Arthroscopic centralization reduces extrusion of the medial meniscus with posterior root defect in the ACL reconstructed knee.

PURPOSE: The purpose of this study was to evaluate the effects of arthroscopic meniscal centralization reinforcement for a medial meniscus (MM) posterior root defect on knee kinematics and meniscal extrusion in the anterior cruciate ligament reconstructed (ACLR) knee. The hypothesis was that the medial meniscus centralization would reduce extrusion and anterior laxity in ACLR knee with a medical meniscal defect. METHODS: Fourteen fresh-frozen human cadaveric knees were tested using a six-degrees-of-freedom robotic system under the following loading conditions: (a) an 89.0 N anterior tibial load, (b) 5.0 Nm internal and external rotational torques, (c) a 10.0 Nm valgus and varus loadings, and (d) a combined 7.0 Nm valgus moment and then a 5.0 Nm internal rotation torque as a static simulated pivot shift. The tested knee states included: (1) anatomic single-bundle cruciate ligament reconstruction with intact medial meniscus (MM Intact), (2) anatomic single-bundle cruciate ligament reconstruction with medial meniscus posterior root defect (MM Defect), (3) Anatomic single-bundle cruciate ligament reconstruction with medial meniscus arthroscopic centralization (MM Centralization). Medial meniscus arthroscopic centralization was performed using 1.4 mm anchors with #2 suture. The MM extrusion (MME) was measured using ultrasound under unloaded and varus loading conditions at 0° and 30° of flexion. RESULTS: Anterior tibial translation (ATT) increased significantly with MM posterior root defect compared to MM intact at all flexion angles. With MM centralization, ATT was not significantly different from the intact meniscus at 15° and 30° of flexion. Meniscus extrusion increased significantly with the root defect compared to intact meniscus and decreased significantly with meniscal centralization compared to the root defect at both flexion angles. CONCLUSIONS: In ACL reconstruction, cases involving irreparable medial meniscal posterior root tears, applying arthroscopic centralization for avoiding the meniscal extrusion should be considered. Clinically, in ACL reconstruction cases with irreparable medial meniscal posterior root tears, applying arthroscopic meniscal centralization for avoiding the meniscal extrusion should be considered. Meniscal centralization decreases the extrusion of the MM and offers improvements in knee laxity.

Posterior tibial slope and meniscal slope correlate with in vivo tibial internal rotation during running and drop jump.

PURPOSE: The relationship between tibial bony and meniscus anatomy and knee kinematics during in vivo, high-impact activities remains unclear. This study aimed to determine if the posterior tibial slope (PTS) and meniscal slope (MS) are associated with in vivo anterior-posterior translation and internal tibia rotation during running and double-leg drop jumps in healthy knees. METHODS: Nineteen collegiate athletes performed fast running at 5.0 m/s on an instrumented treadmill and double-leg drop jump from a 60 cm platform while biplane radiographs of the knee were acquired at 150 Hz. Tibiofemoral kinematics were determined using a validated model-based tracking process. Medial and lateral PTS and MS were measured using magnetic resonance imaging (MRI). RESULTS: In fast running, more internal tibia rotation was associated with greater PTS (ρ = 0.336, P = 0.039) and MS (ρ = 0.405, P = 0.012) in the medial knee compartment. In the double-leg drop jump, more internal tibia rotation was associated with greater PTS (ρ = 0.431, P = 0.007) and MS (ρ = 0.323, P = 0.005) in the medial knee compartment, as well as a greater PTS in the lateral knee compartment (ρ = 0.445, P = 0.005). CONCLUSION: These findings suggest that the medial and lateral PTS and medial MS are associated with the amount of knee rotation during high-impact activities. These in vivo findings improve our understanding of ACL injury risk by linking bone and meniscus morphology to dynamic kinematics.

Environmental Sustainability in Orthopaedic Surgery.

