McG 22: Central Rays

Question 1

pain on dorsal MT suggests what

Answer 1

stress fx, periostitis, capsulitis, or tendinitis

Question 2

pain in the inter metatarsal space is consistent w/

Answer 2

neuroma or inter metatarsal bursitis

Question 3

when evaluating the metatarsal heads it is important to differentiate between

Answer 3

plantar plate pain from prominent MT head

Question 4

structural causes of metatarsalgia

Answer 4

long 2nd ray, previous sx

Question 5

mechanical causes of metatrsalgia

Answer 5

HAV, hallux limitus, previous surgery

Question 6

how do digital deformities cause metatarsalgia

Answer 6

rigid hammertoes with contracture of the MTPJ cause excessive retrograde pressures to the MT heads

Question 7

what pts will have a decreased fat pad causing metatarsalgia

Answer 7

elderly, RA pts

Question 8

what do you assess on AP

Answer 8

MT length or parabola

Question 9

what is the normal MT parabola

Answer 9

2>1>3>4>5

Question 10

what do you assess on the oblique view

Answer 10

• sagittal plane deformities

- central Mts should be parallel to one another

Question 11

what do you assess on the sesamoid axial view

Answer 11

• sagittal plane deformities

- Mts should be aligned no the supporting surface

Question 12

what do you assess on the lateral view

Answer 12

• position of the 1st ray

- first ray elevates can be determined by comparing the dorsal cortices of the 1st and 2nd ray

Question 13

conservative tx for metatarsalgia

Answer 13

• functional and accommodative devices
• avoidance of flimsy shoes and barefoot walking
• rocker sole
• MT bar
• shoe with rigid sole

Question 14

2 basic surgical categories for metatarsalgia

Answer 14

1. osteotomy

2. condylectomy

Question 15

what are types of corrective osteotomies are performed

Answer 15

• alter length

- alter sagittal plane position

Question 16

indications for condylectomy

Answer 16

• osteopenic bone

- poor candidate for osteotomy and internal fixation

Question 17

when is a Weil osteotomy performed

Answer 17

dislocated toe at the MTPH

Question 18

why should proximal osteotomies be casted and possible NWB

Answer 18

the longer the lever arm, therefore likely to displace

Question 19

describe the dissection for a condylectomy and distal metaphysical osteotomy

Answer 19

-skin incision over MTPJ from base of the proximal phalanx to the MT neck
-identify extensor tendon
incise hood fibers longitudinally (laterally on the second and medial to the extensors on the 3rd and 4th Mts)
-collateral ligs severed
-McG Mts elevator inserted

Question 20

when performing an osteotomy on the MT neck do you need to incise the joint capsule

Answer 20

No

Question 21

name common distal MT osteotomies to allow for shortening

Answer 21

• V or chevron
• oblique osteotomy
• dorsal wedge tilt-up osteotomy

Question 22

name mid shaft osteotomies

Answer 22

• Giannestras (sagittal- Z)

- basilar osteotomies to DF or PF

Question 23

complications follow central MT osteotomies

Answer 23

• over/undercorrection
• recurrence or transfer of pain
• failure of fixation
• malunion/nonunion
• MTPJ stiffness
• floating toe

Question 24

why are floating toes a complication

Answer 24

• shortening a MT will reduce tension on the ligaments and tendons crossing the joint resulting in a flail toe
• as the MT head is elevated, the intrinsic muscles lose their mechanical advantage and no longer effectively stabilize the toe in PF

Question 25

how do you avoid a flail toe

Answer 25

flexor to extensor tendon transfer

Question 26

Tips and Pearls

Answer 26

* MT heads do not float and heal by seeking the correct level. Fixation of the MT osteotomies is recommended to prevent excessive bone callus, nonunion/malunion * When performing a condylectomy, consider early ROM exercises ASAP following sx to prevent adhesions of the plantar capsule structures * Intra-op use of fluoroscopy is recommended for assessing appropriate amounts of shortening of the MT. An oblique view can assess the sagittal position of the MT head * Bandaging the toes in excessive PF and splint in this position for the first several weeks post-op will reduce the likelihood of floating toes * Distal chevron osteotomies can be cut w/ arms of unequal lengths. This “check” configuration facilities fixation w/ a k-wire