Distal Metatarsal Articular Angle in Hallux Valgus Deformity. Fact or Fiction? A 3-Dimensional Weightbearing CT Assessment

Preoperative increased pronation angle of the first metatarsus associated with correction loss after hallux valgus surgery: A semi-weight-bearing computed tomography study

BACKGROUND

The effect of preoperative first metatarsal pronation on postoperative prognosis of hallux valgus (HV) surgery is under investigation. Utilizing semi-weight-bearing computed tomography, the preoperative pronation angle was assessed to quantify its impact on postoperative prognosis.

METHODS

In a retrospective analysis of 31 feet, those with re-increased hallux valgus angle postoperatively were classified as the non-maintained group, and the remainder as the maintained group. Preoperative pronation angles were compared to establish a threshold. Subsequently, feet were re-classified into high or low-pronation categories. The relative risk of non-maintenance in high-pronation category was calculated.

RESULTS

The non-maintained group exhibited a significantly higher preoperative pronation angle (p = 0.021), with a 28.4º threshold. The high-pronation category had a relative risk of 2.34 for non-maintenance.

CONCLUSIONS

Increased preoperative first metatarsal pronation angle is associated with correction loss after HV surgery. Utilizing sWBCT to measure the pronation angle provides valuable insights into postoperative prognosis.

LEVEL OF EVIDENCE

III.

Midfoot width changes after first metatarsal osteotomy in hallux valgus surgery: A biomechanical effect?

Hallux valgus is a challenging pathology characterized by a valgus deformity in the metatarsophalangeal area of the first ray. The aim of this study was to analyze the influence of first metatarsal osteotomy on the relationship between midfoot bones in patients with hallux valgus. The sample consisted of patients from the orthopedics and traumatology outpatient clinic who underwent surgical treatment for hallux valgus. Preoperative and postoperative X-rays were compared regarding the width of the midfoot and the tarsometatarsal joint. The sample consisted of 17 women, with 22 feet assessed in each group. The distance from the medial cuneiform to the cuboid, the distance from the intermediate cuneiform to the cuboid, the distance between the first and fifth metatarsals, and the distance between the second and fifth metatarsals reduced significantly between pre- and postoperative assessments. Hallux valgus correction through osteotomy of the first metatarsal leads to a structural change in the midfoot. Further studies should determine whether these changes persist over time.

Is there a tolerance for extension of the first metatarsal after the Lapidus procedure? A clinical, functional, and hindfoot radiographic analysis

PURPOSE

Based on the tripod concept of load distribution, our study aimed to evaluate whether a slight extension of first metatarsal (M1) that may occur after the Lapidus procedure (LP) could alter the radiographic measurements of the hindfoot and influence clinical and functional outcomes.

METHODS

Twenty-five patients (27 feet) were reviewed. Hindfoot radiographic analysis was based on seven measurements. Clinical and functional outcomes were evaluated with self-reported questionnaires. Transfer metatarsalgia was also assessed. Correlation analysis was performed according to variations of the studied variables.

RESULTS

The average extension of the M1 was 4.26 degrees (p < 0.001). None of the hindfoot radiographic measurements changed significantly (p = 0.13, p = 0.50, p = 0.19, p = 0.70, p = 0.11, p = 0.36, p = 0.83). Patients improved on most questionnaires (p < 0.001). None presented transfer metatarsalgia. No correlation between M1 extension and clinical and functional outcomes was found.

CONCLUSION

Possibly there is a tolerance of M1 extension in which it does not alter the radiographic measurements of the hindfoot, overload the lesser metatarsals, or compromise clinical and functional outcomes.

Radiological outcome of hallux valgus deformity correction with metatarsal osteotomy from a single-center cohort - Best results achieved by foot and ankle surgeons

BACKGROUND

To evaluate the radiological outcome, especially undercorrection of hallux valgus deformity correction with first metatarsal osteotomy.

