Computed tomographic evaluation of bone tunnel enlargement following single bundle anterior cruciate ligament reconstruction with hamstring autograft

<p class="abstract">The purpose of this study is to evaluate tibial and femoral tunnel diameter following single bundle anterior cruciate ligament (ACL) reconstruction and correlation between tunnel enlargement and clinical outcome. Twelve patients who underwent primary arthroscopic single bundle ACL reconstruction with hamstring graft were included in prospective case series. Preoperative clinical evaluation was performed using international knee documentation committee (IKDC) subjective score and grade, Tegner knee score and Lysholm knee score. Computed tomography (CT) evaluation of the femoral and tibial tunnels were done on post-operative day (POD) 1 and at a mean follow up of 9 months (range 7-12 months) and were compared with functional scores. Our study shows significant tibial and femoral tunnel enlargement on CT scan at 9 months (range 7-12 months) postoperatively. All the clinical evaluation scales showed improvement postoperatively. The mean average femoral tunnel diameter increased significantly (p&lt;0.001) from 8.17±0.57 to 9.08±0.660 (10%) and tibial tunnel diameter increased significantly (p&lt;0.001) from 8.08±0.669 to 9.07±0.601 (11%) postoperatively at a mean follow up of 9 months (range 7-12 months). No statistically significant difference between tunnel enlargement and clinical values were found. In our current prospective CT based study, we conclude use of extracortical fixation of femoral tunnel with stronger fixation of the tibial tunnel, tunnel orientation and anatomic fixation close to the joint line along with less aggressive rehabilitation protocol with use of extension knee brace may result in minimization of tunnel widening with quadrupled hamstring autograft.</p>

Tissue Wrapping Augmentation for Anterior Cruciate Ligament Reconstruction

Anterior cruciate ligament reconstruction (ACLR) has become a popular surgery in orthopedic practice today, and the technique has evolved significantly over time. Surgical procedure, graft choice, and fixation systems have varied over the years. Nonetheless, several challenges like insufficient graft ligamentization, tunnel enlargement, and insufficient reestablishment of proprioception remain in ACLR. A vision of better graft healing and integration for improved outcomes after ACLR introduced the idea of the biological ACLR. Various techniques with growth factors, cellular therapies, or tissue augment have been researched with ACLR surgery for better integration and ligamentization. This review highlights the tissue wrappingmodalities currently being explored in biological ACLR.

Outcomes of human umbilical cord blood-derived mesenchymal stem cells in enhancing tendon-graft healing in anterior cruciate ligament reconstruction: an exploratory study

Background The study investigated whether allogeneic human umbilical cord blood-derived MSCs (hUCB-MSCs) could be safely used without treatment-related adverse events, reducing tunnel enlargement, and improve clinical results in human anterior cruciate ligament (ACL) reconstruction. Methods Thirty patients were enrolled consecutively. They were divided into three groups by randomization. In the negative control group, ACL reconstruction surgery without additional treatment was performed. In the experimental group, a hUCB-MSC and hyaluronic acid mixture was applied to the tendon-bone interface of the femoral tunnels during ACL reconstruction surgery. In the positive control group, only hyaluronic acid was applied. Finally, 27 patients were analyzed after the exclusion of three patients. The incidence of treatment-related adverse events, clinical outcomes, including second-look arthroscopic findings, and the amount of tunnel enlargement, were evaluated. Results There were no treatment-related adverse events in the treatment groups. Tunnel enlargement in the experimental group (579.74 ± 389.85 mm3) was not significantly different from those in the negative (641.97 ± 455.84 mm3) and positive control (421.96 ± 274.83 mm3) groups (p = 0.6468). There were no significant differences between the groups in clinical outcomes such as KT-2000 measurement (p = 0.793), pivot shift test (p = 0.9245), International Knee Documentation Committee subjective score (p = 0.9195), Tegner activity level (p = 0.9927), and second-look arthroscopic findings (synovial coverage of the graft, p = 0.7984; condition of the graft, p = 0.8402). Conclusions Allogeneic hUCB-MSCs were used safely for ACL reconstruction without treatment-related adverse event in a 2-year follow-up. However, our study did not suggest any evidence to show clinical advantage such as the prevention of tunnel enlargement postoperatively and a decrease in knee laxity or improvement of clinical outcomes. Trial registration CRIS, Registration Number: KCT0000917. Registered on 12 November 2013; https://cris.nih.go.kr/cris/index.jsp

