Current concepts: lateral ankle instability

Surgical Treatment of Chronic Lateral Ankle Instability Using an Inferior Extensor Retinaculum Flap: A Retrospective Study

Chronic lateral ankle instability causes significant problems with physical activity. The purpose of the present study was to evaluate the results of ligamentous retensioning combined with reinforcement using an extensor retinaculum flap. A consecutive series of 38 patients were included with a minimum follow-up duration of 2 years. The functional results were assessed using the Karlsson and American Orthopaedic Foot and Ankle Society scale scores. The pre- and postoperative radiologic assessment was performed using stress radiographs to measure varus tilt and anterior drawer tests. All 38 patients were followed up for 2.5 to 7.2 years, and 35 patients were satisfied. The American Orthopaedic Foot and Ankle Society scale score had improved significantly from 57 (range 20 to 70) points preoperatively to 95 (range 80 to 100) points postoperatively (p < .0001), and 35 patients believed their ankle was more stable after surgery. The patients had returned to their previous sports activities an average of 4.7 (range 2 to 12) months after surgery. On the stress radiographs, the mean talar tilt angle had improved significantly from 15.2° (range 6° to 26°) preoperatively to 3.8° (range 1° to 8°) at the final follow-up visit (p < .001), and the mean anterior talar had improved significantly from 13.2 (range 8 to 18) mm preoperatively to 4 (range 4 to 7) mm at the final follow-up visit (p < .002). Regarding the prognostic factors, a link was found between the functional result and residual radiologic laxity measured on the stress radiographs. Reconstruction of the lateral ligaments for chronic ankle instability combining capsuloligamentous retensioning and reinforcement with an extensor retinaculum flap resulted in successful outcomes, excellent ankle stability, and preservation of ankle joint mobility. This technique addressed both lateral ankle and subtalar instability by developing an extraarticular interosseous ligament.

Intermediate- to Long-Term Longevity and Incidence of Revision of the Modified Broström-Gould Procedure for Lateral Ankle Ligament Repair: A Systematic Review

The Broström-Gould procedure is an effective procedure for chronic lateral ankle instability. However, long-term studies are limited, and the durability of this procedure remains unclear. A systematic review of the published data was undertaken to determine the outcomes and incidence of revision after long-term follow-up. Eleven studies involving 669 Broström-Gould procedures met the inclusion criteria. The revision rate was 1.2% at a weighted mean follow-up period of 8.4 years. Our systematic review of the available data revealed that the Broström-Gould procedure results in low revision rates for chronic lateral ankle instability. However, additional prospective comparative analyses are needed regarding this topic.

Fracture Through a Distal Fibular Tunnel Used for an Anatomic Lateral Ankle Ligament Reconstruction

Anatomic lateral ankle ligament reconstruction using free tendon graft with osseous tunnels has become a popular technique for revision reconstruction of the lateral ankle ligaments. With the procedure’s burgeoning popularity, an accompanying increase in postoperative complications is likely to occur. We report on one such complication: traumatic distal fibula fracture through the transosseous tunnels.

Comparative Evaluation Between Anatomic and Nonanatomic Lateral Ligament Reconstruction Techniques in the Ankle Joint: A Computational Study

Biomechanical studies have indicated that the conventional nonanatomic reconstruction techniques for lateral ankle sprain (LAS) tend to restrict subtalar joint motion compared to intact ankle joints. Excessive restriction in subtalar motion may lead to chronic pain, functional difficulties, and development of osteoarthritis (OA). Therefore, various anatomic surgical techniques to reconstruct both the anterior talofibular and calcaneofibular ligaments (CaFL) have been introduced. In this study, ankle joint stability was evaluated using multibody computational ankle joint model to assess two new anatomic reconstruction and three popular nonanatomic reconstruction techniques. An LAS injury, three popular nonanatomic reconstruction models (Watson-Jones, Evans, and Chrisman–Snook) and two common types of anatomic reconstruction models were developed based on the intact ankle model. The stability of ankle in both talocrural and subtalar joint were evaluated under anterior drawer test (150 N anterior force), inversion test (3 N·m inversion moment), internal rotational test (3 N·m internal rotation moment), and the combined loading test (9 N·m inversion and internal moment as well as 1800 N compressive force). Our overall results show that the two anatomic reconstruction techniques were superior to the nonanatomic reconstruction techniques in stabilizing both talocrural and subtalar joints. Restricted subtalar joint motion, which is mainly observed in Watson-Jones and Chrisman–Snook techniques, was not shown in the anatomical reconstructions. Evans technique was beneficial for subtalar joint as it does not restrict subtalar motion, though Evans technique was insufficient for restoring talocrural joint inversion. The anatomical reconstruction techniques best recovered ankle stability.

Open and arthroscopic lateral ligament repair for treatment of chronic ankle instability: A systematic review

BACKGROUND

Chronic ankle instability is defined by an instability lasting more than 6 months, in those cases where a comprehensive conservative treatment fails a surgical stabilization is required. Several surgical techniques have been proposed for the management of the chronic lateral instability of the ankle and even after 50 years, the Broström-Gould technique is still considered the gold standard for the treatment of this pathology. Recently, many authors have developed completely arthroscopic lateral ligament repair and the use of these procedures is rapidly increasing. The aim of this review is to provide an updated overview of open and new arthroscopic lateral ligament repair techniques in order to summarize and compare the effectiveness of these strategies.

METHODS

A systematic literature review using PubMed/Medline databases was performed (July 1972-July 2015). Clinical results, satisfaction rate and complications of both patient populations were recorded and statistically analyzed.

RESULTS

The total ankles treated with an open Broström ATFL repair in the 13 studies was 505 with a mean follow up of 73.4 months (range 9 months-27.9 years). Postoperative AOFAS score was reported in 11 studies, with a mean value of 90.1 (range, 60-100), patient's satisfaction rate was 91.7%. Surgery-related complications occurred in 40 (7.92%) out of 505 treated ankles. The total number of ankles treated within the 6 arthroscopic studies was 216 with a mean follow up of 37.2 months (range 6 months-14 years). Five studies reported a mean postoperative AOFAS score of 92.48 (range, 44-100) with a patient's satisfaction rate of 96.4%. Surgery-related complications were observed in 33 (15.27%) cases.

CONCLUSIONS

The results of this review show the excellent efficacy of open and arthroscopic surgical procedures in the treatment of the chronic ankle instability. The higher complication rate of arthroscopic procedures respect to the open ones represents the major issue: however, this does not seem to affect the patient's satisfaction. Because of statistical heterogeneity observed no definitive conclusions can be statistically drawn. Finally, to definitively validate the effectiveness of arthroscopic procedures prospective and comparative studies are needed.

