In vivo cartilage contact strains in patients with lateral ankle instability

Analysis of stress response distribution in patients with lateral ankle ligament injuries: a study of neural control strategies utilizing predictive computing models

Background

Ankle sprains are prevalent in sports, often causing complex injuries to the lateral ligaments. Among these, anterior talofibular ligament (ATFL) injuries constitute 85%, and calcaneofibular ligament (CFL) injuries comprise 35%. Despite conservative treatment, some ankle sprain patients develop chronic lateral ankle instability (CLAI). Thus, this study aimed to investigate stress response and neural control alterations during landing in lateral ankle ligament injury patients.

Method

This study recruited twenty individuals from a Healthy group and twenty CLAI patients performed a landing task using relevant instruments to collect biomechanical data. The study constructed a finite element (FE) foot model to examine stress responses in the presence of laxity of the lateral ankle ligaments. The lateral ankle ligament was modeled as a hyperelastic composite structure with a refined representation of collagen bundles and ligament laxity was simulated by adjusting material parameters. Finally, the validity of the finite element model is verified by a high-speed dual fluoroscopic imaging system (DFIS).

Result

CLAI patients exhibited earlier Vastus medialis (p < 0.001) and tibialis anterior (p < 0.001) muscle activation during landing. The FE analysis revealed that with laxity in the ATFL, the peak von Mises stress in the fifth metatarsal was 20.74 MPa, while with laxity in the CFL, it was 17.52 MPa. However, when both ligaments were relaxed simultaneously, the peak von Mises stress surged to 21.93 MPa. When the ATFL exhibits laxity, the CFL is subjected to a higher stress of 3.84 MPa. Conversely, when the CFL displays laxity, the ATFL experiences a peak von Mises stress of 2.34 MPa.

Conclusion

This study found that changes in the laxity of the ATFL and the CFL are linked to shifts in metatarsal stress levels, potentially affecting ankle joint stability. These alterations may contribute to the progression towards CLAI in individuals with posterolateral ankle ligament injuries. Additionally, significant muscle activation pattern changes were observed in CLAI patients, suggesting altered neural control strategies post-ankle ligament injury.

Evaluation of Open Versus Arthroscopic Anterior Talofibular Ligament Reconstruction for Chronic Lateral Ankle Instability With Talar and Subtalar Cartilage MRI T2 Mapping: A 3-Year Prospective Study

BACKGROUND

Previous studies have examined patients with chronic lateral ankle instability (CLAI) undergoing open and arthroscopic anterior talofibular ligament (ATFL) reconstruction, reporting equivalent clinical results between the 2 procedures. However, data on the magnetic resonance imaging (MRI) outcomes on cartilage health after the 2 procedures are limited.

PURPOSE

To compare the cartilage MRI T2 values of the talar and subtalar joints between patients with CLAI undergoing open and arthroscopic ATFL reconstruction.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

A prospective study was conducted on patients who underwent open or arthroscopic ATFL reconstruction between January 2018 and December 2019, with a mean follow-up duration of 3 years. MRI scans and American Orthopaedic Foot & Ankle Society (AOFAS) and Tegner score estimations were completed by patients ≤1 week before surgery, as a baseline measurement, and at a 3-year follow-up. A total of 21 healthy volunteers were included who underwent MRI at baseline. Cartilage health was evaluated using MRI T2 mapping. The talar and subtalar cartilage regions were segmented into 14 subregions.

RESULTS

At baseline, patients with CLAI had substantially higher T2 values in the medial anterior, medial center, medial posterior, and lateral center regions on the talus compared with the healthy controls (P = .009, .003, .001, and .025, respectively). Remarkable increases in T2 values in the lateral posterior region on the talus were observed from baseline to follow-up in the open group (P = .007). Furthermore, T2 values were considerably higher in the medial center, medial posterior, lateral posterior, and lateral posterior calcaneal facets of the posterior subtalar joint at follow-up in the arthroscopic group compared with the baseline values (P = .025, .002, .006, and .044, respectively). No obvious differences in ΔT2 values were noted between the 2 groups at follow-up. The AOFAS and Tegner scores remarkably improved from baseline to follow-up for the 2 groups (open: 3.25 ± 0.58 vs 5.13 ± 0.81, P < .001; arthroscopic: 3.11 ± 0.90 vs 5.11 ± 1.08, P < .001), with no considerable difference between them.

CONCLUSION

The elevated T2 values of cartilage could not be fully recovered after open or arthroscopic ATFL reconstruction. Both arthroscopic and open ATFL reconstruction displayed similar effects on cartilage health concerning ΔT2, but the arthroscopic group demonstrated more degenerative cartilage subregions than the open group.

Chronic lateral ankle ligament instability - Current evidence and recent management advances

Lateral ankle sprain is a common injury with a substantial negative impact on physical function, quality of life and health economic burden. Chronic lateral ankle instability (CLAI) as a sequela of lateral ankle sprain can lead to the development of posttraumatic ankle osteoarthritis in the long term. In this article, we explore the epidemiology, burden and definition of CLAI for the appropriate clinical assessment and imaging evaluation of patients with lateral ankle sprain and CLAI. Following that, recent advances and evidence on management of CLAI is critically distilled and summarized.

Three-dimensional ankle kinematics of the full gait cycle in patients with chronic ankle instability: A case-control study

Objectives

The ankle kinematic characteristics of chronic ankle instability (CAI) at different gait phases and dimensions were not directly and overall explained. These characteristics have yet to be established. This study aimed to observe ankle kinematic changes of CAI, and explore their mechanisms, at different gait phases and dimensions in full gait cycle.

Methods

A three-dimensional (3D) motion capture system measured the 3D ankle movements of 53 individuals with CAI (meanage = 25.11 ± 6.01years, meanheight = 170.77 ± 7.80 cm, meanmass = 64.28 ± 9.28 kg) and 53 healthy controls (meanage = 24.66 ± 6.32 years, meanheight = 169.98 ± 9.00 cm, meanmass = 63.11 ± 9.62 kg) during barefoot walking overground at a self-selected speed. Once the acquisition results were processed with visual 3D software, the kinematics data were exported, and the eight phases of the gait cycle were identified.

Results

As compared with the control group, individuals with CAI displayed a significantly smaller plantarflexion in toe off (P = 0.049, Cohen's d = 0.387), a significantly increased inversion in heel strike (P = 0.007, Cohen's d = 0.271) and initial swing (P = 0.035, Cohen's d = 0.233), mid-swing (P = 0.019, Cohen's d = 0.232) and end-swing (P = 0.021, Cohen's d = 0.214), and significantly smaller eversion in mid stance（P = 0.010, Cohen's d = 0.288）and heel off (P = 0.033, Cohen's d = 0.089). Significant between-group differences in ankle kinematics were observed in the sagittal and frontal planes, but not in the horizontal plane, during walking.

Conclusion

When walking, patients with CAI have altered sagittal- and frontal-plane kinematics during different stance and swing phases. These kinematic changes require multi-dimensional, dynamic, continuous functional assessment and specialized rehabilitation intervention.

Ability to return to sports after early lateral ligament repair of the ankle in 147 elite athletes

PURPOSE

The literature on elite athletes' ability to return to sports (RTS) after early lateral ligament repair of the ankle remains inadequate. The time needed to RTS after modified Broström repair for acute grade III lateral ligament injuries in a large cohort of elite athletes was evaluated while assessing the impact of other associated injuries.

METHODS

Prospective data from 147 elite athletes who underwent a primary lateral ligament repair for acute grade III injuries with clinical ankle instability from 2015 to 2019 with a minimum of 2-year follow-up were reviewed. Pertinent details such as characteristics of injury, time taken to RTS, impact of associated injuries on RTS and complications were recorded and analysed.

RESULTS

The average age was 24.4 years (S.D = 4.9) with 89.1% males. Approximately two-thirds of the elite athletes were football players (66.0%) and 21.1% were rugby players. Isolated lateral ligament complex injuries were sustained by 122 (83%) patients, while 25 (17%) had associated injuries (osteochondral lesions of the talus/deltoid injury/syndesmosis injury). All 147 athletes returned to their preinjury level of sports with a median time of 69 days (range 58-132 days). There was no significant difference found in time to RTS between gender, age, and types of sports. However, there was a statistically significant difference noted in the time taken to RTS earlier in patients with isolated lateral ligament injuries when compared to those with associated injuries (68.6 vs. 82.8 days; p = 0.004). Multiple conditional linear regression yielded three independent predictors of longer time taken to RTS which were associated deltoid injury (7.5 days longer; 95% CI 2.9-12.3; p = 0.002), associated syndesmosis injury (6.7 days longer; 95% CI 0.5-12.8; p = 0.034) and associated OLT (30.3 days longer; 95% CI 25.1-35.5; p = 0.000).

CONCLUSION

Early surgical repair for acute grade III lateral ligament injuries in elite athletes yielded excellent rate of RTS at 9-10 weeks and a re-injury rate of 2%. Concomitant injuries will delay RTS after surgical intervention. These findings serve as important guide to managing elite athletes following acute rupture of the lateral ligament complex.

LEVEL OF EVIDENCE

Level III.

In vivo evaluation of ankle kinematics and tibiotalar joint contact strains using digital volume correlation and 3 T clinical MRI

BACKGROUND

In vivo evaluation of ankle joint biomechanics is key to investigating the effect of injuries on the mechanics of the joint and evaluating the effectiveness of treatments. The objectives of this study were to 1) investigate the kinematics and contact strains of the ankle joint and 2) to investigate the correlation between the tibiotalar joint contact strains and the prevalence of osteochondral lesions of the talus distribution.

METHODS

Eight healthy human ankle joints were subjected to compressive load and 3 T MRIs were obtained before and after applying load. The MR images in combination with digital volume correlation enabled non-invasive measurement of ankle joint kinematics and tibiotalar joint contact strains in three dimensions.

