Second-look arthroscopy after anatomic anterior cruciate ligament reconstruction: Bone-patellar tendon-bone versus hamstring tendon graft

Factors affecting the post-operative over-constraint after anatomic double-bundle anterior cruciate ligament reconstruction

Objective

Initial tension at graft fixation is one of key factors for good outcomes in anterior cruciate ligament (ACL) reconstruction. Identifying the pre-operative factors that influence postoperative knee laxity under the anterior tibial load is useful in determining the initial tension at graft fixation. Thus, the purpose of this study was to clarify the pre-operative factors affecting the side-to-side difference in anterior laxity immediately after the anatomic double-bundle ACL reconstruction with a constant initial tension.

Methods

Fifty-five patients underwent the anatomic double-bundle ACL reconstruction with hamstring tendon grafts. Anterior tibial displacement (ATD) was measured on both knees using KT-2000 Knee Arthrometer under anterior drawer load of 67 N, 89 N, 134 N and manual maximum load at 30° of flexion before ACL reconstruction under anesthesia, and was also measured on the operated knees under 89 N immediately after ACL reconstruction under anesthesia. Then, side-to-side difference (SSD) before and immediately after ACL reconstruction was calculated. Correlative relation between the SSD immediately after ACL reconstruction and the ATD/the SSD in each condition was analyzed.

Results

The side-to-side difference of ATD immediately after surgery was -3.8 ± 1.7 mm (0 to -8mm) in response of 89 N of anterior load. There was correlation between the SSD immediately after ACL reconstruction and all ATD on both knees except for the ATD under manual maximum load on the injured knee, while little correlation between the SSD immediately after ACL reconstruction and that before ACL reconstruction was found. Especially, ATD under 89 N on the opposite knees and ATD under 134 N on the injured knees showed selective correlation with the SSD immediately after surgery in the step-wise multiple regression analysis.

Conclusion

As the anterior tibial displacements under 89 N on the contra-lateral knee and under 134 N on the injured knee had a significant correlation with the SSD immediately after ACL reconstruction, those values may be helpful in determining the increase or decrease in initial tension at graft fixation.

Strategies to promote tendon-bone healing after anterior cruciate ligament reconstruction: Present and future

At present, anterior cruciate ligament (ACL) reconstruction still has a high failure rate. Tendon graft and bone tunnel surface angiogenesis and bony ingrowth are the main physiological processes of tendon-bone healing, and also the main reasons for the postoperative efficacy of ACL reconstruction. Poor tendon-bone healing has been also identified as one of the main causes of unsatisfactory treatment outcomes. The physiological process of tendon-bone healing is complicated because the tendon-bone junction requires the organic fusion of the tendon graft with the bone tissue. The failure of the operation is often caused by tendon dislocation or scar healing. Therefore, it is important to study the possible risk factors for tendon-bone healing and strategies to promote it. This review comprehensively analyzed the risk factors contributing to tendon-bone healing failure after ACL reconstruction. Additionally, we discuss the current strategies used to promote tendon-bone healing following ACL reconstruction.

In-office needle arthroscopic assessment after primary ACL repair: short-term results in 15 patients

Purpose

In-office needle arthroscopy has been reported as a diagnostic tool for different knee pathologies. In addition, ACL repair has seen a resurgence with the advent of innovative orthopedic devices. The aim of this study was to assess clinical, radiological, and in-office needle arthroscopic findings in 15 adult patients who underwent acute (within 14 days from injury) anterior cruciate ligament (ACL) repair.

Methods

Fifteen patients voluntarily participated in the study. A second-look arthroscopy was performed with an in-office needle arthroscopy at an average of 7.2 months after the primary repair. The parameters included in the investigation were the continuity of the anatomical footprint of the repaired ACL, subjective assessment of the ACL tension with the probe, and synovial coverage of the ACL. All patients had a Magnetic Resonance Imaging (MRI) at 6 months after repair and an arthrometric evaluation with the KT-1000. Clinical evaluation with the scores, Tegner Lysholm Knee Scoring Scale (TLKSS), the Knee Injury and Osteoarthritis Outcome Score (KOOS), and International Knee Documentation Committee (IKDC) was performed at the final follow-up of 2 years. Moreover, a correlation between the characteristics of ACL appearance at the time of the second look in-office needle arthroscopy, MRI and KT-1000 was performed.

Results

The mean TLKSS was 97.86, the mean KOOS was 98.08 and the mean subjective IKDC was 96.71. The objective IKDC was A in 10 patients and B in 5 patients. ACL healing was graded as A in 11 patients and B in 4 patients. Synovial coverage was graded as good in 10 patients and fair in 5 while MRI assessment showed a type I ACL in 10 patients, type II in 4 patients and type III in 1 patient.

