Can a bladder contusion (bladder injury) occur in an elderly patient with potential underlying medical conditions, who fell and hit their right buttock, but not directly on the abdomen, and is now experiencing transient and reversible bladder dysfunction, including urinary retention or incontinence?

Bladder Injury Can Occur from Buttock Trauma Without Direct Abdominal Impact

Yes, bladder contusion and dysfunction can absolutely occur from a fall onto the buttock, even without direct frontal or abdominal trauma, through two primary mechanisms: sacral fracture causing nerve root injury and indirect force transmission to the pelvic structures.

Mechanism of Injury from Buttock Trauma

Sacral Fracture with Nerve Root Injury

• Sacral fractures from simple falls can cause bilateral traction of the S2-S3 nerve roots, producing transient bladder paralysis through parasympathetic fiber injury and incomplete sphincter dysfunction through somatic fiber injury 1
• Sacral fractures are of particularly high clinical suspicion for urinary retention in elderly patients because they commonly result from simple falls, not just high-energy trauma 1
• The S2-S3 nerve roots control bladder function, and their injury produces an acontractile detrusor (inability to contract the bladder) with neurogenic sphincter dysfunction 1

Indirect Force Transmission

• Falls causing pelvic trauma can result in bladder injury through force transmission even without direct anterior impact, particularly when associated with pelvic ring fractures 2
• Bladder contusion is actually the most common type of bladder injury following blunt trauma and represents a diagnosis of exclusion 3
• The World Journal of Emergency Surgery guidelines explicitly state that entrance/exit wounds in the buttocks are indicators warranting bladder injury evaluation, confirming that posterior trauma mechanisms can cause bladder pathology 4

Clinical Presentation Matches Transient Neurogenic Dysfunction

Expected Findings

• The combination of urinary retention or incontinence following a fall onto the buttock is consistent with transient neurogenic bladder dysfunction secondary to sacral nerve root injury 1
• The American Geriatrics Society recommends considering falls as a cause of reversible factors affecting bladder function, including direct trauma and temporary neurological dysfunction 5
• Patients typically present with difficulty voiding, inability to void, or urinary retention following the traumatic event 3

Prognosis for Recovery

• Bladder contusions require no specific treatment and represent reversible injuries that typically resolve spontaneously 5
• In documented cases of sacral fracture with nerve root injury, patients gradually regain the ability to urinate, though recovery may take several months 1
• The World Journal of Emergency Surgery confirms that bladder contusions are self-limited and require only clinical observation as primary management 5

Diagnostic Approach for This Clinical Scenario

Initial Evaluation

• Perform focused physical examination looking for suprapubic tenderness, perineal/genital ecchymosis, and pelvic fracture signs, particularly over the sacrum and coccyx 5
• Obtain post-void residual (PVR) assessment to distinguish between storage and emptying dysfunction 6
• Check for gross hematuria, which is present in 77-100% of bladder injuries but may be absent in contusions 5

Imaging Studies

• Obtain lateral sacral X-ray to evaluate for sacral fracture, as this is the most likely mechanism in elderly patients falling onto the buttock 1
• If persistent hematuria, inability to void, or suprapubic tenderness is present, perform retrograde cystography (CT or conventional) to definitively exclude bladder rupture 5
• Urinalysis should be obtained to exclude urinary tract infection as a contributing or complicating factor 5

Management Strategy

• If bladder contusion is confirmed without rupture, clinical observation is the primary management approach 5
• Initiate intermittent catheterization every 4-6 hours if PVR >100-200 mL to prevent bladder overdistension beyond 500 mL 5
• Monitor for spontaneous resolution over weeks to months, as transient neurogenic dysfunction from sacral nerve root injury typically recovers gradually 1

Critical Pitfall to Avoid

Do not assume that bladder injury requires direct anterior or abdominal trauma—posterior impact mechanisms through sacral fracture and nerve root injury are well-documented causes of bladder dysfunction in elderly patients with falls 1. The absence of frontal impact does not exclude bladder pathology, and the clinical presentation of urinary retention or incontinence following buttock trauma warrants full evaluation for both structural bladder injury and neurogenic dysfunction 4, 5.