Signal/noise Quotient Research Articles

Comparative Study of Graft Healing in 2 Years after “Tension Suspension” Remnant-Preserving and Non-Remnant-Preserving Anatomical Reconstruction for Sherman Type II Anterior Cruciate Ligament Injury

To evaluate the degree of graft healing after "tension suspension" reconstruction of "Sherman II" anterior cruciate ligament injuries versus non-remnant preserving anatomical reconstruction and to compare the clinical outcomes of the two procedures. The clinical data of 64 patients were retrospectively included. There were 31 cases in the "tension suspension" remnant-preserving reconstruction group and 33 cases in the non-remnant-preserving anatomical reconstruction group. The International Knee Documentation Committee (IKDC) score, the Tegner score, and the Lysholm activity score were assessed preoperatively and at 6 months, 1 year, and 2 years postoperatively, respectively. The signal/noise quotient (SNQ) of the grafts was measured at 6 months, 1 year, and 2 years after surgery to quantitatively evaluate the maturity of the grafts after ACL reconstruction; the fractional anisotropy (FA) and apparent diffusion coefficient (ADC) of the reconstructed ACL region of interest (ROI) were measured using DTI. A total of 64 patients were included in the study. The mean SNQ values of the grafts in the 6 months, 1 year, and 2 years postoperative remnant-preserving reconstruction (RP) groups were lower than those in the non-remnant-preserving (NRP) reconstruction group, with a statistically significant difference (p < 0.05). At each postoperative follow-up, the SNQ values of the tibial and femoral sides of the RP group were lower than those of the NRP group; the SNQ values of the femoral side of the grafts in both groups were higher than those of the tibial side, and the differences were statistically significant (p < 0.05). At 6 months, 1 year, and 2 years postoperatively, the FA and ADC values of the grafts were lower in the RP group than in the NRP group, and the differences were statistically significant (p < 0.05); the IKDC score and Lysholm score of the RP group were higher than the NRP group, which was statistically significant (p < 0.05). For Sherman II ACL injury, the graft healing including ligamentization and revascularization at 2 years after the "tension suspension" remnant-preserving reconstruction was better than that of non-remnant-preserving anatomic reconstruction.

Morphological Changes in the Tibial Tunnel After ACL Reconstruction With the Outside-In Technique and Adjustable Suspensory Fixation.

Anterior cruciate ligament reconstruction (ACLR) using the complete tibial tunnel technique and adjustable-loop cortical suspensory fixation is known to leave a "dead space" that holds the loop device in the tibial tunnel. The consequence of the dead space and its effect on graft healing are still uncertain. To investigate morphological changes in the tibial tunnel and their effect on graft healing, and to identify factors affecting bone healing in the tibial loop tunnel after ACLR with a quadrupled semitendinosus tendon autograft using adjustable suspensory fixation. Case series; Level of evidence, 4. Included were 48 patients (34 male, 14 female; mean age, 25.2 ± 5.6 years) who underwent ACLR with a quadrupled semitendinosus tendon autograft using adjustable suspensory fixation. To evaluate tibial tunnel morphology, computed tomography was performed at 1 day and 6 months postoperatively. At 1 year postoperatively, graft healing was assessed on magnetic resonance imaging using the graft signal-to-noise quotient (SNQ). Multivariate regression and correlation analyses were performed to determine any associations between volumetric changes in bone healing and operative variables. At 6 months after ACLR, a mean of 63.2% of the tibial loop tunnel was filled by bone. Multivariate regression analysis showed that remnant preservation was significantly associated with the loop tunnel filling rate (P < .001). At 1 year after ACLR, the tibial loop tunnel was almost completely closed (98.5%). There were no correlations between loop tunnel volume and graft integration or graft SNQ. A significant but weak correlation was found between graft tunnel volume and intratunnel graft SNQ (P = .10) as well as integration grade in the tibial tunnel (P = .30). Excellent bone filling in the tibial loop tunnel was seen at 1 year after ACLR. Remnant preservation was significantly associated with the loop tunnel filling rate. A weak correlation was found between graft tunnel volume and intratunnel graft SNQ as well as integration grade in the tibial tunnel.

Early Postoperative MRI Evaluation of a Fascia Lata Autograft With and Without Polypropylene Mesh Augmentation After Superior Capsular Reconstruction

