Talocalcaneal coalition classifications: A critical analysis review and suggested new classification system with implications for treatment.

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.

A retrospective magnetic resonance imaging analysis of bone and soft tissue changes associated with the spectrum of tarsal coalitions.

We aimed to investigate the bone and soft tissue changes accompanying tarsal coalition (TC) and aimed to evaluate their association with the location and type of coalition. Ankle magnetic resonance imagings of 65 patients with TC were included. The relationship between the location and type of coalition and bone marrow edema, subchondral cysts, sinus tarsi syndrome, tarsal tunnel syndrome, posterior impingement syndrome, accessory bone, tibiotalar effusion, talar osteochondritis dissecans, ganglion cysts, and calcaneal spur were evaluated. Twenty-nine patients without coalition were selected as the control group, and the distribution of these variables between the two groups was analyzed. There were 33 females and 32 males in the coalition group (mean age: 42.0 ± 15.63 years), and 22 females and seven males in the control group (mean age: 44.79 ± 12.33 years). Coalition was most common in the talocalcaneal joint (n = 33, 50.8%), and the most common coalition type was non-osseous (n = 57, 87.6%). We find no significant difference between the pathologies defined in terms of coalition location and type. Sinus tarsi syndrome, tarsal tunnel syndrome, subchondral cysts, and tibiotalar effusion were found to be more common in the coalition group (p = 0.028, p = 0.010, p = 0.023, and p = 0.006, respectively). The presence of coalition increased the probability of developing tarsal tunnel syndrome 9.91 times (95% CI: [1.25-78.59]; p = 0.029), and sinus tarsi syndrome 3.66 times (95% CI: [1.14-11.78]; p = 0.029). Tarsal coalition may predispose bone and soft tissue changes. In this study, sinus tarsi syndrome, tarsal tunnel syndrome, subchondral cysts and tibiotalar effusion were found to be more common in the coalition group.

Bone stress injuries in the presence of tarsal coalition as a cause of hindfoot pain in adolescents: case series of 6 patients with literature review.

OBJECTIVE: To highlight causal relationship between stress fracture in the presence of tarsal coalition and hindfoot pain in adolescents on magnetic resonance imaging (MRI). MATERIAL AND METHODS: A retrospective review was performed of the clinical and MRI imaging findings of 6 adolescents referred for MRI to evaluate symptoms of hindfoot pain with possible tarsal coalition. MRI studies were systematically assessed for cause of hindfoot pain, types of tarsal coalition, patterns of stress fractures, bone marrow oedema and any other associated features. RESULTS: All the 6 patients (4 male: 2 female) aged between 12 and 19 years developed insidious onset of hindfoot or midfoot pain over a period of weeks to months. On MRI, all 6 cases had features of fibrous tarsal coalition predominantly in the calcaneonavicular articulation (5 out of 6 patients). Associated stress fractures/response were in the posterior facet/body of the calcaneus (3), talar head (2), cuboid (1) and third metatarsal bone in one patient. CONCLUSION: Stress fractures/response adjacent to tarsal coalition could be because of altered biomechanics and can be an unusual cause of hindfoot pain in adolescents. A high index of suspicion and complementary MRI findings is crucial to interpret this condition to direct appropriate patient management.

Osteochondritis dissecans of the talar dome in patients with tarsal coalition.

