Histopathological study of nonosseous tarsal coalition

A Rare Case of Naviculo-medial Cuneiform Coalition Treated with Naviculo-medial Cuneiform Arthrodesis: A Case Report

CASE

A 19-year-old woman developed spontaneous onset of right midfoot pain in the absence of trauma. Conservative management including orthotics and steroid injection reduced, but did not resolve, pain. Weight-bearing x-ray and CT confirmed naviculo-medial cuneiform coalition. After failure of conservative treatment, the patient elected to undergo right naviculo-medial cuneiform arthrodesis and returned to normal activity without pain postoperatively and at 4-year follow-up.

CONCLUSION

Naviculo-medial cuneiform coalition is a rare source of midfoot pain, but should be considered as a differential diagnosis. This case suggests that naviculo-medial cuneiform arthrodesis can successfully resolve symptoms if conservative measures fail.

Tarsal Coalitions

Tarsal coalitions are recognized as a congenital anomaly whereby the two or more bones of the hindfoot and midfoot are fused resulting in limitation of foot motion and pain. Tarsal coalitions were found to be the cause of painful flatfeet in adolescents and young adults. Developing a clinical understanding of tarsal coalitions as well as developing a step-wise conservative and surgical approach for their treatment can alleviate patient symptomatology and provide excellent long-term benefits. Conservative treatment consists of immobilization, NSAIDs, and casting for symptomatic patients, and surgical treatment for symptomatic tarsal coalition consists of resection and/or arthrodesis.

Surgical Treatment of Calcaneonavicular and Talocalcaneal Coalitions

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.

Morphologic Analysis of Nonosseous Talocalcaneal Coalitions Using 3D Reconstruction

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.

Conclusion:

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.

Level of Evidence:

Level III, retrospective comparative study.

Suture anchor stabilization of symptomatic accessory navicular in adolescents: Clinical and radiographic outcomes

BACKGROUND

Screw fixation used in modified Kidner procedures to treat persistent symptomatic accessory navicular in adult cases is often challenging in adolescent cases with a small accessory fragment. The present study aimed to document the clinical effect of a suture anchor stabilization technique applicable to such cases where osteosynthesis is considered an ideal outcome.

METHODS

Consecutive clinical cases who received this surgical treatment from 2009 to 2016 were retrospectively reviewed. The focus of interest included radiographic union of the accessory bone, changes in symptoms evaluated using a validated clinical outcome scale introduced by the Japanese Society for Surgery of the Foot, and changes in the medial arch bony alignment measured in lateral weight-bearing plain radiographs.

RESULTS

Twenty-two feet in 15 individuals (11 females and 4 males, age at surgery 10-16 years) were identified. In 14 feet (64%), radiographic bone union was confirmed within 8 weeks postoperatively. At the final follow-up ranging 12-51 months postoperation, the clinical scores have significantly improved (p < 0.001) to 96 ± 5.71 (mean ± standard deviation, range 87-100), from 54 preoperatively. Radiographic measurements revealed significant postoperative increase of the sagittal talar tilt angle (p < 0.001, increment 4 ± 3°, range 0-11) and the talo-first metatarsal angle (p < 0.001, increment 5 ± 4°, range 0-12). No significant changes were identified in the calcaneal pitch angle, first metatarsal tilt angle, calcaneo-navicular angle, and the navicular height.

CONCLUSION

Despite the modest bone union rate, the clinical outcomes suggest distinct symptom-relieving effect, at least in the short- to midterm, while the radiographic measurements suggest positive biomechanical effects. The present suture-anchor stabilization concept appears to be a promising treatment option for persistent symptomatic accessory navicular in adolescent cases.

Determining the factors influencing the symptoms related to naviculo-medial cuneiform coalition

PURPOSE

We aimed to determine the factors that influence the symptoms of naviculo-cuneiform (NC) coalition using radiography and computed tomography (CT).

METHODS

We retrospectively reviewed the radiographic and CT findings of 37 NC coalition cases. The existence of a large pit (depth >3 mm), irregular articular surface, joint space narrowing, dorsal bony spur, subchondral sclerosis, multiple subchondral bony cysts, and intra-articular loose body were evaluated on radiographs or CT. The size of the largest subchondral bony cyst was also measured using CT. All cases were divided into two subgroups according to the symptoms. Fisher's exact test was used to distinguish the factors influencing the symptoms.