Background: Recently, a polypropylene mesh has been introduced and reported to improve clinical outcomes after superior capsular reconstruction (SCR) using a fascia lata autograft (FLA). However, mesh-related events such as a foreign body response may trigger inflammation, which might affect graft healing and remodeling. Purpose/Hypothesis: The aim was to investigate whether the healing and remodeling of an FLA were affected by the use of a mesh by comparing the signal intensity of an FLA-alone group vs an FLA + Mesh group on postoperative magnetic resonance imaging (MRI). The hypothesis was that the use of a mesh would decrease the MRI signal intensity of FLA during the early postoperative phase. Study Design: Cohort study; Level of evidence, 3. Methods: Patients who had undergone SCR using an FLA with or without a mesh between March 2013 and August 2021 were retrospectively analyzed. Follow-up MRI was performed at 3 months. A total of 78 patients (24 in the FLA group and 54 in the FLA + Mesh group) with intact grafts were included. Graft remodeling was evaluated by analyzing the signal-to-noise quotient (SNQ) at the humeral, mid-substance, and glenoid sites. Theoretically, lower SNQ ratios indicate higher strength and better healing of the graft. Results: The mean SNQ was 30.603 (range, 11.790-72.710) in the FLA group and 18.367 (range, 4.464-69.500) in the FLA + Mesh group (P < .001). Furthermore, significant differences were found between the 2 groups at the humeral and mid-substance sites (37.863 [range, 5.092-81.187] vs 15.512 [range, 1.814-80.869], P < .001; and 29.168 [range, 6.103-73.900] vs 16.878 [range, 2.454-92.416], P = .003; respectively). However, there was no difference between the 2 groups at the glenoid site (25.346 [range, 7.565-86.353] vs 20.354 [range, 3.732-88.468], P = .057). Conclusion: At the 3-month follow-up, the FLA + Mesh group showed a lower MRI signal intensity than the FLA group. The healing and remodeling of an FLA may be enhanced when a mesh is used.

Revascularization character of autologous fascia lata graft following shoulder superior capsule reconstruction by enhanced magnetic resonance imaging

BackgroundFascia lata has been used for arthroscopic superior capsule reconstruction (ASCR) and verified to achieve a good clinical outcome. However, it is still not known about revascularization character of the fascia lata after ASCR. This study was performed to evaluate the revascularization of autologous fascia lata grafts after ASCR by enhanced magnetic resonance imaging (MRI).MethodsA prospective study of 19 patients with irreparable rotator cuff tears underwent ASCR with autologous fascia lata grafts from September 2019 to April 2021. Radiography examinations and clinical evaluations were performed preoperatively and postoperatively at 6 weeks and 3, 6, and 12 months. The signal-to-noise quotient (SNQ) value and enhancement index (EI) of autologous fascia lata grafts in the great tubercle insertion (GTI), midpoint of the graft (MG), and glenoid insertion (GI) were compared for radiography examination. Clinical evaluation included the American Shoulder and Elbow Surgeons (ASES) score, University of California Los Angeles (UCLA) shoulder score, and Visual Analog Scale (VAS) score.ResultsThe SNQ values in T1WI enhancement at GI and GTI were significantly higher than those at the plain MRI scan at all postoperative observation timepoints; however, the SNQ values in T1WI enhancement at MG did not show a significant difference until 3 months postoperation. EI values at GTI and GI were significantly higher than those at MG at 6 weeks and 3 months postoperation, while there was no significant difference in the EI value between GTI and GI. At 6 months postoperation, the EI value at GI was significantly higher than those at MG. At 12 months postoperation, the EI value at GI was significantly higher than those at MG and GTI; however, there was no significant difference between GTI and MG. The EI values at GTI and MG peaked at 3 months and 6 months postoperation, respectively, and then plateaued at 12 months postoperation. However, there was no significant difference in the EI value among the different postoperative timepoints at GI. The EI value did not correlate with the VAS and ASES, UCLA scores at any time point or any postoperative observation location.ConclusionRevascularization of the fascia lata was dependent on the location of the fascia lata and plateaus at 12 months postoperation. The EI value did not correlate with the VAS and ASES, UCLA scores during12 months postoperation.

Effect of a new remnant-preserving technique with anatomical double-bundle anterior cruciate ligament reconstruction on MRI-based graft maturity: a comparison cohort study.

To investigate the effects of a new remnant-preserving double-bundle anterior cruciate ligament reconstruction (ACLR) technique, focused on avoiding remnant damage and preserving continuity of remnants, on graft maturity using magnetic resonance imaging (MRI). A total of 169 patients were divided into three groups: 41 in the preservation group, 70 in the resection group, and 58 in the absent group. In the preservation group, rather than passing the graft through the remnant tissue, the graft was reconstructed such that the anteromedial and posterolateral bundles sandwiched the remnant to avoid damage to the remnant and maintain its continuity. Based on 1-year postoperative MRI, the grafts were divided into three regions: distal, middle, and proximal. The signal/noise quotient (SNQ) of each region of interest was calculated to evaluate the signal intensity of the graft and was compared among the three groups. Additionally, to identify factors influencing graft maturity, a multiple regression analysis was performed with SNQ as the dependent variable and patient demographics, bone morphology, and surgical factors as independent variables. In a three-group comparison of mean SNQs, the distal region was 3.3 ± 3.4, 8.9 ± 8.3, and 9.0 ± 8.6 (p < 0.001), the middle region was 5.3 ± 3.7, 10.9 ± 11.1, and 11.3 ± 10.2 (p < 0.001), and the proximal region was 6.8 ± 4.5, 11.1 ± 8.8, and 11.7 ± 10.8 (p = 0.017), in order of the preservation, resection, and absent groups, respectively. That indicated that the remnant-preserving ACLR was more hypointense than ACLR with remnant resection or absent in all three regions. Multiple regression analysis showed that remnant preservation remained the relevant factor affecting SNQ of the graft at the distal and middle levels. The new remnant-preserving anatomic double-bundle ACLR had significantly better graft maturity, measured by SNQ on MRI, than the remnant resection and absent groups. The remnant procedure was the relevant factor affecting graft maturity. Level III.

