Osseous and non-osseous coalition of the middle facet of the talocalcaneal joint

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.

Outcomes of surgical management for tarsal coalitions: a systematic review

PURPOSE

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.

CONCLUSION

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.

Cavus Foot Deformity with Calcaneonavicular and Medial Cuneiform-Navicular Coalition: A Case Series

Tarsal coalitions have only very infrequently been observed in the context of cavus foot abnormalities. Recognizing this diagnosis could be crucial to effective cavus repair. We report tarsal coalitions observed in cavus deformity here. Between 2022 and 2023, the records of every patient treated by one of the authors for a varus deformity who was later determined to have either a unilateral or bilateral tarsal coalition were examined. Two patients with cavus deformities who were treated by one of the authors have either a unilateral or bilateral tarsal coalition. Three foot (medial cuneiform-navicular n = 1 and calcaneonavicular n = 2) with tarsal coalition were examined. All of these cases occurred in patients with idiopathic cavus deformity. Computed tomography scans were used to make a firm diagnosis for each patient. We advise surgeons to keep an awareness for this potential comorbid issue in all cavus foot abnormalities and to take advanced imaging into consideration. In these uncommon cases, the medial cuneiform-navicular and calcaneonavicular joints formed an osseous coalition with pes cavus deformity, which successfully resolved with conservative and surgical treatment, respectively. Level of Clinical Evidence: IV.

Decision-Making and Management of Tarsal Coalition in the Young Adult Patient: A Critical Analysis Review

» Tarsal coalitions most commonly affect the calcaneonavicular and talocalcaneal joints in up to 13% of the general population. They alter the mechanics of the subtalar joint, limiting inversion and eversion, and place excessive stress on neighboring joints causing pain, recurrent ankle sprains, and/or progressive pes planus during the adolescent growth spurt.» While many coalitions are identified on radiographs, advanced imaging with computed tomography or magnetic resonance imaging is sometimes required. These advanced imaging modalities also serve an essential role for surgical planning to quantify coalition involvement, identify fibrous or cartilaginous coalitions, and aid in determining the degree of deformity within the foot.» Surgical treatment is reserved for feet with persistent activity-related pain not relieved by prolonged attempts at nonoperative management, which include nonsteroidal anti-inflammatory drugs, shoe orthotics, and periods of non-weight-bearing in a cast. These conservative modalities may be successful in up to 85% of cases.» For adolescent patients, recent surgical options attempt to avoid arthrodesis and focus on coalition resection and interposition grafting with or without deformity correction. The ultimate decision is based on the location of the pain, the size and histology of the coalition, the health of the posterior subtalar facet, the degree of flatfoot deformity, and the presence of degenerative changes in the subtalar and/or adjacent joints.» While many studies focus on subtalar motion and gait kinematics, the critical outcomes remain pain relief and future need for arthrodesis, which may be related not only to resection of the coalition but assessment of deformity, including after the resection has been performed.

Racial differences in prevalence and anatomical distribution of tarsal coalition

Previous studies have reported a prevalence of tarsal coalition of 0.03-13%. Calcaneonavicular coalition is known as main anatomical type, and the bilateral occurrence of tarsal coalition is known to be 50% or more. These are the results of studies on Caucasians, there have been few studies targeting large number of East Asians so far. We hypothesized that the prevalence and characteristics of tarsal coalition in East Asians might differ from those in Caucasians. The medical records of 839 patients who underwent bilateral computed tomography on foot and ankle in our hospital from January 2012 to April 2021 were retrospectively reviewed. The overall prevalence was 6.0%, talocalcaneal coalition was the most common anatomical type. The overall bilateral occurrence was 56.5%, talocalcaneal coalition had the highest bilateral occurrence (76.0%) among anatomical types. Isolated union of the posterior facet was the most common subtype of talocalcaneal coalition (43.2%). Talocalcaneal coalition had a significantly higher proportion of coalition-related symptomatic patients than calcaneonavicular coalition (p = 0.019). Our study showed a similar trend to other East Asian studies, confirming the existence of racial differences. The possibility of tarsal coalition in foot and ankle patients in East Asians should always be considered, and bilateral examination is essential for diagnosis.

Lateral endoscopy of the sinus tarsi: Anatomy, technique and current indications

Numerous pathologies are reported in the lateral mid- and hind-foot. Access to the sinus tarsi is difficult, making lateral endoscopy the preferred approach. The present technical note describes the anatomy, technique and current indications for lateral endoscopy of the sinus tarsi.

8 out of 10 patients do well after surgery for tarsal coalitions: A systematic review on 1284 coalitions

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.

CONCLUSION

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.

LEVEL OF EVIDENCE

Level IV, Systematic Review.

Lateral Arthroscopic Subtalar Arthrodesis for Talocalcaneal Coalition: Surgical Technique

Resection of symptomatic talocalcaneal coalitions (TCCs) has been performed for patients with normal tarsal joints and <50% involvement of the subtalar joint. For those with TCCs >50% of subtalar articulation or/and subtalar arthritis, a subtalar arthrodesis is done. The purpose of this Technical Note is to describe the arthroscopic resection of TCC and talocalcaneal arthrodesis during the same procedure by using a 2 lateral portal technique. With the patient in lateral decubitus under general or locoregional anaesthesia, the foot and ankle are extended beyond the edge of the surgical table. A lateral portal is created 1 cm anterior to the tip of the lateral malleolus in which the arthroscope is introduced. The anterolateral portal is created 1 cm inferior and 2 cm anterior to the tip of the lateral malleolus. The posterior subtalar surface is prepared progressively. The TCC resection is completed. The fixation is obtained with 2 cannulated screws. The arthroscopic resection of TCC and subtalar arthrodesis during the same procedure by using 2 lateral portals can be done for correctly selected patients.

