Long-term outcomes of surgery using the Ligament Advanced Reinforcement System as treatment for anterior cruciate ligament tears.

AIMS: The aim of this prospective study was to assess the long-term clinical, radiological, functional, and quality of life (QoL)-related outcome of patients treated with the synthetic Ligament Advanced Reinforcement System (LARS) device for anterior cruciate ligament (ACL) rupture. METHODS: A total of 41 patients who underwent ACL reconstruction with the LARS device (mean age 39.8 years (SD 12.1 ); 32% females (n = 13)) were prospectively included between August 2001 and March 2005. MRI scans and radiographs were performed at a median follow-up of 2.0 years (interquartile range (IQR) 1.3 to 3.0; n = 40) and 12.8 years (IQR 12.1 to 13.8; n = 22). Functional and QoL-related outcome was assessed in 29 patients at a median follow-up of 12.8 years (IQR 12.0 to 14.0) and clinically reconfirmed at latest median follow-up of 16.5 years (IQR 15.5 to 17.9). International Knee Documentation Committee (IKDC) and Tegner scores were obtained pre- and postoperatively, and Lysholm score postoperatively only. At latest follow-up, range of motion, knee stability tests, 36-Item Short Form Health Survey (SF-36), and IKDC scores were ascertained. Complications and reoperations during follow-up were documented. RESULTS: Cumulative complication rate was 66% (n = 27), with 11 developing within one year from surgery and 16 after one year (including five patients with both early and late complications). Ten graft failures (24%) and eight cases of reactive synovitis were observed (20%). All 11 patients with early complications and ten with late complications underwent reoperation (including five with another surgical procedure for early complications), amounting to a cumulative reoperation rate of 51% (n = 21). Revision ACL reconstruction was performed in one patient (2.4%). Median IKDC at latest follow-up was 89.7 (IQR 78.2 to 93.1), being significantly worse in the event of previous complications. Lachman test was positive in 56% (n = 15) of reconstructed knees. All norm-based SF-36 items were at or above median at latest follow-up, and did not differ depending on development of complications. CONCLUSION: Despite good functional and QoL-related results in the long term, the cumulative complication rate of 66%, including graft failures and reactive synovitis, has to be viewed with great concern. Cite this article: Bone Joint J 2022;104-B(2):242-248.

Tratamiento de las lesiones del ligamento cruzado anterior y meniscales en adolescentes: reporte de un caso / Treatment for anterior cruciate ligament and meniscal tears in adolescents: a case report / Tratamento das lesões do ligamento cruzado anterior e meniscais em adolescentes: relatório de um caso

Dada la creciente popularidad de las actividades deportivas, el número de roturas del ligamento cruzado anterior (LCA) y lesiones meniscales ha aumentado en particular en niños y adolescentes. El manejo de estas lesiones es desafiante debido las fisis abiertas. Por un lado las opciones de reconstrucción del LCA incluyen técnicas: transfisarias, extra-articulares y intraepifisarias. Por otro lado se han descrito diferentes técnicas de reparación meniscal: "all-inside", "inside-out" y "outside-in". Estas tiene como objetivo lograr la cicatrización meniscal, evitando los efectos adversos de la meniscectomía. Presentamos un reporte de caso de un adolescente de 14 años con una rotura completa del LCA y una lesión del cuerno posterior del menisco interno que fue sometido a una reconstrucción transfisaria del LCA y a una reparación meniscal "inside-out".

With the raising popularity of sporting activity, the number of anterior cruciate ligament (ACL) ruptures and meniscal tears has increased in particular in children and adolescents. Management of these injuries is challenging due to open growth plates. On the one hand the ACL reconstructions options includes: transphyseal, extra-articular and epiphyseal-only techniques. On the other hand there have been described different meniscal repair techniques: "all-inside", "inside-out" and "outside-in". These aim to achieve meniscal healing, avoiding the adverse effects of meniscectomy. We present a case report of a 14-year adolescent with an ACL complete rupture and a posterior horn tear of the medial meniscus who underwent an ACL transphyseal reconstruction and a "inside-out" meniscal repair.

