Safe femoral condyle range for the reverse Rigidfix femoral fixation device in anterior cruciate ligament reconstruction

Background: To determine the characteristics of cross-pin protrusion in patients treated with the reverse Rigidfix femoral fixation device for femoral tunnel preparation through the anteromedial portal in ACLR, analyse the reasons for this outcome, and identify safety hazards of this surgical technique for improvement. Methods: A retrospective analysis of patients who underwent ACLR using this technology at our hospital in 2018 was conducted. Patients with and without cross-pin protrusion were included in the case and control groups, respectively. The sex, age and imaging characteristics of the patients with cross-pin protrusion were identified, and the reasons for cross-pin protrusion were analysed. Results: There were 64 and 212 patients in the case and control groups, respectively. The proportion of cross-pin protrusion cases was 23.19% (64/276). There was a significant difference in the ratio of males to females (P <0.001, χ2=185.184), the mediolateral femoral condyle diameter (case group, 70.59 ±2.51 mm; control group, 82.65±4.16 mm; P <0.001, t=28.424), and the anteroposterior diameter of the lateral femoral condyle (case group, 58.34±2.89 mm; control group, 66.38±3.53 mm; P <0.001, t=16.615). The cross-pins did not penetrate the lateral femoral condyle cortex in patients with a mediolateral femoral condyle diameter ≥76 mm, but the cross-pins definitely penetrated the cortex when the diameter was ≤70 mm. The cross-pins did not penetrate when the anteroposterior lateral femoral condyle diameter was ≥66 mm, but the cross-pins definitely penetrated it when the diameter was ≤59 mm. Conclusion: The patients with cross-pin protrusion after reverse Rigidfix femoral fixation treatment to prepare the femoral tunnel through the anteromedial portal in ACLR were mainly females with small femoral condyles. For patients with a mediolateral femoral condyle diameter ≥76 mm and an anteroposterior lateral femoral condyle diameter ≥ 66 mm, there is no risk of cross-pin protrusion, so this technique can be used with confidence.

Hybrid Transtibial Femoral Preparation for Transphyseal Anterior Cruciate Ligament Reconstruction: A Radiographic Comparison With the Transtibial and Anteromedial Portal Techniques

Background: Transphyseal anterior cruciate ligament (ACL) reconstruction remains the most commonly used technique for pubescent patients. The transtibial (TT) drilling technique creates vertical and central femoral tunnels to minimize the physeal area of injury at the expense of a nonanatomic femoral tunnel. The hybrid TT (HTT) technique offers the potential of an anatomic femoral position with tunnel geometry similar to that using the TT technique. Purpose/Hypothesis: The purpose was to perform a radiographic comparison of the HTT technique with TT and anteromedial portal (AM) techniques in adolescent patients undergoing transphyseal ACL reconstruction. It was hypothesized that femoral tunnels created during HTT would be similar to TT tunnels but significantly more vertical and central than AM tunnels. Study Design: Cohort study; Level of evidence, 3. Methods: We retrospectively screened primary transphyseal ACL reconstructions performed in adolescents at our institution between 2013 and 2019. The youngest 20 eligible patients were selected from each technique cohort: TT, AM, and HTT. Postoperative radiographs were assessed for the coronal femoral tunnel angle, as well as the location of the tunnel-physis penetration on the anteroposterior and lateral views. Physeal lesion surface area was calculated. Data were compared among the 3 groups using 1-way analysis of variance followed by pairwise comparisons. Results: Included were 47 patients with a mean ± SD age of 14.3 ± 1.2 years (n = 9 with TT, 18 with AM, and 20 with HTT techniques). The coronal tunnel angle was significantly more vertical in the TT (60.7° ± 7.2°) and HTT (54.4° ± 5.7) groups as compared with the AM group (48.8° ± 5.9; P = .0037 and P = .02, respectively). There was no significant difference between the TT and HTT groups ( P = .066). The only significant finding regarding femoral tunnel location was that the HTT tunnels (28.9% ± 4.8%) penetrated the physis more centrally than did the AM tunnels (20.0% ± 5.1%; P = .00002) on lateral radiographs. Conclusion: The HTT technique presents an option for transphyseal ACL reconstruction, with femoral tunnel obliquity and estimated physeal disruption similar to that of the TT technique and significantly less than that of the AM technique. The HTT technique also results in the most central physeal perforation of all techniques, predominantly in the sagittal plane.

