Anatomic Tunnel Placement in Anterior Cruciate Ligament Reconstruction

Anterior Cruciate Ligament (ACL) Reconstruction Augmentation With Bone Marrow Aspirate, Demineralized Bone Matrix, and Suture Tape Demonstrates No Difference In Outcomes, But Faster Functional Recovery, Versus Non-augmented ACL Reconstruction

PURPOSE

To compare outcomes after anterior cruciate ligament reconstruction (ACLR) with bone marrow aspirate concentrate (BMAC), demineralized bone matrix (DBM), and suture tape augmentation (STA) vs. ACLR without biologic augmentation or STA.

METHODS

A prospective randomized controlled trial at a single institution was performed to compare ACLR with BMAC, DBM, and STA (Group A) vs. ACLR without biologic or STA (Group NA). One hundred patients were required. Skeletally mature patients <25 years old received quadriceps tendon autografts, while patients ≥25 years old received allograft ACLR with an all-inside technique. Concomitant meniscal pathologies were included. Primary outcomes compared were range-of-motion (ROM), limb symmetry, and patient-reported outcomes (PROs). Secondary outcomes included radiographic outcomes and surgical complications. Univariate and mixed-model regression analysis were used to compare outcomes.

RESULTS

Fifty-nine patients were included (Group A: 29 patients, 11 females, 38%; Group NA: 30 patients, 15 females, 50%). Early range-of-motion at 6 weeks (125° vs 109° flexion, p<0.0001) and limb symmetry testing at 12 weeks (80.6 % vs. 36.7% [Delta 43.9%], p<0.001) were significantly improved in Group A. At two years, International Knee Documentation (IKDC) scores were similar (91.1 ± 12.7 vs. 85.3 ± 10.8, p=0.109). Knee Injury and Osteoarthritis and Outcome Score (KOOS) Quality of Life (QOL) scores were significantly enhanced in Group A (85.2 ± 20.9 vs. 72.1 ± 20.4, p=0.042). Twenty-two patients (12 Group A, 10 Group NA) underwent CT scans at 6-months to compare bone tunnel healing. Overall, the mean increase in bone tunnel diameter was significantly smaller in Group A vs. NA. No difference in graft re-ruptures or re-operations was observed. Seven of 59 patients (11.9%) underwent re-operation for stiffness (A: 3 (10%) vs. NA: 4 (13%), p=1.0).

CONCLUSION

There were no differences in IKDC scores between groups at 2-year follow-up. Functional outcomes including early range-of-motion and limb symmetry were significantly improved in patients who received ACLR with BMAC, DBM, and STA. ACLRACLR.ACLR.

Evaluating femoral graft placement using three-dimensional magnetic resonance imaging in the reconstruction of the anterior cruciate ligament via independent or transtibial drilling techniques: a retrospective cohort study

PURPOSE

Anterior cruciate ligament (ACL) reconstruction is a common surgical procedure, yet failure still largely occurs due to nonanatomically positioned grafts. The purpose of this study was to retrospectively evaluate patients with torn ACLs before and after reconstruction via 3D MRI and thereby assess the accuracy of graft position on the femoral condyle.

METHODS

Forty-one patients with unilateral ACL tears were recruited. Each patient underwent 3D MRI of both knees before and after surgery. The location of the reconstructed femoral footprint relative to the patient's native footprint was compared.

RESULTS

Native ACL anatomical location of the native ACL had a significant impact on graft position. Native ACLs that were previously more anterior yielded grafts that were more posterior (3.70 ± 1.22 mm, P = 0.00018), and native ACL that were previously more proximal yielded grafts that were more distal (3.25 ± 1.09 mm, P = 0.0042). Surgeons using an independent drilling method positioned 76.2% posteriorly relative to the native location, with a mean 0.1 ± 2.8 mm proximal (P = 0.8362) and 1.8 ± 3.0 mm posterior (P = 0.0165). Surgeons using a transtibial method positioned 75% proximal relative to the native location, with a mean 2.2 ± 3.0 mm proximal (P = 0.0042) and 0.2 ± 2.6 mm posterior (P = 0.8007). These two techniques showed a significant difference in magnitude in the distal-proximal axis (P = 0.0332).

CONCLUSION

The femoral footprint position differed between the native and reconstructed ACLs, suggesting that ACL reconstructions are not accurate. Rather, they are converging to a normative reference point that is neither anatomical nor isometric.

Analysis of Changing Practice Trends in Anterior Cruciate Ligament Reconstruction: A Multicenter, Single-Institution Database Analysis

PURPOSE

To identify trends in anterior cruciate ligament reconstruction (ACLR), including graft choice, femoral tunnel drilling techniques, and augmentation techniques, and to assess how various surgeon factors impact these trends.

METHODS

A retrospective review of primary ACLRs performed between 2014 and 2022 was completed using a multicenter institutional database. Patient demographic characteristics, graft type, femoral drilling technique, use of extra-articular tenodesis, and use of suture augmentation were recorded from the medical record. Surgeon fellowship training (sports trained vs non-sports trained), experience (high [minimum of 15 years in practice] vs low), and volume (high [minimum of 15 ACLRs/year] vs low) were used to stratify technique utilization. The z test for proportions was used to compare categorical variables. Pearson correlation analyses identified trends and assessed statistical significance, defined as P < .05.

RESULTS

Our cohort consisted of 2,032 ACLRs performed in 2,006 patients. The average patient age was 28.3 ± 11.6 years, with more procedures performed in male patients (67.3%). The average length of surgeon experience was 19.7 ± 11.4 years, with an average annual procedural volume of 4.0 ± 5.4 ACLRs. Most surgeons were sports trained (n = 55, 64.7%), high experience (n = 44, 57.1%), and low volume (n = 80, 94.1%). There was an increasing annual proportion of ACLRs performed by sports-trained surgeons (R = 0.748, P = .020) and low-experience surgeons (R = 0.940, P < .001). Autograft reconstructions were most often performed by sports-trained (71.2%), low-experience (66.1%), and high-volume (76.9%) surgeons. There was an increasing proportion of autograft ACLRs that used quadriceps tendon among sports-trained (R = 0.739, P = .023), high-experience (R = 0.768, P = .016), and low-volume (R = 0.785, P = .012) surgeons. Independent drilling techniques were used in an increasing proportion of ACLRs performed by non-sports-trained (R = 0.860, P = .003) and high-volume (R = 0.864, P = .003) surgeons. Augmentation of ACLR with concomitant suture augmentation (n = 24, 1.2%) or extra-articular tenodesis (n = 6, 0.3%) was rarely performed.

