Clinics in diagnostic imaging (196). Complete PCL tear

A 21-year-old man presented with left knee pain and instability that persisted three months after a road traffic accident. Physical examination revealed a positive posterior drawer test. Anterior drawer and pivot tests were negative. Magnetic resonance imaging of the knee demonstrated a complete tear of the posterior cruciate ligament (PCL). Recognition of the normal and injured appearances of the PCL is useful to aid the reader in the detection and characterisation of PCL injuries. Isolated acute PCL tears are usually managed conservatively. However, an active search for associated injuries is essential, as their presence may upstage the patients for surgical management.

Clinics in diagnostic imaging (185)

A 20-year-old National Serviceman presented with left knee pain and swelling after training for his physical fitness test. Lateral knee radiography and magnetic resonance (MR) imaging showed patellar tendon-lateral femoral condyle friction syndrome (PT-LFCFS), on a background of patella alta and patellar malalignment. The patient was treated non-operatively with a course of physiotherapy and given advice on rest and activity modification. PT-LFCFS is a less well-recognised but important cause of anterior knee pain and represents an entity in a spectrum of disorders related to patellofemoral instability. We herein discuss the MR imaging findings specific to and associated with this condition, as well as briefly describing treatment options. In addition, we showcase a range of commonly encountered abnormalities that affect the infrapatellar fat pad and briefly discuss their specific MR imaging findings.

Clinics in diagnostic imaging (177). Medical meniscus bucket-handle tear with medial oblique meniscomeniscal ligament

A 29-year-old man with a previous football injury to his left knee presented with pain of the same knee. The patient twisted it as he was turning a corner quickly while going up the stairs, leading to internal rotation of his femur on his tibia with his knee in flexion. MR imaging revealed a bucket-handle tear of the medial meniscus, as well as a complete tear of the anterior cruciate ligament. However, image interpretation was complicated by the presence of a medial oblique meniscomeniscal ligament, a rare normal variant among intermeniscal ligaments of the knee. All four recognised variants of intermeniscal ligaments are discussed, with emphasis on their prevalence, imaging and anatomical features, and the way in which they may mimic meniscal tears.

You can never have too many accessories - a case of two accessory muscles of the ankle

Accessory muscles are relatively rare anatomic duplications of muscles that may appear anywhere in the muscular system. Though a wide array of accessory and supernumery muscles involving the ankle have been described in the literature, this is the first reported case we are aware of that features two accessory muscles. Accessory muscles are typically asymptomatic and often picked up as incidental findings but are important to be identified in the presence of chronic persistent ankle pain and the absence of other more common aetiologies.