Time Of Anterior Cruciate Ligament Reconstruction Research Articles

Arthroscopic Repair of a Lateral Meniscus Oblique Radial Tear

Background: Lateral meniscal oblique radial tears (LMORTs) are the most common type of lateral meniscal tears and occur concomitantly with anterior cruciate ligament (ACL) tears in up to 12% of cases. Four types of LMORTs have been classified in the literature based on proximity to the meniscal root and extent of the tear. Type 1 and 2 LMORTs represent partial and complete posterior root tears less than 10 mm from the root insertion. Type 3 and 4 LMORTs are partial and complete posterior radial meniscus tears greater than 10 mm from the root insertion. Indications: Type 3 and 4 LMORTs can and should be addressed with an all-inside side-to-side repair at the time of ACL reconstruction. LMORTs that are not repaired at the time of ACL reconstruction can contribute to persistent instability and meniscal extrusion. Technique Description: Diagnostic arthroscopy is performed to evaluate the posterior aspects of both the medial and lateral meniscus. The medial leaflet is commonly flipped into the notch and scarred to ACL remnant. After identifying and isolating the medial leaflet, an arthroscopic suture passer is used to pass a suture from inferior to superior through the medial leaflet. A second suture is passed from inferior to superior through the lateral leaflet. This is used to shuttle the suture pass through the medial leaflet to the bottom of the meniscus, where it can be tied in a horizontal mattress fashion. The sutures are tied down with aide of an arthroscopic knot pusher. A second set of sutures is passed and used to shuttle a second suture that would be tied posterior to the first suture, again in a horizontal mattress fashion. This allows reduction of the fragments in apposition across the tear. Postoperatively, patients are allowed range of motion from 0° to 90° and to toe touch weightbearing for the first 4 weeks. Patients are advanced to weightbearing as tolerated at 5 weeks. Typical return to sport ranges from 6 to 9 months postoperatively. Results: Results have been published for 2-year outcomes of type 3 and 4 LMORT repairs and have demonstrated persistent improved patient-reported outcomes as well as healing rates that are greater than 80% and in some series approach nearly 100%. Discussion/Conclusion: Arthroscopic all-inside side-to-side surgical repair is a durable and reliable treatment option for patients presenting for ACL reconstruction with concomitant type 3 or 4 LMORT. Patient Consent Disclosure Statement: The author(s) attests that consent has been obtained from any patient(s) appearing in this publication. If the individual may be identifiable, the author(s) has included a statement of release or other written form of approval from the patient(s) with this submission for publication.

Patients with higher numbers of allergies have lower levels of anti-inflammatory cytokines and increased pain at the time of ACL reconstruction

BackgroundSynovial fluid biomarkers are well studied indicators of inflammation and healing in the setting of orthopedic injuries. However, it has not been studied if patients with one or more allergies have a difference in the concentrations of synovial fluid inflammatory cytokines compared to patients without allergies. The purpose of the current study is to analyze the concentration of 10 pro- and anti-inflammatory cytokines in the synovial fluid of isolated ACL injury patients with and without at least one allergy. Study DesignRetrospective Case-Control. MethodsA database of patients who underwent surgery for isolated ACL injury between September 2011 and July 2023 was analyzed. All patients had SF aspirated from the operative knee prior to the surgical incision and the concentrations of pre- and anti-inflammatory biomarkers were quantified. From this cohort, 24 patients were identified to have allergies by chart review. These patients were matched 1:1 to 24 patients without allergies based on age and sex. ResultsThere were no significant differences between the allergy and no allergy cohorts with respect to age (28.5 ± 10.3 vs. 29.5 ± 8.9, p = 0.76) and sex (70.8 % female vs. 70.8 % female, p = 1.00). The allergy cohort had a decreased concentration of TIMP-1 (492.41 ± 616.20 ng/mL vs. 1041.48 ± 942.04 ng/mL, p = 0.03) and IL-1Ra (101.70 ± 93.37 pg/mL vs. 359.94 ± 399.77 pg/mL, p = 0.01) compared to patients without allergies. A linear regression analysis found a significant association between increasing number of patients reported allergies and decreasing concentration of TIMP-1 (β = -231.59, p = 0.03) and IL-1Ra (β = -71.69p = 0.03) concentrations when controlling for age and sex. Finally, the allergy cohort was found to have a significantly higher value for the VAS pain scale at the time of surgery (26.84 ± 24.73 vs. 7.37 ± 10.98, p < 0.01) compared to those without an allergy. ConclusionPatients undergoing ACL reconstruction with at least one allergy were found to have decreased concentrations of the anti-inflammatory cytokines TIMP-1 and IL-1Ra in their synovial fluid compared to those without allergies on the day of surgery. Furthermore, an increase in total number of allergies was found to be an associated with a decrease in TIMP-1 and IL-1Ra levels. Finally, the allergy cohort also had a higher value for the VAS pain scale at the time of surgery, implicating the role of a patient’s innate immune system to their biologic and symptomatic response to injury.

Incidence of and Risk Factors for Medial Meniscal Lesions at the Time of ACL Reconstruction: An Analysis of 4697 Knees From the SANTI Study Group Database

