Biomechanical effects of Evans versus Hintermann osteotomy for treating adult acquired flatfoot deformity: a patient-specific finite element investigation.

BACKGROUND: Evans and Hintermann lateral column lengthening (LCL) procedures are both widely used to correct adult acquired flatfoot deformity (AAFD), and have both shown good clinical results. The aim of this study was to compare these two procedures in terms of corrective ability and biomechanics influence on the Chopart and subtalar joints through finite element (FE) analysis. METHODS: Twelve patient-specific FE models were established and validated. The Hintermann osteotomy was performed between the medial and posterior facets of the subtalar joint; while, the Evans osteotomy was performed on the anterior neck of the calcaneus around 10 mm from the calcaneocuboid joint surface. In each procedure, a triangular wedge of varying size was inserted at the lateral edge. The two procedures were then compared based on the measured strains of superomedial calcaneonavicular ligaments and planter facia, the talus-first metatarsal angle, and the contact characteristics of talonavicular, calcaneocuboid and subtalar joints. RESULTS: The Hintermann procedure achieved a greater correction of the talus-first metatarsal angle than Evans when using grafts of the same size, indicating that Hintermann had stronger corrective ability. However, its distributions of von-Mises stress in the subtalar, talonavicular and calcaneocuboid joints were less homogeneous than those of Evans. In addition, the strains of superomedial calcaneonavicular ligaments and planter facia of Hintermann were also greater than those of Evans, but both generally within the safe range (less than 6%). CONCLUSION: This FE analysis study indicates that both Evans and Hintermann procedures have good corrective ability for AAFD. Compared to Evans, Hintermann procedure can provide a stronger corrective effect while causing greater disturbance to the biomechanics of Chopart joints, which may be an important mechanism of arthritis. Nevertheless, it yields a better protection to the subtalar joint than Evans osteotomy. CLINICAL RELEVANCE: Both Evans and Hintermann LCL surgeries have a considerable impact on adjacent joints and ligament tissues. Such effects alongside the overcorrection problem should be cautiously considered when choosing the specific surgical method. LEVEL OF EVIDENCE: Level III, case-control study.

Biomechanical Effects of Subtalar Joint Fusion and Medial Ligament Reconstruction in Simulated Progressive Collapsing Foot Deformity.

BACKGROUND: The purpose of this study is to investigate the biomechanical effect of medial displacement calcaneal osteotomy (MDCO), subtalar joint fusion (SF), and medial ligament reconstruction (MLR: deltoid-spring ligament) in a severe flatfoot model. We hypothesized that (1) combination of MDCO and SF improves the tibiotalar and foot alignment in severe progressive collapsing foot deformity (PCFD) cadaver model. (2) However, if a residual valgus heel alignment remains after MCDO and SF, it can lead to increased medial ligament strain, foot malalignment, and tibiotalar valgus tilt, which will be mitigated by the addition of MLR. METHODS: Ten fresh-frozen cadaveric foot specimens were used to create a severe flatfoot model. The foot alignment changes, including the talo-first metatarsal angle in the axial and sagittal planes, subtalar angle, and tibiotalar angle in the coronal plane, were measured. The angles were measured at the initial condition, after creating the severe flatfoot model, and after each successive reconstructive procedure in the following order: (1) MDCO, (2) SF, and (3) MLR. RESULTS: Tibiotalar valgus tilt was decreased with the MDCO procedure: 4.4 vs 1.0 degrees (P = .04). Adding in situ SF to the MDCO led to increased tibiotalar tilt to 2.5 degrees was different from the initial condition (P = .01). Although the tibiotalar valgus tilt was significantly decreased after adding the MLR to the MDCO/SF procedure compared with the severe flatfoot model (0.8 vs 4.4 degrees, P = .03), no significant difference in the tibiotalar valgus tilt was observed between MDCO/SF and MDCO/SF with MLR. CONCLUSION: Our results demonstrated that MDCO significantly improved forefoot abduction and medial arch alignment, with no significant additional improvement observed with addition of SF. Following SF, a residual valgus heel alignment can contribute to subsequent tibiotalar valgus tilt. The addition of MLR did not show significantly decreased tibiotalar valgus tilt following SF. CLINICAL RELEVANCE: Residual valgus heel alignment after subtalar joint fusion in the surgical treatment of PCFD can lead to increased medial ligament strain. Although MLR might be considered for providing medial stability, it may not necessarily prevent the development of tibiotalar valgus tilt.

