Hallux Valgus Patients Research Articles

Hallux valgus measurements using weight-bearing computed tomography: what changes?

Objective: To assess whether traditional hallux valgus (HV) measurements obtained with conventional radiography (CR) correspond to those obtained with weight-bearing computed tomography (WBCT). Methods: In this retrospective case-control study, 26 HV feet and 20 control feet were analyzed with CR and WBCT. Hallux valgus angle (HVA), intermetatarsal angle (IMA), interphalangeal angle (IPA), distal metatarsal articular angle (DMAA), sesamoid station (SS), and first metatarsal head shape were measured. Chi-square tests were used to compare hallux valgus and control patients. T-tests were used to compare CR and WBCT. P-values less than 0.05 were considered significant. Results: WBCT was capable of discriminating patients with HV from controls, showing higher mean values for HV patients than controls in HVA (35.29 and 9.02, p < 0.001), IMA (16.01 and 10.01, p < 0.001), and DMAA (18.90 and 4.10, p < 0.001). When comparing the two methods, differences were not significant between CR and WBCT measurements in HVA (-0.84, p = 0.79), IMA (-0.93, p = 0.39), IPA (1.53, p = 0.09), or SS (p = 0.40), but were significant for DMAA (13.43, p < .0001). CR analysis yielded varied metatarsal head shapes, while all WBCT shape classifications were round. Conclusion: Unidimensional HV measurements were similar between WBCT and CR, while more three-dimensional findings were not. CR may be used to assess the axial aspects of HV, but multidimensional aspects of the deformity may not be accurately assessed with plain radiographs. Level of Evidence III; Therapeutic Studies; Retrospective Case-Control Study.

The Association of Crista Volume With Sesamoid Position as Measured From 3D Reconstructions of Weightbearing CT Scans.

Malposition of the sesamoids relative to the first metatarsal head may relate to intersesamoid crista underdevelopment or erosion. Using 3-dimensional models created from weightbearing CT (WBCT) scans, the current work examined crista volume and its relationship to first metatarsal pronation and sesamoid station. Thirty-eight hallux valgus (HV) patients and 10 normal subjects underwent weightbearing or simulated WBCT imaging. The crista was outlined by the inferior articular surface, and a line was drawn to connect the lowest point of each sulcus on either side of the intersesamoidal crista throughout the length of the crista. The volume was calculated. Sesamoid station and first metatarsal pronation were calculated from the 3D reconstructions. The mean crista volumes between HV and normal patients were statistically compared, as were the crista volume and pronation angle between sesamoid stations. The mean crista volume in HV patients was 80.10 ± 35 mm3 and in normal subjects was 150.64 ± 24 mm3, which differed significantly between the 2 groups (P < .001). Mean crista volumes were found to be statistically significantly different between the sesamoid stations (P < .001) with decreasing crista volumes significantly and strongly correlated with increasing sesamoid station (r = -0.80, P < .001). There was no difference in the mean pronation angle between the 4 sesamoid stations (P = .37). The pronation angle was not associated with crista volume (P = .52). HV patients have lower mean crista volume than normal patients. Crista volume is correlated with sesamoid station. Pronation of the first metatarsal was not associated with crista volume. Crista volume may offer an additional determinant for the severity of hallux valgus.

Outcomes of Scarf and Akin Osteotomy with Intra-Articular Stepwise Lateral Soft Tissue Release for Correcting Hallux Valgus Deformity in Rheumatoid Arthritis.

Background. The effectiveness of scarf and Akin osteotomy with intra-articular lateral soft tissue release for the correction of hallux valgus (HV) in patients with rheumatoid arthritis (RA) has not been elucidated. Methods. A total of 36 feet in 28 patients with RA who had scarf and Akin osteotomy with intra-articular stepwise lateral soft tissue release between 2015 and 2020 at a single institute were investigated retrospectively, with a mean follow-up period of 32.0 ± 16.9 months. Radiographic evaluations including the HV angle, intermetatarsal angle, and sesamoid position were performed preoperatively and postoperatively. Clinical outcomes were assessed using the Japanese Society of Surgery of the Foot (JSSF) hallux scale and self-administered foot evaluation questionnaire (SAFE-Q). Results. The procedure resulted in significant HV correction, with a recurrence rate of 13.9%. The JSSF scale and all five SAFE-Q subscale scores significantly improved (p < 0.05), with no major complications. More than 90% of cases achieved adequate lateral soft tissue release without sacrificing the adductor tendon of the hallux. Conclusions. Intra-articular stepwise lateral soft tissue release in combination with scarf and Akin osteotomy provided satisfactory radiographic and patient-reported outcomes for the correction of HV in patients with RA with minimum lateral soft tissue release.

