Foot Procedures

Julia Crim, MD

TERMINOLOGY

Abbreviations

Tarsometatarsal (TMT)
Metatarsophalangeal (MTP)

PRE-PROCEDURE

Indications

Most foot injections are therapeutic
- Useful to treat pain, identify source of pain
Can be used to evaluate cartilage, ligament injury
- Usually in subtalar and metatarsophalangeal joints

Getting Started

Medications
- Povidone-iodine (Betadine) or chlorhexidine gluconate (Betasept) antiseptic
- 1% lidocaine, 5 cc
- 0.5% bupivacaine, 5 cc
- Nonionic iodinated contrast
- For therapeutic arthrogram: Corticosteroid
- For MR: Gadolinium mixed to dilution of 1:200 with iodinated contrast, bupivacaine
Equipment list: Standard arthrogram tray

PROCEDURE

Equipment Preparation

Use same 25-gauge needle for superficial anesthesia and joint injection

Procedure Steps

Posterior subtalar joint
- Patient in lateral decubitus position
- Affected side up, foot supported on towels, pillow under knee as needed
- Adjust rotation of foot until lateral process talus and angle of Gissane clearly seen
- Localize for injection between tip of lateral process and angle of Gissane
- Can confirm location on AP or mortise view
Talocalcaneonavicular joint
- Middle and anterior subtalar facets communicate with each other and talonavicular joint
- Easiest way to inject middle, anterior subtalar facets is by injecting talonavicular joint
- Patient supine, knee bent, foot flat on fluoroscopy table
- Localize for injection between talus and navicular on AP view
- Contrast flow into subtalar joint often seen best on lateral view
Calcaneocuboid joint
- Position as for posterior subtalar joint
- Rotate foot until joint in profile
- Usually achieved with slight internal rotation
Naviculocuneiform joint
- Patient supine, knee bent, foot flat on fluoroscopy table
- Localize for injection between navicular and 1st or 2nd cuneiform on AP view
Tarsometatarsal joint
- Patient supine, knee bent, foot flat on fluoroscopy table
- If using C-arm, angle beam slightly to catch joint in optimal profile
- 3 separate joint capsules
- 1st TMT: Inject at center of joint
- 2nd-3rd TMT: May inject either ray, choose site where less severe osteoarthritis allows easier joint entry
- 4th-5th TMT: Turn foot to internal oblique position, inject either ray
Metatarsophalangeal joints
- Patient supine, knee bent, foot flat on fluoroscopy table
- Inject centered on joint

Findings and Reporting

Pain relief
Variant communications between joints
Contrast extravasation from joints

PROBLEMS & COMPLICATIONS

Problems

Posterior subtalar injections often misplaced
- Be certain to visualize lateral portion of joint when injecting from lateral approach
- Lateral process of talus and angle of Gissane are key landmarks
Osteophytes may block injection, especially in midfoot
- Osteophytes may not be seen well on fluoroscopy if en face
- Turn foot or fluoroscope to see and avoid osteophytes
- “Walk” needle along bone surface until able to advance
  - Anesthetize periosteum well if using this technique

SELECTED REFERENCES

1. Lucas PE et al: Fluoroscopically guided injections into the foot and ankle: localization of the source of pain as a guide to treatment—prospective study. Radiology. 204(2):411-5, 1997

2. Mitchell MJ et al: Localization of specific joint causing hindfoot pain: value of injecting local anesthetics into individual joints during arthrography. AJR Am J Roentgenol. 164(6):1473-6, 1995

Image Gallery

(Left) Clinical photograph shows patient positioned for posterior subtalar joint injection. (Right) Lateral arthrogram shows needle between tip of lateral process talus