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Second metatarsophalangeal joint dislocation in hallux valgus: a radiographic study using a two-dimensional coordinate system

BMC Musculoskeletal Disorders volume 26, Article number: 204 (2025) Cite this article

Abstract

Background

Hallux valgus (HV) poses additional challenges when accompanied by second metatarsophalangeal (MTP) joint dislocation, often requiring complex surgical intervention. This study aimed to analyze HV feet with second MTP joint dislocation using a 2-dimensional coordinate system to better understand the anatomical structure of this condition.

Methods

Weightbearing foot radiographs of 49 HV feet with second MTP joint dislocation (group D), 68 HV feet without second MTP joint dislocation (group W), and 54 control feet (group N) were analyzed. A 2-dimensional coordinate system was used to map standardized points on radiographs into X and Y coordinates, which were compared across groups. Radiographic parameters measured included hallux valgus angle (HVA), intermetatarsal angle (IMA), second toe MTP angle (2MTPA), metatarsus adductus angle (MAA), great toe length, first metatarsal (MT1) length, second toe length, and second metatarsal (MT2) length. The 2MTPA was further analyzed based on the deviation direction (medial, neutral, or lateral).

Results

The proximal phalanx head of the third toe in groups D and W was lateral compared to group N (P <.05 and P <.001, respectively), while the distal point in group D was medial to group W (P <.001). The base of MT1 in group D was significantly medial compared to other groups (P <.001). Additionally, the distal point of the great toe in group D was significantly lateral compared to other groups (P <.01 and P <.001, respectively).

Conclusions

Patients with second MTP joint dislocation exhibited a proximally translated second toe, an adducted third toe, a medialized MT1 base, and a lateralized great toe tip. The M1/2 angle influenced dislocation direction: higher angles led to medial or neutral deviation, while lower angles caused lateral deviation. Radiographic coordinate mapping provided novel insights into foot anatomy in HV with second MTP joint dislocation, laying the groundwork for future research on anatomical risk factors and optimizing surgical approaches to improve patient outcomes.

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Background

Hallux valgus (HV) is a prevalent forefoot deformity with a global incidence of 19%.5,19,29 Lesser toe deformities, including crossover toes, flexion deformities, and lateral deviation have been associated with HV deformities [7, 10, 24, 36]. In some cases of HV, dislocation of the second metatarsophalangeal (MTP) joint occurs and necessitates a supplementary procedure alongside HV correction [27]. Second MTP joint dislocation is seen as an end-stage deformity of various conditions in previous studies [7, 10, 17, 47]. Anatomical studies show second MTP joint dislocation restraints include the volar plate, collateral ligaments, and deep transverse metatarsal ligament [1, 6, 16, 38, 39, 44]. Previous reports suggested a potential link between second metatarsal (MT2) length and crossover toe, ultimately leading to MTP dislocation if untreated [7, 10, 46]. However, conflicting reports found no clear relationship between MT2 length and second toe deformity [24].

Plantar plate injury, frequently affecting the second MTP joint, has been identified as a cause of dislocation [14, 22]. However, limited evidence exists regarding how HV predisposes individuals to second MTP joint dislocation, despite reports suggesting the HV severity as a risk factor [34]. Additionally, factors such as medial deviation (e.g., crossover toe) [7, 14, 47], or lateral deviation [36] may contribute to second MTP joint dislocation. It remains unclear how osseous architecture of the HV forefoot influences the plantar soft-tissue and plantar plate, eventually leading to a second MTP joint dislocation [24, 26, 27].

Only a few studies have evaluated the relationship between HV and second MTP joint dislocation, and more specifically, the risk factors that may influence the progression of one over the other. To learn about the anatomic structure of this deformity, this study aimed to use a 2-dimensional coordinate system to evaluate radiographic alignments and osseous features [41], shedding light on the relationship between HV and second MTP joint dislocation. The advantage of a 2-dimensional coordinate system lies in its ability to visually map the entire foot and highlight key differences of normal and abnormal feet using standard radiographs. We hoped to determine any potential anatomic factors in HV that may affect second MTP joint dislocation. The findings could enhance diagnostic accuracy, guide surgical planning, and improve treatment outcomes for patients with these deformities, ultimately optimizing patient care in clinical practice.

