Femoral Tunnel Length Research Articles

A Hybrid Transtibial Technique Combines the Advantages of Anteromedial Portal and Transtibial Approaches: A Prospective Randomized Controlled Trial

Background: The anteromedial (AM) portal and transtibial (TT) approaches are 2 common anterior cruciate ligament (ACL) femoral tunnel drilling techniques, each with unique benefits and disadvantages. A hybrid TT (HTT) technique using medial portal guidance of a flexible TT guide wire has recently been described that may combine the strengths of both the AM portal and the TT approaches. Hypothesis: The HTT technique will achieve anatomic femoral tunnel apertures similar to the AM portal technique, with improved femoral tunnel length and orientation. Study Design: Randomized controlled trial; Level of evidence, 2. Methods: A total of 30 consecutive patients with primary ACL tears were randomized to undergo the TT, AM portal, or HTT technique for femoral tunnel positioning at the time of reconstruction. All patients underwent 3-dimensional computed tomography of the operative knee at 6 weeks postoperatively. Femoral and tibial tunnel aperture positions and tunnel lengths, as well as graft bending angles in the sagittal and coronal planes, were measured. Results: Tibial tunnel lengths and aperture positions were identical between the 3 groups. The AM portal and HTT techniques achieved identical femoral aperture positions in regard to both height (P = .629) and depth (P = .582). By contrast, compared with the AM portal and HTT techniques, femoral apertures created with the TT technique were significantly higher (P < .001 and P < .001, respectively) and shallower (P = .014 and P = .022, respectively) in the notch. The mean femoral tunnel length varied significantly between the groups, measuring 35.2, 41.6, and 54.1 mm for the AM portal, HTT, and TT groups, respectively (P < .001). Last, there was no difference between the mean coronal (P = .190) and sagittal (P = .358) graft bending angles between the TT and HTT groups. By contrast, compared with the TT and HTT techniques, femoral tunnels created with the AM portal technique were significantly more angulated in the coronal plane (17.7° [P < .001] and 12.5° [P = .006], respectively) and sagittal plane (13.5° [P < .001] and 10.5° [P = .013], respectively). Conclusion: This prospective randomized controlled trial found that the HTT technique achieved femoral aperture positions equally as anatomic as the AM portal technique but produced longer, less angulated femoral tunnels, which may help reduce graft strain and mismatch. As such, this hybrid approach may represent a beneficial combination of both the TT and the AM portal techniques. Registration: NCT02795247 (ClinicalTrials.gov identifier)

The Relationship Between Lateral Femoral Anatomic Structures and the Femoral Tunnel Outlet in Anterior Cruciate Ligament Reconstruction Using the Transportal Technique: A 3-Dimensional Simulation Analysis.

Background:The relationship between the lateral femoral anatomic structures and femoral tunnel outlet according to changes in knee flexion and transverse drill angle during femoral tunnel creation in anterior cruciate ligament (ACL) reconstruction remains unclear.Purpose:To investigate the relationships between the lateral femoral anatomic structures and femoral tunnel outlet according to various knee flexion and transverse drill angles and to determine appropriate angles at which to minimize possible damage to the lateral femoral anatomic structures.Study Design:Controlled laboratory study.Methods:Simulation of ACL reconstruction was conducted using a 3-dimensional reconstructed knee model from the knees of 30 patients. Femoral tunnels were created using combinations of 4 knee flexion and 3 transverse drill angles. Distances between the femoral tunnel outlet and lateral femoral anatomic structures (minimum safe distance, 12 mm), tunnel length, and tunnel wall breakage were assessed.Results:Knee flexion and transverse drill angles independently affected distances between the femoral tunnel outlet and lateral femoral anatomic structures. As knee flexion angle increased, the distance to the lateral collateral ligament, lateral epicondyle, and popliteal tendon decreased, whereas the distance to the lateral head of the gastrocnemius increased (P < .001). As the transverse drill angle decreased, distances to all lateral femoral anatomic structures increased (P < .001). Considering safe distance, 120°, 130°, or 140° of knee flexion and maximum transverse drill angle (MTA) could damage the lateral collateral ligament; 130° or 140° of knee flexion and MTA could damage the lateral epicondyle; and 110° or 120° of knee flexion and MTA could damage the lateral head of the gastrocnemius. Tunnel wall breakage occurred under the conditions of MTA – 10° or MTA – 20° with 110° of knee flexion and MTA – 20° with 120° of knee flexion.Conclusion:Approximately 120° of knee flexion with MTA – 10° and 130° or 140° of knee flexion with MTA – 20° or MTA – 10° could be recommended to prevent damage to the lateral femoral anatomic structures, secure adequate tunnel length, and avoid tunnel wall breakage.Clinical Relevance:Knee flexion angle and transverse drill angle may affect femoral tunnel creation, but thorough studies are lacking. Our findings may help surgeons obtain a stable femoral tunnel while preventing damage to the lateral femoral anatomic structures.

