Separated ossicles of the lateral malleolus

Avulsion fracture is associated with more pain after anatomic repair procedure for ATFL injury at the talar side

PURPOSE

To evaluate the clinical outcomes of anatomic repair procedure for chronic anterior talofibular ligament (ATFL) injury at the talar side, and to compare the outcomes between patients with and without concomitant avulsion fractures. It was hypothesized that anatomic repair procedure could produce similarly satisfactory outcomes for those two groups.

METHODS

Thirty-nine consecutive patients with chronic ATFL injuries at the talar side who underwent anatomic repair procedure at the department of sports medicine at Peking University Third Hospital between 2013 and 2018, were retrospectively evaluated. The pain visual analogue scale (VAS), American Orthopaedic Foot & Ankle Society (AOFAS) score, Tegner score, and Foot & Ankle Outcome Score (FAOS) were recorded as the primary outcomes. Time to return to sports (RTS), surgical satisfaction, deficiency of ankle range of motion (ROM), recurrent sprain, and postoperative complications were recorded as the secondary outcomes. Outcomes were compared between patients with (Group A, 16 cases) and without (Group B, 23 cases) concomitant avulsion fractures.

RESULTS

The mean follow-up time was 79.4 ± 17.0 and 76.6 ± 18.5 months for Group A and B, respectively. VAS, AOFAS, Tegner, FAOS, and all subscale scores of FAOS were significantly improved in both groups at the final follow up. Patients in group A had inferior postoperative VAS, AOFAS, FAOS, and pain score of FAOS compared to group B (1.1 ± 1.1 vs. 0.4 ± 0.5, 89.1 ± 10.1 vs. 95.2 ± 5.2, 87.2 ± 7.2 vs. 91.5 ± 4.1, and 88.4 ± 11.3 vs. 96.7 ± 3.5, respectively).The mean time to RTS, rate of satisfaction and recurrent sprain had no significant differences between group A and B (6.1 ± 2.8, 93.8%, and 18.8% vs. 5.2 ± 2.2, 100.0%, and 13.0%, respectively), and the rate of ROM deficiency was significantly higher in group A (37.5 vs. 8.7%). Avulsion fracture was identified as an independent risk factor for inferior pain score of FAOS.

CONCLUSION

Anatomic repair procedure for chronic ATFL injuries at the talar side produces favourable results for patients with and without avulsion fractures at 5 to 10 years follow-up, however, avulsion fracture is associated with more pain.

LEVEL OF EVIDENCE

III.

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.

Outcomes of ossicle resection and anatomic reconstruction of lateral ligaments for chronic ankle instability with large malleolar accessory ossicles

BACKGROUND

Malleolar accessory ossicles can be found in patients with chronic lateral ankle instability (CLAI). Ossicle resection combined with the modified Broström procedure is the most commonly used surgical method. However, an unrepairable gap after ossicle resection often occurs in patients with large ossicles.

PURPOSE

This study analysed the clinical outcomes of ossicle resection and anatomic ligament reconstruction (ALR) for CLAI with large malleolar accessory ossicles.

METHODS

This study was a retrospective case series. Since 2014, we have adopted ALR for patients with difficulties using the modified Broström procedure after ossicle resection. Sixteen patients with chronic ankle instability and malleolar accessory ossicles were treated with this method between December 2014 and February 2018. The average age of the patients at the time of surgery was 28.9 (range, 16-65) years. They were followed up for an average time of 26.9 (range, 12-47) months. The clinical outcomes were evaluated using the Visual Analogue Scale, Karlsson-Peterson ankle scoring system, subjective satisfaction of patients, and radiographic parameters.

RESULTS

All unrepairable cases occurred in patients with ossicles larger than or equal to 10 mm. The VAS score improved from 3.5 ± 1.6 preoperatively to 1.4 ± 1.0 at the final follow-up (p < 0.05), and the Karlsson-Peterson score improved significantly from 52.7 ± 15.1 to 86.4 ± 8.2 (p < 0.05). There was also an obvious change in the varus talar tilt angle (15.4 ± 2.0° vs 6.2 ± 1.6°, p < 0.05) and anterior talar displacement (14.3 ± 2.1 mm vs 6.3 ± 1.4 mm, p < 0.05). Fourteen patients (87.5%) were satisfied (excellent or good) with their clinical outcomes.

