Correlation Analysis of Magnetic Resonance Imaging-Based Graft Maturity and Outcomes After Anterior Cruciate Ligament Reconstruction Using International Knee Documentation Committee Score

Which technique provides more benefits in return to sports and clinical outcomes after anterior cruciate ligament reconstruction: Double-bundle or single-bundle? A randomized controlled study

BACKGROUND

The achievement of an optimal return to sport (RTS) has remained a key goal after sports-related injuries, with the ongoing debate on the effectiveness of different surgical approaches for anterior cruciate ligament (ACL) rupture. This study aims to assess clinical outcomes and RTS across various surgical methods, such as anatomical single-bundle reconstruction (ASBR), central-axial single-bundle reconstruction (CASBR), and double-bundle reconstruction (DBR).

METHODS

A randomized clinical trial was conducted, comprising 191 patients who underwent ACL rupture. These patients were divided into three groups based on the ACL reconstruction techniques they received (ASBR, CASBR, DBR). Over the 2-year follow-up period, the study assessed RTS through four single-hop tests, isokinetic extension tests, and limb asymmetry indices. Postoperative graft status was determined using the signal-to-noise quotient (SNQ), while knee function was evaluated using the International Knee Documentation Committee 2000 (IKDC-2000) score, Lysholm score, Tegner score, and degree of knee laxity. A binary logistic regression model was developed to forecast the factors influencing ideal RTS.

RESULTS

DBR (67.63%) and CASBR (58.00%) exhibited higher RTS passing rates compared to ASBR (30.39%; χ2 = 19.57, P <0.05). Quadriceps strength symmetry in the lower limbs was identified as the key determinant of RTS (χ2 = 17.08, P <0.05). The RTS rate was influenced by SNQs of the graft's tibial site (odds ratio: 0.544) and quadriceps strength of the reconstructed knee joint at 60°/s (odds ratio: 6.346). Notably, the DBR group showed enhanced knee stability, evidenced by superior results in the Lachman test (χ2 = 13.49, P <0.01), objective IKDC-2000 (χ2 = 27.02, P = 0.002), and anterior instability test (χ2 = 9.46, P <0.01). Furthermore, DBR demonstrated superior clinical outcomes based on the Lysholm score (DBR: 89.57 ± 7.72, CASBR: 83.00 ± 12.71, ASBR: 83.21 ± 11.95; F = 10.452, P <0.01) and IKDC-2000 score (DBR: 90.95 ± 7.00, CASBR: 84.64 ± 12.68, ASBR: 83.63 ± 11.41; F = 11.78, P <0.01).

CONCLUSION

For patients with ACL rupture, more ideal RTS rate and clinical outcomes were shown in the DBR group than in the ASBR and CASBR groups. Autograft status and quadriceps strength are postively related to RTS.

TRIAL REGISTRATION

ClinicalTrials.gov (NCT05400460).

Proximally positioned femoral grafts decrease passive anterior tibial subluxation in anterior cruciate ligament reconstruction using a posterior trans-septal portal

PURPOSE

To compare the anterior and posterior trans-septal (TS) portal approaches in anterior cruciate ligament reconstruction (ACLR) by evaluating femoral tunnel positioning and passive anterior tibial subluxation (PATS).

METHODS

A total of 205 patients who underwent primary ACLR using the outside-in technique between March 2018 and December 2021 were retrospectively enrolled. Patients were classified into two groups based on the viewing techniques: the anterior group was treated using anteromedial or anterolateral portals (n = 155), and the TS group was treated using posterior TS portal (n = 55). The relative locations of the femoral tunnel were evaluated using the deep-shallow planes (X-axis) and superior-inferior planes (Y-axis) with the quadrant method in the lateral femoral condyle on a 3-dimensional computed tomography image. Anterior tibial subluxation for the lateral and medial compartments relative to the femoral condyles was evaluated as measured on magnetic resonance imaging. Knee laxity was assessed using the pivot-shift test and stress radiography.