A new classification of talocalcaneal coalitions based on computed tomography for operative planning

BACKGROUND

Current classifications emphasize the morphology of the coalition, however, subtalar joint facets involved should also be emphasized.

OBJECTIVE

The objective of this study was to develop a new classification system based on the articular facets involved to cover all coalitions and guide operative planning.

METHODS

Patients were diagnosed with talocalcaneal coalition using a CT scan, between January 2009 and February 2021. The coalition was classified into four main types according to the shape and nature of the coalition: I, inferiorly overgrown talus or superiorly overgrown calcaneus; II, both talus and calcaneus overgrew; III, coalition with an accessory ossicle; IV, complete osseous coalition (I-III types are non-osseous coalition). Then each type was further divided into three subtypes according to the articular facets involved. A, the coalition involving the anterior facets; M, the coalition involving the middle facets, and P, the coalition involving the posterior facets. Interobserver reliability was measured at the main type (based on nature and shape) and subtype (articular facet involved) using weighted Kappa. Results There were 106 patients (108 ft) included in this study. Overall, 8 ft (7.5%) were classified as type I, 75 ft (69.4%) as type II, 7 ft (6.5%) as type III, and 18 ft (16.7%) as type IV. Twenty-nine coalitions (26.9%) involved the posterior facets only (subtype-P), 74 coalitions (68.5%) involved both the middle and posterior facets (subtype-MP), and five coalitions (4.6%) simultaneously involved the anterior, middle, and posterior facets (subtype-AMP). Type II-MP coalition was the most common. The value of weighted Kappa for the main type was 0.93 (95%CI 0.86-0.99) (p<0.001), and the value for the subtype was 0.78 (95%CI 0.66-0.91) (p<0.001).

CONCLUSION

A new classification system of the talocalcaneal coalition to facilitate operative planning was developed.

Surgical Treatment of Severe Idiopathic Flexible Flatfoot by Evans-Mosca Technique in Adolescent Patients: A Long-Term Follow-Up Study

Flexible idiopathic flatfoot is very common in growing age and rarely causes pain or disability. Surgery is indicated only in severe symptomatic cases that are resistant to conservative treatment, and numerous surgical procedures have been proposed. Lateral column calcaneal lengthening as described by Evans and modified by Mosca is a widely used surgical technique for the correction of severe symptomatic flexible flatfoot. In the present study, we report the long-term clinical and radiographic results in 14 adolescent patients (mean age: 12.8 years) affected by severe symptomatic flexible flatfoot, surgically treated by Evans–Mosca procedure, for a total of 26 treated feet (12 cases bilateral and 2 unilateral). In all cases, surgery was indicated for the presence of significant symptoms resistant to nonsurgical management. Clinical evaluation was made according to the American Orthopedic Foot and Ankle Society (AOFAS) Ankle-Hindfoot Scale, the Foot and Ankle Disability Index (FADI) Score, and Yoo et al.'s criteria. Radiographic evaluation was made using anteroposterior and lateral weight-bearing radiographs of the feet to evaluate Meary's angle and Costa–Bertani's angle and to evaluate possible osteoarthritic changes in the midtarsal joints. At follow-up (mean: 7 years and 7 months), we observed a satisfactory result in all patients. The mean average score of the AOFAS Ankle-Hindfoot Scale improved from 60.03 points to 95.26; the mean FADI score improved from 71.41 to 97.44; and according to Yoo et al.'s criteria, the average clinical outcome score was 10.96. At radiographic examination, nonunion of the calcaneal osteotomy was never observed. Meary's angle improved from an average preoperative value of 25° to 1.38° at follow-up; Costa–Bertani's angle improved from an average preoperative value of 154.2° to 130.9° at follow-up. In no case, significant radiographic signs of midtarsal joint arthritis were observed. According to our results, we believe that Evans–Mosca technique is a valid option of surgical treatment for severe idiopathic flexible flatfoot and allows a satisfactory correction of the deformity with a low rate of complications.

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.

Operative versus nonoperative treatment in children with painful rigid flatfoot and talocalcaneal coalition

Background

The management of painful rigid flatfoot (RFF) with talocalcaneal coalition (TCC) is controversial. We aimed to compare operative and nonoperative treatment in children with RFF and TCC.

Methods

We retrospectively reviewed medical records and radiographs of children with RFF and TTC treated between 2005 and 2015. The nonoperative treatment consisted of manipulation under anesthesia, cast immobilization and shoe insert after cast removal. The operative treatment consisted of combined TCC resection, graft interposition and subtalar arthroereisis.

Results

Thirty-four children (47 ft) in the nonoperative group and twenty-one children (34 ft) in the operative group were included. No differences were found between groups, concerning baseline characteristics. The mean age at treatment was 11.8 years (9–17): 11.6 (9–17) for the nonoperative group, 12.2 (10–15) for the operative group. The mean follow-up averaged 6.6 (3–12) years and was significantly longer in the nonoperative group (7.8 versus 4.7 years; p < 0.0005), since the operative procedure was increasingly practiced in the latest years.