The Effect of Peroneal Muscle Strength on Functional Outcomes After the Modified Broström Procedure for Chronic Ankle Instability

BACKGROUND

Although the peroneal muscles are known to be the major dynamic lateral stabilizers of the ankle, little information is available regarding the change in muscle strength and relation with the outcomes after lateral ligament repair surgery. The purpose of this study was to identify the effects of peroneal strength on the validated functional outcome measures after the modified Broström procedure (MBP) for chronic ankle instability.

METHODS

Forty-one patients (41 ankles) who underwent MBP using suture anchors were eligible and followed up to 2 years postoperatively. Functional evaluation consisted of the Foot and Ankle Outcome Score (FAOS), and Foot and Ankle Ability Measure (FAAM). The changes of peroneal strength were evaluated using an isokinetic dynamometer. Differences in the functional outcomes between the 3 groups divided according to the recovery rate of peroneal strength were analyzed.

RESULTS

Peak torque and total work for eversion in 60 degrees/s angular velocity significantly improved from a mean 8.1 and 5.2 Nm preoperatively to 11.4 and 6.9 Nm at postoperative 2 years, respectively ( P < .001, P = .038). The deficit ratio of peak torque for eversion significantly improved from a mean 38.6% to 17.4%, and a significant side-to-side difference was found ( P = .011). There were no significant differences in FAOS, FAAM, and measurements of stress radiograph between the 3 groups.

CONCLUSIONS

Although restoration of peroneal strength postoperatively was about 82.6% of the unaffected ankle, patient-reported function in daily and sport activities were satisfactorily improved. Postoperative isokinetic strength of the peroneals demonstrated no statistically significant effects on the functional outcomes after MBP.

LEVEL OF EVIDENCE

Level III, prospective comparative case series.

Revision anatomical reconstruction of the lateral ligaments of the ankle augmented with suture tape for patients with a failed Broström procedure

AIMS

The aim of this prospective study was to evaluate the intermediate-term outcomes after revision anatomical ankle ligament reconstruction augmented with suture tape for a failed modified Broström procedure.

PATIENTS AND METHODS

A total of 30 patients with persistent instability of the ankle after a Broström procedure underwent revision augmented with suture tape. Of these, 24 patients who were followed up for more than two years were included in the study. There were 13 men and 11 women. Their mean age was 31.8 years (23 to 44). The mean follow-up was 38.5 months (24 to 56) The clinical outcome was assessed using the Foot and Ankle Outcome Score (FAOS) and the Foot and Ankle Ability Measure (FAAM) score. The stability of the ankle was assessed using stress radiographs.

RESULTS

The mean FAOS and FAAM scores improved significantly to 87.5 (73 to 94) and 85.1 (70 to 95) points at final follow-up, respectively (p < 0.001). The mean angle of talar tilt and anterior talar translation improved significantly to 2.8° (0° to 6°) and 4.1 mm (2 to 7) at final follow-up, respectively (p < 0.001). Side to side comparison in stress radiographs at final follow-up showed no significant difference. The revision failed in one patient who underwent a further revision using allograft tendon.

CONCLUSION

The revision modified Broström procedure augmented with suture tape is an effective form of treatment for recurrent instability of the ankle following a failed Broström procedure. This technique provides reliable stability and satisfactory clinical outcomes at intermediate-term follow-up. Cite this article: Bone Joint J 2017;99-B:1183-9.

[Anatomic stabilization of chronic lateral instability of the ankle : Gold technique]

OBJECTIVES

Anatomical reconstruction of the lateral ligament complex in the ankle.

INDICATIONS

Chronic lateral ankle instability.

CONTRAINDICATIONS

Severe osteoarthritis, obesity, hindfoot varus, general contraindications (infection, circulatory disorders, diabetic foot syndrome).

SURGICAL TECHNIQUE

Anatomical V‑shaped reconstruction of the lateral ligament complex with half of the peroneus brevis tendon and additional retinaculum stabilization.

POSTOPERATIVE MANAGEMENT

Lower leg orthesis (e. g. protect.CAT Walker, medi GmbH, Bayreuth, Germany) for 6 weeks. Week 1-2, no weight bearing, no active pro- and supination. Starting in week 3-4, begin with partial weight bearing, pain adapted. Starting in week 7, free range of motion, begin with progressive training.

RESULTS

Between March 2014 and June 2016, 16 patients (6 female, 10 male) were treated with the above-named technique. Average age was 32.8 years (range 17.9-57.1 years). Ten patients completed the 6‑ and 12-month follow-ups. None of these 10 patients reported a feeling of instability. In the clinical examination, the lateral ligament complex was stable. Patients showed a free range of motion at the 12-month follow-up.

Outcomes of the Modified Broström Procedure Augmented With Suture-Tape for Ankle Instability in Patients With Generalized Ligamentous Laxity

BACKGROUND

Although recent biomechanical studies have reported mechanical superiority of augmented anterior talofibular ligament reconstruction using suture-tape, clinical evidence regarding the efficacy of suture-tape augmentation is still insufficient. This prospective study was performed to evaluate the outcomes of the modified Broström procedure augmented with suture-tape for chronic ankle instability with generalized ligamentous laxity, which has been known to be a poor prognostic factor for anatomic ligament repair.

METHODS

Twenty-eight patients with generalized ligamentous laxity were followed for more than 2 years after the augmented modified Broström procedures for chronic ankle instability. Generalized ligamentous laxity was defined as a Beighton score ≥4 points. The clinical evaluation consisted of the Foot and Ankle Outcome Score (FAOS) and Foot and Ankle Ability Measure (FAAM) score. Measurement of talar tilt angle and anterior talar translation was obtained from stress radiographs to evaluate mechanical ankle stability.

RESULTS

FAOS and FAAM scores had significantly improved from preoperative average 63.2 and 54.3 points to 90.6 and 89.5 points at final follow-up, respectively ( P < .001). Talar tilt angle and anterior talar translation had significantly improved from preoperative average 16.2° and 12.1 mm to 3.6° and 4.2 mm at final follow-up, respectively ( P < .001). Preoperative side-to-side comparison with stress radiographs was significantly different, but this returned to within nonstatistical differences at final follow-up, respectively ( P = .105, .532). Although 6 patients sustained an ankle sprain after operation, only 1 patient (3.6%) showed a recurrence of subjective and mechanical instability.

CONCLUSIONS

Suture-tape augmentation for the modified Broström procedure appears to be an effective operative alternative for chronic ankle instability with generalized ligamentous laxity. As one of the methods to improve the clinical outcomes in patients with relative contraindications of the modified Broström repair, this procedure provided reliable stability with the advantages of anatomic ligament repair through the augmentation using suture-tape.

LEVEL OF EVIDENCE

Level IV, prospective case series.

Comparison of Magnetic Resonance Imaging and Stress Radiographs in the Evaluation of Chronic Lateral Ankle Instability

BACKGROUND

In patients who develop chronic ankle instability, clinicians often obtain magnetic resonance imaging (MRI) as part of the evaluation prior to operative referral. The purpose of this study was to analyze the diagnostic efficacy of MRI in the diagnosis of chronic lateral ankle instability. Our hypothesis was that magnetic resonance imaging would not be a specific diagnostic tool in the evaluation of chronic lateral ankle instability.

