A 66 year old presents to you with an acute left knee injury. He had been golfing and on follow through his left foot slipped and when he regained footing he felt a snap. He has had difficulty walking since. The pain is localized to his anterior knee superior to his patella.
He notes that it started swelling almost immediately.
He enters your clinic room, non-weightbearing using crutches from an old right ankle injury. There is a large suprapatellar effusion, warm to palpation. There does not appear to be a joint effusion on exam.
His patella is tender superiorly as is his quadriceps tendon.
His ligamentous examination is normal. When passively flexing his knee slowly he notes severe pain anteriorly over his distal quadriceps. However once you stop any passive movement it goes away. He is able to help you flex his knee. However when you ask him to extend his knee by straight leg raise, there is a 20 degree lag (he lacks 20 degrees of extension compared to the ipsilateral leg) as he lifts his left foot off the bed.
Xray: Avulsion of superior patella along with retraction proximally of fragment.
Figure 1 – Xray Lateral of left knee
Figure 2 – Xray Lateral hilighting avulsion of patella and retraction from patella.
Ultrasound: Complete rupture of quadriceps tendon
MRI: Showed complete rupture of quadriceps tendon with 3 cm retraction of quadriceps tendon
Assessment: Left Quadriceps tendon rupture
Zimmer brace to hold knee in extension.
Urgent referral for MRI to determine extent of Quadriceps tear and retraction and assist in planning for surgery. Urgent referral to see an Orthopedic surgeon. Patients can be left with a permanent quadriceps lag if not treated promptly.
In our patient’s case he had surgery within the week to repair the quadriceps tendon.
Dr. Neil Dilworth (Sept 22, 2014)