Does the Presence of Asymptomatic Flatfoot Deformity Impact the Clinical and Radiographic Outcomes of the Minimally Invasive Chevron and Akin Bunionectomy?

BACKGROUND: Flatfoot deformity is believed to play a role in hallux valgus development and recurrence. While symptomatic flatfoot deformity can be treated with separate procedures at the time of hallux valgus correction, the question remains whether the patient undergoing correction of a symptomatic hallux valgus deformity should have their asymptomatic flatfoot concurrently addressed. We aimed to investigate whether the presence of asymptomatic flatfoot influences patient-reported and radiographic outcomes of the minimally invasive chevron and Akin bunionectomy. METHODS: A total of 104 patients were included in this study. Forty-two asymptomatic patients met the radiographic criteria for flatfoot while 62 had a normal arch. Patient-reported outcomes were evaluated and compared between the two groups using validated PROMIS measures preoperatively and at a minimum one-year postoperatively. Radiographic outcomes including hallux valgus angle (HVA), intermetatarsal angle (IMA), Meary's angle, calcaneal pitch (CP), and talonavicular coverage angle (TNCA) were measured and compared preoperatively and minimum six-months postoperatively. RESULTS: Both groups demonstrated similar preoperative and postoperative PROMIS scores with significant improvements in physical function, pain interference, pain intensity, and global physical health. Preoperatively, HVA was similar between both groups, however the flatfoot group showed a greater IMA, Meary's angle, TNCA, and lower CP. Postoperatively, HVA and IMA were similar between groups, although patients in the flatfoot group retained a significantly greater Meary's angle, TNCA, and lower CP. Both groups showed significant improvements in HVA, IMA, and TNCA. CONCLUSION: Our study indicates that the minimally invasive chevron and Akin bunionectomy leads to improved clinical and radiographic hallux valgus outcomes without adversely impacting radiographic flatfoot parameters. Therefore, the MIS bunionectomy may be an effective option for hallux valgus correction in patients with mild, asymptomatic flatfoot. LEVEL OF EVIDENCE: Level III, retrospective cohort.

In silico comparative biomechanical analysis of oblique and chevron medial displacement calcaneal osteotomies for pes planus deformity.

BACKGROUND: Medializing displacement calcaneal osteotomy is commonly performed as part of reconstructive surgery for patients with valgus hindfoot and progressive pes planus deformity. Among several types of calcaneal osteotomies, the oblique and Chevron osteotomy patterns have been commonly described in the literature and gained popularity as they are easily reproducible through percutaneous techniques. Currently, there is scarce evidence in the literature on which cut pattern is superior in terms of stability. To investigate the impact of cut pattern and posterior fragment medialization level on foot biomechanics, computational methods are employed. METHODS: Ankle weightbearing computer tomography (CT) scans of seven patients diagnosed with stage II pes planus deformity are segmented and converted into 3D computational models. Oblique and Chevron osteotomy patterns are modeled independently for each patient. The posterior fragments are medially translated by 8-, 10- and 12-mm and subsequently fixated to the anterior calcaneus with two screws. A total of 42 models are exported to finite element software for biomechanical simulations. Among the investigated parameters, the higher stiffness and lower von Mises stress at the osteotomy interface and the screw site are assumed to be precursors of better stability. RESULTS: It is recorded that as the medialization level increases, the stiffness decreases, and overall stresses increase. Also, it is observed that the Chevron cut produces a stiffer construct while the overall stresses are lower, indicating better stability when compared to the oblique cut. The statistical comparisons of the relevant groups that support these trends are found to be significant (p < 0.05). CONCLUSION: Chevron osteotomy showed superior stability compared to the oblique osteotomy while underscoring the negative impact of increased medialization of the posterior fragment. CLINICAL RELEVANCE: Opting for a lower medialization level and implementing the Chevron technique may facilitate union and earlier weightbearing.

Minimally invasive surgery in medial displacement calcaneal osteotomy for acquired flatfoot deformity: a systematic review of the literature.

