Sinus tarsi syndrome and subtalar joint instability

Ultrasound guided injections in ankle and foot

Ultrasound guidance is particularly useful for percutaneous injections in the diagnosis and management of painful conditions of the ankle and foot. The injectates used include steroids and local anesthetics, such as lidocaine, mepivacaine, bupivacaine, ropivacaine, and platelet-rich plasma. Osteoarthritis is the main indication for joint injections. Joints amenable to being injected include the tibiotalar, subtalar, midtarsal, and metatarsophalangeal joints. Tendon injections mainly involve the Achilles, peroneus, extensors, and tibialis tendons, while plantar fascia injections are useful for treating plantar fasciitis and plantar fibromatosis. Forefoot injections include joint arthritis, intermetatarsal bursitis, and Morton neuroma. The standardized approaches and doses reviewed in this paper are based on the authors' experience and can lead to high success in symptomatic relief for various conditions. These injections can be curative or serve as a guide to identify the source of pain when surgery or other therapeutic options are planned.

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.

The Evolution of Sinus Tarsi Syndrome-What Is the Underlying Pathology?-A Critical Review

Background and Objectives: Sinus tarsi syndrome (STS) is defined as pain located at the lateral opening of the tarsal sinus. The exact etiology of sinus tarsi syndrome is not completely understood. Some do not believe it to be a true pathology. This review aims to clarify the definition of sinus tarsi syndrome to better understand the underlying pathologies. We further propose an algorithm to evaluate sinus tarsi pain and provide advice for consecutive treatment options. Design: This is a narrative review. By searching PubMed, the available current literature was reviewed. Articles were critically analyzed to determine the pathoanatomy, biomechanics, and etiology of sinus tarsi pain. Algorithms for clinical evaluation, diagnosis, and treatment were also recorded. Finally, the authors approach to evaluating and treating sinus tarsi pain was included in this review. Results: Reviewing the available literature, STS seems to be a catch-all phrase used to describe any pain in this anatomic region. Many causes of sinus tarsi pain were listed, including impingement, subtalar instability, and many other pathologies around the ankle. Conclusions: A thorough evaluation of patients presenting with pain in the sinus tarsi or instability of the hindfoot is essential to determining the underlying cause. When the cause of pain is still not clear after clinical exam and radiologic assessment, subtalar arthroscopy can be helpful as both a diagnostic and treatment tool. We propose that the term of STS should be avoided and that a more accurate diagnosis be used when possible. Once a diagnosis is made, appropriate treatment can be initiated.

Arthroscopy of Foot and Ankle: Subtalar Joint Arthroscopy in Intra-articular Calcaneal Fractures

The utilization of subtalar joint arthroscopy in intra-articular calcaneal fractures provides optimal visualization of articular surfaces for a more precise anatomical reduction, thus yielding better surgical outcomes. Current literature shows good functional and radiographic outcomes, fewer wound complications, and low incidence of post-traumatic arthritis with this technique than when utilizing an isolated lateral extensile incision of the calcaneus. As subtalar joint arthroscopy continues to grow in popularity and technological advancement, patients may benefit when surgeons incorporate this tool in conjunction with a minimally invasive technique for treatment of intra-articular calcaneal fractures.

Acute and Chronic Subtalar Joint Instability: Does It Really Exist?

Acute and chronic subtalar instability and commonly coexistent with other hindfoot pathology but can be difficult to diagnose. A high degree of clinical suspicion is required as most imaging modalities and clinical maneuvers are poor at detecting isolated subtalar instability. The initial treatment is similar to ankle instability, and a wide variety of operative interventions have been presented in the literature for persistent instability. Outcomes are variable and limited.

Sinus tarsi and sinus tarsi syndrome: An imaging review

The sinus tarsi is a funnel-shaped region at the junction of mid-foot and hind-foot which contains fat, vessels, nerves and ligaments. The ligaments help stabilise the subtalar joint and maintain the longitudinal arch of the foot. The nerve endings contain proprioceptive fibres indicating a role for the sinus tarsi in movement of the foot. Sinus tarsi syndrome is a clinical entity characterised by lateral hind-foot pain with worsening on palpation and weight-bearing, and perceived instability. It is associated with both traumatic and non-traumatic causes. Magnetic resonance imaging is the imaging modality of choice for assessment of the sinus tarsi and sinus tarsi syndrome. In this review article, we review the anatomy and various aetiologies of sinus tarsi syndrome, along with the imaging appearances.

The frondiform ligament sling: a sonographic landmark for injection into the sinus tarsi

Localisation and injection of the sinus tarsi can be challenging, particularly for the less experienced musculoskeletal sonographer/practitioner. The inferior extensor retinaculum arises from the sinus tarsi in the form of three roots (medial, intermediate and lateral) which are collectively termed the frondiform ligament. This is readily identified on ultrasound and can be used as a reference point to aid the safe delivery of injectate material into the sinus tarsi. This article describes the technique and its anatomical basis.

A high rate of talocalcaneal interosseous ligament tears was found in chronic lateral ankle instability with sinus tarsi pain

PURPOSE

To evaluate the arthroscopic findings of subtalar joints, including interosseous talocalcaneal ligament (ITCL) tear, in patients with chronic lateral ankle instability (CLAI) and sinus tarsi pain.

METHODS

A total of 118 ankles (109 patients) having CLAI with sinus tarsi pain who had undergone subtalar arthroscopy and lateral ankle ligament surgery were evaluated. The medical records, radiologic images, and the arthroscopic images and videos were reviewed. ITCL tears were classified into 4 grades: grade 0 (no tear), grade 1 (mild), grade 2 (moderate), and grade 3 (severe). The efficacy of magnetic resonance imaging (MRI) in diagnosing ITCL tears was also evaluated by comparing preoperative official readings of MRI to arthroscopic findings. The pre- and postoperative functional scores were also assessed.