All-Epiphyseal Physeal-Sparing Anterior Cruciate Ligament Reconstructive Surgery: A Study of 3-Dimensional Modeling to Characterize a Safe and Reproducible Surgical Approach

PurposeThe purpose of this study was to use 3-dimensional magnetic resonance imaging modeling of the skeletally immature knee to help characterize safe and reproducible tunnel positions, diameters, lengths, trajectories, and distances from anatomic landmarks and the physeal and articular cartilage for physeal-sparing anterior cruciate ligament (ACL) reconstructive surgery.MethodsMagnetic resonance imaging from 19 skeletally immature knees with normal anatomy were gathered. The 3-dimensional models were created, and the relevant anatomic structures were identified. Cylinders simulating tunnel length, diameter and trajectory were superimposed onto the models, and descriptive measurements were performed.ResultsA safe position for the creation of an 8 mm diameter femoral tunnel was described in the lateral femoral condyle. The femoral tunnel length averaged 25.5 ± 2.6 mm. The bony entry point was located 3.8 ± 2.4 mm proximally and 12.7 ± 2.2 mm posteriorly to the lateral epicondyle. The shortest distance from the tunnel edge to the physis and femoral articular cartilage was 2.8 ± 0.7 mm and 3.7 ± 0.9 mm, respectively. The safe position for an 8 mm diameter tibial tunnel was also identified and described in the proximal tibia. The epiphyseal tibial tunnel length from the ACL footprint to the physis averaged 15.5 ± 1.6 mm. The proximal tibial epiphysis was found to accommodate a tibial crosspin measuring 63.5 ± 5.9 mm in length and 8.2 ± 1.5 mm in diameter without disrupting the physis or articular cartilage.ConclusionsThree-dimensional modeling created from magnetic resonance imaging can help define important anatomic relationships for physeal-sparing ACL reconstructive surgery in skeletally immature knees and may assist in reducing the risk of injury to local anatomic structures.Clinical RelevanceKnowledge of the anatomic relationships in skeletally immature knees serves as a valuable reference for surgeons performing physeal-sparing ACL reconstruction surgery.

Excellence in Research:A Hybrid Transtibial Technique Combines the Strengths of theAnteromedial Portal and Transtibial Approaches: A Prospective Randomized Controlled Trial

Objectives:Improved biomechanical and clinical outcomes have been reported when femoral anterior cruciate ligament (ACL) tunnels are centered on the native footprint. The anteromedial (AM) portal technique achieves improved aperture position when compared to a transtibial (TT) approach but sacrifices technical ease and creates a shorter more acutely angulated tunnel. A hybrid transtibial technique (HTT) technique using medial portal guidance of a flexible transtibial guide wire without the need for knee hyperflexion may combine the strengths of both the AM and TT approaches. The authors hypothesized that this HTT technique would achieve anatomic femoral tunnel apertures similar to the AM technique, but with longer and less angulated femoral tunnels similar to a TT technique.Methods:A prospective randomized controlled trial was implemented where 30 consecutive patients with acute, primary ACL tears were randomized to receive a TT, AM or HTT technique for their reconstruction. A total of 46 patients were assessed for eligibility in the investigation (Figure 1). All patients underwent 3D CT scans of the operative knee 6 weeks postoperatively to characterize tunnel positions. Femoral and tibial tunnel aperture positions and tunnel lengths, as well as the graft bending angle in the sagittal and coronal plane were measured.Results:There were no significant differences between the patient demographics of the three groups. Tibial tunnel lengths and aperture positions were identical between the three groups. The AM portal and HTT techniques achieved identical femoral aperture positions in regards to both height (p=0.75) and depth (p=0.72). On the other hand, compared to the AM portal and HTT techniques, respectively, femoral apertures created by the TT technique were significantly higher (p<0.001 and p<0.001) and shallower (p=0.001 and p<0.001) in the notch. The average femoral tunnel lengths varied significantly between the three groups measuring 35.16 mm, 41.64 mm, and 54.13 mm for the AM, HTT and TT groups, respectively (p<0.001). Lastly, there were no differences between the average coronal (164.0 degrees versus 158.8 degrees, p=0.190) and sagittal (114.0 degrees versus 111.0 degrees, p=0.358) graft bending angles between the TT and HTT groups, respectively. By contrast, compared to the TT and HTT groups, respectively, the graft bending angles created with an AM technique were significantly more acutely angled in the coronal (146.3 degrees, p<0.001, p<0.006) and sagittal (100.5 degrees, p=0.014, p=0.013) planes.Conclusion:The HTT technique achieves femoral aperture positions equally as anatomic as an AM portal technique, but with longer and less acutely oriented grafts similar to a transtibial approach. These advantages will decrease the incidence of graft tunnel mismatch as well as reduce the amount of stress imparted onto the graft by avoiding an acute graft bending angle. As such, this hybrid approach may represent a beneficial combination of both transtibial and AM portal techniques.

