Loading pattern of postoperative hallux valgus feet with and without transfer metatarsalgia: a case control study

Three-dimensional gait analysis of orthopaedic common foot and ankle joint diseases

Walking is an indispensable mode of transportation for human survival. Gait is a characteristic of walking. In the clinic, patients with different diseases exhibit different gait characteristics. Gait analysis describes the specific situation of human gait abnormalities by observing and studying the kinematics and dynamics of limbs and joints during human walking and depicting the corresponding geometric curves and values. In foot and ankle diseases, gait analysis can evaluate the degree and nature of gait abnormalities in patients and provide an important basis for the diagnosis of patients' diseases, the correction of abnormal gait and related treatment methods. This article reviews the relevant literature, expounds on the clinical consensus on gait, and summarizes the gait characteristics of patients with common ankle and foot diseases. Starting from the gait characteristics of individuals with different diseases, we hope to provide support and reference for the diagnosis, treatment and rehabilitation of clinically related diseases.

Forefoot Function after Hallux Valgus Surgery: A Systematic Review and Meta-Analysis on Plantar Load Measurement

While hallux valgus (HV) surgeries are useful for correcting skeletal alignment problems, their effects on plantar load, which reflects forefoot functions, are less understood. The objective of this study is to conduct a systematic review and meta-analysis on the plantar load change after HV surgeries. A systematic search of Web of Science, Scopus, PubMed, CENTRAL, EMBASE, and CINAHL was performed. Studies that assessed the pre- and post-operative plantar pressure of HV patients undergoing surgeries and reported load-related parameters over the hallux, medial metatarsal, and/or central metatarsal regions were included. Studies were appraised by using the modified NIH quality assessment tool for before-after study. Studies suitable for meta-analysis were pooled with the random-effects model, using the standardized mean difference of the before-after parameters as an effect measure. Twenty-six studies containing 857 HV patients and 973 feet were included for the systematic review. Meta-analysis was conducted on 20 of them, and most studies did not favor HV surgeries. Overall, HV surgeries reduced the plantar load over the hallux region (SMD -0.71, 95% CI, -1.15 to -0.26), indicating that forefoot function worsened after surgeries. For the other five outcomes, the overall estimates were not statistically significant, indicating that surgeries did not improve them either. There was substantial heterogeneity among the studies, which in most cases could not be resolved by pre-planned subgroup analyses by surgical classification, year of publication, median age of patients, and length of follow-up. Sensitivity analysis removing lower-quality studies showed that the load integrals (impulse) over the central metatarsal region significantly increased (SMD 0.27, 95% CI, 0 to 0.53), indicating that surgeries increased the risk of transfer metatarsalgia. There is no solid evidence that HV surgeries could improve forefoot functions from a biomechanical point perspective. Currently available evidence even suggests that surgeries might reduce the plantar load over the hallux and adversely affect push-off function. The reasons behind and the effectiveness of alternative surgical methods warrant further investigation.

Establishment and Validation of a Predictive Nomogram for Hallux Valgus with Pain Under the Second Metatarsal

Objective

To investigate the risk factors for hallux valgus complicated with pain under the second metatarsal and construct an effective model and method for predicting hallux valgus complicated with pain under the second metatarsal based on risk factors.

Methods

A total of 545 patients with hallux valgus who were admitted to our hospital were divided randomly into a training set and a validation set. The demographic characteristics, imaging indices and gait test indices of the patients were collected. The risk factors were identified by univariate and multivariate logistic regression analyses. A risk prediction model for hallux valgus with pain under the second metatarsal was established, and the area under the curve (AUC) of the receiver operating characteristic and a decision curve analysis were used for verification and identification. The value of the model was tested in the verification group.

Results

Second metatarsal length, second metatarsal peak pressure, hallux valgus angle (HVA), intermetatarsal angle 1–2 (IMA1–2) and weight were the risk factors for hallux valgus complicated with pain under the second metatarsal. Based on the weighting of these seven risk factors, a prediction model was established. The AUC of the prediction model was 0.84 (95% confidence interval [CI]: 0.802~0.898, P < 0.05), and the results of a Hosmer–Lemeshow test showed a good degree of calibration (χ² = 10.62, P > 0.05). The internal validation of the AUC was 0.83 (95% CI: 0.737–0.885, P < 0.05). The model had obvious net benefits when the threshold probability was 10%–70%.

