Comparing Postoperative Outcomes of Isolated Anterior Cruciate Ligament Reconstruction and the “Terrible Triad” Anterior Cruciate Ligament Reconstruction With Medial Meniscus Ramp and Lateral Meniscus Root Repairs

Patient Selection

We used an electronic medical record to search for all patients between April 2016 and November 2021 who underwent an isolated ACLR (isolated cohort) or an ACLR with concomitant medial ramp and lateral root repairs—the “terrible triad” (triad cohort)—from 4 sports medicine fellowship–trained orthopaedic surgeons (B.P.B., C.M.L., C.A.W., and R.F.L). Institutional review board approval was obtained for this study. We identified an initial cohort of 1228 patients with ACLRs who were treated and followed at private ambulatory surgery centers. Of these, 41 patients had an ACLR with concomitant medial meniscus ramp and lateral meniscus root repairs. Identification of triad pathology was preoperatively observed diagnostically (via MRI) and was confirmed arthroscopically by direct visualization and probing intraoperatively. A total of 41 patients with an isolated ACLR were matched based on age and sex to the triad cohort and served as the control. Patients with concomitant injuries who did not match the triad pathology or had an ACL tear in isolation were excluded.

Patient Demographics

Demographic and patient characteristics included age, sex, prior surgical procedures, additional pathologies, concomitant procedures, follow-up, and any complications. The laterality, graft type, and meniscal repair technique, were also recorded. Compiled information was derived from operative notes, patient electronic medical records, and first-hand communication.

Surgical Technique

The surgical technique for each patient varied depending on the graft used and the extent of the injury. The graft of choice for the ACLR was a bone–patellar tendon–bone autograft, with hamstring tendon and quadriceps tendon being used secondarily to that. Autografts were used preferentially over allografts. The ACLR was performed via standard arthroscopic fashion and single transtibial and femoral tunnels. The insertion trajectory of the ACL tibial tunnel should be 7.1 mm anteromedial to the insertion of the anterior horn of the lateral meniscus. For the femoral ACL tunnel, the attachment center should insert 6.1 mm posterior to the lateral intercondylar ridge and 1.7 mm proximal to the bifurcate ridge. ⁵ Assessments of articular cartilage and intra-articular structures were made concurrently. Fixation of the ACL grafts was performed with an interference screw or buttons for the femur and a screw, button, or staple for the tibia. For the triad cohort, the medial meniscus ramp tear was repaired using an all-inside or inside-out technique depending on the size of the tear, with larger tears requiring an inside-out repair. For inside-out repairs, a posteromedial approach was made. Then, a spoon was placed to serve as a retractor in the medial interval on the posteromedial aspect of the capsule to catch the suture needles and protect the neurovascular structures. A self-delivery gun fitted with a cannula was used to pass double-loaded nonabsorbable sutures in a vertical mattress suture technique at the superior and inferior portions of the meniscus and capsule along the length of the tear. Sutures were securely tied over the exterior of the capsule. For all-inside meniscal repairs, a double-loaded all-inside suture device was used to deploy 2 anchor-based sutures with slipknots in a similar vertical mattress suture fashion as the inside-out repair. Anchors were deployed on the exterior portion of the capsule, and knots were fixed on the interior of the intra-articular meniscal surface. For lateral meniscus root repairs, the tears were repaired with a transtibial tunnel for type 2 root tears and all-inside or inside-out suture repairs for type 4 root tears (large radial flap tears at root attachment). ¹⁵ For transtibial root repairs, the lateral meniscus root insertion was decorticated with a curette, and 2 tunnels were drilled from the anterior tibial cortex posterior into the decorticated attachment of the lateral meniscus root. Sutures were then passed through the detached portion of the root. A suture passer was used to pull the sutures down the tunnels and return the meniscus root to its anatomic attachment. The sutures were tied over a cortical button.

Postoperative Rehabilitation

Patient postoperative rehabilitation was dependent on the type of surgery performed. In the isolated ACLR cohort, the patients were allowed full range of motion and were weightbearing as tolerated after surgery. Patients weaned off crutches once they could ambulate without a limp, usually at weeks 2 and 3.

Patients in the triad cohort were nonweightbearing for the first 6 weeks to protect their lateral meniscus root repair. Flexion was limited to 0° to 90° for the first 2 weeks and then progressed as tolerated after that. At 6 weeks, triad patients initiated a progressive weightbearing protocol, increasing weightbearing at 25% bodyweight per week until they were full weightbearing and could ambulate without a limp. For the first 4 months, the status of the root repair dictated most of the postoperative therapy regimen, with avoidance of squatting and sitting cross-legged for triad patients. Overall, for both cohorts, physical therapy initially focused on edema control, quadriceps activation, and regaining knee range of motion beginning day 1 postoperatively. Mobility, strengthening, stabilization, and neuro-reeducation were prioritized as the patient progressed throughout the protocol.

Outcome Evaluation

All patients included in this study were sent surveys from OBERD via email at milestone timepoints (preoperatively, 3 months, 6 months, 1 year, 2 years, and yearly) that included the International Knee Documentation Committee (IKDC), Cincinnati, Lysholm, Tegner, and Knee injury and Osteoarthritis Outcome Score (KOOS) Daily, Pain, Quality of Life (QoL), and Sports and Recreation (Sport) questionnaire forms. Any patients ≥2 years postoperatively without these PROs were contacted by telephone or email. Electronic medical records were reviewed to assess revision and reoperation rates. Reoperation was classified as any pertinent surgical intervention that occurred postoperatively to address persistent symptoms associated with initial injury mechanism or reconstructive surgery.

Statistical Analysis

Preoperative and postoperative PRO scores on the IKDC, Cincinnati, Lysholm, Tegner, and KOOS questionnaires between each cohort and within each cohort were analyzed using 2-tailed t tests assuming equal variance. The Shapiro-Wilk test for normality was used to confirm normality in preoperative PROs (P > .05). Revision and reoperation rates between the isolated and triad cohorts were analyzed using a chi-square goodness-of-fit test. Statistical analysis was performed using Microsoft Excel (Version 16.85; Microsoft Corp) and Statistical Package for the Social Sciences (Version 29.0.2.0; IBM Corp). The alpha level for significance was set at P≤ .05.

Limitations

This study is not without limitations. One limitation was the inability to match all relevant demographic variables including body mass index, injury mechanism, sports, and other contributing factors to recovery. Furthermore, we did not have a cohort of patients with ACLR and unrepaired medial meniscus ramp and LMRTs, which would have allowed direct comparison between performing and not performing the meniscal repairs. The retrospective nature of this study further limited the reliability of preoperative assessment data characterizing rotary instability, laxity, and increased translation. The addition of consistent physical assessments would allow for intercohort pre- and postoperative comparison of the biomechanical effects of this injury combination. This, in combination with postoperative imaging, can assess whether degenerative consequences exist. Furthermore, our conclusions on increasing triad prevalence are limited by the nonepidemiological nature of the study. The future direction of this study would optimally obtain larger patient cohorts and report over a longer time frame to improve the support of definitive inferences.