Subtalar arthroereisis with metallic implant is a safe and effective treatment for pediatric patients with symptomatic flexible flatfeet. A 10-year clinical and radiographic follow-up.

BACKGROUND: Subtalar arthroereisis (SA) is an increasingly applied minimally invasive approach for flexible flat foot (FFF) not responsive to conservative treatment. This study aimed at evaluating the long-term clinical and radiographic outcomes of SA in pediatric patients with symptomatic FFF. METHODS: Thirty-seven patients (11.9 ± 1.6yy) underwent SA (74 feet), with outcomes assessed after a mean 10-year follow-up. Pain, quality of life, foot functionality, and alignment were evaluated using validated tools and radiographic parameters, calculated on weightbearing x-rays pre- and post-operatively. RESULTS: Clinical outcomes reached excellent postoperative results (FFI: 9.1, AOFAS: 94.5) with a low 0.9 NRS pain (p < 0.01) and a 92 % satisfaction. All radiographic parameters improved significantly towards normal values: CP 17.5 ± 3.9, MA 4.3 ± 5.8, TCA 42.8 ± 6.2, TNCA 21.1 ± 8.5, TNU% 26.6 ± 8.4 (all p < 0.01). CONCLUSIONS: SA with a metallic endosinotarsal device provided significant long-term clinical and radiographic improvements, with low complication rates and high patient satisfaction, supporting its efficacy as a treatment option for pediatric symptomatic FFF. LEVEL OF EVIDENCE: IV.

Effects of subtalar arthroereisis in children, assessed on the basis of quality-of-life questionnaires.

INTRODUCTION AND OBJECTIVE: Subtalar arthroereisis is a procedure commonly performed in children with flat feet. The procedure is performed when conservative treatment did not have the desired effect,or when the patient's abnormal symptoms are very severe and make it difficult for them to function normally in daily life. The aim of this study was to assess whether subtalar arthroereisis and physiotherapy improve the quality of life among children with flat feet. MATERIAL AND METHODS: The study comprised 79 patients (140 operated feet) diagnosed with a flat foot defect who underwent a subtalar arthroereisis procedure. A self-administered questionnaire and a shortened version of the standardised WHOQOL-BREF questionnaire were used in the research. RESULTS: The study confirmed that the patients' quality of life after surgery was high in all the areas regarding the somatic, psychological, social and environmental domains. In the group of children assessed 13-24 months after surgery. it was also found that rapid fatigue after exercise (30% ± 9%) and Achilles tendon contracture (7% ± 4%) were significantly reduced. The results of the study confirmed that subtalar arthroereisis contributes to a decreased demand for orthoses in children (9% ± 6%) and for orthopaedic footwear (11% ± 5%) than before surgery. CONCLUSIONS: The employment of subtalars arthroereisis has a positive effect on the quality of life of children with flat feet. The surgery contributes to a reduction in pain and other abnormal symptoms that are associated with flat feet. In addition, physiotherapy performed after the procedure had a positive effect on the healing process and contributed to the improvement of the children's quality of life.

Clinical outcomes of subtalar arthroereisis for the treatment of stage 1 flexible progressive collapsing foot deformity.

