Is the Rotational Deformity Important in Our Decision-Making Process for Correction of Hallux Valgus Deformity?

Frontal Plane Correction of Hallux Valgus Deformity With a Minimally Invasive Third Generation Tecnique: Short-Term Radiographic Outcomes of a Prospective Case Series

A number of minimally invasive osteotomies have been described for the repair of hallux abducto valgus (HAV) deformities. However, there are no known published studies that evaluate the effects of minimally invasive surgery techniques on the reduction of frontal plane rotation in patients with HAV. The purpose of this study was to assess correction in the transverse and frontal planes in patients undergoing surgical repair of HAV deformity utilizing a modified percutaneous technique. One hundred and five feet in 105 patients with HAV deformity were treated with a third generation minimally invasive technique using a first metatarsal osteotomy that allowed for frontal plane correction in conjunction with an Akin osteotomy. The minimum follow-up time was 12 months. Preoperative and postoperative anteroposterior weightbearing x-ray images were assessed and four measurements were evaluated: hallux abductus angle (HAA), intermetatarsal angle (IMA), tibial sesamoid position and frontal plane rotation of the first metatarsal. There were statistically significant differences for each of the assessments between the preoperative and postoperative radiographs (p < .001). There was a mean reduction in the HAA of 23.5° ± 9.6°, in the IMA, 7.0° ± 3.5°, in the tibial sesamoid position, 2.6 ± 1.3, and an improvement in the assessment of first metatarsal pronation (1.4 ± 0.9). The overall complication rate was 18.1%, with 5.7% of the feet requiring reoperation. The minimally invasive procedure employed by the authors demonstrated suitable outcomes in reducing deformity in both the transverse and frontal planes.

Validity and Reliability of a New Radiological Method to Estimate Medial Column Internal Rotation in Hallux Valgus Using Foot Weight-Bearing X-Ray

BACKGROUND

Medial column internal rotation in hallux valgus (HV) can be measured using weight-bearing computed tomography (WBCT). Anteroposterior weight-bearing foot radiographs' (WBXR) ability to estimate medial column internal rotation in HV was evaluated comparing these measurements with those obtained from WBCT.

METHODS

Three observers evaluated WBCT and WBXR of 33 HV feet twice. Medial column internal rotation was measured with WBCT and classified into 3 levels according to WBXR findings. Intra- and interobserver reliability were obtained for WBXR and WBCT, in addition to WBXR-WBCT correlation.

RESULTS

WBXR and WBCT intraobserver agreement was substantial and near perfect, respectively (κ 0.79 and 0.84). Their interobserver agreement was excellent (intraclass correlation 0.85 and 0.9, respectively). The WBXR-WBCT correlation was substantial (κ 0.68). WBXR diagnostic accuracy to predict the WBCT results was 85%.

CONCLUSIONS

The proposed method for medial column internal rotation measurement using WBXR is reliable and has a substantial agreement with WBCT measurements.

LEVELS OF EVIDENCE

Level III.

Fourth-Generation Minimally Invasive Hallux Valgus Surgery With Metaphyseal Extra-Articular Transverse and Akin Osteotomy (META): 12 Month Clinical and Radiologic Results

BACKGROUND

Fourth-generation minimally invasive surgery (MIS) includes the multiplanar rotational deformity correction achieved through manipulation of an extra-articular distal first metatarsal osteotomy that is held with rigid fixation using 2 fully threaded screws, of which one must be bicortical to provide rotational and biomechanical stability. The aim of this study is to report the clinical and radiologic outcomes of an evolved fourth-generation MIS hallux valgus technique.

METHODS

A prospective single-surgeon series of consecutive patients undergoing fourth-generation MIS was performed using a distal transverse osteotomy with a minimum 12-month follow-up. The primary outcome was the Manchester-Oxford Foot Questionnaire (MOXFQ), a validated clinical patient-reported outcome measure (PROM). Secondary outcomes included radiographic deformity correction, clinical assessment, and EuroQol-5D-5L PROMs.