BACKGROUND: Minimally invasive surgery (MIS) in medial displacement calcaneus osteotomy (MDCO) has been proposed for surgical correction of adult-acquired flat foot deformity (AAFD) to reduce complications of open approaches. The aim of our study is to systematically analyze complications and the clinical and radiological results of MIS- MDCO. METHODS: A systematic review of the English literature was performed on 30th October 2023. Randomized controlled trials and non-randomized trials, cohort studies, case-control studies and case series concerning surgical correction of AAFD with MIS-MDCO and with at least 15 patients were included. Case reports, technical notes, animal or cadaveric studies were excluded. The quality and risk of bias of the studies included were evaluated using GRADE and MINORS systems. Complications rate, clinical and radiological results were inferred from the studies included. RESULTS: Nine articles were included. A total of 501 cases treated with MIS-MDCO were analysed with a mean follow-up of 11.9 ± 5.1 months. The reported wound infection rate was about 3% and sural neuropathy was rated about 1%. Only 4% of the cases required removal of the screw for pain. In the comparative studies (MIS versus Open MDCO), comparable clinical results but with significant differences (P < 0.001) in infection rates (1% versus 14%) and sural neuropathy (2% versus 1%) were observed. CONCLUSION: AAFD correction performed with MIS-MDCO, with the limitation of a poor quality and high risk of bias of the included studies, seems to provide good clinical results and high subjective satisfaction with a lower complication rate compared to open approach. Further high-quality long-term comparative studies could better clarify complications and clinical and radiological outcomes of the MIS technique in the treatment of AAFD. LEVEL OF EVIDENCE: Level IV.

Medializing Calcaneal Osteotomy for progressive collapsing foot deformity alters the three-dimensional subtalar joint alignment.

BACKGROUND: A medializing calcaneal osteotomy (MCO) is considered as one of the key inframalleolar osteotomies to correct progressive collapsing foot deformity (PCFD). While many studies were able to determine the post-operative hind- and midfoot alignment, alternations of the subtalar joint alignment remained obscured by superposition on plain radiography. Therefore, we aimed to assess the hind-, midfoot- and subtalar joint alignment pre- compared to post-operatively using 3D weightbearing CT (WBCT) imaging. METHODS: Seventeen patients with a mean age of 42 ± 17 years were retrospectively analyzed. Inclusion criteria consisted of PCFD deformity corrected by a medializing calcaneal osteotomy (MCO) as main procedure and imaged by WBCT before and after surgery. Exclusion criteria were patients who had concomitant calcaneal lengthening osteotomies, mid-/hindfoot fusions, hindfoot coalitions, and supramalleolar procedures. Image data were used to generate 3D models and compute the hindfoot (HA), midfoot (MA) - and subtalar joint (STJ) alignment in the coronal, sagittal and axial plane, as well as distance maps. RESULTS: Pre-operative measurements of the HA and MA improved significantly relative to their post-operative equivalents p < 0.05). The post-operative STJ alignment showed significant inversion (2.8° ± 1.7), abduction (1.5° ± 1.8), and dorsiflexion (2.3° ± 1.7) of the talus relative to the calcaneus (p < 0.05) compared to the pre-operative alignment. The displacement between the talus and calcaneus relative to the sinus tarsi increased significantly (0.6 mm±0.5; p < 0.05). CONCLUSION: This study detected significant changes in the sagittal, coronal, and axial plane alignment of the subtalar joint, which corresponded to a decompression of the sinus tarsi. These findings contribute to our clinical practice by demonstrating the magnitude of alteration in the subtalar joint alignment that can be expected after PCFD correction with MCO as main procedure.

Endoscopic assisted flexor digitorum longus transfer in flexible flatfoot.

BACKGROUND: Posterior tibial tendon insufficiency is the commonest cause of adult flexible flatfoot. Transfer of the flexor digitorum longus (FDL) has been described a therapeutic arsenal in flexible flat feet and posterior tibial tendon disorders. It is often combined with bony procedure (open or percutaneous calcaneal osteotomy). METHODS: We describe a technique and the steps endoscopic approach of FDL transfer. RESULTS: The procedure is able to be performed safely and reproducible under perfect viewing CONCLUSION: In the future with a clinical study investigating, we purpose the results of such surgery in a cohort of patients with flexible flatfoot. Level IV Therapeutic study: case serie. No funding was received for this research project.

