Biomechanical Evaluation of Suture Tape Internal Brace Reinforcement of Soft Tissue Allografts for ACL Reconstruction Using a Porcine Model

Primary All-Soft Tissue Quadriceps Tendon Autograft Anterior Cruciate Ligament Reconstruction With Suture Tape Augmentation Resulted in Satisfactory Patient Outcomes and a Low Graft Failure Rate in High School and Collegiate Athletes

PURPOSE

To evaluate ≥2-year patient outcomes after primary all-soft tissue quadriceps tendon autograft (ASTQ) anterior cruciate ligament reconstruction (ACLR) with suture tape augmentation (STA) in skeletally mature high school and collegiate athletes.

METHODS

All high school and collegiate athletes who underwent primary ASTQ ACLR with STA with a minimum of 2-year follow-up were analyzed retrospectively. Patients were administered validated patient-reported outcome measures (PROMs) pre- and postoperatively. The minimal clinically important difference was calculated for each PROM based on this study population and applied to the individual patient. Return to sport, subsequent surgical intervention including contralateral ACLR, and KT-1000 arthrometer measurements for knee laxity were collected. Complications were assessed by physical examination, radiologic studies, or obtained via telephone.

RESULTS

In total, 60 patients were included in the final data analysis, with a mean age of 16.8 years (95% confidence interval 13-23) and mean final follow-up of 37.1 months (95% confidence interval 33.1-41.1). Twelve patients (20%) required subsequent surgery on the ipsilateral knee, which included 7 patients having a subsequent meniscal procedure and 3 patients who underwent arthrolysis. None sustained a graft failure, and 6 patients sustained a contralateral ACL injury necessitating surgery. All PROMs improved at the final follow-up (P < .001). In addition, KT-1000 arthrometer measurements significantly improved postoperatively at 1-year clinical follow-up (P < .001). Most patients obtained the minimal clinically important difference thresholds for each PROM at the final follow-up. There were 48 patients (80%) who participated in pivoting sports. The return-to-sport rate at same level was 54 patients (90%), with 6 patients (10%) not returning to the same level because of graduation.

CONCLUSIONS

ASTQ ACLR with STA in a young athletic patient population may result in a low graft failure rate while maintaining satisfactory patient outcomes at short-term follow-up, including a return to sport at the same level of 90%.

LEVEL OF EVIDENCE

Level IV, retrospective case series.

Editorial Commentary: Anterior Cruciate Ligament Repair or Reconstruction With Internal Bracing, for Properly Indicated Patients, Is Safe, Biocompatible, and Biomimetic

Anterior cruciate ligament (ACL) reconstruction with internal bracing (IB)-and ACL repair with IB when indicated-reduces graft or repair failure. IB is safe and protects ligament reconstructions and repairs. The IB construct should not be misunderstood as a synthetic ligament. To be effective, suture tape must be independently secured with the knee in full extension, reflecting the terminal length of the ACL. Regardless of graft type, the graft must be cyclically tensioned independent of the IB to allow for creep, and when properly performed, this significantly increases the ultimate tensile strength of the construct and reduces graft elongation, without stress shielding. Thus, the generic term "suture augmentation" may be misleading because the successful results reported apply to the IB technique. In our experience, the failure rate after ACL reconstruction with IB is 1% at the 5-year follow-up period. Notably, these results were achieved without an additional lateral extra-articular procedure.

Analysis of Changing Practice Trends in Anterior Cruciate Ligament Reconstruction: A Multicenter, Single-Institution Database Analysis

PURPOSE

To identify trends in anterior cruciate ligament reconstruction (ACLR), including graft choice, femoral tunnel drilling techniques, and augmentation techniques, and to assess how various surgeon factors impact these trends.