OBJECTIVE: Tarsal coalition is known to cause abnormal talocrural stress, hindfoot malalignment, and ankle sprains. These can all be associated with osteochondritis dissecans (OCD) of the talar dome. We present the first detailed description of a series of talar OCDs occurring in patients with tarsal coalition, with the goal of determining whether there is an increased prevalence of OCDs among patients with tarsal coalition. MATERIALS AND METHODS: We studied ankle MRIs in 57 patients with tarsal coalitions, excluding those with a reported inciting traumatic event. The MRIs were performed on magnetic field strengths ranging from 0.3 to 1.5 T and included axial, coronal, and sagittal T1 and T2 or PD fat-suppressed sequences. We evaluated the morphology and location of classically described OCDs in these patients, type and location of concomitant tarsal coalition, and, when available, the presence of pes planus and hindfoot valgus on weight-bearing radiographs. Chi-squared analysis was used to compare categorical variables and a Student's t test was used for parametric continuous variables. Additionally, logistic regression was used to compute the odds ratio of talar OCD associated with patient age, gender, laterality, pes planus status, hindfoot valgus status, and coalition type. RESULTS: Eighty-nine percent of tarsal coalitions were non-osseous coalitions and the calcaneonavicular space was the most common site of abnormal tarsal connection (54.4%). In the 29 patients with tarsal coalitions and talar OCDs, OCDs commonly occurred medially (75.9%). In the sagittal plane, talar OCDs occurred centrally, with only one case sparing the central talar dome. The mean surface area of the 29 OCDs was 89.7 mm2. Both osseous coalition and hindfoot valgus were associated with smaller talar OCD mean surface area (p = 0.015 and p = 0.0001, respectively). There was no association between depth and surface area of talar OCD with either coalition location or presence of pes planus (coalition location: p = 0.455 for depth and p = 0.295 for surface area; presence of pes planus: p = 0.593 for depth and p = 0.367 for surface area). CONCLUSION: Talar OCD prevalence is higher in patients with tarsal coalition than that reported for the general population. This occurrence may relate to altered biomechanics and repetitive talocrural stress owing to altered subtalar motion, particularly given the findings of increased odds of talar OCD in older patients, as well as weak associations between OCD surface area and both non-osseous coalition and hindfoot alignment. However, we did not find any specific OCD morphologic features attributable to the precise location of the tarsal coalition.

Talocalcaneal Tarsal Coalition Size: Evaluation and Reproducibility of MRI Measurements.

BACKGROUND: The size of talocalcaneal tarsal coalitions (TCCs) is one of the main factors that is thought to influence patient outcomes after resection. Magnetic resonance imaging (MRI) is increasingly being used to diagnose and characterize TCCs. However, there is no reproducible MRI-based measurement of TCC size reported in the literature. The purpose of this study was to create a method to reproducibly measure TCC size using MRI. METHODS: Twenty-seven patients with TCCs diagnosed by a hindfoot coronal proton density (PD) MRI between 2017 and 2020 were included. Five independent raters measured coalition width, healthy posterior facet width, and healthy middle facet width on individual slices of coronal PD hindfoot MRIs using discrete MRI measurement guidelines. Individual slice measurements were summed to determine total size of the coalition and the remaining healthy cartilage of the posterior and middle facets. Inter-rater reliability of MRI measurements between the 5 independent examiners was evaluated using intraclass correlation coefficient (ICC). ICC was calculated for total coalition width, total healthy posterior facet width, total coalition width/total healthy posterior facet width, total coalition width/total healthy middle facet width, total coalition width/total healthy subtalar facet width (posterior facet+middle facet), and total coalition width/total subtalar facet width (coalition+posterior facet+middle facet). RESULTS: The ICC scores for all but one of the MRI measurements indicated good to excellent inter-rater reliability among the 5 examiners. The ICC was 0.932 (95% confidence interval: 0.881-0.966) for measurement of total coalition width/total healthy posterior facet width and 0.948 (95% confidence interval: 0.908-0.973) for measurement of total coalition width/total subtalar facet width (middle+posterior+coalition). CONCLUSIONS: Measurements of coalition size using novel MRI guidelines were reproducible with good to excellent inter-rater reliability. These guidelines allow for determination of TCC size using coronal PD MRI. LEVEL OF EVIDENCE: Level II-diagnostic reproducibility study.

The role of ultrasonography in the diagnosis of talocalcaneal coalitions.