Climate change has been increasingly recognized in the healthcare sector over recent years, with global implications in infrastructure, economics, and public health. As a result, a growing field of study examines the role of healthcare in contributing to environmental sustainability. These analyses commonly focus on the environmental impact of the operating room, due to extensive energy and resource utilization in surgery. While much of this literature has arisen from other surgical specialties, several environmental sustainability studies have begun appearing in the field of orthopaedic surgery, consisting mostly of waste audits and, less frequently, more comprehensive environmental life cycle assessments. The present study aims to review this limited evidence. The results suggest that methods to reduce the environmental impact of the operating room include proper selection of anesthetic techniques that have a smaller carbon footprint, minimization of single use instruments, use of minimalist custom-design surgical packs, proper separation of waste, and continuation or implementation of recycling protocols. Future directions of research include higher-level studies, such as comprehensive life cycle assessments, to identify more opportunities to decrease the environmental impact of orthopaedic surgery.

Superb microvascular imaging (SMI) detects increased vascularity of the torn anterior cruciate ligament.

PURPOSE: Ultrasound with superb microvascular imaging (SMI) is a novel microvascular imaging technology which may be useful to assess the vascularity of the torn anterior cruciate ligament (ACL) as a potential measure of healing potential following surgery. This study aimed to quantify the vascularity of the torn and intact ACL using ultrasound with SMI. METHODS: 23 patients (mean age ± standard deviation, 27.1 ± 12.8 years), who were diagnosed with an ACL tear with an intact contralateral ACL were enrolled (ACL injury group). Ten healthy volunteers (36.1 ± 4.9 years) who had intact ACLs in both knees were also recruited (ACL healthy controls). The vascularity of the ACL was assessed using SMI within 15 mm from the tibial insertion in both knees. The amount of the vascular signal was assessed using a semi-quantitative grading scale (vascularity grade: grade 0-3) and a quantified ratio of vascularized area with respect to total area of the region of interest (vascularity ratio). RESULTS: In the ACL injury group, a significantly higher vascularity grade and ratio were observed in the torn ACL (vascularity grade 0-3: 1, 8, 7, and 7 patients, respectively; vascularity ratio: 1.3 ± 1.4%) than the contralateral intact ACL (vascularity grade 0-3: 21, 1, 1, and 0 patients, respectively; vascularity ratio: 0.1 ± 0.5%) (P < 0.001), whereas no significant difference was observed between both ACLs in the ACL healthy control group. CONCLUSIONS: SMI was useful to assess the increased vascularity in torn ACL, which may reflect the potential for, or state of, ACL maturation following reconstruction or repair. LEVEL OF EVIDENCE: Level III.

ACL graft with extra-cortical fixation rotates around the femoral tunnel aperture during knee flexion.

PURPOSE: An understanding of the behavior of a new ACL graft in the femoral tunnel during knee motion and external loading can provide information pertinent to graft healing, tunnel enlargement, and graft failure. The purpose of the study was to measure the percentage of the tunnel filled by the graft and determine the amount and location of the graft-tunnel contact with knee motion and under external knee loads. METHODS: Single bundle anatomical ACL reconstruction was performed on six cadaveric knees. Specimens were positioned with a robotic testing system under: (1) passive flexion-extension, (2) 89-N anterior and posterior tibial loads, (3) 5-N m internal and external torques, and (4) 7-N m valgus moment. The knees were then dissected, repositioned by the robot and the geometry of the femoral tunnel and graft were digitized by laser scanning. The percentage of tunnel filled and the contact region between graft and tunnel at the femoral tunnel aperture were calculated. RESULTS: The graft occupies approximately 70% of the femoral tunnel aperture and anterior tibial loading tended to reduce this value. The graft contacted about 60% of the tunnel circumference and the location of the graft-tunnel contact changed significantly with knee flexion. CONCLUSION: This study found that the graft tends to rotate around the tunnel circumference during knee flexion-extension and contract under knee loading. The "windshield-wiper" and "bungee cord" effect may contribute to femoral tunnel enlargement, affect graft healing, and lead to graft failure. There can be a considerable motion of the graft in the tunnel after surgery and appropriate rehabilitation time should be allowed for graft-tunnel healing to occur. To reduce graft motion, consideration should be given to interference screw fixation or a graft with bone blocks, which may allow an earlier return to activity.