Feasibility and safety of minimally invasive calcaneal osteotomy (MICO) through a medial approach: a case-control study.

INTRODUCTION: Minimally invasive calcaneal osteotomy (MICO) is already an established surgical procedure for correcting hindfoot deformities using a lateral approach. So far, no description of a medial approach for MICO has been published. MATERIAL AND METHODS: Between August 2022 and March 2023, 32 consecutive patients (MICO with medial approach, MMICO: n = 15; MICO with lateral approach, LMICO: n = 17) underwent MICO as part of complex reconstructive surgery of the foot and ankle with concomitant procedures. The amount of correction in the axial view of the calcaneus and consolidation rates were evaluated radiographically. Subjective satisfaction, stiffness of the subtalar joint, and pain level (numeric rating scale, NRS) at the level of the heel were assessed clinically. The last follow-up was at 6 months. RESULTS: All osteotomies consolidated within 6 months after surgery. Displacement of the tuber was 9 mm on average in either group. Relevant subtalar joint stiffness was detected in 5 MMICO and 6 LMICO patients. No relevant differences between the groups were detected for wound healing problems, nerve damage, heel pain or patient satisfaction. CONCLUSION: In this study lateral and medial approaches for MICO were performed. Similar degrees of correction and low complication rates were found in both groups. The medial approach for MICO is safe and can be beneficial regarding patient positioning and arrangement of the C­arm.

Flatfoot Reconstruction for Painful Pediatric Idiopathic Flexible Flatfoot: Prospective Study Demonstrates Improved Alignment, Function, and Patient-reported Outcomes.

BACKGROUND: This prospective study was undertaken to report outcomes following reconstructive surgery for patients with painful pediatric idiopathic flexible flatfoot. METHODS: Twenty-five patients with pediatric idiopathic flexible flatfoot were evaluated pre- and post flatfoot reconstruction with lateral column lengthening (LCL). All patients had lengthening of the Achilles or gastrocnemius, while 13 patients had medial side soft tissue (MSST) procedures, 7 underwent medial cuneiform plantarflexion osteotomy (MCPO), and 5 had medializing calcaneal osteotomy. Measures of static foot alignment-both radiographic parameters and clinical arch height indices-were compared, as were measures of dynamic foot alignment and loading, including arch height flexibility and pedobarography. Preoperative and postoperative patient-reported outcome (PRO) scores were compared between those treated with or without MSST procedures. RESULTS: The median subject age was 13.8 years (range: 10.3 to 16.5) at the time of surgery. All radiographic parameters improved with surgery ( P <0.001). The mean sitting arch height index showed a modest increase after surgery ( P =0.023). Arch height flexibility was similar after surgery. The mean center-of-pressure excursion index increased from 14.1% to 24.0% ( P <0.001), and the mean first metatarsal head (MH) peak pressure dropped ( P <0.001), while the mean fifth MH peak pressure increased ( P =0.018). The ratio of peak pressure in the fifth MH to peak pressure in the second MH increased ( P =0.010). The ratio of peak pressure in the first MH to peak pressure in the second MH decreased when an MCPO was not used ( P <0.002), but it remained stable when an MCPO was included. Mean scores in all PRO domains improved ( P <0.001). Patients treated without MSST procedures showed no difference in PROMIS Pain Interference scores compared to those without MSST procedures. CONCLUSIONS: Flatfoot reconstruction surgery using an LCL with plantarflexor lengthening results in improved PROs. LCL changes but does not normalize the distribution of MH pressure loading. The addition of an MCPO can prevent a significant reduction in load-sharing by the first MH.

[A painful collapse: the flat foot management]. / Un effondrement douloureux : la prise en charge du pied plat.

Flatfoot is a progressive deformity with a collapse of the foot. Its therapeutic approach has undergone a conceptual shift. Initially focused on posterior tibial tendon insufficiency, it is now defined by a sum of anatomical alterations resulting in a three-dimensional deformity. If the deformity is symptomatic, we look for hindfoot valgus, forefoot abduction and varus, as well as valgus ankle instability. The clinical rigidity of the deformities and the weight-bearing radiological examinations help guide treatment. Although plantar supports and rigid orthoses are sufficient for mild cases, surgical treatment using bone, ligament, tendon or even prosthetics procedures are the final stage of management for severe cases.

