Additional suture augmentation to anterior cruciate ligament reconstruction with hamstring autografts bring no benefits to clinical results, graft maturation and graft-bone interface healing

BACKGROUND

From the perspective of graft protection and early rehabilitation during the maturation and remodeling phases of graft healing, suture augmentation (SA) for anterior cruciate ligament reconstruction (ACLR) has attracted more and more attention.

STUDY DESIGN

Retrospective study.

PURPOSE

To determine whether the additional SA affects clinical results, graft maturation and graft-bone interface healing during two years follow-up after ACLR.

METHODS

20 ACLRs with additional SA (ACLR-SA group) and 20 ACLRs without additional SA (ACLR group) were performed between January 2020 and December 2021 by the same surgeon and were retrospectively analyzed. Pre- and postoperative International Knee Documentation Committee (IKDC) scores, Lysholm scores, graft failure and reoperation were evaluated. The signal/noise quotient (SNQ) of autografts and the signal intensity of graft-bone interface were analyzed. All 40 patients in ACLR-SA group and ACLR group completed 2-years follow-up.

RESULTS

There was no patient in the two cohorts experienced graft failure and reoperation. The postoperative IKDC and Lysholm scores have been significantly improved compared with preoperative scored in both ACLR-SA group and ACLR group, however, there was no significant difference between two groups. The SNQ of proximal graft of ACLR-SA group (14.78 ± 8.62 vs. 8.1 ± 5.5, p = 0.041) was significantly greater while the grades of graft-bone interface healing of posterior tibial was significantly lower than that of ACLR group at 1-year postoperatively (p = 0.03), respectively. There were no significant differences between the two groups of the SNQ of proximal, distal medial graft segments, and the graft-bone interface healing grades of anterior femoral, posterior femoral, anterior tibial and posterior tibial at other time points (p>0.05).

CONCLUSIONS

The additional SA in ACLR had no effect on IKDC scores, Lysholm scores, graft maturation and graft-bone interface healing at 2-year postoperatively. Our research does not support the routine use of SA in ACLR.

Effect of bone marrow aspiration concentrate and platelet-rich plasma combination in anterior cruciate ligament reconstruction: a randomized, prospective, double-blinded study

BACKGROUND

The effect of bone marrow aspirate concentrate (BMAC) and platelet-rich plasma (PRP) combination in enhancing graft maturation and tendon-bone tunnel interfacial healing after anterior cruciate ligament (ACL) reconstruction remains unclear. We hypothesised that BMAC and PRP combination could lead to better clinical results and better graft maturation/interface healing than PRP alone or conventional ACL reconstruction without any other biologic augmentation.

METHODS

In this randomised double-blind prospective study, patients undergoing ACL reconstruction surgery were randomly assigned into three groups: (1) control group (without any biologic augmentation), (2) PRP treatment group, and (3) combined BMAC and PRP (BMAC + PRP) group. Moreover, they were evaluated using the clinical functional score, laxity examination, and magnetic resonance imaging (MRI) analysis.

RESULTS

No significant difference was observed in the improvement of functional scores among groups. However, laxity improvement at 24 weeks showed a significant difference with the BMAC + PRP group having the lowest laxity. MRI analysis showed no significant change in whole graft maturation among groups. In particular, the BMAC + PRP group showed delayed signal peak and higher graft signal at 24 weeks compared with the other two groups; however, the difference was not significant. With regard to tendon-bone interfacial healing, the BMAC + PRP group showed significantly wider tendon-bone interface in the femoral bone tunnel at 24 weeks compared with the other two groups. Moreover, the BMAC + PRP group showed significantly higher peri-tunnel edema signal in the femoral bone tunnel at 12 weeks compared with the other two groups.

CONCLUSION

PRP alone and BMAC and PRP combination showed limited enhancing effect in clinical function, graft maturation and tendon-bone interfacial healing compared with control (no additional treatment). When BMAC is used in ACL reconstruction, the possibility of greater inflammation in the early stage to graft maturation and bone tunnel healing should be considered.

