Posterior ankle impingement syndrome in football players: Case series of 26 elite athletes

Injection therapy in professional footballers

BACKGROUND

Injection therapy offers a minimally invasive approach for symptomatic relief that allows concurrent training, limiting time loss and providing a faster recovery. However, there is a lack of scientific evidence to support it, and there are controversies about its use. The present narrative review aims to present the available scientific literature on injection therapies in professional footballers (PF), highlighting the advantages and disadvantages of its use in the most common injuries.

METHODS

The authors searched and reviewed contemporary literature on injection therapies in PF in electronic databases, summarizing them in a narrative review.

RESULTS

Injection therapies such as hyaluronic acid and PRP have shown an adequate safety profile that allows their use. Current evidence suggests that hyaluronic acid injections are a valid option for managing symptomatic cartilage injuries. At the same time, PRP injections have failed to prove beneficial in treating muscle injuries and should be avoided until further evidence proves the opposite. Yet, PRP may have potential use in partial ACL injuries, anterior inferior tibiofibular ligament injuries (ankle syndesmosis), and fifth metatarsal fractures and needs further study. Due to the long-term health repercussions, other injection therapies should be preferred over corticosteroids in PF.

CONCLUSIONS

There is a paucity of evidence on the use and benefits of injection therapies in PF despite its extensive use among physicians. Viscosupplementation may have a role in improving symptomatic cartilage injuries. In contrast, PRP injection therapy needs further high-quality clinical trials to assess its role in PF sports injuries.

Arthroscopic treatment of ankle impingement syndrome

Arthroscopic treatment of ankle impingement syndrome (AIS) is a minimally invasive surgical procedure used to address symptoms caused by impingement in the ankle joint. This syndrome occurs when there is abnormal contact between certain bones or soft tissues in the ankle, leading to pain, swelling, or limited range of motion. Traditionally, open surgery was the standard approach for treating AIS. However, with advancements in technology and surgical techniques, arthroscopic treatment has become a preferred method for many patients and surgeons. With improved visualization and precise treatment of the arthroscopy, patients can experience reduced pain and improved functionality, allowing them to return to their daily activities sooner. In this paper, we reviewed the application and clinical efficacy the of arthroscopic approach for treating AIS, hoping to provide a reference for its future promotion.

Update on Ankle and Foot Impingement

Ankle impingement syndromes are a well-recognized cause of chronic ankle symptoms in both the elite athletic and general population. They comprise several distinct clinical entities with associated radiologic findings. Originally described in the 1950s, advances in magnetic resonance imaging (MRI) and ultrasonography have allowed musculoskeletal (MSK) radiologists to further their understanding of these syndromes and the range of imaging-associated features. Many subtypes of ankle impingement syndromes have been described, and precise terminology is critical to carefully separate these conditions and thus guide treatment options. These are divided broadly into intra-articular and extra-articular types, as well as location around the ankle. Although MSK radiologists should be aware of these conditions, the diagnosis remains largely clinical, with plain film or MRI used to confirm the diagnosis or assess a surgical/treatment target. The ankle impingement syndromes are a heterogeneous group of conditions, and care must be taken not to overcall findings. The clinical context remains paramount. Treatment considerations are patient symptoms, examination, and imaging findings, in addition to the patient's desired level of physical activity.

Posterior Ankle Impingement Syndrome Clinical Features Are Not Associated With Imaging Findings in Elite Ballet Dancers and Athletes

OBJECTIVE

To assess the association between clinical features and magnetic resonance imaging (MRI) findings in posterior ankle impingement syndrome (PAIS) and to compare the prevalence of imaging findings between participants with and without a clinical diagnosis of PAIS.

DESIGN

Case-control study.

SETTING

Elite ballet and sport.

PARTICIPANTS

Eighty-two male (54%) and female participants comprising ballet dancers (n = 43), cricket fast bowlers (n = 24), and football (soccer) players (n = 15).

