Os trigonum: a discussion of its role in posterior ankle impingement syndrome and a meta-analysis of its prevalence.

PURPOSE: the os trigonum is a supernumerary bone that may lead to posterior ankle impingement syndrome. The present study aims to assess the prevalence of this bone. METHODS: A meta-analysis regarding the presence of the os trigonum was performed. For this, the MEDLINE and SciElo databases were searched using "os trigonum" as the keyword. Only original articles, theses, books, dissertations, and monographs were included. Papers with a sample size of < 50 individuals were excluded. The data extracted from the articles were: the total sample size, the prevalence of the trigonum, the method of analysis, the region of the sample, and data regarding sex and side (left or right). Statistical analysis was performed using MedCalc Statistical Software version 14.8.1 (MedCalc Software bvba, Ostend, Belgium). The heterogeneity between the studies was assessed using the I² estimation and the Cochran Q test. For all analyses, a random effect was used and a value of p < 0.05 was considered significant. RESULTS: 249 papers were found, while 18 were included in the meta-analysis. A total of 17,626 ankles were included. The pooled prevalence of the os trigonum was 10.3% (95% CI 7-14.1%) in the present study. There was no significant difference regarding sex or side, while studies conducted in imaging exams showed a higher prevalence in comparison to cadaveric studies. CONCLUSION: Our results suggest that the os trigonum is relatively common. Knowledge of the prevalence of the os trigonum may help surgeons and clinicians diagnose posterior ankle impingement syndrome.

Weight-bearing Ultrasound to Diagnose Talar Dislocation Causing Tarsal Tunnel Syndrome.

The neuropathic compression of the tibial nerve and/or its branches on the medial side of the ankle is called tarsal tunnel syndrome (TTS). Patients with TTS presents pain, paresthesia, hypoesthesia, hyperesthesia, muscle cramps or numbness which affects the sole of the foot, the heel, or both. The clinical diagnosis is challenging because of the fairly non-specific and several symptomatology. We demonstrate a case of TTS caused by medial dislocation of the talar bone on the calcaneus bone impacting the tibial nerve diagnosed only by ultrasound with the patient in the standing position.

Radiographic Analysis of Valgus Ankle Deformity With or Without Medial Longitudinal Arch Collapse.

BACKGROUND: Establishing a surgical plan for ankle deformities necessitates a comprehensive understanding of the deforming forces involved, and the morphology of the ankle deformity plays an important role as well. Valgus tibiotalar tilt development has mostly been described in patients with a low medial longitudinal arch, as seen in progressive collapsing foot deformity (PCFD). However, some valgus ankles demonstrate no radiographic evidence of a collapsed medial arch. This study aims to investigate whether there are differences in the radiographic morphology of valgus ankle deformities between patients with and without a low medial longitudinal arch to explore if they have different etiologies. METHODS: We retrospectively reviewed patients who underwent surgical treatment for asymmetric valgus ankle deformity at our institution between 2017 and 2021. Patients with a valgus tibiotalar tilt (TT) greater than 4 degrees and Meary angle greater than 30 degrees (mean: 38.9) were included in the PCFD group (n = 29). The non-PCFD group (n = 24) with TT greater than 4 degrees and Meary angle less than 4 degrees (mean: 0.3) was also established. In the weightbearing ankle anteroposterior view, the TT and medial distal tibial angle were measured. Additionally, to assess the mediolateral position of the talus, the talar center migration (TCM) and lateral talar dome-plafond distance (LTD-P) ratio in the coronal plane were measured. In weightbearing computed tomography (WBCT), the degree of axial plane talocalcaneal subluxation and the prevalence of sinus tarsi bony impingement were assessed. Intergroup comparison was conducted. RESULTS: Both groups demonstrated a similar degree of TT, with a mean of 11.6 degrees in the PCFD group and 13.7 degrees in the non-PCFD group (P = .2330). However, the PCFD group showed a significantly greater TCM and LTD-P ratio compared with those of the non-PCFD group (P < .0001), indicating that PCFD patients have a more medially translated talus in ankle anteroposterior radiographs. WBCT showed that the PCFD group on average had 18 degrees greater axial plane talocalcaneal subluxation (P < .0001) and 52% higher prevalence of sinus tarsi bony impingement (P = .0002) compared with the non-PCFD group. CONCLUSION: This study suggests that valgus ankles may exhibit different radiographic morphologies depending on the status of the longitudinal arch. Valgus ankles in PCFD patients tend to have a more medially translated talus. This finding may suggest the presence of different deforming forces between the 2 groups and may indicate the need for different treatment strategies to address talar tilt. LEVEL OF EVIDENCE: Level III, case-control.