Intra-femoral tunnel graft lengths less than 20 mm do not predispose to early graft failure, inferior outcomes or poor function. A prospective clinico-radiological comparative study

PURPOSE

Increasing demands on skills with mounting pressures from expectations from arthroscopic anterior cruciate ligament (ACL) reconstructions requires precise knowledge of technical details by surgeons. One such element is the minimum length of graft in femoral tunnel to allow for adequate tendon-to-bone healing and early return to activities and sports. This has, however, remained an unanswered question.

PURPOSE

To study and compare clinico-radiological outcomes of ACL reconstructions in patients with < 20 mm of intra-femoral tunnel graft length with those measuring ≥ 20 mm.

METHODS

All eligible patients undergoing arthroscopic ACL reconstruction were sequentially divided into two groups based on the intra-femoral tunnel graft lengths (A: < 20 mm, n = 27; and B: ≥ 20 mm, n = 25). Exclusions were made for those > 45 years of age, with chondral and/or multi-ligamentous injuries and with systemic pathologies. All patients were postoperatively evaluated in clinics by physical examination and functional scoring (Lysholm and modified Cincinnati scores) at 3, 6 and 12-month intervals. Graft vascularity was assessed by signal-to-noise quotient ratio (SNQR) using magnetic resonance imaging (MRI) at 3 and 12 months.

RESULTS

No significant differences were noted in mean Lysholm and modified Cincinnati scores between the two groups at the end of 1 year. There were also no significant differences in graft maturation over time and SNQR at 3 and 12 months in the region of interest (ROI).

CONCLUSIONS

Intra-femoral tunnel graft length of less than 20 mm does not compromise early clinical and functional outcomes of ACL reconstructions.

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

PURPOSE

The primary purpose of this study was to evaluate the second-look arthroscopic findings 1 year postoperatively and magnetic resonance imaging (MRI) findings 2 years 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 2 years after surgery.

METHODS

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 2 years 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.

RESULTS

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 ± 1.1 mm; HT: 2.0 ± 1.9 mm).

CONCLUSION

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 OF EVIDENCE

Level IV.

Anterior cruciate ligament autograft maturation on sequential postoperative MRI is not correlated with clinical outcome and anterior knee stability

PURPOSE

Magnetic resonance imaging (MRI) signal intensity is correlated to structural postoperative changes of the anterior cruciate ligament (ACL) autograft. The purpose of this study was to investigate the ACL autograft maturation process via MRI over 2 years postoperatively, compare it to a native ACL signal and correlate the results with clinical outcome, return to preinjury sports levels, and knee laxity measurements.

METHODS

ACL autograft signal intensity was measured in 17 male patients (age, 28.3 ± 7.0 years) who underwent ACL reconstruction with hamstring autograft at 6 weeks, 3-, 6-, 12-, and 24 months postoperatively by 3 Tesla MRI. Controls with an intact ACL served as control group (22 males, 8 females; age, 26.7 ± 6.8 years). An ACL/PCL ratio (APR) and ACL/muscle ratio (AMR) was calculated to normalize signals to soft tissue signal. APR and AMR were compared across time and to native ACL signal. Clinical outcome scores (IKDC, Lysholm), return to preinjury sports levels (Tegner activity scale), and knee laxity measurement (KT-1000) were obtained and correlated to APR and AMR at the respective time points.

RESULTS

The APR and AMR of the ACL graft changed significantly from the lowest values at 6 weeks to reach the highest intensity after 6 months (p < 0.001). Then, the APR and AMR were significantly different from a native ACL 6 months after surgery (p < 0.01) but approached the APR and AMR of the native ACL at 1- and 2 years after surgery (p < 0.05). The APR changed significantly during the first 2 years postoperatively in the proximal (p < 0.001), mid-substance (p < 0.001), and distal (p < 0.01) intraarticular portion of the ACL autograft. A hypo-intense ACL MRI signal was associated with return to the preinjury sports level (p < 0.05). No correlation was found between ACL MRI graft signal and clinical outcome scores or KT-1000 measurements.