The radiographic tibial spine area is correlated with the occurrence of ACL injury.

PURPOSE: The purpose of this study was to reveal the possible influence of the tibial spine area on the occurrence of ACL injury. METHODS: Thirty-nine subjects undergoing anatomical ACL reconstruction (30 female, 9 male: average age 29 ± 15.2) and 37 subjects with intact ACL (21 female, 16 male: average age 29 ± 12.5) were included in this study. In the anterior-posterior (A-P) and lateral knee radiograph, the tibial spine area was measured using a PACS system. In axial knee MRI exhibiting the longest femoral epicondylar length, the intercondylar notch area was measured. Tibial spine area, tibial spine area/body height, and tibial spine area/notch area were compared between the ACL tear and intact groups. RESULTS: The A-P tibial spine area of the ACL tear and intact groups was 178 ± 34 and 220.7 ± 58mm2, respectively. The lateral tibial spine area of the ACL tear and intact groups was 145.7 ± 36.9 and 178.9 ± 41.7mm2, respectively. The tibial spine area was significantly larger in the ACL intact group when compared with the ACL tear group (A-P: p = 0.02, lateral: p = 0.03). This trend was unchanged even when the tibial spine area was normalized by body height (A-P: p = 0.01, lateral: p = 0.02). The tibial spine area/notch area of the ACL tear and intact groups showed no significant difference. CONCLUSION: The A-P and lateral tibial spine area was significantly smaller in the ACL tear group when compared with the ACL intact group. Although the sample size was limited, a small tibial spine might be a cause of knee instability, which may result in ACL injury. LEVEL OF EVIDENCE: Level III.

Current trends in the anterior cruciate ligament part 1: biology and biomechanics.

A trend within the orthopedic community is rejection of the belief that "one size fits all." Freddie Fu, among others, strived to individualize the treatment of anterior cruciate ligament (ACL) injuries based on the patient's anatomy. Further, during the last two decades, greater emphasis has been placed on improving the outcomes of ACL reconstruction (ACL-R). Accordingly, anatomic tunnel placement is paramount in preventing graft impingement and restoring knee kinematics. Additionally, identification and management of concomitant knee injuries help to re-establish knee kinematics and prevent lower outcomes and registry studies continue to determine which graft yields the best outcomes. The utilization of registry studies has provided several large-scale epidemiologic studies that have bolstered outcomes data, such as avoiding allografts in pediatric populations and incorporating extra-articular stabilizing procedures in younger athletes to prevent re-rupture. In describing the anatomic and biomechanical understanding of the ACL and the resulting improvements in terms of surgical reconstruction, the purpose of this article is to illustrate how basic science advancements have directly led to improvements in clinical outcomes for ACL-injured patients.Level of evidenceV.

Low to moderate risk of nerve damage during peroneus longus tendon autograft harvest.

PURPOSE: This study aims to evaluate the proximity of the tendon stripper to both the peroneal and sural nerves during peroneus longus tendon (PLT) autograft harvesting. METHODS: Ten fresh-frozen human cadaveric lower extremities were used to harvest a full-thickness PLT autograft using a standard closed blunt-ended tendon stripper. The distance to the sural nerve from the PLT (at 0, 1, 2 and 3 cm proximal to lateral malleolus (LM), and the distance to the peroneal nerve and its branches from the end of the tendon stripper were measured by two separate observers using ImageJ software. RESULTS: The average distance from the PLT to the sural nerve increased significantly from 0 to 2 cm proximal to LM. The average distance to the sural nerve at the LM was 4.9 ± 1.5 mm and increased to 10.8 ± 2.4 mm (2 cm proximal to LM). The average distance from the tendon stripper to the deep peroneal nerve was 52.9 ± 11.4 mm. The average distance to the PLT branch of peroneal nerve was 29.3 ± 4.2 mm. The superficial peroneal nerve, which coursed parallel and deep to the tendon stripper, was on average 5.2 ± 0.7 mm from the end of the stripper. No transection injuries of the nerves were observed in any of the ten legs after harvesting. CONCLUSION: This cadaver study found during a full-thickness PLT harvest, the distances between the tendon stripper and the nerves were greater than 5 mm with an initial incision at 2 cm proximal to LM which is recommended.