A comparative study of a new “off-centre:off-centre” technique of transtibial ACL reconstruction with “centre:centre” transportal ACL reconstruction

Background & introductionA Single Bundle ACL Reconstruction aims at placing Tibial and Femoral attachment sites of graft from Centre of Native Tibial Foot-print to Centre of Native Femoral Footprint. In tibial tunnel independent Transportal Reconstruction, where the two points are chosen separately, the objective is easily achievable. In Tibial tunnel dependent Transtibial ACL reconstruction, Capture of Centre of femoral tunnel is dictated by Trajectory of Tibial Tunnel. Heming et al. remarked that a TT technique could produce tunnel centred in the both the tibial and femoral footprint but only if a starting point “prohibitively close” to the joint line with a correspondingly short tibial tunnel were used. A new technique wherein authors aim to place the mouths of Tibial & Femoral tunnel at off-centre location, taking care to contain these tunnels still within native footprints to achieve a tunnel which is of adequate length and does not come too close to the joint and saves MCL from violation. ObjectiveTo study the clinic-radiological outcome of a new “Off-centre to Off-centre” method of Transtibial Reconstruction and compare the results with “centre to centre” method of Transportal reconstruction. MethodsA prospective randomised comparative study of consecutive 75 clinico-radiological cases of ACL tear with definitive clinical symptoms of knee instability who underwent arthroscopic ACL reconstruction by Same Arthroscopy Surgeon was conducted between 2016 and 2018. A modification, as described herein below, was used in Transtibial technique with placement of centre of mouth of internal opening of tibial tunnel “off-centre” that allowed a predictable capture of Femoral Footprint in “off-centre” location without tunnel being too close to joint line. Only those cases were included in which the mouths of tunnel were completely contained within footprints. Capture of footprints was verified during arthroscopy. 11 cases were excluded because either the native footprint was not clearly delineated, or surgeon failed to completely contain the mouth of tunnel/socket within the delineated footprint of tibia or femur. Hence 64 patients, 32 each in Transtibial & Transportal group were enrolled into the study. The results were analysed with the objective to arrive at recommendations for improving capture of anatomical footprints at both ends by Transtibial technique. ResultsThere were no statistically significant differences in Clinical outcome scores. However there were statistically significant differences in length of Femoral Tunnel, Obliquity of Femoral tunnel as well as Femoral Tunnel Placements. Likewise, Tibial Tunnel Angle in AP & Lateral View as well as Tibial tunnel placement were also significantly different. ConclusionIt is concluded that tunnels follow much different trajectories in the bones in two techniques and trying to apply “Centre of Tibial footprint to Centre of Femoral footprint” philosophy of Transportal technique may be imprudent for Transtibial Technique. An “Off-centre to Off-centre but contained within Footprints” may afford a more predictable and reliable capture of anatomical foot prints without any adverse effect on outcomes.

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

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. 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 2days 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. 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 ± 4.5mm) 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%). 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. Retrospective case series; level of evidence, 4.

To evaluate the accuracy of the femoral tunnel length measurements for acl reconstruction using the endobutton indicator selection device from outside the knee joint and the Transportal endobutton depth probe