FINDINGS

The total translation of the calcaneus was smaller (0.48 ± 0.15 mm, p < 0.05) than the distal tibia (0.93 ± 0.16 mm) and the talus (1.03 ± 0.26 mm). These movements can produce compressive and shear joint contact strains (approaching 9%), which can cause development of lesions on joints. 87.5% of peak tensile, compressive, and shear strains in the tibiotalar joint took place in the medial and lateral zones.

INTERPRETATION

The findings suggested that ankle bones translate independently from each other, and in some cases in opposite directions. These findings help explain the distribution of osteochondral lesions of the talus which have previously been observed to be in medial and lateral regions of the talar dome in 90% of cases. They also provide a reason for the central region of talar dome being less susceptible to developing osteochondral lesions.

The Superficial Peroneal Nerve Is at Risk during the "All Inside" Arthroscopic Broström Procedure: A Cadaveric Study

Background: The arthroscopic Broström procedure is a promising treatment for chronic ankle instability. However, little is known regarding the location of the intermediate superficial peroneal nerve at the level of the inferior extensor retinaculum; knowledge about this location is important for procedural safety. The purpose of this cadaveric study was to clarify the anatomical relationship between the intermediate superficial peroneal nerve and the sural nerve at the level of the inferior extensor retinaculum. Methods: Eleven dissections of cadaveric lower extremities were performed. The origin of the experimental three-dimensional axis was defined as the location of the anterolateral portal during ankle arthroscopy. The distances from the standard anterolateral portal to the inferior extensor retinaculum, sural nerve, and intermediate superficial peroneal nerve were measured using an electronic digital caliper. The location of inferior extensor retinaculum, the tract of sural nerve, and intermediate superficial peroneal nerve were checked using average and standard deviations. For the statistical analyses, data are presented as average ± standard deviation, and then they are reported as means and standard deviations. Fisher's exact test was used to identify statistically significant differences. Results: At the level of the inferior extensor retinaculum, the mean distances from the anterolateral portal to the proximal and distal intermediate superficial peroneal nerve were 15.9 ± 4.1 (range, 11.3-23.0) mm and 30.1 ± 5.5 (range, 20.8-37.9) mm, respectively. The mean distances from the anterolateral portal to the proximal and distal sural nerve were 47.6 ± 5.7 (range, 37.4-57.2) mm and 47.2 ± 4.1 (range, 41.0-51.8) mm), respectively. Conclusions: During the arthroscopic Broström procedure, the intermediate superficial peroneal nerve may be damaged by the anterolateral portal; the proximal and distal parts of the intermediate superficial peroneal nerve were located within 15.9 and 30.1 mm, respectively, at the level of the inferior extensor retinaculum in cadavers. These areas should be considered danger zones during the arthroscopic Broström procedure.

The Burden of the "Simple Ankle Sprains": A Review of the Epidemiology and Long-Term Impact

Lateral ankle sprain (LAS) is not as simple as it was believed to be as it has substantial negative impacts on the active sporting population. The negative impact on physical function, quality of life (QoL) and economic burden is significant with increased risk of reinjury, development of chronic lateral ankle instability and posttraumatic ankle osteoarthritis resulting in functional deficits, decreased QoL and chronic disabilities. Economic burden from a societal perspective demonstrated notably higher indirect costs from productivity loss. Preventative interventions with early surgery for a selective cohort of active sporting population may be considered to mitigate morbidities associated with LAS.

Effects of foot intensive rehabilitation (FIRE) on clinical outcomes for patients with chronic ankle instability: a randomized controlled trial protocol

BACKGROUND

Lateral ankle sprains account for a large proportion of musculoskeletal injuries among civilians and military service members, with up to 40% of patients developing chronic ankle instability (CAI). Although foot function is compromised in patients with CAI, these impairments are not routinely addressed by current standard of care (SOC) rehabilitation protocols, potentially limiting their effectiveness. The purpose of this randomized controlled trial is to determine if a Foot Intensive REhabilitation (FIRE) protocol is more effective compared to SOC rehabilitation for patients with CAI.

METHODS

This study will use a three-site, single-blind, randomized controlled trial design with data collected over four data collection points (baseline and post-intervention with 6-, 12-, and 24-month follow-ups) to assess variables related to recurrent injury, sensorimotor function, and self-reported function. A total of 150 CAI patients (50 per site) will be randomly assigned to one of two rehabilitation groups (FIRE or SOC). Rehabilitation will consist of a 6-week intervention composed of supervised and home exercises. Patients assigned to SOC will complete exercises focused on ankle strengthening, balance training, and range of motion, while patients assigned to FIRE will complete a modified SOC program along with additional exercises focused on intrinsic foot muscle activation, dynamic foot stability, and plantar cutaneous stimulation.

DISCUSSION

The overall goal of this trial is to compare the effectiveness of a FIRE program versus a SOC program on near- and long-term functional outcomes in patients with CAI. We hypothesize the FIRE program will reduce the occurrence of future ankle sprains and ankle giving way episodes while creating clinically relevant improvements in sensorimotor function and self-reported disability beyond the SOC program alone. This study will also provide longitudinal outcome findings for both FIRE and SOC for up to two years. Enhancing the current SOC for CAI will improve the ability of rehabilitation to reduce subsequent ankle injuries, diminish CAI-related impairments, and improve patient-oriented measures of health, which are critical for the immediate and long-term health of civilians and service members with this condition. Trial Registration Clinicaltrials.gov Registry: NCT #NCT04493645 (7/29/20).

Mechanical and Sensorimotor Outcomes Associated With Talar Cartilage Deformation After Static Loading in Those With Chronic Ankle Instability

CONTEXT

Those with chronic ankle instability (CAI) demonstrate deleterious changes in talar cartilage composition, resulting in alterations of talar cartilage loading behavior. Common impairments associated with CAI may play a role in cartilage behavior in response to mechanical loading.

OBJECTIVE

To identify mechanical and sensorimotor outcomes that are linked with the magnitude of talar cartilage deformation after a static loading protocol in patients with and those without CAI.

DESIGN

Cross-sectional study.

SETTING

Laboratory setting.

PATIENTS OR OTHER PARTICIPANTS

Thirty individuals with CAI and 30 healthy individuals.

MAIN OUTCOME MEASURES(S)

After a 60-minute off-loading period, ultrasonographic images of the talar cartilage were acquired immediately before and after a 2-minute static loading protocol (single-legged stance). Talar cartilage images were obtained and manually segmented to enable calculation of medial, lateral, and overall average talar thickness. The percentage change, relative to the average baseline thickness, was used for further analysis. Mechanical (ankle joint laxity) and sensorimotor (static balance and Star Excursion Balance Test) outcomes were captured. Partial correlations were computed to determine associations between cartilage deformation magnitude and the mechanical and sensorimotor outcomes after accounting for body weight.

RESULTS

In the CAI group, greater inversion laxity was associated with greater overall (r = -0.42, P = .03) and medial (r = -0.48, P = .01) talar cartilage deformation after a 2-minute static loading protocol. Similarly, poorer medial-lateral static balance was linked with greater overall (r = 0.47, P = .01) and lateral (r = 0.50, P = .01) talar cartilage deformation. In the control group, shorter posterolateral Star Excursion Balance Test reach distance was associated with greater lateral cartilage deformation (r = 0.42, P = .03). No other significant associations were observed.

CONCLUSIONS

In those with CAI, inversion laxity and poor static postural control were moderately associated with greater talar cartilage deformation after a 2-minute static loading protocol. These results suggest that targeting mechanical instability and poor balance in those with CAI via intervention strategies may improve how the talar cartilage responds to static loading conditions.

Acetabular labrum and cartilage contact mechanics during pivoting and walking tasks in individuals with cam femoroacetabular impingement syndrome

Femoroacetabular impingement syndrome (FAIS) is a motion-related pathology of the hip characterized by pain, morphological abnormalities of the proximal femur, and an elevated risk of joint deterioration and hip osteoarthritis. Activities that require deep flexion are understood to induce impingement in cam FAIS patients, however, less demanding activities such as walking and pivoting may induce pain as well as alterations in kinematics and joint stability. Still, the paucity of quantitative descriptions of cam FAIS has hindered understanding underlying hip joint mechanics during such activities. Previous in silico studies have employed generalized model geometry or kinematics to simulate impingement between the femur and acetabulum, which may not accurately capture the interplay between morphology and motion. In this study, we utilized models with participant-specific bone and articular soft tissue anatomy and kinematics measured by dual-fluoroscopy to compare hip contact mechanics of cam FAIS patients to controls during four activities of daily living (internal/external pivoting and level/incline walking). Averaged across the gait cycle during incline walking, patients displayed increased strain in the anterior joint (labrum strain: p-value = 0.038, patients: 11.7 ± 6.7 %, controls: 5.0 ± 3.6 %; cartilage strain: p-value = 0.029, patients: 9.1 ± 3.3 %, controls: 4.2 ± 2.3). Patients also exhibited increased average anterior cartilage strains during external pivoting (p-value = 0.039; patients: 13.0 ± 9.2 %, controls: 3.9 ± 3.2 %]). No significant differences between patient and control contact area and strain were found for level walking and internal pivoting. Our study provides new insights into the biomechanics of cam FAIS, including spatiotemporal hip joint contact mechanics during activities of daily living.

Surgical management of concurrent lateral ankle instability and osteochondral lesions of the talus increases dynamic sagittal ankle range of motion

PURPOSE

A biomechanical study, in which imaging modalities are used to strictly include patients with concurrent lateral ankle instability (LAI) and osteochondral lesions of the talus (OLT), is needed to demonstrate the static and dynamic ankle range of motion (ROM) restriction in these patients, and determine whether ankle ROM restriction can be corrected postoperatively.

METHODS

Eight patients with concurrent LAI and OLT treated with the arthroscopic modified Broström procedure and microfracture were recruited from June 2019 to January 2020. Patients were assessed using outcome scales, static ankle ROM, and a stair descent gait analysis for dynamic ankle ROM, a day prior to surgery and one year postoperatively. Eight healthy subjects were assessed using the same modalities upon recruitment. Operative outcomes and variables during stair descent were documented and compared among the preoperative, postoperative, and healthy groups. A curve analysis, one-dimensional statistical parametric mapping, was performed to compare the dynamic ankle kinematics and muscle activation curves over the entire normalised time series.