BACKGROUND: The use of subtalar arthroereisis as an adjunct to the surgical treatment of stage 1 flexible progressive collapsing foot deformity (PCFD) is controversial. The aim was to investigate the clinical outcomes and report the implant removal rate of subtalar arthroereisis as an adjunct for stage 1 PCFD. METHODS: A retrospective study of 212 consecutive feet undergoing operative management of stage 1 PCFD with adjunctive subtalar arthroereisis between October 2010 and April 2018. The primary outcome was the Foot and Ankle Outcome Score (FAOS). Secondary outcomes included Foot and Ankle Disability Index (FADI), Euroqol-5D-5L Index and implant removal rate. RESULTS: Post-operative clinical FAOS outcomes were collected for 153 feet (72.2%). At mean 2.5-year follow-up, the mean ± standard deviation FAOS for each domain was as follows; Pain: 81.5 ± 18.5, Symptoms: 79.5 ± 12.9, Activities of Daily Living: 82.5 ± 15.4 and Quality of Life: 64.2 ± 23.7. EQ-5D-5L Index was 0.884 ± 0.152. Pre-operative scores were available for 20 of these feet demonstrating a statistically significant improvement in all FAOS, FADI and EQ-5D-5L domains (p < 0.05). The implant removal rate for persistent sinus tarsi pain was 48.1% (n = 102). CONCLUSION: Use of a subtalar arthroereisis implant as an adjunct to conventional procedures in stage 1 flexible PCFD can result in significant improvement in pain and function. Patients should be counselled as to the relatively frequent rate of subsequent implant removal. LEVEL OF EVIDENCE: IV.

Gait Analysis in Patients with Symptomatic Pes Planovalgus Following Subtalar Arthroereisis with the Talus Screw.

Background: Pes planovalgus is one of the most common pediatric skeletal deformities. There have been no studies to analyze in detail the spatiotemporal variables of gait following arthroereisis. Purpose of the study: The purpose of our study was to assess gait parameters in patients with symptomatic flexible flatfoot following treatment with the talus screw. Methods: This was a prospective study assessing the 22 patients treated surgically due to symptomatic flexible flatfoot with the talus screw. Patients underwent gait assessment with a G-Sensor. We analyzed the following gait parameters: gait cycle duration, step length, support phase duration, swing phase duration, double support duration, single support duration, cadence, velocity, step length. Results: The post-operative gait parameter assessment for the operated and non-operated foot showed a significant difference only in terms of step length. Cadence increased from the pre-operative mean of 82.29 steps/min to a post-operative mean of 102.94 steps/min. Gait velocity increased significantly from 0.81 m/s before to 0.96 m/s after surgery. Discussion: Arthroereisis with the talus screw helps improve gait parameters following surgery. Post-operatively, we observed increased gait velocity and cadence and decreased gait cycle duration in the operated limb. Conclusion: Short-term biomechanical outcomes of pes planovalgus treatment with the talus screw are good.

Resection of Calcaneonavicular and Talocalcaneal Coalitions With Surgical Correction of the Hindfoot Valgus Deformity in One Step.

Background: Calcaneonavicular (CNC) and talocalcaneal (TCC) coalitions are the most common cause of rigid flatfoot in children. After resection, correction of the most frequent valgus-hindfoot deformity usually requires a second-step surgery. We report results of a retrospective study of patients treated with a one-step correction. Methods: Between 2008 and 2019, data were collected on 26 patients (19 male, 7 female) affected by CNC (n = 18) and TCC (n = 13), all with rigid symptomatic flatfeet. Average age at surgery was 12.5 ± 1.1 (SD) years (range, 9.8-15.2). All patients (26/26) underwent resection, 20 of 26 underwent at the same time subtalar extraarticular screw arthroereisis (SESA) for correction of residual hindfoot valgus deformity. Pre- and postoperative talocalcaneal angle according to Costa Bartani and Talar inclination angle in weightbearing were measured. Twenty-five of 26 patients had postoperative American Orthopaedic Foot & Ankle Society (AOFAS) ankle-hindfoot score. Results: Pre- and postoperative talocalcaneal average angle for CNC was respectively 141.5 ± 7.7 degrees and 130.5 ± 5.2 degrees (P < .0001) and 143.7 ± 7.7 degrees and 129.7 ± 7.0 degrees (P < .0001) for TCC. Talar inclination average angle for CNC was 29.2 ± 5.3 degrees and 19.3 ± 1.6 degrees (P < .0001) and 31.2 ± 6.4 degrees and 21.4 ± 3.4 degrees (P < .0001) for TCC. Average follow-up (FU) was 4.7 ± 3.0 years (range, 6 months-11.9 years, median 4.9 years), with a mean age at FU of 17.2 ± 5.8 (SD) years (min 12.1, max 25.3, median 16.8 years). The mean AOFAS ankle-hindfoot score for CNC and for TCC was 96.6 (range 83-100) for resection and valgus correction as one-step procedure with no statistical difference (P = .5) between CNC and TCC. No patients had additional surgery for complications or recurrence. Conclusion: Symptomatic rigid flatfeet affected by CNC and TCC treated with coalition resection and minimally invasive subtalar arthroereisis (SESA) for residual hindfoot valgus correction in one step in adolescent age achieved good to excellent results in all cases. Further surgery to correct malalignment was avoided. Level of Evidence: Level IV, retrospective study.