INDEPENDENT VARIABLES

Clinical: posterior ankle pain on body chart, passive plantarflexion pain provocation test. Patient-reported outcome measures: Oslo Sports Trauma Research Center Overuse Injury Questionnaire, Foot and Ankle Ability Measure Sports subscale.

MAIN OUTCOME MEASURES

Imaging findings including posterior ankle bone marrow edema, os trigonum (± bone marrow edema, and increased signal at synchondrosis), Stieda process (± bone marrow edema), talocrural and subtalar joint effusion-synovitis size, flexor hallucis longus tendinopathy, and tenosynovitis identified as present or absent on 3.0-Tesla MRI.

RESULTS

Imaging findings were not associated with posterior ankle pain or a positive ankle plantarflexion pain provocation test. Imaging findings were not associated with patient-reported outcome measures. Imaging findings did not differ between PAIS-positive and PAIS-negative groups. Os trigonum and Stieda process were prevalent despite clinical status.

CONCLUSIONS

The lack of association between imaging findings and clinical features questions the role of imaging in PAIS. Clinicians should rely primarily on clinical assessment in the diagnosis and management of patients with PAIS.

Anterior ankle impingment syndrome is less frequent, but associated with a longer absence and higher re-injury rate compared to posterior syndrome: a prospective cohort study of 6754 male professional soccer players

PURPOSE

To study the epidemiology and return to play characteristics of anterior and posterior ankle impingement syndromes (AAIS and PAIS) over 18 consecutive seasons in male professional soccer players.

METHODS

Between the 2001-2002 and 2018-2019 seasons, 120 European soccer teams were followed prospectively for various seasons. Time loss injuries and player exposures were recorded individually in 6754 unique players. Injury incidence and burden were reported as the number of injuries and days absence per 1000 h with 95% confidence intervals (CIs). Injury severity was reported as median absence in days with the interquartile range (IQR).

RESULTS

Out of 25,462 reported injuries, 93 (0.4%) were diagnosed as AAIS (38%) or PAIS (62%) in 77 players. AAIS and PAIS were similar regarding injury characteristics except for a greater proportion of AAIS having a gradual onset (69% vs.47%; P = 0.03) and being re-injuries (31% vs. 9%; P = 0.01). Impingement syndromes resulted in an overall incidence of 0.03 injuries (95% CI 0.02-0.03) per 1000 h and an injury burden of 0.4 absence days per 1000 h. PAIS incidence was significantly higher than that for AAIS [0.02 (95% CI 0.002-0.03) vs. 0.01 (95% CI 0.005-0.01) injuries per 1000 h (RR = 1.7). The absence was significantly longer in AAIS than in PAIS [10 (22) vs. 6 (11) days; P = 0.023]. Impingement syndromes that presented with a gradual onset had longer absences in comparison to impingement with an acute onset [8 (22) vs. 5 (11) days; P = 0.014]. Match play was associated with a higher incidence and greater injury burden than training: 0.08 vs. 0.02 injuries per 1000 h (RR 4.7), respectively, and 0.9 vs. 0.3 days absence per 1000 h (RR 2.5).

CONCLUSION

Ankle injuries are frequent in men's professional soccer and ankle impingement is increasingly recognized as a common source of pain, limited range of motion, and potential time loss. In our study, ankle impingement was the cause of time loss in less than 0.5% of all injuries. PAIS was more frequently reported than AAIS, but AAIS was associated with more absence days and a higher re-injury rate than PAIS. The findings in this study can assist the physician in best practice management on ankle impingment syndromes in professional football.

LEVEL OF EVIDENCE

II.

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.