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

IntroductionIn 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. MethodsPatients 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 (rs) and by comparing mean WBCT pronation of the first metatarsal between plain radiograph pronation groups. ResultsAgreement 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 (rs < 0.15). Preoperatively, there was weak correlation between the alpha angle and the radiographic pronation groups (rs = 0.371, P = 0.048) although this relationship did not hold postoperatively (rs = 0.330, P = 0.081). There was no difference in mean pronation calculated on WBCT scans between the plain radiographic groups. ConclusionPronation 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 evidenceIII, retrospective cohort study.

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

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). 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. 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). 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 III, retrospective cohort study.

Suture Anchor-Enhanced Medial Capsulorrhaphy of the Great Toe.

A standard medial approach to the 1st metatarsophalangeal joint is performed. A medial midline horizontal capsulotomy is performed starting just proximal to the medial eminence and extending distally to the base of the proximal phalanx. Once the concomitant osseous and soft-tissue procedures are completed, a vertical capsulotomy is made in the inferior capsular flap at the level of the metatarsophalangeal joint in a manner perpendicular to the first ray in order to form an L shape. A 3 to 4-mm wedge of capsule is formed near the base of the vertical limb, running obliquely to the horizontal limb, and is excised. Optionally, the free limbs of the inferior capsule are imbricated. A unicortical hole is then drilled in the first metatarsal head, and a 2.7-mm outer diameter by 7-mm deep suture anchor with 2-0 FiberWire (Arthrex) is placed. The free ends of the suture are then utilized to close the horizontal capsulotomy in a running-locking interrupted fashion. Fluoroscopic imaging is performed throughout the procedure to prevent overcorrection and varus malignment. Alternative treatments include L-shaped capsulorrhaphy without suture anchor augmentation, dorsolinear capsulorrhaphy, Y-shaped capsulorrhaphy, and proximal hallux osteotomy or distal hallux osteotomy without capsulorrhaphy. Anchor-enhanced capsulorrhaphy has been proven to assist in early maintenance of hallux valgus angle correction when combined with relevant distal osteotomy techniques. The anchor-enhanced capsulorrhaphy has an advantage over traditional capsulorrhaphy methods because it allows enhanced tightening of the capsule to the bone and, therefore, the potential for enhanced short-term maintenance. Additionally, the use of a running-locking interrupted suture technique reduces the number of suture knots required for capsular closure, potentially reducing the chance of complications such as suture granuloma formation. This technique is useful in all patients with hallux valgus deformity because it helps to provide durable deformity correction through additional modification of the soft tissues surrounding the 1st metatarsophalangeal joint. Medial capsulorrhaphy has been shown to help with short-term reduction of the hallux valgus angle, both with and without the use of suture anchors1-3. Gould et al. demonstrated the superiority of adding suture anchors to the L-shaped medial capsulorrhaphy in order to aid in prevention of early postoperative relapse of the valgus deformity in patients undergoing chevron or modified McBride osteotomy1. We have utilized this suture anchor-enhanced capsulorrhaphy technique as an adjuvant procedure in most patients receiving osteotomies or Lapidus procedures for hallux valgus correction with consistent, reproducible results. In our experience, the suture anchor-enhanced medial capsulorrhaphy is an effective and time-efficient adjunctive soft-tissue corrective procedure in hallux valgus patients. Always excise a small capsular wedge to start with.Throughout the capsular tightening process, utilize clinical judgment and fluoroscopy to avoid pulling the hallux into varus malalignment.If varus is noted during plication of the plantar capsule, simply undo the tightening stitch.Because the majority of capsular tightening occurs at the first distal knot during the running horizontal capsular closure, if varus is noted, untie the knot and proceed with less correction.The extra cost of the suture anchor is a drawback but should be weighed against the enhanced durability of capsular correction compared with a traditional capsulorrhaphy.Always check the position of the suture anchor under fluoroscopy before proceeding with capsular closure in order to ensure proper deployment and adequate osseous purchase.Suture anchor failure can cause misleading radiographic presentation or joint impingement. VAS = Visual analog scaleAOFAS = American Orthopaedic Foot & Ankle SocietyHV = Hallux valgusHVA = Hallux valgus angleMTP = Metatarsophalangeal jointDVT = Deep venous thrombosis.

