title: Acute calcific periarthiritis of the knee presenting with calcification within the lateral collateral ligament.
abstract: A 71-year-old woman was admitted with acute swelling of the right knee, pain on the lateral aspect and restricted movement. There was no instability or locking. She had no history of trauma and was generally in good health. Plain radiographs demonstrated a calcific opacity adjacent to the lateral femoral condyle. This was shown to be within the lateral collateral ligament (LCL) at ultrasound and MRI. A diagnosis of acute calcific periarthritis (ACP) was made. The patient's symptoms resolved within a few weeks with simple analgaesia. ACP presenting with calcification within the LCL is rare. It is important to recognise the clinical and imaging findings of this condition as it may mimic other more serious pathologies such as infection and gout. This may result in unnecessary investigations, misdiagnoses and incorrect treatments.
authors.affiliation: North Bristol NHS Trust, Bristol, UK.
authors.forename: Karen
authors.initials: K
authors.lastname: Watura
authors.affiliation: University of Birmingham, Birmingham, UK.
authors.forename: Davyd
authors.initials: D
authors.lastname: Greenish
authors.affiliation: Department of Radiology, North Bristol NHS Trust, Bristol, UK.
authors.forename: Martin
authors.initials: M
authors.lastname: Williams
authors.affiliation: Department of Trauma and Orthopaedic Surgery, North Bristol NHS Trust, Bristol, UK.
authors.forename: Jason
authors.initials: J
authors.lastname: Webb
mesh_terms: D000082:Acetaminophen / Q000627:therapeutic use*; D059787:Acute Pain / Q000209:etiology*; D000368:Aged; D000698:Analgesia; D002114:Calcinosis / Q000150:complications / Q000175:diagnosis* / Q000188:drug therapy; D003061:Codeine / Q000627:therapeutic use*; D017885:Collateral Ligaments / Q000473:pathology*; D004338:Drug Combinations; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007719:Knee Joint / Q000473:pathology*; D016896:Treatment Outcome; D016474:Weight-Bearing
chemical_list: D004338:Drug Combinations; C526278:acetaminophen, codeine drug combination; D000082:Acetaminophen; D003061:Codeine