Magnetic resonance imaging findings associated with posterior ankle impingement syndrome are prevalent in elite ballet dancers and athletes.

OBJECTIVE: To report the prevalence of MRI features commonly associated with posterior ankle impingement syndrome in elite ballet dancers and athletes and to compare findings between groups. MATERIALS AND METHODS: Thirty-eight professional ballet dancers (47.4% women) were age- and sex-matched to 38 elite soccer or cricket fast bowler athletes. All participants were training, playing, and performing at full workload and underwent 3.0-T standardised magnetic resonance imaging of one ankle. De-identified images were assessed by one senior musculoskeletal radiologist for findings associated with posterior ankle impingement syndrome (os trigonum, Stieda process, posterior talocrural and subtalar joint effusion-synovitis, flexor hallucis longus tendon pathology and tenosynovitis, and posterior ankle bone marrow oedema). Imaging scoring reliability testing was performed. RESULTS: Posterior talocrural effusion-synovitis (90.8%) and subtalar joint effusion-synovitis (93.4%) were common in both groups, as well as the presence of either an os trigonum or Stieda process (61.8%). Athletes had a higher prevalence of either os trigonum or Stieda process than dancers (74%, 50% respectively, P = 0.03). Male athletes had a higher prevalence of either os trigonum or Stieda process than male dancers (90%, 50% respectively, P = 0.01), or female athletes (56%, P = 0.02). Posterior subtalar joint effusion-synovitis size was larger in dancers than athletes (P = 0.02). Male and female dancers had similar imaging findings. There was at least moderate interobserver and intraobserver agreement for most MRI findings. CONCLUSION: Imaging features associated with posterior impingement were prevalent in all groups. The high prevalence of os trigonum or Stieda process in male athletes suggests that this is a typical finding in this population.

Posterior Ankle Decompression With Os Trigonum or Stieda Process Resection in Dancers: Case Series Report and Review of the Literature.

This case series reports the outcome of posterior ankle decompression and os trigonum or Stieda process resection utilizing an open posterolateral approach in 54 professional, pre-professional, and dedicated recreational dancers. All procedures were performed by a single surgeon at the same facility between 2008 and 2018. The surgical technique is described in detail. Data related to results of the surgery were gathered via follow-up questionnaire and verified by referencing the patients' medical records. Outcomes were self-assessed in terms of categories ranging from excellent through moderate to poor. Eighty-nine percent of the dancers (N = 48 of 54) chose excellent or good, 11% (N = 6) chose moderate, and none selected poor. These results were compared with those achieved in 17 previous studies reporting the use of both open (posterolateral and posteromedial) and arthroscopic/endoscopic techniques in dancers. This comparison found similarly favorable reported outcomes, but also great variation in methodology for determining patient reported outcomes (PROs). While the preferred surgical technique for posterior ankle decompression remains controversial, the open posterolateral approach utilized in this series resulted in high expectation of return to dance with minimal complications. The need for a dancer-specific PRO tool is discussed.

Delayed diagnosis of posterior ankle impingement in pediatric and adolescent patients: does radiology play a role?

