Inside-Out Versus All-Inside Repair of Isolated Meniscal Tears: An Updated Systematic Review

Meniscal tears are common in the young, active population. In this group of patients, repair is advised when possible. While inside-out repair remains the standard technique, recent advances in all-inside repair devices have led to a growth in their popularity. Previous reviews on the topic have focused on outdated implants of limited clinical relevance.

To determine the difference in failure rates, functional outcomes, and complications between inside-out and modern all-inside repairs.

Systematic review.

A systematic review was registered with PROSPERO and performed following Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines using the MEDLINE, EMBASE, and Cochrane databases. Inclusion criteria were (1) clinical study reporting on all-inside or inside-out repair, (2) evidence levels 1 to 4, and (3) use of modern all-inside implants for all-inside repairs. Exclusion criteria were (1) use of meniscal arrows or screws and (2) concomitant surgical procedures. Study characteristics, subjects, surgical technique, clinical outcomes, and complications were collected and analyzed.

A total of 481 studies were screened and assessed for eligibility, which identified 27 studies for review. Studies defined clinical failure as persistent mechanical symptoms, effusion, or joint line tenderness, while anatomic failure was incomplete or no healing on MRI or second-look arthroscopy. There were no significant differences in clinical or anatomic failure rates between inside-out and all-inside repairs (clinical failure: 11% vs 10%, respectively, P = .58; anatomic failure: 13% vs 16%, respectively, P = .63). Mean ± SD Lysholm and Tegner scores for inside-out repair were 88.0 ± 3.5 and 5.3 ± 1.2, while the respective scores for all-inside repair were 90.4 ± 3.7 and 6.3 ± 1.3. Complications occurred at a rate of 5.1% for inside-out repairs and 4.6% for all-inside repairs.

The quality of the evidence comparing inside-out and all-inside meniscal repair remains low, with a majority of the literature being evidence level 4 studies. In this review comparing modern all-inside devices with inside-out repair, no differences were seen in failure rates, functional outcome scores, or complication rates.