RESULTS

Between September 2019 and June 2021, 50 feet underwent fourth-generation MIS. The mean age was 55.8±15.3 years with a mean follow-up of 1.4 years. Preoperative and minimum 12-month primary outcome data were available for 100% of feet. There was a significant improvement in all MOXFQ domain scores, with the index domain improving from 53.4 to 13.1 (P < .001). There was a significant improvement (P < .001) in hallux valgus angle (32.7 to 7.9 degrees), intermetatarsal angle (14.0 to 4.2 degrees) and distal metatarsal articular angle (18.5 to 5.6 degrees). There was a significant improvement in general health-related quality of life EQ-5D-5L index and EQ-VAS scores (P < .05).

CONCLUSION

The fourth-generation MIS technique is a safe and effective approach to hallux valgus deformity correction with significant improvement in clinical and radiographic outcomes.

LEVEL OF EVIDENCE

Level IV, prospective case series.

Proximal to distal phalangeal articular angle of the first proximal phalanx: Reliability and correlation with round sign

BACKGROUND

To reduce the rate of correction loss in hallux valgus surgery, a proximal to distal phalangeal articular angle (PDPAA) of the proximal phalanx of the greater toe of> 8° is considered an indication for a combined Akin and Chevron osteotomy. The PDPAA is measured between the articular surfaces of the proximal phalanx of the greater toe. Viewed from a sagittal perspective, the joint surfaces are not perpendicular aligned to the phalanx axis. Therefore, the PDPAA might be confounded by pronation. This study aims to, first, evaluate the intra- and interobserver reliability of the PDPAA and, second, to analyze the correlation to first ray pronation.

METHODS

In a consecutive series of 59 feet who underwent hallux valgus (HV) surgery, PDPAA, round sign and other angles were measured on weight-bearing radiographs pre- and postoperatively. After power analysis, the intraclass correlation coefficient (ICC) was used to calculate the intra- and interobserver reliability. The correlation of PDPAA with the round sign as well as angles defining the HV and the Hallux valgus interphalangeus (HVI) were evaluated.

RESULTS

The PDPAA showed an excellent intra- and interobserver reliability (ICC 0.92 and 0.89, p < 0.05). The round sign did not correlate significantly with the PDPAA (p = 0.51). However, the PDPAA showed a moderate correlation with the interphalangeal angle (r = 0.51, p < 0.05) and fair inversely with the intermetatarsal angle (r = -0.45, p < 0.05).

CONCLUSION

First, measurement of PDPAA is reliable. Second, PDPAA is not associated with first ray pronation, but a false low PDPAA is geometrically possible. A high PDPAA correlates with a relevant HVI and inversely correlates with the HV like the HVI. Hence, first ray pronation should be treated first and a remaining PDPAA of> 8° after intraoperatively reevaluation separately.

Short- and long-term results for severe hallux valgus correction using a first metatarsal distal osteotomy

PURPOSE

The purpose of this study is to analyze the short- and long-term results of severe hallux valgus (HV) treated with a L-Reverse osteotomy.

METHODS

Patients treated with L-Reverse osteotomy for severe HV between the years 2006-2015 were included. Patients were evaluated preoperatively, at 3 months and 4 or more years postoperatively. Changes in the HV angle (HVA) and intermetatarsal angle (IMA) were measured. Clinical outcomes were assessed using the AOFAS score.

RESULTS

28 patients were included. Pre-operative IMA changed from 18.1° (18-18.9°) to 7° (6.3-8.5°), and HVA from 38.5° (34.5-41.3°) to 10.0° (8.4-11.8°) at 3 month follow up (p < 0.005). Long term follow up was of 5.6 (4.9-6.4) years. IMA value was 7.5° (6.1°-8.1°) and HVA was 10.1° (6.7°-16.3°), with no statistical difference with initial correction (p = 0.14). Median AOFAS score was 92.7 (89-4-96.1).

CONCLUSION

L-Reverse osteotomy can achieve correction of HV severe deformities with good outcomes in long term follow up.

LEVEL OF EVIDENCE

III.

