Talocalcaneal coalitions (TCC) is the second most frequent tarsal coalition reported. Our aim was to review talocalcaneal coalition classifications and to propose a new classification emphasizing a therapeutic approach. None of the classifications described for TCC mention the presence of flatfoot or valgus hindfoot, which are the key elements when defining the optimal treatment of this disease. We defined five clinical and radiological factors that would guide the choice of surgical treatment and based on these, we proposed a new classification system.

UNASSIGNED: 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.
UNASSIGNED: 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.
UNASSIGNED: 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.
UNASSIGNED: 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.
UNASSIGNED: Level IV, retrospective study.

OBJECTIVE: To analyze the outcome of surgical treatment of tarsal coalition, assess the role of the surgical technique, as well as of coalition size and type on outcomes.
METHODS: The search followed the Preferred Reporting Items of Systematic Review and Meta-Analysis and was performed in four databases: MEDLINE, Central, Scopus and Web of Science. The protocol has been registered in the international prospective register of systematic reviews. Patient-reported outcomes (PROMs), complications, revisions and radiographic recurrence were collected. Risk of bias was assessed using MINORS criteria. A random-effects model for meta-analysis was applied for analysis of data heterogeneity.
RESULTS: Twenty-five studies including 760 tarsal coalitions were included and had a weighted average follow-up of 44 months. Studies scored fair to poor on the risk of bias assessment with a mean MINORS score of 67% (44-81%). In 77.8% (37.5-100%) of surgically treated tarsal coalitions, good/excellent/non-limiting or improved PROMs were reported. Calculated data heterogeneity was moderate (I2 = 57%). Open bar resection with material interposition had a clinical success rate of 78.8% (50-100%). Complications occurred in 4.96% of cases. Coalition size did not prove to be a determining factor in postoperative outcome. The influence of the coalition type was not investigated by any of the studies.
CONCLUSIONS: Data on outcomes of surgical management for tarsal coalitions is limited to retrospective case series with high risk of bias and moderate data heterogeneity. In about ¾ of cases, open resection and interposition of material results in improved PROMs. The arbitrary margin of ≥ 50% of TC coalition size in relation to the posterior facet has little importance in surgical decision-making. None of the studies reported on the influence of the coalition type on postoperative clinical success.

Tarsal coalitions are abnormal fibrous or bony connections between the tarsal bones of the foot. While not always symptomatic, coalitions can cause pain, alterations in forefoot and hindfoot morphology, and alterations in foot and ankle biomechanics. Previous research has described the association of tarsal coalitions with fractures of the lower extremity. Multiple reports of acute fracture in the presence of tarsal coalition have been presented, as have reports of stress fractures of the foot and ankle with concomitant coalition, insidious in onset and thought to be related to aberrancies in foot and ankle biomechanics. The purpose of this review is to discuss the biomechanics seen in tarsal coalitions and to describe reports of fracture occurring concomitantly with tarsal coalitions. We will discuss diagnostic options and treatment approaches in the setting of fracture with preexisting tarsal coalition.

