Background: Resection is a common procedure for the treatment of
comminuted fractures of the radial head. While radial head resection is
associated with a high success rate when performed for appropriate
indications, a number of well-defined biomechanical complications have been
reported following this procedure, including proximal migration of the radius,
the development of valgus deformity, and recurrent elbow instability in the
acute setting. However, posterolateral rotatory instability has not previously
been recognized as a complication of radial head resection. While the absence
of the radial head makes the diagnosis difficult, we have identified a series
of patients with posterolateral rotatory instability following radial head
resection. We believe that this instability is secondary to unrecognized
lateral ulnar collateral ligament deficiency.
Methods: Between November 1995 and September 2000, forty-two
patients were evaluated because of elbow or forearm complaints following
radial head resection. Seven patients (17%) were diagnosed with posterolateral
rotatory instability on the basis of characteristic clinical and radiographic
Results: The study group included five men and two women with a mean
age of forty-two years. All seven patients had had radial head excision for
the treatment of a comminuted radial head fracture at a mean of forty-four
months (range, four months to sixteen years) prior to referral. All seven
patients had lateral elbow pain, a sense of instability and/or weakness, and a
positive lateral pivot-shift test. Posterolateral rotatory instability
secondary to lateral ulnar collateral ligament insufficiency was confirmed
intraoperatively in the four patients who were managed surgically.
Conclusions: Clinicians should be aware that posterolateral rotatory
instability may be a cause of unexplained elbow pain and instability following
radial head resection. This diagnosis has implications for the prevention and
treatment of this condition.
Level of Evidence: Therapeutic Level IV. See Instructions
to Authors for a complete description of levels of evidence.