A 35-year-old lady presented with complaints of pain and swelling of large and small joints of the bilateral upper and lower limbs of 1 year duration. She had early morning stiffness lasting for more than 2 h. She also complained of difficulty in lifting heavy objects for the last 4 months. She was intermittently taking nonsteroidal anti-inflammatory drugs for her complaints. There was no history of any trauma or intra-articular injections in any of the joints. Examination revealed active arthritis with 27 tender (shoulders, elbows, wrists, metacarpophalangeal, proximal interphalangeal, knees, and ankle joints) and 13 swollen joints (metacarpophalangeal, proximal interphalangeal, and knee joints). In addition, anterior aspect of both arms showed hollowness in the upper half and soft, nontender, globular swelling in the lower half [Figure 1]. Hollowness and swellings became more prominent on active elbow flexion and forearm supination against resistance [Video]. She was seropositive (rheumatoid factor >300 IU/mL and anticitrullinated peptide antibody 293 AU/mL). Erythrocyte sedimentation rate and C-reactive protein were 85 mm and 16.3 mg/dL, respectively.
Figure 1: Anterior aspect of bilateral arms showing hollowness in the upper half and soft globular swelling in the lower half
The history and examination were suggestive of symmetrical inflammatory polyarthritis and presence of the rheumatoid factor, and ACPA favors the diagnosis of rheumatoid arthritis (RA). The abnormality that this patient had on both arms is known as "Popeye deformity."  Popeye deformity is due to the contracted belly of biceps brachii when it loses its attachment either at its origin or insertion. Biceps brachii flexes the elbow and is the chief supinator of the forearm in a semiflexed position of the elbow. It has two tendons (short head and long head) at the origin and a single tendon at the insertion. If there is a rupture of the single insertion tendon (i.e., bicipital tendon), neither of these actions will be possible with marked functional compromise. In contrast, if Popeye deformity is due to the rupture of one of the origin tendons [i.e., either long head of biceps (LHB) or short head of biceps (SHB)], these actions are possible but weak, causing less functional impairment because of the intact attachment of the other tendon at the origin that still allows some action of the muscle. Since this patient had only mild functional limitation and she could flex and supinate her arms [as shown in [Figure 1] and Video], rupture of one of the tendons at the origin was more likely. Among the origin tendons, rupture of the LHB is much more common than the SHB. So, the likely mechanical problem in this patient was bilateral rupture of the long head of biceps brachii tendon in the setting of RA. The diagnosis was confirmed by doing a magnetic resonance imaging (MRI) of the shoulder joint [Figure 2]a and b that showed synovitis with full thickness tear of the long head of biceps brachii tendon bilaterally.
Figure 2: MRI (2a Proton density - fat saturated sequence and 2b T2-weighted gradient echo sequence) axial sections of the right shoulder joint showing absence of tendon of LHB in the bicipital groove (arrowhead in 2a) and presence of synovial fluid in its place (arrowhead in 2b)
RA is an inflammatory condition affecting the synovial membrane of joints and the synovial sheath of tendons. RA can lead to tendon rupture because of persistent tenosynovitis or because of the movement of tendons over the roughened eroded margins of the joint. Since RA involves small joints of the hands more often, tendon rupture is more common in the tendons of the hand muscles. This complication rarely involves the larger tendons. LHB is intra-articular and its tendon sheath communicates with the synovial cavity of the shoulder joint.  Therefore, synovitis of the shoulder joint directly affects the LHB and makes it vulnerable to rupture if the disease activity is uncontrolled.  Studies looking at ultrasonographic features of painful shoulder in RA showed a significant proportion (44-81%) of patients having LHB involvement in the form of effusion and rupture. , The risk factors for this rare complication of RA are uncontrolled synovitis at the shoulder, misplacement of the intra-articular steroids in the tendon of the biceps during shoulder injection, and occupations involving the lifting of heavy objects.  In this patient, it was probably uncontrolled disease activity. She did not require any specific intervention because of mild functional impairment. She was started on oral methotrexate and her joint symptoms improved significantly.