Background: Medial meniscal (MM) lesions (MMLs) are a common finding at the time of anterior cruciate ligament reconstruction (ACLR). It is recognized that evaluation of the posteromedial compartment reduces the rate of missed MML diagnoses. Purpose: To determine the incidence of MMLs in patients undergoing ACLR, when using a standardized arthroscopic approach that included posteromedial compartment evaluation, as well as to determine how the incidence of MMLs changed with increasing time intervals between injury and surgery, and to investigate what risk factors were associated with their presence. Study Design: Case series; Level of evidence, 4. Methods: A retrospective analysis of prospectively collected data was performed. All patients who underwent primary ACLR between January 2013 and March 2023 were considered for study eligibility. The epidemiology was defined by categorizing and reporting the incidence and categorizing the spectrum of MM tear types. Risk factors associated with MMLs were analyzed using a logistic regression model. Results: MMLs were identified in 1851 (39.4%) of 4697 consecutive patients undergoing ACLR. The overall incidence of MMLs was 33.1% for the period of 0 to 3 months, 38.7% for the period of 3 to 12 months, and 59.6% for the period of >12 months. The overall incidence of MMLs increased with longer durations of time between injury and surgery, along with significant increases in complex, bucket-handle, ramp, and/or flap lesions. The largest increase in incidence of MMLs was observed for complex MM tear patterns. Risk factors associated with MMLs included time between injury and surgery >3 months (odds ratio [OR], 1.320; 95% CI, 1.155-1.509; P < .0001) and >12 months (OR, 3.052; 95% CI, 2.553-3.649; P < .0001), male sex (OR, 1.501; 95% CI, 1.304-1.729; P < .0001), body mass index (BMI) ≥25 (OR, 1.193; 95% CI, 1.046-1.362; P = .0088), and lateral meniscal lesion (OR, 1.737; 95% CI, 1.519-1.986; P < .0001). Conclusion: Overall, MMLs were identified in 39.4% of 4697 patients undergoing ACLR when posteromedial compartment evaluation was performed in addition to standard anterior viewing. The incidence of MMLs and the complexity of tear types increased significantly with increasing time intervals between the index injury and ACLR. Secondary risk factors associated with an increased incidence of medial meniscal tears include male sex, increased BMI, and lateral meniscal lesions.

Incidence and risk factors for medial meniscus lesions at the time of ACL reconstruction: An analysis of 4697 knees

Incidence and risk factors for medial meniscus lesions at the time of ACL reconstruction: An analysis of 4697 knees

The posterior cruciate ligament-posterior femoral cortex angle (PCL-PCA) and the lateral collateral ligament (LCL) sign are useful parameters to indicate the progression of knee decompensation over time after an ACL injury.

The posterior cruciate ligament-posterior cortex angle (angle between the most vertical part of the anterolateral PCL bundle and the posterior diaphyseal cortex of the femur; PCL-PCA) is the most accurate approach to describe the PCL buckling phenomenon observed in anterior cruciate ligament (ACL)-deficient knees. The aim of this study was to determine whether the PCL-PCA is associated with chronicity of the ACL rupture, the meniscal status, preoperative knee laxity or imaging signs such as the lateral collateral ligament (LCL) sign or the posterior tibial slope (PTS) in ACL-injured knees. Patients with a primary ACL reconstruction (ACLR) after physeal closure were selected retrospectively from a hospital-based ACL registry from 2015 to 2021. Exclusion criteria were: previous ipsilateral/contralateral knee surgery, previous ipsilateral ACL or meniscal tear, ipsilateral PCL and/or collateral ligament injuries or tibial plateau fracture. The ACL deficiency was defined as chronic if time from injury to MRI was > 6months. The meniscal status was assessed during ACLR, separately for the medial and lateral meniscus, and classified into no tear, minor or major unstable tear. The MRI analyses included the assessment of the PCL-PCA and the LCL sign. PTS was assessed from the lateral plain radiographs of the injured knee. The side-to-side difference in anterior tibial translation (ATT) at 200N was obtained with the GNRB. Eighty-two patients (forty-eight males/thirty-four females) were included in this study. The median PCL-PCA was 16.2° (Q1-Q3: 10.6-24.7) and differed between acute (18.4°) and chronic (10.7°) injuries (p < 0.01). The median PCL-PCA was significantly lower (- 4.6°) in patients with a positive LCL sign (p = 0.03) No significant association could be found between PCL-PCA and meniscal status, PTS or preoperative anterior knee laxity (Lachman, pivot shift and ATT in millimetres). The PCL-PCA was significantly lower in chronic ACL injuries and in patients with a positive LCL sign, indicating a higher buckling phenomenon of the PCL in these patients. These results support the fact that PCL-PCA and the LCL sign may be useful parameters to indicate the progression of knee decompensation over time after an ACL injury, and therefore may constitute a helpful tool to optimise treatment choice and timing of ACL reconstruction if necessary. III.

Risk Factors for Concomitant Meniscal Injury With Sport-Related Anterior Cruciate Ligament Injury.

Previous studies of concomitant meniscal injury in athletes with anterior cruciate ligament (ACL) injury have examined age, sex, body mass index (BMI), injury mechanism, and time from injury to surgery as potential risk factors. To identify additional risk factors for concomitant meniscal injury, including preinjury joint laxity and lower extremity alignment, in athletes with sport-related ACL injury. Cross-sectional study; Level of evidence, 3. This study included 180 participants aged 13 to 26 years who underwent ACL reconstruction (ACLR) after a first-time ACL injury sustained during participation in sport. Contralateral lower extremity alignment and joint laxity were used as surrogate measures for the injured knee before trauma. Concomitant meniscal tear patterns were identified at the time of ACLR. Sex-specific analyses were conducted. Concomitant meniscal injury was observed in 60.6% of the subjects. The prevalence of concomitant injury was higher in male than female participants (69.9% vs 54.2%; P = .035) due to a higher prevalence of lateral meniscal injuries (56.2% vs 38.3%; P = .018). Among male patients, there was a significant difference in the prevalence of concomitant lateral meniscal tear according to sport participation (≥9 vs <9 h/week: 67.4% vs 35.7%; P = .032). Among male patients, the likelihood of concomitant injury to both the lateral and medial menisci increased by 28.8% for each 1-mm decrease in navicular drop. Among female patients, the likelihood of concomitant injury to the lateral meniscus increased by 15% per degree increase in genu recurvatum and 14% per degree decrease in standing quadriceps angle, with similar effects on the likelihood of concurrent injury to both the lateral and medial menisci. Measures of lower extremity alignment and genu recurvatum previously identified as risk factors for ACL injury were also associated with concomitant meniscal injury in female patients while other risk factors, including BMI and joint laxity, were not. Increased time spent participating in sport and navicular drop were associated with concomitant meniscal injury in male patients.

