Ligament Augmentation And Reconstruction System Research Articles

Acromioclavicular joint Stabilization: Our experience with the lockdown technique

BackgroundAcromioclavicular joint (AC joint) disruption is a common injury with considerable variation with regards to surgical management. The Lockdown™ procedure (previously known as Surgilig™), Modified Weaver-Dunn procedure, Arthroscopic AC joint stabilization and Ligament Augmentation and Reconstruction system (LARS) procedure have all been described for treatment of this injury with varying outcomes. PurposeTo measure the functional and radiological outcomes following all cases of AC joint reconstruction using the Lockdown™ technique over the last 10 years at Medway Maritime Hospital. MethodsData on a total of 53 patients who underwent AC joint reconstruction between 2012 and 2021 were collected. Electronic records were used to extract data regarding patient characteristics, surgery details, and duration of follow-up. Telephonic interviews of patients were conducted to collect data on hand dominance, surgical complications, and responses to Oxford shoulder score (OSS) and QuickDASH score questionnaires. Hospital PACS data were reviewed to record preoperative injury severity and postoperative acromioclavicular joint reduction. ResultsResults for 42 patients were available and analysed as 10 could not be contacted and 1 patient sadly passed away. Of the patients reviewed, 92.9% were males with a mean age of 42.2 years (Range 16–67 years) and mean follow up of 68 months (12–119.1 months). The injury involved the dominant arm in 59.5%cases. Majority of the cases were Rockwood type V injuries (71.43%) while the rest were either type III(19.05%) or type IV(9.52%).The mean preoperative OSS was 21.3/48 which improved to 44.3/48 in the postoperative period. Similarly, the mean QuickDASH score was 50.6 preoperatively, that improved to 9.1 postoperatively.The most common patient reported complication was prominent metalwork seen in 5 cases (11.6%) followed by stiffness seen in 3 cases (7%) and superficial infection seen in 1 case (2.3%). The AC joint remained reduced radiologically in 81% of cases, while a resubluxation between 50 and 100% was seen in the rest of the cases. Patients with radiological resubluxation did not report this as a complication in 87.5% of the cases. Overall, 38 patients reported their outcome as excellent, 2 patients rated it good while 1 patient reported it as fair and 1 as poor. ConclusionThe Lockdown™ technique for stabilization of AC joint has excellent or good patient satisfaction in 95.2% of cases in long term follow up of more than 5.7 years. Prominent metalwork and stiffness are the commonest clinical complications. Radiological resubluxation can be seen in a fifth of the cases but does not directly lead to patient dissatisfaction. Level of evidenceLevel IV Retrospective case series.

STRESS DISTRIBUTION ANALYSIS ON LIGAMENT AUGMENTATION AND RECONSTRUCTION SYSTEM (LARS) USING FINITE ELEMENT METHOD (FEM)

The Ligament Augmentation and Reconstruction System (LARS) is a prosthetic device used to support knee ligaments severed due to injury. The role of LARS in supporting the knee ligaments is to take over the position of the natural ligaments that have been severed, binding the thigh bone and shin bone. LARS is made from polyethylene terephthalate (PET) material, commonly used in industry. LARS is a prosthetic product widely used to heal ligament injuries. However, despite its everyday use, no one has confirmed whether LARS can support a severed ligament. There has never been a study analyzing this tool, even from the company that makes LARS. They only state that LARS is safe and suitable for healing ligament injuries. Therefore, a LARS analysis is needed to convince the public that the tool is safe. This study analyzed the stress distribution in LARS during the standing-to-squatting condition. The results show an uneven stress distribution between the LARS inside the femur and other parts of the LARS. However, the stress distribution is still in a safe condition that does not directly reduce the strength of the LARS.