Purpose: To evaluate the accuracy of femoral length measurements for ACL reconstruction using the endobutton indicator selection device from outside the knee joint and the transportal endobutton depth gauge. Methods: 50 cases of primary ACL injuries, both single bundle and double bundle reconstructions were evaluated for their intra operative femoral tunnel lengths by using the Endobuttton indicator selection device from outside the knee joint and the transportal Endobuttton depth gauge and were compared with the post-operative CT femoral tunnel lengths obtained using the Osiri X imaging software. Results: The mean femoral tunnel lengths measured intraoperatively using the Endobutton selection device (35.68­±3.99mm for anteromedial tunnel [AM],) significantly longer than the measurements obtained using the Endobutton depth probe. However, there was no statistically significant difference in the posterolateral tunnel [PL] measurements [37.17±3.83mm for Endobutton selection device and 37.22±3.74 for Endobutton depth probe]. Also the measurements obtained using Endobutton depth probe were closer to the CT measurements and better correlation with the longer CT tunnel wall measurements. Conclusion: Measurements by both the Endobutton depth probe and the Endobutton selection device are longer than the actual femoral tunnel length for ACL reconstruction. Even though the difference between the mean measurements obtained by the two devices is statistically significant but the actual difference is so minimal that it barely has any effect in the decision making for the selection of the fixed loop device the graft length in ACL reconstruction. Thereby we suggest that the Endobutton Indicator Device is an easy to use and more convenient alternative to the Endobutton depth probe for measuring the femoral tunnel length in ACL reconstruction.

Evaluation of functional outcome of arthroscopic anterior cruciate ligament reconstruction by modified AMP technique

&lt;p class="abstract"&gt;&lt;strong&gt;Background:&lt;/strong&gt; In anterior cruciate ligament (ACL) reconstruction, transtibial (TT) drilling of the femoral tunnel has been criticized for its vertical and less anatomical tunnel, which accompanied rotational instability of knee. Antero medial portal (AMP) drilling technique creates more oblique and anatomic femoral tunnel. However, recent researches show that oblique tunnel is related to risks of too short femoral tunnel, blowout of back wall, and posterolateral structures injury. Modified AMP technique creates vertical tunnel with anatomical FSP (femoral starting point).&lt;/p&gt;&lt;p class="abstract"&gt;&lt;strong&gt;Methods:&lt;/strong&gt; In our study we have functionally evaluated 30 patients of ACL tear who underwent reconstruction by modified AMP technique. Modified AMP technique creates vertical tunnel with anatomical FSP.&lt;strong&gt;&lt;/strong&gt;&lt;/p&gt;&lt;p class="abstract"&gt;&lt;strong&gt;Results:&lt;/strong&gt; Mean postoperative Lysholm score is 94.4±1.22 and mean postoperative subjective IKDC score is 93.308. All the cases of ACL tear reported their knees as normal or near normal according to objective IKDC score after reconstruction. Mean coronal angle is 51.112±6.3 and mean femoral tunnel length is 41.8±3.55 mm while posterior wall blowout of lateral femoral condyle and postero lateral structure injury has not been observed.&lt;/p&gt;&lt;p class="abstract"&gt;&lt;strong&gt;Conclusions:&lt;/strong&gt; The modified AMP technique provides an anatomic and safe mode with vertical tunnel and oblique graft, by reduces the risks involved in the AMP technique.&lt;/p&gt;

Anteversion and length of the femoral tunnel in ACL reconstruction: in-vivo comparison between rigid and flexible instrumentation

BackgroundDue to it being tangential to the distal femoral axis, the anteromedial portal presents significant risk of causing iatrogenic damage, and of producing tunnels that are too short for optimal osseointegration. Flexible reamers were developed to eliminate the need for knee hyperflexion and offer better-controlled orientation of the femoral tunnel. We aimed to compare the anteversion and length of femoral tunnels drilled using flexible reamers to those drilled using rigid reamers.MethodsBetween May 2012 and December 2013, all patients receiving ACL reconstruction performed by one surgeon were operated on using either a rigid or a flexible reamer from the same supplier (Versi-Tomic® system, Stryker, Kalamazoo, Michigan). The height of each patient was recorded, and the length and anteversion of the femoral tunnels were measured intra-operatively and on true lateral radiographs, respectively.ResultsThirty-seven patients underwent operations using the rigid instrumentation, and 43 using the flexible instrumentation. There was no statistically significant difference between the two groups in either sex or height (p = n.s.). The patients operated on using the rigid instrumentation had tunnels anteverted by 18.6° ± 6° and 33.6 ± 2.9 mm long. Those operated on using the flexible instrumentation had tunnels anteverted by 40° ± 2° and 41.1 ± 3.57 mm long. Both anteversion and tunnel length were significantly greater for tunnels drilled using the flexible instrumentation (p < 0.001).ConclusionsThis study demonstrated that flexible reamers produce significantly more anteverted and longer femoral tunnels during ACL reconstruction than rigid reamers. Clinical studies remain necessary to assess the outcomes of ACL reconstruction using flexible reamers.

Anatomic femoral tunnel creation during anterior cruciate ligament reconstruction using curved dilator system.