RESULTS

In the posterior TS group, the femoral tunnel was usually located deeper on the X-axis and more superior on the Y-axis, which corresponds to a more proximal position, than in the anterior group (deeper on the X-axis and superior on the Y-axis). Moreover, the femoral tunnel locations in this group were more compactly distributed than those in the anterior group. The TS group showed significantly better reduction of postoperative PATS in the lateral compartments than the anterior group (anterior group vs. TS group: lateral compartment, 3.2 ± 3.1 vs. 4.5 ± 3.2 mm; p = .016). Significantly better results were found in the TS group for knee stability as assessed by the pivot-shift grade (p = .044); however, there were no significant differences between the two groups with respect to patient-reported outcome measures (p > .05) and other complications (p = .090).

CONCLUSION

Our results suggest that positioning the femoral tunnel using the posterior TS portal approach may lead to better outcomes in terms of PATS and rotational stability compared to the anterior portal approach in ACLR.

Periosteal wrapping of the hamstring tendon autograft improves graft healing and prevents tunnel widening after anterior cruciate ligament anatomic reconstruction

INTRODUCTION

The periosteum is a readily available tissue at the hamstring harvest site that could be utilized to enhance graft healing and prevent tunnel widening without additional cost or morbidity. This study aimed to compare graft healing using magnetic resonance imaging (MRI) and functional clinical outcome scores in a matched cohort of patients who underwent anterior cruciate ligament (ACL) reconstruction with hamstring autografts with or without periosteal augmentation.

MATERIAL AND METHODS

Forty-eight patients who underwent ACL reconstruction (ACLR) were prospectively enrolled: 25 with standard ACLR (ST-ACLR) and 23 with periosteal augmented grafts (PA-ACLR). The same surgical techniques, fixation methods, and postoperative protocol were used in both groups. Signal-to-noise quotient (SNQ), graft healing at the bone-graft interface, graft signal according to the Howell scale, and femoral tunnel widening were evaluated using MRI after 1 year of follow-up. International knee documentation score (IKDC), Lysholm, Tegner activity scale, and visual analog scale for pain were used for functional evaluation at a minimum of 2 years postoperative.

RESULTS

The mean SNQ of the proximal part of the graft was 9.6 ± 9.2 and 2.9 ± 3.3 for the ST-ACLR and PA-ACLR groups, respectively (P = 0.005). The mean femoral tunnel widening was 30.3% ± 18.3 and 2.3% ± 9.9 for the ST-ACLR, PA-ACLR groups, respectively (P < 0.001). Complete graft tunnel healing was observed in 65% and 28% of cases in the PA-ACLR and ST-ACLR groups, respectively. Both groups showed marked improvements in functional scores, with no statistically significant differences.

CONCLUSION

Periosteal wrapping of hamstring tendon autografts is associated with better graft healing and maturation and lower incidence of femoral tunnel widening based on MRI analysis 1 year after ACL reconstruction. However, patient-reported outcomes and measured laxity were similar between the two groups at 2 years follow up.

TRIAL REGISTRATION

Trail registration number: PACTR202308594339018, date of registration: 1/5/2023, retrospectively registered at the Pan African Clinical Trial Registry (pactr.samrc.ac.za) database.

Association of Graft Maturity on MRI With Return to Sports at 9 Months After Primary Single-Bundle ACL Reconstruction With Autologous Hamstring Graft

Background

The relationship between graft maturity on magnetic resonance imaging (MRI) and return to sports (RTS) after anterior cruciate ligament (ACL) reconstruction is unclear.

Purpose

To compare signal-to-noise quotient (SNQ) values and ACL graft T2* (gradient echo) values between patients who did RTS and those who did not RTS (NRTS) after ACL reconstruction and to evaluate the predictive value of T2* mapping for RTS after ACL reconstruction.

Study Design

Case-control study; Level of evidence, 3.

