Last updated: Wednesday, January 26 2005
|Traditionally it is stated that rotator cuff tears must be differentiated from cuff tendinitis and bursitis and that tests such as arthrography or ultrasonography are necessary to make this distinction.
About rotator cuff tear diagnosis
Perhaps a more realistic view is that many of the symptoms often attributed to tendinitis and bursitis are in actuality episodes of acute fiber failure that are not clinically detected.
|Patients with a frozen shoulder demonstrate by definition a restricted range of passive motion with normal glenohumeral radiographs. Patients with partial-thickness cuff defects may similarly demonstrate motion restriction whereas patients with major full-thickness defects usually have a good range of passive shoulder motion but may be limited in strength or range of active motion. An arthrogram in the case of frozen shoulder shows a diminished volume and obliteration of the normal recesses of the joint.
Snapping scapula may produce shoulder pain on elevation and a catching sensation somewhat reminiscent of the subacromial snap of a cuff tear. However the latter can usually be elicited with the scapula stabilized while the arm is rotated in the flexed and somewhat abducted position. Scapular snapping usually arises from the superomedial corner of the scapula producing local discomfort and is elicited on scapular movement without glenohumeral motion.
Glenohumeral arthritis may also produce shoulder pain weakness and catching. This diagnosis can be reliably differentiated from rotator cuff disease by a careful history physical examination and roentgenographic analysis (see figure 1).
Acromioclavicular arthritis may imitate cuff disease. Characteristically however the shoulder is most painful with cross-body movements and with activities requiring strong contraction of the pectoralis major. Tenderness is commonly limited to the acromioclavicular joint. Relief of pain on selective lidocaine injection and coned-down radiographs may help establish the diagnosis of acromioclavicular arthritis.
Suprascapular neuropathy and cervical radiculopathy are common imitators of cuff disease. The suprascapular nerve and the fifth and sixth cervical nerve roots supply two of the most important cuff muscles: the supra and infraspinatus. Thus patients with involvement of these structures may have lateral shoulder pain and lack strength of elevation and external rotation.
In the presence of weakness the neurologic examination should test the cutaneous distribution of the nerve roots from C5 to T1. The biceps reflex and the triceps reflex help to screen C5/6 and C7/8 respectively. The next component of the neurologic examination requires recognition of the segmental innervation of joint motion: abduction C5 adduction C6 7 and 8. External rotation C5 internal rotation C6 7 and 8. Elbow flexion C5 and 6 elbow extension C7 and 8. Wrist extension and flexion C6 and 7. Finger flexion and extension C7 and 8. Finger adduction/abduction T1.