Radiographic and Symptomatic Knee Osteoarthritis 32 to 37 Years After Acute Anterior Cruciate Ligament Rupture

Automated quantitative assessment of bone contusions and overlying articular cartilage following anterior cruciate ligament injury

Quantitative methods to characterize bone contusions and associated cartilage injury remain limited. We combined standardized voxelwise normalization and 3D mapping to automate bone contusion segmentation post-anterior cruciate ligament (ACL) injury and evaluate anomalies in articular cartilage overlying bone contusions. Forty-five patients (54% female, 26.4 ± 11.8 days post-injury) with an ACL tear underwent 3T magnetic resonance imaging of their involved and uninvolved knees. A novel method for voxelwise normalization and 3D anatomical mapping was used to automate segmentation, labeling, and localization of bone contusions in the involved knee. The same mapping system was used to identify the associated articular cartilage overlying bone lesions. Mean regional T1ρ was extracted from articular cartilage regions in both the involved and uninvolved knees for quantitative paired analysis against ipsilateral cartilage within the same compartment outside of the localized bone contusion. At least one bone contusion lesion was detected in the involved knee within the femur and/or tibia following ACL injury in 42 participants. Elevated T1ρ (p = 0.033) signal were documented within the articular cartilage overlying the bone contusions resulting from ACL injury. In contrast, the same cartilaginous regions deprojected onto the uninvolved knees showed no ipsilateral differences (p = 0.795). Automated bone contusion segmentation using standardized voxelwise normalization and 3D mapping deprojection identified altered cartilage overlying bone contusions in the setting of knee ACL injury.

Anterior Cruciate Ligament Tear: Individualized Indications for Non-Operative Management

Anterior cruciate ligament (ACL) rupture represents a common sports injury that is mostly managed operatively. However, non-operative treatment can also play a role, despite the limited high-quality published data on ACL tear management. Both methods have shown favorable outcomes, but clear guidelines based on high-quality research are lacking. Several factors should be considered and discussed with the patient before deciding on the best treatment method. These include patient characteristics and expectations, concomitant injuries, and clinical evaluation, with laxity or/and instability being one of the most essential parameters examined. This should eventually lead to an individualized approach for each patient to ensure the best possible outcome. This review aims to delve into all parameters that are related to ACL rupture and guide physicians in choosing the most appropriate treatment method for each patient.

Association of Serum Biochemical Biomarker Profiles of Joint Tissue Inflammation and Cartilage Metabolism With Posttraumatic Osteoarthritis-Related Symptoms at 12 Months After ACLR

BACKGROUND

Anterior cruciate ligament injury and anterior cruciate ligament reconstruction (ACLR) are risk factors for symptomatic posttraumatic osteoarthritis (PTOA). After ACLR, individuals demonstrate altered joint tissue metabolism indicative of increased inflammation and cartilage breakdown. Serum biomarker changes have been associated with tibiofemoral cartilage composition indicative of worse knee joint health but not with PTOA-related symptoms.

PURPOSE/HYPOTHESIS

The purpose of this study was to determine associations between changes in serum biomarker profiles from the preoperative sample collection to 6 months after ACLR and clinically relevant knee PTOA symptoms at 12 months after ACLR. It was hypothesized that increases in biomarkers of inflammation, cartilage metabolism, and cartilage degradation would be associated with clinically relevant PTOA symptoms after ACLR.

STUDY DESIGN

Case-control study; Level of evidence, 3.

METHODS

Individuals undergoing primary ACLR were included (N = 30). Serum samples collected preoperatively and 6 months after ACLR were processed to measure markers indicative of changes in inflammation (ie, monocyte chemoattract protein 1 [MCP-1]) and cartilage breakdown (ie, cartilage oligomeric matrix protein [COMP], matrix metalloproteinase 3, ratio of type II collagen breakdown to type II collagen synthesis). Knee injury and Osteoarthritis Outcome Score surveys were completed at 12 months after ACLR and used to identify participants with and without clinically relevant PTOA-related symptoms. K-means cluster analyses were used to determine serum biomarker profiles. One-way analyses of variance and logistic regressions were used to assess differences in Knee injury and Osteoarthritis Outcome Score subscale scores and clinically relevant PTOA-related symptoms between biomarker profiles.

RESULTS

Two profiles were identified and characterized based on decreases (profile 1: 67% female; age, 21.4 ± 5.1 years; body mass index, 24.4 ± 2.4) and increases (profile 2: 33% female; age, 21.3 ± 3.2 years; body mass index, 23.4 ± 2.6) in sMCP-1 and sCOMP preoperatively to 6 months after ACLR. Participants with profile 2 did not demonstrate differences in knee pain, symptoms, activities of daily living, sports function, or quality of life at 12 months after ACLR compared to those with profile 1 (P = .56-.81; η2 = 0.002-0.012). No statistically significant associations were noted between biomarker profiles and clinically relevant PTOA-related symptoms (odds ratio, 1.30; 95% CI, 0.23-6.33).

CONCLUSION

Serum biomarker changes in MCP-1 and sCOMP within the first 6 months after ACLR were not associated with clinically relevant PTOA-related symptoms.

Knee Arthroscopic Surgery in Middle-Aged Patients With Meniscal Symptoms: A 10-Year Follow-up of a Prospective, Randomized Controlled Trial

BACKGROUND

Short- and midterm evaluations of arthroscopic meniscal surgery have shown little or no effect in favor of surgery, although long-term effects, including radiographic changes, are unknown.

PURPOSE

To compare the 10-year outcomes in middle-aged patients with meniscal symptoms between a group that received an exercise program alone and a group that received knee arthroscopy in addition to the exercise program with respect to the prevalence of radiographic and symptomatic osteoarthritis (OA), patient-reported outcomes, and clinical status.

STUDY DESIGN

Randomized controlled trial; Level of evidence, 1.