Association of Smoking With Graft Rupture After Anterior Cruciate Ligament Reconstruction.

Background:The effect of smoking on graft rupture after anterior cruciate ligament (ACL) reconstruction is not well understood.Hypothesis:It was hypothesized that there will be no relationship between tobacco use and graft rupture after ACL reconstruction, as reflected by postoperative magnetic resonance imaging (MRI) and arthroscopic examination.Study Design:Cohort study; Level of evidence, 3.Methods:Included were 233 patients who received primary ACL reconstruction with hamstring tendon autograft between January 1, 2013, and December 31, 2019, and who underwent MRI evaluation at 20.2 ± 1.9 months postoperatively. The patients were categorized by smoking history into 2 groups: 39 smokers and 194 nonsmokers. The 2 groups did not differ significantly in age, sex, operative technique, preinjury Tegner score, or mean time until postoperative MRI. The primary outcome was graft rupture rate, with rupture confirmed by either arthroscopic assessment or postoperative MRI diagnosis. The secondary outcome measure was degree of graft ligamentization, evaluated by measuring the signal-to-noise quotient (SNQ) of the graft.Results:The overall ACL graft rupture rate was 6.0%. The rupture rate was significantly higher in smokers than in nonsmokers (12.8% vs 4.6%, respectively; P = .0498). Smokers also had a significantly higher whole-graft SNQ compared with nonsmokers (4.7 ± 4.4 vs 3.3 ± 3.7, respectively; P = .028), suggesting less satisfactory ligamentization in smokers.Conclusion:Smoking was associated with a higher risk of graft rupture of ACL reconstruction and a higher SNQ of the intact graft as shown on postoperative MRI.

Effect of Joint Infection After Arthroscopic Single-Bundle ACL Reconstruction With Autologous Hamstring Tendon: A Retrospective Matched MRI Study.

Background:Joint infection after anterior cruciate ligament (ACL) reconstruction is a rare but serious complication.Purpose:To assess the effect of joint infection on the graft, cartilage, and bone tunnel using magnetic resonance imaging (MRI) after arthroscopic single-bundle ACL reconstruction with autologous hamstring tendons.Study Design:Cohort study; Level of evidence, 3.Methods:This retrospective matched cohort study included 26 patients who underwent arthroscopic single-bundle ACL reconstruction with hamstring tendon graft at the authors’ institute between January 2002 and December 2017 and developed postoperative joint infection. These patients were matched 1:3 to patients who did not sustain joint infection after ACL reconstruction (control group). MRI scans were collected at the time of follow-up. The following parameters were evaluated: graft signal-to-noise quotient (SNQ); graft signal intensity at the bone-graft interface and within the knee joint; bone tunnel enlargement at the tunnel aperture, midsection, and exit of the tibial and femoral tunnels; and cartilage integrity.Results:The average follow-up time was 47.8 months in the infection group and 48.5 months in the control group. Compared with the control group, the infection group had a significantly higher SNQ (20.01 ± 12.08 vs 7.61 ± 6.70; P = .014) as well as a higher signal intensity at the bone-graft interface (P = .037) and higher Howell grade (P = .031). The mean enlargement at the femoral tunnel aperture was 31.20% ± 26.76% in the infection group and 19.22% ± 20.10% in the control group (P = .037). The articular cartilage of the patellofemoral and lateral femorotibial joints showed more degenerative change in the infection group.Conclusion:Study findings indicated that graft ligamentization and incorporation graft maturity were inferior in patients who experienced a joint infection after ACL reconstruction compared with patients who did not.

Postoperative MRI signal intensity correlates functional outcomes after superior capsular reconstruction.

Superior capsular reconstruction (SCR) using fascia lata autograft has been performed for irreparable rotator cuff tear recently. The signal-to-noise quotient (SNQ) of the graft on magnetic resonance imaging (MRI) may reflect the degree of graft maturity and healing. However, how SNQ changes with graft remodelling and time and whether this change correlates with postoperative clinical outcomes after SCR remain unknown. This study aimed to explore the correlation between SNQ of the fascia lata autograft and clinical functional outcomes after SCR. Patients with irreparable posterosuperior rotator cuff tear undergoing SCR using fascia lata autograft between 2013 and 2017 were retrospectively analysed. For clinical outcomes, the American Shoulder and Elbow Surgeons (ASES) score, Constant-Murley score, Single Assessment Numeric Evaluation (SANE), and Visual Analogue Scale (VAS) for pain and range of motion (ROM; forward flexion and external rotation) were evaluated at postoperative 6 and 12months. Signal intensity of the humeral, mid-substance, and glenoid sites and background were measured to calculate the SNQ values on follow-up MRI at 3 and 12months. The correlations between clinical outcomes and SNQ at different time points were then analysed. A total of 15 patients were enrolled in the study. The mean postoperative VAS score significantly increased at postoperative 6months and significantly decreased at postoperative 12months. Except for forward flexion, all other functional outcomes were improved at postoperative 6months. Analysis of MRI showed SNQ at the humeral (SNQh), mid-substance, and glenoid sites decreased from postoperative 3to 12months with a statistical significance detected in SNQh (P < 0.01). Correlation analyses showed that the SNQh values negatively correlated with VAS, ASES, Constant-Murley score, SANE, ROM (forward flexion), and ROM (external rotation) (all P < 0.05). SNQ of the fascia lata autograft decreased with time in patients receiving SCR. SNQ at the humeral site was negatively correlated with clinical outcomes. III.

