Long-term outcomes of meniscal-sparing vs meniscectomy approaches in ACL reconstruction: a systematic review with meta-analysis

Meniscal injury is concomitant in roughly two-thirds of ACL ruptures. Historically, partial meniscectomy was the default approach because of its technical simplicity and shorter rehabilitation. Increasing evidence has raised concern that meniscectomy accelerates compartmental cartilage wear and drives early-onset post-traumatic osteoarthritis (PTOA). Meniscal-sparing approaches — repair, transplant, or augmentation — promise compartmental preservation but require longer rehabilitation and carry higher technical failure rates in the first 6 months.

Pooled data from 38 studies (n=11,420) showed that at 10-year follow-up, the meniscal-sparing cohort had a 38% lower incidence of Kellgren-Lawrence grade ≥2 osteoarthritis on the operated knee compared with the meniscectomy cohort (RR 0.62, 95% CI 0.54-0.71). At 15-year follow-up the effect persisted (RR 0.67, 95% CI 0.58-0.78). Patient-reported outcomes (IKDC, KOOS-symptom) at 10 years favoured meniscal-sparing by a clinically meaningful margin (mean difference 8.4 IKDC points, 95% CI 6.1-10.7). Return-to-sport rates at 1 year were not significantly different between groups (74% sparing vs. 76% meniscectomy), though sparing participants returned to high-impact sport at lower rates (46% vs. 58%, RR 0.79). Sub-analysis by meniscal-sparing technique showed that all-inside repair and inside-out repair had comparable long-term outcomes; meniscal transplant data were sparse (n=412) and showed wider confidence intervals.

The 10-year osteoarthritis difference is large enough to influence individual patient counselling and policy. For active patients in their 20s and 30s — the median ACL-reconstruction demographic — every percentage point of OA risk translates into decades of joint health. The trade-off (longer rehab, higher early technical failure) appears clearly net-favourable for the meniscal-sparing approach in this population.

Database search of PubMed, Embase, and CENTRAL through January 2025. Inclusion: cohort studies of primary ACL reconstruction with concurrent meniscal pathology, comparing sparing vs. meniscectomy approaches, with minimum 5-year follow-up. Exclusion: revision ACL surgery, paediatric cohorts (<14 yrs), case series without comparator. Two reviewers independently screened titles, abstracts, and full texts. Disagreements resolved by a third reviewer. Risk of bias assessed via ROBINS-I; 12 studies were high risk and were excluded from the primary pooled estimate (retained for sensitivity analysis). Random-effects meta-analysis with DerSimonian-Laird estimator. Heterogeneity assessed via I² and τ². Publication bias assessed via Egger's test and funnel plot inspection. PROSPERO protocol CRD42024501XXX.

Selection bias is the central limitation: meniscal-sparing was preferentially offered to patients judged to have repair-amenable tear patterns, who may have had systematically less severe baseline injury. Propensity-matched sub-analysis (8 studies, n=2,840) attenuated but did not eliminate the effect, suggesting that selection accounts for some but not all of the 10-year OA difference. The meta-analysis includes substantial heterogeneity (I² = 64%) reflecting surgical-technique and follow-up-interval variation.

Optimal technique selection within the meniscal-sparing approach — when to repair, when to augment, when to transplant — remains under-studied at long-term horizons. The role of orthobiologic adjuncts (PRP, BMAC) in improving repair durability is uncertain. The question of whether early meniscectomy outcomes can be rescued by later interventions (transplant, osteotomy) is poorly addressed in the literature and warrants prospective study.