Changes in calcaneal pitch and heel fat pad thickness in static weight bearing radiographs while wearing shoes with arch support and heel cup orthotics

Comparing lateral plantar process trabecular structure to other regions of the human calcaneus

Investigating skeletal adaptations to bipedalism informs our understanding of form-function relationships. The calcaneus is an important skeletal element to study because it is a weight-bearing bone with a critical locomotor role. Although other calcaneal regions have been well studied, we lack a clear understanding of the functional role of the lateral plantar process (LPP). The LPP is a bony protuberance on the inferolateral portion of the calcaneus thought to aid the tuberosity in transmission of ground reaction forces during heel-strike. Here, we analyze LPP internal trabecular structure relative to other calcaneal regions to investigate its potential functional affinities. Human calcanei (n = 20) were micro-CT scanned, and weighted spherical harmonic analysis outputs were used to position 251 volumes of interest (VOI) within each bone. Trabecular thickness (Tb.Th), spacing (Tb.Sp), degree of anisotropy (DA), and bone volume fraction (BV/TV) were calculated for each VOI. Similarities in BV/TV and DA (p = 0.2741) between the LPP and inferior tuberosity support suggestions that the LPP is a weight-bearing structure that may transmit forces in a similar direction. The LPP significantly differs from the inferior tuberosity in Tb.Th and Tb.Sp (p < 0.05). Relatively thinner, more closely spaced trabeculae in the LPP may serve to increase internal surface area to compensate for its relatively small size compared to the tuberosity. Significant differences in all parameters between LPP and joint articular surfaces indicate that trabecular morphology is differently adapted for the transmission of forces associated with body mass through joints.

Analysis of Diabetic Foot Deformation and Plantar Pressure Distribution of Women at Different Walking Speeds

Official guidelines state that suitable physical activity is recommended for patients with diabetes mellitus. However, since walking at a rapid pace could be associated with increased plantar pressure and potential foot pain, the footwear condition is particularly important for optimal foot protection in order to reduce the risk of tissue injury and ulceration of diabetic patients. This study aims to analyze foot deformation and plantar pressure distribution at three different walking speeds (slow, normal, and fast walking) in dynamic situations. The dynamic foot shape of 19 female diabetic patients at three walking speeds is obtained by using a novel 4D foot scanning system. Their plantar pressure distributions at the three walking speeds are also measured by using the Pedar in-shoe system. The pressure changes in the toes, metatarsal heads, medial and lateral midfoot, and heel areas are systematically investigated. Although a faster walking speed shows slightly larger foot measurements than the two other walking speeds, the difference is insignificant. The foot measurement changes at the forefoot and heel areas, such as the toe angles and heel width, are found to increase more readily than the measurements at the midfoot. The mean peak plantar pressure shows a significant increase at a faster walking speed with the exception of the midfoot, especially at the forefoot and heel areas. However, the pressure time integral decreases for all of the foot regions with an increase in walking speed. Suitable offloading devices are essential for diabetic patients, particularly during brisk walking. Design features such as medial arch support, wide toe box, and suitable insole material for specific area of the foot (such as polyurethane for forefoot area and ethylene-vinyl acetate for heel area) are essential for diabetic insole/footwear to provide optimal fit and offloading. The findings contribute to enhancing the understanding of foot shape deformation and plantar pressure changes during dynamic situations, thus facilitating the design of footwear/insoles with optimal fit, wear comfort, and foot protection for diabetic patients.

Decision Tree-Based Foot Orthosis Prescription for Patients with Pes Planus

Pes planus, one of the most common foot deformities, includes the loss of the medial arch, misalignment of the rearfoot, and abduction of the forefoot, which negatively affects posture and gait. Foot orthosis, which is effective in normalizing the arch and providing stability during walking, is prescribed for the purpose of treatment and correction. Currently, machine learning technology for classifying and diagnosing foot types is being developed, but it has not yet been applied to the prescription of foot orthosis for the treatment and management of pes planus. Thus, the aim of this study is to propose a model that can prescribe a customized foot orthosis to patients with pes planus by learning from and analyzing various clinical data based on a decision tree algorithm called classification and regressing tree (CART). A total of 8 parameters were selected based on the feature importance, and 15 rules for the prescription of foot orthosis were generated. The proposed model based on the CART algorithm achieved an accuracy of 80.16%. This result suggests that the CART model developed in this study can provide adequate help to clinicians in prescribing foot orthosis easily and accurately for patients with pes planus. In the future, we plan to acquire more clinical data and develop a model that can prescribe more accurate and stable foot orthosis using various machine learning technologies.