Knee stiffness post anterior cruciate ligament reconstruction- factors to worry about

Background: Knee stability is affected by integrity of anterior cruciate ligament (ACL). Knee stiffness is a worrying postoperative complication, preventing patients from returning back to pre-injury sport level. In this study, we analyzed incidence of knee stiffness post ACL reconstruction and possible associated risk factors. Methods: This is retrospective study, was held in Royal Medical Services/Jordan–Queen Alia Military hospital/Arthroscopic and Sport injuries division. We analyzed 250 patients’ data using computerized patients record system (CPRS) called Hakeem complaining of knee stiffness post ACL reconstruction between July 2022 and July 2023, whom ACL reconstructive surgeries were performed between March and September 2022. Results: Incidence of knee stiffness post ACL reconstruction is about 1.5% (4 out of 250). All of those 4 patients were males,3 of them had limited flexion (75%), while 1 of them had limited extension (25%). All of the 3 patients having extension contracture had an associated medial meniscus tear, repaired at time of ACL reconstruction, while flexion contracture patient had an isolated ACL tear. Conclusions: Incidence of knee stiffness post ACL reconstruction is about 1.5%. 75% of patients were associated with medial meniscus tear, who underwent meniscus repair and hinged knee brace was applied. We conclude that ACL patients having an associated meniscus tear managed by meniscus repair and hinge knee brace are at higher risk to develop knee stiffness. Therefore, we recommend limiting the usage of knee brace for ACL reconstruction with meniscus repair only.

Poster 321: MENISCAL RAMP LESIONS IN ADOLESCENT PATIENTS UNDERGOING PRIMARY ACL RECONSTRUCTION

Objectives: Meniscal ramp lesions describe a specific injury to the meniscocapsular junction at the posterior horn of the medial meniscus. The lesions are strongly associated with anterior cruciate ligament (ACL) injuries and may affect the biomechanical stability of the knee if left untreated. Despite the increasing rates of ACL reconstructions performed in adolescents each year, the prevalence and risk factors for ramp lesions in this patient population is poorly understood. The purpose of this study was to determine the prevalence and risk factors for ramp lesions in children and adolescent patients undergoing primary ACL reconstruction. Methods: All patients ≤19 who underwent primary ACL reconstruction at a single institutional between 2019 and 2021 were included. All surgeries were performed by three fellowship trained orthopedic surgeons. Patients were considered to have a ramp lesion if one was identified arthroscopically at the time of ACL reconstruction. Basic demographic data, preoperative imaging, and other arthroscopic findings at the time of ACL reconstruction were reviewed. Results: 247 consecutive patients who underwent ACL reconstruction were reviewed. Patients were excluded if they had had prior ACL injury, prior knee surgery, fibular hemimelia, or incomplete documentation. A total of 230 patients met inclusion criteria. Average age at time of injury was 15.7 years (range 4.0-18.2 years). A ramp lesion was identified in 12% of patients. Posteromedial tibial bone bruise on preoperative MRI and medial femoral chondromalacia at time of ACL reconstruction were associated with the presence of a ramp lesion, Figure 1A (OR = 2.6, 95% CI [1.15, 5.93]). A striation pattern of medial femoral chondromalacia was highly specific for the presence of a ramp lesion, Figure 1B (OR = 424.3, 95% CI [50.99, 3531.3]). Sensitivity and specificity for detecting a ramp lesion was 68% and 76% with preoperative MRI and 68% and 99.5% with medial condyle striations, respectively. Conclusions: The prevalence of a ramp lesion in our cohort was 12%, mirroring historical reports in adult patients. Posteromedial bone bruising and medial femoral chondromalacia, especially in a striation pattern, should increase suspicion for the presence of a ramp lesion in patients undergoing ACL reconstruction.

Poster 150: Immunophenotyping of Synovial Tissue in Adolescents Undergoing ACL Reconstruction Reveals Distinct Inflammatory Responses to Injury

