Tunnel In Anterior Cruciate Ligament Reconstruction Research Articles

Use of Unidirectional Porous β-Tricalcium Phosphate in the Tibial Tunnel for Anterior Cruciate Ligament Reconstruction: A Case Series.

Bone defects in the tibial tunnel for anterior cruciate ligament (ACL) reconstruction can cause adverse events. The unidirectional porous tricalcium β-phosphate (UDPTCP) has the potential to be used as a filling substitute for bone defects. In this case series, we present the first nine cases in which UDPTCP was used as a bone substitute in the tibial tunnel during ACL reconstruction. The patients comprised six males and three females, with an average age of 32 years (range: 16-50 years). A cylindrical UDPTCP measuring 10 x 20 mm was molded to fit the tibial tunneland then implanted. At the one-year postoperative follow-up, none of the patients demonstrated any complications, and bone remodeling was observed on radiographs. Therefore, UDPTCP may provide a safe and reliable filling substitute for the tibial tunnel in ACL reconstruction.

Posterior Proximal Cartilage of the Lateral Femoral Condyle as a Reference for Positioning the Femoral Tunnel in ACL Reconstruction

Background: Due to the similarity among specimens in the height of the anterior cruciate ligament (ACL) on the distal proximal axis in relation to the proximal posterior cartilage of the lateral femoral condyle (point C), it is known this point can be used as an arthroscopic intraoperative parameter to define the position of the femoral tunnel in ACL reconstruction. Indications: For ACL reconstruction, point C can be used as an arthroscopic intraoperative parameter to define the position of the femoral tunnel on the distal proximal and anteroposterior axes. Technique Description: For access to the joint, standard arthroscopic ports, both anterolateral (AL) and anteromedial (AM), are used. By directing the camera toward the posterior region of the lateral femoral condyle through the AM port, it is possible to visualize the end of the posterior and proximal articular cartilage, the so-called C point. In this case, we sought to position the center of the femoral tunnel in the center of the AM band of the ACL. Holding the camera through the AM portal and visualizing point C, a millimeter-scale femoral guide is introduced through the AL portal toward the posterior femoral cartilage (point C) and positioned over it, creating a line between point C and the lateral distal femoral cartilage. The distance between point C and the distal femoral cartilage is measured. At this time, an accessory AM portal 1.5 cm from the AM port is constructed. Through it, with the aid of an ice pick or radiofrequency tip, a marking is made in the deep to shallow axis at 35% of this distance. Then, approximately 2 mm above the imaginary line formed by the union of point C and the lateral distal femoral cartilage, the center of the femoral tunnel is marked. Results: Point C is an anatomical landmark that is easy to view and is present in all knees; thus, it can be used as a reference during surgery for positioning the femoral tunnel. Discussion/Conclusion: Point C can be used as an arthroscopic intraoperative parameter to define the position of the femoral tunnel in ACL reconstruction. Patient Consent Disclosure Statement: The author(s) attests that consent has been obtained from any patient(s) appearing in this publication. If the individual may be identifiable, the author(s) has included a statement of release or other written form of approval from the patient(s) with this submission for publication.

Increased Bone Plug Depth From the Joint Increases Tunnel Enlargement in Anterior Cruciate Ligament Reconstruction Using Bone–Patellar Tendon–Bone Autograft With Suspensory Femoral Fixation

To determine a safe bone plug depth fixation zone based on early tunnel enlargement rates in anterior cruciate ligament (ACL) reconstruction using bone-patellar tendon-bone (BPTB) autograft with suspensory femoral fixation. Patients who had undergone rectangular tunnel ACL reconstruction using BPTB autograft with suspensory femoral fixation were retrospectively identified. Femoral and tibial tunnel aperture areas were measured on computed tomography 2 weeks and 6 months after surgery to calculate rates of femoral and tibial tunnel enlargement (FTE and TTE), respectively. Femoral bone plug depth (FBPD) and tibial bone plug depth (TBPD) were defined as the distance of the tip of the plug from the respective joint lines. Optimal FBPD and TBPD cutoff values were calculated for the following rates of FTE and TTE, respectively: 0%, 15%, 30%, and 50%. Sixty-four patients (19 females, 45 males; mean age, 29.5 ± 12.3 years) were included in the study. The femoral and tibial tunnel apertures significantly enlarged over time. FBPD (P < .001; r= 0.607) and TBPD (P= .013; r= 0.308) were positively correlated with FTE and TTE, respectively. The optimal FBPD cutoff value was 2.8 mm for FTE rates of 0% and 15%, 3.6 mm for 30%, and 6.0 mm for 50%. The optimal TBPD cutoff value was 1.48 mm for a 0% TTE rate and 5.1 mm for those higher. The cutoff value specificities were lower for the tibial tunnel than the femoral tunnel for each tunnel enlargement rate. Early tunnel enlargement and bone plug depth were significantly correlated in bone the femoral and tibial tunnels. The degree of correlation was higher in the femoral tunnel. To minimize bone tunnel enlargement, the distal end of the femoral bone plug should be placed less than 2.8 mm from the tunnel aperture. Level IV, therapeutic case series.

