Characteristics, Patterns and Optimal Treatment Strategies of Morel-Lavallee Lesions: A Systematic Review

OBJECTIVES: To evaluate the diagnostic accuracy of imaging modalities and outcomes of treatment strategies for Morel-Lavallée lesions (MLLs) and provide evidence-based recommendations for optimal management. METHODS: Data Sources : MEDLINE, Embase, and Emcare databases were systematically searched for English-language studies published up to September 2024. Study Selection: Observational studies and randomized controlled trials (RCTs) reporting diagnostic accuracy or treatment outcomes for MLLs were included. Case reports, small series, animal studies, and non-English articles were excluded. Data Extraction: Study quality was assessed using the Methodological Index for Non-randomized Studies (MINORS) tool. Data on demographics, lesion characteristics, imaging modalities, and outcomes were extracted. Lesions were categorized as small (<100 cm 3 ) or large (≥100 cm 3 ) based on volume. Data Synthesis: Descriptive statistics summarized outcomes. Recurrence rates were calculated and pooled proportions compared across treatment modalities. RESULTS: Twenty-nine studies (928 patients, 964 lesions) were included. MLLs most frequently occurred in the thigh (26.5%), greater trochanter (24.9%), and lumbar region (20.3%). Among smaller lesions (<100 cm 3 ), nonoperative treatment had a low recurrence rate (5.6%), while for larger lesions (>100 cm 3 ), percutaneous management was associated with the highest recurrence rate (15%) compared to other treatment approaches. Operative treatment of large lesions had a 50% recurrence rate in one study, while sclerodesis achieved the lowest rate (4.8%) for lesions averaging 387 cm 3 , however, this finding is based on a limited number of cases (21 lesions). MRI was the most common single imaging modality reported (n=162 lesions, 19.5%), favoured for its superior soft-tissue characterization. Ultrasound was used in 121 lesions (14.6%) as an accessible initial assessment tool, while CT, often performed incidentally during trauma evaluation, diagnosed 339 lesions (40.9%). CONCLUSIONS: MRI was the most used single modality for diagnosing MLLs. Small, acute lesions were effectively managed nonoperatively. Large lesions (>100 cm 3 ) often required operative management. Sclerodesis appears promising with the lowest recurrence (4.8%), but further studies are needed. Standardized treatment protocols may help improve outcomes and reduce recurrence. LEVEL OF EVIDENCE: IV, systematic review