Comparison of Plantar Pressure Distribution Between Postoperative Hallux Valgus Feet and Healthy Feet

Immediate effect of hallux valgus surgery on the biomechanical behavior of the first ray

BACKGROUND

The surgical treatment of hallux valgus (HV) deformity has been the subject of countless publications but few focus on the altered windlass mechanism or analyze the biomechanical behavior immediately after surgery.

METHODS

Patients treated for HV between January and March 2023 were included. The surgery consisted of a L-reverse first metatarsal osteotomy. To analyze the windlass mechanism we record two different measurements; the isolated first metatarsophalangeal joint (MTPJ) dorsiflexion angle (IDA) and dynamic plantarization of the first metatarsal head when performing first MTPJ dorsiflexion imprinting a mark on a modeling foam.

RESULTS

A total of 30 patients diagnosed with symptomatic HV were included. In all patients, a change in the IDA angle was evident, being overall statistically significant. About modeling foam imprinted mark, all measurements, in all planes of space, had a clear tendency to increase, which turned out to be statistically significant (p < 0.001).

CONCLUSIONS

An altered windlass mechanism may be successfully recovered immediately after hallux valgus deformity surgery. This could be evinced by an indirect measurement analyzing the imprint of the head of the first metatarsal in a modeling foam and the IDA.

LEVELS OF EVIDENCE II

None.

Plantar Pressure Distribution Before and After Surgery for Lesser Metatarsophalangeal Joint Dislocation With Hallux Valgus

Hallux valgus surgery and open reduction of the lesser metatarsophalangeal joints with metatarsal shortening osteotomy help treat severe hallux valgus concomitant with the lesser metatarsophalangeal joint dislocation; however, pre- and postoperative plantar pressure distribution and its effect on the foot remain unclear. The pre- and postoperative groups comprised 16 patients with moderate-to-severe symptomatic hallux valgus with lesser metatarsophalangeal joint dislocation. All feet underwent open reduction and collateral ligament reconstruction of the second metatarsophalangeal joint and proximal metatarsal shortening osteotomy under the second metatarsal with proximal osteotomy of the first metatarsal. Twenty healthy participants (20 feet) were included in the control group. The plantar pressure distribution was determined by measuring the peak pressure, maximum force, contact area, and force-time integral for 12 regions. Under the second toe, all measurements in the preoperative group were significantly lower than those of the control group. The peak pressure, maximum force, and contact area of the postoperative group were significantly greater than those of the preoperative group. However, no differences were observed between the postoperative and control groups. Under the second metatarsal head, the peak pressure of the preoperative group was significantly higher than that of the control group. The peak pressure of the postoperative group was significantly lower than that of the preoperative group and showed no differences from the control group. Open reduction and collateral ligament reconstruction of the lesser metatarsophalangeal joints and proximal metatarsal shortening osteotomy with proximal osteotomy of the first metatarsal in hallux valgus with lesser metatarsophalangeal joints dislocation cases may improve operative outcomes, including favorable foot function.

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.

Footsteps required for reliable and valid in-shoe plantar pressure assessment during gait per foot region in people with hallux valgus

BACKGROUND

Plantar pressure assessment is commonly performed to identify pathognomonic gait characteristics and evaluate therapeutics against them in people with various foot disorders. Little is known about the reliability and validity of this assessment in people with hallux valgus (HV) per foot region.

RESEARCH QUESTION

This study aimed to assess the reliability and validity of the in-shoe plantar pressure measurement method during gait in people with HV and the required number of footsteps, as an intra-subject sample size, to ensure a reliable and valid use of this method.

METHODS

With an inserted disposable insole plantar pressure sensor in shoes, 17 females with HV (HV angle > 15°) completed three gait trials over the ground at a comfortable speed. Peak plantar pressure data and its distribution in 15 stance phases on the foot clinically diagnosed with HV in each participant were extracted by dividing the foot into eight regions. The intraclass correlation coefficient per foot region and the number of footsteps required to produce a valid peak plantar pressure and distribution (intraclass correlation coefficient > 0.90) were used to measure reliability. Based on the limit of agreement analysis, the coefficient of variation between the averaged value from each incremental footstep (2-14 footsteps) and 15 reference footsteps was calculated.

RESULTS

The intraclass correlation coefficient of plantar pressure assessment with the in-shoe sensor was 0.606-0.847 in the eight foot regions in people with HV. Additionally, the number of steps required for a valid assessment ranged from two to nine. Hence, the application of averaged values from more than nine footsteps is recommended for this evaluation.

SIGNIFICANCE

This reference sample size is intended to be used in future studies and clinical settings to determine the efficacy of HV treatment.

Immediate Effect of Customized Foot Orthosis on Plantar Pressure and Contact Area in Patients with Symptomatic Hallux Valgus

Foot orthotics are recommended for the treatment of hallux valgus. The effects of customized foot orthoses (FOs) designed with both medial longitudinal and transverse arch supports are poorly understood, however. This study aimed to investigate the immediate effect of customized FOs on the plantar pressure and contact area in patients with symptomatic hallux valgus. We recruited 18 patients with a mean hallux valgus angle of 27.3 ± 11.1°. Plantar pressure while walking with FOs or flat insoles (FIs) was monitored with a wireless in-shoe plantar pressure-sensing system. Peak pressure (PP), peak force (PF), pressure-time integral (PTI), force-time integral (FTI), and contact area with FOs and FIs were compared. The PF, PTI, and FTI of the midfoot were significantly higher (p < 0.05), and the PP and PTI of the rearfoot were significantly lower (p < 0.05) with the FOs than the FIs. The FOs significantly increased the contact area of the midfoot and rearfoot (p < 0.05) and reduced the contact area of the forefoot (p < 0.05). These results suggest that customized FOs redistribute plantar pressure and the contact area of the midfoot and rearfoot, improving the functional support of the midfoot for patients with hallux valgus.

Plantar pressure distribution in hallux valgus feet after a first metatarsal proximal crescentic osteotomy with a lesser metatarsal proximal shortening osteotomy

BACKGROUND

Plantar pressure distribution after the first metatarsal proximal crescentic osteotomy (FMPCO) with lesser metatarsal proximal shortening osteotomy (LMPSO) for hallux valgus with metatarsalgia has not been previously described.

METHODS

The pre- (Pre) and postoperative (Post) groups comprised of 18 patients who underwent unilateral FMPCO with LMPSO; fifteen healthy volunteers constituted the control (C) group. For each of the 10 regions, peak pressure (Peak-P), maximum force (Max-F), contact time (Con-T), contact area (Con-A), and force-time integral (FTI) were measured.

RESULTS

The mean Peak-P of the second metatarsal head was significantly lower in the Post group than the Pre group. The mean Peak-P, Max-F, Con-T, and FTI were not significantly different between the Post and C groups. The mean Con-A was significantly lower in the Post group than the C group.

CONCLUSION

FMPCO with LMPSO may improve the plantar pressure of the central forefoot comparable to healthy subjects.