Methods

At a minimum of 9 months after arthroscopic single-bundle ACL reconstruction with autologous hamstring tendon graft, 82 patients underwent RTS assessment as well as MRI evaluation. The patients were classified into RTS (n = 53) and NRTS (n = 29) groups based on the results of the assessment. The SNQ values in the proximal, middle, and distal regions of the graft and the T2* values of the graft were measured on MRI. The correlation between T2* values and RTS was assessed using Spearman correlation analysis. Receiver operating characteristic curves were constructed to compare the diagnostic performance, and the optimal T2* cutoff value for detecting RTS was determined based on the maximum Youden index.

Results

At 9 months after ACL reconstruction, the proximal, middle, and mean SNQ values in the RTS group were significantly lower than those in the NRTS group (proximal: 17.15 ± 4.85 vs 19.55 ± 5.05, P = .038; middle: 13.45 ± 5.15 vs. 17.75 ± 5.75, P = .001; mean: 12.37 ± 2.74 vs 15.07 ± 3.32, P < .001). The T2* values were lower in the RTS group (14.92 ± 2.28 vs 17.69 ± 2.48; P < .001) and were correlated with RTS (r = -0.41; P = .02). The area under the curve of T2* was 0.79 (95% CI, 0.75-0.83), and the optimal cutoff value for T2* was 16.65, with a sensitivity and specificity for predicting failure to RTS of 67.9% and 88.2%, respectively.

Conclusion

Study findings indicated that the SNQs (mean, proximal, and middle) and the T2* values of the graft in the RTS group were significantly lower than those in NRTS group. A T2* value of 16.65 was calculated to predict patients who failed RTS tests with a sensitivity of 67.9% and specificity of 88.2%.

MRI Assessment of Tendon Graft After Lateral Ankle Ligament Reconstruction: Does Ligamentization Exist?

BACKGROUND

No description exists in the literature about the normal evolution of tendon graft after a lateral ankle ligament (LAL) reconstruction.

PURPOSE

To assess the magnetic resonance imaging (MRI) characteristics and the evolution of the tendon graft during different moments in the follow-up after an endoscopic reconstruction of the LAL.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

This prospective study included 37 consecutive patients who underwent an endoscopic reconstruction of the LAL with an autograft using the gracilis tendon to treat chronic ankle instability (CAI) resistant to nonoperative treatment (CAI group) and 16 patients without ankle instability (control group). All patients in the CAI group underwent a postoperative assessment at 6, 12, and 24 months using the Karlsson score and MRI examination. Only patients with good and excellent results were included in the study. Graft assessment consisted of qualitative measurements and quantitative evaluations of the reconstructed anterior talofibular ligament (RATFL) and reconstructed calcaneofibular ligament (RCFL), including signal-to-noise quotient (SNQ) and contrast-to-noise quotient (CNQ) measurements in proton density-fat suppressed (PD-FS) and T1-weighted sequences. The analysis of variance test was used to compare the SNQ and the CNQ at different time points for each sequence.

RESULTS

The MRI signal at 6 months was increased compared with that of the control group. Next, a significant signal decrease from 6 to 24 months was noted on PD-FS and T1-weighted images. SNQ measurements on PD-FS weighted images for both the RATFL and the RCFL demonstrated a significantly higher signal (P < .01 and P = .01, respectively) at 6 months compared with that of the control group. Subsequently, the signal decreased from 6 to 24 months. Similarly, CNQ measurements on PD-FS weighted images for both the RATFL and the RCFL demonstrated a significantly higher signal (P < .01 and P < .01, respectively) at 6 months compared with that of the control group. Subsequently, the signal decreased from 6 to 24 months.

CONCLUSION

The present study demonstrated an evolution of the MRI characteristics, suggesting a process of graft maturation toward ligamentization. This is important for clinical practice, as it suggests an evolution in graft properties and supports the possibility of creating a viable ligament.

Combined Anterior Cruciate Ligament and Anterolateral Ligament Reconstruction Decreases Passive Anterior Tibial Subluxation Compared With Isolated Anterior Cruciate Ligament Reconstruction Despite Similar Rotational Stability and Clinical Outcomes

PURPOSE

To analyze the effect of augmenting a hamstring autograft anterior cruciate ligament reconstruction (ACLR) with an anterolateral ligament reconstruction (ALLR) on a primary outcome of passive anterior tibial subluxation (PATS) and a secondary outcome of the clinical outcomes.

