Anterior cruciate ligament primary repair revision rates are increased in skeletally mature patients under the age of 21 compared to reconstruction, while adults (>21 years) show no significant difference: A systematic review and meta-analysis.

PURPOSE: To evaluate the impact of age as a risk factor on the revision rates of anterior cruciate ligament (ACL) primary repair (ACLPR), dynamic intraligamentary stabilization (DIS) and bridge-enhanced ACL restoration (BEAR) compared to ACL reconstruction (ACLR). METHODS: A systematic literature search was performed for comparative studies comparing outcomes for ACLPR, DIS or BEAR to ACLR. A random-effects meta-analysis was performed to assess nondifferentiated and age-differentiated (skeletally mature patients ≤21 and >21 years) ACL revision and reoperation risk, as well as results for subjective outcomes. Methodological study quality was assessed using the Risk of Bias Tool 2.0c and Methodological Index for Nonrandomized Studies tools. RESULTS: A total of 12 studies (n = 1277) were included. ACLR demonstrated a lower nonage-stratified revision risk at 2 years versus ACLPR, DIS and BEAR, but a similar revision risk at 5 years when compared to DIS. However, an age-stratified analysis demonstrated a significantly increased ACLPR revision risk as compared to ACLR in skeletally mature patients ≤21 years of age (risk ratios [RR], 6.33; 95% confidence interval [CI], 1.18-33.87, p = 0.03), while adults (>21 years) showed no significant difference between groups (RR, 1.48; 95% CI, 0.25-8.91, n.s.). Furthermore, DIS reoperation rates were significantly higher than respective ACLR rates (RR, 2.22; 95% CI, 1.35-3.65, p = 0.002), whereas BEAR (RR, 1.07; 95% CI, 0.41-2.75, n.s.) and ACLPR (RR, 0.81; 95% CI, 0.21-3.09, n.s.) showed no differences. IKDC scores were equivalent for all techniques. However, ACLPR exhibited significantly better FJS (mean difference, 11.93; 95% CI, 6.36-17.51, p < 0.0001) and Knee injury and Osteoarthritis Outcome Score Symptoms (mean difference, 3.01; 95% CI, 0.42-5.60, p = 0.02), along with a lower Tegner activity reduction. CONCLUSIONS: ACLPR in skeletally mature patients ≤21 years of age is associated with up to a six-fold risk increase for ACL revision surgery compared to ACLR; however, adults (>21 years) present no significant difference. Based on the current data, age emerges as a crucial risk factor and should be considered when deciding on the appropriate treatment option in proximal ACL tears. LEVEL OF EVIDENCE: Level III.

Prospective Comparison of Postoperative Pain and Opioid Consumption Between Primary Repair and Reconstruction of the Anterior Cruciate Ligament.

Background: Anterior cruciate ligament (ACL) reconstruction (ACLR) is associated with postoperative pain and necessitates using perioperative nerve blocks and multimodal analgesic plans. Purpose: To assess postoperative pain and daily opioid use after ACL repair versus ACLR and to assess whether ACL repair could be performed successfully without using long-acting nerve blocks. Study Design: Cohort study; Level of evidence, 2. Methods: All eligible patients who underwent ACL surgery between 2019 and 2022 were prospectively enrolled. Patients were treated with primary repair if proximal tears with sufficient tissue quality were present; otherwise, they underwent single-bundle ACLR with either hamstring tendon or quadriceps tendon autograft. The patients were divided into 3 groups: ACLR with adductor canal nerve block (up to 20 mL of 0.25% bupivacaine with 2 mg dexamethasone), primary repair with nerve block, and primary repair without nerve block. Pain visual analog scale and number of opioids used were recorded during the first 14 postoperative days (PODs). Furthermore, patients completed the Quality of Recovery-15 (QoR-15) survey, and range of motion was assessed. Group differences were compared using Mann-Whitney U test and chi-square test. Results: Seventy-eight patients were included: 30 (39%) underwent ACLR, 19 (24%) ACL repair with nerve block, and 29 (37%) ACL repair without nerve block. Overall, the ACL repair group used significantly fewer opioids than the ACLR group on POD 1 (1 vs 3, P = .027) and POD 2 (1 vs 3, P = .014) while also using fewer opioids in total (3 vs 8, P = .038). This difference was even more marked when only analyzing those patients who received postoperative nerve blocks (1 vs 8, P = .029). Repair patients had significantly higher QoR-15 scores throughout the first postoperative week, and they had greater range of motion (all P < .05). There were no significant differences in pain scores, opioid usage, or QoR-15 scores between patients who underwent repair with versus without nerve block. Conclusion: The ACL repair group experienced less postoperative pain during the first 2 weeks after surgery and used significantly fewer opioids than the ACLR group. Furthermore, they had improved knee function and higher recovery quality than patients who underwent ACLR during the initial postoperative period. Postoperative nerve blocks may not be necessary after ACL repair.