Tibial tunnel expansion does not correlate with four-strand graft maturation after ACL reconstruction using adjustable cortical suspensory fixation.

Anterior cruciate ligament reconstruction (ACLR) using a short, quadrupled semitendinosus (ST-4) autograft, fixed with an adjustable suspensory fixation (ASF), has several potential advantages. However, the construct is suspected to generate micromotion, tunnel widening and poor graft maturation. The aim of this study was to evaluate post-operative tibial tunnel expansion, graft maturation and clinical outcomes for this type of ACLR. One-hundred and forty-nine patients were reviewed at a minimum of 2 years following 4-ST ACLR, mean 25.6 ± 3.5months [24-55], with clinical follow-up and MRI scans. Graft maturity of the intra-articular part of the graft and the tibial tunnel portion was assessed using Signal-to-Noise Quotient (SNQ) and Howell score. Tibial tunnel expansion, bone-graft contact and graft volume in the tibial tunnel were calculated from the MRI scans. Mean tibial tunnel expansion was 13 ± 16.5% [12-122]. Mean SNQ for graft within the tibial tunnel was 3.8 ± 7.1 [ - 7.7 to 39] and 2.0 ± 3.5 [ - 14 to 17] for the intra-articular portion of the graft. The Howell score for graft within the tibial tunnel was 41% Grade I, 37% Grade 2, 20% Grade 3, 2% grade 4, and for the intra-articular part 61% Grade 1, 26% Grade 2, 13% Grade 3 and 1% Grade 4. The mean tibial tunnel bone-graft contact was 81 ± 23% [0-100] and mean graft volume was 80 ± 22% [0-100]. No correlation was found between tibial tunnel expansion and graft maturity assessed at both locations. Graft maturity was correlated with higher graft-bone contact and graft volume in the tibial tunnel (p < 0.05). ST-4 ACLR with ASF had low levels of tunnel enlargement at 2years. No correlation was found between graft maturation and tibial tunnel expansion. Graft maturity was correlated with graft-bone contact and graft volume in the tibial tunnel. Level III.

Transtibial pull-out repair of lateral meniscus posterior root is beneficial for graft maturation after anterior cruciate ligament reconstruction: a retrospective study

PurposeTo determine the repair of LMPR lesions would improve the ACL graft maturation.MethodA total of 49 patients underwent ACL reconstruction were included in this study. Patients were furtherly sub-grouped according to the status of LMPR: intact (17), repair (16) and resected (16). Assessments performed pre- and 2 years post-operatively included patients-reported scores and arthrometer side-to-side difference. Magnetic resonance imaging was used 2 years after the surgery to compare the lateral meniscal extrusion (LME), anterior tibial subluxation of the medial compartment (ATSMC), anterior tibial subluxation of the lateral compartment (ATSLC), the difference of ATSMC and ATSLC, and signal/noise quotient (SNQ) of ACL graft.ResultsIn LMPR resected group, it showed greater post-operative ATSMC-ATSLC difference when compared with pre-operatively (P = 0.006) and with the other 2 groups (intact: P = 0.031; repair: P = 0.048). SNQ of ACL graft was higher in LMPR resected group than those in LMPR intact (P = 0.004) and repair group (P = 0.002). The LMPR repair group showed significant reduction in LME post-operatively (P = 0.001). Post-operative measures on ATSLC-ATSMC difference (β = 0.304, P = 0.049) and LME (β = 0.492, P = 0.003) showed significant association with graft SNQ.ConclusionsTranstibial repair of LMPR concomitant with ACL reconstruction restored translational stability, reduced meniscus extrusion, making it beneficial for ACL graft maturation.

Randomized controlled trial of all-inside and standard single-bundle anterior cruciate ligament reconstruction with functional, MRI-based graft maturity and patient-reported outcome measures