The dominant leg is more likely to get injured in soccer players: systematic review and meta-analysis

In soccer (football), dominant limb kicking produces higher ball velocity and is used with greater frequency than the non-dominant limb. It is unclear whether limb dominance has an effect on injury incidence. The purpose of this systematic review with meta-analysis is to examine the relationship between limb dominance and soccer injuries. Studies were identified from four online databases according to PRISMA guidelines to identify studies of soccer players that reported lower extremity injuries by limb dominance. Relevant studies were assessed for inclusion and retained. Data from retained studies underwent meta-analyses to determine relative risk of dominant versus non-dominant limb injuries using random-effects models. Seventy-four studies were included, with 36 of them eligible for meta-analysis. For prospective lower extremity injury studies, soccer players demonstrated a 1.6 times greater risk of injury to the dominant limb (95% CI [1.3-1.8]). Grouped by injury location, hamstring (RR 1.3 [95% CI 1.1-1.4]) and hip/groin (RR 1.9 [95% CI 1.3-2.7]) injuries were more likely to occur to the dominant limb. Greater risk of injury was present in the dominant limb across playing levels (amateurs RR 2.6 [95% CI 2.1-3.2]; youths RR 1.5 [95% CI 1.26-1.67]; professionals RR 1.3 [95% CI 1.14-1.46]). Both males (RR 1.5 [95% CI 1.33-1.68)] and females (RR 1.5 [95% CI 1.14-1.89]) were more likely to sustain injuries to the dominant limb. Future studies investigating soccer injury should adjust for this confounding factor by using consistent methods for assigning limb dominance and tracking use of the dominant versus non-dominant limb.

Arthroscopic Treatment of Posterior Ankle Impingement Syndrome: Mid-Term Clinical Results and a Learning Curve

Purpose

To report mid-term clinical results of posterior ankle arthroscopy in the treatment of posterior ankle impingement syndrome (PAIS) and to assess the learning curve and its influence on the results.

Methods

This was a retrospective evaluation of the clinical outcomes of posterior ankle arthroscopy and its learning curve in a series of patients with PAIS. Demographic and clinical data, surgical time, the American Orthopaedic Foot Ankle Society (AOFAS) ankle/hindfoot scores, and time to resumption of sports were recorded.

Results

Fifty-nine patients with 72 posterior ankle arthroscopies were evaluated at a mean follow-up period of 60 months (24-133 months). Causes of PAIS were an os trigonum (50), a large posterior talar process (14), and soft-tissue impingement (8). There were 29 male and 30 female patients. The average age was 21.8 years (12-74 years). The average preoperative AOFAS score improved significantly from 79.6 to 97.6 postoperatively (P < .0001). The average time taken to resume training was 5.3 weeks, and the time to return to a competitive condition was 13.4 weeks. The times to resumption of training were shorter in elite athletes than local competitive athletes. The learning curve of the posterior ankle arthroscopy was detected and determined by a logarithmic trendline and moving averages. An experience of 26 cases was required to be proficient in posterior arthroscopies. The postoperative AOFAS scores were not statistically different between the initial and the latest 10 series each.

Conclusions

The mid-term follow-up results of endoscopic treatment for the PAIS were good, with a high success rate in returning to sports activities. Although a learning curve effect was detected in our series of arthroscopic treatment for the PAIS due to os trigonum, a low volume of experience did not affect the results.

Level of Evidence

Level IV, therapeutic case series.

Ankle Impingement: A Critical Analysis Review

Ankle impingement presents with painful and limited range of motion with dorsiflexion or plantar flexion, originating from pathological contact between bone and/or soft-tissue structures. Diagnosis is made primarily through clinical examination with adjunct radiographs and magnetic resonance imaging, with care taken to rule out a plethora of similarly presenting pathologies. Arthroscopic surgical approaches bring satisfactory short, mid, and long-term outcomes, with the current body of evidence dominated by Level-IV studies. Minimally invasive techniques offer improvements in time to return to play and complication rates relative to open approaches. Recent advances in the arthroscopic management of ankle impingement include long-term outcome studies, novel prognostic classification systems, and strategies for concomitant lesion management.

Arthroscopic os trigonum en-bloc removal outcomes at 6-month follow-up are better compared to Stieda's process resection in patients with posterior ankle impingement syndrome: a prospective comparative study

OBJECTIVE

To evaluate the potential differences in American Orthopaedic Foot and Ankle Society (AOFAS) hindfoot score and Foot Function Index (FFI) at 6-month and 12-month postoperative follow-up of arthroscopic treatment for posterior ankle impingement (PAIS) between os trigonum (OT) and Stieda's process (SP) patients.