Acute Percutaneous Repair of Medial Collateral Ligament With Suture Augmentation in the Multiligamentous Injured Knee Results in Good Stability and Low Rates of Postoperative Stiffness.

Purpose: To assess the clinical and patient-reported outcome measures (PROMs) of acute superficial medial collateral ligament (sMCL) repair with suture augmentation (SA) in the setting of a multiligamentous injured knees (MLIKs) at 2-year follow-up. Methods: A retrospective analysis of consecutive patients with MLIK with grade III sMCL injuries who underwent acute (<6 weeks) sMCL repair with SA was conducted. Clinical follow-up was performed at minimum 1-year postoperatively, and PROMs were collected at the latest follow-up (minimum 2 years' postoperatively). Continuous variables were reported in median with interquartile range (IQR). Results: A total of 20 patients (41.4 [28.5-47.9] years of age) with grade III sMCL injury and additional injury to 1 cruciate ligament (KDI-M; n = 13) or bicruciate (KDIII-M; n = 7) were enrolled with a median follow-up of 4.3 (3.6-5.2) years. In total, 90% (n = 18) of patients with MLIK treated with acute sMCL repair and early range of motion rehabilitation protocol demonstrated negative valgus laxity stress testing in 0 and 30° flexion and low reoperation rates (n = 1, 5%) due to stiffness. In addition, good-to-excellent subjective outcomes were reported at final follow-up: median International Knee Documentation Committee 82.2 (78.7-90.8), Lysholm 95.0 (90.0-100.0), modified Cincinnati Score 89.0 (83.3-96.0), Single Assessment Numeric Evaluation 90.0 (83.8-95.0), Forgotten Joint Score 79.2 (62.5-91.7), Tegner 5.0 (IQR 4.0-6.0), and ACL-Return to Sport after Injury Scale 78.3 (IQR 66.7-90.0). Conclusions: In this study, 20 heterogenous patients with MLIKs treated with acute percutaneous sMCL repair with SA had excellent stability, low rates of postoperative stiffness, and good-to-excellent PROMs at short-term follow-up. Level of Evidence: Level IV, therapeutic case series.

Anatomic Arthroscopic Primary Repair of Proximal Anterior Cruciate Ligament Tears.

Within the last decade, various highly diverse anterior cruciate ligament (ACL) preservation techniques have been proposed, as contemporary selective arthroscopic ACL preservation experienced a resurgence. Among surgical techniques, there are a variety of suturing, fixation, and augmentation methods, whereas a common thread, considering essential anatomic and biomechanical properties, is missing. This technique aims to anatomically reapproximate both the anteromedial (AM) and posterolateral (PL) bundles to their respective femoral footprints. Additionally, a PL compression stitch is performed to increase the ligament-bone contact area and recreate the anatomic vectors of the native bundles, therefore, creating a more anatomic and biomechanical construct. This technique is a minimally invasive procedure, with no graft harvesting nor tunnel drilling, which leads to decreased pain levels, earlier return of full range motion (ROM), and faster rehabilitation, while failure rates seem to be comparable to that of ACL reconstruction. We present an updated surgical technique of anatomic arthroscopic primary repair with suture anchor fixation for patients with proximal ACL tears.

Age and Bone Bruise Patterns Predict Tear Location in the Anterior Cruciate Ligament.

