Open Joint

An Open-and-Shut Case? Diagnosis and Management of Open Fractures in the Emergency Department

Case

A 53 year-old woman with no past medical history stepped out of the house to walk her dog when she slipped on the icy front stairs. She noted immediate pain and an obvious deformity of her right ankle, but denied head strike, loss of consciousness, or other symptoms.

On physical exam, the there was appreciable skin tenting over the ankle deformity, as well as a nearby abrasion across her lateral malleolus. She was neurovascularly intact, but the ankle was immediately reduced, due to skin tenting. She thinks she remembered scraping the ankle while on the ground but was not positive about that fact. With the reduction performed, the next step was to determine if the fracture was open or not...


Background

An open fracture occurs when a fracture site communicates with the outside environment. Open fractures have much higher rates of infection, up to 25%, depending on a number of factors. The most important way to reduce infection rate is early administration of antibiotics, so prompt identification of an open fracture is crucial.[1]

Another consideration with open fractures is to remember that compartment syndrome is still possible, despite the soft tissue disruption. One study found that, among patients with open tibial fractures, the rate of compartment syndrome was 9.1%.[2], although tibial fractures tend to develop compartment syndrome more often than other locations, so the rates associated with other sites is likely lower.

Interestingly, the majority of open fractures occur with low energy mechanisms.[3] The most common mechanism is crush injury, followed by ground-level falls and motor vehicle crashes. There is also a bi-modal distribution with most high-energy open fractures occurring in young males and most low-energy injuries occurring in elderly females. Finger phalanges are the most common sites, followed by the tibia and distal radius.

Generally, the worse the open fracture, the higher the rate of infection.[4] Fractures are graded on a number of scales, but the most commonly used is the Gustilo Classification, which correlates with infection rate:

Gustilo Classification

Fracture type Definition Infection rate (%)
I

Wound <1 cm; minimal contamination,
comminution and soft-tissue damage

0-2

II Wound >1 cm; moderate soft-tissue
damage, minimal periosteal stripping

2-5

III A Severe soft-tissue damage and substantial
contamination; coverage adequate

5-10

III B Severe soft-tissue damage and substantial
contamination; coverage inadequate

10-50

III C Arterial injury requiring repair

25-50

Other factors that increase the rate of infection include the bacterial contamination[5], diabetes[6], age > 80, tobacco use, location of the fracture, malignancy, and immunocompromised state[7].

 

Diagnosis

Some open fractures are easy to diagnose, but many will be more subtle. For injuries unrelated to the joint, copious irrigation and cleaning of the site, followed by sterile probing is the standard of care.

A potential traumatic arthrotomy, or open joint, has historically been diagnosed with a saline load test (SLT). The amount of fluid necessary to achieve 95% sensitivity varies by joint, but the most common are:

  • 155 mL for knees[8]

  • 55 mL for ankles[9]

  • 40 mL for elbows[10]

  • 7 mL for wrists[11]

Emerging evidence, though, is supporting heavier reliance on advanced imaging to diagnose traumatic arthrotomy. One study found 100% sensitivity and specificity for finding air in potentially open knees using computed tomography[12], compared to 92% when SLT was performed on this same group of patients. Meta-analyses show that more research is needed into both SLT as well as using CT imaging for the diagnosis of traumatic arthrotomy[13].

Treatment

In addition to standard treatment for a fracture (analgesia, immobilization, neurovascular exam etc.), open fractures warrant:

  • Immediate antibiotics (first generation cephalosporin)

  • Orthopedic surgery consult

  • Irrigation and debridement

  • Tetanus prophylaxis

Antibiotics within 3 hours of injury have been associated with a six-fold decrease in infection, so early administration is critical. For irrigation and debridement, one study recommended very low pressure sterile saline irrigation, as re-operation rates were no higher when comparing the low pressure and high pressure groups.[1]

Case Conclusion

After reducing the patient’s ankle, the emergency department provider probed the patient’s soft tissue injury but was unable to track to bone. Was this simply an abrasion from the ice? Could it be skin breakdown secondary to the swelling? Was it an injury from a fracture fragment?

