Satisfactory outcomes from the double-row fixation procedure for ankle lateral ligaments injury with os subfibulare.

Background: Ossicles of avulsed fractures of the lateral malleolus can result in pain or chronic ankle instability. The purpose of this study was to evaluate and compare the arthroscopic double-row fixation procedure with anatomic ankle lateral ligaments reconstruction for the treatment of ankle lateral ligaments injury with os subfibulare. Methods: This retrospective study included 38 patients with ankle lateral ligaments injury with concomitant os subfibulare who were treated between July 2016 and November 2021. The patients were divided into a double-row fixation group (n = 19) and an ankle lateral ligaments reconstruction group (n = 19). The Karlsson and Peterson Scoring System for Ankle Function (KAFS), American Orthopedic Foot and Ankle Society (AOFAS) score, Tegner score, visual analog scale (VAS), and anterior drawer test (ADT) were obtained preoperatively and at the last post-operative follow-up. Magnetic resonance imaging (MRI) was also performed at the last post-operative follow-up. Results: The KAFS, AOFAS, VAS, and Tegner scores increased significantly after the surgery. Furthermore, the pre- and post-operative functional scores were comparable between the two groups. The ADT was negative in all participants post-operatively. There were no significant differences between the double-row fixation and ligaments reconstruction groups regarding the proportions of patients who achieved a minimally clinically important difference (MCID) in KAFS, AOFAS, and Tegner scores. There was no significant difference in T2 mapping values for the tibial and talar side post-operatively between the two groups. Moreover, there were no significant differences in functional scores post-operatively between bony fusion and non-fusion patients in the double fixation group. Conclusion: The double-row fixation procedure provided similar satisfactory clinical outcomes when compared with lateral ligaments reconstruction for the treatment of ankle lateral ligaments injury with os subfibulare over a short follow-up duration.

Surgical treatment of ankle instability in children with os subfibulare.

INTRODUCTION: Ankle instability in children due to soft tissue injury usually resolves after non-operative treatment. However, some children and adolescents with chronic instability require surgical treatment. A rarer cause of developing ankle instability is injury to the ligament complex in the presence of os subfibulare, an accessory bone inferior to the lateral malleolus. The aim of this study was to assess the results of operative management of chronic ankle instability in children with os subfibulare. MATERIALS AND METHODS: 16 children with os subfibulare and chronic ankle instability who failed non-operative treatment were enrolled prospectively into the study. One child was lost to follow-up and excluded from analysis. The mean age at the time of the surgery was 14 years and 2 months (range 9.5-17 years). The mean follow-up time was 43.2 months (range 28-48 months). Surgical treatment in all cases involved removal of os subfibulare and a modified Broström-Gould lateral complex reconstruction with anchors. Ankle status was assessed before and after surgery with The 100 mm Visual Analogue Scale and Foot and Ankle Outcome Score questionnaire. RESULTS: The mean Foot and Ankle Outcome Score improved from 66.8 to 92.3 (p < 0.001). Pain level improved from 67.1 preoperatively to 12.7 (p < 0.001). All children reported improvement in their ankle stability. There was one case of scar hypersensitivity that improved during observation and one superficial wound infection that resolved with oral antibiotics. One child reported intermittent pain without symptoms of instability following another injury. CONCLUSIONS: Ankle joint sprain with associated injury to os subfibulare complex can lead to chronic instability in children. If conservative management fails, then surgical treatment with modified Broström-Gould technique and excision of accessory bone is a safe and reliable method.

Chronic Lateral Ankle Instability with Os Subfibulare in a Child Treated with Modified Broström/Gould Surgical Technique - A Case Report.