METHODS

ACL-injured patients who underwent primary ACLR between March 2014 and February 2020 at our center were enrolled. Patients who underwent combined procedures (ACLR + ALLR) were matched in a 1:1 propensity ratio to patients who underwent ACLR only. We evaluated PATS, knee stability (side-to-side laxity difference, pivot-shift test), and patient-reported outcome measures (PROMs) after the procedure and documented complications.

RESULTS

From an initial cohort of 252 patients with a minimum follow-up period of 2 years (48.4 ± 16.6 months), 35 matched pairs were included, and 17 patients (48.6%) in each group underwent second-look arthroscopy. The combined ACLR + ALLR group showed significantly better improvement of PATS in the lateral compartments than the isolated ACLR group (P = .034). There were no significant differences between the groups regarding knee stability (side-to-side laxity difference, pivot-shift test), PROMs, complications, and second-look arthroscopic findings (all P > .05). Moreover, the proportions of patients who achieved the minimal clinically important difference in PROMs were not different between groups.

CONCLUSIONS

The combined ACLR + ALLR procedure was associated with a mean improvement in anterior tibial subluxation for the lateral compartment that was 1.2 mm better than an isolated ACLR procedure, despite its lack of clinical significance.

LEVEL OF EVIDENCE

Level III, cohort study.

Adaptation of the Signal Noise Quotient MRI classification for graft ligamentization analysis following ATFL and CFL anatomical reconstruction: Validation of the SNQA

BACKGROUND

Chronic ankle instability is the most frequent clinical sign of an antero tibiofibular (ATFL) and/or calcaneo fibular ligament (CFL) tear. One common surgical technique is to use the distal tendon of the gracilis muscle to reconstruct both the ATFL and CFL. In the knee, the hamstring tendons used in anterior cruciate ligament (ACL) reconstruction may go through structural modifications called "ligamentization ". A noninvasive MRI technique has been developed using the Signal/Noise Quotient to compare the signal of the graft following reconstruction to that of the posterior cruciate ligament. To our knowledge no studies have ever evaluated radiographic changes in the graft over time. The main goal of this study was to develop a specific MRI protocol to evaluate graft remodeling following ATFL and CFL reconstruction over time.

METHODS

A prospective study of the changes in the MRI signal of the ATFL-CFL graft 3-months postoperatively was performed in 20 patients. The main outcome was a comparison of the graft signal to that of the peroneal fibular tendon and the surrounding noise to determine the Ankle SNQ (SNQA). MRI images were evaluated by two senior radiologists to assess inter-rater reliability and then 2 weeks later for the intra-rater reproducibility.

RESULTS

The intraclass correlation (ICC) showed excellent inter- and intra rater reliability for the ATFL SNQA (0.96 and 0.91, respectively); and for the CFL SNQA, the ICC was 0.97 and 0.99, respectively. Bland-Altman analysis showed very limited bias in the interpretation of SNQA.

CONCLUSION

This preliminary study confirmed the inter- and intra- rater reliability of a new tool using the SNQA.

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

Background

All-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.

Purpose

This study focused on the functional, knee laxity, and MRI-based graft maturity characteristics of all-inside and standard single-bundle ACLR.

Study Design

Randomized controlled trial (RCT).

Methods

Fifty-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.

Results

The 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).

Conclusions

All-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 registration

Clinical trial registration numbers: ChiCTR1800018543.

Date of registration: 09/23/2018.

Different timing in allograft and autograft maturation after primary anterior cruciate ligament reconstruction does not influence the clinical outcome at mid-long-term follow-up

PURPOSE

The use of allografts in primary anterior cruciate ligament reconstruction (ACLR) is increasing although they are still supposed to be associated to greater risk of re-rupture due to a slower and less efficient graft maturation. The aim of this prospective randomized controlled study was to compare the graft maturation after ACLR with allograft and autograft by MRI at 6- and 12-month follow-up and integrate these data with the functional and clinical results observed at 6-, 12- and 60-month follow-up.

