ACL injury with meniscus ramp lesion in 24-year-old professional athlete
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A 24-year-old male professional soccer player sustained an acute twisting injury during match play. He presented 1 week later and reported having acute right knee swelling and the inability to bear weight on his right lower extremity.
Physical examination demonstrated range of motion (ROM) from 0° to 100° with pain at the terminus of flexion over the posteromedial (PM) knee. Lachman and anterior drawer tests demonstrated grades of 2B and grade II, respectively. The knee was stable on posterior drawer testing and at varus/valgus stress at 0° and 30°. Furthermore, the dial test was negative at 0° and 90° and heel heights were noted to be symmetric.
What are the best next steps in management of this patient?
See answer below.
Arthroscopic ACL reconstruction, inside-out repair of medial meniscus
Plain radiographs were obtained and did not demonstrate any acute fracture or subluxation of the right knee.
MRI of the right knee was then obtained, which demonstrated an acute ACL rupture and injury of the posterior horn of medial meniscus (MM) at the meniscocapsular junction (Figure 1).
Source: Robert F. LaPrade, MD, PhD, FAAOS
Based on the findings of physical examination (knee instability) and the findings of the MRI, which were an ACL tear and ramp lesion of the MM, the patient was indicated for ACL reconstruction and meniscal repair of the MM.
Surgical technique
An initial diagnostic arthroscopy was performed with standard anterolateral (AL) and anteromedial portals directly adjacent to the patellar tendon. The lateral compartment was found to be free of significant meniscal or chondral injuries. Given that this patient was undergoing concurrent ACL reconstruction, the ACL remnant was debrided and the femoral tunnel was reamed with a 10-mm reamer.
Attention was then turned to the medial compartment. To visualize the posterior aspect of the MM from the AL portal, the arthroscope was advanced through the intercondylar notch with the knee in 30° flexion. The posterior MM was probed and found to be separated from its posterior capsular attachments and its attachment to the tibia inferiorly.
A PM approach to the tibia was then performed to allow for an inside-out repair of the MM. Dissection was carried down to the interval between the medial head of the gastrocnemius, semimembraosus tendon and the PM joint capsule. A retractor was placed along the posterior border of the tibia to protect the neurovascular structures. Meniscal repair began by introducing inside-out meniscal sutures from the AL portal. With application of a valgus force, the cannula was directed toward the tear under arthroscopic visualization. The initial suture needle was passed through the meniscus, and the second one was passed through the adjacent capsule to create a vertical or oblique repair pattern. The knee was placed in 10° to 20° flexion during needle advancement through the meniscus and capsule; after passage, knee flexion of 70° to 90° allowed for needle retrieval. Multiple inside-out sutures were placed 3-mm to 5-mm apart until stable fixation of the ramp lesion was confirmed (Figure 2).
Attention was then turned to harvesting of the patella tendon autograft in the usual fashion. The tibial tunnel for the ACL was then reamed with a 10-mm reamer in its anatomic footprint. The ACL graft was secured in the femoral and tibial tunnels using metal interference screws. The knee was taken through ROM and stability tests and was found to have excellent motion and stability.
Postoperative rehabilitation
The patient was encouraged to bear weight as tolerated upon discharge and was instructed to use crutches until he was able ambulate without a limp. Physical therapy commenced within 24 hours after surgery to initiate early ROM and muscle reactivation and to control edema. Rehabilitation included straight-leg raises in an immobilizer until there was no extension lag, at which point the patient was transitioned to a functional hinge knee brace.
The patient was allowed to begin straight-ahead running exercises at 4 months, with restrictions on pivoting and twisting. Gradual return to play progression was initiated at 6 months after successful completion of a functional sports test. Return to sports or activity was allowed at 9 months when the patient achieved normal strength, stability and knee ROM.
Discussion
Combined ACL and unstable ramp lesions of the MM represent a common injury pattern. The first step in treating ramp lesions is to have a high index of suspicion for these in patients with ACL injuries, as the ramp lesions have been reported to be present in 18% to 21% of patients with ACL tears. Unfortunately, there is not a dedicated physical exam maneuver to detect ramp lesions. However, surgeons should raise their clinical concern among patients with ACL tears who have a high-grade pivot shift or high-grade Lachman exam. Furthermore, surgeons must diligently look for missed ramp lesions in cases of failed ACL reconstruction. Studies have reported the sensitivity of MRI for ramp lesions at 48%, while the secondary finding of a PM tibial bone bruise was identified on preoperative MRI in 72% of patients. Given the challenges in diagnosis, it is paramount that surgeons visualize and probe the superior and inferior surfaces of the posterior horn of the MM.
Recent literature has demonstrated the importance of repairing meniscal ramp lesions. Muturi G. Muriuki, PhD, and colleagues performed a biomechanical analysis of 11 cadaveric knees with either radial or vertical tears of the MM and subsequent meniscal repair. Specimens were tested at varying degrees of axial load and contact pressures were measured. The authors reported increases in medial compartment contact pressures in both the vertical and radial tear groups, with meniscal repair reversing these increased contact forces. These findings are bolstered by clinical outcome studies that have demonstrated significant improvements in patient-reported outcomes after meniscal repair of multiple tear patterns. Taken together, laboratory and clinical data support the repair of MM tears to restore the ability of the meniscus to distribute hoop stresses and decrease joint forces.