CONCLUSION

ACL grafts undergo a continuous maturation process in the first 2 years after surgery. The ACL graft signals became hyper-intense 6 months postoperatively and approximated the signal of a native intact ACL at 12- and 24 months. Patients with a hypo-intense ACL graft signal at 2 years follow-up were more likely to return to preinjury sports levels. The results of the present study provide a template for monitoring the normal ACL maturation process via MRI in case of prolonged clinical symptoms. However, subjective outcome and clinical examination of knee laxity remain important to assess the treatment success and to allow to return to sports.

LEVEL OF EVIDENCE

III.

Extracorporeal shock wave promotes activation of anterior cruciate ligament remnant cells and their paracrine regulation of bone marrow stromal cells' proliferation, migration, collagen synthesis, and differentiation

Aims

Proliferation, migration, and differentiation of anterior cruciate ligament (ACL) remnant and surrounding cells are fundamental processes for ACL reconstruction; however, the interaction between ACL remnant and surrounding cells is unclear. We hypothesized that ACL remnant cells preserve the capability to regulate the surrounding cells' activity, collagen gene expression, and tenogenic differentiation. Moreover, extracorporeal shock wave (ESW) would not only promote activity of ACL remnant cells, but also enhance their paracrine regulation of surrounding cells.

Methods

Cell viability, proliferation, migration, and expression levels of Collagen-I (COL-I) A1, transforming growth factor beta (TGF-β), and vascular endothelial growth factor (VEGF) were compared between ACL remnant cells untreated and treated with ESW (0.15 mJ/mm², 1,000 impulses, 4 Hz). To evaluate the subsequent effects on the surrounding cells, bone marrow stromal cells (BMSCs)' viability, proliferation, migration, and levels of Type I Collagen, Type III Collagen, and tenogenic gene (Scx, TNC) expression were investigated using coculture system.

Results

ESW-treated ACL remnant cells presented higher cell viability, proliferation, migration, and increased expression of COL-I A1, TGF-β, and VEGF. BMSC proliferation and migration rate significantly increased after coculture with ACL remnant cells with and without ESW stimulation compared to the BMSCs alone group. Furthermore, ESW significantly enhanced ACL remnant cells' capability to upregulate the collagen gene expression and tenogenic differentiation of BMSCs, without affecting cell viability, TGF-β, and VEGF expression.

Conclusion

ACL remnant cells modulated activity and differentiation of surrounding cells. The results indicated that ESW enhanced ACL remnant cells viability, proliferation, migration, and expression of collagen, TGF-β, VEGF, and paracrine regulation of BMSC proliferation, migration, collagen expression, and tenogenesis.Cite this article: Bone Joint Res 2020;9(8):458-468.

Superior graft maturation after anatomical double-bundle anterior cruciate ligament reconstruction using the transtibial drilling technique compared to the transportal technique

PURPOSE

To evaluate and compare the femoral tunnel aperture position, graft bending angle and the magnetic resonance imaging (MRI) graft signal intensity after anatomical double-bundle anterior cruciate ligament (ACL) reconstruction between transtibial and transportal drilling techniques of the femoral tunnel.

METHODS

Eighty-seven patients who underwent anatomic double-bundle ACL reconstruction with hamstring tendon autograft between January 2012 and December 2014 were included in this retrospective study. Forty-one patients underwent reconstruction using a transportal technique (TP group) and 46 patients underwent reconstruction using a transtibial technique (TT group). The anteromedial (AM) femoral aperture position and the graft bending angle were assessed using transparent three-dimensional CT 2 weeks postoperatively. MRI assessment was performed with proton density-weighted images in an oblique coronal plane 6 and 12 months postoperatively. Signal/noise quotient was calculated for two specific graft sites (femoral tunnel site and mid-substance site). Femoral aperture position, the graft bending angle and signal/noise quotient were compared between the TP and TT groups.

RESULTS

There was no significant difference in the aperture position between the two groups. The graft bending angle of the AM tunnel in the axial plane was significantly greater in the TP group (p < 0.001). On the other hand, the TP group had a significantly more acute angle in the coronal plane (p < 0.001). There was no significant difference at either site in the signal/noise quotient of the graft between the two groups at 6 months. However, the TT group had a lower signal/noise quotient at 12 months at both sites (femoral aperture: p = 0.04, mid-substance: p = 0.004).