Ultrasonic Technique for Femoral Tunnel Creation in Anterior Cruciate Ligament Reconstruction

Bone tunnel creation in the anatomical location is essential in anterior cruciate ligament (ACL) reconstruction with an autogenous graft and is commonly performed with a drill bit matched to graft diameter. Anatomic rectangular tunnel ACL reconstruction with a bone–patellar tendon–bone autograft has been developed to anatomically create bone tunnels inside the ACL footprints and has been reported to achieve excellent outcomes. To make the rectangular tunnel, the surgeon needs to dilate 2 adjacent bone tunnels after creation of 2 round tunnels with a drill bit, while the tunnel wall occasionally cracks during dilating. An ultrasonic (US) device was developed with improvement of output power and has been implemented with a rectangular shape blade in the field of arthroscopic surgery. This US device can provide a precise and effective bone cut compared to drills. We introduced this device to clinically create a rectangular tunnel during ACL reconstruction. The US device can be useful for rectangular femoral tunnel creation and can create a precise rectangular femoral tunnel in the ACL footprint.

Technology-assisted anterior cruciate ligament reconstruction improves tunnel placement but leads to no change in clinical outcomes: a systematic review and meta-analysis.

To investigate the effect of technology-assisted Anterior Cruciate Ligament Reconstruction (ACLR) on post-operative clinical outcomes and tunnel placement compared to conventional arthroscopic ACLR. CENTRAL, MEDLINE, and Embase were searched from January 2000 to November 17, 2022. Articles were included if there was intraoperative use of computer-assisted navigation, robotics, diagnostic imaging, computer simulations, or 3D printing (3DP). Two reviewers searched, screened, and evaluated the included studies for data quality. Data were abstracted using descriptive statistics and pooled using relative risk ratios (RR) or mean differences (MD), both with 95% confidence intervals (CI), where appropriate. Eleven studies were included with total 775 patients and majority male participants (70.7%). Ages ranged from 14 to 54years (391 patients) and follow-up ranged from 12 to 60months (775 patients). Subjective International Knee Documentation Committee (IKDC) scores increased in the technology-assisted surgery group (473 patients; P = 0.02; MD 1.97, 95% CI 0.27 to 3.66). There was no difference in objective IKDC scores (447 patients; RR 1.02, 95% CI 0.98 to 1.06), Lysholm scores (199 patients; MD 1.14, 95% CI -1.03 to 3.30) or negative pivot-shift tests (278 patients; RR 1.07, 95% CI 0.97 to 1.18) between the two groups. When using technology-assisted surgery, 6 (351 patients) of 8 (451 patients) studies reported more accurate femoral tunnel placement and 6 (321 patients) of 10 (561 patients) studies reported more accurate tibial tunnel placement in at least one measure. One study (209 patients) demonstrated a significant increase in cost associated with use of computer-assisted navigation (mean 1158€) versus conventional surgery (mean 704€). Of the two studies using 3DP templates, production costs ranging from $10 to $42 USD were cited. There was no difference in adverse events between the two groups. Clinical outcomes do not differ between technology-assisted surgery and conventional surgery. Computer-assisted navigation is more expensive and time consuming while 3DP is inexpensive and does not lead to greater operating times. ACLR tunnels can be more accurately located in radiologically ideal places by using technology, but anatomic placement is still undetermined because of variability and inaccuracy of the evaluation systems utilized. Level III.