Symptomatic Bilateral Talonavicular Coalition in a Seven-Year-Old Boy.

Congenital talonavicular coalition is less frequent than the talocalcaneal or the calcaneonavicular and accounts for around 1% of all tarsal coalitions. Commonly, patients are asymptomatic and rarely need surgical treatment. Herein, we present a case of bilateral symptomatic talonavicular coalition in a seven-year-old boy who underwent surgery with full relief of symptoms. We also review the literature and discuss this pathological condition in detail.

Prenatal ultrasound diagnosis of congenital vertical talus.

OBJECTIVE: This study aimed to analyze the ultrasound characteristics of fetal congenital vertical talus (CVT) to provide a detailed basis for the prenatal diagnosis of CVT. METHODS: We retrospectively analyzed the ultrasonographic findings of fetuses with CVT confirmed by X-ray, surgery, or autopsy from 2010 to 2020. Clinical characteristics and ultrasonographic findings of CVT, including foot morphology, ossification center of the calcaneus and talus, associated deformities, and chromosomal test results, were recorded. RESULTS: Thirteen patients diagnosed with CVT by prenatal ultrasound were confirmed postpartum. Nine cases were bilateral, and four were unilateral. Under two-dimensional ultrasound, 13/13 cases had abnormal foot morphology, and 10 of 13 cases (76.9%) showed that the ossification center of the talus moved downward, and the calcaneus moved laterally. Under three-dimensional ultrasound, 11 cases (84.6%) presented a "rocking chair" appearance, and two cases did not obtain satisfactory three-dimensional image due to oligohydramnios and fetal position. In this group of cases, two cases (15.4%) were isolated CVT, and the other 11 cases (84.6%) were complicated with other abnormalities. Eleven cases of non-isolated CVT and 1 case of isolated CVT were induced, and another patient with isolated CVT had undergone postnatal surgery, which had been followed up for 8 years and recovered well. CONCLUSIONS: The combination of fetal foot morphology, ossification center position of the calcaneus and talus, and three-dimensional ultrasound can provide a reliable diagnosis of CVT. Furthermore, we should pay more attention to the evaluation of other systemic and chromosomal abnormalities in CVT cases.

Comparison of Different Surgical Techniques in Correction of Congenital Vertical Talus Deformity: A Systematic Review and Meta-Analysis of the Literature.

BACKGROUND: Congenital Vertical Talus (CVT) is a rare form of congenital rigid flatfoot. Numerous surgical techniques have been developed over the years in an attempt to definitively correct this deformity. We performed a systematic review and meta-analysis of the existing literature to compare the outcomes of children with CVT treated with different methods. METHODS: A detailed systematic search was conducted in accordance with PRISMA guidelines. Radiographic recurrence of the deformity, reoperation rate, ankle arc of motion, and clinical scoring was compared between the following 5 methods: Two-Stage Coleman-Stelling Technique, Direct Medial Approach, Single-Stage Dorsal (Seimon) Approach, Cincinnati Incision, and Dobbs Method. Meta-analyses of proportions were performed, and data were pooled through a random effects model using the DerSimonian and Laird approach. Heterogeneity was assessed using I^2 statistics. The authors used a modified version of the Adelaar scoring system to assess clinical outcomes. An alpha of 0.05 was used for all statistical analysis. RESULTS: Thirty-one studies (580 feet) met the inclusion criteria. The reported incidence of radiographic recurrence of talonavicular subluxation was 19.3%, with 7.8% requiring reoperation. Radiographic recurrence of the deformity was highest in the children treated with the direct medial approach (29.3%) and lowest in the Single-Stage Dorsal Approach cohort (11%) ( P <0.05). The reoperation rate was significantly lower in the Single-Stage Dorsal Approach cohort (2%) compared with all other methods ( P <0.05). There was no significant difference in the reoperation rates between the other methods. The highest clinical score was seen in the Dobbs Method cohort (8.36), followed by the group treated with the Single-Stage Dorsal Approach (7.81). The Dobbs Method resulted in the largest ankle arc of motion. CONCLUSION: We found the lowest radiographic recurrence and reoperation rates in the Single-Stage Dorsal Approach cohort, while the highest rate of radiographic recurrence was seen in those treated with the Direct Medial Approach. The Dobbs Method results in higher clinical scores and ankle arc of motion. Future long-term studies focusing on patient-reported outcomes are needed. LEVEL OF EVIDENCE: Level III.