Dada a crescente popularidade das atividades esportivas, o número de rupturas do ligamento cruzado anterior (LCA) e lesões meniscais aumentou especialmente em crianças e adolescentes. O manejo destas lesões é desafiador devido às fissuras abertas. Por um lado as opções de reconstrução do LCA incluem técnicas: transfisárias, extra-articulares e intraepifisárias. Por outro lado, foram descritas diferentes técnicas de reparação meniscal: "all-inside", "inside-out" e "outside-in". Estes têm como objetivo alcançar a cicatrização meniscal, evitando os efeitos adversos da meniscectomia. Apresentamos um relatório de caso de um adolescente de 14 anos com uma ruptura completa do LCA e uma lesão do corno posterior do menisco interno que foi submetido a uma reconstrução transfisária do LCA e a uma reparação meniscal "inside-out".

Arthroscopic treatment of tibial eminence fractures using double-loop endobutton device: Surgical technique and short-term treatment outcomes.

OBJECTIVES: This study aims to explain the arthroscopic surgical technique of double-loop endobutton device for tibial eminence fractures and share the outcomes of this treatment method. PATIENTS AND METHODS: Thirteen patients (10 males, 3 females; mean age 19.9±5.6 years; range, 14 to 34 years) with tibial eminence fractures type II, IIIa, and IIIb were analyzed retrospectively between March 2017 and March 2019. Knee laxity, Tegner Lysholm knee scores, the International Knee Documentation Committee (IKDC) scores, knee mobility, Lachman test, and bone union were analyzed after the arthroscopic fracture fixation with double-loop endobutton device at first and sixth months after surgery. RESULTS: First month mean IKDC scores were 38.0±7.0 and mean Tegner Lysholm scores were 50.3±5.8. Sixth month mean IKDC scores were 80.2±4.0 and mean Tegner Lysholm scores were 87.1±5.4. All patients showed negative Lachman test and negative pivot-shift test at final follow-up. Radiological bone union without reduction loss was also seen in all patients. CONCLUSION: Using double-loop endobutton device provides successful results to fix tibial eminence fractures.

Clinical Outcome of Fixed Versus Adjustable Loop Cortical Suspension Devices in Arthroscopic Anterior Cruciate Ligament Reconstruction.

BACKGROUND: Anterior cruciate ligament (ACL) reconstruction has remained the gold standard for ACL injuries, especially for young individuals and athletes exposed to high level sporting activities aiming to return to their preinjury level of activity. Cortical suspensory femoral fixation is commonly performed for graft fixation to the femur in anterior cruciate ligament reconstruction using hamstring tendons. The aim of this study was to compare the clinical results of using fixed and adjustable loop cortical suspension devices in arthroscopic ACL reconstruction using the Lysholm Knee Scoring Scale after 12 months postoperatively. MATERIAL AND METHODS: This study included a total of sixty patients who underwent transportal arthroscopic ACL reconstruction using a hamstring tendon autograft from November 2016 to December 2017. For femoral graft fixation, a fixed-length loop device was used in 30 patients (fixed-loop group) and an adjustable-length loop device was used in 30 patients (adjustable-loop group) randomly.For tibial graft fixation, interference screw was used for all patients. RESULTS: The present study shows that there was no statistically significant difference between the two groups regarding the Lysholm score with highly statistically significant difference between preoperative and postoperative Lysholm score in each group separately. CONCLUSION: Both fixed loop and adjustable loop devices in ACL reconstruction provided good clinical outcomes but without significant statistical difference between both groups from the clinical point of view postoperatively using the Lysholm score.

Anterior Cruciate Ligament Reconstruction: A Comparative Clinical Study Between Adjustable and Fixed Length Suspension Devices.

Background: Adjustable-length cortical suspension devices provide technical advantages over fixed-length devices for femoral graft fixation during anterior cruciate ligament (ACL) reconstruction but have shown increased lengthening during cyclic loading in biomechanical studies. The purpose of this study was to prospectively measure graft elongation in vivo along with patient reported outcomes. Methods: Thirty-seven skeletally mature patients diagnosed with anterior cruciate insufficiency who underwent ACL reconstruction using autogenous hamstring graft were included in this study. Thirteen patients received an ACL reconstruction using a fixed loop device (FL) and twenty-four patients were treated with an adjustable-length device (AL) based on surgeon preference. Bilateral knee laxity was measured with a KT1000 Arthrometer before surgery and immediately after surgery with the patient under anesthesia, and at the 6-week, 3-month, and 6-month clinical follow-up appointments. All measurements were made by the same operator with maximum force testing. Differences between the affected knee and the contralateral knee were measured. Patient reported outcomes were collected at 6 and 24 months post-operatively. Results: No difference was found between the FL and AL groups in either knee laxity or patient reported outcomes. Average side-to-side difference at 6 months was 1.8 ± 2.6 mm for the FL group and 1.7 ± 2.4 mm for the AL group (p=.874). One patient in the FL group (7.7%) and two in the AL group (9.5%) had a side to side difference in laxity greater 5 mm. Patient reported outcomes did not differ between groups and no patients underwent revision surgery. Conclusions: The adjustable-length cortical suspension device (AL) did not demonstrate increased laxity as compared to fixed-length devices. There was no difference in patient reported outcomes between the groups.Level of Evidence: IV.

