Os Trigonum Excision in Dancers via an Open Posteromedial Approach

Pediatric Foot: Development, Variants, and Related Pathology

Pediatric foot development throughout childhood and adolescence can present a diagnostic dilemma for radiologists because imaging appearances may be confused with pathology. Understanding pediatric foot development and anatomical variants, such as accessory ossification centers, is essential to interpret musculoskeletal imaging in children correctly, particularly because many of these variants are incidental but others can be symptomatic. We first briefly review foot embryology. After describing common accessory ossification centers of the foot, we explain the different patterns of foot maturation with attention to irregular ossification and bone marrow development. Common pediatric foot variants and pathology are described, such as tarsal coalitions and fifth metatarsal base fractures. We also discuss pediatric foot alignment and various childhood foot alignment deformities.

The Utilization of Minimally Invasive Surgery for Os Trigonum Syndrome: A Systematic Review

BACKGROUND

A symptomatic os trigonum is a common cause of posterior ankle pain that has been traditionally managed with open excision. Minimally invasive surgery (MIS) has been proposed as an alternative to open excision for improved outcomes and decreased complication rates; however, no systematic review to date has examined the utilization of MIS for a symptomatic os trigonum.

PURPOSE

To examine patient outcomes, return to sport, and complications associated with MIS for a symptomatic os trigonum.

STUDY DESIGN

Systematic review; Level of evidence, 4.

METHODS

A systematic review was performed on February 22, 2023, using the PubMed, CINAHL, MEDLINE, and Web of Science databases from database inception until February 22, 2023, on the topic of MIS for a symptomatic os trigonum.

RESULTS

Of 885 articles retrieved from an initial search, 17 articles (N = 435 patients) met full inclusion criteria. The mean age of the cohort was 26.01 ± 4.68 years, with a mean follow-up time of 34.63 ± 18.20 months. For patients treated with MIS, the mean preoperative American Orthopaedic Foot and Ankle Society (AOFAS) score was 55.85 ± 12.75, the mean final postoperative AOFAS score was 94.88 ± 4.04, the mean preoperative visual analog scale pain score was 7.20 ± 0.43, and the mean final postoperative visual analog scale score was 0.71 ± 0.48. The mean time to return to sport for patients undergoing MIS was 7.76 ± 1.42 weeks. MIS had an overall complication rate of 5.0%, the majority of which consisted of transient neurapraxia of the sural or superficial peroneal nerve.

CONCLUSION

Minimally invasive management of a symptomatic os trigonum appears to be a viable alternative to open surgery in terms of outcomes, return to sport, and complication rates. More high-quality evidence will be required to definitely recommend minimally invasive approaches as the standard of care over open surgery.

Os Trigonum Syndrome: A Cause of Posterior Ankle Pain

BACKGROUND

Os trigonum syndrome represents a cause of posterior ankle pain that is predominantly seen in athletes. The os trigonum ossicle forms from a secondary ossification center of the talus and is located at its posterior aspect in an interval between the posterior lip of the tibial plafond and calcaneus. The os trigonum ossicle is often an incidental finding and asymptomatic. However, repetitive plantarflexion and push-off maneuvers can cause symptoms and lead a patient to pursue orthopedic care.

MATERIALS AND METHODS

A review of the literature was conducted using the PubMed search engine with the following keywords: "os trigonum", "os trigonum ossicle", "os trigonum syndrome", "posterior ankle impingement", and "Stieda process".

RESULTS

The pertinent anatomy, clinical presentation, diagnostic evaluation, and treatment of os trigonum syndrome were reviewed in the literature and are extensively discussed in this article.

CONCLUSION

Os trigonum syndrome represents a potential cause of posterior ankle pain that needs thorough evaluation regarding history, physical examination, and imaging. Once diagnosed, treatment ranges from conservative to surgical interventions depending on surgeon preference and specific case presentation. [Orthopedics. 2024;47(2):e67-e72.].