Introduction: Patients with lateral instability of the ankle have a much higher prevalence of an os subfibulare compared with the general population. In children and adolescents with known os subfibulare and chronic instability of the ankle, surgical resection of the os subfibulare and the Broström/Gould procedure to reattach the ATFL to the fibula has been described if conservative therapy fails. Case Report: Our case is about a 10-year-old girl with chronic instability of the ankle and a symptomatic os subfibulare, with additional cystic and edematous changes in the distal fibula in the MRI. Due to the reduced bone density, we assumed a higher risk of anchor pullout with the normal refixation at the distal fibula. Therefore, the surgical technique according to Broström/Gould was modified and the ATFL was refixed on the talar side. Conclusion: In cases of symptomatic os subfibulare with clinical instability of the ankle, a Broström/Gould operation and resection of the os subfibulare is recommended after failure of conservative therapy. Our case showed that a very satisfying post-operative result can be achieved with a modification of the Broström/Gould operation, with reattachment of the ATFL to the talus instead of the fibula.

Surgical outcome of avulsion fractures of the distal fibula: a systematic literature review.

PURPOSE: To provide a systematic overview of clinical and radiographic outcomes in patients who underwent surgical treatment of a painful avulsion fragment of the distal fibula also known as posttraumatic os subfibulare. METHODS: A systematic literature search across two major sources (PubMed and Scopus) was performed. Twenty-seven studies were included and analyzed using the modified Coleman score to assess the methodologic quality. RESULTS: The surgical treatment of symptomatic os subfibulare, with or without concomitant ankle instability, generally results in substantial improvement in clinical and radiographic outcomes with relative low complication rates. Clinical outcome measures may not be affected by the presence of ankle instability or by the fragment size. The methodological quality of analyzed studies was satisfactory. CONCLUSION: Posttraumatic os subfibulare may result in chronic pain and ankle instability. If surgery is indicated, ankle instability should be concomitantly addressed when present. Based on available literature, satisfactory postoperative outcomes can be reliably expected following surgical treatment. LEVEL OF EVIDENCE: Systematic Review of Level III and Level IV Studies, Level IV.

Optimal Visualization of Os Subfibulare Using 3D Water Selective Cartilage Scan (3D_WATSc) MRI Sequencing: A Case Report.

Os subfibulare is an accessory ossicle of the lateral malleolus at the distal end of the fibula. In most instances, os subfibulare is found incidentally on radiographs. While os subfibulare typically remains asymptomatic, some cases may present with ankle pain or instability. To initiate appropriate treatment and maximize patient outcomes, it is crucial to accurately visualize the accessory ossicle. Here, we report a symptomatic case of os subfibulare diagnosed with ankle radiographs and a 3D water selective cartilage scan (3D_WATSc, Ingenia, Philips Healthcare, The Netherlands) magnetic resonance imaging sequence and treated surgically with open ossicle excision and a modified Broström procedure.

Simultaneous ossicle resection and lateral ligament repair give excellent clinical results with an early return to physical activity in pediatric and adolescent patients with chronic lateral ankle instability and os subfibulare.

PURPOSE: To elucidate surgical outcomes in pediatric/adolescent patients with chronic lateral ankle instability and os subfibulare. METHODS: A retrospective chart review was conducted of pediatric/adolescent patients with chronic lateral ankle instability and os subfibulare following simultaneous ossicle resection and lateral ligament repair using suture anchors with subsequent immediate full weightbearing and active range of motion exercises for the ankle in our department between 2013 and 2017. Clinical outcomes were evaluated by comparing preoperative and final follow-up American Orthopaedic Foot and Ankle Society Ankle-Hindfoot Scale (AOFAS) and Karlsson-Peterson ankle function scores. Intervals between surgery and return to physical education in school were determined. RESULTS: 31 feet of 15 male and 16 female patients were examined. Mean postoperative follow-up duration was 40.7 ± 12.7 (range 24-66) months. Mean AOFAS score increased significantly from 66.3 ± 2.5 (range 62-77) preoperatively to 96.5 ± 4.9 (range 87-100) at final follow-up (p < 0.001). Mean Karlsson-Peterson score increased significantly from 51.7 ± 4.0 (range 47-70) preoperatively to 95.3 ± 6.7 (range 80-100) at final follow-up (p < 0.001). Mean interval between surgery and return to physical education in school was 11.4 ± 1.6 (range 10-18) weeks. CONCLUSION: Simultaneous ossicle resection and lateral ligament repair using suture anchors with subsequent immediate full weightbearing and active ankle range of motion exercises may give excellent clinical outcomes with early return to physical activity for chronic lateral ankle instability with os subfibulare in pediatric/adolescent patients desiring an early return to physical activity. Level of evidence III.