Arthroscopic resection of the talocalcaneal coalition (TCC) has been reported to be associated with good short-term outcomes. However, the midterm outcomes of this approach remain uncertain.
We performed a retrospective study of patients who underwent arthroscopic resection for symptomatic TCC. The patients were divided into 2 groups (group P, patients with isolated posterior facet coalition; and group MP, patients with both middle and posterior facet coalition). The preoperative and postoperative visual analog scale (VAS) scores for pain and American Orthopaedic Foot & Ankle Society (AOFAS) scale scores were calculated. The postoperative AOFAS and VAS scores between the 2 groups were analyzed. Patient satisfaction was also assessed.
Thirty-two patients were included in this study. The mean age at the time of surgery was 26.0±8.5 years, and the mean follow-up period was 56.9±18.0 months. Thirteen (41%) patients were in group P, whereas 19 (59%) patients were in group MP. Postoperative VAS and AOFAS scores improved more significantly than preoperative scores. At the final follow-up, excellent and good subjective outcomes were attained in 26 patients (81%), fair and poor outcomes in 6 patients (19%). There were no statistical differences in the postoperative AOFAS (91.0±7.0 vs 85.8±10.8, P = .532) and VAS score (2.1±1.7 vs 4.0±2.6, P = .537) between patients with the ratio of coalition/posterior facet more than or less than 50%. There were no statistical differences in postoperative VAS score (1.8±1.3 vs 2.6±2.2, P = .236) and AOFAS score (92.5±5.6 vs 89.2±8.7, P = .297) between group P (n=13) and group MP (n=19), either. Three patients (9.4%) had complications, including these notable findings: 1 patient complained of restricted dorsal flexion, 1 with computed tomography-proven coalition recurrence, and 1 with partial tibial nerve injury.
We found that TCC arthroscopic resection was generally associated with reasonable outcomes at midterm follow-up.
Level IV, case series.

BACKGROUND: The primary aim was to determine the clinical success rate after treatment for talocalcaneal (TCC) and calcaneonavicular coalitions (CNC). The secondary aim was to evaluate the complication, recurrence and revision rate.
METHODS: A search was carried out in MEDLINE, EMBASE and Cochrane Library. Methodological quality was assessed using the Methodological Index for Non-Randomised Studies (MINORS) criteria. The primary outcome was the clinical success rate and was pooled per type of coalition and treatment modality. 95% Confidence Intervals (CI) of the success rates were calculated. Secondary outcomes included complication rates, coalition recurrence rates, revision rates and pain improvement using the Visual Analogue Scale (VAS). A sub-analysis on interposition material was performed.
RESULTS: 43 articles comprising of 1284 coalitions were included, with a pooled mean follow-up of 51 months. Methodological quality was fair. The overall pooled success rate for TCCs was 79% (95% CI, 75%-83%). Conservative treatment, open resection and arthroscopic resection of TCCs resulted in success rates of 58% (95% CI, 42%-73%), 80% (95% CI, 76%-84%) and 86% (95% CI, 71%-94%), respectively. CNCs have an overall success rate of 81% (95% CI, 75%-85%), with 100% (95% CI, 34%-100%), 80% (95% CI, 74%-85%) and 100% (95% CI, 65%-100%) for conservative treatment, open resection and arthroscopic resection, respectively. Pooled complication rates of 4% (95% CI, 3%-7%) for TCCs and 6% (95% CI, 4%-11%) for CNCs were found. The success rates of resection with and without interposition material for TCCs were 83% (95% CI, 78%-87%) and 79% (95% CI, 65%-88%), and for CNCs 81% (95% CI, 76%-86%) and 69% (95% CI, 44%-85%), respectively.
CONCLUSIONS: Treatment of tarsal coalitions can be considered good to excellent as well as safe, with an overall clinical success rate of 79% for TCCs and 81% for CNCs. Arthroscopic resection of the coalition appears to be non-inferior to open resection of TCCs and CNCs.
METHODS: Level IV, Systematic Review.

OBJECTIVE: Pathologies of the medial talus (e.g., fractures, tarsal coalitions) can lead to symptomatic problems such as pain and nonunion. Bony resection may be a good solution for both. It is unclear how much of the medial talus can be taken before the subtalar joint becomes unstable. The aim of this study was to evaluate the effect a limited resection of the medial talar facet and the anteromedial portion of the posterior talar facet has on subtalar stability.
METHODS: Eight fresh-frozen human cadaveric lower limbs were mounted in a frame for simulated weight-bearing. Computed tomography scans were obtained under 700 N single-legged stance loading, with the foot in neutral, 15° inversion, and 15° eversion positions. A sequential resection of 10, 20, and 30% of the medial facet and the anteromedial portion of the posterior talar facet to the calcaneus, based on the intact talus width, was performed. Measurements of subtalar vertical angulation, talar subluxation, coronal posterior facet angle and talocalcaneal (Kite) angle in the anteroposterior and lateral view were performed.
RESULTS: Gross clinical instability was not observed in any of the specimens. No significant differences were detected in the measurements between the resected and intact states (P ≥ 0.10) as well as among the resected states (P ≥ 0.11).
CONCLUSIONS: In a biomechanical setting, resecting up to 30% of the medial facet and anteromedial portion of the posterior facet based on the intact talus width-does not result in any measurable instability of the subtalar joint in presence of intact ligamentous structures.
METHODS: V.

