- See:
Osteochondral Frx
- Discussion:
- type of osteochondral frx of the patella which results from high impact jumping activities
- mechanism: eccentric contraction of the quadriceps on the flexed knee;
- occurs when the inferior pole of the patella of a child or adolescent is pulled off
together with a large amount of articular cartilage and retinaculum;
- superior fragment (devoid of cartilage) is pulled superiorly;
- diff dx:
-
Bipartite patella
-
Sindig-Larsen-Johanssen disease
- Exam:
-
hemarthrosis:
- local pain & tenderness
- extension lag (inability to fully extend the knee actively);
- Radiographs:
- the small bone fragment will suggest the diagnosis, but it can be difficult
to see on standard radiographs;
- high-riding patella in comparison with contralateral side;
- MRI: study of choice to confirm the dianosis;
- Treatment:
- these injuries require surgical intervention w/ anatomical reduction and rigid internal fixation
of the patellar frx and the sleeve of articular fracture;
Houghton G, Ackroyd C: Sleeve
fractures of the patella in children.
J
Bone Joint Surg 1979;61B:165-168.
Avulsion fractures of the patella.
Partial sleeve fractures of the tibia in children: an unusual fracture pattern.