There were no complications in either groups, but 6 patients (7 ft) in the nonoperative group were unsatisfied and required surgery. At the latest follow-up, the AOFAS-AHS improved in both groups, although the operative group showed significantly better improvement. The operative group reported also significantly better FADI score, after adjustment for follow-up and baseline variables.

Conclusion

The operative treatment showed better results compared to the nonoperative treatment. Symptomatic RFF with TCC in children can be effectively treated in one step with resection, graft interposition and subtalar arthroereisis. Further prospective randomized studies are needed to confirm our findings and to identify the best operative strategy in this condition.

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.

Anteroposterior Radiograph of the Ankle with Cross-Sectional Imaging Correlation

The focus of this article is to illustrate various pathologic entities and variants, heralding disease about the ankle, based on scrutiny of AP radiographs of the ankle, with correlative findings on cross-sectional imaging. Many of these entities can only be detected on the AP ankle radiograph and, if not recognized, may lead to delayed diagnosis and persistent morbidity to the patient. However, a vigilant radiologist, equipped with the knowledge of the characteristic appearance and typical locations of the imaging findings, should be able to make the crucial initial diagnosis and surmise additional findings to be confirmed on cross-sectional imaging.

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.

Tarsal coalition in paediatric patients

Tarsal coalition is due to failure of segmentation between two or more foot bones during embryological development at a site where the joint cleft fails to develop. Depending on the nature of the tissue connecting the bones, the abnormality is a syndesmosis, synchondrosis, or synostosis. Although the coalition exists at birth, synostosis usually develops only late during growth. Talo-calcaneal and calcaneo-navicular coalitions account for over 90% of all cases of tarsal coalition. The joint at the site of the coalition is stiff. Pain during physical activity is the main symptom, although recurrent ankle sprain is another possible presenting manifestation. During the physical examination, range-of-motion limitation at the hindfoot or midfoot should be sought, as well as varus or valgus malalignment of the hindfoot. Either pes planus or pes cavus may be seen. Calcaneo-navicular coalition may be visible on the standard radiograph, whereas talo-calcaneal coalition is best visualised by computed tomography or magnetic resonance imaging. As growth proceeds, the coalition becomes ossified and range-of-motion diminishes. Onset of the pain is often in the second decade of life or later. In patients with symptomatic tarsal coalition, the initial management should always consist in non-operative treatment for at least 6 months. A consensus exists that surgery should be offered when non-operative treatment fails. Open resection of the coalition is the treatment of choice, although endoscopic resection is also an option. Sound evidence exists that resection of the coalition can produce favourable outcomes even in the long-term. Fusion should be reserved for failure of resection, extensive coalitions, multiple coalitions, and patients with advanced osteoarthritis.

Resection of Medial Talocalcaneal Coalition With Interposition of a Pediculated Flap of Tibialis Posterior Tendon Sheath

BACKGROUND

The purpose of the study was to present a novel operative technique in the management of medial talocalcaneal coalition (TC) and to report our clinical and radiologic results after interposition of a pediculated flap (PF) of the tibialis posterior tendon sheath.

METHODS

Twelve feet of 10 patients with a medial TC were treated with the interposition of PF of the tibialis posterior tendon sheath following resection. Pre- and postoperative clinical examinations were performed to evaluate the range of motion and the function of the tibialis posterior muscle of the affected foot. Pain was registered by visual analog scale (VAS) and the function of the foot by the American Orthopaedic Foot & Ankle Society (AOFAS) hindfoot score. The mean follow-up duration was 57.2 months (SD ±37.2 range 12-128) after surgery. Magnetic resonance imaging (MRI) was carried out to assess the outcome.

RESULTS

All patients reported a significant reduction of pain ( P = .002) at the final follow-up. The activity level had improved since the operation, and the subtalar joint motion was increased, but no weakness of the tibialis posterior muscle could be observed. The AOFAS hindfoot score was significantly improved ( P = .002). MRI did not reveal any migration of the tibialis posterior tendon sheath, and the interposed PF was confirmed at the resection zone. Furthermore, no TC relapse or ruptures of the functional anatomical structures could be observed.

CONCLUSION

The resection combined with the interposition of a PF of the tendon sheath seems to avoid relapse of TC and improves symptoms and the function of the foot.

LEVEL OF EVIDENCE

Level IV, case series.

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.

Subtalar coalition resection utilizing live navigation: a technique tip

PURPOSE

Describe the surgical technique of talocalcaneal coalition resection using live CT navigation.

METHODS

A ten-year-old female with left talocalcaneal coalition hindfoot pain refractory to conservative management underwent surgical coalition resection using live CT navigation. The procedure and discussion of this technique is described in detail.

RESULTS

With minimal radiation exposure to the patient, CT navigation for this complex talocalcaneal coalition was both helpful and potentially timesaving by allowing immediate localization and guided resection of the coalition.

CONCLUSION

In the case of a complex subtalar coalition resection, CT navigation poses minimal patient radiation exposure and allows immediate localization and guided resection of the coalition.

LEVEL OF EVIDENCE

Level V.

Tarsal tunnel disease and talocalcaneal coalition: MRI features

OBJECTIVE

To assess, utilizing MRI, tarsal tunnel disease in patients with talocalcaneal coalitions. To the best of our knowledge, this has only anecdotally been described before.

