European Radiology: long-term prognosis compared with ultrasound-guided corticosteroid injections for Morton neuroma

Morton neuroma (MN) is not a true neuroma, but a degenerative process of the nerve characterized by fibrosis
of the outlet, perimembrane, and intimal membranes.
33% to 54% of patients may be asymptomatic, and when symptomatic, management of MN can be divided into non-surgical and surgical
.
Non-surgical treatments include conservative or percutaneous interventions
.

A mixture of corticosteroids and anesthetics is one of
the main injections used.
Percutaneous injections can be performed blindly, i.
e.
according to anatomical landmarks or under the guidance of US
.
Compared with US-guided injections, blind piercing injections often cause short-term pain within 6 months with poor
relief.

A study published in the journal European Radiology compared blinded injections with US-guided injections for the long-term (up to 3 years) efficacy of MN to determine which approach is more appropriate in non-surgical treatment of this condition and evaluated the impact
of other variables (patient age, size of neuroma, presence or absence of ipsilateral neuroma) on patient outcomes.

This review was a randomized trial with evaluator-blinding in which 33 patients with MN were injected according to anatomical markers by an experienced orthopedic surgeon (blind puncture, Group 1) and 38 patients were injected by an experienced musculoskeletal radiologist under the guidance of US (Group 2).

Patients were assessed
using a visual analogue scale and the Manchester Foot Pain and Disability Index (MFPDI).
The injection consists of injecting 1 ml of 2% mepevacaine and 40 mg of triamcinolone acetonide
into each intraperitoneal cavity.
During the first 3 months of follow-up, up to 4 injections
are allowed.
Follow-up by phone and/or appointment at 15 days, 1 month, 45 days, 2 months, 3 months, 6 months, and 1, 2, and 3 years
.
The statistical analysis used an unpaired student t-test
.

No differences
were found in age or clinical measures between the first group (VAS, 8.
5±0.
2; MFPDI, 40.
9±1.
1) and the second group (VAS, 8.
4±0.
2; MFPDI, 39.
8±1.
2).
At 3 years of follow-up, VAS improved better in group 2 (P < 0.
05).

At follow-up from 45 days to 2 years, MFPDI improved better in the second group (P < 0.
05).

At 3 years of follow-up, the second group (87%) was more satisfied with treatment than the first group (59.
1%)
.

Figure Normal measurement
of the finger nerve and Morton neuroma.
A long-axis sagittal view shows that the normal common digital nerve (arrow) is divided into two digital nerves (arrowhead).

B Short-axis coronary view showing the common pedophalangeal nerve (+).

C Measurements made in the sagittal view, including sagittal (+) and back diameter (X).

D Transverse diameter (+) measured in the minor axis coronal plane

This study suggests that ultrasound-guided corticosteroid injections are more effective
than blinded injections in patients with MN in the medium to long term.

Original source:

Fernando Ruiz Santiago,Pablo Tomás Muñoz,Antonio Jesús Láinez Ramos-Bossini,et al.
Long-term comparison between blind and ultrasound-guided corticoid injections in Morton neuroma.
DOI:10.
1007/s00330-022-08932-y