Review Question - QID 8605

In the position of 90 degrees forward flexion and internal rotation, the most important static stabilizer of the glenohumeral joint is the posterior band of the inferior glenohumeral ligament. This position places the posterior-inferior glenohumeral ligament in an anterior-posterior direction and under tension. The superior glenohumeral ligament and the middle glenohumeral ligament provide static stability in the fully adducted and midrange-adducted positions, respectively. The subscapularis and infraspinatus provide primarily dynamic stability to the glenohumeral joint. Though not fully clear, the rotator interval appears to provide more static stability with the arm adducted, limiting inferior and posterior translation, and less so in the forward flexion and internal rotation position.This patient has cellulitis, which is typically caused by group A Streptococcus or Staphylococcus. The patient's lack of improvement with first-line antibiotics is concerning for methicillin-resistant Staphylococcus aureus (MRSA) infection. MRSA cellulitis is becoming more prevalent in young athletes, and a high index of suspicion is required to provide appropriate intervention during this aggressive disease process. The diagnosis is typically made clinically without the use of cultures. Oral trimethoprim-sulfamethoxazole (a sulfonamide-class drug) double strength twice daily for 10 to 14 days or doxycycline (a tetracycline-class drug) 100 mg twice daily for 10 to 14 days are recommended for first-line treatment of suspected MRSA cellulitis. There is no indication to proceed with irrigation and debridement; however, if the patient develops a soft-tissue abscess or the underlying joint becomes involved, this would be an appropriate intervention. Switching the athlete to an IV cephalosporin (cefazolin) is not likely to be effective against the presumed resistant bacteria. Ciprofloxacin (a fluoroquinolone-class drug) is effective against many bacteria, but not MRSA. The current recommendation for wrestlers with cellulitis is that return to competition be allowed after 72 hours of antibiotic treatment if there has been no extension of the cellulitis for 48 hours, the lesion can be covered, and there is no drainage from the lesion. The other responses are not current recommendations for return to competition.