Calcaneal offset index to measure hindfoot alignment in pes planus

INTRODUCTION

Pes planus is a common three-dimensional (3D) deformity characterised by forefoot abduction, the collapse of the medial longitudinal arch, and hindfoot valgus. Several radiological measurements such as anteroposterior talocalcaneal angle (Kite's) and 'Calcaneal pitch angle' (CPA) exist to calculate the degree of hindfoot alignment in these patients with variable intra- and interobserver reliability.

OBJECTIVE

To describe a new radiological ancillary method of measuring hindfoot alignment, the calcaneal offset index (COI).

MATERIAL AND METHODS

Anteroposterior (mortise) and lateral view weight-bearing (WB) ankle radiographs of 200 consecutive patients referred for foot and ankle pain were reviewed. Demographic details, clinical indication, and COI calculation were undertaken on the mortise view along with the measurement of CPA for each patient. A one-way analysis of variance (ANOVA) was performed. Intraclass correlation coefficient (ICC) analysis was evaluated to assess the intraclass reliability between observers.

RESULTS

There was a female preponderance of 2:1 in the study population with a mean age of 51.21 years (13-86 years). The calcaneal offset was increased in pes planus (hindfoot valgus). The p-value was 0.00023 on ANOVA. The COI gave an excellent interobserver correlation with ICC of 0.9 and moderate intraobserver reliability on the ICC analysis of 0.55.

CONCLUSION

The COI can be an additional index of measuring hindfoot alignment in patients with pes planus. Contrary to the traditional angular measurements, this linear transverse plane measure is easier to calculate and reproducible. COI measurement has shown moderate intraobserver reliability but excellent interobserver reliability.

Arch-Support Insoles Benefit the Archery Performance and Stability of Compound Archers

The purpose of this study was to analyze the effects of the use of arch-support insoles on the archery performance and center of plantar pressure (CoP) excursion in compound archers. Fifteen highly skilled compound archers were the subjects. A pressure plate was used to measure the CoP excursion and percentage distribution of plantar pressure. The parameters were compared between archers wearing flat and arch-support insoles using a paired-sample t-test. The results demonstrated that the shooting score in archers wearing the arch-support insole was significantly greater than in those wearing the flat insoles. The CoP excursion of the left foot, right foot, and both feet in archers wearing the arch-support insole were significantly smaller than in those wearing the flat insole. The distributed percentage of the plantar pressure showed that the arch-support insole significantly reduced the plantar pressure in the left posterior zone by 3.54% compared with the flat insole, and increased the plantar pressure in the right anterior zone by 2.54%. The principal conclusion was that compound archers wearing arch-support insoles during the arrow-release process can reduce the CoP excursion of the foot and increase their shooting score. The plantar pressure was distributed evenly in arch-support insoles.

Staged Ilizarov distraction histogenesis and corrective reconstruction for severe malunited calcaneal fractures

PURPOSE

Severe calcaneal malunion is a clinical conundrum for the difficulty of calcaneal reconstruction without soft tissue complications. The aim of this study is to introduce the treatment strategy and preliminary results of staged Illizarov distraction histogenesis and corrective reconstruction for severe malunion of calcaneal fractures.

METHODS

From June 2014 to May 2020, 14 patients with severe calcaneal malunion treated with the staged strategy were retrospectively analyzed. At the first stage, calcaneal osteotomy and external fixation with Ilizarov frame were performed. The restoration of the approximate configuration of calcaneus and the expansion of contractural soft tissue were achieved by gradual calcaneal distraction. At the second stage, corrective reconstruction was performed and autogenous iliac crest bone graft was used. Clinical and radiographic outcomes were evaluated at final follow-up.

RESULTS

The average time of Ilizarov distraction and total fixation was 21.4 days and 41.0 days at first-stage treatment. At a mean follow-up of 33.1 months, the average American Orthopaedic Foot and Ankle Society (AOFAS) ankle and hindfoot score increased significantly from 24.0 to 72.4 (p < 0.01). And the mean visual analogue scale (VAS) score had improved remarkably from 8.2 to 2.4 (p < 0.01). Radiographs showed that talocalcaneal height, calcaneal width, calcaneal tuberosity height, hindfoot alignment angle, and talar declination angle were improved to a great extent (p < 0.01). Only one patient had minor pin site infection at first-stage treatment and one got superficial wound infection after second-stage surgery. No wound dehiscence, skin necrosis, or deep infection occurred.

CONCLUSION

Staged Ilizarov distraction histogenesis and corrective reconstruction is a safe and effective treatment strategy for reducing soft tissue complications and improving reconstruction results in surgical correction of severe calcaneal malunion.