A patient presents with shoulder pain and weakness. What physical exam finding would suggest a rotator cuff tear?
The correct answer and explanation is:
The correct physical exam finding that would suggest a rotator cuff tear is a positive drop arm test. In this test, the patient is asked to abduct their arm to 90 degrees and then slowly lower it. If the arm drops suddenly or the patient is unable to control the descent of the arm, it indicates weakness or damage in the rotator cuff muscles, especially the supraspinatus tendon.
Explanation:
The rotator cuff consists of four muscles: supraspinatus, infraspinatus, teres minor, and subscapularis. These muscles work together to stabilize the shoulder joint and allow for smooth, controlled movements. A tear in any of these muscles or tendons, especially the supraspinatus tendon, can cause significant weakness and pain in the shoulder.
The drop arm test specifically targets the supraspinatus muscle, which is responsible for initiating shoulder abduction. When this muscle or tendon is torn, the patient may experience pain, weakness, and an inability to hold the arm in the abducted position. The drop arm test is a simple and effective way to assess this.
Other physical exam findings that may suggest a rotator cuff tear include:
- Positive Neer’s Test: The examiner passively raises the patient’s arm in the forward flexion position while stabilizing the scapula. Pain during this maneuver indicates impingement of the rotator cuff tendons, often associated with tears.
- Positive Hawkins-Kennedy Test: The examiner flexes the patient’s shoulder and elbow to 90 degrees, then internally rotates the arm. Pain during this test suggests impingement, which can be due to a rotator cuff tear.
- Weakness on resisted external rotation: If the infraspinatus or teres minor tendons are involved, resistance to external rotation may be weakened.
Rotator cuff tears are often associated with shoulder pain, limited range of motion, and weakness. Early identification through physical examination and confirmation through imaging (like MRI) can help guide treatment, which may range from physical therapy to surgical intervention depending on the severity of the tear.