Bilateral, simultaneous rupture of the quadriceps tendon: a diagnostic pitfall? Report of three cases and meta-analysis of the literature.

Bilateral, simultaneous quadriceps tendon rupture (QTR) represents a rare entity and delay in establishing the correct diagnosis is not uncommon. Another three cases are reported here and in all the correct diagnosis was missed initially. A review of the English and German literature retrieved 105 cases of bilateral, simultaneous QTR and in 32 patients (30.5%) the correct diagnosis was established with delay. In 28 cases--representing 25 men (89.3%) and 3 women (10.7%)--sufficient data was available for further analysis. In the majority of patients (n = 19/28; 67.9%) rupture was associated with trauma, while no trauma was reported in 9/28 cases (32.1%). No direct correlation between age and the kind of rupture form (traumatic/spontaneous) could be detected (P = 0.35). Most partients (n = 18/28; 64.3%) presented risk factors associated with QTR and obesity (n = 6/28; 21.4%) was most frequently encountered. A direct association between the rate of risk factors and the rupture form was not seen (P = 0.5). Overall diagnostic delay lasted 64.7 days on an average (traumatic ruptures 67.7 days/spontaneous ruptures 58.7 days) with this period being longer than 2 weeks in 51.9% and longer than 3 months in 33.3% of patients. Delay varied distinctly in different medical institutions as this period lasted in hospital departments 93.9 days, in ambulances 24 days and in General Practitioners 7.6 days on an average. Initially 25 incorrect diagnoses were established in 21/28 (75%) patients, while 7/28 cases (25%) were discharged initially without any diagnosis. Clinical examination revealed most often palpable suprapatellar gaps (n = 17/24) and effusions (n = 13/24), while the classic trias of painful swelling, suprapatellar gap and loss of knee extension was found in only 58.3% of reported patients (n = 14/24). The correct diagnosis of bilateral QTR was established in 60.7% (n = 17/28) by history and clinical examination alone. In 10.7% (n = 3/28) clinical suspect was supported by sonography and in 14.3% (n = 4/28) by MRT; in 14.3% (n = 4/28) the correct diagnosis represented a by chance finding during diagnostic or operative procedures of other indication. In 52 tendons detailed information about repair was provided and most often transosseous fixation (n = 30/52; 57.7%) and direct repair (n = 14/52; 26.9%) were used, while a tenoplasty was performed in only 15.4% (n = 8/52). Only 34.6% of patients (n = 9/26) with follow-up data (n = 26/28) reported a full recovery with a trend that early surgical repair (limit 2 weeks) improves the final outcome.