METHODS

A retrospective review of primary ACLRs performed between 2014 and 2022 was completed using a multicenter institutional database. Patient demographic characteristics, graft type, femoral drilling technique, use of extra-articular tenodesis, and use of suture augmentation were recorded from the medical record. Surgeon fellowship training (sports trained vs non-sports trained), experience (high [minimum of 15 years in practice] vs low), and volume (high [minimum of 15 ACLRs/year] vs low) were used to stratify technique utilization. The z test for proportions was used to compare categorical variables. Pearson correlation analyses identified trends and assessed statistical significance, defined as P < .05.

RESULTS

Our cohort consisted of 2,032 ACLRs performed in 2,006 patients. The average patient age was 28.3 ± 11.6 years, with more procedures performed in male patients (67.3%). The average length of surgeon experience was 19.7 ± 11.4 years, with an average annual procedural volume of 4.0 ± 5.4 ACLRs. Most surgeons were sports trained (n = 55, 64.7%), high experience (n = 44, 57.1%), and low volume (n = 80, 94.1%). There was an increasing annual proportion of ACLRs performed by sports-trained surgeons (R = 0.748, P = .020) and low-experience surgeons (R = 0.940, P < .001). Autograft reconstructions were most often performed by sports-trained (71.2%), low-experience (66.1%), and high-volume (76.9%) surgeons. There was an increasing proportion of autograft ACLRs that used quadriceps tendon among sports-trained (R = 0.739, P = .023), high-experience (R = 0.768, P = .016), and low-volume (R = 0.785, P = .012) surgeons. Independent drilling techniques were used in an increasing proportion of ACLRs performed by non-sports-trained (R = 0.860, P = .003) and high-volume (R = 0.864, P = .003) surgeons. Augmentation of ACLR with concomitant suture augmentation (n = 24, 1.2%) or extra-articular tenodesis (n = 6, 0.3%) was rarely performed.

CONCLUSIONS

In our multicenter institution, the quadriceps tendon autograft has been increasingly used in ACLR by sports-trained, low-volume, and high-experience surgeons. Independent drilling techniques have been increasingly used by non-sports-trained and high-volume surgeons.

CLINICAL RELEVANCE

Surgeons must stay current with the literature that affects their procedures to ensure that evidence-based medicine is being practiced.

A Biomechanical Study of Calcaneal Tuberosity Avulsion Fracture: A Comparison Between Three-Screw Versus Two-Screw Fixation Strength

A calcaneal tuberosity avulsion fracture constitutes a sub-group of calcaneal fractures and it poses a high risk of soft tissue compromise, necessitating urgent reduction and fixation. This fracture was commonly treated with screw fixation, and fixation failure associated with this method has been reported in the literature. In light of this, we tested and compared the strength of two-screw (2S) versus three-screw (3S) fixations, where the third screw was fixed from the posterior calcaneal tuberosity towards the anterior process in addition to the two parallel screws. Synthetic calcaneum models were tested with an Instron machine to measure the maximum tensile load and stiffness. The mean maximum tensile loads for 3S and 2S were 455.8 N (SD = 47.4) and 341.0 N (SD = 30.9), respectively, and the difference was statistically significant. The mean stiffnesses for 3S and 2S were 29.2 N/mm (SD = 1.8) and 29.7 N/mm (SD = 2.0), but this difference did not reach statistical significance. Based on our findings, the added third screw increased the pull-out strength and can be inserted percutaneously to minimize soft tissue compromise.

Insufficient Evidence for Anterior Cruciate Ligament Reconstruction Utilizing Suture Tape Augmentation: A Systematic Review of Clinical Outcomes at Minimum 1-Year Follow-up

PURPOSE

To perform a systematic review of clinical studies to directly compare clinical outcomes of patients undergoing anterior cruciate ligament reconstruction (ACLR) with versus without suture tape (ST) augmentation.

METHODS

A systematic review was performed by searching PubMed, the Cochrane Library, and Embase to identify comparative studies directly comparing outcomes of ACLR with versus without ST augmentation with a minimum follow-up of 12 months. The search terms used were anterior cruciate ligament suture tape. Patients were evaluated based on graft failure rates, return to sport (RTS), anteroposterior (AP) laxity, and patient-reported outcomes (PROs).