BACKGROUND: Patients with talocalcaneal coalitions (TCC) often undergo computed tomography (CT). However, ultrasonography diagnosis of TCC has been seldom done according to the literature. PURPOSE: To investigate the accuracy of ultrasonography in diagnosing TCC compared to CT. MATERIAL AND METHODS: Ninety-seven consecutive patients with a clinical suspicion of TCC were included. Ultrasonography was used to assess the classification and complication of TCC. The main sonographic criteria for a positive diagnosis in cases of osseous coalition were the joint space between the medial surface of talar head and the underlying sustentaculum tali of calcaneus disappearing and being replaced by a continuous hyperechoic bony structure. In cases of fibrous coalition, ultrasonography revealed a reduced space of the joint associated with an irregular, angular appearance of its outline and hypoechoic fibrous tissue inside. These data were compared with CT findings. κ statistic was applied to determine the level of agreement. The sensitivity, specificity, positive and negative predictive values, accuracy, and Youden index of ultrasonography as a diagnostic method were assessed. RESULTS: Ultrasonography findings were positive in 20 of 97 patients with a clinical suspicion of TCC. The diagnosis was confirmed by CT in 21 patients. There were one false-positive result and two false-negative results by ultrasonography. The κ value was 0.907. The sensitivity, specificity, positive and negative predictive values, accuracy, and Youden index of ultrasonography were 90.5%, 98.7%, 95.0%, 97.4%, 96.9%, and 0.892, respectively. CONCLUSION: Ultrasonography could be a reliable, accurate, and non-radioactive diagnostic imaging method in diagnosis of patients with suspected TCC.

Prospective Evaluation of Tarsal Coalition Excision Show Significant Improvements in Pain and Function.

BACKGROUND: Excision of pediatric tarsal coalition has been successful in most patients. However, some patients have ongoing pain after coalition excision. This study prospectively assessed patient-based clinical outcomes before and after surgical excision of tarsal coalition, with particular emphasis on comparison to radiologic imaging. METHODS: We prospectively studied 55 patients who had symptomatic coalition excision for 2 years postoperatively. Patients filled out the modified American Orthopaedic Foot and Ankle Society score, the University of California Los Angeles activity score, and the simple question "does foot pain limit your activity" at 4 different time points: preoperative, 6 months postoperative, 12 months postoperative, and 24 months postoperative. Comparisons were done utilizing patient demographics, imaging parameters, and patient-reported outcomes. RESULTS: Compared with preoperative levels, patients showed improvements in all outcome parameters. Patients with calcaneonavicular coalitions showed initial rapid improvement with later slight decline, while patients with talocalcaneal coalitions showed more steady improvement; both were similar at 2 years postoperatively. CONCLUSIONS: This prospective study demonstrated remarkable clinical improvements after tarsal coalition excision regardless coalition type, though postoperative courses differed between calcaneonavicular and talocalcaneal types. Finally, a subset of patients has ongoing activity limiting foot pain after coalition excision which could not be explained by the data in this study. LEVEL OF EVIDENCE: Level II-prospective cohort study.

Radiological findings of fibrocartilaginous coalition of the third tarsometatarsal joint: a retrospective cross-sectional study with computed tomography and magnetic resonance imaging.

BACKGROUND: Fibrocartilaginous coalition of the third tarsometatarsal joint has been indicated as an extremely rare form of tarsal coalition in the radiological literature, and most articles concerned with tarsal coalition do not mention involvement of this joint. Only two reports written in the English language that approach this subject were found, an orthopedic report and an anthropological report. PURPOSE: To evaluate the prevalence of this finding and discuss and illustrate the radiological characteristics of this coalition. MATERIAL AND METHODS: A retrospective analysis of 614 computed tomography or magnetic resonance imaging scans of the ankle and/or foot, acquired at a health service within a period of three months, was performed to assess the prevalence of this coalition. RESULTS: Of the examinations characterized as valid for analysis for the purposes of the study, 17 cases compatible with fibrocartilaginous coalition of the third tarsometatarsal joint were found, thus indicating an involvement of approximately 2.97% of the examined feet. CONCLUSION: Our radiological findings are typical, and the prevalence found in this study was statistically significant, being similar to that described in the anthropological report (3.2%-6.8%).

The radiological diagnosis of extra-articular posteromedial talocalcaneal coalition.

