Patients suffering from the most common form of degenerative
arthritis in the foot — hallux rigidus — showed
improvement in pain and function by wearing a relatively inexpensive and simple
over-the-counter show insert, according to recent research.
Investigators at the University of Rochester in N.Y. found that using a
Morton’s extension, a rigid carbon foot orthotic that extends to the
distal tip of the hallux, resulted in reducing hallux rigidus pain as well as
modified the plantar loading patterns resulting in improved load distribution.
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| Judith F. Baumhauer |
“Morton’s extension was popularized many years ago for turf
toe and sporting injuries to the great toe that led to some arthritic
change,” lead author Judith F. Baumhauer, MD, a professor of orthopedics
at the university, said. “I always wondered if this product in fact was
effective. Often, it was incorporated into a costly custom insert, an orthosis.
But can you make it affordable?”
The roughly $70 to $80 carbon footplate, with an extension the length of
the hallux, is dispensed through a certified pedorthist and “lasts
forever,” according to Baumhauer, who has been writing prescriptions for
Morton’s extension for more than 20 years.
Results of the 30-patient study were presented at the American
Orthopaedic Foot and Ankle Society (AOFAS) Annual Summer Meeting in National
Harbor, Md. Patients with a mean age of 54 years self-reported pain and
functional outcomes prior to therapy and at 6 weeks. Data were assessed with
the Foot Functional Index – Revised (FFI-R).
Six-week intervention with the Morton’s insert achieved an overall
22% improvement in total FFI-R scores.
“This change was primarily driven by the improvement in pain,”
Baumhauer, president-elect of the AOFAS, said. Furthermore, an “increase
in plantar loading to the medial forefoot and hallux did not exacerbate
symptoms.”
Plantar loading data including maximum mean pressures, pressure time
integral and load distribution were collected with an in-shoe pressure
measurement device while patients walked in their preferred footwear.
“The pressure patterns following intervention resembled the 18
asymptomatic control patients and may be reflective of improved loading
distribution on the plantar foot,” Baumhauer said.
She is “surprised how well Morton’s extension works. I thought
you would have needed a full foot bed of carbon footplates.” Baumhauer
also intuitively believed the product would function by “stopping motion
at the great toe because of its stiffness. But it only limits about 4·
of motion, which is pretty remarkable, so functionally it is a win.”
Likewise, “for reducing pain, it is truly a win. The therapy is probably
effective because those 4· that the extension stops are likely the last
4· of motion that cause impingement of the arthritic bone spurs or
osteophytes on the top of the great toe. I feel it is the end of the
metatarsophalangeal (MPT) joint that causes people the symptoms.”
For someone with symptomatic hallux rigidus, Morton’s extension
“is a simple and extremely thin insert that should be tried before
surgery,” Baumhauer said. — by Bob Kronemyer
Disclosure: Judith F. Baumhauer, MD is
a paid consultant for DJ Orthopaedics, Carticept and Orthocon. She in an unpaid
consultant for Biomimetics. She receives research support from DJO
Incorporated.
Traditionally a Morton’s extension is an orthosis that has a
full-length extension under the great toe, but the remainder of the distal end
of the orthotic device ends at the web spaces. It is used to reduce pain
associated with dorsiflexion of the hallux and can be made of a rigid or
semi-rigid material such as the carbon fiber in this study. It is interesting
to note that the limitation in dorsiflexion need not be extreme to reduce the
pain of hallux rigidus. We have found this extension to also be helpful in the
treatment of turf toe as it still allows the athlete some agility.
— Carol C. Frey MD
Director, orthopedic
foot and ankle surgery, West Coast Center for Orthopedic Surgery and Sports
Medicine and The Cartilage Restoration Center