Symmetry of bilateral hallux valgus deformity: A radiographic study

Hallux valgus (HV) is a common anatomical deformity leading to pain and difficulty with footwear and mobility. Bilateral HV deformity is much more common than unilateral although it remains unclear whether the severity of deformity is equal between feet. The objective was to investigate the severity and symmetry of HV in patients with bilateral symptomatic deformity presenting for surgery. Weight-bearing radiographs of patients presenting with symptomatic bilateral HV were reviewed. The hallux valgus angle (HVA) and intermetatarsal angle (IMA) were measured and classified as mild, moderate, or severe. Left-to-right comparison was undertaken to assess whether the degree of deformity was similar for each foot. The relationship between age, HVA, and IMA was also assessed. Between July 2014 and June 2020, 322 ft (161 patients with bilateral deformity) underwent corrective HV surgery. Of those, 6.8%, 64.6%, and 28.4% were classified as mild, moderate, and severe, respectively on the left side, and on the right 6.2%, 67.7%, and 26.1% were classified as mild, moderate, and severe respectively. There was no statistically significant difference between feet for either IMA (p=0.06) or HVA (p=0.85). There was a moderate correlation (R=0.41, p ≤ 0.001) between HVA and IMA. There was only a 'weak' or 'very weak' correlation between age and HVA or IMA. Patients presenting for surgery with symptomatic bilateral HV have symmetrical moderate radiographic deformity at the time they present for consideration of surgical intervention.

WITHIN-DAY AND BETWEEN-DAY RELIABILITY OF A FBG-BASED SMART SOCK SYSTEM FOR MEASURING ACTIVE TOE FLEXION DISPLACEMENT OF THE HALLUX

This study examined the test-retest reliability of hallux flexion displacement measured using a smart sock system with embedded fiber Bragg grating (FBG) sensors. Thirty female participants consisting of 15 hallux valgus (HV) patients and 15 control participants were recruited. Maximum active hallux flexion displacement was measured twice on each participant in the first visit; the same procedures were repeated 7 days later. Intraclass correlation coefficients (ICC2,1) and standard error of measurement (SEM) were applied to test within-day and between-day reliability. Paired-samples T-test was performed to compare the displacements between trials. Results showed almost perfect within-day reliability for both HV and control groups ([Formula: see text] and 0.977, respectively) with small SEM (both 0.5[Formula: see text]cm). However, fair to moderate between-day reliability was found (0.323 and 0.438, respectively). Significant differences were found between repeated measurements taken on the same day (mean [Formula: see text][Formula: see text]cm, [Formula: see text]) and on different days (mean [Formula: see text][Formula: see text]cm, [Formula: see text]), though the effect size was small. The poorer between-day reliability is likely due to the inconsistency in fitting the sock onto the foot. Future optimization of the prototype design is called for to improve the fitting consistency of wearable sensors onto patients.

Multiplanar instability of the first tarsometatarsal joint in hallux valgus and hallux rigidus patients: a case-control study.

Hypermobility of the first ray has been considered associated with various forefoot diseases including hallux valgus (HV) and hallux rigidus (HR). Weightbearing CT scan can be a reliable method for analysis of the first tarsometatarsal (TMT) joint in axial, sagittal, and coronal planes. Our objective was to comparatively investigate signs of instability of the first TMT joint on weightbearing CT between three groups (control, HV, and HR). In this single-centre, retrospective, case-control study, 27 HV patients (30 feet; mean age 54.2years), 26 HR patients (30 feet; mean age 56.6years), and 30 controls (30 feet; mean age; 43years) were enrolled. Measurements of signs of instability were performed in multiplanes including first TMT angle, dorsal translation of the first metatarsal (M1) at the first TMT joint, plantar distance between the medial cuneiform (C1) and M1 in sagittal plane, hallux valgus angle (HVA), intermetatarsal angle (IMA) in axial plane, rotational profiles of C1 and M1 in coronal plane. Analysis of variance (ANOVA) test and chi-square test were performed to compare each parameter between the three groups. Interobserver reliabilities were assessed using interclass correlation coefficients (ICCs). The HV group had significantly increased first TMT angle (0.23° in controls, 1.15° in HV, 0.19° in HR, p < 0.001), HVA (7.52°, 33.50°, 11.21°, p < 0.001), IMA (9.46°, 16.98°, 11.87°, p < 0.001), C1-M1 angle (22.44°, 29.46°, 23.74°, p < 0.001), and rotational profile of the distal M1 (7.06°, 17.88°, 9.85°, p < 0.001) compared with the control and HR groups. Dorsal translation of M1 (23% in controls, 63% in HV, 70% in HR, p < 0.001) was frequently found in the HV and HR groups with significantly increased plantar distance (0.37mm, 1.14mm, 1.46mm, p < 0.001) compared with controls. Multiplanar instability of the first TMT joint was confirmed using weightbearing CT in HV and HR groups compared with controls. HV group demonstrated instability mainly in sagittal and axial planes; HR group had sagittal instability predominantly. Our measurement of rotational instability at the first TMT joint was not able to detect differences between groups. A surgical correction of the instability at the first TMT joint can be an option to address HV and HR. First ray hypermobility at the first TMT joint is an important consideration when addressing HV and HR, a surgical correction of the instability at the first TMT joint should be taken in consideration as an option.

