The mechanism of the injury determines the likelihood of disruption to underlying tissue, the risk of a retained foreign body, and the degree of potential contamination. The following circumstances are associated with specific pathogens: (a) farming accidents (Clostridium perfringens), (b) wading in a freshwater stream (Aeromonas hydrophila), and (c) high-pressure water systems used for cleaning surfaces (Acinetobacter calcoaceticus). Evaluation of wounds in general is discussed in Chapter 9. It is important to determine the position of the limb at the time of injury, which will help to uncover occult tendon injuries.
Assessment for associated nerve, vessel, or tendon injury is mandatory. Before anesthetizing the area, inspect the wound for position at rest, and assess sensory neurologic function using light touch and 2-point discrimination testing. Compare one side with the other. Motor function and wound exploration may be better assessed after the wound is anesthetized (Tables 13-1 and 13-2). Move the limb through its full range of motion to exclude tendon injury. Test each tendon function individually and inspect visually to rule out a partial laceration.
Table 13-1 Motor Function of Lower Extremity Peripheral Nerves ||Download (.pdf)
Table 13-1 Motor Function of Lower Extremity Peripheral Nerves
|Superficial peroneal||Foot eversion|
|Deep peroneal||Foot inversion|
|Tibial||Ankle plantar flexion|Table 13-2 Tendon Function of the Lower Extremities ||Download (.pdf)
Table 13-2 Tendon Function of the Lower Extremities
|Extensor hallucis longus||Great toe extension with ankle inversion|
|Tibialis anterior||Ankle dorsiflexion and inversion|
|Achilles tendon||Ankle plantar flexion and inversion|
Laboratory studies usually are not indicated. Obtain an x-ray if there is a possibility of fracture or a radiopaque foreign body. Ultrasonography may be used to help identify a foreign body, a tendon injury, or bony abnormality. All injuries caused by glass should be radiographed unless physical examination can reliably exclude a foreign body (see Chapter 14).
See Chapter 9 for discussion of wound preparation; thorough irrigation of lower extremity wounds is essential.
Wounds on the lower extremities are usually under greater tension than those on the upper limb. Consequently, a layered closure with 4-0 absorbable material to the fascia and interrupted 4-0 nonabsorbable sutures to the skin are preferred. The foot is an exception to this guideline.
Avoid deep sutures in diabetics and patients with stasis changes because of the increased risk of infection.
Always ask about tetanus immunization status. The elderly are at particular risk for being nonimmunized.
Cyanoacrylate glue is usually not used on the lower extremities because of greater wound tension.
Splint lacerations involving the joint or tendons in a position of function.
Examine knee wounds throughout the range of ...