The Foot



The Foot





INJECTIONS AND ASPIRATIONS


Plantar Fascia Injection



Description of Procedure



  • Position the patient upright with the ankle dependent with gravity.


  • Prepare a wide area of the skin with antibacterial solution.


  • The ankle and foot lend themselves to careful palpation, given their subcutaneous location.


  • The perfect spot for the plantar fascia injection is in-line with the posterior aspect of the medial malleolus extended distally to the level of the skin transition to the glabrous skin from the plantar side of the foot (Fig. 8-1).


  • Optional: Anesthetize the skin overlying the planned entry site with 2 to 3 mL of local anesthetic. However, this is a relatively painful and sensitive area of the skin, and we would warn against this.



  • Direct the needle through the medial skin and toward the calcaneus. We typically use a 22G or 25G needle for injections. Once bone is encountered, withdraw the needle slightly and raise your hand to plantarly direct the needle into the fascia origin area.


  • Apply a sterile, compressive dressing or a adhesive dressing after any initial bleeding is stopped with direct pressure.






FIGURE 8-1


Tips and Other Considerations



  • A plantar approach for this injection has been described, but we find it excessively painful for the patient and do not use it.


  • The topical use of an ethylene chloride spray can minimize the discomfort of this injection. If using a 25G needle, be careful not to spray and freeze the needle making the injection even more difficult.


  • We typically use 1 cc of lidocaine 1% plain mixed with 1 cc of a steroid of your choosing. Usually, we use either depomedrol 40 mg/ml or Kenalog 10 mg/ml. 0.5% plain Marcaine can be added as well, but it can lengthen the duration of the injection.


  • This injection is among the most difficult to perform.


  • This is usually a second-tier option for the treatment of plantar fasciitis. Initially, we try plantar fascia-specific stretching, nonsteroidal anti-inflammatory drug (NSAIDs), physical therapy, and night splints. After the above have failed to relieve the pain for 4 to 6 weeks, an injection is indicated.


Subtalar Joint Injection and Aspiration: Sinus Tarsi Approach



Description of Procedure



  • Position the patient sitting with the leg internally rotated.


  • Inverting the ankle can help to “open” the sinus tarsi.


  • Alternatively, the use of gravity helps manually distract the joint. If needed, an assistant can “pull” the ankle as well, but usually this is not needed.


  • Prepare a wide area of the skin with antibacterial solution.


  • The ankle and foot then themselves to careful palpation, given their subcutaneous location.


  • The perfect spot for a sinus tarsi injection is just anterior to the distal tip of the fibula, usually about two fingerbreadths anteriorly. The sinus tarsi can usually be palpated by running your thumb toward the toes from the anterior aspect of the distal fibula until a soft spot is felt as the thumb enters into the sinus tarsi (Fig. 8-2).


  • Optional: Anesthetize the skin overlying the planned entry site with 2 to 3 mL of local anesthetic. However, if an infection is being ruled out, do not use local anesthesia as lidocaine can act as a bacteriostatic agent and decrease the chance of a positive culture.


  • Direct the needle superiorly and posteriorly through the skin into the sinus tarsi. We typically use a 22G needle for injections. If bone is encountered, either raise or lower
    your hand as the needle is hitting either dorsal calcaneus or plantar talus. Usually, the error is to be too superior, so raising your hand will lower the needle into the tarsi.


  • Aspirate synovial fluid to verify that the needle is appropriately positioned. If no fluid is withdrawn, attempt injecting minimally. Often, it is difficult to withdraw fluid from the sinus tarsi unless an effusion is present. If there is resistance, stop the injection and consider using a fluoroscopic image machine for assistance.


  • Continue aspirating or inject the desired solution.


  • Apply a sterile, compressive dressing.






FIGURE 8-2


Tips and Other Considerations



  • The use of local anesthetic is debatable. Some physicians feel it is not helpful because only the skin will be anesthetized and a second injection is required. In the pediatric setting, the fewer injections given the better.