BackgroundAll-inside anterior cruciate ligament reconstruction (ACLR) is a novel technique that has gained attention due to its minimally invasive and graft-saving properties. However, studies comparing MRI-based graft maturity between all-inside and standard ACLR are lacking.PurposeThis study focused on the functional, knee laxity, and MRI-based graft maturity characteristics of all-inside and standard single-bundle ACLR.Study DesignRandomized controlled trial (RCT).MethodsFifty-four patients were randomly assigned to an all-inside reconstruction group (n = 27) or standard reconstruction group (n = 27). Using the same rehabilitation strategy. The Tegner, International Knee Documentation Committee, and Lysholm scores were recorded at postoperative months 3, 6, and 12 to assess functional recovery. MRI was conducted to measure the signal/noise quotient (SNQ) of the intra-articular graft to assess the maturity. A higher SNQ indicates lower graft maturity. Knee laxity was assessed using GNRB arthrometer at the postoperative month 12.ResultsThe graft SNQ of the all-inside group was significantly higher than that of the standard group at postoperative month 6 (p < 0.05). There was no statistical difference in graft SNQ between the two groups at postoperative months 3 and 12 (p > 0.05). Both groups exhibited the highest SNQ in the middle region of the graft, followed by the proximal region, and the distal region. Functional scores improved significantly for both groups and had no statistical difference (p > 0.05). The knee laxity was higher in the all-inside group (p < 0.05) at postoperative month 12. There was no correlation between the functional scores and graft maturity in both groups (p > 0.05).ConclusionsAll-inside and standard single-bundle ACLR show good functional outcomes; however, knee laxity was relatively higher in the all-inside ACLR group than in the standard ACLR group. Moreover, both techniques exhibited poor maturity in the middle graft region and the best in the distal region. Graft maturity with all-inside ACLR is inferior to that with standard ACLR in the early postoperative stages. There is no correlation between knee function and graft maturity.Trial registrationClinical trial registration numbers: ChiCTR1800018543.Date of registration: 09/23/2018.

Sufficient MRI graft structural integrity at 9months after anterior cruciate ligament reconstruction with hamstring tendon autograft.

To assess the MRI-measured structural integrity of hamstring autograft at 9months after anterior cruciate ligament reconstruction (ACLR) surgery. A prospective cohort study was conducted including 34 patients (mean age 36.8 ± 11.8years; 73.5% males) who underwent ACLR with hamstring autograft. In addition, 36 patients (mean age 39.2 ± 10.5years; 69.4% males) without any ACL injury were also reviewed and served as control group. The primary outcome used for examining graft maturity at 9months after ACLR was the MRI-based signal-to-noise quotient (SNQ) of reconstructed ACL. SNQ values were stratified into 3 different categories: excellent: < 0.1; good: ≥ 0.1 and ≤ 0.19; fair: ≥ 0.2. The KT-1000 knee arthrometer was used to measure the side-to-side difference in the anterior tibial translation between the ACLR knee and the contralateral healthy knee in the ACLR group. Reconstructed ACLs were found with a mean SNQ of 0.078 ± 0.061, while almost all ACL-reconstructed patients (97%; 33 out of 34) were found with excellent or good SNQ values (< 0.019). The mean KT-1000 in the ACLR group was 0.071mm ± 0.926mm, while there were no patients in the ACLR cohort with a KT-1000 value > 3mm. The mean 9-months MRI-based SNQ of ACLR group was significantly higher compared to the mean MRI-based SNQ of the control group (p < 0.001). Multiple regression analysis showed no correlation between SNQ and age, gender, time from injury to ACLR, graft size, or simultaneous treatment of additional intra-articular knee lesions. In this cohort of 34 ACL-reconstructed patients, 97% of hamstring tendon autografts demonstrated excellent/good MRI signal intensity and excellent functional results (KT-1000 < 3mm) at 9months after surgery. Based on this finding, it is suggested that return to sports after ACLR with hamstring autograft can be considered safe at 9months post surgery. Furthermore, while structural integrity of the graft has been achieved at this time point, statistical differences found in SNQ values of ACL-reconstructed patients compared to ACLs of healthy individuals highlight the continuing process of graft maturation and remodelling. Level III.

Remnant preservation with tensioning can improve the clinical outcome after anterior cruciate ligament reconstruction.

Many studies exist about remnant preservation in anterior cruciate ligament (ACL) reconstruction. However, concern remains for development of a cyclops lesion during remnant preservation. To prevent this, a tensioning method has been suggested. Current study evaluated the clinical and radiologic results of remnant preservation in ACL reconstruction with tensioning compared to classical ACL reconstruction. From January 2016 to June 2017, ACL reconstruction patients who underwent magnetic resonance imaging (MRI) 2 years postoperatively were enrolled. For comparison, all participants were divided in two groups: remnant preservation with tensioning (group R) and controls (group C). Clinically, Hospital for Special Surgery (HSS), International Knee Documentation Committee (IKDC), Lysholm scores, and incidence of symptomatic cyclops lesions were evaluated. Radiologically, signal-to-noise quotient (SNQ) and size of the synovium on MRI as well as anterior instability in Telos stress radiographs were evaluated. A total of 64 patients were enrolled (42 in group R and 22 in group C). The IKDC score in group R (70) was better than that in group C (62; p < 0.05). One patient in group R had a cyclops lesion with clinical symptoms and arthroscopic excision was recommended. Radiologically, the SNQ, synovium area, and anterior instability on Telos radiography showed no difference between the two groups. Remnant preservation with tensioning is a good option for ACL reconstruction without the development of a cyclops lesion.

