Instability of the first metatarsal-cuneiform joint: diagnosis and discussion of an independent pain generator in the foot

Comparative Reliability of a Novel Electromechanical Device and Handheld Ruler for Measuring First Ray Mobility

BACKGROUND

Quantifying first ray mobility is crucial to understand aberrant foot biomechanics. A novel device (MAP1^st) that can perform measurements of first ray mobility in different weightbearing conditions, foot alignments, and normalization was tested. The reliability of these measurement techniques was assessed in comparison to a handheld ruler considered representative of the common clinical examination.

METHODS

The study included 25 participants (50 feet). Two independent raters performed baseline, test-retest, and remove-replace measurements of first ray mobility with MAP1^st and the handheld device. The effects of non-, partial, and full weightbearing in subtalar joint neutral and the resting calcaneal stance position were assessed. Measurement normalization relative to foot size was also investigated. Intra- and interclass correlation coefficients (ICCs) were calculated for each device between the 2 raters. In addition, Bland-Altman plots were constructed to determine if fixed biases or substantial outliers were present.

RESULTS

Similar intrarater ICC values were found for both devices (≥0.85). However, interrater ICC values were substantially improved by MAP1^st compared with the handheld device (0.58 vs 0.06). Bland-Altman plots demonstrated biases of 1.27 mm for the handheld ruler, and 2.88 to 0.05 mm and -1.16 to 0.00 for linear and normalized MAP1^st measurements, respectively. Improved reliability was achieved with MAP1^st for normalized assessments of first ray mobility while the foot was placed in partial- and full-weightbearing resting calcaneal stance positions.

CONCLUSION

MAP1^st provided reliable assessments of partial- and full-weightbearing first ray mobility. It should help investigators to explore the potential relationships between first ray function and aberrant foot biomechanics in future research.

LEVEL OF EVIDENCE

Level II, prospective cohort study.

Clinical indications for image-guided interventional procedures in the musculoskeletal system: a Delphi-based consensus paper from the European Society of Musculoskeletal Radiology (ESSR)-part VI, foot and ankle

Objectives

Clarity regarding accuracy and effectiveness for interventional procedures around the foot and ankle is lacking. Consequently, a board of 53 members of the Ultrasound and Interventional Subcommittees of the European Society of Musculoskeletal Radiology (ESSR) reviewed the published literature to evaluate the evidence on image-guided musculoskeletal interventional procedures around this anatomical region.

Methods

We report the results of a Delphi-based consensus of 53 experts from the European Society of Musculoskeletal Radiology who reviewed the published literature for evidence on image-guided interventional procedures offered around foot and ankle in order to derive their clinical indications. Experts drafted a list of statements and graded them according to the Oxford Centre for evidence-based medicine levels of evidence. Consensus was considered strong when > 95% of experts agreed with the statement or broad when > 80% but < 95% agreed. The results of the Delphi-based consensus were used to write the paper that was shared with all panel members for final approval.

Results

A list of 16 evidence-based statements on clinical indications for image-guided musculoskeletal interventional procedures in the foot and ankle were drafted after a literature review. The highest level of evidence was reported for four statements, all receiving 100% agreement.

Conclusion

According to this consensus, image-guided interventions should not be considered a first-level approach for treating Achilles tendinopathy, while ultrasonography guidance is strongly recommended to improve the efficacy of interventional procedures for plantar fasciitis and Morton’s neuroma, particularly using platelet-rich plasma and corticosteroids, respectively.

Key Points

• The expert panel of the ESSR listed 16 evidence-based statements on clinical indications of image-guided musculoskeletal interventional procedures in the foot and ankle.

• Strong consensus was obtained for all statements.

• The highest level of evidence was reached by four statements concerning the effectiveness of US-guided injections of corticosteroid for Morton’s neuroma and PRP for plantar fasciitis.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00330-021-08125-z.