Recently, tunnel placements in anatomic positions have been emphasized for successful restoration of knee function after anterior cruciate ligament (ACL) reconstruction. The anteromedial portal technique is considered to be more favorable than the transtibial technique for anatomic femoral tunnel placements; however, it has some technical disadvantages. To minimize these disadvantages, the authors developed the curved dilator system (CDS). The purpose of this study was to evaluate the femoral tunnel position, length, and intraoperative complications with CDS. Sixty-two consecutive patients who underwent ACL reconstruction with CDS were subjects of this study. The femoral tunnel was created using a 4.5 mm-diameter curved guide trocar and was widened in a step-by-step manner, increasing by 1 mm dilator diameter to match the graft with the knee flexed to slightly over 90°. Femoral tunnel positions were evaluated by the quadrant method from postoperative computed tomographic images. Femoral tunnel length was measured using the curved depth gauge during surgery. Complications such as posterior wall blowout and cartilage damage were checked intraoperatively. Peroneal nerve injury was observed during the hospital stay. Femoral tunnel position was 32.7% ± 5.4% and 39.1% ± 5.9% in the superior-inferior and anterior-posterior positions, respectively. Femoral tunnel length was 39.2 ± 4.1 mm. Damage to medial femoral condyle cartilage, posterior wall blowout, and peroneal nerve injury did not occur in any case. ACL reconstruction with CDS resulted in anatomic positioning of the femoral tunnel and sufficient femoral tunnel length without intraoperative complications.

Comparison of 2 femoral tunnel drilling techniques in anterior cruciate ligament reconstruction. A prospective randomized comparative study.

BackgroundTo evaluate the length and position of femoral tunnel,and exam whether knee stability and clinical functional outcomes are superior in AMP method.MethodsFrom August 2014 to February 2015, we prospectively recruited 104 patients undergoing anterior cruciate ligament reconstruction. They were randomized to anteromedial portal or transtibial method. All patients underwent Lysholm score, International Knee Documentation Committee score,Tegner score at pre-operative and last follow-up point as subjective assessment of clinical function. The Lachman test, the Pivot-shift test and KT-1000 were performed at the last follow-up as a evaluation of knee joint stability. We measured the length of femoral tunnel intraoperatively and at 1 week post-operatively, CT-based three-dimensional reconstruction was used to assess femoral tunnel location.ResultsThe average follow-up time of anteromedial portal group was 25.7 ± 6.8 months (range:12–36.5 months), and the average follow-up time of the transtibial group was 24.9 ± 6.0 months (range:12–37 months). There was no significant difference between the groups pre-operative Lysholm score, IKDC score and Tegner scores. Both groups showed significantly improvement in these clinical function scores at follow up for their ACL reconstruction. However, there was no significant difference in the function scores between the two groups at last follow up. However, the mean femoral tunnel length in the anteromedial portal group was significantly shorter than that in the transtibial group. And tunnel location was significantly lower and deeper with the anteromedial portal technique than with the transtibial technique.ConclusionThe use of anteromedial portal method resulted in a significantly lower and deeper placement of the femoral tunnel, and a shorter tunnel length compared to the transtibial method. However, there was no statistical difference in terms of clinical function and knee joint stability between the anteromedial portal method and the transtibial method.Trial registrationName of the registry: Chinese Clinical Trial Registry.The registration number: ChiCTR1800014874.The date of registration: 12 February, 2018.The study is retrospectively registered.

Comparison of three approaches for femoral tunnel during double-bundle anterior cruciate ligament reconstruction: A case controlled study

BackgroundIt is still controversial whether which femoral tunnel creation technique is best during anterior cruciate ligament reconstruction (ACLR). We aimed to clarify the features of three different techniques based on the femoral tunnel position created with the same tunnel-creating concept and the measurement data. MethodsThe femoral tunnel of double-bundle (DB) ACLR was created using the behind-remnant approach in a remnant preserved manner following the policy of our institute. The trans-tibial approach (TT) was applied for all primary ACL injured cases until December 2012. The trans-portal approach (TP) was applied from January to September 2013, and the outside-in approach (OI) was indicated from October 2013 to March 2014. We compared the femoral tunnel aperture positions with the postoperative three-dimensional computed tomography (3D-CT). Additionally, the femoral tunnel length and the septum distance of each anteromedial (AM) and posterolateral (PL) tunnel were analyzed. ResultsThe AM tunnel aperture position of TT was significantly higher and shallower than that of TP in knee flexion position. The femoral tunnel length of TP was significantly shorter than that of TT and OI. The septum between each tunnel of OI trended wider than that of TT and TP. ConclusionsThe AM tunnel aperture position of TT runs the risk of a high and shallow position. TP runs the risk of insufficiently short tunnel length. It is important to apply each method flexibly to each case because no single best approach was found.