Morphological Characteristics of Os Subfibulare Related to Failure of Conservative Treatment of Chronic Lateral Ankle Instability.

BACKGROUND: The os subfibulare is usually asymptomatic and found incidentally on radiographs. However, sometimes it may cause subfibular pain and may be associated with chronic lateral ankle instability (CLAI). We hypothesized that os subfibulare could interrupt the talofibular space causing impingement, resulting in chronic pain and functional instability around the lateral malleolus. The purposes of this study were to analyze morphologic characteristics of os subfibulare, and to evaluate the clinical significance of the os subfibulare in patients with CLAI. METHODS: Between November 2011 and April 2015, 70 patients who had both computed tomography (CT) and magnetic resonance imaging (MRI) among 252 patients who visited our hospital with the symptom of lateral ankle instability were included in this study. The location of the ossicle was classified into 3 zones in reference to the attachment site of the lateral ankle ligaments. The impingement was classified into 2 groups according to the presence of talofibular encroachment. Digital radiographs were used to measure the ossicle width and shape determined by the length and width on an magnetic resonance (MR) image. RESULTS: The most common shape of ossicles was oval, and the most common location of ossicles was at the anterior talofibular ligament (ATFL) attachment site. Sixty-one percent of patients showed talofibular impingement on coronal MR images. In 48 cases, the dimension of fibula plus os subfibulare was larger than that of the contralateral normal fibula. The larger size and talofibular impingement of the ossicle were associated with greater need for operative treatment in patients with ankle instability. CONCLUSION: The morphologic analysis of the os subfibulare revealed that there might be impingement of the talofibular space by the ossicle in some patients. We suggest that morphologic characteristics of the os subfibulare should be considered when selecting treatment options in patients with CLAI and os subfibulare. LEVEL OF EVIDENCE: Level III, retrospective comparative series.

The Role of the Accessory Malleolar Ossicles and Malleolar Avulsion Fractures in Lateral Ankle Ligament Reconstruction.

While it is well known that ankle sprains are one of the most common injuries in the United States, predictive factors regarding failure of conservative treatment are not well known. There are many biomechanical and epidemiological factors that play a role in recurrence and failure of conservative treatment, but most cases are able to be treated with immobilization and/or rest, ice, elevation, physical therapy, and bracing. We propose that one important risk factor is often overlooked simply due to the fact that a vast majority of these cases resolve without the need for surgery. Accessory ossicles and avulsion fractures of the malleoli or talus may represent a predisposition or marker for ligamentous damage that may lead to the need for lateral ankle ligament repair or reconstruction in the future. We have identified 61 consecutive patients who underwent lateral ankle ligament repair or reconstruction by the primary surgeon from the years 2007 to 2017. Out of those patients who met our inclusion and exclusion criteria, 66% had the presence of osseous pathology consisting of accessory ossicles or avulsion fractures of the medial or lateral malleolus or talus. The proportion of osseous pathology seen with lateral ankle ligament repair or reconstruction was higher than what has been previously reported in both operative and nonoperative settings. This may help identify a risk factor for failure of conservative treatment in patients presenting with acute ankle sprains or ankle instability especially in the active cohort. LEVELS OF EVIDENCE: Level IV: Case series.

Radiologic findings for prediction of rehabilitation outcomes in patients with chronic symptomatic os subfibulare.

