To the Editor:
We read with great interest the article, “Estimating
the Risk of Nonunion Following Nonoperative Treatment of a Clavicular Fracture”
(2004;86:1359-1365). This is a large consecutive series of 868 patients seen at
the Shoulder Injury Clinic, Orthopaedic Trauma Center in Edinburgh, Scotland.
The authors are to be congratulated and commended on greater than 75% follow-up
at 24 weeks in such a large population.
While the authors have provided a means for the reader to
estimate the probability of nonunion by age, gender, and fracture type, we
believe an important take-home message has been obscured by the method of
written presentation. Specifically: what should orthopaedic surgeons now tell
their patients about the outcome of displaced and comminuted diaphyseal fractures?
The classic teaching about clavicle fractures has been that
they all do well and that closed isolated injuries rarely, if ever, require
operative stabilization. Several recent studies1-3 have challenged this
“conventional wisdom” by demonstrating a relatively high rate of nonunion in
displaced diaphyseal fractures and even unsatisfactory results in some patients
who heal in a non-anatomic position. Consequently, there has been a move
towards more frequent operative stabilization of acute displaced mid-third
clavicle fractures, and we believe the literature fully supports this trend.
We are concerned that this article may lead to confusion
regarding the natural history of clavicle fractures and that our learning curve
on this topic may become a circle. The Abstract reports the prevalence of
nonunion at 24 weeks as follows: overall prevalence 6.2%; medial end 8.3%;
diaphyseal 4.5%; lateral end 11.5%. The authors conclude “nonunion at
twenty-four weeks after a clavicle fracture is an uncommon occurrence, although
the prevalence is higher than previously reported.” This data and the
Abstract’s conclusion will undoubtedly lead many to once again believe that
almost all closed clavicle fractures do well and rarely, if ever, require
operative treatment. This, of course, could not be further from the truth,
which is actually buried within the authors’ robust data.
The authors’ Table IV provides Cox regression coefficients
“to predict fracture union” and the 95% confidence intervals for relative risk of
nonunion for patients with certain characteristics. As an example, the 95% confidence
interval for “displaced fracture,” when inverted to represent relative risk of
nonunion rather than “risk” of union, indicates that patients with a displaced
fracture are 2 to 3 times more likely to have a nonunion than are patients with
a nondisplaced diaphyseal fracture. Using the information in the authors’ Table
IV in combination with Figure 2, we were able to compute approximate rates of
nonunion at 24 weeks for displaced and displaced-comminuted diaphyseal
fractures (our Table A).
As can be seen, the rates of nonunion for displaced and
displaced-comminuted diaphyseal fractures are relatively high, with a worse prognosis
for women and older patients. The Abstract and Discussion do not clearly state
that the rate of nonunion for displaced fractures in women ranges between 19%
and 33%, and rises to range from 33% to 47% when there is also comminution.
Clearly, operative intervention should be strongly contemplated for certain
subgroups presented in our Table A.
Again, we commend the authors on their excellent work, but
wish they had stated some of their important findings more clearly. The optimal
treatment for clavicle fractures has evolved over the last decade and more
patients are receiving operative stabilization for fractures prone to nonunion.
Table A provides useful summary data of this excellent series, which may be
helpful to treating orthopaedic surgeons and their patients.
Table A. Probability of nonunion at 24 weeks for diaphyseal
clavicle fractures.
|
|
Displaced
|
Comminuted
|
Displaced &
Comminuted
|
Not
Displaced,
Not
Comminuted
|
|
Age (yrs)
|
Females
|
Males
|
Females
|
Males
|
Females
|
Males
|
Females
|
Males
|
|
25
|
19%
|
8%
|
7%
|
3%
|
33%
|
20%
|
3%
|
<1%
|
|
35
|
20%
|
11%
|
8%
|
4%
|
35%
|
21%
|
4%
|
<1%
|
|
45
|
25%
|
14%
|
10%
|
5%
|
37%
|
25%
|
5%
|
1%
|
|
55
|
28%
|
18%
|
12%
|
6%
|
42%
|
29%
|
6%
|
2%
|
|
65
|
33%
|
20%
|
18%
|
7%
|
47%
|
33%
|
7%
|
3%
|
Sincerely,
Mark R. Brinker, MD
Director of Acute and Reconstructive Trauma
Texas Orthopedic Hospital
T. Bradley Edwards, MD
Shoulder Service
Texas Orthopedic Hospital
Daniel P. O’Connor, PhD
Director, Joe W. King Orthopedic Institute
1. Wick M, Muller EJ, Kollig E, Muhr G.
Midshaft fractures of the clavicle with a shortening of more than 2 cm
predispose to nonunion. Arch Orthop
Trauma Surg, 2001;121: 207-11.
2. Robinson
CM. Fractures of the clavicle in the adult. Epidemiology and
classification. J Bone Joint Surg Br,
1998;80: 476-84.
3. Hill
JM, McGuire MH, Crosby LA. Closed treatment of displaced middle-third
fractures of the clavicle gives poor results. J Bone Joint Surg Br, 1997;79: 537-9.
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