The excessive length of first ray as a risk factor for hallux valgus recurrence

Developing Machine Learning-Based Predictive Models for Hallux Valgus Recurrence Based on Measurements From Radiographs

BACKGROUND

Machine learning (ML) is increasingly used to predict the prognosis of numerous diseases. This retrospective analysis aimed to develop a prediction model using ML algorithms and to identify predictors associated with the recurrence of hallux valgus (HV) following surgery.

METHODS

A total of 198 symptomatic feet that underwent chevron osteotomy combined with a distal soft tissue procedure were enrolled and analyzed from 2 independent medical centers. The feet were grouped according to nonrecurrence or recurrence based on 1-year follow-up outcomes. Preoperative weightbearing radiographs and immediate postoperative nonweightbearing radiographs were obtained for each HV foot. Radiographic measurements (eg, HV angle and intermetatarsal angle) were acquired and used for ML model training. A total of 9 commonly used ML models were trained on the data obtained from one institute (108 feet), and tested on the other data set from another independent institute (90 feet) for external validation. Optimal feature sets for each model were identified based on a 2000-resample bootstrap-based internal validation via an exhaustive search. The performance of each model was then tested on the external validation set. The area under the curve (AUC), classification accuracy, sensitivity, and specificity of each model were calculated to evaluate the performance of each model.

RESULTS

The support vector machine (SVM) model showed the highest predictive accuracy compared to other methods, with an AUC of 0.88 and an accuracy of 75.6%. Preoperative hallux valgus angle, tibial sesamoid position, postoperative intermetatarsal angle, and postoperative tibial sesamoid position were identified as the most selected features by several ML models.

CONCLUSION

ML classifiers such as SVM could predict the recurrence of HV (an HVA >20 degrees) at a 1-year follow-up while identifying associated predictors in a multivariate manner. This study holds the potential for foot and ankle surgeons to effectively identify individuals at higher risk of HV recurrence postsurgery.

Radiological Analysis of the Syndesmosis Concept in Metatarsus Primus Varus and Hallux Valgus Deformities Recurrence Prevention

Hallux valgus (HV) is a common deformity of the foot. Its postoperative recurrence is not uncommon and is closely related to the recurrence of its underlying metatarsus primus varus (MPV) deformity. The syndesmosis procedure uses 1 to 2 intermetatarsal cerclage sutures to realign the first metatarsal and then induces a biological bonding between the 2 metatarsals to prevent the MPV deformity from recurring. This radiological study aimed to assess its effectiveness in long-term MPV and HV deformities recurrence prevention. Ninety-two feet of 51 consecutive patients had syndesmosis procedures that were prospectively followed up for more than 1 y and up to 14 y, averaging 100.5 (SD 45.2) months. Patients underwent X-ray examinations regularly at fixed intervals of their feet. We used Hardy's methods in measuring the intermetatarsal angle (IMA), hallux valgus angle (HVA), and medial sesamoid position from standing foot X-rays. More than 450 relevant X-ray and photo images were submitted as Supplementary Material for online viewing and reference. There was a significant final correction of IMA from 14.30° (SD 2.70) to 6.70° (SD 1.75) (p < .0001). There was no significant increase in IMA after the sixth postoperative month to their final follow-up endpoints, regardless of their lengths. There was a significant final correction of HVA from 31.95° (SD 7.45) to 19.1° (SD 7.45) (p < .0001). This study reconfirmed past findings that the MPV deformity could be corrected without osteotomies. Creating a syndesmosis-like intermetatarsal bonding was effective for long-term MPV recurrence prevention. Three feet had postoperative stress fracture of the second metatarsal. However, the HV deformity correction was less satisfactory, and the reasons were explained.

Recurrence Rates With Longer-Term Follow-up After Hallux Valgus Surgical Treatment With Distal Metatarsal Osteotomies: A Systematic Review and Meta-analysis

BACKGROUND

Recurrence of hallux valgus (HV) following corrective surgery is a frequent concern. A recent systematic review estimated recurrence of HV in only 4.9%, which may be an underestimation, as most included studies had short- to mid-term follow-up. The purpose of this systematic review and meta-analysis was to assess long-term outcomes of distal osteotomies of the first metatarsal (M1) to treat HV without inflammatory disease or degenerative arthritis, and to assess HV recurrence rates reported in studies that had a minimum follow-up of 5 years.

METHODS

This systematic review conforms to the PRISMA guidelines. The authors conducted a search using PubMed, Embase, and Cochrane Central Register of Controlled Trials databases. Studies that report outcomes of distal osteotomies of the M1 for noninflammatory and nondegenerative HV at a minimum follow-up of 5 years.

RESULTS

We found 17 eligible studies comprising 18 data sets, reporting outcomes of 4 categories of osteotomies: Chevron, Mitchell, Bösch, and "others." The HV recurrence rate was 64% considering the threshold of >15 degrees hallux valgus angle (HVA), 10% having >20 degrees, and 5% having >25 degrees.

