Influence of Graft Bending Angle on Femoral Tunnel Widening After Double-Bundle ACL Reconstruction: Comparison of Transportal and Outside-In Techniques

Background: Previous studies have suggested that increased mechanical stress due to acute graft bending angle (GBA) is associated with tunnel widening and graft failure after anterior cruciate ligament (ACL) reconstruction. Few studies have compared the GBA between the outside-in (OI) and the transportal (TP) techniques. Purpose: To evaluate the influence of GBA on clinical outcomes and tunnel widening after ACL reconstruction with OI versus TP technique. Study Design: Cohort study; Level of evidence, 3. Methods: Included in the study were 56 patients who underwent double-bundle ACL reconstruction (n = 28 in the OI group and n = 28 in the TP group). Clinical outcomes (Lysholm, International Knee Documentation Committee, Tegner score, and knee laxity) 1 year postoperatively were evaluated. Computed tomography scans at 5 days and 1 year postoperatively were used for imaging measurements, and the femoral tunnel was divided into the proximal third, middle, and aperture sections. The GBA and cross-sectional area (CSA) were measured using image analysis software and were compared between groups. A correlation analysis was performed to determine if the GBA affected clinical outcomes or tunnel widening. Results: No significant difference was observed in clinical outcomes between the groups. The GBA of both the anteromedial (AM) and posterolateral bundles were more acute in the OI group compared with the TP group ( P < .05). The CSA at the AM tunnel aperture increased significantly in the OI group (84.2% ± 64.3%) compared with the TP group (51.4% ± 36.7%) ( P = .04). However, there were no differences in the other sections. In the Pearson correlation test, GBA was not correlated with tunnel widening or clinical outcomes. Conclusion: Regardless of technique, the GBA did not have a significant influence on tunnel widening or clinical outcomes. Considering a wider AM tunnel aperture, a more proximal and posterior AM tunnel position might be appropriate with the OI technique.

Effect of Demineralized Bone Matrix, Bone Marrow Mesenchymal Stromal Cells, and Platelet-Rich Plasma on Bone Tunnel Healing After Anterior Cruciate Ligament Reconstruction: A Comparative Micro-Computed Tomography Study in a Tendon Allograft Sheep Model

Background: The effect of demineralized bone matrix (DBM), bone marrow–derived mesenchymal stromal cells (BMSCs), and platelet-rich plasma (PRP) on bone tunnel healing in anterior cruciate ligament reconstruction (ACLR) has not been comparatively assessed. Hypothesis: These orthobiologics would reduce tunnel widening, and the effects on tunnel diameter would be correlated with tunnel wall sclerosis. Study Design: Controlled laboratory study. Methods: A total of 20 sheep underwent unilateral ACLR using tendon allograft and outside-in interference screw fixation. The animals were randomized into 4 groups (n = 5 per group): Group 1 received 4mL of DBM paste, group 2 received 10 million BMSCs in fibrin sealant, group 3 received 12 mL of activated leukocyte-poor platelet-rich plasma, and group 4 (control) received no treatment. The sheep were euthanized after 12 weeks, and micro-computed tomography scans were performed. The femoral and tibial tunnels were divided into thirds (aperture, midportion, and exit), and the trabecular bone structure, bone mineral density (BMD), and tunnel diameter were measured. Tunnel sclerosis was defined by a higher bone volume in a 250-µm volume of interest compared with a 4-mm volume of interest surrounding the tunnel. Results: Compared with the controls, the DBM group had a significantly higher bone volume fraction (bone volume/total volume [BV/TV]) (52.7% vs 31.8%; P = .020) and BMD (0.55 vs 0.47 g/cm3; P = .008) at the femoral aperture and significantly higher BV/TV at femoral midportion (44.2% vs 32.9%; P = .038). There were no significant differences between the PRP and BMSC groups versus controls in terms of trabecular bone analysis or BMD. In the controls, widening at the femoral tunnel aperture was significantly greater than at the midportion (46.7 vs 41.7 mm2; P = .034). Sclerosis of the tunnel was common and most often seen at the femoral aperture. In the midportion of the femoral tunnel, BV/TV ( r = 0.52; P = .019) and trabecular number ( r S = 0.50; P = .024) were positively correlated with tunnel widening. Conclusion: Only DBM led to a significant increase in bone volume, which was seen in the femoral tunnel aperture and midportion. No treatment significantly reduced bone tunnel widening. Tunnel sclerosis in the femoral tunnel midportion was correlated significantly with tunnel widening. Clinical Relevance: DBM might have potential clinical use to enhance healing in the femoral tunnel after ACLR.

