Relationship of Frontal Plane Rotation of First Metatarsal to Proximal Articular Set Angle and Hallux Alignment in Patients Undergoing Tarsometatarsal Arthrodesis for Hallux Abducto Valgus: A Case Series and Critical Review of the Literature

Rotation of the first metatarsal, as a component of hallux abducto valgus, is rarely discussed and is not addressed as a component of most hallux valgus corrective procedures. We believe frontal plane rotation of the first metatarsal to be an integral component of hallux abducto valgus deformity (the “third plane of deformity”) and believe de-rotation is necessary for complete deformity correction. We observed the change in angular measurements commonly used in the evaluation of hallux valgus deformity in patients who underwent a modified lapidus procedure. We measured the intermetatarsal angle, hallux abductus angle, proximal articular set angle, and tibial sesamoid position on weightbearing radiographs of 25 feet in 24 patients who had undergone tarsal metatarsal corrective arthrodesis and lateral capsular release. Specific attention was given to reduction of the frontal plane rotation of the first metatarsal during correction. Our results showed a change in the angular measurements observed by 4 investigators as follows. The mean change in the intermetatarsal angle was 10.1° (p < .0001). The mean change in the hallux abductus angle was 17.8° (p < .0001). The mean change in the proximal articular set angle was 18.7° (p < .0001). The mean change in the tibial sesamoid position was 3.8 (p < .0001). Also, a consistent valgus, or everted position of the first metatarsal, was noted as a component of the hallux abducto valgus deformity in our patient population and was corrected by varus rotation or inversion of the metatarsal. We also reviewed the current literature related to anatomic changes in the first ray in the patient with hallux valgus deformity and reviewed our hypothesis regarding the reduction in the proximal articular set angle, which we believe to be related to frontal plane rotation of the first metatarsal, resulting in a radiographic artifact.     

Effect of proximal articular set angle-correcting osteotomies on the hallucal sesamoid apparatus: A cadaveric and radiographic investigation

A cadaveric and radiographic study was undertaken to demonstrate the change in intersesamoidal crista architecture after an osteotomy that corrects the proximal articular set angle (PASA). Three cadaveric first metatarsals with hallux valgus deformity were utilized. Separate Kirschner wires representing the longitudinal axis bisection, PASA, and the long axis of the crista were placed into each specimen. After osteotomy, the metatarsal heads were translated laterally, rotated parallel to the transverse plane to correct PASA, and impacted. The relationship between the crista and the long axis of the metatarsal was determined. A deviation in the alignment between the intersesamoidal crista and the long axis of the metatarsal following the osteotomy was observed. The radiographic portion of this study correlated intermetatarsal angle, PASA, and tibial sesamoid position with intersesamoidal crista appearance on sesamoidal axial radiographs. Radiographic parameters in 19 patients (34 feet) were compared and two distinct patterns were evident: 1) A proximal articular set angle greater than 15 degrees was associated with complete crista erosion in 10 feet (91% of this subgroup); 2) a tibial sesamoid position greater than three was associated with partial or complete erosion in 17 feet (100% of this subgroup). A higher deviation of PASA and increased displacement of the sesamoidal apparatus correlated with crista erosion. These findings suggest that the crista fails to adapt with PASA as hallux valgus progresses and undergoes erosion instead. This study suggests that when correcting the PASA, misalignment of the sesamoid apparatus may lead to sub-first metatarsal arthrosis.     

The offset V modification of the Chevron bunionectomy: a retrospective study.

This is a retrospective study of two different types of fixation for the offset-V modification of the Chevron (Austin) bunionectomy for correction of hallux abducto valgus deformity. Both screw fixation and Kirschner wire fixation were evaluated radiographically for hallux abductus angle, intermetatarsal angle, proximal articular set angle, tibial sesamoid position, and first metatarsal length. In addition, charts were reviewed for complications selective to each type of fixation. Radiographically, there was no apparent difference in preoperative and postoperative measurements between the two types of fixation. However, chart review led the authors to conclude certain advantages to screw fixation, in terms of clinical results and patient satisfaction.     

