The effect of ankle injury on subtalar motion

Reconstruction of the interosseous talocalcaneal ligament using allograft for subtalar joint stabilization is effective

PURPOSE

The aim of this study was to assess the biomechanical effects of subtalar ligament injury and reconstruction on stability of the subtalar joint in all three spatial planes.

METHODS

Fifteen fresh frozen cadaveric legs were used, with transfixed tibiotalar joints to isolate motion to the subtalar joint. An arthrometer fixed to the lateral aspect of the calcaneus measured angular displacement in all three spatial planes on the inversion and eversion stress tests. Stress manoeuvres were tested with the intact joint, and then repeated after sequentially sectioning the inferior extensor retinaculum (IER), cervical ligament (CL), interosseous talocalcaneal ligament (ITCL), arthroscopic graft reconstruction of the ITCL, and sectioning of the calcaneo-fibular ligament (CFL).

RESULTS

Sectioning the ITCL significantly increased angular displacement upon inversion and eversion in the coronal and sagittal planes. Reconstruction of the ITCL significantly improved angular stability against eversion in the axial and sagittal planes, and against inversion in the axial and coronal planes, at the zero time point after reconstruction. After sectioning the CFL, resistance to eversion decreased significantly in all three planes.

CONCLUSION

Progressive injury of ligamentous stabilisers, particularly the ITCL, led to increasing angular displacement of the subtalar joint measured with the inversion and eversion stress tests, used in clinical practice. Reconstruction of the ITCL using tendon graft significantly stabilised the subtalar joint in the axial and sagittal planes against eversion and in the axial and coronal planes against inversion, immediately after surgery.

Safe Talar Tunnel Placement During Reconstruction of the Deep Layer of the Deltoid Ligament: A Comparison of 4 Different Anatomic Landmarks on the Lateral Malleolus

Background

Deltoid ligament reconstruction of the ankle can be considered when the ruptured ligament is insufficient for direct repair.

Purpose

To compare the safety of talar tunnels oriented toward 4 different anatomic landmarks on the lateral malleolus during reconstruction of the deep layer of the deltoid ligament (DDL).

Study Design

Descriptive laboratory study.

Methods

A total of 30 computed tomography scans of the ankle joint in healthy adults were collected to generate 3-dimensional models. Virtual talar tunnels with a diameter of 5 mm and with different lengths (20.0, 25.0, and 30.0 mm) were created from the talar insertion of the DDL and were oriented toward the talar neck as well as the most anterior, the most distal, and the most posterior points of the distal fibula. The minimal safe distance (MSD) of a drilling route was calculated for the tunnels, and the safe distance from the end of the tunnel to the bone surface was measured for each tunnel. The nonpaired Student t test was used to detect differences among the safe distances of the 4 different bone tunnels.

Results

For the 20.0-mm tunnels, the safe distance of the tunnel oriented toward the talar neck (5.90 ± 1.16 mm) did not meet the MSD (6.0 mm). For the 25.0-mm tunnels, the safe distances of the tunnels oriented toward the talar neck (4.53 ± 1.13 mm) and the anterior point of the fibula (5.91 ± 1.52 mm) did not meet the MSD (6.9 mm).

Conclusion

Tunnels that were 5 mm in diameter and 20.0 and 25.0 mm in length, oriented toward the most distal or most posterior point of the distal fibula, were safe for DDL reconstruction.

Clinical Relevance

Knowledge of safe talar tunnel placement is important, especially to avoid bone surface penetration during DDL reconstruction.

Role of Robotic Gait Simulators in Elucidating Foot and Ankle Pathomechanics

Testing with cadaveric foot and ankle specimens began as mechanical techniques to study foot function and then evolved into static simulations of specific instances of gait, before technologies were eventually developed to fully replicate the gait cycle. This article summarizes the clinical applications of dynamic cadaveric gait simulation, including foot bone kinematics and joint function, muscle function, ligament function, orthopaedic foot and ankle pathologies, and total ankle replacements. The literature was reviewed and an in-depth summary was written in each section to highlight one of the more sophisticated simulators. The limitations of dynamic cadaveric simulation were also reviewed.

Anatomy of the Deltoid-Spring Ligament Complex

A thorough knowledge of the anatomy of the deltoid and spring ligament complex is important for treatment of deformities that impact the foot and ankle. Both ligaments are interconnected, and the study of their anatomic characteristics is better performed together than in isolation. The deltoid ligament is a group of ligaments that derives its origin from the medial malleolus, and the spring ligament complex consist of a group of ligaments that connects the navicular and the sustentaculum tali of the calcaneus. They both play an important role in stabilization of the medial ankle and medial column of the foot.

