Portable dynamic ultrasonography is a useful tool for the evaluation of suspected syndesmotic instability: a cadaveric study

Comparison of ultrasonographic evaluation methods for ankle syndesmosis in non-weight bearing and weight bearing conditions

BACKGROUND

This study aimed to investigate ankle syndesmosis in healthy subjects under non-weight bearing (NWB) and weight bearing (WB) conditions using two US methods.

METHODS

The anterior tibiofibular clear space (ATFCS) was measured in healthy subjects in NWB and WB conditions using two US procedures. Method 1 measured 10 mm above the ankle joint and Method 2 measured 30° from the line of 10 mm above the ankle joint.

RESULTS

A total of 60 ankles from 30 subjects (male/female, 15/15) were included. There was a significant difference in the ATFCS between the two US methods (p < 0.001), and Method 2 was better at detecting the change in diastasis from NWB to WB conditions. The ATFCS was significantly greater on WB than on NWB, irrespective of the US method.

CONCLUSIONS

Method 2 was better at detecting diastasis of the syndesmosis from NWB to WB conditions. The influence of WB needs to be considered when evaluating syndesmosis using US.

LEVEL OF EVIDENCE

Cross-sectional cohort study; Level of evidence, Ⅳ.

Acute clinical evaluation for the diagnosis of lateral ankle ligament injuries is useful: A comparison between the acute and delayed settings

PURPOSE

To determine the diagnostic value of seven injury history variables, nine clinical tests (including the combination thereof) and overall clinical suspicion for complete discontinuity of the lateral ankle ligaments in the acute (0-2 days post-injury) and delayed setting (5-8 days post-injury).

METHODS

All acute ankle injuries in adult athletes (≥18 years) presenting up to 2 days post-injury were assessed for eligibility. Athletes were excluded if imaging studies demonstrated a frank fracture or 3 T MRI could not be acquired within 10 days post-injury. Using standardized history variables and clinical tests, acute clinical evaluation was performed within 2 days post-injury. Delayed clinical evaluation was performed 5-8 days post-injury. Overall, clinical suspicion was recorded after clinical evaluation. MRI was used as the reference standard.

RESULTS

Between February 2018 and February 2020, a total of 117 acute ankle injuries were screened for eligibility, of which 43 were included in this study. Complete discontinuity of lateral ankle ligaments was observed in 23 (53%) acute ankle injuries. In the acute setting, lateral swelling had 100% (95% confidence interval [CI]: 82-100) sensitivity, haematoma had 85% (95% CI: 61-96) specificity and the anterior drawer test had 100% (95% CI: 77-100) specificity. In the delayed setting, sensitivity for the presence of haematoma improved from 43% (95% CI: 24-65) to 91% (95% CI: 70-98; p < 0.01) and the sensitivity of the anterior drawer test improved from 21% (95% CI: 7-46) to 61% (95% CI: 39-80; p = 0.02). Clinical suspicion had a positive likelihood ratio (LR) of 4.35 (95% CI: 0.55-34.17) in the acute setting and a positive LR of 6.09 (95% CI: 1.57-23.60) in the delayed setting.

CONCLUSIONS

In the acute setting, clinical evaluation can exclude complete discontinuity (e.g., absent lateral swelling) and identify athletes with a high probability of complete discontinuity (e.g., positive anterior drawer test) of the lateral ankle ligaments. In the delayed setting, the sensitivity of common clinical findings increases resulting in an improved diagnostic accuracy. In clinical practice, this study underlines the importance of meticulous clinical evaluation in the acute setting.

LEVEL OF EVIDENCE

Level III.

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.

Unveiling Syndesmotic Malreduction: A Proof-of-Concept towards Portable Ultrasound Detection

Objectives

To evaluate the utility and diagnostic performance of portable handheld ultrasound for evaluating fibular rotation at the distal tibiofibular articulation after syndesmotic disruption.

Methods

Four above-the-knee cadaveric specimens were included. Syndesmotic disruption was precipitated by transecting the Anterior Inferior Tibiofibular Ligament, Interosseous Ligament, and Posterior Inferior Tibiofibular Ligament. Thereafter, a proximal fibular osteotomy was performed, and three conditions were modeled at the distal syndesmosis: 1) reduced, 2) 5 degree internal rotation malreduction, and 3) 5 degree external rotation malreduction. Two blinded observers performed separate ultrasonographic examinations for each condition at the level of both the anterior and posterior distal tibiofibular articular surfaces. Syndesmotic gap penetrance, defined as the ability of the P-US to generate signal between the distal fibula and tibia at the level of the incisura, was graded positive if the sonographic waves penetrated between the distal tibiofibular joint and negative if no penetrating waves were detected. The accuracy measures of the anterior and posterior gap penetrance were evaluated individually.

