Superior Dislocation of the Patella: Case Report and Review of the Literature

Superior Patellar Dislocation Misdiagnosed as Patellar Tendon Rupture: The Value of Ultrasonography

“…Superior dislocation of the patella with intact patellar tendon is a rare condition, only 20 of which have been reported in English medical literature [1]. The first case was reported by Watson-Jones in 1956 [22].…”

“…Superior dislocation of the patella with intact patellar tendon is a rare condition [1]. The age group of the patient is between 45 and 80 years.…”

“…The age group of the patient is between 45 and 80 years. Most of them had preexisting degenerative joint [1–23]. Most cases in literature review were usually diagnosed by clinical examination and plain radiography.…”

Multiligamentous injuries and knee dislocations

“…Superior patellofemoral dislocations are extremely rare with approximately 20 cases reported in English literature. This dislocation can occur as the result of hyperextension or a direct blow to the lower aspect of the patella, and osteoarthritis may be a predisposing factor [42]. Radiographs may show a superiorly dislocated patella with interlocking of osteophytes between the inferior pole of the patella and anterior surface of the femur (Fig.…”

“…14b, c and 15d), which include injuries of the medial retinaculum or medial patellofemoral ligament (MPFL), Bkissing contusions^or an osteochondral injury of the inferomedial pole of the patella, and an impaction injury at the anterolateral aspect of the lateral femoral condyle including cartilage injuries [24,29,32,36]. The MPFL is injured in 94-100 % of cases with tearing more commonly at its femoral attachment [42]. Hemorrhage deep to the vastus medialis oblique (VMO) may cause uplifting of this muscle from the underlying medial femoral condyle and stripping from its femoral attachment [24,29].…”