Suture du LCA : comparaison avec la reconstruction du LCA avec évaluation par IRM

The aim of this study is to compare the healing of a repaired ACL and the healing of a reconstructed ACL as evaluated by 1.5 T MRI at 1-year follow-up. A total of 60 patients who underwent early ACL surgery (injury- surgery interval < 14 days) were prospectively enrolled. Patients with proximal ACL tears (type I and type II with good tissue quality according to Sherman classification) underwent primary ACL repair (ACLRep) with trans-osseus pullout technique. Patients with type III and IV and a fair tissue quality underwent ACL reconstruction (ACLRec) with doubled gracilis and semitendinosus tendons (DGST) graft. A total of 30 patients underwent ACL repair and 30 underwent ACLR. There were 18 males and 12 females in the repair group and 16 males and 14 females in the reconstruction group. The two groups showed no demographic differences. Two criteria have been used to evaluate graft incorporation at MRI : signal-to-noise quotient (SNQ) and graft maturity (water content of the graft based on the Howell scale). 1.5 T MRI was used to evaluate graft status and graft integration at 1-year post-operatively using the following parameters: signal-to-noise quotient (SNQ), and ligament signal determined using the Howell scale. Radiological parameters were evaluated by an expert radiologist and an orthopedic surgeon and Chronbac's Alpha was made to assess inter observer (0,86) and intraobserver (0,82) reliability. There were no significant differences in demographics between groups. The mean signal-to-noise quotient (SNQ) was 2.21 for ACLrep and 2.52 for ACLrec ( p = 0.266). The unilateral 95% CI for SNQ in ACLrep was 2,21 (to 3,08) (< to 4,21 limit for noninferiority) and ACLrec was 2,52 (to 3,12), p = 0,128. Hence, there are non-statistically differences between the two groups according to the SNQ and the noninferiority was proven. One year post-operatively the MRI appearance of a repaired ACL showed non-inferior maturation compared with a reconstructed ACL.

Bone-patellar tendon-bone autograft maturation is superior to double-bundle hamstring tendon autograft maturation following anatomical anterior cruciate ligament reconstruction.

The primary purpose of this study was to evaluate the second-look arthroscopic findings 1year postoperatively and magnetic resonance imaging (MRI) findings 2years after anterior cruciate ligament reconstruction (ACLR) using bone-patellar tendon-bone autograft (BTB) or hamstring tendon autograft (HT). Secondary purpose included clinical results from physical examination, including range of motion, Lachman test, pivot shift test, and knee anterior laxity evaluation, and the clinical score for subjective evaluations at 2years after surgery. Between 2015 and 2018, 75 patients with primary ACL injuries were divided into either the BTB group (n = 30) or HT group (n = 45). When using HT, an anatomical double-bundle ACLR was performed. BTB was indicated for athletes with sufficient motivation to return to sporting activity. Graft maturation on second-look arthroscopy was scored in terms of synovial coverage and revascularization. All participants underwent postoperative MRI evaluation 2years postoperatively. The signal intensity (SI) characteristics of the reconstructed graft were evaluated using oblique axial proton density-weighted MR imaging (PDWI) perpendicular to the grafts. The signal/noise quotient (SNQ) was calculated to quantitatively determine the normalized SI. For clinical evaluation, the Lachman test, pivot shift test, KT-2000 evaluation, Lysholm score, and Knee injury and Osteoarthritis Outcome Score (KOOS) were used. Arthroscopic findings showed that the graft maturation score in the BTB group (3.6 ± 0.7) was significantly greater than that in the anteromedial bundle (AMB; 2.9 ± 0.2, p = 0.02) and posterolateral bundle (PLB; 2.0 ± 0.9, p = 0.001) in the HT group. The mean MRI-SNQs were as follows: BTB, 2.3 ± 0.5; AMB, 2.9 ± 0.9; and PLB, 4.1 ± 1.1. There were significant differences between BTB, AMB, and PLB (BTB and AMB: p = 0.04, BTB and PLB: p = 0.003, AMB and PLB: p = 0.03). Second-look arthroscopic maturation score and MRI-SNQ value significantly correlated for BTB, AMB, and PLB. No significant differences were detected in clinical scores. There was a significant difference (p = 0.02) in the knee laxity evaluation (BTB: 0.9 ± 1.1mm; HT: 2.0 ± 1.9mm). BTB maturation is superior to that of double-bundle HT based on morphological and MRI evaluations following anatomical ACLR, although no significant differences were found in clinical scores. Regarding clinical relevance, the advantages of BTB may help clinicians decide on using the autograft option for athletes with higher motivation to return to sporting activity because significant differences were observed in morphological evaluation, MRI assessment, and knee anterior laxity evaluation between BTB and double-bundle HT. Level IV.

Two-year postoperative MRI appearances of anterior cruciate ligament hamstrings autografts are not correlated with functional outcomes, anterior laxity, or patient age.