The orthopedic surgery team evaluated the patient and were also unsure whether or not the wound communicated with the fracture site. In fact, this is a relatively common situation, as the injury has time to clot, the bones have shifted, and full wound exploration in the emergency department is difficult.

In this case, the injury was treated as an open fracture and the patient was immediately given antibiotics. She was admitted to the hospital to undergo a thorough washout and debridement in the operating room.

Take Away Points

  • When in doubt, treat a fracture with associated soft tissue injury as open

  • Use antibiotics as soon as possible

  • Do not discount the mechanism, as most open fractures occur from low energy injuries

  • Compartment syndrome is still possible

  • If you see air in the joint on imaging, it is an open fracture

Faculty Reviewer: Dr. Jeffrey Feden


References

  1. FLOW Investigators. A trial of wound irrigation in the initial Management of Open Fracture Wounds. N Engl J Med. 2015;373:2629–41.

  2. Blick SS, Brumback RJ, Poka A, Burgess AR, Ebraheim NA: Compartment syndrome in open tibial fractures. J Bone Joint Surg Am 1986;68: 1348-1353.

  3. Court-Brown CM, Bugler KE, Clement ND, Duckworth AD, McQueen MM. The epidemiology of open fractures in adults. A 15-year review. Injury. 2012; 43(6):891–7. https://doi.org/10.1016/j.injury.2011.12.007.

  4. Okike K, Bhattacharyya T. Trends in the management of open fractures. A critical analysis. J Bone Joint Surg Am. 2006;88:2739–48.

  5. Merritt K. Factors increasing the risk of infection in patients with open fractures. J Trauma 1988; 28: 823–7. doi: http://dx.doi.org/10.1097/00005373-198806000-00018

  6. Lavery LA, Walker SC, Harkless LB, et al. Infected puncture wounds in diabetic and nondiabetic adults. Diabetes Care 1995;18(12):1588–91.

  7. Bowen TR, Widmaier JC: Host classification predicts infection after open fracture. Clin Orthop Relat Res 2005;433:205-211.

  8. Nord R.M., Quach T., Walsh M., Pereira D., Tejwani N.C. Detection of traumatic arthrotomy of the knee using the saline solution load test. J Bone Jt Surg Am Vol. 2009;91(1):66–70.

  9. Bohl DA, Frank RA, Lee SI, Hamid KA, Holmes GE, Lin JO. Sensitivity of the Saline Load Test for Traumatic Arthrotomy of the Ankle With Ankle Arthroscopy Simulation. Foot & Ankle International Vol. 39; 39(6):736-740.

  10. Feathers T., Stinner D., Kirk K. Effectiveness of the saline load test in diagnosis of traumatic elbow arthrotomies. J Trauma. 2011;71(5):E110–E113.

  11. Gittings DJ, Fryhofer GW, Hast MW, Steinberg DR, Levin LS, Gray BL. The Saline Load Test is Effective at Diagnosing Traumatic Arthrotomies of the Wrist. Tech Hand Up Extrem Surg. doi: 10.1097/BTH.0000000000000233.

  12. Konda S.R., Davidovitch R.I., Egol K.A. Computed tomography scan to detect traumatic arthrotomies and identify periarticular wounds not requiring surgical intervention: an improvement over the saline load test. J Orthop Trauma. 2013;27(9):498–504.

  13. Browning BB, Ventimiglia AV, Dixit A, et al. Does the saline load test still have a role in the orthopaedic world? A systematic review of the literature. Acta Orthop Traumatol Turc 2016;50:597–600.doi:10.1016/j.aott.2016.01.004.