RESULTS

The overall tear rate of ITCL was 107/118 (90.7%). There were 29 ankles (23.6%) with grade 1, 42 ankles (35.6%) with grade 2, and 36 ankles (30.5%) with grade 3 tears. Isolated lateral ankle instability (LAI) was diagnosed in 43 ankles (36.4%), subtalar instability (STI) in 30 ankles (25.4%), and LAI with STI in 45 ankles (38.1%). There was a statistically significant relationship between the ITCL tear grade and the final diagnosis. ITCL tear was confirmed or suspected in 81 ankles (68.6%) on preoperative MRI. Pain Visual Analog Score and functional outcome scores including the American Orthopaedic Foot & Ankle Society and Karlsson-Peterson scores showed significant improvement after the surgery.

CONCLUSION

A high rate (90.7%) of ITCL tears was noted in CLAI patients with sinus tarsi pain. ITCL damage may play an important role in subtalar instability in patients with CLAI and sinus tarsi pain. Subtalar arthroscopic evaluation for ITCL tear is important for correct diagnosis for CLAI with sinus tarsi pain.

LEVEL OF EVIDENCE

IV.

Feasibility of MRI for the evaluation of interosseous ligament vertical segment via subtalar arthroscopy correlation: comparison of 2D and 3D MR images

Background

Interosseous ligament vertical segment (IOLV) and calcaneofibular ligament (CFL) have been reported to be important in stabilizing the subtalar joint. Unlike CFL, there is not much information regarding the comparison of MRI results with surgical evaluation of IOLV and the comparison between 2D and 3D MRI on IOLV evaluation. The feasibility of MRI in IOLV evaluation has yet to be reported. The purpose of this study was to evaluate the validity and reliability of MRI in IOLV tear detection via correlation with arthroscopic results. We also compared the diagnostic performance of 2D and 3D MR images.

Methods

In this retrospective study, 52 patients who underwent subtalar arthroscopy after ankle MRI were enrolled. Arthroscopic results confirmed IOLV tear in 25 cases and intact IOLV in 27 cases. Two radiologists independently evaluated the IOLV tears using only conventional 2D images, followed by isotropic 3D images, and comparison with arthroscopic results.

Results

Only the 2D sequences interpreted by two readers showed a sensitivity of 64.0–96.0%, a specificity of 29.6–44.4%, a positive predictive value of 51.6–56.4%, and a negative predictive value of 57.1–88.9%. Addition of isotropic 3D sequences changed the sensitivity to 60.0–80.0%, specificity to 63.0–77.8%, positive predictive value to 64.3–76.9%, and negative predictive value to 66.7–80.8%. The overall diagnostic performance of isotropic 3D sequences (AUC values: 0.679–0.816) was higher than that of 2D sequences (AUC values: 0.568–0.647). Inter-observer and intra-observer agreement between the two readers was moderate-to-good for both 2D and 3D sequences. The diagnostic accuracy in 19 patients with tarsal sinus fat obliteration tended to increase from 26.3–42.1% to 57.9–73.7% with isotropic 3D sequences compared with 2D sequences.

Conclusions

Isotropic 3D MRI was feasible for the assessment of IOLV tear prior to subtalar arthroscopy. Additional 3D sequences showed higher diagnostic accuracy compared with conventional 2D sequences in IOLV evaluation. Isotropic 3D sequences may be more valuable in detecting IOLV tear in case of tarsal sinus fat obliteration.

Current Concepts on Subtalar Instability

Subtalar instability remains a topic of debate, and its precise cause is still unknown. The mechanism of injury and clinical symptoms of ankle and subtalar instabilities largely overlap, resulting in many cases of isolated or combined subtalar instability that are often misdiagnosed. Neglecting the subtalar instability may lead to failure of conservative or surgical treatment and result in chronic ankle instability. Understanding the accurate anatomy and biomechanics of the subtalar joint, their interplay, and the contributions of the different subtalar soft tissue structures is fundamental to correctly diagnose and manage subtalar instability. An accurate diagnosis is crucial to correctly identify those patients with instability who may require conservative or surgical treatment. Many different nonsurgical and surgical approaches have been proposed to manage combined or isolated subtalar instability, and the clinician should be aware of available treatment options to make an informed decision. In this current concepts narrative review, we provide a comprehensive overview of the current knowledge on the anatomy, biomechanics, clinical and imaging diagnosis, nonsurgical and surgical treatment options, and outcomes after subtalar instability treatment.

Accessory Talar Facet Impingement and Sinus Tarsi Pain Associated With Accessory Anterolateral Talar Facet

BACKGROUND

Sinus tarsi pain caused by accessory talar facet impingement (ATFI) owing to accessory anterolateral talar facet (AALTF) is not well documented. We evaluated prevalence of AALTF and differences of magnetic resonance imaging (MRI) findings between persons with and without sinus tarsi pain, and investigated the relevant association between MRI findings and sinus tarsi pain in persons with AALTF.

METHODS

We performed a case-control study on 120 ankles with sinus tarsi pain and 120 age- and gender-matched ankles without sinus tarsi pain. As MRI findings, bone marrow edema (BME), sinus tarsi fat obliteration (STFO), calcaneal cyst, talocalcaneal coalition, Gissane angle, talar inferolateral surface (TILS) angle, and calcaneal cortical thickness (CCT) were evaluated. The MRI findings were compared between persons with and without sinus tarsi pain, and between persons with and without AALTF. Among persons with AALTF, MRI findings were compared between those with and without sinus tarsi pain. Relevant association was evaluated between MRI findings and sinus tarsi pain in persons with AALTF.