MATERIALS AND METHODS

Sixty-seven ankle MRIs with talocalcaneal coalition were retrospectively reviewed for disease of tendons and nerves of the tarsal tunnel. Interobserver variability in diagnosing tendon disease was performed in 30 of the 67 cases. Tarsal tunnel nerves were also evaluated in a control group of 20 consecutive ankle MRIs.

RESULTS

Entrapment of the flexor hallucis longus tendon (FHL) by osseous excrescences was seen in 14 of 67 cases (21 %). Attenuation, split tearing, tenosynovitis, or tendinosis of the FHL was present in 26 cases (39 %). Attenuation or tenosynovitis was seen in the flexor digitorum longus tendon (FDL) in 18 cases (27 %). Tenosynovitis or split tearing of the posterior tibial tendon (PT) was present in nine cases (13 %). Interobserver variability ranged from 100 % to slight depending on the tendon and type of disease. Intense increased signal and caliber of the medial plantar nerve (MPN), indicative of neuritis, was seen in 6 of the 67 cases (9 %). Mildly increased T2 signal of the MPN was seen in 15 (22 %) and in 14 (70 %) of the control group.

CONCLUSIONS

Talocalcaneal coalitions may be associated with tarsal tunnel soft tissue abnormalities affecting, in decreasing order, the FHL, FDL, and PT tendons, as well as the MPN. This information should be provided to the referring physician in order to guide treatment and improve post-surgical outcome.

Posteromedial subtalar coalitions: prevalence and associated morphological alterations of the sustentaculum tali

BACKGROUND

A variant form of subtalar coalition isolated to the posterior sustentaculum has been previously described, though its prevalence is not known and its relationship to the middle facet has not been characterized.

OBJECTIVE

To determine the prevalence and morphological alterations of isolated posteromedial subtalar coalitions.

MATERIALS AND METHODS

Computed tomography (CT) images of the foot or ankle performed from 2004 to 2012 were reviewed and 97 patients (mean age: 13.3+/-2.9 years; range: 9-19 years) with subtalar coalition were identified. In 41 (42%) of these, the condition was bilateral, yielding a total of 138 subtalar coalitions. In the 33 patients where CT demonstrated isolated posteromedial subtalar coalitions, multiplanar reformats along the long axis of the sustentaculum tali were generated, from which the anteroposterior dimensions of the sustentaculum tali and middle facet were measured. Posterior sustentaculum measurements defining the posterior extension of the sustentaculum beyond the middle facet were directly measured by two radiologists. Ratios of middle facet to posterior sustentaculum measurements were calculated. Thirty-three patients undergoing CT for ankle fracture served as controls.

RESULTS

Ninety-seven of 138 coalitions (70.2%) affected the middle facet and 2/138 (1.4%) involved the posterior facet. There were 39 (28.2%) posteromedial subtalar coalitions in 33 patients. Mean AP measurements of the middle facet and posterior sustentaculum in patients with posteromedial subtalar coalitions were 12.6 mm and 18.2 mm, respectively, compared to 16.6 mm and 9.2 mm in controls (P<0.001). Mean middle facet/posterior sustenaculum (MF/PS) ratios were 0.74 for posteromedial subtalar coalitions vs. 1.92 for controls (P<0.001).

CONCLUSION

Posteromedial subtalar coalitions comprise more than one-quarter of subtalar coalitions, and are associated with an intact, but shorter, middle facet and longer sustentaculum tali. This observation may aid in accurate diagnosis and management of this relatively common disorder.

Talocalcaneal Coalitions

Talocalcaneal coalitions present with complaints of flatfeet, foot or ankle pain after minor injury, or recurrent ankle sprains. Physical examination findings include limited subtalar motion and prominence inferior to the medial malleolus. Use of computed topography (CT) scan is recommended for preoperative planning. Confirmation of resection with intraoperative CT. Resection of talocalcaneal coalitions with fat-graft interposition has superior results to primary arthrodesis. Improved outcomes have been reported after resection, with foot scores averaging 90/100 (AOFAS).

Imaging of the subtalar joint

Imaging of the subtalar joint can be challenging because of its complex planar anatomy. This article reviews the anatomy and common anatomic variants as seen with different imaging techniques. Although radiography remains the initial mode of imaging, computed tomography and MRI are frequently needed to better delineate the joint anatomy and improve the sensitivity and the specificity of detection of joint pathology. A short review of arthrographic techniques and various examples of imaging of common pathology involving this joint are also included.

Subtalar coalitions in the adult

Tarsal coalitions, while relatively uncommon, are typically identified in adult patients during an evaluation for ankle instability, sinus tarsus pain, and/or pes planovalgus. The true incidence of tarsal coalition is unknown with estimates ranging from 1% to 12% of the overall population. The most common area of involvement of the subtalar joint is the middle facet, and heightened awareness should be present in adult patients with limited motion of the subtalar joint. Standard radiographic imaging, to include a Harris heel view, is recommended initially, although computerized tomography scan and MRI are often necessary to confirm the diagnosis.

Subtalar coalition in pediatrics

Subtalar tarsal coalition is an autosomal dominant developmental maldeformation that affects between 2% and 13% of the population. The most common locations are between the calcaneus and navicular and between the talus and calcaneus. If prolonged attempts at nonoperative management do not relieve the pain, surgery is indicated. The exact surgical technique(s) should be based on the location of the pain, the size and histology of the coalition, the health of the other joints and facets, the degree of foot deformity, and the excursion of the heel cord.