Take a Knee…

Case:

An otherwise healthy 17-year-old male presents to the ED after an ATV accident. He was riding at a low speed when he swerved to avoid a branch, lost control, forcing him to bail forward over the handlebars. He sustains a laceration to his knee during the fall, but suffers no other injuries. Exam of the right knee is notable for a 2.5 cm deep, jagged laceration (Figure 1), tenderness to the patella and a joint effusion, no palpable bony deformities, stable ligamentous exam, with the distal extremity neurovascularly intact. Radiographs of the knee are obtained:

Figure 1: Right knee laceration

Figure 1: Right knee laceration

Figure 2: Lateral and AP right knee radiographs

Figure 2: Lateral and AP right knee radiographs

Now what?

The above radiographs demonstrate no evidence of fracture or dislocation; however, subcutaneous gas is visible in the region of the laceration. Given the depth and location of the injury, there is concern for traumatic arthrotomy. Orthopedics is consulted.

 

Overview:

Knee injuries are a common reason for patient presentation to the emergency department, often with concomitant wounds adjacent to the joint. These injuries typically occur in young adult males, with common mechanisms including gunshot wounds, motor vehicle accidents, motorcycle accidents, or injury due to sharp objects[1]. When there is concern for wounds entering the joint space, the saline load test (SLT) is used for further evaluation.

 

Technique:

The knee contains the largest synovial joint cavity in the body. To perform arthrocentesis, the knee should be placed in approximately 15-20 degrees of flexion (often helpful to place a folded blanket or pillow in the popliteal fossa to aid in positioning); a medial or lateral approach may be used, but should enter at the superior third of the patella, with the needle aimed towards the intercondylar notch[2].

A systematic review by Daley, et al, in 2011 of needle entry location showed that the superolateral approach had the overall greatest success of 91%[9]. In difficult cases, use of ultrasound has been shown to improve accuracy of intra-articular needle placement, a modality readily used and available in the ED[10].

Figure 3: Anatomic overview and appropriate targets for arthrocentesis, from Thomsen, et al, 2006[2].

Figure 3: Anatomic overview and appropriate targets for arthrocentesis, from Thomsen, et al, 2006[2].

Video: 

https://www.emrap.org/episode/knee/knee

How much is enough?

 In examination of the saline load test, varying sensitivities have been reported using a range of infused volumes. Using an arthroscopy model with a 1 cm incision, Nord et al, showed that 95% sensitivity could be achieved using a volume of 155 cc, if tolerated by the patient[3]. In the ED setting, potentially lower volumes may be used due to generally larger arthrotomy sizes. Konda, et al, demonstrated 94% sensitivity with a dynamic (moving the knee through flexion and extension) saline load test using a volume of 74.9 cc +/- 28.2 cc, but had a 9% false positive rate[4].

But don’t I need to inject that blue stuff?

A single study comparing injection of normal saline alone vs. methylene blue in patients undergoing routine knee arthroscopy showed instillation of methylene blue did not improve sensitivity in diagnosis of arthrotomy[5].

 

Is a picture alone worth a thousand words?

A retrospective study in 2013 compared the traditional SLT to CT scan identification of intra-articular air in evaluation of a traumatic arthrotomy. This study revealed that CT scan was more sensitive in detection of traumatic arthrotomy over the traditional SLT (100% vs. 92%)[6]. The additional benefit of performing a CT scan is detection of periarticular fractures, and in the study group, findings on CT scan in evaluation of traumatic arthrotomy altered management in 43% of patients[8].

Figure 4: Intra-articular air visualized on CT scan on bone and lung windows (A and B respectively), from Konda, et al, 2014[1].

Figure 4: Intra-articular air visualized on CT scan on bone and lung windows (A and B respectively), from Konda, et al, 2014[1].

What about pediatrics?

A prospective study of 87 pediatric patients with mean age 13.4 years +/- 3.0 years undergoing elective knee arthroscopy were studied. After a 5-mm superolateral arthrotomy site was made, the authors concluded that a minimum of 47 mL was required to detect 90% of the arthrotomies in this population[7]. A limitation, however, is that all patients were anesthetized during joint injection, preventing assessment of patient comfort with this infused volume.