OBJECTIVES: Extra-articular posteromedial talocalcaneal coalition (EA-PM TCC) accounts for approximately one-third of TCC, but its radiographic features are not well-described. The current study aims to compare the radiographic features of EA-PM TCC with normal ankles and with the commoner forms of TCC. MATERIALS AND METHODS: A retrospective review of cases of TCC over 12 years for whom radiographs, CT, and/or MRI study were available. Radiographs were assessed by 2 radiologists for the presence of the C-sign, talar beak, dysmorphic sustentaculum, absent middle facet, and prominence of the posterior subtalar joint. TCC was classified by a third radiologist based on CT/MRI findings into 3 groups: no TCC, EA-PM TCC, and other TCCs. The radiographic findings for the 3 groups were compared. RESULTS: The study included 50 patients, 28 males and 22 females with a mean age of 21.1 years (range 8-70 years). In 15 patients, both ankles had been imaged, resulting in a total of 65 cases. In 17 ankles, no TCC was identified, while 15 ankles were classified as EA-PM TCC and 33 as having other types of TCC. There were no statistically significant differentiating radiological features between the groups with no TCC and EA-PM TCC apart from prominence of the posterior subtalar joint, while only the C-sign allowed identification of patients with other types of TCC. CONCLUSIONS: The study suggests that EA-PM TCC cannot be diagnosed based on the classical indirect radiological signs of TCC, but can be identified by prominence of the posterior subtalar joint.

Accessory anterolateral talar facet associated with tarsal coalition: prevalence and cross-sectional characterization.

OBJECTIVE: The accessory anterolateral talar facet (AALTF) is a developmental entity described as a potential cause for rigid, painful flat foot. This study evaluates the possible association between the AALTF and other flat foot etiologies, specifically different types of tarsal coalitions. MATERIALS AND METHODS: We evaluated patients with tarsal coalition or sinus tarsi syndrome for an AALTF on CT and MRI. Exclusion criteria included acute ankle trauma, recent surgery, motion or metal artifacts. We evaluated the AALTF length and height, and the lateral talocalcaneal structures for associated findings. The presence of calcaneonavicular (CNC), intra-articular middle facet talocalcaneal (MFTCC), posterior facet talocalcaneal (PFTCC), extra-articular posteromedial talocalcaneal (EATCC) and other rare coalitions were also evaluated. RESULTS: One hundred eighty-seven patients were included (age range 14-91 years; mean ± SD; 50 ± 17 years). The AALTF prevalence in the study population was 31.55% (59/187), 40.91% in men, and 23.23% in women. The AALTF average length was 4.5 ± 1.1 mm, and average height was 8.9 ± 3.4 mm. The AALTF was found to be significantly associated with lateral talocalcaneal osseous changes such as cortical thickening and cystic changes (34/59 and 24/59 respectively, P < 0.01). The AALTF was also found to be significantly associated with sinus tarsi edema on MRI (45/52, P < 0.05). The AALTF was also significantly associated with EATCC (19/59, P < 0.01) and MFTCC (7/59, P < 0.05). No significant association was found with CNC, PFTCC or other rare coalitions. CONCLUSION: The AALTF is common and significantly associated with some tarsal coalitions, specifically EATCC and MFTCC. When an AALTF or coalition is identified, special attention should be made to evaluate for other associated pathologies, as this could potentially affect management.

Correlation between the accessory anterolateral talar facet, bone marrow edema, and tarsal coalitions.

OBJECTIVE: The purposes of this study was to determine the prevalence of the accessory anterolateral talar facet (AALTF); to evaluate the relationship between AALTF, focal abutting bone marrow edema (FABME), and sinus tarsi edema; and to study the prevalence of tarsal coalitions in patients with the AALTF utilizing ankle MR images. MATERIALS AND METHODS: 5-T ankle MR images were reviewed for the presence of AALTF, FABME, sinus tarsi edema, tarsal coalition, and location and type of coalition (cartilaginous, fibrous, and osseous). Multivariate analysis was performed to examine the correlation between AALTF and the other variables. RESULTS: Three hundred ninety-one consecutive patients were included (age range 5-86 years; mean age 45 years). An AALTF was present in 3.6% (14/391) of patients. The AALTF prevalence was 2% in women and 6.6% in men. There was a significantly association between AALTF and FABME (9/14, p < 0.05), sinus tarsi edema (13/14, p < 0.05), and tarsal coalition (4/14, p < 0.05). CONCLUSION: AALTF is relatively often detected on MRI of the ankle and significantly associated with BME, sinus tarsi edema, and subtalar coalition. Patients with a tarsal coalition should be evaluated for the concurrent presence of an AALTF.