RESULTS

Twenty-three and fourteen feet were enrolled into the symptomatic and asymptomatic groups, respectively. The rates of the large pit on either radiograph (47.83 vs. 21.43%) or CT (65.22 vs. 28.57%) were significantly different between both groups ( p = 0.001). The mean size of the largest subchondral bony cyst on CT was also significantly greater in the symptomatic group (4.25 vs. 1.53 mm, p = 0.005).

CONCLUSION

A large deep pit and huge subchondral bony cyst on the radiograph or CT can be related to symptoms for the patient with NC coalition. A CT is highly recommended for a more accurate evaluation in patients with NC coalition.

Diagnosing tarsal coalition in medieval Exeter

OBJECTIVE

The objective of this study is to estimate the frequency and types of tarsal coalition represented in medieval remains from Exeter, England.

MATERIALS

183 individuals from the Cathedral Green site in Exeter, England.

METHODS

Gross macroscopic analysis combined with radiographic examination and comparison with clinical and archaeological literature.

RESULTS

Eight coalitions of various forms were ultimately identified; these include five calcaneonavicular, one talocalcaneal, one calcaneocuboid, and one lateral cuneiform-third metatarsal coalition.

CONCLUSIONS

These frequencies are quite high for clinical imaging estimations, but consistent with other reported archaeological frequencies.

SIGNIFICANCE

This study contributes to known frequencies of tarsal coalition in the past. It also provides descriptive diagnostic criteria for identifying tarsal coalition in archaeological populations.

LIMITATIONS

Poor preservation of some of the individuals in this sample means that the true frequencies of tarsal coalition may be underrepresented.

SUGGESTIONS FOR FURTHER RESEARCH

This study should be expanded to include more archaeological sites, especially medieval British sites, to determine overall prevalence rates. Additionally, the diagnostic criteria should be compared with other examples of known tarsal coalition to further our understanding of this rare pathology.

Rare Combination of a Cuboid-navicular Tarsal Coalition with a Closed Tibialis Anterior Tendon Rupture: A Case Report and Review of the Literature

Introduction

Tibialis anterior tendon (TAT) rupture and cuboid-navicular coalition (CNC) are rare, to the best of our knowledge, only 238 cases of TAT rupture and 34 cases of CNC are described in the past century.

Case Report

A 47-year-old man came with a sudden onset of foot pain including drop foot to our department. We diagnosed a TAT rupture, which was fixed through suture. The pathologist testified degenerative changes in the tendon. In addition, a CNC was diagnosed. No extra treatment was necessary for the CNC. At the 6-year follow-up examination, the patient had no pain and went back to normal day activities (AOFAS 95/100 points).

Conclusion

We presume that, in our case, the long-term stress at the TAT through the foot deformity, caused by the CNC, may have supported the tendon rupture. CNC normally is symptom free. Therapy of a painful CNC should start with a conservative therapy. When this fails, an operation can be considered.

Coalitions of the Tarsal Bones

Tarsal coalitions are the result of impaired mesenchymal separation of the tarsal bones. The most common types include calcaneonavicular or talocalcaneal coalitions. Subtalar stiffness results in pathologic kinematics with increased risk of ankle sprains, planovalgus foot deformity, and progressive joint degeneration. Resection of the coalition yields good results. Tissue interposition may reduce the risk of reossification, and concomitant deformity should be addressed in the same surgical setting.

Technetium-99m Methylene Diphosphonate Single-photon Emission Computed Tomography/Computed Tomography of the Foot and Ankle

The complex anatomy and function of the foot and ankle can make it difficult to determine the cause of symptoms in patients with foot and ankle pathology. Following initial clinical and radiographic assessment, additional imaging with magnetic resonance imaging may be required, which is often seen as the modality of choice. Although sensitive to pathological changes in bone metabolism and vascularity, technetium-99m (Tc-99m) bone scintigraphy often lacks the specificity and resolution required to evaluate the structures of the foot and ankle. Tc-99m methylene diphosphonate single-photon emission computed tomography/computed tomography (SPECT/CT) combines this sensitivity with the superior anatomical detail of CT, enabling better localization of pathological uptake and evaluation of associated structural changes. As a result, SPECT/CT has been growing in popularity for the assessment of patients with foot and ankle pathology where it can provide additional information that may change the initial diagnosis and subsequent management plan. Studies have reported modification of the surgical approach and site of intra-articular local anesthetic injections following SPECT/CT with good results. Interpretation of SPECT/CT studies requires an understanding of the pathological changes that result in increased tracer accumulation in addition to the CT changes that may be seen. This review aims to highlight the advantages of SPECT/CT, potential applications and explain the imaging appearances of common pathologies that may be observed.