METHODS

Thirty consecutive patients (32 ankles) treated in our Institution for PAIS with posterior arthroscopy were prospectively enrolled in the study from December 2012 to July 2019. Indications were patients with PAIS with persistent symptoms following conservative management. Exclusion criteria were the coexistence of concomitant pathologies and patients who underwent additional surgical procedures. An independent investigator interviewed and evaluated the patients according to the AOFAS hindfoot score and FFI preoperatively, at 6-month and 12-month follow-up.

RESULTS

Except for AOFAS scores in the SP group (MD (mean difference) 11.28, p=0.08), patients undergoing arthroscopic treatment for bony PAIS had an overall significant improvement in AOFAS score (OT MD 22.29, p<0.05) and FFI (OT MD -70.07, p<0.05; SP MD -50.96, p<0.05) from their preoperative scores at 6-month follow-up. Similarly, a significant improvement in AOFAS score (OT MD 5.78, p=0.01; SP MD 12.14, p<0.05) and FFI (OT MD -9.36, p=0.04; SP MD -26.43, p<0.05) was observed from the 6-month to 12-month follow-up in all groups. At 6-month follow-up, the OT group had significantly better FFI outcomes (MD -33.57, p=0.04) compared with the SP group. No differences were found by group when comparing AOFAS score and FFI score at 12-month follow-up.

CONCLUSIONS

When comparing patients undergoing OT excision or SP resection, better FFI outcomes were observed in the OT group at 6-month follow-up.

LEVEL OF EVIDENCE

Prospective comparative study. Level II.

Causes of delayed diagnosis of posterior ankle impingement in the pediatric and adolescent population

PURPOSE

The purpose of this study was to identify and characterize various causes of delay in the diagnosis of posterior ankle impingement syndrome (PAIS) in pediatric patients.

METHODS

IRB approved prospective study of patients under 18 years who underwent arthroscopic surgery for the diagnosis of posterior ankle impingement after failed conservative treatment at a tertiary children's hospital. Radiographic findings were compared with an age-matched control group. Descriptive and inferential statistics were employed.

RESULTS

47 patients (61 ankles), mean age 13 years, had an average 14 months delay in diagnosis of PAIS from the initial presentation. 33 (70%) patients had seen multiple medical providers and given other diagnoses. 9 (19%) patients participated in ballet or soccer, and 16 (34%) patients had unrelated associated foot and ankle diagnoses. 25 (41%) of 61 ankles did not have pain on forced plantar flexion; all 61(100%) ankles had tenderness to palpation over the posterior ankle joint line. Radiographs were reported to be normal in 37/52 (71%) ankles, while MRI report did not mention the diagnosis in 20/41 (49%) studies. There was a significant difference in the MRI findings in the patient population when compared to the control group. Indication for surgery was failed conservative treatment. All 61 ankles had posterior ankle impingement pathology confirmed visually during arthroscopy. At average 15 months follow-up, there was significant improvement pre- to post-operatively (p<0.001) for both pain VAS (6.9-0.9) and AOFAS ankle-hindfoot scores (65-94).

CONCLUSION

Multiple clinical and imaging factors can lead to delayed diagnosis of posterior ankle impingement. An increased awareness about the features of PAIS is needed amongst medical providers involved in treating young patients.

Foot and Ankle Injections in Athletes

CONTEXT

Injections are commonly used by health care practitioners to treat foot and ankle injuries in athletes despite ongoing questions regarding efficacy and safety.

EVIDENCE ACQUISITION

An extensive literature review was performed through MEDLINE, Google Scholar, and EBSCOhost from database inception to 2021. Keywords searched were injections, athletes, sports, foot and ankle, corticosteroids, platelet-rich plasma, and placental tissue. Search results included articles written in the English language and encompassed reviews, case series, empirical studies, and basic science articles.

STUDY DESIGN

Clinical review.

