Simultaneous Bilateral Rupture of Quadriceps Tendons

Mrugeshkumar K. Shah, MD, MPH, MS


South Med J. 2002;95(8) 

In This Article


Historically, bilateral quadriceps tendon rupture occurred most commonly in men more than 50 years old.[4,5] However, many of the cases reported recently in the literature are in younger individuals with chronic illnesses.[4,6] Of the 66 patients described, 53 (80%) were male and 13 (20%) were female. The youngest patient was 22 years of age and the oldest was 84. The mean age of all the patients was 51 years (median, 51.5 years). The mean age for female patients was 44 years old (range 22 to 76 years, median 39 years) while the mean age for males was 53 years old (range 22 to 84 years, median 54 years). Male patients were more likely to be older (P < .05). Sex was not related to type of chronic disease (P > .05). Age has been shown to predispose patients to rupture.[6] Younger individuals were more likely to have chronic renal failure, gout, hyperparathyroidism, or a previous history of rupture, whereas adolescents were more likely to be involved in direct trauma leading to rupture.[4,6] Older individuals were more likely to have diabetes mellitus, obesity, or other unknown risk factors.[6] The results of this review showed that younger individuals were more likely to have chronic renal disease or an endocrine disorder, whereas older patients were more likely to be obese, hypertensive, or have some other risk factor (P < .05). No known cause was reported in 12 cases.

Bilateral quadriceps tendon rupture is an injury that is associated with falling down stairs or spontaneously occurring while walking.[7,8,9,10] This review showed that 41 cases (65%) were attributed to falls and missteps, and 22 cases (35%) occurred spontaneously while walking. Older individuals were more likely to have ruptured tendons due to a fall (P < .05), whereas sex and type of chronic disease did not correlate with mechanism of injury (P > .05).

Sudden violent contraction of the quadriceps muscles in the presence of a flexed knee joint and a fixed foot may lead to rupture.[7] However, McMaster[11] noted that normal tendons should not rupture under this stress. In the absence of trauma, generally an underlying condition leads to abnormal tendons that rupture under ordinary stress. Risk factors for quadriceps rupture include diabetes mellitus, advanced age, pararthyroidism, chronic renal failure, obesity, systemic lupus erythematosus, steroid use, and gout.[8,12,13,14,15] The underlying pathophysiology that leads to rupture varies with the disease process.

In this review, simultaneous bilateral rupture of the quadriceps tendon occurred most often in patients with renal disease (43%). Studies have reported a relationship between duration of hemodialysis and duration of renal failure with tendon ruptures.[16] This review showed that only duration of dialysis was related to spontaneous tendon rupture (P < .05). The underlying mechanism causing rupture in chronic renal failure is poorly understood. It is thought that chronic acidemia associated with chronic renal disease degenerates tendons.[2] Also, uremia may affect the structure of the protein-polysaccharide complex, which is responsible for the maturation of collagen.[16] This disruption may lead to rupture.

Endocrine disorders associated with rupture are hyperparathyroidism and diabetes. Secondary hyperparathyroidism associated with chronic renal disease was present in 16 cases (28%), while primary hyperparathyroidism was present in only 3 cases (5%). Hyperparathyroidism causes dystrophic calcifications and subperiosteal bone resorption, which weakens the osseotendionus junction and leads to tendon rupture.[6,16] An increase in parathyroid hormone (PTH) and alkaline phosphatase has been documented before rupture.[12,16,17] Diabetes mellitus was present in 6 cases (10%). Patients with diabetes have fibrinous necrosis with calcifications and arteriosclerosis with an inflammatory reaction found on pathologic analysis of their tendons.[6,8,15]

Steroid use accounted for 3 cases of rupture (5%). Steroid use is thought to alter the structure of collagen, thus leading to tendon rupture.[18] Gout and pseudogout accounted for 3 cases (5%). Gout is believed to cause fibrinoid necrosis and chronic inflammation leading to tendon rupture.[6,10] Obesity was present in 9 cases (16%). Obesity is thought to cause fatty changes in the tendon.[4,6] Patients who are obese also place greater stress on their knees when flexed.

It has been reported that older individuals are predisposed to rupture.[6] There were 34 cases of rupture in older individuals (age >50). Age-related changes in the tendon include fatty degeneration, tendon sclerosis, tendon infiltration and fibrinoid degeneration, and a decrease in the strength and number of collagen fibers.[4,6] Hypertension was present in 6 cases (10%). Hypertension has never been directly reported as a risk factor, but it may cause tendon rupture through its association with other conditions such as obesity and renal disease, or it may be related to age-related changes and athlerosclerosis. Multiple diseases were present in 25 cases. Patients with multiple diseases were younger (P < .05) and female (P < .05). However, multiple chronic diseases were not associated with location of injury, mechanism of injury, or time interval for diagnosis (P > .05).

