Patellar/Quadriceps Tendon Rupture
Patellar/Quadriceps Tendon Rupture
Warren Bodine
Jeffrey W. R. Dassel
Basics
Description
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Partial or complete rupture of the patellar or quadriceps tendon
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Synonym(s): Extensor mechanism disruption
Epidemiology
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In the general population, quadriceps and patellar tendon ruptures are the 2nd and 3rd most common cause of extensor mechanism disruption, respectively (following patellar fracture). Both have increased in prevalence in recent decades but remain rare.
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True incidence and prevalence not known, but in a higher-risk active-duty military population, the incidences of patellar and quadriceps tendon ruptures were 13 and 4 per 100,000, respectively (1).
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Patellar tendon ruptures are more common in athletes and individuals <40 yrs of age.
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Complete quadriceps tendon ruptures are more common in those >40 yrs of age.
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Ruptures most commonly occur unilaterally; systemic disease increases the risk of bilateral ruptures.
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Ethnicity may influence incidence and prevalence, with blacks and Hispanics more predisposed to tendon ruptures than whites (1).
Risk Factors
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Trauma
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History of patellar/quadriceps tendinosis or patellar spurs
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High-power sports (eg, high jump, basketball, weight lifting)
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Steroid injection in the patellar or quadriceps tendon
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Fluoroquinolone use in previous 6 mos
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Systemic lupus erythematosus
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Rheumatoid arthritis
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Diabetes mellitus
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Hyperparathyroidism
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Chronic kidney disease
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Uremia
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Obesity
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Gout
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Previous total-knee arthroplasty, ACL reconstruction using patellar autograft or excision of tendinosis
Etiology
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Most commonly due to eccentric overload of myotendinous unit with foot planted and knee partially flexed, as occurs in landing from a jump or fall.
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Patellar tendon ruptures usually are complete, occurring most commonly at the osseotendinous junction in athletic trauma versus midsubstance in those with systemic disease (2).
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Quadriceps tendon ruptures usually occur distally, through pathologic tissue 0–2 cm from the superior patellar pole. Pathologic changes are most commonly degenerative in nature (2).
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Chronic tendinosis, corticosteroids, fluoroquinolones, and systemic disease change tendon structure, decreasing its failure point.
Commonly Associated Conditions
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Jumper's knee/tendinopathy
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Patellar spurs
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Quadriceps injury
Diagnosis
History
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Mechanism of injury: Specifically jumping, stumbling, or slipping
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Hearing or feeling “pop” or tearing sensation
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Immediate, disabling pain
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Difficulty straightening or bearing weight on affected extremity
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Acute onset of swelling
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History of chronic patellar or quadriceps tendinosis
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History of steroid injection in tendon
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Recent fluoroquinolone use
Physical Exam
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Diffuse swelling or effusion
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Ecchymosis, possible hemarthrosis
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Patella alta in complete patellar tendon rupture
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Patella baja in complete quadriceps tendon rupture
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Palpable defect (may be masked by swelling acutely or by scar tissue in delayed evaluation)
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Tenderness to palpation over patellar poles, retinaculum, or tibial tuberosity
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Pain with knee flexion
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Inability to actively achieve full extension/having significant extension lag
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Absence of/altered patellar tendon reflex
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Altered gait if able to bear weight
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Quadriceps atrophy (in chronic cases)
Diagnostic Tests & Interpretation
Lab
Laboratory studies are rarely indicated but, depending on history and physical exam, may be performed to evaluate for associated risk factors.
Imaging
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Plain radiographs:
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Diagnosis usually based solely on history, physical exam, and plain radiographs.
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Obtain anteroposterior, lateral, tunnel, and patellar (sunrise or Merchant) views.
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Contralateral films allow comparison of patellar height.
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Superior or inferior patellar migration without fracture is conclusive for rupture.
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Avulsion fractures may occur at the superior or inferior patellar poles or the tibial tuberosity.
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US:
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More commonly performed in Europe than U.S.
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High-resolution US shows hypoechogenicity in acute tears, tendon thickening, and heterogeneous echotexture in chronic tears.
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MRI:
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May be performed if diagnosis cannot be made by clinical and radiographic examination
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Findings include tendon fiber disruption with associated edema or hemorrhage.
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P.447
Pathological Findings
Pathologic changes usually are degenerative, including hypoxic degenerative tendinopathy, mucoid degeneration, tendolipomatosis, and calcifying tendinopathy (2)[B].