MATERIALS AND METHODS

A retrospective chart review of 187 consecutive patients (190 ankles) was performed. Inclusion criteria for the study group required a primary complaint of instability that required operative repair or reconstruction, a documented clinical evaluation consistent with instability, stress radiographs, and MRI. Stress radiographs and clinical examinations for the study group and a control group were reviewed independently by both a musculoskeletal radiologist and a board-certified orthopaedic foot and ankle surgeon. Predictive values in terms of sensitivity, specificity, and prevalence were performed. In total, 112 patients (115 ankles) were identified who underwent an operative reconstruction of their lateral ligaments with a history, physical examination, and stress radiographs consistent with lateral ankle instability. A control group was selected consisting of 75 patients seen in the foot and ankle clinic with a diagnosis other than lateral ankle instability. Thirty-seven of the patients in the control group had stress radiographs performed in the clinic to rule out instability as part of their evaluation, and this allowed for an evaluation of the efficacy of stress radiographs in addition to MRI. Statistical analysis was performed using predictive values from sensitivity, specificity, and prevalence.

RESULTS

The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) in regards to MRI in the evaluation of patients found to have clinical lateral ankle instability and those who did not had statistical significance. Sensitivity of MRI was 82.6%, specificity was 53.3%, NPV was 66.7%, and PPV was 73%. Since 37 patients in the control group also had stress radiographs, a subanalysis was performed to identify the same values with stress radiographs. Sensitivity, specificity, NPV, and PPV were 66%, 97%, 48%, and 98.7%, respectively. The overall accuracy within this study was 71% for MRI and 74% for stress radiographs.

CONCLUSION

This study demonstrated that MRI has high sensitivity but low specificity in the evaluation of clinical ankle instability. While MRI has value as a screening tool for concomitant ankle pathology, it should not be considered diagnostic in terms of lateral ankle instability.

LEVEL OF EVIDENCE

Level III, retrospective cohort, comparative series.

Operative treatment of lateral ligament instability

PURPOSE OF REVIEW

Ankle sprains, which account for 40% of sports injuries in the USA, can lead to chronic ankle instability. Chronic ankle instability can be classified as functional, mechanical, or a combination of both and is diagnosed using a combination of a physical exam, an MRI, and stress radiographs. This review focuses on different approaches to treatment, including non-operative and operative techniques, of chronic ankle instability, including reviewing traditional procedures as well as more novel and newer techniques.

RECENT FINDINGS

Based on existing literature, non-operative treatment should always precede operative treatment of chronic ankle instability. If rehabilitation fails, Brostrom-Gould type ankle stabilization has been the preferred surgical option. Recent literature suggests that arthroscopic repair might reduce recovery time and improve outcomes in certain populations; however, there are higher rates of complication following these surgeries. In more high-risk populations, some literature reports that ligament repair with peroneus brevis transfer could be a more effective treatment option. Currently, varying surgical techniques exist for the treatment of chronic ankle instability. While the more recently reported techniques show promise, it is important to note that there is little evidence showing they are more successful than traditional techniques. It is imperative that future studies focus on outcomes and complication rates of these newer procedures.

Weber B Fracture of the Lateral Malleolus with Concomitant Anterior Talofibular Ligament Injury following an Ankle Supination Injury

The Lauge-Hansen (LH) classification attempts to predict patterns of ankle injuries based upon the preceding mechanism of injury. Although it is widely used in clinical practice, it has been criticized mainly due to numerous reports of cases conflicting the prediction system. Here, we report a case of a 32-year-old male who sustained a Weber B fracture of the lateral malleolus following a supination ankle injury, which was treated conservatively, following which the patient presented with ankle instability and was found to have concurrent anterior talofibular ligament tear. Critical review of the LH classification along with its shortcomings is discussed.

Systematic Quantification of Stabilizing Effects of Subtalar Joint Soft-Tissue Constraints in a Novel Cadaveric Model

BACKGROUND

Distinguishing between ankle instability and subtalar joint instability is challenging because the contributions of the subtalar joint's soft-tissue constraints are poorly understood. This study quantified the effects on joint stability of systematic sectioning of these constraints followed by application of torsional and drawer loads simulating a manual clinical examination.

METHODS

Subtalar joint motion in response to carefully controlled inversion, eversion, internal rotation, and external rotation moments and multidirectional drawer forces was quantified in fresh-frozen cadaver limbs. Sequential measurements were obtained under axial load approximating a non-weight-bearing clinical setting with the foot in neutral, 10° of dorsiflexion, and 10° and 20° of plantar flexion. The contributions of the components of the inferior extensor retinaculum were documented after incremental sectioning. The calcaneofibular, cervical, and interosseous talocalcaneal ligaments were then sectioned sequentially, in two different orders, to produce five different ligament-insufficiency scenarios.

RESULTS

Incremental detachment of the components of the inferior extensor retinaculum had no effect on subtalar motion independent of foot position. Regardless of the subsequent ligament-sectioning order, significant motion increases relative to the intact condition occurred only after transection of the calcaneofibular ligament. Sectioning of this ligament produced increased inversion and external rotation, which was most evident with the foot dorsiflexed.

CONCLUSIONS

Calcaneofibular ligament disruption results in increases in subtalar inversion and external rotation that might be detectable during a manual examination. Insufficiency of other subtalar joint constraints may result in motion increases that are too subtle to be perceptible.

CLINICAL RELEVANCE

If calcaneofibular ligament insufficiency is established, its reconstruction or repair should receive priority over that of other ankle or subtalar periarticular soft-tissue structures.

Activity Level and Function After Lateral Ankle Ligament Repair Versus Reconstruction

BACKGROUND

Few studies have compared outcomes of Broström-Gould repair and allograft reconstruction.

HYPOTHESIS/PURPOSE

The purpose of this study was to compare outcomes and revision rates after Broström-Gould lateral ankle ligament repair versus anatomic allograft reconstruction in patients with lateral ankle instability. The hypothesis was that patients who underwent lateral ankle ligament repair would have outcomes and revision rates similar to those of patients who underwent anatomic allograft reconstruction.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

All patients who underwent surgical repair or reconstruction of the anterior talofibular ligament and/or the calcaneofibular ligament by a single surgeon between September 2009 and February 2013 were included in this study. Patients completed a subjective questionnaire at minimum 2 years after ankle surgery. Outcomes measures included the Foot and Ankle Disability Index (FADI), American Orthopaedic Foot and Ankle Society (AOFAS) Ankle-Hindfoot Score, Lysholm score, Western Ontario and McMaster Universities Arthritis Index (WOMAC), Short Form-12 Physical Component Summary (PCS) and Mental Component Summary (MCS) scores, Tegner activity scale, and patient satisfaction with outcome. Detailed surgical data and intraoperative findings were documented at the time of surgery. All data were collected prospectively and reviewed retrospectively.