Maintenance of Correction of First Metatarsal Closing Base Wedge Osteotomies Versus Modified Lapidus Arthrodesis for Moderate to Severe Hallux Valgus Deformity

A retrospective radiographic review of 57 feet was conducted to compare maintenance of correction of the modified Lapidus arthrodesis with the first metatarsal closing base wedge osteotomy for moderate to severe hallux valgus deformity. Radiographic parameters were measured on the preoperative, early postoperative, and greater than 11-month postoperative weightbearing radiographs. These measurements included the intermetatarsal angle, the hallux abductus angle, and the tibial sesamoid position. The patients who underwent the closing base wedge osteotomy had an average initial intermetatarsal correction of 10.4 degrees; for the modified Lapidus arthrodesis, it was 7.6 degrees. The patients who underwent the closing base wedge osteotomy had an average loss of intermetatarsal correction of 2.55 degrees from early to late postoperative radiographs; for the modified Lapidus arthrodesis, it was 1.08 degrees. Our results demonstrated that the modified Lapidus arthrodesis maintains correction to a greater degree than the first metatarsal closing base wedge osteotomy with statistical significance (P = .0039). Both the modified Lapidus arthrodesis and the first metatarsal closing base wedge osteotomy are effective procedures with respect to degree of radiographic correction for moderate to severe hallux valgus deformities.     

Observed Changes in Radiographic Measurements of the First Ray after Frontal Plane Rotation of the First Metatarsal in a Cadaveric Foot Model

We observed the changes in the angular measurements commonly used in the evaluation of the first metatarsal and first metatarsophalangeal joint in cadaveric specimens before and after frontal plane rotation of the first metatarsal. Measurements of the first and second intermetatarsal angle (IMA), hallux abductus angle, proximal articular set angle, and tibial sesamoid position (TSP) were taken after varying degrees of varus and valgus rotation of the first metatarsal. Standard dorsoplantar radiographs were taken at 0°, 10°, 20°, and 30° of valgus rotation of the first metatarsal and repeated at 10°, 20°, and 30° varus rotation of the first metatarsal. The data were analyzed using a mixed linear model to compare the change in each angle measurement over the range of valgus and varus rotation. The change in the TSP was significant in both valgus and varus rotations (p = .0004 and p = .028, respectively), an increase in valgus rotation causing an increase in the TSP and an increase in varus rotation causing a decrease in TSP. The change in the IMA was significant compared with valgus rotation (p = .028), showing that as the valgus rotation increased, the IMA also increased. However, compared with the varus rotation, the correlation was not significant (p = .18). The proximal articular set angle and hallux abductus angle measurements, compared with metatarsal rotation, showed positive trends but were not statistically significant. From our results and a review of the published data, we have hypothesized that frontal plane rotation of the first metatarsal is an integral component of hallux abducto valgus pathologic features, specifically in relation to the TSP and IMA.     

Degenerative osteoarthrosis of tarsometatarsal joints in hallux valgus: a radiographic study

To clarify the pathogenesis of degenerative osteoarthrosis of the tarsometatarsal joints in hallux valgus, we evaluated dorsoplantar and lateral radiographs during weight-bearing in 16 patients (25 feet) with hallux valgus accompanied by degenerative osteoarthrosis of the tarsometatarsal joints and 25 controls (25 feet) with hallux valgus alone. The proximal second metatarsal articular angle (a parameter we devised), the hallux valgus angle, intermetatarsal angle, metatarsal length, sesamoid displacement, calcaneal pitch, and foot length were measured and then evaluation using a mapping system was performed. There were no significant differences in the hallux valgus angle, intermetatarsal angle, sesamoid displacement, calcaneal pitch, or foot length. In the presence of degenerative osteoarthrosis of the tarsometatarsal joints, the second, third, and fourth metatarsals were long, and a large inclination of the proximal articular surface of the second metatarsal and adduction of the first to fourth metatarsals were observed. These findings appeared to be involved in the development of this disorder.     

Multivariate Analysis of Hallux Valgus Radiographic Parameters

This investigation aimed to better understand the complex relationship of common radiographic measurements performed during the perioperative evaluation of the hallux valgus deformity while accounting for interactions and potential interdependence. Several analyses utilizing the first intermetatarsal angle, hallux valgus angle, tibial sesamoid position, Engel's angle, subject age and subject gender were performed with varying independent and dependent variables. The hallux valgus angle (p < .001), tibial sesamoid position (p < .001), and Engel's angle (p < .001) were found to be independently associated with the first intermetatarsal angle. The first intermetatarsal angle (p < .001), tibial sesamoid position (p < .001), and Engel's angle (p < .001) were found to be independently associated with the hallux valgus angle. This suggests that there is significant interdependence of these variables during a preoperative radiographic examination. However, only the change in tibial sesamoid position (p < .001) was found to be independently associated with the change in the first intermetatarsal angle following surgical correction, while no studied variables were found to be independently associated with the change in hallux valgus angle following surgical correction. This suggests that correction of the intermetatarsal angle and tibial sesamoid position might not always reliably predict correction of the hallux valgus angle following surgical intervention. It might also suggest that additional procedures beyond metatarsal osteotomies are required to reliably correct the hallux valgus angle in some deformities. It is hoped that this investigation adds to the body of knowledge with respect to the perioperative radiographic evaluation of the hallux valgus deformity.     