Intra‑ and Interobserver Reliability of Yamaguchi's Method for the Assessment of First Metatarsal Pronation in Hallux Valgus Deformity

Pronation of the first metatarsal is a risk factor for the formation and progression of the hallux valgus deformity. Recently, Yamaguchi et al published a study that showed how the round sign increases on digitally reconstructed radiography taken from a CT scan when pronation is applied. In this study, the shape of the lateral edge of the first metatarsal head was evaluated on weightbearing dorsoplantar radiographs. Yamaguchi's signs were presented to observers after the visual presentation of each foot as an image. The best-fit circle was drawn using the PACS drawing function. Ninety radiographs of adults presenting hallux valgus deformities were classified as mild-to-moderate, based on hallux valgus angle and intermetatarsal angle. The global average observations were 3.72 ± 3.92 (range 2.3°-4.6°). The interclass correlation (Fleiss Kappa index κ = 0.225) and the Spearman correlation (0.16 of Kappa) coefficients were poor for interobserver measurements and statistically significant. Using the linear model, there was no significant variability between the repetitions corresponding to each observer (t-value -1.527, p value .127). Our findings show that the Yamaguchi method can be very subjective and should not be the exclusive technique to assess the rotation of the first metatarsal or head roundness.

Pronation on weightbearing radiographs does not correlate with pronation from weightbearing CT scans

INTRODUCTION

In hallux valgus (HV), first metatarsal pronation is increasingly recognized as an important aspect of the deformity. The purpose of this study was to compare pronation in HV patients determined from the shape of the lateral head of the first metatarsal on AP weightbearing radiographs with pronation calculated from weightbearing CT (WBCT) scans.

METHODS

Patients were included in this study if they had preoperative and 5-month postoperative WBCT scans and corresponding weightbearing AP radiographs of the affected foot. Pronation of the first metatarsal on WBCT scans was measured using a 3D CAD model and the alpha angle and categorized into four groups on radiographs. Association between pronation groups on radiographs and WBCT scans was determined using Spearman correlation coefficients (r_s) and by comparing mean WBCT pronation of the first metatarsal between plain radiograph pronation groups.

RESULTS

Agreement between the two observers' pronation on radiographs was good (k = 0.634) and moderate (k = 0.501), respectively. There was no correlation between radiographic pronation and the 3D CAD model (r_s < 0.15). Preoperatively, there was weak correlation between the alpha angle and the radiographic pronation groups (r_s = 0.371, P = 0.048) although this relationship did not hold postoperatively (r_s = 0.330, P = 0.081). There was no difference in mean pronation calculated on WBCT scans between the plain radiographic groups.

CONCLUSION

Pronation of the first metatarsal measured on weightbearing AP radiographs had moderate interobserver agreement and was only weakly associated with pronation measured from WBCT scans. These results suggest that first metatarsal pronation measured on weightbearing radiographs is not a substitute for pronation measured on WBCT scans.

LEVEL OF EVIDENCE

III, retrospective cohort study.

Association of First Metatarsal Pronation Correction With Patient-Reported Outcomes and Recurrence Rates in Hallux Valgus

BACKGROUND

The purpose of this study was to determine if a postoperative decrease in first metatarsal pronation on 3-dimensional imaging was associated with changes in patient-reported outcomes as measured by the Patient-Reported Outcomes Measurement Information System (PROMIS) physical function, pain interference, and pain intensity domains or recurrence rates in patients with hallux valgus (HV) who undergo a first tarsometatarsal fusion (modified Lapidus procedure).

METHODS

Thirty-nine consecutive HV patients who met the inclusion criteria and underwent a modified Lapidus procedure had preoperative and ≥2-year postoperative PROMIS scores and had first metatarsal pronation measured on preoperative and at least 5-month postoperative weightbearing CT scans were included. Multivariable regression analyses were used to investigate differences in the change in PROMIS domains preoperatively and 2 years postoperatively between patients with "no change/increased first metatarsal pronation" and "decreased first metatarsal pronation." A log-binomial regression analysis was performed to identify if a decrease in first metatarsal pronation was associated with recurrence of the HV deformity.

RESULTS

The decreased first metatarsal pronation group had a significantly greater improvement in the PROMIS physical function scale by 7.2 points (P = .007) compared with the no change/increased first metatarsal pronation group. Recurrence rates were significantly lower in the decreased first metatarsal pronation group when compared to the no change/increased first metatarsal pronation group (risk ratio 0.25, P = .025).

CONCLUSION

Detailed review of this limited cohort of patients who underwent a modified Lapidus procedure suggests that the rotational component of the HV deformity may play an important role in outcomes and recurrence rates following the modified Lapidus procedure.

LEVEL OF EVIDENCE

Level III, retrospective cohort study.