METHODS

Fifty patients with indication to primary ACLR were randomly and equally divided into hamstring autograft or allograft tendon groups. The graft maturation was measured at 6- and 12-month follow-up by the SNQ score and other radiological parameters on MRI scans. Clinical and functional recovery was evaluated by Lysholm score, Visual Analogues Scale, Tegner activity scale and modified Cincinnati knee rating system at 6, 12 and 60 months after surgery to estimate the predictive value of the radiological parameters for clinical outcomes. Return-to-sport (ACL-RSI) was measured 60 months after surgery.

RESULTS

Three patients had retear of the neo-ligament (two from Auto group and one from Allo group). All the clinical/functional parameters significantly improved over time, with no statistically significant difference between the groups. At 6 months, the SNQ value was significantly higher in the Auto than in the Allo group (12.9 vs 7.9, p = 0.038), but at 12 months they were comparable (9.8 vs 10.4). The 6-month SNQ values did not correlate with the clinical scores, whereas the 12-month SNQ values significantly correlated with the Cincinnati score, Lysholm score and Tegner activity scale collected at 60-month follow-up.

CONCLUSION

No clinical or functional differences have been found between the two treatment groups, supporting the suitability of using allograft in primary ACLR, when available. The results at MRI scans showed a different graft maturation trend in the two groups, with allografts being more reactive in the first 6 months. MRI together with the subjective evaluation allows to evaluate objectively the status of the neo-ligamentization process and therefore helps the surgeon to dictate the individual time for return-to-sport.

LEVEL OF EVIDENCE

Level I.

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

Aims

MRI 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.

Methods

A 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.

Results

Two-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.

Conclusion

The 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.

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

OBJECTIVE

To investigate the correlation between graft maturity and knee function after anterior cruciate ligament (ACL) reconstruction.

METHODS

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.

RESULTS

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).

CONCLUSION

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.

Influence of Posterior Tibial Slope on Clinical Outcomes and Survivorship After Anterior Cruciate Ligament Reconstruction Using Hamstring Autografts: A Minimum of 10-Year Follow-Up

PURPOSE

To investigate the influence of medial and lateral posterior tibial slope (PTS) on long-term clinical outcomes and survivorship after anterior cruciate ligament (ACL) reconstruction using hamstring autografts.

METHODS

A total of 232 patients (mean age, 28.2 ± 8.9 years) who underwent primary ACL reconstruction from October 2002 to July 2007 were retrospectively reviewed. Patients with multiple ligament reconstruction, total meniscectomy, contralateral knee surgery before ACL reconstruction, open growth plate, and less than 10-year follow-up were excluded in the study. The medial and lateral PTS were measured from preoperative magnetic resonance imaging. Based on Li et al.'s previous study, the patients were divided into 2 groups according to their medial PTS (≤5.6° vs >5.6°) and lateral PTS (≤3.8° vs >3.8°), respectively. Clinical outcomes (clinical scores, stability tests and failure rate) were compared between the groups at the last follow-up. Furthermore, survival analysis was performed using the Kaplan-Meier method.

RESULTS

All clinical scores (International Knee Documentation Committee subjective, Lysholm, and Tegner activity scores) and stability tests (physical examinations and side-to-side difference in Telos stress radiographs) were insignificantly different between the 2 groups classified based on medial or lateral PTS. However, the failure rate was significantly higher in patients with medial PTS >5.6° (16.1% vs 5.1%, P = .01) or lateral PTS >3.8° (14.5% vs 4.7%; P = .01). The odds ratios of graft failure due to increased medial and lateral PTS were 3.18 (95% confidence interval, 1.22-8.28; P = .02) and 3.43 (95% confidence interval, 1.29-9.09; P = .01), respectively. In addition, the 10-year survivorship was significantly lower in patients with medial PTS >5.6° (83.9% vs 94.9%, P = .01) or lateral PTS >3.8° (85.5% vs 96.0%; P = .01).