Observed Changes in Radiographic Measurements of the First Ray after Frontal and Transverse Plane Rotation of the Hallux: Does the Hallux Drive the Metatarsal in a Bunion Deformity?

It is well known that the pathologic positions of the hallux and the first metatarsal in a bunion deformity are multiplanar. It is not universally understood whether the pathologic changes in the hallux or first metatarsal drive the deformity. We have observed that frontal plane rotation of the hallux can result in concurrent positional changes proximally in the first metatarsal in hallux abducto valgus. In the present study, we observed the changes in common radiographic measurements used to evaluate a bunion deformity in 5 fresh frozen cadaveric limbs. We measured the tibial sesamoid position, 1-2 intermetatarsal angle, and first metatarsal cuneiform angle on anteroposterior radiographs after frontal and transverse plane manipulation of the hallux. When the hallux was moved into an abducted and valgus position, a statistically significant increase was found in the tibial sesamoid position (p = .016). However, we did not observe a significant increase in the intermetatarsal angle (p = .070) or medial cuneiform angle (p = .309). When the hallux was manipulated into an adducted and varus position, a statistically significant decrease in the intermetatarsal angle (p = .02) and a decrease in the tibial sesamoid position (p = .016) was seen, with no significant change in the medial cuneiform angle (p = .360). We also observed a consistent rounding of the lateral aspect of the first metatarsal head and an increase in the concavity of the lateral metatarsal shaft, with valgus rotation of the hallux. From these observations, it is possible that the hallux could drive the proximal changes in the first ray that lead to metatarsus primus adducto valgus deformity.     

Radiographic Outcomes of a Percutaneous,Reproducible Distal Metatarsal Osteotomy for Mild and Moderate Bunions: A Multicenter Study

Hallux valgus is a prevalent condition. Many open surgical methods of correction have been described. We performed a percutaneous, extra-articular distal metatarsal osteotomy for mild to moderate bunion deformity. The minimally invasive technique was used in 217 feet (180 patients; age 49 ± 4.7 years, mean ± standard deviation) at 4 centers in North America (Center 1: November 2012 to March 2017; Center 2: January 2010 to May 2016; Center 3: October 2013 to June 2016; Center 4: January 2015 to June 2017). The procedure was used in simultaneous bilateral cases in 28 patients (15.6%) and in nonsimultaneous bilateral cases in 9 patients (5.0%). Immediate postoperative weightbearing was used in all cases. The mean preoperative intermetatarsal angle, hallux abductus angle, and tibial sesamoid position were 14.6° ± 3.5°, 30.7° ± 7.8°, and 5.4 ± 1.4, respectively. At final follow-up of 9.3 ± 6.1 months, the mean intermetatarsal angle, hallux abductus angle, and tibial sesamoid position were 4.7° ± 2.8°, 8.4° ± 6.1°, and 2.0 ± 1.0, respectively (p < .0001 for all comparisons). No major complications were noted. All 217 osteotomies achieved union; 3 feet (1.4%) in 3 patients (1.7%) experienced asymptomatic malunion. Superficial pin-site infection was seen in 42 (19.4%) of the 217 feet (39 patients, 21.7%). The radiographic results of this percutaneous technique appear to be reproducible across multiple centers, and the technique is useful when correcting intermetatarsal and hallux abductus angles. This percutaneous osteotomy for realignment of the first ray allows immediate postoperative weightbearing and, in this initial review, appears to be safe and effective, even in simultaneous bilateral cases.     