Congenital vertical talus deformity in children with distal arthrogryposis: good clinical outcomes despite high rate of residual radiographic deformity.

Patients with a diagnosis of arthrogryposis often present with various orthopedic conditions, one of which is congenital vertical talus (CVT). This is the first study of this specific subset of syndromic patients to evaluate the medium-term outcomes of CVT correction using the minimally invasive Dobbs method. All patients with vertical talus and distal arthrogryposis who received treatment at our institution between January 2006 and June 2021 were identified. Radiographs, clinical notes and Patient-Reported Outcome Measurement Information System (PROMIS) scores (when available) were retrospectively reviewed. An alpha of 0.05 was used for all statistical analyses. In total 12 patients (19 feet) met all inclusion criteria and were included in the final analysis. By the time of the most recent visit, the average lateral Talar-Axis First Metatarsal Base Angle of the entire cohort increased from 13.73 ± 9.75 degrees 2 weeks postoperatively to 28.75 ± 23.73 degrees ( P = 0.0076). Radiographic recurrence of the talonavicular deformity was seen in nine feet (47.4%), 4 (21.1%) of which required additional unplanned surgery, The average PROMIS scores of the entire cohort in the pain interference, mobility and peer relationship domains were 48.97 ± 9.56, 47.9 ± 11.60 and 52.87 ± 8.31, respectively. Despite a higher radiographic recurrence rate of talonavicular deformity in this specific subset of syndromic patients, these patients still report PROMIS scores near the population average in the pain interference, mobility and peer relationships domains. We believe that the minimally invasive Dobbs method should be recommended as the first-line treatment method for these patients. Level of evidence: Level III.

Relapsed Congenital Vertical Talus Deformity: Outcomes of a Modified Minimally Invasive Method.

BACKGROUND: To date, there is little literature that describes the optimal management for recurrent talonavicular subluxation after an initial attempt at surgical correction in children with congenital vertical talus (CVT). The purpose of this study is to evaluate the outcomes of a modified minimally invasive technique for the management of recurrent talonavicular subluxation in patients with CVT who have previously undergone at least 1 attempt at surgical correction. METHODS: International Classification of Diseases codes were used to identify all patients with recurrent CVT deformity treated at our institution between 2006 and 2021. Retrospective chart review, including radiographic measurements of talocalcaneal and talar axis-first metatarsal base angles (TAMBA), was performed. Complications including recurrent talonavicular subluxation (lateral TAMBA >30 degrees) and hindfoot valgus (Anteroposterior talocalcaneal >40 degrees) were recorded. All statistical analysis was performed using an alpha of 0.05. RESULTS: Seventeen patients (24 feet) met all inclusion criteria, 9 (52.9%) of whom had underlying neurological syndromes. The average age at repeat treatment initiation was 26±17 months (range: 7 to 60 mo). Talonavicular reduction was achieved in all patients as evidenced by an average of 24.6 degrees and 54.9 degrees of correction in the Anteroposterior and lateral TAMBA, respectively. Radiographic recurrence of the talonavicular deformity was seen in 12 feet (50.0%). Six (25.0%) of the feet in 4 patients required a revision surgery, all of which occurred in patients with underlying syndromes ( P =0.02). The average patient-reported outcome measurement information system scores in the pain interference, mobility, and peer relations domains were 44.5±7.7, 44.1±13.5, and 54.8±9.9, respectively. CONCLUSIONS: Our midterm results suggest that many cases of recurrent CVT can be effectively managed through a modified minimally invasive revision surgery consistent with what has been described by Dobbs and colleagues for initial treatment. Further prospective studies with longer-term follow-up are warranted to confirm these findings. LEVEL OF EVIDENCE: Level III.