OBJECTIVE: To retrospectively evaluate the radiologic findings for predicting rehabilitation outcomes in patients with chronic symptomatic os subfibulare. MATERIALS AND METHODS: 38 patients with chronic lateral ankle pain and os subfibulare underwent a standardized rehabilitation program. Rehabilitation outcome was evaluated after ≥3 months of intervention as the following: good response group (n = 20) without the need for further treatment and poor response group (n = 18) who underwent surgery after rehabilitation. Size, shape and location of os subfibulare, anterior talofibular ligament abnormality and attachment to the os subfibulare, interposition of fluid signal intensity between the os subfibulare and the fibula, and bone marrow edema in the os subfibulare on radiographs and MRI were evaluated by two radiologists blinded to rehabilitation outcomes and were compared between the two groups. RESULTS: The mean size of os subfibulare was significantly different between good and poor response groups: 7 versus 12 mm (p < 0.01), respectively. The prevalence of interposition of fluid signal intensity between the os subfibulare and the fibula and bone marrow edema in the os subfibulare on MRI was significantly different between the two groups (p < 0.01). However, other radiologic findings were not significantly different (p ≥ 0.08). The optimal size to classify the two groups was 9 mm with sensitivity of 83.3% and specificity of 80%. Inter-observer reliability was good to excellent (ICC = 0.991 for size and kappa = 0.735-0.923 for others). CONCLUSIONS: MRI may be used to predict rehabilitation outcome in patients with chronic symptomatic os subfibulare.

Sonographic Findings of Chondral Avulsion Fractures of the Lateral Ankle Ligaments in Children.

In this series, we aimed to describe the sonographic findings of chondral avulsion fractures that develop concomitant with lateral ankle ligament injury in children. We performed stress sonography during a manual anterior drawer stress procedure of the ankle in 9 skeletally immature patients who had recently had a lateral ankle sprain. Echo videos were obtained through the course of treatment, and all videos were reviewed. We elucidated the common features of chondral avulsion fractures of the lateral ankle ligaments in the children. The features of avulsion fractures on conventional sonography included absence of a fracture with hyperechoic spots (sonographic occult fracture type), cortical discontinuity with hyperechoic spots (cortical disruption fracture type), fracture line in the cortical bone (double-line fracture type), and a step-off deformity of the cortical bone with cartilage (displaced fracture type). In contrast, the features of chondral fractures on stress sonography included abnormal motion of the chondral lesions and mobility/fluidity of hyperechoic spots along the chondral fracture site. The presence of hyperechoic spots around the chondral lesion is an important sonographic sign for diagnosing chondral fractures concomitant with ankle lateral ligament injury. Hence, we believe that stress sonography should be considered for the detection of chondral fractures concomitant with radiographically negative ankle lateral ligament injuries in skeletally immature patients with lateral ankle pain and ankle sprains, if hyperechoic spots are present in the cartilage of the distal fibula.

MRI of the anterior talofibular ligament, talar cartilage and os subfibulare: Comparison of isotropic resolution 3D and conventional 2D T2-weighted fast spin-echo sequences at 3.0 T.

PURPOSE: To determine the accuracy of a three-dimensional (3D) T2-weighted fast spin-echo (FSE) magnetic resonance (MR) sequence compared with two-dimensional (2D) sequence for diagnosing anterior talofibular ligament (ATFL) tears, chondral lesion of the talus (CLT) and os subfibulare/avulsion fracture of the distal fibula (OSF). MATERIALS AND METHODS: Thirty-five patients were included, who had undergone ankle MRI with 3D T2-weighted FSE and 2D T2-weighted FSE sequences, as well as subsequent ankle arthroscopy, between November 2013 and July 2014. Each MR imaging sequence was independently scored by two readers retrospectively for the presence of ATFL tears, CLT and OSF. The area under the receiver operating curve (AUC) was compared to determine the discriminatory power of the two image sequences. Interobserver agreement was expressed as unweighted kappa value. RESULTS: Arthroscopic findings confirmed 21 complete tears of the ATFL, 14 partial tears of the ATFL, 17 CLTs and 7 OSFs. There were no significant differences in the diagnoses of ATFL tears (p = 0.074-0.501), CLT (p = 0.090-0.450) and OSF (p = 0.317) obtained from the 2D and 3D sequences by either reader. The interobserver agreement rates between two readers using the 3D T2-weighted FSE sequence versus those obtained with the 2D sequence were substantial (κ = 0.659) versus moderate (κ = 0.553) for ATFL tears, moderate (κ = 0.499) versus substantial (κ = 0.676) for CLT and substantial (κ = 0.621) versus substantial (κ = 0.689) for OSF. CONCLUSION: Three-dimensional isotropic T2-weighted FSE MRI of the ankle resulted in no statistically significant difference in diagnostic performance compared to two-dimensional T2-weighted FSE MRI in the evaluation of ATFL tears, CLTs and OSFs.