METHODS

Of 179 eligible patients aged 45 to 64 years, 150 were randomized to undergo either 3 months of exercise therapy (nonsurgery group) or knee arthroscopy in addition to the exercise therapy (surgery group). Surgery usually consisted of partial meniscectomy (n = 56) or diagnostic arthroscopy (n = 8). Radiographs were assessed according to the Kellgren-Lawrence score at the baseline and 5- and 10-year follow-ups. Patient-reported outcome measures were reported at the baseline and 1-, 3-, 5-, and 10-year follow-ups. Clinical status was assessed at a 10-year follow-up. The primary outcomes were radiographic OA and changes in the Knee injury and Osteoarthritis Outcome Score Pain subscale (KOOSPAIN) from the baseline to the 10-year follow-up. The primary analysis was performed using the intention-to-treat approach.

RESULTS

At the time of the 10-year follow-up, eight patients had died, leaving 142 eligible patients. Radiographic OA was assessed for 95 patients (67%), questionnaires were answered by 110 (77%), and the clinical status was evaluated for 95 (67%). Radiographic OA was present in 67% of the patients in each group (P≥ .999); symptomatic OA was present in 47% of the nonsurgery group and 57% of the surgery group (P = .301). There were no differences between groups regarding changes from baseline to 10 years in any of the KOOS subscales.

CONCLUSION

Knee arthroscopic surgery, in most cases consisting of partial meniscectomy or diagnostic arthroscopy, in addition to exercise therapy in middle-aged patients with meniscal symptoms, did not increase the rates of radiographic or symptomatic OA and resulted in similar patient-reported outcomes at the 10-year follow-up compared with exercise therapy alone. Considering the short-term benefit and no long-term harm from knee arthroscopic surgery, the treatment may be recommended when first-line treatment-including exercise therapy for ≥3 months-does not relieve patient's symptoms.

REGISTRATION

Clinical Trials NCT01288768 (ClinicalTrials.gov identifier).

Correlation between higher lateral tibial slope and inferior long term subjective outcomes following single bundle anterior cruciate ligament reconstruction

BACKGROUND

The impact of anatomical factors, such as the lateral tibial slope (LTS), on outcomes following anterior cruciate ligament (ACL) reconstruction is an area of growing interest. This study was led by the observation that patients with a higher LTS may have different recovery trajectories.

HYPOTHESIS/PURPOSE

The purpose of this study was to investigate the correlation between a higher LTS and long term subjective outcomes following single-bundle ACL reconstruction.

STUDY DESIGN

This study was designed as a retrospective cohort study.

METHODS

The study comprised 138 patients who underwent single-bundle ACL reconstruction. The LTS was measured on preoperative radiographs. Patient-reported outcome measures (PROMs) were collected, which included the Lysholm Knee Score, UCLA Activity Score, IKDC Score, and Tegner Activity Score, over a mean follow-up duration of 137 months.

RESULTS

A significant negative correlation was found between LTS and all measured PROMs (p < 0.001). The established cut-off value of LTS distinguishing between "Good" and "Fair" Lysholm scores was 8.35 degrees. Female patients have statistically significant higher LTS and lower PROMs scores than male. Patients with LTS greater than or equal to 8.35 had significantly lower PROMs, indicative of poorer functional and subjective outcomes.

CONCLUSION

Our findings suggest that a higher LTS is associated with inferior subjective outcomes following single-bundle ACL reconstruction in long term. The LTS cut-off value of 8.35 degrees could potentially be used as a reference in preoperative planning and patient counseling.

CLINICAL RELEVANCE

Understanding the relationship between LTS and ACL reconstruction outcomes could inform surgical planning and postoperative management. These findings highlight the need to consider anatomical variances, such as LTS, when assessing patient-specific risks and recovery expectations, contributing to the advancement of personalized care in sports medicine.

Outcomes >30 Years After Initial Nonoperative Treatment of Anterior Cruciate Ligament Injuries

BACKGROUND

It is unclear how anterior cruciate ligament (ACL) reconstruction (ACLR) affects the development of osteoarthritis (OA). This uncertainty is partly caused by the lack of long-term studies on ACL injuries treated primarily without reconstruction and the underreporting of symptomatic OA.

PURPOSE

To determine (1) the knee function, symptoms, and activity level, as well as the presence of radiographic and symptomatic OA; (2) how these clinical outcomes have changed over time; and (3) the frequency of subsequent knee surgeries after the index ACL injury in a cohort of patients with ACL injuries treated primarily without reconstruction.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

A total of 100 patients underwent initial nonoperative treatment >30 years ago (mean, 33.2 ± 1.4 years). Of these, 81 patients (mean age, 59 ± 8 years) completed the Knee injury and Osteoarthritis Outcome Score (KOOS), Lysholm Knee Scoring Scale, and Tegner Activity Scale. Seventy-three patients underwent radiography to evaluate tibiofemoral and patellofemoral OA in the ACL-injured knee. Patients only underwent late ACLR if they experienced insufficient knee stability.

RESULTS

At 33 years after the ACL injury, the KOOS Activities of Daily Living subscore was better than population-based reference values, but scores were similar for the remaining KOOS subscales. Furthermore, 65% of patients had a good or excellent Lysholm score (≥84 points). The Tegner score decreased 4 points from before the injury to 33-year follow-up (P < .001). Most patients (75%) had evidence of radiographic tibiofemoral and/or patellofemoral OA, but only 38% were classified as having symptomatic OA (defined as radiographic OA in combination with a symptomatic knee according to cutoffs on the KOOS). Approximately 50% underwent meniscal surgery, and 29% subsequently underwent ACLR for recurrent instability. There were 2 patients who underwent total knee replacement.

CONCLUSION

Despite a high prevalence of radiographic OA, patients achieved acceptable subjective knee function and had a relatively low prevalence of symptomatic OA at >30 years after an ACL injury when an initial nonoperative treatment strategy was employed.

Knee-Related Quality of Life Compared Between 20 and 35 Years After an Anterior Cruciate Ligament Injury Treated Surgically With Primary Repair or Reconstruction, or Nonsurgically

BACKGROUND

Quality of life (QoL) is affected up to 5 years after an anterior cruciate ligament (ACL) injury. Knee impairment and osteoarthritis (OA) development increase over time, and this may affect QoL at a long-term follow-up.

