Copyright © 2007 by The Journal of Bone and Joint Surgery, Inc.
Commentary & Perspective
Commentary & Perspective by
Vernon T. Tolo, MD*,
Children's Hospital, Los Angeles, California
Posted April 2007
It has been nearly thirty years since the initial reports of
operative treatment of supracondylar humeral fractures in children were
presented in the United States. Prior to the late 1970s, the usual treatment
for this type of fracture consisted of two to three weeks of in-patient
treatment with skin or pin traction, followed by a period of cast
immobilization. This nonoperative treatment was associated with a high
prevalence of complications, and the rates of cubitus varus in that era
commonly were in the range of 10% to 30%. Replacing the lengthy and costly
traction and casting treatment of this fracture with a relatively simple
surgical procedure with predictably excellent results has been one of the truly
great advances made in pediatric orthopaedics.
Now the debate has shifted to the question of which operative
technique is the safest and most effective for the treatment of supracondylar
humeral fractures in children1. The two manuscripts published in
this issue of JBJS add a good deal of
additional information and insight regarding how best to treat this fracture.
At the time of this writing, operative treatment is essentially
the universally accepted treatment of choice for Gartland type-II and type-III supracondylar
humeral fractures in children. Closed reduction and cast immobilization can be
used in selected type-II fractures, but it has been demonstrated that the elbow
needs to be flexed to about 120° in the cast to maintain reduction of a type-II
fracture2. Because this treatment can lead to possible vascular
compromise due to the hyperflexed position of the elbow, surgical treatment is
a safer and often easier method of managing this fracture. In the past, when
nonoperative treatment was chosen, there was a tendency to undertreat type-II
fractures by stabilizing them with a long arm cast in about 90° to 100° of
flexion, without fully anatomically reducing the fracture. If the distal
fragment heals in an angulated position in extension (i.e, if the lateral
radiograph shows that the anterior humeral line passes anteriorly to the
capitellum), hyperextension as well as some varus deformity of the elbow may be
noted on clinical examination after healing is complete. In my opinion, the
undertreatment of type-II fractures has led to more medical liability claims
than has the management of the much more displaced type-III fractures, which
are aggressively reduced to the original anatomic position and are stabilized
operatively. The type-II fracture is simple to treat through closed reduction,
with the patient under sedation or anesthesia, by placement of percutaneous pins
to hold the reduction and without the need to hyperflex the elbow. In the paper
by Sankar et al., none of the type-II fractures in their study group lost any
reduction. Once reduced, type-II fractures are very stable, so the pin
configuration is less critical than it is when treating a type-III fracture. Two
lateral pins, placed either parallel to or slightly divergent from one another,
work very well to stabilize a type-II fracture, with no danger of later
displacement and with much less risk of the vascular compromise that can occur
with nonoperative cast treatment in which the elbow is immobilized in full
flexion.
When the distal fragment of a supracondylar fracture in a
child is displaced, often widely, from the proximal fragment, the keys to successful
treatment of the fracture are (1) anatomic reduction under anesthesia and (2)
maintenance of fracture reduction with the least risk of iatrogenic injury to
adjacent nerves. Iatrogenic injury to the ulnar nerve has been reported to occur
more commonly with the use of crossed pins for the fixation of supracondylar humeral
fractures than when only lateral pins are used. In their prospective,
randomized study, Kocher and fourteen coauthors detected no difference in loss
of reduction or in ulnar nerve injury between the group of twenty-eight
patients who had lateral pin placement only and the group of twenty-four
patients who had medial and lateral pin placement. The number of patients
treated was small but was shown to be sufficient for the detection of 10%
difference between the two arms of this study group. The final study group of fifty-two
patients represented about one-third of the 153 children who were eligible for
the study. Perhaps partly illustrative of how difficult it is to carry out a
Level-1 study among orthopaedic surgeons, approximately 10% of their initial
study group had to be excluded because some of the ten experienced pediatric
orthopaedic surgeons deviated from the protocol by adding additional pins to
stabilize the fracture (four patients) or by placing the pins in an unacceptable
configuration (two patients).
Sankar and coauthors appropriately urge caution in using
only two lateral pins in unstable type-III fractures. Once the closed reduction
is completed in the operating room, it is essential to ensure that there is
anatomic reduction before placing the pins. With the elbow held in a fully
flexed position, the shoulder should be rotated externally and internally to
obtain a 45° oblique fluoroscopic image of the distal portion of the humerus to
confirm that the cortical reduction is anatomic. In addition, a lateral
fluoroscopic image is needed to confirm that there is full reduction in this
plane as well. If there is even slight offset on the anteroposterior or oblique
images or if there is rotational malalignment of the fracture fragments on the
lateral image, the reduction needs to be repeated. The elbow is extended and
the fracture displaced to its resting position for a further attempt at
fracture reduction. If medial comminution is present, a valgus force on the
elbow is useful in maintaining the appropriate anteroposterior alignment as the
elbow is flexed and the distal fragment is pushed anteriorly.