RESULTS

The functional outcomes of patients with concurrent LAI and OLT were significantly worse than those of healthy subjects preoperatively, but were partially improved postoperatively. Patients had decreased static and dynamic ROM preoperatively, and static ROM did not significantly increase postoperatively (preoperative, 39.6 ± 11.3; postoperative, 44.9 ± 7.1; healthy, 52.0 ± 4.6; p = 0.021). Patients showed increased dynamic ankle flexion ROM (preoperative, 41.2 ± 11.6; postoperative, 53.6 ± 9.0; healthy, 53.9 ± 3.4; p = 0.012) postoperatively, as well as increased peroneus longus activation (preoperative, 35.8 ± 12.0; postoperative, 55.4 ± 25.1; healthy, 71.9 ± 13.4; p = 0.002) and muscle co-contraction of the tibialis anterior and peroneus longus (preoperative, 69.4 ± 23.4; postoperative, 88.4 ± 9.3; healthy, 66.2 ± 18.1; p = 0.045).

CONCLUSIONS

Patients with concurrent LAI and OLT had decreased static and dynamic sagittal ankle ROM and altered neuromuscular activation patterns. The arthroscopic modified Broström procedure and microfracture did not significantly increase the static sagittal ankle ROM. However, the dynamic sagittal ankle ROM, peroneus longus activation and muscle co-contraction of the tibialis anterior and peroneus longus increased postoperatively.

LEVEL OF EVIDENCE

IV.

15% of Talar Osteochondral Lesions Are Present Bilaterally While Only 1 in 3 Bilateral Lesions Are Bilaterally Symptomatic

BACKGROUND

The primary aim of the present study was to determine the prevalence of osteochondral lesions of the contralateral talus in patients with computed tomography (CT)-confirmed osteochondral lesions of the talus (OLT). The secondary aims were to determine if the contralateral lesions were symptomatic and to describe the demographic characteristics and radiographic presentation of patients with bilateral OLT.

METHODS

To identify patients with bilateral OLT, we utilized a cross-sectional database of consecutive patients with a CT-proven OLT who had undergone bilateral CT scanning at our hospital between January 1989 and June 2021. The primary outcome was the prevalence of bilateral OLT. Patients with bilateral OLT were grouped into a unilaterally symptomatic group and a bilaterally symptomatic group. Patient and lesion characteristics were compared between these groups as well as between the symptomatic and asymptomatic ankles in the unilaterally symptomatic group. Radiographic examination included lesion volume, location, and morphology.

RESULTS

Of 1,062 patients with OLT, 161 (15%) had bilateral OLT. Of the patients with bilateral OLT, 53 (33%) were bilaterally symptomatic. Patients who were bilaterally symptomatic were younger (p = 0.03) and more likely to present with a non-traumatic etiology (p < 0.01) in comparison with those who were unilaterally symptomatic. No differences were observed between the unilaterally and bilaterally symptomatic groups in terms of lesion morphology, volume, or location. In the unilaterally symptomatic group, lesion volume was significantly larger in symptomatic ankles in comparison with the contralateral, asymptomatic ankles (p < 0.01), but no significant differences were observed in terms of lesion morphology or location.

CONCLUSIONS

In patients presenting with symptomatic OLT, the prevalence of bilateral OLT was 15%, and 1 in 3 patients with bilateral OLT were symptomatic on both sides. Larger lesion volume was associated with the presence of symptoms in patients with bilateral OLT. For patients with bilateral OLT, the treating team should be aware that younger patients and patients without a history of trauma are at a higher risk for having bilateral symptoms.

LEVEL OF EVIDENCE

Prognostic Level III . See Instructions for Authors for a complete description of levels of evidence.

Lower limb kinematics during single leg landing in three directions in individuals with chronic ankle instability

OBJECTIVES

To compare the lower limb kinematics of participants with chronic ankle instability (CAI) and healthy participants during forward, lateral, and medial landings.

DESIGN

Cross-sectional study.

SETTING

Laboratory.

PARTICIPANTS

Eighteen athletes with CAI and 18 control athletes.

MAIN OUTCOME MEASURES

Hip, knee, and ankle joint kinematics during forward, lateral, and medial single-leg landings were compared between the groups using two-way ANOVA for discrete values and statistical parametric mapping two-sample t-tests for time-series data.

RESULTS

The CAI group had significantly greater ankle dorsiflexion than the control group (P ≤ 0.013), which was observed from the pre-initial contact (IC) for lateral and medial landings and post-IC for forward landing. The CAI group showed greater knee flexion than the control group from the IC for lateral landing and post-IC for forward landing (P ≤ 0.014). No significant differences in ankle inversion kinematics were found between the CAI and control groups. Lateral landing had a greater peak inversion angle and velocity than forward and medial landings (P < 0.001). Medial landing had a greater inversion velocity than forward landing (P < 0.001).

CONCLUSIONS

This study suggests that individuals with CAI show feedforward protective adaptations in the pre-landing phase for lateral and medial landings.

Concomitant osteochondral lesions of the talus affect the stair descent biomechanics of patients with chronic ankle instability: A pilot study

BACKGROUND

Previous studies on the kinematics of patients with chronic ankle instability (CAI) that did not incorporate MRI and arthroscopic assessment could not differentiate between patients with CAI without osteochondral lesion of the talus (OLT) and patients with CAI and OLT and have thus presented contradictory results.

RESEARCH QUESTION

This study aimed to investigate the kinematic and electromyographic differences between patients with and without OLT.

METHODS

Sixteen subjects with CAI (eight without OLT and eight with OLT confirmed through MRI and arthroscopic assessment) and eight healthy subjects underwent gait analysis in a stair descent setting. The three groups' patient-reported outcomes; ankle joint range of motion in flexion, inversion and rotation; and muscle activation of the peroneus, tibialis anterior, and gastrocnemius during a gait cycle were analyzed and compared. A curve analysis, namely, one-dimensional statistical parametric mapping, was performed to compare the dynamic ankle kinematics and muscle activation curves over the entire normalized time series.

RESULTS

The patients with and without OLT had no difference in patient-reported outcomes. The maximal ankle plantarflexion of the patients without OLT and the healthy subjects was significantly larger than that of patients with OLT (p = 0.005). The maximal ankle internal rotation of patients without OLT was significantly larger than that of patients with OLT (p = 0.048). The peroneal activation during 0-6% of the gait cycle of patients with OLT was reduced compared with the healthy subjects.

SIGNIFICANCE

Patients with CAI and OLT and patients with CAI without OLT have no difference in patient-reported outcomes, but patients with OLT can be differentiated using the post-initial-contact peroneal activation deficit and the restriction of ankle plantarflexion and internal rotation during stair descent. These variables can be utilized to monitor the function of patients with CAI and their possibility of developing OLT.

Dorsiflexion and Hop Biomechanics Associate with Greater Talar Cartilage Deformation in Those with Chronic Ankle Instability

PURPOSE

This study aimed to identify associations between dorsiflexion range of motion (DFROM), functional hop test performance, and hopping biomechanics with the magnitude of talar cartilage deformation after a standardized hopping protocol in individuals with and without chronic ankle instability (CAI).

METHODS

Thirty CAI and 30 healthy individuals participated. Ankle DFROM was assessed using the weight-bearing lunge test. Four different functional hop tests were assessed. Three-dimensional kinematics and kinetics were sampled during a 60-cm single-leg hop. We calculated cartilage deformation after a dynamic loading protocol consisting of sixty 60-cm single-leg forward hops by assessing the change in average thickness for the overall, medial, and lateral talar cartilage. Linear regressions examined the associations between cartilage deformation magnitude and DFROM, functional hop tests, and hop biomechanical variables after accounting for body weight and time since the initial ankle sprain.

RESULTS

In CAI group, lesser static DFROM (ΔR2 = 0.22) and smaller peak ankle dorsiflexion angle (ΔR2 = 0.17) was associated with greater medial deformation. Greater peak vertical ground reaction force (vGRF) (ΔR2 = 0.26-0.28) was associated with greater medial and overall deformation. Greater vGRF loading rate (ΔR2 = 0.23-0.35) was associated with greater lateral and overall deformation. Greater side hop test times (ΔR2 = 0.31-0.36) and ankle plantarflexion at initial contact (ΔR2 = 0.23-0.38) were associated with greater medial, lateral, and overall deformation. In the control group, lesser side hop test times (ΔR2 = 0.14), greater crossover hop distances (ΔR2 = 0.14), and greater single-hop distances (ΔR2 = 0.21) were associated with greater overall deformation.

CONCLUSIONS

Our results indicate that lesser static DFROM, poorer functional hop test performance, and hop biomechanics associate with greater talar cartilage deformation after a dynamic loading protocol in those with CAI. These factors may represent targets for therapeutic interventions within this population to slow ankle posttraumatic osteoarthritis progression.

Incidence of (Osteo)Chondral Lesions of the Ankle in Isolated Syndesmotic Injuries: A Systematic Review and Meta-Analysis

OBJECTIVE

To determine and compare the incidence rate of (osteo)chondral lesions of the ankle in patients with acute and chronic isolated syndesmotic injuries.

DESIGN

A literature search was conducted in the PubMed (MEDLINE) and EMBASE (Ovid) databases from 2000 to September 2021. Two authors independently screened the search results, and risk of bias was assessed using the MINORS (Methodological Index for Non-Randomized Studies) criteria. Studies on acute and chronic isolated syndesmotic injuries with pre-operative or intra-operative imaging were included. The primary outcome was the incidence rate with corresponding 95% confidence intervals (CIs) of (osteo)chondral lesions of the ankle in combined and separate groups of acute and chronic syndesmotic injuries. Secondary outcomes were anatomic distribution and mean size of the (osteo)chondral lesions.