RESULTS

A total of 86 patients were included in this study: 45 men and 41 women (mean age, 38 years; range, 19-68 years) with a mean body mass index of 26.5 (range, 17.5-47.1). There were 61 (71%) patients in the repair cohort and 25 (29%) in the reconstruction cohort. There was no significant difference in age or sex between cohorts. Seventy-six (88%) patients had minimum 2-year follow-up (mean follow-up, 3.0 years; range, 2.0-5.3 years). There was no significant difference in FADI (87 vs 91; P = .553), AOFAS (77 vs 82; P = .372), Lysholm score (83 vs 87; P = .110), Tegner activity scale (6 vs 4; P = .271), patient satisfaction (9 vs 10; P = .058), WOMAC (8 vs 5; P = .264), or Short Form-12 PCS (51.3 vs 54.6; P = .169) or MCS (54.8 vs 51.5; P = .239) score between the repair cohort and the reconstruction cohort, respectively. No patient in either cohort underwent revision lateral ligament surgery.

CONCLUSION

When compared with lateral ankle repair, anatomic allograft reconstruction produced similarly favorable outcomes, including high patient satisfaction, high function and activity levels, and no revision surgeries in either cohort.

Can Bassett's ligament be removed?

PURPOSE

To investigate the functional characteristics of Bassett's ligament in the ankle, focusing on mechanoreceptors and potential problems following resection of Bassett's ligament.

METHODS

Bassett's ligament, the anterior talofibular ligament (ATFL), and synovium were obtained from 20 ankles of 10 fresh-frozen cadavers. Histologically, mechanoreceptors were identified and classified as Ruffini (type I), Vater-Pacini (type II), Golgi-Mazzoni (type III) corpuscles, and free nerve endings (type IV). Differences in receptor densities were compared.

RESULTS

Type I clusters were observed with three to six ramifications; type II mechanoreceptors were encapsulated in clusters of two to four with ovoid or cylindrical shape; type III were amorphous, long and wide, and fusiform- or spindle-shaped; and type IV were long and fine without a defined shape. Differences in the densities of the mechanoreceptors inside three soft tissues (Bassett's ligament, ATFL, and synovium) were not significant.

CONCLUSION

There were no significant differences in the densities of the four types of mechanoreceptors among the soft tissues studied. In Bassett's ligament, type I mechanoreceptors were present at significantly higher densities than the other receptors.

Biomechanical stability of tape augmentation for anterior talofibular ligament (ATFL) repair compared to the native ATFL

PURPOSE

Current methods of anterior talofibular ligament (ATFL) reconstruction fail to restore the stability of the native ATFL. Therefore, augmented anatomic ATFL reconstruction gained popularity in patients with attenuated tissue and additional stress on the lateral ankle ligament complex. The aim of the present study was to evaluate the biomechanical stability of the InternalBrace (Arthrex Inc., Naples, FL, USA), a tape augmentation designed to augment the traditional Broström procedure.

METHODS

Twelve (12) fresh-frozen human anatomic lower leg specimens were randomized into two groups: a native ATFL (ATFL) and a tape augmentation group (IB). Dual-energy X-ray absorptiometry (DEXA) scans were carried out to determine bone mineral density (BMD) of the specimens. The ligaments were stressed by internally rotating the tibia against the inverted fixated hindfoot. Torque at failure (Nm) and angle at failure (°) were recorded.

RESULTS

The ATFL group failed at an angle of 33 ± 10°. In the IB group, construct failure occurred at an angle of 46 ± 16°. Failure torque reached 8.3 ± 4.5 Nm in the ATFL group, whereas the IB group achieved 11.2 ± 7.1 Nm. There was no correlation between angle at ATFL or IB construct failure or torque at failure, respectively, and BMD for both groups.

CONCLUSION

This study reveals that tape augmentation for ATFL reconstruction shows similar biomechanical stability compared to an intact native ATFL in terms of torque at failure and angle at failure. BMD did not influence the construct stability. Tape augmentation proved an enhanced initial stability in ATFL reconstruction which may allow for an accelerated rehabilitation process.

LEVEL OF EVIDENCE

II.

[Calcaneo-fibular ligament surgery for chronic lateral instability of the upper ankle : Broström technique with modification by Wille. Video article]

BACKGROUND

An acute ligament rupture of the lateral ligament complex of the ankle joint is treated without surgery. Treatment failure may lead to a chronically unstable situation of the ankle joint, in which case surgery is an effective procedure for stabilizing the ruptured ligaments. Anatomical reconstruction is the best operative technique if the ligament tissue is of good quality.

METHOD

In our video we demonstrate a new possibility for the positioning of an anchor to tighten the calcaneo-fibular ligament. Modified Broström repairs are described in the literature in which the calcaneo-fibular ligament is released and reattached to the fibula to tighten it. We present the option to release the ligament at the calcaneus and reattach it using a suture anchor. This offers the advantage of preventing the possible dislocation of the peroneal tendons.

Anatomical Reconstruction of Lateral Ankle Ligaments Using Free Tendon Allografts and Biotenodesis Screws

BACKGROUND

Lateral ankle instability is one of the most common musculoskeletal disorders and can result in ankle damage. This study reports on the results of the anatomical reconstruction of ligaments using semitendinosus tendon allograft and bioabsorbable tenodesis screws for chronic lateral ankle instability, as well as the functional and radiological results of this procedure.

METHODS

From February 2007 to January 2013, 70 patients (72 ankles) underwent this procedure. Six patients were lost to follow-up, and ultimately 64 patients (66 ankles) were evaluated. Visual Analog Scale (VAS) pain scores, American Orthopaedic Foot & Ankle Society (AOFAS) scores, Karlsson-Peterson ankle scores, and patient satisfaction were evaluated at a mean of 22.1 months (range, 12-68 months) postoperatively. The talar tilt angle and anterior translation were assessed radiographically in pre- and postoperative ankle stress views. The mean patient age at surgery was 30.1 years (range, 16-59 years).

RESULTS

The mean VAS pain score decreased from 5.5 to 1.3 (P < .05), and the mean AOFAS improved from 71.0 to 90.9 (P < .05). The mean Karlsson-Peterson score improved from 55.1 to 90.3, whereas talar tilt decreased from 14.8 degrees to 3.9 degrees. There was no significant difference in clinical outcomes between the pretensioned and nonpretensioned groups.

CONCLUSION

This procedure yielded successful results, including satisfactory ankle stability and clinical outcomes, in ankles with poor lateral ligament tissues.

LEVEL OF EVIDENCE

Level IV, case series.