Femoral tunnel length in anatomical single-bundle ACL reconstruction is correlated with height, weight, and knee bony morphology.

The purpose of this study was to reveal the correlation between femoral tunnel length in anatomical single-bundle anterior cruciate ligament (ACL) reconstruction and body size and/or knee morphology. Thirty-one subjects undergoing anatomical single-bundle ACL reconstruction were included in this study (20 female, 11 male; median age 46, 15-63). Pre-operative height, body weight, and body mass index (BMI) were measured. In pre-operative magnetic resonance imaging, the thickness of the quadriceps tendon and the whole anterior-posterior (AP) length of the knee were measured using the sagittal slice. Using post-operative three-dimensional computed tomography, accurate axial and lateral views of the femoral condyle were evaluated. The correlation of femoral tunnel length, which was measured intra-operatively, with the height, weight, BMI, quadriceps tendon thickness, AP length of the knee, trans-epicondylar length, the notch area (axial), length of Blumensaat's line, and the height and area of the lateral wall of the femoral intercondylar notch were statistically analyzed. Tunnel placement was also evaluated using a Quadrant method. The average femoral tunnel length was 35.6 ± 4.4mm. The average height, body weight, and BMI were 162.7 ± 7.2cm, 61.9 ± 10kg, and 23.4 ± 3.5, respectively. Femoral tunnel length was significantly correlated with height, body weight and the height and area of lateral wall of the femoral intercondylar notch, and the length of the Blumensaat's line. For clinical relevance, the risk of creating a femoral tunnel of insufficient length in anatomical single-bundle ACL reconstruction exists in subjects with small body size. Surgeons should pay careful attention to prevent this from occurring. Case-controlled study, Level III.

Comparison of functional outcome of ACL reconstruction using modified transtibial technique (MTT) and transportal technique (TP) for making the femoral tunnel in a randomised prospective study

Introduction: In ACL reconstruction, the placement and obliquity of tibial and femoral tunnels affect the orientation of graft in coronal and sagittal planes hence important for its function. Commonly used conventional transtibial technique (TT) had the disadvantage of more vertical tunnel. In the modified transtibial technique (mTT) the entry for the tibial tunnel is shifted slightly superomedially, and the leg is adducted and internally rotated. Aim: To compare the functional outcome of Arthroscopic ACL reconstruction using Bone –Patellar tendon – Bone graft with two different techniques (mTT vs. TP) of femoral tunnel placement. Methods: It was a prospective study of two groups (30 each) in which group 1 underwent Arthroscopic ACL reconstruction using PTB graft using the modified transtibial technique (mTT) for making the femoral tunnel and group 2 using transportal technique(TP). The outcome was assessed in terms of knee function (Lysholm knee scoring), clinical testing and radiological assessment (X-ray and CT) of tunnel orientation. Short-term and mid-term functional results were analyzed. Results: The short-term results have shown that the transportal technique(TP) had given slightly better functional outcome with the more anatomical femoral tunnel as compared to the modified transtibial technique(mTT)but statistically not significant. But midterm results have shown that there is no much difference in the knee function, and there was no statistically significant difference (p-value < 0.05) noted between the two groups. The transportal technique (TP) group had better rotary stability, but the femoral tunnel length was more in mTT group.Conclusion: At short-term and midterm follow up, no statistically significant difference(p-value < 0.05) was noted between the two groups (mTT vs. TP) in terms of knee function, rehabilitation, and patient’s satisfaction. Long-term results should be compared.

Minimizing Graft-Tunnel Mismatch in Allograft Anterior Cruciate Ligament Reconstruction Using Blumensaat's Line: A Cadaveric Study