PURPOSE

To investigate changes in health- and knee-related QoL between 20 and 35 years after ACL injury and compare it between patients treated with or without ACL surgery, as well as to study how symptomatic OA (SOA) is associated with change in QoL.

STUDY DESIGN

Cohort study; Level of evidence, 2.

METHODS

Between 1980 and 1983, 139 patients with acute ACL rupture were allocated to surgical or nonsurgical treatment of the ACL. Both groups completed a structured rehabilitation program. Of those patients, 59 were followed for 20 and 35 years after ACL rupture. After 10 crossovers, 33 patients were treated with primary repair or ACL reconstruction, and 26 were treated without ACL surgery. Combined radiographic OA and knee symptoms at 35 years was defined as SOA. QoL was assessed at 20 and 35 years after injury with the Knee injury and Osteoarthritis Outcome Score QoL (KOOS-QoL) subscale (range, 1-100), ACL-QoL questionnaire (total score and 5 subscales; range, 1-100), European QoL-5 Dimensions Questionnaire, and visual analog scale. Results were analyzed with paired and independent-sample t tests and chi-square tests.

RESULTS

Knee-related QoL was impaired at both 20 and 35 years after ACL injury, and differences were dependent on the measurement outcome. In the total cohort, KOOS-QoL did not change but both total ACL-QoL score (7.1 points; 95% CI, 2.2-11.9) and 4 of 5 subscales (5-10 points) decreased (P < .05). No differences were found between treatment groups. QoL decreased overall in patients with SOA, with a 21-point difference within-group change in KOOS-QoL (SOA or non-SOA) between 20 and 35 years of follow-up (P = .001; Cohen d = 1.0).

CONCLUSION

An ACL injury impairs knee-related QoL for up to 35 years, with no difference between treatment approaches (initial repair or later reconstruction compared with nonsurgical treatment). The deterioration decreases with longer follow-up. Clinicians should be aware of differences in QoL depending on the measurement outcome.

Prevalence of post-traumatic osteoarthritis after anterior cruciate ligament injury remains high despite advances in surgical techniques

Aims

The aim of this study was to report the pooled prevalence of post-traumatic osteoarthritis (PTOA) and examine whether the risk of developing PTOA after anterior cruciate ligament (ACL) injury has decreased in recent decades.

Methods

The PubMed and Web of Science databases were searched from 1 January 1980 to 11 May 2022. Patient series, observational studies, and clinical trials having reported the prevalence of radiologically confirmed PTOA after ACL injury, with at least a ten-year follow-up, were included. All studies were analyzed simultaneously, and separate analyses of the operative and nonoperative knees were performed. The prevalence of PTOA was calculated separately for each study, and pooled prevalence was reported with 95% confidence intervals (CIs) using either a fixed or random effects model. To examine the effect of the year of injury on the prevalence, a logit transformed meta-regression analysis was used with a maximum-likelihood estimator. Results from meta-regression analyses were reported with the unstandardized coefficient (β).

Results

The pooled prevalence of PTOA was 37.9% (95% CI 32.1 to 44) for operatively treated ACL injuries with a median follow-up of 14.6 years (interquartile range (IQR) 10.6 to 16.7). For nonoperatively treated ACL injuries, the prevalence was 40.5% (95% CI 28.9 to 53.3), with a median of follow-up of 15 years (IQR 11.7 to 20.0). The association between the year of operation and the prevalence of PTOA was weak and imprecise and not related to the choice of treatment (operative β -0.038 (95% CI -0.076 to 0.000) and nonoperative β -0.011 (95% CI -0.101 to 0.079)).

Conclusion

The initial injury, irrespective of management, has, by the balance of probability, resulted in PTOA within 20 years. In addition, the prevalence of PTOA has only slightly decreased during past decades. Therefore, further research is warranted to develop strategies to prevent the development of PTOA after ACL injuries.

A Systemic and Local Comparison of Senescence in an Acute Anterior Cruciate Ligament Injury-A Pilot Case Series

BACKGROUND

Senescence, a characteristic of cellular aging and inflammation, has been linked to the acceleration of osteoarthritis. The purpose of this study is to prospectively identify, measure, and compare senescent profiles in synovial fluid and peripheral blood in patients with an acute knee injury within 48 h.

METHODS

Seven subjects, aged 18-60 years, with an acute ACL tear with effusion were prospectively enrolled. Synovial fluid and peripheral blood samples were collected and analyzed by flow cytometry, using senescent markers C12FDG and CD87. The senescent versus pro-regenerative phenotype was probed at a gene and protein level using qRT-PCR and multiplex immunoassays.

RESULTS

C₁₂FDG and CD87 positive senescent cells were detected in the synovial fluid and peripheral blood of all patients. Pro-inflammatory IL-1β gene expression measured in synovial fluid was significantly higher (p = 0.0156) than systemic/blood expression. Senescent-associated factor MMP-3 and regenerative factor TIMP-2 were significantly higher in synovial fluid compared to blood serum. Senescent-associated factor MMP-9 and regenerative factor TGFβ-2 were significantly elevated in serum compared to synovial fluid. Correlation analysis revealed that C12FDG⁺⁺/CD87⁺⁺ senescent cells in synovial fluid positively correlated with age-related growth-regulated-oncogene (ρ = 1.00, p < 0.001), IFNγ (ρ = 1.00, p < 0.001), IL-8 (ρ = 0.90, p = 0.0374), and gene marker p16 (ρ = 0.83, p = 0.0416).

CONCLUSIONS

There is an abundance of senescent cells locally and systemically after an acute ACL tear without a significant difference between those present in peripheral blood compared to synovial fluid. This preliminary data may have a role in identifying strategies to modify the acute environment within the synovial fluid, either at the time of acute ligament injury or reconstruction surgery.

