CLINICAL QUESTION

Are corticosteroid injections and surgical interventions effective in treating Morton neuroma?

EVIDENCE-BASED ANSWER

In patients with Morton neuroma, combined corticosteroid/local anesthetic injection does not improve pain, function, or quality of life at 3 to 6 months vs. local anesthetic injection alone. More adverse events, including skin and plantar fat pad atrophy and hypopigmentation, occur with the addition of a corticosteroid. (Strength of Recommendation [SOR]: B, inconsistent or limited-quality patient-oriented evidence.)

Compared with non–ultrasound-guided corticosteroid/local anesthetic injection, ultrasound-guided injection probably improves pain, function, and patient satisfaction at 6 months with little to no difference in adverse events. (SOR: B, inconsistent or limited-quality patient-oriented evidence.)

There appears to be little to no difference in patient satisfaction or rates of adverse events between plantar incision neurectomy and dorsal incision neurectomy.¹ (SOR: B, inconsistent or limited-quality patient-oriented evidence.)

PRACTICE POINTERS

Morton neuroma manifests as the benign enlargement of the common plantar digital nerve, predominantly in the third, or occasionally second, webspace of the foot.¹ Its hallmark symptom is plantar pain between metatarsal heads, intensified by walking and the constraints of tight-fitting, high-heeled shoes. The pain is described as burning, stabbing, or tingling or the sensation of walking on a pebble.² Diagnosis is based on characteristic symptoms and physical examination; ultrasonography is the preferred imaging modality for confirmation.^3,4

Conservative treatment includes footwear alteration to allow the metatarsal heads to spread out, metatarsal pads, radiofrequency ablation, and corticosteroid injection.^2,5 Some patients may eventually require surgical intervention.^4–6 The authors of this Cochranereview sought to determine the effectiveness of corticosteroid injection and surgical intervention in treating Morton neuroma.

The Cochrane review included six randomized controlled trials with 373 participants who had Morton neuroma.¹ Studies were conducted in Spain, the United Kingdom, Sweden, and South Korea; demographic characteristics of the participants were not provided. Pain was measured with a visual analog scale. Function was measured with the American Orthopaedic Foot and Ankle Society Lesser Toe Metatarsophalangeal-Interphalangeal Scale and the Manchester Foot Pain and Disability Index. Quality of life was measured with a health-related quality-of-life questionnaire. Patient satisfaction was measured with the EuroQol five dimension instrument. The analyzed studies were published before July 2022.

Compared with local anesthetic injection alone, corticosteroid/local anesthetic injection did not improve pain or function at 3 to 6 months (two studies with 157 participants). Very low-certainty evidence demonstrated that more adverse events, including mild skin atrophy (3.9%), hypopigmentation of the skin (3.9%), and plantar fat pad atrophy (2.6%), could occur with corticosteroid/local anesthetic injection (risk ratio [RR] = 9.84; 95% CI, 1.28 to 75.56; P = .03). Moderate- and low-certainty evidence due to small sample sizes and high risk of bias, respectively, showed that adding a corticosteroid to a local anesthetic also did not seem to improve health-related quality of life (one study with 122 participants; moderate-certainty evidence) or patient satisfaction (one study with 35 participants; low-certainty evidence).

Ultrasound-guided corticosteroid/local anesthetic injection, when compared with non–ultrasound-guided corticosteroid/local anesthetic injection, probably resulted in pain reduction at 2 months (mean difference [MD] = −29.00; 95% CI, −41.63 to −16.37; P = < .001; one study; 72 feet), 6 months (MD = −15.01; 95% CI, −27.88 to −2.14; P = .02; two studies; 116 feet), and 12 months (MD = −15.46; 95% CI, −26.02 to −4.90; P = .004; two studies; 116 feet). These results were considered clinically meaningful. Ultrasound-guided injection also probably improved function at 2 months (MD = −6.80; 95% CI, −11.25 to −2.35; P = .003; one study; 72 feet), 6 months (standardized MD = −0.47; 95% CI, −0.84 to −0.10; P = .01; two studies; 116 feet), and 12 months (standardized MD = −0.52; 95% CI, −0.94 to −0.10; P = .02; two studies; 116 feet) vs. non–ultrasound-guided injection, although it was not specified whether the change was clinically meaningful. In these comparisons, ultrasound-guided injection also may have increased patient satisfaction at 2 months (RR = 2.02; 95% CI, 1.28 to 3.17; P = .002; one study; 72 feet), 6 months (RR = 1.71; 95% CI, 1.19 to 2.44; P = .003; two studies; 114 feet), and 12 months (RR = 1.82; 95% CI, 1.17 to 2.83; P = .008; one study; 68 feet). There was little to no difference in reported adverse events.

At 34 months, when comparing surgical removal of Morton neuroma via plantar incision neurectomy vs. dorsal incision neurectomy, low-certainty evidence demonstrated little to no difference in patient satisfaction (one study; 73 participants) or incidence of adverse events (one study; 75 participants).

The 2009 Clinical Practice Guideline Forefoot Disorders Panel of the American College of Foot and Ankle Surgeons recommends initial treatment of Morton neuroma with foot-wear alteration, metatarsal pads, and injection therapy, followed by surgical interventions, such as nerve decompression, nerve excision, and cryogenic neuroablation, if needed.⁷

PATIENT PERSPECTIVE

The physician must be prepared to address patient questions and preferences. Shared decision-making necessitates patience as the physician elicits how long the condition has persisted and whether any home remedies have been attempted, as well as patient expectations. A clear and unbiased description of treatment options should be provided, along with risks and benefits of each approach. The physician should not be afraid to respond to patient questions by saying that there is not a clear answer, as is often the case. Patients will undoubtedly have questions about what they have found online about treatment options.

Editor’s Note: The patient perspective is the opinion of the patient perspective author and, although peer reviewed, does not represent evidence-based conclusions.

The practice recommendations in this activity are available at https://www-cochrane-org.lib3.cgmh.org.tw:30443/CD014687.