Keywords carpal bones/injuries - wrist injuries - joint dislocations - fractures, bone
Introduction
Wrist perilunate fractures and dislocations are uncommon conditions, corresponding
to approximately 7% of all carpal injuries.[1 ] These lesions have serious repercussions for affected patients if not properly diagnosed
and treated. Perilunate fractures and dislocations are caused by high-energy traumas,
such as car accidents, falls from height and contact sports, and they are often associated
with other traumatic injuries. Patients present with diffuse wrist pain, edema, loss
of range of motion and fingers in a semi-flexed position. Subjects may also complaint
of paresthesia in the median nerve territory and acute carpal tunnel syndrome.[2 ]
Radiographic evaluation is essential to manage these patients, and posteroanterior
(PA) and lateral (L) views are sufficient for diagnosis. Posteroanterior radiography
with ulnar deviation of the wrist helps to assess trans-scaphoid perilunate fracture-dislocations.[2 ] On PA radiography, it is important to observe Gilula lines, which are imaginary
lines drawn through the proximal and distal aspects of the proximal row and the proximal
aspect of the distal row. These three lines should be smooth, parallel arches, and
breaks suggest carpal incongruity.[3 ] Lateral radiographies show the alignment of the capitate, lunate and radius bones.
These bones must be properly aligned, and any alignment change strongly suggests a
perilunate dislocation. Computed tomography scans can be useful when there are associated
complex fractures, such as scaphoid and pyramidal fractures, and they must be performed
after dislocation reduction.[4 ]
In 1980, Mayfield et al.[5 ] performed a cadaveric study and classified this condition in four progressive stages.
An axial force was applied with wrist hyperextension associated with ulnar deviation
and intercarpal supination to reproduce the injury. In stage I, they observed scapholunate
ligament rupture or scaphoid fracture. In stage II, a lunate-capitate subluxation
was observed, and some cases may present capitate fractures. Stage III was characterized
by lunate-pyramidal ligament injury or pyramidal fracture, with a dorsal perilunate
dislocation of the entire carpus. Stage IV presented palmar lunate dislocation towards
the carpal tunnel when the capitate is reduced to the lunate fossa.[5 ]
Due to the low frequency of these injuries and low familiarity of most orthopedists
with the complex anatomy of carpal bones, perilunate dislocations often are not diagnosed
at the first visit.[1 ]
[2 ] In a multicenter study with 166 patients, Herzberg et al.[6 ] demonstrated that diagnosis was not made at the initial evaluation in 25% of the
cases of simple dislocations and trans-scaphoid lunate fracture-dislocations. This
data is troublesome, since early diagnosis and treatment are critical to minimize
serious complications such as stiffness, chronic pain and posttraumatic arthrosis.[2 ]
[4 ]
[7 ]
[8 ] In addition, treatment delay was shown to negatively impact the final outcome.[6 ]
[9 ]
This reality reported by international studies does not seem to be different from
the Brazilian reality. Our service, which specializes in hand surgery, receives many
patients with chronic perilunate dislocations who were not properly diagnosed at a
first orthopedic visit, affecting the treatment outcome.
The present study aimed to evaluate the failure rate in perilunate fractures and dislocations
diagnosis using plain wrist radiographs by orthopedists and orthopedic residents.
In addition, this study attempted to identify possible groups presenting a greater
or lesser chance of a correct diagnosis.
Materials and Methods
An online questionnaire was prepared and applied using the Google Forms platform (Google
LLC, Menlo Park, CA, USA) [10 ] and sent to orthopedists and orthopedic residents through e-mail, social networks
(Workplace from Facebook [Facebook Inc., Menlo Park, CA, USA] from Sociedade Brasileira de Ortopedia e Traumatologia [SBOT]), and smartphone-based communication applications (WhatsApp [Facebook Inc.]).
These platforms were chosen because they can provide a wide reach for the questionnaire
and provide a convenient way for orthopedists and orthopedics residents to answer
it. The questionnaire consisted of four initial questions to analyze the profile of
the study subjects. These questions were related to time (in years) since medical
residency, area of activity, SBOT accreditation, and work in urgency/emergency units
for patients with upper limb trauma. In the second stage of the questionnaire, eight
PA and lateral radiographs of the wrist were shown, with three normal images and five
with pathological findings. Pathological radiographs include a simple perilunate dislocation,
a perilunate fracture-dislocation, a scaphoid fracture, and two images showing a distal
radial fracture. After analysis, professionals answered whether the radiograph was
normal or if there was a fracture and/or dislocation. Radiographs were presented in
a random order. Questionnaires answered in an incomplete or contradictory way were
excluded. A chi-square test was used to verify the association between qualitative
variables. In addition, this association was quantified using logistic regression
models[11 ] to calculate the gross odds ratio (OR) and their respective 95% confidence intervals.