CONCLUSIONS

In our multicenter institution, the quadriceps tendon autograft has been increasingly used in ACLR by sports-trained, low-volume, and high-experience surgeons. Independent drilling techniques have been increasingly used by non-sports-trained and high-volume surgeons.

CLINICAL RELEVANCE

Surgeons must stay current with the literature that affects their procedures to ensure that evidence-based medicine is being practiced.

A Novel Predictor of the Length and Size of ACL Grafts in Chinese Han Adults for ACL Reconstruction: An MRI Study

OBJECTIVE

Currently, there is no simple and valid method to predict the length and size of the native anterior cruciate ligament (ACL) in each adult patient who will undergo ACL reconstruction. This study aimed to develop an imaging prediction method that can predict the length and size of ACL grafts using the intact posterior cruciate ligament (PCL), in order to enhance the graft preparation individualized sizing.

METHODS

Three hundred and nineteen patients aged 18 years or older who underwent magnetic resonance imaging (MRI) of the knee at an orthopaedic clinic between September 9, 2021, and February 5, 2023, were included. The length, sagittal diameter, and coronal diameter of the ACL and PCL were measured in all patients, and F-test were performed to explore linear relationship between ligament measurements.

RESULTS

Equations were established to predict a variable of the native ACL for the corresponding variable of the intact PCL (i.e., sagittal diameter of the ACL = 4.32 + 1.08 × sagittal diameter of the PCL, and coronal diameter of the ACL = 2.45 + 0.59 × coronal diameter of the PCL, length of the male ACL = 10.92 + 0.64 × length of the male PCL, length of the female ACL = 11.76 + 0.58 × length of the female PCL) (R2  = 0.532; R2  = 0.417; R2  = 0.488; R2  = 0.509; respectively).

CONCLUSIONS

The length and size of the intact PCL in cases without PCL buckling are predictors of the length and size of the native ACL in adults, respectively. The use of this information to optimize graft diameter may lower the rates of ACL graft failure in the future.

Role of Quadriceps Tendon Autograft in Primary and Revision Anterior Cruciate Ligament Reconstruction

» The quadriceps tendon (QT) autograft is becoming increasingly popular in both primary and revision anterior cruciate ligament reconstruction (ACLR).» The biomechanical properties of the QT are similar to those of the native ACL, the hamstring tendon (HT), and bone-patellar tendon-bone (BTB) autografts.» QT autograft allows surgeons to be flexible with their graft size and reconstruction technique.» The QT autograft performs in a similar fashion to the BTB and HT autografts, with excellent patient-reported outcomes, consistent postoperative knee stability, and low rates of postoperative complications including graft failure and donor site morbidity.» There are emerging data that the QT autograft is a viable option in revision ACLR.

Revision Rates After Primary Allograft ACL Reconstruction by Allograft Tissue Type in Older Patients

Background

While there is extensive literature on the use of allograft versus autograft in anterior cruciate ligament (ACL) reconstruction, there is limited clinical evidence to guide the surgeon in choice of allograft tissue type.

Purpose

To assess the revision rate after primary ACL reconstruction with allograft and to compare revision rates based on allograft tissue type and characteristics.

Study Design

Cohort study; Level of evidence, 3.

Methods

Patients who underwent primary allograft ACL reconstructions at a single academic institution between 2015 and 2019 and who had minimum 2-year follow-up were included. Exclusion criteria were missing surgical or allograft tissue type data. Demographics, operative details, and subsequent surgical procedures were collected. Allograft details included graft tissue type (Achilles, bone-patellar tendon-bone [BTB], tibialis anterior or posterior, semitendinosus, unspecified soft tissue), allograft category (all-soft tissue vs bone block), donor age, irradiation duration and intensity, and chemical cleansing process. Revision rates were calculated and compared by allograft characteristics.

Results

Included were 418 patients (age, 39 ± 12 years; body mass index, 30 ± 9 kg/m2). The revision rate was 3% (11/418) at a mean follow-up of 4.9 ± 1.4 years. There were no differences in revision rate according to allograft tissue type across Achilles tendon (3%; 3/95), BTB (5%; 3/58), tibialis anterior or posterior (3%; 5/162), semitendinosus (0%; 0/46), or unspecified soft tissue (0%; 0/57) (P = .35). There was no difference in revision rate between all-soft tissue versus bone block allograft (6/283 [2%] vs 5/135 [4%], respectively; P = .34). Of the 51% of grafts with irradiation data, all grafts were irradiated, with levels varying from 1.5 to 2.7 Mrad and 82% of grafts having levels of <2.0 Mrad. There was no difference in revision rate between the low-dose and medium-to high-dose irradiation cohorts (4% vs 6%, respectively; P = .64).

Conclusion

Similarly low (0%-6%) revision rates after primary ACL reconstruction were seen regardless of allograft tissue type, bone block versus all-soft tissue allograft, and sterilization technique in 418 patients with mean age of 39 years. Surgeons may consider appropriately processed allograft tissue with or without bone block when indicating ACL reconstruction in older patients.

Anatomic Anterior Cruciate Ligament Reconstruction

Anterior cruciate ligament reconstruction (ACLR) techniques have substantially evolved over the past several decades, driven by evidence that nonanatomic techniques increase the risk for instability, loss of motion, surgical failure, and posttraumatic osteoarthritis. Early techniques used transtibial femoral tunnel drilling, although improved understanding of the anatomy and biomechanics has led to independent femoral tunnel. Anatomic ACLR requires careful consideration of the native ACL dimensions and orientation. Although there is significant variation between patients, understanding of anatomic patterns allows for reliable identification of the ACL footprints and appropriate tunnel positioning, particularly in chronic injuries where the remanent ACL stump is degraded or absent. The femoral tunnel should be placed low and posterior on the lateral femoral condyle using the lateral intercondylar and bifurcate ridges as landmarks. The center of the tibial footprint can be determined by referencing the medial tibial spine and posterior border of anterior horn of lateral meniscus. Measurement of the dimensions of the native ACL and intercondylar notch is also critical for determining graft size and minimizing the risk of impingement, with a goal of reconstructing 50% to 80% of the tibial footprint area. Clinical outcome studies have demonstrated superior anteroposterior and rotatory knee stability with low surgical revision rates (reported between 3% and 5%). By adhering to the principles of anatomic ACLR, surgeons can produce an appropriately sized and located graft for the individual patient, thereby best restoring native knee kinematics and maximizing function. The aim of this infographic is to highlight essential features of anatomic ACLR techniques, which a focus on the native anatomy and surgical planning to achieve an anatomic ACLR.

