Femoral avulsion fracture of the posterior cruciate ligament in association with a rupture of the popliteal artery in a 9-year-old boy: a case report

Abstract

Ruptures of the posterior cruciate ligament (PCL) and especially proximal bony avulsion fractures in children are very rare. This in combination with a rupture of the popliteal artery is extremely rare. Thus, an exact incidence is not available from the literature. Overall, these injuries are severe and often lead to chronic knee instability. We report a case of a 9-year-old boy who suffered a traumatic displacement of the left knee with a rupture of the popliteal artery. Prior to transfer to our department, he was treated by a saphenous vein bypass graft and by a transfixation of the knee using two oblique percutaneous pins. We performed magnetic resonance imaging (MRI) scan of the knee which revealed a femoral avulsion fracture of the PCL. Other ligaments and menisci were intact. A transosseous femoral fixation using non-absorbable stitches was carried out. A 1-year follow-up after surgery demonstrates intact peripheral perfusion and sensation, straight axes of both legs and a physiological gait. Minimal differences of the length and circumference of both legs could be measured. The posterior laxity (Lachman-test) was about 5/8 mm (right/left knee) and 2/5 mm (right/left knee) in 90 degrees flexion. The range of motion (extension/flexion) was 5/0/140 degrees -/5/100 degrees (right-left knee). Intact cruciate ligaments were confirmed by MRI. Minimal experience exists in treatment of combined injuries to the PCL and the popliteal artery in children.

Pediatric PCL Insufficiency from Tibial Insertion Osteochondral Avulsions

“…Furthermore, the relative weakness of the physis and bone in comparison to the ligament more commonly results in osteochondral avulsions rather than ligamentous substance tears as seen in adults [2,6,9,13,19,21,22,[26][27][28]. However, femoral avulsions of the PCL are reported more frequently than those of the tibial insertion site in children [10,12,13,19,21,25,26,28] (Table 1), and clinicians may not be as aware of the specific history, physical examination, and radiographic findings of these tibial-sided injuries as compared with those of the femur such as the need for specific imaging.…”

Case Report: Osteochondral Avulsion Fracture of the Posteromedial Bundle of the PCL in Knee Hyperflexion

“…After a comprehensive search, we found 11 cases of PCL avulsion fractures of femoral origin in adolescents in the literature [6,14,15,21,27]. In contrast, only four cases of PCL avulsions of femoral origin have been reported in adults [8,17,22,23] (Table 1).…”

“…Three of the five patients had involvement of only the lateral cortex of the medial femoral condyle and the other two had osteochondral avulsions (Table 1). Damages from PCL avulsions include medial collateral ligament avulsion [22,23], ACL avulsion [22,23], capsule rupture [8], and possible vascular or nerve injury [14], especially in a dislocated knee. Hesse et al [14] reported a femoral avulsion fracture of the PCL was associated with rupture of the popliteal artery in a 9-year-old boy.…”

“…Avulsion fracture of the PCL with a femoral origin in adults has not been reported often. We performed a comprehensive literature search and found most cases of avulsion of the PCL with femoral origin were reported in adolescents [6,14,15,19,21,27]. In contrast we found only four reported cases in adults [8,17,22,24].…”

The effect of posterior cruciate ligament deficiency on knee laxity

“…Different degrees of PCL injury result in varied laxity of the PCL, and the degree of laxity is an important clinical reference for treatment choices for PCL injury patients (Adachi et al, 2003;Doberstein et al, 1997;Logan et al, 2004;Wang et al, 2002;Hesse et al, 2006). To the authors' knowledge, only a few studies have quantified tibiofemoral laxity in knees with different PCL injuries.…”