This work was approved by the institutional ethics committee under CAAE number 84365318.3.0000.5440.
Results
A total of 511 responses were obtained. Of these, 194 (38%) orthopedists had more
than 10 years of experience, 225 (44%) had less than 10 years of experience, and 92
(18%) were residents. Of the 419 trained orthopedists, 352 (84%) were accredited by
the SBOT, and 67 (16%) did not have a specialist title recognized by SBOT. In addition,
among these 419 orthopedists, 172 (41%) work in hand surgery, 90 (21.5%) are general
orthopedists, and 157 (37.5%) work as specialists in other areas, such as spine, knee,
and shoulder. Of the 511 professionals, 436 currently work in an emergency unit treating
upper limb trauma (85.3%).
[Figure 1 ] shows a radiograph from a simple, Mayfield stage III perilunate dislocation. The
diagnostic error rate was 8.81%. This error rate was 23.91% among residents and 5.49%
among trained orthopedists ([Figure 2 ]). The chance of a resident missing a diagnosis (OR) was 4.3 times higher compared
to orthopedists with more than 10 years of experience and 6.7 times higher compared
to orthopedists with less than 10 years of experience. When compared by surgical area,
hand surgeons had the lowest error rate, of 1.74%. The chance of a general orthopedist
and a specialized orthopedist making a mistake was about 5 times higher compared to
hand surgeons (OR 0.211 and 0.197, respectively). Comparing residents with hand surgeons,
the chance of error was about 17.5 times higher (OR 0.057). P values were lower than
0.001 ([Table 1 ]).
Fig. 1 Perilunate dislocation, Mayfield stage III.
Fig. 2 Correct diagnoses percentage: Residents versus Nonresidents.
Table 1
X-ray 1
Miss (0)
Hit (1)
n (%)
n (%)
Total
p -value[* ]
Gross odds ratio
Confidence interval (95%)
Question 1: What is your current degree?
1
13 (2.54)
181 (35.42)
194 (37.96)
< 0.001
4.376
(2.090–9.163)
2
10 (1.96)
215 (42.07)
225 (44.03)
6.757
(3.052–14.958)
3
22 (4.31)
70 (13.70)
92 (18.00)
1.000
Reference
Question 2: What is your area of expertise?
1
3 (0.59)
169 (33.07)
172 (33.66)
< 0.001
1.000
Reference
2
7 (1.37)
83 (16.24)
90 (17.61)
0.211
(0.053–0.835)
3
13 (2.54)
144 (28.18)
157 (30.72)
0.197
(0.055–0.704)
4
22 (4.31)
70 (13.70)
92 (18.00)
0.057
(0.016–0.195)
Question 3: Are you an orthopedist/traumatologist accredited by Sociedade Brasileira de Ortopedia e Traumatologia (SBOT)?
1
19 (3.72)
333 (65.17)
352 (68.88)
< 0.001
5.508
(2.831–10.719)
2
4 (0.78)
63 (12.33)
67 (13.11)
4.950
(1.618–15.147)
3
22 (4.31)
70 (13.70)
92 (18.00)
1.000
Reference
Question 4: Do you currently work in an urgency/emergency unit for upper limb trauma orthopedic
treatment?
1
37 (7.24)
399 (78.08)
436 (85.32)
0.5382
1.288
(0.575–2.886)
2
8 (1.57)
67 (13.11)
75 (14.68)
1.000
Reference
The radiograph from [Figure 3 ] shows a stage III trans-scaphoid perilunate fracture. The global diagnostic error
rate was 1.76%. Error rate was 7.61% among residents and 0.48% among orthopedists
([Figure 2 ]). This represents an OR of 9.1 for orthopedists with less than 10 years of experience
and 3.6 for general orthopedists, with a p -value < 0.001. All orthopedists with more than 10 years of experience, hand surgeons,
and specialized orthopedists correctly diagnosed this radiography ([Table 2 ]).
Fig. 3 Trans-scaphoid lunate fracture-dislocation, Mayfield stage III.
Table 2
X-ray 2
Miss (0)
Hit (1)
n (%)
n (%)
Total
p -value[* ]
Gross odds ratio
Confidence interval (95%)
Question 1: What is your current degree?
1
0 (0.00)
194 (37.96)
194 (37.96)
< 0.001
–
–
2
2 (0.39)
223 (43.64)
225 (44.03)
9.182
(1.870–45.082)
3
7 (1.37)
85 (16.63)
92 (18.00)
1.000
Reference
Question 2: What is your area of expertise?