CONCLUSION

If modified Broström procedure is difficult to accomplish effectively after ossicle resection for chronic ankle instability with large malleolar accessory ossicles, ALR is a viable option with satisfactory clinical results.

Type VII All-epiphyseal Fractures of the Lateral Malleolus and the Origin of Subfibular Ossicles

BACKGROUND

A subfibular ossicle (SO), also known as an os subfibulare, is present in ∼1% of the general population. Two theories have been proposed to explain the origin of SOs: (1) as a failure of fusion of a secondary center of ossification; (2) as a posttraumatic sequela. This report offers prospective, longitudinal radiographic evidence for the formation of SOs as a posttraumatic sequela of type VII transepiphyseal fractures of the lateral malleolus in children.

METHODS

This Institutional Review Board-approved study was performed at a tertiary care pediatric hospital from March 2012 to April 2019. The study group included 37 children with a type VII fracture of the lateral malleolus and a minimum follow-up of 6 months.

RESULTS

Twenty-one children (57%) healed their fracture. Sixteen children (43%) went on to form SOs. The most common location for the fractures was the distal third of the epiphysis, and the most common fracture type forming SOs was a sleeve avulsion fracture. Four of the children forming SOs have had surgery to address pain and recurrent sprains.

CONCLUSIONS

Overall, 43% of children who sustained a type VII fracture of the lateral malleolus went on to form SOs, giving support to the posttraumatic theory of origin. Sleeve avulsion fractures have the greatest chance of forming SOs. So far, 4 of the 16 children forming SOs have undergone surgery for ankle pain and recurrent sprains.

LEVEL OF EVIDENCE

Level II.

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.

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.

Arthroscopic Stabilization of Unstable Os Subfibulare

Os subfibulare is an ossicle at the tip of the lateral malleolus. The ossicle is sometimes symptomatic and presents with local pain or lateral ankle instability. The purpose of this Technical Note is to describe the details of arthroscopic stabilization of the os subfibulare. It is indicated for symptomatic mechanical lateral ankle instability resulting from an unstable os subfibulare. The technique has the advantages of minimally invasive surgery, evaluation and treatment of concomitant ankle pathology, and preservation of integrity of the anterior talofibular ligament.

Avulsion fracture of the distal fibula is associated with recurrent sprain after ankle sprain in children

PURPOSE

The purpose of this study was to clarify radiographic and clinical outcomes, as well as their association, of ankle sprain in children.

METHODS

Patients who sustained a first-time ankle sprain were prospectively surveyed. Patients underwent radiography of the ankle in the mortise, lateral, anterior talofibular ligament (ATFL), and calcaneofibular ligament views at the first clinic visit to assess avulsion fractures of the distal fibula. Patients with avulsion fractures underwent radiography after 8 weeks to assess bone union. The treatment method was not standardized and was determined by the patient, their parents, and the treating physician. Recurrent sprain and quality of life were evaluated by using the Self-Administered Foot Evaluation Questionnaire and reviewing the medical records of patients. The association between avulsion fracture and recurrent sprain was assessed using univariate and multivariate analyses.

RESULTS

A total of 143 patients with a median age of 9 (range 6-12) years were analyzed. Avulsion fractures were present in 89 (62%) patients. The sensitivity of the ATFL view for the diagnosis of avulsion fractures was 0.94, whereas that for the anteroposterior and lateral views was significantly lower at 0.46 (P < 0.001). Only 17% of fractures united at 8 weeks. Of 114 (follow-up rate, 80%) patients who were followed up for a median period of 24 months, recurrent sprain occurred in 41 (36%) patients. The incidence rate was significantly higher in patients with avulsion fractures than in patients without the fractures (44 vs. 23%, P = 0.027). In multivariate logistic regression analysis, avulsion fracture was independently associated with recurrent sprain (P = 0.027).

