Arthroscopic excision of a symptomatic os trigonum in a lateral decubitus position

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.].

Symptomatic Accessory Ossicles of the Foot and Ankle

Accessory ossicles are small noncalcified, calcified or ossified structures found throughout the body, often noted as incidental findings. Specifically in the foot and ankle, there are at least 24 different ossicles described the majority of which are incidental. However, there are accessory ossicles that can be symptomatic, leading to significant pain and discomfort. While many of the symptomatic ossicles have been described in the literature, there are several that are under-recognized or under-reported for example, os interphalangeus and os calcaneus secundarius syndromes. This manuscript will review common and uncommon accessory ossicles including painful os peroneum, os naviculare, os calcaneus secundarius, os trigonum and os interphalangeus syndromes as well as medial sesamoiditis, with attention to the clinical and imaging findings and with an outline of the current management.

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.

Outcomes of a 2-Portal Endoscopic Technique for Osseous Lesions Resulting in Posterior Ankle Impingement Syndrome

Posterior ankle impingement syndrome is common in sporting populations and encompasses a range of disorders that cause posterior ankle pain during maximal forced plantarflexion. The aim of this study was to evaluate the short- and medium- to long-term outcomes of 2-portal endoscopic surgery for osseous lesions causing posterior ankle impingement syndrome. This was a retrospective case series analysis of all patients who underwent 2-portal endoscopic surgery at a single institution between 2005 and 2016. Visual analogue scales and selected components of the Short Form of the Revised Foot Function Index were used to assess ankle function, with the median follow-up time being 4.8 years. Of the 52 patients, 49 (94%) were able to return to their previous sport/physical activity, with the mean time taken being 5.8 months. At the completion of follow-up, the mean pain score during exercise had improved from 7.5 to 0.9 points. The mean work and sporting function scores also improved, from 5.9 to 9.6 points and 2.9 to 8.8 points, respectively. The mean score of the Short Form of the Revised Foot Function Index also improved by 77.7 points, from 84.4 to 6.7 at the completion of follow-up. There were no postoperative infections or any other major complications. This study provides strong supporting evidence for the use of hindfoot endoscopy in the treatment of posterior ankle impingement syndrome in athletes.

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.

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.

Isolated Posterior Medial Ankle Dislocation with Associated Os Trigonum Dislocation after Low-Energy Mechanism

We describe a case of an isolated posteromedial ankle dislocation, without malleolar fracture, with associated dislocation of an os trigonal process after a low-energy tennis injury. We demonstrate that nonoperative treatment results in excellent functional outcome scores with minimal arthritic progression at 2 years of follow-up. We discuss pathoanatomic risk factors of pure dislocations and propose that an os trigonum is a risk factor for isolated dislocations of the ankle.

Role of Subtalar Arthroscopy for Displaced Intra-Articular Calcaneal Fractures

Subtalar arthroscopy has an important role in enhancing the reduction of the posterior facet in percutaneous and open approaches of displaced intra-articular calcaneal fractures. In the percutaneous approach, arthroscopically assistant percutaneous approach must be selected carefully for mild-to-moderately displaced fractures. In the open approach, there is still little evidence of the utility of subtalar arthroscopy. Therefore, intraoperative arthroscopy should always be used in conjunction with fluoroscopy to achieve reduction and assess the internal fixation placement.

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.

Role of Subtalar Arthroscopy in Operative Treatment of Sanders Type 2 Calcaneal Fractures Using a Sinus Tarsi Approach

BACKGROUND

This study was conducted to evaluate the usefulness of subtalar arthroscopy in the operative treatment of Sanders type 2 calcaneus fractures using a sinus tarsi approach.

METHODS

Forty-six Sanders type 2 calcaneal fractures were consecutively treated using a sinus tarsi approach. Intraoperative fluoroscopy was used to evaluate fracture reduction in the first 23 patients (fluoroscopy group), and intraoperative fluoroscopy and subtalar arthroscopy were used in the latter 23 patients (arthroscopy group). Clinical evaluations were performed using a visual analog scale, the Ankle-Hindfoot Scale developed by the American Orthopaedic Foot & Ankle Society, and Short Form Health Survey. Radiographic evaluations were performed using calcaneal and lateral radiographs and computed tomography (CT) scans. Böhler's angles and calcaneal widths were compared between the groups. Reduction of the posterior facet was graded according to articular step, defect, and angulation of the posterior facet on CT.