Tarsal Coalitions: Preliminary Results After Operative Excision and Silicone Sheet Interposition in Children

Symptomatic tarsal coalitions that begin in early adolescence are usually treated by resection and interposition (fat, muscle, or bone wax) to prevent recurrence. The purpose of the present retrospective study was to describe our operative technique and report our clinical and radiologic outcomes with sterile silicone sheet interposition after resection of painful tarsal coalitions in 4 children (4 feet). The present series included 1 case of talocalcaneal synchondrosis and 3 of synostosis (2 talocalcaneal and 1 cuboid-navicular). Two validated functional scales were used to assess the patients' overall outcome and satisfaction with the procedure: the American Orthopaedic Foot and Ankle Society ankle-hindfoot score and the Foot Function Index. Conventional radiography, computed tomography with 3-dimensional reconstruction, and magnetic resonance imaging were performed at the final follow-up visit. The mean follow-up period was 40 (range 12 to 80) months. The mean age at surgery was 10.5 (range 8 to 13) years. All patients had achieved their desired activity level at 6 months postoperatively. The mean American Orthopaedic Foot and Ankle Society ankle-hindfoot score was 93.5 (range 74 to 100), and the mean Foot Function Index was 3.25% (range 0% to 13%). No recurrence of the coalition on imaging at the final follow-up visit was observed in this patient series. Sterile silicone sheet interposition can be used to prevent recurrence of tarsal coalition in symptomatic tarsal coalitions after failure of conservative management.

Endoscopic coalition resection

Excision of symptomatic tarsal coalitions, after failure of attempted conservative treatment, is a widely accepted surgical procedure, when the surrounding joints are not degenerated. Historically, the literature has supported open resection. Recently, arthroscopic/endoscopic resection has been described for both calcaneonavicular (CNC) and talocalcaneal (TCC) coalitions. This article describes indications, preoperative planning, surgical techniques, and results of arthroscopic/endoscopic CNC and TCC resection.

Talocalcaneal coalition combined with flatfoot in children: diagnosis and treatment: a review

Talocalcaneal coalition often leads to a flatfoot deformity in children. Previous reports have uncovered many aspects of tarsal coalition and flatfoot respectively, including the etiology, clinical presentation, and diagnostic imaging, as well as treatment. However, the optimum surgical procedure for talocalcaneal coalition combined with flatfoot has not been definitively determined. The nonconformity of treatment options is due to our incomplete knowledge of biomechanics, diagnosis, and indication of treatment for talocalcaneal coalition with flatfoot. The objectives of this review are to provide an overview of the current knowledge about etiology, biomechanics, classification, diagnosis, and treatment options for talocalcaneal coalitions with flatfoot and highlight its therapies in children.

Ultrasound of talocalcaneal coalition: retrospective study of 11 patients

OBJECTIVE

To present the ultrasound appearance of talocalcaneal coalitions (TCC).

MATERIALS AND METHODS

We present a retrospective review of 11 patients (8 women and 3 men, age range 17-58 years, mean age 35.3 years) in which ultrasound, the first imaging study carried out, detected a TCC that was not known or suspected clinically. Patients were subsequently examined by standard radiographs, computed tomography (CT) or magnetic resonance imaging (MRI).

RESULTS

In 9 patients with fibrous coalition ultrasound showed a reduced joint space of the medial aspect of the anterior talocalcaneal joint associated with an irregular, pointed appearance of its outline. In 2 patients with osseous coalitions ultrasound revealed a smooth continuity of the hyperechoic bone surface between the medial talus and the substentaculum tali. The diagnosis was confirmed in 4 patients with CT and in 3 with MRI. In the remaining 4 patients standard radiographs were consistent with TCC.

CONCLUSION

Owing to its tomographic capabilities ultrasound can detect TCC. We suggest that study of the anterior subtalar joint should be a part of every ankle ultrasound examination as it can show a clinically unsuspected TCC. Confirmation of the coalition by CT or MRI is required in the preoperative assessment to better assess the type and extent of the congenital anomaly as well as the adjacent joints.

Bilateral tarsal coalition in a National Collegiate Athletic Association Division I basketball player: a case report

OBJECTIVE

To present a case of bilateral subtalar joint coalition in a National Collegiate Athletic Association Division I basketball player and the treatment plan that was used to manage the coalition from the beginning of conference play through the postseason.

BACKGROUND

A 20-year-old male basketball athlete (height = 182.8 cm, mass = 83.4 kg) presented with bilateral subtalar joint tarsal coalition that became symptomatic in 2006 and resulted in constant pain with any form of activity.

DIFFERENTIAL DIAGNOSIS

Traumatic injury of the talocalcaneal joint.

TREATMENT

Nonsurgical intervention of conservative therapy was elected.

UNIQUENESS

Less than 13% of the overall population is affected with tarsal coalition, so it is safe to assume that very few athletes competing at the collegiate or elite level suffer from this condition. This is the first report in the literature to document conservative manual therapies used to manage the symptoms of subtalar joint tarsal coalition in a Division I basketball player.

CONCLUSIONS

After the intensive treatment program for tarsal coalition was implemented, the patient experienced pain relief and was able to continue to compete at a competitive level. This case represents the need to further explore and document a conservative treatment protocol for tarsal coalition.