Cryopreserved Amniotic Membrane and Autogenous Adipose Tissue as an Interpositional Spacer After Resection of a Cubonavicular Coalition: A Case Report and Review of the Literature.

Coalitions of the hindfoot are a relatively rare but challenging condition encountered by foot and ankle surgeons. Those that manifest between the cuboid and navicular (cubonavicular coalitions) are seen even more infrequently and are estimated to comprise ∼1% of all tarsal coalitions. Treatment for cubonavicular coalitions parallels protocols for more common hindfoot coalitions. Typically, resection versus hindfoot arthrodesis procedures are used. The present study describes the case of a 34-year-old male with a painful cubonavicular coalition and early secondary signs of arthrosis. Despite the recommended guidelines of hindfoot arthrodesis, he elected for surgical resection. Autogenous adipose tissue and cryopreserved amniotic membrane were used for interposition at the resection site. This case demonstrates that surgical resection with interpositional grafting can be successful even in advanced disease states.

Nonsyndromic Massive Tarsal and Tarsometatarsal Coalitions in a Young Female.

Tarsal coalition is an abnormal connection between 2 or more tarsal bones, with the most common sites being between the talus and the calcaneus and between the navicular and the calcaneus. The occurrence of multiple and massive tarsal coalitions is rare. We describe a rare case of nonsyndromic bilateral tarsal coalition involving most of the tarsal bones and extending to the metatarsal bones in a 4-year-old female. The condition was not painful and did not affect her gait. The main concern was the abnormal shape of her feet. Tarsal coalition can occur as an isolated anomaly or in association with other congenital disorders, usually presenting around the age of 12 years. The coexistence of nonsyndromic bilateral multiple tarsal coalitions is seldom reported. Regardless of the presentation, treatment is not indicated in cases of asymptomatic tarsal coalition. Our patient had a unique presentation of tarsal coalition, involving both the tarsal and tarsometatarsal bones. To our knowledge, this is the first report of this type of presentation.

Technique Article: Tarsal Coalition Resection Using Kirschner Wires Across the Subtalar Joint in a Two-Incision Approach.

Subtalar coalitions are a significant cause of morbidity, especially in the pediatric population. Arthrodesis was considered the standard of care, with coalitions involving >50% of the joint until the mid-1990s. Today, some are recommending resection of the coalition first and to save hindfoot arthrodesis as a salvage procedure. As a result, resection of talocalcaneal coalitions is becoming more common, and optimizing the surgical technique is a necessity in the field of orthopedics. We present a technique to optimize surgical resection of talocalcaneal coalitions by using Kirschner wires inserted from the lateral side, which allows us to demarcate the coalition. This gives us a greater ability to perform a more complete resection and also helps prevent iatrogenic trauma to the articulating surface.

Functional and Radiological Outcomes After Tarsal Coalition Resections: A Minimum 5-Year Follow-Up.