To evaluate the accuracy of Blumensaat's line (BL) in predicting the tendinous graft length and tibial tunnel length (TTL) in an independent-tunnel anterior cruciate ligament reconstruction (ACLR) using a bone-patellar tendon-bone (BTB) allograft. Eighteen ACLRs were performed on cadaveric specimens using an anteromedial portal technique. All knees had no previous surgeries or deformities. Lateral knee radiographs of each specimen were taken prior to the ACLR, and BL was measured. Length-specific allografts for the tendinous portion of the grafts were then ordered by adding 20mm to the length of BL. The TTL was predicted by subtracting BL and femoral tunnel length (FTL) from the overall graft length. Graft-tunnel mismatch (GTM) was recorded for each specimen. Statistical analysis compared overall results with the gold standard (0mm) of GTM. The average lateral femoral condyle width measured in line with the femoral tunnel was 33 ± 3.43mm. The average FTL was 25 ± 0.54mm. The average intra-articular distance (IAD) between femoral and tibial tunnel apertures was 31 ± 3.65mm. The average TTL was 35 ± 2.21mm. The difference between the predicted TTL and the actual TTL was not statistically significant (P= .3). The mean GTM was-0.9 ± 3.15mm. There was no statistically significant difference between the BL method and the gold standard (P= .45). The mean percent difference between BL and the IAD was 5.2%. The BL method can accurately predict the desired length for the tendinous portion of a BTB allograft as well as the TTL, thereby potentially minimizing GTM during arthroscopic BTB allograft ACLR. Patient-specific allografts can be ordered preoperatively based on BL. This method provides the surgeon a way to avoid GTM preoperatively by ordering patient-specific grafts prior to performing an independent-tunnel BTB allograft ACLR.

Drilling through anteromedial portal with a femoral aiming device ensures a sufficient length and a proper graft position, and prevents posterior wall breakage during anterior cruciate ligament reconstruction.

The aim of this study was to evaluate the characteristics of the femoral tunnel (FT) which was drilled through the AM portal by using a femoral aimer device and AP stability of the knee. Thirty-eight patients, with the mean age 29.6 (range: 20-43) years, were evaluated after ACL reconstruction. The mean follow-up time was 31.9 (range: 16-57) months. The FT was drilled using a femoral aimer with different offset according to the graft size measured, through the AM portal. The semitendinous and gracilis tendon autograft was used for reconstruction. The angles of FT and the exit point on the lateral condyle were measured on AP views of the knee. AP stability of the knee was measured with the KT-2000. The mean angle of FT was 46.5° (± 8.4°), on the AP view. The mean distance between the exit point of FT and the most distal end of the femoral condyles was 46.7 (± 4.9) mm. The mean FT length was 36.1 (± 3.1) mm. The mean difference of anterior translation compared to the intact knee was 1.9 (± 1.6) mm. Except the three patients, with "one positive" pivot shift test, in the remaining 35 knees stability was equal to the healthy knee. Femoral drilling by using a femoral aimer device through AM portal provided long enough FT for safe graft fixation and appropriate coronal plan obliquity. The exit point was far proximal from the insertion site of the popliteus tendon and lateral collateral ligament. Furthermore, the AM portal technique significantly improved AP stability of the knee.

Arthroscopic Viewing Position Affects Anterior Cruciate Ligament Reconstruction Femoral Tunnel Length Measurements

PurposeTo purpose of this study was to compare arthroscopic anterior cruciate ligament (ACL) reconstruction femoral tunnel length measurements from the anterolateral portal between the standard notch view using a 30° arthroscope versus a “top-down” view utilizing a 70° arthroscope to visual the far side of the femoral tunnel aperture.MethodsArthroscopic femoral tunnel length measurements using calibrated reamers from the standard notch versus the “top-down” view were obtained and reviewed in 54 skeletally mature patients undergoing ACL reconstruction with no prior bony knee surgery. Patient age, height, weight, sex, and surgery laterality were also recorded. Measurements of femoral tunnel length were repeated using both views for inter-observer and intra-observer correlation.ResultsInter-observer and intra-observer intra-class correlation coefficients for the standard notch view and “top-down” views were excellent, with higher reliability values appreciated using the “top down” view. Mean overall femoral tunnel length measurements obtained using the standard notch view were significantly longer than measurements from the “top-down” view (p < 0.001).ConclusionsThe standard notch view provides significantly longer femoral tunnel length measurements in comparison to the “top-down” view.

How to Avoid Graft-Tunnel Length Mismatch in Modified Transtibial Technique for Anterior Cruciate Ligament Reconstruction Using Bone-Patellar Tendon-Bone Graft.