The Relationship between Types of Os Trigonum and Findings of Conventional Ankle Magnetic Resonance Imaging: A Study Based on Three-Dimensional Magnetic Resonance Imaging

This study aimed to investigate the dimensions and types of the os trigonum and evaluate their relationship with various pathologic conditions on the posterior ankle using ankle MRI images. A total of 124 non-contrast-enhanced ankle and foot MR images of 123 consecutive patients were included in this retrospective study. The images were presented randomly, and they contained no patient information. The MR images were retrospectively and independently reviewed by two reviewers with a fellowship-trained musculoskeletal radiologist. The images were classified as type I and II based on the ossicle's medial border overlying the talus's posterior process and the groove for the flexor hallucis longus tendon (FHL). The study revealed that patients with type II os trigonum had a longer transverse diameter of the ossicle than type I, and there were statistically significant differences. Detachment status tended to be less in type I than in type II os trigonum, and the differences between the groups were statistically significant. There were no significant differences between type I and II os trigonum regarding posterior talofibular ligament (PTFL) abnormality, bone marrow edema, FHL tenosynovitis, and posterior synovitis. The study concluded that the os trigonum is a common cause of posterior ankle impingement, and type II os trigonum has a longer transverse diameter of the ossicle than type I.

Dance-Related Foot and Ankle Injuries and Pathologies

Dancers are highly vulnerable to injuries due to high dynamic overload, extreme positions and motions, and excessive use. Increased load at the forefoot with jumping and high-impact lands can cause sesamoiditis and stress fractures of the metatarsals. Significant plantarflexion can lead to posterior joint impingement and flexor hallucis longus tendonitis, whereas forced dorsiflexion can cause anterior joint impingement. Most pathologies can be diagnosed on physical examination and various imaging modalities. Treatment should be tailored to the dancers' needs and should begin with a course of conservative therapy with immobilization, physical therapy, and activity cessation.

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.

Open Versus Endoscopic Surgical Treatment of Posterior Ankle Impingement: A Meta-analysis

BACKGROUND

Surgical treatment of symptomatic posterior ankle impingement consists of resection of the bony impediment and/or debridement of soft tissue. Historically, open techniques were used to perform surgery with good results. However, since the introduction of endoscopic techniques, advantages attributed to these techniques are shorter recovery time, fewer complications, and less pain.

PURPOSE

The primary purpose was to determine whether endoscopic surgery for posterior ankle impingement was superior to open surgery in terms of functional outcome (American Orthopaedic Foot & Ankle Society [AOFAS] score). The secondary aim was to determine differences in return to full activity, patient satisfaction, and complications.

STUDY DESIGN

Systematic review and meta-analysis.

METHODS

MEDLINE, EMBASE (Classic), and CINAHL databases were searched. Publication characteristics, patient characteristics, surgical techniques, AOFAS scores, time to return to full activity, patient satisfaction, and complication rates were extracted. The AOFAS score was the primary outcome measure. Data were synthesized, and continuous outcome measures (postoperative AOFAS score and time to return to full activity) were pooled using a random-effects inverse variance method. Random-effects meta-analysis of proportions using continuity correction methods was performed to determine the proportion of patients who were satisfied and who experienced complications.

RESULTS

A total of 32 studies were included in this review. No statistically significant difference was found in postoperative AOFAS scores between open surgery (88.0; 95% CI, 82.1-94.4) and endoscopic surgery (94.4; 95% CI, 93.1-95.7). There was no difference in the proportion of patients who rated their satisfaction as good or excellent, 0.91 (95% CI, 0.86-0.96) versus 0.86 (95% CI, 0.79-0.94), respectively. No significant difference in time to return to activity was found, 10.8 weeks (95% CI, 7.4-15.9 weeks) versus 8.9 weeks (95% CI, 7.6-10.4 weeks), respectively. Pooled proportions of patients with postoperative complications were 0.15 (95% CI, 0.11-0.19) for open surgery versus 0.08 (95% CI, 0.05-0.14) for endoscopic surgery. Without the poor-quality studies, this difference was statistically significant for both total and minor complications, 0.24 (95% CI, 0.14-0.35) versus 0.02 (95% CI, 0.00-0.06) and 0.14 (95% CI, 0.09-0.20) versus 0.03 (95% CI, 0.01-0.05), respectively.

