Do Arch Supports Alter Foot Alignment in Patients with Metatarsalgia? A Weightbearing CT and x-ray Study

Category: Midfoot/Forefoot; Lesser Toes Introduction/Purpose: Arch-support insoles are frequently included in the treatment plans for common foot ailments including metatarsalgia. Literature has demonstrated that insoles with metatarsal and arch support could relieve walking pain and improve patient-reported measures of function in metatarsalgia. The purpose of this study was to examine alterations in foot alignment among metatarsalgia patients who used arch support insoles. Methods: A clinical trial was initiated after the approval by the institutional review board. Patients with metatarsalgia (age: 18-65 y/o) were included after they consented to participate. Individuals with open wounds, feet asymmetry, using assistive device or brace, and those with BMI more than 35 were excluded. Participants underwent weightbearing computed tomography (WBCT), and weight-bearing x-ray of their feet while standing barefoot or on the insoles (Good Feet™, Dr.’s Own, LLC). The radiological measurements on WBCT and X-rays conducted in these patients are shown in Table 1. The Wilcoxon-Signed Rank test was used for comparison of the continuous measurements, and the interobserver reliability was analyzed with Intraclass Correlation Coefficient (ICC). Results: Ten patients with a mean age of 46.9±13.06 years were included in the study. Observed changes on X-rays include decreased 4th-5th intermetatarsal angle (p=0.04), 2nd-4th/2nd-5th metatarsal tangent angles (p=0.003, p=0.001), and 1st metatarsal length on antroposterior (AP) view (p=0.02). Also, 1st metatarsal declination angle (p=0.002), and talo-first metatarsal angle on AP view (p=0.05) were increased. No significant changes on the WBCT were found, except for a decrease in the first metatarsal pronation angle (p=0.02). Conclusion: Arch support insoles can bring about anatomical changes especially in the forefoot area of patients with metatarsalgia. While the causal correlation between these changes and alleviation of the symptoms cannot be proven based on our data, these outcomes can guide future clinical trials comparing different treatment for metatarsalgia to determine contributing factors to the healing process of this condition

Measurement of the Medial Clear Space: An Intra-Observer Comparison of Various Measurement Methods

Category: Ankle; Trauma Introduction/Purpose: The Medial Clear Space (MCS) is an anatomic space between the lateral cortex of the medial malleolus and the medial cortex of the talus. Measurement of the MCS is helpful in differentiating which ankle fractures are amenable to non- operative treatment, and which may require fixation. The MCS is often evaluated on radiographic views of the ankle, and several different methods of measuring the MCS have been described in the literature. There is little information on intra-observer reliability of MCS measurement, nor validation of the various medial clear space measurement techniques. As such, the aim of this study was to better understand intra-observer reliability of MCS via several of the most popularly described techniques. Methods: Patients with matched ankle X-rays and CT scans - either weight bearing or non-weight bearing imaging pairs - were identified via electronic medical record database review of a Level-1, academic medical system after IRB approval. Measurement of the MCS on CT scan was used as the gold standard against which radiographic measurements were compared given its superior osseous definition. Four independent reviewers measured the medial clear space on 20 weight bearing, and 20 non-weight bearing x-rays via the five most commonly described methods: 5mm inferior to the talar dome (MCS #1), half way down the medial articular surface of the talus (MCS #2), obliquely at the supero-medial corner of the talus (MCS #3), and at the level of the talar dome (MCS #4). Intraclass Correlation Coefficients (ICC) were then calculated for each of the four MCS measurements methods after compilation of all independent reviewer data. Results: The ICC varied between each of the four MCS measurement techniques. For measurements 5mm below the talar dome (MCS #1) the ICC was 0.041. Measured halfway down the medial talar articular surface, the ICC was 0.466. The superior oblique MCS measurement ICC was 0.725, and the MCS measured at the level of the talar dome had an ICC of 0.419. MCS measurement 5mm below the talar dome had poor intra-observer reliability, while measurement halfway down the medial articular surface and at the level of the talar dome had fair intra-observer correlation. Overall, measurement of the MCS at the superomedial talar dome had good intra-observer reliability, ranking as the most favorable measurement method. Conclusion: The commonality of ankle fractures demands accurate radiographic interpretation for the determination of need for surgical intervention. The medial clear space measurement is the most common metric used to determine the need for surgery. There is no consensus regarding the optimal method, nor reliability of the various MCS measurement techniques. The results of this study suggest that measurement of the medial clear space at the superomedial corner of the talar dome has the highest intra- observer reliability