  • Entry into the joint may be facilitated by plantarflexing and inverting the ankle.


  • If fluid is not initially obtained, redirect the needle. The needle must be withdrawn until it is just within the skin before redirection. Changing the angle of the needle without withdrawing it first will simply push tissue around (not change its path) and may even risk damage to surrounding tissue, as the bevel may act like a knife.


  • This is among the most difficult injections to perform.


  • If available, the use of fluoroscopy is very helpful. A radiographic marker is placed on the proposed insertion side, and a lateral fluoroscopic image is taken to confirm the correct insertion point. If the mark is incorrectly placed, then move it until it is directly over the sinus tarsi.


  • Using fluoroscopy, the subtalar joint can also be approached from posterior to enter the joint at the larger posterior facet.



    • In the lateral position, place the needle just anterior to the lateral aspect of the Achilles tendon. Using the fluoroscopy unit, direct the needle into the posterior facet of the subtalar joint. You will feel a slight “pop” as the needle pierces the joint capsule. Confirm the position with the fluoroscopy and inject as desired (Fig. 8-3).






FIGURE 8-3



Digital Toe Block



Description of Procedure



  • Position the patient in a supine position with the knee extended.


  • Prepare a wide area of the skin with antibacterial solution at the base of the affected toe.


  • We prefer to inject the local solution with a 25G needle. An 18G or 22G needle seems to be too large and can cause too much damage. A 22G needle is used when difficulty injecting the fluid is encountered.


  • We typically use 1% or 2% lidocaine. To help with postprocedure pain, 0.5% Marcaine can be added later, but it takes longer to work and can delay the onset of the procedure.


  • Never use epinephrine, as it is felt to increase the risk of digital ischemia.


  • The digital nerves to the toes are found at the medial and lateral base of the toe of interest. Two different injections should be given: one medially and one laterally



    • Initially, a wheal is raised medial or lateral. Next, through the wheal, the needle is advanced in dorsal and plantar direction. The most common error is to not place the needle planter enough. Finally, the needle is turned horizontally and the dorsum of
      the toe is blocked. If needed, the needle can be advanced out the plantar skin to ensure the block is plantar enough.


Tips and Other Considerations



  • Make sure to give the block enough time to work. We find it helpful to place the block, complete other tasks and paperwork, and return to the patient in 10 to 15 minutes. One of the main failures and causes of pain for patients is not letting the block set up adequately.


  • In an awake patient, when performing the toe block, it is much less painful for the patient to inject in areas that have already been touched subcutaneously with local anesthesia. Therefore, when creating a block, watch as the skin is elevated (wheal) and then inject in that area. Do not try to obtain access in areas that have not been touched yet by the anesthetic.


  • For the great toe, 4 to 6 mL of 1% lidocaine is typically used for a complete toe block. For the lesser toes, less volume is needed.


FRACTURES AND DISLOCATIONS


Reduction of Tongue-Type Calcaneal Fractures



Description of Procedure



  • Position the patient prone, if possible. Keep in mind that the majority of calcaneal fractures are not isolated injuries and the energy imparted can lead to other musculoskeletal injuries making prone positioning impractical. If not possible, this can be done in the lateral position as well.


  • Pressure on the posterior heel while plantarflexing the foot may help reduce pressure on the posterior skin.


  • If this does not result in a change in the fracture pattern or displacement, then urgent closed reduction in the operating room with percutaneous fixation should be undertaken.


Tips and Other Considerations



  • An ominous sign for skin compromise is blanching of the skin over the prominent fragment or a hemorrhagic fracture blister on the posterior heel (Fig. 8-5).


  • These are important fractures not to be missed. If the patient is discharged from the emergency room (ER) with these types of fractures, skin damage can be catastrophic.







FIGURE 8-4

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Mar 14, 2020 | Posted by in ORTHOPEDIC | Comments Off on The Foot
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