RESULTS

Presence of AALTF, BME, and STFO were significantly higher in the group with sinus tarsi pain. The Gissane angle was significantly smaller, and the TILS angle and CCT were significantly larger in the group with sinus tarsi pain. The BME (OR 7.571, CI 1.453-39.446) and small Gissane angle (OR 0.891, CI 0.804-0.986) were significantly associated with sinus tarsi pain in persons with the AALTF.

CONCLUSION

The study provides evidence for ATFI related to impingement of an AALTF associated with talocalcaneal BME.

LEVEL OF EVIDENCE

Level III, case-control study.

Sinus Tarsi Syndrome on Bone Scintigraphy With SPECT/CT: Spectrum of Findings

ABSTRACT

Sinus tarsi syndrome is a common cause of hindfoot pain in adults; however, diagnosis on planar bone scintigraphy can be challenging. We present 3 cases of sinus tarsi syndrome, review the spectrum of imaging findings associated with sinus tarsi syndrome, and show the key role that SPECT/CT can play in its diagnosis.

Secondary Effects of the Rupture and Reconstruction of the Interosseous Talocalcaneal Ligament on the Peritalar Joints

Background

The interosseous talocalcaneal ligament (ITCL) is the main soft-tissue contributor to subtalar joint stability. The role of ITCL reconstruction in retaining this stability is minimally reported. Therefore, we conducted this study to investigate the effects of rupture and reconstruction of the ITCL on the subtalar and peritalar joints.

Material/Methods

This experimental study randomly divided 72 rabbits into 3 equal groups of 24 rabbits each. Group I underwent reconstruction surgery, group II underwent resection, and group III was the control group. The cartilages between the talocrural and calcaneocrural joints, and between the subtalar and talonavicular joints on both sides were assessed by gross observation, ink staining, histology, and immunohistochemistry at weeks 4, 8, 16, and 32, postoperatively.

Results

In group II, the quantitative ink staining analysis revealed degeneration of the articular cartilages on the talonavicular joint (T=2.070, P=0.038) and the posterior subtalar joint (T=2.121, P=0.034) compared with the 2 sides of the same rabbit at 4 and 8 postoperative weeks. Comparing the operated sides of all the groups showed the posterior subtalar joints (Hc=9.563, P=0.008) and talonavicular joints (Hc=9.714, P=0.008) had an obvious difference at postoperative week 4; and in the calcaneocrural joints (Hc=6.750, P=0.034), it was noticed at postoperative week 8. Histology and immunohistochemistry findings confirm these observations.

Conclusions

An ITCL resection can lead to the progressive degeneration of the talonavicular and posterior subtalar joints, while an ITCL reconstruction can be beneficial in restoring the stability of these joints, preventing or postponing their degeneration, and protecting the articular cartilages.

Biomechanical comparison of tenodesis reconstruction for subtalar instability: a finite element analysis

Background

There are several types of tenodesis reconstruction designed for subtalar instability. However, no comprehensive comparison has been conducted among these procedures in terms of their correcting power so far. The objective of this study is to evaluate the biomechanical behaviors of 5 representative procedures through finite element analysis.

Methods

Finite element models were established and validated based on one of our previous studies. The Pisani interosseous talocalcaneal ligament (ITCL) reconstruction, Schon cervical ligament (CL) reconstruction and Choisne calcaneofibular ligament (CFL) reconstruction were compared on the model with the CFL, ITCL and CL sectioned. The Schon triligamentous reconstruction and Mann triligamentous reconstruction were compared on the model with the CFL, ITCL and CL, as well as the ATFL sectioned. The inversion and external/internal rotation were quantified at different ankle positions based on the rotational moment. Then, the stress in ligaments and reconstructed grafts and the contact characteristics of the subtalar joint under inversional stress test were calculated and compared accordingly.

Results

For single ligament reconstruction, the Choisne CFL reconstruction provided the greatest degree of correction for subtalar instability, followed by the Schon CL reconstruction and then the Pisani ITCL reconstruction. For triligamentous reconstruction, the Mann procedure outperformed the Schon procedure in alleviating the subtalar instability.

Conclusion

The finite element analysis showed that the Choisne CFL reconstruction and Mann triligamentous reconstruction provided the greatest degree of immediate postoperative subtalar stability. However, both procedures could not restore the biomechanical behaviors of the subtalar joint to normal. The long-term efficacy of these procedures warrants further investigation using a substantially larger sample of clinical cases.

Surgical Treatment of Subtalar Joint Instability: Safety and Accuracy of a New Technique in a Cadaver Model

New surgical strategies to treat symptomatic subtalar joint (STJ) instability are evolving. We modified a previously described reconstruction strategy and then refined our new surgical technique through simulated surgery and subsequent cadaver dissections. Our purpose was to show that a tunnel intended to facilitate STJ stabilization surgery could safely be drilled across the footprints of the interosseous talocalcaneal ligament (ITCL). A percutaneous fluoroscopically guided tunnel for the purpose of ITCL reconstruction was created in 10 cadaveric below-knee specimens. Accuracy of the tunnel with relation to the anatomic boundaries of the ITCL attachment sites as well as damage to relevant structures at risk were recorded. Two sets of 5 surgeries were performed to assess for improvement in technique. Mean distances from the tunnel to the ITCL on the calcaneus improved between groups 1 and 2: 4.04 and 1.80 mm, respectively (p = .04). Mean distances from the tunnel to the ITCL on the talus improved between groups 1 and 2: 6.2 and 1.8 mm, respectively (p = .08). With information obtained from this study, an osseous tunnel can be safely placed within 2 mm of the ITCL footprints.