Methods

This is a retrospective study comparing radiographic parameters among three groups of females aged at least 18 years: those with hallux valgus (HV) and second MTP joint dislocation (Group D), those with HV without second MTP joint dislocation (Group W), and individuals with control feet (Group N). Standardized points on weightbearing anteroposterior (AP) radiographs were mapped using a 2-dimensional coordinate system. Dislocation was defined as less than 50% articulation of the proximal phalanx articular surface with the metatarsal head [4, 11]. Patients with a hallux valgus angle (HVA) ranging from 40 to 59 degrees were included to match groups and minimize variables associated with severity, while controls had an HVA of 20 degrees or less and no abnormal radiographic findings or history of ipsilateral ankle arthritis or flatfoot. Patients with peripheral nerve disease, rheumatoid arthritis, cerebral palsy, or other conditions predisposing to HV were excluded.

Data were gathered from hospital records spanning January 2013 to August 2023. Of the 368 patients with HV (430 feet) who underwent surgery, 288 feet were excluded for not meeting the inclusion criteria, leaving 142 feet. Further exclusions for rheumatoid arthritis (25 feet) resulted in 117 feet being categorized into Group D (47 patients, 49 feet) and Group W (49 patients, 68 feet). Group N included 49 control subjects (54 feet). Table 1 presents the mean age, laterality, and HVA. The study was approved by the Institutional Review Board.

Table 1 Patient demographics for each group
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Radiographic technique

Weightbearing AP and lateral radiographs of feet were performed at a distance of 100 cm. The tube was tilted approximately 15 degrees from the vertical plane for the AP view, with the center aligned to the midfoot. For the lateral view, the navicular was positioned at the center.

Mapping system

Marked points on digital radiographs were converted into X and Y coordinates in the 2-dimensional framework [41]. The metatarsal axis, defined as a line connecting the midpoints of the proximal and distal metaphyses, served as the reference line. The X-axis was aligned along the second metatarsal (MT2), with its origin (0,0) positioned at the intersection of the X-axis and MT2 base. The Y-axis, perpendicular to the X-axis and passing through the origin, was established accordingly (Fig. 1).

In this coordinate framework:

  • Positive X values indicate locations distal to the origin, while negative X values indicate proximal locations.

  • Positive Y values indicate medial deviations, while negative Y values indicate lateral deviations.

To standardize measurements across varying foot sizes, all coordinate values were expressed as a percentage of MT2 length, allowing for consistent comparisons. The base of MT2 (MB2) was consistently defined as (0,0), while the MT2 head (MH2) was always mapped to (100,0).

A set of key anatomical landmarks were selected for mapping to assess foot morphology and alignment, including:

  • Distal ends of distal phalanges (DPH1-DPH5), distal ends of proximal phalanges (PPH1-PPH5), and midpoints of proximal phalangeal joint surfaces (PPB1-PPB5) to analyze toe positioning.

  • Intersections of metatarsal axes with distal (MH1-MH5) and proximal (MB1-MB5) metatarsal ends to assess metatarsal positioning.

  • Joint space midpoints of the first metatarsocuneiform (1MC), talonavicular (TN), fifth metatarsocuboid (5MC), and calcaneocuboid (CC) joints to evaluate midfoot alignment.