Minimally Invasive Method in Treatment of Idiopathic Congenital Vertical Talus: Recurrence is Uncommon.

BACKGROUND: Historically, treatment for congenital vertical talus (CVT) has included open reduction of the talonavicular joint and extensive soft tissue release. In 2006, a new minimally invasive method consisting of serial manipulation and casting followed by percutaneous fixation of the talonavicular joint and percutaneous Achilles tenotomy was introduced. Although the early results of this new technique are promising, more research is needed to verify that the talonavicular correction is maintained with time. METHODS: We conducted a retrospective chart review of all patients with idiopathic CVT who underwent minimally invasive correction by a single surgeon at a tertiary care institution. Radiographic evaluation of the preoperative, immediate postoperative, 1 year postoperative and latest follow-up appointments were performed. Complications and clinical outcomes were recorded. Radiographic recurrence of the deformity was defined as lateral talar axis-first metatarsal base angle >30 degrees. Statistical analysis was performed on the maintenance of radiographic correction and factors associated with recurrence. RESULTS: Forty seven feet in 35 patients were included in the study with average follow-up of 45 months. The average preoperative lateral talar axis-first metatarsal base angle was 74±18 compared with 12±8 after initial surgical intervention. In addition, radiographic correction of all other measured angles was achieved in every child following the initial surgery. Radiographic recurrence of talonavicular deformity was seen in 4 feet (9%). No cases of recurrence required a second corrective surgery during the follow-up period. There was a significant association between patient age at the time of treatment and recurrence of talonavicular deformity with patients older than 12 months being more likely to experience recurrence ( P =0.041). CONCLUSIONS: In this large series, we found that correction of talonavicular deformity can be achieved and maintained in a large majority of children with idiopathic CVT who undergo treatment with this minimally invasive technique and recurrences are uncommon. Treatment with this technique should be initiated as soon as a diagnosis of CVT is confirmed and the patient is medically stable to decrease the likelihood of experiencing recurrence of talonavicular deformity. LEVEL OF EVIDENCE: Level III.

Congenital vertical talus open reduction surgery: Technique description and our twenty-years personal experience.

Congenital vertical talus foot is a complex deformity, characterized by a dislocation of the talus-calcanear navicular joint. It is a rare form of congenital flat foot, where the hindfoot is valgus and equine, the midfoot dorsiflexed and the forefoot abducted. Regardless of the type of classification, the therapeutic approach and prognosis must take into account the functionality and motility of the foot. Initial treatment is manipulative. After 3 months of age, it is possible to think about soft tissue surgery. In this study, we present congenital vertical talus feet treated at the Pediatric Orthopedics Department of SS. Antonio Biagio and Cesare Arrigo Children's Hospital of Alessandria from 1995 to 2022. All 8 patients (12 feet) underwent through the surgical operation technique of open reduction described by Tachdjian and further reviewed and subjected to the American Orthopaedic Foot and Ankle Society (AOFAS) Ankle-Hindfoot Score. The mean follow up is 13 years. Global functional result was good and surgery allowed the growth of the foot, which would otherwise be blocked by an ax that is the vertical talus. Questioned remotely, all patients perform sporting activities and wear normal footwear.

Surgical management of an isolated symptomatic talonavicular coalition: a paediatric perspective.

Talonavicular (TN) coalition is a rare pathological union of the talus and navicular bones. We report the case of a 7-year-old girl with a symptomatic TN coalition, who underwent operative management with a lateral column lengthening procedure using autologous iliac crest bone grafting. There are no complications to report and the graft was incorporated at an early stage. At 3 year follow-up the patient has remained pain-free since the operation and maintained alignment. To our knowledge, this is the first reported case of TN coalition treated with reconstructive surgery in a paediatric patient.

Lateral Column Lengthening for Flexible Flat Foot: Was It Short to Begin With?

