Clinical Scorecard: Letter to the Editor: Superior Wall Fractures of the Acetabulum as a Distinct Fracture Type

At a Glance

Key Highlights

• A 16-year multicenter analysis identified 9 superior acetabular-region avulsions at the reflected-head origin among pediatric pelvic avulsion fractures.
• All 9 patients were treated conservatively because displacement did not exceed 1 cm; no complications, non-union, or post-traumatic femoroacetabular impingement occurred in this small series.
• Clinical findings and plain radiography are used for diagnosis; for an initially nondisplaced avulsion projecting at the superior acetabular margin, native hip MRI demonstrates the avulsion and can identify concomitant labral injury.
• The authors state that MRI should be selected in preference to low-dose CT in pediatric patients.
• Combined pelvic-ring and superior acetabular-wall injuries are described as extremely uncommon in children; none occurred in the reported group.

Guideline-Based Recommendations

Diagnosis

• The authors describe clinical findings and plain radiographs as part of assessment for reflected-head avulsion fractures.
• For an initially nondisplaced avulsion projecting at the superior acetabular margin, the authors perform native hip MRI to demonstrate the avulsion and identify any concomitant intra-articular labral injury.
• The authors state that MRI should be selected in preference to low-dose CT in pediatric patients.

Management

• All 9 patients in the reported series were treated conservatively because displacement did not exceed 1 cm.
• The letter notes earlier recommendations for open reduction and screw fixation through a limited Smith-Petersen approach when reflected-head avulsion displacement exceeded 1 cm; the procedure was comparatively frequently followed by paraarticular calcifications and lateral femoral cutaneous nerve neuropathy.
• The letter describes an endoscopic stabilization method for fractures involving anterior inferior iliac spine and reflected-head avulsions. It reports fewer paraarticular calcifications and lateral femoral cutaneous nerve lesions; the principal advantage is the ability to treat a labral lesion concomitantly when required, while the stabilization technique has a longer learning curve.

Monitoring & Follow-up

• MRI can identify concomitant intra-articular labral injury.
• The letter reports no complications, non-union, or post-traumatic femoroacetabular impingement among the 9 isolated reflected-head avulsions in its series.

Risks

• Open reduction and screw fixation through the Smith-Petersen approach was comparatively frequently followed by paraarticular calcifications and lateral femoral cutaneous nerve neuropathy.
• The letter states that post-traumatic femoroacetabular impingement is generally linked to dislocated avulsions exceeding 1.5 cm.
• The endoscopic stabilization technique has a longer learning curve.

Patient & Prescribing Data

The multicenter analysis followed pediatric pelvic avulsion fractures over 16 years and identified 9 superior acetabular-region reflected-head avulsions. The patients participated in football (4), running (3), and other sports (2).

All 9 reflected-head avulsions were treated conservatively because displacement did not exceed 1 cm. The letter also describes earlier open fixation recommendations for displacement greater than 1 cm and a more recently described endoscopic stabilization method.

Clinical Best Practices

• The authors distinguish reflected-head avulsions from anterior inferior iliac spine avulsions because their mechanisms differ.
• For an initially nondisplaced avulsion projecting at the superior acetabular margin, the authors describe native hip MRI to assess the avulsion and any labral injury.
• The authors state that MRI should be selected in preference to low-dose CT in pediatric patients.
• The letter describes complications associated with open fixation and a longer learning curve for endoscopic stabilization.

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