The PM aspect of the MM also plays a role in decreasing anterior tibial translation (ATT) and rotational stability. Ji Hyun Ahn and colleagues performed a cadaveric study to define the role of the posterior horn of the MM in resisting ATT. The authors reported significantly greater ATT in specimens with ACL and posterior horn of the MM deficiency compared with isolated ACL-deficient specimens. Similarly, Nicholas N. DePhillipo, PhD, ATC, OTC, and colleagues studied the biomechanical effects of meniscocapsular and meniscotibial lesions of the posterior horn of the MM in ACL-deficient and ACL-reconstructed cadaveric knees. The authors reported in a study from 2018 that sectioning of the meniscocapsular and meniscotibial attachments of the posterior horn of the MM significantly increased ATT in ACL-deficient knees at 30° and 90°. Moreover, the authors reported that sectioning of meniscocapsular and meniscotibial attachments increased tibial internal and external rotation at all flexion angles in ACL-reconstructed knees.
Surgeons should have a high index of suspicion for ramp lesions in patients who sustain ACL tears. Ramp lesions should be repaired to restore both the joint protective function and the role in knee stability. It is essential for surgeons to actively probe the meniscocapsular aspect of the posterior horn of the MM in all knee arthroscopies and, to a greater degree, during revision ACL reconstruction cases.
Key points
- A high level of suspicion and a comprehensive review of the imaging is vital to detect these lesions. Surgeons must scrutinize MRIs for meniscocapsular bone bruise patterns and meniscocapsular separation.
- Failing to address a meniscal ramp lesion can result in changed knee biomechanics and increased failure rates.
- Extra attention should be placed on ramp lesion identification in the setting of failed ACL reconstructions. Restoring of the PH MM normalizes joint contact forces and helps prevent excessive ATT, as well as external and internal rotation.
- Excellent clinical results following ramp lesion repairs with and those without ACL reconstruction have been reported.
- References:
- Ahn JH, et al. Orthop Traumatol Surg Res. 2020;doi:10.1016/j.otsr.2020.03.025.
- Chahla J, et al. Arthrosc Tech. 2017;doi:10.1016/j.eats.2017.04.001.
- Chahla J, et al. Orthop J Sports Med. 2016;doi:10.1177/2325967116657815.
- Cinque ME, et al. Am J Sports Med. 2017;doi:10.1177/0363546517704425.
- DePhillipo NN, et al. Am J Sports Med. 2017;doi:10.1177/0363546517704426.
- DePhillipo NN, et al. Am J Sports Med. 2018;doi:10.1177/0363546518774315.
- DePhillipo NN, et al. Am J Sports Med. 2019;doi:10.1177/0363546518814258.
- DePhillipo NN, et al. Orthop J Sports Med. 2020;doi:10.1177/2325967120912427.
- Kunze KN, et al. Am J Sports Med. 2021;doi:10.1177/0363546520986817.
- Moatshe G, et al. Am J Sports Med. 2017; doi:10.1177/0363546517719244.
- Muriuki MG, et al. J Bone Joint Surg Am. 2011;doi:10.2106/JBJS.I.01241.
- Peltier A, et al. Knee Surg Sports Traumatol Arthrosc. 2015;doi:10.1007/s00167-015-3751-0.
- Sonnery-Cottet B, et al. Am J Sports Med. 2014;doi:10.1177/0363546514522394.
- For more information:
- Mark E. Cinque, MD, MS, and Christopher M. LaPrade, MD, can be reached at Stanford Health Care, Department of Orthopaedic Surgery, 450 Broadway Ave., Redwood City, CA 94063. Cinque’s email: mec89@stanford.edu. LaPrade’s email: claprade@stanford.edu.
- Robert F. LaPrade, MD, PhD, FAAOS, can be reached at Twin Cities Orthopedics, 4010 W. 65th St., Edina, MN 55435; email: laprademdphd@gmail.com.
- Gilbert Moatshe, MD, PhD, a specialist in orthopedic surgery, can be reached at Oslo University Hospital – Ullevål, PB 4014, Ullevål Stadion, 0806 Oslo, Norway; email: gilbertmoatshe@gmail.com.
- Edited by Mark E. Cinque, MD, MS, and Filippo F. Romanelli, DO, MBA. Cinque is a chief resident in the department of orthopedic surgery at Stanford. He will pursue a fellowship in sports medicine at The Steadman Clinic/Steadman Philippon Research Institute following residency completion. His interest is in complex knee surgery and multiligament reconstruction. Romanelli is a chief orthopedic resident at Rutgers – Jersey City Medical Center with an interest in adult reconstruction. He will be at New York University for his fellowship. For information on submitting Orthopedics Today Grand Rounds cases, please email: orthopedics@healio.com.
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