Foot structural factors and ground reaction force in hallux valgus grades

BACKGROUND

Little attention has been paid to foot structural factors and ground reaction force in hallux valgus. Investigating the structural factors in detail and determining their biomechanical effects can help to better manage hallux valgus.

METHODS

In this case-control study, 120 females, 90 hallux valgus and 30 healthy, were recruited. Hallux valgus grades (mild, moderate, severe), first metatarsal mobility, foot pronation, hallux rotation, and pain were assessed by clinical tests. Ground reaction forces were measured in barefoot and shod conditions for both feet and analyzed using mixed within-between MANOVA. The association between structural factors and pain with force was analyzed using Spearman correlation coefficient.

RESULTS

The frequency of foot structural factors and pain severity were reported in hallux valgus grades. A significant difference was seen in the force values between groups (P<0.001). Bonferroni post hoc test indicated that the mean of the first peak for the severe group was significantly higher than the mild group (P=0.013) and the mean of second peak for the moderate group was higher than that of the healthy group (P=0.009). The force values were affected by wearing shoe (P<0.001) but not by foot side (P=0.086). There was a medium, positive correlation between the hallux rotation and force in the moderate group (r=0.39, P=0.03) and also between the pronation and force in the severe group (r=0.36, P=0.04).

CONCLUSION

Foot structural factors, pain, and force were different in each hallux valgus grads. Similar force in both feet, and increased force by wearing shoe were seen. The relationship between the pronation and hallux rotation with force revealed the importance of these factors from the biomechanical viewpoint.

Mobility of the first ray: review article

Since its introduction by Morton in the early 20th century, first metatarsal instability has been debated as a contributing cause of many foot ailments. Given our evolutionary origins, some instability at the first ray seems inevitable. It makes sense that hypermobility could be the pathology leading to the development of various forefoot disorders. The problem is that it has been difficult to prove. Only in the last decade have there been any devices with which to quantify mobility, and each of the devices measures slightly different variables. However, each of these devices has been shown to be consistent and reliable. Excessive mobility of the first ray probably cannot be considered the only "suspect." With disorders such as hallux valgus and metatarsalgia, environment and footwear may play just as important a role as hypermobility. There are some conclusions, though, that can be safely drawn at this point. * We should define the measures of first ray mobility. One recent study has suggested the terms metatarsal elevation and metatarsal translation to describe two different aspects of the problem. * Simple clinical tools may be as useful as more cumbersome research tools for assessing first ray instability. * First ray mobility on average is increased in patients with hallux valgus. * First ray mobility is increased in some patients with transfer metatarsalgia. * Although some studies show increased elevation or mobility of the first ray in hallux rigidus, other studies do not. The burden is on the current generation of foot and ankle practitioners to resolve the debate of its predecessors. By first defining the measures of instability and then applying them to large populations, the role of hypermobility may be better defined. Then we can debate how best to "fix" the problem!

First ray mobility increase in patients with metatarsalgia

BACKGROUND

The significance and measurement of first metatarsal hypermobility has been difficult to quantify in relation to transfer metatarsalgia. We evaluated the hypothesis that dynamic elevation of the first metatarsal relative to the second metatarsal could be measured with a simple device and would be associated with transfer metatarsalgia. We also assessed intraobserver and interobserver reliability of the simple device.

MATERIALS AND METHODS

A series of 352 patients were prospectively measured for dynamic metatarsal elevation: 64 patients with transfer metatarsalgia and 288 patients without symptoms.

RESULTS

Those with metatarsalgia symptoms had significantly greater first ray mobility (9 mm versus 7 mm; p < 0.0002) and metatarsal elevation (5 mm versus 3 mm; p < 0.0002) than patients without symptoms.

CONCLUSION

In this prospective series, the device was reliable for measuring dynamic first metatarsal elevation at different time points with different examiners. Patients with metatarsalgia had higher dynamic metatarsal elevation compared to patients without metatarsalgia, suggesting a mechanism by which load can be transferred from the first to lesser metatarsals.