PATIENTS AND METHODS

439 1st metatarsal osteotomies including 241 distal (55 %), 175 midshaft (40 %), and 23 proximal (5 %) were available for analysis with median follow-up time was 48 days (range 27-990 days).

RESULTS

The postoperative HVA was normal in 237 (54 %), mild in 110 (25 %), moderate in 87 (20 %), and severe in 5 (1 %) of the cases. BMI (p = 0.0127), sex (p = 0.0004), preoperative HVA (p = 0.0028), and surgeons experience (p < 0.0001) were associated with radiological outcome, whereas age, hospital, and type of osteotomy had no effect. Foot and ankle surgeons achieved normal postoperative HVA in 76 %, general orthopedic surgeons in 41 %, and residents in 47 % of the operations.

CONCLUSION

Radiological undercorrection was common. As foot and ankle surgeons achieved best radiological correction, hallux valgus deformity should be operated by specialists.

Diagnostic applications and benefits of weightbearing CT in the foot and ankle: A systematic review of clinical studies

BACKGROUND

Foot and ankle weightbearing CT (WBCT) imaging has emerged over the past decade. However, a systematic review of diagnostic applications has not been conducted so far.

METHOD

A systematic literature search was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines after Prospective Register of Systematic Reviews (PROSPERO) registration. Studies analyzing diagnostic applications of WBCT were included. Main exclusion criteria were: cadaveric specimens and simulated WBCT. The Methodological Index for Non-Randomized Studies (MINORS) was used for quality assessment.

RESULTS

A total of 78 studies were eligible for review. Diagnostic applications were identified in following anatomical area's: ankle (n = 14); hindfoot (n = 41); midfoot (n = 4); forefoot (n = 19). Diagnostic applications that could not be used on weightbearing radiographs (WBRX) were reported in 56/78 studies. The mean MINORS was 9.8/24 (range: 8-12).

CONCLUSION

Diagnostic applications of WBCT were most frequent in the hindfoot, but other areas are on the rise. Post-processing of images was the main benefit compared to WBRX based on a moderate quality of the identified studies.

Evaluate the Influencing Factors of Congruency of the First Metatarsophalangeal Joint in Hallux Valgus Based on Weightbearing CT

The purpose of this study was to explore the difference between congruency and incongruency of the first metatarsophalangeal (MTP) joint in hallux valgus using weightbearing CT (WBCT) and to identify the risk factors for incongruency. From January 2019 to January 2021, WBCT scans were retrospectively analyzed for 110 (191 feet) consecutive patients. According to whether the metatarsal articular surface and phalanx articular surface were parallel, they were divided into congruency (73 feet) and incongruency groups (118 feet). The age, intermetatarsal angle (IMA), hallux valgus angle (HVA), distal metatarsal articular surface angle (DMAA), first metatarsal coronal pronation angle (α angle), tibial sesamoid 7 positions (TSP), and tibial sesamoid coronal grading (TSCG) were compared between the 2 groups. Binary logistic regression was used to analyze the influencing factors of incongruency. Receiver operating characteristic (ROC) curve analysis was applied to determine the cutoff value. There were significant differences in IMA, HVA, DMAA, α angle, age, TSP, and TSCG between congruency and incongruency groups (p < .05). Binary logistic regression analysis showed that TSCG, HVA, α angle were the influencing factors of incongruency. ROC curve analysis demonstrated that the cutoff values for incongruency were 1 position for TSCG (sensitivity: 0.835; specificity: 0.884) with the area under curve (AUC) of 0.892, 30° (sensitivity: 0.795; specificity: 0.812) for HVA with the AUC of 0.878, and 24° (sensitivity: 0.530; specificity: 0.797) for α angle with the AUC of 0.686. Incongruency of the first MTP joint indicated a more severe hallux valgus, and was associated with increased HVA, α angle, and TSCG.

Relationship Between Obesity and Medial Longitudinal Arch Bowing

BACKGROUND

There have been reports about the association between obesity and the medial longitudinal arch (MLA) of foot. The purpose of this study is to investigate the change of various parameters related to the MLA according to obesity classification severity by the World Health Organization using weightbearing computed tomography (WBCT).