Conclusion

Second metatarsal length, second metatarsal peak pressure, HVA, IMA1–2 and weight were the risk factors for hallux valgus combined with second metatarsal pain. The risk prediction model for hallux valgus complicated with pain under the second metatarsal based on these seven variables was proven effective.

Level of Evidence

Level III, retrospective comparative study.

Iatrogenic second transfer metatarsalgia and the first metatarsal shortening and elevation after Scarf osteotomy

BACKGROUND

Transfer metatarsalgia is a potential complication of hallux valgus surgery. This study aimed to investigate the shortened first metatarsal length and elevation and to compare groups with and without second transfer metatarsalgia after Scarf osteotomy.

METHODS

The first metatarsal length of 123 feet was measured via the Maestro's method using the metatarsal axial length and the relative second metatarsal protrusion to the first metatarsal. Metatarsal elevation was measured using the first metatarsal angle.

RESULTS

Second transfer metatarsalgia occurred after Scarf osteotomy in 11 (8.9%) feet. When baseline characteristics were considered in propensity score matching, the 11 feet were compared with the 33 feet in the control group. The group with transfer metatarsalgia showed a more shortened first metatarsal axial length (-4.1 ± 1.8 mm vs. -2.5 ± 2.2 mm, p = 0.032), a significantly longer relative second metatarsal protrusion (+5.8 ± 2.6 mm vs. +1.2 ± 2.6 mm, p < 0.001), and a significantly lower first metatarsal angle (18.1 ± 4.3° vs. 21.5 ± 4.0°, p = 0.012) than the control group postoperatively.

CONCLUSIONS

To avoid iatrogenic transfer metatarsalgia, first metatarsal length shortening should be minimized to at least less than 4.0 mm. Furthermore, the metatarsal parabola should be retained.

Hallux valgus with and without metatarsalgia in women: a matched-cohort study of plantar pressure measurements

BACKGROUND

Few previous studies focused on plantar loading patterns in HV patients with metatarsalgia. Are there any differences in plantar pressure measurements in women with HV with and without metatarsalgia?

METHODS

A prospective matched-cohort study was designed to analyze plantar pressure measurements in women with HV with and without metatarsalgia from January 2017 to December 2019. The inclusion criteria were age over 18 years old, women, diagnosis of HV with metatarsalgia. Control group had the same inclusion criteria, except metatarsalgia. Patient-reported outcomes scores included American Orthopedic Foot and Ankle Society Score (AOFAS), and Visual Analog Scale (VAS). Radiographic data were obtained according to the guidelines of the AOFAS Committee on Angular Measurements. Plantar pressure measurements were performed using a platform.

RESULTS

Forty-seven patients met the inclusion criteria. An age-, BMI-, and hallux valgus angle-matched cohort of 47 patients were also selected. There were no statistically significant differences in demographic data and radiographic assessment. HV with metatarsalgia group showed greater values in peak and mean force, peak and mean pressure, and pressure-time integral under toes and metatarsal heads. These differences reached statistically significant in mean force (p = 0.009) and peak force (p = 0.003) under T1; mean pressure (p = 0.01) and peak pressure (p = 0.04) under T1; and mean force (p = 0.003) under MH1. The binary logistic regression analysis showed mean force under T1 as the most associated plantar pressure measurement with the presence of metatarsalgia. C-statistic was 0.66. Mean force > 35 N had a 70% of sensitivity and a 57% of specificity as a cut-off value for the presence of metatarsalgia.

CONCLUSION

HV patients with metatarsalgia had greater values in plantar pressure measurements. Mean force under T1 could be used as a plantar pressure measurement to predict metatarsalgia.

Planning tool for first metatarsal length in hallux valgus surgery

BACKGROUND

The precise planning of metatarsal (MT) I length in hallux valgus surgery is important. However, currently no tool exists which allows the surgeon to reliably predict this parameter.

METHODS

30 virtual 3-dimensional hallux valgus surgeries were performed on varied deformation models based on cadaveric feet scans. The shortening of the first ray during distal metatarsal I osteotomy for different osteotomy angles were measured. An algebraic 2-dimensional calculation was done and compared to the results obtained from the 3-dimensional models.