The Influence of Bone Bruises on Bone Tunnel Enlargement Regarding ACL Rupture

Purpose: The purpose was to determine the impact of the size of bone bruises (BBs) on bone tunnel enlargement (BTE) occurrence. Materials and methods: Twenty-four (24) patients who underwent anterior cruciate ligament reconstruction (ACLR) were included in this retrospective study. The measurements of BBs based on the initial MRI scan, bone tunnel size based on the control MRI scan, and the spatial determination of BB in relation to the bone tunnel location were evaluated. To analyze the relationship between BBs and BTE in homogeneous groups regarding the time from injury to ACLR (t(I-S)), the largest subgroup B (n = 15), in which t(I-S) was 31 to 60 days, was isolated for further investigation. Results: Based on subgroup B, a weak correlation (r = 0.33) existed between the BB volume and BTE size in the femur and tibia. Considering the relationship between the distance from the BB to the bone tunnel in the femur (f-l) and its enlargement (Δfd), there was a moderate and statistically significant (p < 0.05) negative correlation (r = −0.64). The correlation between those parameters was even stronger (r = −0.77) in subgroup B (time interval between injury and surgery ranged from 31 to 60 days). Conclusions: A retrospective analysis of MRI data in patients after ACL reconstruction surgery showed a relevant association between the distance from the BB to the bone tunnel and BTE in the femur. The relationship was not confirmed in the tibia.

Clinical study of anatomical ACL reconstruction using a rounded rectangular dilator

Background The aim of this study was that to compare clinical results between the rounded rectangular femoral tunnel ACL reconstruction (RFTR) and the conventional round femoral tunnel ACL reconstruction using a hamstring tendon. The hypothesis was that ACL reconstruction performed using the rounded rectangular dilator technique was better than that performed using the conventional round femoral tunnel technique in terms of clinical results and bone tunnel enlargement. Methods We conducted retrospective study. After exclusions, 40 patients were included in the conventional anatomical single-bundle ACL reconstruction (ASBR) group and 40 patients were included in the RFTR group. The evaluation items were knee stability, Lysholm knee score, IKDC subjective score at 2 years after surgery and bone tunnel enlargement. Results The RFTR group had a larger femoral tunnel area (average area, 53.1 ± 4.0 mm2 vs. 46.1 ± 7.0 mm2; P < 0.01), better anteroposterior stability, and higher Lysholm scores than the ASBR group (average side-to-side difference for anterior tibial translation, 0.6 ± 0.8 mm vs. 1.6 ± 1.4 mm; P < 0.01; average Lysholm score, 98.5 ± 2.1 vs. 97.5 ± 3.5; P < 0.01). Further, bone tunnel enlargement ratio was significantly lower in the RFTR group (73 ± 38% vs. 107 ± 41%; P < 0.01). Conclusions We designed and developed an original rounded rectangular dilator to perform a novel ACL surgery. This technique can create a larger bone tunnel and improve clinical results than the conventional round anatomical single-bundle ACL reconstruction.

Tunnel Enlargement Correlates With Postoperative Posterior Laxity After Double-Bundle Posterior Cruciate Ligament Reconstruction

Background: There exists little information in the relevant literature regarding tunnel enlargement after posterior cruciate ligament (PCL) reconstruction (PCLR). Purpose: To sequentially evaluate tunnel enlargement and radiographic posterior laxity through double-bundle PCLR using autologous hamstring tendon grafts. Study Design: Case series; Level of evidence, 4. Methods: We prospectively analyzed 13 patients who underwent double-bundle PCLR for an isolated PCL injury. Three-dimensional computed tomography images were obtained at 3 weeks, 6 months, and 1 year postoperatively, and the tunnel enlargement was calculated by sequentially comparing the cross-sectional areas of the bone tunnels. We also sequentially measured radiographic posterior laxity. The correlation between the tunnel enlargement ratio and the postoperative increase in posterior laxity was evaluated. Results: The cross-sectional area at the aperture in each tunnel significantly increased from 3 weeks to 6 months ( P < .003), but it did not continue doing so thereafter. The 6-month tunnel enlargement ratios of the femoral anterolateral tunnel, the femoral posteromedial tunnel, the tibial anterolateral tunnel, and the tibial posteromedial tunnel were 31.6% ± 23.5%, 90.3% ± 54.7%, 30.5% ± 26.8%, and 49.6% ± 37.0%, respectively, while the corresponding ratios at 1 year were 28.1% ± 19.8%, 83.1% ± 56.9%, 26.8% ± 32.8%, and 47.6% ± 39.0%, respectively. The posterior laxity was 9.0 ± 4.0 mm, −1.5 ± 2.3 mm, 3.4 ± 2.0 mm, and 3.9 ± 1.9 mm, preoperatively, immediately after surgery, 6 months and 1 year postoperatively, respectively. From the immediate postoperative period, the posterior laxity significantly increased at 6 months postoperatively ( P < .001), but it did not thereafter. The postoperative increase in posterior laxity had a significant positive correlation with the anterolateral tunnel enlargement ratio in both femoral and tibial tunnels at 6 months (ρ = 0.571-0.699; P = .011-.041) and 1 year (ρ = 0.582-0.615; P = .033-.037). Conclusion: Tunnel enlargement after PCLR mainly occurred within 6 months, with no progression thereafter. The anterolateral tunnel enlargement positively correlated with postoperative increase in posterior laxity.

