Second-look arthroscopic findings and clinical results after polyethylene terephthalate augmented anterior cruciate ligament reconstruction

Material Properties of Suture Augmentation of Knee Medial Collateral Ligament Repair Did Not Influence Length Changes or Failure Loads in a Caged Porcine Model

Purpose

To investigate whether the biomechanical properties of the healed superficial medial collateral ligament (sMCL) repaired by augmentation vary depending on the material properties of the suture augmentation.

Methods

In 8 of 10 porcines (16 hindlimbs), the sMCL was detached from the femoral attachment using a scalpel under intubated general anesthesia. sMCL repair was performed using an ultra-high-molecular-weight polyethylene (UHMWPE) tape for the right hindlimbs and polyester tape (PE) for the left hindlimbs. They were sacrificed at 4 weeks postoperatively. The remaining 2 animals were assigned to the native control group (left and right hindlimb; n = 4). All connective tissues and suture augmentation, except for the repaired sMCL, were removed, and their biomechanical properties were evaluated.

Results

No significant differences were observed in the upper yield load (PE group, 247.4 ± 116.0 N; UHMWPE group, 279.9 ± 95.7 N; and sham group, 231.6 ± 50.6 N; P = .70), maximum yield load (PE group, 310.1 ± 166.1 N; UHMWPE group, 334.6 ± 95.2 N; and sham group, 290.9 ± 42.3 N; P = .84), linear stiffness (PE group, 43.3 ± 16.5 N/mm; UHMWPE group, 52.0 ± 28.2 N/mm; and sham group, 44.7 ± 7.2 N/mm; P = .66), and elongation at failure (PE group, 9.4 ± 4.3 mm; UHMWPE group, 9.1 ± 2.7 mm; and sham group, 10.1 ± 2.1 mm; P = .89). Statistical analysis of failure modes showed no significant difference between the groups (P = .21).

Conclusions

The material properties of suture augmentation used for sMCL repair did not significantly influence length changes during cyclic loading, postoperative structural properties, or failure modes.

Clinical Relevance

The results of this study provide valuable information regarding the efficacy of suture augmentation repair regardless of the materials used.

Anatomical Double-Bundle Anterior Cruciate Ligament Reconstruction With Suture Augmentation

Ultra-high molecular weight polyethylene sutures are used for repair and reconstruction of extra-articular ligaments in the knee, elbow, and ankle joints. In recent years, the use of these sutures has become popular in a suture augmentation technique and has been applied for use in the reconstruction of the anterior cruciate ligament, which is an intra-articular ligament. Although several surgical techniques have been described in Technical Notes, all reports have been for single-bundle reconstruction, and none have applied the technique to double-bundle reconstruction. This Technical Note provides a detailed description of an anatomical double-bundle anterior cruciate ligament reconstruction combined with the suture augmentation technique.

Suture Augmentation Does Not Change Biomechanical Properties and Histological Remodeling of Tendon Graft in Anterior Cruciate Ligament Reconstruction: A Study in a Porcine Model

PURPOSE

To evaluate the initial safety of the combined use of ultra-high molecular weight polyethylene (UHMWPE) sutures for suture augmentation (SA) in a porcine ACL reconstruction model and examine whether the procedure can affect the anterior knee laxity and structural properties of the tendon graft itself, influence histological remodeling, and cause a foreign body-induced inflammation.

METHODS

Ten pigs were divided into SA and non-SA Groups to undergo ACL reconstruction using an autologous semitendinosus tendon with and without SA, respectively. At 12 weeks postoperatively, the tibial fixation of the grafted tendon and SA was removed, and the anterior knee laxity and structural characteristics of the grafted tendon were evaluated for mechanical testing. Histological evaluation, including the ligament tissue maturation index (LTMI) score and the presence or absence of foreign-body reaction, was evaluated.

RESULTS

There was no significant difference in anterior laxity between the two groups (SA Group, 1.19 ± 0.78 mm; non-SA Group, 1.08 ± 0.42 mm; P = 1). There were no significant differences in maximum load failure, yield strength, stiffness, elongation at failure, and the LTMI score between the two groups (P = 0.31, 1, 1, 1, and 0.24, respectively). All grafted tendons showed no foreign-body reactions.