Objectives: Tears of the anterior cruciate ligament (ACL) are common in the pediatric athletic population. In spite of trends towards early surgical reconstruction to minimize the risk of secondary meniscus and cartilage injuries, long term disruption of knee joint homeostasis and progression to post- traumatic osteoarthritis (PTOA) occurs in 50-90% of patients - a particularly challenging problem in this young cohort. The exact pathogenesis of PTOA after ACL injury and reconstruction remains unknown. Evidence from animal models of PTOA suggests a critical role of synovial inflammatory infiltration in both the onset and progression of PTOA. However, there is a scarcity of in vivo human data documenting the synovial inflammatory response to ACL injury. One recent study has looked at immune cell composition in synovial fluid, but there are no comparable publications using synovial tissue. Our primary objective was to use flow cytometry with an advanced immune cell panel to provide a snapshot of the cellular composition of immune infiltrates in the synovium of adolescent patients at the time of ACL reconstruction. Our secondary objective was to look for correlations between demographic and injury parameters and inflammatory cell composition. Methods: Patients between the ages of 12 and 18 years who were undergoing primary ACL reconstruction were enrolled in an IRB-approved prospective study. Exclusion criteria included multiligament knee injuries, revision ACL reconstruction, history of prior knee surgery, and history of inflammatory joint disease. Demographic variables and intraoperative data were recorded. At the time of surgery, an arthroscopic synovial biopsy from the prefemoral synovium was obtained. Synovium tissue was enzymatically digested into a single cell suspension for immune profiling by multicolor flow cytometry. Data was acquired on a BD lsrFortessa flow cytometer and analyzed with FlowJo v10. Statistical analyses were performed with GraphPad Prism including parametric ANOVA (one-way or two- way), simple linear regression, Kruskal Wallis analysis of variance, Mann Whitney T-test, and parallel Principal component analyses (Eigenvalue with Monte Carlo simulation). Heat map variable scaling was calculated relative to the mean and standard deviation of all measurements. Results: Twelve patients were prospectively enrolled in the study (33% male, 67% female, n = 12). Mean age was 15.5 +/- 2.02 years. Median time between injury and surgery was 35.5 days (23.3-67.5). Meniscal tears were present in 58.3% of patients (8.3% medial only, 33.3% lateral only, 16.7% both). Cells isolated from synovium were 36.8% fibroblasts, 9.89% fibrocytes, and 36.0% hematopoietic lineage cells (Fig. 1A). Within the hematopoietic lineage, the dominant cell types were monocytes, macrophages, and T-cells (Fig. 1B). Principle component analysis (PCA) revealed three immunophenotypes. Immunotype 1 had higher mast cell content than other groups and fewer inflammatory cells such as T cells, B cells, and macrophages. Immunotype 2 had strong T/B cell infiltration and lower levels of innate immune cells. These patients also had the highest overall levels of inflammatory cells (Figure 2). Immunotype 3 had a strong innate immune response - in particular higher levels of M2 polarized macrophages - and significantly fewer T/B cells. There were no obvious effects of age, skeletal maturity, or the presence of meniscal tears on immunotype (Table 1). There was a trend towards a correlation between delay in surgery and classification within immunotype 1 (p = 0.09, Table 1). Conclusions: Our study provides the first in vivo analysis of inflammatory cell behavior in the synovium of ACL injured knees. In young patients undergoing primary ACL reconstruction, three immunotypes were discovered. Our pilot data suggest a possible relationship between delay in surgery and a high prevalence of synovial mast cells. This would be of particular interest since mast cells are known to play a role in the development of OA and possibly PTOA. In the more acute setting, two separate immunotypes were encountered, one with heavy inflammation and a predominance of T/B cells, and the other with more moderate inflammation and a higher percentage of innate immune cells / M2 polarized macrophages. These were not clearly tied to patient demographic factors, and could represent intrinsic differences in the response to injury. Future work investigating the correlation between initial immunotype and clinical outcomes – in particular the development of PTOA – may provide insight into the role of synovial inflammation in post-ACL joint health and degeneration, as well as provide strategies for personalized treatments in the prevention of PTOA. [Table: see text]

Poster 248: Lateral extra-articular tenodesis augmentation of anterior cruciate ligament reconstruction does not impact cartilage health in the patellofemoral joint based on post-operative two year qualitative and quantitative MRI analysis

Objectives: Lateral extra-articular tenodesis (LET) augmentation of anterior cruciate ligament reconstruction (ACLR) has been shown in multiple clinical and biomechanics studies to be an effective procedure to control rotational laxity, reducing failure rates. However, it is uncertain whether augmentation with an iliotibial band based LET may cause increased contact pressure in the patellofemoral joint (PFJ), resulting in cartilage damage. The purpose of the current study was to assess PFJ cartilage status in patients that underwent ACLR with or without LET augmentation using magnetic resonance imaging (MRI). It was hypothesized that 1) the addition of LET at the time of ACLR would have no effect on cartilage health on post-operative two-year MRI; 2) higher cartilage relaxation values would be associated with worse patient reported and functional outcomes at two years post-operatively. Methods: A subset of patients from the STABILITY 1 randomized controlled trial were included. All patients underwent primary ACLR with a hamstring autograft. The patients were randomized either to receive LET augmentation (modified Lemaire technique) or not. Cartilage status in the PFJ between ACLR alone group and ACLR+LET group were compared by quantitative MRI (qMRI) analysis of T2 and T1 rho sequences (figure 1), and qualitative assessment by ACL osteoarthritis score (ACLOAS) on post-operative two year MRI for surgical and contralateral non-surgical knees. Objective functional outcomes (range of motion (ROM), hop test and isokinetic strength) and patient reported outcome measures including Knee injury Osteoarthritis and Outcome Score (KOOS) and International Knee Documentation Committee (IKDC) score were attained. Descriptive statistics were calculated for each group using means and standard deviations (SD) for continuous variables and proportions for categorical variables. ANCOVA was used to determine the adjusted mean difference in T1rho and T2 relaxation times between groups for each compartment in the patella and trochlea. Spearman’s rho was used to assess the correlation between relaxation times within each compartment and patient-reported and functional outcomes at two-years postoperative. Statistical significance was set at P = 0.05. Results: Ninety-two patients (43 patients in ACLR group, mean age (±SD) 18.9±3.2 years, 60.5% female, and 49 patients in ACLR+LET group, 18.7±3.2 years, 63.3% females) were included. No significant differences were seen in patient background, meniscal treatment and cartilage status at the time of surgery (table 1). No significant differences were seen in the mean values (milliseconds) for qMRI for adjusted T1 rho relaxation times in the medial patella (MP) (47.8 vs 47.3), central patella (CP) (45.5 vs 44.1), and lateral patella (LP) (48.2 vs 47.3), and medial trochlea (MT) (54.7 vs 56.4), central trochlea (CT) (53.3 vs 53.1), and lateral trochlea (LT) (54.9 vs 53.9), and adjusted T2 relaxation times in MP (42.2 vs 43.2), CP (42.5 vs 42.7), LP (43.5 vs 43.0), MT (50.9 vs 50.9), CT (51.1 vs 52.0), LT (52.1 vs 52.6) between ACLR and ACLR+LET groups. Similarly, no difference in ACLOAS scores (overall score 10 vs 11, p = 0.99) were observed. An increase in medial patellar T2 relaxation times were associated with decreasing IKDC score (p = 0.046), KOOS symptoms subscale (p = 0.01), and total KOOS score (p = 0.01). Increasing limb symmetry on the hop test was associated with increasing T1ρ (p = 0.04) and T2 (p = 0.01) relaxation in the lateral trochlea Conclusions: No difference was found in patellofemoral cartilage health between knees undergoing primary ACLR with hamstring tendon autograft with or without LET at two years post-operative. Statistically significant correlations were found between qMRI relaxation times and functional outcome scores and PROMs, however the correlations were weak and the clinical significance of these changes are undetermined. [Table: see text]