Purpose: To assess the influence of demographic risk factors, anatomic risk factors, and injury mechanisms on anterior cruciate ligament (ACL) tear patterns. Methods: All patients undergoing knee magnetic resonance imaging at our institution for acute ACL tears (within 1 month of injury) in 2019 were retrospectively analyzed. Patients with partial ACL tears and full-thickness posterior cruciate ligament injuries were excluded. On sagittal magnetic resonance images, the proximal and distal remnant lengths were measured, and the tear location was calculated as the distal remnant length divided by the total remnant length. Previously reported demographic and anatomic risk factors associated with ACL injury were then reviewed, including the notch width index, notch angle, intercondylar notch stenosis, alpha angle, posterior tibial slope, meniscal slope, and lateral femoral condyle index. In addition, the presence and severity of bone bruises were recorded. Finally, risk factors associated with ACL tear location were further analyzed using multivariate logistic regression. Results: A total of 254 patients (44% male patients; mean age, 34 years; age range, 9-74 years) were included, of whom 60 (24%) had a proximal ACL tear (tear at the proximal quarter). Multivariate enter logistic regression analysis showed that older age (P = .008) was predictive of a more proximal tear location whereas open physes (P = .025), bone bruises in both compartments (P = .005), and posterolateral corner injury (P = .017) decreased the likelihood of a proximal tear (R 2 = 0.121, P < .001). Conclusions: No anatomic risk factors were identified to play a role in tear location. Although most patients have midsubstance tears, proximal ACL tears were more commonly found in older patients. Bone contusions involving the medial compartment are associated with midsubstance tears; these findings may indicate that different injury mechanisms play a role in the location at which the ACL tears. Level of Evidence: Level III, prognostic, retrospective cohort study.

Early and Delayed Surgery for Isolated ACL and Multiligamentous Knee Injuries Have Equivalent Results: A Systematic Review and Meta-analysis.

BACKGROUND: Early surgery for acute ligamentous injuries has recently shown good clinical and functional outcomes. PURPOSE: To assess the advantages of early vs delayed surgery in patients undergoing isolated anterior cruciate ligament (ACL) or multiligament-injured knee (MLIK) surgery. STUDY DESIGN: Meta-analyses of Level 1, 2, and 3 studies; Level of evidence, 4. METHODS: A systematic search was performed via PubMed, EMBASE, and Cochrane for studies reporting outcomes of timing of surgery after isolated ACL injury or in the MLIK setting using accelerated rehabilitation protocols. Two analyses were conducted to differentiate early and delayed treatment (3- and 6-week cutoffs). Collected outcomes included meniscal or chondral lesions, failure and reoperation rates, range of motion (ROM) deficits, other complications, muscle strength, instrumented laxity, and functional outcomes. Outcomes were reported in risk ratios (RR) or mean differences with 95% CIs. RESULTS: For timing of isolated ACL surgery, 16 studies were included with 2093 patients. High-grade evidence indicated that there were no differences in meniscal or chondral lesions, failure and reoperation rates, stiffness, ROM deficits, complications, muscle strength, instrumented laxity, and functional outcomes between patients treated early and late (all P > .05). When including only studies that set no preoperative criteria for early surgery, the findings were similar. Regarding MLIK surgery, 14 studies were included with 1172 patients. Low evidence was noted for the following: patients treated early had significantly fewer meniscal injuries (RR, 0.7; P = .04) and chondral injuries (RR, 0.5; P < .001), while no differences were found in reoperation rates, complications, stiffness, ROM deficits, muscle strength, instrumented laxity, and functional outcomes between the groups. Other than higher Lysholm scores in the early group for the 3-week analysis (mean difference, 6.8; P = .01), there were no differences between cutoff analyses. CONCLUSION: This systematic review with meta-analysis found no differences in clinical and functional outcomes between early and delayed surgery for isolated ACL injuries. For MLIK injuries, there were also no differences in surgical outcomes between early and delayed surgery.

Treating Combined Anterior Cruciate Ligament and Medial Collateral Ligament Injuries Operatively in the Acute Setting Is Potentially Advantageous.