Preoperative factors associated with failure to reach the patient acceptable symptom state after anterior cruciate ligament reconstruction in patients aged 40 and older

PURPOSE

To perform a predictive analysis to identify preoperative patient factors associated with failure to achieve a newly defined patient acceptable symptom state (PASS) for the International Knee Documentation Committee (IKDC) Score after anterior cruciate ligament reconstruction (ACLR) in patients aged ≥ 40 years with a minimum of 2-year follow-up.

METHODS

This was a secondary analysis of a retrospective review of all patients aged 40 years or older receiving a primary allograft ACLR at a single institution between the years of 2005 and 2016, with 2-year minimum follow-up. Using an updated PASS threshold of 66.7 for the International Knee Documentation Committee (IKDC) score previously established for this patient cohort, a univariate and multivariate analysis was performed to identify preoperative patient characteristics predictive of failure to achieve PASS.

RESULTS

A total of 197 patients with a mean follow-up of 6.2 ± 2.1 years (range 2.7 - 11.2) were included in the analysis (48.5 ± 5.6 years, 51.8% female, Body Mass Index (BMI) 25.9 ± 4.4). PASS was achieved by 162 patients (82.2%). Patients who failed to achieve PASS more often had lateral compartment cartilage defects (P = 0.001) and lateral meniscus tears (P = 0.004), higher BMIs (P = 0.004), and Workers' Compensation status (P = 0.043) on univariable analysis. Factors predictive of failure to achieve PASS on multivariable analysis included BMI and lateral compartment cartilage defect (OR 1.12 [1.03-1.23], P = 0.013; OR 5.1 [1.87-13.9], P = 0.001).

CONCLUSION

Among patients ≥ 40 years who receive a primary allograft ACLR, patients who fail to achieve PASS more often had lateral compartment cartilage defects and higher BMIs.

LEVEL OF EVIDENCE

Level IV.

The Swedish version of the Anterior Cruciate Ligament Quality Of Life measure (ACL-QOL): translation and measurement properties

PURPOSE

To translate the ACL-QOL from English to Swedish and evaluate measurement properties for use after surgical and non-surgical management of anterior cruciate ligament (ACL) injury.

METHODS

The ACL-QOL was translated from English to Swedish and data were pooled from 13 cohorts to enable a comprehensive evaluation of measurement properties in line with COSMIN guidelines. We evaluated internal consistency, test-re-test reliability, measurement error, structural validity [confirmatory factor analysis (CFA)], construct validity and responsiveness (hypothesis testing), and floor/ceiling effects. Results were stratified by time since injury (≤ 1.5 years; 2-10 years, 15-25 years; > 30 years) and ACL management strategy [surgical (n = 1163), non-surgical (n = 570)].

RESULTS

The Swedish ACL-QOL had sufficient internal consistency (total and domain scores) for use in surgically managed (Cronbach's alpha ≥ 0.744) and non-surgically managed (≥ 0.770) ACL-injured individuals at all time-points. Test-re-test reliability was sufficient [intraclass correlation coefficients: all domains > 0.80, total score 0.93 (95% CI 0.86-0.96)]. The standard error of measurement was 5.6 for the total score and ranged from 7.0 to 10.3 for each domain. CFA indicated sufficient SRMR values when using the total score or five domains; however, CFI and RMSEA values did not meet cut-offs for good model fit. Hypothesis testing indicated sufficient construct validity and responsiveness. Floor effects were negligible and ceiling effects were negligible or minor.

CONCLUSION

The Swedish version of the ACL-QOL has sufficient internal consistency, test-re-test reliability, construct validity and responsiveness, for use in people with ACL injury managed with or without ACL surgery. Model fit could be improved and investigation into the source of misfit is warranted.

Risk factors for knee osteoarthritis after traumatic knee injury: a systematic review and meta-analysis of randomised controlled trials and cohort studies for the OPTIKNEE Consensus

OBJECTIVE

To identify and quantify potential risk factors for osteoarthritis (OA) following traumatic knee injury.

DESIGN

Systematic review and meta-analyses that estimated the odds of OA for individual risk factors assessed in more than four studies using random-effects models. Remaining risk factors underwent semiquantitative synthesis. The modified GRADE (Grading of Recommendations Assessment, Development and Evaluation) approach for prognostic factors guided the assessment.

DATA SOURCES

MEDLINE, EMBASE, CENTRAL, SPORTDiscus, CINAHL searched from inception to 2009-2021.

ELIGIBILITY

Randomised controlled trials and cohort studies assessing risk factors for symptomatic or structural OA in persons with a traumatic knee injury, mean injury age ≤30 years and minimum 2-year follow-up.

RESULTS

Across 66 included studies, 81 unique potential risk factors were identified. High risk of bias due to attrition or confounding was present in 64% and 49% of studies, respectively. Ten risk factors for structural OA underwent meta-analysis (sex, rehabilitation for anterior cruciate ligament (ACL) tear, ACL reconstruction (ACLR), ACLR age, ACLR body mass index, ACLR graft source, ACLR graft augmentation, ACLR+cartilage injury, ACLR+partial meniscectomy, ACLR+total medial meniscectomy). Very-low certainty evidence suggests increased odds of structural OA related to ACLR+cartilage injury (OR=2.31; 95% CI 1.35 to 3.94), ACLR+partial meniscectomy (OR=1.87; 1.45 to 2.42) and ACLR+total medial meniscectomy (OR=3.14; 2.20 to 4.48). Semiquantitative syntheses identified moderate-certainty evidence that cruciate ligament, collateral ligament, meniscal, chondral, patellar/tibiofemoral dislocation, fracture and multistructure injuries increase the odds of symptomatic OA.

CONCLUSION

Moderate-certainty evidence suggests that various single and multistructure knee injuries (beyond ACL tears) increase the odds of symptomatic OA. Risk factor heterogeneity, high risk of bias, and inconsistency in risk factors and OA definition make identifying treatment targets for preventing post-traumatic knee OA challenging.