Few studies have evaluated the long-term functional and radiological outcomes of tarsal coalition resections. This study aimed to report and compare the functional and radiological outcomes after talocalcaneal (TC) and calcaneonavicular (CN) coalition resections. Thirty-three patients between 12 and 35 years old with symptomatic tarsal coalitions participated, each undergoing tarsal coalition resections (24 TC and 9 CN). The range of motion, visual analog scale score, American Orthopedic Foot and Ankle Society hindfoot scale, Maryland foot score, tripod index, and modified Kellgren-Lawrence scale for subtalar osteoarthritis were used to evaluate the functional and radiological outcomes. The mean age at the time of surgery and mean follow-up in the TC group were 17.8 ± 5.6 years (range 13 to 35) and 6.2 ± 1.7 years (range 5 to 12), respectively, and 16.0 ± 4.4 years (range 12 to 23) and 7.7 ± 3.0 years (range, 5 to 12) in the CN group. There was no difference in the range of motion, outcome scores, tripod index score, and modified Kellgren-Lawrence scale score between patients in the 2 groups. A positive correlation was noted between the size of the TC coalition, coalition/joint surface ratio, and hindfoot valgus angle regarding outcome scores. However, there was no association between the modified Kellgren-Lawrence scale score and outcome scores. At the minimum 5-year follow-up, the functional and radiological outcomes were similar between TC and CN resections. Subtalar joint osteoarthritis developed in all patients with TC resections and most patients with CN resections, but patients did not have functional impairment.

Bilateral Triple Talocalcaneal, Calcaneonavicular, and Talonavicular Tarsal Coalition: A Case Report.

We report a rare case of a female, aged 42 years, with symptomatic bilateral triple tarsal coalition, that is, talocalcaneal, calcaneonavicular, and talonavicular tarsal coalition. The patient was treated conservatively by adjusting her activities. At the 12-month follow-up, the patient was asymptomatic. Bilateral triple tarsal coalition is a rare disorder, especially in nonsyndromic patients. The purpose of this case report was to highlight this rare type of multiple bilateral tarsal coalitions and to discuss the relevant existing literature.

Subtalar Coalitions: Does the Morphology of the Subtalar Joint Involvement Influence Outcomes After Coalition Excision?

Posteromedial subtalar (PMST) coalitions are a recently described anatomic subtype of tarsal coalitions. We compared with clinical patient-based outcomes of patients with PMST and standard middle facet (MF) coalitions who had undergone surgical excision of their coalition. The included patients had undergone surgical excision of a subtalar tarsal coalition, preoperative computed tomography (CT), and patient-based outcomes measures after surgery (including the American Orthopaedic Foot and Ankle Society [AOFAS] scale and University of California, Los Angeles [UCLA], activity score). Blinded analysis of the preoperative CT scan findings determined the presence of a standard MF versus a PMST coalition. The perioperative factors and postoperative outcomes between the MF and PMST coalitions were compared. A total of 51 feet (36 patients) were included. The mean follow-up duration was 2.6 years after surgery. Of the 51 feet, 15 (29.4%) had a PMST coalition and 36 (70.6%) had an MF coalition. No difference was found in the UCLA activity score; however, the mean AOFAS scale score was higher for patients with PMST (95.7) than for those with MF (86.5; p = .018). Of the patients with a PMST, none had foot pain limiting their activities at the final clinical follow-up visit. However, in the group with an MF subtalar coalition, 10 (27.8%) had ongoing foot pain limiting activity at the final follow-up visit (p = .024). Compared with MF subtalar tarsal coalitions, patients with PMST coalitions showed significantly improved clinical outcomes after excision. Preoperative identification of the facet morphology can improve patient counseling and expectations after surgery.

Intraoperative Three-Dimensional Navigation for Talocalcaneal Coalition Resection.

Talocalcaneal tarsal coalitions are a common source of foot pain, stiffness, and deformity. These coalitions are treated symptomatically with rest and periods of immobilization. When those measures fail, surgical resection is attempted. This procedure is an anatomic challenge with the consequence of leaving residual coalition. The residual coalition primarily results from difficulty with intraoperative imaging because fluoroscopy does not provide adequate detail of this area. Some investigators have recommended intraoperative computed tomography after resection with reasonable results. We describe the combination of an intraoperative computed tomography with a navigated instrument system for resection of talocalcaneal coalitions. The use of a navigated probe and burr aids in defining the most anterior, posterior, and medial extents of the coalition. This technique reduces the morbidity, with less bone removed and preservation of intact subtalar articulations and allows for an efficient, thorough, and controlled resection.