BackgroundWe conducted this study to determine the optimal length of patellar and tibial bone blocks for the modified transtibial (TT) technique in anterior cruciate ligament (ACL) reconstruction using the bone-patellar tendon-bone (BPTB) graft.MethodsThe current single-center, retrospective study was conducted in a total of 64 patients with an ACL tear who underwent surgery at our medical institution between March 2015 and February 2016. After harvesting the BPTB graft, we measured its length and that of the patellar tendon, patellar bone block, and tibial bone block using the arthroscopic ruler and double-checked measurements using a length gauge. Outcome measures included the length of tibial and femoral tunnels, inter-tunnel distance, length of the BPTB graft, patellar tendon, patellar bone block, and tibial bone block and graft-tunnel length mismatch. The total length of tunnels was defined as the sum of the length of the tibial tunnel, inter-tunnel distance and length of the femoral tunnel. Furthermore, the optimal length of the bone block was calculated as (the total length of tunnels − the length of the patellar tendon) / 2. We analyzed correlations of outcome measures with the height and body mass index of the patients.ResultsThere were 44 males (68.7%) and 20 females (31.3%) with a mean age of 31.8 years (range, 17 to 65 years). ACL reconstruction was performed on the left knee in 34 patients (53%) and on the right knee in 30 patients (47%). The optimal length of bone block was 21.7 mm (range, 19.5 to 23.5 mm). When the length of femoral tunnel was assumed as 25 mm and 30 mm, the optimal length of bone block was calculated as 19.6 mm (range, 17 to 21.5 mm) and 22.1 mm (range, 19.5 to 24 mm), respectively. On linear regression analysis, patients' height had a significant correlation with the length of tibial tunnel (p = 0.003), inter-tunnel distance (p = 0.014), and length of patellar tendon (p < 0.001).ConclusionsOur results indicate that it would be mandatory to determine the optimal length of tibial tunnel in the modified TT technique for ACL reconstruction using the BPTB graft. Further large-scale, multi-center studies are warranted to establish our results.

Is Preoperative Anthropometric Data Assessment Reliable Indicator for Estimating Femoral Tunnel Length in Anterior Cruciate Ligament Reconstruction?

Introduction: Correct length of the femoral tunnel is required for adequate length of graft inside the femoral canal. Length of femoral tunnel depends on mass, height, dimensions of lateral femoral condyle and amount of flexion of knee intraoperatively. Increasing weight and BMI affects the length of femoral canal since they affect positioning of limb in maximal knee flexion.Aim: To measure tunnel length in independent femoral tunnel drilling using the medial portal and to correlate the tunnel length with anthropometric data (height, weight, BMI of patient) and with width and depth of Lateral Femoral Condyle (LFC) based on MRI.Materials and Methods: The present prospective study including 40 patients were conducted. Participants were selected by a non-random convenience sampling methodology. Complete details of patients were collected by verbal communication with the patients and their attendees, clinical examination, baseline investigations, radiological investigations and surgical findings. Radiological investigations included preoperative assessment of LFC in MRI. Surgical findings were determined by measuring the femoral tunnel length after initial drilling through the medial portal using a depth gauge placed through the medial portal. SPSS version 17.0 was used for data analysis. Results: A total of 40 patients, 30 males and 10 females were included. Mean BMI was 24.22 kg/m2 with the range of 18 to 30. Mean width of LFC was 32.9 mm with range of 26.2 mm to 37.3 mm and depth of LFC was 58.79 with range of 50.7 mm to 66.2 mm. Mean femoral tunnel length was 38.4 mm with range from 32 mm to 44 mm. Conclusion: Average femoral tunnel length in Anterior Cruciate Ligament (ACL) reconstruction was 38.4 mm for assessed 40 patients. This correlated positively with height and weight of the patient. It also correlated positively with the width (p=0.027) and depth (p=0.029) of lateral femoral condyle.

Effects of Graft Selection in Arthroscopic Anterior Cruciate Ligament Reconstruction: Midterm Functional Results.

Objectives:This study is a comparison of the midterm clinical results of patients who underwent anterior cruciate ligament (ACL) reconstruction using an allograft and those who had an autograft procedure.Methods:The results of 70 patients who underwent ACL reconstruction with an anterior tibial tendon (ATT) allograft (n=18) or a hamstring (HT) autograft (n=52) were evaluated retrospectively. At the last follow-up, International Knee Documentation Committee (IKDC) and Tegner-Lysholm scores were used to assess functional status, as well as results of the Lachman test, the anterior drawer test, and the pivot-shift test.Results:There was no significant difference between the 2 groups in terms of age, gender, length of time before operation, graft thickness, or femoral tunnel length (p>0.05). The results were satisfactory in both groups in the postoperative period in terms of the length of time until a return to sports, IKDC score, Tegner-Lysholm score, range of motion, quadriceps circumference, and laxity, with no significant difference between the groups (p>0.05).Conclusion:The results of this study suggested that midterm clinical outcomes of ACL reconstruction with an ATT allograft or an HT autograft are similar when the correct technique is used according to the appropriate indications by an experienced surgeon and a successful rehabilitation program implemented after the operation.