Knee Osteoarthritis Following Anterior Cruciate Ligament Reconstruction: Frequency, Contributory Elements, and Recent Interventions to Modify the Route of Degeneration

Half of the individuals who experience an anterior cruciate ligament reconstruction (ACLR) suffer from knee osteoarthritis (OA) 12-14 years later. Elements that make a contribution to the appearance of OA following ACLR are anomalous anterior tibial displacement and anomalous tibial rotation in the course of the stance phase of walking (exhibited in 85% of operated knees). Individuals who undergo an early ACLR (5 days on average following anterior cruciate ligament [ACL] breakage) have an inferior frequency of radiographically apparent tibiofemoral OA at 32-37 years of follow-up than individuals with ACL rupture who did not experience the procedure. Nevertheless, the percentage of symptomatic OA, radiographically apparent patellofemoral OA and knee symptoms are alike in both groups. At 15 years of follow-up, 23% of knees that experienced an anatomic ACLR suffer from OA, while this percentage augments to 44% if the ACLR was non-anatomic. Knees of individuals who experience ACLR need total knee arthroplasty at an earlier age than healthy knees. Intra-articular injections of interleukin-1 receptor antagonist and corticosteroids may reduce the risk of OA after ACLR.

The development of long-term osteoarthritis following anterior cruciate ligament injury: reconstruction vs no reconstruction

PURPOSE

The high incidence of osteoarthritis (OA) in relatively young sportspeople following anterior cruciate ligament (ACL) reconstruction is concerning. Surgery is considered to reduce the development of OA compared to conservative management. This long-term study aimed to compare the incidence and severity of tibiofemoral OA (TFOA) and patellofemoral OA (PFOA) between reconstructed and non-reconstructed treatment groups and to determine which factors influence the development of OA.

MATERIALS AND METHODS

Fifty-six ACL-reconstructed and 45 conservatively treated patients from a cohort of 330 were followed for 11 years (mean) post-injury. Twenty-nine patients had received a bone-patellar tendon-bone (B-PT-B) graft, and 27 had received a hamstring (semitendinosus/gracilis) tendon (HT) graft. Assessment included objective and subjective stability, quadriceps and hamstring strength and radiology. Chi-square analyses compared OA between reconstructed and non-reconstructed groups and between B-PT-B, HT and non-surgical groups. Further analysis assessed the relationship between OA and age, time post-injury, meniscal injury/meniscectomy, quadriceps strength, hamstring strength, objective and subjective stability and sporting activity.

RESULTS

Forty-eight per cent reconstructed  and 53% non-reconstructed patients developed TFOA (p = 0.690). Thirty-six per cent reconstructed and 38% non-reconstructed patients developed PFOA (p = 0.831) with moderate PFOA occurring only in the non-reconstructed group. Close to significant differences (p = 0.075) were found comparing the severity of TFOA between groups with a higher incidence of moderate/severe OA in the non-reconstructed and B-PT-B groups. TFOA differed significantly between the B-PT-B and HT groups. The development of OA was related to age, time post-injury, meniscal injury/meniscectomy, quadriceps strength and subjective stability.

CONCLUSIONS

There were no significant differences in OA incidence between reconstructed and non-reconstructed groups but fewer patients developed TFOA following HT grafting compared to B-PT-B grafting and to non-surgical treatment. Quadriceps weakness and meniscal injuries/meniscectomy, both potentially modifiable, were strongly associated with the development of TF and PFOA.

Effect of Remnant-Preserving Reconstruction of Acute Anterior Cruciate Ligament Injuries in a Rabbit Model: Histological and Biomechanical Analysis

Acute anterior cruciate ligament (ACL) is a key structure that stabilizes knee joints. The objective of this research is to investigate the influence of ligament remnants preserved on the tendon-bone healing following ACL reconstruction and to examine postoperative articular cartilage degeneration in rabbit as a model animal. Sixty New Zealand rabbits are randomly divided into an ACL reconstruction without remnant preservation group (Group A; n = 30) or ACL reconstruction with remnant preservation group (Group B; n = 30). The expression of HIF-1α, VEGF, and micro vessel density (MVD) in the transplanted tendon was detected by immunohistochemical staining at week 6 and 12 after the operation. The signal intensity of the transplanted tendon was observed by MRI scanning, and the width of the bone tunnel was measured by CT scanning at week 6 and 12 after the operation. The graft biomechanics was tested 12 weeks after the operation. The JNK and MMP-13 expression levels were compared to analyze the cartilage degeneration of the knee at week 12 after the operation. The experimental results were analyzed and showed that the remnant-preserving ACL reconstruction is beneficial for bone healing of the tendon in rabbits, but ACL reconstruction with or without ligament remnants preserved will not affect knee articular cartilage degeneration post-surgery.

Non-anatomic tunnel position increases the risk of revision anterior cruciate ligament reconstruction

PURPOSE

Anterior cruciate ligament (ACL) graft failure is a complication that may require revision ACL reconstruction (ACL-R). Non-anatomic placement of the femoral tunnel is thought to be a frequent cause of graft failure; however, there is a lack of evidence to support this belief. The purpose of this study was to determine if non-anatomic femoral tunnel placement is associated with increased risk of revision ACL-R.

METHODS

After screening all 315 consecutive patients who underwent primary single-bundle ACL-R by a single senior orthopedic surgeon between January 2012 and January 2017, 58 patients were found to have both strict lateral radiographs and a minimum of 24 months follow-up without revision. From a group of 456 consecutive revision ACL-R, patients were screened for strictly lateral radiographs and 59 patients were included in the revision group. Femoral tunnel placement for each patient was determined using a strict lateral radiograph taken after the primary ACL-R using the quadrant method. The center of the femoral tunnel was measured in both the posterior-anterior (PA) and proximal-distal (PD) dimensions and represented as a percentage of the total distance (normal center of anatomic footprint: PA 25% and PD 29%).

RESULTS

In the PA dimension, the revision group had significantly more anterior femoral tunnel placement compared with the primary group (38% ± 11% vs. 28% ± 6%, p < 0.01). Among patients who underwent revision; those with non-traumatic chronic failure had statistically significant more anterior femoral tunnel placement than those who experienced traumatic failure (41% ± 13% vs. 35% ± 8%, p < 0.03). In the PD dimension, the revision group had significantly more proximal femoral tunnel placement compared with the primary group (30% ± 9% vs 38% ± 9%, p < 0.01).