Comparing the Use of Flexible and Rigid Reaming Systems Through an Anteromedial Portal for Femoral Tunnel Creation During Anterior Cruciate Ligament Reconstruction: A Systematic Review

Background: Recent studies have suggested that femoral tunnel drilling during anterior cruciate ligament (ACL) reconstruction (ACLR) with the use of a flexible reaming system through a standard anteromedial portal (AM-FR) may result in a different tunnel geometry compared with a rigid reamer through an accessory anteromedial portal with hyperflexion (AM-RR). Purpose: To summarize radiologic, anatomic, and clinical outcomes from available studies that directly compared the use of AM-FR versus AM-RR for independent femoral tunnel creation during ACLR. Study Design: Systematic review; Level of evidence, 4. Methods: A literature search was performed using the MEDLINE (PubMed) and Web of Science databases to identify all studies that directly compared radiologic, anatomic, and clinical outcomes between the use of AM-FR and AM-RR. The literature search, data recording, and methodological quality assessment was performed by 2 independent reviewers. The outcomes analyzed included resultant ACL graft positioning and graft bending angle; femoral tunnel positioning, aperture morphology, length, and widening; posterior wall breakage; and distance from various posterolateral knee structures. Results: A total of 13 studies met the eligibility criteria for inclusion. There was no difference in femoral tunnel aperture location between techniques. There were conflicting findings among studies regarding which technique resulted in a more acute graft bending angle. One study reported greater femoral tunnel widening upon follow-up with the use of AM-FR. AM-FR produced longer and more anteverted femoral tunnels than did AM-RR. The difference in tunnel length was significant and more prominent in lesser degrees of knee flexion. With AM-FR, femoral tunnels were farther from the lateral collateral ligament and peroneal nerve, and 1 of 5 studies had fewer reports of posterior wall breakage. There has been no literature comparing the clinical or functional outcomes of these techniques. Conclusion: Although no clinical studies exist comparing AM-FR and AM-RR for femoral tunnel creation during ACLR, both systems allow for reproducible positioning of an anatomic femoral tunnel aperture. The use of AM-FR results in longer and more anteverted femoral tunnels than using AM-RR, with exit points on the lateral femur that are different but safe. Surgeons should be aware of the technical differences with each method; however, further study is needed to identify any clinically important difference that results.

Clinical outcome of anterior cruciate ligament reconstruction with modified transtibial and anteromedial portal

Arthroscopic ACL reconstruction is the current standard care of treatment for anterior cruciate ligament (ACL) injuries. Modified transtibial (mTT) and anteromedial portal (AMP) techniques aim at the anatomical placement of femoral tunnel. Controversy existed in the literature with regard to the outcome of these techniques. Hence, we designed a retrospective comparative study to analyse the clinical and functional outcomes of mTT and AMP techniques. We hypothesized that there would be no difference between the clinical and functional outcomes in mTT and AMP techniques. This retrospective observational study was conducted in consecutive patients who underwent arthroscopic ACL reconstruction using semitendinosus-gracilis (STG) quadrupled graft in our tertiary care centre with a minimum follow-up of two years. Out of 69 patients, 37 had undergone ACL reconstruction by mTT technique and remaining by AMP technique. All the patients were assessed clinically by anterior drawer, Lachman’s, pivot shift and single-legged hop test. Lysholm Knee Scoring Scale and International Knee Documentation Committee (IKDC) subjective knee evaluation score were used for the functional status. Knee instability was assessed objectively by KT-1000 arthrometer. There was no statistically significant difference in baseline demographic characteristics between mTT and AMP groups. At the end of 2 years, no statistically significant difference was noted in the anterior drawer and Lachman’s test. Though not significant, IKDC scores and Lysholm’s scores showed a better outcome in the AMP group when compared to the mTT group. AMP group showed significantly better outcome with KT-1000 arthrometer. Based on the results obtained, we presume that overall both mTT and AMP have similar functional outcome. However, as AMP technique offers significantly improved subjective rotational stability on pivot shift test, better hop limb symmetry index and KT 1000 readings compared to mTT, we suggest AMP over mTT.