Bilateral Comparisons of Quadriceps Thickness after Anterior Cruciate Ligament Reconstruction.

Background and objectives: Anterior cruciate ligament reconstruction (ACLR) often results in quadricep atrophy. The purpose of this study was to compare the bilateral thickness of each quadricep component before and after ACLR. Materials and Methods: Cross-sectional study design. In 14 patients who underwent ACLR, bilateral quadricep muscle thicknesses were measured using a portable ultrasound device, 1 h before and 48-72 h after ACLR. Two-way analysis of variance (ANOVA) was used to compare muscle thickness pre- and post-ACLR between the limbs. Results: The primary finding was that the vastus intermedius (VI) muscle was significantly smaller in the reconstructed limb after ACLR compared to that in the healthy limb (Reconstructed limb; RCL = Pre-operated (PRE): 19.89 ± 6.91 mm, Post-operated(POST): 16.04 ± 6.13 mm, Healthy limb; HL = PRE: 22.88 ± 6.07, POST: 20.90 ± 5.78 mm, F = 9.325, p = 0.009, η2p = 0.418). Conclusions: The results represent a selective surgical influence on the quadricep muscle thickness. These findings highlight the need of advanced strengthening exercises in order to restore VI thickness after ACLR.

A novel protection liner to improve graft-tunnel interaction following anterior cruciate ligament reconstruction: a finite element analysis.

BACKGROUND: Deteriorated bone-graft interaction at the tunnel entrance following ACL reconstruction (ACLR) is considered one of the primary causes of long-term tunnel enlargement and graft wear. Methods have been introduced to improve the long-term outcome, such as novel graft materials or alternative fixation methods, but have been met with varying degrees of success. This study aims to design a protection liner to improve the bone-graft interaction at the tunnel entrances. METHODS: A finite element model of a human cadaveric knee was used to simulate traditional ACLR and ACLR using the protection liner. Stress distribution around the tunnel entrances and on the ACL graft were calculated under a combined loading of 103 N anterior tibial load, 7.5 Nm internal tibial moment, and 6.9 Nm valgus tibial moment at a joint flexion angle of 20°. Results were compared between the traditional ACLR and ACLR using a double liner (femoral and tibial) setup, as well as between the ACLR using a double liner setup and a single liner (femoral side) setup. Different materials (PEEK, Ti-6Al-4V, CoCrMo) for the liner were also evaluated. RESULTS: The traditional ACLR resulted in concentrated stress on the graft where it contacted the tunnel entrance. Correspondingly, there were stress concentrations at the distal posterior zone of the femoral tunnel entrance and medial posterior zone of the tibial tunnel entrance, while the other zones suffered from a stress reduction. Use of the protection liner reduced the stress concentration around the tunnel entrances by up to 89% and increased the stress at the unloaded zones by up to 106%. Also, stress concentration on the graft was slightly decreased (15.4 vs 15.1 MPa) after using the liner. The single liner setup increased the stress concentration around the tibial tunnel entrance. Stiffer materials improved the stress distribution around tunnel entrances but had little effect on the stress on the graft. CONCLUSIONS: The novel protection liner can improve the stress distribution on the graft and at the tunnel entrances, which may be beneficial for improving the clinical outcome of ACLR.

Biomechanical comparison of anterior cruciate ligament repair with internal brace augmentation versus anterior cruciate ligament repair without augmentation.

