Percentage of ACL Reconstruction and Meniscus Repair Patients Requiring Total Knee Arthroplasty
Patients who undergo ACL reconstruction with meniscus repair have an extremely low rate (approximately 0.01%) of subsequently requiring total knee arthroplasty (TKA). 1
Risk Factors and Conversion Rates
- ACL reconstruction with meniscus repair has the lowest rate of subsequent TKA (0.01%) among common sports medicine procedures of the knee 1
- ACL reconstruction alone (without meniscus repair) has a similarly low rate of conversion to TKA with an odds ratio of 0.17 compared to other knee procedures 1
- Patients who undergo ACL reconstruction with meniscus repair have the longest period from index procedure to TKA at approximately 2,827 days (7.7 years) 1
Impact of Meniscus Status
- The status of the meniscus at the time of ACL reconstruction is a strong predictor of the risk of osteoarthritis and subsequent need for TKA 2
- Patients who undergo total meniscectomy are at 2- to 10-fold increased risk of developing osteoarthritis relative to those with intact menisci 2
- Partial meniscectomy carries a more than 6-fold increased risk of TKA compared with isolated ACL reconstruction 3
- ACL reconstruction with medial meniscectomy increases osteoarthritis odds 3.14 times compared with ACL reconstruction alone 4
- ACL reconstruction with partial meniscectomy increases osteoarthritis odds 1.87 times compared with ACL reconstruction alone 4
Long-Term Outcomes
- Long-term TKA failure rates are generally <1% per year for the general TKA population 4
- The prevalence of osteoarthritis in ACL-deficient knees is about 40% after 15 years and close to 90% after 25 to 35 years 2
- 94% of patients who underwent ACL reconstruction had stable knees after 15-20 years and significantly lower percentage of osteoarthritis compared to conservatively treated patients 5
Risk Factors for Meniscus Repair Failure
- The failure rate of repaired medial meniscus is approximately 10.0% and lateral meniscus is 7.1% 6
- Risk factors for subsequent meniscal surgery after ACL reconstruction include:
- Presence of medial meniscus injury at the time of ACL reconstruction
- Increased anterior tibial translation post-surgery
- Longer follow-up period after ACL reconstruction 6
Clinical Implications
- Meniscus preservation during ACL reconstruction is critical for long-term knee health and minimizing the risk of requiring TKA 1, 3
- Cartilage injury at the time of ACL reconstruction increases osteoarthritis odds 2.31 times compared with either no or less severe injury 4
- Salvage interventions such as meniscus transplantation have the highest risk of conversion to TKA (odds ratio = 3.06) 1
Common Pitfalls and Caveats
- Identifying the cause of a painful knee after ACL reconstruction is critical before considering revision surgery, as "reoperation is unwise and frequently associated with suboptimal results" in cases of unexplained pain 4
- The all-inside technique for medial meniscus repair has shown a significantly higher failure rate compared to other repair techniques or partial resection 6
- Patients showing early evidence of arthritis at short- to medium-term follow-up after ACL reconstruction are at high risk for progression over subsequent years 2