Arthroereisis with a Talar Screw in Symptomatic Flexible Flatfoot in Children.

BACKGROUND: Pes planovalgus, or flexible flatfoot, deformity is a common problem in pediatric orthopedic patients. There is no consensus on using the technique of arthroereisis in the treatment of symptomatic pes planovalgus. The aim of our study was to prospectively assess the functional outcomes following symptomatic pes planovalgus treatment with the use of the Spherus talar screw. METHODS: Twenty-seven patients (11 females, 16 males), at a mean age of 10.5 years (7-14 years) were included in the prospective study. We assessed the level of physical activity (including sports) based on the University of California, Los Angeles (UCLA) activity scale, a 10-point level-of-activity VAS scale, and the Grimby physical activity scale. Pain was assessed based on a VAS pain scale; foot function was assessed with the revised Foot Function Index (FFI-R); and ankle joint mobility was measured. RESULTS: The mean follow-up period was 18 months (14-26 months). There was a significant improvement in VAS-measured physical activity scores from 5.47 to 7 at follow-up, p = 0.048. There was a significant improvement in UCLA activity scale scores from 4.78 to 6.05 at follow-up, p = 0.045. Pain levels decreased from a mean VAS score of 4.73 prior to surgery to a mean score of 2.73 at follow-up, p = 0.047. The functional FFI-R scores showed a significant improvement from 140 points prior to surgery to 97.75 points at follow-up, p = 0.017. Comparison of the preoperative and follow-up values of the range of plantar flexion, adduction, and abduction in the operated limb also showed no significant changes in those individual parameters. The mean values of dorsiflexion, plantar flexion, adduction, and abduction at the ankle joint at follow-up, compared individually between the operated and non-operated foot showed no statistically significant differences. CONCLUSIONS: The use of a talar screw in the treatment of symptomatic pes planovalgus helps reduce pain and improve functional outcomes after treatment. Foot function assessments showed diminished pain, improved levels of physical and sport activity, and no effect on the range of motion after surgery in comparison with preoperative data. Arthroereisis with a talar screw is a valid surgical technique for the treatment of symptomatic pes planovalgus.

[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.

Mid-term assessment of subtalar arthroereisis with Talar-Fit implant in pediatric patients with flexible flatfoot and comparing the difference between different sizes and exploring the position of the inserted implant.

