Association between patella spurs and quadriceps tendon ruptures

Abstract

Background: quadriceps tendon (QT) ruptures are significant injuries that are relatively uncommon. The diagnosis of QT ruptures is frequently missed or delayed. An association between the presence of a patella spur and QT ruptures has been suggested in the literature.

Patients and methods: the Hospital Inpatient Enquiry system was used to gather data on all patients who sustained a QT rupture over a six year period from 2008 to 2014. A retrospective review of the medical notes as well as radiographs was undertaken. We reviewed 200 knee radiographs of patients without QT ruptures to establish the incidence of patella spurs in our normal population. Statistical analysis was performed using SPSS version 11.5 for Windows(®).

Results: the records of 20 consecutive patients with 21 QT ruptures were reviewed. The mean age was 60.9 yrs (range 44.9-82.1 yrs) and the majority were male (n=17; 85%). There was one bilateral QT ruptures. Patella spurs were noted in 13 cases (62%) which were significantly higher than in patients without QT rupture 19% (P≤0.05).

Conclusion: we noted a significantly higher incidence of patella spurs in patients with QT ruptures compared to those without. The presence of a QT rupture should be ruled out in patients with a knee injury and a patella spur on the knee radiographs.

Keywords: injury; knee; patella spur; quadriceps tendon; ruptures.

Figure 1

Lateral radiograph of a knee demonstrating a proximal patellar pole spur (white arrow).

Figure 2

Lateral radiograph of a knee with a quadriceps tendon rupture demonstrating a low lying patella (patella baja), suprapatella calcific density (dashed arrow) and obliteration of the quadriceps tendon shadow and haematoma (solid arrow).

Figure 3

Magnetic resonance imaging (T1 and T2 weighted sagittal views) of the knee illustrating a ruptured QT (solid arrows) and a large haematoma (dashed arrow).