3rd generation MICA with the "K-wires-first technique" - a step-by-step instruction and preliminary results

BACKGROUND

Minimally-invasive techniques for hallux valgus correction are becoming increasingly popular. In the last decades, multiple techniques for minimally-invasive hallux valgus correction have been described. MICA (Minimally-invasive Chevron & Akin), representing the 3rd generation of minimally-invasive hallux valgus correction, combines the advantages of an extraarticular osteotomy, stable internal fixation, and high potential for correction. This report aims to provide a step-by-step instruction of the surgical technique with the "K-wires-first" MICA modification, illustrated by detailed imaging of both intraoperative fluoroscopy and clinical imaging as well as corresponding sawbone models for each step. Preliminary results including radiological outcome and complications of the first 50 cases will be discussed.

METHODS

Between May 2018 and May 2021, 50 consecutive MICAs in 47 patients were performed with the K-wires-first technique. There were 40 women and 7 men with an average of 57.4y (range 25-78). The mean preoperative IMA was 16.2° (range 11.0-21.5), the HVA 30.6° (range 21.8-42.1).

RESULTS

There was one intraoperative conversion to an open surgical bunion correction corresponding to a 2% conversion rate respectively (1/50). On 3 feet (2 patients), removal of the Chevron screws was performed after 7, 9, and 12 months due to prominent and disturbing screw heads at the level of the medial cortex, accounting for a revision rate of 6% (3/50). There were no other secondary revision surgeries. The IMA decreased after MICA by a mean of 10.8° from 16.2° to 5.4° and the HVA by a mean of 22.1° from 30.6° to 8.5°, demonstrating MICA's high potential for correction.

CONCLUSIONS

Compared to other MICA techniques, the K-wires-first modification helps to reduce hardware malpositioning and the risk of conversion to open surgery. Furthermore, our preliminary results demonstrate a high potential for correction even for severe hallux deformities.

TRIAL REGISTRATION

Retrospectively registered, swissethics BASEC-ID 2021-01537, July 16th, 2021 ( www.raps.swissethics.ch ).

Management of the Tarsometatarsal Joint in the Rotational Correction of Hallux Valgus by the Modified Lapidus Procedure: Intraoperative Technical Tips to Prevent Complications

The modified Lapidus procedure is considered a useful tool for correction of multiplanar deformities in the hallux valgus, including first metatarsal pronation. It offers a greater power of correction compared to most other osteotomies. However, postoperative complications can occur in up to 12% of cases. The aim of this study was to describe intraoperative technical tips in the management of the tarsometatarsal joint during multiplanar correction of severe hallux valgus deformity using the modified Lapidus procedure. It is not the authors' intention to describe a new technique, but to draw attention to intraoperative details in order to prevent complications as nonunion, extension of the first metatarsal and undercorrection of the deformity. Rotational correction of the first metatarsal with adequate bone coaptation of the first metatarsal and the medial cuneiform are the cornerstone for a satisfactory result.Levels of Evidence: Level V, expert opinion.

Correction Power of Percutaneous Adductor Tendon Release (PATR) for the Treatment of Hallux Valgus: A Cadaveric Study

Osteotomies are commonly used in order to correct hallux valgus deformity. However, soft tissue structures also play an essential role in the etiology, progression, and treatment of hallux valgus (HV). The purpose of the present study was to analyze the correcting power (varus), reduction strength (sesamoid) and rotation of metatarsal and proximal phalanx after percutaneous adductor tendon release (PATR). To date, no study addresses this issue. Eleven cadaveric fresh-frozen below-the-knee cadaveric lower limbs with associated hallux valgus deformity were used. These specimens were subjected to a constant abduction force after PATR. HV and intermetatarsal angles showed statistically significant differences when comparing the preoperative and postoperative periods. PATR showed to be a reliable technique as the adductor tendon was completely released in 9 cases, and 75% released in the remaining 2 feet. The study supports that PATR provides powerful and quantifiable correction of HV deformity and can be accurately performed percutaneously.

Correlation between indirect radiographic parameters of first metatarsal rotation in hallux valgus and values on weight-bearing computed tomography

PURPOSE

To verify if indirect radiographic signs of first metatarsal pronation, determined by the head round sign, correspond to weight-bearing computed tomography (WBCT) measurements.

