Subtalar Joint Arthrography

Case Report: Portable handheld ultrasound facilitates intra-articular injections in articular foot pathologies

Background

Intra-articular injections are commonly used to manage joint pathologies, including osteoarthritis. While conventional ultrasound (US) guidance has generally improved intra-articular injection accuracy, forefoot and midfoot joint interventions are still often performed without imaging guidance. This pilot study aims to evaluate the efficacy of office-based, portable ultrasound (P-US) guided intra-articular injections for forefoot and midfoot joint pain caused by various degenerative pathologies.

Methods

A retrospective analysis was conducted on a series of consecutive patients who underwent P-US guided intra-articular injections following a chief complaint of forefoot or midfoot joint pain. Patients reported their pain levels using the Visual Analog Scale (VAS) pre-injection and at 3 months follow-up. The procedure was performed by an experienced foot and ankle surgeon using a linear array transducer for guidance, and a 25-gauge needle was used to inject a combination of 2 cc 1% lidocaine and 12 cc of Kenalog (40 mg/ml). Complications and pain scores were analyzed using a paired t-test and p < 0.05 was considered significant.

Results

We included 16 patients, 31% male and 69% female with a mean age (±SD) of 61.31 (±12.04) years. None of the patients experienced immediate complications following the intervention. The mean pre-injection VAS score was significantly reduced from 5.21 (±2.04) to a mean of 0.50 (±1.32) at 3 months follow-up (P < 0.001). Thirteen patients reported complete resolution of pain at the 3-month follow-up. No adverse events were reported throughout the duration of the study.

Conclusion

This pilot study suggests P-US-guided intra-articular injections offer a safe and effective method for managing forefoot and midfoot joint pain caused by various arthritic pathologies. Further research is warranted to establish the long-term efficacy and comparative effectiveness of P-US-guided injections in larger patient cohorts as compared to non-image guided injections.

Ultrasound-guided joint interventions of the lower extremity

The purpose of this article is to better understand the role ultrasound plays in lower extremity joint interventions. Ultrasound is an important and reliable tool diagnostically and therapeutically. Real-time feedback, lack of ionizing radiation, and dynamic maneuverability make ultrasound an important tool in the proceduralist's armament. This article will touch upon the important anatomic considerations, clinical indications, and technical step-by-step details for lower extremity ultrasound interventions. Specifically, we will look at interventions involving the hip, knee, ankle, and foot. In addition, this article will discuss the roles corticosteroid and platelet-rich plasma may play in certain interventions.

☆Diagnostic and therapeutic injections of the foot and ankle-An overview

Foot and ankle injections are useful diagnostic and therapeutic tools, particularly when the pain etiology is uncertain. A variety of foot and ankle injuries and pathologies, including degenerative joint disease, plantar fasciitis and different tendinopathies are amenable to injections. Understanding the foot and ankle anatomical landmarks, a thorough physical exam and knowledge of the different injection techniques is key for a successful approach to different pathologies. The objective of this study is to review the use of foot and ankle injections in the orthopaedic literature, present the readers with the senior author's experience and provide a comprehensive clinical guideline to the most common foot and ankle diagnostic and therapeutic injections.

Diagnostics in tarsal fusion: The theory and practise in The Netherlands

BACKGROUND

This study compares the preferences of Dutch orthopaedic surgeons for different diagnostic modalities in performing tarsal fusions versus consensus, evidence or expert opinion reported in the literature.

METHODS

A literature search of Medline was performed to obtain evidence-based information on various diagnostic tools. In addition, 89 registered Dutch foot and ankle surgeons were sent a questionnaire concerning the diagnostic modalities use in tarsal fusion.

RESULTS

Fifty-eight (65%) questionnaires were returned. The experienced surgeons measured outcomes significantly more often than other surgeons. Diagnostic injections were often used, although scant evidence exists in the literature. Postoperative diagnostics mainly consist of X-ray examination, although there is consensus in the literature that computed tomography is more accurate.

CONCLUSIONS

The study revealed some surprising discrepancies concerning the use of diagnostic imaging in tarsal fusion. More clinical research is needed to identify the most effective diagnostic imaging modalities so as to encourage their wider adoption.