BACKGROUND: Posterior ankle impingement syndrome (PAIS) results from the pinching of anatomical structures in the posterior part of the ankle. OBJECTIVE: To identify the possible role of imaging in the delayed diagnosis of PAIS and identify key findings on imaging to suggest PAIS in pediatric and adolescent patients. MATERIALS AND METHODS: Data were collected prospectively in patients younger than 18 years of age who underwent arthroscopy after being diagnosed with PAIS. Imaging was reviewed retrospectively by two radiologists, compared with findings in literature and an age-matched control group, and correlated with arthroscopic findings. Pre- and postsurgical Visual Analogue Scale (VAS) pain and American Orthopedic Foot Ankle Society (AOFAS) ankle-hindfoot scores were noted. RESULTS: Thirty-eight patients (20 females, 18 males), 51 ankles, with an average age of 12.9 years had an average 18-month delay in diagnosis. Twenty-seven of the 38 (73%) patients had previously seen multiple medical providers and were given multiple misdiagnoses. Radiographs were reported normal in 34/47 (72%) ankles. Thirty patients had magnetic resonance imaging (MRI) and findings included the presence of an os trigonum/Stieda process (94%) with associated osseous edema (69%), flexor hallucis longus (FHL) tenosynovitis (16%), and edema in Kager's fat pad (63%). Although individual findings were noted, the impression in the MRI reports in 16/32 (50%) did not mention PAIS as the likely diagnosis. There was a significant difference in the MRI findings of ankle impingement in the patient population when compared to the control group. Surgery was indicated after conservative treatment failed. All 51 ankles had a PAIS diagnosis confirmed during arthroscopy. At an average follow-up of 10.2 months, there was improvement of VAS pain (7.0 to 1.1) and AOFAS ankle-hindfoot scores (65.1 to 93.5). CONCLUSION: PAIS as a diagnosis is commonly delayed clinically in young patients with radiologic misinterpretation being a contributing factor. Increased awareness about this condition is needed among radiologists and physicians treating young athletes.

Fracture of the Posterior Process of the Talus With Concomitant Subtalar Dislocation.

Fracture of the posterior process of the talus with concomitant subtalar dislocation is rare; thus, the mechanism of injury, appropriate treatment, and prognosis are unclear. We report the case of a 50-year-old male with a fracture of the posterior process of the talus with concomitant subtalar dislocation that was recognized early and successfully treated operatively.

Posterior Ankle Impingement in Two Athletic Twin Brothers, Could Genetics Play a Role?

Pain posteriorly in the ankle can be caused by bony impingement of the posterolateral process of the talus. This process impinges between the tibia and calcaneus during deep forced plantar flexion. If this occurs it is called posterior ankle impingement syndrome. We report the case of 2 athletic monozygotic twin brothers with bony impingement posteriorly in the left ankle. Treatment consisted of ankle arthroscopy in both patients during which the symptomatic process was easily removed. At 3 months after surgery, both patients were completely free of pain, and 1 of the brothers had already returned to sports. The posterior ankle impingement syndrome is not a rare syndrome, but it has not been described in siblings thus far. That these 2 patients are monozygotic twin brothers suggests that genetics could play a role in the development of skeletal deformities that can result in posterior ankle impingement syndrome.

The management of posterior ankle impingement syndrome in sport: a review.

A literature review has been undertaken to assess the efficacy of management of Posterior Ankle Impingement Syndrome with an emphasis on sport. The evidence is confined to Level IV and V studies. There is a lack of prospective studies on the natural history of this condition and the outcomes of conservative treatment. Dance dominates the literature accounting for 62% of reported sports. Forty-seven papers have reported on the surgical outcomes of 905 procedures involving both open and artho-endoscopic techniques. 81% of patients required excision of osseous pathology and 42% soft-tissue problems resolving. There is a lack of standardisation of outcome reporting particularly in the open surgery group. However, the complication rates are relatively low: 3.9% for open medial, 12.7% for open lateral and 4.8% for arthro-endocopic surgery. Return to sport appears quicker for all activities in the arthro-endoscopic group but comparison of long term outcomes is more difficult with no evidence supporting superior long term results of one technique over another. Soccer players appear to return more quickly to activity than dancers.

Magnetic resonance imaging, computed tomography, and radiographic correlation of nonunion of the posteromedial tubercle of the talus: a case report.

Fracture of the posteromedial tubercle of the talus is an uncommon injury that is often missed on plain radiographs. In the present report, we describe the case of an adult male with a chronic nonunited fracture of the medial tubercle of the posterior process of the talus after having undergone clinical and radiographic evaluation in a community hospital emergency department. A review of the computed tomographic, magnetic resonance imaging, and plain film radiographic findings associated with nonunion of the posteromedial tubercle of the talus is also presented.

Hindfoot endoscopy for the treatment of posterior ankle impingement syndrome: a safe and reproducible technique.