Le pied plat est une déformation progressive avec un effondrement du pied. Son approche a fait l'objet d'un changement de concept. Initialement centré sur l'insuffisance du tendon tibial postérieur, il est maintenant défini par une somme d'altérations anatomiques engendrant une déformation tridimensionnelle. Si celle-ci est symptomatique, on recherche le valgus d'arrière-pied, l'abduction et le varus d'avant-pied ainsi que l'instabilité de cheville en valgus. La rigidité clinique des déformations et les examens radiologiques en charge permettent de guider le traitement. Bien que des supports plantaires ou des orthèses plus rigides soient suffisants pour les cas légers, un traitement chirurgical par procédures osseuses, ligamentaires, tendineuses, voire prothétiques est le stade final de la prise en charge pour les cas sévères.

A 28-Year-Old Woman with Down Syndrome, Congenital Heart Disease, and a History of Knee Surgery and Plantar Fasciitis, with Hallux Abducto Valgus (Bunion) and Lapiplasty Three-Dimensional Correction Surgery.

BACKGROUND Tarsometatarsal joint (TMJ) arthrodesis is common method used for correcting hallux abductus valgus (HAV). Its popularity has grown due to studies revealing HAV's triplanar deformity with frontal plane rotation. This case report presents a 28-year-old woman with Down syndrome, congenital heart disease, and a history of knee surgery and plantar fasciitis, with severe HAV deformity and flexible valgus flatfoot associated with ligamentous hyperlaxity. CASE REPORT Examination revealed severe foot deformities, and radiographic studies confirmed the condition. A surgical intervention was planned, and the patient's cardiologist confirmed she was fit for the procedure. The modified Lapidus technique with frontal plane rotational correction included realigning the metatarsal joint, resecting spurs, osteosynthesis material, and arthrosis in the sinus tarsi. After surgery, the patient underwent a recovery period without support for 8 weeks and received appropriate medical care. Radiographs showed successful alignment, and the patient gradually resumed her daily activities. The patient had an uneventful recovery, and postoperative radiographs showed good alignment in all planes. CONCLUSIONS The hyperlaxity associated with Down syndrome makes the incidence of HAV more frequent, and TMJ fusion is preferable to correction by osteotomy. The modified Lapidus technique with frontal plane rotational correction could be a good technique to achieve satisfactory correction in patients with severe HAV deformity and flexible valgus flatfoot associated with ligamentous hyperlaxity. TMJ fusion is indicated when severe or recurrent rotational component is observed in X-rays.

Radiologic foot alignment and clinical outcome after percutaneous drilling for symptomatic accessory navicular in skeletally immature children.

Various surgical treatments are available for a symptomatic AN, including percutaneous drilling (PD). PD is reportedly effective for ANs in skeletally immature children. However, no reports have described the foot alignment after PD in skeletally immature children. This study was performed to compare the radiographic parameters between the preoperative period and the final follow-up after PD for symptomatic ANs in skeletally immature children. From October 2013 to December 2020, PD was performed on 13 feet in 10 skeletally immature children. The patients comprised 5 boys and 5 girls with a mean age at surgery of 11.9 years. The mean follow-up period was 14.8 months. We measured 5 radiographic findings preoperatively and at the final follow-up: calcaneal pitch angle (CPA), talocalcaneal angle (TCA), talonavicular coverage angle (TNCA), anteroposterior talo-first metatarsal angle (ATMA), and lateral talo-first metatarsal angle (LTMA). Ten feet were assessed as excellent, 1 as fair, and 2 as poor. Ten unions (76.9%) were achieved among the 13 feet. The mean CPA improved from 16.4 ±â€…4.1 degrees preoperatively to 18.2 ±â€…3.4 degrees at the final follow-up, the TCA improved from 43.0 ±â€…3.7 to 45.2 ±â€…4.4 degrees, and the TNCA improved from 19.9 ±â€…4.4 to 15.4 ±â€…5.0 degrees (P < .05). The ATMA and LTMA were not significantly different between the preoperative period and final follow-up. We found that PD for symptomatic ANs in skeletally immature children was effective treatment, and some radiographic parameters showed significant differences between the preoperative period and final follow-up.