BACKGROUND: Newer repair techniques of anterior cruciate ligament tears, including augmentation with internal brace, have shown promising clinical results. Few biomechanical studies exist comparing anterior cruciate ligament repair only versus repair with internal brace. The purpose of this study was to compare the load to failure and stiffness of anterior cruciate ligament repair with internal brace augmentation versus repair-only. METHODS: Proximal femoral avulsion type anterior cruciate ligament injuries were created in 20 cadaver knees. Anterior cruciate ligament repair-only or repair with internal brace was performed using arthroscopic tools. Load to failure and failure modes were collected, with calculations of stiffness and energy to failure performed. FINDINGS: The average load to failure for the internal brace group was higher than the repair-only group: 693 N (SD 248) versus 279 N (SD 91), P = .002. The stiffness and energy to failure values were higher for the internal brace group than the repair-only group: 83 N/mm versus 58 N/mm, P = .02 and 16.88 J (SD 12.44) versus 6.91 J (SD 2.49), P = .04, respectively. Failure modes differed between groups (P = .00097) with 80% failure in the repair-only due to suture pull through the anterior cruciate ligament and 90% failure in the internal brace group due to suture button pull through the femur. INTERPRETATION: There was higher load to failure, stiffness, and energy to failure for the internal brace group compared to the repair-only group, and a high positive correlation between bone density and load to failure for the internal brace group. CLINICAL SIGNIFICANCE: Anterior cruciate ligament repair with internal brace augmentation demonstrates significantly higher load to failure. It may be a useful adjunct to protect the anterior cruciate ligament repair from failure during the early stages of healing.

Assessment of fixation for anterior cruciate ligament reconstruction using oversized suspensory devices on full-length femoral tunnels.

BACKGROUND: In ACL repair, full-length single-diameter tunnels facilitate anatomic femoral fixation with suspensory devices, especially with outside-in techniques, and are required after accidental cortical perforation. With tunnel diameters over 6 mm, fixation resistance using regular suspensory devices may not suffice. Oversized cortical footprint devices could be a solution to guarantee fixation performance in larger tunnel diameters. This study aims to assess the biomechanical properties of ACL femoral fixation provided by two enlarged suspensory devices of similar characteristics, a fixed loop (G-Lok™ with G-Lok-XL™) and an adjustable loop (ProCinch™ with G-Lok-XL™), resting on a full-length 9 mm diameter tunnel compared to the widely accepted regular fixed-loop device (G-Lok™) on a socket tunnel. METHODS: Twenty-seven fresh frozen porcine femurs and flexor digitorum profundus tendons were randomly assigned to a study group depending on the fixation method used (N = 9). Graft-femur constructs were subjected to a traction cyclic test (5000 cycles, [50-250]N load, 1 Hz) followed by a load-to-failure test (v = 1 mm/s). Residual displacement during the cyclic test and stiffness, displacements at physiological loads, ultimate load and corresponding displacement during the load-to-failure test were determined. FINDINGS: No significant differences could be established for any parameter measured in the comparison between the control with the socket tunnel and the oversized fixations with full-length tunnels. INTERPRETATION: ACL femoral fixation achieved in full-length single diameter tunnels by using an enlarged suspension device, both with a fixed or an adjustable loop, provide similar biomechanical properties to the gold-standard fixed-loop device in a socket tunnel. Therefore, its clinical use may be safe.

Comparative Risk-Benefit Profiles of Individual Devices for Graft Fixation in Anterior Cruciate Ligament Reconstruction: A Systematic Review and Network Meta-analysis.