INTRODUCTION: Posterior ankle impingement is a clinical syndrome characterized by posterior ankle pain that is mainly presented on plantar flexion. The aim of this study is to compare and evaluate the results of posterior ankle impingement treated by endoscopic hindfoot posterior portals. MATERIALS AND METHODS: Between 2004 and 2009, a total of 38 endoscopic hindfoot procedures were performed to treat posterior ankle impingement. The indication for procedure was posterior ankle impingement syndrome in all cases. There were 38 patients, 17 females and 21 males. Mean age was 27.6 years (16-59 years). Mean follow-up was 27.6 months (12.5-52 months). The results were evaluated following the AOFAS score. Data statistical analysis was performed using the Student's t-test. RESULTS: The main preoperative AOFAS score increased from 67.42 (range 41-91) to 97.13 (range 84-100) at follow-up. No complications were reported in any case. CONCLUSION: Hindfoot endoscopy is a reproducible and safe procedure which offers excellent outcomes in posterior ankle impingement syndrome.

Posterior Ankle Impingement Syndrome.

Posterior ankle impingement is typically seen in athletes, primarily dancers and soccer players, secondary to dynamic and repetitive push-off maneuvers and forced hyperplantarflexion. Posterior ankle impingement results from chronic, repetitive trauma to the posterior ankle capsule, flexor hallucis longus tendon, and/or os trigonum. It is important to perform a thorough workup by isolating and testing the posterior compartment muscles and obtaining proper imaging with radiographs to identify any osseous abnormalities and MRI to evaluate the soft tissue structures. Nonsurgical treatment includes activity modification, physical therapy, and steroid injections.

Systematic review: Diagnostics, management and outcome of fractures of the posterior process of the talus.

BACKGROUND: Fractures of the posterior process of the talus are rare and frequently overlooked, possibly leading to pseudo-arthrosis and chronic pain. To gain more insight into the diagnosis, treatment and outcome of fractures of the posterior process of the talus (PPTF), a systematic review of the current literature was performed to provide recommendations for the management of PPTF. METHODS: A literature search in the electronic databases of PubMed, EMbase, Google Scholar and Cochrane library was performed in January 2020 to identify all clinical studies on PPTF with more than three patients. Amongst other variables, the type of study, number of patients, mechanism of injury, type of fracture (anatomy), imaging modality, treatment, postoperative protocol, outcomes, complications and duration of follow-up were noted for systematic analysis of the available evidence, adherent to the PRISMA guidelines. RESULTS: Seven original studies were included with a total of 66 patients. More than one third of patients presented with a (sub)talar joint dislocation (n = 25, 37.9%) and 51.5% sustained associated ipsilateral lower extremity fractures (n = 34). Delayed diagnosis occurred in 36.4% of patients (n = 24). Out of 48 patients with outcome data available, 41.7% (n = 20) reported impaired function. In the non-operative group, 64.7% (n = 11) had impaired functional outcome, compared to 33.3% (n = 6) in the ORIF group, and 30.8% (n = 4) in the fragment excision group (p < 0.001). One third of the patients developed one or more complications (n = 25, 37.9%), mostly found in the non-operatively treated group (73.7%, n = 14) compared to ORIF (25.0%, n = 8, p < 0.001). CONCLUSION: Early recognition and timely treatment is warranted in order to achieve pre-injury functional outcome and reduce morbidity. Given the significantly higher complication rate and lower return to the previous level of functionality reported after non-operative treatment, ORIF is recommended if there is (even minimal) displacement, articular involvement or if the fracture extends into the talus body.

Posterior talar process as a suitable cell source for treatment of cartilage and osteochondral defects of the talus.