The Ankle-Joint Complex: A Kinesiologic Approach to Lateral Ankle Sprains

Copious research exists regarding ankle instability, yet lateral ankle sprains (LASs) persist in being among the most common recurrent musculoskeletal injuries. Key anatomical structures of the ankle include a triform articulating structure that includes the inferior tibiofibular, talocrural, and subtalar joints. Functionally, force absorption and propulsion through the ankle complex are necessary for any task that occurs in weight bearing. For optimal ankle performance and avoidance of injury, an intricate balance between stability and mobility is necessary to ensure that appropriate force transfer occurs during sports and activities of daily living. Consideration for the many structures that may be directly or indirectly involved in LASs will likely translate into advancements in clinical care. In this clinical review, we present the structure, function, and relevant pathologic states of the ankle complex to stimulate a better understanding of the prevention, evaluation, and treatment of LASs.

Subtalar arthroscopic debridment for the treatment of sinus tarsi syndrome: case series

OBJECTIVE

The objective of this study is to report the results of arthroscopic debridement of the subtalar joint in eight patients with Sinus Tarsi Syndrome (STS) refractory to conservative treatment.

METHODS

This is a retrospective study of eight patients with STS who underwent subtalar arthroscopy for debridement of the sinus tarsi between January 2015 and January 2017 after six months of conservative treatment. All patients answered an epidemiological questionnaire and underwent functional evaluation with the Visual Analogue Pain Scale (VAS) and the American Orthopedic Foot and Ankle Society Score (AOFAS) in the preoperative and in the last evaluation (average of 12 months - 6-24 months).

RESULTS

All patients showed severe synovitis in the region. Seven patients had remnants of the talocalcaneal ligaments and six of the cervical ligament. AOFAS increased by 30 points on average (51.75 in the preoperative period to 82.62 in the last follow-up) and the VAS decreased on average by 5 points (7.37 preoperatively to 2.12 in the last follow-up). These results were statistically significant with p = 0.043 and p = 0.032 respectively. Six patients described the result as excellent and two as good. No complications were reported. All patients returned to sports after six months of follow-up.

CONCLUSION

The arthroscopic debridement of the subtalar joint is an effective and safe alternative in the treatment of STS refractory to conservative treatment. More studies, with a prospective methodology, are necessary to prove the results of this technique.

Role of Subtalar Arthroscopy for Displaced Intra-Articular Calcaneal Fractures

Subtalar arthroscopy has an important role in enhancing the reduction of the posterior facet in percutaneous and open approaches of displaced intra-articular calcaneal fractures. In the percutaneous approach, arthroscopically assistant percutaneous approach must be selected carefully for mild-to-moderately displaced fractures. In the open approach, there is still little evidence of the utility of subtalar arthroscopy. Therefore, intraoperative arthroscopy should always be used in conjunction with fluoroscopy to achieve reduction and assess the internal fixation placement.

Effect of generalized ligamentous hyperlaxity related of quality of life in the foot: a case controlled study

Generalized ligamentous hyperlaxity (GLH) has been shown to predispose an individual to a number of orthopaedic conditions. Little is known about how GLH affects people' foot health-related quality of life. This study analyses a sample of people with GLH and people without GLH with normalised reference values of the scores collected with regard to using the Foot Health Status Questionnaire (FSHQ). A total of 100 respondents with mean age of 22.69 ± 3.78 years old, who attended a health centre were classified as GLH (n = 50) or non-GLH (n = 50). The GLH was determined of the patients with and without GLH using assessment with Beighton tool and the scores on the FHSQ were compared. The control group recorded higher scores in the First Section for foot pain, foot function and general foot health, and lower scores in footwear. In the Second Section, they obtained higher scores in social capacity and lower scores in physical activity, vigour and general health. Differences between the two groups were evaluated through a t-test for independent samples, showing statistical significance (P<0.001). This study has detected measurable differences of association between GLH (Beighton score ≥4) with impaired quality of life related to foot health.

Update on Subtalar Joint Instability

Subtalar joint stability is ensured by the osseous geometry of the talocalcaneal joint and the complex array of the ligaments at the medial and lateral aspect of the ankle joint, the sinus and canalis tarsi, and the talocalcaneonavicular joint, respectively. There is still a substantial lack of knowledge about the interaction of the ankle and subtalar joint complex. Subtalar joint instability appears to be more frequent than is generally assumed. The diagnosis of chronic subtalar joint instability makes the application of a comprehensive algorithm necessary. There is ongoing debate about the preferable techniques for restoration of subtalar joint stability.

Differences Between Subtalar Instability and Lateral Ankle Instability Focusing on Subtalar Ligaments Based on Three Dimensional Isotropic Magnetic Resonance Imaging

OBJECTIVE

The purpose of this study was to assess the differences between subtalar instability (STI) and lateral ankle instability (LAI) focusing on subtalar ligaments using 3-dimensional (3D) isotropic magnetic resonance imaging (MRI).

METHODS

Preoperative MRIs of 10 patients with STI who failed nonoperative treatment and consequently underwent arthroscopic subtalar reconstruction were compared with preoperative MRIs of 23 patients with LAI who underwent ligament repair or reconstruction. Dimensions of anterior capsular ligament (ACL), interosseous talocalcaneal ligament (ITCL), calcaneofibular ligament (CFL), and anterior talofibular ligament (ATFL) were measured. Tears of ACL, ITCL, CFL, ATFL, cervical ligament, and inferior extensor retinaculum were analyzed.