CONCLUSION

In this retrospective study of 58 patients with successful primary ACL-R compared with 59 patients with failed ACL-R, anterior and proximal (high) femoral tunnels for ACL-R were shown to be independent risk factors for ACL revision surgery. As revision ACL-R is associated with patient- and economic burden, particular attention should be given to achieving an individualized, anatomic primary ACL-R. Surgeons may reduce the risk of revision ACL-R by placing the center of the femoral tunnel within the anatomic ACL footprint.

LEVEL OF EVIDENCE

Level III.

Predictors of Osteoarthritis Development at a Median 25 Years After Anterior Cruciate Ligament Reconstruction Using a Patellar Tendon Autograft

BACKGROUND

Few studies have investigated the outcome ≥20 years after an anterior cruciate ligament reconstruction (ACLR) with a bone-patellar tendon-bone autograft, and there is a wide range in the reported rates of radiographic osteoarthritis (OA).

PURPOSE

To report on radiographic OA development and to assess risk factors of knee OA at a median 25 years after ACLR with a bone-patellar tendon-bone autograft.

STUDY DESIGN

Case-control study; Level of evidence, 3.

METHODS

Unilateral ACLRs performed at a single center from 1987 to 1994 were included (N = 235). The study population was followed prospectively with clinical testing and questionnaires. Results from the 3-month, 12-month, and median 25-year follow-up are presented. In addition, a radiographic evaluation was performed at the final follow-up. Radiographic OA was defined as Kellgren-Lawrence grade ≥2 or having undergone ipsilateral knee replacement surgery. Possible predictors of OA development included patient age, sex, time from injury to surgery, use of a Kennedy ligament augmentation device, any concomitant meniscal surgery, and return to preinjury sports after surgery.

RESULTS

At long-term follow-up, 60% (141/235) of patients had radiographic OA in the involved knee and 18% (40/227) in the contralateral knee (P < .001). Increased age at surgery, male sex, increased time between injury and surgery, a Kennedy ligament augmentation device, and medial and lateral meniscal surgery were significant predictors of OA development in univariate analyses. Return to preinjury level of sports after surgery was associated with less development of OA. In the multivariate model, medial meniscal surgery and lateral meniscal surgery were independently associated with OA development. The adjusted odds ratio was 1.88 (95% CI, 1.03-3.43; P = .041) for medial meniscal surgery and 1.96 (95% CI, 1.05-3.67; P = .035) for lateral meniscal surgery. Patients who had developed radiographic signs of OA had significantly lower Knee injury and Osteoarthritis Outcome Score and Lysholm scores at long-term follow-up.

CONCLUSION

At 25 years after ACLR, 60% of patients had developed OA in the involved knee, and these patients reported significantly lower subjective outcomes. Medial meniscal surgery and lateral meniscal surgery were independent predictors of OA development at long-term follow-up.

High variability and lack of standardization in the evaluation of return to sport after ACL reconstruction: a systematic review

PURPOSE

Return to sport (RTS) after ACL reconstruction (ACLR) has been recognized as an important outcome, which is associated with success of the surgery. This study aimed to assess the methods used to determine return to sport after ACLR in the published literature, report on variability of methods and evaluate their strength in establishing accurate RTS data.

METHODS

Electronic databases (PubMed, Cochrane Library and Embase) were searched via a defined search strategy with no limits, to identify relevant studies from January 2008 to December 2020 for inclusion in the review. Defined eligibility criteria included studies specifically measuring and reporting on return to sport after ACLR with a clear methodology. Each included study was assessed for the definition of successful RTS, successful return to pre-injury level of sport and for methods used to determine RTS.

RESULTS

One hundred and seventy-one studies were included. Of the included studies, six studies (4%) were level of evidence 1 and seventy-two studies (42%) were level of evidence 4. Forty-one studies (24%) reported on return to a specific sport and 130 studies (76%) reported on return to multiple sports or general sport. Sixteen studies (9%) reported on RTS in the pediatric population, 36 (21%) in the adult population and 119 (70%) reported on a mixed-aged population. The most commonly used definition of successful RTS was return to the same sport (44 of 125 studies, 35%). The most common method used to determine RTS was a non-validated study-specific questionnaire (73 studies, 43%), which was administered in various ways to the patients. Time of RTS assessment was variable and ranged between 6 months and 27 years post-surgery.

CONCLUSION

This review demonstrates high variability in defining, evaluating and reporting RTS following ACLR. The findings of this study reveal low reliability and unproven validity of methods used to evaluate RTS and highlight the challenges in interpreting and using RTS data reported in literature.

LEVEL OF EVIDENCE

IV.

Osteoarthritis Progression after ACL Reconstruction Was Significantly Higher Than That of the Healthy Contralateral Knees: Long-Term Follow Up Study of Mean 16.4 Years

Background: This study aimed to assess long-term progression of osteoarthritis (OA) after isolated anterior cruciate ligament (ACL) reconstruction in athletes compared to the healthy contralateral side. Methods: The study included 15 patients and 30 knees with a mean age of 40 years (range, 35–46) years, none of whom had had revision surgery or an injury to the contralateral side. The mean follow-up period was 16.4 years (range, 13–22). Clinical and radiographic assessment included the Tegner activity scale (TAS), International Knee Documentation Committee (IKDC) score, Knee injury and Osteoarthritis Outcome Score (KOOS), and Kellgren and Lawrence (KL) grade. The long-term results of the injured knees were compared with the status of the healthy contralateral side and compared with previously published mid-term results of the same cohort of patients. Results: Patients generally remained clinically asymptomatic or mildly symptomatic at final follow-up, which is reflected by a KOOS pain score of 33 points (maximum 36 points) and an IKDC total subjective score of 87% (maximum 100%). There was a significant difference between mid-term and final follow-up in terms of the function score of the IKDC subjective questionnaire (p = 0.031), compartment findings and donor site morbidity of the IKDC functional examination (both p = 0.034), and the total KOOS score (p = 0.047). The KL score indicated significant progression of OA from mid-term to final follow-up in the injured knees (p = 0.004) and healthy contralateral knees (p = 0.014). Mean OA grades of the injured knees were significantly higher compared with the healthy contralateral side (p = 0.006) at final follow-up, and two patients showed moderate to severe signs of OA in the injured knee. Conclusions: Although most patients remained clinically asymptomatic or mildly symptomatic, long-term progression of OA after isolated ACL reconstruction in athletes was significantly higher compared with the healthy contralateral knee.