PURPOSE: To compare the efficacy and safety of individual devices for femoral and/or tibial graft fixation in anterior cruciate ligament (ACL) reconstruction. METHODS: The PubMed, Embase, Cochrane Library, and Web of Science databases were searched from inception to December 12, 2018. Randomized controlled trials comparing individual devices for ACL graft fixation were included. Bayesian network meta-analysis was performed to assess the efficacy profile using the following outcomes: Lysholm score, International Knee Documentation Committee (IKDC) category, laxity, range of motion, and Tegner score. The incidence of infection, effusion, and graft rupture for each device was reported. RESULTS: We included 57 randomized controlled trials involving 4,304 patients aged 23.8 to 40.9 years. The female proportion ranged from 0% to 100%. The length of follow-up ranged from 6 to 144 months. Of the 13 studied femoral fixation devices, none was significantly different from the others regarding the Lysholm score, IKDC category, range of motion, and Tegner score. Bioabsorbable interference screws (standardized mean difference, 1.3; 95% credible interval, 0.0-2.5) showed higher laxity than the EndoPearl at a borderline level of statistical significance, but the difference varied substantially within multiple sensitivity analyses. Infection (2.0%) was most commonly seen with the EndoPearl, whereas the bone mulch screw had the highest incidence of effusion (5.5%) and graft rupture (5.5%). For the 9 studied tibial fixation devices, no significant difference was observed in the aforementioned efficacy measurements. Bioabsorbable interference screws with staples had the highest incidence of infection (11.1%) and effusion (15.6%), whereas graft rupture was most commonly seen with the bone plug (4.0%). CONCLUSIONS: Graft fixation devices in ACL reconstruction share a similar efficacy profile in terms of the Lysholm score, IKDC category, range of motion, and Tegner score but not laxity. On the other hand, safety profiles seem to vary among different devices. These findings can support surgeons, alongside their experience and preference, as well as the relative cost of each device, in delivering an individualized plan for an optimal operation. LEVEL OF EVIDENCE: Level II, meta-analysis of Level I and II studies.

Anterior knee translation measurements after ACL reconstruction are influenced by the type of laximeter used.

PURPOSE: Laximeters were designed to diagnose an anterior cruciate ligament (ACL) deficient knee, but their use has now focused on providing an objective assessment of the anterior translation (AT) of an intact and ACL-reconstructed knee. In this study we report the introduction and direct comparison of an automated and computerized AT measurement device, GNRB, with the device previously established by the institute and as the current literature standard, the KT1000. METHODS: A prospective data collection was commenced upon introduction of the GNRB. The measurements of AT in each patient were performed by the same investigator with each device using 134 N applied to both knees, giving a side-to-side difference. The investigators were a sport scientist, a biomechanical engineer and a physiotherapist. Increased AT was defined as a difference > 3 mm. RESULTS: Three investigators performed the measurements in 122 patients, 9.8 (± 1.8) months after ACL reconstruction. Mean AT of the healthy knee was 5.7 mm with KT1000 and 4.4 mm with GNRB (p = 0.002). Mean AT of the ACL reconstructed knee was 7.0 mm with the KT1000 and 5.3 mm with the GNRB (p = 0.037). The KT1000 had a higher variance of results than the GNRB (p < 0.001). There were 25 patients with increased AT measured by KT1000 compared with 12 patients using the GNRB (p < 0.016), with only 5 on both devices. CONCLUSIONS: GNRB has better consistency of results when compared to the KT1000. Both devices lack comparability for detecting increased AT, with the KT1000 recording a side-to-side difference of more than 3 mm in twice as many patients as the GNRB. LEVEL OF EVIDENCE: II.

A two-portal technique using a flexible reamer system is a safe and effective method for transportal anterior cruciate ligament reconstruction.

INTRODUCTION: A flexible reamer system (FRS) for transportal anterior cruciate ligament reconstruction (ACLR) has been developed to overcome the technical challenges of a rigid reamer system. The purpose of this study was to investigate the safety and effectiveness of the two-portal technique using an FRS by evaluating femoral tunnel geometry. METHODS: This study included 30 patients (mean age 30 ± 12.1) who underwent transportal single-bundle ACLR. Operations were performed with the two-portal technique using an FRS. Three-dimensional computed tomography was performed for all patients 2 days after the operation. The femoral tunnel position, femoral graft bending angle, femoral tunnel length, and posterior wall breakage were evaluated. These radiologic outcomes were compared to previous literature-reported outcomes. RESULTS: The mean distances (measured as a percentage) from the posterior wall and the intercondylar notch roof to the femoral tunnel center were 29.6 ± 5.5% and 20.1 ± 6.7%, respectively. The femoral graft bending angle (108.4° ± 6.9°) was similar to that associated with the traditional transportal technique using a rigid reamer system, but it was less acute than that associated with the three-portal technique using an FRS. The femoral tunnel length (32.8 ± 4.5 mm) was also similar to the results of the traditional transportal technique using a rigid reamer system, but it was shorter than that of three-portal technique using an FRS. The prevalence of posterior wall breakage was as low as the reported outcomes of the outside-in technique (2 cases, 6.6%). CONCLUSIONS: The two-portal technique for transportal ACLR using an FRS can achieve comparable femoral graft bending angle and femoral tunnel length compared with the conventional three-portal technique using the rigid reamer system and had a low risk of posterior wall breakage. Therefore, the two-portal technique using the FRS can be considered a safe and effective method for transportal ACLR. LEVEL OF EVIDENCE: Retrospective case series; level of evidence, 4.

