A tendon rupture is described by many reports as one of the most severe forms of tendon injury. The etiology seems to be multifactorial, as trauma and intense eccentric contractions (seen predominantly during sports activities), as well as iatrogenic causes (the use of fluoroquinolones and corticosteroids have been confirmed as risk factors for tendon rupture), seem to be equally important [1] [2] [3] [4] [5]. However, degenerative changes that have been histologically confirmed in many cases (particularly in those who suffered from Achilles tendon rupture) are considered as a prerequisite in order for tendons to rupture [1] [2] [3]. Various studies have described that virtually any tendon in the body could rupture, with respective differences in the clinical presentation [1] [2] [3] [4] [5] [6] [7] [8] [9] [10]:

• Achilles tendon rupture - The Achilles tendon, whose function is to allow plantar flexion of the ankle induced by the triceps surae muscle (two heads of the gastrocnemius and the soleus muscle) is most commonly mentioned in the literature in relation to tendon ruptures [1]. It is encountered in adults who are engaged in strenuous sports activities during their fourth and fifth decades of life and there is a significant predilection for male gender [1] [2]. A sudden onset of pain after an intense plantar flexion is the typical clinical presentation, and many patients cannot stand or bear any weight on the affected leg [2]. In addition, a "pop" sound is reported, denoting the separation of the tendon from its attachment site on the bone [2].
• Biceps rupture - Although it is not commonly encountered in clinical practice, excessive eccentric contractions of this muscle (for example, during heavy lifting) might cause rupture of its tendon, both in the proximal, and less commonly the distal part [6]. A sudden onset of pain accompanied by a tearing sensation in the antecubital region (where the rupture has occurred) is seen in virtually all cases [6]. Similar to Achilles tendon rupture, a "pop" sound is usually heard [6].
• Quadriceps and patellar tendon rupture - Tendons of the quadriceps and patella are also susceptible to rupture, most often caused by an abnormal contraction of the quadriceps muscle while the knee is in moderate flexion, during strenuous running activities (such as sprinting) or due to trauma [7] [10].
• Flexor and extensor ruptures of the fingers - As with other types of ruptures, traumatic tendon injury following excessive activity been attributed as causing the rupture of the tendons in the hand [8] [9].

• Collapse

  The collapsed scaphoid was removed, followed by 4-corner fusion and tendon transfer of the extensor digiti minimi to the EIP. [ncbi.nlm.nih.gov]

• Malingering

  The differential diagnosis is vast and includes but is not limited to: spinal cord injury, Guillain-Barré syndrome, myopathies, and even malingering. This case report details an uncommon cause for a common ED presentation. [ncbi.nlm.nih.gov]

• Soft Tissue Mass

  CASE: We present a case of rice-body formation and partial flexor tendon rupture in a 3-year-old child with seronegative juvenile idiopathic arthritis (JIA), which presented as a painless soft-tissue mass of the volar aspect of the hand. [ncbi.nlm.nih.gov]

• Muscle Strain

  Strain Cramps DOMS - Delayed Onset Muscle Soreness Overuse Injuries Systemic Conditions Rheumatoid Arthritis Fibromyalgia Psoriatic Arthritis Lupus Neurological Conditions Sciatica Restless Leg Syndrome Pinched Nerve References Cary DV. (2009) How to [physioworks.com.au]

  Differential Diagnosis Differential diagnosis includes: Acute achilles tendon peritendinitis Gastrocnemius tear Calf muscle strain or rupture Posterior tibialis stress syndrome Fracture Posterior tibialis tendon injuries Peroneal injuries Classification [physio-pedia.com]

• Hip Pain

  We are reporting a case of apparently spontaneous iliopsoas tendon rupture that occurred in an elderly patient presenting with severe debilitating hip pain whose etiology initially was unrecognized. [ncbi.nlm.nih.gov]

• Myalgia

  Three days after starting this new treatment, she presented with intense arthralgia that symmetrically affected the shoulders, hands, and hips without myalgia. [ncbi.nlm.nih.gov]

• Anterior Knee Pain

  Abstract Various complications after intramedullary (IM) nailing of the tibia have been reported, the most common of which are anterior knee pain and symptoms similar to patella tendonitis. [ncbi.nlm.nih.gov]

• Wrist Pain

  The patient could not flex the little finger and did not have wrist pain. Plain radiographs of the affected wrist joint showed severe arthritic changes of the pisotriquetrum joint and calcification around the joint. [ncbi.nlm.nih.gov]

• Guillain-Barré Syndrome

  The differential diagnosis is vast and includes but is not limited to: spinal cord injury, Guillain-Barré syndrome, myopathies, and even malingering. This case report details an uncommon cause for a common ED presentation. [ncbi.nlm.nih.gov]

• Limb Weakness

  CASE REPORT: A 46-year-old white man presented to the Emergency Department (ED) via ambulance, reporting sudden onset of bilateral lower limb weakness. [ncbi.nlm.nih.gov]

A meticulous physical examination is the essential step in recognizing tendon rupture and is supported by data obtained during history taking. Information regarding prior event that led to the injury is vital in assessing the severity and extent of tissue damage, whereas recent fluoroquinolone or corticosteroid use must be excluded, given their well-established roles in the pathogenesis of tendon ruptures [4] [5]. Various probes and tests can be implemented to confirm clinical suspicion toward rupture. In the setting of Achilles tendon rupture, clinical findings include a weak strength when performing plantar flexion, a palpable and often visible defect (retraction of the tendon will produce an abnormal muscular appearance) and the absence of plantar flexion when the triceps surae muscle is mechanically compressed (known as the Thompson test) [2]. Studies have illustrated that up to 100% of ruptures are diagnosed without the need for imaging studies if the examination is conducted properly, thus illustrating the role of a good physical exam [2]. Weakness in the forearm and elbow accompanied by a lack of supination when compressing the biceps belly (the biceps squeeze test) and the inability to palpate the distal biceps tendon while the elbow is flexed and supinated (the hook test) are highly suggestive of a biceps tendon rupture [6]. Quadriceps tendon ruptures are recognized by the inability of the patients to perform active knee extension [7]. If strong clinical suspicion is raised, imaging studies may be used to confirm the diagnosis. Ultrasonography and magnetic resonance imaging (MRI) are recommended because of their ability to assess the extent of the injury [2] [6].

• Cytopenia

  Side effects of rituximab include fever, rash, cytopenia and hypotension, back pain, arthralgia, and myalgia. Here, we report on 3 patients who developed moderate to severe tendonitis after the second infusion of rituximab. [ncbi.nlm.nih.gov]

• Polyps

  RESULTS: The association between the exposure of low 25(OH)D levels and myofascial pain was compared to all cancers, colon polyps, and tendon ruptures. [ncbi.nlm.nih.gov]

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8. Gilman L, Cage DN, Horn A, Bishop F, Klam WP, Doan AP. Tendon rupture associated with excessive smartphone gaming. JAMA Intern Med. 2015;175(6):1048-1049.
9. Proubasta IR, Lamas CG, Natera L, Arriaga N. Delayed rupture of all finger flexor tendons (excluding thumb) following nonoperative treatment of Colles’ fracture: A case report and literature review. J Orthop. 2015;12(1):S65-S68.
10. Ciriello V1, Gudipati S, Tosounidis T, Soucacos PN, Giannoudis PV. Clinical outcomes after repair of quadriceps tendon rupture: a systematic review. Injury. 2012;43(11):1931-1938.