RESULTS

Nine articles (402 syndesmotic injuries) were included in the final analysis. Overall (osteo)chondral lesion incidence was 20.7% (95% CI: 13.7%-29.9%). This rate was 22.0% (95% CI: 17.1-27.7) and 24.1% (95% CI: 15.6-35.2) for acute and chronic syndesmotic injuries, respectively. In the combined acute and chronic syndesmotic injury group, 95.4% of the lesions were located on the talar dome and 4.5% of the lesions were located on the distal tibia. (Osteo)chondral lesion size was not reported in any of the studies.

CONCLUSIONS

This meta-analysis shows that (osteo)chondral lesions of the ankle are present in 21% of the patients with isolated syndesmotic injuries. No difference in incidence rate was found between the different syndesmotic injury types and it can be concluded that the majority of lesions are located on the talar dome.

PROSPERO REGISTRATION NUMBER

CRD42020176641.

Effects of gait training with auditory biofeedback on biomechanics and talar cartilage characteristics in individuals with chronic ankle instability: A randomized controlled trial

BACKGROUND

Altered walking gait is a typical impairment following ankle sprains which may increase susceptibility to recurring injuries and development of posttraumatic osteoarthritis at the ankle. There is a lack of targeted gait training interventions focusing on specific modifications in individuals with chronic ankle instability (CAI). Additionally, there is a need to focus on cartilage health changes following gait training to mitigate osteoarthritis progression.

RESEARCH QUESTION

To determine the immediate and retention effects of gait training using auditory biofeedback (AudFB) in patients with chronic ankle instability (CAI) on biomechanics and talar cartilage characteristics.

METHODS

Eighteen participants with CAI were randomly assigned into Control (n = 7) or AudFB (n = 11) groups. Each group completed 8-sessions of 30-minute treadmill walking. The AudFB group received biofeedback through a pressure sensor fashioned to the lateral foot and instructions to walk while avoiding noise from the sensor. The Control group did not receive instructions during sessions. An in-shoe insole system measured peak pressure, maximum force, and center of the pressure gait line (COP) during walking. Ultrasonography captured talar cartilage thickness and echo intensity before and after walking. Biomechanics and ultrasound were measured at baseline, immediately, and 1-week after the intervention. Repeated measures mixed-methods analysis of variance assessed changes within groups across time.

RESULTS

The AudFB group significantly reduced pressure and force in the lateral foot and medially shifted their COP at Immediate and 1-week Post. There were no observed changes in the Control group. In addition, neither group demonstrated changes in ultrasound measures at follow-up.

SIGNIFICANCE

Implementation of auditory biofeedback during gait training can be a valuable tool for clinicians treating patients with CAI.

Gait Biomechanics and Balance Associate with Talar and Subtalar T1ρ Relaxation Times in Those with Chronic Ankle Instability

PURPOSE

This study aimed to determine associations between T1ρ relaxation times of talar and subtalar articular cartilage and commonly altered gait biomechanics and postural control outcomes in those with chronic ankle instability (CAI).

METHODS

Fifteen individuals with CAI (21.13 ± 1.81 yr) completed a T1ρ magnetic resonance imaging as well as a postural control and an overground gait assessment. Talocrural and subtalar cartilage was segmented manually to calculate T1ρ relaxation times. Greater T1ρ relaxation times were interpreted as decreased proteoglycan content. Pearson product-moment bivariate correlations examined the relationships between T1ρ relaxation times and the gait biomechanics and postural control outcomes.

RESULTS

Across multiple variables, worse postural control demonstrated moderate to strong associations (range, 0.433-0.642 and -0.713) with greater talar T1ρ relaxation times. At the subtalar joint, greater T1ρ relaxation times were associated with lower peak vertical ground reaction forces, lower average vertical ground reaction force loading rates, and lower peak loading rates (range, -0.438 to -0.622). At the talar dome, greater talar T1ρ relaxation times were associated with increased knee extensor moments (r = 0.457), as well as greater knee flexion (r = 0.482) and knee adduction (r = 0.407) at initial contact. Larger step spatiotemporal gait parameters also associated with greater talar and subtalar T1ρ relaxation times (range, 0.434-0.697).

CONCLUSIONS

In individuals with CAI, worse postural control and altered kinematic, kinetic, and spatiotemporal outcomes demonstrate moderate to strong associations with greater talar T1ρ and/or subtalar relaxation times (i.e., less proteoglycan content). Associations between modifiable neuromechanical variables and greater T1ρ relaxation times may represent potential therapeutic interventions to mitigate ankle joint degeneration in those with CAI.

Plantar pressure profile during walking is associated with talar cartilage characteristics in individuals with chronic ankle instability

BACKGROUND

Individuals with chronic ankle instability typically present with abnormal gait patterns favoring the lateral foot. This gait pattern may alter cartilage stress potentially increasing the risk of osteoarthritis development, thus exploring this relationship may provide insights for early interventions. The purpose of this study was to examine the relationship gait biomechanics and talar articular cartilage characteristics.

METHODS

Talar articular cartilage was assessed with ultrasound at rest and after walking for 30-min in twenty-five adults (14 females, 22.6 ± 3.12 years, 168.12 ± 9.83 cm, 76.00 ± 15.47 kg) with chronic ankle instability. Cartilage was segmented into Total, Medial, and Lateral regions. During the 30-min walking period, plantar pressure of the entire foot was recorded every 5-min and condensed to create a biomechanical loading pattern and center of pressure gait line. Relationships between resting cartilage thickness and echo intensity, changes in thickness and echo intensity, and plantar pressure profiles were assessed with correlation coefficients.

FINDINGS

There was a significant relationship between plantar pressure in the lateral forefoot and medial talar cartilage deformation (r = 0.408, p < .05). Early stance center of pressure was correlated with deformation in the total (r = 0.439-0.524) and lateral (r = 0.443-0.550) regions (p < .05). There were no significant correlations between echo intensity and biomechanics.

INTERPRETATION

This study contributes to the growing evidence that talar cartilage strain patterns are associated with biomechanics during walking. Further validation is needed to determine a causal relationship between biomechanics and ultrasound cartilage characteristics after ankle sprains. In addition, research should continue determining the utility of ultrasound to monitor joint health after musculoskeletal injuries.

One in Three Patients With Chronic Lateral Ankle Instability Has a Cartilage Lesion

BACKGROUND

Chronic lateral ankle instability (CLAI) is associated with the presence or development of intra-articular pathologies such as chondral or osteochondral lesions, or (O)CLs. Currently, the incidence of (O)CLs in patients with CLAI is unknown.

PURPOSE

To determine the incidence of (O)CLs in patients with CLAI.

STUDY DESIGN

Systematic review and meta-analysis; Level of evidence, 4.

METHODS

A literature search was conducted in the PubMed (MEDLINE), Embase (Ovid), and Cochrane databases for articles published from January 2000 until December 2020. Two authors independently screened the search results and conducted the quality assessment using the methodological index for non-randomized studies (MINORS) criteria. Clinical studies were included that reported findings on the presence of ankle (O)CLs based on pre- or intraoperative diagnostic measures in patients with CLAI (>6 months of symptoms). Patient and lesion characteristics were pooled using a simplified method. Lesion characteristics included localization and chondral and osteochondral involvement. The primary outcome was the incidence of (O)CLs in ankles with CLAI. A random-effects model with 95% CIs was used to analyze the primary outcome. The distribution of (O)CLs in the ankle joint was reported according to talar or tibial involvement, with medial and lateral divisions for talar involvement.

RESULTS

Twelve studies were included with 2145 patients and 2170 ankles with CLAI. The pooled incidence of (O)CLs in ankles with CLAI was 32.2% (95% CI, 22.7%-41.7%). Among all lesions, 43% were chondral and 57% were osteochondral. Among all (O)CLs, 85% were located on the talus and 17% on the distal tibia. Of the talar (O)CLs, 68% were located medially and 32% laterally.

CONCLUSION

(O)CLs were found in up to 32% of ankles with CLAI. The most common location was the talus (85%). Furthermore, most lesions were located on the medial talar dome (68%). These findings will aid physicians in the early recognition and treatment of ankle (O)CLs in the context of CLAI.

The Immediate Carryover Effects of Peroneal Functional Electrical Stimulation Differ between People with and without Chronic Ankle Instability

Chronic ankle instability (CAI) is a common condition that may develop after an ankle sprain. Compared with healthy individuals, those with CAI demonstrate excessive ankle inversion and increased peroneal electromyography (EMG) activity throughout the stance phase of gait, which may put them at greater risk for re-injury. Functional electrical stimulation (FES) of targeted muscles may provide benefits as a treatment modality to stimulate immediate adaptation of the neuromuscular system. The present study investigated the effect of a single, 10 min peroneal FES session on ankle kinematics and peroneal EMG activity in individuals with (n = 24) or without (n = 24) CAI. There were no significant differences in ankle kinematics between the groups before the intervention. However, after the intervention, healthy controls demonstrated significantly less ankle inversion between 0-9% (p = 0.009) and 82-87% (p = 0.011) of the stance phase. Furthermore, a significant within-group difference was observed only in the control group, demonstrating increased ankle eversion between 0-7% (p = 0.011) and 67-81% (p = 0.006) of the stance phase after the intervention. Peroneal EMG activity did not differ between groups or measurements. These findings, which demonstrate that peroneal FES can induce ankle kinematics adaptations during gait, can help to develop future interventions for people with CAI.

Energy dissipation during single-leg landing from three heights in individuals with and without chronic ankle instability

Inadequate energy dissipation during landing may increase the risk of ankle sprain. Mechanical demands (landing height) in landing tasks may affect the biomechanical differences between individuals with and without chronic ankle instability (CAI). However, energy dissipation strategies during landing from various heights in individuals with CAI are unclear. The purpose of this study was to compare the effect of landing height on lower extremity biomechanics between individuals with and without CAI. Eleven participants in each of the CAI and Control group performed a single-leg landing from three heights (30, 40, and 50 cm). We calculated the contribution of each joint to total energy dissipation at 50-ms intervals during 0-200 ms post-initial contact (IC). Peak joint angles and moments and joint stiffnesses were calculated during 0-200 ms post-IC. Two-way mixed analysis of variance revealed significant group-by-height interactions for hip energy dissipation at 101-150 ms post-IC and peak ankle plantarflexion and hip extension moment. These significant interactions suggested that the effects of landing height on the ankle and hip joints differ between individuals with and without CAI. The effect of mechanical demands on altered landing biomechanics among CAI populations should be considered in biomechanical studies and clinical practice.