Evaluation of a bioengineered ACL matrix's osteointegration with BMP-2 supplementation.

A poly (l-lactic) acid bioengineered anterior cruciate ligament (ACL) matrix has previously demonstrated the ability to support tissue regeneration in a rabbit ACL reconstruction model. The matrix was designed for optimal bone and ligament regeneration by developing a matrix with differential pore sizes in its bone and ligament compartments. Building upon past success, we designed a new bioengineered ACL matrix that is easier to install and can be used with endobutton fixation during ACL reconstruction. To achieve this, a new braiding procedure was developed to allow the matrix to be folded in half, making two-limbs, while maintaining its bone and ligament compartments. The osteointegration of the matrix with and without bone morphogenetic protein 2 (BMP-2) supplementation was evaluated in a rabbit ACL reconstruction model. Two doses of BMP-2 were evaluated, 1 and 10 µg, and delivered by saline injection into the bone tunnel at the end of surgery. A fibrous matrix-to-bone interface with occasional Sharpey's fibers was the primary mode of osteointegration observed. The matrix was also found to support a fibrocartilage matrix-to-bone interface. In some cases, the presence of chondrocyte-like cells was observed at the aperture of the bone tunnel and the center of the matrix within the bone tunnel. Treatment with BMP-2 was associated with a trend towards smaller bone tunnel cross-sectional areas, and 1 µg of BMP-2 was found to significantly enhance osteoid seam width in comparison with no BMP-2 or 10 µg of BMP-2 treatment. Regenerated tissue was well organized within the bioengineered ACL matrix and aligned with the poly (l-lactic) acid fibers. Disorganized tissue was found between the two-limbs of the bioengineered ACL matrix and hypothesized to be due to a lack of structural scaffolding. This study suggests that the bioengineered ACL matrix can undergo similar modes of osteointegration as current autografts and allografts, and that BMP-2 treatment may enhance osteoblastic activity within the bone tunnels.

Is Intraoperative Fluoroscopy Necessary to Confirm Device Position for Femoral-Sided Cortical Suspensory Fixation during Anterior Cruciate Ligament Reconstruction?

Increased laxity within the graft construct system can lead to graft failure after anterior cruciate ligament (ACL) reconstruction. Suboptimal cortical device positioning could lead to increased laxity within the system, which could influence the mechanics and function of the graft reconstruction. This study evaluates the benefit of intraoperative fluoroscopy to confirm device position on the femur during ACL reconstruction using cortical suspensory fixation. One hundred consecutive patients who underwent soft tissue ACL reconstruction using a suspensory cortical device for femoral fixation were retrospectively evaluated. Patients were split into two groups: Group A utilized anteromedial portal visualization and had intraoperative fluoroscopic imaging performed at the time of ACL graft fixation to confirm femoral device placement on the lateral femoral metaphyseal cortex. Group B utilized anteromedial portal visualization alone. Both groups had radiographic X-rays performed at the first postoperative visit to evaluate device location and all images were independently evaluated by three fellowship trained orthopaedic surgeons. Device position was classified as optimal if there was complete apposition of the entire device against the femoral cortex and suboptimal if it was > 2 mm off the cortex. Fisher's exact test, analysis of variance, and 95% confidence intervals were calculated to compare the groups for statistical significance. The results showed 0/60 (0%) patients in group A had suboptimal device position at postoperative follow-up, while 4/40 (10%) patients in group B had suboptimal device position (p = 0.013). There were no graft failures in group A and one graft failure in group B. There was a significant difference in cortical device position in patients who had intraoperative fluoroscopic imaging versus patients who had no intraoperative imaging. The use of confirmatory intraoperative imaging may be beneficial to confirm appropriate device location when using a femoral cortical suspensory fixation technique for ACL reconstruction.

Patellar Bone-Tendon-Bone Autografts versus Quadriceps Tendon Allograft with Synthetic Augmentation in a Canine Model.