Effect of flatfoot correction on the ankle joint following lateral column lengthening: A radiographic evaluation.

OBJECTIVES: The effects of foot deformities and corrections on the ankle joint without osteoarthritis has received little attention. This study aimed to investigate the effect of flatfoot correction on the ankle joint of patients without osteoarthritis. METHODS: Thirty-five patients (24 men and 11 women; mean age 17.5 years) who underwent lateral column lengthening for flatfoot deformities were included. The mean postoperative follow-up period was 20.5 months (standard deviation [SD]: 15.7 months). Radiographic indices were measured pre- and postoperatively, including anteroposterior (AP) and lateral talo-first metatarsal angles, naviculocuboid overlap, position of the articulating talar surface, and lateral talar center migration. Postoperative changes in the radiographic indices were statistically analyzed. RESULTS: There was significant postoperative improvement in flatfoot deformity in terms of AP and lateral talo-first metatarsal angles (p<0.001 and p<0.001, respectively) and naviculocuboid overlap (p<0.001). On lateral radiographs, the talar articulating surface dorsiflexed by 7.3% (p<0.001), and the center of the talar body shifted anteriorly by 0.85 mm (p<0.001) postoperatively. CONCLUSIONS: Flatfoot correction using lateral column and Achilles tendon lengthening caused dorsiflexion and an anterior shift of the articular talar body in patients without osteoarthritis. Correction of flatfoot deformity might affect the articular contact area at the ankle joint. The biomechanical effects of this change need to be investigated further.

Relationship Between Obesity and Medial Longitudinal Arch Bowing.

BACKGROUND: There have been reports about the association between obesity and the medial longitudinal arch (MLA) of foot. The purpose of this study is to investigate the change of various parameters related to the MLA according to obesity classification severity by the World Health Organization using weightbearing computed tomography (WBCT). METHODS: WBCT data of the noninvolved side of patients presenting with unilateral foot and ankle problems or healthy candidates from September 2014 to October 2022 were extracted from a single referral hospital. Forty-four cases in each of 5 obesity classes were selected sequentially. Two orthopaedic surgeons measured foot and ankle offset, forefoot arch angle (FAA), hindfoot moment arm, percentage of uncoverage of the middle facet of the subtalar joint, talonavicular angle (TNA), navicular-medial cuneiform angle, medial cuneiform-first metatarsal angle, talus-first metatarsal angle (TMT1A), first tarsometatarsal subluxation (TMT1S), talonavicular coverage angle, navicular floor distance (NFD), and NFD per height. Positive values indicate plantar collapse. Intra- and interobserver reliabilities were assessed using intraclass correlation coefficients. One-way analysis of variance tests were performed for parametric data with equal variances, and Welch's test for unequal variances. Kruskal-Wallis test was performed for nonparametric data. Post hoc analysis was performed for statistically significant parameters. Correlation analysis between body mass index (BMI) and 12 parameters were performed using Pearson test. RESULTS: Intraobserver and interobserver reliability were excellent, except for TMT1S. The TNA and TMT1A showed a statistically significant difference. FAA (r = -0.2), TNA (r = 0.182), TMT1A (r = 0.296), and NFD (r = -0.173) showed a statistically significant correlation with BMI. CONCLUSION: In nonsymptomatic feet, we found that the talonavicular joint, as measured by the TNA, to be influenced by obesity classification. Obesity and increased BMI was associated with a negative influence on the MLA. LEVEL OF EVIDENCE: Level III, retrospective cohort study.

An evaluation of subtalar titanium screw arthroereisis for the treatment of symptomatic paediatric flatfeet - early results.