A STUDY OF FUNCTIONAL OUTCOME OF ACL RECONSTRUCTION WITH ANATOMICAL HAMSTRING TENDON AUTOGRAFT

Background: The Anterior Cruciate ligament (ACL) is the primary stabilizer of the knee and prevents the knee against anterior translation. It is also important in counteracting rotational and valgus stress. Anterior Cruciate Ligament (ACL) reconstruction is an established and widely practiced surgical procedure with proven efcacy and a low morbidity prole. The arthroscopically aided approach has the advantages of smaller skin and capsular incisions, improved viewing of the intercondylar notch for placement of the tunnel and attachment sites, less postoperative pain, fewer adhesions, earlier motion, and easier rehabilitation. The advantages with anatomical hamstring grafts are availability of a greater sectional area and unaffected integrity of the extensor mechanism. Moreover tensile strength of quadrupled anatomical hamstring is found to be even better than a normal ACL. The rate of complications like extension loss, anterior knee pain and surgical site infections was also lower than other procedures. Cortical suspension devices have the necessary biomechanical properties with regard to ultimate failure strength, displacement, and stiffness for initial xation of soft tissue in the femoral tunnel for ACL reconstruction. The aperture xation methods like the interference screws allows for early rm xation and heal with tight bone-tendon interface. To evalua Objectives: te functional outcome of arthroscopy assisted ACL reconstruction with anatomical hamstring tendon graft using Endobutton and Bioabsorbable interference screw and tibial disc. The Methodology: study results included 30 patients admitted with clinical and radiological deciency of ACL during October 2021 to December 2022, in Department of Orthopaedics, SMIMER Hospital, Surat. Study aims to assess the functional outcome of arthroscopy assisted anterior cruciate ligament reconstruction with anatomical hamstring tendon graft using Endobutton and Bioabsorbable interference screw and tibial disc in terms of range of motion, postoperative knee stability, graft site morbidity, subjective knee functions and prospective assessment of functional outcome using Tegner Lysholm knee scoring system. All the patients included in the s Results: tudy were 23 male and 2 female patient. The analysis of the studied cases revealed that the most common affected age group was between 18 to 24 years .. Majority of patients were operated more than 6 months after injury. Sports/BPET (Battle Physical Efciency Test) injuries was the most common mode of injury. The mean size of graft used was 8.2±0.39.Post-operatively at 3, 6, 12month follow up,1 case (4%) had a positive Pivot shift test with a "Glide" (Grade-I), whereas remaining 24 cases (96%) had a negative Pivot shift test. None of the patients had grade III laxity. The mean postoperative Lysholm score improved from preoperative score of 66±5.2 to 88.70±5.54. The overall satisfactory result (excellent + good) at follow up was 95%. All the patients had returned to preinjury level of activity. ACL injuries are common in younger age group individuals. S Conclusion: ports related injury and RTA are the most common modes of injury. Arthroscopy assisted ACL reconstruction using Anatomical hamstring tendon autograft provides a stable knee, reduces postoperative morbidity and enables early rehabilitation. Graft xation using endobutton and and Bioabsorbable interference screw will help the graft to facilitate graft tunnel healing and also maintain its strength until there is a good graft to bone healing occurs. It allows the patients to return to preinjury level of activity, allows the patient to squat, sit crossed leg and climb stairs without difculty. Degeneration of the articular surfaces rarely occurs and the re-operation rates are minimal.

A balance between native footprint coverage and overlap of the anterolateral meniscal root in tibial tunnel positioning during anterior cruciate ligament reconstruction: A 3D MRI study

BackgroundTibial footprint of anterior cruciate ligament (ACL) is situated close to the anterior lateral meniscal root (ALMR) attachment. PurposeTo investigate the impact of the size and location of the tibial tunnel for ACL reconstruction on the ACL footprint coverage and overlap to the ALMR. Study designControlled laboratory study. MethodsTwenty knee MRI scans from twenty healthy subjects were recruited, and three-dimensional (3D) tibia models were created to show the tibial attachment sites of ACL and ALMR. Surgical simulation of the tibial tunnel drilling was performed on each 3D model, entering the joint at an angle set at 60 degrees from the tibial plateau plane and 55 degrees from the posterior tibial condylar axis, with analysis for six different drill sizes; 7.5, 8, 8.5, 9, 9.5 and 10 mm; and nine locations; the center of the ACL attachment and eight locations 2% of the tibial width apart surrounding it. The width of the tibial plateau, the distance between ACL and ALMR attachment centers, and the size and location of the potential tibial tunnel were evaluated to determine association with the area of the ACL footprint coverage and ALMR overlap using a linear mixed effects model. ResultsA large tunnel (p <.001), a central and anterior location (p <.029), and small tibial width (p =.015) were all associated with larger coverage of the ACL footprint. A large tunnel (p <.001), posteriorly and laterally located (p ≤ 0.001), and a small distance between the ACL and ALMR centers (p =.001) were significantly associated with a larger ALMR overlap. The association of the tunnel size to ALMR overlap reduced with a medial tunnel location. ConclusionsThe short distance between the centers of the ALMR attachment and native ACL footprint suggests that the ALMR will always be susceptible to overlap when the tibial tunnel is drilled in ACL reconstruction. Small alterations in tunnel location can lead to a statistically significant alteration with the amount of ALMR overlap. To minimize this overlap, whilst maintaining acceptable coverage of the ACL footprint, a tibial tunnel positioned in a medial or anteromedial location from the center of the ACL footprint is recommended.