Comparison of the TightRope system versus hook plate in acute acromioclavicular joint dislocations: a retrospective analysis

This study compared the results of the minimally invasive coracoclavicular (CC) fixation with a single TightRope (MITR) procedure and the hook plate (HP) procedure for acute acromioclavicular (AC) joint dislocation treatment. Sixteen patients with a mean age of 44.9 ± 11 years were treated with the MITR procedure. Nineteen patients with a mean age of 40.2 ± 8.7 years were treated using the HP procedure. Clinical outcomes were evaluated with the Visual Analog Scale (VAS) for pain, Constant–Murley Score (CMS), and University of California at Los Angeles (UCLA) Shoulder score. Vertical displacement of the clavicle with reference to the height of the acromion was measured in standard anteroposterior radiographs. The mean follow-up was 27 months in the MITR group and 30 months in the HP group. No statistically significant differences were found between the MITR group and the HR group in terms of VAS score (0.4 ± 0.6 vs 0.7 ± 0.6, P = 0.138), UCLA Shoulder score (33.9 ± 2.5 vs 33.7 ± 1.5, P = 0.843), or CMS (95.7 ± 7.3 vs 93.7 ± 6.6, P = 0.400). No redislocation was identified in the HP group, while redislocation occurred in 1 of 16 (6.3%) patients in the MITR group. One patient in the HP group (5.3%) had acromial osteolysis, while no acromial osteolysis was found in the MITR group. No other adverse events, such as infections, tunnel widening, fractures, or implant-related complications, were observed. Both procedures provided satisfactory results. The HP procedure provided better reduction, while the MITR procedure provided a slightly lower tendency of pain. Long-term follow-up is needed to investigate the clinical outcomes and radiological outcomes of both groups.

Computed Tomography Imaging of BioComposite Interference Screw After ACL Reconstruction With Bone–Patellar Tendon–Bone Graft

Background: Bioabsorbable interference screws tend to have high resorption rates after anterior cruciate ligament (ACL) reconstruction; however, no studies have examined screws composed of 30% biphasic calcium phosphate and 70% poly-d-lactide (30% BCP/70% PLDLA). Purpose: To evaluate femoral and tibial tunnel widening and resorption of 30% BCP/70% PLDLA interference screws and replacement with bone at 2 to 5 years after ACL reconstruction using bone–patellar tendon–bone (BTB) autograft. Study Design: Case series; Level of evidence, 4. Methods: Included were 20 patients who had undergone ACL reconstruction using BTB autograft and were reevaluated 2 to 5 years after surgery using computed tomography scans. Tunnel measurements were obtained from computed tomography scans in the sagittal and coronal planes and were compared with known tunnel measurements based on operative reports. These images and measurements were used to assess tunnel widening, resorption of the 30% BCP/70% PLDLA screw, its replacement with bone, and possible cyst formation. Paired t tests were used to compare initial and final femoral and tibial tunnel measurements. Results: The cross-sectional area of the femoral tunnel decreased at the aperture ( P = .03), middle ( P = .0002), and exit ( P < .0001) of the tunnel compared with the initial femoral tunnel size, and the tibial tunnel cross-sectional area decreased at the aperture ( P < .0001) and exit ( P = .01) of the tunnel compared with the initial tibial tunnel size. Bone formation was observed in 100% of femoral tunnels and 94.7% of tibial tunnels. Screw resorption was 100% in the femur and 94.7% in the tibia at the final follow-up. Cysts were noted around the femoral tunnel in 2 patients (5.1%). Conclusion: The 30% BCP/70% PLDLA interference screws used for ACL reconstruction using BTB autograft had high rates of resorption and replacement with bone, and there were no increases in tunnel size at 2 to 5 years postoperatively. The authors observed a low rate of cyst formation and no other adverse events stemming from the use of this specific biointerference screw, suggesting that this type of screw is a reasonable option for graft fixation with minimal unfavorable events and a reliable resorption profile.