Anterior Cruciate Ligament Return to Play: Where Are We Now?

Anterior cruciate ligament reconstruction (ACLR) is a commonly performed orthopaedic procedure, and it is crucial to assess an athlete's readiness to safely return to sports following ACLR to minimize the risk of reinjury. Despite this, determining optimal return to play (RTP) criteria following ACLR that is accurate, accessible, and reproducible remains challenging. This review aims to discuss commonly employed RTP criteria domains, including functional assessments, patient-reported outcomes, and psychological tests, as well as emerging technologies such as magnetic resonance imaging (MRI) that may play a role as a gold standard in RTP assessment. The findings of this review suggest RTP decision making after ACL surgery is nuanced and traditionally used objective measures do not perfectly predict RTS rates or clinical outcomes. In the future, a standardized MRI screening tool could help predict reinjury. The role of functional and psychological patient-reported outcome measures needs to defined, and objective criteria should be rigorously evaluated for whether they accurately screen an athlete's physical readiness and should be expanded to include more sport-specific movement analysis.

Biomechanical Analysis of Ideal Knee Flexion Angle for ACL Graft Tensioning Utilizing Multiple Femoral and Tibial Tunnel Locations

Anterior cruciate ligament (ACL) graft failure rate has been reported to be greater than 5% at 5 years. Our study evaluated ACL excursion with anatomic and nonanatomic femoral and tibial tunnels to determine optimal flexion angle to tension the ACL to minimize excursion. Ten cadaveric knee specimens were used. The ACL was sectioned and the femoral and tibial attachments were marked. A 1/16-inch drill created a tunnel in the center of the ACL footprint on the tibia and femur and additional tunnels were made 5 mm from this. A suture was passed through each tunnel combination and attached to a string potentiometer. The knee was ranged from full extension to 120 degrees of flexion for 10 cycles while mounted in a custom fixture. The change in length (excursion) of the suture during movement was recorded for each combination of femoral and tibial tunnels. Anatomic reconstruction of the ACL with tunnel placement in the center of the femoral and tibial footprint did not result in an isometric graft, with excursion of the ACL during knee motion of 7.46 mm (standard deviation [SD]: 2.7mm), greatest at 2.84 degrees of flexion (SD: 4.22). The tunnel combination that resulted in the least excursion was a femoral footprint 5 mm anterior to the femoral and 5 mm posterior to the tibial footprint (4. 2mm, SD: 1.37 mm). The tunnel combination that resulted in the most excursion utilized femoral footprint 5 mm proximal to the femoral and 5 mm posterior to the tibial footprint (9.81 mm, SD: 2.68 mm). Anatomic ACL reconstruction results in significant excursion of the ACL throughout motion. If not tensioned properly, the ACL can stretch during range of motion, potentially leading to rerupture. To prevent stretching of the graft, the current biomechanical study recommends tensioning an anatomic ACL reconstruction at its point of maximal excursion, or between 0 and 5 degrees of flexion. The level of evidence is IV.

Anatomic anterior cruciate ligament reconstruction: Freddie Fu's paradigm

Anterior cruciate ligament (ACL) reconstruction techniques have evolved over the past four decades. There is evidence that non-anatomic reconstruction techniques, such as traditional transtibial drilling, fail to recreate the native anatomy of the ACL, which can lead to increased rotatory knee instability, revision risk, and post-traumatic osteoarthritis. Anatomic ACL reconstruction has emerged as the gold standard, with the goal of restoring the patient's native anatomy and knee kinematics. This review will summarise the relevant anatomy, modern anatomic ACL reconstruction techniques, and literature supporting anatomic ACL reconstruction as the new paradigm. LEVEL OF EVIDENCE: Level V, review article.

Posttreatment Imaging of the Knee: Cruciate Ligaments and Menisci

Cruciate ligament reconstruction and meniscal surgery are frequently performed for restoration of knee joint stability and function after cruciate ligament and meniscus injuries, and they contribute to the prevention of secondary osteoarthritis. In cruciate ligaments, the most common procedure is anterior cruciate ligament (ACL) reconstruction. Meniscal surgery most frequently consists of partial meniscectomy and suture repair, rarely of a meniscus transplant. In patients with symptoms following surgery, imaging reevaluation for a suspected intra-articular source of symptoms is indicated and mainly consists of radiography and magnetic resonance imaging. For proper imaging assessment of cruciate ligament grafts and the postoperative meniscus, it is crucial to understand the surgical techniques applied, to be familiar with normal posttreatment imaging findings, and to be aware of patterns and specific findings of recurrent lesions and typical complications. This article presents an updated review of the techniques and the imaging of cruciate ligament reconstruction and meniscus surgery, recurrent lesions, treatment failure, and potential complications.

Failure rate analysis and clinical outcomes of two different femoral tunnel positions using anteromedial portal technique in anterior cruciate ligament reconstruction

AIM

To analyze two different femoral tunnel positions and to evaluate their correlation with clinical, functional outcomes and surgical revision rate in patients who underwent primary arthroscopic anterior cruciate ligament (ACL) reconstruction with anteromedial (AM) portal technique.

METHODS

From January 2015 to October 2018, we recruited 244 patients that underwent primary single-bundle ACL reconstruction, using four strand-semitendinosus graft and AM portal technique for femoral tunnel placement. Patients were divided into two groups based on the different femoral tunnel positions: 117 patients of group A had ACL footprint center femoral tunnel position compared with 127 patients of group B, with femoral tunnel placement close to the AM bundle footprint. Preoperatively and at last follow up, all patients were assessed subjectively by Lysholm, Tegner, and International Knee Documentation Committee (IKDC) scores, while Lachman, Pivot-shift, and KT-1000 tests were performed to evaluate knee joint stability.

RESULTS

Group B patients showed significantly better results in Lysholm, objective, and subjective IKDC scores compared with patients of group A (P < 0.001). A significantly higher surgical failure rate was found in group A than in group B (10.26% vs. 2.3%; P < 0.001). A higher anterior knee laxity was recorded in patients of group A than in patients of group B (1.9 ± 1.1 vs. 1.3 ± 1 mm; P < 0.001); a reduction in mean anterior tibial translation from preoperative to final follow up was found in group B compared with group A (3.5 ± 1.2 vs. 2.7 ± 1.1 mm; P < 0.001). No significant differences in the Tegner scale were found between the two groups.

