|
Abstract
This study aimed to study
the role played by the CT scan in decision making in the
management of intra-articular fractures of the calcaneum.
Twenty-four patients with intra-articular fractures of the
calcaneum were included. Their initial radiographs and CT films
were blinded and assessed by three independent observers. Based
on these they were selected for operative or non-operative
management. The actual management was also recorded. The data
was then subjected to statistical analysis to look at the
association between the decision from radiograph, that from the
CT scan and the actual management undertaken. Non-parametric
tests for related samples were performed to look at the
association between the actual management and the decisions made
by assessing the radiographs and the CT scans. There was no
significant difference between the actual management and
decisions made by assessing the plain radiographs or the CT
scan, for all three observers. There was also no significant
difference between the radiograph based decisions and CT based
decisions. However, the Cochran Q test showed that there was
significant variation between the three observers, for the CT
based assessment. Our results, show that the CT scan should only
be done when a definite decision is made to operate on a
patient, based on plain radiographs. Calcaneal fractures which
are selected for non-operative management, based on X rays,
should not have a CT scan as a routine as it provides no
valuable additional information affecting the management
decision.
Key words: Calcaneum,
Computerised Tomogram, Intra-articular, Os Calcis.
J.Orthopaedics 2006;3(2)e4
Introduction:
Fractures of the calcaneum
account for 1-2 percent of all fractures and the most common of
the tarsal bones fractures1,2. They are usually the result of a
fall from a height.They are commonly bilateral and are
associated with fractures of the spine.. The fractures can be
classified as those involving the talo-calcaneal joint, subtalar,
( intra-articular) and those that do not. The injury is found
predominantly in young or middle aged men and causes a very
significant loss to economic activity, as it make take up to 18
months for full weight bearing3. It also results in residual
heel pain, deformity and swelling in many individuals. It is
thus imperative to get a good pain free functional outcome in
these patients.
The management of
calcaneal fractures is the subject of much debate and
controversy4,5,6,7 .It may be operative or non-operative, and
there have been various studies in the literature which claim
similar results in both these groups. However, recently
published, randomised control trial, comparing operative and
non-operative management, show slightly better outcomes in
certain groups of patients treated surgically8. Non-operative
interventions involve the use of ice, elevation, plaster
splintage and early mobilisation. The operative methods involve
closed reduction with pins, open reduction and internal fixation
and arthrodiesis2,6. The management decision to operate or not
is based on assessment of the axial and lateral radiographs and
a CT scan. There have been various classification systems based
on radiographs9,10 and CT11,12,13,14.The classification system
proposed by Sanders15, has been found useful in determining
treatment and prognosis. However this CT based classification
system has high degrees of variability and inconsistencies16. It
has been suggested that the best method of assessing a calcaneal
fracture is a CT scan. We set out to see the role that a CT scan
plays in the management of these fractures and to determine if
it makes any difference in the decision making process.
Material and Methods :
This was a retrospective
cohort study. Twenty three individuals with twenty four
fractures of the calcaneum were included in the study. Only
intra-articular fractures, involving the talo-calcaneal joint,
were included. These fractures were investigated with lateral
and axial radiographs, and a CT Scan. The actual management, in
dichotomous groupings, (operative or non-operative), was also
documented. The films were then blinded to name and age, placed
in random order and assessed by three individual observers at
different points in time. The observers were asked to assign the
radiographs to operative or non-operative management. The CT
scan films were then similarly assessed for operative or
non-operative treatment. The observers were not told of the
management decision that they had made based on the radiographs
, before they graded the CT scan films. The results were then
analysed using a statistical software (SPSS version 11).
Results :
The agreement between the
actual management and the management decision made from
assessing the radiographs, and the actual management and
management decision assessing the CT scans were analysed, for
each of the three observers. The data was non-parametric and
related. The Sign test was used to analyse if the decisions made
in each of the groups were significantly different from the
actual management. The results are enumerated in table 1 and
table 2.
The p value, for the Sign
test, was greater than 0.05 for all sets of observations. This
means that there is no statistically significant difference, at
the 5 percent level, between the management decision from the
radiographs and actual management ( Table 1) or the CT films
and the actual management (Table 2), for each of the observers.
This implies that there is good agreement between the decisions
and the actual management, for both the CT and the radiographs.
Table 1: SIGN
test – Radiographs versus Actual management
|
|
Significance,
(P value) |
Number of agreements
( out of 24) |
|
Observer 1 |
0.75 |
14 |
|
Observer 2 |
0.06 |
13 |
|
Observer 3 |
0.72 |
16 |
Table 2: SIGN
test – CT scan versus Actual management
|
|
Significance, (P
value) |
Number of agreements
( out of 24) |
|
Observer 1 |
0.75 |
14 |
|
Observer 2 |
0.05 |
10 |
|
Observer 3 |
0.29 |
16 |
The change in management
that the CT scan brought about was also assessed for each of the
observers using the McNemars test. This test is used to detect
changes in responses in each case, brought about by the CT scan.
This was carried out as the data was non-parametric, related and
the response, dichotomous. There was no statistically
significant difference ( P >0.05) in the decision made ( i.e
non-operative or operative), between the radiographs and the CT
scan assessments, for all three observers. Thus, a CT scan did
not make any significant difference to the decision made based
on the plain radiographs, on whether to operate.
A statistical analysis was
also performed to assess the variability of the management
decisions of the 24 fractures between the three observers. A
Cochran Q test was used for the analysis showing that there was
no significant difference ( Q=3.84, p value = 0.14) between the
radiograph based assessments of the three observers. However,
there was statistically significant difference (Q=9.50, p value
=0.009) between the CT scan based assessments of the observers.