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

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

Quantifying the Dynamic Stability of Gait Patterns in People with Hallux Valgus

Hallux valgus (HV), which is mainly caused by the wearing of narrow-width and high-heeled shoes, disrupts gait behavior because it deforms lower limb joints. There is limited information regarding the relationship between the foot disease HV and lower limb joints. Previous studies evaluating abnormal gait patterns caused by deformity used spatiotemporal parameters; however, they failed to characterize the overall gait dynamics. To address this issue, this study is aimed at characterizing the gait stability of patients with HV and examining the joints that are critically affected by HV. To assess complex gait dynamics, we quantified the potential changes in gait stability by using the maximum Lyapunov exponent (MLE). Angular displacements of the ankle, knee, and hip in the sagittal plane during walking were investigated to calculate the MLE for gait stability based on foot conditions (i.e., barefoot, flat shoes, and high heels). During walking, a large MLE (P < 0.05) was noted for the knee joints of subjects with HV, relative to the other lower limb joints. HV appears to have the most critical effect on the knee joints during walking. Ankle movement exhibited higher dynamic stability than the other joint movements of the lower limb (P < 0.05). The type of shoe used in the experiment showed no significant dependence with gait stability and joint movement (P > 0.05). Quantitative assessments of dynamic stability using the MLE may help clinicians assess the overall gait dynamics of HV patients and other people suffering from gait disturbances.

Outcomes of Simultaneous Bilateral vs Unilateral Distal Chevron Metatarsal Osteotomy in Hallux Valgus Patients Aged ≥60 Years.

The purpose of this study was to compare radiographic outcomes of simultaneous bilateral and unilateral distal chevron metatarsal osteotomy (DCMO) in hallux valgus patients aged ≥60 years. This retrospective study analyzed consecutive outcomes of simultaneous bilateral DCMO and unilateral DCMO performed between June 2010 and August 2018 in 90 feet of 60 patients. Thirty patients underwent simultaneous bilateral DCMO, and 30 underwent unilateral DCMO. Comparative analysis of radiographic and clinical parameters between a simultaneous bilateral DCMO group (SB) and a unilateral DCMO group (U) was performed. Mean age at surgery (65.7±4.8 vs 65.2±5.2 years), mean length of follow-up period (20.0 vs 18.6 months), and preoperative radiographic parameters were similar between the 2 groups (SB vs U). Mean hallux valgus angle (HVA) improved from 34.2 to 5.4 degrees (correction angle SB 28.8 vs U 28.8 degrees). Mean first-to-second intermetatarsal angle improved from 15.8 to 6.8 degrees (correction angle SB 8.9 vs U 8.9 degrees). Hallux varus deformity was observed in 4 feet (SB 3 vs U 1), and mechanical instability with callus formation in 1 foot in the unilateral group. DCMOs in patients aged ≥60 years were radiographically effective and safe, even performed in one stage bilaterally. Radiographic parameters were similar in patients who underwent simultaneous bilateral and unilateral DCMO. Level III, retrospective cohort study.

Radiographic measurements have limited effect in dynamic plantar pressures in hallux valgus patients.

Radiographic measurements are the gold standard in the management for preoperative surgical planning of hallux valgus deformity. Plantar pressure technology is a tool that is not commonly used to evaluate and manage hallux valgus patients, and few studies have reported the correlation of plantar pressure measurements and radiography. A prospective cohort study was designed to analyze plantar pressure measurements and radiographic variables. The inclusion criteria were age over 18 years old, and diagnosis of hallux valgus requesting surgical correction because of discomfort, pain or difficulty with shoe wear. Plantar pressure measurements were performed using a platform. Radiographic data were obtained according to the guidelines of the AOFAS Committee on Angular Measurements. A total of 114 patients met the inclusion criteria. Mean age of the patients was 50 years, and 94 patients (82.5%) were women. We found significant correlations between dynamic plantar pressure measurements and HVA, DMAA, and MDA. Mean pressure under third metatarsal head was the most associated plantar pressure measurement with hallux valgus angle and metatarsal declination angle. However, this association showed signs of weakness. Hallux valgus angle and metatarsal declination angle had a minimal influence on plantar-loading parameters. Pressure values did not discriminate the magnitude of HV deformity. Others factors responsible for the observed plantar pressures pattern should be addressed.