RESULTS

Patients with subtalar instability had significantly lower ACL thickness and width than patients with LAI (thickness: 1.48 vs 2.12 mm, P = 0.045; width: 7.30 vs 8.64 mm, P = 0.029). An ACL thickness of 1.8 mm or less had sensitivity and specificity both at 75.0%, and an ACL width of 8 mm or less had sensitivity of 75.0% and specificity of 85.0% for discriminating STI from LAI. Absence or complete tear of ACL was more frequent in patients with STI than in patients with LAI (60.0% vs 13.0%, P = 0.010). The ATFL thickness was significantly greater in patients with LAI (P = 0.001). Complete tear of ATFL was more common in patients with LAI (P = 0.008). Complete tear of CFL was common in both the STI and LAI groups without significant difference (20.0% vs 21.7%). There was no significant difference in thickness and width of ITCL and in CFL thickness. Complete tear of ITCL, cervical ligament, and inferior extensor retinaculum were rare without significant difference.

CONCLUSION

In patients with STI, the ACL is thin and narrow and more commonly absent or torn compared with patients with LAI. Complete tear of ATFL was more common in patients with LAI. Complete tear of CFL was commonly encountered in both the STI and LAI groups.

Electromyographic analysis of balance exercises in single-leg stance using different instability modalities of the forefoot and rearfoot

PURPOSE

To investigate the activity of lower extremity muscles in response to single-leg stance on a training device, destabilizing the forefoot while the rearfoot stands on a fixed plate and vice versa compared with a balance pad and the floor.

DESIGN

Cross-sectional study.

SETTING

University's laboratory.

PARTICIPANTS

Twenty-seven healthy adults.

METHODS

Surface electromyography and 2D video analysis were used to record the activity of lower extremity muscles and to control sagittal knee joint angle during single-leg stance trials under one stable control condition and five unstable conditions.

RESULTS

The majority of lower extremity muscles were significantly more active when the forefoot was destabilized while the rearfoot remained stable compared with the stable condition and the conditions where the forefoot was stable and the rearfoot unstable (p <0 .001). Mean change of knee joint angle was significantly increased under the conditions rearfoot stable/forefoot unstable (p = 0.001). The soleus muscle activation was significantly increased when balancing on the balance pad (p < 0.001).

CONCLUSIONS

Increased activity in the majority of lower extremity muscles and sagittal knee joint angles indicate that destabilizing the forefoot while the rearfoot remains stable is the most challenging balance task. Soleus muscle activation increased when performing ankle plantarflexion on the soft balance pad.

Anatomical Study of the Cervical and Interosseous Talocalcaneal Ligaments of the Foot with Surgical Relevance

There is conflicting evidence regarding the morphology and orientation of the cervical ligament (CL) and interosseous talocalcaneal ligament (ITCL). The morphology of the CL and its relationship to the ITCL were studied to obtain an understanding of these structures. Twenty-six feet (13 left, 13 right) were obtained from formalin-fixed cadavers (14 females, four males) with the mean standard deviation (SD) age at death 80.9 (12.9) years. All measurements were made with a digital caliper. The length and width of the foot, the width and height of the talus, were measured. The talus was cut coronally to expose the ITCL and qualitative observations were noted. The mean (SD) heights and widths of the CL at the anterior, posterior, superior, and inferior points were 8.27 (2.52), 13.95 (5.96), 9.15 (2.45), and 11.90 (4.30) mm, respectively. The mean (SD) thicknesses of the CL at the superoanterior, superoposterior, inferoanterior, inferoposterior, and central points were 0.62 (0.24), 1.05 (0.30), 0.70 (0.26), 1.20 (0.34), and 0.97 (0.31) mm, respectively. The fibers of the CL are oriented at a slight superoanterior to inferoposterior angle, whereas the fibers of the ITCL are oriented in a slight superomedial to inferolateral angle. The fibers of the CL and ITCL overlap inside the tarsal sinus with the CL positioned anteriorly, which helps to distinguish the two ligaments. In this study, we identified the morphometrics of the CL and described the CL and ITCL qualitatively. These results are relevant to introducing innovative techniques for reconstructive surgery of the subtalar ligaments in order to repair, for example, subtalar instability.

Subtalar joint instability

PURPOSE

Subtalar joint instability may frequently be overlooked and erroneously be integrated under the diagnosis of ankle joint instability. It was the scope of this review to characterize the present state-of-art with regard to the adequate diagnosis and treatment.

METHODS

While the clinical picture is mostly inconclusive for subtalar joint instability, a high degree of suspicion for this diagnosis is needed to employ weight-bearing x-rays, standardized stress radiography, CT scanning and MRI to further elucidate the etiopathology

RESULTS

Geometrical reasons as hindfoot deformities, isolated or combined injuries or instabilities in conjunction with the ankle ligament complex do exist which should be differentiated in detail and classified to indicate the adequate treatment. Treatment of acute lesions is simple and effective. A certain percentage of the patients with chronic subtalar instability is incorrectly labeled with the diagnosis of a sinus tarsi syndrome.

CONCLUSION

Subtalar joint arthroscopy for reconfirmation of the correct diagnosis conjoined with restoration of physiological hindfoot alignment and a preferably anatomical ligamentous reconstruction provide the basis for a good functional recovery.

Sonographically guided posterior subtalar joint injections via the sinus tarsi approach

OBJECTIVES

To determine the feasibility and accuracy of sonographically guided posterior subtalar joint (PSTJ) injections performed through the sinus tarsi.