CONCLUSION

ACL reconstruction performed using the AM portal technique showed better and more satisfactory clinical and functional outcomes associated with a lower failure rate when the femoral tunnel had been placed more eccentrically in the footprint, in the AM bundle center position.

The "Not" Good, the Bad and the Ugly: Prevention and Management of Common Intraoperative and Delayed Complications in Orthopedic Sports Medicine Surgical Procedures

Despite advances in techniques designed to make arthroscopic sports medicine procedures simple, complications still arise in the operating room; even in the most trained hands. However, what marks a skilled surgeon is not just the ability to steer the ship amidst smooth seas, but a knack for getting out of trouble once things deviate from the set course. Each surgical case presents a unique challenge, and no 2 are the same. For this reason, a true expert surgeon must know how to deal with "complications" ranging from a mild swell to a raging storm. In this review we present strategies to prevent and navigate some of the most common, and fearsome complications a sports medicine surgeon may face during surgery. A great surgeon is one that acknowledges that throughout their career it is not a question of "if" these situations will arise, but "when"; and preparation is the key to success.

The morphology of the femoral footprint of the anterior cruciate ligament changes with aging from a large semicircular shape to a small flat ribbon-like shape

PURPOSE

Compare the differences in the morphology of the ACL femoral footprint between the cadavers of the young and elderly in consideration of the degenerative physiological process that occurs with aging.

METHODS

The femoral footprint of the ACL was dissected in 81 knees of known gender and age (45 male/36 female). They were divided into four groups by age and gender, establishing 50 years as the cut-off point to divide patients by age. Three observers analyzed the femoral footprint dissections, and the shapes were described and classified. The area and morphometric characteristics of the femoral insertion of the ACL were determined and these were compared between genders and age groups.

RESULTS

The femoral footprint of the ACL from the cadavers of males younger than 50 years of age presented a semicircular morphology in 90% of the cases. In males aged more than 50 years, a ribbon-like morphology was found in 96% of the cases. In women less than 50 years old, the semicircular morphology was observed in 93.7% of the cases. In women aged over 50 years old, the ribbon-like morphology was found in 95% of the cases. A significant difference was observed between the prevalence rates of the morphologies, area size and measurements of the younger and older groups (p < 0.001 for both genders).

CONCLUSIONS

The femoral insertion of the ACL presents variations in its morphology, area and morphometric characteristics over time. It goes from a large semicircular shape that almost contacts the posterior articular cartilage to a smaller, flattened ribbon-like shape that moves away from the edge of the articular cartilage. It is bounded anteriorly by the lateral intercondylar ridge. These findings should be considered to avoid employing reconstruction techniques in which femoral tunnels with oval or rectangular shapes are used in patients under 50 years of age because they do not correspond to the morphology of the femoral insertion of the ACL in this age group.

Higher Incidence of Complete Lateral Meniscal Root Tears in Revision Compared With Primary Anterior Cruciate Ligament Reconstruction

Purpose

To evaluate the incidence of complete lateral meniscal posterior root tears (LMPRTs) repaired at revision as compared with primary anterior cruciate ligament (ACL) reconstruction (PACLR) and to determine whether other demographic or surgical characteristics were associated with LMPRTs needing repair.

Methods

A chart review was performed to identify the PACLR and revision ACL reconstruction (RACLR) cohorts. Demographic and surgical characteristics were recorded. Cases with concurrent lateral meniscal posterior root repair were identified. Cases were classified as acute (<5 months) or chronic (>5 months) based on the time from reported injury to surgery. Tunnel malposition in revision cases was recorded if either tunnel or both tunnels were malpositioned on radiographs and magnetic resonance imaging.

Results

Data from 167 cases, 140 PACLR and 27 RACLR cases, were included. The cohorts had similar demographic characteristics including age, sex, and lateral meniscal injury. The overall incidence of lateral meniscal root repair in ACL reconstruction patients was 12.6% (21 of 167 patients). The incidence of LMPRT repair was 7.1% (10 of 140 patients) in the PACLR cohort versus 40.7% (11 of 27 patients) in the RACLR cohort. The revision cohort was significantly more likely to have a chronic injury (66.7% [18 of 27 patients] vs 31.4% [44 of 140 patients]). The most significant predictor of concurrent lateral meniscal posterior root repair was RACLR versus PACLR for both univariate and multivariate logistic regression analyses (χ² = 20.603; P < .0001; odds ratio, 13.887; 95% confidence interval, 1.531-125.993). Analysis of tunnel positions for the revision group revealed that PACLR tunnel malposition was a significant predictor of LMPRTs (χ² = 4.91, P = .027).

Conclusions

Complete LMPRTs warranting repair are encountered with a significantly greater frequency at RACLR as compared with PACLR. The overall incidence of LMPRT repair at RACLR is high. In this cohort, LMPRT repair in RACLR cases was associated with tunnel malposition of the PACLR.

Level of Evidence

Level III, retrospective cohort study.

Optimal cutoff score for patient-reported outcome measures after anterior cruciate ligament reconstruction using load-displacement curve analysis

To assess psychological components after anterior cruciate ligament (ACL) injury, we developed a new patient-reported outcome measure, the Japanese anterior cruciate ligament injury questionnaire 25 (JACL-25), and demonstrated that the JACL-25 is valid, reliable, and sufficiently responsive to evaluate psychological factors that are associated with outcomes in individuals with ACL injuries. The purpose of this study was to identify the optimum cutoff score for the JACL-25 that indicates successful clinical outcomes, combining with the graphical data obtained using the KT-2000. We studied 30 patients who underwent primary ACL reconstruction with a patella tendon or hamstring tendon autograft. On the same day of the JACL-25 evaluation, anterior knee laxity tests were performed using the KT-2000 arthrometer. ACL stiffness was calculated on the graphs of the hysteresis, which can be used to measure side-to-side differences in anterior translation. Akaike's information criterion (AIC) was used to determine the most appropriate cutoff level for the JACL-25 score for the stiffness reduction ratio and anterior-posterior (AP) translation. The average JACL-25 score was 23.8 (standard deviation (SD) 18.4). The average side-to-side displacement difference in AP translation was 2.4 (SD 4.2) mm. The average stiffness reduction ratio was 24.4% (SD 31.8). The smallest AIC values for the cutoff level for the JACL-25 score, the stiffness reduction ratio, and side-to-side differences of the anterior translation were 9, 27%, and 1.1 mm, respectively. We determined the optimal cutoff score for the JACL-25 that identifies successful clinical outcomes.

