Background: There has been controversy regarding the optimal pin
configuration in the management of supracondylar humeral fractures in
children. A crossed-pin configuration may be mechanically more stable than
lateral pins in torsional loading, but it is associated with a risk of
iatrogenic injury to the ulnar nerve. Previous clinical studies have suggested
that lateral pins provide sufficient fixation of unstable supracondylar
fractures. However, these studies were retrospective and subject to
Methods: A displaced supracondylar humeral fracture was fixed with
only lateral-entry pins in 124 consecutively managed children. Medical records
and radiographs were reviewed to identify any complications, including loss of
fracture reduction, iatrogenic ulnar nerve injury, infection, loss of motion
of the elbow, and the need for additional surgery. In addition, eight
displaced supracondylar humeral fractures that had been reduced and fixed with
lateral pins at other institutions and had lost reduction were analyzed to
determine the causes of the failures.
Results: Sixty-nine children had a type-2 fracture, according to
Wilkins's modification of Gartland's classification system; forty-three (62%)
of those fractures were stabilized with two pins and twenty-six (38%), with
three pins. Fifty-five children had a type-3 fracture; nineteen (35%) of those
fractures were stabilized with two pins and thirty-six (65%), with three pins.
A comparison of perioperative and final radiographs showed no loss of
reduction of any fracture. There was also no clinically evident cubitus varus,
hyperextension, or loss of motion. There were no iatrogenic nerve palsies, and
no patient required additional surgery. One patient had a pin-track infection.
Our analysis of the eight clinical and radiographic failures of lateral pin
fixation that were not part of the consecutive series showed that the loss of
fixation was due to fundamental technical errors.
Conclusions: In this large, consecutive series without selection
bias, the use of lateral-entry pins alone was effective for even the most
unstable supracondylar humeral fractures. There were no iatrogenic ulnar nerve
injuries, and no reduction was lost. The important technical points for
fixation with lateral-entry pins are (1) maximize separation of the pins at
the fracture site, (2) engage the medial and lateral columns proximal to the
fracture, (3) engage sufficient bone in both the proximal segment and the
distal fragment, and (4) maintain a low threshold for use of a third
lateralentry pin if there is concern about fracture stability or the location
of the first two pins.
Level of Evidence: Therapeutic study, Level IV (case
series [no, or historical, control group]). See Instructions to Authors for a
complete description of levels of evidence.