Lateral Ankle Stabilization Using Acellular Human Dermal Allograft Augmentation

BACKGROUND

We describe a retrospective study that uses the Broström-type surgical procedure with modifications that augment deficient and torn ligaments with acellular human dermal grafts. At the onset of this study, the most prevalent dermal graft available to us was GraftJacket (Wright Medical Technology, Arlington, Tennessee). Greater than 50% of the study participants were grafted with this product, but more recently other equally effective human dermal grafts have been used with no apparent difference.

METHODS

Thirty-five lateral ankle stabilization procedures were performed in the past 6 years on 33 patients. Eight patients were considered athletes (mean age, 23 years). The balance of the study group consisted of sedentary patients (mean age, 41 years). The mean patient body mass index (calculated as the weight in kilograms divided by the square of the height in meters) was 31.

RESULTS

All of the patients were satisfied with their results, with no recurrent instability. Two patients in this group went on to have contralateral ankle stabilization in a similar manner owing to their satisfaction. Complications included two soft-tissue infections.

CONCLUSIONS

Lateral ankle stabilization using acellular human dermal graft augmentation is a useful tool in the surgical treatment of ankle instability. This procedure offers distinct advantages over traditional methods of ankle repair and can be performed with relatively limited surgical exposure. Ease of operation, consistent results, and limited patient morbidity should allow surgeons to use this procedure independently or adjunctively to improve surgical outcomes.

All-inside, anatomical lateral ankle stabilization for revision and complex primary lateral ankle stabilization: a technique guide

Lateral ankle instability is a common mechanical problem that often requires surgical management when conservative efforts fail. Historically, myriad open surgical approaches have been proposed. Recently, consideration for arthroscopic management of lateral ankle instability has become popular, with promising results. Unfortunately, recurrent inversion ankle injury following lateral ankle stabilization can occur and require revision surgery. To date, arthroscopic management for revision lateral ankle stabilization has not been described. We present a novel arthroscopic technique combining an arthroscopic lateral ankle stabilization kit with a suture anchor ligament augmentation system for revision as well as complex primary lateral ankle stabilization.

Management of chronic lateral ankle instability in military service members

Chronic lateral ankle instability is a condition frequently encountered by orthopedic surgeons treating highly active patient populations, particularly military service members. Providers treating military service members must have a high index of suspicion for this condition when signs and symptoms of functional or mechanical instability exist. Stress testing and ankle MRI, although not definitive in sensitivity for detecting instability or other concomitant injuries, should be considered during the treatment decision-making process. Appropriate nonoperative treatment should be attempted initially; however, when nonoperative treatment fails, surgical management is warranted to prevent untoward long-term sequelae. Proper surgical treatment and subsequent postoperative management are at the discretion of the individual surgeon but must account for the concomitant diseases frequently associated with chronic lateral ankle instability. Low recurrence of lateral instability can be achieved even in high-demand military patient populations with a focused treatment plan.

Examining the relation of osteochondral lesions of the talus to ligamentous and lateral ankle tendinous pathologic features: a comprehensive MRI review in an asymptomatic lateral ankle population

Given the frequency and burden of ankle sprains, the pathologic features identified on magnetic resonance imaging (MRI) scans are widely known in the symptomatic population. Ankle MRI pathologic features in the asymptomatic population, however, are poorly understood. Such examinations are rarely undertaken unless an ankle has been injured or is painful. We report the systematic MRI findings from the reports of 108 consecutive asymptomatic lateral ankles (104 patients). Our purpose was to (1) report the prevalence of osteochondral lesions of the talus (OLTs) and pathologic features of the medial and lateral ligaments, peroneal tendons, and superior peroneal retinaculum (SPR); (2) correlate the presence of OLTs with the pathologic features of the medial and lateral ligaments, peroneal tendons, and SPR; and (3) correlate ligamentous discontinuity with the peroneal pathologic features, OLTs, and SPR pathologic features. A total of 16 OLTs (14.81%) were present (13 medial and 3 lateral). Of the 16 patients with OLTs, 8 (50.00%) had concomitant peroneal pathologic findings. Healthy medial and lateral ligaments were noted in 41 patients (37.96%), and ligamentous discontinuity was grade I in 25 (23.15%), II in 32 (29.63%), III in 5 (4.63%), and grade IV in 5 patients (4.63%). A weak positive correlation was found between attenuation or tears of the superficial deltoid and medial OLTs (phi coefficient = 0.23, p = .0191) and a moderate positive correlation between tears of the posterior talofibular ligament and lateral OLTs (phi coefficient = 0.30, p = .0017). Additionally, a moderate positive correlation between ligamentous discontinuity and tendinopathy of the peroneus brevis was noted [Spearman's coefficient(106) = 0.29, p = .0024]. These findings add to the evidence of concomitant pathologic features in the asymptomatic population. To definitively assess causation and evaluate the clinical evolution of radiologic findings, future, prospective, longitudinal cohort studies are necessary.

Anterior talofibular ligament ruptures, part 2: biomechanical comparison of anterior talofibular ligament reconstruction using semitendinosus allografts with the intact ligament

BACKGROUND

Anatomic reconstructions of the lateral ankle ligaments with grafts have been proposed for patients with generalized ligamentous laxity, long-standing instability with attenuated native tissues, varus hindfoot misalignment, or failed prior lateral ligament surgery and for very large patients or elite athletes because of increased demands.

HYPOTHESIS

Anatomic reconstruction of the anterior talofibular ligament (ATFL) using a semitendinosus allograft fixed with biocomposite interference fit screws would have similar biomechanical properties to the intact ATFL at time zero in a cadaveric model.

STUDY DESIGN

Controlled laboratory study.

METHODS

Allograft reconstruction of the ATFL was performed in 6 fresh-frozen cadaveric ankles. The specimens were loaded to failure to determine the strength and stiffness of the reconstruction and compared with data from 6 cadaveric specimens with intact ATFLs.

RESULTS

The mean ultimate load to failure of the allograft reconstruction (170.7 ± 54.8 N) was not significantly different from that of the intact ATFL (154.0 ± 63.7 N). The mean stiffness of the allograft reconstruction (23.1 ± 9.3 N/mm) was also not significantly different from that of the intact ATFL (14.5 ± 4.4 N/mm).

CONCLUSION

Anatomic reconstruction of the ATFL with allografts demonstrated similar strength and stiffness to the native ligament at time zero in a fresh-frozen cadaveric model.

CLINICAL RELEVANCE

This technique of anatomic reconstruction of the ATFL with allografts has biomechanical validation for use in clinical situations where a Broström repair of the lateral ankle ligaments is unlikely to be successful or has previously failed.