Technetium-99m Methylene Diphosphonate Single-photon Emission Computed Tomography/Computed Tomography of the Foot and Ankle

The complex anatomy and function of the foot and ankle can make it difficult to determine the cause of symptoms in patients with foot and ankle pathology. Following initial clinical and radiographic assessment, additional imaging with magnetic resonance imaging may be required, which is often seen as the modality of choice. Although sensitive to pathological changes in bone metabolism and vascularity, technetium-99m (Tc-99m) bone scintigraphy often lacks the specificity and resolution required to evaluate the structures of the foot and ankle. Tc-99m methylene diphosphonate single-photon emission computed tomography/computed tomography (SPECT/CT) combines this sensitivity with the superior anatomical detail of CT, enabling better localization of pathological uptake and evaluation of associated structural changes. As a result, SPECT/CT has been growing in popularity for the assessment of patients with foot and ankle pathology where it can provide additional information that may change the initial diagnosis and subsequent management plan. Studies have reported modification of the surgical approach and site of intra-articular local anesthetic injections following SPECT/CT with good results. Interpretation of SPECT/CT studies requires an understanding of the pathological changes that result in increased tracer accumulation in addition to the CT changes that may be seen. This review aims to highlight the advantages of SPECT/CT, potential applications and explain the imaging appearances of common pathologies that may be observed.

Ultrasound-Guided Interventional Procedures in Pain Medicine: A Review of Anatomy, Sonoanatomy, and Procedures: Part VI: Ankle Joint

Ultrasound-guided injections in pain medicine are emerging as a popular technique for pain interventions. Ultrasound can be applied for procedures of the ankle joint and surrounding structures. This review describes the anatomy and sonoanatomy of the ankle joint, subtalar joint, and surrounding extra-articular structures relevant for intra-articular injection. Second, it reviews injection techniques and the accuracy and efficacy of these intra-articular ankle injections.

Imaging of the subtalar joint

Imaging of the subtalar joint can be challenging because of its complex planar anatomy. This article reviews the anatomy and common anatomic variants as seen with different imaging techniques. Although radiography remains the initial mode of imaging, computed tomography and MRI are frequently needed to better delineate the joint anatomy and improve the sensitivity and the specificity of detection of joint pathology. A short review of arthrographic techniques and various examples of imaging of common pathology involving this joint are also included.

Ultrasound-guided joint injections for MR arthrography in pediatric patients: how we do it

In children, MR arthrography is typically performed using fluoroscopic guidance. This article explores the role of US-guided joint injections as an alternative for MR arthrography in children, discussing its advantages and disadvantages compared to standard methods. We describe techniques for performing US-guided injection of the shoulder, elbow, hip, knee, ankle and posterior subtalar joints, highlighting pertinent anatomy, routes of access and unique considerations for this modality in children. Written descriptions, images and links to video clips are used to illustrate proper arthrographic technique. We conclude that US provides effective guidance for intra-articular injection prior to MR arthrography, with the advantages of improved visualization of internal structures, reduced radiation exposure, convenience of performing the procedure portably and ease of performance. Although this paper does not address therapeutic steroid injections, these techniques could easily be translated for such purposes. We propose US guidance as a viable alternative to fluoroscopic technique for arthrography in children.

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.

Can diagnostic injections predict the outcome in foot and ankle arthrodesis?

BACKGROUND

Intra-articular anesthetic drug injections are claimed to confirm the localization of the pain in order to treat the pain. The aim of the present study was to evaluate whether a positive effect of injection could be indicative for a successful outcome of future arthrodesis.

METHODS

74 Patients underwent fluoroscopically guided and contrast confirmed anesthetic joint injections for diagnostic reasons. Before and after injection, pain was measured by use of the Visual Analogue Scale (VAS) in rest and after exercise. Pain reduction was expressed as delta VAS (dVAS). Also, the Foot Function Index (FFI) was obtained. Based on the effect of the diagnostic injection and various clinical factors, patients were advised a conservative treatment (conservative group, n = 34) or an arthrodesis of the affected joint (operative group, n = 40). After a median follow-up period of 3.6 years (range 2.1 to 4.3 years) patients were again invited to complete the FFI and VAS in rest and after exercise. For data-analysis purposes the patients were assigned to four different groups, based on the result of injection and the occurrence of surgery. Wilcoxon signed rank tests and Mann Whitney U tests were used for statistical analysis.

RESULTS

Based on the analysis of the four groups we found that surgery, irrespective of the presence of pain reduction after injection, was related to improvement of VAS and FFI. Patients with conservative treatment always showed worse VAS and FFI scores, even when previous injections showed an improvement of VAS.

CONCLUSIONS

Fluoroscopically-guided anesthetic injections of the supposed painful foot-ankle joint seem not to be indicative for a successful outcome of an arthrodesis of the affected joint. However, the sole occurrence of surgery shows a significant difference in VAS and FFI scores, where conservative treatment does not. The local hospital review board granted permission for this study. Ethical approval was not required for this study.

The posterolateral fluoroscopy-guided injection technique into the posterior subtalar joint: description of the procedure and pilot study on patient outcomes

OBJECTIVE

To describe a posterolateral fluoroscopy-guided injection technique into the posterior subtalar joint and to report patient outcomes 1 month post-injection.