CONCLUSION

There was a significant difference in signal/noise quotient between the two drilling techniques 12 months postoperatively. There was no significant difference in femoral tunnel aperture position between the two groups. However, graft bending angle at the femoral tunnel aperture was significantly different between the two groups, indicating the possibility that graft bending angle is a factor that influences graft maturation. This indicates that the TT technique has an advantage over the TP technique in terms of graft maturation.

Feasibility of T1rho and T2 map magnetic resonance imaging for evaluating graft maturation after anatomic double-bundle anterior cruciate ligament reconstruction

Background

Although T1rho and T2 map magnetic resonance imaging (MRI) have been perceived as useful diagnostic modalities for cartilage degeneration, no studies have assessed whether these two sequences are useful for monitoring ACL graft maturation after ACL reconstruction. The present study examined whether the two sequences reflect graft function and maturation after ACL reconstruction.

Methods

Twenty consecutive patients who consented to undergo MRI at 3, 6, and 12 months after double-bundle ACL reconstruction were enrolled. MRI was performed using T1 rho and T2 map sequences in a single session. Temporal changes in T1rho and T2 values of a purely tendinous portion of graft were assessed at each time point. Correlations were analyzed between T1rho or T2 map values and clinical results, including anteroposterior laxity at 2 and 4 years postoperatively, pivot shift test results at 4 years, and graft tension on second-look arthroscopy. Separate analyses were performed for the anteromedial bundle (AMB) and posterolateral bundle (PLB).

Results

T1rho sequence was able to visualize the tendinous portions of AMB and PLB more clearly than T2 map sequence even on gray-scale images. Mean T1rho and T2 map values gradually decreased during the first operative year, but the trend was more prominent and consistent for T1rho values than for T2 map values. Correlation analysis revealed that T1rho and T2 map values at 1 year correlated significantly with anteroposterior laxity at 2 and 4 years. This trend was found in both AMB and PLB. Both T1rho and T2 map values failed to exhibit a statistical correlation with arthroscopic findings of graft tension.

Conclusions

The present study was the first trial to assess the feasibility of T1rho and T2 map sequences to objectively monitor the course of graft maturation after ACL reconstruction. Both sequences successfully detected purely tendinous portions of graft, and mean values gradually decreased during the first year postoperatively. Both values at 1 year correlated significantly with anteroposterior laxity of the knee joint at 4 years, indicating that the values reflected graft fate.

Anterior laxity and patient-reported outcomes 7 years after ACL reconstruction with a fresh-frozen tibialis allograft

PURPOSE

After reconstructing a torn ACL with a soft tissue allograft, the long-term healing process of graft maturation following the short-term healing process of graft incorporation into the bone tunnels might lead to recurring instability and concomitant decreases in the activity level, function, and patient satisfaction. Relying on roentgen stereophotogrammetric analysis (RSA), the primary purpose was to determine whether anterior laxity increased and whether patient-reported outcomes declined between 1 and 7 years for a particular graft construct, surgical technique, and rehabilitation programme.

METHODS

Eighteen of 19 patients, who participated in an earlier RSA study which extended to 1 year after the surgical procedure, were contacted 7 years after the surgical procedure. An examiner, different from the treating surgeon, measured anterior laxity under 150 N of anterior force using RSA in 16 patients and obtained outcome scores in 17 patients. One patient moved abroad and could not be contacted. One patient reinjured his reconstructed ACL and was excluded.

RESULTS

The average increase in anterior laxity of 1.5 ± 2.1 mm between 1 and 7 years after surgery was not significant (p = 0.08), and the average increase in anterior laxity of 2.7 ± 2.3 mm between the day of surgery and 7 years was significant (p < 0.001). There were no significant declines in activity (median Tegner score, 6 at 1 year, 6 at 7 years), function (average Lysholm score, 94 at 1 year, 91 at 7 years), and subjective satisfaction (average International Knee Documentation Committee score, 90 at 1 year, 87 at 7 years) between 1 and 7 years after surgery.