METHODS

In this case-control retrospective study, we analyzed 26 hallux valgus (HV) feet and 20 controls through conventional radiograph (CR) and WBCT images. Two blinded orthopaedic foot and ankle surgeons performed the measurements. Pronation classification (head roundness), head diameter (HD), traditional HV angles, arthritis, sesamoid positioning, and first metatarsal rotation angle (MRA) (alpha angle) were evaluated. Comparisons were performed by Student's T-test and a multivariate regression was executed. P-values less than 0.05 were considered significant.

RESULTS

Mean values were higher in HV patients than controls when evaluating MRA (11.51 [9.42-13.60] to 4.23 [1.84-6.62], 95%CI), HD (22.35 [21.52-23.18] to 21.01 [20.07-21.96]), and sesamoid rotation angle (SRA) (26.72 [24.09-29.34] to 4.56 [1.63-7.50]). The MRA had a low influence in head roundness classification (R²: 0.15). Changes in the pronation classification were explained chiefly by the sesamoid station (SS) (R²: 0.37), where stations 4 to 7 were found to be strong predictors of roundness classifications 2 and 3.

CONCLUSION

Indirect signs of metatarsal pronation, determined by the head round sign, correlate weakly with the alpha angle measured in WBCT. The presence of arthritis and sesamoids displacement might modify the perception of first head roundness. The influence of MRA in the classification was low, where SS from 4 to 7 was strong predictors of a higher pronation classification.

Percutaneous, intra-articular, chevron osteotomy (PeICO) for the treatment of mild-to-moderate hallux valgus: a case series

PURPOSE

Treatment for hallux valgus (HV) remains challenging. Third-generation percutaneous procedures try to reproduce chevron-type osteotomies to replicate their benefits, such as intrinsic stability and reproducibility. We report the first results using a percutaneous, intra-articular, chevron osteotomy (PeICO) technique that mimics the classic intra-articular open chevron procedure, associated with a percutaneous adductor tendon release (PATR) for the treatment of mild-to-moderate HV.

METHODS

From May 2015 to October 2018, a total of consecutive 114 feet (74 patients) were included. Primary outcome measures included radiographic (hallux valgus and intermetatarsal angles) and clinical parameters such as visual analog scale (VAS), FAAM Activities of Daily Living (ADL), and FAAM Sport, AOFAS Score, and MOXFQ, preoperatively and at final follow-up (Minimum 18 months). A patient satisfaction survey was also performed. Pronation and length of the first metatarsal were also assessed. Secondary outcomes included fluoroscopic time, length of surgery, complications, recurrence, and re-operation rates.

RESULTS

At 24.09 months on average, the AOFAS score improved from 52.1 points preoperatively to 91.1 (p < 0.001) at the latest follow-up. VAS decreased from 6.3 to 1. Also, FAAM ALD, FAAM Sport, and MOXFQ showed statistically significant differences (p < 0.001) when comparing pre-operative and post-operative periods. Patients found the procedure to be excellent in 82% and very good in 13.5% of cases. Our global complication and re-operation rates were 5.26% and 3.5% (screw removal), respectively.

CONCLUSION

PeICO combined with PATR proved to be a safe, reliable, and effective technique for the correction of mild-to-moderate HV deformity.

First Metatarsal Rotation in Hallux Valgus Deformity

Rotation of the first metatarsal (M1) as a potential etiological factor of hallux valgus (HV) deformity was described relatively early in the description of HV pathoanatomy. However, because biplanar radiographs have been the standard method for imaging HV, clinicians primarily developed measurement methods and corrective operations confined to 2 dimensions, medial-lateral and inferior-superior. Recently, as our understanding of HV pathoanatomy has further developed, aided in part by advanced imaging technology, M1 rotation about its axis ("axial rotation") and its implications for HV deformity and treatment has reemerged. The goal of this review is to summarize M1 rotation in HV from a historical perspective, to present the current understanding of its potential role in the etiology/pathogenesis of HV, and to summarize relevant imaging and operative considerations with respect to M1 rotation.Level of Evidence: Level III, systematic review.

