EDITOR'S NOTE: The corresponding author was invited to respond to this letter but to date has not done so.
To the Editor:
I read with interest the article by Leitch, et al,(1) which describes
a technique that immobilizes the patients’ arm while moving the
C-Arm to obtain AP and lateral radiographs during the percutaneous pinning
of multidirectionally unstable supracondylar humeral fractures in a
paediatric population. I agree that this fracture should be classified as Gartland IV as
suggested by the authors(1) to ensure that it is considered as a complex and unstable fracture.
Our technique varies somewhat from that recommended by the authors. We prefer to introduce the lateral wire prior to manipulation. Once
it is secured into the proximal cortex, only then is the medial wire
introduced as this now gives stability to the distal fragment. Before we began to use this technique,
we had problems with the slippage of fragments when we moved the arm to take the lateral radiograph. An important help in
the use of this technique is to use a separate table rather than using C-
ARM as a table.
It would be interesting to know the modal age of the study group. This is important because some authors have
recommended that different K Wire sizes be used depending on patient age. The authors(1) used K wires of 0.62mm diameter in their study. In a clinical audit carried
out in United Kingdom only wires of 1.6mm were used; failure to follow
the guidelines regarding age and K wire diameter resulted in unsatisfactory outcomes(2).
It would also be helpful to know the interval between the injury and the operative prodedure because delay is associated with complications. With delay, there is increased
swelling that may result in difficulty in palpating bony landmarks intra-operatively(3). One
would expect that in these severe injuries where the periostial hinge is not
intact, the swelling could be more than usual.
Treatment of supracondylar humeral fractures by K- wires was first
described by Swenson(4) more than 50 years
ago but we have not yet reached a consensus on which method is superior. Zionts, et al, have shown using an adult human cadaver model, that 2
crossed medial and lateral k wires, are likely to be more stable than 3
or 2 parallel lateral k wires after using four different configurations of
K wires. In a comparison of all the groups, the torque required to produce
10 degrees of rotation averaged 37 per cent less with use of two lateral
parallel k wires and 80 per cent less with use of two lateral crossed K
wires (p < 0.05 for both). The average torque required to produce 10
degrees of rotation with use of three lateral k wires was 25 per cent less
than with use of two medial and lateral crossed k wires. The maximum
stability was provided by two crossed k wires placed from the medial and
lateral condyles(5).
The argument that when using a medial K-Wire, there is an increased risk of
damage to ulnar nerve is valid(6) but attention to following points can
help avoid this complication:
• Try to pass K-Wire obliquely through medial epicondyle, just proximal to
olecranon fossa
• Do not flex the elbow (with flexion, the ulnar nerve can sublux over
the medial condyle placing it at risk with medial k wire insertion)
• Using one’s thumb over the cubital tunnel area helps to keep the ulnar
nerve in its posterior position
• Make a small stab incision in the skin over the medial epicondyle, and
then spread with an artery forceps
• Using soft tissue protector to further protect the ulnar nerve
• Directing the medial k wire slightly anteriorly, as medial epicondyle is
slightly posterior to the shaft of Humerus
• Ensuring that the medial K Wire enters straight into the epicondyle
rather than distal to the medial epicondyle;
• The two wires should cross proximal to the olecranon fossa (7)
Finally, It would be
interesting to know whether any specific criteria such as those of Flynn
(8) or the post operative measurement of Baumann’s Angle were used,
or was success measured in terms of range of motion only. Was there a uniform post operative mobilization regimen?
In
our experience we are not able to achieve full ROM of the elbow and there
is always a residual extension lag.
References:
1. K.K. Leitch, R.M. Kay, J.D. Femino, V.T. Tolo, S.K. Storer, and
D.L. Skaggs, Treatment of Multidirectionally Unstable Supracondylar
Humeral Fractures in Children. A Modified Gartland Type-IV Fracture J Bone
Joint Surg Am. 2006;88:980-985
2. O'Hara LJ, Barlow JW, Clarke NM. JBJS Br 2000 Mar;82(2):204-10.
Displaced Supracondylar fractures of the Humerus in children. Audit
changes practice. Southampton General Hospital, England.
3. Charles T. Mehlman. J Bone Joint Surg [Am] 83-A: 323-7, 2001, The
Effect of Surgical Timing on the Perioperative Complications of Treatment
of Supracondylar Humeral Fractures in Children.
4. Swenson AL: Treatment of Supracondylar fractures of the Humerus by
Kirschner wire transfixation. J Bone Joint Surg 30:993-7, 1948.
5. Zionts , L.E. et al JBJS 76A: 253-256, 1994 Torsional strength of
pin configurations used to fix Supracondylar fractures of the humerus in
children.
6. David L. Skaggs, MD. JBJS (Am) 83:735-740 (2001) Operative
Treatment of Supracondylar Fractures of the Humerus in Children. The
Consequences of Pin Placement
7. Otsuka NY, Kasser JR: Supracondylar fractures of the humerus in
children. J Am Acad Orthop Surg 5:19-26, 1997.
8. Flynn JC, Richards JF Jr., Saltzman RT: Prevention and treatment
of non-union of slightly displaced fractures of the lateral humeral
condyle in children. J Bone Joint Surg 57A:1087, 1975