Tarsal Coalitions--Calcaneonavicular Coalitions

Calcaneonavicular coalitions are an important cause of adolescent foot pain and deformity. The congenital condition is characterized by an aberrant osseous, cartilaginous, or fibrinous union of the calcaneal and navicular bones. Calcaneonavicular coalitions are the most common form of tarsal coalitions identified within epidemiologic studies. A thorough understanding of this clinically significant entity is important for restoring joint motion and preventing long-term disability.

Naviculocuneiform Coalition: Case Reports of Two Sibling Soccer Players

Tarsal coalitions are an abnormal union between 2 tarsal bones. They occur most commonly between the calcaneus and talus or the calcaneus and navicular but can also arise from other joints in the foot. Isolated cases of coalitions between the medial cuneiform and navicular are extremely rare, and only a few cases have been reported. Treatment recommendations are, therefore, sparse, and no long-term follow-up data have been reported. We present the case of 2 sisters, each diagnosed with a symptomatic naviculocuneiform coalition. To our knowledge, this is the first reported case in 2 first-degree relatives. Both sisters were involved in sports and presented with pain during physical activities. After conservative treatment had failed, they were both treated successfully with surgical excision of the coalition and arthrodiastasis, followed by a progressive return to activities. At the last follow-up examination at 5 and 3 years postoperatively, they remained pain free and fully involved in college soccer, making excision of a naviculocuneiform coalition with arthrodiastasis a valid treatment in the young athletic population.

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.

Isolated Fifth Metatarsocuboid Coalition: A Case Report

Isolated tarsometatarsal coalitions are extremely rare, and the previous 5 documented cases involved the first and third metatarsocuneiform joints. We report the case of a 69-year-old female with symptomatic fifth metatarsocuboid coalition associated with ipsilateral varus-type ankle osteoarthritis and instability. The patient was successfully treated by arthrodesis of the fifth metatarsocuboid joint, resection of the hypertrophied tuberosity of the fifth metatarsal, advancement of the peroneus brevis tendon, opening wedge distal tibial osteotomy, and calcaneal displacement osteotomy. After 1 year, 6 months, she was able to walk well, although she complained of minor discomfort under the fifth metatarsal base, which resolved with the use of protective padding. Radiographs at this stage confirmed consolidation of both the arthrodesis and the osteotomy sites. Although isolated fifth metatarsocuboid coalition is less likely to be encountered than other tarsal coalitions, it can sometimes be painful enough to necessitate surgery.

Focal Periphyseal Edema (FOPE) zone on MRI of the adolescent knee: a potentially painful manifestation of physiologic physeal fusion?

OBJECTIVE

We have termed an MRI finding in the knees of adolescents characterized by a focal bone marrow edema pattern centered about the closing physis a "FOPE"-that is, focal periphyseal edema-zone. The cause of this appearance is unknown. Therefore, the purpose of this article is to review the MRI appearance of the FOPE zone and to postulate a causative mechanism.

MATERIALS AND METHODS

FOPE zones were identified on knee MRI examinations performed for pain in 12 patients (seven girls, five boys; age range, 11 years 9 months-15 years 8 months); the examinations were collected over 5 years. Clinical history, skeletal maturity, size and location of FOPE zone, and concomitant ipsilateral knee abnormalities were recorded at presentation and on follow-up MRI examinations when available. Bone ages were estimated from knee radiographs using published standards.

RESULTS

Fifteen FOPE zones measuring 2-27 mm were identified: eight were femoral; six, tibial; and one, fibular. All were centrally located. All physes were patent, albeit narrowed. The radiographic appearance of the physes was similar for both sexes. All patients with estimated bone ages of 11 and 12 years were girls. Two other girls had bone ages closer to 14 years, whereas all boys had estimated bone ages of 13 or 14 years.