BACKGROUND: Flexible flatfoot (FF) is a common foot deformity that can often consist of foot pain. Surgical treatment is designed to lengthen the lateral column. OBJECTIVES: To resolve whether radiographic standing feet measurements of normo-plantigrade feet and FF, symptomatic or not, differ and to determine whether the lateral column is shorter. METHODS: The study comprised 72 patients (127 feet) consecutive patients, 18 years of age and older, who were divided into three groups: normal feet (56), asymptomatic FF (29), and symptomatic FF (42). All patients had a standing anterior posterior (AP) and lateral radiographs. AP images were used for the measurement of the talocalcaneal angle, talar-1st metatarsal angle, and talonavicular coverage. Lateral X-rays were used to estimate the talocalcaneal angle, talar-1st metatarsal angle, calcaneal pitch, naviculocuboid overlap, and column ratio. RESULTS: All three of the AP radiograph measurements differed among groups, and higher values were measured in the symptomatic FF group. Post hoc analysis found that the talonavicular coverage and the talocalcaneal angles also differed between symptomatic and asymptomatic FF patients. While some lateral measurements differed within groups, only the lateral talar-1st metatarsal angle distinguished between asymptomatic and symptomatic patients. The lateral column length was not found to be shorter among FF patients, weather symptomatic or not. CONCLUSIONS: Only the talonavicular coverage, the AP talocalcaneal, and the lateral talar-1st metatarsal angles were found to differ between asymptomatic and symptomatic FF patients. The lateral column was not found to be shorter.

Outcomes of a Minimally Invasive Approach for Congenital Vertical Talus With a Comparison Between the Idiopathic and Syndromic Feet.

BACKGROUND: Congenital vertical talus (CVT) is a rare congenital foot disorder. Approximately half of the affected children have associated neuromuscular syndromes which may further complicate the treatment. The traditional treatment involved extensive soft tissue and bony reconstructions. The minimally invasive method (Dobbs method/reverse Ponseti) has changed the treatment of CVT. There is significant variation of the reported outcome of this method in the current literature. In this study we report the outcome of this minimally invasive technique for treatment of CVT and compare the results of treatment in syndromic and idiopathic patients. METHODS: Idiopathic and syndromic patients treated from CVT with minimally invasive method from 2006 till 2016 were included in this retrospective study. We reviewed the patients' notes, radiographs and collected parents reported outcome questionnaire (Roye score) in addition to clinical examination to comprehensively report the treatment outcome. RESULTS: A total of 21 patients 30 feet were included in this study. The average age of commencing treatment was 6 months (1 to 17 mo). The mean follow-up was 6.5 years (1 to 11 y). Correction of the deformities and abnormal angles were achieved in all feet. Five of the 17 syndromic feet had recurrence while no recurrence was reported in any if the 13 idiopathic feet. At the time of the index procedure no supplementary procedures were required. The average arc of motion for foot ankle dorsiflexion and plantar flexion was 30 degrees. Patients with idiopathic CVT had a mean the Roye score of 11 while syndromic patients had a mean score of 22. CONCLUSION: The minimally invasive method is a valuable option for treatment of CVT. Idiopathic patients had no recurrence and better functional scores compared syndromic patients. There was no requirement for supplementary procedures such as tibialis anterior transfer or anterolateral release at the time of the initial surgery. LEVEL OF EVIDENCE: Level IV-case series.

Mid-term Results of Subtalar Arthroereisis with Talar-Fit Implant in Pediatric Flexible Flatfoot and Identifying the Effects of Adjunctive Procedures and Risk Factors for Sinus Tarsi Pain.