Diagnosis and Management of Deltoid Ligament Insufficiency

Background:

Surgical management of patients with acute and chronic ankle instability (CAI) has historically focused on the lateral ligament complex. Recent studies in CAI patients have shown that magnetic resonance imaging (MRI) and arthroscopy demonstrate concomitant injury to the deltoid ligament complex We performed a systematic review to determine if consistent clinical, diagnostic imaging, or arthroscopic findings of deltoid ligament injury in the setting of CAI have been described. In addition, we sought to determine if treatment options and/or clinical outcomes have been described.

Methods:

A systematic review was conducted using the PubMed, MEDLINE, and Embase databases. Articles were included if they had a majority of patients 18 years of age or older, focused on deltoid ligament injury in ankle instability, and reported diagnostic and/or treatment methods. Articles were excluded if the study focused on the deltoid ligament in the acute fracture setting. All included articles were assessed for diagnostic criteria, treatments, and patient outcomes.

Results:

Our search yielded 157 articles, of which a total of 13 were included in our study. Arthroscopy was described as the gold standard to diagnose and evaluate the severity of deltoid ligament injury, however, little objective data on the arthroscopic diagnosis of deltoid ligament insufficiency was reported. MRI was the imaging modality of choice to evaluate deltoid ligament injury and had a high sensitivity and specificity when compared with arthroscopy. No standard MRI diagnostic criteria for deltoid ligament injury were identified in the literature. Specific treatment techniques and long-term outcomes were not well described in the manuscripts included in this review.

Conclusion:

There is limited knowledge on deltoid ligament insufficiency in the setting of chronic ankle instability. Criteria for characterizing deltoid ligament damage with diagnostic imaging appear to be evolving, but there is no standard classification. Only 1 author has described a method to evaluate deltoid ligament competency on arthroscopic examination. There are currently no objective data to guide treatment decisions.

Level of Evidence:

Level III.

Anatomic feature of deltoid ligament attachment in posteromedial osteochondral lesion of talar dome

BACKGROUND

Osteochondral lesions of the talus (OLT) are recognized as being commonly associated with trauma. However, the etiology of OLT remains unclear. In the case of a posteromedial lesion of OLT (medial OLT), the deep layer of the deltoid ligament is located close to the medial OLT, and this relationship between a medial lesion and deltoid ligament could be a risk factor for medial OLT. The purpose of this study is to investigate the unique anatomic feature of the deep deltoid attachment to the talus in patients with medial OLT compared with patients with non-medial OLT.

METHODS

Forty ankles with medial OLT and 40 ankles without medial OLT were retrospectively reviewed in this study. On the coronal images of MRI, the attachment of deltoid ligament was measured. The continuity of the osteochondral fragment and its bed was evaluated on MRI and arthroscopic findings.

RESULTS

Coronal MRI images showed that the attachment of the deep deltoid ligament to the medial OLT was broader and located more proximally than in non-medial OLT. The continuity of fibers from the insertion site of deltoid ligament to the talus to the osteochondral fragment was observed (76.7%). In the arthroscopic findings, the osteochondral fragment was obviously connected to the talus at the medial site in 85.2% of feet.

CONCLUSIONS

The location of the deep deltoid ligament attachment to the medial OLT was more proximal and there was the possibility of these anatomic feature might contribute to the pathogenesis of medial OLT.

The subtalar joint: A complex mechanism

Subtalar joint anatomy is complex and can vary significantly between individuals.

Movement is affected by several adjacent joints, ligaments and periarticular tendons.

The subtalar joint has gained interest from foot and ankle surgeons in recent years, but its importance in hindfoot disorders is still under debate.

The purpose of this article is to give a general overview of the anatomy, biomechanics and radiographic assessment of the subtalar joint.

The influence of the subtalar joint on the evolution of ankle joint osteoarthritis is additionally discussed.

Cite this article: EFORT Open Rev 2017;2:309-316. DOI: 10.1302/2058-5241.2.160050

Noninvasive quantification of subtalar joint kinematics: a pilot investigation

A noninvasive method of assessing the motion of the subtalar joint was developed for use in clinical and research settings. Anatomical reference frames for the calcaneus and talus were produced using a marker placement model utilizing 14 markers. An asymptomatic individual was tested during barefoot walking with a CODA MPX30 system. Intertrial variability and motion patterns, in all three planes, of the calcaneus with respect to the talus were analyzed as part of a validation study. The observed patterns in all three planes were found to have good face validity with published literature as well as good consistency during stance. The findings of this study support the further use of this model in both clinical and research settings, allowing investigation of the motion patterns of a larger cohort than has hitherto been possible.