Fig. 1
figure 1

Points marked on the radiograph for the mapping system (points) and length measured (dotted line). T1 to T5: most distal point of soft tissue; DPH1 to DPH5: distal phalanx tips; PPH1 to PPH5: midpoint of distal joint surface of proximal phalanx; PPB1 to PPB5: midpoint of proximal joint surface of proximal phalanx; MH1 to MH5: point of intersection of metatarsal axes with distal metatarsal ends; MB1 to MB5: point of intersection of metatarsal axes with proximal metatarsal ends; 1MC: most medial edge of first metatarsocuneiform joint; TN: most medial edge of talonavicular joint; 5MC: most lateral edge of fifth metatarsocuboid joint; CC: most lateral edge of the calcaneocuboid joint; big toe length: distance of the point T1 to PPB1; second toe length: distance of the point T2 to PPB2; first metatarsal length: distance of point MH1 to MB1; second metatarsal length: distance of point MH2 to MB2

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By overlaying coordinate maps of different groups (e.g., HV with vs. without second MTP joint dislocation), the spatial relationships between key foot structures were visualized, providing insights beyond conventional angular measurements. This technique offers a novel approach to quantifying foot morphology and identifying structural patterns in hallux valgus with second MTP joint dislocation.

To validate the accuracy and reproducibility of this method, twenty randomly selected radiographs were analyzed twice by two independent observers on separate occasions. The standard deviation for all angular measurements remained within 1 degree, while the standard deviation of X and Y coordinates was within 1% for all measured points. The absolute value of the coefficient of variation was within 5%, confirming the system’s reliability. The reliability of the mapping system has been previously validated [41, 42].

Radiographic examination

Measured parameters included the HVA, intermetatarsal angles (IMA), second toe metatarsophalangeal angle (2MTPA), metatarsus adductus angle (MAA), and toe and metatarsal length. This selection was based on findings establishing associations between HV and radiographic features including toe length [41], increased first-second intermetatarsal angle (M1/2),8,12,29 metatarsus adductus (MA) [8, 9, 19], and splay foot [2, 18]. The 2MTPA was associated with second MTP joint dislocation [27]. The central axis of each metatarsal was determined by connecting the midpoints of the proximal and distal ends of its diaphysis [35]. This method was used to determine the IMA and HVA. The proximal phalanx axis was formed by connecting the most concave points on its proximal and distal articular surfaces, and any pronation of the proximal phalanx had minimal impact on these points [41]. The HVA was defined as the line formed by the axes of the first metatarsal (MT1) and first proximal phalanx. The IMA was defined as the angle formed by the axes of adjacent metatarsals. The angle between the axes of the second and fourth metatarsals formed the 2–4 intermetatarsal angle (M2/4), while the 2–5 intermetatarsal angle (M2/5) was determined by the axes of the second and fifth metatarsals. The 2MTPA represented the angle formed by the axes of MT2 and the second proximal phalanx, with medial deviation considered negative and lateral deviation considered positive. Group D (dislocation group) was subdivided into 3 subgroups according to the 2MTPA: group D1 (2MTPA less than − 5 degrees: medial-deviation type), group D2 (2MTPA not less than − 5 degrees and less than 20 degrees: neutral type), and group D3 (2MTPA 20 degrees or more: lateral-deviation type). The absolute (mm) and relative (%) lengths of toes and metatarsals were also measured (Fig. 1). Great toe length was defined as the distance between T1 and PPB1. Second toe length was the distance between T2 and PPB2. The lengths of MT1 and MT2 were measured as distances from MH1 to MB1 and MH2 to BM2, respectively. The great toe, second toe, and MT1 were measured in percentages relative to MT2. Coughlin’s method [29] for measuring MA was used (Fig. 2). Figures of all groups were rotated on its origin (MB2) according to its MAA to visualize each result. The new X-axis was defined as the midfoot axis extending beyond MB2, with the new Y-axis perpendicular and passing through MB2.