Syndesmosis and lateral ankle sprains in the National Football League

Syndesmosis sprains in the National Football League (NFL) can be a persistent source of disability, especially compared with lateral ankle injuries. This study evaluated syndesmosis and lateral ankle sprains in NFL players to allow for better identification and management of these injuries. Syndesmosis and lateral ankle sprains from a single NFL team database were reviewed over a 15-year period, and 32 NFL team physicians completed a questionnaire detailing their management approach. A comparative analysis was performed analyzing several variables, including diagnosis, treatment methods, and time lost from sports participation. Thirty-six syndesmosis and 53 lateral ankle sprains occurred in the cohort of NFL players. The injury mechanism typically resulted from direct impact in the syndesmosis and torsion in the lateral ankle sprain group (P=.034). All players were managed nonoperatively. The mean time lost from participation was 15.4 days in the syndesmosis and 6.5 days in the lateral ankle sprain groups (P⩽.001). National Football League team physicians varied treatment for syndesmosis sprains depending on the category of diastasis but recommended nonoperative management for lateral ankle sprains. Syndesmosis sprains in the NFL can be a source of significant disability compared with lateral ankle sprains. Successful return to play with nonoperative management is frequently achieved for syndesmosis and lateral ankle sprains depending on injury severity. With modern treatment algorithms for syndesmosis sprains, more aggressive nonoperative treatment is advocated. Although the current study shows that syndesmosis injuries require longer rehabilitation periods when compared with lateral ankle sprains, the time lost from participation may not be as prolonged as previously reported.

Proximity of arthroscopic ankle stabilization procedures to surrounding structures: an anatomic study

PURPOSE

To examine the anatomy of the lateral ankle after arthroscopic repair of the lateral ligament complex (anterior talofibular ligament [ATFL] and calcaneofibular ligament [CFL]) with regard to structures at risk.

METHODS

Ten lower extremity cadaveric specimens were obtained and were screened for gross anatomic defects and pre-existing ankle laxity. The ATFL and CFL were sectioned from the fibula by an open technique. Standard anterolateral and anteromedial arthroscopy portals were made. An additional portal was created 2 cm distal to the anterolateral portal. The articular surface of the fibula was identified, and the ATFL and CFL were freed from the superficial and deeper tissues. Suture anchors were placed in the fibula at the ATFL and CFL origins and were used to repair the origin of the lateral collateral structures. The distance from the suture knot to several local anatomic structures was measured. Measurements were taken by 2 separate observers, and the results were averaged.

RESULTS

Several anatomic structures lie in close proximity to the ATFL and CFL sutures. The ATFL sutures entrapped 9 of 55 structures, and no anatomic structures were inadvertently entrapped by the CFL sutures. The proximity of the peroneus tertius and the extensor tendons to the ATFL makes them at highest risk of entrapment, but the proximity of the intermediate branch of the superficial peroneal nerve (when present) is a risk with significant morbidity.

CONCLUSIONS

Our results indicate that the peroneus tertius and extensor tendons have the highest risk for entrapment and show the smallest mean distances from the anchor knot to the identified structure. Careful attention to these structures, as well as the superficial peroneal nerve, is mandatory to prevent entrapment of tendons and nerves when one is attempting arthroscopic lateral ankle ligament reconstruction.

CLINICAL RELEVANCE

Defining the anatomic location and proximity of the intervening structures adjacent to the lateral ligament complex of the ankle may help clarify the anatomic safe zone through which arthroscopic repair of the lateral ligament complex can be safely performed.

Biomechanical analysis of Brostrom versus Brostrom-Gould lateral ankle instability repairs

BACKGROUND

The traditional Brostrom repair and the modified Brostrom-Gould repair are 2 historically reliable procedures used to address lateral ankle instability. The purpose of this study was to evaluate the biomechanical stability conferred by the Brostrom repair as compared to the Brostrom-Gould modification in an unstable cadaveric ankle model.

METHODS

A total of 10 cadaveric specimens were placed in a Telos ankle stress apparatus in an anterior-posterior position and then in a lateral position, while a 170 N load was applied to simulate anterior drawer (AD) and talar tilt (TT) tests, respectively. In both circumstances, the ankle was held in 15 degrees of plantarflexion, neutral, and 15 degrees of dorsiflexion, while the movement of the sensors was measured using a video motion analysis system. Measurement of the translation between the talus and tibia in the AD test and the angle between the tibia and talus in the TT test were calculated for specimens in the (1) intact, (2) sectioned (division of the ATFL and CFL), (3) Brostrom repair and (4) Gould modification states.

RESULTS

When compared to both the repaired states and the intact states, the sectioned state demonstrated increased inversion and translation at all ankle positions during TT and AD testing. Furthermore, no significant differences were found between the intact state and either of the repaired states. Finally, no difference in the biomechanical stability could be identified between the traditional Brostrom repair and the modified Brostrom-Gould procedure.

CONCLUSIONS

Our findings indicate that there is no significant biomechanical difference in initial ankle stability conferred by augmenting the traditional Brostrom repair with the Gould modification in this time-zero cadaveric model.

CLINICAL RELEVANCE

These data suggest that the additional reinforcement of an ankle's lateral ligament complex repair of the ankle with the inferior extensor retinaculum may be marginal at the time of surgery.

Surgical approach for combined ankle and subtalar joint chronic mechanical instability

Combined ankle and subtalar joint instability can lead to severe disability of the lower extremity. Multiple procedures have been described for hindfoot and ankle instability, including anatomic and non-anatomic reconstructions. The authors present their technique consisting of a free autogenous split peroneus longus tendon graft combined with a modified Brostrom-Gould repair.

Evaluation of a modified Broström-Gould procedure for treatment of chronic lateral ankle instability: A retrospective study with critical analysis of outcome scoring

BACKGROUND

Chronic lateral ankle instability accounts for 20% of the ankle injuries. This study evaluates functional outcome of the modified Broström-Gould technique using suture anchors, with 4 different clinical scores.

METHODS

A consecutive series of 41 patients were included with a minimum follow-up of one year. The function was assessed using 4 clinical scores including: the AOFAS for hind foot; the FAAM; the CAIT and the CAIS.

RESULTS

Out of 41 patients; 27 patients were very satisfied, 11 satisfied and 3 were not satisfied. Ankle mobility returned to normal in 93% of patients. At follow-up the AOFAS was 89/100 (37-100), the FAAM 85/100% (35-100%), the CAIT 20/30 (5-30), and the CAIS 74/100% (27-100%).

CONCLUSION

Outcome of modified Broström-Gould procedure is good with high satisfaction rate in terms of ankle mobility. The disparity in outcome of scores, signals towards the need of a standard evaluation system.

The varus ankle and instability

Varus ankle associated with instability can be simple or complex. Multiple underlying diseases may contribute to this complex pathologic entity. These conditions should be recognized when attempting proper decision-making. Treatment options range from conservative measures to surgical reconstruction. Whereas conservative treatment might be a possible approach for patients with simple varus ankle instability, more complex instabilities require extensive surgical reconstructions. However, adequate diagnostic workup and accurate analysis of varus ankle instability provide a base for the successful treatment outcome.