Current trends in the anterior cruciate ligament part II: evaluation, surgical technique, prevention, and rehabilitation.

Clinical evaluation and management of anterior cruciate ligament (ACL) injury is one of the most widely researched topics in orthopedic sports medicine, giving providers ample data on which to base their practices. The ACL is also the most commonly treated knee ligament. This study reports on current topics and research in clinical management of ACL injury, starting with evaluation, operative versus nonoperative management, and considerations in unique populations. Discussion of graft selection and associated procedures follows. Areas of uncertainty, rehabilitation, and prevention are the final topics before a reflection on the current state of ACL research and clinical management of ACL injury. Level of evidence V.

Stress Shielding of Ligaments Using Nonabsorbable Suture Augmentation May Influence the Biology of Ligament Healing.

Nonabsorbable suture augmentation of ligament reconstruction has seen an increase in use over the past several years with the goal of protecting the newly reconstructed ligament while allowing early rehabilitation for a potential earlier return to activity and sport. By spanning the joint with a durable nonabsorbable suture, this construct shares the stress and load seen by the reconstructed ligament, thereby protecting it from forces that could result in an early failure during the early ligamentization phase of the tendon graft. However, stress shielding of the ligament via nonabsorbable suture augmentation is also a double-edged sword, as a reduction in the stress and load seen by the ligament during this healing phase may ultimately have an impact on the final strength and composition of the reconstructed ligament. Although the long-term effects of this stress shielding have yet to be studied or reported in human subjects, multiple biomechanical and animal studies have demonstrated overall changes in architecture, tensile strength, and mechanical properties of a stress-shielded autograft ligament reconstruction.

The posterior cruciate ligament inclination angle is higher in anterior cruciate ligament insufficiency.

PURPOSE: Magnetic resonance imaging (MRI) is the gold standard image examination for anterior cruciate ligament (ACL) lesion diagnosis. Our hypothesis was that measuring the posterior cruciate ligament inclination angle (PCLIA) using MRI images may be an auxiliary tool to aid the recognition of ACL insufficiency. The purpose of this study was to compare the PCLIA measurement in MRIs of individuals with and without ACL injury. METHODS: The PCLIA was measured by two radiologists in 65 knee MRIs of patients with intact ACL (control group) and in 65 knee MRIs of people with ACL injury (study group). In both groups, the posterior cruciate ligament was intact. The control group was included 35 men (53.8%) and 30 women (46.1%). The patients' average age was 38.7 years (range 15-75; SD ± 14.8 years). In this group, 31 (47.6%) MRIs were from right knees and 34 (52.3%) were from left knees. The study group consisted of 45 men (69.2%) and 20 women (30.7%). The patients' average age was 36.8 years (range 14-55; SD ± 10.3 years). In this group, 33 (50.7%) were right knees and 32 (49.2%) were left knees. PCLIA was formed by the intersection of two lines drawn in MRI sagittal images. The first passed tangentially to the articular surface of the tibial condyle and the second was drawn over the fraction of the ligament that originated where the first crossed the PCL, outlined proximally. RESULTS: The average PCLIA was 44.2 ± 3.8° in the control group and 78.9 ± 8.6° in the study group. Statistical analyses showed that the PCLIA was higher in the group with ACL injury (p < 0.05). Conclusion The PCLIA was significantly higher in individuals with ACL injuries. The measurement of this angle using MRI images may allow for detection of ACL insufficiency and thus assist in an individualized and precise approach to the treatment of injuries to the ACL. CLINICAL RELEVANCE: PCLIA may be a way to detect ACL insufficiency and thus help surgeons to decide which patient might need ACL reconstruction. LEVEL OF EVIDENCE: III.

Return to preinjury sports after anterior cruciate ligament reconstruction is predicted by five independent factors.

