 20-30%, stiffness, contractures), that residual LLD of 2-5cm is common, and that ankle problems may persist. I would also discuss that Syme amputation is an alternative with better function in some cases, but respect their preference for reconstruction.

KEY POINTS TO SCORE

Recognize Type 1 (foot preservable, 4 rays)

Staged reconstruction: foot centralization, then lengthenings

Multiple lengthenings needed (2-3, each 4-6cm)

Long treatment course (10-15 years)

Realistic expectations about complications and outcomes

COMMON TRAPS

✗Not planning multiple lengthenings - 12cm LLD needs 2-3 lengthenings

✗Missing foot centralization - essential first step

✗Unrealistic expectations - must discuss complications and long course

LIKELY FOLLOW-UPS

"What if the first lengthening fails?"

"How do you prevent ankle stiffness during lengthening?"

"When would you abandon reconstruction and consider amputation?"

VIVA SCENARIOCritical

Scenario 3: Syme Amputation Technique

EXAMINER

"You have decided to perform a Syme amputation for a 2-year-old with Type 2 fibular hemimelia. Describe the key technical steps and how you preserve the heel pad for end weight-bearing."

EXCEPTIONAL ANSWER

Syme amputation is the appropriate choice for Type 2 fibular hemimelia. I would perform the procedure with careful attention to heel pad preservation: First, incision design - I would make a transverse incision across the anterior ankle just above the joint line, then extend plantarly in a racquet fashion to encompass the entire plantar heel pad. This design preserves the thick, durable heel pad which is essential for end weight-bearing. Second, dissection - I would carefully identify and divide nerves high to prevent neuroma formation: sural nerve (lateral), saphenous nerve (medial), deep peroneal nerve (anterior), and tibial nerve (posterior). I would ligate the posterior tibial and anterior tibial arteries, and divide all tendons. Third, disarticulation - I would disarticulate the ankle joint, remove the foot, resect the medial malleolus flush with the tibial shaft, and smooth the tibial end. Fourth, and most critical - heel pad preservation: I would carefully preserve the plantar heel pad with its blood supply from branches of the posterior tibial artery. The heel pad must remain vascularized and attached. I would fix the heel pad centrally to the tibia using non-absorbable sutures passed through drill holes in the tibia, ensuring it is centered and will not migrate. Fifth, closure - I would close the wound without tension, ensuring the heel pad is well-positioned. The key to success is preserving the vascularized heel pad and securing it centrally to the tibia - this allows end weight-bearing and excellent prosthetic function, which is the advantage of Syme over below-knee amputation.

KEY POINTS TO SCORE

Incision design: transverse anterior + plantar extension (racquet)

Divide nerves high (prevent neuroma)

Preserve heel pad with posterior tibial artery branches

Fix heel pad centrally to tibia (drill holes, sutures)

End weight-bearing capability is key advantage

COMMON TRAPS

✗Not preserving heel pad vascularity - will fail

✗Not fixing heel pad to tibia - will migrate

✗Dividing nerves too low - causes neuroma

LIKELY FOLLOW-UPS

"What if the heel pad becomes ischemic?"

"How do you prevent heel pad migration?"

"What are the advantages of Syme over below-knee amputation?"

MCQ Practice Points

Treatment Decision Question

Q: What is the most important factor in determining treatment for fibular hemimelia - amputation vs reconstruction? A: Foot preservability (number of functional rays), NOT fibula length - this is the key principle. Under 3 foot rays (Type 2) = usually Syme amputation. 4-5 foot rays (Type 1) = reconstruction possible. The decision is based on the foot, not the fibula.

Classification Question

Q: What is the Achterman-Kalamchi Type II fibular hemimelia? A: Complete absence of fibula with foot having 0-3 rays - this is the most severe form. Treatment is usually Syme amputation, as reconstruction is complex and often has inferior outcomes compared to amputation in these severe cases.

Syme Indication Question

Q: What are the indications for Syme amputation in fibular hemimelia? A: Predicted LLD over 30-40cm, foot with under 3 functional rays (Type 2), severe ankle valgus over 30 degrees, and family acceptance - Syme amputation provides better function than complex reconstruction in severe cases and is the standard treatment for Type 2 fibular hemimelia.

Reconstruction Question

Q: How many lengthening procedures are typically needed for fibular hemimelia reconstruction? A: 2-4 lengthenings, each achieving 4-8cm - reconstruction requires multiple staged lengthenings starting at age 6-8 years. Each lengthening takes 2-3 months per cm for consolidation. Total treatment course is 10-15 years with significant complication rates.

Associated Anomaly Question

Q: What percentage of fibular hemimelia cases are associated with proximal femoral focal deficiency (PFFD)? A: 50% - fibular hemimelia and PFFD are commonly associated. Always assess the hip when evaluating fibular hemimelia. Other common associations include anteromedial tibial bowing, tarsal coalition, equinovalgus foot, and cruciate ligament deficiency.

Australian Context and Medicolegal Considerations

Healthcare System:

Fibular hemimelia management requires specialized pediatric orthopedic centers
Syme amputation and reconstruction both available
Public hospital system provides comprehensive care
Multidisciplinary teams available (orthopedics, prosthetics, psychology)

Multidisciplinary Care:

Pediatric orthopedic surgeon (primary)
Prosthetist (for Syme amputation cases)
Physiotherapist (critical for reconstruction rehabilitation)
Occupational therapist (activities of daily living)
Psychologist (support for child and family)
Social worker (financial and social support)

Medicolegal Considerations:

Informed consent critical - major decision (amputation vs reconstruction)
Shared decision making essential - no "wrong" choice
Realistic expectations about outcomes and complications
Documentation of foot assessment (ray count)
Family counseling about both options
Long-term follow-up until skeletal maturity

Prosthetic Services:

Available through public and private providers
Regular adjustments needed as child grows
Functional prostheses for activities and sports
High-quality prostheses available

Research and Outcomes:

Australian centers contribute to international research
Registry data helps track long-term outcomes
Quality of life studies important for treatment decisions