CONCLUSION

At a minimum of 5 years following distal osteotomies of the M1, the mean weighted postoperative HVA was significantly higher for Mitchell osteotomies compared with the 3 other osteotomies reviewed. There were otherwise no significant differences in recurrence rates using the 3 HVA thresholds, or intermetatarsal angle among any of the surgical techniques reported in 2 or more studies. The pooled HV recurrence rates considering the various thresholds of HVA were as follows: 64% having >15 degrees, 10% having >20 degrees, and 5% having >25 degrees. The recurrence rates in the long term for all categories of surgical procedures suggest that better understanding of pathogenesis and prognosis of HV is required before modifying or introducing new surgical techniques.

LEVEL OF EVIDENCE

Level IV, meta-analysis.

Outcomes of V-cut Osteotomy on the First Metatarsal Head Combined with Fixation in Mortise-shaped Bone Groove-Plasty and Akin Osteotomy on the First Toe for Hallux Valgus Correction

Objective

Hallux valgus (HV) is a common foot deformity, and recurrence is one of the most serious complications after HV correction. As a result, the surgical technique with a lower recurrence rate is a dream. The purpose of the article should be to observe the correction effect of hallux valgus using a novel “V‐cut” osteotomy on the first metatarsal head combined with fixation in mortise‐shaped bone groove‐plasty technique.

Methods

Twenty‐three consecutive patients (40 feet) with HV were included from March 2019 to May 2020, who were all treated using single screw fixation with V‐cut osteotomy on the first metatarsal head combined with mortise‐shaped metatarsal bone groove‐plasty and Akin osteotomy on the first toe for hallux valgus correction. With a mean follow‐up time of 21.7 months, the visual analogue scale (VAS) score and American Orthopedic Foot and Ankle Society (AOFAS) forefoot score and the changes of the hallux valgus angle (HVA), intermetatarsal angle (IMA) and distal metatarsal articular angle (DMAA) were evaluated during the clinical follow‐up. The paired t test was used for analytical statistics.

Results

The VAS score improved from 6.78 ± 1.74 to 1.87 ± 1.45 and the AOFAS score improved from 53.9 ± 12.3 preoperatively to 94.7 ± 6.8 in the latest follow‐up postoperatively (P < 0.01). Besides, the HVA improved from 30.0 ± 6.1° to 5.7 ± 2.8° (P < 0.01); the IMA changed from 13.1 ± 2.8° into 3.3 ± 1.6° (P < 0.01); and the DMAA ameliorated from 27.0 ± 8.4° to 5.9 ± 3.5° (P < 0.01). Only five toes had slight numbness and stiffness in early postoperative period, and these symptoms disappeared completely at 6 months after the surgery. Only one foot was corrected to excess. One screw stern protruding beneath the skin happened, which needed secondary screw removal under local anesthesia.

Conclusions

Single screw fixation with V‐cut osteotomy on the first metatarsal head combined with fixation in mortise‐shaped metatarsal bone groove‐plasty and Akin osteotomy on the first toe is an effective way with low recurrence rate for HV correction.

Effect of Displacement Degree of Distal Chevron Osteotomy on Metatarsal Stress: A Finite Element Method

BACKGROUND

The stress of foot bone can effectively evaluate the functional damage caused by foot deformity and the results of operation. In this study, the finite element method was used to investigate the degree of displacement of distal chevron osteotomy on metatarsal stress and metatarsophalangeal joint load; Methods: Four finite element models of displacement were established by using the CT images of a patient with moderate hallux valgus (hallux valgus angle and intermetatarsal angle were 26.74° and 14.09°, respectively), and the validity of the model was verified. Each finite element model consisted of bones and various cartilage structures, ligaments, and plantar fascia, as well as encapsulated soft tissue. Except for soft tissue, the material properties of other parts were isotropic linear elastic material, and the encapsulated soft tissue was set as nonlinear hyperelastic material. The mesh was tetrahedral mesh. Link elements were used in ligament and plantar fascia. A ground reaction force with a half-body weight was applied at the bottom of the floor to simulate the ground reaction when standing. The upper surfaces of the encapsulated soft tissue, distal tibia, and distal fibula were fixed. The stress distribution of metatarsals and the stress of cartilage of the first metatarsophalangeal joint were compared and analyzed; Results: Compared with the hallux valgus without osteotomy, the stress of the first metatarsals and second metatarsals of 2-4 mm decreased, and the stress of the interarticular cartilage of the first metatarsophalangeal joint with 4 mm was reduced. In the case of 6 mm, the stress value between the first metatarsal and the first metatarsophalangeal joint increased, and 4 mm was the most suitable distance; Conclusions: Compared with the hallux valgus without osteotomy, the stress of the first metatarsals and second metatarsals of 2-4 mm decreased, and the stress of the interarticular cartilage of the first metatarsophalangeal joint with 4 mm was reduced. In the case of 6 mm, the stress value between the first metatarsal and the first metatarsophalangeal joint increased, and 4 mm was the most suitable distance. For the degree of displacement of the distal chevron osteotomy, the postoperative stability and the stress distribution of metatarsal bone should be considered. Factors such as hallux valgus angle, intermetatarsal angle, patient's age, body weight, and metatarsal width should be considered comprehensively. The factors affecting osteotomy need to be further explored. The degree of displacement of osteotomy can be evaluated by FE method before the operation, and the most suitable distance can be obtained.