CONCLUSION

More than one-third of patients experienced recurrent sprain. The presence of avulsion fracture was associated with an increased risk of recurrent sprain. Patients with avulsion fracture and their parents should be informed about the risk of recurrent sprain and subsequent ankle instability, and careful follow-up is needed for these patients.

LEVEL OF EVIDENCE

III.

Presence of Subfibular Ossicle Does Not Affect the Outcome of Arthroscopic Modified Broström Procedure for Chronic Lateral Ankle Instability

PURPOSE

To evaluate the clinical and radiological outcomes of the all-inside, arthroscopic, modified Broström procedure (MBP) used to treat chronic lateral ankle instability (CLAI) according to subfibular ossicle (SFO) status.

METHODS

Between January 2013 and September 2016, we retrospectively analyzed CLAI patients who underwent the arthroscopic MBP. When performing the arthroscopic MBP, SFO was removed with all inside technique regardless of size. Patients who were not followed for more than a minimum of 12 months after surgery were excluded. The patients were divided into 2 groups: ankles with SFOs were assigned to the SFO group and the others to the non-SFO (NSFO) group. The evaluation tools used included the American Orthopedic Foot and Ankle Society (AOFAS) ankle-hind foot score, a pain visual analog scale, and the talar tilt angle.

RESULTS

Following the inclusion criteria, we included 125 patients (125 ankles) in this study. The SFO group consisted of 26 patients and the NSFO group consisted of 99 patients. The preoperative scores in the 2 groups shows no significant difference except for AOFAS scores. The final AOFAS scores in both groups improved compared with the preoperative scores (18.4 ± 16.3 and 22.1 ± 21.6 for the SFO and NSFO groups, respectively). The final follow-up visual analog scale scores also improved in both groups (5.0 ± 1.7 and 5.2 ± 1.4, respectively). The mean ± standard deviation talar tilt improved from 8.7 ± 5.0° preoperatively to 4.6 ± 3.6° at the final follow-up in the SFO group, and from 7.3 ± 4.4° preoperatively to 3.2 ± 3.0° at the final follow-up in the NSFO group. Neither the preoperative nor final talar tilt angle differed between the 2 groups (P = .300 and P = .072, respectively).

CONCLUSIONS

All-inside arthroscopic MBP after SFO resection was as successful as the same surgery without SFO resection. The clinical outcomes of the SFO and NSFO groups did not differ. Both groups achieved successful radiological outcomes at the last follow-up. All-inside arthroscopic MBP is a reliable treatment for CLAI patients regardless of SFO status.

LEVEL OF EVIDENCE

Level III, retrospective comparative study.

Posttraumatic Subfibular Ossicle Formation in Children: Experience in a Single Primary Care Unit

BACKGROUND

Although subfibular ossicles have been linked to various clinical problems, whether its origin is congenital or traumatic remains unclear. The objectives of this study were to determine the incidence of subfibular ossicle formation after ankle inversion in children.

METHODS

Among 896 pediatric patients who visited a single primary care unit after foot and ankle trauma, 593 patients sustaining ankle inversion injury were included in this study. For each pediatric patient, physical examination and radiographic examination were performed. The incidence of subfibular ossicle was evaluated based on initial radiographic examination. To analyze the incidence of unprecedented subfibular ossicle formation after ankle inversion injury, radiographs of 188 patients who were followed up for >6 months were evaluated according to the grade of initial injury.

RESULTS

At initial visit, 1.0% of examined ankles (12 from 1186 ankles) showed well-corticated subfibular ossicle not related to initial injuries. Overall incidence of subfibular ossicle at final follow-up after ankle inversion injury was 39.4% (74/188). Incidence of subfibular ossicle at final follow-up was associated with initial injury grade. As for the morphology of ossicle, 93.2% (55/59) of cases with wafer bone fragment at the time of initial injury became oval or round-shaped subfibular ossicle at final radiograph.

CONCLUSIONS

The chance of ossicle formation after ankle inversion injury was substantially high in pediatric population. On the basis of the findings of our study, we carefully suggest that majority, if not all, of subfibular ossicles would be posttraumatic in pediatric period.

LEVEL OF EVIDENCE

Level IV-case series.

