Good evening everyone, hope the week is going well, and I hope you are at least mildly excited for the holiday. Today’s trauma Tuesday inspired by a patient I saw with Dr. Jenny Yu
A common pathology we encounter in the ED are lacerations to the extremities, particularly to the wrists and hands. Although these are often apparently benign with no underlying soft tissue or muscular damage, a common point of litigation, patient harm, and missed diagnoses is flexor tendon injury. Extensor injuries are usually superficial, but flexor tendon injury can easily hide under an upper extremity laceration due to swelling, tenderness, tissue, and bleeding. Although complete tendon lacerations are very evident with a thorough physical exam, partial tendon lacerations are often hidden, and those are what I’d like to focus on. Any suspected complete laceration or laceration also involving a nerve definitely requires a call to the hand specialist.
By the very nature of these injuries, the patients who have them may be intoxicated, have psychiatric issues, or otherwise cannot provide an adequate exam.
However, it is important to maintain a high index of suspicion even with a complete and thorough exam. A tendon that is nearly completely lacerated (80-90%) can still flex a finger. This tendon will likely rupture later and will require repair by a hand surgeon. Fortunately, it is not the mandate of the emergency physician to repair flexor tendon lacerations. Although there are many suggestions as to how to deal with partial thickness injuries, as long as the tendon is splinted correctly and it remains protected, the tendon will heal, and will survive until urgent follow-up with a hand surgeon.
It is our job to correctly identify that there may be a tendon laceration, and it is our responsibility to provide the patient with adequate hand surgery follow-up and to splint the extremity. If there is an equivocal exam, always consult the hand specialist or orthopedics. We are lucky to have orthopedic residents in the hospital who usually perform their own exam and designate who to follow up with. However, if hand specialists are not readily available emergently in the ED, any remotely suspected flexor tendon lacerations should receive a dorsal splint with the hand somewhat flexed with urgent follow-up.
Another key to these injuries is that oftentimes patients with hand injuries will likely have difficulty with follow-up. They may have been injured while intoxicated, or while having a psychotic event. They may be undomiciled or they may have minimal access to healthcare resources like insurance. It is important to be cognizant of these barriers and to try and provide as thorough and adequate follow-up, and possibly consult social work for insurance issues. One important aspect is to be thorough in documentation. An article in Emergency Medicine News by Dr. John Roberts suggests the following template for documenting a hand history and physical exam:
Default History:
*Detailed history includes ________________.
*Position at time of injury ________________.
*Occurred_____ hrs prior to admission.
*Environment of injury ___________________.
*Care prior to ED visit ____________________.
*Pt. denies sensation/concern for fracture, foreign body, excessive debris, numbness/tingling of fingers, weakness of fingers, or difficulty moving any joint.
*Prior hand/finger problems _______________.
Default Exam:
*Hand/wrist/fingers held in normal resting position.
*Flexor tendons: Full active/passive ROM, and normal flexion of all superficialis/profundus tendons against resistance.
*Extensor tendons: Full active/passive ROM, and normal extension of all fingers against resistance.
*No FB seen on exam consisting of __________.
*Normal light touch/sharp/two-point discrimination of all fingers.
*Tendon visualization ____________________.
How about extensor injury? They can sometimes be repaired in the ED, but as I’ve already been somewhat long-winded I will paste some quick pearls from EM Docs about both flexor and extensor injuries below:
Flexor Tendon/Volar Injuries: Require urgent hand specialist for definitive repair- either consultation in ER or follow up within 24 hours depending on your local practice patterns. Tendon injuries are often missed, particular partial tendon injuries and lead to decreased hand function if not appropriately identified. Clean wound and suture the skin- if tendon is not repaired immediately by a specialist, splint wrist and MCPs with flexion and PIPs/DIPs in extension and ensure timely follow up with hand surgeon.
Extensor Tendon/Dorsal Injuries: Can be repaired in ED, but will require follow up with hand specialist. Tendons should be repaired with 4-0 or 5-0 nonabsorbable suture in a figure-of-eight stitch to bring the cut edges together or closely approximated simple interrupted sutures. Splint hand in functional position with wrist in slight extension/ulnar deviation and MCP/DIP/PIPs in slight flexion for follow up with hand surgeon.
My take home for flexor injuries: It is not just important that we determine the extent of a tendon injury (what percentage, etc) but that we identify the risk for a tendon injury, do a thorough irrigation, check for foreign bodies, and make sure the patient is properly splinted and has urgent follow-up with hand surgery. Antibiotics should be given to patients at high risk for infection (dirty mechanism, immunocompromised, incomplete irrigation). Injuries whose repair is delayed by even up to three weeks can have good outcomes. However, a missed flexor tendon injury that is evaluated >3 weeks after the injury can be devastating. Please, if you have any suspicion for this injury, call orthopedics, splint the patient, and provide adequate follow-up. Even the most benign appearing penetrating injuries to the hand can cause tendon damage.
Thank you again and hope everyone enjoys their holiday week!
Mak Sarich MD
https://journals.lww.com/em-news/fulltext/2011/12000/ed_treatment_of_flexor_tendon_injuries.4.aspx