In order to make sense of the joint examination, you must have an understanding of functional anatomy. Without this, the provocative maneuvers used to define the precise nature of the joint problem will make no sense. By gaining an appreciation for the basic structures and functioning of the joint, you’ll be able to “logic” your way thru the exam, even if you can’t remember the eponym attached to each specific test! The complete examination of the knee or shoulder is usually performed in the setting of pain, decline in function or other focal complaint.
Gamekeeper Technique That Lead To UCL Injury (Don’t Worry, Bunny Used In Photo Is Not Real!)
The ulnar collateral ligament (UCL) is a strong band of tissue that connects the first phalanx of the thumb to the metacarpal bone along the ulnar side. Injury to this structure was first described in Scottish Gamekeepers, who damaged the ligament as a result of the manner in which they killed rabbits. The head of the rabbit was grasped between thumb and first finger of one hand while they pulled on the rabbit’s hind quarters with their other. This force chronically stressed the UCL, leading to weakening or frank rupture. After its initial description, it was quickly recognized that the ligament could be torn by any strong force that acutely abducts the extended thumb. Patient’s are usually immediately aware that something is wrong, developing swelling, pain and instability at the metacarpal-phalangeal (MCP) joint . It has become a relatively common ski injury, occurring when a person falls on a hand that has a ski pole gripped between the thumb and forefinger.
Mechanism Of UCL Injury In Skiers
Examination is remarkable for swelling and pain at the MCP. The key maneuver assesses the degree of laxity at the joint. Place the thumb in extension (see picture below for positioning). Gently grasp the end of the thumb and apply an abducting force. If the UCL has been disrupted, you will be able to distract the thumb to a much larger degree then when compared to the normal side.
Picture on Left Demonstrates Normal Degree Of Laxity At The MCP Joint. Picture On The Right Demonstrates Markedly
Increased Laxity Resulting From Disrupted UCL.
X-Ray Demonstrating Gamekeeper’s Fracture (Fragment At Proximal End Phalnax).
The ligament may become disrupted at it’s insertion on the proximal phalanx, pulling away a small piece of bone that can be seen on x-ray.