Percutaneous lateral ligament reconstruction with allograft for chronic lateral ankle instability

BACKGROUND

The majority of lateral ankle instability can be treated successfully with conservative method. However, if such treatments fail, surgical treatment should be considered. A wide variety of procedures have been introduced to treat chronic lateral ankle instability. The percutaneous method avoids dissection which is associated with open surgery and can lead to excessive morbidity. The purpose of this study was to evaluate the clinical and radiological outcomes of percutaneous lateral ligament reconstruction with an allograft in the treatment of chronic lateral ankle instability.

METHODS

Between October 2006 and April 2009, percutaneous lateral ligament reconstruction using an allograft was performed on 15 ankles in 13 patients for chronic lateral ankle instability. The patients included in this study satisfied at least one of the following criteria: a previously failed reconstruction of the ligament, severe ankle instability (more than 15 degrees of talar tilt, more than 10 mm of anterior drawer), general laxity of ligaments, body mass index (BMI) higher than 25. The mean followup period was 18.1 (range, 12 to 40) months. The grafted tendon was secured by double tenodeses at both the talus and calcaneus or triple tenodeses which included a fibular tenodesis. The clinical outcomes were evaluated with Visual Analogue Scale (VAS) for pain, Karlsson-Peterson ankle score, and patients' subjective satisfaction. The radiological results were evaluated using the varus tilting angle and the anterior displacement distance.

RESULTS

The VAS improved from preoperative 3.7 ±2.2 to 1.6 ±1.3 at the last followup (p = 0.002). The Karlsson-Peterson ankle score increased from 54.2 ±8.8 to 80.9 ±7.2 (p = 0.001). Patients were satisfied in 13 cases (86.7%) with excellent or good results. Radiologically, the mean varus tilting angle was 15.5 ±4.4 degrees preoperatively and 7.3 ±3.6 at the last followup (p = 0.001). The anterior drawer distance was 10.1 ±3.3 mm preoperatively and 7.2 ±2.7 mm at last followup (p = 0.001).

CONCLUSION

We believe percutaneous lateral ligament reconstruction with allograft to be a useful method as a salvage procedure for the treatment of severe and complicated types of chronic lateral ankle instability. Furthermore, the minimal invasiveness of this technique provides a good cosmetic outcome and we found it to be a technically easy and fast procedure.

Usefulness of oblique axial scan in magnetic resonance imaging evaluation of anterior talofibular ligament in ankle sprain

The purpose of the present study was to clarify the usefulness of the oblique axial scan parallel to the course of the anterior talofibular ligament in magnetic resonance imaging of the anterior talofibular ligament in patients with chronic ankle instability. We evaluated this anterior talofibular ligament view and routine axial magnetic resonance imaging planes of 115 ankles. We diagnosed the grade of the anterior talofibular ligament injury and confirmed full-length views of the anterior talofibular ligament. Associated lesions were also checked. The subjective diagnostic convenience of associated problems was determined. The full-length view of the anterior talofibular ligament was checked in 85 (73.9%) patients in the routine axial view and 112 (97.4%) patients in the anterior talofibular ligament view. The grade of injury increased in the anterior talofibular ligament view in 26 (22.6%) patients compared with the routine axial view. There were 64 associated injuries. The anterior inferior tibiofibular ligament, posterior inferior tibiofibular ligament, and posterior tibialis tendinitis were more easily diagnosed on the routine axial view than on the anterior talofibular ligament view. An additional anterior talofibular ligament view is useful in the evaluation of the anterior talofibular ligament in patients with chronic ankle instability.

Hemi-Castaing ligamentoplasty for the treatment of chronic lateral ankle instability: a retrospective assessment of outcome

PURPOSE

In the treatment of chronic ankle instability, most non-anatomical reconstructions use the peroneus brevis tendon. This, however, sacrifices the natural ankle stabilising properties of the peroneus brevis muscle. The aim of this study was to evaluate the functional outcome of patients treated with a hemi-Castaing procedure, which uses only half the peroneus brevis tendon.

METHODS

We performed a retrospective cohort study of patients who underwent hemi-Castaing ligamentoplasty for chronic lateral ankle instability between 1993 and 2010, with a minimum of one year follow-up. Patients were sent a postal questionnaire comprising five validated outcome measures: Olerud-Molander Ankle Score (OMAS), Karlsson Ankle Functional Score (KAFS), Tegner Activity Level Score (pre-injury, prior to surgery, at follow-up), visual analog scale on pain (VAS) and the Short Form 36 (SF-36).

RESULTS

Twenty patients completed the questionnaire on functional outcome. The OMAS showed good to excellent outcome in 80% and the KAFS in 65%, the Tegner Score improved from surgery but did not reach pre-injury levels, the VAS on pain was 1 of 10 and the SF-36 returned to normal compared with the average population.

CONCLUSIONS

Even though most patients were satisfied with the results, outcome at long-term follow-up was less favourable compared with the literature on anatomical reconstructions. In accordance with the literature, we therefore conclude that the initial surgical treatment of chronic lateral ankle instability should be an anatomical repair with augmentation (i.e. the Broström-Gould technique) and the non-anatomical repair should be reserved for unsuccessful cases after anatomical repair or in cases where no adequate ligament remnants are available for reconstruction.

Magnetic resonance imaging and incidental findings of lateral ankle pathologic features with asymptomatic ankles

We prospectively evaluated 102 magnetic resonance imaging (MRI) examinations in 100 patients with asymptomatic lateral ankles. The patients were undergoing MRI for other ankle pathologic features, including medial ankle, posterior ankle, soft tissue masses, or Achilles tendon pain. No patient had had a recent lateral ankle injury or any surgery. Whether the anterior talofibular ligament, calcaneofibular ligament, and peroneal tendons were intact, torn, or absent was recorded. The average patient age was 46.4 years. Of the 100 patients, 67 (66%) had no history of a lateral ankle sprain, and 35 (34%) had sustained 1 or more sprains in the remote past. Also, 72 had an intact anterior talofibular ligament (71%), 90 had an intact calcaneofibular ligament (89%), 67 had intact peroneus brevis tendons (66%), and 68 (67%) had intact peroneus longus tendons. One accessory peroneal tendon was noted. Approximately 30% of asymptomatic patients undergoing MRI had abnormal anterior talofibular ligaments and peronei. Because the published data show that functional rehabilitation is successful for 90% of symptomatic lateral ankle patients, caution is warranted if choosing surgical treatment on the basis of the MRI findings alone.