RESULTS

Five studies (all Level III) met inclusion criteria, including a total of 246 patients undergoing ACLR with ST augmentation (SA group) and 282 patients undergoing ACLR without augmentation (control group). Patient age ranged from 14.9 to 29.7 years. The mean follow-up time ranged from 24.0 to 48.6 months. The mean body mass index ranged from 25.3 to 26.3 kg/m2 and the overall percentage of males ranged from 43.4% to 69.0%. Overall, the graft failure rate ranged from 1.0% to 25.0% in the SA group and 8.0% to 20.0% in the control group. Among the studies that reported RTS rates, the rate ranged from 69.2% to 88.9% in the SA group and 51.5% to 87.5% in the control group. Among all PROs, 2 studies found a significant difference in the Tegner score favoring the SA group. Otherwise, no significant differences were found between groups in terms of PROs. No significant differences in AP laxity were found between groups within any particular study. There was heterogeneity between studies regarding surgical techniques, postoperative rehabilitation protocols, and reported PROs.

CONCLUSIONS

There is insufficient evidence to suggest that patients undergoing ACLR with ST augmentation may experience favorable clinical outcomes compared with ACLR alone.

LEVEL OF EVIDENCE

Level III, systematic review of Level III studies.

Analysis of Graft Types Augmented With an Internal Brace for ACL Reconstruction: A Systematic Review

BACKGROUND

New techniques are being developed to decrease the failure rate of anterior cruciate ligament (ACL) grafts and prevent revision surgery. One such technique involves high-strength suture tape (ST), also referred to as internal bracing. Recent literature has highlighted the use of ST for ACL reconstruction, but no study has compared ST augmentation between graft types.

PURPOSE

To compare the use of ST augmentation for ACL reconstruction based on the type of graft used (ie, bone-patellar tendon-bone [BPTB], quadriceps, hamstring).

STUDY DESIGN

Systematic review; Level of evidence, 5.

METHODS

An online search of multiple databases was performed according to PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines and was completed April 2022 to identify studies related to ST augmentation of ACL grafts.

RESULTS

Of 926 studies identified, 10 met inclusion criteria. Five studies (50%) used hamstring tendon (HT), 3 (30%) used quadriceps tendon (QT), 1 (10%) used BPTB, and 1 (10%) used both HT and QT grafts. HT autografts augmented with ST had decreased dynamic and peak elongation (15%-56%), increased load to failure, and increased initial and final dynamic stiffness compared with controls. There was no significant difference in postoperative physical examination findings (range of motion, Lachman, pivot shift), except that ST-augmented grafts had significantly less laxity after surgery compared with HT alone (0.8 vs 1.9 mm; P < .05). QT allografts with ST augmentation showed increased graft strength. Human QT autograft studies showed higher Knee injury and Osteoarthritis Outcome Score scores compared with controls. BPTB allografts with ST augmentation had decreased cyclic displacement by 31% (P = .015) and increased load (758 ± 128 N; P < .001) and stiffness (156 ± 23 N/mm; P = .003) compared with nonaugmented groups. The complication rate was low or showed no increase in the ST augmentation groups compared with control groups.

CONCLUSION

HT, QT, and BPTB grafts augmented with ST demonstrate an effective method for ACL reconstruction. All graft types with ST augmentation showed no evidence of clinical disadvantage, with some studies indicating significant biomechanical or clinical advantages compared with conventional ACL reconstruction.

Biomechanical Comparison of Coracoclavicular Fixation Using Metallic Versus All-Suture Anchors

Background

A coracoclavicular (CC) fixation technique using an all-suture anchor with the assistance of fluoroscopy can prevent iatrogenic anterior deltoid detachment from the clavicle; however, soft anchor pullout has been reported as a complication.

Purpose

To compare the biomechanical properties of conventional metallic and all-suture anchors for CC suture fixation.

Study Design

Controlled laboratory study.