Effect of Metatarsus Adductus on Hallux Valgus Treated With Proximal Reverse Chevron Metatarsal Osteotomy.

This study aimed to compare clinical and radiographic outcomes and recurrence rates after reverse proximal chevron metatarsal osteotomy (PCMO) for patients with hallux valgus (HV) with or without metatarsus adductus (MA). We hypothesized that patients with MA would have poorer outcomes and a higher radiographic recurrence rate than those without MA. This retrospective single-surgeon series comprised 144 patients (173 feet) with moderate to severe HV, treated with PCMO and Akin osteotomy without lesser metatarsal procedures, who were grouped according to the presence (MA group) or absence of MA (non-MA group). Clinical assessment included the American Orthopaedic Foot & Ankle Society (AOFAS) score, pain visual analog scale (VAS), and patient satisfaction rating. Radiographic assessments included metatarsus adductus angle (MAA), HV angle (HVA), and intermetatarsal angle (IMA). The prevalence of the MA was 24.2%. The mean MAA was 23.1 ± 3.3 degrees in the MA group. There were no differences in the mean AOFAS score and pain VAS score at the final follow-up between the 2 groups (all P > .05). The patient satisfaction rate was 73.8% in the MA group vs 90.1% in the non-MA group (P = .017). The mean postoperative HVA and IMA significantly improved at the final follow-up in both groups, respectively (all P < .001). Preoperative and postoperative HVA were larger in the MA group vs non-MA group. However, no significant difference was found in the improvement of HVA and IMA after surgery between the 2 groups (all P > .05). The recurrence rate was 28.6% in the MA group and 6.1% in the non-MA group (P < .001). HV patients associated with the MA had a higher degree of preoperative HV, lower correction of the HVA, higher radiographic recurrence rate, and poorer patient satisfaction than those without MA post-PCMO without lesser metatarsal procedures. Therefore, a more extensive HV correction procedure or the addition of a lesser metatarsal realignment procedure may need to be considered. Level III, retrospective comparative series.

Women after Bilateral Surgical Correction of Hallux Valgus Do Not Show Improvement in Spatiotemporal Gait Parameters at 18 Weeks Postoperatively.

Background: Hallux valgus (HV) is a gait-altering orthopedic deformity, somewhat more prevalent in women, which often affects both limbs. Although surgery is a commonly applied treatment, there is no consensus in the literature on how invasive HV correction affects spatiotemporal gait parameters, or how quickly improvement can be expected. We investigated gait parameters in female HV patients who underwent bilateral surgical correction of hallux valgus, both preoperatively and 18 weeks following surgery (a timeframe relevant from the perspective of physical therapy), and also in relation to a non-HV control group. Methods: A total of 23 women aged 40–70 years, with moderate to severe HV deformity in both feet, were assessed preoperatively and 18 weeks postoperatively, and an age-matched control group of 76 healthy women was also assessed. A total of 22 spatiotemporal parameters were collected during 30 s walks over an electronic walkway (Zebris Medical System). Results: Of the 22 parameters analyzed, significant differences between the preoperative experimental and control groups were found only in 4 parameters (Velocity, Right step time, Total double support and Stride time), but in 16 parameters between the postoperative experimental and control groups (the greatest impact being found for: Left and Right Step time, Stride time, Cadence, Right Foot rotation, Left Step length (% leg length) and Stride length (% leg length)). Conclusions: Women after bilateral HV correction did not exhibit improved (i.e., more normal) gait parameters at 18 weeks postoperatively; rather, they showed more gait abnormalities than preoperatively. These findings urge longer-term planning of postoperative rehabilitation, involving continual evaluation of gait improvement.

Triplanar Chevron Osteotomy: A Newly Proposed Method to Treat Hallux Valgus Deformities.