Background: Subtalar arthroereisis (STA) has gained growing acceptance as a viable approach solution for the management of pediatric flexible flatfoot. However, STA still remains controversial. The purpose of this study is to assess the effect of STA using the Talar-Fit implant for treating pediatric flexible flatfoot. Specifically, the aims of the study are as follows: first, to present the mid-term outcomes of STA using the Talar-Fit implant; second, to compare the radiographic and clinical outcomes associated with varying sizes of Talar-Fit implant; and third, to analyze the optimal position of the inserted implants. Methods: A retrospective analysis was conducted on a cohort of 57 pediatric patients diagnosed with flexible flatfoot (77 feet) who underwent STA utilizing Talar-Fit between January 2014 and December 2021. The participants were categorized into five groups according to the size of the implant: Group 8, Group 9, Group 10, Group 11, and Group 12. The evaluation included the assessment of clinical function using the American Orthopaedic Foot and Ankle Society (AOFAS) ankle-hind foot score, as well as the assessment of radiographic data such as the calcaneal pitch angle (CPA), lateral Meary angle (LMA), talar declination angle (TDA), and medial longitudinal arch angle (MLAA) were evaluated. Furthermore, the position of the inserted implants was also recorded, including angle, depth, and distance. The comparison of pre- and postoperation was conducted using the paired Student's t-test, whereas the analysis of differences among subgroups was performed using the Wilcoxon rank-sum test. A P-value < 0.05 is considered statistically significant. Results: In total, 57 pediatric patients (77 feet) were successfully followed-up for an average period of 26.8 months. The overall AOFAS score significantly improved from 58.6 ± 10.9 to 85.2 ± 8.6 (P < 0.001). Furthermore, the LMA decreased from 20.3° ± 3.6° to 4.5° ± 1.3°, the CPA increased from 14.8° ± 1.6° to 23.6° ± 2.7°(P < 0.05), the TDA decreased from 40.2° ± 2.3° to 25.5° ± 3.2°(P < 0.05), and the MLAA decreased from 140.1° ± 2.8° to 121.4° ± 3.9°(P < 0.05). No statistically significant differences were observed among subgroups regarding the final outcomes. The improvements of CPA, TDA, and MLAA among different groups were significantly different; however, the adjusted P-values were all greater than 0.05. The implant were inserted at a mean angle of 89.5° ± 2.4°, a mean depth of 0.9 mm ± 2.1 mm, and a mean distance of 9.9 mm ± 0.9 mm. Eight patients experienced complications, including six cases of pain occurrence and two cases of implant dislocation. Conclusion: STA with Talar-Fit has demonstrated satisfactory mid-term outcomes. A Talar-Fit with a larger size may demonstrate a superior effect when compared with that of a smaller size. The implants were inserted in a similar position, indicating that the medial edge of the implant may be possible to transcend the midline of the talus neck.

Efficacy of modified kidner procedure combined with subtalar arthroereisis treating adolescent type 2 painful accessory navicular with flexible flatfoot.

Purpose: To investigate the clinical efficacy of modified kidner procedure combined with subtalar arthroereisis in the treatment of adolescent type II painful accessory navicular with flexible flatfoot. Methods: From January 2018 to January 2022, 25 adolescent patients (40 feet) with painful type II accessory navicular and flexible flatfoot admitted to our hospital were enrolled in the study, including 13 males (23 feet) and 12 females (17 feet). All patients underwent modified kidner procedure combined with subtalar joint arthrodesis. The Meary's Angle, the first metatarsal Angle of talus (APTMT), the second metatarsal Angle of talus, Pitch Angle, talus tilt Angle, talonavicular coverage Angle (TCA), talus calcaneal Angle (LTCA), and calcaneal Angle were measured on weight-bearing anteroposterior and lateral x-ray films before operation and at last follow-up. The American Orthopaedic Foot and Ankle Society (AOFAS) midfoot score and visual analogue scale (VAS) were used to evaluate the improvement of foot function and pain. Results: All patients were followed up for average 17.4 ± 2.6 months (12-24). The incisions of 25 patients healed by first intention. The weight-bearing anteroposterior and lateral x-ray films of the foot showed that the suture anchors did not pull out or break, and the foot arch did not collapse further. There was no screw withdrawal or secondary operation to remove the screw in all patients. At the last follow-up, the postoperative visual analogue scale (VAS) score of the affected foot was significantly lower than that before operation (P < 0.01), and the American Orthopaedic Foot and Ankle Society (AOFAS) foot function score was significantly higher than that before operation (P < 0.01). At the last follow-up, the weight-bearing anteroposterior and lateral foot x-ray films showed that: The Meary's Angle, the first metatarsal Angle of the talus (APTMT), the second metatarsal Angle of the talus, Pitch Angle, talar tilt Angle, talonavicular overbite Angle (TCA), talocalcaneal Angle (LTCA), and calcaneal Angle significantly improved when compared with those before operation (P < 0.01). Conclusions: The modified kidner procedure combined with subtalar arthroereisis has a good clinical effect in the treatment of adolescent type II painful accessory navicular with flexible flatfoot, which can effectively improve the pain symptoms, improve the foot function and imaging manifestations, and correct the flatfoot deformity.