Outcome of subtalar instability reconstruction using the semitendinosus allograft tendon and biotenodesis screws

PURPOSE

Subtalar instability (STI) has often been obscured by lateral ankle instability. Moreover, although there have been several reports of techniques for reconstructing STI, no clinical outcome results are known to have been published. The authors report the clinical and radiographic outcomes of the ligament reconstruction of STI with a recently reported novel technique utilising a semitendinosus tendon allograft and interference screws.

METHODS

This study is based on 20 ankles that underwent ligament reconstruction for STI between 2009 and 2013. The average follow-up period was 15.0 ± 5 months, and the average age at surgery was 28.1 ± 10.8 years old. Visual analogue (VAS) pain scores, American Orthopedic Foot and Ankle Society (AOFAS) and Karlsson-Peterson ankle scores as well as patient satisfaction were evaluated. Radiographic evaluation of medial translations of calcaneus and subtalar tilt angles was preformed with ankle and Broden's stress radiographs.

RESULTS

The VAS pain score decreased from 6.1 ± 1.1 preoperatively to 1.8 ± 1.2 post-operatively (p < 0.05). The AOFAS score improved from 66.0 ± 12.2 preoperatively to 89.6 ± 6.7 post-operatively, and the Karlsson-Peterson score improved from 57.0 ± 13.5 to 91.1 ± 6.8 (p < 0.05). There were no complications such as recurred STI or subtalar joint stiffness. All of the patients were satisfied with the surgery. Subtalar tilt angle decreased from 11.5° preoperatively to 3.0° post-operatively, and the calcaneal medial translations decreased from 7.4 to 3.9 mm.

CONCLUSION

This is the first report on the comprehensive clinical and radiographic outcomes of STI reconstruction using a semitendinosus tendon allograft and interference screws. The novel technique of STI reconstruction was found to show encouraging clinical outcomes with high patient satisfaction.

LEVELS OF EVIDENCE

IV.

Comparison of different locking plate fixation methods in distal tibia fractures

PURPOSE

The aim of our study was to assess the outcome of locking plate fixation of distal tibia fractures and evaluate which surgical approach and method of plate fixation is related to better functional result and lower complication rate.

METHODS

A retrospective analysis of treatment of 45 patients was made. Patients were divided into two subgroups regarding surgical approach (medial vs anterior) and fixation method (bridge plating vs rigid fixation). Time from injury to full bone union was noted, and clinical outcome was assessed by AOFAS score.

RESULTS

Nonunion was the most prevalent complication and was observed in 26.6 % of patients. Infection rate was 11.1 %. Higher rate of bone union complications was noted in the anterior approach group with anterolateral anatomical plate. Infection and re-operation rates were similar in all subgroups. There were no correlations between fracture extension, length of plate and screw placement with bone healing time and AOFAS score.

CONCLUSIONS

Outcome of plate fixation of distal tibia fracture did not depend on the fixation method or surgical approach but, when possible, the medial plating via MIPO technique is a favourable method of treatment.

Dynamic in vivo subtalar joint kinematics measured using a skin marker-based protocol a face validity study

BACKGROUND

The subtalar joint allows complex motion of the foot relative to the leg, the analysis of which has presented a major challenge for researchers. The considerable interpatient variation in structure and function of the subtalar joint highlights the importance of developing a protocol to assess the kinematics in individuals rather than developing an overarching description of function. The use of skin-mounted markers is, therefore, preferable, allowing the noninvasive collection of data. We sought to assess the face validity of a skin-mounted marker-based protocol to measure the in vivo kinematics of the subtalar joint.

METHODS

Thirty participants were recruited using minimal exclusion criteria. A previously tested skin-mounted marker placement protocol was used in conjunction with two CODA MPX 30 sensors to capture data during walking. The data produced were compared with those from previous studies that used bone-mounted markers.

RESULTS

The results in all three planes represented feasible outcomes compared with those of previous studies, the data falling within the ranges published. Patterns of movement demonstrated are similar to, although not the same as, those shown by previous investigations.

CONCLUSIONS

This study did not produce patterns of movement that exactly matched those of previous investigations. The results were, however, within the ranges previously published, and the patterns of movement shown were feasible. The results suggest the face validity of the method as a means of assessing the in vivo kinematics of the subtalar joint during the stance phase of gait.

The deltoid ligament: an in-depth review of anatomy, function, and treatment strategies

PURPOSE

A literature review of the deltoid ligament was conducted, examining the current literature on anatomy, function, and treatment strategies. In particular, anatomical inconsistencies within the literature were evaluated, and detailed anatomical dissections are presented.

METHODS

A literature search was conducted on PubMed using keywords relevant to the deltoid ligament in the ankle and medial ankle instability. Primary research articles, as well as appropriate summary articles, were selected for review.