Does Bone Plug and Graft Orientation (Inferior Versus Posterior) Alter Native Femoral Footprint Coverage in Bone Patellar Tendon Bone Anterior Cruciate Ligament Reconstruction?

PURPOSE

The purpose of this study was to compare the percentage of native femoral anterior cruciate ligament (ACL) footprint covered by the 2 most clinically relevant bone plug/graft orientations used with interference screw fixation in ACL reconstruction. A secondary purpose was to assess whether a transtibial or tibia-independent drilling technique would affect this outcome.

METHODS

Five matched pairs of cadaver knees were used. Each matched pair had 1 knee assigned to a 10-mm femoral socket prepared via a transtibial (TT) drilling technique and the other via an anteromedial (AM) drilling technique. The bone plug of each graft was press-fitted into the femoral socket with the graft collagen in 2 distinct clinically relevant orientations (collagen inferior or posterior). The digitized graft collagen cross-sectional area (CSA) in each orientation was overlaid onto the native femoral ACL footprint CSA to generate a percentage of native ACL footprint covered by graft collagen.

RESULTS

The average native ACL femoral footprint CSA was 110.5 ± 9.1 mm², with no difference between knees assigned to TT or AM drilling (112.6 ± 2.7 vs 108.4 ± 13.0 mm², P = .49). The average femoral socket CSA was 95.4 ± 8.7 mm², with no difference between TT and AM tunnels (95.5 ± 9.9 vs 95.3 ± 8.4 mm², P = .96). There was no difference between the percentage of native footprint covered between TT and AM sockets (76.8% ± 7.8% vs 82.2% ± 13.7%, P = .47). Irrespective of drilling technique, there was significantly greater native ACL footprint covered by graft collagen when the bone plug was oriented with graft collagen inferior rather than posterior (75.6% ± 6.3% vs 65.4% ± 11.4%, P = .02).

CONCLUSION

Orienting the femoral bone plug such that the graft collagen is inferior rather than posterior significantly increases native ACL femoral footprint coverage in bone-patellar tendon-bone ACL reconstruction. This effect is consistent across AM and TT drilling techniques.

CLINICAL RELEVANCE

Surgeons attempting to restore an anatomic ACL footprint should consider bone plug-graft orientation when performing ACL reconstruction.

STUDY DESIGN

Controlled laboratory study.

Oval femoral tunnel technique is superior to the conventional round femoral tunnel technique using the hamstring tendon in anatomical anterior cruciate ligament reconstruction

PURPOSE

This study was conducted to compare the efficacy between the oval femoral tunnel technique and the conventional round femoral tunnel technique in ACL reconstruction using an autologous hamstring tendon on the basis of the postoperative clinical outcomes and ACL graft tendon maturity. The hypothesis was that ACL reconstruction performed using the oval femoral tunnel technique was better than that performed using the round femoral tunnel technique in clinical functions and graft maturity.

METHODS

One hundred and eight patients who underwent anatomical single-bundle ACL reconstruction were included in this study and the follow-up period was at least 2 years. Thirty-nine patients admitted between February and August in 2016 were included in the oval femoral tunnel group and 69 patients admitted between September 2016 and March 2017 were included in the round femoral tunnel group. The Lachman test result, pivot-shift test result, Lysholm score, IKDC score, and VAS score were used for the clinical evaluation. An objective assessment of anteroposterior stability was performed using a KT1000 arthrometer. Postoperative MRI was conducted to compare the ACL graft maturity differences between the oval femoral tunnel group and round femoral tunnel group, where the signal/noise quotient (SNQ) was calculated. In addition, second-look arthroscopy was conducted to compare the graft status and synovial coverage at 24 months postoperatively.

RESULTS

All the patients presented with significant improvement in all clinical scores from the preoperative period to the 24-month follow-up. During the postoperative follow-up period, no statistically significant differences were found between the two groups in terms of the VAS score, knee ROM, Lachman test results, and graft status determined in the second-look arthroscopic evaluation. The Lysholm score was 97.1 ± 3.9 and 94.8 ± 5.6 in the oval femoral tunnel group and round femoral tunnel group, respectively, at the 24-month follow-up (p = 0.031). The IKDC subjective score was 92.0 ± 2.6 and 89.0 ± 3.6 in the oval femoral tunnel group and round femoral tunnel group, respectively, at the end of the follow-up period (p < 0.001). Significantly more patients with 1-degree positive pivot-shift test results were observed in the round femoral tunnel group (10/65) than in the oval femoral tunnel group (1/37) at the end of the follow-up period (p = 0.048). The mean SNQ of the oval femoral tunnel group was 2.7 ± 0.9, which was significantly lower than that of the round femoral tunnel group (3.6 ± 1.1) at the 24-month postoperative follow-up (p < 0.001).

CONCLUSIONS

Based on the clinical evaluations, MRI findings and second-look arthroscopy results of the two groups, the oval femoral tunnel technique yielded significantly better knee function and knee laxity restoration and more mature ACL grafts than the round femoral tunnel technique, whereas no significant differences were found at the second-look arthroscopy.

LEVEL OF EVIDENCE

III.

Three-Dimensional Magnetic Resonance Imaging for Guiding Tibial and Femoral Tunnel Position in Anterior Cruciate Ligament Reconstruction: A Cadaveric Study

Background:

Femoral and tibial tunnel malposition for anterior cruciate ligament (ACL) reconstruction (ACLR) is correlated with higher failure rate. Regardless of the surgical technique used to create ACL tunnels, significant mismatches between the native and reconstructed footprints exist.

Purpose:

To compare the position of tunnels created by a standard technique with the ones created based on preoperative 3-dimensional magnetic resonance imaging (3D MRI) measurements of the ACL anatomic footprint.

Study Design:

Controlled laboratory study.

Methods:

Using 3D MRI, the native ACL footprints were identified. Tunnels were created on 16 knees (8 cadavers) arthroscopically. On one knee of a matched pair, the tunnels were created based on 3D MRI measurements that were provided to the surgeon (roadmapped technique), while on the contralateral knee, the tunnels were created based on a standard anatomic ACLR technique. The technique was randomly assigned per set of knees. Postoperatively, the positions of the tunnels were measured using 3D MRI.

