Your patient is a 35 year old male who presents with right hand laceration, he states he was reaching blindly into a drawer of utensils, and cut the volar aspect of digits 2-5. The laceration appears deep.
How do you assess for ligament and tendon function in the fingers/hand?
I) Central slip extensor tendon injury:
Patients will be tender over the dorsal aspect of the PIP joint.
To test, hold the PIP joint in 15-30 degrees of flexion, and have the patient actively extend at the PIP joint. Even with this injury, passive extension should be intact.
To treat, splint in full extension for six weeks.
II) Collateral ligament injury:
Patients will be tender over the collateral ligament.
To test, have the patient hold their affected joint in 30 degrees of flexion, with the MCP flexed to 90 degrees, apply valgus and varus stress and assess for stability.
To treat, buddy tape.
III) Extensor tendon injury (at the DIP joint):
Patients will be tender over the dorsum of the DIP joint.
To test, check the patient’s ability to actively extend at the DIP joint. Inability to fully passively extend the joint may indicate entrapment.
To treat, splint the DIP in either a neutral or hyperflexed position.
IV) Flexor digitorum profundus injury:
Patients will be tender over the volar aspect of the DIP joint.
To test, hold the finger’s MCP and PIP joints in extension, while the other fingers are flexed, and have the patient actively flex at the affected DIP joint.
*Also, test the flexor digitorum superficialis tendon by holding the unaffected fingers in extension and asking the patient to flex the affected finger.
V) Volar plate injury:
Patients will have tenderness over the volar aspect of the affected joint.
To test, have the patient move the affected finger into a fully flexed and fully extended position. Also, assess the collateral ligaments (as above).
To treat, splint in 30 degrees of flexion.
Always involve a hand surgeon early and arrange for close follow-up.
References:
Tintinalli JE, Kelen GD, Stapczynski JS, Ma, OJ, Cline DM, editors. Tintinalli’s
Emergency Medicine. 6th ed. New York: McGraw-Hill; 2004
http://www.aafp.org/afp/2006/0301/p810.html
http://handcare.assh.org/Hand-Anatomy/Details-Page/ArticleID/27968/Extensor-Tendon-Injuries.aspx