Combined injury of the anterior cruciate ligament (ACL) and medial collateral ligament (MCL) remains among the most common knee injury patterns in orthopaedics. Optimal treatment of grade III MCL injuries is still debated, especially when combined with ACL injury. Most patients with these severe injuries are treated conservatively for at least 6 weeks to allow for MCL healing, followed by delayed ACL reconstruction. Although acute treatment of the MCL was common in the 1970s, postoperative stiffness was frequently reported. Moreover, studies of such treatment failed to show clinical benefits of surgical over conservative treatment, and the MCL exhibited intrinsic healing capacity, leading to the consensus that all MCL injuries are treated conservatively. The current delayed treatment algorithm for ACL-MCL injuries has several disadvantages. First, MCL healing may be incomplete, resulting in residual valgus laxity that places the ACL graft at greater risk of failure. Second, delayed treatment lengthens the overall rehabilitation period, thereby prolonging the presence of atrophy and delaying return to preinjury activity levels. Third, the initial healing period leaves the knee unstable for longer and risks further intra-articular damage. Acute simultaneous surgical treatment of both ligaments has the potential to avoid these shortcomings. This article will review the evolution of treatment of ACL-MCL injuries and explain how it shifted toward the current treatment algorithm. We will (1) discuss why the consensus shifted, (2) discuss the shortcomings of the current treatment plan, (3) discuss the potential advantages of acute simultaneous treatment, and (4) present an overview of the available literature.

Bilateral simultaneous anterior cruciate ligament tears treated with single staged simultaneous primary repair: A case report.

INTRODUCTION AND IMPORTANCE: Simultaneous bilateral anterior cruciate ligament (ACL) injuries are a rare injury pattern within the literature. There is not a consensus optimal management of this injury. Bilateral primary ACL repair in a single stage surgery provides knee stability with a minimally morbid surgery in a single rehabilitation period. This case report offers another option for surgeons to consider in the treatment of this rare injury. CASE PRESENTATION: A 45-year-old female skier presented with simultaneous bilateral isolated proximal anterior cruciate ligament injuries. MRI demonstrated bilateral proximal ACL tear patterns which were amenable to primary ACL repair. The patient subsequently underwent acute single-staged arthroscopic primary ACL repair with suture augmentation of both knees. She attained rehabilitation milestones and was fully cleared to return to sporting activities one year post-operatively. Two years post-operatively the patient continues to do well with excellent clinical outcomes. CLINICAL DISCUSSION: The other treatment modalities reported in the literature were single staged and two staged ACL reconstruction with either autograft or allograft. While single staged procedures are more time and cost efficient, the primary concern is that simultaneous rehabilitation of bilateral ACL reconstructions may lead to severe quadriceps deconditioning. Primary ACL repair poses a potential solution as a minimally morbid surgery with faster rehabilitation from surgery. CONCLUSION: Due to the limited invasiveness and morbidity of ACL primary repair with suture augmentation, simultaneous primary repair surgery could be an excellent treatment option for this rare patient population, saving time and cost while providing appropriate knee stability. LEVEL OF EVIDENCE: Level IV, Case Report.

Primary Repair versus Reconstruction in Patients with Bilateral Anterior Cruciate Ligament Injuries: What Do Patients Prefer?

Purpose: The purpose is to evaluate knee preference and functional outcomes of patients with primary anterior cruciate ligament (ACL) repair in one knee and ACL reconstruction in the contralateral side. Methods: All patients who underwent both procedures were retrospectively reviewed at minimum two-year follow-up. Patients were asked to complete questionnaires regarding their operated knees' preferences during rehabilitation, daily activities, sports activities, and overall function. Furthermore, the Subjective International Knee Documentation Committee, Forgotten Joint Score-12, and Anterior Cruciate Ligament-Return to Sport after Injury were completed. Results: Twenty-one patients were included. All patients underwent ACL reconstruction first, which was displayed at younger age at surgery (24 vs. 33 years, p = 0.010) and longer follow-up (10.2 vs. 2.3 years, p < 0.001), respectively. Thirty-three percent preferred the repaired knee, 11% the reconstructed knee, and 56% had no preference; however, 78% indicated that their repaired knee was less painful during rehabilitation and 83% reported earlier range of motion (ROM) return following repair, which was similar for both knees in 17%. Eighty-three percent of patients indicated better function and progression during rehabilitation with their repaired knee and 11% with their reconstructed knees. No statistical differences were found in patient-reported outcomes between both procedures (all p > 0.4). Objective laxity assessment showed mean side-to-side difference of 0.6 mm between both sides in favor of the reconstructed knee. Conclusion: This study showed that ACL repair and ACL reconstruction lead to similar functional outcomes. However, patients undergoing both procedures may have less pain, earlier ROM return, and faster rehabilitation progression following primary repair.

Primary repair with suture augmentation for proximal anterior cruciate ligament tears: A systematic review with meta-analysis.