METHODS

A single experienced operator completed 10 sonographically guided PSTJ injections via the sinus tarsi on 10 unembalmed cadaveric ankle-foot specimens. Injections were performed using a 17-5-MHz linear transducer, a 25-gauge, 50-mm needle, and an out-of-plane, anterior-to-posterior needle trajectory parallel to the calcaneal surface. Sonographic assessment for fluid in the posterior and lateral PSTJ recesses, sinus tarsi, and peroneal tendon sheath was performed before and after injections of 2 and 4 mL of tap water. Two additional specimens were injected with a contrast agent: 1 via the sonographically guided approach and another by a computed tomographically guided approach.

RESULTS

All 10 sonographically guided PSTJ tap water injections were accurate, distending both the posterior and lateral PSTJ recesses. In addition, all 10 specimens showed posterior recess distension by 2 mL, whereas only 2 specimens (20%) showed lateral recess distension at this volume. By 4 mL, both recesses were clearly distended in all specimens. Both contrast agent injections produced similar PSTJ computed tomographic arthrograms and patterns of recess distension similar to the sonographically guided tap water injections. No sonographically guided PSTJ injection placed fluid in the peroneal tendon sheath.

CONCLUSIONS

Sonographically guided PSTJ injections via the sinus tarsi can accurately and specifically deliver injectate into the PSTJ while monitoring injectate flow within the posterior recess. The sinus tarsi approach may be used as an alternative technique to perform sonographically guided PSTJ injections when clinically appropriate.

Sonographic visibility of the sinus tarsi with a 12 MHz transducer

OBJECTIVES

To assess the value of ultrasonography in studies of the ligaments within the sinus tarsi (ST) in healthy subjects.

MATERIALS AND METHODS

We examined 20 healthy volunteers using a 12-MHz transducer with THI and compound imaging. With the foot in inversion, the following structures were examined with coronal and transverse scans: (1) the root of the inferior extensor retinaculum (RIER); (2) the interosseous talocalcaneal ligament (ITCL); (3) the cervical ligament (CL); (4) the bifurcate ligament (BL); (5) the synovial recesses, which were examined for possible distention (distended synovial recesses, DSR). The sonographic features, orientation, and thickness of each ligament were assessed.

RESULTS

The easiest structure to identify (visualized in 20/20 subjects) was the RIER, which formed a semiarch. The two deeper layers were hypoechoic, the superficial layer hyperechoic. The ITCL was situated posteriorly and deep with an oblique course. It appeared hypoechoic with a mean thickness of 4.06 mm ± 0.7. It was visualized in 18/20 (90 %) subjects. The CL (isoechoic/hyperechoic) was located more anteriorly at an intermediate depth. The orientation was almost vertical. It was visualized in 17/20 (85 %) subjects, with a mean thickness of 2.28 mm ± 0.34. The BL appeared hypoechoic. It was visualized in 19/20 (95 %) subjects with transverse (anterior end of the ST) and longitudinal scans. The calcaneonavicular and calcaneocuboid components displayed mean (SD) thicknesses of 2.09 mm ± 0.37 and 2.7 mm ± 0.32, respectively. The ITCL and RIER were visualized in the same scan as a semiarch. DSR was observed in 4/20 (20 %) subjects.

CONCLUSIONS

The present study shows that, in patients with suspected ST pathology, the anatomic structures that make up this recess can be adequately examined with ultrasonography performed with ordinary 12-MHz transducers.

Distribution of sensory nerve endings around the human sinus tarsi: a cadaver study

The aim of this study was to analyse the pattern of sensory nerve endings and blood vessels around the sinus tarsi. The superficial and deep parts of the fat pads at the inferior extensor retinaculum (IER) as well as the subtalar joint capsule inside the sinus tarsi from 13 cadaver feet were dissected. The distribution of the sensory nerve endings and blood vessels were analysed in the resected specimens as the number per cm(2) after staining with haematoxylin-eosin, S100 protein, low-affinity neurotrophin receptor p75, and protein gene product 9.5 using the classification of Freeman and Wyke. Free nerve endings were the predominant sensory ending (P < 0.001). Ruffini and Golgi-like endings were rarely found and no Pacini corpuscles were seen. Significantly more free nerve endings (P < 0.001) and blood vessels (P = 0.01) were observed in the subtalar joint capsule than in the superficial part of the fat pad at the IER. The deep part of the fat pad at the IER had significantly more blood vessels than the superficial part of the fat pad at the IER (P = 0.012). Significantly more blood vessels than free nerve endings were seen in all three groups (P < 0.001). No significant differences in distribution were seen in terms of right or left side, except for free nerve endings in the superficial part of the fat pad at the IER (P = 0.003). A greater number of free nerve endings correlated with a greater number of blood vessels. The presence of sensory nerve endings between individual fat cells supports the hypothesis that the fat pad has a proprioceptive role monitoring changes and that it is a source of pain in sinus tarsi syndrome due to the abundance of free nerve endings.

Ligament structures in the tarsal sinus and canal

BACKGROUND

The concrete anatomy and functional characteristics of the subtalar ligaments have been a matter of debate that some believe has hampered the progress of clinical ligament reconstruction.

METHODS

In 32 fresh-frozen cadaver feet, the course of the inferior extensor retinaculum (IER) and other subtalar ligaments was carefully measured and photographed both from the portal of the tarsal sinus and from a posterior view.