CONCLUSION

Suture augmentation did not have significant effect on the anterior knee laxity and the structural properties of the grafted tendon, interfere with histological remodeling, or cause foreign body-induced reactions.

CLINICAL RELEVANCE

The results of our study may lay the foundation for further clinical studies to verify the usefulness of ACL reconstruction with SA.

Long-term outcomes of surgery using the Ligament Advanced Reinforcement System as treatment for anterior cruciate ligament tears

AIMS

The aim of this prospective study was to assess the long-term clinical, radiological, functional, and quality of life (QoL)-related outcome of patients treated with the synthetic Ligament Advanced Reinforcement System (LARS) device for anterior cruciate ligament (ACL) rupture.

METHODS

A total of 41 patients who underwent ACL reconstruction with the LARS device (mean age 39.8 years (SD 12.1 ); 32% females (n = 13)) were prospectively included between August 2001 and March 2005. MRI scans and radiographs were performed at a median follow-up of 2.0 years (interquartile range (IQR) 1.3 to 3.0; n = 40) and 12.8 years (IQR 12.1 to 13.8; n = 22). Functional and QoL-related outcome was assessed in 29 patients at a median follow-up of 12.8 years (IQR 12.0 to 14.0) and clinically reconfirmed at latest median follow-up of 16.5 years (IQR 15.5 to 17.9). International Knee Documentation Committee (IKDC) and Tegner scores were obtained pre- and postoperatively, and Lysholm score postoperatively only. At latest follow-up, range of motion, knee stability tests, 36-Item Short Form Health Survey (SF-36), and IKDC scores were ascertained. Complications and reoperations during follow-up were documented.

RESULTS

Cumulative complication rate was 66% (n = 27), with 11 developing within one year from surgery and 16 after one year (including five patients with both early and late complications). Ten graft failures (24%) and eight cases of reactive synovitis were observed (20%). All 11 patients with early complications and ten with late complications underwent reoperation (including five with another surgical procedure for early complications), amounting to a cumulative reoperation rate of 51% (n = 21). Revision ACL reconstruction was performed in one patient (2.4%). Median IKDC at latest follow-up was 89.7 (IQR 78.2 to 93.1), being significantly worse in the event of previous complications. Lachman test was positive in 56% (n = 15) of reconstructed knees. All norm-based SF-36 items were at or above median at latest follow-up, and did not differ depending on development of complications.

CONCLUSION

Despite good functional and QoL-related results in the long term, the cumulative complication rate of 66%, including graft failures and reactive synovitis, has to be viewed with great concern. Cite this article: Bone Joint J 2022;104-B(2):242-248.

Synovitis following anterior cruciate ligament reconstruction using the LARS device

PURPOSE

The Ligament Augmentation and Reconstruction System (LARS^®) has been at the forefront of a recent revival in the use of synthetic ligaments for ACL reconstruction. However, despite promising short-to-mid-term results its role has been approached with caution due to a high number of major complications in previous synthetic graft designs including mechanical failures, synovitis and osteoarthritis. This study aims to report on the incidence of synovitis in a series of patients undergoing second-look surgery following LARS ACL reconstruction.

METHODS

A retrospective analysis was performed of a single surgeon's series of 12 patients that underwent second-look arthroscopic surgery following primary LARS ACL surgery for indications including mechanical symptoms (meniscal tears/cyclops lesions/chondral flaps) and/or symptomatic instability secondary to LARS failure. In all cases an examination under anaesthesia (EUA) was performed, and a qualitative assessment of the synovium was carried out and graded as normal, reactive or inflammatory. A synovial biopsy was performed in all knees with visible evidence of synovitis and in all cases of LARS failure.

RESULTS

The second-look arthroscopy was performed at a mean of 23 months (7-66) after the index surgery. In 6 (50%) knees the LARS device had failed necessitating removal and revision ACL reconstruction, while in the remaining 6 knees the LARS was still intact. Arthroscopic evaluation of the synovium revealed a normal appearance in 8 knees (67%) and reactive synovitis in 4 knees (23%); of these 4 knees, one had an intact LARS device and 3 had failed LARS. Histological examination from these 4 knees and the 3 knees with graft failures without visible synovitis revealed chronic hypertrophic synovitis (moderate 2, mild 5) in all cases with rare giant cells, consistent with a reaction to foreign body material.