This shows that there is more inter-observer variability in
decision making, using the CT based assessment.
The results show that both
the radiograph based management and the CT scan based management
decision, did not significantly differ from the actual
management. There was also no statistically significant
difference between the decisions based on the two modalities. A
CT scan, therefore, does not significantly change the management
decision, from what has already been decided from assessing the
plain radiographs.
Discussion :
The typical assessment of
intra-articular fractures of the Os Calcis are lateral and axial
plain radiographs, followed by a CT scan. There is a tendency to
request a scan to delineate the fracture fragments, as a
routine, when the plain radiograph suggests an intra-articular
fracture. It has been suggested that the best method of
assessing an intra-articular fracture, to decide management is a
CT scan. It is thought that the scan would help to delineate the
fracture fragments better than a plain radiograph and thus, help
in making the management decision. However, the best known CT
based classification system of Sanders, has been shown to have
high degrees of variability and inconsistencies1. In our present
study, it was demonstrated that there was good correlation
between the final actual management and both, the plain
radiograph and the CT scan. There was no difference in the
management decisions ( operative or non-operative), between the
plain radiographs and the CT scan. The McNemars test performed
to see if the CT scan made any change to the management decision
made based on plain radiograph showed that it did not
significantly alter the decision, for all three observers. In
fact, the decisions based on the CT scan showed a greater degree
of variability between the observers, than the decisions based
on plain radiographs. This was demonstrated by the Cochran Q
test , (p<0.01). These tests suggest that the management
decision on whether to operate or not, can reliably be based
solely on plain radiographs. Thus, there may be no need to
obtain a CT scan as a routine in all intra-articular fractures
of the Os Calcis. However once, the decision has been made to
operate, the CT scan is useful in providing further detail of
the fracture pattern.
Conclusion:
We conclude that, the CT
scan should only be requested when a decision is made to operate
on the fracture, based on plain radiographs. This may help in
delineating the fragments in a comminuted fracture, and may help
in pre-operative planning of fracture fixation. It does not have
to be obtained as a routine to assess all intra-articular
fractures of the calcaneum.
Acknowledgements:We would
sincerely like to thank Mr R Liow, Consultant Orthopaedic
Surgeon, Friarage Hospital, Northallerton and Mr J Candal-Couto,
Consultant Orthopaedic Surgeon, Wansbeck General Hospital, for
kindly sparing their time to classify the radiographs and the
scans.
Reference :
-
Burns AE. Fractures of the calcaneum-
Symposium on osseous trauma of the foot. Clinical Podiatric
Medicine and Surgery 1985;2:311.
-
Gurtowski J, Ries MD,
Levin PE. Fractures and Dislocations of the foot In:Dee R,
Mango E, Hurst L, editor(s). Principles of Orthopaedic
Practice. USA. McGraw-Hill Inc,1989:1242-1260.
-
Bridgman SA, Dunn KM,
McBride DJ, Richards PJ. Interventions for treating calcaneal
fractures ( Cochrane review ) In: The Cochrane Library, Issue
2, 2004. Chichester UK, John Wiley & Sons, Ltd.
-
Kenwright J. Fractures
of the calcaneum. Journal of Bone and Joint Surgery (Br)
1993;75:176-77.
-
Lowery RB, Calhoun JH.
Fractures of the Calcaneus. Part 1: Anatomy, Injury mechanism
and classification. Foot and Ankle International
1996;17:230-35.
-
Lowery RB, Calhoun JH.
Fractures of the Calcaneus. Part 2: Treatment. Foot and Ankle
International 1996;17:360-66.
-
Thordarson DB, Krieger
LE. Operative Vs Non-operative treatment of Intra- articular
fractures of the calcaneum. A prospective randomised trial.
Foot & Ankle International 1996; 17(1): 2-9.
-
8. Buckley R, Tough S,
McCormack R et al. Operative compared with non-operative
treatment of displaced intra-articular calcaneal fractures.
Journal of Bone and Joint Surgery (Am) 2002;84-A:1733-44.
-
Essex-Lopresti P. The
mechanism, reduction techniques and results in fractures of
the Os Calcis. British Journal of Surgery 1952;39:395-419.
-
Soeur R, Remy R.
Fractures of the calcaneus with displacement of the thalamic
portion. Journal of Bone and Joint Surgery(Br)
1975;57-B:413-21.
-
Crosby LA, Fitzgibbons
TC. Computerised tomography scanning of acute intra-
articular fractures of the calcaneum: a new classification
system. Journal of Bone and Joint Surgery (Am)
1990;72-A:852-9.
-
Eastwood DM, Gregg PJ,
Atkins RM. Intra-articular fractures of the calcaneum part 1:
pathological anatomy and classification. Journal of Bone and
Joint Surgery (Br)1993;75-B:183-8.
-
Sanders R. Displaced
Intra-articular fractures of the Calcaneus. Journal of Bone
and Joint Surgery(Am) 2000;82A:225-50.
-
Zwipp H, Tscherne H,
Thermann H, Weber T. Osteosynthesis of displaced intra-articular
fractures of the calacaneus: results in 123 cases. Clinical
Orthopaedics 1993;290:76-86.
-
Sanders R, Fortin P,
Dipasquale T, Walling A. Operative treatment in 120 displaced
intra-articular calcaneal fractures: results using a
prognostic computed tomographiy scan classification. Clinical
Orthopaedics 1993;290:87-95.
-
Bhattacharya R, Vassan
UT, Finn P, Port A. Sanders classification of fractures
of the Os Calcis. An analysis of inter- and intra-observer
variability. Journal of Bone and Joint Surgery (Br)
2005;87-B:205-8.
|