Surgical Treatment of Subfibular Ossicle in Children: A Retrospective Study of 36 Patients with Functional Instability

BACKGROUNDS

To evaluate the surgical management of a symptomatic subfibular ossicle after severe ankle sprain with functional instability and pain sequelae in children.

METHODS

We analyzed 36 patients complaining of functional instability without laxity, 1 year after an ankle inversion trauma associated with the observation of a subfibular ossicle. We systematically suggested the open excision of the residual ossicles, followed by 6 weeks of immobilization and proprioceptive physiotherapy. Seventeen of them, constituting the "resection" group accepted this surgical approach. The remaining 19 patients, the "control" group, received only rehabilitative care. The American Orthopaedic Foot and Ankle Society ankle pain and function score was evaluated in both groups.

RESULTS

The mean latest follow-up was 4 years and 4 months (range, 1 y 8 mo to 14 y 7 mo). A significant improvement of the American Orthopaedic Foot and Ankle Society score was observed and was significantly higher in the resection group with a mean gain of 31 points (SD=31.8), versus 7 points (SD=7) in the control group (P<0.001).

CONCLUSIONS

We conclude that in the absence of objective laxity, excision of the os subfibulare appears as a simple and effective technique in the treatment of posttraumatic functional instability and ankle pain.

LEVEL OF EVIDENCE

Level IV-retrospective case-control study.

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.

Comparison of the Modified Broström Procedure for Chronic Lateral Ankle Instability With and Without Subfibular Ossicle

BACKGROUND

Subfibular ossicles are frequently found in patients with chronic lateral ankle instability (CLAI). However, there is a lack of consensus about the optimal surgical treatment for CLAI with subfibular ossicle.

PURPOSE

To evaluate the clinical and radiographic outcomes of the modified Broström procedure with subfibular ossicle excision compared with the same procedure for CLAI without subfibular ossicle.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

Ninety-six patients (96 ankles) treated with the modified Broström procedure using bone tunnel and suture anchor techniques for CLAI constituted the study cohort. The 96 ankles were divided into 2 groups with and without subfibular ossicles. The ossicle group (42 ankles) and nonossicle group (54 ankles) consisted of patients with a mean age of 26.6 and 30.3 years, respectively, at the time of surgery with a mean follow-up duration of 63.7 and 62.1 months, respectively. Subfibular ossicles were excised in the ossicle group.

RESULTS

Mean Karlsson scores improved from 55.2 to 95.3 in the ossicle group and from 56.4 to 94.8 in the nonossicle group at final follow-up. Mean American Orthopaedic Foot and Ankle Society (AOFAS) ankle-hindfoot scores also improved from 63.3 to 95.9 in the ossicle group and from 62.8 to 95.1 in the nonossicle group at final follow-up. Mean talar tilt angles were 14.0° in the ossicle group and 12.2° in the nonossicle group preoperatively and 7.6° and 6.8° at the final follow-up, respectively. Mean anterior talar translations in the ossicle group and nonossicle groups improved from 9.3 and 9.4 mm preoperatively to 5.8 and 5.7 mm at final follow-up, respectively. No significant differences were found between the 2 groups in terms of Karlsson score, AOFAS score, talar tilt angle, and anterior talar translation at final follow-up (P > .05).

CONCLUSION

The modified Broström procedure with subfibular ossicle excision provided similarly good clinical and radiographic outcomes compared with the same procedure without subfibular ossicle excision. Accordingly, the study results suggest that these procedures appear to be effective and reliable method for the treatment of CLAI with subfibular ossicle.

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.

A novel 9-region systematic assessment tool for separated ossicle at the fibular tip effects on lateral ankle ligament complex integrity: a cadaveric study

PURPOSE

Fibular tip ossicle separation can cause ligament injury leading to chronic lateral ankle instability. A cadaveric study was conducted to preliminarily assess the effects of fibular tip separated ossicle location and size on lateral ankle ligament complex integrity.

METHODS

X-ray examinations and dissection of the anterior talofibular and calcaneofibular ligaments were conducted in ten radiographically confirmed normal below-knee cadaveric specimens extracted from donated fresh cadavers. Ossicle and bone fragment location and size were recorded, and distal fibula, articular surface, and adjacent ligament effects were determined by a novel 9-region matrix.

