Stress radiographs in orthopaedic surgery

Identifying Intra-Articular Pathology With Arthroscopy Prior to Open Ankle Fracture Fixation

Purpose

To assess the prevalence of intra-articular findings with ankle arthroscopy in patients undergoing operative fixation for ankle fractures.

Methods

This is a retrospective review of ankle fractures that were treated with arthroscopy and open reduction and internal fixation by a single surgeon. Between August 2016 and July 2018, operative reports, office notes, and images were reviewed to identify intra-articular pathology and fracture type. An analysis was performed with regard to fracture type, presence and location of osteochondral lesions, loose-bodies, syndesmotic injury, and deltoid injury.

Results

Fifty-seven ankle fractures were identified that met inclusion criteria. In total, 84.2% of the fractures had intra-articular pathology, most commonly a syndesmotic injury followed by presence of intra-articular loose bodies and osteochondral defects.

Conclusions

In our study, use of arthroscopy before open ankle fracture fixation identified intra-articular pathology in 84.2% of subjects. The most common pathology was syndesmotic injury. The addition of an arthroscopic assessment in patients with operatively treated ankle fractures may help improve treatment provided to patients during ankle fracture surgery.

Level of Evidence

Level 4 Therapeutic Case Series.

How sensitive and specific is 1.5 Tesla MRI for diagnosing injuries in patients with knee dislocation?

PURPOSE

The purpose of this study was to assess the sensitivity and specificity of 1.5 T magnetic resonance imaging (MRI) in diagnosing and identifying the specific injury pattern in patients with knee dislocation. The hypothesis was that the sensitivity and specificity are low in patients with posterolateral corner injury and/or PCL tear.

METHODS

A retrospective study was performed on 38 patients (m:f = 29:9, mean age ± SD 34.3 ± 14.0) with traumatic knee dislocation, who underwent 1.5 T MRI prior to surgery. MRI scans were analysed by a musculoskeletal radiologist, and the presence and type of tears to ligaments, tendons and meniscus or bone were recorded. Comparison was made with the intraoperative findings from the surgical records using the same reporting scheme. The agreement between MRI and surgical findings was assessed using kappa statistics, and the sensitivity and specificity were calculated.

RESULTS

In patients with knee dislocation, MRI was found to have low sensitivity (25-38 %) but high specificity (94-97 %) for diagnosing injury to the posterolateral corner. There was high sensitivity in the diagnosis of tears in the cruciate and collateral ligaments (97-100 %); the specificity, however, was lower (50-67 %). The diagnosis of meniscal injury showed low sensitivity (36-56 %) and moderate specificity (69-83 %).

CONCLUSIONS

MRI is a sensitive measure of cruciate and collateral ligament injury in acute knee dislocation; however, it does not reliably diagnose injury to the posterolateral corner or meniscus, and therefore, a higher index of suspicion is required during arthroscopy to prevent misdiagnosis which could affect long-term clinical outcome.

LEVEL OF EVIDENCE

Diagnostic study, Level II.

Anterior talocrural joint laxity: diagnostic accuracy of the anterior drawer test of the ankle

STUDY DESIGN

Prospective, blinded, diagnostic-accuracy study.

OBJECTIVES

To investigate the diagnostic accuracy of the ankle anterior drawer test (ADT) to detect anterior talocrural joint laxity in adults with a history of lateral ankle sprain.

BACKGROUND

The ADT is used to manually detect anterior talocrural joint laxity following lateral ankle sprain injury; however, the diagnostic accuracy of this test has not been established.

METHODS

Sixty-six subjects with a history of lateral ankle sprain were examined with the ADT. Anterior talocrural joint laxity was measured digitally from ultrasound images of the talofibular interval during performance of the ADT. In addition, anterior talocrural joint laxity was measured digitally in 20 control subjects to establish a reference standard. ADT results were defined as "positive" or "negative," based on this and a second reference standard established from the literature.

RESULTS

The group with a history of lateral ankle sprain had a mean ± SD anterior talocrural joint laxity of 3.36 ± 3.25 mm, compared with 0.17 ± 1.87 mm in the control group. Thirty-five of 66 (53%) subjects demonstrated anterior talocrural joint laxity at a reference standard of 2.3 mm or greater, and 24 (36%) at a reference standard of 3.7 mm or greater. Sensitivity of the ADT was 0.74 (95% confidence interval [CI]: 0.58, 0.86) and 0.83 (95% CI: 0.64, 0.93) at the 2.3 mm or greater and 3.7 mm or greater reference standards, respectively. Specificity of the test was 0.38 (95% CI: 0.24, 0.56) and 0.40 (95% CI: 0.27, 0.56), respectively. Positive likelihood ratios were 1.2 and 1.4, whereas the negative likelihood ratios were 0.66 and 0.41, respectively.

CONCLUSION

The ADT provides limited ability to detect excessive anterior talocrural joint laxity; however, it may provide useful information when used in side-to-side ankle comparisons and in conjunction with other physical exam procedures, such as palpation.

LEVEL OF EVIDENCE

Diagnosis, level 3b.