Proximal tibial flake fracture mimicking a cystic lesion
Himanshu Sharma and J M Latham
ABSTRACT
Diagnostic errors in orthopaedics are usually caused by missing a fracture or misreading radiographs. We report a case of a proximal tibial metaphyseal flake fracture which mimicked a cystic lesion in the standard radiograph. This case stresses on the importance of third view (i.e. oblique film), apart from the routine anteroposterior and lateral films in solving such diagnostic dilemma. It avoids unnecessary further imaging like CT scan and related ionising radiations.
KEYWORDS: Tibia, Flake fracture, Cystic lesion.
INTRODUCTION
In busy emergency departments where large number of patients are seen, there is a significant risk of radiological errors. The majority of orthopaedic injuries require x-ray films performed in two planes to all suspected areas to reach a final diagnosis. Diagnostic errors in orthopaedics are usually caused by missing a fracture or misreading radiographs [1].
We describe a report on a 19 year old man presented with a laceration over the left upper leg as a result of low energy road traffic accident. An oblique view confirmed a proximal tibial metaphyseal flake fracture, which mimicked a cystic lesion as revealed in the initial anteroposterior and lateral radiographs.
CASE REPORT
A 19-year-old otherwise fit and healthy man had a low energy road traffic accident. He sustained a deep laceration to the left upper leg. The wound was washed out, and primarily closed in the emergency department. An X-ray of the knee revealed no obvious fracture, but a cystic lesion with fluffy calcification in proximal tibial metaphyseal area [Figure 1].
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Prior to CT-scanning, an oblique radiograph was obtained. Surprisingly, the calcified lytic lesion was found to be caused by a piece of bone depressed into and flaked off from the proximal tibia mimicking a cystic appearance [Figure 2].
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The wound was re-explored in the theatre and the loose bony fragment was removed. He was treated in a plaster cast for 4 weeks. He had an uneventful recovery postoperatively.
DISCUSSION
The diagnosis of orthopaedic injuries requires a carefully taken history, including the mechanism of injury, past medical history, full physical examination of the patient and requesting x-ray films of all suspected areas in two planes.
The rule of two's is helpful when ordering films for orthopaedic complaints i.e. two views, two joints, two limbs (if comparison required) and on two occasions (eg fracture Scaphoid) [2]. Injuries that initially present with negative radiographs require an organised management plan to avoid misdiagnosis [3].
In busy A & E departments where large number of patients are seen, there is the risk of significant radiological errors. One should have a high index of suspicion with such lesions associated with history of trauma. Further views and senior review should support final radiological interpretation [4].
This case stresses on the importance of third oblique view apart from standard anteroposterior and lateral films, which can be helpful in clearing diagnostic dilemmas and to avoid unnecessary heavy radiations imposed by CT-scanning. The diagnostic accuracy can be increased remarkably with addition of an oblique film. Awareness of the possibility of such confusing fractures alerts the clinicians to the appropriate management.
REFERENCES
1 Guly HR. Diagnostic errors in an accident and emergency department. Emerg Med J 2001 Jul; 18(4): 263-9.
2 Moore MN. Orthopaedic pitfalls in emergency department. South Med J 1988 Mar; 81(3): 371-8.
3 Miller MD. Commonly missed orthopaedic problems. Emerg Med Clin North Am 1992 Feb; 10(1):151-61.
4 Williams SM, Connelly DJ, Wadsworth S, Wilson DJ. Radiological review of accident and emergency radiographs: a 1-year audit. Clin Radiol 2000 Nov; 55(11): 861-5.