CONCLUSION

On knee MRI, a FOPE zone can be seen in adolescents and likely relates to the early stages of physiologic physeal closure. It may be associated with pain particularly when no other MRI abnormalities are present. When the characteristic appearance of a FOPE zone is observed on MRI, we suggest that it not be mistaken for an abnormality, requires no invasive diagnostic procedure, and does not need imaging follow-up.

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 review of tarsal coalition and pes planovalgus: clinical examination, diagnostic imaging, and surgical planning

Pediatric pes planovalgus deformity may be classified as flexible or rigid. The rigid pes planovalgus is often a result of a tarsal coalition, which is typically characterized as a painful unilateral or bilateral deformity, frequently associated with peroneal spasm. However, many tarsal coalitions are asymptomatic and demonstrate no peroneal spasm or pes planovalgus deformity. Likewise, the severe pes planovalgus foot type can demonstrate some of the same clinical and radiographic features of a tarsal coalition, especially in the obese adolescent patient. Also, peroneal spasm may occur in the noncoalesced foot, making diagnosis and etiology more difficult to elucidate. The authors believe that many patients with a pes planovalgus deformity lie in this "gray zone": somewhere between the frank osseous coalition and the flexible pes planovalgus. The "step-forward Hubscher maneuver" is introduced as an effective means of evaluating the flexibility of a pes planovalgus foot by negating the effects of a gastrocnemius or gastrocnemius-soleus equinus. This article focuses on the clinical examination and findings of specific imaging studies to assist in an accurate diagnosis of these complicated patients. This will also help to reveal the various surgical options that are appropriate for the individual patient. Emphasis is placed on computerized tomography (CT) imaging and offers enhanced methods for ordering this test to specifically evaluate middle facet coalitions of the subtalar joint. The authors also introduce "lateral tarsal wedging," an image finding associated with severe deformities, the implications of this finding, as well as its impact on surgical planning.

Preliminary report: resection and interposition of a deepithelialized skin flap graft in tarsal coalition in children

Six tarsal coalitions in children were managed surgically using a deepithelialized skin flap for interposition after resection of the bony, fibrous or cartilaginous coalition. The advantage of this technique is that due to positioning the skin flap, joint motion can be preserved. The clinical results using the Ankle Hindfoot Scale of the American Orthopedic Foot and Ankle Society were excellent in two and good in four cases. The radiographs at follow-up showed no recurrences of the resected coalitions. This study shows that the use of deepithelialized skin flap interposition is effective in providing pain relief for the patients in symptomatic coalitions.

Rigid pediatric pes planovalgus: conservative and surgical treatment options

Rigid pediatric pes planovalgus refers to a condition of the foot in which the medial longitudinal arch height is abnormally decreased along with a significant loss of midfoot and hindfoot motion in the pediatric patient. Known causes for this condition are well documented and consist of congenital vertical talus, tarsal coalitions, and peroneal spastic flatfoot without coalition. This article outlines conservative and surgical treatment of rigid pediatric pes planovalgus.

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.

Cavovarus foot deformity with multiple tarsal coalitions: functional and three-dimensional preoperative assessment

In rare instances, tarsal coalition leads to cavovarus foot deformity, although the pathologic mechanism leading to this deformity is not clear. This article reports a case of a 14-year-old boy presenting a severe cavovarus deformity of the right foot with talocalcaneal and calcaneonavicular coalitions, and a mild cavus deformity of the left foot with a single talocalcaneal coalition. Computed tomography and postoperative histologic analysis demonstrated a synostosis between talus and calcaneus and a fibrous calcaneonavicular coalition with partial ossification. Instrumented gait analysis revealed a limited range of ankle plantar flexion and increased external rotation of the ankle. Associated skeletal malformations including incomplete hemimelia of the forearm and scoliosis raised the possibility of a teratologic condition, but neurologic examination, spinal magnetic resonance imaging, and nerve conduction velocities were normal. The progressive ossification of combined coalitions during growth of the foot may have been one factor leading to this complex foot deformity. The fine-wire electromyogram showed normal tibialis anterior and posterior muscle activity. Small soft tissue tears in the sinus tarsi may have led to a mild reflexive increase of the muscle tone and tendon shortening, which pulled the forefoot into adduction and the heel into varus, and raised the medial arch. Mechanical alterations of the ankle appear secondary to the heel varus and to the progressive deformity of the talus. Three-dimensional computed tomography reconstruction and gait analysis appeared to be helpful additional parameters to understanding the pathomechanics of this complex foot deformity and for preoperative planning of triple arthrodesis.