Once I am satisfied that the closed reduction is anatomic, I
prefer to place two lateral pins initially. I agree with the authors of these two
papers that the initial two lateral pins need to be placed in a divergent or
parallel fashion, with at least 2 mm of space between the two pins. I always
stress the pinned fracture by moving the elbow through a full range of flexion
and extension maneuvers while viewing the elbow under fluoroscopy in the
lateral plane, and I also place the elbow under varus and valgus stress while
viewing it under fluoroscopy in the frontal plane, as suggested by Sankar and
coauthors. If any motion at the fracture site is seen on these stress views, either
an additional pin must be added or at least one of the original pins must be
repositioned, or possibly both of these steps may need to be performed. Before applying
the cast and leaving the operating room, a fluoroscopic examination must be
performed to verify that the reduction is anatomic and the fracture is stable. In
the series of Kocher et al., seven of their fifty-two patients had "a mild loss
of reduction," which was noted not to be significant, but the goal of surgical
treatment should be to avoid all loss of fracture reduction postoperatively.
Iatrogenic injury to the ulnar nerve during pinning of a
supracondylar humeral fracture in a child remains a concern with use of the crossed
pin technique, in which at least one of the pins is placed medially. Flexion of
the elbow often results in anterior dislocation or subluxation of the ulnar
nerve in young children, particularly in children who are younger than five
years, and the prevalence increases with decreasing age3. In both of
the present series, if a medial pin was used, a small incision was made to help
locate and avoid the ulnar nerve. Sankar and associates report using a 5-mm
incision, and Kocher and associates used a 15 to 30-mm incision. When a medial
incision is used to locate the ulnar nerve, it has been my experience that the
incision should be at least 15 mm in length to permit adequate identification
of this nerve and protect it when the medial pin is inserted. Care should also
be taken to insert the pin anteriorly on the medial epicondyle, with the
position confirmed on a lateral fluoroscopic image; a posterior entry site for
the medial pin is more likely to injure the ulnar nerve. While the authors of both
of these papers recommend that the medial pin, when used, should be placed with
the elbow in relative extension, I have found that pin placement becomes
technically more difficult as elbow extension increases. In practice, relative
extension is most practically a position of about 70° of elbow flexion,
particularly if a medial incision has been used for the purpose of visualizing
the nerve.
Supracondylar humeral fractures in children are common, and
large numbers of children with this fracture are treated annually at all
pediatric hospitals. Operative treatment of this fracture has markedly lowered
the rate of cubitus varus deformity after fracture-healing. As with pediatric
fractures in general, there is more reluctance on the part of general
orthopaedists to treat these injuries than was the case a generation ago. In
truth, the large majority of these supracondylar humeral fractures have no
vascular or neurological injury associated with the fracture and can be readily
and relatively easily treated by general orthopaedists. The information
provided in these two papers helps to lay out the framework for that treatment.
In type-II fractures, two lateral divergent or parallel pins, separated by at
least 2 mm, are sufficient fixation to avoid displacement. In type-III
fractures, anatomic reduction and the placement of either two or three lateral
pins or one medial and one or two lateral pins will provide appropriate
stability; the exact final pin configuration can be guided by assessing the
amount of stability present on fluoroscopic examination in the operating room
after the initial two pins have been placed. When a medial pin is used, an open
incision to visualize the ulnar nerve prior to pin placement has resulted in
lower iatrogenic injury to the ulnar nerve than has been reported historically.
Keeping these guidelines in mind will lead to excellent clinical results with
few complications in the treatment of this common childhood fracture.
*The author did not receive any outside funding or grants in support of his research for or preparation of this work. Neither he nor a member of his immediate family received payments or other benefits or a commitment or agreement to provide such benefits from a commercial entity. No commercial entity paid or directed, or agreed to pay or direct, any benefits to any research fund, foundation, division, center, clinical practice, or other charitable or nonprofit organization with which the author, or a member of his immediate family, is affiliated or associated.
References
1. Skaggs DL, Hale JM, Bassett J, Kaminsky C, Kay RM, Tolo VT. Operative treatment of supracondylar fractures of the humerus in children. The consequences of pin placement. J Bone Joint Surg Am. 2001;83:735-40.
2. Millis MB, Singer IJ, Hall JE. Supracondylar fracture of the humerus in children. Further experience with a study in orthopaedic decision-making. Clin Orthop Relat Res. 1984:188:90-7.
3. Zaltz I, Waters PM, Kasser JR. Ulnar nerve instability in children. J Pediatr Orthop. 1996;16:567-9.
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