A prospective study to evaluate the functional and clinical outcome of anterior cruciate ligament reconstruction with standard hamstring autograft

Background: The anterior cruciate ligament (ACL) is the primary stabilizer of the knee and prevents the knee against anterior translation. It is also important in counteracting rotational and valgus stress. The arthroscopically aided approach has the advantages of smaller skin and capsular incisions, improved viewing of the intercondylar notch for placement of the tunnel and attachment sites, less postoperative pain, fewer adhesions, earlier motion, and easier rehabilitation. The advantages with semitendinosus grafts are the availability of a greater sectional area and the unaffected integrity of the extensor mechanism. Moreover, the tensile strength of quadrupled hamstring is found to be even better than a normal ACL. The rate of complications such as extension loss, anterior knee pain, and surgical site infections was also lower than in other procedures such as in BPTB grafts. Cortical suspension devices have the necessary biomechanical properties with regard to ultimate failure strength, displacement, and stiffness for the initial fixation of soft tissue in the femoral tunnel for ACL reconstruction. The aperture fixation methods such as the interference screws allow for early firm fixation and heal with a tight bone–tendon interface.Objective: A prospective study to evaluate the functional and clinical outcome of ACL reconstruction with standard hamstring autograft.Materials and Methods: The study results included 30 patients admitted with clinical and radiological deficiency of ACL from September 2019 to March 2021 using endobutton and bioabsorbable interference screw in terms of range of motion, postoperative knee stability, subjective knee functions, and prospective assessment of functional outcome using Tegner Lysholm knee scoring system.Results: Sports injuries were the most common mode of injury (n = 17, 56.7%). The mean size of graft used was 8.2 ± 0.39 mm. Postoperatively at 2-year follow-up, 30 cases (100%) had 0 grade pivot-shift test, 0 grade Lachman test, and anterior drawer test. The mean postoperative Lysholm score improved from preoperative score of 62.83 ± 5.2–91.0 ± 5.54. The overall satisfactory result (excellent + good) at 6-month follow-up was (excellent – 30 and good – 70) 100%. Out of this, 27 (90%) patients had returned to preinjury level of activity in 1 year. In this study, one patient had superficial infection and two patients had knee pain.Conclusion: Arthroscopy-assisted ACL reconstruction using hamstring tendon autograft provides a stable knee, reduces postoperative morbidity, and enables early rehabilitation.

The effects of initial graft tension on femorotibial relationship following anatomical rectangular tunnel anterior cruciate ligament reconstruction using bone–patellar tendon–bone graft

BackgroundThe purpose of this study was to elucidate the effects of the difference of initial graft tension on the femorotibial relationship on an axial plane and its chronological change following anatomical anterior cruciate ligament (ACL) reconstruction. MethodsA total of 63 patients who underwent anatomical ACL reconstruction were included in this study. The graft was fixed at full knee extension with manual maximum (higher graft tension; group H) and 80 N (lower graft tension; group L) pulls in 31 and 32 patients, respectively. The femorotibial positional relationship in axial computed tomography at 1 week and 1 year postoperatively were retrospectively evaluated. The side-to-side differences (SSDs) and the amount of changes of SSDs over 1 year were compared between groups. ResultsThe SSDs of the external rotational angle of the tibia in group H were significantly larger than those in group L at postoperative 1 week (2.7 ± 3.9° vs. 0.3 ± 3.3°; P < 0.01). The amount of internal rotational changes of SSDs of the internal–external rotational angles over 1 year in group H was significantly larger than that in group L (−3.6 ± 3.9° vs. − 0.3 ± 2.7°; P < 0.01). No significant differences were observed on the anterior–posterior translation distance and medial–lateral shift distance. ConclusionThe application of higher initial graft tension resulted in excessive external rotation of the tibia to the femur at 1 week postoperatively in anatomical ACL reconstruction, and the excessive early external tibial rotation had resolved over 1 year.

Better Coverage of the ACL Tibial Footprint and Less Injury to the Anterior Root of the Lateral Meniscus Using a Rounded-Rectangular Tibial Tunnel in ACL Reconstruction: A Cadaveric Study.