MATERIALS AND METHODS

Twenty-three consecutive adult patients who underwent fluoroscopy-guided injection into the posterior subtalar joint using a direct posterolateral approach and who returned an outcomes-based postal questionnaire after receiving this injection were included. Numerical pain rating scale (NRS) data were collected prior to injection. NRS and Patient's Global Impression of Change (PGIC) scales were completed 1 day, 1 week, and 1 month after injection. The proportion of patients who improved was calculated for each time period. Baseline NRS data were compared to each time point using the Wilcoxon test to assess differences. Spearman's correlation coefficient was used to compare the 20 min NRS score with all follow-up NRS scores. All available images were reviewed for the presence of subtalar osteoarthritis (OA). Patient charts were reviewed to identify characteristics of patients referred for subtalar injections. Risk ratios were calculated comparing presence of OA or other abnormalities with improvement.

RESULTS

A posterolateral approach for fluoroscopy-guided injections into the subtalar joint is described. There was a significant reduction in the mean NRS score at all time periods compared to baseline (p ≤ 0.004). One-third of patients (7/21) reported clinically relevant improvement at 1 month.

CONCLUSIONS

Fluoroscopy-guided puncture of the posterior subtalar joint using a posterolateral approach is possible. Clinically significant improvement is reported in 33% of patients after 1 month.

Percutaneous foot joint needle placement using a C-arm flat-panel detector CT

PURPOSE

Image guidance is valuable for diagnostic injections in foot orthopaedics. Flat-detector computed tomography (FD-CT) was implemented using a C-arm, and the system was tested for needle guidance in foot joint injections.

METHODS

FD-CT-guided joint infiltration was performed in 6 patients referred from the orthopaedic department for diagnostic foot injections. All interventions were performed utilising a flat-panel fluoroscopy system utilising specialised image guidance and planning software. Successful infiltration was defined by localisation of contrast media depot in the targeted joint. The pre- and post-interventional numeric analogue scale (NAS) pain score was assessed.

RESULTS

All injections were technically successful. Contrast media deposit was documented in all targeted joints. Significant relief of symptoms was noted by all 6 participants.

CONCLUSIONS

FD-CT-guided joint infiltration is a feasible method for diagnostic infiltration of midfoot and hindfoot joints. The FD-CT approach may become an alternative to commonly used 2D-fluoroscopically guidance.

Accuracy of anterolateral versus posterolateral subtalar injection

INTRODUCTION

Injections into the subtalar joint may be performed for diagnostic or therapeutic reasons. The anterolateral approach is most commonly utilised for this purpose. We evaluated the success of an intra-articular puncture by using the anterolateral in comparison to the posterolateral approach.

METHODS

Sixty-eight cadaver adult feet were used for performing injections into the subtalar joint without fluoroscopic or ultrasound guidance. Methylene blue dye was infiltrated into 34 of the 68 subtalar joints through an anterolateral approach and into 34 through an posterolateral approach. An arthrotomy was then performed to confirm the placement of the dye within the joint.

RESULTS

Twenty-three of the anterolateral injections (67.6%) were successful as were 31 of 34 (91.2%) of the posterolateral. The posterolateral approach showed a greater accuracy with a statistically significance (p = 0.016).

CONCLUSION

Unintended peri-articular injection can cause complications and an unsuccessful aspiration can delay diagnosis. Comparing the anterolateral to the posterolateral approach with regards to the rate of successful intra-articular puncture of the subtalar joint without the use of imaging there is a greater accuracy with the PL with statistically significance.

Accuracy of sonographically guided posterior subtalar joint injections: comparison of 3 techniques

OBJECTIVE

The primary purpose of this investigation was to determine the accuracy of 3 different sonographically guided posterior subtalar joint (PSTJ) injection techniques in an unembalmed cadaveric model.

METHODS

A single experienced examiner injected the PSTJs of 12 unembalmed cadaveric ankle-foot specimens using the anterolateral, posterolateral, and posteromedial approaches. The injection order for each specimen was randomized, and each technique was completed with a different-color diluted latex solution. Coinvestigators blinded to the injection technique dissected each specimen and graded the colored latex location as accurate (in the PSTJ), accurate with overflow (within the PSTJ but also in other regions), or inaccurate (no latex in the joint).

RESULTS

All 3 sonographically guided PSTJ injection approaches accurately placed latex into the PSTJ (100% accuracy). Latex was also found in adjacent regions in 19.4% (7 of 36) of injections: 8.3% (3 of 36) within the tibiotalar joint, 8.3% (3 of 36) in the peroneal (fibularis) tendon sheath, and 2.8% (1 of 36) in the flexor hallucis longus tendon sheath. The anterolateral approach placed latex outside the PSTJ 25% of the time (3 of 12 injections: 1 tibiotalar and 2 peroneal [fibularis] sheath), the posterolateral approach 25% of the time (3 of 12 injections: 1 tibiotalar, 1 peroneal [fibularis] sheath, and 1 flexor hallucis longus tendon sheath), and the posteromedial approach 8.3% of the time (1 tibiotalar).