Conclusion

In-office needle arthroscopy is a reliable tool to assess the condition of a repaired ACL. In addition, ACL repair performed in acute proximal tears demonstrated excellent clinical results.

No Differences In Clinical Outcomes Between Rectangular and Round Tunnel Techniques For Anterior Crucial Ligament Reconstruction

PURPOSE

To compare the clinical outcomes between conventional round tunnel and rectangular tunnel in anatomic anterior cruciate ligament (ACL) reconstruction.

METHODS

This was a retrospective comparative cohort study between March 2015 and September 2018. The primary ACL reconstructions using anteromedial portal technique with minimum of 2 years follow-up were enrolled for this study. The exclusion criteria were patients with revision ACL reconstruction, high tibial osteotomy, multiligament injuries, and associated fractures around the knee. Outcome measures included the subjective International Knee Documentation Committee score, Tegner activity score, knee laxity testing, and measurement of the centers of the femoral and tibial tunnels on postoperative computed tomography (CT) images.

RESULTS

Forty-seven patients with ACL reconstruction with rectangular tunnel (group 1) and 108 patients with ACL reconstructions with conventional rounded tunnel (group 2) were included consecutively. There were no significant differences between groups in terms of clinical scores or knee laxity, as well as femoral and tibial tunnel positions on CT. One patient in group 2 had ACL failure because of trauma and was treated with revision surgery. Two patients had incomplete tibial fracture, but they healed spontaneously and showed no residual laxity at final follow-up. The intraobserver and interobserver reliability for the radiological measurements ranged from 0.78 to 0.86.

CONCLUSIONS

There were no differences in radiological and clinical results between rectangular tunnel group and conventional round tunnel group for arthroscopic ACL reconstruction. ACL reconstruction with a rectangular tunnel could be considered as a reliable technique, but care should be taken during tunnel establishment because of risk of fractures and malposition of rectangular tunnel.

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.

Rectangular bone-patellar tendon bone grafts reduce early graft failure in chronic ACL-Deficient knees

BACKGROUND

The aim of this study was to assess early graft failure after anterior cruciate ligament (ACL) reconstruction according to chronicity of ACL deficiency (ACLD) and clarify predisposing factors.

METHODS

A total of 731 patients who underwent anatomic ACL reconstruction were divided into 3 groups based on chronicity of ACLD: <6 months (Group 1), 6 months to 2 years (Group 2), and >2 years (Group 3). Types of ACL grafts used included single-bundle hamstring tendon (HT), multiple-bundle HT, and rectangular bone-patellar tendon-bone (BTB) grafts. Preoperatively and immediately postoperatively, lateral radiographs in full extension were taken to examine anterior tibial subluxation (ATS). All ACL grafts were evaluated by MRI at 6 months to identify graft failure. The group with the highest failure rate was further examined to compare possible risk factors between the intact and failure subgroups, followed by multivariate logistic regression analysis to identify predisposing factors.

RESULTS

Early graft failure on MRI without any episode of postoperative trauma was observed in 7 (1.4%), 2 (1.8%), and 11 (9.2%) patients in Groups 1, 2, and 3, respectively, with a significantly higher rate in Group 3 (P < 0.001). Of the 119 patients in Group 3, significant differences were observed between intact and failure subgroups with regard to surgical procedure (P = 0.03), chondral lesions (P < 0.01), and preoperative ATS (P < 0.01). Multivariate logistic regression analysis revealed that surgical procedures (odds ratio, 3.8; 95%CI, 1.16-12.59) and preoperative ATS (odd ratio, 2.4; 95%CI, 1.26-4.38) were predisposing factors of early graft failure.

CONCLUSION

Patients with ACLD for >2 years experienced early graft failure with an incidence rate of 9.2%. Predisposing factors of early graft failure in these patients included the use of single-bundle HT grafts and preoperative ATS. The use of rectangular BTB grafts resulted in a lower graft failure rate.

STUDY DESIGN

Case Series.

Second-look arthroscopy after double-bundle posterior cruciate ligament reconstruction: Effect of patient age

Purpose

Second-look arthroscopy is invasive but still one of the most useful postoperative evaluation methods since graft morphology including graft tension, graft tear, and synovial coverage can be directly evaluated. However, only a few studies have evaluated transplanted posterior cruciate ligament (PCL) grafts. This study aimed to clarify the PCL graft morphology and chondral damages at second-look arthroscopy after double-bundle PCL reconstruction (PCLR) and to investigate the effects of patient age on these arthroscopic findings.