Is Kidner procedure necessary during subtalar arthroereisis for pediatric flexible flatfoot that combined with symptomatic type 2 accessory navicular? A retrospective comparative study.

BACKGROUND: Kidner procedure is thought to be able to eliminate the medial foot pain and contribute to restoring the medial longitudinal foot arch, making it particularly suitable for surgical treatment of pes planus that combined with symptomatic type 2 accessory navicular (AN). However, controversy remains, and the clinical evidence is still lacking. The aim of the current study is to verify the necessity of Kidner procedure during subtalar arthroereisis (STA) for pediatric flexible flatfoot (PFF) that combined with symptomatic type 2 AN. METHODS: Forty pediatric patients (72 feet) who had undergone STA for flexible flatfoot and were also diagnosed with symptomatic type 2 AN concomitantly were reviewed retrospectively and divided into two groups (STA + Kidner vs STA alone). The visual analog scale (VAS), the American Orthopaedic Foot and Ankle Society (AOFAS) Ankle-Hindfoot Scale, the Oxford ankle foot questionnaire for children (OAFQC), and the radiographic parameters that quantifying pes planus were evaluated as primary outcomes. Secondary outcomes included the incidence of complications. RESULTS: There were 35 feet in the STA + Kidner group and 37 feet in the STA alone group, with mean follow-up periods of 2.7 years and 2.1 years, respectively. The VAS, AOFAS, OAFQC scores and radiographic parameters presented no significant difference between the two groups both preoperatively and at final follow-up (P > 0.05 for each). The complications of STA surgery occurred equally in both groups, and Kidner procedure could lead to more incision problems (22.9% vs. 2.7%) and a longer time to return to activity. CONCLUSION: Kidner procedure may be unnecessary during surgical treatment of PFF that combined with painful type 2 AN. Correcting the PFF while leaving the AN alone has a high possibility of relieving the pain in the AN region, and tibialis posterior tendon (TPT) rerouting hardly aids in reconstruction of the medial foot arch. LEVEL OF EVIDENCE: III.

Subtalar arthroereisis post-operative management in children: A literature review.

PURPOSE: Subtalar arthroereisis is a minimally-invasive technique for the treatment of flexible flatfoot. Some issues regarding the procedure are still debated, such as post-operative management. The aim of this study is to offer a review of the pertaining literature to identify current post-operative protocols and describe possible differences among them. METHODS: We searched the PubMed database for all papers related to subtalar arthroereisis in children specifying the post-operative protocols. After reviewing all studies according to excluding criteria, 50 articles were selected for analysis. RESULTS: Based on the literature review, different post-operative protocols emerged in the treatment of patients undergoing subtalar arthroereisis, in particular regarding length of hospital stay, type and duration of immobilization, weight-bearing management, adopted rehabilitation scheme, sport resumption and implant removal. CONCLUSIONS: The most important finding was the existence of a wide variety in post-operative management after subtalar arthroereisis in children, thus confirming that no clear consensus still exists in this field.

Comparison of the effectiveness of two kinds of surgeries for treatment of flexible flatfoot combined with painful accessory navicular bone in children / 中国修复重建外科杂志

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.

[Controversy of subtalar arthroereisis in symptomatic flatfoot].