RESULTS

At the last follow-up, clinical results as well as Böhler's angles and calcaneal widths were not different between the groups. On immediately postoperative CT, reduction of the posterior facet showed a higher-than-good grade in 17 feet (73.9%) in the fluoroscopy group and a higher-than-good grade in 22 feet (95.7%) in the arthroscopy group, and these values were significantly different between the groups ( P = .04).

CONCLUSION

A combined approach using fluoroscopy and subtalar arthroscopy showed better reduction of the posterior facet on CT than using fluoroscopy alone. Therefore, subtalar arthroscopy could be a useful method for detecting joint incongruence when using the sinus tarsi approach for Sanders type 2 calcaneal fractures.

LEVEL OF EVIDENCE

Level III, comparative series.

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.

Os Trigonum Excision in Dancers via an Open Posteromedial Approach

BACKGROUND

An os trigonum is a potential source of posterior ankle pain in dancers, often associated with flexor hallucis longus (FHL) pathology. Options for operative excision include open excision, subtalar arthroscopy, and posterior endoscopy. The purpose of this paper was to present a series of dancers who underwent excision of a symptomatic os trigonum via an open posteromedial approach.

METHODS

This study is a retrospective case series of 40 ankles in 38 dancers who underwent os trigonum excision via an open posteromedial approach with FHL tenolysis between 2000 and 2013. All patients were interviewed and charts retrospectively analyzed. Collected variables included pre- and postoperative pain level, time to return to dance, and subjective satisfaction. The average age was 19.2 years; ballet was the primary dance form in 36 (95%) of patient-cases. Eight (20%) of the patient-cases were professional dancers, and 30 (75%) were students or preprofessional dancers.

RESULTS

Average preoperative pain level was 7.7/10, which decreased to 0.6/10 postoperatively. Seventeen (42.5%) experienced concurrent preoperation-associated FHL symptomatology, all of whom experienced relief postoperatively. The average time to return to dance was 7.9 weeks, and time to pain-free dance was 17.7 weeks. Of the 37 patient-cases desiring to return to dance, 35 (94.6%) returned to their preoperative level of dance. There were no neurovascular or other major complications. Four (10%) had minor wound complications that resolved, and 38 cases (95%) considered the procedure a success.

CONCLUSION

Open posteromedial excision of an os trigonum in dancers provided satisfactory pain relief, return to dance, and complication rates compared to other approaches, and allowed for identifying and treating any associated FHL pathology.

LEVEL OF EVIDENCE

Level IV, retrospective case series.

Disorders of the Flexor Hallucis Longus and Os Trigonum

Os trigonum syndrome with disease of the flexor hallucis longus tendon, so-called stenosing flexor tenosynovitis, is a common cause of posterior ankle impingement. Conservative treatment is the recommended first line of treatment, with secondary treatment options of either open or arthroscopic os trigonum excision with flexor hallucis longus retinaculum release. The arthroscopic approaches have gained popularity in the past decade because of less scarring, less postoperative pain, minimal overall morbidity, and earlier return to activities. However, comprehensive understanding of the anatomy of the posterior ankle is crucial to warrant successful outcomes and minimizing complications.

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.

Os trigonum syndrome

Os trigonum syndrome is the result of an overuse injury of the posterior ankle caused by repetitive plantar flexion stress. It is predominantly seen in ballet dancers and soccer players and is primarily a clinical diagnosis of exacerbated posterior ankle pain while dancing on pointe or demi-pointe or while doing push-off maneuvers. Symptoms may improve with rest or activity modification. Imaging studies, including a lateral radiographic view of the ankle in maximal plantar flexion, will typically reveal the os trigonum between the posterior tibial lip and calcaneus. If an os trigonum is absent on radiography, an MRI may reveal scar tissue behind the posterior talus, a condition associated with similar symptoms. Os trigonum syndrome is often associated with pathology of the flexor hallucis longus tendon. Treatment begins with nonsurgical measures. In addition to physical therapy, symptomatic athletes may need surgical excision of os trigonum secondary to unavoidable plantar flexion associated with their sport. This surgery can be performed using open or arthroscopic approaches.