Comparison of Autografts vs Allografts for Anterior Cruciate Ligament Reconstruction: A Meta-Analysis of Current Perspective

Objective: To describe the outcomes of autografts and allografts in anterior cruciate ligament (ACL) and posterior cruciate ligament (PCL) reconstruction with respect to instrumented laxity measurements, patient-reported outcome scores, complications, and graft failure risk. Methods: We searched PubMed, Cochrane Library, and EMBASE for published randomized controlled trials (RCT) and case controlled trials (CCTs) to compare the outcomes of the autografts versus allografts after cruciate ligament reconstruction. Data analyses were performed using Cochrane Collaboration RevMan 5.0. Results: Nine studies were identified from the literature review. Of these studies, three studies compared the results of bone–patellar tendon–bone (BPTB) and ligament augmentation and reconstruction system (LARS), while six studies compared the results of four-strand hamstring tendon graft (4SHG) and LARS. The comparative study showed no difference in Lysholm score and failure risk between autografts and synthetics. Discussion: The combined results of the meta-analysis indicated that there was a significantly lower rate of side-to-side difference > 3 mm (Odds Ratio [OR] 2.46, 95% confidence intervals [CI] 1.44–4.22, P = 0.001), overall IKDC (OR 0.40, 95% CI 0.19–0.83, P = 0.01), complications (OR 2.54, 95% CI 1.26–5.14, P = 0.009), and Tegner score (OR −0.31, 95% CI −0.52–0.10, P = 0.004) in the allografts group than in the autografts group. Conclusion: This systematic review comparing long-term outcomes after cruciate ligament reconstruction with either autograft or allografts suggests no significant differences in failure risk. Autografts were inferior to allografts with respect to restoring knee joint stability and patient-reported outcome scores, and were also associated with more postoperative complications.

Massive foreign body reaction and osteolysis following primary anterior cruciate ligament reconstruction with the ligament augmentation and reconstruction system (LARS): a case report with histopathological and physicochemical analysis

BackgroundAutologous hamstrings and patellar tendon have historically been considered the gold standard grafts for anterior cruciate ligament reconstruction (ACLR). In the last decades, the utilization of synthetic grafts has re-emerged due to advantageous lack of donor site morbidity and more rapid return to sport. The Ligament Augmentation and Reconstruction System (LARS) has demonstrated to be a valid and safe option for ACLR in the short term. However, recent studies have pointed out the notable frequency of associated complications, including synovitis, mechanical failure, and even chondrolysis requiring joint replacement.Case presentationWe report the case of a 23-year-old male who developed a serious foreign body reaction with wide osteolysis of both femoral and tibial tunnels following ACLR with LARS. During first-stage arthroscopy, we performed a debridement of the pseudocystic mass incorporating the anterior cruciate ligament (ACL) and extending towards the tunnels, which were filled with autologous anterior iliac crest bone graft chips. Histological analysis revealed the presence of chronic inflammation, fibrosis, and foreign body giant cells with synthetic fiber inclusions. Furthermore, physicochemical analysis showed signs of fiber depolymerization, increased crystallinity and formation of lipid peroxidation-derived aldehydes, which indicate mechanical aging and instability of the graft. After 8 months, revision surgery was performed and ACL revision surgery with autologous hamstrings was successfully carried out.ConclusionsThe use of the LARS grafts for ACLR should be cautiously contemplated considering the high risk of complications and early failure.

Clinical and arthroscopic outcomes of single-bundle anterior cruciate ligament reconstruction using autologous hamstrings augmented with ligament augmentation and reconstruction systems compared with four-strand hamstring tendon grafts alone.

To compare the clinical, radiological, and second-look arthroscopic outcomes in patients who underwent anterior cruciate ligament (ACL) reconstruction using a four-strand hamstring tendon graft (hamstring group) either without augmentation or with ligament augmentation and reconstruction system (LARS) augmentation (LARS augmentation group). From January 2018 to December 2019, patients who underwent ACL reconstruction were included. Patient-reported outcome measures (PROMs) were undertaken pre-operatively and at three, six, 12, and 24months post-operatively. Arthroscopic evaluation was performed focusing on the morphology of the graft based on graft tension, graft tear, and synovial coverage. A total of 178 consecutive patients received single-bundle ACL reconstruction, 89 patients in each group, and 20 patients were lost to follow-up in the first twoyears. At the threemonth follow-up, the LARS augmentation group had significantly higher Lysholm scores, IKDC scores, and KOS-ADLS scores than the hamstring group (P < 0.001). At the three, six and 12-month follow-ups, there were significantly higher Tegner scores and ACL-RSI scores in the LARS augmentation group than in the hamstring group (P < 0.05). At the three and sixmonth follow-ups, the LARS augmentation group had significantly higher rates of return to sports and return to sports at their preinjury level (P < 0.05). There were no between-group differences in other outcomes, including arthroscopic outcomes, graft signal intensity, post-operative complications or rerupture rates. Autologous hamstring augmented with the LARS augmentation technique provides good and realistic clinical and functional results during the early post-operative period with high levels of satisfaction of patients, including participation in sports and physical activity, and high rates of return to sports at the preinjury level, without any apparent complications compared with hamstring ACL reconstruction alone. No increases in complication, reinjury rates, or increased lateral laxity were observed at the 12-month or 24-month follow-up.