Arthroscopic resection of talocalcaneal coalitions--a bicentre case series of a new technique

BACKGROUND

Symptomatic tarsal coalitions failing conservative treatment are traditionally managed by open resection. We describe an arthroscopic technique for excising talocalcaneal coalitions and present a retrospective two-surgeon case series of the first eight patients (nine feet).

METHODS

Outcome measures include restoration of subtalar movements, return to work and sports, visual analogue pain scales and Sports Athlete Foot and Ankle Scores (SAFAS). Follow-up ranges from 1 to 5.5 years.

RESULTS

Pain and SAFAS improved in 7 patients. Subtalar movements were improved in all feet. All patients achieved early good function but one relapsed requiring subsequent fusions. One posterior tibial nerve was damaged.

CONCLUSIONS

Minimal destruction of bone and soft tissues allows early mobilization and minimizes pain. Patient selection and preoperative planning are crucial to avoid relapse and complication. This series from two independent surgeons supports the feasibility and effectiveness of this technique.

Treatment of talocalcaneal coalitions

BACKGROUND

The purpose of this study was to review outcomes of patients treated for symptomatic talocalcaneal coalition with resection and interposition of fat graft.

METHODS

A retrospective review was performed on all patients who underwent surgical treatment for symptomatic talocalcaneal coalition over a 13-year period. Ninety-three feet were treated with excision and fat graft interposition by 6 surgeons. All patients underwent a chart review. Patient's outcome was assessed at the last follow-up using the American Orthopaedic Foot and Ankle Society Hindfoot scale. Postoperative computed tomography scans were available for 20 feet.

RESULTS

Forty-nine feet had follow-up of at least 12 months and had a score obtained through the American Orthopaedic Foot and Ankle Society Hindfoot scale. At an average of 42.6 months of follow-up, the average score obtained was 90/100 (excellent). The postoperative computed tomography scans demonstrated 1 recurrence (3%), which was treated with repeat excision. An additional patient was reoperated for failure to excise the coalition completely. Eleven patients (34%) underwent a subsequent surgery to correct the alignment of the foot. To the best of our knowledge, none of the patients excluded because of short follow-up had repeat surgery or recurrence.

CONCLUSIONS

A symptomatic talocalcaneal coalition can be treated with excision and fat graft interposition, and achieve good to excellent results in 85% of patients. Patients should be counseled that a subset may require further surgery to correct malalignment.

LEVEL OF EVIDENCE

Level IV-case series.

Tarsal coalitions in the adult population: does treatment differ from the adolescent?

There is a paucity of information on adult coalitions without large, well-designed outcome studies. Current recommendations are thus similar to those for adolescents. Based on the available literature, current recommendations include an initial trial of adequate nonoperative treatment in symptomatic coalitions. Unlike adolescent coalitions, nonoperative treatment may be even more effective in the adult patient as many are asymptomatic or discovered after injury. If nonoperative treatment fails, then surgical intervention is considered and tailored to the location of the coalition, existing advanced arthrosis, and any existing deformity. Similar to the adolescent, surgical treatment for adult calcaneonavicular coalitions typically involves an attempt at resection with some type of interposition. Resection can be attempted for talocalcaneal coalitions that do not present with advanced arthrosis or significant hindfoot malalignment. For those patients with advanced arthrosis, more than 50% involvement of the joint hindfoot malalignment, subtalar or triple arthrodesis is recommended. The decision between resection and arthrodesis is controversial in the adolescent population. With few outcome studies in adults, it is even more difficult to make definitive treatment recommendations; however, the indications for resection are likely even more limited. It is likely that the adult subtalar coalition that becomes symptomatic and fails nonoperative treatment will require arthrodesis for full pain relief and improvement in objective outcome measures, such as the AOFAS hindfoot score. Our treatment algorithm focuses first on a trial of nonoperative treatment of at least 3 months regardless of coalition location. After failed nonoperative treatment, calcaneonavicular coalitions are in most cases treated with excision and interpositional fat graft. For talocalcaneal coalitions, resection is offered to patients with neutral hindfoot alignment, some preservation of subtalar joint motion and no adjacent joint arthrosis. The patients are advised that the outcome after resection of talocalcaneal coalitions is less predictable than resection of calcaneonavicular coalitions. Those patients with absent subtalar motion and relatively normal hindfoot alignment are candidates for in situ fusion of the subtalar joint. For those patients with greater than 15° of valgus hindfoot malalignment on a weight-bearing hindfoot alignment view or adjacent joint arthrosis, a triple arthrodesis is recommended with or without medial displacement osteotomy of the calcaneus. Adjacent joint arthrosis may be determined by radiographs, CT scan, or preoperative MRI.

Child calcaneonavicular coalitions: MRI diagnostic value in a 19-case series

INTRODUCTION

In case of hindfoot pain, diagnosis of calcaneonavicular tarsal coalition may be missed on X-ray due to the absence of any visible synostosis. All other possible etiologies (too-long anterior process (TLAP) of the calcaneum, synchondrosis, syndesmosis) must be investigated. The literature tends to recommend imaging associating standard X-ray and CT, and possibly bone scintigraphy. MRI is, however, also worth assessing, due to the many non-osseous forms calcaneonavicular pain may take.