Fig. 2
figure 2

Angles measured on the radiographs. HVA: Hallux valgus angle; M1/2 angle: angle between first and second metatarsals axes; M2/3 angle: angle between second and third metatarsal axes; M3/4 angle: angle between third and fourth metatarsal axes; M4/5 angle: angle between fourth and fifth metatarsal axes; M2/4 angle: angle between second and fourth metatarsal axes; M2/5 angle: angle between second and fifth metatarsal axes; 2MTPA: angle between second metatarsal and the second proximal phalangeal axes; MAA: metatarsus adductus angle - A line was drawn along the medial border of the midfoot connecting 2 points: the most medial edge of the first metatarsocuneiform joint (1MC) and the most medial edge of the talonavicular joint (TN). Afterwards, a line was drawn along the lateral border of the midfoot connecting 2 points: the most lateral edge of the calcaneocuboid joint (CC) and the most lateral edge of the fifth metatarsocuboid joint (5MC). A line was then drawn connecting the 2 midpoints that bisected the midfoot. The line perpendicular to the line bisecting the midfoot is the midfoot axis. The angle formed by the axis of the second metatarsal and the midfoot axis is the metatarsus adductus angle

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Statistical analysis

Using SPSS software version 26 (SPSS, Inc, an IBM Company, Chicago, IL), a Multivariate Analysis of Variance (MANOVA) and post hoc comparison (Games-Howell) were used to differentiate the same point in each group. One-factor analysis of variance and post hoc pairwise comparison (Scheffe) were used to estimate the difference between the angles and lengths measured. The level of significance was 0.05.

Results

Measured angles are outlined in Table 2. Coordinates for each point are detailed in Table 3. Mapping results are seen in Fig. 3.

Table 2 Results of the angles and P values
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Table 3 Coordinates and P values for each point in the 3 groups
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Fig. 3
figure 3

Mapping representation of the 3 groups. D = hallux valgus with second metatarsophalangeal joint dislocation (continuous line); W = hallux valgus foot with normal lesser toes (segmented line); N = normal foot (dotted line); DPH1 to DPH5 = distal phalangeal head of first to fifth toe; PPH1 to PPH5 = proximal phalangeal head of first to fifth toe; PPB1 to PPB5 = proximal phalangeal base of first to fifth toe; MH1 to MH5 = metatarsal head of first to fifth metatarsal; MB1 to MB5 = metatarsal base of first to fifth metatarsal; TN = talonavicular junction; CC = calcaneocuboid junction

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Intermetatarsal angles

There was no significant difference in M1/2 angle between group D and group W; however, both HV groups were significantly larger than group N (P <.001).

The 2–3 intermetatarsal angle (M2/3) and 2–4 intermetatarsal angle (M2/4) of group D were larger than group N (P <.01). The 3–4 intermetatarsal (M3/4), 4–5 intermetatarsal (M4/5), and 2–5 intermetatarsal (M2/5) angles were not significant among all groups (Table 2).

Position of the lesser metatarsals

The Y-coordinates of lesser metatarsal heads (MH3, MH4, MH5) in groups D and W were significantly lateral to group N demonstrating widening of HV feet (Fig. 3). The MH4 of both HV groups was significantly proximal to group N (Table 3).

Position of the second toe

All second toe points of group D were proximal to other groups (P <.001), with the second toe base located proximal to the MT2 head denoting MTP joint dislocation (Fig. 3). The distal phalanx head, proximal phalanx head, and proximal phalanx base of the second toe of groups D and N had no difference in the Y-axis but were significantly lateral in group W (Table 3).

Second toe deviation after dislocation

In group D, the 2MTPA ranged from − 41 to 36. Neutral type (subgroup D2) was the most common (25 feet) followed by lateral-deviation type or subgroup D3 (14 feet) then medial-deviation type or subgroup D1 (10 feet). Mean M1/2 angles of D1, D2, and D3 were: 21.0 ± 2.4, 19.0 ± 4.0, 16.4 ± 3.5 degrees, respectively. The 2MTPA of D1 was significantly medially deviated compared to D3, but not D2. The MA angles were 14.1 ± 3.9, 14.8 ± 4.5, and 17.6 ± 3.5 for subgroups D1, D2, D3, respectively. No differences in other IMA among subgroups were found.

