Normative Distribution of First Metatarsal Axial Rotation

TY - JOUR

T1 - Normative Distribution of First Metatarsal Axial Rotation

AU - Steadman, Jesse

AU - Bakshi, Neil

AU - Arena, Christopher

AU - Leake, Richard

AU - Barg, Alexej

AU - Saltzman, Charles L

PY - 2021/8

Y1 - 2021/8

N2 - BACKGROUND: First metatarsal (M1) axial rotation is recognized as a clinically relevant component of hallux valgus deformity. Methods to realign the M1 in 3 dimensions have been developed. One goal of these operations is to restore normal rotation of the first ray. The aim of this study is to provide estimates for the normal distribution of M1 rotation in patients without relevant anatomic pathology.METHODS: Using stringent clinical and radiographic criteria, we evaluated a set of plain radiograph and weightbearing computed tomography (WBCT) images of 62 feet from a consecutive patient database. Subjects included had normal foot alignment without bunion symptoms. M1 rotation of each foot was measured using 2 unique methods (Saltzman et al and Kim et al methods). Measurement of rotation was performed by 2 observers from coronal WBCT images. Mean values and confidence intervals (CIs) of M1 rotation were calculated for each method. Inter- and intraobserver reliability values were also reported.RESULTS: Mean M1 rotation values of 2.1 degrees (95% CI: 0.9-3.4) and 6.1 degrees (95% CI: 4.4-7.8) were identified using the Saltzman et al and Kim et al methods, respectively. Inter- and intraobserver reliability values were interpreted as excellent for both methods.CONCLUSION: In this study, we describe the natural distribution of the M1 axial rotation in subjects without bunion or other identifiable bony foot deformities. This information should provide a normative reference for surgeons correcting rotational issues of the first metatarsal.LEVEL OF EVIDENCE: Level III, retrospective cohort study.

AB - BACKGROUND: First metatarsal (M1) axial rotation is recognized as a clinically relevant component of hallux valgus deformity. Methods to realign the M1 in 3 dimensions have been developed. One goal of these operations is to restore normal rotation of the first ray. The aim of this study is to provide estimates for the normal distribution of M1 rotation in patients without relevant anatomic pathology.METHODS: Using stringent clinical and radiographic criteria, we evaluated a set of plain radiograph and weightbearing computed tomography (WBCT) images of 62 feet from a consecutive patient database. Subjects included had normal foot alignment without bunion symptoms. M1 rotation of each foot was measured using 2 unique methods (Saltzman et al and Kim et al methods). Measurement of rotation was performed by 2 observers from coronal WBCT images. Mean values and confidence intervals (CIs) of M1 rotation were calculated for each method. Inter- and intraobserver reliability values were also reported.RESULTS: Mean M1 rotation values of 2.1 degrees (95% CI: 0.9-3.4) and 6.1 degrees (95% CI: 4.4-7.8) were identified using the Saltzman et al and Kim et al methods, respectively. Inter- and intraobserver reliability values were interpreted as excellent for both methods.CONCLUSION: In this study, we describe the natural distribution of the M1 axial rotation in subjects without bunion or other identifiable bony foot deformities. This information should provide a normative reference for surgeons correcting rotational issues of the first metatarsal.LEVEL OF EVIDENCE: Level III, retrospective cohort study.

KW - Hallux Valgus/diagnostic imaging

KW - Humans

KW - Metatarsal Bones/diagnostic imaging

KW - Reproducibility of Results

KW - Retrospective Studies

KW - Rotation

U2 - 10.1177/10711007211001015

DO - 10.1177/10711007211001015

M3 - SCORING: Journal article

C2 - 33890512

VL - 42

SP - 1040

EP - 1048

JO - FOOT ANKLE INT

JF - FOOT ANKLE INT

SN - 1071-1007

IS - 8

ER -