The Role of Weightbearing Computed Tomography Scan in Hallux Valgus

BACKGROUND

Hyperpronation of the first metatarsal in hallux valgus (HV) is poorly understood by conventional weightbearing radiography. We aimed to evaluate this parameter using weightbearing computed tomography (WBCT) and to understand its association with other standard measurements.

METHODS

Retrospective evaluation of WBCT and weightbearing radiographs (WBXRs) was performed for 20 patients with HV feet and 20 controls with no such deformity. Axial computed tomography images of both groups were compared for the first metatarsal pronation angle (alpha angle) and tibial sesamoid subluxation (TSS) grades. The HV angle (HVA), first-second intermetatarsal angle (IMA), first metatarsal-medial cuneiform angle (MMCA), Meary's angle, and calcaneal pitch (CP) angle of the study and control groups were compared on both WBXR and the corresponding 2-dimensional images of WBCT. All measurements were independently performed by 1 musculoskeletal radiology fellow and 1 foot and ankle surgical fellow. Measurements were averaged and interobserver reliability was calculated.

RESULTS

The HV group demonstrated significantly higher values for TSS grade (P < .001) but not for alpha angle (P = .121) compared with controls. Likewise, significantly elevated HVA and IMA were noted in the HV group on both imaging modalities, while no such differences were observed for the CP angle. Higher MMCA and Meary's angle in the HV group were evident only on WBXR (MMCA, P = .039; Meary's, P = .009) but not on WBCT (MMCA, P = .183; Meary's, P = .171).Among all, the receiver operating characteristic (ROC) curves demonstrated the greatest area under the curve (AUC) for HVA, followed by IMA. The alpha angle performed only just outside the range of chance (AUC, 0.65; 95% CI, 0.52-0.69). The Pearson's correlations of the alpha angle, in the HV group, revealed a significant linear relationship with TSS grade and with HVA on WBXR, and only trended toward a weak linear relationship with IMA and with HVA on WBCT.

CONCLUSION

The alpha angle, a measure of abnormal hyperpronation of the first metatarsal, was an independent factor that may coexist with other parameters in HV, but in isolation had limited diagnostic utility. "Abnormal" alpha angles were even observed in individuals without HV. Increases in IMA and MMCA were not necessarily associated with similar increases in alpha angle, despite moderate correlations with TSS grade and HVA on WBXR. Nevertheless, the WBCT was a useful method for assessing hyperpronation and guiding surgical management in individual cases.

LEVEL OF EVIDENCE

Level III, retrospective comparative study.

The shape of the first metatarsal head and its association with the presence of sesamoid-metatarsal joint osteoarthritis and the pronation angle

BACKGROUND

The purpose of this study was to evaluate the associations of the shape of the first metatarsal head with (1) the presence of osteoarthritis in the sesamoid-metatarsal joint and (2) the pronation angle of the first metatarsal head on foot radiographs.

METHODS

A total of 121 patients, with the mean age of 61 years, underwent weight-bearing dorsoplantar, lateral, and first metatarsal axial radiographs. The shape of the first metatarsal head's lateral edge was classified as either rounded, intermediate, or angular in shape in the dorsoplantar view. The presence of osteoarthritis in the sesamoid-metatarsal joint and the pronation angle of the first metatarsal head were assessed in the first metatarsal axial view. Other variables that could affect the first metatarsal shape, including the lateral first metatarsal inclination angle, were also assessed. Univariate and multivariate analyses were performed to determine the associations.

RESULTS

The prevalence of sesamoid-metatarsal osteoarthritis was significantly higher (77%, 27%, and 29% for rounded, intermediate, and angular, respectively, P < .001), and the metatarsal pronation angle was significantly larger (14°, 8°, and 4° for rounded, intermediate, and angular, respectively, P < .001) in feet with a rounded metatarsal head. These associations were also significant in the multiple regression analysis.

CONCLUSION

A rounded metatarsal head was associated with a higher prevalence of osteoarthritis within the sesamoid-metatarsal joint, as well as a larger first metatarsal head pronation angle. A negative round sign can be used as a simple indicator of an effective correction to the first metatarsal pronation angle during hallux valgus surgery. However, in feet with sesamoid-metatarsal osteoarthritis, surgeons will need to be cautious as overcorrection may occur.