RESULTS

The IER inserted inside the tarsal sinus and canal by means of 3 roots: a lateral, an intermediate, and a medial one. These roots, along with the tarsal canal, divided the subtalar space into 3 parts. In front of the IER and inside the tarsal sinus, the thick cervical ligament (CL) lay at a 45-degree angle to the calcaneus. Behind the IER and inside the posterior capsule, in most cases (25 of 32 specimens), the posterior capsular ligament (PCaL) lay directly in front of the posterior talocalcaneal facet. Inside the tarsal canal, the fan-shaped medial root of the IER spread from outside upper lateral to lower medial, and the interosseous talocalcaneal ligament (ITCL) ran from upper medial to lower lateral; fibers of these 2 ligaments blended tightly together to form a V-shaped ligament complex. Just anterior to this complex in some cases (20 of 32 specimens), a short narrow upright ligament, the tarsal canal ligament (TCL), was located behind the middle talocalcaneal joint.

CONCLUSION

The results of this study show that the CL is the primary ligament in the tarsal sinus and that the ITCL is a thin single band rather than a strong bilaminar ligament located inside the tarsal canal. Instead, the medial root of the IER is the primary ligamentous structure in the tarsal canal.

CLINICAL RELEVANCE

The anatomical description provided here may provide a more accurate theoretical foundation for clinical subtalar stability restoration.

The effects of a semi-rigid ankle brace on a simulated isolated subtalar joint instability

Subtalar joint instability is hypothesized to occur after injuries to the calcaneofibular ligament (CFL) in isolation or in combination with the cervical and the talocalcaneal interosseous ligaments. A common treatment for hindfoot instability is the application of an ankle brace. However, the ability of an ankle brace to promote subtalar joint stability is not well established. We assessed the kinematics of the subtalar joint, ankle, and hindfoot in the presence of isolated subtalar instability, investigated the effect of bracing in a CFL deficient foot and with a total rupture of the intrinsic ligaments, and evaluated how maximum inversion range of motion is affected by the position of the ankle in the sagittal plane. Kinematics from nine cadaveric feet were collected with the foot placed in neutral, dorsiflexion, and plantar flexion. Motion was applied with and without a brace on an intact foot and after sequentially sectioning the CFL and the intrinsic ligaments. Isolated CFL sectioning increased ankle joint inversion, while sectioning the CFL and intrinsic ligaments affected subtalar joint stability. The brace limited inversion at the subtalar and ankle joints. Additionally, examining the foot in dorsiflexion reduced ankle and subtalar joint motion.

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.

Ganglia of the tarsal sinus: MR imaging features and clinical findings

PURPOSE

To analyze MR imaging and clinical findings associated with ganglia of the tarsal sinus.

MATERIALS AND METHODS

In a record search, ganglia of the tarsal sinus were retrospectively identified in 26 patients (mean age 48±16 years), who underwent MR imaging for chronic ankle pain. Images were reviewed by two radiologists in consensus for size and location of ganglia, lesions of ligaments of the ankle and the tarsal sinus, tendon abnormalities, osteoarthritis, osseous erosions and bone marrow abnormalities. Medical records were reviewed for patient history and clinical findings.

RESULTS

Ganglia were associated with the interosseus ligament in 81%, the cervical ligament in 31% and the retinacula in 46% of cases. Signal alterations suggesting degeneration were found in 85%, 50% and 63% in case of the interosseus ligament, the cervical ligament and the retinacula, respectively. Scarring of the anterior talofibular ligament and the fibulocalcaneal ligament was found in 68% and 72% of the patients, respectively, while only 27% of the patients recalled ankle sprains. Ganglia at the retinacula were highly associated with synovitis and tendinosis of the posterior tibial tendon (p<0.05).

CONCLUSION

All patients with ganglia in the tarsal sinus presented with another pathology at the ankle, suggesting that degeneration of the tarsal sinus may be a secondary phenomenon, due to pathologic biomechanics at another site of the hind foot. Thus, in patients with degenerative changes of the tarsal sinus, one should be alerted and search for underlying pathology, which may be injury of the lateral collateral ligaments in up to 70%.

Subtalar arthroscopy using a 2.4-mm zero-degree arthroscope: indication, technical experience, and results

The subtalar joint is complex. With the advent of smaller diameter arthroscopes, subtalar arthroscopy has become an important diagnostic and therapeutic tool for subtalar joint disorders. The objective of this study was to evaluate the outcome of patients who underwent arthroscopy for subtalar joint disorders using a 2.4-mm zero-degree arthroscope. In this prospective study, 6 patients who underwent subtalar arthroscopy from September 2008 to January 2009 in the authors' institution were included. The American Orthopaedic Foot & Ankle Society (AOFAS) hindfoot scores were recorded preoperatively and at 3 and 6 months postoperatively. Mean +/- SD age was 45.5 +/- 16.2 years (range, 27.5-63.2). Postoperative diagnosis included arthrofibrosis, osteoarthritis, and osteochondral disease of the subtalar joint. Mean +/- SD AOFAS scores improved from 49.67 +/- 18.83 (range, 22-76) to 67.33 +/- 14.92 (range, 53-91) at 3 months (P = .03) and 75 +/- 19.74 (range, 54-100) at 6 months (P = .004). Subtalar arthroscopy using the 2.4-mm zero-degree arthroscope shows promising results in the diagnosis and treatment of subtalar pathologies. Patients have a significant improvement in their AOFAS hindfoot scores as early as 3 months and continue to improve subsequently. Usage of the zero-degree arthroscope allows the "instrumentation hand" to maneuver more easily in space and perform the operative procedure without getting in the way of the "camera hand." It can also save on inventory costs for centers that already have the zero-degree arthroscope. The role of specialized imaging is still unclear. Diagnosis of sinus tarsi syndrome should be historical with direct visualization of the joint revealing exact etiology.