ObjectiveTo present a novel method called triplanar chevron osteotomy to treat hallux valgus (HV).MethodsThis is a retrospective study. In this study, the CT data of HV patients with painful callosities were evaluated retrospectively between 1 June 2018 and 1 June 2020. CT data from 49 consecutive patients (59 feet) with HV were evaluated. The average age at the time of surgery was 49.6 years (range, 30–63 years). The apex of the chevron osteotomy procedure was located at the center of the first metatarsal and was defined as the line formed by the central point perpendicular to the fourth metatarsal bone. The cut planes of the plantarward oblique chevron osteotomy (POCO) were defined as follows: chevron osteotomy along with 20° of plantarward obliquity. The triplanar osteotomy incision was made using the POCO method, with the direction inclined by 10° distally. The intermetatarsal angle (IMA), the HV angle (HVA), the projection of the second metatarsal (PSM), the metatarsal protrusion index (MPI), and the metatarsal protrusion distance (MPD) were all calculated before and after the operations. The length of the first metatarsal was measured and calculated with an equation.ResultsThe results showed that the HVA was significantly decreased after surgery (32.7° ± 4.6° vs 14.9° ± 2.1°, t = 25.583, P < 0.001) in the triplanar, traditional, and POCO groups. The IMA was also significantly decreased (14.7° ± 2.0°) compared with the results before surgery (8.0° ± 1.1°, t = 22.739, P < 0.001) in these groups. Compared with traditional osteotomy and POCO, there were no differences in correcting deformities on axial planes for the HVA (14.5° ± 1.7° vs 14.9° ± 2.1°, t = 1.835, P = 0.072) and IMA (8.1° ± 1.1° vs 8.0° ± 1.1°, t = −0.97, P = 0.336). There was a statistically significant decrease following surgery in terms of the PSM, MPI, and MPD after triplanar osteotomy. The length of the first metatarsal increased (10.9 ± 1.3 mm), as measured through three‐dimensional images in the triplanar osteotomy group. The length was calculated as follows: H = L2 * Tan θ ≈ L/COS β * Tan θ.ConclusionThe new triplanar osteotomy technique is safe and effective for treating HV, and in simulation experiments reveals potential benefits of correction and preventing transfer metatarsalgia.

Relationship between Demographic and Radiographic Characteristics and 2nd Ray Pathology in Hallux Valgus Patients

Category:Bunion; Midfoot/ForefootIntroduction/Purpose:Hallux valgus can alter load bearing in the foot and may result in secondary pathologies such as hammertoes of the second ray. However, there has been little research on the development of second ray pathology in patients with pre-existing hallux valgus. Additionally, most research examining these three-dimensional foot deformities relies on two- dimensional plain radiographs. The goal of this study was to determine if hallux valgus is associated with second ray hammertoes using three-dimensional weightbearing CT scans.Methods:71 patients who underwent a modified Lapidus procedure for hallux valgus and had preoperative weightbearing CT scans were separated into 2 outcome groups: (1) hallux valgus only (47 feet), and (2) hallux valgus with second ray hammertoe (29 feet). Preoperative age, BMI, sex, hallux valgus angle (HVA), intermetatarsal angle (IMA), absolute and effective first, second, and third metatarsal lengths, the ratios between metatarsal lengths, Meary’s angle, metatarsus adductus angle (MAA), and pronation were measured. Mean values of continuous variables were compared using one-way ANOVA tests or Kruskal-Wallis tests. Simple logistic regression models were created to evaluate associations between variables and hammertoe occurrence: (1) comparing hammertoe to hallux valgus only, (2) comparing hammertoe to hallux valgus with mild hammertoe removed, and (3) comparing hammertoe to hallux valgus with severe hammertoe removed. Multivariable logistic regression models were generated to evaluate potential risk factors for hammertoe after adjusting for patient age and BMI.Results:Patients in the hammertoe group were found to be significantly older and have significantly higher BMIs, HVAs, effective second MT lengths, IMAs, and more apex plantar Meary’s angles (all P-values < 0.05). BMI and HVA were also found to be significant predictors of second ray hammertoe in simple logistic regression models (OR=5.66 (95% CI: 1.67-22.79) and OR=4.5 (95% CI: 1.13-21.06), respectively). The multivariable analysis demonstrated that higher IMA and a more apex plantar Meary’s angle were the only significant predictors of second ray hammertoe risk (P= 0.03 and P = 0.01, respectively) once corrected for age and BMI.Conclusion:Significant associations were found between older age, higher BMI, and more severe deformity and the occurrence of hammertoe in hallux valgus patients. These relationships may aid in determining which patients are at a greater risk of progressing to secondary pathologies and which patients could potentially benefit from earlier surgical intervention to correct hallux valgus.