BACKGROUND: Idiopathic flexible flatfoot is a common condition in children which typically improves with age and remains asymptomatic. However, the condition can sometimes be more severe, and cause mechanical impairment or pain. The aim of the study was to perform a prospective clinical, radiological, podoscopic and pedobarographic assessment (static and dynamic) of subtalar titanium screw arthroereisis for the treatment of symptomatic, idiopathic, flexible flatfeet. METHODS: A prospective, consecutive, non-controlled, cohort, clinical follow-up study was performed. In total, 30 patients (41 feet), mean age 10 (6 to 16 years), were evaluated. Clinical and standing radiological assessments, static and dynamic pedobarography, as well as podoscopy, were performed before surgery and at final follow-up. RESULTS: Treatment was associated with significant improvements in heel valgus angle, radiographic parameters (lateral and dorso-planar talo-first metatarsal angle, calcaneal inclination angle, talar declination angle, longitudinal arch angle) and podoscopic parameters (Clark's angle, Staheli's arch index and Chippaux-Smirak index). Significant increases were noted for lateral loading, forefoot contact phase and double support / swing phase, and reduced medial loading (dynamic pedobarography), as well as lateral midfoot area and loading, but decreased were observed for medial forefoot loading (static pedobarography). Four patients reported persistent pain in the sinus tarsi region (six feet), and in one case, the implant was replaced for a larger one due to undercorrection. No overcorrections or infection complications were noted in the study group. CONCLUSIONS: Subtalar arthroereisis is a minimally-invasive and effective surgical method for treating symptomatic, idiopathic, flexible flatfeet; it has an acceptable complication rate with good early clinical results. LEVEL OF EVIDENCE: II b.

[Comparison of the effectiveness of two kinds of surgeries for treatment of flexible flatfoot combined with painful accessory navicular bone in children].

Objective: To compare the effectiveness of subtalar arthroereisis (STA) combined with modified Kidner procedure versus STA alone in the treatment of flexible flatfoot combined with painful accessory navicular bone in children. Methods: The clinical data of 33 children with flexible flatfoot combined with painful accessory navicular bone who were admitted between August 2018 and August 2021 and met the selection criteria were retrospectively analyzed. They were divided into a combination group (17 cases, treated by STA combined with modified Kidner procedure) and a control group (16 cases, treated by STA alone) according to the surgical methods. There was no significant difference in baseline data between the two groups ( P>0.05), such as gender, age, affected side of the foot, disease duration, and preoperative visual analogue scale (VAS) score, American Orthopaedic Foot and Ankle Society (AOFAS) ankle-hindfoot score, talus-first metatarsal angle (T1MT), talus-second metatarsal angle (T2MT), talonavicular coverage angle (TCA), talus first plantar angle (Meary angle), calcaneal inclination angle (Pitch angle), and heel valgus angle (HV). The operation time, incision length, intraoperative blood loss, number of intraoperative fluoroscopies, and perioperative complications were recorded in both groups. The anteroposterior, lateral, and calcaneal axial X-ray films for the affected feet were taken regularly, and T1MT, T2MT, TCA, Meary angle, Pitch angle, and HV were measured. The VAS score, AOFAS ankle-hindfoot score were used to evaluate pain and functional recovery before and after operation. Results: Surgeries in both groups were successfully performed without surgical complication such as vascular, nerve, or tendon injuries. Less operation time, shorter incision length, less intraoperative blood loss, and fewer intraoperative fluoroscopies were found in the control group than in the combination group ( P<0.05). One case in the combination group had partial necrosis of the skin at the edge of the incision, which healed after the dressing change and infrared light therapy, and the rest of the incisions healed by first intention. All children were followed up 12-36 months, with a mean of 19.6 months. At last follow-up, VAS score and AOFAS ankle-hindfoot score significantly improved in both groups when compared with preoperative ones ( P<0.05), and the differences of these scores between before and after operation improved more significantly in the combination group than in the control group ( P<0.05). Imaging results showed that the T1MT, T2MT, TCA, Meary angle, and HV significantly improved in both groups at last follow-up when compared with preoperative ones ( P<0.05), and the Pitch angle had no significant difference when compared with preoperative one ( P>0.05). But there was no significant difference in the difference of these indicators between before and after operation between the two groups ( P>0.05). Conclusion: Both procedures are effective in the treatment of flexible flatfoot children with painful accessory navicular bone. STA has the advantage of minimally invasive, while STA combined with modified Kidner procedure has better effectiveness.

Changes in gait pattern and quality of life of adolescents with flexible flat foot after Calcaneal Lengthening Osteotomy.