Anterior Cruciate Ligament Reconstruction Using Autologous Hamstrings Augmented With the Ligament Augmentation and Reconstruction System Versus Hamstrings Alone: A Comparative Cohort Study.

Background:Few studies have reported the return-to-sports (RTS) rate in patients after augmentation of autologous anterior cruciate ligament reconstruction (ACLR) with the Ligament Augmentation and Reconstruction System (LARS).Purpose/Hypothesis:The purpose of this study was to compare postoperative outcomes in patients who underwent ACLR with single-bundle 4-strand hamstring autograft either without augmentation (HA-ACLR group) or with LARS augmentation (AUG-ACLR group). It was hypothesized that clinical outcomes and RTS rates would be better in the AUG-ACLR group at the 1-year follow-up, with similar outcomes in both cohorts by 2 years.Study Design:Cohort study; Level of evidence, 3.Methods:Patients who underwent ACLR between April 2014 and December 2017 were included in the current comparative study if they were skeletally mature and had 1- and 2-year follow-up outcomes; patients with concomitant meniscal surgery were also included. Included were 66 patients with AUG-ACLR (mean age, 26.8 years; 67% male) and 130 patients with HA-ACLR (mean age, 27.5 years; 61% male). Subjective outcome measures included the International Knee Documentation Committee Subjective Knee Evaluation Form, Knee injury and Osteoarthritis Outcome Score, Lysholm scale, Tegner activity scale, and the Noyes sports activity rating scale. Objective measures included knee laxity, maximal isokinetic knee flexion and extension strength, and the results of 4 functional hop tests.Results:There were no significant differences between the study groups in age, sex distribution, body mass index, time to surgery, or number of concurrent meniscal surgeries. At the 1-year follow-up, the AUG-ACLR group had a significantly higher Tegner score (P = .001) and rates of RTS (P = .029) and return to preinjury level of sport (P = .003) compared with the HA-ACLR group. At the 2-year follow-up, there were no differences in these measures between groups. There were no between-group differences in other subjective outcomes, knee laxity, or strength and hop test results at either postoperative time point. There were also no differences in rerupture rates or other complications between the groups.Conclusion:Patients with AUG-ACLR had higher 1-year postoperative Tegner scores and rates of RTS and preoperative sport level compared with the HA-ACLR group. The 2-year rerupture rate for the AUG-ACLR group was low, and no intra-articular inflammatory complications were noted.

A Prospective 2-Year Clinical Evaluation of Augmented Hip Abductor Tendon Repair.

