Morton’s extension carbon footplate orthotic found to benefit patients with hallux rigidus

Issue: October 2010

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 shoe 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.

“Morton’s extension was popularized many years ago for turf toe and sporting injuries to the great toe that led to some arthritic change,” said lead author Judith F. Baumhauer, MD, a professor of orthopedics at the university. “I always wondered if this product in fact was effective. Often, it was incorporated into a very costly custom insert, an orthosis. But can you make it affordable?”

Last forever

Judith F. Baumhauer, MD told attendees at the 2010 American Orthopaedic Foot and Ankle Society (AOFAS) Summer Meeting that she was “surprised how well Morton’s extension works.”

Image: Beadling L, Orthopedics Today

The roughly $70 to $80 carbon footplate, with an extension the length of the hallux, is dispensed through a certified pedorthists and “lasts forever,” said Baumhauer, who has been writing prescriptions for Morton’s extension for over 20 years.

Results of the 30-patient study were presented at the 2010 American Orthopaedic Foot and Ankle Society (AOFAS) Annual 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 said. Furthermore, an “increase in plantar loading to the medial forefoot and hallux did not exacerbate symptoms.”

In-shoe measurements

Plantar loading data including maximum mean pressures, pressure time integral and load distribution were collected with an in-shoe pressure measurement device while subjects walked in their preferred footwear.

“The pressure patterns following intervention resembled the 18 asymptomatic control subjects and may be reflective of improved loading distribution on the plantar foot,” Baumhauer said.

She told Orthopedics Today that 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.”

Conservative option

For someone with symptomatic hallux rigidus, Morton’s extension “is a very simple and extremely thin insert that should be tried before surgery,” said Baumhauer, president-elect of the AOFAS.

Interestingly, a surgical arm of the study found that a dorsal cheilectomy “does not really increase motion, even though the dogma is that by shaving these osteophytes, patients will regain motion,” Baumhauer said. – by Bob Kronemyer

Reference:
Baumhauer J, Nawoczenski D, Patel A, et al. Dynamic assessment of the Morton’s extension carbon footplate on pain, function and plantar loading patterns in patients with hallux rigidus. Presented at the 2010 American Orthopaedic Foot and Ankle Society Summer Meeting. July 7-10. National Harbor, Md.

Judith F. Baumhauer, MD, can be reached at 601 Elmwood Ave., Box 665, Orthopedics Department, University of Rochester, Rochester, NY 14642; 585-275-5933; e-mail: judy_baumhauer@urmc.rochester.edu.

Traditionally a Morton’s extension is an orthosis which 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
Orthopedics Today Editorial Board foot and ankle section editor