Methods

A total of 24 fresh-frozen cadaveric specimens were divided into 2 groups: metal anchor group (group M) and all-suture anchor group (group A). In group M, 5.0-mm metallic suture anchors were used for CC fixation, whereas 2.8-mm all-suture anchors were used in group A. The prepared specimens were mounted on a materials testing machine. After preconditioning at 0 to 20 N for 10 cycles, the specimens were subjected to cyclic loading from 20 to 70 N for 1000 cycles. Finally, all the specimens were loaded to failure. Cyclic elongation, linear stiffness, ultimate load, and failure modes were recorded, and the Mann-Whitney U test was used to compare nonparametric parameters between the 2 groups.

Results

All of the specimens completed the cyclic loading test. The elongation after cyclic loading in group M (1.6 ± 0.6 mm) was significantly smaller compared with that in group A (2.5 ± 1.2 mm) (P = .02). No between-group differences were found in linear stiffness (42 ± 17 N/mm in group M and 41 ± 17 N/mm in group A). The ultimate failure load in group M (263 ± 66 N) was significantly greater than that in group A (177 ± 76 N) (P = .02). All specimens failed because of suture anchor pullout.

Conclusion

The use of all-suture anchors in CC fixation resulted in significantly greater cyclic displacement and smaller ultimate failure load than that of metallic anchors.

Clinical Relevance

Understanding the most biomechanically sound suture anchor may assist in lowering the risk of clinical failure in CC fixation and repair.

Outcomes of Anterior Cruciate Ligament Reconstruction With Independently Tensioned Suture Tape Augmentation at 5-Year Follow-up

BACKGROUND

Reconstruction using autograft remains the gold standard surgical treatment for anterior cruciate ligament (ACL) injuries. However, up to 10% to 15% of patients will suffer a graft failure in the future. Cadaveric studies have demonstrated that the addition of suture tape augmentation to ACL autograft constructs can increase graft strength and reduce elongation under cyclical loading.

PURPOSE/HYPOTHESIS

This study aimed to investigate the clinical outcomes and rerupture rates after ACL reconstruction (ACLR) with suture tape augmentation. We hypothesized that augmentation with suture tape would lead to lower rerupture rates.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

Patients undergoing primary ACLR using hamstring or patellar tendon autografts augmented with suture tape between 2015 and 2019 were recruited prospectively. Patients with multiligament injuries or a concomitant lateral extra-articular procedure were excluded. Patients were observed in person for 6 months, and patient-reported outcome measures (PROMs) were collected at 2 and 5 years postoperatively. All patients were contacted, and records were reviewed to determine the incidence of graft failure. PROMs collected were as follows: Knee injury and Osteoarthritis Outcome Score (KOOS), Veterans RAND 12-Item Health Survey (VR-12), Tegner and Marx activity scores, and visual analog scale for pain (VAS).

RESULTS

A total of 97 patients, with a mean age of 34.7 (±13.4) years, were included (76% men; 52 hamstring and 45 patellar tendon grafts). The mean graft diameter was 8 (±1) mm. There was 1 rerupture (1.1%) out of the 90 patients who were contactable at a mean of 5 years postoperatively. Median KOOS scores at 2 years were as follows: Pain, 94; Symptoms, 86; Activities of Daily Living, 99; Sport and Recreation, 82; and Quality of Life, 81. The postoperative scores were significantly higher than the preoperative scores (P < .001). The VR-12 Physical score improved from 43 preoperatively to 55 at 2 years and remained at 56 at 5 years. The VAS pain, Tegner, and Marx scores were 0, 6, and 9, respectively, at 2 years postoperatively. There was no difference in PROMs between graft types.

CONCLUSION

This study demonstrates encouraging results of suture tape augmentation of autograft ACLR for both hamstring and patellar tendon grafts. The failure rate of 1.1% at a mean follow-up of 5 years is lower than published rates for reconstruction, and PROMs results are satisfactory. The technique is safe to use and may permit a return to the preinjury sporting level with a lower chance of reinjury.