1
0 (0.00)
172 (33.66)
172 (33.66)
< 0.001
–
–
2
2 (0.39)
88 (17.22)
90 (17.61)
3.624
(0.732–17.938)
3
0 (0.00)
157 (30.72)
157 (30.72)
–
–
4
7 (1.37)
85 (16.63)
92 (18.00)
1.000
Reference
Question 3: Are you an orthopedist/traumatologist accredited by Sociedade Brasileira de Ortopedia e Traumatologia (SBOT)?
1
1 (0.20)
351 (68.69)
352 (68.88)
< 0.001
28.906
(3.509–238.094)
2
1 (0.20)
66 (12.92)
67 (13.11)
5.435
(0.653–45.274)
3
7 (1.37)
85 (16.63)
92 (18.00)
1.000
Reference
Question 4: Do you currently work in an urgency/emergency unit for upper limb trauma orthopedic
treatment?
1
7 (1.37)
429 (83.95)
436 (85.32)
0.5187
1.679
(0.342–8.241)
2
2 (0.39)
73 (14.29)
75 (14.68)
1.000
Reference
There were no relevant differences between trained orthopedists with SBOT, accreditated
or not. As for the normal radiographs presented in the questionnaire, 38.49% of the
answers classified them as pathological.
Discussion
There was a very significant number of responses, with good participation from the
orthopedic community. The 511 responses obtained correspond to approximately 3% of
Brazilian orthopedists.[12 ] However, this was a convenience sample, which may limit the external validity of
the study and may not necessarily be representative of all geographic regions of the
country.
Most articles regarding the diagnostic failure rate in simple or complex perilunate
dislocation cite a study from Herzberg et al.,[6 ] performed in Europe in 1993. These authors reported a 25% rate, with no discrimination
between simple and complex dislocations. In a more recent study published in Turkey
in 2018, there was a 22.7% rate of diagnostic failure in 44 patients with perilunate
dislocation or fracture-dislocation. The only risk factor found was the orthopedist
inexperience with the condition. Among the surgeons missing the diagnosis, 70% said
it was the first time they encountered this condition.[13 ] Another recent study, published in 2018, evaluated perilunate dislocation and fracture-dislocation
in a population of military personnel in the United States and found a diagnostic
failure at initial care in 27.5% of cases.[14 ] We found significantly lower error rates, of 8.81% for simple perilunate dislocations
and 1.76% for perilunate fractures-dislocations. Such results may be due to a high
suspicion rate among orthopedists, who, feeling observed and tested, may have changed
their behavior for fear of making mistakes. This is indicated by findings of fractures
or dislocations in 38.49% of the answers related to normal radiographs. Another aspect
interfering with the diagnostic accuracy rate is the time the patient was seen in
the emergency room and the amount of rest the doctor had.[13 ]
[15 ] In Turkey, Çolak et al.[13 ] reported that 70% of patients diagnosed incorrectly were admitted to the emergency
room at night. The design of our study did not allow an analysis of this variable,
which is a particular feature of the clinical practice.
It should also be considered that the questionnaire does not correspond to the clinical
practice, in which it is possible to take the history and perform a physical examination
of the patient, generating a greater or lesser index of suspicion for a given condition
depending on the clinical findings. However, our study may suggest that the diagnostic
failure rate is not as high as previously thought and that the European study from
Herzberg et al.[6 ] does not represent the Brazilian reality. Another hypothesis is that errors may
be decreasing due to the improved training of physicians in residency programs since
1993, when Herzberg's study was carried out. One aspect that corroborates this last
hypothesis is that there was a significant difference between resident doctors and
trained orthopedists (23.9% versus 5.49%), thus demonstrating that the orthopedics
and traumatology residency is effective in instructing residents to identify this
condition on plain radiographs.
Hand surgeons had the lowest error rates, as expected, due to their greater familiarity
with the condition. In contrast, SBOT accreditation as a specialist was not related
to differences in the correct diagnosis rate.
Our study indicates that the diagnostic error rate for perilunate dislocations may
be lower than that described in the classical literature. However, this statement
requires studies with a higher level of scientific evidence in order to be confirmed.
A suitable option would be a multicenter case-control study, as it reflects clinical
practice with greater reliability and provides a satisfactory number of cases, since
perilunate dislocations are not common and one hospital alone could bias the study
due to its specific demographic features.
Conclusion
The diagnostic error rate of plain radiographs was 8.91% for isolated perilunate dislocations
and 1.76% for perilunate fractures-dislocations, suggesting that this is an effective
method and that the error rate may not be as high as expected. Hand surgeons and orthopedic
residents, respectively, presented the lowest and highest diagnostic error rates.