Biomechanical Effects of Aspect Ratio of the Knee during Outside-In Anterior Cruciate Ligament Reconstruction Surgery

We analyzed tunnel length, graft bending angle, and stress of the graft according to tunnel entry position and aspect ratio (ASR: ratio of anteroposterior depth to mediolateral width) of the articular surface for the distal femur during single-bundle outside-in anterior cruciate ligament reconstruction (ACLR) surgery. We performed multiflexible body dynamic analyses with four ASR (98, 105, 111, and 117%) knee models. The various ASRs were associated with approximately 1 mm changes in tunnel length. The graft bending angle increased when the entry point was far from the lateral epicondyle and was larger when the ASR was smaller. The graft was at maximum stress, 117% ASR, when the tunnel entry point was near the lateral epicondyle. The maximum stress value at a 5 mm distance from the lateral epicondyle was 3.5 times higher than the 15 mm entry position, and the cases set to 111% and 105% ASR showed 1.9 times higher stress values when at a 5 mm distance compared with a 15 mm distance. In the case set at 98% ASR, the low-stress value showed a without-distance difference from the lateral epicondyle. Our results suggest that there is no relationship between the ASR and femoral tunnel length. A smaller ASR causes a higher graft bending angle, and a larger ASR causes greater stress in the graft.

Prognostic Factors for Patient-Reported Outcomes at 32 to 37 Years After Surgical or Nonsurgical Management of Anterior Cruciate Ligament Injury

Background:

Knowledge to inform the identification of individuals with a poor long-term prognosis after anterior cruciate ligament (ACL) injury is limited. Identifying prognostic factors for long-term outcomes after ACL injury may inform targeted interventions to improve outcomes for those with a poor long-term prognosis.

Purpose:

To determine whether ACL treatment (early augmented or nonaugmented ACL repair plus rehabilitation, rehabilitation alone, or rehabilitation plus delayed ACL reconstruction [ACLR]) and 4-year measures (quadriceps and hamstrings strength, single-leg hop, knee laxity, flexion and extension deficit, self-reported knee function, activity level) are prognostic factors for patient-reported outcomes at 32 to 37 years after acute ACL injury.

Study Design:

Cohort study; Level of evidence, 2.

Methods:

A total of 251 patients aged 15 to 40 years with acute ACL rupture between 1980 and 1985 were allocated to early ACL repair (augmented or nonaugmented) plus rehabilitation or to rehabilitation alone, based on birth year. One hundred ninety of 234 completed 32- to 37-year follow-up questionnaires (response rate, 81%); 18 people were excluded, resulting in 172 patients available for analysis (mean age, 59 ± 6 years; 28% female). Potential prognostic factors assessed 4 years after ACL injury were ACL treatment (early ACL repair, rehabilitation alone, or delayed ACLR), isokinetic quadriceps and hamstrings strength, single-leg hop performance, knee flexion and extension deficit, knee laxity, Tegner activity scale, and Lysholm score. Outcomes included Knee injury and Osteoarthritis Outcome Score (KOOS) subscales and the Anterior Cruciate Ligament Quality of Life (ACL-QOL) measure. Linear regression adjusted for age, sex, baseline meniscal injury, and contralateral ACL injury was used to assess potential prognostic factors for 32- to 37-year outcomes. Multiple imputation accounted for missing data.

Results:

A fair/poor Lysholm score (vs excellent/good) at 4 years was a prognostic factor for worse KOOS Pain (adjusted regression coefficient, −12 [95% confidence interval (CI), −19 to −4]), KOOS Symptoms (−15 [95% CI, −23 to −7]), KOOS Sport and Recreation (−19 [95% CI, −31 to −8]), and ACL QOL (−9 [95% CI, −18 to −1]) scores. A 4-year single-leg hop limb symmetry index <90% was a prognostic factor for worse KOOS Pain (adjusted regression coefficient, −9 [95% CI, −17 to −1]) and ACL QOL (−13 [95% CI, −22 to −3]) scores at long-term follow-up. A lower activity level, delayed ACLR, and increased knee laxity were prognostic factors in the crude analysis. Rehabilitation alone versus early repair, quadriceps and hamstring strength, and flexion and extension deficit were not related to 32- to 37-year outcomes.

Conclusion:

Reduced self-reported knee function and single-leg hop performance 4 years after ACL injury were prognostic factors for worse 32- to 37-year outcomes. Estimates exceeded clinically important thresholds, highlighting the importance of assessing these constructs when managing individuals with ACL injuries.

Registration:

NCT03182647 (ClinicalTrials.gov identifier).

Clinical Implications of Bone Bruise Patterns Accompanying Anterior Cruciate Ligament Tears

BACKGROUND

Anterior cruciate ligament (ACL) tears are common injuries; they are often associated with concomitant injuries to other structures in the knee, including bone bruises. While there is limited evidence that bone bruises are associated with slightly worse clinical outcomes, the implications of bone bruises for the articular cartilage and the risk of developing osteoarthritis (OA) in the knee are less clear. Recent studies suggest that the bone bruise pattern may be helpful in predicting the presence of meniscal ramp lesions.

EVIDENCE ACQUISITION

A literature review was performed in EMBASE using the keyword search phrase (acl OR (anterior AND cruciate AND ligament)) AND ((bone AND bruise) OR (bone AND contusion) OR (bone AND marrow AND edema) OR (bone AND marrow AND lesion) OR (subchondral AND edema)).

STUDY DESIGN

Clinical review.

