ACL Re-Injury
Kenneth G. Swan, Jr., M.D.
June 2, 2015
ACLR—Return to Play?
• Rate of return to play (RTP) after ACLR in NFL players is only 63% – Shah, AJSM 2010
– Level IV study
• ACL failure rate is variable across the literature – From <2% to as high as 29%
– Failures skewed towards young adolescents with allograft ACLR
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ACL Return to Play Failure
• Peri-operative complications – Infection
– Arthrofibrosis
• Poor surgical technique
• Psychological factors
• Graft failure/re-tear
• [Contralateral ACL injury]
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Allograft vs. Autograft
• Pallis, AJSM 2012
– Prospective cohort of 122 ACLR in West Point cadets
– Avg 2 yr f/u
– Failure rate measured as need for revision ACLR
– Results:
• BTB autograft: 11% failure rate
• HS autograft: 13% failure rate
• Allograft: 44% failure rate
– Level 2 Evidence
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Allograft
• Kaeding, SportsHealth 2011
• MOON study group
• Prospective longitudinal cohort, Level II
• Findings: Patient age and ACL graft type significant predictors of graft failure
• Risk of graft rupture: Allograft 4x that of auto
• Youngest, most active patients are not good candidates for allograft ACLR
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Incidence of 2nd Injury: What’s the Evidence?
• Substantial Level 2 evidence emerging re: risks of additional injury to the knees
• Wright, AJSM 2007 MOON group
• 2 year f/u
• 3% risk of re-tear of ACL graft; 3% risk of new c/l ACL tear
• Phone interviews, Op note f/u…..
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Risk of 2nd injury: What’s the Evidence?
• Shelbourne, AJSM 2009
• Prospective cohort with 5 year f/u
• Level II evidence
• 1,415 patients followed
• 4.3% re-injured the ACL; 5.3% had c/l ACL injury
• Females reinjured the same knee 4.3%, but injured the c/l knee at a higher rate 7.8% (men, 3.7%)
• Risk to either knee age dependant: 17% if <18yrs, 7% if 18-25yrs, 4% if > 25 yrs old
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Incidence of 2nd Injury: What’s the evidence?
• Andernord, AJSM 2015
• Swedish Nat’l Knee Ligament Registry
• Level 2 Evidence cohort, 5yr f/u
• 3% of pts required c/l ACLR
• Age <20 increased this risk by 3x
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2nd ACL Injury
• Paterno, AJSM 2014
• 78 young (avg age 17yrs) athletes followed prospectively for 24 mos.
• Pivoting, cutting sports
• Level 2 cohort study
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• Paterno, AJSM 2014 • Results
– Control group: 8.5% rate of primary ACL tear – Prior ACLR group: 29.5% rate of 2nd injury
• 70% c/l tear • 30% re-tear of ACL [graft] • Females likely more likely to tear c/l ACL than graft…. • Risk of 2nd injury calculated as 6x greater than controls
(both genders)
• Mean time from RTP to 2nd injury: 215 days
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What is the risk of re-injury after ACLR?
• What does the evidence tell us?
– Level II or higher
– As much as a 30% chance of re-injury (ipsilateral or contralateral)
– Risk is highest in young, active, female athletes, especially if used allograft
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Re-Injury References
• Andernord D, Desai N, Bjornsson H. Predictors of contralateral anterior cruciate ligament reconstruction: a cohort study of 9061 patients with 5-year follow-up. Am J Sports Med 2015;43(2):295-302
• Kaeding CC, Aros B, Pedroza A, et al. Allograft versus autograft anterior cruciate ligament reconstruction: Predictors of failure from a MOON prospective longitudinal cohort. Sports Health 2011;3(1):73-81
• Pallis M, Svoboda SJ, Cameron KL, et al. Survival comparison of allograft and autograft anterior cruciate ligament reconstruction at the United States Military Academy. Am J Sports Med 2012;40(6);1242-1246
• Paterno MV, Rauh MJ, Schmitt LC, et al. Incidence of second ACL injuries 2 years after primary ACL reconstruction and return to sport. Am J Sports Med 2014;42(7):1567-1573
• Shelbourne KD, Gray T, Haro M. Incidence of subsequent injury to either knee within 5 years after anterior cruciate ligament reconstruction with patellar tendon autograft. Am J Sports Med 2009;37(2):246-251
• Wright RW, Dunn WR, Amendola A. Risk of tearing the intact anterior cruciate ligament in the contralateral knee and rupturing the anterior cruciate ligament graft during the first 2 years after anterior cruciate ligament reconstruction: a prospective MOON cohort study. Am J Sports Med 2007:35(7):1131-1134
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ACL Injury Risk Factors? • Modifiable
– High BMI? – Jump landing mechanics – Hormonal? – Playing surface?
