Patellar pubic percussion test

Key takeaways

The patellar pubic percussion test screens for occult hip fractures by comparing how sound travels from each patella to the pubic symphysis.

A dull or absent sound on one side suggests a femoral neck or proximal femur fracture, so order imaging straight away.

Reported sensitivity runs from 75% to 96% and specificity from 70% to 90%, depending on the population studied.

A negative result never rules a fracture out, so keep imaging on the table when clinical suspicion stays high.

Practice management software like Pabau keeps the percussion finding, the imaging referral, and the follow-up note in one patient record.

An occult hip fracture can hide behind a clean X-ray while the patient keeps limping. The patellar pubic percussion test gives you a second read at the bedside, using a stethoscope and a reflex hammer. Both sit in most exam rooms already.

This guide covers the technique step by step, how to read the sound difference, and what the published accuracy figures support. It also compares the test with the other hip fracture exams used in emergency departments and physical therapy practices.

What is the patellar pubic percussion test?

The patellar pubic percussion test is a bedside assessment for stress fractures and occult fractures of the femoral neck and proximal femur.

The examiner rests a stethoscope over the pubic symphysis and taps one patella with a reflex hammer or a finger. Tapping the other patella gives the comparison. A dull or absent sound on one side points to a fracture interrupting bone conduction.

Intact bone carries vibration efficiently from the patella through the femur to the pelvis. A fracture line interrupts that path, so the sound arriving at the stethoscope loses volume and clarity. The asymmetry is what you are listening for, which is why both sides always get tested.

That makes the test useful wherever imaging is slow to arrive, including emergency departments, acute care units, and physical therapy or sports medicine practices.

When to use the test

Reach for it in these situations:

• Acute hip pain after a fall, especially in older patients or anyone with osteoporosis risk factors.
• Suspected femoral neck stress fracture in an athlete with insidious groin or hip pain.
• Strong clinical suspicion of fracture despite a negative or inconclusive X-ray.
• Post-fall screening in geriatric patients at high risk of hip fracture complications.
• Bedside assessment during emergency evaluation when imaging is not immediately available.
• Teaching orthopedic examination technique to physical therapy students and residents.

The test earns its keep where imaging is slow, queued, or already read as normal. A positive result still sends the patient for confirmatory imaging, whether that is MRI, CT, or repeat radiographs with specialized views.

Equipment required

The kit list is short, which is most of the appeal:

• Stethoscope: A standard acoustic stethoscope works. Check that the earpieces seal and the tubing is intact.
• Percussion instrument: A reflex hammer is traditional, though firm, controlled taps with a finger work just as well.
• Examination table: Any firm surface where the patient can lie supine comfortably.
• Quiet room: Background noise masks the subtle sound difference you are trying to hear.

How to perform the test step by step

Follow the same sequence every time, so your results stay comparable between patients:

1. Position the patient supine: Have them lie flat, with the legs extended and relaxed.
2. Expose the pelvis: Uncover the lower abdomen and hips so you can reach both patellae and the pubic symphysis.
3. Find the pubic symphysis: Palpate the midline bony prominence above the pubic area and note its position.
4. Place the stethoscope: Hold the diaphragm against the pubic symphysis with firm skin contact.
5. Percuss the first patella: Tap the center of the patella two or three times, then listen to the sound quality.
6. Note what you hear: Decide whether the sound is clear, muted, diminished, or absent. A normal side gives a crisp percussion note.
7. Repeat on the other side: Keep the stethoscope over the pubic symphysis and percuss the opposite patella with the same force.
8. Compare the two: A duller sound on one side counts as a positive test.

Consistency decides the result. Vary your percussion force or shift the stethoscope between sides and you have measured your own technique rather than the patient’s femur. Practice on unaffected volunteers first.

Interpreting the results

A positive test means the sound arriving from one patella is quieter than the other. That side is where you suspect the fracture.