Prevalence and Predisposing Factors for Recurrence after Hallux Valgus Surgery: A Systematic Review and Meta-Analysis

Recurrence is a frequent and undesirable outcome after hallux valgus (HV) surgery. However, the prevalence of HV recurrence and the pre- and postoperatory factors associated with it have not been adequately studied. This study aimed to quantify the prevalence rate of HV recurrence and to analyze its predisposing factors. MEDLINE and EMBASE databases were systematically searched for observational studies including individuals undergoing HV surgical correction. The random-effects restricted maximum likelihood model was used to estimate the pooled effect size (correlation coefficient (r)). Twenty-three studies were included, yielding a total of 2914 individuals. Pooled prevalence of HV recurrence was 24.86% (95% confidence interval (CI), 19.15 to 30.57, I² = 91.92%, p = 0.00). Preoperative HV angle (HVA) (r = 0.29; 95% CI, 0.14 to 0.43) and preoperative intermetatarsal angle (IMA) (r = 0.13; 95% CI, 0.00 to 0.27) showed a moderate positive relationship with recurrence. Postoperative HVA (r = 0.57; 95% CI, 0.21 to 0.94) and sesamoid position (r = 0.46; 95% CI, 0.31 to 0.60) showed strong relationships with recurrence. In conclusion, preoperative HVA, IMA, and postoperative HVA and sesamoid position are significant risk factors for HV recurrence, and the association of these factors with recurrence is affected by age.

The Biomechanical Relationship between Hallux Valgus Deformity and Metatarsal Pain

Metatarsal pain is a common pathological outcome in patients with a hallux valgus (HV) deformity. However, the relationship between the degree of HV deformity and metatarsal pain has not been systematically examined. The purpose of the present study was to investigate the correlation between metatarsal pain and the degree of HV deformity. Between October 2017 and September 2018, 512 HV patients (944 feet) participated in an evaluation of their HV angle (HVA) using X-ray images. The participants were divided into four groups corresponding to their HVA (<15°, 15° to 20°, 21° to 40°, or >40°). Load rate, impulse, contact duration, and contact area were measured and recorded as dynamic gait parameters using the RsScan system. Data were evaluated using SPSS statistical software. The visual analog scale (VAS) was used to assess metatarsal pain. For the four HV deformity groups, the peak value of impulse and contact duration was concentrated on the second and third metatarsals (Meta2 and Meta3) (P < 0.05); contact area was also shown on metatarsals 1, 2, and 5 (P < 0.05). Metatarsal pain on Meta2 had the highest VAS score (VAS: 6.57), followed by Meta3 (Mean VAS: 5.72). In the HV > 40° group, the load location on Meta2 was transferred to Meta1. The percent of pain attributed to Meta2 and Meta3 was also increased in this group. These findings illustrated that metatarsal pain was primarily located on Meta2 and Meta3 in the different degrees of HV deformity. This information can provide the location to target for pain relief and help guide further rehabilitation.

Detailed analysis of the transverse arch of hallux valgus feet with and without pain using weightbearing ultrasound imaging and precise force sensors

Background

Hallux valgus is the most common forefoot deformity and affects the transverse arch structure and its force loading patterns. This study aims to clarify the differences in the transverse arch structure and the force under the metatarsal heads individually, between normal feet and hallux valgus feet, and between hallux valgus feet with pain and without pain. We further test the association between the parameters of the transverse arch and hallux valgus angle and between the parameters and pain in hallux valgus.

Methods

Women’s feet (105 feet) were divided into normal group (NORM) and hallux valgus group (HVG); and further into subgroups: hallux valgus without pain (HV Pain (-)) and hallux valgus with pain (HV Pain (+)). Transverse arch height and metatarsal heads height were measured using weight-bearing ultrasound imaging. Force under the metatarsal heads was measured using force sensors attached directly on the skin surface of the metatarsal heads. The measurements were taken in three loading positions: sitting, quiet standing and 90% weight shift on the tested foot. Differences between the groups were compared using Student t-test and Wilcoxon Exact test. Multivariate logistic analysis with adjustment for physical characteristics was also conducted.

Results

Transverse arch height was significantly higher in HVG than in NORM in all positions; there were no significant differences between HV Pain (+) and HV pain (-). Lateral sesamoid was significantly higher in HVG and HV Pain (+) than in NORM and HV Pain (-) respectively when bearing 90% of the body weight unilaterally. There was a trend of higher forces under the medial forefoot without significant difference. Transverse arch height and lateral sesamoid height were associated with the hallux valgus angle, while lateral sesamoid height was associated with forefoot pain in hallux valgus deformity.

Conclusions

This study shows the differences in the transverse arch structure between normal feet and feet with hallux valgus, and between hallux valgus feet with and without pain. This finding is noteworthy when considering future treatments of painful feet, notably the height of the lateral sesamoid which seems to play a role in forefoot pain.