Bunion surgery using locking-plate fixation of proximal metatarsal chevron osteotomies

BACKGROUND: Symptomatic large hallux valgus deformities commonly require surgical intervention with a proximal metatarsal osteotomy. A number of fixation methods have been described for proximal chevron osteotomies; one of the most recent is locking plates. METHODS: We retrospectively reviewed the records of 16 consecutive patients (20 feet) with severe bunion deformities who had locking-plate fixation of proximal chevron osteotomies. Clinical evaluation focused on osteotomy healing, transfer lesions, and hardware-related complications. Preoperative and postoperative radiographic evaluation included the hallux valgus angle (HVA), 1-2 intermetatarsal angle (IMA), medial 1-2 intermetatarsal distance (MIMD; the amount of narrowing of the foot), sesamoid position, first metatarsal elevation, and metatarsal length change. A postoperative American Orthopaedic Foot and Ankle Society (AOFAS) score was obtained in all patients. RESULTS: The average radiographic improvements were HVA, 16.0 degrees, IMA, 7.6 degrees, and MIMD, 9.0 mm. Sesamoid position improved in 16 of 20 feet. First metatarsal elevation averaged 0.8 degrees, and the average metatarsal shortening was less than 1 mm. The AOFAS score averaged 94.1 points. Two complications were unrelated to plate fixation. CONCLUSIONS: The locking plate held alignment and position of the first ray after chevron osteotomy without clinical evidence of transfer lesions or hardware-related symptoms. Locking plates may improve stability of the proximal metatarsal after a chevron osteotomy for correction of hallux valgus.     

Is Double Metatarsal Osteotomy Superior to Proximal Chevron Osteotomy in Treatment of Hallux Valgus With Increased Distal Metatarsal Articular Angle?

We compared the results of proximal chevron osteotomy and double metatarsal osteotomy for hallux valgus with an increased distal metatarsal articular angle (DMAA). From October 2008 to December 2012, first metatarsal osteotomies were performed in 64 patients (69 feet) with symptomatic hallux valgus associated with an increased DMAA. Proximal chevron with Akin osteotomy and lateral soft tissue release was performed in 46 feet (PCO group); double metatarsal osteotomy and Akin osteotomy without lateral soft tissue release was performed in 23 feet (DMO group). Clinical assessments were performed using the American Orthopaedic Foot and Ankle Society (AOFAS) scale and visual analog scale (VAS). The hallux valgus angles, intermetatarsal angles, sesamoid positions, metatarsus adductus angles, and DMAAs were compared at different postoperative times. Postoperative shortening of first the metatarsal and complications were compared. The mean AOFAS scale and VAS scores showed significant improvement in both groups after surgery; however, no significant difference was observed between the 2 groups. The immediate postoperative hallux valgus angle and sesamoid position were significantly larger in DMO group; however, no intergroup difference was observed at the last follow-up visit, with the hallux valgus angle gradually increasing in the PCO group. The postoperative DMAA was significantly smaller in the DMO group. The mean shortening of the first metatarsal after surgery was significantly larger in the DMO group than in the PCO group. Transfer metatarsalgia developed in 1 foot (2.2%) in the PCO group and 2 feet (8.7%) in the DMO group. Partial avascular necrosis of the metatarsal head with advanced arthritis of the first metatarsophalangeal joint developed in 1 foot (4.3%) in the DMO group. In conclusion, no differences in the clinical and radiographic results were observed between the 2 groups for hallux valgus deformity with an increased DMAA.     

The Effect of Hallux Valgus Surgery on the Transverse Plane Hallux Proximal Phalanx Position

The objective of this investigation was to evaluate the apparent movement of the hallux proximal phalanx in the transverse plane relative to the second metatarsal following hallux valgus surgery. Pre- and postoperative radiographs of a consecutive series of 45 feet undergoing hallux valgus surgery were analyzed. Significant improvements were observed in the first intermetatarsal angle (12.4 vs 7.5 degrees; p < .001), hallux valgus angle (24.3 vs 13.4 degrees; p < .001), tibial sesamoid position (4.6 vs 2.7; p < .001), and second metatarsal-hallux proximal phalanx angle (80.1 vs 84.6 degrees; p < .001). No difference was observed in the distance between the second metatarsal bisection and the medial aspect of the tibial sesamoid (31.7 vs 31.5 mm; p = .756) nor between the second metatarsal bisection and medial aspect of the hallux proximal phalanx base (34.6 vs 34.2 mm; p = .592). Significant differences were observed between the second metatarsal bisection and the central aspect of hallux proximal phalanx base (26.5 vs 23.9 mm; p < .001) and between the second metatarsal bisection and the lateral aspect of the hallux proximal phalanx base (19.3 vs 15.4 mm; p < .001). A statistically significant difference was observed in the change of distance between the second metatarsal bisection and the medial, central, and lateral aspects of the hallux proximal phalanx base (-0.4 vs -2.6 vs -3.9 mm; p = .002). These results indicate that the hallux proximal phalanx does not translocate in the transverse plane following hallux valgus surgery, but instead pivots about the medial aspect of the joint.     