PURPOSE: To assess the outcomes of arthroscopic primary repair of proximal anterior cruciate ligament (ACL) tears with suture augmentation in the literature. METHODS: A systematic search was performed using PubMed, EMBASE, and Cochrane for studies reporting on outcomes of primary repair of proximal ACL tears with suture augmentation between 2015 and 2021. Primary outcomes included failure and reoperation rates, whereas secondary outcomes consisted of functional outcomes. Proportion meta-analysis was performed to assess the overall incidence of failure rates. Outcomes of adults and adolescent were reported separately. RESULTS: Thirteen studies with 418 patients were included in this study (mean age 32 years, mean follow-up 2.0 years, 49% male). There were no randomized studies and overall grade of recommendation was weak. Overall failure rate for primary repair with suture augmentation was 8% (95% CI 3.9-14.4), but this was higher for younger patients (17%; 95% CI 2.5-63.9) than for older patients (6%; 95% CI 3.8-8.9). The risk for additional reoperations, complications, or hardware removal was low (all <2%), while functional outcomes were good to excellent (all >80% of maximum score). CONCLUSION: Current literature shows that primary repair with suture augmentation is a reliable treatment option for proximal ACL tears with a failure rate of 8% and good functional outcome scores at short-term follow-up. Although functional outcomes were good irrespective of age, failure rates were higher in young patients (17% vs 6%, respectively). There is a need for high-quality comparative studies with large group of patients to compare these outcomes with ACL reconstruction.

Differential regional perfusion of the human anterior cruciate ligament: quantitative magnetic resonance imaging assessment.

PURPOSE: Surgical reconstruction is the current standard for ACL rupture treatment in active individuals. Recently, there is renewed interest in primary repair of proximal ACL tears. Despite this, ACL biology and healing potential are currently not well understood. Vascularity is paramount in ACL healing; however, previous ACL vascularity studies have been limited to qualitative histological and dissection-based techniques. The study objective was to use contrast-enhanced quantitative-MRI to compare relative perfusion of proximal, middle, and distal thirds of the in situ ACL. We hypothesized perfusion would be greatest in the proximal third. METHODS: Fourteen cadaveric knees were studied (8 females, 6 males), age 25-61 years. Superficial femoral, anterior tibial, and posterior tibial arteries were cannulated; without intraarticular dissection. Contrast-enhanced quantitative-MRI was performed using a previously established protocol. ACL regions corresponding to proximal, middle, and distal thirds were identified on sagittal-oblique pre-contrast images. Signal enhancement (normalized to tibial plateau cartilage) was quantified to represent regional perfusion as a percentage of total ACL perfusion. Comparative statistics were computed using repeated measures ANOVA, and pairwise comparisons performed using the Bonferroni method. RESULTS: Relative perfusion to proximal, middle, and distal ACL zones were 56.0% ±17.4%, 28.2% ±14.6%, and 15.8% ±16.3%, respectively (p = 0.002). Relative perfusion to the proximal third was significantly greater than middle (p = 0.007) and distal (p = 0.001). No statistically relevant difference in relative perfusion was found to middle and distal thirds (p = 0.281). Post-hoc subgroup analysis demonstrated greater proximal perfusion in males (66.9% ± 17.3%) than females (47.8% ± 13.0%), p = 0.036. CONCLUSION: Using quantitative-MRI, in situ adult ACL demonstrated greatest relative perfusion to the proximal third, nearly 2 times greater than the middle third and 3 times greater than the distal third. Knowledge of differential ACL vascular supply is important for understanding pathogenesis of ACL injury and the process of biological healing following various forms of surgical treatment.

Reliable Internal Consistency and Adequate Validity of the Forgotten Joint Score-12 after Primary Anterior Cruciate Ligament Repair.