CONCLUSION

We found no statistically significant difference in postoperative AOFAS scores, patient satisfaction, and return to preinjury level of activity between open and endoscopic techniques. The proportion of patients who experienced a minor complication was significantly lower with endoscopic treatment when studies of poor methodological quality were excluded.

Flexor Hallucis Longus Tenolysis and Tenosynovectomy in Dancers

The purpose of this study was to report on a series of dancers who had undergone flexor hallucis longus (FHL) tenolysis/tenosynovectomy after having failed conservative management. Institutional human subjects committee approval was obtained prior to initiating this study. This study is a retrospective case series of 58 dancers and 63 ankles who underwent FHL tenolysis/tenosynovectomy via an open posteromedial approach by a single surgeon between 1993 and 2017. All patients were interviewed and charts reviewed. Collected variables included: preoperative and postoperative pain levels, time to return to dance, and subjective satisfaction with the procedure. Age, primary dance form, and level of dance were determined. Mean preoperative pain level decreased significantly postoperatively. Mean time to return to dance was 7.1 weeks. There was a 98% (62/63) return to dance at some level while 97% (61/63) of patients returned to dance symptom-free. There were no neurovascular or other major complications. Minor complications included stiffness at follow-up (6.3%, 4/63), superficial wound infection (3.1%, 2/63), and hypertrophic scar (4.8%, 3/63). Over 97% (61/63) of dancers considered the procedure a success and 98% (62/63) of dancers would repeat the procedure. This is one of the largest series reported of isolated FHL tenolysis/tenosynovectomy in dancers who have failed nonoperative management. Satisfactory pain relief and return to dance with a low complication rate may be expected from this surgical procedure. The results of this study can be used to help dancers and their providers make informed decisions about treatment in isolated FHL tendinitis.

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.

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.

Os Trigonum Syndrome

This article offers an overview of os trigonum syndrome, complications, operative techniques, and the authors' preferred protocol. Os trigonum is an ossicle like many other ossicles in the foot and ankle. Individuals who require repetitive plantarflexion of the ankle for activity may develop symptoms of an enlarged os trigonum. Usually, symptoms will be isolated to the posteriolateral aspect of the ankle. Because of the normal anatomic route of the flexor hallucis longus tendon, its range of motion may also elicit pain to the posterolateral ankle. Conservative, as well as surgical including both endoscopic and open excision, has been described.

Posterior Ankle Impingement and Flexor Hallucis Longus Pathology

Posterior ankle pain is a common complaint, and the potential causative pathologic processes are diverse. The constellation of these numerous etiologies has been collectively referred to as posterior ankle impingement syndrome. The pain associated with posterior ankle impingement is caused by bony or soft tissue impingement of the posterior ankle while in terminal plantar flexion. This condition is most frequently encountered in athletes who participate in sports that involve forceful, or repetitive, ankle plantar flexion. This article discusses the associated pathology, diagnosis, conservative treatment, and surgical techniques associated with flexor hallucis longus and posterior ankle impingement syndrome.

Surgical Outcomes of Os Trigonum Syndrome in Dancers: A Case Series

Background

Management of ankle pain in dancers can be challenging because of the repetitive stress and complex demands placed on this region. Despite the prevalence of ankle injuries in this population, literature on surgical outcomes and return to dance is limited.

Purpose

To retrospectively evaluate the efficacy and functional outcomes after surgical excision of a symptomatic os trigonum in dancers.

Study Design

Case series; Level of evidence, 4.