Reduced Incidence of Revision Anterior Cruciate Ligament Reconstruction With Internal Brace Augmentation

Background

Revision rates and outcome measures after anterior cruciate ligament reconstruction (ACLR) with suture tape as an internal brace is not well-documented because of the emerging nature of the technique.

Hypothesis

ACLR with internal bracing (IB) would lead to decreased revision ACLR compared with traditional ACLR while exhibiting comparable patient outcomes.

Study Design

Cohort study; Level of evidence, 3.

Methods

A total of 200 patients were included in this study. Patients aged between 13 and 39 years at the time of surgery who underwent primary autograft ACLR with IB between 2010 and 2020 and were enrolled in our institution's registry with a minimum of 2-year follow-up were identified and matched 1 to 1 with a non-internal brace (no-IB) group based on concomitant procedures and patient characteristics. Pre- and postoperatively, patients completed the Knee injury and Osteoarthritis Outcome Score, Marx activity rating scale, Veterans RAND 12-Item Health Survey, and visual analog scale for pain. Knee laxity measurements via the KT-1000 arthrometer were included in the pre- and postoperative objective clinical assessments.

Results

A total of 100 IB patients were matched with 100 no-IB patients based primarily on concomitant procedures and secondarily on patient characteristics. The IB group underwent significantly fewer revision ACLRs (1% vs 8%; P = .017). Even though the no-IB group had a significantly longer mean final follow-up time (48.6 months [95% CI, 45.4-51.7] vs 33.4 months [95% CI, 30.3-36.5]; P < .001), the time elapsed from the original ACLR to the revision did not differ significantly between groups, and the mean ages for the IB and no-IB groups were comparable (19 vs 19.9 years). All postoperative patient-reported outcome scores between the 2 groups were comparable and significantly improved postoperatively except for the Marx score, which significantly decreased stepwise for both groups postoperatively. KT-1000 measurements significantly improved in both groups after surgery with the IB and no-IB cohorts yielding comparable results at the manual maximum pull (0.97 vs 0.65 mm).

Conclusion

ACLR with IB resulted in a significantly decreased risk of revision ACLRs while maintaining comparable patient-reported outcomes. Therefore, incorporating an internal brace into ACLR appears to be safe and effective within these study parameters.

Clinical Research Progress of Internal Brace Ligament Augmentation Technique in Knee Ligament Injury Repair and Reconstruction: A Narrative Review

Knee ligament injuries are most common in sports injuries. In general, ligament repair or reconstruction is necessary to restore the stability of the knee joint and prevent secondary injuries. Despite advances in ligament repair and reconstruction techniques, a number of patients still experience re-rupture of the graft and suboptimal recovery of motor function. Since Dr. Mackay's introduction of the internal brace technique, there has been continuous research in recent years using the internal brace ligament augmentation technique for knee ligament repair or reconstruction, particularly in the repair or reconstruction of the anterior cruciate ligament. This technique focuses on increasing the strength of autologous or allograft tendon grafts through the use of braided ultra-high-molecular-weight polyethylene suture tapes to facilitate postoperative rehabilitation and avoid re-rupture or failure. The purpose of this review is to present detailed research progress in the internal brace ligament enhancement technique of knee ligament injury repair as well as the reconstruction from biomechanical and histological research and clinical studies and to comprehensively assess the value of the application of this technique.

Postless Tape Augmentation for Anterior Cruciate Ligament (ACL) Reconstruction

Suture or tape augmentation for anterior cruciate ligament (ACL) reconstruction has been described as a technique to increase biomechanical strength and potentially improve clinical outcomes. However, the suture or tape used for augmentation usually requires independent tibial fixation from the ACL graft in the form of an anchor or post. This may introduce the potential for graft and augment tension mismatch, while increasing surgical cost. We present our technique for ACL reconstruction with postless tape augmentation. The ACL graft and tape are fixed at the same tension with interference fixation using a single tibial sheath and screw construct, which allows for ACL augmentation without the need for an additional post or implant.