Focused examination of the child's hip for slipped upper femoral epiphysis (SUFE) and Perthes disease including Drehmann sign, internal rotation assessment, and gait analysis.
The child with a painful limp requires careful hip examination. Examiners expect you to recognize the classic findings of SUFE (obligate external rotation with flexion - Drehmann sign) and Perthes disease (limited abduction and internal rotation), and understand the importance of always examining both hips.
High-Yield Exam Summary
Slipped Upper Femoral Epiphysis:
Demographics:
Presentation:
Risk Factors:
Critical Point - Knee Pain: Hip pathology (especially SUFE) commonly presents with KNEE pain. Always examine the hip in any child with knee pain!
Clinical Rule: "A limping child with normal knee = hip problem until proven otherwise"
SUFE Gait:
Perthes Gait:
Observation (Supine):
Key Points:
Normal Paediatric Hip ROM:
Pattern in SUFE:
Pattern in Perthes:
Pathognomonic for SUFE
Hip obligatorily externally rotates as it flexes (patient cannot internally rotate while flexed)
SUFE - femoral head is posteroinferior to neck, so flexion causes mechanical external rotation
Ability to detect true positives
Ability to exclude false positives
Understanding Drehmann Sign: In SUFE, the femoral epiphysis slips posteroinferior relative to the neck. When you flex the hip:
Assess hip pathology (SUFE, Perthes, septic)
Marked reduction or loss of internal rotation compared to opposite side
Hip pathology. In SUFE: often less than 10°. In Perthes: usually 20-30° (less dramatic loss)
Ability to detect true positives
Ability to exclude false positives
Hip joint irritability
Pain, guarding, or muscle spasm with gentle rotation
Hip joint irritability (any intra-articular pathology: infection, Perthes, SUFE, transient synovitis)
Ability to detect true positives
Ability to exclude false positives
Abductor function
Pelvis drops on the unsupported (swing) side
Abductor weakness - common in Perthes due to pain inhibition and disease duration
Ability to detect true positives
Ability to exclude false positives
Hip containment assessment (Perthes)
Limited abduction compared to normal side
Hip adductor tightness/contracture (common in Perthes). Important for treatment planning - head containment requires adequate abduction
Ability to detect true positives
Ability to exclude false positives
Critical for Prognosis:
| Classification | Definition | AVN Risk |
|---|---|---|
| Stable | Able to weight bear (with or without crutches) | 0-10% |
| Unstable | Unable to weight bear (acute, severe pain) | 20-50% |
Unstable SUFE = Urgent Surgical Treatment
Severity (Southwick Angle):
Poor Prognosis (Head at Risk Signs):
Herring Lateral Pillar Classification:
| Group | Lateral Pillar Height | Prognosis |
|---|---|---|
| A | 100% (normal) | Good |
| B | Greater than 50% preserved | Intermediate |
| B/C border | 50% preserved | Guarded |
| C | Less than 50% preserved | Poor |
| condition | age | presentation | keySign | xray |
|---|---|---|---|---|
| SUFE | 10-15 years | Groin/knee pain, obese | Drehmann positive, loss of IR | Frog lateral shows slip |
| Perthes | 4-8 years | Limp, thin child | Loss of abduction/IR | Fragmented/flattened head |
| Transient Synovitis | 3-8 years | Post-viral, acute limp | Irritable hip, log roll + | Normal (may have effusion on US) |
| Septic Arthritis | Any | Unwell, fever, refuse weight bear | Unable to move, very irritable | May be normal (MRI/US) |
| DDH (Missed) | Any | Limp, short leg | Trendelenburg, positive Galeazzi | Dysplasia, subluxation |
Kocher Criteria (Septic vs Transient Synovitis):
0 criteria = less than 0.2% chance septic 4 criteria = 99% chance septic
If in doubt, aspirate the hip!
"13-year-old obese boy with 6-week history of left groin pain and limp. Initially thought to be growing pains."
"6-year-old boy with 3-month history of limp and occasional thigh pain. Small for his age."
High-Yield Exam Summary