BACKGROUND: Resection of talocalcaneal coalitions has generally involved osseous coalitions. We attempted to evaluate the morphology of nonosseous talocalcaneal coalitions. This study aimed to investigate if the calcaneal articular surface area of feet with talocalcaneal coalitions is different than that of normal feet.
METHODS: Twenty nonosseous talocalcaneal coalition cases with analyzable computed tomography (CT) scans were compared to 20 control cases. Three-dimensional models of the talus and calcaneus were constructed, and the surface areas of the posterior facet (SPF), whole talocalcaneal joint of the calcaneus (SWJ), and coalition site (SCS) of each 3D-CT model were measured. \"Calibrated\" values of the 2 groups were created to adjust for relative size of the tali and then compared. The preoperative and postoperative AOFAS Ankle-Hindfoot scale was calculated for 9 cases that had undergone single coalition resection.
RESULTS: The calibrated SPF and SWJ were significantly greater in the coalition group than in the control group (40% and 12%, respectively). No significant difference was detected between the calibrated (SWJ - SCS) value of the coalition group and the calibrated SWJ value of the control group. The AOFAS scale was improved postoperatively in all 9 cases analyzed.
CONCLUSIONS: The calcaneal articular surface of nonosseous talocalcaneal coalition feet in our series was larger than that of the normal feet. This study indicates that the total calcaneal articular surface after coalition resection may be comparable to the calcaneal articular surface of normal feet. We suggest that the indication for coalition resection be reconsidered for nonosseous coalition.
METHODS: Level III, retrospective comparative study.

Tarsal coalition is determined by an absence of segmentation between one or more foot bones. The main symptom is activity-related foot pain, usually dorsolateral for calcaneonavicular coalitions and medial for talocalcaneal ones. At presentation, a symptomatic tarsal coalition must be treated conservatively for at least 6 months. If the conservative treatment fails and the foot is still painful, resection is the treatment of choice. Advantage of surgery is to restore mobility and reduce the risk of subsequent degenerative arthritis. Common pitfalls of surgery include failure to recognize associated coalitions, inadequate or extensive resection, and injury of adjoining bones.

Concomitant talocalcaneal coalition (TCC) in idiopathic clubfeet is not well documented in the literature. The purpose of this study was to describe our experience with very early relapsing idiopathic clubfeet associated with TCC. Although cases have been successfully treated with the Ponseti casting method, all recurred within 2 months of removing the final cast. A single-centre cohort of twelve feet in eight patients treated by a single surgeon between 2006 and 2020 was investigated retrospectively. Recurred cavus with variable degrees of equinus was the earliest findings noted. TCC was incidentally detected during the open reduction of the earliest three feet in our series. Afterwards, ultrasonography was advised as a screening tool for detecting an associated anomaly; however, only the use of magnetic resonance imaging (MRI) was 100% accurate in diagnosing concurrent TCC. All coalitions were cartilaginous and the posterior facet was most commonly involved facet. The average age was 18 months for the coalition resection and open reduction of a dislocated talonavicular joint, and the average duration of follow-up was 52 months. None of the patients showed clinical signs of relapse at the latest follow-up. We recommend that an associated TCC should be considered in very early relapsing idiopathic clubfoot cases.