Platelet-Rich Plasma in Anterior Cruciate Ligament Quadriceps Tendon Bone Reconstruction—Impact of PRP Administration on Pain, Range of Motion Restoration, Knee Stability, Tibial Tunnel Widening and Functional Results

Background: Using Platetet-Rich Plasma (PRP) in anterior cruciate ligament reconstruction (ACLR) has been suggested to improve patient outcomes. The aim of this study was to assess the impact of PRP administration on pain, range of motion (ROM) restoration and the functional results of ACLR performed with quadriceps tendon bone (QTB) autografts. Methods: A total of 106 patients were included in this multicenter study. Fifty-two patients underwent single-bundle QTB ACLR and 54 patients underwent the same procedure with additional PRP administration. Results: Mean time of need for on-demand analgesia was 8 days in the PRP group and 11 days in no-PRP group. Symmetric full extension was restored in a mean of 40 days in the PRP group and 53 days in the no-PRP group. Ninety degrees of flexion was restored at a mean of 21 days in the PRP group and 25 days in the no-PRP group. At 18 months postoperatively, the mean side-to-side difference in anterior tibial translation with the use of an arthrometer (Rolimeter, Aircast Europa) was 1.3 mm in the PRP group vs. 2.7 mm in the no-PRP group. Mean tibial tunnel widening was 1.4 mm in the PRP group vs. 2.1 mm in the no-PRP group. The mean score in the pain section of the KOOS scale was 93 in the PRP group vs. 89 in the no-PRP group. For the IKDC scale, 53 patients in the PRP group graded A or B and 1 patient graded C. In the no-PRP group, 48 patients graded A or B and 4 patients graded C or D. Conclusions: The use of PRP in QTB ACLR may decrease the need for on-demand analgesia and accelerate ROM restoration as well as improve knee stability, lessen the extent of tibial tunnel widening and potentially diminish pain at 18 months postoperatively. Further studies will be needed to confirm all authors’ conclusions.

Maturation of Anterior Cruciate Ligament Graft—Possibilities of Surgical Enhancement: What Do We Know So Far?

The purpose of this study is to review the surgical methods of enhancing anterior cruciate ligament (ACL) graft maturation. Several methods of ACL maturation enhancement were identified through research of the literature available in the PubMed database. ACL remnant preservation was the most extensively investigated technique. ACL reconstruction with a pedunculated hamstring graft provides superior revascularization of the graft along with higher mechanical strength. The usage of a graft enveloped with a periosteum was proposed to enhance the tendon-bone unit formation, and consequently, to prevent the bone tunnel widening. The muscle tissue on the graft is a potential source of stem cells. However, an excessive amount may weaken whole graft strength despite its enhanced remodeling. Similarly, amniotic tissue may augment the ACL reconstruction with stem cells and growth factors. Despite the existence of several surgical techniques that utilize amnion, the outcomes of these augmentation methods are lacking. Lastly, the intra-articular transplantation of the synovium on the surface of an ACL was proposed to augment the graft with synovial tissue and blood vessels. In conclusion, diverse approaches are being developed in order to enhance the maturation of an ACL reconstruction graft. Although these approaches have their foundation in on well-established scientific research, their outcomes are still equivocal. Clinical trials of high quality are needed to evaluate their utility in clinical practice.

Femoral Tunnel Widening Via Transcondylar Cross-Pin Fixation Versus Extracortical Suspensory Fixation After Single-Bundle ACLR: A Systematic Review and Meta-analysis

Background: Compared with extracortical suspensory fixation, the close-to-joint transcondylar cross-pin fixation method in anterior cruciate ligament reconstruction (ACLR) is believed to entail less intratunnel graft motion and subsequently lead to less tunnel widening. Purpose: To assess femoral tunnel widening via the transcondylar cross-pin method or the suspensory femoral fixation method in patients who had undergone ACLR. Study Design: Systematic review; Level of evidence, 4. Methods: This review focused on studies on femoral-tunnel widening after single-bundle ACLR with cross-pin (Rigidfix or Transfix) and/or Endobutton closed loop (CL). Two reviewers independently recorded data from each study, including the sample size and magnitude of tunnel widening after ACLR. Results: Overall, 19 studies were included in this meta-analysis. There was no significant difference between cross-pin and Endobutton CL fixations in the pooled absolute change in tunnel widening from the immediate postoperative period to the final follow-up; this was true at both the tunnel aperture (2.48 mm [95% CI, 1.76-3.2 mm] vs 2.93 mm [95% CI, 1.73-4.13 mm], respectively; P = .527) and the midpoint of the femoral tunnel (2.43 mm [95% CI, 1.77-3.1 mm] vs 2.54 mm [95% CI, –0.33 to 5.42 mm], respectively; P = .937). No significant difference was found in the relative percentage of femoral-tunnel widening between the 2 fixation methods (cross-pin, 43.3% [95% CI, 25.8%-60.8%] vs Endobutton CL, 42.0% [95% CI, 34.1%-49.9%]; P = .965). Conclusion: No significant difference in femoral tunnel widening was found to be associated with the use of either cross-pin or extracortical suspensory fixation in patients who underwent single-bundle ACLR.