Clinical results and functional evaluation of the Chrisman-Snook procedure for lateral ankle instability in athletes

There is no consensus regarding optimum surgical treatment for chronic ankle instability. The purpose of this study is to describe a variation of the Chrisman-Snook lateral ligament reconstruction that the senior author uses in patients with chronic ankle instability recalcitrant to conservative management. All patients who underwent reconstruction from 1997 to 2006 were identified, and those with a minimum 2-year follow-up were included, representing a total of 44 ankles in 43 patients. All underwent clinical evaluation and completion of the Foot and Ankle Outcome Survey and the Kaikkonen Scale. At mean follow-up of 4.4 years, mean dorsiflexion loss was 2° compared with the nonoperative side. The postoperative mean Foot and Ankle Outcome Survey score was 74 ± 16 (range, 36-98), while the mean Kaikkonen total score was 77 ± 14 (range, 40-95). Thirty-eight patients (84.6%) were satisfied with their result. Six patients (13.6%) underwent reoperation, including 4 with peroneal tendon scarring requiring tenolysis. Return to sport was achieved in 28 of 35 patients (80%) at a median of 6 months postoperatively. It is concluded that dorsiflexion loss can be minimized and return to sport expected in most patients following this variation of the Chrisman-Snook reconstruction.

In vivo cartilage contact strains in patients with lateral ankle instability

Damage to the anterior talofibular ligament (ATFL) and cacaneofibular ligament (CFL) during an ankle sprain may be linked to the development of osteoarthritis. Although altered tibiotalar kinematics have been demonstrated, the effects of lateral ankle instability (LAI) on in vivo cartilage strains have not been described. We hypothesized that peak cartilage strains increase, and the location is shifted in patients with ATFL injuries. We used 3-D MRI models and biplanar fluoroscopy to evaluate in vivo cartilage contact strains in seven patients with unilateral LAI. Subjects had chronic unilateral ATFL injury or combined ATFL and CFL injury, and were evaluated with increasing load while stepping onto a force plate. Peak cartilage strain and the location of the peak strain were measured using the contralateral normal ankle as a control. Ankles with LAI demonstrated significantly increased peak strain when compared with ATFL-intact controls. For example, at 100% body weight, peak strain was 29+/-8% on the injured side compared to 21+/-5% on the intact side. The position of peak strain on the injured ankle also showed significant anterior translation and medial translation. At 100% body weight, the location of peak strain in the injured ankle translated anteriorly by 15.5+/-7.1mm and medially by 12.9+/-4.3mm relative to the intact ankle. These changes correspond to the region of clinically observed osteoarthritis. Chronic LAI, therefore, may contribute to the development of tibiotalar cartilage degeneration due to altered cartilage strains.

Chronic ankle and subtalar joint instability in the athlete

Chronic ankle and subtalar joint (STJ) instability is a common clinical entity and the physician must be able to determine the exact pathologic condition for proper treatment. There are many diagnostic techniques that can be used to evaluate the ankle joint and STJ. These diagnostic techniques do not take the place of a proper patient history taking. Appropriate and aggressive rehabilitation should be attempted in all cases of chronic ankle and subtalar instability before electing surgical reconstruction.

Evaluation of arthrometer for ankle instability: a cadaveric study

BACKGROUND

Stress tests are used to diagnose both acute and chronic lateral ankle instability. Commonly used stress tests require radiography and their reliability and sensitivity is still under debate. We developed a non radiographic ankle arthrometer to objectively assess mechanical ankle stability. This device was validated against stress radiographs in a cadaver investigation.

MATERIALS AND METHODS

Nine cadaver specimens were tested under: 0, 15, and 30 degrees ankle plantarflexion and 50 N, 100 N, 150 N, and 200 N anterior drawer load application. First, intact specimens were tested. Then the anterior talofibular ligament, calcaneofibular ligament and posterior talofibular ligament were sequentially cut. Anterior drawer displacement was analyzed simultaneously by a displacement transducer and by radiographic measurement. Stiffness was calculated as the linear increment of the load deformation curve. Results of a commercially available stress testing device served as a standard.

RESULTS

Stable and unstable ankles were differentiated by ankle arthrometer displacement and stiffness analyses (p = 0.012 and 0.003) with the arthrometer adjusted to 0 degrees of plantarflexion and 50 N anterior drawer load application. Standardized stress testing device and ankle arthrometer stress radiographic measurements correlated significantly (p = 0.000 to 0.027). Transducer measured anterior drawer instability was highly sensitive (96.3%), while specificity was 44.4%. Setting a cut off value of 4.5 N/mm, the stiffness analyses discriminated stable and unstable ankles with a sensitivity of 91.7% while the specificity was 62.5%.

CONCLUSION

The ankle arthrometer was able to measure anterior subluxation of the talus in relation to the tibia in a cadaver experiment. The procedure is non-radiographic and highly sensitive in differentiating unstable from stable ankles.

CLINICAL RELEVANCE

Availablity of a nonradiographic device to measure ankle instability could improve diagnostic accuracy and facilitate decision making in patients with chronic ankle instability.

Management of acute and chronic ankle instability

Acute lateral ankle ligament injuries are common. If left untreated, they can result in chronic instability. Nonsurgical measures, including functional rehabilitation, are the management methods of choice for acute injuries, with surgical intervention reserved for high-demand athletes. Chronic lateral ankle instability is multifactorial. Failed nonsurgical management after appropriate rehabilitation is an indication for surgery. Of the many surgical options available, anatomic repair of the anterior talofibular and calcaneofibular ligaments is recommended when the quality of the ruptured ligaments permits. Anatomic reconstruction with autograft or allograft should be performed when the ruptured ligaments are attenuated. Ankle arthroscopy is an important adjunct to ligamentous repair and should be performed at the time of repair to identify and address intra-articular conditions associated with chronic ankle instability. Tenodesis procedures are not recommended because they may disturb ankle and hindfoot biomechanics.

Microfracture for osteochondral lesions of the ankle: outcome analysis and outcome predictors of 105 cases

PURPOSE

The purpose of this study was to identify outcomes and outcome predictors of arthroscopic debridement with osteochondral bone stimulation (microfracture) for osteochondral lesions of the ankle.

METHODS

One hundred five consecutive patients with osteochondral lesions of the ankle who underwent ankle arthroscopy with microfracture were prospectively followed up for a mean of 31.6 +/- 12.1 months. Study patients were evaluated at 6 weeks, 3 months, 6 months, 12 months, and annually after surgery. Assessments via a visual analog scale for pain during daily activities and sport activity, the Roles and Maudsley score, and the American Orthopaedic Foot & Ankle Society ankle and hindfoot scoring system were obtained at each visit. Outcome predictors were analyzed by logistic regression model.

RESULTS

There were no failures of treatment with lesions smaller than 15 mm. In contrast, only 1 patient met the criteria for success in the group of lesions greater than 15 mm. Statistical analysis revealed that increasing age, higher body mass index, history of trauma, and presence of osteophytes negatively affected outcome. The presence of instability and the presence of anterolateral soft-tissue scar were correlated with a successful outcome.

CONCLUSIONS

This study found a strong correlation between lesion size and success across its entire population. For lesions smaller than 15 mm, regardless of location, excellent results were obtained. In addition, increasing age, higher body mass index, history of trauma, and presence of osteophytes negatively affect outcome. The presence of instability and anterolateral soft-tissue scar correlated with a successful outcome.

LEVEL OF EVIDENCE

Level IV, prognostic case series, prognostic study.