Background:To better restore the anatomy of the native anterior cruciate ligament (ACL) attachment and fiber arrangement, researchers have developed techniques for changing the shape of the ACL bone tunnel during ACL reconstruction.Purpose:To compare the coverage of the ACL tibial footprint and influence on the anterior root of lateral meniscus (ARLM) between a rounded-rectangular tibial tunnel and a conventional round tibial tunnel for ACL reconstruction.Study Design:Controlled laboratory study.Methods:A total of 16 (8 matched-paired) fresh-frozen human cadaveric knees were distributed randomly into 2 groups: a rounded-rectangular tunnel (RRT) group and a round tunnel (RT) group. One of the knees from each pair was reamed with rounded-rectangular tibial tunnel, whereas the other was reamed with round tibial tunnel. Coverage of the ACL tibial footprint and areas of ARLM attachment before and after reaming were measured using 3-dimensional isotropic magnetic resonance imaging.Results:In the RRT group, the average percentage of ACL tibial footprint covered by the tunnel was 70.8% ± 2.5%, which was significantly higher than that in the RT group (48.2% ± 6.4%) (P = .012). As for the ARLM attachment area, in the RT group, there was a significant decrease (22.5% ± 5.9%) in ARLM attachment area after tibial tunnel reaming compared with the intact state (P < .001). Conversely, in the RRT group, the ARLM attachment area was not significantly affected by tibial tunnel reaming.Conclusion:Rounded-rectangular tibial tunnel was able to better cover the native ACL tibial footprint and significantly lower the risk of iatrogenic injury to the ARLM attachment than round tibial tunnel during ACL reconstruction.

Autologous Dedifferentiated Osteogenic Bone Marrow Mesenchymal Stem Cells Promote Bone Formation in a Rabbit Model of Anterior Cruciate Ligament Reconstruction versus Bone Marrow Mesenchymal Stem Cells

This study aimed to verify whether transplantation of dedifferentiated osteogenic bone marrow mesenchymal stem cells (De-BMSCs) at the tendon-bone interface could result in more bone formation than BMSC transplantation in anterior cruciate ligament (ACL) reconstruction. BMSCs from femur and tibia of New Zealand White rabbit were subjected to osteogenic induction and then cultured in osteogenic factor-free medium; the obtained cell population was termed De-BMSCs. Bilateral ACL reconstruction was performed in 48 adult rabbits. Three groups were established: control group with alginate gel injection, BMSCs group with the BMSCs injection, and De-BMSCs group with the De-BMSCs injection. At week 4 and 12 postoperatively, tendon-bone healing by histologic staining, micro-computed tomography examination, and biomechanical test were evaluated. The expression of α1 chain of type I collagen, osteocalcin, and osteopontin at the tendon-bone interface in the De-BMSCs group was greater than in the control or BMSCs group. The bone volume/total volume by micro-computed tomography scan was significantly greater in the De-BMSCs group than that in the control group (P= .013) or BMSCs group (P= .045) at 4 weeks, and greater than that in the control group (P= .014) or BMSCs group (P= .017) at 12 weeks. The tunnel area was significantly smaller in the De-BMSCs group than in the control group (P= .013) or BMSCs group (P= .044) at 12 weeks. The failure load and stiffness in De-BMSCs group were both significantly enhanced at 4 and 12 weeks than control group or De-BMSCs group. De-BMSCs transplantation can promote bone formation at the tendon-bone interface better than BMSCs transplantation in ACL reconstruction and increase the early biomechanical strength of the reconstructed ACL CLINICAL RELEVANCE: De-BMSCs transplantation is a potential choice for enhancing early bone formation in the tunnel in ACL reconstruction.

The Proximal Tibia Loses Bone Mineral Density After Anterior Cruciate Ligament Injury: Measurement Technique and Validation of a Quantitative Computed Tomography Method

PurposeTo develop a standardized method for tibial tunnel volumetric bone mineral density (BMD) analysis with quantitative computed tomography (qCT) using cadaveric specimens to provide validation of this technique on a healthy control population and to determine whether osteopenia occurs following an anterior cruciate ligament (ACL) injury.Methods: qCT was used to develop a volumetric BMD (mg/cm3) measurement technique throughout the region of a standard tibial tunnel. This method was applied to 90 lower extremities, including 10 matched cadaveric knees, 10 matched healthy knees, 25 ACL-injured knees, and 25 contralateral ACL-uninjured knees. The mean total and segmental (proximal, middle, and distal) tibial tunnel BMD were analyzed.ResultsThe mean entire tibial tunnel BMD measured 165.8 ± 30.5 mg/cm3 (cadaver), 255.9 ± 28.2 mg/cm3 (healthy control), 290.3 ± 36.4 mg/cm3 (ACL-injured), and 300.1 ± 35.1 (ACL-uninjured). Segmental tibial tunnel BMD demonstrated distal one-third segments as the greatest areas of BMD, followed by proximal one-third, and middle one-third for all cohorts with all pairwise comparisons (P < .001). The mean BMD was significantly greater in the uninjured extremity compared with the injured extremity in the entire tunnel (290.3 vs 300.1; P < .001), proximal (271.2 vs 279.1; P = .002), middle (167.6 vs 179.6; P < .001), and distal segments (432.7 vs 441.7; P = .004) at an average of 8 weeks following ACL injury.ConclusionsA standardized method to quantitatively measure the volumetric BMD within the region of a standard tibial tunnel for ACL reconstruction was successfully developed and validated. Significant osteopenia of the injured knee occurs following ACL injury when compared with the contralateral uninjured knee. This observation has potential clinical implications for ACL graft tibial fixation and healing.Level of EvidenceDescriptive diagnostic study, Level III.