PURPOSE: To validate the Forgotten Joint Score-12 (FJS-12) as a subjective outcome metric for patients undergoing arthroscopic primary anterior cruciate ligament (ACL) repair. METHODS: In this retrospective study, all patients undergoing primary ACL repair for complete isolated proximal tears between 2008 and 2018 were eligible for inclusion. Patients were contacted and asked to complete the FJS-12, Lysholm Knee Score, modified Cincinnati score, Single Assessment Numeric Evaluation (SANE), Subjective International Knee Documentation Committee (IKDC), and Anterior Cruciate Ligament Return to Sport after Injury (ACL-RSI) scale at a minimum of 1 year of follow-up. Internal consistency, convergent validity, and ceiling effects were analyzed. RESULTS: Ninety-six patients could be included (62%), with a mean FJS-12 score of 86.9 ± 14.0 (range, 31.3-100). The FJS-12 showed reliable internal consistency (Cronbach's alpha = 0.89). Construct validity was moderate to strong (r = 0. 621-0.702). Ceiling effect for the FJS-12 was 21.9%, which was lower than for the Lysholm (44.6%), modified Cincinnati (45.1%), equal to the IKDC subjective (21.9%), and SANE score (22.0%) but higher compared to the ACL-RSI (12.8%). Furthermore, internal consistency for the other scores was also good to excellent (range Cronbach's alpha = 0.627-0.953). CONCLUSION: The FJS-12 shows high internal consistency and construct validity after primary ACL repair. Furthermore, this metric showed equal or less ceiling effect than most other scores, although still notable. This study suggests that the FJS-12 is an easy and validated outcome metric to evaluate subjective primary repair outcomes. LEVEL OF EVIDENCE: Level III, diagnostic study.

Primary Repair of Anterior Cruciate Ligament Injuries: Current Level of Evidence of Available Techniques.

¼: Recently, there has been a resurgence of interest in primary anterior cruciate ligament (ACL) repair that has the potential to preserve native tissue using a more minimally invasive approach. Multiple repair techniques for different tear types have been reported over the last decade. ¼: From a healing perspective, proximal tears can be reapproximated directly to the femoral wall because they have better intrinsic healing capacity than midsubstance tears. These procedures can be classified further as direct suture repair with or without static or dynamic augmentation. Current evidence does not support direct repair of midsubstance tears because of their limited healing capacity. In many instances, biological augmentation is needed to enhance the healing potential of the ACL. ¼: While ACL repair is certainly not an effective surgical approach for all tears or in all patients, this procedure can be an effective and less morbid alternative to ACL reconstruction in carefully selected patients. ¼: The overall current reported level of evidence of published studies has ranged from low to moderate, and thus there is a need for higher-quality, comparative studies in which outcomes of larger patient groups are compared with the current gold standard of ACL reconstruction.

Repair versus reconstruction for proximal anterior cruciate ligament tears: a study protocol for a prospective multicenter randomized controlled trial.

BACKGROUND: For active patients with a tear of the anterior cruciate ligament (ACL) who would like to return to active level of sports, the current surgical gold standard is reconstruction of the ACL. Recently, there has been renewed interest in repairing the ACL in selected patients with a proximally torn ligament. Repair of the ligament has (potential) advantages over reconstruction of the ligament such as decreased surgical morbidity, faster return of range of motion, and potentially decreased awareness of the knee. Studies comparing both treatments in a prospective randomized method are currently lacking. METHODS: This study is a multicenter prospective block randomized controlled trial. A total of 74 patients with acute proximal isolated ACL tears will be assigned in a 1:1 allocation ratio to either (I) ACL repair using cortical button fixation and additional suture augmentation or (II) ACL reconstruction using an all-inside autologous hamstring graft technique. The primary objective is to assess if ACL repair is non-inferior to ACL reconstruction regarding the subjective International Knee Documentation Committee (IKDC) score at two-years postoperatively. The secondary objectives are to assess if ACL repair is non-inferior with regards to (I) other patient-reported outcomes measures (i.e. Knee Injury and Osteoarthritis Outcome Score, Lysholm score, Forgotten Joint Score, patient satisfaction and pain), (II) objective outcome measures (i.e. failure of repair or graft defined as rerupture or symptomatic instability, reoperation, contralateral injury, and stability using the objective IKDC score and Rollimeter/KT-2000), (III) return to sports assessed by Tegner activity score and the ACL-Return to Sports Index at two-year follow-up, and (IV) long-term osteoarthritis at 10-year follow-up. DISCUSSION: Over the last decade there has been a resurgence of interest in repair of proximally torn ACLs. Several cohort studies have shown encouraging short-term and mid-term results using these techniques, but prospective randomized studies are lacking. Therefore, this randomized controlled trial has been designed to assess whether ACL repair is at least equivalent to the current gold standard of ACL reconstruction in both subjective and objective outcome scores. TRIAL REGISTRATION: Registered at Netherlands Trial Register ( NL9072 ) on 25th of November 2020.

