The JBJS Quiz of the Month is a collection of 10 relevant questions from each orthopaedic subspecialty. The questions are drawn from JBJS Clinical Classroom, which houses over 4,500 questions and 3,100 learning resources. Take the Quiz to see how you score against your peers!

NOTE: This quiz does not earn users CME credits. The questions must be answered within Clinical Classroom to earn CME credits.

You are called to see a female newborn who is not moving her arm normally. The newborn seems to be holding her arm straight by her side with the shoulder internally rotated, elbow extended, and wrist flexed. This injury pattern is referred to as:
    • Complete brachial plexus palsy
    • Apan-plexus birth palsy affects the C5 through T1 nerve roots. It is important to examine for associated Horner’s syndrome (ptosis, miosis, and anhidrosis), which may suggest a preganglionic injury


    • Pseudoparalysis
    • Pseudoparalysis refers to an inability to abduct the shoulder due to rotator cuff insufficiency rather than axillary nerve palsy


    • Klumpke palsy
    • Klumpke palsy refers to a lower trunk brachial plexus birth palsy, which affects C8 and T1. Deficits include finger flexion and intrinsic hand function


    • Erb’s palsy
    • Erb’s palsy refers to an upper trunk brachial plexus birth palsy, which affects C5 and C6, and sometimes C7. Deficits include shoulder abduction, shoulder external rotation, elbow flexion, forearm supination, and wrist extension