RESULTS

Ligament risk varied by region. Anterior talofibular ligament width, perpendicular distance to fibular tip, sagittal width of distal fibula, and coronal width of distal fibula at attachment were 7.45 ± 0.22, 11.75 ± 1.03, 20.56 ± 1.54, and 8.68 ± 0.12 mm, respectively. Sagittal distal fibula and calcaneofibular ligament maximum widths at fibular attachment articular surfaces were 16.81 ± 0.96 and 3.50 ± 0.44 mm, respectively. Anterior talofibular to calcaneofibular ligament distance was 2.35 ± 0.14 mm. Separated ossicles >10 mm in regions 1-3 affected anterior talofibular ligaments, calcaneofibular ligaments, and fibular ankle joints; while those in regions 4, 8, and 7 or 9 affected anterior talofibular or calcaneofibular ligaments or were without impact.

CONCLUSIONS

At the fibular tip, separated ossicles sized >10 mm impact collateral ligaments and articular surfaces, while those 5-10 and <5 mm impact anterior talofibular or calcaneofibular ligaments, potentially impairing the lateral ankle ligament complex. Thus, systematic matric-based assessment of ossicle size and location can potentially improve and standardize ankle fracture care.

Arthroscopic excision of separated ossicles of the lateral malleolus

BACKGROUND

We have conducted a retrospective review of 19 patients for whom 20 separated ossicles of the lateral malleolus were excised arthroscopically. We examined the operating methods, findings, and overall results.

METHODS

The patients' indications for this procedure were as follows. The main complaints were pain alone; ossicle sizes were small and ankle instability was minimal. There were 12 ankles of 12 males and eight ankles of seven females. The patients' average age was 17.6 years. A 2.7-mm, 30° arthroscope was inserted into the ankle joint through the anterolateral portal. Instruments were inserted through the accessory anterolateral portal, and ossicles were removed piece by piece. Talar tilt angles and anterior displacements were examined and compared before and after surgery by use of stress radiographs. Japanese Society for Surgery of the Foot (JSSF) ankle/hindfoot scales were assessed pre and postoperatively.

RESULTS

All patients recovered their original levels of activity. The mean talar tilt angle changed from 6.1° ± 2.4° preoperatively to 6.0° ± 1.8° postoperatively (p = 0.93), and the mean anterior displacement changed from 5.9 ± 1.7 mm preoperatively to 6.1 ± 2.0 mm postoperatively (p = 0.42). Average JSSF ankle/hindfoot scale improved from 77.6 ± 2.6 points preoperatively to 97.2 ± 5.2 points postoperatively (p < 0.01).

CONCLUSIONS

Arthroscopic excision of separated ossicles of the lateral malleolus achieved good results with minimum incisions, and relatively early resumption of daily and sports activity was possible. However, when the ossicles were embedded within the fibers of the anterior talofibular ligament, it was impossible to avoid cutting of ligament fibers. To reduce the possibility of ligament dysfunction, we believe postoperative treatment should conform to the accepted method for treatment of acute ankle sprains.

The effect of an ossicle of the lateral malleolus on ligament reconstruction of chronic lateral ankle instability

BACKGROUND

Ossicles at the tip of the lateral malleolus are frequently found in patients with chronic lateral ankle instability (CLAI). However, the relationship between the presence or the size of an ossicle and the outcome of ligament reconstruction is poorly understood. Therefore, this study aimed to evaluate the effect of an ossicle at the tip of the lateral malleolus on ligament reconstruction in CLAI.

MATERIALS AND METHODS

Seventy-four ankles with chronic lateral instability that received lateral ligament reconstruction using a modified Broström technique between January 2001 and March 2007 were included. The mean followup was 47 (range, 25 to 89) months. Ankles were divided into 2 groups: the ossicle group (26 ankles, 35.1%) and the non-ossicle group (48 ankles, 64.9%). Then, depending on the size, the ossicle group was subdivided into small (less than 10 mm, 14 ankles) and large ossicles (greater than 10 mm, 12 ankles). Pre- and postoperative Karlsson-Peterson ankle scores and findings on stress radiographs were compared between the groups.