Anatomical rectangular tunnel anterior cruciate ligament reconstruction provides excellent clinical outcomes.

The purpose of this study was to prospectively evaluate the clinical outcomes following anatomical rectangular tunnel anterior cruciate ligament (ACL) reconstruction with a bone-patellar tendon-bone (BTB) graft using an adjustable-length femoral cortical fixation device with enough patients and a high follow-up rate. This study included 125 patients who underwent anatomical rectangular tunnel ACL reconstruction with a BTB graft. A BTB TightRope® was used for femoral graft fixation. Clinical evaluations were performed more than 2years after surgery using the International Knee Documentation Committee (IKDC) Form. Patients interviewed by telephone were only subjectively evaluated. The side-to-side difference in anterior laxity at a manual maximum force was measured using the KT-2000 Arthrometer®. Among the 125 patients, 99 were ultimately included and 26 were lost to follow-up (follow-up rate: 79%). Eight patients had re-tear (re-tear rate: 8%) and six patients had ACL injuries to the contralateral knee. Three patients did not follow our rehabilitation programme. One patient suffered septic arthritis. These 18 patients were considered ineligible for clinical evaluations. Therefore, clinical evaluations were performed in 81 of the 99 patients (64 were available for direct follow-up and 17 were available for a telephone interview). The follow-up period was 30 ± 10months (range 24-68months). According to the IKDC subjective assessment, 48 (59%) and 33 (41%) knees were graded as normal and nearly normal, respectively. A loss of extension (3°-5°) was observed in five patients (8%), whereas one patient (2%) exhibited a loss of flexion (3°-5°). The Lachman test was negative in 63 patients (98%). The pivot shift test was negative in 59 patients (92%). The side-to-side difference in KT value was 0.4 ± 0.7mm (range - 1-4mm). Anatomical rectangular tunnel ACL reconstruction with a BTB graft using an adjustable-length femoral cortical fixation device provided excellent clinical outcomes both subjectively and objectively more than 2years after surgery, whereas 8 of the 99 patients had re-tear of the graft. The adjustable-length femoral cortical fixation device could be safely used in anatomical rectangular tunnel ACL reconstruction with a BTB graft. III.

Comparison of Acorn and Fluted Reamers on Tibial Tunnel Outer Aperture Dimensions in ACL Reconstruction.

The aim of this study was to determine if the type of reamer used in tibial tunnel creation during anterior cruciate ligament (ACL) reconstruction influences the dimensions of the tunnel's outer aperture. Tibial tunnels were created in tibial saw bones by reaming over a guidewire using an 8 mm acorn or fluted reamer in an antegrade manner. Reaming was aimed either in line with the guidewire, or with 10-degree inferior/superior deviation in relation to the wire. The shape and size of the outer aperture of the tibial tunnel were compared between the two reamers. When using the acorn reamer, a 10-degree deviation in relation to the guidewire resulted in minimal change in outer aperture length (mean 13.6 vs. 15.6 mm, p = 0.11) and width (11.6 vs. 11.1 mm, p = 0.51). However, when using the fluted reamer, although the aperture width showed no substantial change with reamer/guidewire deviation (11.4 vs. 11.2 mm, p = 0.71), the mean length almost doubled (14.7 vs. 28.1 mm, p = 0.002). The use of a fluted reamer when reaming the tibial tunnel creates a distal aperture which is inconsistently sized, larger, and of oblong shape compared with an acorn-shaped reamer. This should be taken in consideration when using a fluted reamer for creating the tibial tunnel in ACL reconstruction.

