Which joint should be included on the AP projection of the fifth digit?

Which joint should be included on the AP projection of the fifth digit?

• A. Metatarsophalangeal (MTP) joint
• B. Interphalangeal (IP) joint
• C. Tarsometatarsal joint
• D. Distal phalanx joint

Answer: (A)

In imaging a toe on an AP view, you want to capture the joint at the base of the digit where it meets the foot—the metatarsophalangeal joint. This joint is the critical landmark for assessing alignment and detecting fractures or dislocations at the base of the toe. The tarsometatarsal joint sits farther back in the foot and isn’t part of the digit being evaluated, and while interphalangeal joints exist along the toe, the AP projection of the fifth digit is focused on the MTP joint to show the proper relationship between the metatarsal head and proximal phalanx. Thus, the metatarsophalangeal joint is the joint to include.

In imaging a toe on an AP view, you want to capture the joint at the base of the digit where it meets the foot—the metatarsophalangeal joint. This joint is the critical landmark for assessing alignment and detecting fractures or dislocations at the base of the toe. The tarsometatarsal joint sits farther back in the foot and isn’t part of the digit being evaluated, and while interphalangeal joints exist along the toe, the AP projection of the fifth digit is focused on the MTP joint to show the proper relationship between the metatarsal head and proximal phalanx. Thus, the metatarsophalangeal joint is the joint to include.