Accuracy of MRI-Based Talar Cartilage Thickness Measurement and Talus Bone and Cartilage Modeling: Comparison with Ground-Truth Laser Scan Measurements

OBJECTIVE

The purpose of this work was to compare measurements of talar cartilage thickness and cartilage and bone surface geometry from clinically feasible magnetic resonance imaging (MRI) against high-accuracy laser scan models. Measurement of talar bone and cartilage geometry from MRI would provide useful information for evaluating cartilage changes, selecting osteochondral graft sources or creating patient-specific joint models.

DESIGN

Three-dimensional (3D) bone and cartilage models of 7 cadaver tali were created using (1) manual segmentation of high-resolution volumetric sequence 3T MR images and (2) laser scans. Talar cartilage thickness was compared between the laser scan- and MRI-based models for the dorsal, medial, and lateral surfaces. The laser scan- and MRI-based cartilage and bone surface models were compared using model-to-model distance.

RESULTS

Average cartilage thickness within the dorsal, medial, and lateral surfaces were 0.89 to 1.05 mm measured with laser scanning, and 1.10 to 1.22 mm measured with MRI. MRI-based thickness was 0.16 to 0.32 mm higher on average in each region. The average absolute surface-to-surface differences between laser scan- and MRI-based bone and cartilage models ranged from 0.16 to 0.22 mm for bone (MRI bone models smaller than laser scan models) and 0.35 to 0.38 mm for cartilage (MRI bone models larger than laser scan models).

CONCLUSIONS

This study demonstrated that cartilage and bone 3D modeling and measurement of average cartilage thickness on the dorsal, medial, and lateral talar surfaces using MRI were feasible and provided similar model geometry and thickness values to ground-truth laser scan-based measurements.

Effects of solvent osmolarity and viscosity on cartilage energy dissipation under high-frequency loading

Articular cartilage is a spatially heterogeneous, dissipative biological hydrogel with a high fluid volume fraction. Although energy dissipation is important in the context of delaying cartilage damage, the dynamic behavior of articular cartilage equilibrated in media of varied osmolarity and viscosity is not widely understood. This study investigated the mechanical behaviors of cartilage when equilibrated to media of varying osmolarity and viscosity. Dynamic moduli and phase shift were measured at both low (1 Hz) and high (75-300 Hz) frequency, with cartilage samples compressed to varied offset strain levels. Increasing solution osmolarity and viscosity both independently resulted in larger energy dissipation and decreased dynamic modulus of cartilage at both low and high frequency. Mechanical property alterations induced by varying osmolarity are likely due to the change in permeability and fluid volume fraction within the tissue. The effects of solution viscosity are likely due to frictional interactions at the solid-fluid interface, affecting energy dissipation. These findings highlight the significance of interstitial fluid on the energy dissipation capabilities of the tissue, which can influence the onset of cartilage damage.

Joint Stabilization Surgery for Chronic Ankle Instability and Medial Ankle Osteoarthritis: A Critically Appraised Topic

Clinical Scenario: Patients with chronic ankle instability (CAI) who require surgical intervention are often diagnosed with medial ankle osteoarthritis (OA). Lateral joint stabilization procedures are commonly performed among this patient population to restore bony alignment and improve cartilage loading patterns to increase patient-reported function and mitigate further degenerative changes. Focused Clinical Question: What is the available evidence to support joint stabilization procedures on patient-reported outcomes and progression of radiographic OA among patients with CAI who have medial ankle OA? Summary of Key Findings: An electronic search of relevant databases was performed to identify peer-reviewed articles examining preoperative and postoperative clinical outcomes and radiographic evidence of ankle OA. A total of 3 peer-reviewed articles were retrieved. All 3 articles employed a retrospective case series study design. All 3 articles demonstrated improved patient-reported outcomes at the final follow-up visit. Two articles demonstrated that between 11% and 27% of patients progressed in at least 1stage of radiographic ankle OA between the preoperative assessment and the final follow-up visit (40-56 mo). Clinical Bottom Line: Joint stabilization surgery for patients with CAI and medial ankle OA is associated with improved clinical outcomes and a low rate of worsening radiographic joint degeneration within the first 5 years. Strength of Recommendation: Consistent evidence exists across all 3 articles. However, this evidence is based on a low-quality study design. Therefore, there is a grade-C level of evidence to support joint stabilization for improving patient-reported and radiographic outcomes within the first 5 years after surgery for patients with CAI and medial ankle OA.

Decreasing the Abnormal Internally Rotated Talus After Lateral Ankle Stabilization Surgery

Background

Increased internal rotation of the talus has been found in patients with mechanical ankle instability (MAI).

Purpose/Hypothesis

To evaluate and compare the talar rotation position before and after lateral ankle lateral stabilization surgery in patients with MAI. We hypothesized that the abnormal internal talus rotation in patients with MAI will decrease after surgery for ankle lateral instability and that there will be no significant difference in internal talus rotation between the ligament repair and reconstruction groups.

Study Design

Case-control study; Level of evidence, 3.

Methods

We retrospectively studied 56 patients with MAI who underwent ankle lateral stabilization surgery after arthroscopic evaluation (repair, 36 cases; reconstruction, 20 cases). Before and after the operation, magnetic resonance images of all the participants were reviewed. The rotated position of the talus was measured and calculated by the Malleolar Talus Index at the magnetic resonance axial plane.

Results

The internal rotation of the talus decreased significantly after ankle lateral stabilization surgery in patients with MAI as compared with before surgery (mean ± SD, 83.3° ± 3.3° vs 86.7° ± 3.9°; P < .01). However, there was no statistically significant difference between the ligament repair and reconstruction groups before or after the operation.

Conclusion

Abnormal internal rotation of the talus in patients with MAI was decreased after ankle lateral stabilization surgery.

Abnormalities of foot and ankle alignment in individuals with chronic ankle instability: a systematic review

Background

To prevent recurrent ankle sprain, it is important to clarify the pathology of chronic ankle instability (CAI). An association has been reported between CAI and abnormalities of foot posture and ankle alignment. There is no consensus on the types of these abnormalities that occur in individuals with CAI. The objective of this systematic review is to clarify the relevance of abnormality of foot posture and ankle alignment for CAI.

Methods

A systematic computerized literature search was performed of the PubMed, CINAHL, SPORTDiscus, Web of Science, and the Cochrane Register of Clinical Trials databases. The selected studies either compared CAI patients with a control group or CAI ankles with contralateral healthy ankles and specifically reported foot posture and alignment of the ankle in the outcomes. They were written in English and published prior to June 2021. The methodological quality of the included studies was evaluated using a 16-question index. Data were extracted independently by two reviewers, and the certainty of evidence was assessed using GRADE approach.

Results

Sixteen studies including 872 patients of high to low methodological quality were included. These showed there was significant anterior displacement and internal rotation of the talus in CAI ankles (low evidence), but there was no consensus on fibular alignment or foot posture.

Conclusions

This review showed there was significant anterior displacement and internal rotation of the talus in CAI ankles but found no consensus on the characteristics of fibular and foot alignment. Further investigations are required to clarify the characteristic foot and ankle malalignment in CAI to facilitate the development of efficient interventions.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12891-021-04537-6.

In Vivo Foot and Ankle Kinematics During Activities Measured by Using a Dual Fluoroscopic Imaging System: A Narrative Review

Foot and ankle joints are complicated anatomical structures that combine the tibiotalar and subtalar joints. They play an extremely important role in walking, running, jumping and other dynamic activities of the human body. The in vivo kinematic analysis of the foot and ankle helps deeply understand the movement characteristics of these structures, as well as identify abnormal joint movements and treat related diseases. However, the technical deficiencies of traditional medical imaging methods limit studies on in vivo foot and ankle biomechanics. During the last decade, the dual fluoroscopic imaging system (DFIS) has enabled the accurate and noninvasive measurements of the dynamic and static activities in the joints of the body. Thus, this method can be utilised to quantify the movement in the single bones of the foot and ankle and analyse different morphological joints and complex bone positions and movement patterns within these organs. Moreover, it has been widely used in the field of image diagnosis and clinical biomechanics evaluation. The integration of existing single DFIS studies has great methodological reference value for future research on the foot and ankle. Therefore, this review evaluated existing studies that applied DFIS to measure the in vivo kinematics of the foot and ankle during various activities in healthy and pathologic populations. The difference between DFIS and traditional biomechanical measurement methods was shown. The advantages and shortcomings of DFIS in practical application were further elucidated, and effective theoretical support and constructive research direction for future studies on the human foot and ankle were provided.

Cartilage Matrix Changes in Hindfoot Joints in Chronic Ankle Instability Patients After Anatomic Repair Using T2-Mapping: Initial Experience With 3-Year Follow-Up

BACKGROUND

Anatomic repair is widely accepted as the primary surgical treatment for chronic lateral ankle instability (CLAI). T2-mapping is a powerful tool for quantitative assessment of biochemical changes in cartilage matrix.

PURPOSE

To longitudinally evaluate cartilage matrix changes in the hindfoot joints of CLAI patients before and after anatomic repair by using T2-mapping with magnetic resonance imaging (MRI).

STUDY TYPE

Prospective.

SUBJECTS

Thirty-two CLAI patients (males/females = 20/12) and 21 healthy controls (males/females = 13/7).

FIELD STRENGTH/SEQUENCE

3 T; sagittal multi-echo spin-echo technique (T2-mapping), coronal, sagittal, and axial spin-echo PD-FS, and sagittal T1WI sequences.

ASSESSMENT

MRI examinations were performed in CLAI patients at baseline (prior to surgery) and 3 years after anatomic repair and in healthy controls. On T2-maps, the hindfoot joints were segmented into 16 cartilage subregions. The T2 value of each subregion was measured. All patients were evaluated with the American Orthopedic Foot and Ankle Society (AOFAS) scale at baseline and after surgery.