AimsMRI has been suggested as an objective method of assessing anterior crucate ligament (ACL) graft “ligamentization” after reconstruction. It has been proposed that the MRI appearances could be used as an indicator of graft maturity and used as part of a return-to-sport assessment. The aim of this study was to evaluate the correlation between MRI graft signal and postoperative functional scores, anterior knee laxity, and patient age at operation.MethodsA consecutive cohort of 149 patients who had undergone semitendinosus autograft ACL reconstruction, using femoral and tibial adjustable loop fixations, were evaluated retrospectively postoperatively at two years. All underwent MRI analysis of the ACL graft, performed using signal-to-noise quotient (SNQ) and the Howell score. Functional outcome scores (Lysholm, Tegner, International Knee Documentation Committee (IKDC) subjective, and IKDC objective) were obtained and all patients underwent instrumented side-to-side anterior laxity differential laxity testing.ResultsTwo-year postoperative mean outcome scores were: Tegner 6.5 (2 to 10); Lysholm 89.8 (SD 10.4; 52 to 100); and IKDC subjective 86.8 (SD 11.8; 51 to 100). The objective IKDC score was 86% A (128 patients), 13% B (19 patients), and 1% C (two patients). Mean side-to-side anterior laxity difference (134 N force) was 0.6 mm (SD 1.8; -4.1 to 5.6). Mean graft SNQ was 2.0 (SD 3.5; -14 to 17). Graft Howell scores were I (61%, 91 patients), II (25%, 37 patients), III (13%, 19 patients), and IV (1%, two patients). There was no correlation between either Howell score or SNQ with instrumented anterior or Lysholm, Tegner, and IKDC scores, nor was any correlation found between patient age and ACL graft SNQ or Howell score.ConclusionThe two-year postoperative MRI appearances of four-strand, semitendinosus ACL autografts (as measured by SNQ and Howell score) do not appear to have a relationship with postoperative functional scores, instrumented anterior laxity, or patient age at surgery. Other tools for analysis of graft maturity should be developed.Cite this article: Bone Jt Open 2021;2(8):569–575.

Tibial slope, remnant preservation, and graft size are the most important factors affecting graft healing after ACL reconstruction.

The aim of this study was to determine the anatomic, operative and biological factors that influenced graft healing after single-bundle anterior cruciate ligament (ACL) reconstruction. One hundred fourteen consecutive patients who underwent anatomic single-bundle ACL reconstruction with quadrupled hamstring tendon autografts between 2016 and 2019 were retrospectively analyzed. Ninety-four patients met the inclusion criteria with minimum follow-up of 12months. Patients were evaluated with multiple clinical measurements, including International Knee Documentation Committee Subjective Knee Form (IKDC-SKF), Lyshom Scores, and Marx activity scale. To evaluate graft healing, the signal-to-noise quotient (SNQ) was measured at intra-articular graft and intra-tunnel integration were evaluated on magnetic resonance imaging (MRI) at one year after surgery. Potential factors affecting graft healing, including age, sex, body mass index, time from injury to surgery, posterior tibial slope, lateral femoral condyle ratio, notch width index, meniscal injury, remnant preservation, tunnel aperture locations, graft size, graft bending angle, graft/remaining notch volume ratio were evaluated for their association with graft SNQ value by stepwise regression analysis. A total of 94 patients were evaluated with mean follow-up 28.5 ± 9months. Univariate regression analysis showed that posterior tibial slope, notch width index, remnant preserving procedure, high femoral tunnel, anterior tibial tunnel, graft bending angle, and graft/remaining notch volume ratio significantly associated with graft SNQ values. Multivariate regression analysis showed that lateral tibial slope, remnant preservation, and graft/remaining notch volume ratio were independent factors correlated with graft SNQ values. Also, the graft SNQ values was weakly correlated with femoral tunnel integration and Marx activity scale at one year. There was no correlation between graft SNQ values and IKDC-SKF and Lysholm scores. There was no correlation between graft SNQ values and International Knee Documentation Committee and Lysholm scores. Tibial slope, remnant preservation and graft/remaining notch volume ratio were significant independent associated factors of graft SNQ value at one year. The graft SNQ values were also weakly correlated with femoral tunnel integration and the Marx activity scale. These factors should be taken into account for ensuring the ideal graft healing and for the return to sport decision-making. Level IV.

Effect of Modified Lemaire Anterolateral Extra-articular Tenodesis on the Magnetic Resonance Imaging Maturity Signal of Anterior Cruciate Ligament Hamstring Graft

Background: Lateral extra-articular tenodesis (LET) is one of the most widely used procedures to restore anterolateral stability. Clinical outcomes after the addition of LET to anterior cruciate ligament (ACL) reconstruction (ACLR) have been widely investigated; however, the potential influence of LET on the ACL ligamentization process has not been examined. Purpose/Hypothesis: The purpose was to use 10-month postoperative magnetic resonance imaging (MRI) scans to determine whether the maturity of grafts after hamstring autograft ACLR was affected by concomitant LET. The hypothesis was that when modified Lemaire lateral extra-articular tenodesis (MLLET) was performed, the MRI parameters of ACL graft maturity would be modified. Study Design: Cohort study; Level of evidence, 3. Methods: The study included patients treated between December 2017 and December 2018 who had undergone anatomic 3-strand hamstring tendon autograft ACLR, with or without concomitant MLLET, and had undergone MRI 10 months postoperatively. Thus, the study included 30 patients who had isolated ACLR and 22 patients who had ACLR plus MLLET. The 2 groups were comparable based on all criteria analyzed. To evaluate graft maturity, the signal-to-noise quotient (SNQ) was measured in 3 regions of interest of the proximal, midsubstance, and distal ACL graft. Lower SNQ ratios indicate less water content and, theoretically, better maturity and healing of the graft. Results: The mean ± SD for SNQ was 4.62 ± 4.29 (range, 3.12-6.19) in the isolated ACLR group and 7.59 ± 4.68 (range, 4.38-8.04) in the ACLR plus MLLET group (P = .012). Upon comparing the mean values of the 3 portions between the 2 groups, we found a significant difference between the 2 groups for the proximal and middle portions (P = .007 and P = .049, respectively) but no difference in the distal portion (P = .369). Conclusion: At the 10-month follow-up, hamstring tendon autografts for anatomic ACLR with MLLET did not show the same MRI signal intensity compared with isolated hamstring anatomic ACLR.