Poster 148: Preoperative Platelet Rich Plasma Injections Decreases Inflammatory and Chondrodegenerative Biomarkers in Patients with Acute Anterior Cruciate Ligament Tears and Reconstruction: A Pilot Study

Objectives: Post-traumatic osteoarthritis occurs at an alarming rate after ACL injury and surgery. The purpose of this study was to compare the effect of two, pre-operative PRP injections upon the progression of inflammatory and chondrodegenerative biomarkers to the natural progression before ACL reconstruction surgery. Our hypothesis was that pre-operative PRP injections would decrease the chondrotoxicity of the presurgery knee fluid. Methods: Participants were randomized to either a control or intervention group. Both groups received joint aspirations within the first 10 days following ACL injury (Time 1). In addition to joint aspiration at Time 1, the PRP group received a PRP injection at Time 1 and an additional PRP injection at a second visit 5-12 days after the initial visit. Synovial fluid samples were harvested in both groups at the time of ACL reconstruction (Time 2). ELISA was performed on all samples to detect cytokine levels of IL-1B, IL-10, IL-6, GM-CSF, IL-5, IFN-γ, TNF-⍺, IL-2, IL-4, and IL-8 Results: A total 24 participants were enrolled, final analysis was completed on 8 participants in the control group and 9 participants in the intervention group. The control group demonstrated a change in concentration (Δ1à2) between time 1 and time 2 that was not statistically significant for any cytokines p&gt;0.05, except for a statistically significant decrease in IL-8 (p=0.005). The intervention group demonstrated a decrease in all cytokine concentrations that was statistically significant for all cytokines p&lt;0.05, except for IL-8 (p=0.074). When comparing the control group to the intervention group at time 1, no significant difference was seen between cytokine concentrations (p&gt;0.05). Likewise, comparing the control group to the intervention group at time 2, no significant difference was seen between cytokine concentrations (p&gt;0.05). The magnitude of decrease was larger in the intervention group than the control group, but with comparison of means between groups there was not a statistically significant difference. The natural history for these biomarkers is a decrease but at a variable rate/amount. Preoperative intervention with PRP has the potential to consistently alter the concentration of chondrodestructive proteins. Conclusions: Intervention with aspiration and 2 injection series of PRP in the acute ACL injured knee resulted in greater reduction in effusion inflammatory markers than control. This may suggest a treatment modality to improve perioperative pain, function and possibly alter the course of post trauma arthritis in these patients, without the deleterious effect of steroid injection. Long term study and follow up is required to determine if intervention alters the natural history of post traumatic arthritis. [Table: see text][Table: see text]

The Impact of Meniscal Tear Type and Surgical Treatment on Quadriceps Strength: A Study of Adolescent Patients Post Anterior Cruciate Ligament Reconstruction

Background: Treatment of meniscal injuries at the time of anterior cruciate ligament reconstruction (ACLR) can result in restrictions on weightbearing and range of motion in the early rehabilitative phases. What is unknown is the effect of (1) meniscal tear type and location at the time of anterior cruciate ligament injury and (2) meniscal treatment at the time of ACLR on quadriceps strength in adolescents during the late rehabilitative phase. Hypothesis: Meniscal tears involving the root and requiring repair would adversely affect quadriceps strength at 6 to 9 months postoperatively. Study Design: Cohort study; Level of evidence, 3. Methods: Patients who underwent ACLR at 1 of 2 research sites between 2013 and 2021 were identified. Adolescent participants were included if they were between the ages of 12 and 20 years at the time of assessment and had undergone primary unilateral ACLR in the previous 6 to 9 months. Participants were subgrouped by meniscal tear type (no tear, nonroot tear, root tear) and meniscal treatment at the time of ACLR (no treatment, meniscectomy, meniscal repair), which were confirmed via chart review. Isokinetic strength testing occurred at 60 deg/s, and quadriceps strength and quadriceps strength limb symmetry index were compared between the meniscal tear type and meniscal procedure subgroups using analysis of covariance while controlling for the effects of age, sex, and ACLR graft source. Results: An overall 236 patients were included in this analysis (109 male, 127 female; mean ± SD age, 16.0 ± 1.9 years). There were no significant differences in ACLR limb quadriceps strength based on meniscal tear type (P = .61) or meniscal procedure at the time of ACLR (P = .61), after controlling for age, biological sex, and ACLR graft source. Similarly, quadriceps strength limb symmetry index did not differ by meniscal tear type (P = .38) or meniscal procedure at the time of ACLR (P = .40). Conclusion: Meniscal tear type and treatment at the time of ACLR did not affect quadriceps strength or quadriceps strength symmetry in adolescents 6 to 9 months after ACLR.

Evaluation of Serum Albumin-Coated Bone Allograft for Bone Regeneration: A Seven-Year Follow-Up Study of 26 Cases.

We have previously reported that serum albumin-coated bone allograft (BoneAlbumin, BA) is an effective bone substitute. It improves bone regeneration at the patellar and tibial donor sites six months after harvesting bone-patellar tendon-bone (BPTB) autografts for primary anterior cruciate ligament reconstruction (ACLR). In the present study, we examined these donor sites seven years after implantation. The study group (N = 10) received BA-enhanced autologous cancellous bone at the tibial and BA alone at the patellar site. The control group (N = 16) received autologous cancellous bone at the tibial and blood clot at the patellar site. We evaluated subcortical density, cortical thickness, and bone defect volume via CT scans. At the patellar site, subcortical density was significantly higher in the BA group at both time points. There was no significant difference in cortical thickness between the two groups at either donor site. The control group's bone defect significantly improved and reached the BA group's values at both sites by year seven. Meanwhile, the bone defects in the BA group did not change significantly and were comparable to the six-month measurements. No complications were observed. There are two limitations in this study: The number of patients recruited is small, and the randomization of the patients could have improved the quality of the study as the control group patients were older compared to the study group patients. Our 7-year results seem to demonstrate that BA is a safe and effective bone substitute that supports faster regeneration of donor sites and results in good-quality bone tissue at the time of ACLR with BPTB autografts. However, studies with a larger number of patients are required to definitively confirm the preliminary results of our study.