STATISTICAL TESTS

Analysis of variance (ANOVA) and Student's t-test were used. The differences corresponding to P < 0.05 were considered statistically significant.

RESULTS

At baseline, the T2 values in most cartilage subregions of talar dome and medial posterior subtalar joint (pSTJ) were higher in CLAI patients than in healthy controls. After surgery, only the T2 value of anteriomedial talar dome decreased from that at baseline (31.11 ± 3.88 msec vs. 34.27 ± 5.30 msec). The T2 values of other subregions with elevated T2 values remained higher than healthy controls. There were no significant differences in T2 values in the midtarsal joints between CLAI patients and healthy controls (P = 0.262, 0.104, 0.169, 0.103). Postoperatively, the patients' AOFAS scores improved significantly from 67.81 to 89.13.

DATA CONCLUSION

CLAI patients exhibited elevated T2 values in most subregions of talar dome and medial pSTJ. After anatomic repair, although the patients exhibited good clinical outcomes, the elevated T2 values could not be fully recovered.

LEVEL OF EVIDENCE

2 TECHNICAL EFFICACY STAGE: 4.

Acute Talar Cartilage Deformation in Those with and without Chronic Ankle Instability

PURPOSE

This study aimed 1) to determine whether talar cartilage deformation measured via ultrasonography (US) after standing and hopping loading protocols differs between chronic ankle instability (CAI) patients and healthy controls and 2) to determine whether the US measurement of cartilage deformation reflects viscoelasticity between standing and hopping protocols.

METHODS

A total of 30 CAI and 30 controls participated. After a 60-min off-loading period, US images of the talar cartilage were acquired before and after static (2-min single-leg standing) and dynamic (60 single-leg forward hops) loading conditions. We calculated cartilage deformation by assessing the change in average thickness (mm) for overall, medial, and lateral talar cartilage. The independent variables include time (Pre60 and postloading), condition (standing and dynamic loading), and group (CAI and control). A three-way mixed-model repeated-measures ANCOVA and appropriate post hoc tests were used to compare cartilage deformation between the groups after static and dynamic loading.

RESULTS

After the static loading condition, those with CAI had greater talar cartilage deformation compared with healthy individuals for overall (-10.87% vs -6.84%, P = 0.032) and medial (-12.98% vs -5.80%, P = 0.006) talar cartilage. Similarly, the CAI group had greater deformation relative to the control group for overall (-8.59% vs -3.46%, P = 0.038) and medial (-8.51% vs -3.31%, P = 0.043) talar cartilage after the dynamic loading condition. In the combined cohort, cartilage deformation was greater after static loading compared with dynamic in overall (-8.85% vs -6.03%, P = 0.003), medial (-9.38% vs -5.91%, P = 0.043), and lateral (-7.90% vs -5.65%, P = 0.009) cartilage.

CONCLUSION

US is capable of detecting differences in cartilage deformation between those with CAI and uninjured controls after standardized physiologic loads. Across both groups, our results demonstrate that static loading results in greater cartilage deformation compared with dynamic loading.

Biomechanical Response to External Biofeedback During Functional Tasks in Individuals With Chronic Ankle Instability

CONTEXT

Altered biomechanics displayed by individuals with chronic ankle instability (CAI) is a possible cause of recurring injuries and posttraumatic osteoarthritis. Current interventions are unable to modify aberrant biomechanics, leading to research efforts to determine if real-time external biofeedback can result in changes.

OBJECTIVE

To determine the real-time effects of visual and auditory biofeedback on functional-task biomechanics in individuals with CAI.

DESIGN

Crossover study.

SETTING

Laboratory.

PATIENTS OR OTHER PARTICIPANTS

Nineteen physically active adults with CAI (7 men, 12 women; age = 23.95 ± 5.52 years, height = 168.87 ± 6.94 cm, mass = 74.74 ± 15.41 kg).

INTERVENTION(S)

Participants randomly performed single-limb static balance, step downs, lateral hops, and forward lunges during a baseline and 2 biofeedback conditions. Visual biofeedback was given through a crossline laser secured to the dorsum of the foot. Auditory biofeedback was given through a pressure sensor placed under the lateral foot and connected to a buzzer that elicited a noise when pressure exceeded the set threshold. Cues provided during the biofeedback conditions were used to promote proper biomechanics during each task.

MAIN OUTCOME MEASURE(S)

We measured the location of center-of-pressure (COP) data points during balance with eyes open and eyes closed for each condition. Plantar pressure in the lateral column of the foot during functional tasks was extracted. Secondary outcomes of interest were COP area and velocity, time to boundary during static balance, and additional plantar-pressure measures.

RESULTS

Both biofeedback conditions reduced COP in the anterolateral quadrant while increasing COP in the posteromedial quadrant of the foot during eyes-open balance. Visual biofeedback increased lateral heel pressure and the lateral heel and midfoot pressure-time integral during hops. The auditory condition produced similar changes during the eyes-closed trials. Auditory biofeedback increased heel pressure during step downs and decreased the lateral forefoot pressure-time integral during lunges.

CONCLUSIONS

Real-time improvements in balance strategies were observed during both external biofeedback conditions. Visual and auditory biofeedback appeared to effectively moderate different functional-task biomechanics.

Lateral Ankle Sprains and Their Association with Physical Function in Young Soccer Players

Purpose

Lateral ankle sprain (LAS) in childhood can result in lateral malleolus avulsion fractures; additionally, bone nonunion may occur. Physical maturity relates to the development of bone morphology and physical functionality. It is unknown how changes in physical functionality attributable to physical maturity affect young soccer players with abnormal lateral malleolus (ALM) morphology. Hence, the present study aimed to investigate the bone morphology of the lateral malleolus in young soccer players and to examine its relationship with physical functionality at different maturity levels.

Subjects and Methods

Two hundred and ninety young soccer players aged 6–15 years were included. The presence of ALM was assessed using ultrasonography. The subjects were allocated to three groups based on physical maturity (Pre-, Mid-, and Post-peak height velocity age [PHVA]). The prevalence of ALM and the relationship between ALM and physical maturity were examined for body composition, foot pressure distribution, foot alignment, ankle mobility, and single-leg balance.

Results

The prevalence of ALM was 17.6%. For physical maturity, the post-PHVA group showed a decrease in ankle dorsiflexion and eversion and an increase in one-leg hop distance compared to the Pre-PHVA group (P < 0.05). In the ALM group, the center of pressure during heel raising was distributed laterally in the Post-PHVA (P < 0.01), and the weight-bearing dorsiflexion angle was decreased in the Mid- and Post-PHVA (P < 0.05).

Conclusion

In the Post-PHVA young soccer players, decreased ankle dorsiflexion and eversion and increased one-leg hop distance were observed. The ALM group exhibited lateral loading during heel raising in the Post-PHVA group and decreased weight-bearing ankle dorsiflexion angle in the Mid- and Post-PHVA groups. The findings indicate the importance of secondary prevention of LAS and ultrasonography. Prospective studies of LAS in young athletes are required in the future.

An Investigation Into Former High School Athletes' Experiences of a Multidisciplinary Approach to Sport Injury Rehabilitation

CONTEXT

A multidisciplinary approach is one of the many forms of professional practice that can be utilized by sports medicine professionals to provide care to injured athletes. While this approach has been empirically supported in the health care domain, studies supporting its utilization in the sport injury rehabilitation context-particularly at the high school level-are limited.

OBJECTIVE

To investigate former high school athletes' experiences of a multidisciplinary model of care for sport injury rehabilitation.

DESIGN

Cross-sectional survey design.

SETTING

In-person, in a classroom setting at 2 Division I universities.

PATIENTS

A total of 186 former high school athletes.

MAIN OUTCOME MEASURE

An author-constructed instrument developed using the multidisciplinary model of care for sport injury rehabilitation as a guide.

RESULTS

Family, athletic coaches, and athletic trainers were the closest professionals/individuals that injured athletes reported interacting with during sport injury rehabilitation. The data also revealed that these professionals/individuals had the closest and most direct relationships with the injured athletes.

CONCLUSIONS

The findings from the present study provided support for the utilization of the multidisciplinary model of care for sport injury rehabilitation with high school athletes.

Contact patterns in the ankle joint after lateral ligamentous injury during internal rotation: A computational study

Lateral ankle instability, resulting from the inability of ankle ligaments to heal after injury, is believed to cause a change in the articular contact mechanics that may promote cartilage degeneration. Considering that lateral ligaments' insufficiency has been related to rotational instability of the talus, and that few studies have addressed the contact mechanics under this condition, the aim of this work was to evaluate if a purely rotational ankle instability could cause non-physiological changes in contact pressures in the ankle joint cartilages using the finite element method. A finite element model of a healthy ankle joint, including bones, cartilages and nine ligaments, was developed. Pure internal talus rotations of 3.67°, 9.6° and 13.43°, measured experimentally for three ligamentous configurations, were applied. The ligamentous configurations consisted in a healthy condition, an injured condition in which the anterior talofibular ligament was cut, and an injured condition in which the anterior talofibular and calcaneofibular ligaments were cut. For all simulations, the contact areas and maximum contact pressures were evaluated for each cartilage. The results showed not only an increase of the maximum contact pressures in the ankle cartilages, but also novel contact regions at the anteromedial and posterolateral sections of the talar cartilage with increasing internal rotation. The anteromedial and posterolateral contact regions observed due to pathological internal rotations of the talus are a computational evidence that supports the link between a pure rotational instability and the pattern of pathological cartilaginous load seen in patients with long-term lateral chronic ankle instability.

Risk Factors for Osteochondral Lesions and Osteophytes in Chronic Lateral Ankle Instability: A Case Series of 1169 Patients

Background:

Osteochondral lesions (OCLs) and bony impingement are common secondary lesions of chronic lateral ankle instability (CLAI), but the risk factors that predict OCLs and bony impingement are unknown.