Correlation between graft maturity and knee function after anterior cruciate ligament reconstruction

To investigate the correlation between graft maturity and knee function after anterior cruciate ligament (ACL) reconstruction. A total of 50 patients who underwent ACL reconstruction with autologous tendons between August 2016 and August 2018 were included in the study. There were 28 males and 22 females, with an average age of 31.0 years (range, 18-50 years). At 6 months and 2 years after operation, the signal to noise quotient (SNQ) values of tibial and femoral ends of graft were measured by MRI, and the mean value was taken as the SNQ value of graft. The function of knee joint was evaluated by Tegner, Lysholm, and International Knee Documentation Committee (IKDC) scores. The differences in SNQ values between tibial and femoral ends were analyzed at 6 months and 2 years after operation. The correlation between SNQ value at 6 months after operation and knee function score at 2 years after operation was analyzed. According to SNQ value at 6 months after operation, the patients were divided into group A (SNQ value≥12) and group B (SNQ value<12) and the correlation between SNQ value and knee function score was further analyzed. All incisions healed primarily without infection or injury of blood vessels and nerves. All patients were followed up 24-28 months (mean, 26.6 months). The IKDC, Lysholm, and Tegner scores at 6 months and 2 years after operation were significantly higher than those before operation ( P<0.05), and all scores at 2 years after operation were also significantly higher than those at 6 months ( P<0.05). The SNQ values at 6 months and 2 years after operation were 12.517±6.272 and 10.900±6.012, respectively, and the difference was significant ( t=1.838, P=0.007). The SNQ values of graft at 6 months after operation were significantly different from those at 2 years after operation ( P<0.05), and the SNQ values of tibial and femoral ends of graft at the same time point were significantly different ( P<0.05). The SNQ value of 50 patients at 6 months after operation was negatively correlated with Lysholm, IKDC, and Tegner scores at 2 years after operation ( r=-0.965, P=0.000; r=-0.896, P=0.000; r=-0.475, P=0.003). The patients were divided into groups A and B according to the SNQ value, each with 25 cases; the SNQ values of the two groups at 6 months after operation were negatively correlated with Lysholm, IKDC, and Tegner scores at 2 years after operation ( P<0.05). After ACL reconstruction, the knee function scores and graft maturity of patients gradually improved. The lower the SNQ value in the early stage, the higher the knee function score in the later stage. The SNQ value of MRI in the early stage after ACL reconstruction can predict the knee function in the later stage.

Evaluation of ACL Graft Remodeling and Prediction of Graft Insufficiency in Sequenced MRI—Two-Year Follow-Up

Background: Postoperative magnetic resonance imaging (MRI) evaluation of anterior cruciate ligament (ACL) graft maturity is a useful and practical tool that allows for assessment of graft status and remodeling stage. The purpose of this study was to evaluate and compare previously described methods of graft evaluation in MRI. We identify factors influencing the maturation and correlating graft appearance in MRI with indirect symptoms of graft insufficiency to identify patients at risk. Methods: Retrospective evaluation was performed in 44 patients who received bone patellar tendon bone (BPTB) ACL reconstruction with nine consecutive postoperative MRIs at 2, 6, 12, 18, 24, 36, 48, 72, and 96 weeks. Graft status was evaluated using signal-to-noise quotient (SNQ) methods in both sagittal and axial planes. We also assessed the homogeneity of the graft by standard deviation (SD) of signal intensity. SNQ was correlated with patient’s age, sex, postoperative weight-bearing, as well as indirect signs of graft insufficiency by MRI including graft appearance, posterior cruciate ligament (PCL) buckling, and measurement of anterior tibia subluxation. Results: We observed that the results of modelling SNQs from both sagittal and axial planes were similar. For both SNQs, the change over weeks quotient was nonlinear where the clinical parameter increased at week 36 and subsequently decreased. The SNQ at week 96 does not reach the levels from week 2. We observed that the model incorporating SNQ and relative SD (rSD) in the sagittal plane predicted the tibia anterior subluxation proportions better than the model with clinical parameters measured in the axial plane. Our results demonstrate that greater SD is associated with less graft homogeneity, which could indicate that this model is a good predictor of graft insufficiency. In addition, the proportion of PCL buckling increased over the course of the study. Conclusions: MRI graft evaluation is very useful for assessing graft ligamentization stage and to predict graft insufficiency.