RESULTS

While it is well defined that the deltoid is contiguous and divided into one superficial and one deep portion, the creation of the individual fibres may be artificial. Furthermore, while improvements in imaging techniques and arthroscopy have not led to a consensus on the anatomy of the ligament, they may help improve recognition of deltoid injuries. Once identified, the majority of deltoid injuries can be treated via conservative treatment. However, reparative and reconstructive treatment strategies can also be used for complex acute injuries or chronic medial ankle instability.

CONCLUSION

Given the continuing evolution of the anatomical understanding of the ligament, the current treatment protocol for deltoid injuries requires further standardization, with an emphasis on proper diagnosis.

Subtalar instability: diagnosis and treatment

Subtalar instability is challenging to diagnose. It rarely follows a complete subtalar dislocation, an event more likely to result in subtalar pain, stiffness, and arthritis. By history, subtalar instability can be suggested by the patient’s feeling of ankle instability, easy “rolling over,” and a need to look at the ground constantly when walking. Clinical measures for inversion and eversion do not accurately reflect isolated subtalar motion, as soft tissue and other joint motion confound the examination. Stress radiographs have high false positive rates. Magnetic resonance imaging can show injured or disorganized ligaments suggestive of recurrent subtalar strain, but are not dynamic studies and cannot alone diagnose instability. Operative treatment, when elected, should focus on determining the source of the problem. Generally direct repair of the lateral ligaments is sufficient. Bony malalignment should always be considered especially in the setting when previous ligament reconstruction has failed.

The in vitro reliability of the CODA MPX30 as the basis for a method of assessing the in vivo motion of the subtalar joint

BACKGROUND

The considerable variation in subtalar joint structure and function shown by studies indicates the importance of developing a noninvasive in vivo technique for assessing subtalar joint movement. This article reports the in vitro testing of the CODA MPX30, an active infrared marker motion analysis system. This work represents the first stage in the development of a noninvasive in vivo method for measuring subtalar joint motion during walking.

METHODS

The in vitro repeatability of the CODA MPX30 system's measurements of marker position, simple and intermarker set angles, was tested. Angular orientations of markers representing the position of the talus and the calcaneus were measured using a purpose-designed marker placement model.

RESULTS

Marker location measurements were shown to vary by less than 1.0 mm in all of the planes. The measurement of a 90° angle was also found to be repeatable in all of the planes, although measurements made in the yz plane were shown to be consistently inaccurate (mean, 92.47°). Estimation of segmental orientation was found to be repeatable. Estimations of marker set orientations were shown to increase in variability after a coordinate transform was performed (maximum SD, 1.14°).

CONCLUSIONS

The CODA MPX30 was shown to produce repeatable estimations of marker position. Levels of variation in segmental orientation estimates were shown to increase subsequent to coordinate transforms. The combination of the CODA MPX30 and an appropriate marker placement model offers the basis of an in vivo measurement strategy of subtalar joint movement, an important development in the understanding of the function of the joint during gait.

Effects of balance training on gait parameters in patients with chronic ankle instability: a randomized controlled trial

OBJECTIVE

To examine the effects of a four-week balance training programme on ankle kinematics during walking and jogging in those with chronic ankle instability. A secondary objective was to evaluate the effect of balance training on the mechanical properties of the lateral ligaments in those with chronic ankle instability.

DESIGN

Randomized controlled trial.

SETTING

Laboratory.

SUBJECTS/PATIENTS

Twenty-nine participants (12 males, 17 females) with self-reported chronic ankle instability were randomly assigned to a balance training group or a control group.

INTERVENTION

Four weeks of supervised rehabilitation that emphasized dynamic balance stabilization in single-limb stance. The control group received no intervention.

MAIN OUTCOME MEASURES

Kinematic measures of rearfoot inversion/eversion, shank rotation, and the coupling relationship between these two segments throughout the gait cycle during walking and jogging on a treadmill. Instrumented ankle arthrometer measures were taken to assess anterior drawer and inversion talar tilt laxity and stiffness.

RESULTS

No significant alterations in the inversion/eversion or shank rotation kinematics were found during walking and jogging after balance training. There was, however, a significant decrease in the shank/rearfoot coupling variability during walking as measured by deviation phase after balance training (balance training posttest: 13.1 degrees +/- 6.2 degrees , balance training pretest: 16.2 degrees +/- 3.3 degrees , P = 0.03), indicating improved shank/rearfoot coupling stability. The control group did not significantly change. (posttest: 16.30 degrees +/- 4.4 degrees , pretest: 18.6 degrees +/- 7.1 degrees , P40.05) There were no significant changes in laxity measures for either group.

CONCLUSIONS

Balance training significantly altered the relationship between shank rotation and rearfoot inversion/eversion in those with chronic ankle instability.