Written by Megan Hilbert
This literature review helps emergency physicians systematically approach evaluation of traumatic arthrotomy (TA) while pointing out diagnostic pitfalls.
Why does this matter?
While traumatic arthrotomy has a low overall prevalence, there is significant morbidity associated with this disease process, meaning we need to keep a high index of suspicion.
SLT = Should I Load That?
TA is a disruption of the joint capsule which allows the possibility of contamination and the development of septic arthritis. Most commonly seen in traumatic mechanisms – men in their 20s to 30s and the knee are most often affected.
History and physical exam alone have low sensitivity (57%); therefore, these patients need further work-up. The next step is often plain radiographs, which have a sensitivity of 78.1% and can be highly suggestive of this diagnosis with identification of intra-articular free air, presence of radiopaque free bodies, or visualized fracture including the joint.
Current gold standard, however, is the SLT (saline load test). Several limitations arise with this diagnostic modality, the first of which is human error. Second, the sensitivity of this test is highly dependent upon the volume of injectant (with smaller volumes associated with lower sensitivities and higher volumes associated with sensitivities as high as 95%). While the answer may seem simple – do a large volume injection every time – saline load is frequently not well tolerated by the patient. While you can increase your sensitivity with dynamic range of motion during SLT, no increase in sensitivity was seen with the addition of methylene blue.
CT is a promising (and less invasive) modality, but sensitivities have not yet been well established and should be considered an adjunct in diagnosis, not definitive (yet).
Significant limitations exist within the literature, as most focus on the knee and have not established recommendations for other joints.
Finally, don’t forget your management with immobilization, irrigation, tetanus prophylaxis, antibiotic coverage (current guidelines follow those established for open fracture), and specialist consultation.
High risk and low prevalence diseases: Traumatic arthrotomy. Am J Emerg Med. 2022 Jan 21;54:41-45. doi: 10.1016/j.ajem.2022.01.013. Online ahead of print.