Flatfoot could be divided into flexible flatfoot and rigid flatfoot. Flatfoot with symptoms is called symptomatic flatfoot, surgical treatment is required if conservative treatment is not effective. Subtalar arthroereisis is a minimally invasive procedure which has been used for many years with good results in flexible flatfoot, however, still has many controversial points. Controversial points focus on indications and contraindications, optimal age, subtalar arthroereisis alone or not, efficacy and safety of absorbable material implants, and implant removal. The paper reviewed and summarized the use and controversies of subtalar arthroereisis in symptomatic flatfoot as follows:the best indication for subtalar arthroereisis was pediatric flexible flatfoot syndrome and aged from 10 to 12 years old was optimal age for treatment;tarsal coalitions with flatfoot and adult flatfoot were relative indications. Stiff flatfoot, joint laxity, and subtalar arthritis were contraindications;obesity and neurogenic flexible flatfoot were relative contraindications. The correction ability of subtalar arthroereisis alone was limited, and it's combined with other procedures depending on patient's situation. The safety and efficacy of absorbable material implants had been reported. Routine removal of the implant was not necessary, the main reason of which was tarsal sinus pain.

Migration of Subtalar Implants in Paediatric Flatfoot Correction: A Pilot Study in Synthetic Bone Models.

BACKGROUND: Subtalar implant migration as a complication following subtalar arthroeresis has been described in the scientific literature. However, clinical studies do not allow for unequivocally determining the underlying causes. The aim of the study is to determine the risk of migration of two geometric types of subtalar implants. Biomechanical tests were carried out on a synthetic bone model with a soft tissue substitute, which allowed for reduction of variability of results caused by biological differences. MATERIAL AND METHODS: A foot model mirroring natural anatomy was made from synthetic bone and a silicone soft tissue substitute with the same hardness as that of the soft tissues of the foot. Two types of 11 mm Ti6Al4V titanium alloy implants were studied, namely, a rectangular subtalar screw and a cylindrical subtalar screw, a type commonly used in flatfoot reconstruction surgery in children. The screws were placed in the sinus tarsi and subjected to cyclic loading (up to 1,000,000 cycles at a frequency of 5 Hz, with a maximum load of 500 N). Comparative pull-out force tests were performed immediately following implantation and after the dynamic loading test. Wyniki. Following the dynamic loading test, all 12 samples were qualified for the pull-out force test. Cylindrical screws demonstrated higher pull-out force values both for the samples tested immediately following implantation and for those that underwent dynamic loading. Implants of the same shape did not show statistically significant differences in the Mann-Whitney U test (p >0.05). Wniosek. The synthetic research model produces reproducible results in the assessment of risk of implant migration. Long-term loading does not significantly affect the risk of implant migration.

HyProCure for Pediatric Flexible Flatfoot: What Affects the Outcome.

Background: The high success rate, minimal invasion, and safety of subtalar arthroereisis (SA) have made it a primary mode of surgical management for pediatric flexible flatfoot. The HyProCure procedure is a new surgery for SA, However, very few available studies reported the therapeutic effects of the HyProCure procedure, especially in pediatric flexible flatfoot. The main aim of the present study was to investigate the clinical and radiological outcomes of the HyProCure procedure for pediatric flexible flatfoot and analyze the risk factors for therapeutic outcomes and sinus tarsi pain. Methods: In this retrospective cohort study, 69 pediatric flexible flatfoot patients (107 feet) who underwent the HyProCure procedure were included between July 2015 and September 2020. All patients underwent the HyProCure procedure with or without gastrocnemius recession. The Maryland foot score (MFS), visual analog scale (VAS), radiographic data, and complications were assessed at a minimum 1-year follow-up and statistically analyzed. Results: The mean follow-up was 35.9 months (range, 13-73 months). At the last follow-up, VAS (0.64 ± 1.16) was significantly lower than the preoperative VAS (4.06 ± 1.43) (p < 0.001); MFS (90.39 ± 12.10) was significantly higher than the preoperative MFS (71.36 ± 10.25) (p < 0.001). The AP talar-second metatarsal angle (T2MT angle) significantly decreased from 17.0 ± 5.4° preoperatively to 11.4 ± 5.2° at the last follow-up (p < 0.001). The lateral talar-first metatarsal angle (Meary's angle) significantly decreased from 13.8 ± 6.4° preoperatively to 6.3 ± 5.0° at the last follow-up (p < 0.001). The calcaneal declination angle (Pitch angle) significantly increased from 13.5 ± 4.9° preoperatively to 14.8 ± 4.4° at the last follow-up (p < 0.001). Logistic regression analysis indicated that patients with a longer distance from the tail end of the implant exceeding the longitudinal talar bisection line had 275.8% greater odds of MFS < 90. Yet, no risk factors were found in connection with sinus tarsi pain. Conclusions: The HyProCure procedure for pediatric flexible flatfoot achieved satisfactory curative effects with a low complication rate; implant depth was associated with unsatisfactory postoperative outcome.