CONCLUSIONS

Foreign body synovitis is a common finding in our series of patients undergoing a repeat arthroscopy following a LARS ACL reconstruction. The histological diagnosis of synovitis was more frequently encountered than an arthroscopic appearance of synovitis. Whilst the results of this case series cannot support a direct causative link between LARS failure and the development of synovitis, this study highlights the need to remain vigilant about the risk of reactive synovitis following LARS ACL reconstruction due to exposure of the knee to foreign body material.

LEVEL OF EVIDENCE

Level IV, case series.

Ankle Lateral Ligament Augmentation Versus the Modified Broström-Gould Procedure: A 5-Year Randomized Controlled Trial

BACKGROUND

"Ankle sprain" is a common injury, and >20% of patients may develop chronic instability for which surgery is indicated. The modified Broström-Gould (MBG) procedure remains the gold standard; however, there are a number of relative contraindications to this procedure, and the longer-term outcomes after the MBG have been questioned. An alternative procedure is augmentation of a primary repair with a ligament augmentation reconstruction system (LARS).

PURPOSE

To conduct a randomized controlled trial testing the null-hypothesis that there is no difference in patient scored outcomes and activity levels, between patients undergoing a MBG procedure compared with those undergoing a primary repair with LARS augmentation, for lateral ligament instability of the ankle.

STUDY DESIGN

Randomized controlled trial; Level of evidence, 1.

METHODS

Patients who satisfied the inclusion criteria were invited to take part in the study. Patients were randomly allocated to undergo the LARS or MBG procedure. Both groups followed similar postoperative rehabilitation. Patients completed the Foot and Ankle Outcome Score (FAOS) before surgery and then at 1, 2, and 5 years after surgery. Tegner activity scores were recorded at 5years. The scores in the 2 groups were compared via statistical analysis ( P < .05).

RESULTS

Of the 50 patients satisfying the inclusion criteria, 47 agreed to take part in the study. Twenty-two were randomized to the LARS group and 25 to the MBG group. At 5 years, follow-up data were complete for 20 patients in the LARS group and 21 in the MBG. There were 2 failures in the MBG group and 0 in the LARS group. The LARS group had significantly better improvement in total FAOS at 1 year (mean ± SD, 92.4 ± 2.5 vs 78.2 ± 3.4, P = .005), 2 years (94.0 ± 3.0 vs 78.0 ± 5.2, P = .003), and 5 years (93.7 ± 6.0 vs 75.1 ± 5.5, P = .002) after surgery. The 5-year Tegner activity scores were higher in the LARS group (8.25 ± 1.1 vs 7.2 ± 0.9, P = .03).

CONCLUSION

Among physically active patients with chronic lateral ligament instability, primary repair combined with LARS results in better total FAOS at 5-year follow-up and higher Tegner activity scores as compared with the MBG procedure.

REGISTRATION

ACTRN12618000906257 (Australia New Zealand Clinical Trial Registry).

Anatomic Placement of the Femoral Tunnels in Double-Bundle Anterior Cruciate Ligament Reconstruction Correlates With Improved Graft Maturation and Clinical Outcomes

PURPOSE

To compare maturation of reconstructed graft on second-look arthroscopy and clinical outcomes between 2 groups: the provisional anatomic (PA) group, with both the anteromedial (AM) and posterolateral (PL) femoral tunnels in their anatomic location, and the nonanatomic (NA) group, with either 1 of the 2 femoral tunnels beyond its anatomic location after double-bundle anterior cruciate ligament reconstruction.

METHODS

We enrolled 154 patients who underwent 3-dimensional computed tomography scanning and second-look arthroscopy after double-bundle anterior cruciate ligament reconstruction. All of the patients were divided into the PA and NA groups according to the femoral tunnel position determined by the quadrant method. Graft maturation was evaluated with 3 subsections, including integrity, tension, and synovial coverage with revascularization, on second-look arthroscopy. We also compared Lachman test, pivot-shift test, KT-2000 (MEDmetric, San Diego, CA), and International Knee Documentation Committee grades at the last follow-up.