Metatarsal Pronation in Hallux Valgus Deformity: A Review

Hallux valgus deformity is a multiplanar deformity, where the rotational component has been recognized over the past 5 to 10 years and given considerable importance. Years ago, a rounded shape of the lateral edge of the first metatarsal head was identified as an important factor to detect after surgery because a less rounded metatarsal head was associated to less recurrence. More recently, pronation of the metatarsal bone was identified as the cause for the rounded appearance of the metatarsal head, and therefore, supination stress was found to be useful to achieve a better correction of the deformity. Using CT scans, up to 87% of hallux valgus cases have been shown to present with a pronated metatarsal bone, which highlights the multiplanar nature of the deformity. This pronation explained the perceived shape of the metatarsal bone and the malposition of the medial sesamoid bone in radiological studies, which has been associated as one of the most important factors for recurrence after treatment. Treatment options are discussed briefly, including metatarsal osteotomies and tarsometatarsal arthrodesis.

Rotational biplanar Chevron osteotomy

INTRODUCTION

The Chevron osteotomy is a reliable and popular osteotomy for treating hallux valgus worldwide. Many modifications have been described, but none of them address the rotational deformity of the first metatarsal. The objective of this study is to describe a variation of biplanar Chevron osteotomy which can address first metatarsal rotation when necessary.

METHODS

The indications for the Rotational Biplanar Chevron Osteotomy (RBCO) are mild to moderate hallux valgus deformity associated with hallux pronation related to internal rotation of the first metatarsal bone. We describe a technique that uses a medial based wedge parallel to the plantar limb of the osteotomy in order to make the distal fragment free to correct rotation.

RESULTS

The more recent concern about hallux valgus surgery is the very interesting concept that this deformity really occurs in three different planes, and we may have mistreated the rotation component with our current techniques. Many authors have revisited many common techniques in order to adapt them to correct metatarsal pronation. To our best knowledge, this is the first paper to describe a modification of the Chevron osteotomy to address the rotation of the first metatarsal.

CONCLUSION

We can conclude that the rotational biplanar Chevron osteotomy can be an useful tool in the treatment of mild hallux valgus associated with metatarsal pronation.

Role of Coronal Plane Malalignment in Hallux Valgus Correction

Coronal malalignment is an important deformity parameter in hallux valgus feet. Approximately 90% of patients with hallux valgus have some degree of metatarsal pronation. In operated hallux valgus, persistent metatarsal pronation is an independent deformity relapse factor. Coronal malalignment can be identified through an anteroposterior (AP) weight-bearing foot radiograph and a weight-bearing forefoot scan. The AP foot view can identify 3 levels of rotation: mild, moderate and severe metatarsal pronation. Regarding the treatment options, some techniques are capable of rotational correction, such as the proximal rotational metatarsal osteotomy, Lapidus, dome osteotomy, and proximal oblique sliding closing wedge.

The Use of a Triplanar Metatarsal Rotational Osteotomy to Correct Hallux Valgus Deformities

Proximal rotational metatarsal osteotomy (PROMO) is a technique that allows the surgeon to correct the varus and pronation of the first metatarsal that is observed in most patients with hallux valgus deformity. Persistent metatarsal pronation is a recognized recurrence factor for operatively treated hallux valgus. The indication for this technique is a mild-moderate hallux valgus deformity (i.e., intermetatarsal angle <18° and hallux valgus angle <40°) in which pronation is present. (Note that according to the literature, 10% to 20% of patients do not have pronation.) The PROMO is performed via a single proximal oblique metatarsal incision. Following completion of the osteotomy, the distal metatarsal segment is supinated (external rotation), correcting pronation and varus deviation, which is achieved as a result of the oblique nature of the osteotomy (i.e., rotation through an oblique plane). Step 1: Preoperative planning: measure the intermetatarsal angle and the metatarsal rotation. For the latter, use the published classification (mild, moderate, severe). With both values, use the table included in the PROMO tray to know which osteotomy angulation should be used. Step 2: medial foot incision. Step 3: drive the guidewire 1 cm distal to the tarsometatarsal joint. Step 4: Under fluoroscopy, ensure that the wire is parallel to the sole of the foot and perpendicular to the metatarsal. Step 5: use the positioning jig to drive a Kirschner wire with the chosen pronation correction. Step 6: slide the osteotomy jig with the previously chosen osteotomy angulation. Step 7: perform the osteotomy. Step 8: use the rotation jig with the desired pronation correction. Step 9: derotate and correct the metatarsal deformity, leaving both wires parallel to each other. Step 10: perform osteotomy transient fixation with 2 Kirschner wires. Step 11: apply a medial locking plate and an interfragmentary screw at the osteotomy site. The expected outcome is complete correction of the first metatarsal varus and pronation.