Results

Our preliminary results showed that posterior gap penetrance showed good performance when detecting either internal or external rotational malreduction of the fibula with very good specificity (87.5%) and PPV (90.0%). On the other hand, the anterior gap penetrance showed limited performance when detecting either form of rotational malreduction.

Conclusion

We introduced a novel sign, the "gap penetrance sign", best measured from the posterior ankle, which can accurately detect syndesmotic malreduction using P-US in a manner that does not require specific quantitative measurements and is readily accessible to early P-US users.

Application of external torque enhances the detection of subtle syndesmotic ankle instability in a weight-bearing CT

PURPOSE

Acute syndesmotic ankle injuries continue to impose a diagnostic dilemma and it remains unclear whether weightbearing and/or external rotation should be added during the imaging process. Therefore, the aim of this study was to assess if combined weightbearing and external rotation increases the diagnostic sensitivity of syndesmotic ankle instability using weightbearing CT (WBCT) imaging, compared to isolated weightbearing.

METHODS

In this retrospective study, patients with an acute syndesmotic ankle injury were analysed using a WBCT (N = 21; Age = 31.6 ± 14.1 years old). Inclusion criteria were an MRI confirmed syndesmotic ligament injury imaged by a WBCT of the ankle during weightbearing and combined weightbearing-external rotation. Exclusion criteria consisted of fracture associated syndesmotic injuries. Three-dimensional (3D) models were generated from the CT slices. Tibiofibular displacement and talar rotation were quantified using automated 3D measurements (anterior tibiofibular distance (ATFD), Alpha angle, posterior Tibiofibular distance (PTFD) and Talar rotation (TR) angle in comparison to the contralateral non-injured ankle.

RESULTS

The difference in neutral-stressed Alpha angle and ATFD showed a significant difference between patients with a syndesmotic ankle lesion and contralateral control (P = 0.046 and P = 0.039, respectively). The difference in neutral-stressed PTFD and TR angle did not show a significant difference between patients with a syndesmotic ankle lesion and healthy ankles (n.s.).

CONCLUSION

Application of combined weightbearing-external rotation reveals an increased ATFD in patients with syndesmotic ligament injuries. This study provides the first insights based on 3D measurements to support the potential relevance of applying external rotation during WBCT imaging. In clinical practice, this could enhance the current diagnostic accuracy of subtle syndesmotic instability in a non-invasive manner. However, to what extent certain displacement patterns require operative treatment strategies has yet to be determined in future studies.

LEVEL OF EVIDENCE

Level III.

Ultrasound is more reliable than clinical tests to both confirm and rule out pathologies of the long head of the biceps: a systematic review and meta-analysis

PURPOSE

To synthesize the literature and critically appraise current evidence to determine the most accurate physical examination (clinical test or ultrasound) to detect pathologies of the long head of the biceps tendon (LHBT).

METHODS

A search was performed on PubMed, Embase®, and Cochrane. Studies that compared the diagnostic accuracy of clinical tests or ultrasound versus arthroscopy for the assessment of LHBT pathologies were included.

RESULTS

Seven studies were included reporting on a total of 448 patients. One study on instability using ultrasound reported sensitivity and specificity of 1.00 and 0.96, respectively. Two studies on full-thickness tears using ultrasound reported sensitivity and specificity of 0.88-0.95 and 0.71-0.98, respectively. Four studies on partial-thickness LHBT tears reported sensitivity and specificity of 0.17-0.68 and 0.38-0.92, respectively, for clinical tests, versus 0.27-0.71 and 0.71-1.00, respectively, for ultrasound. Three studies on other LHBT pathologies reported sensitivity and specificity of 0.18-0.79 and 0.53-0.85, respectively, for clinical tests, versus 0.50 and 1.00, respectively, for ultrasound.

CONCLUSION

To detect LHBT pathologies, sensitivity is high-to-excellent using ultrasound, and moderate using Neer's sign and Speed's test, while specificity is high-to-excellent also using ultrasound, as well as the belly press, lift-off and Kibler's tests. The clinical relevance of these findings is that clinical tests are only reliable either to confirm or rule out LHBT pathologies, whereas ultrasound is reliable both to confirm and rule out LHBT pathologies. While diagnostic imaging cannot substitute for patient history and physical examination, the reliability and accessibility of ultrasound render it practical for routine use, particularly if clinical tests render unclear or contradictory findings.

LEVEL OF EVIDENCE

Level III.