Date Published: February 8, 2011
Publisher: SAGE-Hindawi Access to Research
Author(s): Stephen Paul Guy, Jan Luigi Marciniak, Nirmal Tulwa, Andrew Cohen.
The initial diagnosis of a sleeve fracture of the patella is key to a successful outcome with poor results well documented in the literature from delayed management. Diagnosis is difficult due to the rarity of this injury and thus the low likelihood the admitting junior doctor would think of this injury in their differential. They are very uncommon in incidence and have features on plain radiography that are difficult to interpret unless the surgeon is familiar with the anatomy of the immature patella. Missing the diagnosis can be disastrous for the patient. In this paper we describe the presentation of bilateral sleeve fractures in a healthy child, our initial investigations and subsequent management. We chose to repair with 5 Ethibond via 3 transosseous tunnels, initially reinforced with a circlage wire. On last review the boy maintains stable, pain-free knees with a full range of motion. The authors hope that this case and literature review will provide a valuable teaching aid and so assist in early, accurate diagnosis and cover the management options to achieve a positive outcome.
Bilateral sleeve fractures of the patella are rare. This is the second example in English literature of this occurring in a healthy child. Often the radiological findings are overlooked due to the cartilaginous injury being far larger than the fleck of bone avulsed. An unfortunate and frequent problem encountered with sleeve fractures is the timing of the diagnosis. Delay can result in suboptimal management and outcome. We have written up this paper primarily as an interesting case report and literature review but principally to draw attention to the difficulties of diagnosis and treatment of this condition.
A healthy 11-year-old boy landed on his trampoline and complained immediately to his parents of bilateral knee pain. He was jumping vertically straight up and down at the time and no other person was on the trampoline. He had no significant past medical, drug, or family histories. He specifically had no history of anterior knee pain nor was he hypermobile (Beighton score 0). He attended hospital with bilateral knee pain with significant effusions, the left being larger clinically than the right (Figure 1). Radiographs of the knees were suspicious of sleeve fractures (Figures 2(a)–2(d)) and an MRI of both knees was organised. The MRI clearly revealed the extent of the displaced sleeve fractures (Figure 3).
Sleeve fractures are a type of paediatric avulsion fracture and were first described by Houghton and Ackroyd in 1979 . A sleeve fracture is defined as an avulsion of a small bony fragment from the distal pole of the patella, along with its articular cartilage, periosteum, and retinaculum, which is pulled off from the main body of the structure . Avulsion fractures can be classified too according to their location . Patellar fractures in the skeletally immature are rare with an incidence of 1–6.5% of all fractures; of these only 5% occur at either pole as an avulsion fracture [2, 4, 5]. The greatest challenge of management is in the initial diagnosis.