MATERIAL AND METHODS

Thirty-two cases of surgically treated calcaneonavicular tarsal coalition were studied. Nineteen cases, in 14 children, over a 10-year period, showed no visible synostosis on initial standard X-ray. In seven cases, bone scintigraphy was performed, CT in seven and MRI in 12. On the basis of the literature, our attitude was in favor of X-ray associated to CT in our early experience. Repeated diagnostic difficulties, however, led us to replace CT by MRI in case of foot pain combined to symptomatology suggestive of coalition.

RESULTS

The series comprised four cartilaginous forms, four fibrous forms and eight TLAPs. In 10 of the 19 feet, radiology was strictly normal, the others showing indirect osseous signs. Only three of the seven scintigraphies showed hyperfixation. CT-scan enabled diagnosis in seven cases (two synchondroses and five rudimentary forms), and missed diagnosis in four (two cartilaginous and two fibrous forms). Second intention MRI showed two synchondroses and two syndesmoses. In the light of these 11 cases, a subsequent series of eight feet was assessed by MRI in first intention, obtaining systematic diagnosis. In all the feet of the series, the symptomatic coalition was treated by surgery, allowing peroperative findings to be compared with the imaging data.

DISCUSSION

Given a rigid and painful foot syndrome suggestive of tarsal coalition, two diagnostic situations arise: (a) the clinical aspect is suggestive and standard X-ray enables diagnosis; (b) the clinical aspect is suggestive, but radiography proves non-contributive, in which case we recommend MRI with sagittal, frontal and axial slices in gadolinium-enhanced T1-weighted and fat-sat T2-weighted sequences, revealing direct (cartilaginous or fibrous coalition) or indirect signs (peripheral inflammation, osteomedullary edema, chondral lesion) unobtainable on CT scans. MRI is particularly effective in as much as most of the children concerned will not have reached bone maturity.

CONCLUSION

We consider MRI to be the most effective means of precise diagnosis (causes and consequences) of tarsal coalition, especially for calcaneonavicular locations. It entails minimal invasion and irradiation, at a lower cost than CT associated to scintigraphy.

LEVEL OF EVIDENCE

IV. Diagnostic study.

[Dorsomedial talocalcaneal coalition: a rare condition]

Talocalcaneal coalitions are rare but a posterior facet talocalcaneal coalition is even rarer. There are three different types: fibrous, cartilaginous and osseous coalitions. Besides conventional x-rays computed tomography is essential for assessment of the subtarsal joint. In the absence of concomitant coalitions and foot deformity resection of the coalition is advocated due to good clinical results when there is an adequate size of the talocalcaneal joint (>50%) and without osteoarthrosis. A case of a rare posterior facet talocalcaneal coalition is reported.

Unilateral subtalar coalition: contralateral sustentaculum tali morphology

PURPOSE

To measure and compare the dimensions of the sustentaculum tali (ST) in pediatric patients with unilateral subtalar coalition to determine if the contralateral side has altered morphology.

MATERIALS AND METHODS

The institutional review board approved this study, which was HIPAA compliant. Informed consent was waived. Radiology records were reviewed to identify 35 patients with unilateral subtalar coalition undergoing computed tomography (CT) (21 male, 14 female; mean age, 14.54 years) and 33 control patients with triplane fracture (21 male, 12 female; mean age, 13.48 years). CT images were reviewed, and reformatted images through the subtalar joint (on the side opposite the coalition) were created. Anteroposterior measurements of the middle facet (MF) and the ST were recorded by two observers with electronic calipers. The MF/ST ratio and the ST length extending posterior to the MF were calculated. Measurements between groups were compared by using Wald tests based on linear regressions. Inter- and intraobserver variabilities were determined by means of a component of variance model.

RESULTS

The lengths of the MF and ST for the study and control groups were 12.86 and 16.82 mm (P < .001) and 23.83 and 22.06 mm (P = .053), respectively. Intra- and interobserver correlations for both measurements were 0.94 and 0.92 and 0.86 and 0.77, respectively. MF/ST ratio was 0.54 versus 0.76 (P < .001), and ST length extending posterior to the MF was 10.97 versus 5.24 mm (P < .001).

CONCLUSION

The MF is smaller and the ST extends further beyond the MF in patients with a contralateral subtalar coalition than in control patients. The morphology of the ST may provide insight into the origins and development of coalitions.

Tarsal coalitions

A tarsal coalition is an aberrant union between 2 or more tarsal bones and can be classified as osseous (synostosis) or nonosseous (cartilaginous [synchondrosis] or fibrous [syndesmosis]). This union may be complete or partial and the joints in the hindfoot and midfoot are most commonly affected. The resulting abnormal articulation presents as a noncorrectable flat foot, usually during adolescence, leading to accelerated degeneration within adjacent joints. An understanding of the condition and presenting symptoms enable the clinician to correctly diagnose and initiate appropriate treatment. This review discusses the evidence-based literature on the cause, diagnosis, and current management of tarsal coalition.

A radiologic classification of talocalcaneal coalitions based on 3D reconstruction

PURPOSE

Talocalcaneal coalitions can be difficult to detect on plain radiographs, despite obvious clinical findings. The purpose of this study is two-fold: (1) to delineate the benefits of thin-cut computed tomography (CT) and 3D reconstructions and (2) to develop a classification scheme for talocalcaneal coalitions that will provide valuable information for surgical planning.