Results:

On the tibial side, the median distance between the center of the native and reconstructed ACL footprints in relation to the root of the anterior horn of the lateral meniscus medially was 1.7 ± 2.2 mm and 1.9 ± 2.8 mm for the standard and roadmapped techniques, respectively (P = .442), while the median anteroposterior distance was 3.4 ± 2.4 mm and 2.5 ± 2.5 mm for the standard and roadmapped techniques, respectively (P = .161). On the femoral side, the median distance in relation to the apex of the deep cartilage (ADC) distally was 0.9 ± 2.8 mm and 1.3 ± 2.1 mm for the standard and roadmapped techniques, respectively (P = .195), while the median distance anteriorly from the ADC was 1.2 ± 1.3 mm and 4.6 ± 4.5 mm for the standard and roadmapped techniques, respectively (P = .007).

Conclusion:

Providing precise radiological measurements of the ACL footprints does not improve the surgeon’s ability to position the tunnels. Future studies should continue to attempt to provide tools to improve the tunnel position in ACLR.

Clinical Relevance:

This cadaveric study indicates that despite the use of 3D MRI in understanding the ACL anatomy, re-creating the native ACL footprints remains a challenge.

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.

Intraoperative fluoroscopy reduces the variability in femoral tunnel placement during single-bundle anterior cruciate ligament reconstruction

PURPOSE

To evaluate the effect of using intraoperative fluoroscopy on femoral and tibial tunnel positioning variability in single-bundle anterior cruciate ligament (ACL) reconstruction.

METHODS

A total of 80 consecutive patients with single-bundle ACL reconstruction between 2014 and 2016 were retrospectively reviewed. Among them, 40 underwent ACL reconstruction without fluoroscopy (non-fluoroscopy group) and 40 underwent fluoroscopy-assisted ACL reconstruction (fluoroscopy group). Femoral and tibial tunnel locations were evaluated using a standardized grid system with three-dimensional computed tomography images. Femoral and tibial tunnel location variability was compared between the groups.

RESULTS

The operation time was longer in the fluoroscopy group than in the non-fluoroscopy group (61.3 ± 5.2 min vs. 55.5 ± 4.5 min, p < 0.001). In the fluoroscopy group, a guide pin was repositioned in 16 (40%) cases on the femoral side and 2 (5%) cases on the tibial side. No significant difference in the femoral tunnel location was observed between the fluoroscopy and non-fluoroscopy groups (anterior-posterior plane, 29.0% ± 3.2% vs. 30.0% ± 6.1%; proximal-distal plane, 30.8% ± 4.8% vs. 29.4% ± 8.3%; all parameters,  n.s.); variability was significantly lower in the fluoroscopy group (p < 0.001 for both anterior-posterior and proximal-distal planes). No significant difference in the tibial tunnel location and variability was observed between the fluoroscopy and non-fluoroscopy groups (medial-lateral plane, 45.8% ± 2.0% vs. 46.6% ± 2.4%; anterior-posterior plane, 31.2% ± 4.0% vs. 31.0% ± 5.4%) (all parameters, n.s.).

CONCLUSIONS

Tunnel positioning with fluoroscopic assistance is feasible and effective in achieving consistency in femoral tunnel placement despite a slightly longer operation time. Intraoperative fluoroscopy can be helpful in cases wherein identifying anatomical landmarks on arthroscopy was difficult or for surgeons with less experience who performed ACL reconstruction.

LEVEL OF EVIDENCE

IV.

Is intraoperative fluoroscopy necessary in anterior cruciate ligament double-bundle reconstruction? A prospective randomized controlled trial

INTRODUCTION

Properly placed tibial and femoral tunnels in anterior cruciate ligament (ACL) reconstruction are important because tunnel misplacement can cause abnormal changes in graft tension patterns, resulting in postoperative knee laxity. To overcome the inaccuracy of tunnel position in ACL reconstruction, intraoperative fluoroscopy has been proven to be a useful method in previous studies focusing on the tunnel position in single-bundle reconstruction, but few studies are available on the efficacy and necessity of intraoperative fluoroscopy for double-bundle (DB) reconstruction. The purpose of this prospective randomized case-control study was to evaluate the effect of intraoperative fluoroscopy on femoral and tibial tunnel position in anatomic DB ACL reconstruction using a postoperative tunnel position in a three-dimensional computed tomography (3D-CT).

HYPOTHESIS

Intraoperative fluoroscopy during ACL DB reconstruction could make an appropriate tunnel position closer to the anatomical center compared to conventional fluoroscopy-free procedure.

MATERIAL AND METHODS

Sixty patients undergoing ACL DB reconstruction (30 fluoroscopy-free reconstruction group and 30 in fluoroscopy-assisted reconstruction group) were included in this prospective study, and randomly allocated into two groups. Mean values of the percentage distance of femoral and tibial tunnel center in a 3D-CT were compared between the two groups. Knee laxity (the anterior translation and pivot-shift grade) and clinical outcomes were also compared at the last follow-up.

RESULTS

There was a significant difference only in femoral anteromedial (AM) bundle tunnel position, but not in femoral posterolateral (PL) bundle, tibial AM, or PL bundle tunnel position between the two groups. Femoral AM bundle tunnel in the fluoroscopy-assisted reconstruction group showed significantly (p=0.005) deeper position compared to that in the fluoroscopy-free reconstruction group. There was no significant difference in anterior translation, pivot-shift grade, or clinical outcomes between the two groups.

DISCUSSION

Fluoroscopy-assisted ACL DB reconstruction can make deeper placement of the femoral AM bundle than the conventional ACL DB reconstruction.

LEVEL OF EVIDENCE

II, prospective randomized controlled trial.

Effect of Femoral Tunnel Position on Stability and Clinical Outcomes After Single-Bundle Anterior Cruciate Ligament Reconstruction Using the Outside-In Technique

PURPOSE

To evaluate the effects of the femoral tunnel location in the femoral footprint of the anterior cruciate ligament (ACL) on postoperative knee stability and clinical outcomes after ACL reconstruction (ACLR) using the outside-in technique.

METHODS

From December 2012 to August 2014, ACLR was performed using the outside-in technique in 137 patients. Among these patients, those who had a follow-up period of over 2 years were retrospectively reviewed. A total of 102 patients met the inclusion criteria. The relative location of the femoral tunnel in the lateral condyle was evaluated as a percentage using the standardized grid system on a 3-dimensional computed tomography image. Each patient was then classified into the anterior group, center group (anteroposterior plane, 29.3% ± 3.5%), or posterior group depending on the location of the femoral tunnel. Knee laxity was evaluated using a GNRB knee arthrometer, stress radiography, and the pivot-shift test. From a clinical perspective, patient-reported outcomes (International Knee Documentation Committee subjective form and Lysholm knee score) were then evaluated.