Intraarticular Entrapment of Os Subfibulare Following a Severe Inversion Injury of the Ankle: A Case Report.

INTRODUCTION: Anterior Talofibular Ligament (ATFL) rupture is the most commonly injured anatomic structure in lateral ankle sprain. In some cases, ATFL avulsion fracture from the lateral malleolus may occur instead of purely ligamentous injuries. The ATFL avulsion fracture is detected as a small ossicle at the tip of lateral malleolus on direct radiographs, which is called os subfibulare in chronic cases. CASE PRESENTATION: Severe displacement of this ossicle to the tibiotalar joint space is an extremely rare injury. Herein, a case of intra-articular entrapment of os subfibulare following a severe inversion injury of the ankle, which caused a diagnostic challenge was presented. CONCLUSIONS: To the best of our knowledge, this is the first case of entrapment of os subfibulare in the talotibial joint space. Fixation of the os subfibulare to lateral malleolus resulted in union and excellent functional results.

The effect of ossicle resection in the lateral ligament repair for treatment of chronic lateral ankle instability.

BACKGROUND: The management of an ossicle or avulsion fragment of the fibular tip in chronic lateral ankle instability is an open question. Some authors maintain the necessity of osteosynthesis for reconstruction of the lateral ligamentous structure if the fragment is large. We hypothesized that the modified Broström procedure with resection of the ossicle would result in good outcomes compared to that of the same procedure for chronic lateral instability patients without ossicle. METHODS: Between December 2004 and December 2010, 102 patients underwent the modified Broström procedure for chronic lateral instability. Of these, 82 patients (86 ankles) were available for this study. Forty ankles had ossicles at the fibular tip (group O), 46 had no ossicle (group N). The average follow-up period was 33 months in group O and 37 months in group N. Irrespective of size, if there were ossicles we resected all fragments and performed the modified Broström procedure. To analyze the surgical outcome, American Orthopaedic Foot and Ankle Society (AOFAS) ankle-hindfoot pain and function scales and Karlsson scores were compared between the 2 groups preoperatively and postoperatively. RESULTS: Preoperative scores in the 2 groups showed no significant difference, except for AOFAS pain score. There was no significant difference in postoperative AOFAS pain and function score between the groups. Postoperative Karlsson score was significantly higher in group O than in group N (P = .001). Group O was divided into 2 subgroups by the largest diameter of the ossicle (< 10 mm and ≥ 10 mm); there was no significant difference in surgical outcomes. CONCLUSIONS: In the treatment of chronic lateral instability of ankle, if there are ossicles on the fibular tip, osteosynthesis of the ossicles may not be necessary, even if the size is considerable. Modified Broström procedure after resection of the ossicle was successful. LEVEL OF EVIDENCE: Level III, retrospective case series.

Operative Treatment of Symptomatic Os Subfibulare / 대한족부족관절학회지

PURPOSE: To evaluate the clinical results of resection of os subfibulare and lateral ligament reattachment or modified Brostrom procedure in patients with symptomatic os subfibulare. MATERIALS AND METHODS: This is a retrospective study on fourteen patients (14 ankles) who have symptoms associated with os subfibulare. Between August 1999 and July 2004, they underwent 4 resection of os subfibulare and lateral ligament reattachment for ankle pain due to os subfibulare or 10 resection of os subfibulare and modified Brostrom procedure available for ankle instability due to os subfibulare. Follow-up period is averaged for 17.6 months (12-24 months). Clinical results were graded according to the AOFAS clinical rating system. RESULTS: Clinical results were rated as good in 4 ankles after resection of os subfibulare and lateral ligament reattachment, excellent in 5, good in 4, and fair in 1 ankle after the resection of os subfibulare and modified Brostrom procedure. In the last follow up period, 1 case of anterolateral ankle instability, 1 case of ankle pain and 1 case of inversion limitation were present postoperatively, but all symptoms were improved progressively. CONCLUSION: Resection of os subfibulare and modified Brostrom procedure is a good surgical technique for chronic ankle instability due to os subfibulare. But if just the ankle pain is present, resection of os subfibulare and lateral ligament reattachment is a sufficient procedure.

