11.   A rugby player is referred to you by a local primary care doctor two days after "jamming" his ring finger in a scrum. The prescription reads "Dx: RF sprain, eval and tx." His RF ROM is as follows:    MP 0/90  PIP 20/85  DIP +5/40.    You want to test the integrity of the central slip.  Which method(s) will you use?             A.  Have the patient rest his hand on the table keeping the MCP in full extension and the PIP flexed over the edge of the table. Apply light resistance and ask the patient to extend the PIP.       B.  Have the patient place injured and uninjured ring fingers knuckle to knuckle with the  PIP joints in 90 degrees of flexion.  Note the symmetry of the DIPs.       C.  Ask the patient to extend the digit from a fully flexed position and check for a lag in MCP exte...

11.  Correct Answer:   D.  Both A. and B.      This patient is beginning to demonstrate a boutonniere deformity, which may develop after an injury to the central slip of the extensor tendon.             Only the central slip can extend the proximal interphalangeal joint (PIP) from a fully flexed position.  The lateral bands may maintain an already extended PIP joint but they cannot initiate PIP extension.  With Elson’s test (Answer A.), the patient keeps the metacarpal phalangeal joint (MCP) in full extension while attempting to extend a fully flexed PIP against light resistance.  An intact central slip will be able to fully extend the PIP joint.  2         Answer B. describes a   Modified Elson’s test. In the uninjured central slip, this test results in the distal interphalangeal joints (DIP) being positioned in slight flexion.  To the examiner the...