CT guided diagnostic foot injections

Clinical impact of 99mTc-HDP SPECT/CT imaging as standard workup for foot and ankle osteoarthritis

Objective

The primary aim of this study was to assess to what extent 99mTc-HDP Single photon emission computed tomography/computed tomography (SPECT/CT) will lead to change of diagnosis and treatment, in patients with suspected foot and ankle osteoarthritis (OA). Secondary aim was to assess the intraobserver variability.

Methods

Retrospectively 107 patients, with suspected foot and/or ankle OA of which a SPECT/CT was made, were included for analysis. All the clinical and radiological data were randomized and blinded before being scored by one experienced orthopaedic surgeon. Firstly, based on the clinical data and conventional radiographs, a diagnosis and treatment plan was scored. Secondly, the observer accessed the SPECT/CT and could change the diagnosis and treatment plan. Additionally, the intraobserver reliability was determined by data of 18 patients that were added in twofold to the dataset, without awareness of the observer and by calculating the κ values.

Results

The diagnosis changed in 53% (57/107) and treatment plans changed in 26% (28/107) of the patients. Intraobserver reliability for the conventional workup was k = 0.54 (moderate strength of agreement), compared to k = 0.66 (substantial strength of agreement) when SPECT/CT data were added.

Conclusions

This study describes the influence of SPECT/CT on diagnosis and treatment plans in patients with suspected symptomatic OA. Also, it shows SPECT/CT leads to a higher intraobserver variability. We believe SPECT/CT has a promising role in the workup for foot and ankle OA.

Advances in knowledge

In addition to what was found in complex foot and ankle cases, this study shows that in patients with non-complex foot and ankle problems, SPECT/CT has a substantial influence on the diagnosis (and subsequent treatment plan).

Accuracy of Intraarticular Injections: Blind vs. Image Guided Techniques-A Review of Literature

Intra-articular injections are widely used for diagnostic and therapeutic purposes of joint pathologies throughout the body. These injections can be performed blind by utilizing anatomical landmarks or with the use of imaging modalities to directly visualize the joint space during injections. This review of the literature aims to comprehensively identify differences in the accuracy of intra-articular injections via palpation vs. image guidance in the most commonly injected joints in the upper and lower extremities. To our knowledge, there are no such comprehensive reviews available. A narrative literature review was performed using PubMed and Google Scholar databases to identify studies focusing on the accuracy of blind or image-guided intra-articular injections for each joint. A total of 75 articles was included in this review, with blind and image-guided strategies being discussed for the most commonly injected joints of the upper and lower extremities. Varying ranges of accuracy with blind and image-guided modalities were found throughout the literature, though an improvement in accuracy was seen in nearly all joints when using image guidance. Differences are pronounced, particularly in deep joints such as the hip or in the small joints such as those in the hand or foot. Image guidance is a useful adjunct for most intra-articular injections, if available. Though there is an increase in accuracy in nearly all joints, minor differences in accuracy seen in large, easily accessed joints, such as the knee, may not warrant image guidance.

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.

VISCOSUPPLEMENTATION IN ANKLE OSTEOARTHRITIS: A SYSTEMATIC REVIEW

To evaluate the efficacy of viscosupplementation in patients with osteoarthritis of the ankle. A systematic review to evaluate the evidence in the literature on the use of viscosupplementation for osteoarthritis of the ankle. For this review, we considered blind randomized prospective studies involving the use of viscosupplementation for osteoarthritis of the ankle. A total of 1,961 articles were identified in various databases. After examining each of the articles, five articles were included in this review. Treatment with intraarticular hyaluronic acid is a safe treatment modality that significantly improves functional scores of patients, with no evidence of superiority in relation to other conservative treatments. Further clinical trials with larger numbers of patients are needed so that we can recommend its use and address unanswered questions. Systematic Review of Randomized Clinical Trials.

99mTc-HDP SPECT-CT Aids Localization of Joint Injections in Degenerative Joint Disease of the Foot and Ankle

BACKGROUND

Pain relating to degenerative joint disease within the foot and ankle can be difficult to localize with clinical examination alone due to the complex anatomy of the joints. The aim of this study was to determine whether single-photon emission computed tomography combined with conventional computed tomography (SPECT-CT) could be used to localize the site of degenerative joint disease for intra-articular injection and thereby improve the clinical success of the procedure.

METHODS

A prospective study was performed involving 203 patients who had undergone triple-phase (99m)Tc-hydroxymethylene diphosphonate bone scans with SPECT-CT of the foot and ankle for degenerative joint disease. Fifty-two patients went on to have joint injections for degenerative joint disease, with clinical follow-up. Correlation with the clinical diagnosis and the outcome of intra-articular injections with 0.5% bupivacaine and 80 mg of Depo-Medrone was performed. A successful outcome was determined by an improvement in the visual analog pain score of at least 50%.

RESULTS

In 19 (37%) patients, the site of degenerative joint disease determined by SPECT-CT differed from the initial clinical assessment and resulted in a change in management. Overall, 46 (88%) patients showed an improvement in symptoms.

CONCLUSION

The study demonstrated a high clinical success rate for SPECT-CT-guided joint injections. The technique was useful in localizing degenerative joint disease of the ankle, hindfoot, and midfoot as an adjunct to clinical examination.

LEVEL OF EVIDENCE

Level IV, case series.

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.