RESULTS

Inadvertent shortening of the first metatarsal bone can be as much as 8 mm depending on the amount of intermetatarsal angle (IMA) correction and osteotomy angle. Comparison of the 3 dimensional simulations and the 2 dimensional model resulted in a very strong correlation (R > 0.99 p < 0.00001). Based on our findings an anterior pointing osteotomy of approximately 10° is necessary to restore the length in distal metatarsal I hallux valgus surgery.

CONCLUSION

A slight misdirection of the osteotomy plane in distal hallux valgus surgery may result in relevant unwanted alterations in first metatarsal bone length and triangulation by eye is insufficient in this complex geometrical situation without appropriate planning. The present study provides surgeons a practical tool to plan and control the change of first metatarsal length during hallux valgus procedure through exact orientation of the osteotomy angle. If no alteration of length is intended, it may be generalized that an anterior direction of the cut relative to the second metatarsal bone will preserve the length of the first metatarsal bone.

Effect of Severity of Deformity on Clinical Outcomes of Scarf Osteotomies

BACKGROUND

Literature is sparse on whether severity of hallux valgus affects outcomes of surgery. We thus aimed to evaluate the impact of hallux valgus severity on the clinical outcomes of surgery.

METHODS

83 consecutive scarf osteotomies performed by a single surgeon for symptomatic hallux valgus between 2007 and 2011 were divided into 3 groups (mild, moderate, and severe) based on severity of their preoperative hallux valgus using the hallux valgus and intermetatarsal angles. Outcomes were assessed using the visual analog scale (VAS) for pain, 36-Item Short Form Health Survey physical functioning (SFPF) and mental health (SFMH) subscales, and American Orthopaedic Foot & Ankle Society (AOFAS) ankle-hindfoot scores. These were assessed preoperatively and at 6 months and 2 years postoperatively. Patient satisfaction was assessed at 6 months and 2 years postoperatively. Eleven (13.2%), 54 (65.1%), and 18 (21.7%) feet were in the mild, moderate, and severe groups, respectively.

RESULTS

There was no difference in preoperative VAS, SFPF, SFMH and AOFAS scores between the groups except for AOFAS scores for the second toe, which were poorer with increasing hallux valgus. Postoperatively, there was improvement across all outcome scores. VAS and AOFAS showed excellent scores, and patient satisfaction was high across all 3 groups (88.9%, 89.4%, and 86.7%). The severe group had slightly lower SFPF scores at 6 months (mild, 81.1; moderate, 84.0; severe, 74.3; P = .031) and 2 years postoperatively (mild, 93.4; moderate, 89.7; severe, 76.4; P = .005), and slightly poorer second toe scores for VAS (mild, 0.0; moderate, 0.1; severe, 1.2; P = .017) and AOFAS (mild, 94.7; moderate, 93.5; severe, 83.4; P = .043) at 2 years postoperatively. All other scores including patient satisfaction showed no between-group differences. Complication and revision rates between the groups were similar.

CONCLUSION

Surgery for symptomatic hallux valgus lead to excellent outcomes and high patient satisfaction regardless of severity of deformity.

LEVEL OF EVIDENCE

Level III, comparative series.

Impact of first metatarsal shortening on forefoot loading pattern: a finite element model study

Backgrounds

There has long been a consensus that shortening of the first metatarsal during hallux valgus reconstruction could lead to postoperative transfer metatarsalgia. However, appropriate shortening is sometimes beneficial for correcting severe deformities or relieving stiff joints. This study is to investigate, from the biomechanical perspective, whether and how much shortening of the first metatarsal could be allowed.

Methods

A finite element model of the human foot simulating the push-off phase of the gait was established. Progressive shortening of the first metatarsal from 2 to 8 mm at an increment of 2 mm were sequentially applied to the model, and the corresponding changes in forefoot loading pattern during push-off phase, especially the loading ratio at the central rays, was calculated. The effect of depressing the first metatarsal head was also investigated.

Results

With increasing shortening level of the first metatarsal, the plantar pressure of the first ray decreased, while that of the lateral rays continued to rise. When the shortening reaches 6 mm, the load ratio of the central rays exceeds a critical threshold of 55%, which was considered risky; but it could still be manipulated to normal if the distal end of the first metatarsal displaced to the plantar side by 3 mm.

Conclusions

During the first metatarsal osteotomy, a maximum of 6 mm shortening length is considered to be within the safe range. Whenever a higher level of shortening is necessary, pushing down the distal metatarsal segment could be a compensatory procedure to maintain normal plantar force distributions.