A positive result always prompts imaging. The test screens and triages, while the diagnosis comes from a radiograph, CT, or MRI. Femur fractures are then coded from the S72 family, where the seventh character records the encounter and healing status, as in S72.302C.

Diagnostic accuracy: sensitivity, specificity, and clinical utility

The evidence base is thinner than the confident numbers suggest. A published case report describes using the test to diagnose a nondisplaced hip fracture after unremarkable radiographs. It cites the largest prospective series, a study of 290 patients by Tiru and colleagues, which reported 96% sensitivity and 86% specificity.

Those figures support the test as a screen rather than a diagnosis. High sensitivity and positive predictive value make it good at flagging fractures that need urgent imaging. The moderate negative predictive value is the catch, since a negative result can still hide a fracture.

How it compares with other hip fracture tests

Several bedside tests compete for the same 30 seconds of an examination. Knowing where each one is strong helps you pick the right one for the setting. In acute trauma the percussion test sits inside a wider sequence, alongside the primary trauma survey and the imaging it triggers.

The percussion test wins on speed and equipment. Read alongside the mechanism of injury and the patient’s risk profile, it is often enough to justify urgent imaging. The fulcrum test, common in sports medicine, is more sensitive than specific. No bedside test replaces a radiograph.

Clinical limitations and considerations

The test has failure modes worth knowing before you lean on it:

• Operator variability: Accuracy depends on consistent percussion force, stethoscope placement, and careful side-to-side comparison.
• Patient factors: Pain, guarding, confusion, or sedation all compromise the comparison. Higher body mass can attenuate the sound.
• Ambient noise: A busy emergency department masks exactly the difference you are listening for.
• Equipment quality: Cracked tubing or a poorly sealing stethoscope produces unreliable sound.
• Not a diagnostic replacement: A positive result means probable fracture and nothing more. Imaging still decides.
• Older and frail patients: Bone quality, comorbidities, and limited mobility all affect how the test performs.

Record the percussion force, the stethoscope position, and what you heard on each side. The same clinical note habits that protect you elsewhere apply here, because an unrecorded equivocal result invites the next examiner to repeat the test blind.

How Pabau keeps percussion findings in the patient record

Right now the finding probably lives in a paper note or a free-text box. The imaging referral sits somewhere else, and the follow-up depends on someone remembering.

Practice management software like Pabau puts that sequence in one place. Build the test into a digital assessment form, so positioning, force, and the sound on each side land as structured fields. The result then writes straight into the patient’s clinical record.

From there, the referral, the imaging result, and the follow-up appointment attach to the same file. Anyone picking the patient up next can see what was heard, when, and what was done about it. Every Pabau subscription includes those features, so nothing here sits behind a higher tier.

Keep assessment findings in one patient record

Pabau’s digital forms and client records capture percussion findings, imaging referrals, and follow-up notes in a single file. Your team stops hunting for what was heard last week.

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Conclusion

Treat the percussion test as a triage decision rather than a diagnosis. A dull side moves the patient up the imaging queue, and on a busy shift that is the whole value.

The trade-off is the negative result. It is the least trustworthy thing the test produces, so equal sound with a suspicious history still needs a scan.

Standardize your technique, write down what you heard, and the test earns a place in your examination sequence. Book a demo to see how Pabau keeps assessment findings, referrals, and follow-ups in one patient record.

Continue your research

Building out your special-test library? Plantar fascia rupture test walks through another quick bedside screen with the same documentation demands.

Need the neurological half of the exam? Deep tendon reflex exam covers grading, technique, and what to record for each reflex.

Tracking how much the hip hurts? Numeric pain rating scale gives you a repeatable score to sit alongside the percussion finding.

Screening athletes before the season? Preparticipation physical evaluation form collects the history that flags stress fracture risk early.

Coding the fracture once imaging confirms it? S72.345C shows how the seventh character records the encounter and healing status.

Frequently asked questions