The radiographic morphology of foot deformities in patients with fibrodysplasia ossificans progressiva

BACKGROUND: The most consistent deformities that allow early diagnosis of fibrodysplasia ossificans progressiva are the presence of bilateral short first rays and hallux valgus. The purpose of this study was to describe the radiographic features observed in the feet of patients with fibrodysplasia ossificans progressiva. METHODS: The radiographs of 26 feet (15 patients with fibrodysplasia ossificans progressiva) were reviewed to evaluate the radiographic changes that occur in the first ray. Variables analyzed were the hallux valgus (HV) angle, the distal metatarsal articular (DMA) angle, the proximal phalangeal articular (PPA) angle, the intermetatarsal (IM) angle, ratio of the lengths of the first and second metatarsal lengths (MT1:MT2), and the first and second ray length ratio. The length ratios were then subtracted from similar ratios in radiographs of age- and gender-matched normal patients previously reported. RESULTS: The proximal phalanx was consistently shortened but morphologically dissimilar from subject to subject. Asymmetry was noted in some patients with bilateral radiographs. The mean HV angle was 28 degrees, and the mean IM angle was 10 degrees. The mean DMA angle was 33 degrees, and the mean PPA angle was 14 degrees. The MT1:MT2 ratio was 0.89, and the mean first ray to second ray length ratio was 0.87. The mean of the differences in the MT1:MT2 and first and second ray length ratios in patients with fibrodysplasia ossificans progressiva compared to the normal controls were 0.05 and 0.01, respectively. Fusion occurred between the abnormal tibial epiphysis of the proximal phalanx and metatarsal head with advancing age, and 68% of the metatarsal heads were fused with the abnormal proximal phalangeal epiphysis. CONCLUSIONS: Foot pathology in patients with fibrodysplasia ossificans progressiva is variable but consistently involves an abnormality of the tibial aspect of the proximal phalangeal epiphysis of the hallux. This results in the clinical observation of hallux valgus in these patients. The first metatarsal is consistently shortened, and fusion between the epiphysis of the abnormal proximal phalanx and the shortened first metatarsal head occurs with advancing age.     

Reverdin手术联合第一跖骨近端截骨治疗(足母)外翻

目的 :探索一种治疗外翻效果较满意的术式。方法 :作者对外翻的传统术式进行了思考 ,运用Reverdin手术联合第一跖骨近端截骨治疗外翻。自 1997年 10月～ 2 0 0 0年 9月 ,13例患者 ,2 1足接受此种手术治疗。术中常规松解软组织及切除内侧骨赘后 ,以Reverdin术式对跖骨头内翻截骨校正近端关节固定角 ,第一跖骨近端外翻截骨校正跖骨内翻畸形。结果 :随访 6个月～ 3年半 ,优 9例 16足 ,良 3例 4足 ,差 1例 1足 ,优良 95 .2 % ,无跖骨头坏死和截骨处不愈合。术前外翻角平均 3 5° ,术后为 11° ,第一跖骨间角术前平均 19° ,术后为 5 .8° ,近端关节固定角术前平均18° ,术后为 2°。结论 :外翻矫形应根据畸形情况及其病理改变选择手术方式。本手术方式矫形满意 ,但需严格掌握其手术适应证。     

Intrasubject Radiographic Progression of Hallux Valgus Deformity in Patients With and Without Metatarsus Adductus: Bilateral Asymmetric Hallux Valgus Deformity

This study was to analyze intrasubject radiographic progression of the hallux valgus deformity by comparing the mildly and severely affected sides in patients with bilateral asymmetric hallux valgus in the whole group as well as the metatarsus adductus and the nonmetatarsus adductus subgroups. A total of 186 patients with bilateral asymmetrical hallux valgus deformity with a difference of 5° or greater in the hallux valgus angle were included, and 11 radiographic measurements were analyzed. The radiographic differences between the mildly and severely affected sides were compared. Correlation between the changes in the hallux valgus angle and those in other measurements was analyzed, and multiple regression analyses were performed. The anteroposterior talo-second metatarsal angle showed no significant difference between the mildly and severely affected sides. Changes in the intermetatarsal angle and sesamoid rotation angle were significantly associated with the progression of hallux valgus angle in the whole group as well as the nonmetatarsus adductus subgroup. Change in the intermetatarsal angle (p = .006) was the significant factor associated with the progression of hallux valgus angle in the metatarsus adductus subgroup. The anteroposterior talo-second metatarsal angle might be useful in evaluating the overall foot shape in the hallux valgus deformity. Progression of the hallux valgus deformity might be pathophysiologically different between those with and without metatarsus adductus.     