Pronation on Weightbearing Radiographs is Not Associated with Pronation Calculated from Weightbearing CT Scans

Category:Bunion; OtherIntroduction/Purpose:In hallux valgus (HV), first metatarsal pronation is increasingly recognized as an important aspect of the deformity. Weightbearing CT (WBCT) scans have allowed investigators to quantify pronation of the first metatarsal. Yamaguchi et al. (J Orthop Sci 2015) proposed that pronation of the first metatarsal can be estimated by looking at the shape of the lateral aspect of the first metatarsal head on weightbearing AP radiographs of the foot, which would provide surgeons with a simple and readily available guide for evaluation of pronation. The purpose of this study was to compare pronation determined from the shape of the lateral head of the first metatarsal on AP weightbearing radiographs in HV patients with pronation calculated from WBCT scans.Methods:Patients were included in this study if they had preoperative (n=22 patients) or 5-month postoperative (n=22 patients) WBCT scans and corresponding weightbearing AP radiographs of the affected foot. Pronation on weightbearing AP radiographs was grouped into four groups 0–9°, 10–19°, 20–30°, and >30° as described by Wagner and Wagner (Foot Ankle Clin 2018) by two independent observers. Pronation of the first metatarsal on WBCT scans was measured using a technique developed by Campbell et al. (Foot Ankle Int 2018), which calculates pronation of the first metatarsal in reference to the second metatarsal using a 3D CAD model, and using the alpha angle as described by Kim et al. (Foot Ankle Int 2015) and was categorized into the same four groups described for the radiographs. Weighted kappa coefficients (k) were used to determine interobserver reliability and agreement between pronation groups on radiographs and WBCT scans. Intraclass correlation coefficients were used to determine reliability of the alpha angle measurements on WBCT scans. After dividing patients into plain radiograph pronation groups, differences in mean WBCT pronation of the first metatarsal was compared using Kruskal-Wallis tests.Results:Agreement between the two observers for preoperative and postoperative pronation on radiographs was moderate (k=.529,P<.001) and fair (k=.382,P=0.001), respectively. Intraclass correlation coefficients for preoperative and postoperative alpha angles were good (ICCs > 0.80, P<.001). Pronation of the first metatarsal on radiographs agreed with pronation on WBCT scans using a CAD method in 7 of 22 cases preoperatively (31.8%) and 8 of 22 cases postoperatively (36.4%). However, statistically, this was represented no agreement by more than chance between preoperative or postoperative pronation on WBCT scans and radiographs (k=.041, P=.774 and k=.059, P=.595, respectively) (Figures 1A-B). Similarly, pronation of the first metatarsal on radiographs did not agree with pronation on WBCT scans using the alpha angle measure either preoperatively or postoperatively (k=.070, P=.474 and k=.063, P=.364, respectively). Preoperatively, in the plain radiograph pronation groups of 10-19° (n=9), 20- 29° (n=11), and >30° (n=2), mean pronation calculated from WBCT scans using a 3D CAD method was 21.1°, 25.2°,and 20.9°, respectively (P=.752), and mean pronation calculated using the alpha angle was 13.2°, 15.8°, and 22.3°, respectively (P=.308).Postoperatively, in the plain radiograph pronation groups of 0-9° (n=9), 10-19° (n=6), and 20-29° (n=7), mean pronation calculated from WBCT scans using a 3D CAD method was 22.3°, 22.5°, and 21.0°, respectively (P=.976), and mean pronation calculated using the alpha angle was 3.1°, 5.7°, and 6.4°, respectively (P=.252).Conclusion:: Pronation of the first metatarsal measured on weightbearing AP radiographs using the lateral first metatarsal head had only fair to moderate interobserver agreement and did not statistically significantly agree with pronation measured on WBCT scans using either a 3D CAD model or the alpha angle. Additionally, mean pronation on WBCT scans did not significantly differ by any magnitude between the plain radiograph pronation groups, which indicates that there was no association between pronation measured on WBCT scans and plain radiographs. These results suggest that surgeons should use caution when trying to derive first metatarsal pronation from AP weightbearing radiographs for surgical planning purposes.

Understanding the Rotational Positioning of the Bones in the Medial Column of the Foot: A Weightbearing CT Analysis