  

Case Conclusion:

The patient undergoes saline load testing of the affected knee in the ED using 155 cc of intra-articular saline, with noted extravasation from the wound. He is placed in a splint, IV antibiotics are started, and he is taken to the operating room for irrigation and debridement. Intra-operatively, he is noted to have a 1 cm traumatic arthrotomy to the lateral joint capsule. The joint is thoroughly irrigated, he is continued on antibiotics, and was discharged home the following day without complication.  

A great post by our EM colleagues at the Las Vegas Emergency Medicine Residency also reviewing this topic can be found here: http://www.lasvegasemr.com/foam-blog/knee-capsule-violation-bedside-rule-out-test

 

Take Home Points:

  • Knee injuries are common: when there is concern for joint violation, the saline load test can be used for further evaluation

  • If using anatomic landmarks, the superolateral approach may be the most successful, and in difficult cases, ultrasound can help improve success

  • Methylene blue does not add additional sensitivity over normal saline alone

  • CT scan can be used to identify traumatic arthrotomy, may have better sensitivity than the SLT, and adds evaluation of potential periarticular fractures not seen on plain radiographs

  • In general, wounds seen in the ED may require less overall volume due to larger arthrotomy size, but optimal volume is still unclear

Faculty Reviewer: Dr. Dina Gozman

References:

  1. Konda, SR., Davidovitch, RI., Egol, KA; “Open knee joint injuries: an evidenced-based approach to management”, Bulletin of the Hospital for Joint Diseases, Vol 72 No. 1, 2014

  2. Thomsen, TW., Shen, S., Shaffer, RW., Setnik, GS; “Arthrocentesis of the knee”, New England Journal of Medicine, Vol 354 No. 19, May 2006

  3. Nord, RM., Quach, T., Walsh, M., et al; “Detection of traumatic arthrotomy of the knee using saline solution load test”, Journal of Bone and Joint Surgery American Volume, Vol 91 No. 1, January 2009

  4. Konda, SR., Howard, D., Davidovitch, RI., Egol, KA; “The saline load test of the knee redefined: a test to detect traumatic arthrotomies and rule out periarticular wounds not requiring surgical intervention”, Journal of Orthopedic Trauma, Vol 27 No. 9, September 2013

  5. Metzger, P., Carney, J., Kuhn, K., Booher, K., Mazurek, M; “Sensitivity of the saline load test with and without methylene blue dye in the diagnosis of artificial traumatic knee arthrotomies”, Journal of Orthopedic Trauma, Vol 26 No. 6, June 2012

  6. Konda, SR., Davidovitch, RI., Egol, KA; “Computed tomography scan to detect traumatic arthrotomies and identify periarticular wounds not requiring surgical intervention: an improvement over the saline load test” Journal of Orthopedic Trauma, Volume 27 No. 9, September 2014

  7. Haller, JM., Beckmann, JT., Kapron, AL., Aoki, SK; “Detection of a traumatic arthrotomy in the pediatric knee using the saline solution load test”, The Journal of Bone and Joint Surgery, Vol 97 No. 10, May 2015

  8. Konda, SR., Howard, D., Davidovitch, RI., Egol, KA; “The role of computed tomography in the assessment of open periarticular fractures associated with deep knee wounds”, Journal of Orthopedic Trauma, Vol 27 No. 9, September 2013

  9. Daley, EL., Bajaj, S., Bisson, LJ., Cole, BJ; “Improving injection accuracy of the elbow, knee, and shoulder: does injection site and imaging make a difference? A systematic review” The American Journal of Sports Medicine, Vol 39 No. 3, March 2011

  10. Daniels, EW., Cole, D., Phillips, SF.; “Existing evidence on ultrasound-guided injections in sports medicine”, Orthopaedic Journal of Sports Medicine, Vol 6 No. 2, February 2018