Hallux valgus repair. DuVries modified McBride procedure

The DuVries modification of the McBride procedure was investigated in 72 feet in 47 patients with hallux valgus deformity. Overall, the patient satisfaction rate was 92%. The hallux valgus averaged 32 degrees preoperatively, and 16 degrees postoperatively. The intermetatarsal angle averaged 14 degrees preoperatively and 9 degrees postoperatively. Anatomic realignment of the remaining tibial sesamoid was achieved in 28% of the feet. As a result of realignment of the first metatarsophalangeal joint, the intractable plantar keratosis beneath the second metatarsal head was resolved in 19 of 20 feet. Six patients developed a hallux varus deformity that averaged 7.5 degrees. All cases of hallux varus had medial displacement of the tibial sesamoid. The number of patients who could withstand unrestricted shoe wear increased from ten patients preoperatively to 30 patients postoperatively. The patient activity level increased in two thirds of the cases. The distal soft-tissue procedure produces the most predictable correction in patients with a hallux valgus deformity measuring less than 30 degrees. In more severe deformities, a proximal metatarsal osteotomy should be added to the procedure.     

A comparison between the Regnauld arthroplasty and osteotomies of the first ray for the treatment of hallux valgus

This article is a retrospective study comparing the efficacy of Regnauld arthroplasty to first ray osteotomies for the treatment of hallux valgus. One hundred consecutive cases of Regnauld arthroplasties were compared with 100 consecutive first ray osteotomies. One hundred fourty-one patients were available for follow-up, and based on clinical/radiographic examinations, 72 were treated with the osteotomy protocol (group A) and 69 with Regnauld arthroplasty (group B). Age at surgery, clinical symptoms, and preoperative radiologic findings were similar for the 2 groups; there was a preponderance of female patients (90%). The average follow-up was 49 months in group A and 51 months in group B. Clinical evaluation showed in the osteotomy group a more stable correction (79% v 49%), greater pain reduction (measured in a visual analog scale from 0 = pain free to 10 = deep intolerable pain), increased residual articular excursion of the first metatarsophalangeal joint (27 degrees of active dorsiflexion from neutral position v 8 degrees ), and less presence of central metatarsalgia (15% v 34%) (P <.05). The radiographic evaluation expressed more stable correction values in group A for the following parameters: joint preservation, sesamoid position, intermetatarsal angle (7 degrees v 12 degrees ), abduction angle of the hallux (14 degrees v 20 degrees ), and proximal articular set angle (8 degrees v 18 degrees ) (P <.05).     

Triplanar Quantitative Radiographic Analysis of the First Metatarsal-Phalangeal Joint in the Hallux Abductovalgus Deformity

Although hallux abductovalgus (HAV) is widely considered to be a triplanar deformity involving the transverse, sagittal, and frontal planes, most of the published literature has focused on evaluating the deformity in only the transverse plane, and we are unaware of any investigation objectively evaluating the relationship among the 3 planes in the setting of HAV deformity. The objective of this investigation was to quantitatively evaluate radiographic measurement of the relationship between the transverse, sagittal, and frontal planes in the HAV deformity. Anteroposterior, lateral, and sesamoid axial radiographs from 42 consecutive feet were evaluated with measurement of the first intermetatarsal angle, hallux abductus angle, metatarsal sesamoid position, first metatarsal inclination angle, sesamoid rotation angle, and tibial sesamoid grade. Variables were graphically depicted against each other on frequency scatter plots with calculation of a regression line and Pearson's correlation coefficient. As transverse plane deformity increased, the frontal plane deformity also tended to increase and the first metatarsal inclination angle tended to decrease. And as frontal plane deformity increased, the first metatarsal inclination angle tended to decrease. To our knowledge, these are the first quantitative and objective data in support of a triplanar component to the HAV deformity, and we believe this reinforces the evaluation of this deformity with emphasis on all 3 planes.