Position of the lesser toes

The third metatarsal base of group D was proximal to group N (P <.05). The third metatarsal heads of both HV groups were lateral to group N (P <.001). The third proximal phalanx bases of both HV groups were lateral to group N (P <.001). The third proximal phalanx head of group D is proximal to groups W and N (P <.01 and P <.001, respectively). The proximal phalanx heads of both HV groups were similar to each other and lateral to group N (P <.05 and P <.001, respectively). The third distal phalanx head of group D is proximal to both groups W and N (P <.01), while group W deviated laterally among the groups (P <.001).

The fourth metatarsal bases of both HV groups was significantly proximal and lateral than control (Table 3). The fourth proximal phalanx heads of both group D and group W were lateral to group N (P <.01). The fourth distal phalanx head of group W was lateral to group N (P <.001).

The fifth metatarsal bases of both HV groups was proximal to control feet (P <.05) with group D deviating laterally to group N (P <.01). There were no significant differences in proximal phalanx head location and distal point of the fifth toe among all groups.

These results show an adducted position with a lateralized base and a medialized third toe distal tip in group D (Fig. 3).

Toe length and metatarsal length

There were no differences in great toe length among the groups (Table 4). The second toe length (%) and true length (mm) of group D were significantly shorter than other groups. However, the second toe length was likely affected by sagittal plane deformities. The MT1 length (%) of group D was longer than group N (P <.05). Lastly, MT2 length (mm) of group D was shorter than group N (P <.001).

Table 4 Length (unit: percentages) and true length (unit: mm) of toes and metatarsals
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Midfoot to hindfoot

The MB1 and 1MC points of group D were significantly medial among groups, while the TN and CC points were proximal among groups (Table 3). The TN point of group D was medial to group N (P <.05). The 5MC point of group D was proximal to group N. These findings show a wider midfoot associated with second toe dislocation (Fig. 3).

Metatarsus adductus

There were no significant differences in MAA among groups. Figure 4 shows lesser metatarsals and lesser toe proximal phalanges of group D diverge laterally from other groups according to the midfoot axis. Additionally, third toe distal tip of group D is medial to group W, showing toe adduction even when rotated according to MAA.

Fig. 4
figure 4

Mapping representation of the 3 groups according to metatarsus adductus angle

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All feet were rotated counterclockwise according to its metatarsus adductus angle, making the midfoot axis the same direction as the new X-axis, the angle formed by the line connecting MH2 and MB2 and the x-axis was the metatarsus adductus angle.

Discussion

Second MTP joint dislocation is the most common chronic foot dislocation [26]. The mechanism is reportedly due to chronic overload during push-off with a transverse axis delivering power and oblique axis balancing the foot [17, 43]. Limited studies have evaluated second MTP joint dislocation associated with HV [27, 34]. In our institution, we observed an 11% incidence of dorsal second MTP joint dislocation over 10 years. This prompted us to assess second MTP joint dislocation in HV by analyzing matched HV groups, focusing on similar HVA and radiographic analysis of osseous structural features.

Severity of HV is a risk factor for second MTP joint dislocation [27, 34]. As HVA increases, plantar pressure distribution shifts from medial to lateral in the forefoot [28], resulting in great toe dysfunction during gait and heightened mechanical load on second and third metatarsal heads in moderate-to-severe HV [21]. Despite similar HVA between groups D and W, the great toe proximal phalanx head and distal phalanx head were significantly lateralized in the dislocation group and distal phalanx head overlapped the X-axis line near the second toe of control group.

