Imaging in early posttraumatic complex regional pain syndrome: a comparison of diagnostic methods.
OBJECTIVE
The complex regional pain syndrome type I (CRPS I) still is difficult to diagnose in posttraumatic patients. As CRPS I is a clinical diagnosis the characteristic symptoms have to be differentiated from normal posttraumatic states. Several diagnostic procedures are applied to facilitate an early diagnosis, although their value for diagnosing posttraumatic CRPS I is unclear.


METHODS
One hundred fifty-eight consecutive patients with distal radial fracture were followed up for 16 weeks after trauma. To assess the diagnostic value of the commonly applied methods a detailed clinical examination was carried out 2, 8, and 16 weeks after trauma in conjunction with bilateral thermography, plain radiographs of the hand skeleton, three phase bone scans (TPBSs), and contrast-enhanced magnetic resonance imaging (MRI). All imaging procedures were assessed blinded.


RESULTS
At the end of the observation period 18 patients (11%) were clinically identified as having CRPS I and 13 patients (8%) revealed an incomplete clinical picture which were defined as CRPS borderline cases. The sensitivity of all diagnostic procedures used was poor and decreased between the first and the last examinations (thermography: 45% to 29%; TPBS: 19% to 14%; MRI: 43% to 13%; bilateral radiographs: 36%). In contrast a high specificity was observed in the TPBS and MRI at the eighth and sixteenth-week examinations (TPBS: 96%, 100%; MRI: 78%, 98%) and for bilateral radiographs 8 weeks after trauma (94%). The thermography presented a fair specificity that improved from the second to the sixteenth week (50% to 89%).


CONCLUSIONS
The poor sensitivity of all tested procedures combined with a reasonable specificity produced a low positive predictive value (17% to 60%) and a moderate negative predictive value (79% to 86%). These results suggest, that those procedures cannot be used as screening tests. Imaging methods are not able to reliably differentiate between normal posttraumatic changes and changes due to CRPS I. Clinical findings remain the gold standard for the diagnosis of CRPS I and the procedures described above may serve as additional tools to establish the diagnosis in doubtful cases.
Schürmann
Matthias
M
Department of Trauma and Orthopedic Surgery, Sana Klinikum Hof, University of Erlangen-Nürnberg, Eppenreuther Strasse 9, 95035 Hof, Germany. matthias.schuermann@klinikumhof.de
Zaspel
Johannes
J
Löhr
Pascal
P
Wizgall
Ingrid
I
Tutic
Michaela
M
Manthey
Nikolaus
N
Steinborn
Marc
M
Gradl
Georg
G
D000368:Aged; D000369:Aged, 80 and over; D003937:Diagnosis, Differential; D005260:Female; D006225:Hand / Q000000981:diagnostic imaging; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D010147:Pain Measurement; D011237:Predictive Value of Tests; D011446:Prospective Studies; D011859:Radiography; D011877:Radionuclide Imaging; D011885:Radius Fractures / Q000150:complications / Q000000981:diagnostic imaging; D012019:Reflex Sympathetic Dystrophy / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000209:etiology*; D015203:Reproducibility of Results; D013817:Thermography; D014947:Wounds and Injuries / Q000150:complications* / Q000000981:diagnostic imaging