METHODS

From 2005 to 2009, 54 feet (35 patients) with a talocalcaneal coalition were evaluated with thin-cut (1 mm) CT, using multi-planar 2D and 3D reconstructions. The talocalcaneal coalitions were classified into five types based on the cartilaginous or bony nature, location, and facet joint orientation.

RESULTS

Bilateral coalitions were found in 22/35 patients. Types I and II were fibrocartilaginous coalitions, which was the most common type, comprising 40.7 and 16.7% of the coalitions, respectively. Of the patients, 14.8% had a shingled Type III coalition, while 11.1% of the feet examined had a complete bony coalition (Type IV). Small peripheral posterior bony coalitions (Type V), which are heretofore not described, were found in 16.7% of feet.

CONCLUSIONS

CT scans can provide valuable information regarding the bony or cartilaginous nature of coalitions, as well as the facet orientation, which is helpful in diagnosis and treatment. In this study, the 2D and 3D reconstructions revealed previously unreported peripheral posterior bony coalitions (Type V), as well as coalitions that are in the same plane as the standard CT cuts or Harris view radiographs (Type I). The CT scan also improved the crucial pre-operative planning of the resection in the more complex vertical and combined horizontal and vertical fibrocartilaginous coalitions (Type I and II). Additionally, the complete bony coalitions (Type IV) can be sized accurately, which is helpful in decision-making on the resectability of the coalition.

A critical evaluation of subtalar joint arthrosis associated with middle facet talocalcaneal coalition in 21 surgically managed patients: a retrospective computed tomography review. Investigations involving middle facet coalitions-part III

Symptomatic middle facet talocalcaneal coalition is frequently associated with rearfoot arthrosis that is often managed surgically with rearfoot fusion. However, no objective method for classifying the extent of subtalar joint arthrosis exists. No study has clearly identified the extent of posterior facet arthrosis present in a large cohort treated surgically for talocalcaneal coalition through preoperative computerized axial tomography. The authors conducted a retrospective review of 21 patients (35 feet) with coalition who were surgically treated over a 12-year period for coalition on at least 1 foot. Using a predefined original staging system, the extent of the arthrosis was categorized into normal or mild (Stage I), moderate (Stage II), and severe (Stage III) arthrosis. The association of stage and age is statistically significant. All of the feet with Stage III arthrosis had fibrous coalitions. No foot with osseous coalition had Stage III arthrosis. The distribution of arthrosis staging differs between fibrous and osseous coalitions. Only fibrous coalitions had the most advanced arthrosis (Stage III), whereas osseous coalitions did not. This suggests that osseous coalitions may have a protective effect in the prevention of severe degeneration of the subtalar joint. Concomitant subtalar joint arthrosis severity progresses with age; surgeons may want to consider earlier surgical intervention to prevent arthrosis progression in patients with symptomatic middle facet talocalcaneal coalition.

Tarsal coalitions: etiology, diagnosis, imaging, and stigmata

Tarsal coalition is a congenital condition characterized by the aberrant union (osseous or fibrous) between 2 bones in the rearfoot, most commonly talocalcaneal coalition, calcaneonavicular coalition, and talonavicular coalition, that results in a restriction or absence of motion. The association between tarsal coalition and a variety of coexisting conditions has been reported over the past 60 years and continues to be better understood. These coexisting conditions (the stigmata of tarsal coalition) have been believed to be secondary effects of the coalition and/or fixed rearfoot position. Advanced imaging has provided significant insights into the concomitant pathology and understanding of tarsal coalition that the symptoms associated with tarsal coalition can be present for a myriad of different reasons. One should consider all the stigmata of tarsal coalition when considering a surgical reconstruction.

Pediatric & adolescent flatfoot reconstruction in combination with middle facet talocalcaneal coalition resection

Surgical reconstruction of symptomatic flatfoot associated with middle facet tarsal coalition is becoming more widely used. This article demonstrates that coalition-concomitant flatfoot is a pathologic entity that is worthy of surgical management. The literature, although limited, has suggested that poor outcomes with isolated simple coalition resection may have been related to the preoperative pes planus that was not addressed. More recently studies have demonstrated improved clinical and radiographic postoperative outcomes when the flatfoot correction is combined with the coalition resection. This article reviews a surgical treatment algorithm that considers the presence of varying degrees of pes planus and rearfoot arthrosis associated with coalition.

Anatomy of the subtalar joint and imaging of talo-calcaneal coalition

Talo-calcaneal coalitions may be intra-articular or extra-articular in position and may be classified as fibrous, cartilaginous or osseous in morphology. Fibrous coalitions, particularly extra-articular talo-calcaneal coalitions, may have cross-sectional imaging findings that resemble normal anatomic variants, particularly the medial talo-calcaneal ligament and to a lesser extent the presence of an accessory articular facet between the posterior margin of the sustentaculum and postero-medial process of the talus. Typically, in the adult fibrous coalition, there will be some osseous deformity at the entheses, allowing differentiation from a medial talo-calcaneal ligament. The anatomy of the subtalar joint and its ligamentous supports, normal anatomic variations and their corresponding imaging appearance are reviewed in the first part of this article. In the second part, the various forms of talo-calcaneal coalition and their imaging appearance are reviewed.

Resection of middle facet coalition with arthroscopic guidance

Middle facet subtalar tarsal coalition poses a challenge to the surgeon, and is traditionally resected using an open medial surgical approach. In this article, we describe a technique of arthroscopic resection of a middle facet talocalcaneal coalition.