PURPOSE: To determine factors that predict return to the same frequency and type of sports participation with similar activity demands as before injury. METHODS: Individuals 1 to 5 years after primary ACL reconstruction completed a comprehensive survey related to sports participation and activity before injury and after surgery. Patient characteristics, injury variables, and surgical variables were extracted from the medical record. Return to preinjury sports (RTPS) was defined as: "Returning to the same or more demanding type of sports participation, at the same or greater frequency with the same or better Marx Activity Score as before injury." Variables were compared between individuals that achieved comprehensive RTPS and those that did not with univariate and multivariate logistic regression models. RESULTS: Two-hundred and fifty-one patients (mean age 26.1 years, SD 9.9) completed the survey at an average of 3.4 years (SD 1.3) after ACL reconstruction. The overall rate of RTPS was 48.6%. Patients were more likely to RTPS if they were younger than 19 years old (OR = 4.07; 95%CI 2.21-7.50; p < 0.01) or if they were competitive athletes (OR = 2.07; 95%CI 1.24-3.46; p = 0.01). Patients were less likely to RTPS if surgery occurred more than 3 months after injury (OR = 0.31, 95%CI 0.17-0.58; p < 0.01), if there was a concomitant cartilage lesion (OR = 0.38; 95%CI 0.21-0.70; p < 0.01), and if cartilage surgery was performed (OR = 0.17; 95%CI 0.04-0.80; p = 0.02). CONCLUSION: Five variables best predicted RTPS including age at time of surgery. Only time from injury to surgery is a potentially modifiable factor to improve RTPS; however, the reasons for which patients delayed surgery may also contribute to them not returning to sports. Regardless, younger patients, those that partake in sports on a competitive level, those that undergo surgery sooner, or do not have a cartilage injury or require cartilage surgery are more likely to return to pre-injury sports participation. LEVEL OF EVIDENCE: III.

The effect of lateral extra-articular tenodesis on in vivo cartilage contact in combined anterior cruciate ligament reconstruction.

PURPOSE: Lateral extra-articular tenodesis (LET) may confer improved rotational stability after anterior cruciate ligament reconstruction (ACLR). Little is known about how LET affects in vivo cartilage contact after ACLR. The aim of this study was to investigate the effect of LET in combination with ACLR (ACLR + LET) on in vivo cartilage contact kinematics compared to isolated ACLR (ACLR) during downhill running. It was hypothesised that cartilage contact area in the lateral compartment would be larger in ACLR + LET compared with ACLR, and that the anterior-posterior (A-P) position of the contact center on the lateral tibia would be more anterior after ACLR + LET than after ACLR. METHODS: Twenty patients were randomly assigned into ACLR + LET or ACLR during surgery (ClinicalTrials.gov:NCT02913404). At 6 months and 12 months after surgery, participants were imaged during downhill running using biplane radiography. Tibiofemoral motion was tracked using a validated registration process. Patient-specific cartilage models, obtained from 3 T MRI, were registered to track bone models and used to calculate the dynamic cartilage contact area and center of cartilage contact in both the medial and lateral tibiofemoral compartments, respectively. The side-to-side differences (SSD) were compared between groups using a Mann-Whitney U test. RESULTS: At 6 months after surgery, the SSD in A-P cartilage contact center in ACLR + LET (3.9 ± 2.6 mm, 4.4 ± 3.1 mm) was larger than in ACLR (1.2 ± 1.6 mm, 1.5 ± 2.0 mm) at 10% and 20% of the gait cycle, respectively (p < 0.01, p < 0.05). There was no difference in the SSD in cartilage contact center at 12 months after surgery. There was no difference in SSD of cartilage contact area in the medial and lateral compartments at both 6 and 12 months after surgery. There were no adverse events during the trial. CONCLUSION: LET in combination with ACLR may affect the cartilage contact center during downhill running in the early post-operation phase, but this effect is lost in the longer term. This suggests that healing and neuromuscular adaptation occur over time and may also indicate a dampening of the effect of LET over time. (337 /350 words) LEVEL OF EVIDENCE: Level II.

Two-fragment Segond fracture validates historical descriptions of independent soft tissue attachments.

