My Orthopaedic Surgeon

See:
- Rupture of the Quadriceps:
- Patellar Tendon Injury:
- Tibial Tubercle Frx:
- Discussion:
- extensor mechanism includes quadriceps, quadriceps tendon, medial & lateral retinaculum, patellofemoral and patellotibial ligaments, Patellar Tendon (ligament), and tibial tubercle;
- superficial location of extensor mechanism make it suseptable to injury;
- extensor mechanism rupture may involve either the quadriceps tendon or patellar ligament and may be either partial or complete;
- complete rupture is rare in young athlete unless assoc w/ steroids;
- patellar ligament ruptures usually occur in pts <40 yrs of age & quads tendon ruptures in pts older than 40 years of age;
Wheeless' Textbook of Orthopaedics

Several types of quadriceps injuries can occur, the most common being the quadriceps contusion, which is painful and disabling. The usual cause of the quadriceps contusion is a direct blow to the anterior thigh from an object or another person (eg, helmet, knee). Very rarely, this injury can be severe enough to progress to an acute compartment syndrome. Because the quadriceps is in contact with the femur throughout its length, it is susceptible to compression forces. The rectus femoris is the most commonly injured portion of the muscle because of its anterior location. Minimally, impact causes cellular edema of the muscle, but complete capillary disruption with localized hemorrhage leading to a tense anterior compartment can occur. The muscle is more resistant to injury if it is struck while in a contracted nonfatigued state. Other quadriceps injuries range from simple strains to more complex and disabling muscle ruptures. Other types of quadriceps injuries include strains of the quadriceps tendon, complete and partial tears of the quadriceps tendon, and fascial rupture of the quadriceps muscle. Specific areas of the quadriceps are affected for each of these diagnoses. The classic quadriceps strain occurs at the conjoined muscle tendon junction (jumper's knee). The partial tear of the quadriceps most commonly affects the indirect (distal) head of the rectus femoris. Fascial rupture usually occurs anteriorly at the mid thigh and causes a muscle hernia.
Synonyms and related keywords: quadriceps contusion, charlie horse, quadriceps strain, muscle pull, quads, quads injury, rectus femoris, quadriceps femoris
DeBerardino, Milne & DeMaio 2006

Ruptures of the quadriceps tendon occur relatively infrequently and usually occur in patients older than 40 years. A strong association exists with numerous systemic diseases and prior degenerative changes in the knee extensor mechanism. Ruptures most often occur unilaterally. Bilateral ruptures are highly correlated with systemic disease but have been reported in healthy patients who do not have predisposing factors.
Synonyms and related keywords: extensor mechanism disruption, tooth sign, patellar tendon ruptures, jumper's knee, unilateral quadriceps tendon ruptures, bilateral quadriceps tendon ruptures, quadriceps tendon tear
Lyle & Crosby 2008

- rupture of quadriceps tendons is most common in the 6th & 7th decades, and is probable associated w/ decreased vasculature;
- Male:female 8:1
- more common w/ cortisone injections, diabetes, chronic renal failure; hyperthyroidism, and gout;
- tear may involve either portion of trilaminar tendon or its entirety;
- usually the tear is initiated centrally and progresses peripherally;
- tendon usually ruptures transversely at the osteotendinous junction;
- rupture often extends thru the vastus intermedius tendon, proximal to the rupture of the rectus femoris tendon;
Wheeless' Textbook of Orthopaedics

Traumatic quadriceps rupture in a patient with patellectomy: a case report Chezhiyan Shanmugam and Nicola Maffulli
Journal of Medical Case Reports 2007, 1:146
We present a 42-year-old male who experienced a unilateral left quadriceps tendon rupture following assault by four people. Twenty-seven years before this injury, the patient had suffered ipsilateral femur and comminuted patellar fractures, which were managed by intramedullary nailing and patellectomy respectively. We performed primary end to end repair of the torn tendon. Postoperatively, histology revealed findings consistent with pre-existent degenerative changes. The patient made good recovery, and returned to his former occupation which was reliant on his ability to drive.
Conclusion Degenerative changes of the tendon of the extensor mechanism of knee following patellectomy may predispose the quadriceps tendon to traumatic rupture. Early operative intervention and protracted rehabilitation are required to obtain the best functional results.