RESULTS

Of 102 patients, 31 (30.4%) were assigned to the anterior group, 46 (45.1%) were assigned to the center group, and 25 (24.5%) were assigned to the posterior group. Postoperative side-to-side differences, which were measured using stress radiographs and the GNRB arthrometer, were significantly smaller in the posterior group (1.7 ± 0.6 mm and 1.5 ± 0.5 mm, respectively) than in the center group (2.3 ± 0.9 mm and 2.2 ± 2.8 mm, respectively) and anterior group (2.4 ± 0.7 mm and 2.4 ± 1.3 mm, respectively) (P = .002 for stress radiography and P = .002 for GNRB arthrometer). No significant between-group differences were observed in the pivot-shift test results and patient-reported outcomes among the 3 groups.

CONCLUSIONS

The location of the femoral tunnel in the anatomic ACL footprint did not affect postoperative stability and clinical outcomes in the case of ACLR using the outside-in technique.

LEVEL OF EVIDENCE

Level III, retrospective comparative study.

No Difference between Extraction Drilling and Serial Dilation for Tibial Tunnel Preparation in Anterior Cruciate Ligament Reconstruction: A Systematic Review

Importance

This review highlights a lack of consensus and need for further study regarding optimal tibial tunnel preparation method in anterior cruciate ligament reconstruction (ACLR).

Objective

This review examines existing clinical and biomechanical outcomes of both extraction drilling (ED) and serial dilation (SD) as a technique for tibial tunnel preparation in ACLR.

Evidence Review

In accordance with PRISMA guidelines, three electronic databases (MEDLINE, EMBASE, and PubMed) were searched and systematically screened in duplicate from database inception to September 6, 2017 for English-language, human studies, of all levels of evidence that examined ED and/or SD for tibial tunnel preparation in ACLR. Data including patient demographics, tibial tunnel preparation techniques, biomechanical and clinical outcomes and complications were retrieved from eligible studies.

Findings

ED was used in 71 patients, who were mean age 29.9 years (range: 17-50), 68% male, and followed for mean 16.5 months (range: 3.8-46). SD was used in 70 patients (70 knees), who were mean age 29.3 years (range: 18-50), 69% male, and followed for mean 14.1 months (range: 3.8-46). There were no statistically significant differences (mean preoperative; mean postoperative) for either tibial preparation technique for Lysholm (50.1; 92.5), Tegner (3.5; 6.1), International Knee Documentation Committee (IKDC) (48.8; 92.7), and Lachman or laxity scores. However, ED demonstrated statistically significant increased postoperative tibial tunnel expansion (1.8 mm versus 1.4 mm) and (at 12 weeks) graft migration at the tibial fixation site (1.3 mm versus 0.8 mm). Across biomechanical studies, there were no statistically significant differences (ED; SD) with forces required to initiate graft slippage (156 N; 174 N), graft stiffness (187 N; 186.5 N), and screw torque (1.6 N/m; 1.8 N/m). ED demonstrated a lower mean load to failure for the graft construct (433 N versus 631 N; p<0.05).

Conclusions and Relevance

Though biomechanical data demonstrated lower mean load to failure for the graft using ED, clinical data suggest increased tibial tunnel expansion and post-operative graft migration at the tibial fixation site. Future studies with long-term follow-up data are required to ascertain the optimal technique for graft incorporation and postoperative success.

Level of Evidence

IV:Systematic Review of Level I-IV studies.

Minimal Ablation of the Tibial Stump Using Bony Landmarks Improved Stability and Synovial Coverage Following Double-Bundle Anterior Cruciate Ligament Reconstruction

Purpose

To evaluate the clinical effects of using anatomical bony landmarks (Parsons’ knob and the medial intercondylar ridge) and minimal ablation of the tibial footprint to improve knee anterior instability and synovial graft coverage after double-bundle anterior cruciate ligament reconstruction.

Materials and Methods

We performed a retrospective comparison of outcomes between patients who underwent reconstruction with minimal ablation of the tibial footprint, using an anatomical tibial bony landmark technique, and those who underwent reconstruction with wide ablation of the tibial footprint. Differences between the two groups were evaluated using second-look arthroscopy, radiological assessment of the tunnel position, postoperative anterior knee joint laxity, and clinical outcomes.

Results

Use of the anatomical reference and minimal ablation of the tibial footprint resulted in a more anterior positioning of the tibial tunnel, with greater synovial coverage of the graft postoperatively (p=0.01), and improved anterior stability of the knee on second-look arthroscopy. Both groups had comparable clinical outcomes.

Conclusions

Use of anatomical tibial bony landmarks that resulted in a more anteromedial tibial tunnel position improved anterior knee laxity, and minimal ablation improved synovial coverage of the graft; however, it did not significantly improve subjective and functional short-term outcomes.

Preservation of remnant with poor synovial coverage has no beneficial effect over remnant sacrifice in anterior cruciate ligament reconstruction

PURPOSE

The purpose of the study was to evaluate the influence of synovial coverage of the remnant on clinical outcomes and graft healing in anterior cruciate ligament (ACL) reconstruction.

METHODS

Seventy-five patients who underwent second-look arthroscopy after a single-bundle ACL reconstruction using autologous quadriceps tendon graft were included. The patients were divided into two groups according to whether the remnant was preserved (group P, n = 42) or sacrificed (group S, n = 33). Group P was further classified according to the degree of synovial coverage of the remnant on initial arthroscopic findings: group A (remnant fully covered with synovium, n = 15), group B (synovial coverage >50%, n = 15), and group C (coverage <50%, n = 12). Clinical outcomes including manual laxity tests, KT-2000 side-to-side difference, modified Lysholm score, Tegner activity score, and International Knee Documentation Committee score were evaluated pre-operatively and prior to the second-look arthroscopy. Graft tension, degrees of synovialization, and gross integrity were evaluated on second-look arthroscopic examination.

RESULTS

There were no statistical differences in manual laxity tests, KT-2000 side-to-side difference, and clinical scores between groups P and S. In second-look arthroscopic examination, graft tension showed no difference between the two groups, but gross integrity and synovialization were significantly higher in group P (P = 0.032 and P = 0.008, respectively). In subgroup analysis, only group A showed higher grade regarding gross integrity and synovialization in comparison with group S (P = 0.007 and P < 0.001, respectively).