Clinical and Radiological Analysis and Results after Anatomical Reduction and Bone Graft for Symptomatic Os Subfibulare / 대한족부족관절학회지

PURPOSE: To analyze the clinical and radiological feature of Os subfibulare and to evaluate the results after anatomical reduction and internal fixation with bone graft for Os subfibulare. MATERIALS AND METHODS: Forty-two cases, which underwent anatomic reduction and bone graft for Os subfibulare from October 1998 to September 2004 were reviewed. We analysed preopertive symptoms and onset of symptoms and radiologically measured the size and amounts of displacement of Os subfibulare under the inversion stress. Postoperatively we evaluated the clinical results measured by Hasegawa method and evidence of union. RESULTS: Preoperatively there were only pain around the lateral malleolus in 16 cases, only instability of ankle joint in 3 cases, and pain and instability in 23 cases. The age of symptom onset averaged 23 years(range, 13-38 years). Radiographically Os sufibulare anteriorly located from lateral malleolus were in 40 cases, posteriorly situated in 2 cases. The size of Os subfibulare ranged from 1 x 4 mm to 8 x 17 mm. In 22 cases of inversion stress view, displacement of the Os sbufibulare averaged 1.5+/-1.1 mm (0 to 5 mm). The postoperative clinical results were excellent in 41 cases, poor in 1 case. There were complications of 1 case of irritation of sural nerve, 1 case of nonunion. CONCLUSION: Anatomic reduction and bone graft is effective treatment method for symptomatic Os subfibulare.

Clinical and Radiological Analysis and Results after Anatomical Reduction and Bone Graft for Symptomatic Os Subfibulare / 대한족부족관절학회지

PURPOSE: To analyze the clinical and radiological feature of Os subfibulare and to evaluate the results after anatomical reduction and internal fixation with bone graft for Os subfibulare. MATERIALS AND METHODS: Forty-two cases, which underwent anatomic reduction and bone graft for Os subfibulare from October 1998 to September 2004 were reviewed. We analysed preopertive symptoms and onset of symptoms and radiologically measured the size and amounts of displacement of Os subfibulare under the inversion stress. Postoperatively we evaluated the clinical results measured by Hasegawa method and evidence of union. RESULTS: Preoperatively there were only pain around the lateral malleolus in 16 cases, only instability of ankle joint in 3 cases, and pain and instability in 23 cases. The age of symptom onset averaged 23 years(range, 13-38 years). Radiographically Os sufibulare anteriorly located from lateral malleolus were in 40 cases, posteriorly situated in 2 cases. The size of Os subfibulare ranged from 1 x 4 mm to 8 x 17 mm. In 22 cases of inversion stress view, displacement of the Os sbufibulare averaged 1.5+/-1.1 mm (0 to 5 mm). The postoperative clinical results were excellent in 41 cases, poor in 1 case. There were complications of 1 case of irritation of sural nerve, 1 case of nonunion. CONCLUSION: Anatomic reduction and bone graft is effective treatment method for symptomatic Os subfibulare.

Symptomatic Os Subfibulare: Two Cases Reports / 대한정형외과학회잡지

Os subfibulare is a accessory bone arround the lateral maleolus, but it is different from many other accessory bones in foot and ankle in its development related to trauma and frequent symptoms of ankle instability. Accessory bone is a developmental anomaly which fails to unite to main secondary ossification center and usually asymptomatic. But os subfibulare is developed by recurrent ankle sprains in younger age or non-union of avulsion fracture of anterior talofibular ligament and causes instability of ankle. We experienced two cases of symptomatic os subfibulare in adolecents and report them with review of literatures.

The Painful Os Subfibulare: Report of Four Cases / 대한정형외과학회잡지

The os subfibulare is a relatively uncommon bony anomaly of the foot. It is usually found between the malleolus and talus and ossifies during adolescence or preadolescence. It can be demonstrated on routine anteroposterior ankle film of the foot. In 4 patients presented, the abnormality caused pain and frequent episodes of ankle strain. The pain was relieved in all patients treated by excision of the accessory bone.