Differential Diagnosis
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Fracture
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Muscular strain (grade I or II)
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Patellar subluxation/dislocation
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Meniscal or ligamentous pathologies
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Osgood-Schlatter disease
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Sinding-Larsen-Johansson syndrome
Treatment
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Immobilization of knee with straight-leg immobilizer, ice, elevation, and crutch-assisted ambulation in the immediate setting.
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Immobilization and crutch use should be continued until evaluation and, if indicated, surgical intervention is completed (3)[C].
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Incomplete tendon ruptures:
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Most can be treated nonoperatively with immobilization and protected ambulation for 6 wks (3)[B].
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Immobilizer can be discontinued when patient can perform straight-leg raise without discomfort (3)[B].
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Surgery is indicated for complete ruptures or for incomplete ruptures failing to respond to nonoperative treatment.
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Additional Treatment
Referral
Patients should be referred for orthopedic evaluation as soon as a patellar/quadriceps tendon rupture is suspected to decrease complications (4)[B].
Surgery/Other Procedures
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Surgery is necessary for all complete ruptures to restore the extensor mechanism of the knee; it is also indicated for partial ruptures failing nonoperative treatment.
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Repair should occur as soon as possible, preferably within 2 wks. Delays >6 wks complicate surgical intervention and lead to poorer outcomes (3)[B].
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The exact surgical intervention depends on which portion of the extensor mechanism was disrupted and the acuity of the injury.
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If ruptures are several months old, semitendinosus tendon or synthetic graft may be used in the repair.
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Postoperative rehabilitation:
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Based on quality of tissue and extent of repair
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Traditionally, a straight-leg cast was in place for 6 wks regardless of repair technique; postoperative knee braces with motion control and extension locks are now favored, with motion increased by 10–15 degrees weekly (3)[C].
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Weight-bearing as tolerated is permitted.
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Straight leg raising typically begins at 3 wks, with cast or brace advancement at 6 wks (3)[C].
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Ambulation without assistance is initiated when motion and strength have returned (3)[C].
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Comprehensive physical therapy program should be completed before return to athletics.
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Ongoing Care
Patient Education
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Reasonable function can be obtained in most individuals, especially in the acute tendon rupture that is repaired immediately.
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Most patients can return to their previous occupation, but many have difficulty returning to their preinjury athletic level, particularly with quadriceps tendon ruptures.
Prognosis
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Outcome after repair is closely related to the length of time between injury and repair, the quality of the preexisting tissues, and the tendon healing at the proper length and tension.
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If the tendon is repaired immediately, most patients experience nearly full return of knee motion.
Complications
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Loss of flexion is common after quadriceps tendon rupture.
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Extensor mechanism weakness
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Postoperative infection
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Degenerative change at the patellofemoral joint
References
1. White DW, Wenke JC, Mosely DS, et al. Incidence of major tendon ruptures and anterior cruciate ligament tears in U.S. Army soldiers. Am J Sports Med. 2007.
2. Kannus P, Józsa L. Histopathological changes preceding spontaneous rupture of a tendon. A controlled study of 891 patients. J Bone Joint Surg Am. 1991;73:1507–1525.
3. Greis PE, Holmstrom MC, Lahav A. Surgical treatment options for patella tendon rupture, Part I: Acute. Orthopedics. 2005;28:672–679; quiz 680–681.
4. Ilan DI, Tejwani N, Keschner M, et al. Quadriceps tendon rupture. J Am Acad Orthop Surg. 2003;11:192–200.
Additional Reading
Griffin LY, ed. Sports Medicine. Rosemont, IL: American Academy of Orthopaedic Surgery, 1994.
Hardy JR, Chimutengwende-Gordon M, Bakar I. Rupture of the quadriceps tendon: an association with a patellar spur. J Bone Joint Surg Br. 2005;87:1361–1363.
Matava MJ. Patellar tendon ruptures. J Am Acad Orthop Surg. 1996;4:287–296.
Shah MK. Outcomes in bilateral and simultaneous quadriceps tendon rupture. Orthopedics. 2003;26:797–798.
Codes
ICD9
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727.65 Nontraumatic rupture of quadriceps tendon
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727.66 Nontraumatic rupture of patellar tendon
Clinical Pearls
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Rupture of the extensor mechanism is an uncommon yet disabling injury requiring prompt diagnosis and early surgical management.
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Misdiagnosis of quadriceps tendon rupture is common, occurring in 10–50% (4).
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Suspect patellar or quadriceps tendon rupture in any patient with acute knee pain and inability to actively extend the knee.