CONCLUSIONS

Preservation of remnant in ACL reconstruction showed no superiority concerning knee stability and clinical outcomes over remnant sacrificing at post-operative 1-year second-look arthroscopy. Preservation of remnant with good synovial coverage had a positive effect on graft synovialization and maintenance of graft integrity, but this effect was not observed in cases of a remnant with poor synovial coverage. When deciding whether to preserve the remnant or not, the degree of synovial coverage should be considered.

LEVEL OF EVIDENCE

III.

Tibial Plateau Fracture Following Anterior Cruciate Ligament Reconstruction with a Bone-Patellar Tendon-Bone Allograft: A Case Report

CASE

A 36-year-old woman sustained a medial tibial plateau fracture involving a tibial tunnel that had been used 4 years prior for an anterior cruciate ligament (ACL) reconstruction with a bone-patellar tendon-bone (BPTB) allograft in the same knee. At 26 months following open reduction and internal fixation of the tibial plateau fracture (6 years following the index ACL reconstruction), the patient returned to full activity.

CONCLUSION

To our knowledge, this is the first report of a tibial plateau fracture following ACL reconstruction with a BPTB allograft, which adds to the paucity of literature discussing tibial plateau fractures following ACL reconstruction and discusses the potential predisposing factors to fracture such as ACL graft selection and surgical technique.

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

Purpose

To 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.

Methods

Arthroscopic 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.

Results

Inter-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).

Conclusions

The standard notch view provides significantly longer femoral tunnel length measurements in comparison to the "top-down" view.

A Method of Accurate Bone Tunnel Placement for Anterior Cruciate Ligament Reconstruction Based on 3-Dimensional Printing Technology: A Cadaveric Study

PURPOSE

To explore a method of bone tunnel placement for anterior cruciate ligament (ACL) reconstruction based on 3-dimensional (3D) printing technology and to assess its accuracy.

METHODS

Twenty human cadaveric knees were scanned by thin-layer computed tomography (CT). To obtain data on bones used to establish a knee joint model by computer software, customized bone anchors were installed before CT. The reference point was determined at the femoral and tibial footprint areas of the ACL. The site and direction of the bone tunnels of the femur and tibia were designed and calibrated on the knee joint model according to the reference point. The resin template was designed and printed by 3D printing. Placement of the bone tunnels was accomplished by use of templates, and the cadaveric knees were scanned again to compare the concordance of the internal opening of the bone tunnels and reference points.

RESULTS

The twenty 3D printing templates were designed and printed successfully. CT data analysis between the planned and actual drilled tunnel positions showed mean deviations of 0.57 mm (range, 0-1.5 mm; standard deviation, 0.42 mm) at the femur and 0.58 mm (range, 0-1.5 mm; standard deviation, 0.47 mm) at the tibia.

CONCLUSIONS

The accuracy of bone tunnel placement for ACL reconstruction in cadaveric adult knees based on 3D printing technology is high.

CLINICAL RELEVANCE

This method can improve the accuracy of bone tunnel placement for ACL reconstruction in clinical sports medicine.

A Prospective Evaluation of Femoral Tunnel Placement for Anatomic Anterior Cruciate Ligament Reconstruction Using 3-Dimensional Magnetic Resonance Imaging

BACKGROUND

The recent emphasis on anatomic reconstruction of the anterior cruciate ligament (ACL) is well supported by clinical and biomechanical research. Unfortunately, the location of the native femoral footprint can be difficult to see at the time of surgery, and the accuracy of current techniques to perform anatomic reconstruction is unclear.

PURPOSE

To use 3-dimensional magnetic resonance imaging (3D MRI) to prospectively evaluate patients with torn ACLs before and after reconstruction and thereby assess the accuracy of graft position on the femoral condyle.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

Forty-one patients with unilateral ACL tears were recruited into the study. Each patient underwent 3D MRI of both the injured and uninjured knees before surgery. The contralateral (uninjured) knee was used to define the patient's native footprint. Patients then underwent ACL reconstruction, and the injured knee underwent reimaging after surgery. The location and percentage overlap of the reconstructed femoral footprint were compared with the patient's native footprint.

RESULTS

The center of the native ACL femoral footprint was a mean 12.0 ± 2.6 mm distal and 9.3 ± 2.2 mm anterior to the apex of the deep cartilage. The position of the reconstructed graft was significantly different, with a mean distance of 10.8 ± 2.2 mm distal ( P = .02) and 8.0 ± 2.3 mm anterior ( P = .01). The mean distance between the center of the graft and the center of the native ACL femoral footprint (error distance) was 3.6 ± 2.6 mm. Comparing error distances among the 4 surgeons demonstrated no significant difference ( P = .10). On average, 67% of the graft overlapped within the native ACL femoral footprint.

CONCLUSION

Despite contemporary techniques and a concerted effort to perform anatomic ACL reconstruction by 4 experienced sports orthopaedic surgeons, the position of the femoral footprint was significantly different between the native and reconstructed ACLs. Furthermore, each surgeon used a different technique, but all had comparable errors in their tunnel placements.

Anterior Cruciate Ligament Tunnel Placement Using the Pathfinder Guide

Reconstruction techniques for the anterior cruciate ligament (ACL) have evolved considerably over the past 3 decades. The femoral tunnel is most commonly made via a transtibial or separate anteromedial portal approach. Benefits and drawbacks for each of these techniques exist. Improper tunnel placement is the cause of failure for ACL reconstruction 70% of the time. We present a hybrid technique for femoral tunnel placement using the Pathfinder ACL guide, which attempts to give the surgeon many of the benefits of both the transtibial and anteromedial portal techniques without the drawbacks.

Single-Bundle Anatomic Anterior Cruciate Ligament Reconstruction: Surgical Technique Pearls and Pitfalls

Anterior cruciate ligament (ACL) ruptures are some of the most common sports-related injuries. Treatment of these injuries with ACL reconstruction has evolved over the last several decades. Anatomic single-bundle ACL reconstruction offers an accurate and reproducible method to reproduce native knee anatomy, restore knee kinematics, and ultimately restore function and decrease long-term degenerative effects. The importance of adequate arthroscopic visualization and a thorough understanding of the native anatomic ACL landmarks are discussed in this article. Furthermore, surgical technique, pearls, pitfalls, potential complications, rehabilitation, and outcomes are reviewed.