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First-time traumatic lateral patellar dislocation — MSRA MCQ

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HardKnee InjuriesFirst-time traumatic lateral patellar dislocationMSRA

A 20-year-old woman attends general practice 8 days after a first episode of traumatic lateral patellar dislocation while pivoting during netball. The patella spontaneously reduced before she reached the emergency department. Initial AP, lateral and skyline radiographs showed no osteochondral fracture or loose body. Pain and swelling have improved. She can walk independently and manage activities of daily living with mild discomfort. Examination shows a small effusion, medial peripatellar tenderness and residual apprehension with lateral patellar translation. She can perform a straight-leg raise, actively extends fully and flexes to 120 degrees. There is no joint-line tenderness, true locking, cruciate or collateral laxity, neurovascular deficit, or recurrent dislocation. What is the most appropriate management now?

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Correct answer: E — Refer to MSK physiotherapy for progressive quadriceps and lower-limb rehabilitation with early mobilisation

Explanation lettering: B = shown as A · A = shown as B · E = shown as C · C = shown as E

This is a first-time traumatic patellar dislocation that has reduced, with radiographs excluding an osteochondral fracture or loose body. She has intact extensor mechanism function (straight-leg raise and full active extension), improving symptoms, functional mobility and no true locking. These features support non-operative rehabilitation rather than urgent imaging or surgery. Referral for progressive physiotherapy focusing on quadriceps activation and lower-limb control is therefore appropriate. Early mobilisation is important; any brace or crutches should be used only briefly for comfort and confidence rather than as prolonged immobilisation. A is inappropriate because immediate stabilisation surgery is not routine after a single uncomplicated episode; orthopaedic assessment becomes more relevant with recurrent instability or failure to progress with rehabilitation. B is attractive because haemarthrosis after patellar dislocation can indicate osteochondral injury, but this has already been assessed with appropriate radiographs and there is no locking or persistent major functional deficit to justify urgent MRI. D risks stiffness and quadriceps inhibition; prolonged immobilisation is not indicated in a recovering, reduced dislocation. E is not indicated without radiographic evidence of an intra-articular fragment or mechanical symptoms suggesting a loose body.

Reference: Patellar Instability (Current page; next review date 2 July 2027) — https://www.rightdecisions.scot.nhs.uk/nhs-tayside-refguide/surgery-and-orthopaedics/orthopaedic-and-trauma-surgery/knee/patellar-instability/?UNLID=&useNavigation=true Patellofemoral instability (Current page; crawled 2026) — https://www.rightdecisions.scot.nhs.uk/ggc-msk-index/knee/patellofemoral-instability/