METHODS

WBCT data of the noninvolved side of patients presenting with unilateral foot and ankle problems or healthy candidates from September 2014 to October 2022 were extracted from a single referral hospital. Forty-four cases in each of 5 obesity classes were selected sequentially. Two orthopaedic surgeons measured foot and ankle offset, forefoot arch angle (FAA), hindfoot moment arm, percentage of uncoverage of the middle facet of the subtalar joint, talonavicular angle (TNA), navicular-medial cuneiform angle, medial cuneiform-first metatarsal angle, talus-first metatarsal angle (TMT1A), first tarsometatarsal subluxation (TMT1S), talonavicular coverage angle, navicular floor distance (NFD), and NFD per height. Positive values indicate plantar collapse. Intra- and interobserver reliabilities were assessed using intraclass correlation coefficients. One-way analysis of variance tests were performed for parametric data with equal variances, and Welch's test for unequal variances. Kruskal-Wallis test was performed for nonparametric data. Post hoc analysis was performed for statistically significant parameters. Correlation analysis between body mass index (BMI) and 12 parameters were performed using Pearson test.

RESULTS

Intraobserver and interobserver reliability were excellent, except for TMT1S. The TNA and TMT1A showed a statistically significant difference. FAA (r = -0.2), TNA (r = 0.182), TMT1A (r = 0.296), and NFD (r = -0.173) showed a statistically significant correlation with BMI.

CONCLUSION

In nonsymptomatic feet, we found that the talonavicular joint, as measured by the TNA, to be influenced by obesity classification. Obesity and increased BMI was associated with a negative influence on the MLA.

LEVEL OF EVIDENCE

Level III, retrospective cohort study.

Minimally Invasive Chevron-Akin for Correction of Moderate and Severe Hallux Valgus Deformities: Clinical and Radiologic Outcomes With a Minimum 2-Year Follow-up

BACKGROUND

The minimally invasive chevron-Akin (MICA) technique has already demonstrated efficacy compared with other known surgical treatments for mild to moderate hallux valgus (HV). MICA combines percutaneous osteotomies with the benefits of modern, rigid internal fixation. The aim of study was to evaluate the radiographic parameters, clinical improvement, and potential complications in moderate to severe HV cases, operated using the MICA technique.

METHODS

Retrospective study including 70 feet with HV operated using the MICA technique. The AOFAS hallux MTP-IP score and radiographics for HV evaluation were applied preoperatively, and after 6 months, 1 year, and 2 years of follow-up. The following radiographic parameters were measured: metatarsophalangeal hallux valgus angle (HVA), distal metatarsal articular angle (DMAA), interphalangeal angle (IPA), and intermetatarsal angle (IMA).

RESULTS

The average preoperative VAS pain score was 8.2 ± 1.5, which improved to 1.2 ± 2.2 at 24 months. The mean preoperative IMA was 14.8 ± 3.6 degrees compared with a mean of 7.5 ± 2.1 degrees (P < .01) at 24 months. The preoperative HVA value averaged 30.4 ± 9.8 degrees and at 6 months postoperatively 11.1 ± 6.8 degrees (P < .01), which remained stable until measured at 24 months. The mean preoperative DMAA was 16.3 ± 8.6 degrees and at the 6-month follow-up was 7.8 ± 5.4 degrees (P < .01). The mean preoperative IPA was 7.63 ± 4.4 degrees compared with a mean of 6.28 ± 3.5 degrees (P > .05) at 24 months. Complications included painful hardware (14.28%), neuropathic pain (2.85%), and loss of correction (4.28%).

CONCLUSION

In this retrospective review from a single center, we found the MICA technique to be an effective procedure for correcting moderate to severe HV, with a low rate of recurrence and an acceptable rate of complications. Patients undergoing the surgical procedure in our series showed a significant reduction in radiographic parameters and a significant improvement in clinical scores, maintaining these results over time.