This is a case report of a 26-year-old male who sustained a Segond fracture in the context of an acute anterior cruciate ligament (ACL) rupture incurred while downhill skiing. Further work-up revealed that the Segond fracture consisted of two distinct fragments with separate soft tissue attachments, including the capsule-osseous layer of the iliotibial band and the short arm of the biceps femoris. Imaging showed interval healing of the Segond fracture between initial presentation and the performance of arthroscopic ACL reconstruction approximately 4 months later. As intraoperative evaluation demonstrated that anatomic ACL reconstruction restored translational and rotatory knee stability, surgical repair of the Segond fracture, or the anterolateral complex of the knee more broadly, was not required. Maintenance of translational and rotatory knee stability was confirmed at serial post-operative appointments up through final follow-up.Level of evidence Level V.

Knees with straight Blumensaat's line have small volume of femoral intercondylar notch.

PURPOSE: Smaller femoral intercondylar notch volume has been identified as a risk factor for anterior cruciate ligament injury. The present study aims to investigate differences in the intercondylar notch volume based on differences in the morphology of Blumensaat's line. METHODS: Eighty-eight (88) subjects (42 male and 46 female: median age 27: range 15-49), were included in this study. Using 3-dimensional computed tomography (3D-CT), the volume of the intercondylar notch was calculated using a truncated-pyramid shape simulation with the formula: [Formula: see text]. Femoral condyle height (h) was measured in the sagittal plane of the knee in 3D-CT. The area of the intercondylar notch was measured in the axial slice containing the most proximal level (S1) and most distal level (S2) of Blumensaat's line. In the sagittal view of the knee, Blumensaat's line morphology was classified into either straight or hill type. Statistical analysis was performed to compare h, S1, S2, and notch volume between the straight and hill type groups. RESULTS: Thirty-six subjects were classified as having straight type morphology and 52 subjects were classified as having hill type morphology. The measured h, S1, and S2, of the straight and hill types were 29 ± 4 and 31 ± 4 mm, 213 ± 72 and 205 ± 51 mm2, 375 ± 114 and 430 ± 94 mm2, respectively. The calculated femoral intercondylar notch volume of the straight and hill types was 8.1 ± 2 and 9.5 ± 2 cm3, respectively. Straight type knees showed significantly smaller S2 (p = 0.04), and notch volume (p = 0.01) when compared with hill type knees. CONCLUSION: Intercondylar notch volume was significantly smaller in knees with straight type Blumensaat's line morphology. Considering that Blumensaat's line represents the roof of the femoral notch, morphological variations in Blumensaat's line are likely to reflect variation in notch volume. For clinical relevance, as a smaller notch volume is a risk factor for ACL injury, straight type Blumensaat's line may also be considered a potential risk factor for ACL injury. LEVEL OF EVIDENCE: Level III.

Preoperative ultrasound predicts the intraoperative diameter of the quadriceps tendon autograft more accurately than preoperative magnetic resonance imaging for anterior cruciate ligament reconstruction.

PURPOSE: Sizing of potential autografts is essential to match the native anterior cruciate ligament (ACL) dimensions when performing ACL reconstruction (ACLR). We aimed to investigate the accuracy and reliability of the thickness and cross-sectional area (CSA) assessments for the prediction of the intraoperative diameter of the QT autograft using preoperative ultrasound and MRI. METHODS: Thirty patients (mean age ± standard deviation, 19.9 ± 5.0 years), who underwent ACLR using QT autograft, were included. The maximum thickness of the QT was assessed at 15 and 30 mm proximal using ultrasound with a long axis image, and at 15 mm proximal to the superior pole of the patella using MRI with a sagittal image. The CSA was assessed at the central 10 mm of the medial-lateral QT width at 30 mm proximal using ultrasound with a short axis image, and at 15 mm proximal to the superior pole of the patella using MRI with an axial image. Intraoperatively, QT autograft was harvested with a 10 mm width and the diameter was measured using a graft sizing device. RESULTS: Intra- and inter-observer reliabilities of all measurements using ultrasound and MRI were good (Intra-class correlation coefficient, 0.720-0.941). Correlation coefficient with the intraoperative diameter of the QT autograft was higher in ultrasound (R = 0.738-0.791, P < 0.001) than MRI (R = 0.449-0.543, P = 0.002-0.013). CONCLUSIONS: Preoperative ultrasound predicted the intraoperative diameter of the QT autograft more accurately than MRI. Ultrasound may be used clinically to assure a sufficiently large QT autograft diameter to match the diameter of the patient's native ACL. LEVEL OF EVIDENCE: Level III.