LEVEL OF EVIDENCE

Level 4.

RESULTS

Corticosteroids, platelet-rich plasma/autologous blood, anesthetic, and placental tissue injections are commonly used in the treatment of foot and ankle injuries. Primary indications for injections in athletes include plantar fasciitis, Achilles tendinosis, isolated syndesmotic injury, and ankle impingement with varying clinical results.

CONCLUSIONS

Despite promising results from limited case series and comparative studies, the data for safety and efficacy of injections for foot and ankle injuries in athletes remain inconclusive.

Anterior and Posterior Ankle Impingement Syndromes: Arthroscopic and Endoscopic Anatomy and Approaches to Treatment

Ankle impingement refers to a chronic painful mechanical limitation of ankle motion caused by soft tissue or osseous abnormality affecting the anterior or posterior tibiotalar joint. Impingement can be associated with a single traumatic event or repetitive microtrauma. These syndromes are a possible etiology of persistent ankle pain. An arthroscopic approach to this pathology, when indicated, is considered as ideal treatment with its high safety and low complication rate. We describe the clinical and potential imaging features, and the arthroscopic/endoscopic management strategies, for the 4 main impingement syndromes of the ankle: anterolateral, anterior, antero-medial, and posterior.

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.

[Effectiveness of Tang's arthroscopy approach for anterior and posterior ankle impingement syndrome]

OBJECTIVE

To investigate the effectiveness of Tang's arthroscopy approach in treatment of anterior and posterior ankle impingement syndrome.

METHODS

Between August 2010 and September 2017, 92 patients with anterior and posterior ankle impingement syndrome were retrospectively analyzed. There were 58 patients were treated with Tang's arthroscopy approach under floating decubitus (group A) and 34 patients were treated with standard anterior and posterior approaches (group B). There was no significant difference in gender, age, body mass index, side, disease duration, preoperative American Orthopaedic Foot and Ankle Society (AOFAS) score, and preoperative visual analogue scale (VAS) score between the two groups ( P>0.05).The operation time, AOFAS score, VAS score, and Roles-Maudsley score were recorded to evaluated the pain and function of the ankle, and patient subjective satisfaction. The X-ray film and MRI at 12 months were used to observe the ankle impingement.

RESULTS

Median operation time of group A was 50.5 minutes ［95%CI (49.3, 54.6)］, which was significantly shorter than that of group B ［88.5 minutes, 95%CI (76.5, 92.8)］ (Z=-4.685, P=0.000). All incisions in group A healed by first intention; while the incisions of 2 cases in group B delayed healed after debridement. The follow-up time of group A was (54.7±18.8) months, while that of group B was (55.4±17.9) months, and there was no significant difference between the two groups ( t=-0.178, P=0.859). The lateral X-ray films at 12 months showed that the talus process was removed incompletely in 2 cases (3.4%) of group A and 1 case (2.9%) of group B. There was no significant difference in the incidence between the two groups (χ 2=0.014, P=0.699). At last follow-up, the AOFAS scores were 83.1±6.6 in group A and 85.2±6.4 in group B; the VAS scores were 1.3±1.1 in group A and 1.6±1.0 in group B. The AOFAS and VAS scores at last follow-up were superior to preoperative ones ( P<0.05), but there was no significant difference between the two groups ( P>0.05). The median subjective satisfaction score of group A was 2.0 ［95%(1.4, 1.7)］, which was better than that of group B ［2.0, 95%(1.6, 2.2)］ ( Z=-2.480, P=0.013).

CONCLUSION

Arthroscopic treatment of anterior and posterior ankle impingement syndrome through Tang's approach can shorten the operation time, simplify the procedures, and obtain good effectiveness and patient satisfaction.