Evaluation of Graft Ligamentization by MRI After Anterior Cruciate Ligament Reconstruction

Background: The tendon graft used in anterior cruciate ligament reconstruction (ACLR) undergoes “ligamentization” after implantation, and the reported length of this process varies from 6 to 48 months. Some grafts have ruptured at subsequent follow-up evaluations. Although the progress of graft ligamentization can be followed with postoperative magnetic resonance imaging (MRI) for reassessment, it is not known whether a delay in ligamentization (as reflected by a higher signal of the graft) is associated with an increased chance of subsequent graft rupture. Hypothesis: Signal intensity of the graft on reassessment MRI (signal-noise quotient [SNQ]) would be associated with the incidence of future graft rupture at subsequent follow-up. Study Design: Case-control study; Level of evidence, 3. Methods: A total of 565 ACLRs with intact graft on first-time reassessment MRI after surgery were followed for a mean period of 67 months. The rates of 1-year and 2-year follow-up were 99.5% and 84.5%, respectively. The signal intensity of the intact graft on the first-time reassessment MRI was evaluated (1) quantitatively by the SNQ and (2) qualitatively with the modified Ahn classification. Among the 565 ACLRs, 23 additional graft ruptures developed during a time interval of 7 months to 9 years after the surgery. Results: Higher SNQ was associated with increased chance of subsequent graft rupture (SNQ 7.3 ± 6 for subsequent graft rupture vs 4.4 ± 4 for grafts without subsequent rupture; P = .004, Mann-Whitney U test). The other important confounders that were associated with increased chance of graft rupture were younger age at the time of ACLR (P < .001) and longer follow-up time (P = .002). Multiple linear regression showed that all 3 factors (higher SNQ, younger age, and longer follow-up) were independent predictors of graft rupture (SNQ, P = .03; age, P < .001; follow-up, P = .012). When the reassessment MRI was performed in the second year after ACLR, the odds ratio of future graft rupture of a heterogeneous hyperintense graft when compared with a homogeneous hypointense graft was 12.1 (95% CI = 2.8 to 52.6) P < .001, Fisher exact test). Conclusion: Higher signal intensity of the intact graft on reassessment MRI (higher SNQ and heterogeneous hyperintense graft) was associated with increased chance of subsequent graft rupture.

Meniscal Ramp Lesions in Adolescent Patients Undergoing Primary Anterior Cruciate Ligament Reconstruction: Significance of Imaging and Arthroscopic Findings

Background: Meniscal ramp lesions are associated with anterior cruciate ligament (ACL) injuries and may affect knee stability when left untreated. The diagnostic accuracy of magnetic resonance imaging (MRI) to identify this meniscocapsular injury of the posterior horn of the medial meniscus remains poor, and the arthroscopic findings require vigilance. Purpose: To determine the concordance of arthroscopic and MRI findings to better identify the presence of a ramp lesion in children and adolescent patients undergoing primary ACL reconstruction. Study Design: Cohort study (diagnosis); Level of evidence, 2. Methods: Patients aged <19 years who underwent primary ACL reconstruction at a single institution between 2020 and 2021 were included. Two cohorts were developed by the presence of a ramp lesion arthroscopically. Basic patient descriptive data, preoperative imaging (radiologist assessment and independent reviewer assessment), and concomitant arthroscopic findings at the time of ACL reconstruction were recorded. Results: An overall 201 adolescents met criteria with a mean age of 15.7 years (range, 6.9-18.2) at the time of injury. A ramp lesion was identified in 14% of patients (28 children). No differences were detected between cohorts with regard to age, sex, body mass index, weeks from injury to MRI, or weeks from injury to surgery (P > .15). The primary predictor of an intraoperative ramp lesion was the presence of medial femoral condylar striations, with an adjusted odds ratio of 722.2 (95% CI, 59.5-8768.2; P < .001); the presence of a ramp lesion on MRI had an adjusted odds ratio of 11.1 (95% CI, 2.2-54.8; P = .003). Patients with neither a ramp lesion on MRI nor medial femoral condylar striations had a 2% rate (2/131) of ramp lesion; those with either of the significant risk factors had a 24% rate (14/54). All patients with both risk factors (100%; n = 12) had a ramp lesion noted on intraoperative examination. Conclusion: The concordance of medial femoral condylar chondromalacia, particularly striations, noted during arthroscopy and posteromedial tibial marrow edema on MRI with or without direct evidence of posterior meniscocapsular pathology should increase suspicion for the presence of a ramp lesion in adolescents undergoing ACL reconstruction.

