What does positive ulnar variance mean?
What does positive ulnar variance mean?
Positive ulnar variance describes where the distal articular surface of the ulna is more than 2.5mm distal to the articular surface of the radius. It plays important role in wrist pathology such as ulnar impaction syndromes and thinning of the triangular fibrocartilage complex.
What is normal ulnar variance?
– mean ulnar variance is 0.9 mm (range: 4.2 to 2.3 mm); – functional anatomy: – w/ neutral variance, 80% of load is born by radius and 20% by ulna; – 2.5 mm increase in ulnar varience will increase load borne by ulno-carpal joint from 18% to 42%;
What causes ulnar abutment syndrome?
CAUSES. Many cases of ulnocarpal abutment occur without injury and are simply a matter of unusual anatomy (the ulna grows too long). The ulna can also become relatively too long if the other forearm bone, the radius, is fractured and heals too short relative to the intact ulna.
What is ulnar shortening surgery?
Ulnar shortening osteotomy is literally a procedure that shortens the ulna, which is the rationale for its use in ulnocarpal impaction syndrome. 31. Ulnar variance affects the load distribution of the wrist. Larger ulnar variance increases the load on the ulnar carpus.
How do you fix positive ulnar variance?
Ulnar shortening osteotomy (USO) is the standard procedure for correcting positive ulnar variance. Goal of this procedure is to minimize the symptoms by restoring the neutral radio – ulnar variance.
Does positive ulnar variance require surgery?
The debridement of the ulna is performed to the degree at which the patient is ulnar neutral or slightly ulnar negative. The benefit of this procedure is that open surgery is not required, and recovery is faster. However, if the ulnar variance is greater than +4mm, this option is not suitable.
How is ulnar variance treated?
What causes ulnar variance?
The most common predisposing factor is positive ulnar variance, an increased ulnar length relative to the radius. In the positive ulnar variance wrist, the TFCC is stretched and thin, and greater biomechanical forces, specially rotation forces, impact the joint.
How is ulnar abutment syndrome treated?
Ulnar abutment syndrome can be treated by a variety of nonsurgical and surgical methods. These range from anti-inflammatory medications, immobilization, and corticosteroid injections to TFCC debridement, ulnar shortening osteotomies, and arthroscopic wafer procedures.
How common is ulnar abutment syndrome?
Current literature reviews suggest a rate of 3–9% of all sports injuries involve the hand or wrist, with 25–50% recognized as overuse injuries. Ulnar impaction syndrome, or ulnocarpal abutment, is a common degenerative condition causing ulnar-sided wrist pain.
How long does it take to recover from ulnar shortening surgery?
Activity: You will have very little use of the operative arm for about 8 weeks after surgery until the tissue and bone heal.