Subtalar Arthroereisis as an Adjunct Procedure Improves Forefoot Abduction in Stage IIb Adult-Acquired Flatfoot Deformity.

BACKGROUND: Our aims were (a) to determine whether subtalar arthroereisis (STA) as adjunct procedure improved radiographic correction of stage IIb adult-acquired flexible flatfoot deformity (AAFD); (b) to assess the STA-related complication rate. METHODS: A retrospective analysis of 22 feet (21 patients) diagnosed with stage IIb AAFD treated by medializing calcaneal osteotomy (MCO), flexor digitorum longus (FDL) transfer, spring ligament (SL) repair with or without Cotton osteotomy and with or without STA in a single institution was carried out. Seven measurements were recorded on pre- and postoperative (minimum 24 weeks) radiographs by 2 observers and repeated twice by 1 observer. Inter- and intraobserver reliabilities were assessed. The association of demographic (gender, side, age, body mass index) and surgical variables (Cotton, STA) with radiographic change was tested with univariate analysis followed by a multivariable regression model. RESULTS: Excellent inter- and intraobserver reliabilities were demonstrated for all measurements (intraclass correlation coefficient range, 0.75-0.99). Gender, side, Cotton osteotomy, and STA were included in the multivariable analysis. Regression showed that STA was the only predictor of change in talonavicular coverage angle (TNCA) (R2 = 0.31; P = .03) and in calcaneo-fifth metatarsal angle (CFMA) (R2 = 0.40; P = .02) on dorsoplantar view. STA was associated to a greater change in TNCA by 10.1° and in CFMA by 5°. Four patients out of 12 STA complained of sinus tarsi pain after STA, and removal of the implant resolved symptoms in 3 of them. CONCLUSION: In this series, STA as an adjunct procedure to MCO, FDL transfer, SL repair in the treatment of stage IIb AAFD led to improvement in correction of forefoot abduction. STA-related complication and removal rates were 33%. LEVELS OF EVIDENCE: Level IV: Retrospective cohort study.

Outcomes Following the Use of Subtalar Arthroereisis in the Correction of Adult Acquired Flatfoot: A Systematic Review.

BACKGROUND: Adult acquired flatfoot deformity (AAFD) is a condition affecting approximately 3% of the adult population. It can lead to severe morbidity, and therefore, prompt treatment is of the upmost importance in maintaining and restoring function. Recently, the use of subtalar arthroereisis has become more widespread in the treatment of AAFD. The purpose of this systematic review is to examine the clinical and radiological outcomes of AAFD when treated with subtalar arthroereisis. METHODS: Studies involving the use of subtalar arthroereisis for the management of AAFD were reviewed, and appropriate studies selected based on inclusion and exclusion criteria. Studies were reviewed for both clinical and radiological outcomes following the use of subtalar arthroereisis as well as reported complications. RESULTS: Nine studies met our inclusion criteria, with most of these involving stage II AAFD. A total of 190 subtalar arthroereisis procedures were performed with all studies demonstrating improvement in both clinical and radiological scores with a low rate of complications. CONCLUSION: Subtalar arthroereisis may have benefits when used as an adjunct to treat stage II AAFD. However, more high-quality studies are needed to establish its best use. LEVELS OF EVIDENCE: Level IV: Systematic review.