Delay of Timing of Anterior Cruciate Ligament Reconstruction Is Associated With Lower Risk of Arthrofibrosis Requiring Intervention

To conduct 2 separate stratum-specific likelihood ratio analyses in patients younger than 40 year of age (<40 years) and those aged 40 and older (40+ years) at time of anterior cruciate ligament (ACL) reconstruction to define data-driven strata between ACL tear and primary isolated ACL reconstruction in which the risk of arthrofibrosis, using manipulation under anesthesia and arthroscopic lysis of adhesions as surrogates, is significantly different. A retrospective cohort analysis was conducted using the PearlDiver Database. Patients who underwent ACL reconstruction were identified using the Current Procedure Terminology code 29888. Patients were stratified to those aged younger than 40 (<40) and those 40 and older (40+) at time of ACL reconstruction. The incidence of 2-year arthrofibrosis was calculated for weekly intervals from initial ACL injury to reconstruction. Stratum specific likelihood ratio analysis was conducted to determine data-driven intervals from initial ACL tear to reconstruction that optimize differences in 2-year arthrofibrosis. Following the identification of these intervals for both those <40 and 40+, multivariable analysis was conducted. For those <40, stratum-specific likelihood ratio analysis identified only 2 data-driven timing strata: 0-5 and 6-26 weeks. For those 40+, stratum-specific likelihood ratio analysis also only identified 2 data-driven strata: 0-9 and 10-26 weeks. A delay in ACL reconstruction from initial injury by at least 6 weeks in patients younger than 40 and at least 10 weeks in patients older than 40 years is associated with a 65% and 35% reduction of 2-year manipulation under anesthesia and arthroscopic lysis of adhesions, respectively. Our analysis showed a delay in ACLR of at least 6 weeks in patients younger than 40 years to be associated with a 65% reduction in the risk of surgical intervention for arthrofibrosis and a delay of at least 10 weeks in patients 40 years and older to be associated with only a 35% reduction in the risk of surgical intervention for arthrofibrosis. The authors propose this difference in reduction to be multifactorial and potentially associated with mechanism of injury, activity level, and preoperative factors such as amount of physical therapy, rather than solely timing. Level III, retrospective comparative prognostic study.

Anterior cruciate ligament reconstruction and concomitant procedures in Finland between 2004 and 2018 based on national registers.

We aimed to assess the incidence of anterior cruciate ligament reconstruction (ACLR) and concomitant procedures in Finland. We identified all the patients who underwent ACLR between 2004 and 2018 in Finland using national registry data. Patients with an ICD-10 diagnosis code S83.5 and the NOMESCO operation codes NGE30 or NGE35 were included. We recorded the patient's age, sex, Charlson comorbidity index, and concomitant procedures. NGE30 or NGE35 was defined as the main procedure and all other procedures attached to this procedure were included as concomitant procedures. Our study included 37,224 ACLRs. The overall incidence of ACLR was 46 (95%CI 34-62) per 105person-years. This increased from 38 per 105person-years in 2004 to its peak of 53 in 2014 before decreasing to 47 by 2018. Male patients had a higher overall incidence of ACLR than female patients (61 [CI 47-78] vs. 32 [CI 22-45] per 105person-years, respectively). However, this difference changed over time: for the males, a decrease in ACLR incidence was observed after 2014, whereas for the females, the trend increased throughout the study period. For both sexes, the highest incidence of ACLRs was in the age group 16-29 years (159 and 71 per 105person-years, respectively). Concomitant procedures were performed at the time of ACLR in 32% of cases. While the total incidence of ACLR decreased slightly from 2014 to 2018, it increased among women over the full study period, which might be due to increased female participation in contact sports. Special attention should be given to girls' and women's ACL rupture prevention and treatment.

Posterior tibial plateau impaction fractures are not associated with increased knee instability: a quantitative pivot shift analysis.

This study aimed to evaluate posterolateral tibial plateau impaction fractures and how they contribute to rotatory knee laxity using quantitative pivot shift analysis. It was hypothesised that neither the presence of nor the degree of involvement of the plateau would affect rotatory knee laxity in the ACL-deficient knee. A retrospective review of prospectively collected data on 284 patients with complete anterior cruciate ligament (ACL) injuries was conducted. Posterolateral tibial plateau impaction fractures were identified on preoperative MRI. The patients were divided into two cohorts: "fractures" or "no fractures". The cohort with fractures was further categorised based on fracture morphology: "extra-articular", "articular-impaction", or "displaced-articular fragment". All data were collected during examination under anaesthesia performed immediately prior to ACL reconstruction. This included a standard pivot shift test graded by the examiner and quantitative data including anterior tibial translation (mm) via Rolimeter, quantitative pivot shift (QPS) examination (mm) via PIVOT tablet technology, and acceleration (m/sec2) during the pivot shift test via accelerometer. Quantitative examinations were compared with the contralateral knee. There were 112 patients with posterolateral tibial plateau impaction fractures (112/284, 39%). Of these, 71/112 (63%) were "extra-articular", 28/112 (25%) "articular-impaction", and 13/112 (12%) "displaced-articular". Regarding the two groups with or without fractures, there was no difference in subjective pivot shift (2 ± 0 vs 2 ± 0, respectively,  n.s.), QPS (2.4 ± 1.6mm vs 2.7 ± 2.2mm, respectively, n.s.), anterior tibial translation measurements (6 ± 3mm vs 5 ± 3mm, respectively, n.s.), or acceleration of the knee during the pivot (1.7 ± 2.3m/s2 vs 1.8 ± 3.1m/s2, respectively, n.s.). When the fractures were further subdivided, subgroup analysis revealed no significant differences noted in any of the measured examinations between the fracture subtypes. This study showed that the posterolateral tibial plateau impaction fractures are commonly encountered in the setting of ACL tears; however, contrary to previous reports, they do not significantly increase rotatory knee laxity. This suggests that this type of concomitant injury may not need to be addressed at the time of ACL reconstruction. Level III.