Bioabsorbable interference screws can be used with less tunnel widening in anatomic rectangular tunnel anterior cruciate ligament reconstruction with a bone–patellar-tendon–bone graft

BackgroundThe purpose of this study was to investigate postoperative tunnel widening after rectangular tunnel bone–patellar-tendon–bone graft anterior cruciate ligament reconstruction using newer-generation bioabsorbable interference screws. MethodsForty-six patients who had undergone primary rectangular tunnel bone–patellar-tendon–bone graft anterior cruciate ligament reconstruction using MILAGRO bioabsorbable interference screws (DePuy Synthes, Warsaw, IN, USA) for femoral fixation and for whom computed tomography was performed at two weeks and one year postoperatively were included in this prospective study. To assess the tunnel widening, the cross-sectional area of the femoral tunnel aperture (compared between two weeks and one year postoperatively) was assessed using computed tomography. Cyst formation, postoperative screw breakage, screw migration, and graft migration were also evaluated using computed tomography one year postoperatively. ResultsMean tunnel widening was 1.9%, and the cross-sectional area of the femoral tunnel aperture was not significantly different between two weeks and one year postoperatively. Postoperative cyst formation, screw breakage, screw migration, and graft migration were not observed in any patient. ConclusionsAfter rectangular tunnel bone–patellar-tendon–bone graft anterior cruciate ligament reconstruction using bioabsorbable interference screws for femoral fixation, tunnel widening was not observed via computed tomography analysis at two weeks and one year postoperatively.

Comparison of clinical results of anteromedial and transtibial femoral tunnel drilling in ACL reconstruction

BackgroundA femoral bone tunnel in ACL reconstruction can be constructed from the outside in or from the inside out. When doing it inside out, the approach can be via the anteromedial (AM) portal or through the tibial bone tunnel. It has been suggested that better results might be expected by doing it anteromedially. Clinical results after femoral tunnel drilling via the AM or transtibial (TT) techniques in reconstruction of anterior cruciate ligament (ACL) are presented.MethodsThree hundred patients with ACL injuries were chosen for this study from previously collected data on ACL reconstructions. They were divided into two groups: 150 patients treated with AM drilling and 150 treated with TT drilling. In the AM group, the reconstructions were performed using a semitendinosus graft with the Tape Locking Screw (TLS™) technique (n = 87) or Retrobutton™ femoral and BioScrew™ tibial fixation with a semitendinosus-gracilis graft (n = 63). In the TT group, the fixation method used was Rigidfix™ femoral and Intrafix tibial fixation with a semitendinosus-gracilis graft. The evaluation methods were clinical examination, knee scores (Lysholm, Tegner and IKDC) and instrumented laxity measurements (KT-2000™). Our aim was to evaluate if there was better rotational stability and therefore better clinical results when using AM drilling compared to TT drilling.ResultsAfter excluding revision ACL reconstructions, there were 132 patients in the AM group and 133 in the TT group for evaluation. At the 2-year follow-up, there were 60 patients in the AM group (45.5%) and 58 in the TT group (43.6%). There were no statistically significant differences between the groups in any of the evaluation methods used.ConclusionBoth drilling techniques resulted in improved patient performance and satisfaction. We found no data supporting the hypothesis that the AM drilling technique provides better rotational stability to the knee.Trial registrationISRCTN registry with study ID ISRCTN16407730. Retrospectively registered Jan 9th 2020.

An ACL reconstruction robotic positioning system based on anatomical characteristics

To improve the positioning accuracy of tunnels for anterior cruciate ligament (ACL) reconstruction, we proposed an ACL reconstruction robotic positioning system based on anatomical characteristics. The system includes a preoperative path planning system, an intraoperative path planning system, and a navigation and positioning system. Brahmet line, anterior, and posterior cortical lines are used for registration of preoperative computed tomography (CT) images and intraoperative X-ray images. A new calibrator of C-arm is applied to establish the mapping between medical images and surgical space. Tunnels for ACL reconstruction can be built anatomically by the robot. The accuracy of the path planning system is 1.73 mm in the four dry bones experiments and 2.17 mm in the two cadaver experiments. The accuracy meets the accuracy requirement of ACL construction surgery.

Chronological Changes in Anterior Knee Stability after Anatomical Anterior Cruciate Ligament Reconstruction Using Bone-Patellar Tendon-Bone and Hamstring Grafts.