Foot Typology, Dynamic and Static Weight Distribution, and Radiographic Changes After Subtalar Arthroereisis in Juvenile Symptomatic Flexible Flat Feet.

Flexible flatfoot is among the most common skeletal disorders in childhood. This study describes the dynamic and static correction effects of subtalar arthroereisis in adolescents with flexible symptomatic flatfeet in comparison to normal subjects as well as to results before and after removal of metal. Eighteen adolescents with 25 symptomatic flexible flatfeet were treated surgically with a subtalar arthroereisis at a mean of 12.5 (10-16) years. At follow-up (mean 3.9 years, range 0.4-8), patients filled out the American Orthopaedic Foot and Ankle Society questionnaire, received radiographs and were examined using dynamic and static pedobarography as well as static hindfoot axis examination. Results were compared to healthy controls (n = 13; 26 feet). Surgically treated feet (n = 25) had better questionnaire results after surgery than before, but lower scores than healthy feet. Radiological parameters improved significantly after surgery. Removal of metal did not influence post-surgical results (follow-up 2.8 years). Surgically treated feet had larger contact areas than normal feet with predominance to the midfoot region. The relative maximum force, relative peak pressure and contact time were higher in the midfoot of treated feet compared to controls. When comparing pedobarography data of treated versus untreated feet of the same patients (subgroup n = 11 feet), there were no differences. Subtalar arthroereisis was able to effectively treat symptomatic flexible flatfeet in this population. Results improved significantly evaluating a questionnaire, radiographs, dynamic and static weight distribution, but were still worse than results of healthy feet. There was no relapse after removal of metal.

Controversy of subtalar arthroereisis in symptomatic flatfoot / 中国骨伤

Flatfoot could be divided into flexible flatfoot and rigid flatfoot. Flatfoot with symptoms is called symptomatic flatfoot, surgical treatment is required if conservative treatment is not effective. Subtalar arthroereisis is a minimally invasive procedure which has been used for many years with good results in flexible flatfoot, however, still has many controversial points. Controversial points focus on indications and contraindications, optimal age, subtalar arthroereisis alone or not, efficacy and safety of absorbable material implants, and implant removal. The paper reviewed and summarized the use and controversies of subtalar arthroereisis in symptomatic flatfoot as follows:the best indication for subtalar arthroereisis was pediatric flexible flatfoot syndrome and aged from 10 to 12 years old was optimal age for treatment;tarsal coalitions with flatfoot and adult flatfoot were relative indications. Stiff flatfoot, joint laxity, and subtalar arthritis were contraindications;obesity and neurogenic flexible flatfoot were relative contraindications. The correction ability of subtalar arthroereisis alone was limited, and it's combined with other procedures depending on patient's situation. The safety and efficacy of absorbable material implants had been reported. Routine removal of the implant was not necessary, the main reason of which was tarsal sinus pain.

Subtalar Arthroereisis for Surgical Treatment of Flexible Flatfoot.

Various surgical techniques are known for the treatment of flexible flatfoot in children after failure of nonsurgical attempts. Data collected in a review of the last 10-year period (2010-2020) show that among the 691 feet undergoing subtalar arthroereisis with endorthesis, average age at surgery was 11.40 years and in the 1856 feet that underwent subtalar arthroereisis with calcaneo-stop 11.69 years, while the complications rate was 9.00% and 6.38%, respectively. These data confirm that subtalar arthroereisis with calcaneo-stop may have an advantage over subtalar arthroereisis with endorthesis as the screw is not placed across the subtalar joint but instead into the calcaneus.