CONCLUSIONS

Increased medial (>5.6°) and lateral (>3.8°) PTS were associated with higher failure rate and lower survivorship at a minimum of 10-year follow-up after primary ACL reconstruction using hamstring autografts.

LEVEL OF EVIDENCE

Level III, retrospective comparative trial.

Clinical Outcomes and the Failure Rate of Revision Anterior Cruciate Ligament Reconstruction Were Comparable Between Patients Younger Than 40 Years and Patients Older Than 40 Years: A Minimum 2-Year Follow-Up Study

PURPOSE

To compare the clinical outcomes and failure rates of revision anterior cruciate ligament reconstruction (ACLR) between young and middle-aged surgery patients.

METHODS

Patients who underwent revision ACLRs between January 2008 and June 2017 with a minimum 2-year follow-up were retrospectively evaluated. Patients were divided into 2 groups according to age: ≥40 years (group A) and <40 years (group B). Detailed patient demographic data, preoperative radiographic data, and concurrent meniscal and chondral lesion were reviewed. Clinical scores, laxity tests results, and graft failures were compared between groups at the final follow-up.

RESULTS

Eighty-six patients (group A, n = 24, 46.6 ± 4.5 years; group B, n = 62, 26.2 ± 6.3 years) were included in this study. Demographic data showed that the time interval from primary to revision ACLR was longer in group A than in group B (96.2 ± 80.9 vs. 52.0 ± 42.1 months, P = .011). Group A had a higher prevalence of chondral defects of the trochlea (P = .016). No significant differences were identified in the prevalence and severity of meniscal lesions. At the final follow-up, all clinical scores were improved postoperatively but did not differ significantly between the groups. No significant differences were identified in side-to-side difference on Telos stress radiographs (group A, 6.3 ± 5.0 mm; group B, 5.6 ± 3.8 mm; P = .403) and graft failure rate (group A, 33.3%; group B, 30.6%; P = .358) at the final follow-up.

CONCLUSIONS

The current study showed that the clinical outcomes of revision ACLRs in patients improved significantly in patients younger than 40 years and were comparable to those observed in patients older than 40 years at a minimum 2-year follow-up.

LEVEL OF EVIDENCE

III.

[Effect of vascularized peroneus longus tendon graft reconstruction on anterior cruciate ligament insertion in rabbits]

OBJECTIVE

To investigate the effect of vascularized peroneus longus tendon graft reconstruction on anterior cruciate ligament (ACL) insertion in rabbits.

METHODS

Eighty healthy New Zealand white rabbits were harvested to prepare ACL injury models and randomly divided into two groups ( n=40). The ACL was reconstructed with vascularized peroneus longus tendon graft in group A and peroneus longus tendon graft without blood supply in group B. The survival of animals and the healing of incision were observed after operation; the grafts were taken for gross and histological observations at 4, 8, and 16 weeks; the biomechanical test of the grafts was carried out to record the maximum tensile strength and incidence of ACL insertion rupture at 8 and 16 weeks.

RESULTS

All animals survived until the experiment completed. General observation showed that the tunnel was combined with grafts, the vascular infiltration was abundant, and no obvious boundary between the tunnel and grafts existed at 16 weeks in group A; there was still an obvious boundary between the tunnel and graft in group B. Histological observation showed that the collagen fibers between tendon and bone in group A increased gradually, the dense fiber connection was formed, and the "tidal-line" like structure similar to the normal ACL insertion was formed at 16 weeks; but the"tidal-line" like structure was not obvious in group B. Biomechanical test showed that there was no significant difference in the incidence of ACL insertion rupture at 8 and 16 weeks between group A and group B ( P=0.680; P=0.590), but the maximum tensile strength at 8 and 16 weeks were higher in group A than in group B ( t=18.503, P=0.001; t=25.391, P=0.001).

CONCLUSION

The vascularized peroneus longus tendon graft for ACL reconstruction can obviously promote the outcome of the ACL insertion.