Patellar bone-tendon-bone (pBTB) autografts are often considered the "gold standard" for complete anterior cruciate ligament (ACL) reconstruction and are also associated with significant complications and early-onset knee osteoarthritis (OA). A novel quadriceps tendon allograft with synthetic augmentation, or "internal brace" (QTIB), has been reported to have potential advantages for ACL reconstruction based on animal model data. In this preclinical canine comparison study, we hypothesized that QTIB allograft compared with pBTB autograft would provide superior durability for knee stability, function, and prevention of OA. Under approval from our Institutional Animal Care and Use Committee, adult purpose-bred research hounds (n = 10) underwent arthroscopic complete transection of the ACL followed by either an arthroscopic-assisted all-inside ACL reconstruction using the QTIB allograft (n = 5) or pBTB autograft (n = 5). Contralateral knees were used as nonoperated controls (n = 10). Radiographic and arthroscopic assessments were performed at 2 and 6 months, respectively, after surgery. Anterior drawer, internal rotation, lameness, kinetics, pain, effusion, and comfortable range of knee motion were measured at 2, 3, and 6 months. Biomechanical and histologic assessments were performed at 6 months. All reconstructed knees were stable and had intact ACL grafts 6 months after surgery. At 6 months, QTIB reconstructed knees had significantly less lameness, lower pain, less effusion, and increased range of motion when compared with BTB knees (p < 0.05). BTB knees had significantly higher radiographic OA scores than QTIB knees at 6 months (p < 0.05). Superior outcomes associated with QTIB allograft may be due to the lack of donor site morbidity, the use of a robust tendon graft, and/or protection of the graft from the synthetic augmentation. Robust tendon grafts combined with a synthetic internal brace and platelet-rich plasma (PRP) may allow for more rapid and robust tendon-bone healing and graft "ligamentization," which protects the graft from early failure and rapid OA development that can plague commonly-used allografts.

Hamstring Anterior Cruciate Ligament Reconstruction Using an Adjustable-Loop Cortical Suspension Device: Immediate Postoperative Magnetic Resonance Imaging.

The purpose of this study is to determine whether the hamstring grafts are fully inserted into the femoral tunnel with the adjustable loop using immediate postoperative magnetic resonance imaging (MRI) after anterior cruciate ligament (ACL) reconstructions. A total of 62 consecutive patients underwent hamstring ACL reconstruction using an adjustable-loop cortical suspension device for the femoral fixation and the Intrafix sheath and screw for the tibial fixation. Multiplanar reformatted images of 3-T MRI scans were obtained at the 1st postoperative day before weight bearing is initiated in all patients to evaluate the gap (the tunnel-graft gap) between the top of the hamstring graft and top of the femoral tunnel. Postoperative MRI scans showed that the tunnel-graft gap was 1.5 ± 2.7 mm (range, 0-12 mm). In 43 (69.4%) patients, there was no gap between the top of the femoral tunnel and hamstring graft. In 19 (30.6%) patients, there was a gap between the tunnel and graft, and nine patients demonstrated a tunnel-graft gap greater than 5 mm. Immediate postoperative MRI scans demonstrated that an adjustable-loop cortical suspension device may not pull the hamstring graft completely into the femoral tunnel.

A Biomechanical Analysis of Tibial Fixation Methods in Hamstring-Graft Anterior Cruciate Ligament Reconstruction.

Background: There are conflicting results on the biomechanical properties of tibial fixation devices in anterior cruciate ligament reconstruction. The objective of this study is to compare the initial biomechanical properties of tibial fixation in hamstring-graft ACL reconstruction with interference screw, suspension button, and Tape Locking ScrewTM devices. We hypothesized there are no differences in the initial biomechanical properties of these three tibial fixation techniques. Methods: Twenty-one fresh-frozen porcine tibiae were equally divided into three groups of seven tibiae to evaluate the fixation of human hamstring tendon grafts with interference screw, suspension button, or Tape Locking Screw fixation. Using a servohydraulic materials testing system, each graft was subjected to 500 cycles of loading followed by a monotonic failure test. Results: Interference screw fixation demonstrated significantly lower cyclic displacement (1.28 ± 0.73 mm) than the other groups fixated with either a suspension button device (2.54 ± 0.27 mm, p = 0.003) or a Tape Locking Screw (2.32 ± 0.42 mm, p = .009), and a significantly greater cyclic stiffness (212.19 ± 40.30 N/mm) than the Tape Locking Screw (137.64 ± 26.17 N/mm, p = 0.002). The interference screw also demonstrated significantly higher pullout stiffness (166.83 ± 23.22 N/mm) than the suspension button (112.78 ± 24.14 N/mm, P = 0.002) and Tape Locking Screw (109.11 ± 12.91 N/mm, P = 0.0002). Conclusions: Tibial fixation with an interference screw demonstrated superior biomechanical properties for cyclic testing compared to the suspension button and Tape Locking Screw. Load to failure did not differ between groups, and there were no significant biomechanical differences between the suspension button and Tape Locking Screw fixation devices. Clinical Relevance: Despite the initial biomechanical differences, all three fixation devices exhibited mean loads to failure and cyclic displacements below clinically relevant thresholds of failure. These data suggest all three fixation methods are viable options for achieving a functional ACL reconstruction.Level of Evidence: V.