Effects of tarsal coalition resection on dynamic plantar pressures and electromyography of lower extremity muscles

The goal of this study was to evaluate kinetic abnormalities in feet after tarsal coalition resection using plantar pressure measurements and electromyography of 4 muscle groups in the lower limb. Eleven subjects (14 feet) with tarsal coalition (3 feet with calcaneocuboid, 6 feet with calcaneonavicular, and 5 feet with talocalcaneal) underwent coalition excision. Patients ranged in age from 9 to 17 years, and mean follow-up was 20 months. Two feet underwent subsequent subtalar fusion and 1 had a triple arthrodesis. Plantar pressure and electromyography measurements were compared with data taken from 68 normal (control) subjects between the ages of 6 to 16 years. Feet with tarsal coalition showed significant differences in the midfoot region, with increases in contact area (40.36 cm2 +/- 14.7 vs 18.02 cm2 +/- 8.0, P < .001), loading (5.63 N/cm2 sec +/- 3.4 vs 1.83 N/cm2 sec +/- 0.9, P < .001) and peak pressure (13.38 N/cm2 +/- 5.8, 6.81 N/cm2 +/- 2.8, P = .01). Tarsal coalition feet also displayed reduced peak pressure and loading at the region of the fifth metatarsal head as compared with uninvolved feet (P < .05). Electromyography measurements were also performed on both the affected and unaffected feet of 9 subjects who had undergone resection of their coalition. These measurements revealed nearly consistent abnormal activity in the peroneal, gastrocnemius, and soleus muscles on both the surgically operated foot and the contralateral side, including either prolonged monophasic activity or biphasic activity. These findings suggest that although resection of coalition may have relieved symptoms of discomfort, it did not restore normal foot alignment or muscular balance.

Coalition of bilateral first cuneometatarsal joints: a case report

The most common types of tarsal coalition are talocalcaneal and calcaneonavicular coalition. This report presents a case of a patient with middle foot pain who was diagnosed as having first cuneometatarsal coalition.

High prevalence of tarsal coalitions and tarsal joint variants in a recent cadaver sample and its possible significance

Tarsal coalitions (TC) are defined as fibrous (beyond normal ligaments), cartilaginous, or osseous unions of at least two tarsal bones. Most of the clinical studies report the prevalence of TC as <1%, but they disregard the asymptomatic coalitions. Because TC have been associated with pathologic conditions, including degenerative arthritic changes, knowledge of their prevalence has clinical importance. The aim of our study was to establish the prevalence of TC and tarsal joint variants. A total of 114 feet from 62 cadavers (average age = 78 years) without obvious foot pathologies were dissected at the Department of Anatomical Sciences, The University of Adelaide. Ten non-osseous TC in eight subjects were identified: two talocalcaneal and eight calcaneonavicular (occurred twice bilaterally). Variant calcaneonavicular and cuboideonavicular joints were found in 8% and 31% of feet, respectively. Other joint variants included a variable number of talocalcaneal joint surfaces and sesamoid bones. No secondary TC (due to trauma, infections, or neoplasm) were found. Our study demonstrated that the overall prevalence of TC is higher (13%) than previously thought; tarsal joint variations (39%) and sesamoid bones (42%) were common as well. The supposed secular increase in the prevalence of TC as well as the high number of anatomical variants could reflect a short-term response to altered life-style or a microevolutionary trend due to relaxed selection.

Multiple osseous tarsal coalitions: a case report and review of the literature

A patient with multiple tarsal coalitions presenting with symptoms at the age of 47 years is reported. The report highlights the presentation of symptomatic coalitions following trauma in adulthood. Coalitions can pose difficulties in diagnosis, particularly without previous history of pain or disability in childhood. A decrease or loss of subtalar movement, painful movement, and valgus deformity of the hindfoot are usually present in the adult patient but are not often pathognomonic and present a diagnostic conundrum, particularly with x-rays being misinterpreted. This report highlights the problem of diagnosing such a condition with the attendant difficulties in formulating treatment.