The second toe buttresses the great toe [40], and both toes influence each other’s position [25]. However, it is unclear how second MTP joint dislocation affects the rest of the forefoot structure. Those with dislocation exhibited proximal translation and deviation of the second toe. Additionally, the proximal phalanx of the adjacent lesser toe displayed lateral deviation, while the distal phalanx showed medial deviation and apparent adduction. The sequence of these positional changes, whether preceding or following dislocation, remain uncertain. A study on lesser toe deviation in HV highlighted the importance of the second MTP joint integrity and the role of the second toe as a supportive structure to the great toe [36]. Second toe dislocation creates a void between the great and third toe, allowing convergence of the great and lesser toes toward the second toe space. Alternatively, preexisting adducted alignment of lateral lesser toes could potentially push on the second toe laterally, with great toe pressing medially, eventually leading to dislocation. Causal relationship between adduction of lateral lesser toes and second toe dislocation, or vice versa, was undetermined. Consistent lateral shifting of the proximal phalanx with medialization of the distal third toe was observed exclusively in group D. Additionally, the fourth and fifth toes showed parallel adduction with the third toe (Fig. 3); although statistical significance was not observed in these coordinates compared to other groups.

This is the first study to demonstrate that lesser toes tend to lean towards adduction in cases of second MTP joint dislocation, suggesting progressive instability in the lateral forefoot. The adducted position of the third toe distal tip potentially indicates a pattern of forefoot collapse. Failure to correct distal deviations may lead to residual deformity, abnormal weight distribution, or recurrence of symptoms [30]. Surgical treatment must address both medial and lateral column corrections to relieve pressure on the lateral rays and restore proper forefoot alignment, reducing postoperative complications [28]. Further studies are needed to clarify the causal relationship underlying these findings.

A study found decreased M1/2 angle increases second MTP joint dislocation risk wherein severe HV leads to sustained pressure on the second toe, contributing to dislocation [27]. Conversely, less severe HV and M1/2 angle widening might theoretically alleviate pressure on the second toe. Our results show no direct association between the M1/2 angle and second MTP joint dislocation. Despite this, upon analyzing the dislocated second toe deviation, we found a significant association of M1/2 angle with deviation direction. Specifically, the M1/2 angle of the medial-deviation group was significantly higher than the lateral-deviation group. This supports findings that while M1/2 angle doesn’t directly affect second MTP joint dislocation, it influences the direction of deviation. A higher M1/2 angle and lower MA likely lead to medial or neutral second toe dislocation due to intermetatarsal splaying, which creates space for the second toe. Conversely, a lower M1/2 angle reduces the distance between the hallux and second toe, causing mechanical crowding and lateral deviation [27]. These findings highlight the need for further research to explore whether the direction of toe dislocation may affect treatment outcomes or has clinical implications, such as whether medial deviation may benefit from proximal procedures like proximal metatarsal osteotomies or Lapidus fusion to address intermetatarsal splaying.

The role of plantar plate and collateral ligaments in second MTP stability has been established [1, 6, 10, 17, 47]; however, the influence of MT2 length remains uncertain [7, 10, 24, 27, 46]. A study found longer MT2 exhibited higher loads beneath the second MTP joint and concluded longer MT2 was related to plantar plate injuries [15]. Moreover, longer MT2 also lead to second MTP joint dislocation [7, 10, 46]. However, others still doubt that MT2 length is a factor [23, 24]. We found relative MT1 length in group D was significantly longer than group N while absolute length was similar. Additionally, the absolute MT2 length of group D was significantly shorter than control. The reason for the apparent lengthening of MT1 in group D is possibly due to absolute shortening of MT2 in group D which increases the relative value of MT1 and affects the percent measurement. In complete dislocation, plantar plate disappearance, MT2 head flattening, and cartilage degeneration could cause absolute shortening of MT2 [27]. Dorsal dislocation of the proximal phalanx further depresses the MT2 head [3, 37], which could lead to subtle sagittal deviation of MT2 and distorted longitudinal positioning on AP radiographs due to the presence of the second toe proximal phalanx on the dorsal aspect of MT2. However, it is possible MT2 shortening was present before dislocation and potentially associated with second MTP joint dislocation. With these findings, we cannot conclude MT2 length contributes to second MTP joint dislocation.