Methods

This study retrospectively included 26 patients who underwent second-look arthroscopy at the time of hardware removal 14 months after double-bundle PCLR for isolated PCL injury from January 2007 to December 2020. The patients were divided into two groups: group A, 39 years or younger (n = 14); and group B, 40 years or older (n = 12). At second-look arthroscopy, the grafts were evaluated based on tension (taut, graft tension as tense as a normal PCL; lax, graft tension looser than a normal PCL, unclassified, completely torn graft), tear (one or more tendon strands torn), and synovial coverage (good, synovial coverage greater than 80% around the graft; fair, synovial coverage greater than 50%; and poor, synovial coverage less than 50%). The chondral damages were evaluated using the Outerbridge classification system. Radiographic posterior tibial translation with gravity sag view as well as clinical outcomes were also evaluated.

Results

Anterolateral (AL) graft tension was lax in 8% of the patients, whereas posteromedial (PM) graft tension was lax or unclassified in 24% (p = 0.043). Graft tear was observed only in the PM graft of 19% patients (p = 0.022). Synovial coverage of AL grafts was good or fair in all cases, whereas that of PM grafts was poor in 28% cases (p < 0.001). Regarding the effect of patient age, the synovial coverage of PM grafts was significantly poorer in group B (p = 0.033), but no statistical difference in graft tension or tear was found. The chondral damages were significantly advanced in group B (p ≤ 0.01), except for the trochlear groove and lateral femoral condyle. No patients had residual subjective posterior instability, knee swelling, or loss of extension exceeding 5° or flexion exceeding 10°. All patients had improved from grade II or III preoperatively to grade I or grade II in the posterior drawer test. The posterior tibial translation significantly improved from 10.0 ± 3.6 mm preoperatively to 3.6 ± 2.1 mm at second-look arthroscopy. No significant differences in the postoperative clinical outcomes were observed between the two groups.

Conclusion

The morphology of the PM grafts at second-look arthroscopy after double-bundle PCLR was poorer than that of the AL grafts. Patient age negatively affected the postoperative graft synovial coverage and chondral status but did not affect the clinical outcomes.

•

Second-look arthroscopy is a direct evaluation of the transplanted graft.

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There are very few studies of second-look arthroscopy of transplanted PCL grafts.

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Arthroscopic findings in the PM graft were inferior to those in the AL graft.

•

Poorer synovial coverage in the PM graft was observed in the patients ≥40 years.

Hamstring Graft Prepared With Suture Tape Is Effective in Anterior Cruciate Ligament Reconstruction: A Biomechanical Analysis

Purpose

To investigate the graft diameters and mechanical properties of hamstring tendons sutured using different materials and techniques.

Methods

This study used 30 fresh, frozen human cadaveric semitendinosus tendons; the free ends of 10 specimens each were sutured by 2 No. 3 braided polyester sutures with the Krackow technique (BP group), SutureTape with the Krackow technique (ST group), or SutureTape Loop with the locking SpeedWhip technique (SL group). First, the changes in graft diameter from before suturing to after suturing were investigated. Each graft was pre-tensioned to 100 N for 3 cycles and then cyclically loaded to 200 N for 200 cycles. Elongation after cyclic loading and displacement in the 200th cycle were calculated. Finally, each specimen was loaded to failure. The ultimate failure load and stiffness were analyzed. These mechanical properties were statistically analyzed using 1-way analysis of variance. The level of statistical significance was set at P < .05.

Results

In the BP group, the changes in graft diameter were significantly larger than those in the ST and SL groups (P = .001). The elongation values after 200 cycles in the BP and ST groups were 3.1 ± 2.0 mm and 5.9 ± 3.4 mm, respectively. In the SL group, elongation (7.7 ± 3.6 mm) was significantly larger compared with that in the BP group (P = .037). In contrast, displacement in the 200th cycle was significantly smaller in the ST and SL groups compared with the BP group (P = .017). No statistically significant difference was evident for the ultimate failure loads among the 3 groups (P = .543).

Conclusions

The results of this study suggest that SutureTape may be an appropriate option for preparing the hamstring graft in anatomic anterior cruciate ligament (ACL) reconstruction.

Clinical Relevance

This biomechanical study shows the effectiveness of SutureTape in ACL graft preparation. Clinically, SutureTape may be of benefit in single- or double-bundle ACL reconstruction.

Quadriceps tendon autograft ACL reconstruction has less pivot shift laxity and lower failure rates than hamstring tendon autografts

PURPOSE

Quadriceps tendon (QT) autograft ACL reconstruction was hypothesized to possess less anterior knee laxity, pivot shift laxity, and lower failure rates than hamstring tendon (HT) autografts.