LEVEL OF EVIDENCE

Level 4.

RESULTS

The literature search returned 93 articles of which 25 were ultimately included in this review. Most studies identified a high prevalence of bone bruises in the setting of acute ACL injury. Individual studies have found relationships between bone bruise volume and functional outcomes; however, these results were not supported by systematic review. Similarly, the literature has contradictory findings on the relationship between bone bruises and the progression of OA after ACL reconstruction. Investigations into concomitant injury found anterolateral ligament and meniscal ramp lesions to be associated with bone bruise presence on magnetic resonance imaging.

CONCLUSION

Despite the ample literature identifying the prevalence of bone bruises in association with ACL injury, there is little evidence to correlate bone bruises to functional outcomes or progression of OA. Bone bruises may best be used as a marker for concomitant injury such as medial meniscal ramp lesions that are not always well visualized on magnetic resonance imaging. Further research is required to establish the longitudinal effects of bone bruises on ACL tear recovery.

STRENGTH OF RECOMMENDATION TAXONOMY

2.

Decision Making for Treatment After ACL Injury From an Orthopaedic Surgeon and Patient Perspective: Results From the NACOX Study

Background:

In the treatment of anterior cruciate ligament (ACL) injuries, there is little evidence of when and why a decision for ACL reconstruction (ACLR) or nonoperative treatment (non-ACLR) is made.

Purpose:

To (1) describe the key characteristics of ACL injury treatment decisions and (2) compare patient-reported knee instability, function, and preinjury activity level between patients with non-ACLR and ACLR treatment decisions.

Study Design:

Cohort study; Level of evidence, 2.

Methods:

A total of 216 patients with acute ACL injury were evaluated during the first year after injury. The treatment decision was non-ACLR in 73 patients and ACLR in 143. Reasons guiding treatment decision were obtained from medical charts and questionnaires to patients and orthopaedic surgeons. Patient-reported instability and function were obtained via questionnaires and compared between patients with non-ACLR and ACLR treatment decisions. The ACLR treatment group was classified retrospectively by decision phase: acute phase (decision made between injury day and 31 days after injury), subacute phase (decision made between 32 days and up to 5 months after injury), and late phase (decision made 5-12 months after injury). Data were evaluated using descriptive statistics, and group comparisons were made using parametric or nonparametric tests as appropriate.

Results:

The main reasons for a non-ACLR treatment decision were no knee instability and no problems with knee function. The main reasons for an ACLR treatment decision were high activity demands and knee instability. Patients in the non-ACLR group were significantly older (P = .031) and had a lower preinjury activity level than did those in the acute-phase (P < .01) and subacute-phase (P = .006) ACLR decision groups. There were no differences in patient-reported instability and function between treatment decision groups at baseline, 4 weeks after injury, or 3 months after injury.

Conclusion:

Activity demands, not patient-reported knee instability, may be the most important factor in the decision-making process for treatment after ACL injury. We suggest a decision-making algorithm for patients with ACL injuries and no high activity demands; waiting for >3 months can help distinguish those who need surgical intervention from those who can undergo nonoperative management.

Registration:

NCT02931084 (ClinicalTrials.gov identifier).

Age, activity level and meniscus injury, but not tear location, tibial slope or anterolateral ligament injury predict coping with anterior cruciate ligament injury

INTRODUCTION

Early recognition of potential predictors on the success of conservative treatment of anterior cruciate ligament (ACL) is important, as appropriate treatment can be applied to each individual patient. The goal of this study is to assess the patient demographic and radiological parameters that predict coping with ACL injuries.

METHODS

All patients presenting with a complete ACL injury between 2014 and 2018 at our clinic were included. The role of patient demographics (age, gender, activity level, meniscus injury and time from injury to clinic), and ACL tear location, bone bruises, tibial slope, and anterolateral ligament (ALL) injury were assessed on the success of conservative treatment using univariate and multivariate analyses.

RESULTS

Sixty-five patients (32%) were copers and 141 (68%) were non-copers. Univariate analysis showed that copers were significantly older (40 vs. 27 years, P < 0.001), had lower preinjury activity level (Tegner 5.7 vs. 6.5, P < 0.001) and less often lateral meniscus tears (16% vs. 5%, P = 0.019) but not medial meniscus tears (17% vs. 14%, P = 0.609) than non-copers. Multivariate analysis revealed that increasing age (P < 0.001), Tegner level ≤ 6 (P = 0.003) and no meniscus injury (P = 0.045) were independent predictors of coping with ACL deficiency.

CONCLUSIONS

Older age, participation in lower activity sports levels and absence of meniscus injury were predictive of coping with ACL deficiency, whereas there was no such role for tear location, tibial slope, lateral bone bruise presence, ALL injury or gender. These findings might help to identify potential copers and guide surgeons early in the optimal treatment for patients with ACL injury.

Posttraumatic osteoarthritis: what have we learned to advance osteoarthritis?

PURPOSE OF REVIEW

Current thinking in the study of posttraumatic osteoarthritis (PTOA) is overviewed: the osteoarthritis which follows acute joint injury. The review particularly highlights important publications in the last 18 months, also reflecting on key older literature, in terms of what have we have we learned and have yet to learn from PTOA, which can advance the osteoarthritis field as a whole.

RECENT FINDINGS

PTOA is a mechanically driven disease, giving insight into mechanical drivers for osteoarthritis. A mechanosensitive molecular tissue injury response (which includes activation of pain, degradative and also repair pathways) is triggered by acute joint injury and seen in osteoarthritis. Imaging features of PTOA are highly similar to osteoarthritis, arguing against it being a different phenotype. The inflammatory pathways activated by injury contribute to early joint symptoms. However, later structural changes appear to be dissociated from traditional measures of synovial inflammation.

SUMMARY

PTOA remains an important niche in which to understand processes underlying osteoarthritis and seek interventional targets. Whether PTOA has true molecular or clinical differences to osteoarthritis as a whole remains to be understood. This knowledge is important for a field where animal modelling of the disease relies heavily on the link between injury and osteoarthritis.