OBJECTIVES: To (i) report the mid-term outcomes of subtalar arthroereisis using Talar-Fit implant for the treatment of flexible flatfoot patients; (ii) compare clinical and radiographic outcomes between arthroereisis with and without adjunctive operative procedures to investigate the effects of adjuncts on the outcomes; and (iii) analyze the risk factors associated with sinus tarsi pain, which is the most common postoperative complication of arthroereisis. METHODS: Thirty-one flexible flatfoot children and adolescents (46 feet) treated with subtalar arthroereisis using Talar-Fit implant from June 2014 to May 2019 were retrospectively analyzed. The feet were divided into four treatment groups: (i) arthroereisis alone, (ii) arthroereisis with gastrocnemius recession, (iii) arthroereisis with Kidner procedure, and (iv) arthroereisis with gastrocnemius recession and Kidner procedure. Clinical function was evaluated based on the American Orthopaedic Foot and Ankle Society (AOFAS) ankle and hindfoot score. The following angles were measured for radiographic evaluation: talar-first metatarsal angle, calcaneal pitch angle, and talar declination angle on the lateral view; and talar-first metatarsal angle, talocalcaneal angle, and anteroposterior talonavicular coverage angle on the anteroposterior (AP) view. The paired Student's t-test was used to compare the pre- and postoperative angular measurements and AOFAS scores. The Wilcoxon rank-sum test was undertaken to determine the outcome differences among four treatment groups. Multivariate logistic regression analysis was used to analyze risk factors for sinus tarsi pain. P value <0.05 is considered statistically significant. RESULTS: The mean follow-up of the feet was 32.8 months (range, 10-71 months). The mean AOFAS score significantly improved from 55.5 ± 14.5 preoperatively to 86.3 ± 9.9 (P < 0.001). Comparison of radiographic outcomes showed that the lateral talar-first metatarsal angle decreased by a mean of 19.1° ± 11.9° (P < 0.001), the calcaneal pitch angle increased by a mean of 5.4° ± 3.4° (P < 0.001), the talar declination angle decreased by a mean of 14.8° ± 9.9° (P < 0.001), the AP talar-first metatarsal angle decreased by a mean of 15.6° ± 10.3° (P < 0.001), the AP talocalcaneal angle decreased by a mean of 7.2° ± 8.3° (P = 0.001), and the AP talonavicular coverage angle decreased by a mean of 20.4° ± 9.0° (P < 0.001). There were no statistically significant differences with regard to AOFAS score and all angle measurements on both the AP and lateral views among the four treatment groups. There was one dislocation case caused by a fall 6 weeks after surgery, which was treated nonoperatively. The incidence of sinus tarsi pain was 13% and logistic regression analysis indicated that patients with a longer distance from the tail end of the implant to the lateral calcaneal wall had 38.8% greater odds of developing sinus tarsi pain. CONCLUSIONS: The mid-term clinical and radiographic results were satisfactory in patients who underwent the subtalar arthroereisis procedure using Talar-Fit implant, alone or in combination with other adjuncts, for the treatment of flexible flatfoot.

Classification of the subtalar articular surface and its matching situation: an anatomical study on Chinese subtalar joint.

PURPOSE: The subtalar joint (STJ) is complex in anatomy and function. The purpose of this study is to classify the articular surface of the calcaneus in a sample Chinese population and discuss the relationship between its matching situation and the stability of STJ. METHODS: 328 patients with 445 STJs were measured and classified using CT three-dimensional reconstruction. The calcaneal facets were classified according to the morphological characteristics. According to the number, shape, and fusion of the calcaneus and talus facets, the matching situation was determined. The parameters of measurement: the Gissane's angle, the Böhler's angle, the long-axis sum and the short-axis sum, and the average total joint facet area. RESULTS: The calcaneal surfaces in a sample Chinese population were classified into five types: Type I (219, 49.2%), Type II (102, 22.9%), Type III (68, 15.3%), Type IV (47, 10.6%) and Type V (9, 2%). The total matching rate of STJ is 98%. In terms of Gissane's angle, there was a significant difference between Type II and Type IV (P < 0.05). The long-axis sum of Type III (4.53 ± 0.58 cm) was significantly smaller than other types (P < 0.05). Type II (3.64 ± 0.47 cm) was statistically larger than other types in the short-axis sum (P < 0.05). The average total joint facet area of Type III (7.05 ± 1.40 cm2) was significantly smaller than other types (P < 0.05). Type V (9.31 ± 3.96 cm2) was statistical differences with Type II, Type III and Type IV (P < 0.05). There was no statistically significant difference between left and right sides of the articular facets in this study (P > 0.05). CONCLUSIONS: According to Bunnins's classification, the type with separated facets predominated but the matching situation between STJ was not elaborated, which was closely linked to the stability of STJ and surgical strategy of calcaneus fracture. The calcaneus articular surfaces in a sample Chinese population were divided into five types. Type I was the most common type and Type V was the rarest. Type II have the highest stability, Type V may be the lowest stability and Type III was more prone to osteoarthritis. The STJ articular surfaces were basically matched, contributing to the coordinate movement of the STJ. The matching articular surfaces of STJ were more stable than the mismatching surfaces. To some extent that STJ facet number, shape, facet area, and matching situation are factors in STJ stability, and the anatomical variations of the STJ offer predictive value in determining the predisposition to STI.