The Use of Ultrasonography for Detection of Meniscal Damage in Dogs

a Knowledge Summary by

Peter Coss BVSc, MRCVS ^1*

¹Langford Vets, University of Bristol, Langford, BS40 5DU
^*Corresponding Author (pc17258@my.bristol.ac.uk)

Clinical scenario

In dogs which have clinically suspected stifle or meniscal pathology, surgical arthrotomy or arthroscopy is often used to evaluate (and treat if indicated) meniscal disease. In those dogs without meniscal pathology, this surgical exploration could be avoided (provided there are no other indications for surgical intervention) if a noninvasive, alternative test could be used. Ultrasonography of the menisci is well described, however, this is not currently widely utilised as a diagnostic test. Given the potential use of ultrasound for this purpose, it is important to know the accuracy of its use as a test for meniscal damage, more precisely the sensitivity and specificity.

Summary of the evidence

Appraisal, application and reflection

The original literature search revealed that there are several examples in the literature and books detailing how to perform an examination of the menisci however there were only three papers which assess this for suitability as a diagnostic test by evaluating sensitivity and specificity.

All papers were prospective cross sectional studies however, and used small numbers of dogs. The population across all three papers consisted of dogs with clinically suspected stifle disease or cranial cruciate ligament rupture and there were no normal dogs available as control subjects in any paper.

Arnault et al. (2009) assessed the use of ultrasound for general stifle lesions against arthrotomy findings. They reported a sensitivity and specificity of 82% and 93% respectively for ultrasonography in the detection of meniscal lesions by experienced ultrasonographers. One limitation of this study when compared to the others is that arthrotomy was used as the gold standard test. Within the discussion the authors comment on and reference the point that arthroscopy is more sensitive and hence would have made for a more suitable gold standard comparison. They also comment further that some meniscal lesions may have been missed at surgery due to their use of solely a craniolateral approach to arthrotomy, which may not allow visualisation of the entire meniscal surfaces. The study was partially blinded in that the imaging results were unknown to the surgeon although there would likely be some degree of bias because the surgeons were aware of the history and clinical examination findings of the dogs.

Franklin et al. (2017) investigated the use of stifle ultrasonography and also MRI for detection of surgical medial meniscal lesions when compared to arthroscopic findings. They reported a sensitivity and specificity of 95% and 82% respectively for ultrasonography in detection of medial meniscal lesions. One flaw in this study was that a surgeon with limited experience of stifle ultrasonography performed the ultrasound examinations. The same surgeon that performed the ultrasound also performed the arthroscopy afterwards and so could be biased with regard to the results. The statistics in this study were performed on the basis of whether a meniscus was surgical rather than if any lesion was present. The specific list of pathological changes which constituted a surgical or non-surgical meniscus was created for this study rather than being based on specific literature, so it may not be directly comparable across studies. Only medial menisci were evaluated in this study, likely because of the majority of meniscal disease to be medial, however it would have been ideal to include both menisci to increase overall number of menisci scanned in the study and to assess for differences in scanning difficulty or findings.

Mahn et al. (2005) also evaluated ultrasound as a diagnostic test as compared to arthroscopic findings. They reported a sensitivity and specificity of 90% and 90.2% respectively for ultrasonography in the detection of meniscal lesions. The surgeon for the arthroscopy was not blinded to the clinical findings so there may be some bias, as seen in the other papers. The experience of the ultrasonographer in this paper was not commented on so is unknown. During the arthroscopy an extra retractor was utilised through a separate port when necessary to maximise visualisation of the menisci which could have aided in lesion detection when compared to the use of a standard arthroscopy technique.

Overall the reported sensitivity varies from 82–95% and specificity from 82–93%. All three papers used high frequency probes for the assessment, which is likely to be an important prerequisite for general lesion identification. They also used cranial, middle and caudal views together for full assessment of the menisci. Two of the papers (Arnault et al., 2009; Franklin et al., 2017) comment on the difficulty involved with stifle ultrasonography and interpretation, therefore the sensitivity and specificity of using ultrasound as a diagnostic test for meniscal damage is likely to be heavily reliant on the experience of the ultrasonographer.

In summary, although there are few studies evaluating the subject, the use of ultrasound for identification of meniscal lesions appears to have good sensitivity and specificity in populations of dogs with suspected stifle disease. It is likely to be a useful diagnostic test however experience of the ultrasonographer may be an important factor to consider.

Methodology Section

Search Strategy
Databases searched and dates covered:	CAB Abstracts via the Ovid platform, covering from 1973 to 2018 Week 19. Medline via the Ovid platform, covering from 1946 to 2018.
Search terms:	(Dog* OR bitch* OR canine*) AND (menisc* OR stifle) AND (ultra*) AND (damage* OR lesion* OR trauma* OR tear OR injur* OR pathol*)
Dates searches performed:	21/05/2018

Exclusion / Inclusion Criteria
Exclusion:	Articles not available in English, single case reports, book chapters, conference proceedings, articles which did not answer the PICO question and literature reviews.
Inclusion:	Articles available in English which were relevant to the PICO. Articles had to involve more than one animal.

Search Outcome
Database	Number of results	Excluded – did not answer the PICO	Excluded – not in English	Excluded – irrelevant to PICO	Excluded – Conference Paper/Book/Review	Total relevant papers
CAB Abstracts	34	7	9	9	7	2
Medline	25	3	5	13	1	3
Total relevant papers when duplicates removed						3

The author declares no conflicts of interest.

1. Arnault, F., Cauvin, E., Viguier, E., Kraft, E., Sonet, J., and Carozzo, C. (2009) ‘Diagnostic value of ultrasonography to assess stifle lesions in dogs after cranial cruciate ligament rupture: 13 cases’, Veterinary and Comparative Orthopaedics and Traumatology, 22(6), pp. 479–485. DOI: 3415/VCOT-08-10-0103.
2. Franklin, S.P., Cook, J.L., Cook, C.R., Shaikh, L.S., Clarke, K.M., and Holmes, S.P. (2017) ‘Comparison of ultrasonography and magnetic resonance imaging to arthroscopy for diagnosing medial meniscal lesions in dogs with cranial cruciate ligament deficiency’, Journal of the American Veterinary Medical Association, 251(1), pp. 71–79. DOI: https://doi.org/10.2460/javma.251.1.71.
3. Mahn, M.M., Cook, J.L., Cook, C.R., and Balke, M.T. (2005) ‘Arthroscopic verification of ultrasonographic diagnosis of meniscal pathology in dogs’, Veterinary Surgery, 34(4), pp. 318–323. DOI: https://doi.org/10.1111/j.1532-950X.2005.00049.x.