LEVEL OF EVIDENCE

Level IV, retrospective study.

Coronal Plane Rotation of the Medial Column in Hallux Valgus: A Retrospective Case-Control Study

BACKGROUND

We previously reported an increase in pronation of the first metatarsal (M1) head relative to the ground in hallux valgus (HV) patients compared to controls. Still, the origin and location of this hyperpronation along the medial column is unknown. Recent studies showed that presence of progressive collapsing foot deformities (PCFDs), which is a condition frequently associated with HV, can strongly influence the medial column coronal plane alignment. The objective of this study was to assess the coronal rotation of the medial column bones in HV feet, HV feet with radiologic markers of PCFD, and controls. We hypothesized that hyperpronation in HV will originate from a combination of M1 intrinsic torsion and first tarsometatarsal joint malposition.

METHODS

The same cohort of 36 HV and 20 controls matched on age, gender, and body mass index was used. Previously, a validation of the measurements was carried out through a cadaveric study. Using these metrics, we assessed the coronal plane rotation of the navicular, medial cuneiform, and the M1 at its base and head with respect to the ground using weightbearing CT images. We measured the Meary angle and the calcaneal moment arm in our 36 HV subjects. We subdivided our cohort into an HV group and a potential PCFD HV group according to these measurements. Comparisons on medial column bones coronal rotation were performed between HV, PCFD HV, and control groups.

RESULTS

Twenty-two HV cases were included in the HV group and 14 in the PCFD HV group. Both groups presented an increase in pronation of the first metatarsal head relative to the ground when compared to the control group (P < .001). Comparing HV and controls showed an 8.3 degrees increase in pronation of M1 intrinsic torsion (P < .001) and a 4.7 degrees pronated malposition of the first tarsometatarsal joint (P = .02) in HV. A 9.7 degrees supinated malposition of the first naviculocuneiform joint (P < .001) was also observed in HV. Comparing PCFD HV and controls showed a significant increase in pronation of the navicular (respectively, 17.2 ± 5.4 and 12.3 ± 3.4 degrees, P = .007) and a 5.5 degrees increase in pronation of M1 intrinsic torsion (P = .02) in PCFD HV, without malposition of the first tarsometatarsal and naviculocuneiform joints.

CONCLUSION

Hyperpronation of the M1 head relative to the ground originated from both increases in pronation of M1 intrinsic torsion and first tarsometatarsal joint malposition in HV, although partially counterbalanced by a supinated malposition of the first naviculocuneiform joint. On the other hand, PCFD HV patients showed a generalized pronated position throughout the medial column from the navicular to the M1 head and may be related to the midfoot and hindfoot deformities frequently present in PCFD.

LEVEL OF EVIDENCE

Level III, retrospective comparative study.

Side-to-Side Difference of Metatarsal Rotation in Normal Individuals

BACKGROUND

A previous study defined the normal first metatarsal pronation angle (MPA) as <16 degrees and normal α angle as <18 degrees. The primary purpose of this study was to assess the side-to-side variation in first metatarsal pronation between feet in normal individuals.

METHODS

MPA and α angles were measured on standardized coronal weightbearing computed tomography slices. Pairedt tests were used to test significance of mean side-to-side differences in a population of 63 normal, asymptomatic individuals.

RESULTS

The mean side-to-side difference in first metatarsal pronation was 4.3 degrees (95% CI 3.3, 5.2 degrees) for MPA and 4.9 degrees (95% CI 3.8, 6.0 degrees) for α angle. The normative range for side-to-side difference was calculated as 12 degrees for MPA and 14 degrees for α angle, as defined by 2 SDs from the mean.

CONCLUSION

In a cohort of normal patients, the mean difference in first metatarsal pronation between sides was approximately 4 to 5 degrees based on MPA and α angle. However, considerable variation in differences was observed. These findings may be considered when assessing first metatarsal pronation using population-based values as it may influence thresholds for identifying pathology in an individual.