RESULTS

Both the ossicle and non-ossicle groups improved significantly on stress radiographs without difference between the groups. Karlsson-Peterson ankle scores showed functional improvement in each group, however, the mean score at last followup was significantly lower in the ossicle group (p=0.01). The prevalence of an osteochondral lesion of the talus was significantly higher in the ossicle group (p=0.046). In ankles with large ossicles, varus stability was achieved but anterior displacement of the talus was not improved after ligament reconstruction.

CONCLUSION

The surgeon should be aware of the inferior functional outcome in ankles with ossicles. Also, when the ossicle is large, excision and modified Broström technique may not be suitable to achieve mechanical anteroposterior stability. Therefore, fusing the ossicle to the fibular tip or using other methods of ligament reconstruction can be considered when performing ligament reconstruction in CLAI with associated large ossicles.

The anatomy in relation to injury of the lateral collateral ligaments of the ankle: a current concepts review

Injuries to the lateral ligament complex of the ankle are common problems in acute care practice. We believe that a well-developed knowledge of the anatomy provides a foundation for understanding the basic mechanism of injury, diagnosis, and treatment, especially surgical treatment, of lateral collateral ankle ligament injury. To address this issue we performed this review with regard to the anatomy of the lateral collateral ankle ligaments.

Ossicles associated with chronic pain around the malleoli of the ankle

We undertook a retrospective review of 24 arthroscopic procedures in patients with symptomatic ossicles around the malleoli of the ankle. Most of the patients had a history of injury and localised tenderness in the area coinciding with the radiological findings. Contrast-enhanced three-dimensional fast-spoiled gradient-echo MRI was performed and the results compared with the arthroscopic findings. An enhanced signal surrounding soft tissue corresponding to synovial inflammation and impingement was found in 20 patients (83%). The arthroscopic findings correlated well with those of our MRI technique and the sensitivity was estimated to be 91%. At a mean follow-up of 30.5 months (20 to 86) the mean American Orthopaedic Foot and Ankle Society score improved from 74.5 to 93 points (p < 0.001). Overall, the rate of patient satisfaction was 88%.

Our results indicate that symptomatic ossicles of the malleoli respond well to arthroscopic treatment.

Assessment of acute ankle sprain with os subfibularein children

Children commonly present with acute inversion injuries of the ankle. Radiographs occasionally show small fragments under the tip of the lateral malleolus. The purpose of our study was to clarify their origin. A prospective standardized clinical examination and a magnetic resonance imaging were carried out. Among the 116 included patients, seven of them showed an os subfibulare. They presented more pains on the lateral ankle area than the other children. We found also more injuries on the anterior talofibular ligament. The os subfibulare could be secondary to an accessory ossification but the lateral area of the ankle would be likely to be injured.

Chronic ankle instability: management of chronic lateral ligamentous dysfunction and the varus tibiotalar joint

Many techniques have been described in acute and chronic lateral ligament insufficiency in the ankle. At present, the Bostrom-Gould and Chrisman-Snook procedures and their variations remain the "gold standard". Recent assessment of important etiologic factors has shed some light on the relationship between the original injury or injuries and the subsequent development of the varus tibiotalar joint with or without secondary osteoarthritis. The development of Taylor Spatial Frame may well revolutionize its management. In the meantime, further consideration should be given to well-designed and evaluated randomized controlled trials, improved understanding of the biomechanics, and function of the ligaments, for example, proprioceptive function and their healing. Newer and less invasive arthroscopic and percutaneous techniques are being developed.

Symptomatic os subfibulare caused by accessory ossification: a case report

Separated ossicles at the tip of the lateral malleolus, the condition known as os subfibulare, are sometimes a cause of ankle pain. There are two theories regarding the origin of os subfibulare. One theory proposes that it is caused by an avulsion fracture attributable to pull of the anterior talofibular ligament, whereas the other theory proposes that it is the result of an accessory ossification center. However, some authors have reported that os subfibulare is an avulsion fracture and few reports of accessory ossification have been described recently. A patient with os subfibulare that may have been caused by accessory ossification rather than an avulsion fracture was treated by the current authors.