Annals of B-Pod: Quick Hit Case

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Plain film radiographs of the left heel show a large soft tissue defect without evidence of osseous abnormalities or foreign bodies.

Plain film radiographs of the left heel show a large soft tissue defect without evidence of osseous abnormalities or foreign bodies.

"Hey Doc, I'm not walking well..."

The patient is a 30-year-old female with no past medical history who presents to the Emergency Department shortly after stepping through a picture frame that was propped up on her floor at home. The glass shattered, lacerating the posterior aspect of her left lower leg. She is complaining of difficulty walking, but denies loss of sensation distal to the injury. Her tetanus is up to date.

+ What Do I See When I Walk in the Room?

The patient is an alert, well-developed female who is hemodynamically stable and in no acute distress. Her musculoskeletal exam is significant for a linear transverse laceration superior to the left calcaneus. She has intact dorsalis pedis and posterior tibialis pulses, and her sensation is intact through the sural, saphenous, tibial, and deep and superficial peroneal distributions. She has decreased plantar flexion of the left foot with a positive Thompson test.

+ What's Wrong With this XRay?

Plain film radiographs of the left heel show a large soft tissue defect without evidence of osseous abnormalities or foreign bodies.

The patient presented with an Achilles tendon laceration. She was started on prophylactic antibiotics with IV cefazolin. Her pain was managed with hydromorphone and the orthopedic surgery team was consulted. After bedside washout, skin closure, and application of a plantar flexion splint, she was admitted to the orthopedic service for operative repair.

+ Discussion and Management

Achilles tendon rupture occurs with a reported yearly incidence of 18 per 100,000,[1] and is most common in men aged 30-40. Specific risk factors include episodic physical exertion (e.g., “weekend warriors"), steroid injections, and fluoroquinolone antibiotics. With regards to antibiotics, the FDA recently updated its black-box warning for fluoroquinolones to clarify that they carry a small but known risk for tendinitis and tendon rupture, and should only be used in patients who have no alternative treatment options for acute bronchitis, sinusitis, and cystitis.[2]

The Achilles tendon attaches to the muscles in the posterior leg responsible for plantar flexion of the foot at the ankle (i.e., gastrocnemius, soleus, and plantaris). Unlike in this patient, rupture usually occurs from blunt trauma involving forced or sudden dorsiflexion of a plantarflexed foot, often during sports. Open injuries are more rare than closed ruptures, but have been reportedly more common in cultures where floor-level toilets pose a unique risk factor.[3]

The Thompson test is a critical physical exam maneuver that should be performed whenever there is suspicion for Achilles tendon injury. To perform the test, the practitioner should have the patient lie prone on the exam table with their feet extending past the edge. Squeezing the calf in this position should elicit plantar flexion of the foot. If it does not, the practitioner should strongly suspect injury to the Achilles tendon.[4] Howver, sensitivity of the Thompson test has ranged from 96% to only 78% in other studies, so it is important to keep a high clinical suspicion in the right clinical context.[8]

Plain films should be obtained in closed ruptures to evaluate for avulsion fractures or other associated osseous injuries. Kager’s triangle is a space bounded by the Achilles tendon, calcaneus, and the tibia, which may be filled with blood and appear as a dark space on x-ray in such cases.[5] In open injuries and lacerations, plain films should be obtained to check for foreign bodies.

Several studies have shown the utility of ultrasonography in helping diagnose Achilles tendon rupture, especially in differentiating partial from full-thickness tears. One study reported that ruptures diagnosed in this way were confirmed by direct intraoperative findings with a high degree of accuracy,[6] and another smaller study reported 100% sensitivity and 83% specificity for distinguishing full from partial thickness tears.[7] Ultrasound is also useful to our orthopedic colleagues in following the process of tendon healing.

In the ED, the focus should be on supportive care and early orthopedic consultation. In the case of an open injury such as this one, proceed as with any open orthopedic injury with pain control, intravenous antibiotics (usually cefazolin), and updating tetanus as necessary. Complete ruptures require operative management. For closed partial ruptures, there is some debate in the literature regarding operative versus nonoperative management, and these decisions should be performed in consult with our orthopedic colleagues.

Authored by Jared Ham, MD                                                                                                    Posted by Grace Lagasse, MD