Does meniscal release confer similar clinical benefits to meniscal tear treatment when compared to meniscectomy?

PICO question 
In adult dogs with naturally occurring medial meniscal tears concurrent to cranial cruciate ligament disease does meniscal release confer the same benefits in lameness resolution as meniscectomy? 
  
Clinical bottom line 
Category of research question 
Treatment 
The number and type of study designs reviewed 
A single prospective cross-sectional study was reviewed, that fulfilled the criteria 
Strength of evidence 
None 
Outcomes reported 
Meniscal release, meniscectomy (partial, hemi- or complete), or the two combined performed for concurrent medial meniscal pathology at time of surgery for naturally occurring cranial cruciate ligament (CCL) rupture resulted in an acceptable long-term outcome. Difference in outcome between the techniques was not reported 
Conclusion 
There is no evidence that meniscal release provides an equal or superior treatment option for medial meniscal injury treated at the time of surgery for CCL rupture when compared to meniscectomy. The study critically reviewed performed meniscal release via radial transection through the meniscotibial ligament, and therefore does not represent mid-body abaxial radial release. Neither is this summary appropriate for considering prophylactic meniscal release of the normal meniscus. In addition, the surgical treatments for cranial cruciate ligament rupture were either ‘Tightrope’ or tibial plateau levelling osteotomy (TPLO) procedures. Further studies are required to compare clinical outcome between meniscal release or meniscectomy for treatment of concurrent meniscal tears 
  
How to apply this evidence in practice 
The application of evidence into practice should take into account multiple factors, not limited to: individual clinical expertise, patient’s circumstances and owners’ values, country, location or clinic where you work, the individual case in front of you, the availability of therapies and resources. 
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. 
  


A 3-year-old male neutered Labrador retriever presents for investigation of a moderate right pelvic limb lameness localising to the right stifle with positive tibial compression and cranial drawer tests. You recommend radiographic investigation, exploratory arthrotomy, and surgical stabilisation to confirm and then treat suspected cranial cruciate ligament rupture. During an exploratory arthrotomy you confirm rupture of the cranial cruciate ligament and note a 'bucket handle' tear of the medial meniscus. You are aware that meniscal release is anecdotally used to treat this injury, but are uncertain this would provide a clinical outcome equal to partial meniscectomy.

The evidence
A single study was reviewed for this Knowledge Summary. There are no studies that directly compares the two treatment techniques investigated in this review making it impossible to perform systematic review or metaanalysis. To the author's knowledge, there are no prospective randomised or blinded studies that directly compare the outcome of meniscal release and meniscectomy surgeries for the treatment of meniscal injury at the time of surgical treatment of cranial cruciate ligament rupture. The evidence presented as part of this summary compares the outcome of the two techniques grouped together with no meniscal treatment. Meniscal treatment performed was selected based on intra-operative assessment and a surgeon's clinical judgement for each patient. Clinical outcomes were assessed at medium and long-term follow-up utilising subjective owner assessment. These results suggest that either surgical intervention for concurrent meniscal tears provides a high level of acceptable patient function when meniscal treatment was selected based upon surgeon assessment and clinical judgement. Criteria for surgical decision making has not yet been defined to determine if and when meniscal release may confer similar clinical benefits to meniscectomy techniques. These were then grouped as successful (full and acceptable) or unsuccessful (unacceptable) outcome.

Limitations:
• Outcome assessed meniscal intervention overall and does not differentiate between treatment types • Meniscectomy included partial, hemi-, or complete • Comparison and outcome were not grouped based on type of meniscal surgical intervention • Meniscal intervention was based on surgeon preference, with surgeon number and skill level not clearly defined • Meniscal treatment elected is not stated to be based on pathology encountered • Concurrent surgery for CCL rupture was not randomised nor its impact on outcome assessed with respect to meniscal surgery • Population of dogs limited to patients referred to a single referral centre • Outcome was owner centric, subjectively assessed, and grouped into broad categories • Non-blinded • Non-randomised • Confidence intervals were performed as per methods, but are not stated • No statistical analysis is performed to consider the significance of outcome achieved • A large proportion of treated dogs were lost to follow-up at both 6-12 months and >1 year

Appraisal, application and reflection
Only a single study was identified from this literature review where meniscal release was used to treat meniscal tears identified at the time of surgery for cranial cruciate ligament rupture.
The study identified was observational, of prospective cross-sectional design, utilising a prospectively maintained database to retrospectively obtain data. Importantly, this study design was not intended to directly compare the effect of meniscal release with meniscectomy in a cohort of dogs. Instead, meniscal release and meniscectomy (partial, hemi-, or complete) were grouped together when considering clinical outcome. Whilst function, therefore successful outcome should be regarded cautiously. Statistical analysis to consider the significance of findings presented are not given within the study. Whilst confidence intervals were discussed in the methodology, these were not expressed further in the results, nor are power calculations presented to determine group sizes. Most importantly in relation to the clinical question, outcome was not separated between meniscal interventions or status at primary examination but instead grouped together. Therefore, when considering this, regardless of limitations this paper only demonstrates successful outcome for the reported meniscal interventions for concurrent tears as a whole. As such, in relation to the clinical question posed here, this Knowledge Summary is unable to provide evidence that meniscal release confers the same benefits as meniscectomy in the clinical outcome obtained.
The amount of available literature to consider this question is sparse, with very limited reference to meniscal release as a therapeutic technique for meniscal pathology. Meniscectomy procedures are the most widely adopted technique for meniscal pathology treatment , with meniscal repair methods described for select meniscal tears (Rovesti et al., 2018, andThieman et al., 2010). Notably, the most robust evidence in this field is a recent meta-analysis by McCready & Ness (2016a and b) investigating both cranial cruciate ligament treatment surgery and meniscal pathology diagnosis and treatment; however meniscal release as a treatment for concurrent tears did not feature in their analysis.
Anecdotally, some surgeons utilise meniscal release as their preferred treatment option for concurrent meniscal tears. Meniscal release is relatively less technically demanding than meniscectomy, is faster, and can be performed via blind or minimally invasive methods (Austin et al., 2007). Given the commonality of cranial cruciate ligament disease in the canine population (Wilke et al., 2005) with reported rates of 10-77% concurrent meniscal tears , successful meniscal treatment via the least invasive method possible may prove beneficial for patients and surgical efficiency considering the similar biomechanics reported between techniques (Pozzi et al., 2008b(Pozzi et al., , 2010a(Pozzi et al., , and 2010b. However, it is therefore important to determine if meniscal release confers the same well documented benefits to patients in lameness resolution as meniscectomy procedures before considering this an evidence based surgical technique. From this Knowledge Summary there is no evidence to support meniscal release as equal to meniscectomy in clinical outcome achieved when treating concurrently diagnosed medial meniscal tears at the time of index surgery for naturally occurring cranial cruciate ligament rupture. Other significant limitations include the unknown effect of the index surgery used to treat CCL rupture on the efficacy of meniscal treatment. Furthermore, the meniscal release utilised was exclusively axial (also known as 'caudal' or 'menisco-tibial') which should be borne in mind when considering clinical application. A well designed, standardised prospective randomised control study would be required with objective long-term outcome measures to investigate this clinical question.

Methodology Section Search Strategy
Databases searched and dates covered: Total relevant papers when duplicates removed 1