Minocycline-induced black bone disease with synovial pigmentation in a patient undergoing revision anterior cruciate ligament surgery: A case report.

INTRODUCTION: Long-term use of minocycline at high doses is associated with hyperpigmentation with multiple sites of involvement. While the cutaneous organs and the oral cavity are most commonly affected, bone discoloration is a rare entity. CASE PRESENTATION: A 19-year-old male patient with a history of acne vulgaris and intermittent treatment with high dose minocycline for three years presented with recurrent anterior cruciate ligament (ACL) tear. During arthroscopic surgery, however, hyperpigmentation of the femur and synovium was observed. Abnormal tissue was biopsied and confirmed through histopathological examination to contain melanin-related minocycline pigmentation. Revision surgery was re-scheduled with no intraoperative complications and excellent long-term clinical outcomes. CLINICAL DISCUSSION: There are several possible causes of hyperpigmentation, including hemosiderin deposition, infection, aseptic necrosis, demineralization, and metastatic disease. Black bone disease, caused by minocycline-induced hyperpigmentation, is rare. While the appearance is grossly abnormal in black bone disease, there has been no evidence suggesting that tissue integrity is compromised. CONCLUSION: This case confirms that hyperpigmentation does not affect bone integrity and that surgical procedures can be performed safely. Knowing the adverse effects of minocycline administration could reduce inappropriate postponement of surgical procedures, thereby saving time and resources.

Acute and delayed anterior cruciate ligament repair results in similar short to mid-term outcomes.

BACKGROUND: To assess whether primary repair of proximal ACL tears in the delayed setting leads to similar clinical and functional outcomes as compared to ACL repair in the acute setting. METHODS: All patients with proximal tears with good tissue quality treated in the acute (≤3 weeks post-injury) and delayed setting (>3 months post-injury) were retrospectively reviewed at minimum 2-year follow-up. Ipsilateral reinjury or reoperation and contralateral injury rates were recorded. Functional outcomes were evaluated using the Lysholm, modified Cincinnati, Single Assessment Numeric Evaluation, International Knee Documentation Committee subjective, Forgotten Joint Score-12, Anterior Cruciate Ligament-Return to Sport after Injury scale, and satisfaction scores. Finally, time to return to work, time to discontinue brace-usage, time to running, and time to return to sports were reviewed. Group differences were compared using chi-square tests and Mann-Whitney U tests. RESULTS: Sixty-nine patients were included, of which 34 (49%) were treated acutely and 35 (51%) in the delayed setting. Besides time from injury to surgery, patient demographics were similar between groups (all p > 0.1). There were three reinjuries (9%) in the acute group and four in the delayed (11%; p > 0.999). Reoperation, complication, and contralateral injury rates were similar between groups (all p > 0.1), while functional outcomes were also comparable (all p > 0.05). CONCLUSION: This study found that acute and delayed primary ACL repair results in similar clinical and functional outcomes at short to mid-term follow-up. Therefore, the most important factors for repair surgery success seem to be tissue quality and tissue length, rather than acuity of the surgery. LEVEL OF EVIDENCE: Level III, retrospective comparative cohort study.

Arthroscopic Primary Repair of the Posterior Cruciate Ligament.

The posterior cruciate ligament (PCL) is one of the four major stabilizers of the knee joint and functions as the primary restraint to posterior tibial translation. PCL tears rarely occur in isolation and most commonly presents in the setting of multiligamentous knee injuries. Several treatment strategies for these injuries have been proposed over the last decades, including ligament reconstruction and primary repair. Arthroscopic primary PCL repair has the potential to preserve native tissue using a more minimally invasive approach, thereby avoiding donor-site morbidity and allowing early mobilization. While arthroscopic PCL repair is certainly not an effective surgical approach for all patients, this procedure may be a reasonable and less morbid alternative to PCL reconstruction in selected patients treated for proximal or distal avulsion tears, with low failure rates, good knee stability, and good to excellent subjective outcomes. The surgical indications, surgical techniques, postoperative management, and outcomes for arthroscopic primary repair of proximal and distal PCL tears will be discussed in this review.