Methods

Between June 2006 and June 2016, a total of 44 dancers underwent surgical excision of a symptomatic os trigonum at a single institution and by a single surgeon. All patients presented with symptoms of posterior ankle impingement syndrome and subsequently failed nonsurgical treatment. Clinical analysis was conducted using various pre- and postoperative patient-reported outcome questionnaires, including the Veterans RAND 12-Item Health Survey (VR-12), Foot Function Index-Revised (FFI-R), and visual analog scale (VAS) for pain, as well as subjective patient satisfaction.

Results

A total of 44 patients (54 ankles; mean age, 18.2 years) were retrospectively evaluated at a mean follow-up of 33.4 months. The VR-12 Physical Health score improved from a mean score of 37.8 ± 11.9 to 51.2 ± 10.5 (P < .001). The cumulative FFI-R score improved from 46.45 ± 13.8 to 31.2 ± 9.7 (P = .044), with the subcategory of "activity limitation" representing the highest-scoring FFI-R subcategory at 65.28 ± 13.4 preoperatively and improving to 34.47 ± 12.4 at follow-up (P < .001). The mean VAS score for subjective pain improved significantly from 5.39 ± 2.84 to 1.73 ± 2.10 (P < .00044).

Conclusion

Overall, the findings of the present study demonstrate that dancers of varying style and level improved significantly according to various clinical measures. Patients included in this study reported that they returned to their previous level of dance upon completion of physical therapy and maintained thriving postoperative careers, which for several meant dancing at the professional level.

Endoscopic Treatment of Posterior Ankle Impingement Secondary to Os Trigonum in Recreational Athletes

Background:

The os trigonum (OT)—the most common accessory bone of the foot—although usually asymptomatic, may cause posterior ankle impingement syndrome (PAIS), which may be a severely debilitating problem for recreational or competitive athletes. The aim of the present study was to evaluate effectiveness of posterior ankle arthroscopy and to assess the outcome in the treatment of PAIS secondary to OT impingement or OT fractures within a group of young athletes and their return to previous sports level.

Methods:

From 2011 to 2018, a retrospective review of 81 recreational athletes of mean age 27.8 years was performed. All patients were diagnosed with PAIS due to OT pathology and were operated on endoscopically with resection of the OT. Pre- and postoperative clinical evaluation were performed at 3 months, 1 year, and 2 years based on visual analog scale (VAS), ankle range of motion (ROM), American Orthopaedic Foot & Ankle Society (AOFAS) hindfoot score, and the Foot & Ankle Disability Index (FADI) scores, in a follow-up of at least 2 years.

Results:

VAS score was significantly improved from an average of 7.5 (5-9) preoperatively to 1.9 (1-3) at 3 months postoperatively and to 0.6 (0-2) and 0.3 (0 -1) at 1 and 2 years postoperatively. Ankle ROM was significantly improved from an average of 24.8 (10-35) preoperatively to 58.0 (50-65) at 3 months postoperatively and to 64.0 (50-65) at 1 year and 64.7 (60-65) at 2 years postoperatively. AOFAS and FADI scores were significantly improved from 39.4 (18-55) and 49.7 (42.3-62.5) preoperatively to 85.2 (74-89) and 87.3 (81.7-88.5) postoperatively at 3 months to 97.7 (85-100) and 97.9 (93.3-100) postoperatively at 1 year, respectively (P < .001). Only 5 patients dropped to a lower activity level. There were 5 complications (4 transient).

Conclusion:

Endoscopic treatment of PAIS due to OT pathology demonstrated excellent results. Posterior ankle arthroscopy was an effective treatment and allowed for a prompt return to a high activity level of their athletic performance.

Level of Evidence:

Level IV, therapeutic study / retrospective case series.