Background:Hip abductor tendon (HAT) tearing is commonly implicated in greater trochanteric pain syndrome. Studies reporting surgical outcomes are often on small cohorts and with limited information on functional improvement.Purpose:To report the 2-year clinical and functional outcomes in a series of patients undergoing HAT repair augmented with a ligament augmentation and reconstruction system (LARS) ligament.Study Design:Case series; Level of evidence, 4.Methods:Between October 2012 and December 2016, a total of 142 patients with symptomatic HAT tears underwent open bursectomy, V-Y lengthening, and reattachment of the tendon with suture anchors augmented with a LARS ligament. This included 132 women (93%) with a mean age of 64.3 years (range, 43-84 years), a mean body mass index of 28.2 kg/m2 (range, 20.0-41.3 kg/m2), and an average duration of symptoms of 4.0 years (range, 6 months-20 years). Following surgery, patients underwent a graduated rehabilitation program consisting of hydrotherapy and land-based exercises. Patient-reported outcome measures (PROMs) were evaluated preoperatively and at 3, 6, 12, and 24 months postoperatively with the Harris Hip Score, Oxford Hip Score, 12-item Short Form Health Survey, and visual analog scale (VAS) for pain. Hip range of motion, hip abduction strength, 30-s single-leg stance (SLS), and 6-minute walk test (6MWT) capacity were evaluated. Patient satisfaction and perceived global rating of change were evaluated postsurgery. Analysis of variance was employed to evaluate clinical improvement over time.Results:A significant improvement (P < .05) was demonstrated up to 24 months in all PROMs and clinical scores, including hip range of motion in all planes, hip abductor strength limb symmetry indices (mean ± SD; presurgery, 90.1% ± 42.5%; 24 months, 102.6% ± 15.0%), and the 6MWT (presurgery, 421.8 ± 91.9 m; 24 months, 509.7 ± 105.1 m). Furthermore, several variables, including pain (VAS and pain scores during the 6MWT and 30-s SLS) and patient-perceived improvement (global rating of change), continued to improve from 12 to 24 months. At 24 months, 95.7% of patients were satisfied with their surgical outcome (excluding 3 patients who underwent reoperation within the 24-month period). There was a 5.6% (n = 8) failure rate over the study period.Conclusion:HAT repair augmented with a synthetic ligament demonstrated significantly improved clinical and functional outcomes, high levels of patient satisfaction, and a relatively low failure rate up to 24 months postsurgery.Registration:ACTRN12616001655437 (Australian New Zealand Clinical Trials Registry).

ACL Reconstruction Using Autologous Hamstrings Augmented With the Ligament Augmentation and Reconstruction System Provides Good Clinical Scores, High Levels of Satisfaction and Return to Sport, and a Low Retear Rate at 2 Years.

Background:There are a number of surgical methods for undertaking anterior cruciate ligament (ACL) reconstruction (ACLR), although relatively high rates of ipsilateral retears and contralateral tears exist, with only 65% of patients returning to their preinjury level of sport. ACLR techniques adopting synthetic augmentation have been proposed in an attempt to improve clinical outcomes and reduce reinjury rates.Purpose:To determine the efficacy of ACLR using autologous hamstrings augmented with the Ligament Augmentation and Reconstruction System (LARS).Study Design:Case series; Level of evidence, 4.Methods:A total of 65 patients were prospectively treated with arthroscopically assisted single-bundle ACLR using hamstrings augmented with the LARS, of whom 50 were available for 1- and 2-year reviews. Patient-reported outcome measures (PROMs), KT-1000 arthrometer testing, knee range of motion, peak isokinetic knee strength testing, and a battery of 4 hop tests were employed. Limb symmetry indices (LSIs) were calculated. Analysis of variance was used to evaluate differences over time and between limbs. Data on return to the preinjury level of sport, retears, and reoperations were collected.Results:High PROM scores were demonstrated at 1 and 2 years. Before the injury, 47 patients (94%) were actively participating in level 1 or 2 sports, with 38 (76%) and 43 (86%) patients having returned at 1 and 2 years, respectively. Normal (<3 mm; 90%) or nearly normal (3-5 mm; 10%) KT-1000 arthrometer side-to-side differences were observed at 2 years. Apart from knee flexion (P < .0001), extension (P = .001), and the 6-m timed hop (P = .039), there were no between-limb differences at 1 year, and there were no differences on any objective measures at 2 years (all P > .05). Mean LSIs across all measures were ≥90%. At 2 years, 84% to 90% of patients were ≥90% on the hop tests, with 72% and 76% of patients having ≥90% for extension and flexion strength, respectively. Two reoperations were undertaken for meniscal tears (7 and 8.5 months), 1 patient (2%) suffered a retear at 7 months, and 2 patients (3%) suffered a contralateral tear (8 and 12 months).Conclusion:This augmented ACLR technique demonstrated good clinical scores, a high rate of return to sport, and low rates of secondary ruptures and contralateral ACL tears at 2 years. Some caution should be noted in interpreting these results, as 15 of 65 patients (23%) were not included in the 2-year follow-up.