The clinical outcomes of anterior cruciate ligament (ACL) reconstruction are typically evaluated at specific time points only. This study aimed to characterize the chronological changes in anterior knee stability after anatomical ACL reconstruction and to compare the anterior knee stability achieved with bone-patellar tendon-bone (BPTB) and hamstring tendon (HT) grafts. A total of 59 patients underwent anatomical rectangular tunnel ACL reconstruction using the BPTB graft and 23 patients underwent anatomical double-bundle ACL reconstruction using the HT graft. Anterior knee stability was quantitatively assessed using the KneeLax 3 arthrometer at 6 months, 1 year, and 2 years after surgery using side-to-side differences. The values for anterior knee stability using the BPTB graft were 0.3 mm after 6 months, 0.2 mm after 1 year, and 0.2 mm after 2 years, and no significant differences were observed during the postoperative study period. Meanwhile, the values for anterior knee stability using the HT graft were -0.3 mm after 6 months, 0.5 mm after 1 year, and 1.2 mm after 2 years, and anterior knee stability decreased chronologically from 6 months up to 2 years. Regarding anterior stability, the HT graft showed significant laxity compared with the BPTB graft only after 2 years. No chronological changes in anterior stability were observed from 6 months up to 2 years after ACL reconstruction using the BPTB graft, whereas anterior laxity developed during the same period after ACL reconstruction using the HT graft. This is a Level IV, therapeutic case series study.

A 3D-printed template for preparation of tibial tunnel in reconstruction of anterior cruciate ligament

Objective To evaluate the accuracy of a 3D-printed template used to assist the preparation of tibial tunnel in reconstruction of anterior cruciate ligament (ACL). Methods Twenty healthy adult cadaveric knees were scanned by computed tomography(CT) and magnetic resonance imaging (MRI). The knees were from 11 males and 9 females who had died at an average age of 36 years (range, from 27 to 68 years) and from 8 left and 12 right sides. Individualized 3D reconstruction models of the knee joint were established based on their imaging data. According to the anatomic footprints of the virtual tibial tunnel, 20 individualized navigation templates were designed and printed by 3D printing. The templates were used to assisst preparation of tibial tunnels in the ACL reconstruction for the 20 cadaveric knees. After operation, CT scanning was conducted again to compare the corresponding postitions between the preoperative virtual tunnel and the postoperative actual tunnel. The positions of the tibial tunnel were described by the Tsukada method. Results The ratio of the distance between the tunnel outlet center and the medial edge of the tibia to the distance between the median and lateral edges of the tibial plateau was 49.7%±2.1% for the preoperative virtual tibial tunnel and 48.8%±2.8% for the postoperative actural tunnel, showing no significant difference between them (t=1.971, P=0.063). The ratio of the distance between the tunnel outlet center and the anterior edge of the tibia to the distance between the anerior and posterior edges of the tibial plateau was 41.3%±1.3% for the preoperative virtual tibial tunnel and 40.3%±3.7% for the postoperative actural tunnel, showing no significant difference between them(t=1.494, P=0.152). Conclusion 3D printing can be used to design and manufacture a navigation template which can accurately assist preparation of tibial bone tunnel in ACL reconstruction. Key words: Knee joint; Anterior cruciate ligament; 3D printing technology; Template; Tibial bone tunnel

Relationship between anterior cruciate ligament and anterolateral meniscal root bony attachment: High-resolution 3-T MRI analysis

BackgroundThe tibial bony attachments of the anterior cruciate ligament (ACL) and the anterolateral meniscal root (ALMR) are very close, and drilling the tibial tunnel in ACL reconstruction may damage the ALMR attachment. This study investigated the relationship between the tibial attachment of the ACL and ALMR using high-resolution 3-T magnetic resonance imaging (MRI). MethodsTwenty healthy subjects (35.8 ± 13.0 years) had 20 knees scanned using high resolution 3-T MRI. The tibial bony attachments of ACL, ALMR, and the tibia were segmented and three-dimensional models were created. The shape, area, and location of each attachment were evaluated using this model. ResultsThe ACL tibial attachment was elliptical in nine knees (45%), C-shaped in nine knees (45%) and triangle in two knees (10%). The mean values of the ACL vs ALMR tibial attachments were as follows: area, 106.2 ± 21.3 vs 56.2 ± 21.3 mm2; length, 16.8 ± 2.0 vs 11.0 ± 1.8 mm; and width, 6.9 ± 1.3 vs 6.6 ± 1.0 mm. The location of the ACL vs ALMR attachment centres was 46.5 ± 1.7% vs 56.5 ± 1.9% in the medial-lateral direction and 36.3 ± 3.6% vs 36.7 ± 3.5% in the anterior–posterior direction. The distance between the ACL and ALMR centres was 8.1 ± 1.3 mm. ConclusionsACL and ALMR tibial attachments were individually distinguished using high resolution 3-T MRI. The short distance between both centres of the attachments may suggest that ALMR can be damaged when the tibial tunnel is drilled in ACL reconstruction.