Purpose:

To analyze the risk factors for the development of OCLs and osteophytes in patients with CLAI.

Study Design:

Case-control study; Level of evidence, 3.

Methods:

Patients diagnosed with CLAI at our institution from June 2007 to May 2018 were enrolled. The assessed potential risk factors were age, sex, postinjury duration, body mass index, injury side, and ligament injury type (isolated anterior talofibular ligament [ATFL] injury, isolated calcaneofibular ligament [CFL] injury, or concomitant ATFL and CFL injuries). Univariate and multivariate logistic regression analyses were performed to evaluate the association between these factors and the presence of OCLs and osteophytes.

Results:

A total of 1169 patients with CLAI were included; 436 patients (37%) had OCLs and 334 (31%) had osteophytes. The presence of OCLs was significantly associated with the presence of osteophytes (P < .001). Male sex and older age were significantly associated with the presence of OCLs in the medial and lateral talus. A postinjury duration of 5 years or longer was significantly associated with the presence of OCLs in the medial talus (odds ratio [OR], 1.532; 95% CI, 1.023-2.293; P = .038) but not in the lateral talus. ATFL and CFL injuries were both significantly associated with the presence of lateral OCLs. Risk factors for the presence of osteophytes were male sex, older age, postinjury duration 5 years or longer, and CFL injury. Patients with concomitant ATFL and CFL injuries were significantly more likely to have osteophytes than were patients with single-ligament injuries (P = .018).

Conclusion:

Risk factors for OCLs and osteophytes were postinjury duration of 5 years or longer, older age, and male sex. ATFL injury was associated with the presence of lateral OCLs, whereas CFL injury was associated with the presence of lateral OCLs and osteophytes. Patients with these risk factors should be closely monitored and treated to reduce the incidence of ankle arthritis.

Decreased perceived ankle and knee joint health in individuals with perceived chronic ankle instability

PURPOSE

Abnormal movement patterns and neuromuscular impairments at the ankle are thought to contribute to ankle joint degeneration in those with chronic ankle instability. However, these impairments are not confided to the ankle; rather, proximal neuromuscular deficiencies at the knee and aberrant movement patterns, thought to be responsible for reductions in knee joint health, have also been identified. While neuromuscular impairments and self-reported functional limitations have been examined in those with chronic ankle instability, patient-generated symptoms associated with joint health of the ankle and knee have not been investigated. Therefore, the purpose was to compare perceived ankle and knee joint health in individuals with and without chronic ankle instability.

METHODS

The Ankle Osteoarthritis Scale and the Knee Injury and Osteoarthritis Outcome Score assessed region-specific ankle and knee joint health.

RESULTS

Participants with chronic ankle instability reported more ankle pain (P < 0.001) and disability (P < 0.001) than the control group. Chronic ankle instability individuals also reported worse knee joint health (P < 0.05).

CONCLUSIONS

The increased symptomology associated with decreased ankle joint health further supports information demonstrating joint degeneration in young adults with chronic ankle instability. The decreased perceived knee joint health provides preliminary evidence of the negative impact proximal neuromuscular impairments associated with chronic ankle instability that may have on joints other than the ankle. Assessing subjective ankle and knee joint function can guide clinicians in developing individualized rehabilitation by providing them with an understanding if a patient presenting with chronic ankle instability suffers from symptoms arising from more than just the ankle.

LEVEL OF EVIDENCE

Case-control, Level III.

Plausible mechanisms of and techniques to assess ankle joint degeneration following lateral ankle sprains: a narrative review

Lateral ankle sprain (LAS) is the most common lower extremity musculoskeletal injury sustained during daily life and sport. The cascade of events that starts with ligamentous trauma leads to clinical manifestations such as recurrent sprains and giving way episodes, hallmark characteristics of chronic ankle instability (CAI). The sequelae of lateral ankle sprains and CAI appear to contribute to aberrant biomechanics. Combined, joint trauma and aberrant biomechanics appear to directly and/or indirectly play a role in talar cartilage degeneration. Up to 80% of all cases of ankle osteoarthritis (OA) are post-traumatic in nature and common etiologies for ankle post-traumatic osteoarthritis (PTOA) are histories of a single and recurrent ankle sprains. Despite known links between LAS, CAI, and PTOA and evidence demonstrating the burden of LAS and its sequelae, early pathoetiological changes of ankle PTOA and how they can be assessed are poorly understood. Therefore, the purpose of this paper is to review the plausible mechanistic links among LAS and its sequelae of CAI and PTOA as well as review non-surgical techniques that can quantify talar cartilage health. Understanding the pathway from ligamentous ankle injury to ankle PTOA is vital to developing theoretically sound therapeutic interventions aimed at slowing ankle PTOA progression. Further, directly assessing talar cartilage health non-surgically provides opportunities to quantify if current and novel intervention strategies are able to slow the progression of ankle PTOA.

Changes in Spinal and Corticospinal Excitability in Patients with Chronic Ankle Instability: A Systematic Review with Meta-Analysis

The objective of this systematic review with meta-analysis was to determine alterations in spinal and corticospinal excitability of ankle muscles in patients with chronic ankle instability (CAI) compared to uninjured controls. Independent researchers performed comprehensive literature searches of electronic databases and included studies that compared groups with and without CAI and investigated neural excitability with Hoffmann reflex (H-reflex) and/or transcranial magnetic stimulation (TMS). A fixed-effect meta-analysis was conducted to determine group differences for (1) soleus and fibularis maximal H-reflex (Hmax)/maximal M-wave (Mmax)-ratios, and (2) soleus and fibularis longus cortical motor thresholds (CMTs). Seventeen studies were included in the current meta-analysis. They showed that the Hmax/Mmax-ratios of the soleus and the fibularis longus in the CAI group were significantly lower than those in the uninjured control group (soleus: d = −0.41, p < 0.001; fibularis longus: d = −0.27, p = 0.04). There was no evidence for changes in the CMT. This systematic review is the first to demonstrate evidence that patients with CAI present decreased spinal reflex excitability in the soleus and fibularis longus. However, there is no evidence of changes in supraspinal excitability when considering only the CMT. The latter result needs to be interpreted with caution as all except one study demonstrate some changes at the supraspinal level with CAI.

Activities of daily living influence tibial cartilage T1rho relaxation times

Quantitative T1rho magnetic resonance imaging (MRI) can potentially help identify early-stage osteoarthritis (OA) by non-invasively assessing proteoglycan concentration in articular cartilage. T1rho relaxation times are negatively correlated with proteoglycan concentration. Cartilage compresses in response to load, resulting in water exudation, a relative increase in proteoglycan concentration, and a decrease in the corresponding T1rho relaxation times. To date, there is limited information on changes in cartilage composition resulting from daily activity. Therefore, the objective of this study was to quantify changes in tibial cartilage T1rho relaxation times in healthy human subjects following activities of daily living. It was hypothesized that water exudation throughout the day would lead to decreased T1rho relaxation times. Subjects underwent MR imaging in the morning and afternoon on the same day and were free to go about their normal activities between scans. Our findings confirmed the hypothesis that tibial cartilage T1rho relaxation times significantly decreased (by 7%) over the course of the day with loading, which is indicative of a relative increase in proteoglycan concentration. Additionally, baseline T1rho values varied with position within the cartilage, supporting a need for site-specific measurements of T1rho relaxation times. Understanding how loading alters the proteoglycan concentration in healthy cartilage may hold clinical significance pertaining to cartilage homeostasis and potentially help to elucidate a mechanism for OA development. These results also indicate that future studies using T1rho relaxation times as an indicator of cartilage health should control the loading history prior to image acquisition to ensure the appropriate interpretation of the data.

Automatic registration of MRI-based joint models to high-speed biplanar radiographs for precise quantification of in vivo anterior cruciate ligament deformation during gait

Understanding in vivo joint mechanics during dynamic activity is crucial for revealing mechanisms of injury and disease development. To this end, laboratories have utilized computed tomography (CT) to create 3-dimensional (3D) models of bone, which are then registered to high-speed biplanar radiographic data captured during movement in order to measure in vivo joint kinematics. In the present study, we describe a system for measuring dynamic joint mechanics using 3D surface models of the joint created from magnetic resonance imaging (MRI) registered to high-speed biplanar radiographs using a novel automatic registration algorithm. The use of MRI allows for modeling of both bony and soft tissue structures. Specifically, the attachment site footprints of the anterior cruciate ligament (ACL) on the femur and tibia can be modeled, allowing for measurement of dynamic ACL deformation. In the present study, we demonstrate the precision of this system by tracking the motion of a cadaveric porcine knee joint. We then utilize this system to quantify in vivo ACL deformation during gait in four healthy volunteers.

Evaluation of the Talar Cartilage in Chronic Lateral Ankle Instability with Lateral Ligament Injury Using Biochemical T2* Mapping: Correlation with Clinical Symptoms

RATIONALE AND OBJECTIVES

This study aims to quantitatively compare T2* measurements of the talar cartilage between chronic lateral ankle instability (LAI) patients with lateral ligament injury and healthy volunteers, and to assess the association of T2* value with American Orthopedic Foot and Ankle Society (AOFAS) score.

MATERIALS AND METHODS

Nineteen consecutive patients with chronic LAI (LAI group) and 19 healthy individuals (control group) were enrolled. Biochemical magnetic resonance examination of the ankle was performed in all participants using three-dimensional gradient-echo T2* mapping. Total talar cartilage was divided into six subcompartments, including medial anterior (MA), central medial, medial posterior, lateral anterior, central lateral (LC), and lateral posterior regions. T2* values of respective cartilage areas were measured and compared between the two groups using Student t test. AOFAS scoring was performed for clinical evaluation. Then, the association of T2* value with AOFAS score was evaluated by Pearson correlation.

RESULTS

The T2* values of total talar cartilage, as well as MA and LC cartilage compartments, in the chronic LAI group were significantly higher than control values (P < .001, P = .039, and P = .014, respectively). Furthermore, the T2* value of MA in the chronic LAI group was negatively correlated with AOFAS score (r = -0.8089, P < .001).