Limb Salvage Using Non-hinged Endoprosthesis and Staged Correction of Leg-length Discrepancy for Children with Distal Femoral Malignant Tumors.

ObjectiveLimb salvage in pediatric patients remains a challenge. We describe a staged strategy. The procedure includes: (i) tumor removal and non‐hinged static endoprosthesis reconstruction; (ii) leg length discrepancy (LLD) correction by shoe lift or distraction osteogenesis; and (iii) maturity reconstruction by regular endoprosthesis. The aim of the study was to investigate the results of non‐hinged static megaprosthesis reconstruction and staged LLD correction in the treatment of malignant tumors in the distal femur in children.MethodsNon‐hinged megaprostheses were implanted in 12 pediatric patients with osteosarcoma in the distal femur. The prosthesis consists of a femoral component with constrained condylar knee (CCK) design, and a tibial component with a small‐diameter press‐fit stem and derotation fins. A posterior stabilizing polyethylene component is fixed on the tibial component. The cases were prospectively followed up with focus on the growth rate of adjacent uninvolved bone in the salvaged limb, joint stability, knee stability, function outcome, length discrepancy, and surgery‐related complications.ResultsThere were five girls and seven boys included in the study, with an average age at the time of primary surgery of 10.0 years (range, 8–12 years). All the tumors were located in the distal femur. The average follow up was 76.3 months (range, 24–139 months). The Ligament Augmentation and Reconstruction System (LARS) ligament was used in two patients to enhance the soft tissue reattachment and reconstruct medial collateral ligament (MCL). Ten patients were alive at the final follow‐up and two had died of lung metastases. Expected LLD was 6.7 cm (range, 3.0–13.2 cm) at initial surgery. At the final follow‐up, nine patients reached skeletal maturity and the actual LLD at the femur was 5.3 cm (range, 3.0–10.1 cm), excluding 1 cm correction at initial surgery by endoprosthesis. The proximal tibia physis showed an average of 86.7% (range, 56.5%–100%) growth of the contralateral side. The mean reduction in tibial length was 1.2 cm (range, 0.5–4.7 cm). Six patients received distraction osteogenesis at a mean length of 5.4 cm (range, 3.0–9.1 cm). Range of knee movement was between 85° and 125°, with an average of 102.5°. The Musculoskeletal Tumor Society 93 score of patients alive was 80.6 (range, 60–90).ConclusionNon‐hinged static megaprosthesis followed by LLD correction with shoe lift or staged distraction osteogenesis appears to be an alternative option to treat children with malignant bone tumors around the knee.

Surgical treatment of acute and chronic AC joint dislocations: Five-year experience with conventional and modified LARS fixation by a single surgeon

BackgroundDifferent surgical fixation methods are available for the treatment of acromioclavicular (AC) joint dislocations. The aim of this study was to present the results of five years of experience with the Ligament Augmentation and Reconstruction System (LARS) fixation technique by a single surgeon. MethodsA single-center retrospective cohort study was performed. All patients treated for an AC joint dislocation with LARS fixation by the same surgeon between 2012 and 2016 (n = 20) were eligible for inclusion. All these dislocations were unstable injuries, Rockwood type-III or higher, requiring acute or chronic repair. The primary outcome was the QuickDASH score. Secondary outcomes were the Subjective Shoulder Value (SSV), Numerical Rating Scale (NRS) pain score, return to work, complications, and implant removal. Results17 patients (85%) were available for final follow-up. The median follow-up was 23 months (IQR; 17─34). The median QuickDASH score was 7 (IQR; 2–18), the median SSV was 90 (IQR; 80–90), and the median NRS pain score was 2 (IQR; 1–3). Patients returned to work after a median of 8 weeks (IQR; 6–12). There was no significant difference in functional outcome scores between acute and chronic repair, or between the conventional and modified LARS fixation groups. There were two major complications requiring revision surgery, one ruptured LARS ligament and one case of deep wound infection. Implant removal was performed in one patient. ConclusionsThe LARS ligament fixation technique seems to be effective for the treatment of AC joint dislocations, resulting in good short- and mid-term patient-reported functional outcome. LARS fixation might also be an acceptable treatment option for active patients with symptomatic chronic AC dislocations. Level of evidenceLevel III, Retrospective Comparative Study, Treatment Study.