Medial positioning of the MT1 base and TN in the dislocation group was seen, indicating medial midfoot widening. A potential correlation is an associated progressive collapsing foot deformity (PCFD) [32]. Medial arch collapse and valgus deformity in PCFD may produce medialization of midfoot points in our 2-dimensional coordinate system. However, the association of PCFD and HV is still inconclusive [13, 20]. Furthermore, we did not assess lateral radiographs making it difficult to confirm the role of PCFD in second toe dislocation.

Management for second MTP joint dislocation with HV is usually performed subsequently with HV surgery which complicates treatment and affects outcome. Various surgical techniques have been developed for second toe dislocation [6, 31, 33, 43, 45]. The present study shows the osseous configuration of the HV foot with an associated second MTP joint dislocation. An understanding of associated anatomy is crucial for surgical planning to improve future treatment methods and outcomes.

This study has limitations, including the retrospective design and the lack of detailed clinical information for the included patients. While this is a radiographic study that describes deformities without determining their causes, it provides a deeper analysis of HV with second MTP joint dislocation by offering a visual map not typically appreciated on standard radiographs. Additionally, we only analyzed AP radiographs. Incorporating lateral views might have offered additional insights, given that these are sagittal deformities; however, we aimed to minimize variability in imaging parameters and enhance the reliability of their measurements and analyses by focusing on only one radiographic view. Including weightbearing CT scans would have provided more insight into the anatomy of this condition; however, since this is a relatively recent diagnostic imaging modality, only a small number of patients underwent this modality. Finally, an unequal number of patients across groups may have impacted results; a larger sample size could enhance the significance of results.

In conclusion, patients with second MTP joint dislocation exhibited a proximally translated second toe, an adducted third toe, a medialized MT1 base, and a lateralized great toe tip. Despite these differences, they shared similarities with HV feet without dislocations, including HVA, IMA, MAA, MT1 length, MT2 length, and first toe length. Notably, the M1/2 angle influenced the direction of second MTP joint dislocation: high M1/2 angles allowed the second toe to remain neutral or deviate medially, while low M1/2 angles caused lateral deviation of the second toe. The value of this study lies in its ability to visually map the entire HV foot with second MTP joint dislocation using coordinates on radiographs, providing a deeper understanding of foot anatomy that has not been previously demonstrated in earlier studies. These findings provide a foundation for future studies utilizing advanced imaging to explore anatomical risk factors and relationships. Understanding these structural dynamics could help surgeons predict associated risks, refine surgical techniques, and optimize patient outcomes.

Data availability

The data used and/or analyzed during the current study are available from the corresponding author on reasonable request.

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Authors and Affiliations

  1. Department of Orthopaedic Surgery, Jose R. Reyes Memorial Medical Center, San Lazaro Compound, Rizal Avenue, Sta. Cruz, Manila, Metro Manila 1012, Manila, Philippines

    Adrian Joseph Castor Tablante & Emiliano Baula Tablante

  2. Department of Orthopaedic Surgery, Nara Medical University, Kashihara, Nara, Japan

    Adrian Joseph Castor Tablante, Hiroaki Kurokawa, Yuki Ueno, Yoshihiro Wanezaki, Nan Mei, Yinghao Li, Akira Taniguchi & Yasuhito Tanaka

  3. Department of Orthopaedic Surgery, Yamagata University Faculty of Medicine, Yamagata City, Yamagata, Japan

    Yoshihiro Wanezaki

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Contributions

AJT: Writing of the original draft, preparation of manuscript; HK: Design of the work, data analysis, manuscript revision; YU, YW, NM, YL: data collection and analysis; AT, ET: manuscript revision; YT: design of the work, final approval of manuscript.

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Correspondence to Adrian Joseph Castor Tablante.

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Tablante, A.J.C., Kurokawa, H., Ueno, Y. et al. Second metatarsophalangeal joint dislocation in hallux valgus: a radiographic study using a two-dimensional coordinate system. BMC Musculoskelet Disord 26, 204 (2025). https://doiorg.publicaciones.saludcastillayleon.es/10.1186/s12891-025-08431-3

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BMC Musculoskeletal Disorders

ISSN: 1471-2474

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