Osteochondral defects of the ankle are common lesions affecting the talar cartilage and subchondral bone. Current treatments include cell-based therapies but are frequently associated with donor-site morbidity. Our objective is to characterize the posterior process of the talus (SP) and the os trigonum (OT) tissues and investigate their potential as a new source of viable cells for application in tissue engineering and regenerative medicine. SP and OT tissues obtained from six patients were characterized by micro-computed tomography and histological, histomorphometric and immunohistochemical analyses. Proliferation and viability of isolated cells were evaluated by MTS assay, DNA quantification and live/dead staining. The TUNEL assay was performed to evaluate cell death by apoptosis. Moreover, the production of extracellular matrix was evaluated by toluidine blue staining, whereas cells phenotype was investigated by flow cytometry. Characterization of ankle explants showed the presence of a cartilage tissue layer in both SP and OT tissues, which represented at least 20%, on average, of the explant. The presence of type II collagen was detected in the extracellular matrix. Isolated cells presented a round morphology typical of chondrocytes. In in vitro studies, cells were viable and proliferating for up to 21 days of culture. No signs of apoptosis were detected. Flow-cytometry analysis revealed that isolated cells maintained the expression of several chondrocytic markers during culture. The results indicated that the SP and OT tissues were a reliable source of viable chondrocytes, which could find promising applications in ACI/MACI strategies with minimal concerns regarding donor zone complications. Copyright © 2015 John Wiley & Sons, Ltd.

Síndrome del impacto posterior del tobillo secundario a proceso de Stieda / Posterior Ankle Impingement secondary to a Stieda process

Introducción: El síndrome de impacto posterior es una condición que resulta de la compresión de tejidos blandos entre la cara posterior del astrágalo y el área posteroinferior de la tibia durante el movimiento de flexión plantar del tobillo y provoca inflamación de los tejidos blandos circundantes. Objetivo: Presentar un caso de síndrome de impacto posterior secundario a proceso de Stieda. Presentación de caso: Se presenta el caso de un varón de 53 años, cocinero de profesión que se quejaba de dolor en la región posterior del tobillo derecho, que se exacerbaba con la flexión plantar del tobillo sin traumatismo previo. Se descartaron lesiones de tipo tendinosas y ligamentosas al examen físico, por lo que se indica radiografía convencional. A través de la radiografía de tobillo se define proceso de Stieda el cual justifica la clínica. Por esto no se realizaron otros estudios. Conclusiones: La radiografía convencional en el contexto clínico de un síndrome de impacto posterior del tobillo permite establecer el diagnóstico sin requerir estudios de imagen de mayor complejidad(AU)

Introduction: The posterior impingement syndrome is a condition resulted of compressed posterior soft tissues, between the posterior talus and the calcaneus. Classically, this is seen at activities that cause extreme plantar flexion. Objective: To describe a posterior Ankle Impingement case secondary to a Stieda process. Case report: We report a 53 years old male, cook profession, with a chronic pain history within the posterior ankle, previous trauma was denied. At clinical examination tendon and ligament injuries were not found. Initial evaluation with conventional radiography showed the presence of a Stieda's process as cause of clinical manifestations. No further imaging studies were required. Conclusion: Conventional radiograph allows to clarify diagnosis in the posterior impingement syndrome(AU)

A comprehensive study of the anatomical variations of the posterolateral tubercle of talus / Un estudio integral de las variaciones anatómicas del tubérculo posterolateral del talo

SUMMARY: The aim of our study was to determine the prevalence and the anatomical variations of the posterolateral tubercle of talus in relation to sex on CT imaging. A total of 1478 ankle CT scans was retrospectively reviewed for the different anatomical variants of the posterolateral tubercle of talus, the type and size of os trigonum. Normal sized lateral tubercle was found in 46.1 %, an enlarged posterolateral tubercle (Stieda's process) in 26.1 %, os trigonum in 20.5 % and almost absent tubercle in 7.3 %. A statistically higher prevalence of Stieda's process was found in males while os trigonum was higher in females (p0.05). The posterolateral tubercle of talus and its accessory ossicle, the os trigonum, could vary morphologically. The data of this study could be helpful in understanding the clinical problems that could be associated with some of these variants.