METHODS

Terms "hamstring tendon autograft" and "ACL reconstruction" or "quadriceps tendon autograft" and "ACL reconstruction" were searched in Embase and PubMed. Inclusion criteria required that studies included patients treated for primary ACL injury with reconstruction using either a QT autograft (Group 1) or a HT autograft (Group 2) and instrumented anterior knee laxity assessment. Extracted information included surgical fixation method, graft type, graft thickness or diameter, single vs. double bundle surgical method, publication year, time between the index knee injury and surgery, % women, initial and final subject number, subject age, follow-up length, side-to-side anterior knee laxity difference, Lysholm Score, Subjective IKDC score, anterior knee laxity side-to-side difference grade, ipsilateral pivot shift laxity grade, and failure rate. The Methodological Index for Nonrandomized Studies was used to evaluate study methodological quality.

RESULTS

The QT group (Group 1) had 17 studies and the HT group (Group 2) had 61 studies. Overall, Group 2 had greater pivot shift laxity (OR 1.29, 95% CI 1.05-1.59, p = 0.005). Group 2 suspensory femoral fixation had greater pivot shift laxity (OR 1.26, 95% CI 1.01-1.58, p = 0.02) than Group 1 compression femoral fixation. Group 2 compression femoral fixation also had more anterior knee laxity (OR 1.25, 95% CI 1.03-1.52, p = 0.01) than Group 1 compression femoral fixation and higher failure rates based on initial (OR 1.69, 95% CI 1.18-2.4, p = 0.002) and final (OR 1.89, 95% CI 1.32-2.71, p = 0.0003) subject number. Failure rate for HT compression femoral fixation was greater than suspensory femoral fixation based on initial (OR 2.08, 95% CI 1.52-2.84, p < 0.0001) and final (OR 2.26, 95% CI 1.63-3.16, p < 0.0001) subject number.

CONCLUSIONS

Overall, QT autografts had less pivot shift laxity and lower failure rates based on final subject number than HT autografts. Compression QT autograft femoral fixation had lower pivot shift laxity than suspensory HT autograft femoral fixation. Compression QT autograft femoral fixation had less anterior knee laxity and lower failure rates than compression HT autograft femoral fixation. Suspensory HT autograft femoral fixation had lower failure rates than compression HT autograft femoral fixation. Greater knee laxity and failure rates may be related to a combination of HT autograft diameter and configuration (tissue quality and dimensions, strands, bundles, and suturing method) variability and fixation mode.

LEVEL OF EVIDENCE

Level IV.

A more flattened bone tunnel has a positive effect on tendon-bone healing in the early period after ACL reconstruction

PURPOSE

The purpose of this study was to evaluate whether a flattened bone tunnel has a positive effect on the tendon-bone healing (TBH) process in the early period after anterior cruciate ligament (ACL) reconstruction.

METHODS

Seventy-two New Zealand White rabbits were randomly allocated into two groups, the flattened tunnel (FT) group and the conventional round tunnel (RT) group. We compared the cross-sectional areas and diameters of the bone tunnels between the two groups through computed tomography (CT) scanning. TBH results between the two groups were assessed by histological analysis, micro-CT scanning and biomechanical tests at 4 weeks, 8 weeks and 12 weeks after operation.

RESULTS

The cross-sectional areas of the bone tunnels between the two groups were almost the same. However, the shape of bone tunnels in the FT group was more flattened. A faster cellular and collagen remoulding process were found in the FT group. Semiquantitative histological analysis of Safranin O staining showed that there was more fibrocartilage formation in the interface region in the FT group (P < 0.05). Sirius Red staining showed that the tissues in the interface areas were more intense in the FT group. Micro-CT scanning showed that more new bone formation could be found in the interface region in the FT group. The biomechanical tests also showed that FT ACL reconstruction will result in a stronger regenerated tendon-bone interface.

CONCLUSIONS

Our study found that a flattened bone tunnel accelerated TBH in the early period after ACL reconstruction surgery in a rabbit model, which lays the groundwork for further clinical practice of this ACL reconstruction method.

Editorial Commentary: Triple-Bundle Anterior Cruciate Ligament Reconstruction: More Is More or Less Is More?

We need ambitious pioneers to explore the frontiers of surgical technique, but the surgeons that follow are wise to wait for independent and robust evidence of clinical benefit. Double-bundle anterior cruciate ligament reconstruction has struggled to establish its role, and triple-bundle reconstruction is perhaps even less likely to gain widespread acceptance, given that cadaveric research has shown only a small biomechanical advantage over a double-bundle or even a single-bundle technique and there is no convincing evidence of improved clinical outcomes.