CONCLUSION

In demonstrating that the ACL graft construct remains functional in the long term, this study supports the use of a fresh-frozen tibialis allograft in patients with an average age of 37 years at the time of surgery when used in conjunction with a surgical technique which avoids roof and PCL impingement, uses slippage-resistant fixation devices, and allows brace-free, self-paced rehabilitation.

LEVEL OF EVIDENCE

IV.

Clinical significance of T2*-weighted gradient-echo MRI to monitor graft maturation over one year after anatomic double-bundle anterior cruciate ligament reconstruction: a comparative study with proton density-weighted MRI

PURPOSE

This study examined the feasibility of T2*-weighted imaging (T2*WI) gradient-echo MRI to reflect actual function of the graft after anatomic double-bundle ACL reconstruction. T2*WI and proton density-weighted imaging (PDWI) were compared in the assessment of ACL grafts.

METHOD

Sixty-one patients underwent T2*WI and PDWI at 3, 6, and 12 months postoperatively. Signal intensity of the anteromedial bundle (AMB) or posterolateral bundle (PLB) graft standardized to the intensity of the PCL was defined as signal intensity ratio (SIR). Correlations between degree of knee instability and SIR were assessed for each bundle, each time point, and each sequence. The diagnostic efficacy of T2*WI sequence to detect poorly functioning knee with anteroposterior translation ≥ 4 mm was assessed.

RESULTS

Significant correlations were observed between SIR and KT values for both AMB and PLB at 12 months on T2*WI (r=0.39 and 0.53, respectively), but not on PDWI. Notably, 9 of 10 patients with poorly functioning graft showing anteroposterior translation ≥ 4 mm at 12 months formed an isolated group with high T2*WI-SIR. Six of the 10 patients displayed an increase in SIR from 6 to 12 months. Defining anteroposterior translation ≥ 4 mm at 12 months as the diagnostic standard for poorly functioning graft, increasing T2*WI-SIR offered 60% sensitivity and > 90% specificity.

CONCLUSIONS

ACL graft intensity on T2*WI is more strongly associated with actual function of the graft than that on PDWI. An increasing trend in T2*WI-SIR from 6 to 12 months postoperatively represents a possible surrogate indicator for poorly functioning grafts.

Comparison between two different platelet-rich plasma preparations and control applied during anterior cruciate ligament reconstruction. Is there any evidence to support their use?

INTRODUCTION

To compare the clinical, analytical and graft maturation effects of two different platelet-rich plasma (PRP) preparations applied during anterior cruciate ligament (ACL) reconstruction.

MATERIALS AND METHODS

A total of 150 patients with ACL disruption were included in the study. Arthroscopic ACL reconstruction with patellar tendon allograft was conducted on all knees using the same protocol. One hundred patients were prospectively randomised to either a group to receive double-spinning platelet-enriched gel (PRP) with leukocytes (n=50) or to a non-gel group (n=50). Finally, we included 50 patients treated with a platelet-rich preparation from a single-spinning procedure (PRGF Endoret(®) Technology) without leukocytes. Inflammatory parameters, including C-reactive protein (CRP) and knee perimeters (PER), were measured 24 hours and 10 days after surgery. Postoperative pain score (visual analogue score [VAS]) was recorded the day after surgery. Follow-up visits occurred postoperatively at 3, 6, and 12 months. The International Knee Documentation Committee scale (IKDC) was included to compare functional state, and MRI was conducted 6 months after surgery.

RESULTS

The PRGF group showed a statistically significant improvement in swelling and inflammatory parameters compared with the other two groups at 24 hours after surgery (p<0.05). The results did not show any significant differences between groups for MRI and clinical scores.

CONCLUSIONS

PRGF used in ACL allograft reconstruction was associated with reduced swelling; however, the intensity and uniformity of the graft on MRI were similar in the three groups, and there was no clinical or pain improvement compared with the control group.

LEVEL OF EVIDENCE

II.