RESUMEN: El objetivo de nuestro estudio fue determinar la prevalencia y las variaciones anatómicas del tubérculo posterolateral del talo en relación con el sexo en la imagen de TC. Se revisaron retrospectivamente un total de 1478 TC de tobillo para las diferentes variantes anatómicas del tubérculo posterolateral del talo, el tipo y tamaño del os trigonum. Se encontró tubérculo lateral de tamaño normal en 46,1 %, tubérculo posterolateral (proceso de Stieda) en 26,1 %, os trigonum en 20,5% y tubérculo casi ausente en 7,3 %. Se encontró una prevalencia estadísticamente más alta del proceso de Stieda en los hombres, mientras que el os trigonum fue mayor en las mujeres (p 0,05) no se observaron diferencias significativas. El tubérculo posterolateral del talo y su osículo accesorio, el os trigonum, podrían originar problemas clínicos que podrían estar asociados con algunas de estas variantes.

Hindfoot endoscopy for posterior ankle impingement syndrome and flexor hallucis longus tendon disorders.

Hindfoot endoscopic surgery is an alternative to conventional open surgery for treatment of posterior ankle pain. This procedure can be applied not only for accurate diagnosis under direct visualization but also for low-invasive therapy. Common indications for hindfoot endoscopy are posterior ankle impingement syndrome and damaged soft tissue. Several studies have reported good clinical outcomes of hindfoot endoscopy with lower complication rates than in the conventional open procedure. Nerve injury remains a common complication. To avoid such injury, make a posterolateral portal just lateral to the Achilles tendon and perform the hindfoot endoscopic procedure in the region lateral to the flexor hallucis longus tendon.

Posterior ankle impingement in athletes: Pathogenesis, imaging features and differential diagnoses.

Posterior ankle impingement is a clinical diagnosis which can be seen following a traumatic hyper-plantar flexion event and may lead to painful symptoms in athletes such as female dancers ('en pointe'), football players, javelin throwers and gymnasts. Symptoms of posterior ankle impingement are due to failure to accommodate the reduced interval between the posterosuperior aspect of the talus and tibial plafond during plantar flexion, and can be due to osseous or soft tissue lesions. There are multiple causes of posterior ankle impingement. Most commonly, the structural correlates of impingement relate to post-traumatic synovitis and intra-articular fibrous bands-scar tissue, capsular scarring, or bony prominences. The aims of this pictorial review article is to describe different types of posterior ankle impingement due to traumatic and non-traumatic osseous and soft tissue pathology in athletes, to describe diagnostic imaging strategies of these pathologies, and illustrate their imaging features, including relevant differential diagnoses.

Prevalence of elongated posterior talar process (stieda process) detected by radiography / Prevalencia del proceso talar posterior alargado (proceso de stieda) detectado por radiografía

SUMMARY: The Stieda process (SP) and os trigonum (OT) are primary risk factors for posterior ankle impingement syndrome. The aim of this study was to elucidate the prevalence of the elongated lateral tubercle of the posterior talar process (SP) and OT in Turkish subjects using lateral ankle radiographs. In this study, 1088 ankle radiographs in the lateral view were evaluated retrospectively using a picture archiving and communication system at two large medical centers. Subjects with a history of mild-to-moderate trauma were selected from the emergency departments of both hospitals from January to June 2019. Data on the presence of SP and OT, the side of the foot that was evaluated, sex, and age were recorded. The prevalence of SP and OT was 16.7 % and 9.3 %, respectively, in the Turkish population. The prevalence of SP was significantly higher in men (20.3 %) than in women (12.7 %) (p = 0.001). The prevalence of OT was also significantly higher in men (13.7 %) than in women (4.3 %) (p = 0.000). The SP and OT were found in 17 % and 9.9 % of the right feet, respectively, and 16.4 % and 8.6 % of the left feet, respectively, with no statistical difference. Approximately one-fourth of the Turkish population had SP or OT, which made them susceptible to posterior ankle impingement syndrome. The prevalence of SP was higher than that of OT, and both were more common in men than in women.