Hybrid Transtibial Femoral Preparation for Transphyseal Anterior Cruciate Ligament Reconstruction: A Radiographic Comparison to Transtibial and Anteromedial Portal Techniques

Background: Transphyseal anterior cruciate ligament (ACL) reconstruction remains the most commonly used technique for pubescent patients. The principles of creating vertical and central femoral tunnels are well accepted to minimize physeal area of injury and are typically accomplished with a transtibial (TT) technique. This, however, may come at the expense of a non-anatomic tunnel. The hybrid transtibial (HTT) technique offers the potential of combining an anatomic femoral position with tunnel geometry similar to the TT technique but has never been assessed in a clinical cohort. Hypothesis/Purpose: We hypothesized that tunnels created by a HTT technique would be similar in orientation and physeal location to TT tunnels, but significantly more vertical and central than tunnels created with an anteromedial portal (AM). Methods: We retrospectively screened all ACL reconstructions performed in children aged 10 to 16 years, at our institution between 2013 to 2019, with the requirements of having a transphyseal reconstruction and an available post-operative radiographs. Radiographs were then assessed for the coronal femoral tunnel angle (FTA), as well as the location of the tunnel-physis penetration on the AP (LTAP) and lateral (LTL) views. Physeal lesion surface area was calculated. Data were compared between the three groups using ANOVA. Results: Forty-seven patients met eligibility criteria with 9 TT, 18 AM, and 20 HTT patients. Mean patient age was 14.3 +/- 1.2 years. The FTA was significantly more vertical in the TT (60.7o +/-7.2) and HTT (54.4o +/- 5.7) groups as compared to the AM group (48.8o +/- 5.9); p = 0.0037 and p = 0.02 respectively. There was no significant difference between the TT and HTT groups ( p = 0.066). The LTAP was not significantly different between groups (p = 0.097). The LTL demonstrated that the HTT tunnels penetrated the physis at a more central location in the sagittal plane (28.9% +/- 4.8%) than the AM tunnels (20.0% +/- 5.1%, p = 0.00002), but was statistically indistinguishable from the TT (24.4%+/- 4.0%, p= 0.066) tunnels. Conclusion: The hybrid transtibial technique presents an option for transphyseal ACL reconstruction, with femoral tunnel obliquity and estimated physeal disruption similar to the TT technique, significantly less than the AM technique. The HTT also results in the most central physeal perforation of all techniques, predominantly in the sagittal plane. With the known ability of the HTT technique to recreate an anatomic femoral footprint, this may represent the “best of both worlds” for transphyseal ACL reconstruction. Tables/Figures: [Figure: see text][Figure: see text][Figure: see text][Figure: see text]

Arthroscopically Assisted Anterior Cruciate Ligament Reconstruction Using Bone–Patellar Tendon–Bone Autograft: Challenges and Solutions of Medial Independent Femoral Tunnel Drilling

Background: As the main translational and rotatory stabilizer of the knee, the anterior cruciate ligament (ACL) plays a critical role in knee biomechanics. Anterior cruciate ligament ruptures generally require surgical attention for not only restoration of knee stability but also prevention of meniscal and chondral injuries. There are countless options for both the surgeon and the patient when contemplating graft choice and surgical technique for ACL reconstruction. However, the literature assessing the outcomes following various autografts has varied with some studies citing no significant difference in clinical and patient-reported outcomes, while others showing notable advantage when using bone–patellar tendon–bone (BPTB) autograft. In addition, there have been challenges associated with femoral tunnel placement using an anteromedial portal technique. Indications: In this study, we present a young female patient with a history of remote mid-substance ACL tear now presenting with worsening knee instability and a bucket-handle medial meniscus tear as a sequela of the incompetent ACL. After extensive discussion regarding the treatment options, patient had decided to proceed with surgical intervention with a BPTB autograft using the anteromedial portal technique for femoral tunnel placement and compression technique with bio-absorbable interference screw fixation. Results: Bone–patellar tendon–bone autograft has been noted to have lower risk of revision when compared with other graft options. Discussion: In this surgical technique study, we underline the importance of peritenon handling. We highlight the use of a 70-degree arthroscope to improve posterolateral wall visualization during femoral tunnel placement as well as for inspection of the reamed tibial tunnel. We also provide technique commentary and solutions for management of the medial femoral condyle (MFC) articular surface and femoral tunnel placement using an anteromedial portal technique. Last, we review graft-related outcomes, postoperative management, and rehabilitation protocol.