Category:Bunion; Midfoot/ForefootIntroduction/Purpose:Rotational deformities of the first ray have been described as essential components of hallux valgus (HV) deformity, influencing its severity and progression. The exact deformity location along the medial column, as well as the typical rotational pattern of each bone, is yet to be fully understood. The objective of this study was to evaluate the rotational position of the navicular, medial cuneiform, first metatarsal and proximal phalanx using three-dimensional weightbearing CT (WBCT) images of a diversity of patients with foot pathologies. Our goal was to describe the rotational profile of medial column bones, serving as a reference for future studies.Methods:A retrospective review of patients that underwent WBCT assessment of multiple foot and ankle pathologies was conducted in a single Institution. A blinded and independent Fellowship-Trained Foot and Ankle Orthopedic Surgeon performed measurements in Multiplanar Reconstruction (MPR) WBCT images assessing the rotational profile of each bone of the medial column (navicular, medial cuneiform, first metatarsal and proximal phalanx of the great toe), as demonstrated in the attached figure. The first metatarsal, representing a long bone, was evaluated on its proximal and distal ends. A total of 110 patients were included. As standard, we considered pronation as positive values and supination as negative values. Comparisons were performed using independent t-tests or Wilcoxon tests. P-values of <0.05 were considered significant.Results:The mean values and 95% Confidence Interval for the rotational profile of the medial column bones were found to be respectively: Navicular, pronated 43.2o (41.1 to 45.2); Medial Cuneiform, supinated -2.5o (-4.3 to -0.7); Proximal First Metatarsal, supinated -28.1o (-32 to -24.1); Distal Metatarsal, pronated 18.5o (16.3 to 20.7); First Toe Proximal Phalanx, pronated of 21.6o (18.7 to 24.5). Significant differences were found in the rotational position of each bone/segment (p<0.0001), with the exception of the distal metatarsal/proximal phalanx (p=0.11), that demonstrated similar amounts of pronation. When considering each segment/joint in isolation, the highest rotational deformity was found to exist within the first metatarsal (pronated 46.6o), naviculo-cuneiform joint (supinated 45.7o), first tarsometatarsal joint (supinated 25.5o) and first metatarsophalangeal joint (pronated 3.1 o).Conclusion:Our study described the rotational profile of the medial column bones using WBCT images, in a population of patients with diverse foot and ankle pathologies. We found significant differences in the rotational position of most of the bones along the medial column. The greatest amount of rotation was found to happen within the first metatarsal, which undergoes an average of 46o of pronation from proximal to distal, probably compensating a considerable amount of supination of the naviculo- cuneiform and first tarsometatarsal joints. Further studies comparing hallux valgus patients and controls are needed.

Crista Volume Measured from 3D Reconstructions of Weightbearing CT Scans Shows a Relationship to Sesamoid Station

Category:BunionIntroduction/Purpose:The progression of hallux valgus (HV) deformities results in dislocation of the sesamoids from their position (station) under the plantar surface of the distal first metatarsal. With this dislocation, the crista separating the two sesamoids erodes as the contact of the medial sesamoid with the crista applies pressure with weightbearing. Recently, three dimensional (3D) reconstructions of the metatarsals and first phalanx have demonstrated a means to find a consistently quantify first metatarsal pronation. These same reconstructions can also produce a reliable technique to compute the volumes of the bones involved. The purpose of the current investigation is to examine the relationship of the volume of the crista to pronation and to sesamoid station.Methods:Eleven HV patients and five normal subjects with weightbearing or weightbearing equivalent CT (WBCT) imaging were randomly selected from the senior author’s patients. Pronation was quantified on WBCT scans using 3D reconstructions as described by Campbell et al. (FAI 2018). Crista volume was determined using a line drawn to connect the nadir of each sulcus on either side of the intersesamoidal crista in each slice of the WBCT image (Figure 1). Sesamoid station was also quantified on WBCT scans using the established four point categorization. A linear regression was performed to determine if the volume of the crista was associated with the pronation angle. The sesamoid station was simplified into two categories - mild medial sesamoid subluxation (less than 50% of the medial sesamoid was lateral to the nadir of the crista) and severe medial sesamoid subluxation - and crista volume between these two groups was compared using a t-test.Results:The regression of crista volume against first metatarsal pronation angle did not show statistical significance (P=0.94, r2=0.03). The mean crista volume in the mild medial sesamoid subluxation group was 156(+-47, range 72 - 231)mm3. The mean crista volume in severe medial sesamoid subluxation was 95 (SD 39, range 35 - 160) mm3. The t-test using simplified sesamoid station to compare crista volumes found that the mean crista volume in the mild medial sesamoid subluxation group was statistically significantly greater the than the mean crista volume in the severe sesamoid subluxation group (P=0.01).Conclusion:In HV, it has been hypothesized that the medial sesamoid erodes the crista resulting in arthritis. This is often overlooked as a source of pain in these patients. Our study found that pronation of the first metatarsal was not correlated with crista volume suggesting that pronation does not affect erosion of the crista. Instead, our results are the first to demonstrate that medial sesamoid subluxation as determined from sesamoid station results in erosion of the crista. This supports the hypothesis that sesamoid subluxation, arthritis, and crista erosion are important components of the HV deformity.