Anterior cruciate ligament grafts display differential maturation patterns on magnetic resonance imaging following reconstruction: a systematic review

PURPOSE

The appearance of anterior cruciate ligament (ACL) grafts on magnetic resonance imaging (MRI) is related to graft maturity and mechanical strength after ACL reconstruction (ACLR). Accordingly, the purpose of this review was to quantitatively analyze reports of serial MRI of the ACL graft during the first year following ACLR; the hypothesis tested was that normalized MRI signal intensity would differ significantly by ACL graft type, graft source, and postoperative time.

METHODS

PubMed, Scopus, and CINAHL were searched for all studies published prior to June 2018 reporting MRI signal intensity of the ACL graft at multiple time points during the first postoperative year after ACLR. Signal intensity values at 6 and 12 months post-ACLR were normalized to initial measurements and analyzed using a least-squares regression model to study the independent variables of postoperative time, graft type, and graft source on the normalized MRI signal intensity.

RESULTS

An effect of graft type (P = 0.001) with interactions of graft type * time (P = 0.012) and graft source * time (P = 0.001) were observed. Post hoc analyses revealed greater predicted normalized MRI signal intensity of patellar tendon autografts than both hamstring (P = 0.008) and hamstring with remnant preservation (P = 0.001) autografts at postoperative month 12.

CONCLUSION

MRI signal varies with graft type, graft source, and time after ACLR. Enhanced graft maturity during the first postoperative year was associated with hamstring autografts, with and without remnant preservation. Serial MRI imaging during the first postoperative year may be clinically useful to identify biologically or mechanically deficient ACL grafts at risk for failure.

LEVEL OF EVIDENCE

IV.

Graft Size and Orientation Within the Femoral Notch Affect Graft Healing at 1 Year After Anterior Cruciate Ligament Reconstruction

BACKGROUND

The combined influence of anatomic and operative factors affecting graft healing after anterior cruciate ligament (ACL) reconstruction within the femoral notch is not well understood.

PURPOSE

To determine the influence of graft size and orientation in relation to femoral notch anatomy, with the signal/noise quotient (SNQ) of the graft used as a measure of graft healing after primary single-bundle ACL reconstruction.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

A total of 98 patients with a minimum 2-year follow-up after primary single-bundle ACL reconstruction with hamstring tendon autografts were included. Graft healing was evaluated at 1 year on magnetic resonance imaging (MRI) scan as the mean SNQ measured from 3 regions situated at sites at the proximal, middle, and distal graft. Patient characteristics, chondropenia severity score, tunnel sizes, tunnel locations, graft bending angle (GBA), graft sagittal angle, posterior tibial slope (PTS), graft length, graft volume, femoral notch volume, and graft-notch volume ratio (measured using postoperative 3-T high-resolution MRI) were evaluated to determine any association with 1-year graft healing. The correlation between 1-year graft healing and clinical outcome at minimum 2 years was also assessed.

RESULTS

There was no significant difference in mean SNQ between male and female patients (P > .05). Univariate regression analysis showed that a low femoral tunnel (P = .005), lateral tibial tunnel (P = .009), large femoral tunnel (P = .011), large tibial tunnel (P < .001), steep lateral PTS (P = .010), steep medial PTS (P = .004), acute graft sagittal angle (P < .001), acute GBA (P < .001), large graft volume (P = .003), and high graft-notch volume ratio (P < .001) were all associated with higher graft SNQ values. A multivariate regression analysis showed 2 significant factors: a large graft-notch volume ratio (P = .001) and an acute GBA (P = .004). The 1-year SNQ had a weak correlation with 2-year Tegner Activity Scale score (r = 0.227; P = .026) but no other clinical findings, such as International Knee Documentation Committee subjective and Lysholm scores and anterior tibial translation side-to-side difference.

CONCLUSION

The 1-year SNQ value had a significant positive association with graft-notch volume ratio and GBA. Both graft size and graft orientation appeared to have a significant influence on graft healing as assessed on 1-year high-resolution MRI scan.