Impingement syndromes of the ankle and hindfoot

Ankle impingement refers to a chronic painful mechanical limitation of ankle motion caused by soft-tissue or osseous abnormality affecting the tibiotalar joint or extraarticular soft tissues. Impingement can be associated with a prior single traumatic event or repetitive microtrauma, often in an adolescent with anatomical predisposition. Impingement syndromes at the tibiotalar joint can be subdivided into anterior, anterolateral, anteromedial, posterior or posteromedial. Extraarticular impingement can consist of talocalcaneal or subfibular impingement. Impingement syndromes are just one possible etiology of persistent ankle pain, and although the diagnosis is often made or suspected clinically, the radiologist might be the first person to raise the possibility of the diagnosis or be called upon to provide support for the clinically suspected diagnosis. In this article I review the etiology, imaging findings and current treatment associated with these conditions.

Posterior ankle impingement–an underdiagnosed cause of ankle pain in pediatric patients

BACKGROUND

Posterior ankle impingement syndrome (PAIS) is a cause of ankle pain due to pinching of bony or soft tissue structures in the hindfoot. The diagnosis is primarily made based on detailed history and accurate clinical examination. The delay in its diagnosis has not yet been described in the pediatric and adolescent population.

AIM

To identify and characterize misdiagnosed cases of PAIS in pediatric and adolescent patients.

METHODS

This descriptive prospective study at a tertiary children’s hospital included patients ≤ 18 years who underwent posterior ankle arthroscopy after presenting with chronic posterior ankle pain after being diagnosed with PAIS. Collected data included: Demographics, prior diagnoses and treatments, providers seen, time to diagnosis from presentation, and prior imaging obtained. Visual Analogue Scale (VAS) for pain and American Orthopedic Foot Ankle Society (AOFAS) ankle-hindfoot scores were noted at initial presentation and follow-up.

RESULTS

35 patients (46 ankles) with average age of 13 years had an average 19 mo (range 0-60 mo) delay in diagnosis from initial presentation. 25 (71%) patients had previously seen multiple medical providers and were given multiple other diagnoses. All 46 (100%) ankles had tenderness to palpation over the posterior ankle joint. Radiographs were reported normal in 31/42 (72%) exams. In 32 ankles who underwent MRI, the most common findings included os trigonum (47%)/Stieda process (47%). Conservative treatment had already been attempted in all patients. Ankle impingement pathology was confirmed during arthroscopy in 46 (100%) ankles. At an average follow-up of 13.1 mo, there was an improvement of VAS (pre-op 7.0 to post-op 1.2) and AOFAS scores (pre-op 65.1 to post-op 94).

CONCLUSION

This is the first study which shows that PAIS is a clinically misdiagnosed cause of posterior ankle pain in pediatric and adolescent population; an increased awareness about this diagnosis is needed amongst providers treating young patients.

Implications of Classification of Os Trigonum: A Study Based on Computed Tomography Three-Dimensional Imaging

BACKGROUND The os trigonum is an accessory bone that is not fully fused with the talus during secondary ossification, and is one of the risk factors of posterior malleolus impact syndrome. The purpose of this study was to classify the os trigonum and to guide the diagnosis and treatment of related clinical diseases. MATERIAL AND METHODS Ankle computed tomography (CT) scans of 586 Chinese patients between October 2014 and October 2018 were reviewed. CT images of 1011 ankle joints were reconstructed to evaluate the classification of the os trigonum and the measurement of anatomical parameters. RESULTS The incidences of os trigonum in 3 groups were determined as type I (1.9%), type II (10.5%), and type III (14.7%). The macro-axis of type II (0.89±0.31) cm was significantly larger than with type I (0.65±0.24 cm) and type III (0.74±0.23 cm) (p<0.05).The minor axis of similar of type I (0.41±0.23 cm) was significantly shorter than that of type II (0.58±0.32 cm) and type III (0.55±0.16 cm) (p<0.05).The distance from os trigonum to calcaneal tubercle was significantly different than that of type I (1.33±0.52 cm), type II (1.67±0.55 cm), and type III (1.84±0.45 cm) (p<0.05). CONCLUSIONS This study showed that os trigonum has a high incidence. Type I was the least common, the volume of type II was larger, and type III was more common. The anatomical parameters of each type may improve treatment of related diseases and the further development of ankle arthroscopic surgery.