Imagine this clinical scenario: you examine a seven-year-old Labrador Retriever with a confirmed complete rupture of the left cranial cruciate ligament. When you discuss the treatment options available, the dog’s owner explains that their finances are constrained. You therefore offer either conservative treatment using non-steroidal anti-inflammatories (NSAIDs) and restricted exercise for six to eight weeks or surgery with the lateral fabellotibial suture (LFTS) technique, both as cost-effective options.
Speed of recovery is the primary factor for the client in choosing between these treatments. You therefore look for evidence comparing the rate of recovery following surgery with the LFTS technique to that of conservative treatment so you can advise the client appropriately.
The evidence
One paper, a retrospective study, was critically reviewed (Chauvet et al., 1996). It examined the use of fibular head transposition (FHT), LFTS and conservative treatment on dogs with cranial cruciate ligament ruptures. The sample size was 72 stifles across 61 dogs weighing more than 22.7kg, treated at a veterinary medical teaching hospital over a five-year period.
Twenty-two stifles (19 dogs) were treated with the FHT technique, and the time between intervention and evaluation was 26.7 months on average (mean). Thirty-nine stifles (36 dogs) were treated with the LFTS technique, with an average (mean) time between intervention and evaluation of 20.4 months. Eleven stifles (10 dogs) were treated with conservative treatment; for these, the time between intervention and evaluation was 7.1 months on average (mean).
The outcomes evaluated were owner evaluation outcomes, investigator physical examination evaluation, investigator radiographic evaluation and investigator force plate evaluation.
Summary of findings
Chauvetet al. (1996) found that there was no statistically significant difference between the reported outcomes for patients treated with LFTS and conservative treatment. The patients recorded were treated across a period of five years – between 1986 and 1991 – at the University of Illinois Veterinary Medical Teaching Hospital. Post-treatment evaluations were conducted between 3 and 66 months after the patient received treatment.
Although owner evaluation demonstrated that patients treated with LFTS had higher functional scores than conservative treatment, the difference was not statistically significant. Additionally, owner evaluation is subjective and difficult to use as a basis for scientific conclusions. Also, the results of owner evaluation could be attributable to the placebo effect in the surgically treated group as the owners were not blinded to which treatment their dog had received.
The only objective method of outcome analysis in this study was force plate analysis, which showed no statistical difference between the two interventions
The only objective method of outcome analysis in this study was force plate analysis, which showed no statistical difference between the two interventions. The comparison of force plate evaluation of the test limb with the contralateral limb is validated (O’Connor et al., 1989); however, there is no evidence that the contralateral limbs were evaluated before the interventions to ensure that they were normal and therefore acceptable as bases for comparison.
The time from intervention to evaluation varied widely in the study (between 3 and 66 months), making it difficult to determine and compare the extent of reduction of time to recovery of the two interventions under comparison. Since the clinical scenario aims to compare the rate of recovery for the two techniques, a standardised time between intervention and evaluation would have provided stronger evidence.
Limitations of the evidence
Overall, the quality of the evidence is weak. Only one paper relating to the clinical scenario was found, and this was a retrospective study. This study has a number of weaknesses, including:
- A relatively small sample size
- The subjectivity of most of the outcomes studied
- A lack of pre-treatment evaluations
- A lack of recording of pre-surgical evaluation of the patients
- A lack of evaluation of owner compliance
- A lack of a randomised or blind selection process
Additionally, no dogs weighing less than 22.7kg were included in the sample, which makes it difficult to conclude whether the evidence applies to a heterogenous dog population.
No dogs weighing less than 22.7kg were included in the sample, which makes it difficult to conclude whether the evidence applies to a heterogenous dog population
Conclusion
There is insufficient evidence to prove whether LFTS or conservative treatment results in faster recovery time, so further research is required to substantiate these findings. This should be obtained using prospective randomised blinded controlled clinical trials with large sample sizes representing a heterogeneous population of dogs with naturally occurring cranial cruciate ligament disease.
The RCVS Knowledge Canine Cruciate Registry aims to plug this gap in the evidence base by collecting data from practitioners in the UK performing surgery to address cruciate ligament disease in dogs. This initiative may provide the greatly needed evidence to inform treatment choices for practitioners and owners alike.
| The full Knowledge Summary can be read in RCVS Knowledge’s open access journal Veterinary Evidence. |
Disclaimer
The application of evidence into practice should take into account multiple factors, not limited to individual clinical expertise, patient’s circumstances, owner’s values, the individual case in front of you, the availability of therapies and resources, and the country, location or clinic where you work.
Knowledge Summaries are a resource to help reinforce or inform decision making. They do not override the responsibility or judgement of the practitioner to do what is best for the animal in their care.