Understanding acute ankle ligamentous sprain injury in sports

This paper summarizes the current understanding on acute ankle sprain injury, which is the most common acute sport trauma, accounting for about 14% of all sport-related injuries. Among, 80% are ligamentous sprains caused by explosive inversion or supination. The injury motion often happens at the subtalar joint and tears the anterior talofibular ligament (ATFL) which possesses the lowest ultimate load among the lateral ligaments at the ankle. For extrinsic risk factors to ankle sprain injury, prescribing orthosis decreases the risk while increased exercise intensity in soccer raises the risk. For intrinsic factors, a foot size with increased width, an increased ankle eversion to inversion strength, plantarflexion strength and ratio between dorsiflexion and plantarflexion strength, and limb dominance could increase the ankle sprain injury risk. Players with a previous sprain history, players wearing shoes with air cells, players who do not stretch before exercising, players with inferior single leg balance, and overweight players are 4.9, 4.3, 2.6, 2.4 and 3.9 times more likely to sustain an ankle sprain injury. The aetiology of most ankle sprain injuries is incorrect foot positioning at landing – a medially-deviated vertical ground reaction force causes an explosive supination or inversion moment at the subtalar joint in a short time (about 50 ms). Another aetiology is the delayed reaction time of the peroneal muscles at the lateral aspect of the ankle (60–90 ms). The failure supination or inversion torque is about 41–45 Nm to cause ligamentous rupture in simulated spraining tests on cadaver. A previous case report revealed that the ankle joint reached 48 degrees inversion and 10 degrees internal rotation during an accidental grade I ankle ligamentous sprain injury during a dynamic cutting trial in laboratory. Diagnosis techniques and grading systems vary, but the management of ankle ligamentous sprain injury is mainly conservative. Immobilization should not be used as it results in joint stiffness, muscle atrophy and loss of proprioception. Traditional Chinese medicine such as herbs, massage and acupuncture were well applied in China in managing sports injuries, and was reported to be effective in relieving pain, reducing swelling and edema, and restoring normal ankle function. Finally, the best practice of sports medicine would be to prevent the injury. Different previous approaches, including designing prophylactice devices, introducing functional interventions, as well as change of games rules were highlighted. This paper allows the readers to catch up with the previous researches on ankle sprain injury, and facilitate the future research idea on sport-related ankle sprain injury.

Fractures of the lateral process of the talus. Retrospective study of 44 cases

PURPOSE OF THE STUDY

Fractures of the lateral process of the talus often go undiagnosed. The cohorts reported in the literature are small. The aim of the study was to analyze these fractures with a large group of patients.

MATERIALS AND METHODS

Forty-four fractures in 43 patients were reviewed with a mean follow-up of 17 months. The diagnosis had been made immediately in 14 cases and secondarily in 30 cases with a delay of 46 months. Patients were evaluated with Kitaoka's score and X-rays using Hawkins classification. Fractures occurred during sports in 19 cases. The most frequent mechanism was association of dorsal flexion and pronation. There were associated lesions in 44% of cases.

RESULTS

In the delayed diagnosis group, we found 14 cases of associated pseudarthrosis and subtalar osteoarthritis, two cases of isolated pseudarthrosis and two cases of isolated subtalar osteoarthritis. After treatment, the result at the last follow-up was excellent in 15 of these cases (50%), good in seven cases (23%), fair in seven cases (23%) and poor in one case (4%). In the immediate diagnosis group, five of 14 patients had at least one complication: 29% pseudarthrosis and 29% subtalar osteoarthritis. After treatment, the result at the last follow-up in this group was excellent in eight cases (58%), good in four cases (28%) and fair in two cases (14%). Immediate diagnosis was correlated with better results at the last follow-up. In the immediate diagnosis group, among patients who had orthopedic treatment, the rate of secondary surgery was 42%.

CONCLUSION

Fracture of the lateral process of the talus is quite frequent and occurs among young people. Spontaneous progression is severe, with two major complications: pseudarthrosis and subtalar osteoarthritis. Treatment is always required in case of displaced fracture.

[Fractures of the lateral process of the talus. Retrospective study of 44 cases]

PURPOSE OF THE STUDY

Fractures of the lateral process of the talus are often not diagnosed. The cohorts of the literature are small. The aim of the study was to analyse these fractures with a large group of patients.

MATERIAL AND METHOD

Forty-four fractures in 43 patients were reviewed with an average follow-up of 17 months. The diagnosis had been made immediately in 14 cases and secondarily in 30 cases with a delay of 46 months. Patients had been evaluated with Kitaoka's score and radiographies using Hawkins classification. Fractures occurred during sport practise in 19 cases. The most frequent mechanism was association of dorsal flexion and pronation. There were associated lesions in 44% of cases.

RESULTS

In the group of delayed diagnosis, we found 14 cases of associated pseudarthrodesis and sub-talar osteoarthritis, two cases of isolated pseudarthrodesis, two cases of isolated sub-talar osteoarthritis. After treatment in this group, the result at the last follow up was very good in 15 cases (50%), good in seven cases (23%), average in seven cases (23%) and bad in one case (4%). In the group of immediate diagnosis five of 14 patients had at least one complication: 29% of pseudarthrodesis and 29% of sub-talar osteoarthritis. After treatment in this group, the result at the last follow-up was very good in eight cases (58%), good in four cases (28%) and average in two cases (14%). Immediate diagnosis was correlated with better results at the last follow-up. In the sub-group of immediate diagnosis, among patients who had an orthopaedic treatment, the rate of secondarily surgery was 42%.

CONCLUSION

The fracture of lateral process of the talus is quite frequent and occurs among young people. Spontaneous evolution is severe with two major complications: pseudarthrodesis and sub-talar osteo-arthritis. Treatment is always required in case of displaced fracture.