Ankle Injuries in Dancers

The term dance encompasses a broad range of different styles; much of the orthopaedic literature has focused on ballet dancers. Injury is common in dancers at all levels, and many serious dancers sustain multiple injuries as they progress through their career. Foot and ankle injuries are among the most common injuries experienced by dancers. These injuries include those that are specific to dancers because of the unique physical maneuvers required to effectively perform, but they can also include common injuries that may require relatively different treatment because of the physical demands of the dancer. Os trigonum syndrome and flexor hallucis longus tenosynovitis generally fall into the former category as they are injuries that are more prevalent in dancers due to the extreme plantarflexion involved in dancing, especially ballet, and the relative demand placed on the toe flexors, most notably the flexor hallucis longus. On the other hand, anterior ankle impingement occurs both in dancers and in the general public. In many cases, a team approach to treatment with knowledgeable physical therapists can obviate the need for surgical treatment. If surgical treatment proves necessary, good results can be achieved with sound surgical technique and a well thought-out rehabilitation program.

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.

Excision of Os Trigonum in Dancers via an Open Posteromedial Approach

An os trigonum is a potential source of posterior ankle pain in dancers, often associated with flexor hallucis longus (FHL) pathology. Surgical excision is indicated on failure of nonoperative management. Options for surgical excision include open excision (via a posterolateral or posteromedial approach), subtalar arthroscopy, and posterior endoscopy. Os trigonum excision via an open posteromedial approach with concomitant FHL tenolysis/tenosynovectomy is a safe and effective method for the operative treatment of a symptomatic os trigonum that allows for identification and treatment of associated FHL pathology. The major steps in the procedure, which are demonstrated in this video article, are: (1) preoperative planning with appropriate imaging; (2) patient is positioned in a supine position with the operative extremity in figure-of-4 position; (3) a 3-cm, slightly curvilinear longitudinal incision is made midway between the posterior aspect of the medial malleolus and the anterior aspect of the Achilles tendon, over the palpated FHL tendon, and the flexor retinaculum is exposed and incised; the neurovascular bundle is retracted anteriorly, exposing the FHL tendon and sheath; (4) FHL tenolysis/tenosynovectomy is performed; (5) the FHL is retracted anteriorly and a capsulotomy is performed over the os trigonum and the os trigonum is excised; (6) the capsule is repaired and closure is performed; and (7) dressings and a CAM (controlled ankle motion) walking boot are applied. The patient begins physical therapy at 2 weeks postoperatively and may return to dance at 4 to 6 weeks postoperatively as tolerated. In our series of 40 cases, 95% of patients who desired to return to dance were able to return to their pre-injury level of dance. There were no major neurovascular complications.

Physical Therapy Rehabilitation of an Adolescent Preprofessional Dancer Following Os Trigonum Excision: A Case Report

Study Design Case report. Background An os trigonum can be a source of pain for dancers due to impingement during repetitive ankle plantar flexion movements. Following excision of an os trigonum, it is important to have a gradual, progressive return-to-dance program for optimal recovery. The purpose of this case report is to describe the postoperative management and return-to-dance progression of an adolescent dancer post os trigonum excision. Case Description An adolescent preprofessional female dancer had an extensive history of left posterior heel pain, beginning at age 8, that led to surgical removal of an os trigonum at age 15. Post surgery, the patient was seen for a total of 22 visits over the course of 20 weeks. Treatment included therapeutic exercises, neuromuscular re-education, and manual therapy. Return-to-dance tests and guidelines were used to safely progress to full, unrestricted dance participation. Outcomes The dancer had a full return of ankle range of motion, strength, and balance, improved patient-reported outcome scores, and was able to fully return to dance participation. Discussion Treating a dancer following os trigonum excision should involve a screen for hypermobility, clear communication with the dance instructor, awareness of dance-specific biomechanics, and proper reintegration into dance participation. Level of Evidence Therapy, level 5. J Orthop Sports Phys Ther 2018;48(3):194-203. Epub 7 Nov 2017. doi:10.2519/jospt.2018.7508.