Flatfoot over the centuries: the background of current conservative and operative treatments

Influence of the transverse tarsal arch on radiological components of progressive collapsing foot deformity

The importance of the transverse tarsal arch (TTA) has recently been extensively reevaluated and has even been considered to play a greater role in foot stability than the medial longitudinal arch (MLA). However, the relevance of this observation in the context of common clinical foot disorders, such as progressive collapsing foot deformity (PCFD), has not yet been fully clarified. In this biomechanical study, we examined ten pairs of human cadaveric feet by serial weight-bearing cone-beam computed tomography under controlled loading using a custom-designed testing machine. The MLA and TTA were transected separately, alternating the order in two study groups. A semiautomated three-dimensional evaluation of their influence on three components of PCFD, namely collapse of the longitudinal arch (sagittal Meary's angle), hindfoot alignment (sagittal talocalcaneal angle), and forefoot abduction (axial Meary's angle), was performed. Both arches had a relevant effect on collapse of the longitudinal arch, however the effect of transecting the MLA was stronger compared to the TTA (sagittal Meary's angle, 7.4° (95%CI 3.8° to 11.0°) vs. 3.2° (95%CI 0.5° to 5.9°); p = 0.021). Both arches had an equally pronounced effect on forefoot abduction (axial Meary's angle, 4.6° (95%CI 2.0° to 7.1°) vs. 3.0° (95%CI 0.6° to 5.3°); p = 0.239). Neither arch showed a consistent effect on hindfoot alignment. In conclusion, weakness of the TTA has a decisive influence on radiological components of PCFD, but not greater than that of the MLA. Our findings contribute to a deeper understanding and further development of treatment concepts for flatfoot disorders.

Comparison of the Acute Postoperative Complications Between Isolated Talonavicular Versus Talonavicular and Subtalar (Double) Arthrodesis in Flatfoot Deformity

BACKGROUND

Both isolated talonavicular arthrodesis and talonavicular and subtalar (such as double) arthrodesis can be effective treatments for adult-acquired flatfoot deformity (AAFD) with good success rates, but double arthrodesis has become more commonly performed in recent years. The purpose of this study is to evaluate whether isolated talonavicular versus talonavicular and subtalar arthrodesis led to significantly different 30-day postoperative complication rates in patients with AAFD.

METHODS

We performed a retrospective review to identify a large cohort of adult patients with the diagnosis of AAFD or posterior tibial tendon deformity (PTTD) who underwent isolated talonavicular or talonavicular and subtalar arthrodesis between 2006 and 2020 from the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP). To investigate whether there was a difference in complication rate between the 2 surgical cohorts, we estimated logistic regression models and log-binomial models on each of the outcomes while also adjusting for sex and age.

RESULTS

We found that there was no significant difference in the rate of major complications (P = .567) or readmissions (P = .567) between patients who underwent isolated talonavicular versus talonavicular and subtalar arthrodesis for AAFD. However, there was a significantly higher rate of minor complications in patients who underwent isolated talonavicular arthrodesis when compared with patients who underwent talonavicular and subtalar arthrodesis (P = .009).

CONCLUSION

This study found that there was no increased risk of 30-day postoperative complications or readmissions with talonavicular and subtalar arthrodesis when compared with isolated talonavicular arthrodesis for AAFD. In addition, there was no increased risk of major complications for talonavicular and subtalar arthrodesis when compared with isolated talonavicular arthrodesis, and isolated talonavicular arthrodesis actually carried a higher risk of minor complications for this surgical cohort. This may provide valuable information for surgeons considering surgical treatment for a particular case of AAFD.

LEVEL OF EVIDENCE

Level III.

Morphological and evolutionary insights into the keystone element of the human foot's medial longitudinal arch

The evolution of the medial longitudinal arch (MLA) is one of the most impactful adaptations in the hominin foot that emerged with bipedalism. When and how it evolved in the human lineage is still unresolved. Complicating the issue, clinical definitions of flatfoot in living Homo sapiens have not reached a consensus. Here we digitally investigate the navicular morphology of H. sapiens (living, archaeological, and fossil), great apes, and fossil hominins and its correlation with the MLA. A distinctive navicular shape characterises living H. sapiens with adult acquired flexible flatfoot, while the congenital flexible flatfoot exhibits a 'normal' navicular shape. All H. sapiens groups differentiate from great apes independently from variations in the MLA, likely because of bipedalism. Most australopith, H. naledi, and H. floresiensis navicular shapes are closer to those of great apes, which is inconsistent with a human-like MLA and instead might suggest a certain degree of arboreality. Navicular shape of OH 8 and fossil H. sapiens falls within the normal living H. sapiens spectrum of variation of the MLA (including congenital flexible flatfoot and individuals with a well-developed MLA). At the same time, H. neanderthalensis seem to be characterised by a different expression of the MLA.

Pediatric Flatfoot: Is There a Need for Surgical Referral?

Pediatric foot deformities are a common finding, concerning up to 44% of preschool aged children. The absence of accepted international guidelines, as well as heterogeneity in definitions and measurements, makes management of pediatric flatfoot a challenge, and decisions surrounding specialized care referral confusing and biased. The objective of this narrative review is to provide guidance to primary care physicians treating these patients. A non-systematic review of the literature regarding the development, etiology, and clinical and radiographic assessment of flatfeet using the PubMed and Cochrane Library databases was performed. The exclusion criteria for the review were adult populations, papers detailing the outcome of a specific surgical procedure, and publications prior to 2001. The included articles showed great heterogeneity in definition and proposed management, which makes the study of pediatric flatfoot challenging. Flatfoot is a common finding in children under 10 years old, and should not be considered pathological unless stiffness or functional limitation are present. Surgical referral should be reserved to children with stiff or painful flatfoot, while simple observation is indicated for flexible, asymptomatic flatfeet.