Effect of Delayed Anterior Cruciate Ligament Reconstruction on Repair of Concomitant Medial Meniscus Tears in Young Athletes

Background: Delayed anterior cruciate ligament (ACL) reconstruction (ACLR) is associated with an increased risk of meniscal injury. Limited data are available regarding the relationship between surgical delay and meniscal repairability in the setting of ACLR in young patients. Purpose: To determine whether time from ACL injury to primary ACLR was associated with the incidence of medial and/or lateral meniscal repair in young athletes who underwent meniscal treatment at the time of ACLR. Study Design: Case-control study; Level of evidence, 3. Methods: Records were retrospectively reviewed for patients aged 13 to 25 years who underwent primary ACLR between January 2017 and June 2020 by surgeons from a single academic orthopaedic surgery department. Demographic data were collected, and operative reports were reviewed to document all concomitant pathologies and procedures. Univariable and multivariable logistic regression analyses were used to determine factors associated with meniscal repair, including time elapsed from ACL injury to surgery. Results: Concomitant meniscal tears were identified and treated in 243 of 427 patients; their mean age was 17.9 ± 3.3 years, and approximately half (47.7%) of patients were female. There were 144 (59.3%) medial tears treated and 164 (67.5%) lateral tears treated; 65 (26.7%) patients had both medial and lateral tears treated. Median time from ACL injury to ACLR was 2.4 months (interquartile range, 1.4-4.7 months). Adjusted univariate analysis showed a statistically significant correlation between medial meniscal repair and time to surgery, with a 7% decreased incidence of medial meniscal repair per month elapsed between injury and surgery (odds ratio, 0.93 per month; 95% CI, 0.89-0.98; P = .006). No similar relationship was found between lateral meniscal repair and time to surgery (odds ratio, 1.02; 95% CI, 0.99-1.06; P = .24). Conclusion: In the setting of concomitant ACL and meniscal injuries, surgical delay decreased the incidence of medial meniscal repair in young athletes by 7% per month from time of injury.

Are Neighborhood Conditions Associated With Surgical Delays and Meniscus Tears in Children and Adolescents Undergoing ACL Reconstruction?

Markers of a patient's social determinants of health, including healthcare insurance and median household income based on ZIP Code, have been associated with the interval between injury and ACL reconstruction (ACLR) as well as the presence of concomitant meniscus tears in children and adolescents. However, the aforementioned surrogate indicators of a patient's social determinants of health may not reflect all socioeconomic and healthcare resources affecting the care of ACL injuries in children and adolescents. The use of multivariate indices such as the Child Opportunity Index (COI) may help to better identify patients at risk for increased risk for delay between ACL injury and surgery, as well as the incidence of meniscus tears at the time of surgery. The COI is a summative measure of 29 indicators that reflect neighborhood opportunities across three domains: education, health and environment, and social and economic factors. COI scores range from 0 to 100 (100 being the highest possible score), as well as five categorical scores (very low, low, moderate, high, and very high) based on quintile rankings. To investigate the relationship between neighborhood conditions and the treatment of ACL injuries in children and adolescents via the COI, we asked: (1) Is a lower COI score associated with a longer delay between ACL injury and surgery? (2) Does a higher proportion of patients with lower COI scores have meniscus tears at the time of ACLR? In this retrospective, comparative study, we considered data from 565 patients, 18 years or younger, who underwent primary ACLR at an urban, tertiary children's hospital between 2011 and 2021. Of these patients, 5% (31 of 565) did not have a clearly documented date of injury, 2% (11 of 565) underwent revision reconstructions, and 1% (5 of 565) underwent intentionally delayed or staged procedures. Because we specifically sought to compare patients who had low or very low COI scores (lowest two quintiles) with those who had high or very high scores (highest two quintiles), we excluded 18% (103 of 565) of patients with moderate scores. Ultimately, 73% (415 of 565) of patients with COI scores in either the top or bottom two quintiles were included. Patient addresses at the time of surgery were used to determine the COI score. There were no differences between the groups in terms of gender. However, patients with high or very high COI scores had a lower median (IQR) age (15 years [2.6] versus 17 years [1.8]; p < 0.001) and BMI (23 kg/m 2 [6.1] versus 25 kg/m 2 [8.8]; p < 0.001), were more commonly privately insured (62% [117 of 188] versus 22% [51 of 227]; p < 0.001), and had a higher proportion of patients identifying as White (67% [126 of 188] versus 6.2% [14 of 227]; p < 0.001) compared with patients with low or very low COI scores. Medical records were reviewed for demographic, preoperative, and intraoperative data. Univariate analyses focused on the relationship of the COI and interval between injury and surgery, frequency of concomitant meniscus tears, and frequency of irreparable meniscus tears treated with partial meniscectomy. Multivariable regression analyses were used to determine factors that were independently associated with delayed surgery (longer than 60 and 90 days after injury), presence of concomitant meniscal injuries, and performance of meniscectomy. Multivariable models included insurance and race or ethnicity to determine whether COI was independently associative after accounting for these variables. Patients with a high or very high COI score had surgery earlier than those with a low or very low COI score (median [IQR] 53 days [53] versus 97 days [104]; p < 0.001). After adjusting for insurance and race/ethnicity, we found that patients with a low or very low COI score were more likely than patients with a high or very high COI score to have surgery more than 60 days after injury (OR 2.1 [95% CI 1.1 to 4.0]; p = 0.02) or more than 90 days after injury (OR 1.8 [95% CI 1.1 to 3.4]; p = 0.04). Furthermore, patients with low or very low COI scores were more likely to have concomitant meniscus tears (OR 1.6 [95% CI 1.1 to 2.5]; p = 0.04) compared with patients with high or very high COI scores. After controlling for insurance, race/ethnicity, time to surgery, and other variables, there was no association between COI and meniscectomy (OR 1.6 [95% CI 0.9 to 2.8]; p = 0.12) or presence of a chondral injury (OR 1.7 [95% CI 0.7 to 3.9]; p = 0.20). As the COI score is independently associated with a delay between ACL injury and surgery as well as the incidence of meniscus tears at the time of surgery, this score can be useful in identifying patients and communities at risk for disparate care after ACL injury. The COI score or similar metrics can be incorporated into medical records to identify at-risk patients and dedicate appropriate resources for efficient care. Additionally, neighborhoods with a low COI score may benefit from improvements in the availability of additional and/or improved resources. Future studies should focus on the relationship between the COI score and long-term patient-reported functional outcomes after ACL injury, identification of the specific timepoints in care that lead to delayed surgery for those with lower COI scores, and the impact of community-based interventions in improving health equity in children with ACL injury. Level III, therapeutic study.