Editorial Commentary: Outcomes After Anterior Cruciate Ligament Reconstruction Are Defined by Individual Anatomy, Including Both Soft Tissue and Bone Morphology: It's All Important.

Well-designed studies add to our understanding of the anatomy, biology, biomechanics, and outcomes of the anterior cruciate ligament (ACL) following injury. Despite improvements in ACL treatment, we are still unable to exactly restore the individually unique function of the native ACL due to the complexity of knee physiology. The ACL is a dynamic structure with a rich neurovascular supply, distinct bundles, and 3-dimensional architecture that function in synergy with the bony morphology to facilitate healthy knee kinematics. Furthermore, the ACL exhibits a wide range of natural, anatomic variation. Since anatomic ACL reconstruction has been defined as functional restoration of the ACL to its native dimensions and collagen orientation, in addition to restoring the native footprint, it is important to restore the native size of the ACL, as the size of the tibial insertion site can vary by a factor of 3 from patient to patient. Moreover, variations in ACL soft tissue reflect differences in bony morphology. Bony morphology influences the static and dynamic biomechanics of the knee. Several bony morphologic factors influence the outcomes following ACL reconstruction, including posterior tibial slope, femoral condylar offset ratio, and notch shape. Morphologic differences that reflect pathologic states, such as the lateral notch sign and posterolateral plateau fracture, have been shown to be associated with greater grade instability. To respect the unique nature of each patient during surgical treatment, it is necessary to perform an individualized, anatomic, and value-based ACL reconstruction.

Anatomic single vs. double-bundle ACL reconstruction: a randomized clinical trial-Part 1: clinical outcomes.

PURPOSE: Compare clinical outcomes of anatomic single-bundle (SB) to anatomic double-bundle (DB) anterior cruciate ligament reconstruction (ACLR). It was hypothesized that anatomic DB ACLR would result in better International Knee Documentation Committee Subjective Knee Form (IKDC-SKF) scores and reduced anterior and rotatory laxity compared to SB ACLR. METHODS: Active individuals between 14 and 50 years of age that presented within 12 months of injury were eligible to participate. Individuals with prior injury or surgery of either knee, greater than a grade 1 concomitant knee ligament injury, or ACL insertion sites less than 14 mm or greater than 18 mm were excluded. Subjects were randomized to undergo SB or DB ACLR with a 10 mm-wide quadriceps tendon autograft harvested with a patellar bone block and were followed for 24 months. The primary outcome measures included the IKDC-SKF and KT-1000 (side to side difference) and pivot shift tests. Other secondary outcomes included measures of sports activity and participation, range of motion (ROM) and re-injury. RESULTS: Enrollment in the study was suspended due to patellar fractures related to harvest of the patellar bone plug. At that time, 57 subjects had been randomized (29 DB) and two-year follow-up was attained from 51 (89.5%). At 24-month follow-up there were no between-group differences detected for the primary outcomes. Twenty-one (77.8%) DB's and 20 (83.3%) SB's reported returning to pre-injury sports 2 years after surgery (n.s) Three subjects (2 DB's, 5.3% of total) sustained a graft rupture and 5 individuals (4 SB's, 8.8% of total) had a subsequent meniscus injury. CONCLUSIONS: Due to the early termination of the study, there were no detectable differences in clinical outcome between anatomic SB and DB ACLR when performed with a quadriceps tendon autograft with a bone block in individuals with ACL insertion sites that range from 14 to 18 mm. LEVEL OF EVIDENCE: Level 2.