Radiologic and Clinical Outcomes After Hamstring Anterior Cruciate Ligament Reconstruction Using an Adjustable-Loop Cortical Suspension Device With Retensioning and Knot Tying.

PURPOSE: To report magnetic resonance imaging (MRI) findings and clinical outcomes after anterior cruciate ligament reconstruction using an adjustable-loop device (ALD) with retensioning and knot tying. METHODS: The inclusion criteria were patients who underwent hamstring anterior cruciate ligament reconstruction using an ALD with retensioning and knot tying between May and December 2015 and were followed up for a minimum of 2 years. The exclusion criteria were patients with combined ligament injury, revision surgery, or reinjury after reconstruction. After initial tightening of the adjustable loop, retensioning and knot tying were performed and the graft was fixed at the tibia. Multiplanar reformatted images of 3-T MRI scans were obtained on the immediate postoperative day and at 6 months after surgery to measure the gap between the top of the graft and the top of the femoral tunnel (i.e., tunnel-graft gap). Differences in the tunnel-graft gap between the immediate postoperative day and 6 months after surgery (i.e., gap difference) were calculated and correlated with knee stability and functional outcomes. RESULTS: Thirty-six patients were enrolled in this study. The mean tunnel-graft gap was 2.1 ± 2.8 mm on the immediate postoperative day and 4.6 ± 3.5 mm at 6 months after surgery (P < .001). The mean gap difference was 2.5 ± 2.0 mm. The mean KT-1000 measurement was 1.5 ± 2.2 mm, and mean Lysholm score and Tegner activity scale score were 93.6 ± 5.5 and 5.6 ± 1.5, respectively. The gap difference correlated negatively with the follow-up Lysholm score (P = .004); however, knee stability and the Tegner activity scale score were not correlated. CONCLUSIONS: Although the ALD was secured by retensioning and knot tying, MRI showed that the graft was not fully inserted in some patients and the tunnel-graft gap increased at 6 months' follow-up. The increase in the tunnel-graft gap did not correlate with knee stability or the Tegner activity scale score but correlated negatively with the Lysholm score. LEVEL OF EVIDENCE: Level IV, therapeutic case series.

Video-based computer navigation in knee arthroscopy for patient-specific ACL reconstruction.

PURPOSE: The anterior cruciate ligament tear is a common medical condition that is treated using arthroscopy by pulling a tissue graft through a tunnel opened with a drill. The correct anatomical position and orientation of this tunnel are crucial for knee stability, and drilling an adequate bone tunnel is the most technically challenging part of the procedure. This paper presents the first guidance system based solely on intra-operative video for guiding the drilling of the tunnel. METHODS: Our solution uses small, easily recognizable visual markers that are attached to the bone and tools for estimating their relative pose. A recent registration algorithm is employed for aligning a pre-operative image of the patient's anatomy with a set of contours reconstructed by touching the bone surface with an instrumented tool. RESULTS: Experimental validation using ex-vivo data shows that the method enables the accurate registration of the pre-operative model with the bone, providing useful information for guiding the surgeon during the medical procedure. Experiments also demonstrate that the guided drilling of the tunnel leads to errors as low as 2.5 mm in the footprint and [Formula: see text] in orientation, which compares favourably to other works in the field. CONCLUSION: The high accuracy and short time overhead evinced by the experimental validation combined with no additional incisions or capital equipment make this video-based computer-aided arthroscopy solution an appealing alternative to the existing approaches.