A dissection and computer tomograph study of tarsal coalitions in 100 cadaver feet

Most of the clinical studies report the incidence of tarsal coalitions (TC) as less than 1% but they disregard the asymptomatic coalitions. TC have been associated with degenerative arthritic changes. After X-rays, computer tomography (CT) is the most commonly used diagnostic test in the detection of TC. The aims of our study were to establish the incidence of TC; the association between TC and accessory tarsal bones and between TC and tarsal arthritis; and to assess the sensitivity of CT as a diagnostic tool in TC. We performed spiral CT scans of 100 cadaver feet (mean age at death 77.7+/-10.4), which were subsequently dissected. The dissections identified nine non-osseous TC: two talocalcaneal and seven calcaneonavicular. There was no osseous coalition. Tarsal arthritis was identified in 31 cases. Both talocalcaneal coalitions were associated with arthritis while none of the calcaneonavicular coalitions were associated with tarsal arthritis. The CT diagnosed an osseous talocalcaneal coalition and was suspicious of fibrocartilaginous coalitions in eight cases. There was correlation between dissection and CT in two talocalcaneal coalitions and three calcaneonavicular coalitions thus CT identifying 55.5% of the coalitions. CT did not diagnose four non-osseous coalitions and diagnosed errouresly four possible coalitions. In conclusion our study demonstrated that the incidence of non-osseous TC is higher than previously thought (12.72%). The calcaneonavicular coalitions are the most common single type (9.09%) and they do not seem to be associated with arthritic changes in the tarsal bones. Our CT results suggest that spiral CT has a low sensitivity in the detection of non-osseous coalitions and questions if multislice CT should be used routinely when TC are suspected.

The anatomical basis for disease localisation in seronegative spondyloarthropathy at entheses and related sites

The 2 major categories of idiopathic inflammatory arthritis are rheumatoid arthritis and the seronegative spondyloarthropathies. Whilst the synovium is the primary site of joint disease in the former, the primary site in the latter is less well defined. However, it has recently been proposed that enthesitis-associated changes in the spondyloarthropathies are primary and that all other joint manifestations are secondary. Nevertheless, some of the sites of disease localisation have not been adequately explained in terms of enthesitis. This article summarises current knowledge of the structure, function, blood supply, innervation, molecular composition and histopathology of the classic enthesis (i.e. the bony attachment of a tendon or ligament) and introduces the concept of 'functional' and articular 'fibrocartilaginous' entheses. The former are regions where tendons or ligaments wrap-around bony pulleys, but are not attached to them, and the latter are synovial joints that are lined by fibrocartilage rather than hyaline cartilage. We describe how these 3 types of entheses relate to other, and how all are prone to pathological changes in spondyloarthropathy. We propose that the inflammatory responses characteristic of spondyloarthropathies are triggered at these seemingly diverse sites, in genetically susceptible individuals, by a combination of anatomical factors which lead to higher levels of tissue microtrauma, and the deposition of microbes.

Non-osseous coalition of the medial cuneiform-first metatarsal joint: a case report

Isolated non-osseous tarsal coalition of the medial cuneiform-first metatarsal joint is rare. Resection of the coalition was performed in a 32-year-old patient, with excellent results. This procedure is an effective option for treatment of small lesions.

Articular surface defects in the third metatarsal and third cuneiform: nonosseous tarsal coalition

Frequencies of articular surface defects on the third metatarsal and third cuneiform, seen as pits of varying sizes on the plantar one third of the tarsometatarsal articular face, were investigated in skeletal populations from North America and Japan, as well as in gibbon, orangutan, chimpanzee, and gorilla skeletons. The apes did not exhibit the defects, although the number of observed specimens of each type was small. The newly presented human frequencies corresponded well with those from other published sources. The defects appeared both unilaterally and bilaterally, with no apparent sex or side biases. Statistical tests between the various populations found that, in general, geographically close populations had more similar frequencies of the defect. Possible etiologies for the defect were investigated, including biomechanical influences, degenerative arthritis, infection, trauma, and a developmental condition known as tarsal coalition, which proved to be the best explanation. Tarsal coalition results from the failure of a joint space to form properly during fetal growth. It can occur between any two adjacent bones of the foot. Several clinically important coalitions, whose presence interferes with normal walking, are known. However, coalition between the third metatarsal and third cuneiform has not been reported in the clinical literature, suggesting that the defect causes little or no foot dysfunction. Tarsal coalition is thought to have a strong genetic component, suggesting that the pit defect may be useful as a skeletal nonmetric trait, as others have stated.