Clinical and radiological outcome after anterior cruciate ligament reconstruction using the T-lock Osteotrans resorbable tendon anchor: early experience and midterm follow-up

Purpose Reconstruction of the Anterior cruciate ligament (ACL) using tendon grafting is an established method for restoring knee function and stability. Multiple methods are established for graft fixation. Several involve anchoring the autograft distant to the joint with hardware that remains implanted. This study reports the first early to midterm results in patients who received ACL reconstruction (ACLR) using the T-Lock Osteotrans femoral near joint fixation method with a tibial fixation using the BioactIF Osteotrans interference screw. Methods This consecutive prospective series included 20 Patients (14 Male, 6 Female) with a primary ACL rupture. All patients were treated with an ACLR using a semitendinosus autograft fixated with the T-Lock Osteotrans and were followed-up postoperatively. The following parameters were assessed: Side-to-side difference of the posterior-anterior translation measured using the KT-1000 arthrometer, Tegner activity score, Lysholm score, IKDC subjective knee evaluation form. Magnetic resonance imaging (MRI) was done to assess tunnel enlargement and integrity of the anchoring device. Results The average follow-up duration was 2 years (range 1–4.2 years). One patient was lost to follow-up. Two Patients suffered a traumatic ACL re-rupture 2 years postoperatively and received a 2-stage revision ACLR. Difference in the posterior-anterior translation was 1.8 mm (range 0–5). The median Tegner score was 6 (range 4–10) and 9 patients (45%) returned to their preinjury level of activity. The mean IKDC subjective knee evaluation form scored 91 points (range 77–100). The mean Lysholm score was 86 points (74–96). All mentioned scores were significantly better compared to preoperative values. No relevant tunnel enlargement was seen on MRI. The anchoring device was evaluated to be intact in all patients. Conclusion ACLR with the aforementioned procedure leads to good clinical and radiological outcome.

Clinical and radiological outcome after Anterior Cruciate Ligament Reconstruction using the T-Lock Osteotrans resorbable Tendon Anchor: Early Experience and Midterm Follow-up

Purpose Reonstruction of the Anterior cruciate ligament (ACL) using tendon grafting is an established method for restoring knee function and stability. Multiple methods are established for graft fixation. Several involve anchoring the autograft distant to the joint with hardware that remains implanted. This study reports the first early to midterm results in patients who received ACL reconstruction (ACLR) using the T-Lock Osteotrans femoral near joint fixation method with a tibial fixation using the BioactIF Osteotrans interference screw. Methods This consecutive prospective series included 20 Patients (14 Male, 6 Female) with a primary ACL rupture. All patients were treated with an ACLR using the semitendinosus autograft fixated with the T-Lock Osteotrans and were followed-up postoperatively. The following parameters were assessed: Side-to-side difference of the posterior-anterior translation measured using the KT-1000 arthrometer, Tegner activity score, Lysholm score, IKDC subjective knee evaluation form. Magnetic resonance imaging (MRI) was done to assess tunnel enlargement and integrity of the anchoring device. Results The average follow-up duration was 2.15 years (range 1–4.2 years). One patient was lost to follow-up. Two Patients suffered a traumatic ACL re-rupture 2 years postoperatively and received 2-stage revision ACLR. Difference in the posterior-anterior translation was 1.8 mm (range 0–5). The median Tegner score was 6 (range 4–10) and 9 patients (45%) returned to their preinjury level of activity. The mean IKDC subjective knee evaluation form scored 91.2 points (range 77–100). The mean Lysholm score was 86.1 points (74–96). All mentioned scores showed were significantly better compared to preoperative values. No relevant tunnel enlargement was seen on MRI. The anchoring device was evaluated to be intact in all patients. Conclusion ACLR with the aforementioned procedure leads to good clinical and radiological outcome.

Biomechanical Modeling of a Bone Tunnel Enlargement Post ACL Reconstruction

BackgroundBone tunnel enlargement is considered as a potential problem following ACL reconstruction and can cause a fixation failure and complicate its revision surgery. This study evaluates post tibial tunnel expansion in ACL reconstruction using an interference screw.MethodsA series of in-vitro experimental tests on animal bone and tissues were used to simulate post ACL reconstruction. The study believes an unbalanced lateral force can cause a local enlargement on the contact zone inside the tunnel. Grayscale X-ray images were used to assess the screw alignment inside the tunnel.ResultsThey showed a slight misalignment between the screw and the tunnel axis as the tendon strands moved along the side of the tunnel, and the screw had partial contact with the tendon and bone along the tunnel. According to the results, increased stress in the tunnel wall causes tunnel enlargement. Although the tunnel created away from the tibial central axis produced a higher strength, it results in higher stress on the wall of the tunnel which can increase the risk of tunnel expansion.ConclusionsThe current study believes the use of an unguided interference screw insertion potentially increases risks of the misaligned fixation and cause a tunnel enlargement. This risk may be controlled by restricting the post-operative rehabilitation.