Sleeve fractures of the patella in children: a report of three cases

Abstract

The clinical characteristics of sleeve fractures of the patella are described and the methods of treatment are reviewed. Attention is drawn to the fact that the diagnosis may be missed because the distal bony fragment may be so small as not to be detectable by radiography. This is important because a large fragment of articular cartilage also separates. The best result was obtained from reconstitution of the extensor apparatus by internal fixation of the patellar fracture with repair of the quadriceps expansion.

Fratura na patela em crianças (fraturas do tipo "sleeve")

“…Sleeve-type patellar fractures occur in children participating in activities requiring knee extension force with quadriceps contraction against resistance, with injury occurring on the supportive leg. Therefore, this injury is not like those caused by direct trauma on the knee (3) . Grogan et al (2) classified patellar fractures in children according to their sites.…”

“…Congenital abnormalities may be confused with fractures (8,9) , and the size of the fragments, particularly in sleeve-type fractures may be underestimated in children due to the partiallycartilaginous nature of the patella (3) . Belman and Neviaser (1) noticed that the lack of diagnosis or a late diagnosis is common for patellar fractures in children.…”

“…Patellar fractures in children are rare (1)(2)(3)(4)(5) , but, when present, affect patients younger than 16 years old. Its incidence occurs especially between 8 and 12 years of age (5) in less than 2% of patients with immature skeleton (6) .…”

“…Those fractures can be caused by direct trauma, excessive contraction of the extensor mechanism, or by both. Houghton and Ackroyd (3) , in 1977, described an avulsion-type fracture of the distal end of the patella, in which a large amount of cartilage was withdrawn from the patella associated to a discreet bone fragment. Although diagnosis can be suggested by clinical and radiographic evaluation, this fracture may not be diagnosed, particularly if there is a large hemarthrosis on knee joint or if x-ray studies cannot clearly show the bone fragment distally withdrawn.…”

Anterior Knee Pain

“…In others, there is no doubt about the bipartite nature of the lower pole of the patella and in this context the sleeve fracture of the patella is a fascinating entity. 12 Perhaps patients with a bipartite lower pole with its characteristic appearance are at high risk of sustaining a fracture (Fig. 2).…”