CONCLUSIONS

Chronic LAI with lateral ligament injury may have a causal connection with early cartilage degeneration in the ankle joint, especially in MA and LC cartilage compartments, as assessed by quantitative T2* measurements. The clinical score correlates highly with T2* value of the MA cartilage compartment, indicating that MA may be the principal cartilage area conferring clinical symptoms.

Treatment of talus osteochondral defects in chronic lateral unstable ankles: small-sized lateral chondral lesions had good clinical outcomes

PURPOSE

To assess and compare the clinical and MRI outcomes of patients with talus osteochondral defect (OCD) and patients without OCD in a cohort with chronic lateral ankle instability.

METHODS

All patients who underwent open or arthroscopic anterior talofibular ligament repair of the lateral ligament complex by a single surgeon were included in this study. Ankle arthroscopic surgery was initially performed to manage any intra-articular OCD, including debridement and microfracture. Functional scores (AOFAS, Karlsson score) and Tegner activity level scores were determined. An MRI scan was performed at follow-up to assess talus OCD after treatment. Spearman's correlation coefficients were calculated between functional scores and various factors.

RESULTS

A total of 104 patients with chronic ankle instability were included in this study. Among them, 33 patients had cartilage injury on the talus (OCD group), and the other 71 patients had no cartilage injury (control group). After surgery, there was a significant increase in the AOFAS scores (p < 0.001), the Karlsson scores (p < 0.001), and the Tegner activity scores (p < 0.001) in both the OCD group and the control group. However, there was no significant difference in the AOFAS scores (90.7 ± 6.6 vs. 92.5 ± 8.5; n.s.), the Karlsson scores (89.7 ± 9.3 vs. 91.2 ± 9.1; n.s.), or the Tegner activity scores (5 vs. 6; n.s.) between the OCD group and the control group postoperatively. In the OCD group, there was a significant negative association between the functional scores (AOFAS, Karlsson score, or Tegner score) and the number of intra-articular lesions. For the lateral OCD, the mean lesion area significantly decreased from 49.0 ± 10.7 mm² preoperatively to 18.3 ± 13.1 mm² at the final follow-up (p < 0.001).

CONCLUSION

No significant difference in functional outcomes was found between the OCD group and the control group postoperatively. Arthroscopic microfracture is a good option for the long-term treatment of lateral talus OCD.

LEVEL OF EVIDENCE

III.

Lateral Ankle Sprain in a Mouse Model: Lifelong Sensorimotor Dysfunction

CONTEXT

  Ankle sprains are the most common orthopaedic injury that occurs during sport and physical activity. Many individuals who sprain their ankles develop chronic ankle instability (CAI), a condition characterized by recurrent injury, decreased physical activity, and decreased quality of life. These residual impairments are believed to persist for the remainder of the patient's life, in part due to the link between CAI and posttraumatic ankle osteoarthritis. However, this belief remains speculative due to the lack of long-term prospective investigations.

OBJECTIVE

  To use a mouse model of mild (MILD) and severe (SEVERE) ankle sprains to quantify balance and locomotor adaptations across the lifespan.

DESIGN

  Cohort study.

SETTING

  University research laboratory.

PATIENTS OR OTHER PARTICIPANTS

  Fifty male mice (CBA/J) were randomly placed into a control (SHAM), MILD, or SEVERE group and housed individually.

INTERVENTION(S)

  The MILD group underwent surgical transection of a single right hind-limb lateral ankle ligament, and the SEVERE group had 2 of the lateral ligaments transected. The SHAM group underwent a sham surgery during which no lateral ligaments were transected.

MAIN OUTCOME MEASURE(S)

  After surgically inducing the ankle sprain, we measured balance and gait using a balance beam and footprint test before and every 6 weeks for 78 weeks.

RESULTS

  Age-related declines in balance but not stride length were exacerbated by an ankle sprain ( P < .001). Balance and stride lengths changed with age ( P < .001). Foot slips were worse in the SEVERE (4.32 ± 0.98) and MILD (3.53 ± 0.98) groups than in the SHAM group (2.16 ± 0.99; P < .001). Right-limb stride length was shorter in the SEVERE group (6.45 cm ± 0.41 cm) than in the SHAM group (6.87 cm ± 0.40 cm; P = .04).

CONCLUSIONS

  Transecting the lateral ligaments of a mouse hind foot resulted in lifelong sensorimotor dysfunction. Declines starting at 42 weeks postinjury may have represented the onset of posttraumatic osteoarthritis.

Application of High-Speed Dual Fluoroscopy to Study In Vivo Tibiotalar and Subtalar Kinematics in Patients With Chronic Ankle Instability and Asymptomatic Control Subjects During Dynamic Activities

BACKGROUND

Abnormal angular and translational (ie, kinematic) motion at the tibiotalar and subtalar joints is believed to cause osteoarthritis in patients with chronic ankle instability (CAI).

METHODS

In this preliminary study the investigators quantified and compared in vivo tibiotalar and subtalar kinematics in 4 patients with CAI (3 women) and 10 control subjects (5 men) using dual fluoroscopy during a balanced, single-leg heel-rise and treadmill walking at 0.5 and 1.0 m/s.

RESULTS

During balanced heel-rise, 69%, 54%, and 66% of mean CAI tibiotalar internal rotation/external rotation (IR/ER), subtalar inversion/eversion, and subtalar IR/ER angles, respectively, were outside the 95% confidence intervals of control subjects. During 0.5-m/s gait, 50% and 60% of mean CAI tibiotalar dorsi/plantarflexion and subtalar IR/ER angles, respectively, were outside the 95% confidence intervals of control subjects. During 1.0-m/s gait, 62%, 65%, and 73% of mean CAI subtalar dorsi/plantarflexion, inversion/eversion, and IR/ER, respectively, were outside the 95% confidence intervals of control subjects. Patients with CAI exhibited less tibiotalar and subtalar translational motion during gait; no clear differences in translations were noted during balanced heel-rise.

CONCLUSION

Overall, the balanced heel-rise activity exposed more tibiotalar and subtalar kinematic variation between patients with CAI and control subjects. Therefore, weight-bearing activities involving large range of motion, balance, and stability may be best for studying kinematic adaptations in patients with CAI.

CLINICAL RELEVANCE

These preliminary results suggest that patients with CAI require more tibiotalar external rotation, subtalar eversion, and subtalar external rotation during weight-bearing stability exercises, all with less overall joint translation.

Effects of ACL graft placement on in vivo knee function and cartilage thickness distributions

Injuries to the anterior cruciate ligament (ACL) frequently lead to early-onset osteoarthritis. Despite advancement in surgical techniques, ACL reconstruction has a limited ability to prevent these degenerative changes. While previous studies have investigated knee function after ACL reconstruction, in vivo investigations of the effects of graft placement on in vivo joint function and cartilage health are limited. This review presents a series of studies that used novel imaging and 3D modeling techniques to determine the in vivo placement of the ACL graft on the femur using two different ACL reconstruction techniques. These techniques resulted in two distinct graft placement groups: one where the ACL was placed anatomically near the center of the native ACL footprint and another where the graft was placed anteroproximally on the femur, centered outside the ACL footprint. We quantified the effects of graft placement on graft deformation during in vivo loading and how these variables affected knee motion. Finally, we quantified whether femoral placement of the graft affected cartilage thickness. Our results demonstrate that achieving anatomic graft placement on the femur is critical to restoring native ACL function and normal knee kinematics. Knees with grafts that more closely restored normal ACL function, and thus knee motion, experienced less focal cartilage thinning than did those that experienced abnormal knee motion. These results suggest that achieving anatomic graft placement is a critical factor in restoring normal knee motion and potentially slowing the development of degenerative changes after ACL reconstruction. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:1160-1170, 2017.

Reoperation rates following ankle ligament procedures performed with and without concomitant arthroscopic procedures

PURPOSE

Over 50 % of the patients with chronic lateral ankle instability present with some degree of intra-articular pathology. To date, no consensus regarding the concomitant ankle arthroscopy procedures along with ankle ligament procedures has been reached. The purpose of current study was to investigate reoperation rates and postoperative complications following ankle ligament procedures with and without concomitant arthroscopic procedures.

METHODS

Reoperations and postoperative complications following ankle ligament procedures with and without concomitant arthroscopic procedures were investigated using the PearlDiver Patient Record Database (PearlDiver Technologies, Inc.; Fort Wayne, IN, USA) between 2007 and 2011. Ankle ligament procedures, including ligament repair and reconstruction, and ankle arthroscopic procedures were investigated as primary surgery. Subsequently, the reoperation procedures, including ankle ligament procedures, arthroscopic procedures, autologous osteochondral transplantation, and ankle arthrodesis, as well as wound complications and nerve injury following primary ankle ligament procedures were identified.

RESULTS

In 8014 patients receiving ligament repair, the arthroscopic group had a significantly higher reoperation rate in comparison with the non-arthroscopic group (8.8 vs. 6.5 %, odds ratio: 1.1, [p < 0.01], 95 % confidence interval (CI) 1.2-1.7). However, the non-arthroscopic group included 29 open arthrodesis procedures following the primary surgery, whereas arthroscopic group had none. Of the 8055 patients who received a ligament reconstruction, there was no significant difference in reoperation rate between the groups (5.9 vs. 5.9 %, odds ratio: 1.0, [n.s], 95 % CI 0.8-1.2). As seen in the ligament repair group, the non-arthroscopic group had a 4.9 % rate of ankle arthrodesis as a secondary procedure. Arthroscopic group had a significantly lower rate of wound dehiscence following ankle ligament procedures than non-arthroscopic group.

CONCLUSION

Concomitant ankle arthroscopy procedures performed with ankle ligament procedures did not decrease the rate of reoperation. However, there was a lower incidence of ankle arthrodesis and a lower rate of wound complications in the arthroscopic group when compared to those in non-arthroscopic group. Based on the results of the study, which analysed 16.069 patients, concomitant ankle arthroscopy is recommended.

LEVEL OF EVIDENCE

IV.