Radiographic Assessment of Foot Alignment in Juvenile Hallux Valgus and Its Relationship to Flatfoot

BACKGROUND

The relationship between juvenile hallux valgus (JHV) and flatfoot has not been clearly established. The aim of this study was to assess radiographic measurements in feet with JHV compared with matched controls and to investigate whether the foot alignment of JHV is related to flatfoot.

METHODS

We retrospectively reviewed 163 patients with JHV as defined as hallux valgus angle greater than 20 degrees and intermetatarsal greater than angle than 10 degrees. Patients with open physes of the feet and who had weight-bearing radiographs of the feet were included. Another 55 normal participants served as controls. Patients with JHV were divided into 2 subgroups: Group 1 included patients with asymptomatic JHV and group 2 consisted of those treated with correctional surgery for painful JHV. Twelve radiographic indices were analyzed, including calcaneal pitch angle, tibiocalcaneal angle, talocalcaneal angle, naviculocuboid overlap, talonavicular coverage angle, lateral talo-first metatarsal angle, anteroposterior talo-first metatarsal angle, metatarsus adductus angle, hallux valgus angle, intermetatarsal angle, distal metatarsal articular angle, and first metatarsal cuneiform angle. The groups were compared by age, gender, and the above radiographic parameters.

RESULTS

There was no significant difference in hindfoot alignment of patients with JHV and controls. Naviculocuboid overlap (P <.001), lateral talo-first metatarsal angle (P = .002), and metatarsus adductus angle (P = .004) were significantly greater in patients with JHV than in controls, whereas the anteroposterior talo-first metatarsal angle (P = .026) was significantly less. Symptomatic and asymptomatic JHV patient subsets showed no significant radiologic differences.

CONCLUSION

Radiographic profiles in patients with JHV were inconsistent with regard to features of flatfoot, and foot alignment was unrelated to the presence of symptoms or degree of deformity in JHV.

LEVEL OF EVIDENCE

Level III, retrospective comparative series.

Should We Use Intermetatarsal Angle as Primary Determinant to Define the Limits of Distal Chevron Osteotomy?

Classic treatment algorithms limit the use of distal chevron osteotomy (DCO) to cases with an intermetatarsal angle (IMA) <14°. As the IMA increases, it is accepted that the contact between the metatarsal head and shaft will be insufficient. We have investigated the reliability of IMA to predict contact area percentage after DCO. Preoperative radiographs of patients with hallux valgus were subdivided as mild, moderate, and severe using traditional algorithms. After excluding the mild cases, we randomly selected 100 patients (50 moderate and 50 severe) and calculated the estimated bony contact (EBC) with our method and investigated the percentage of patients who could have >50% contact area if we perform a DCO. Thirty of 50 (60%) and 17 of 50 (34%) patients had >50% EBC in moderate and severe groups, respectively. We performed DCO for 24 patients (14 moderate and 10 severe cases). The 100-point American Orthopaedic Foot and Ankle Society (AOFAS) hallux-metatarso-phalangeal-interphalangeal scale was used to assess the clinical outcome. For the moderate group, we calculated mean IMA 16° (standard deviation [SD] ± 1.4°) and mean EBC 66.9% (SD ± 10.8%). For the severe group, we calculated mean IMA 20.9° (SD ± 0.7°) and mean EBC 63.1% (SD ± 10.4%). Paired t tests showed significant improvement comparing preoperative and postoperative AOFAS scores, IMA, hallux valgus angle, and sesamoid position for all operated patients (p < .001). We did not see any recurrence of hallux valgus or hallux varus and had only 1 minor complication that we managed conservatively. IMA may not always be a reliable parameter to predict the stability of DCO. Because the stability depends on the contact surfaces of osteotomy fragments, metatarsal head diameter and remaining bone contact should be the primary concerns. Two patients with the same IMA can have a different contact surface varying on a broad spectrum.