CONCLUSIONS

This cadaveric investigation suggests that all 3 sonographically guided PSTJ techniques may be used to access the PSTJ with a high degree of accuracy. Clinicians should consider sonographically guided PSTJ injections as a favorable alternative to fluoroscopy and computed tomographic guidance when diagnostic or therapeutic image-guided PSTJ injections are indicated.

Ankle arthrodesis

Numerous techniques for ankle arthrodesis have been reported since the original description of compression arthrodesis. From the early 1950s to the mid 1970s, external fixation was the dominant technique utilized. In the late 1970s and 1980s, internal fixation techniques for ankle arthrodesis were developed. In the 1990s, arthroscopic ankle arthrodesis was developed for ankle arthrosis with minimal or no deformity. The open technique is still widely used for ankle arthrosis with major deformity. For complex cases that involve nonunion, extensive bone loss, Charcot arthropathy, or infection, multiplanar external fixation with an Ilizarov device, with or without a bone graft, may achieve successful union. The fusion rate in most of the recently published studies is 85% or greater, and may depend on the presence of infection, deformity, avascular necrosis, and nonunion.

Accuracy of posterior subtalar joint injection without fluoroscopy

Injection into the posterior subtalar joint has not been validated for accuracy using radiographic end points. We asked whether needle placement into a normal posterior subtalar joint could be performed accurately and selectively by experienced surgeons without fluoroscopic guidance. Three fellowship-trained orthopaedic foot and ankle surgeons each injected the posterior subtalar joint of 20 cadaveric specimens using an anterolateral approach. Fluoroscopic images were obtained by an independent investigator and blinded. A separate fellowship-trained foot and ankle surgeon interpreted the images. Of 60 injections, 58 were accurate and two were extraarticular based on interpretation by an independent foot and ankle surgeon. Extravasation into the ankle occurred in 14 samples and into the peroneal sheath in two samples. Experienced surgeons can place intraarticular injections into a radiographically normal posterior subtalar joint without fluoroscopy with a high degree of accuracy. However, extravasation into the ankle or peroneal tendon sheath occurred in an unpredictable fashion, suggesting selectivity of injection placement is relatively limited without the use of fluoroscopy. Fluoroscopy may not be necessary for injections used solely for therapeutic purposes. However, if the injection is intended for diagnostic purposes or to assist in surgical decision-making or if the joint is abnormal, we recommend fluoroscopy to ensure the subtalar joint is the only anatomic structure impacted by the injection.

CT of the musculoskeletal system: what is left is the days of MRI?

Magnetic resonance imaging (MRI) plays a central role in the modern imaging of musculoskeletal disorders, due to its ability to produce multiplanar images and characterise soft tissues accurately. However, computed tomography (CT) still has an important role to play, not merely as an alternative to MRI, but as being the preferred imaging investigation in some situations. This article briefly reviews the history of CT technology, the technical factors involved and a number of current applications, as well as looking at future areas where CT may be employed. The advent of ever-increasing numbers of rows of detectors has opened up more possible uses for CT technology. However, diagnostic images may be obtained from CT systems with four rows of detectors or more, and their ability to produce near isotropic voxels and therefore multiplanar reformats.

CT guided diagnostic foot injections

AIM

To describe a CT technique for guiding diagnostic and therapeutic injections in the hind- and mid-foot.

MATERIALS AND METHODS

Over a period of 50 months, 28 individuals were referred for diagnostic and therapeutic hind- and mid-foot injections before possible arthrodesis. A CT technique was developed that allowed entry into the various joints using a vertical approach. Numbers of joints injected were as follows: posterior subtalar, 21; talonavicular, 4; calcaneonavicular, calcaneocuboid, navicular-cuneiform and 5th metatarsocuboid joints, 1 each.

RESULTS

All injections but one were technically successful. Significant relief of symptoms was noted by 16 participants, whereas for 9 there was no improvement and for 3 a partial response was achieved.

CONCLUSION

CT is a simple and safe alternative to fluoroscopy for guiding diagnostic and therapeutic foot injections, and may be the technique of choice in cases of disordered anatomy.

Diagnostic and therapeutic injections of the foot and ankle

Directed injections of the foot and ankle performed under fluoroscopic guidance have both considerable diagnostic value and the potential for targeted therapy by accurately delivering corticosteroid and/or anesthetic to the source of pain. Both large and small joints in the foot and ankle are readily accessed, offering precise information to the foot and ankle surgeon who may be contemplating arthrodesis or other intervention. In addition to its role in pain management, ankle arthrography may be performed in conjunction with MRI or CT, with improved evaluation of articular cartilage and capsular abnormalities.