RESULTS

Of the 154 patients, 88 were classified as the PA group and 66 as the NA group by the quadrant method. A difference existed between groups for the AM tunnel position but not for the PL tunnel position. The PA group showed a higher graft maturation score (P < .001 for all comparisons) and better results according to the International Knee Documentation Committee knee rating, Lachman test, pivot-shift test, and KT-2000 assessment (P < .001 for all comparisons).

CONCLUSIONS

The PA group with anatomic femoral tunnel placement showed a higher graft maturation score on second-look arthroscopy, along with better clinical outcomes, than the NA group. There was a significant difference in the AM femoral tunnel position but not in the PL tunnel position between the 2 groups.

LEVEL OF EVIDENCE

Level III, retrospective comparative study.

Primary ankle ligament augmentation versus modified Brostrom-Gould procedure: a 2-year randomized controlled trial

BACKGROUND

More than 20% of patients develop chronic instability following appropriate management of an 'ankle sprain'. There is little research comparing surgical techniques. 'Anatomical' procedures, such as the modified Brostrom-Gould (MBG), are generally preferred. However, not all patients are suitable for this procedure. Augmentation of a primary repair using a synthetic ligament, such as the ligament augmentation reconstruction system (LARS), is another 'anatomic' option. Our objective was to compare the clinical outcome following the MBG with that following the LARS technique using a prospective randomized clinical trial.

METHODS

Patients who satisfied the study criteria were randomly allocated to undergo the LARS procedure or the MBG procedure. All patients followed a similar rehabilitation programme. Patients completed the foot and ankle outcome score (FAOS) before surgery, and then at 1 year and 2 years following surgery. Statistical analysis was used to compare the groups (P < 0.05).

RESULTS

Forty-one patients took part in the study, 21 were randomized to the LARS group and 20 to the MBG group. The LARS group had a significantly better improvement in the total FAOS at both 1 year (25.5 standard error (SE) 3.8 versus 16.0 SE 3.3) and 2 years (27.1 SE 4.5 versus 15.8 SE 4.9) post-surgery.

CONCLUSION

Primary repair combined with LARS results in better patient-scored clinical outcome, at 2 years post-surgery, than the MBG procedure. Although longer follow-up is required, the LARS procedure may be considered as an alternative, especially in those patients for whom the MBG is relatively contra-indicated.

Biomedical coatings on polyethylene terephthalate artificial ligaments

This review comprehensively covers research conducted to enhance polyethylene terephthalate (PET) artificial ligament osseointegration in the bone tunnel. These strategies, using biocompatible or bioactive coatings, had a positive effect in promoting PET ligament osseointegration by increasing bone formation and decreasing fibrous scar tissue at the ligament-to-bone interface. The improved osseointegration can be translated into a significant increase in the biomechanical pull-out loads. However, the load-to-failure of coated ligament is far lower than that of native ACL. Coatings to promote intra-articular ligamentization are also discussed in this study. Collectively, our investigations may arouse further study of the biological coating of PET artificial ligaments in order to effectively enhance ligament osseointegration and promote artificial ligament ligamentization.

Anterior cruciate ligament reconstruction with LARS™ artificial ligament results at a mean follow-up of eight years

PURPOSE

The aim of this study was to review patients that underwent ACL reconstruction with the LARS™ ligament in the First Orthopaedic Division of Pisa University during the period between January 2003 and December 2005.

METHODS

Twenty-six patients were reviewed with an average follow-up of 95.3 months (7.9 years). The review protocol was articulated in three phases: (1) a subjective evaluation using three grading scales: VAS, KOOS and the Cincinnati knee rating scale, (2) a clinical and objective evaluation, and (3) a biomechanical evaluation of the knee stability.

RESULTS

A global positive result was obtained in 92.3 % of the patients (16 optimal results and eight good results), with a fast functional recovery and a high knee stability. A global poor result was reported in two cases. In our series we did not record cases of infection or knee synovitis. We recorded only one case of mechanical graft failure. The results obtained from our study are encouraging and similar to those in the literature.

CONCLUSIONS

We conclude that the LARS™ ligament can be considered a suitable option for ACL reconstruction in carefully selected cases, especially for older patients needing a fast functional recovery.