• Non-modifiable – Female Gender – Genetics? – Notch width – ACL size – Tibial slope – Ligamentous laxity
– PRIOR Hx ACL Surgery
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ACL Injury Risk Factors? • Modifiable
– High BMI? – Jump landing mechanics – Hormonal? – Playing surface?
• Non-modifiable – Female Gender – Genetics? – Notch width – ACL size – Tibial slope – Ligamentous laxity
– PRIOR Hx ACL Surgery
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What about bracing?
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Functional Bracing after ACLR
• Wright RW, Fetzer GB. Bracing after ACL reconstruction. CORR 2007;455:162-168
• Systematic Review of 12 randomized studies • Level I
• “No evidence to support the use of functional braces after ACLR”
• However….Recommendations vary; surgeon specific
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ACL and Osteoarthritis
• Patients with a history of an ACL tear are thought to have increased risk of developing osteoarthritis
• Daniel, AJSM 1994 “Fate of the ACL-injured patient”
• Questions:
– What factors contribute to OA after an ACL injury?
– Does ACLR prevent the onset of OA?
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ACL and OA
• Neuman, AJSM 2008
• Prospective prognostic cohort study, Level II, Sweden
• 15yr f/u of non-operatively tx’d ACLIs
– Avg age at injury: 26yrs
– all underwent initial arthroscopy, then therapy
– Neuromuscular physical therapy and activity modification
– 60/100 pts had meniscal tear at presentation; 25 had meniscectomy at initial surgery (35 did not!)
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• Neuman, AJSM 2008
• Results:
– Most patients were doing well (KOOS scores) – 31% required add’l menisectomy – 16% osteoarthritis (OA)** (avg age 45yrs) – Meniscectomy major risk factor for OA, ACLR or not – 23% eventually underwent ACLR at an avg of 4yrs – 68% were asymptomatic – Patients with non reconstructed knees and intact
menisci had best KOOS scores
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ACL and OA
• Keays, AJSM 2010
• Level I cohort study
• 56 patients followed over 6 years for development of OA after ACLR
• Graft choice, presence of meniscus and chondral injuries among factors investigated
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Keays, AJSM, 2010
• Results: – 48% of patients (now avg age 33yrs) had mild or moderate OA.
No one had severe OA – Tibiofemoral osteoarthritis
• Risk factors for OA post-ACLR
– Meniscectomy at time of ACLR – Chondral damage at time of ACLR – BTB autograft (62%) vs HS autograft (33%) – Quads strength and Q/HS strength ratio <1.27)
• Delay from injury to surgery trended towards significance……
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Does ACL surgery alter the Natural History of ACL injury?
• Chalmers, JBJS 2014 – Systematic Review
– Level III Evidence
– ~14 yrs after ACLR, patients had fewer subsequent meniscus injuries, less need for further surgery, and better (Tegner) activity level compared to non-op treatment
– However, no difference in IKDC and Lysholm knee scores and no difference in development of OA
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ACL and Osteoarthritis
• Bottom Line: – Patients who have suffered an ACL injury are at
increased risk of developing osteoarthritis in that knee
– ACLR likely does NOT alter that risk….yet
– ACLR may protect against further meniscus injury/surgery
– Meniscectomy at time of ACLR appears to be a risk factor for OA
– But, ACLR has not been proven to prevent OA…..
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ACL and OA References
• Keays SL, Newcombe PA, Bullock-Saxton JE, et al. Factors involved in the development of osteoarthritis after anterior cruciate ligament surgery. Am J Sports Med 2010;38(3):45-463
• Neuman P, Englund M, Kostogiannis I, et al. Prevalence of tibiofemoral osteoarthritis 15 years after nonoperative treatment of anterior cruciate ligament injury. Am J Sports Med 2008;36(9):1717-1725
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THANK YOU!
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