Procedure-oriented sectional anatomy of the ankle

This is the sixth in a series of articles related to procedure-oriented joint anatomy. This article reviews the anatomy of the ankle and its relationship to procedures in the clinical setting with or without ultrasound guidance. Anatomically correct axial and oblique axial schematics allow injections to be envisioned relative to clinically important anatomy for common ankle procedures. Cross-sectional schematics for the ankle were drawn as they appear in imaging projections. The levels and planes of cross section were selected to highlight important anatomic landmarks for injection. It is hoped these schematics allow for safer and more accurate needle procedures in the ankle area.

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.

Fluoroscopically guided diagnostic and therapeutic injections into foot articulations: report of short-term patient responses and comparison of outcomes between various injection sites

OBJECTIVE

A few studies have reported on short-term outcomes of patients receiving imaging-guided injections into the foot articulations, but none have compared patient responses depending on the anatomic site injected. This study includes a large sample size facilitating the investigation of postinjection pain reduction overall and by specific articulation.

MATERIALS AND METHODS

Three hundred forty-eight patients with imaging-guided diagnostic or therapeutic injections into the foot articulations, with complete preinjection and 20- to 30-minute postinjection numeric rating scale pain data were included. The proportions of patients reporting clinically relevant pain reduction (≥ 50%) were calculated overall and for specific subgroups. The risk ratio comparing patients with osteoarthritis to those without osteoarthritis was calculated. Analysis of variance was used to compare outcomes between subgroups of patients based on injection site. The unpaired Student t test was used to compare responses of men versus women, those with and without a diagnosis of osteoarthritis, and more experienced versus less experienced radiologists.

RESULTS

Sixty-four percent of patients (224/348) reported clinically relevant pain reduction. The average decrease overall was 56% (SD, 36). Injections into the Lisfranc articulation were significantly more effective (61% pain reduction, p = 0.007) compared with other sites, with 74% of patients obtaining clinically relevant pain relief. Patients with osteoarthritis reported more relief (62%) compared with those without (50%, p = 0.002). No difference in outcomes comparing musculoskeletal radiologists with residents or fellows in training was found.

CONCLUSION

Nearly two thirds of patients receiving imaging-guided injections into the foot articulations reported clinically relevant pain reduction. Lisfranc joint injections and patients with a diagnosis of osteoarthritis responded better.

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.

Pain in osteochondral lesions

Pain is the key symptom of patients suffering from osteochondral lesions (OCLs) of the ankle joint. Routine radiographic imaging methods for diagnosis and staging of OCL fail to visualize the pain-inducing focus within the joint. SPECT-CT (Single-photon emission computed tomography-computed tomography) is a new hybrid imaging technique allowing exact digital fusion of scintigraphic and computer tomographic images. This allows precise localization and size determination of an OCL within the joint. Using this novel imaging method, we conducted a study to evaluate the correlation between pathological uptake within an OCL and pain experienced by patients suffering from this condition; 15 patients were assessed in the orthopaedic ambulatory clinic for unilateral OCL of the ankle joint. Pain status was measured with the Visual Analogue Scale (VAS). A SPECT-CT was performed. All patients underwent CT-guided ankle injection with a local anesthetic and iodine contrast medium. The VAS score assessed immediately postinfiltration was compared with the preinterventional VAS score obtained in the outpatient clinic. Pain relief was defined as a reduction of the VAS score to ≤50% of the preinterventional score, if expected immediately after infiltration. Pain relief was found in all 15 patients. The results of our study show that there is a highly significant correlation between pain and pathological uptake seen on SPECT-CT, indicating that pathologically remodeled bone tissue is an important contributor to pain in OCL. Adequate addressing of involved bone tissue needs to be taken into consideration when choosing a surgical treatment method.

Sonographically guided proximal tibiofibular joint injection: technique and accuracy

OBJECTIVE

The purpose of this investigation was to describe a technique for sonographically guided proximal tibiofibular joint (PTFJ) injections and compare its accuracy with that of palpation guided injections in a cadaveric model.

METHODS

A single experienced operator completed 12 sonographically guided and 12 palpation guided PTFJ injections in unembalmed cadavers. The injection order was randomized, and all injections were completed with diluted colored latex. Coinvestigators blinded to the injection technique dissected each specimen and graded the colored latex location as accurate (in the PTFJ), accurate with overflow (within the PTFJ but also in other regions), or inaccurate (no latex in the joint). For statistical analysis, all injections placing latex within the PTFJ were considered "accurate," whereas "inaccurate" injections resulted in no PTFJ latex.

RESULTS

All 12 sonographically guided PTFJ injections accurately placed latex into the PTFJ (100% accuracy), whereas only 7 of 12 palpation guided injections (58%) placed latex within the PTFJ (P = .01). All 5 inaccurate palpation guided injections were superficial and inferior to the PTFJ. Four of 12 accurate sonographically guided PTFJ injections (33%) showed some overflow into the adjacent anterior musculature, whereas 5 of the accurate palpation guided injections (42%) resulted in overflow into the anterior musculature (1), knee joint (2), or both (2).

CONCLUSIONS

This cadaveric investigation suggests that sonographic guidance can be used to inject the PTFJ with a high degree of accuracy and should be considered superior to palpation guidance. Clinicians should consider using sonographic guidance to inject the PTFJ for diagnostic or therapeutic purposes when clinically indicated.

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.

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.