RESUMEN: El proceso de Stieda (Stieda process) (SP) y el Os trigonum (OT) son factores de riesgo primarios para el síndrome de pinzamiento del tobillo posterior. El objetivo de este estudio fue determinar la prevalencia del tubérculo lateral alargado del proceso talar posterior (SP) y OT en sujetos turcos mediante radiografías laterales de tobillo. Se evaluaron retrospectivamente 1088 radiografías de tobillo con vista lateral, utilizando un sistema de archivo y comunicación de imágenes en dos centros médicos importantes. Los sujetos con antecedentes de trauma leve a moderado fueron seleccionados en las unidades de urgencia de ambos hospitales de enero a junio de 2019. Se registraron datos sobre la presencia de SP y OT, el lado del pie que se evaluó, el sexo y la edad. La prevalencia de SP y OT fue de 16,7 % y 9,3 %, respectivamente, en la población turca. La prevalencia de SP fue significativamente mayor en hombres (20,3 %) que en mujeres (12,7 %) (p = 0,001). La prevalencia de OT también fue significativamente mayor en hombres (13,7 %) que en mujeres (4,3 %) (p = 0,000). El SP y OT se encontraron en 17 % y 9,9 % de los pies derechos, respectivamente, y 16,4 % y 8,6 % de los pies izquierdos, respectivamente, sin diferencia estadística. Aproximadamente un cuarto de la población turca tenía SP u OT, lo que los hizo susceptibles al síndrome de pinzamiento del tobillo posterior. La prevalencia de SP fue mayor que la de OT, y ambos fueron más comun en hombres que en mujeres.

"Os trigonum" y "proceso de stieda" en el síndrome del impacto posterior del tobillo / Os trigonum and stieda process in posterior ankle impingement syndrome

El Os trigonum (OT) y el Proceso de Stieda (PS), corresponden a la osificación separada o extensiva del tubérculo lateral de la cara posterior del talus (TA), respectivamente. Son indicados como factores causales del Síndrome del Impacto Posterior del Tobillo (SIPT), disturbio, agudo o crónico, con dolor en la región posterior del tobillo a los movimientos del pie. El objetivo fue analizar la importancia morfológica de la presencia del OT y/o PS y su posible relación con el SIPT. Fueron utilizados 80 TA secos. La morfometría del TA y del Tubérculo Lateral del TA (TL) fueron calculadas y expresas como: LTA = largo total del TA; ATA = ancho total del TA; LTL/LPS = largo total de TL/PS; ETL = espesor total de TL/PS. Los análisis mostraron valores de LTA: 55,22 (+/-4,16) mm; ATA: 39,51 (+/-2,46) mm; LTL/LPS: 8,06 mm (+/-2,14) y ETL: 8,46 (+/-1,01) mm. Nuestros resultados ofrecen informaciones no encontradas en la literatura especializada y ayudan en el diagnóstico y tratamiento del SIPT.

Os Trigonum (OT) and Stieda Process (SP), separate or extensive ossification of the lateral tubercule of posterior face of Talus (TA), respectively, are indicative of causal factors of the Posterior Impingement Syndrome of The Ankle (PISA) - disturbance, sharp or chronic pain, with pain in the posterior region of the ankle caused by foot movements. The objective of this study was to analyze the morphological importance of the presence of OT and or SP and the possible relationship with PISA for which we used 80 dry TA. The morphometry of TA and Lateral Tubercule of TA (LT) were calculated and expressed as mean: LTA= total length of TA; WTA= total width of TA; LLT/LPS= total length of LT/SP; TLT= total thickness of LT/SP. The measures were LTA: 55.22 (+/-4.16) mm; WTA: 39.51 (+/-2.46) mm; LLT/LPS: 8.06 (+/-2.14) mm; TLT: 8.46 (+/-1.01) mm. Our results provide useful information not found in the specialized literature and are of assistance in the diagnosis and treatment of PISA.