Patients with bilateral quadriceps rupture most often complain of knee pain. There is a history of a fall onto flexed knees or a sudden, sharp pain above the patella, with inability to stand without assistance. Physical examination often reveals a palpable gap above the patella known as the "gap test" or "sulcus sign." Patients will be unable to actively extend the knee, but passive range of motion and active knee flexion will be normal. Other physical signs include a mobile, free-floating patella, hemarthrosis, and absent patellar reflexes.[19,20,21]

No specific laboratory test is diagnostic of ruptures; however, laboratory testing may aid in identifying the underlying disease process. For patients less than 50 years of age, it is important to rule out endocrine, rheumatologic, and renal disease. The workup for these diseases includes measurement of serum electrolytes, blood urea nitrogen, creatinine, glucose, thyroid function, uric acid, alkaline phosphatase, calcium, phosphorous, and antinuclear antibodies.

Radiologic workup can include plain radiographs, ultrasonography, and magnetic resonance imaging (MRI). Findings on plain films are nonspecific, but they help rule out other possible conditions such as a fracture. Nonspecific findings on plain films include effusion, calcifications, soft tissue defects, forward-tilting patella, or low-lying patella.[2,7,22] Also seen is a distal displacement of the patella with calcification in the quadriceps or a bone fragment from avulsion of the superior pole of the patella. Recently, ultrasonography has been used for diagnosing tendon disease and was used in 2 of the reported cases of rupture.[2,18] Ultrasonography can be done quickly at the bedside for immediate results, but it is operator dependent. Although MRI is a more expensive method of diagnosing a rupture than ultrasonography, MRI is the test of choice for preoperative identification of anatomy, including the exact location of the rupture. It is the best noninvasive test for evaluating the surrounding soft tissues and ligaments, and it was used in 6 cases.[2,23,24,25]

Diagnosis of bilateral quadriceps rupture is a clinical one. The history of a fall or bilateral knee pain with inability to actively extend the knee, along with a palpable gap in the suprapatellar region, is highly suggestive of bilateral quadriceps tendon rupture. Ultrasonography and MRI can aid in uncertain cases or can be used for preoperative details. The definitive diagnosis of rupture is by direct visualization during surgery.

Direct visualization allows localization of the rupture. The tendon can rupture at three sites: the osseotendinous junction, the musculotendionous junction, or within the tendon. Dhar[5] stated that the most common location for rupture was the musculotendinous junction. This review shows that 12 cases were in the musculotendinous junction, 23 cases in the osseotendinous junction, and 3 cases within the tendon. In 2 cases, each side had a different location of rupture. Others have stated that location of rupture is age dependent, with younger individuals having rupture within the tendon and older patients having rupture at the osseotendinous junction. This review of all reported cases, however, showed older patients were more likely to have rupture at the musculotendinous junction and younger individuals were more likely to have rupture at the osseotendinous insertion (P < .05). Further, spontaneous ruptures were more likely to occur at the osseotendinous junction (P < .05). Neither time interval before diagnosis nor sex was associated with location of tendon rupture (P > .05).

Bilateral rupture may be misdiagnosed up to 50% of the time.[26] The differential diagnosis for knee pain is extensive, since the pain may be from soft tissue structures, ligaments, tendon ruptures (either quadriceps or patellar), or bone fractures. Quadriceps ruptures have been misdiagnosed as neurologic disorders such as stroke and paralysis, as well as an acute flare of rheumatoid arthritis and knee effusions and sprains.[26] The awareness of risk factors and clinical features associated with injury are important in correct diagnosis, proper treatment, and good functional outcome.

It has been reported that immediate surgical intervention is imperative. In this review, there was 1 case in which nonoperative treatment alone led to full recovery, but the recovery time was longer.[27] In 3 cases, nonoperative treatment on one side resulted in full recovery, but recovery time was greater.[28,29] Nonoperative treatment includes immobilzation with a plaster splint, cylindrical cast, or commercial immobilizer. Surgery is generally viewed as the preferred treatment, and surgical intervention was done in all but 1 of the 66 cases (98%). Numerous surgical techniques have been described in the literature.[6,7,28] The technique used for repair depends on many factors such as the surgeon's preference and training.

Postoperative treatment involves immobilization in a cast and physical therapy after removal of the cast to regain range of motion and strength. The length of immobilization varies, though most advocate at least 6 weeks. In 43 cases, duration of plaster cast immobilization was 4 to 6 weeks. The shortest duration of immobilization was 2 weeks (by an elastic band), and the longest duration was 6 months (in a locked knee brace).[3,29]

Follow-up was mentioned in 80% of cases (53/66). A majority of those patients (57%) had a good outcome (full range of motion or strength). However, 10 patients (19%) had an extensor lag, 7 (13%) walked with an assistive device, and 6 (11%) had an extensor lag and used an assistive device at follow-up. Most patients (12 cases) were seen at 4 months for follow-up (range 30 days to 5 years, median 4 months).