BACKGROUND: Calcaneal Lengthening Osteotomy is a surgical technique to correct flexible flat foot deformities in patients who did not show any change in their symptoms after conservative treatment. In this study, the effects of CLO on the kinematic and kinetic changes of gait was analyzed and the clinical and quality of life improvements in children treated by CLO for moderate to severe symptomatic flexible flat foot deformities were assessed. METHODS: Participants were seven adolescents (13 feet) with symptomatic FFF who underwent during 2019-2022 and seven (10 feet) healthy children as control group. Three items were evaluated in each foot before and after surgery including: 1. Clinical examination 2.quality of life (using Pediatric Quality of Life Inventory version 4 questionnaire) 3. Gait analysis (Vicon motion systems, Oxford metrics Inc., UK). Also, the kinetic and kinematic analysis between patients and healthy groups were compared. RESULTS: Kinematic results of control was significantly better than FFF group. Ankle range of motion(32.94 ± 13.39 compared to 32.94 ± 13.39,P-Value:0.01),foot progression angle (-9.26 ± 7.67 compared to -16.07 ± 9.00,P-Value:0.01),and internal rotation of ankle was higher in control group compared to FFF. FFF patients demonstrated improvement in kinematic results after CLO surgery. Foot progression angle was improved after surgery (-11.31 ± 6.07 compared to -16.19 ± 7.06, P-value:0.00), maximum plantar flexion decreased after CLO surgery due to achil tendon procedure during CLO surgery. Kinetic results of FFF patients showed significant increase in ankle Power in coronal and transverse plane, Also knee and hip power showed similar results.Quality of life parameters showed significant improve in all parameters (Physical,Social, emotional and school function), Also ADKE and ADKF improved after surgery. CONCLUSION: CLO surgery significantly improved patients' quality of life of patients with symptomatic FFF. Also, kinetic results showed improvement in some parameters of gait results after CLO surgery. Thus, our study suggested CLO surgery as an excellent surgical option for symptomatic FFF.

[Pelvic coronal inclination change in adolescent flexible flatfoot surgically treated with arthroereisis].

Objective: To evaluate adolescent pelvic coronal inclination angle change after flatfoot treated with arthroereisis. Method: A case-series study. From June 2018 to September 2020, 25 children with flexible flat foot and pelvic obliquity were included in this retrospective study in Peking University Shenzhen Hospital. There were 17 males and 8 females with a mean age of (11.2±2.2) years (9-15 years). There were 5 cases of unilateral flatfoot and 20 cases of bilateral flatfoot. All of the patients were surgically treated with arthroereisis. Regular follow-up was done in 3 months, 1 and 2 years postoperatively. Weightbearing fluoroscopy of entire lower limb and foot were investigated to measure Meary's angle, calcaneal pitch angle, height difference at ankle and pelvic plane, pelvic inclination and sacrum-iliac distance (F value) on coronal plane. Results: The mean Mearys' angle at 3 month postoperatively was improved when compared with that before the operation (3.1°±1.5° vs 25.9°±4.3°, P<0.001), and it remained at the same level 2 years after the operation (compared with that at 1 year after the operation, P=0.748). The calcaneal pitch angle improved significantly at 3-month follow-up when compared with that before the operation (16.6°±2.4° vs 9.9°±1.5°, P<0.001), and there was no significant change between 1 year and 2 years after operation (P=0.542). The height difference at mortise plane were also reduced at the 3-month follow-up(P<0.001), and it remained at the same level at 1 year and 2 years after the operation (P=0.159). Pelvic height difference decreased dramatically from (12.4±1.7) mm (before operation) to (7.1±1.2) mm(3 month after the operation) (P<0.001), it decreased to (3.6±1.8) mm 1 year after the operation (compared with that at 3 months after the operation, P<0.001), and no further reduction was observed 2 years after the surgery (P=0.483). The pelvic inclination angle and sacrum-iliac distance were also improved at 3-month follow-up when compared with those before the operation (both P<0.001), and they declined further 1 year after the operation(both P<0.05), but the decreasing trend disappeared at the 2-year follow-up (both P>0.05). Conclusion: For adolescent flexible flat foot patients with pelvic obliquity, the coronal inclination and pelvic height discrepancy would partially recovered with correction of flatfoot deformity, but it could not be completely corrected in the mean follow-up period of 2 years after the operation.