- Arthrodesis, or joint fusion, is often recommended for osteoarthritis of the big toe (hallux rigidus) but how much it actually helps has not previously been examined in a prospective controlled trial.
- In this trial randomizing patients to immediate surgery or “watchful waiting,” most outcomes including pain on walking were substantially improved at 1 year with surgery.
- Imaging showed asymptomatic nonunion in about 10% of patients undergoing surgery, but these patients said they were satisfied and no revisions were performed; no serious adverse events were recorded in either study arm.
Patients with painful osteoarthritis of the first metatarsophalangeal joint (MTPJ) — aka the big toe — would do better with immediate surgery than letting nature take its course, results of a randomized trial indicated.
Among 90 patients randomized to arthrodesis (joint fusion) or “watchful waiting,” pain scores with walking were reduced after 1 year from a baseline mean of about 6 on the standard 0-10 scale to an average of 1.3 in the intervention group compared with 5.7 among controls, according to Mikko Miettinen, MD, of Helsinki University Hospital in Finland, and colleagues.
That translated to a mean adjusted difference of 5.0 points, which was both statistically significant (95% CI 3.9-6.1) and far greater than the prespecified margin of 1.7 points for clinical significance, the researchers reported in Annals of Internal Medicine. Most secondary outcomes also favored surgery.
Although arthrodesis is the most common surgical remedy for the condition, also called hallux rigidus, it had never before been tested in a randomized controlled trial against nonsurgical or no treatment, Miettinen and colleagues noted.
“Our finding that first MTPJ arthrodesis produced a clinically meaningful reduction in walking-related pain and other important clinical outcomes compared with watchful waiting has considerable clinical importance,” the group wrote. “Arthrodesis should be considered an important treatment option for people aged 40 years or older who have pain and disability due to hallux rigidus for 1 year or more.”
Typically, treatment for hallux rigidus begins with over-the-counter painkillers, orthotics, and “activity modifications,” Miettinen and colleagues explained, although their effectiveness hasn’t been rigorously tested either. A variety of surgical procedures may be performed when symptoms worsen, but arthrodesis “is widely regarded as the gold standard … particularly in advanced disease,” the researchers observed.
For the current trial, the investigators recruited patients at least 40 years old with hallux rigidus symptoms lasting 1 year or more and with pain on walking self-rated as 4 or higher on the 0-10 scale. Exclusion criteria included pain in other toes, prior foot trauma, diabetes, rheumatoid arthritis, or hallux valgus angle exceeding 15 degrees. However, patients with hallux rigidus in both feet could be enrolled, with attention focused on the toe with more pain. Patients with osteoarthritis in other joints such as the knee also remained eligible, and indeed, three-quarters of those enrolled did have such involvement.
“Watchful waiting” in the study consisted of education on osteoarthritis and use of painkillers and footwear modifications as desired. Patients were discouraged from seeking other treatments such as injections outside the study protocol but it’s possible some did so.
Mean age at baseline was 59 for those randomized to surgery and 57 in the control group. Just over half were women. Pain scores at baseline averaged 6.0 and 5.8 in the two groups, respectively. The investigators rated osteoarthritis severity in the affected toe at grade 3 in 60% of the surgery group and 49% of controls; most of the rest were at grade 2. Statistical analyses adjusted for these and other baseline differences between the study arms.
Pain on walking after 1 year was the trial’s primary outcome, with secondary outcomes including pain at rest, self-rated overall satisfaction, use of analgesics, and scores for clinician-administered instruments such as the Foot and Ankle Ability Measure and the Manchester-Oxford Foot Questionnaire.
While scores for pain on walking hardly budged in the watchful-waiting group, the surgical group showed marked improvement in the first 6 months, with an average rating of 2.4 at that point. Pain at rest actually increased among controls (mean 3.6 at month 12 from 3.1 at baseline), while it declined modestly with surgery (to 0.6 from 3.6 at baseline).
Nearly 90% of the intervention group declared themselves satisfied at 1 year, compared with 20% of controls (relative risk 4.4, 95% CI 2.4-8.0). Similarly, surgery was associated with a 1.7-fold greater probability (95% CI 1.3-2.3) that patients would not be taking painkillers at 1 year. Use of orthotics was not common in either group at baseline, but it declined somewhat more with surgery than watchful waiting. Other secondary outcomes covering foot-related and overall quality of life also significantly favored arthrodesis.
Four control patients asked for surgical treatment before the 1-year mark, and another 25 requested it upon completing follow-up. In total, therefore, 64% of controls wanted the intervention. (That left seven control patients who rated their symptoms as “unacceptable” at 1 year but did not then seek surgery, at least to the investigators’ knowledge.)
No serious adverse events were seen in either group. In the surgical arm, two patients were left with a hallux valgus angle less than 0 degrees, and four showed asymptomatic nonunion on CT scans. These events were rated as minor, and none of those with nonunion requested or received further imaging or surgery.
Limitations to the study included its single-center, unblinded design, and the relatively small number of participants. The study’s many exclusion criteria may also limit its generalizability to patients seen in routine practice, the authors noted.