Foreign Body Reaction Associated With Artificial LARS Ligaments: A Retrieval Study.

Background:Artificial ligaments have been developed and used in the treatment of ligamentous injuries since the 1970s. The early generation of artificial ligaments showed promising short-term results but resulted in high rates of rupture and inflammatory reaction in the surrounding tissues.Purpose:To determine whether the use of Ligament Augmentation and Reconstruction System (LARS) ligaments is associated with the development of intra-articular foreign body reaction.Study Design:Case series; Level of evidence, 4.Methods:LARS ligaments were explanted from 15 patients under 6 consultant orthopaedic surgeons at 8 surgical centers. Of these, 14 explanted samples were sent for macroscopic and histological analysis, with the 1 remaining sample sent for scanning electron microscopy, to assess for inflammatory change as well as the degree of fibrous tissue ingrowth.Results:We observed a foreign body reaction in 10 of 14 explanted LARS ligaments. Seven samples demonstrated fibrous tissue ingrowth, with 5 producing only focal or incomplete ingrowth. The 2 samples with extensive fibrous coverage were completely free of any foreign body reaction, while all 5 remaining samples with only focal or partial fibrous ingrowth were associated with at least some degree of harmful immune response.Conclusion:The LARS ligament is still associated with a clinically significant degree of foreign body reaction despite the LARS Company’s efforts to reduce complications through improved design. The development and completion of fibrous tissue ingrowth may work to reduce the occurrence of a foreign body reaction.

Complex knee injuries treated in acute phase: Long-term results using Ligament Augmentation and Reconstruction System artificial ligament.

AIMTo present the long-term results of complex knee injuries, treated early using the Ligament Augmentation and Reconstruction System (LARS) artificial ligament to reconstruct posterior cruciate ligament (PCL).METHODSFrom September 1997 to June 2010, thirty-eight complex knee injuries were treated, where early arthroscopic PCL reconstructions were undergone, using the LARS (Surgical Implants and Devices, Arc-sur-Tille, France) artificial ligament. Exclusion criteria were: Late (> 4 wk) reconstruction, open technique, isolated PCL reconstruction, knee degenerative disease, combined fracture or vascular injury and use of allograft or autograft for PCL reconstruction. Clinical and functional outcomes were assessed with IKDC Subjective Knee Form, KOS-ADLS questionnaire, Lysholm scale and SF-12 Health Survey. Posterior displacement (PD) was measured with the Telos Stress Device.RESULTSSeven patients were excluded; two because of co-existing knee osteoarthritis and the remaining five because of failure to attend the final follow-up. The sample consisted of 31 patients with mean age at the time of reconstruction 33.2 ± 12.5 years (range 17-61). The postoperative follow-up was on average 9.27 ± 4.27 years (range 5-18). The mean average IKDC and KOS scores were 79.32 ± 17.1 and 88.1 ± 12.47% respectively. Average PD was 3.61 ± 2.15 mm compared to 0.91 ± 1.17 mm in the uninjured knees (one with grade 1 + and two with grade 2 +). Dial test was found positive in one patient, whereas the quadriceps active drawer test was positive in three patients. None was tested positive on the reverse-pivot shift test. The range of motion (ROM) was normal in thirty knees, in comparison with the contralateral one. There was no extension deficit. Osteoarthritic changes were found in three knees (9.6%).CONCLUSIONEarly treatment of complex knee injuries, using LARS artificial ligament for PCL reconstruction sufficiently reduces posterior tibia displacement and provides satisfactory long-term functional outcomes.

LARS Artificial Ligament Versus ABC Purely Polyester Ligament for Anterior Cruciate Ligament Reconstruction.

Background:Graft choice for anterior cruciate ligament (ACL) reconstruction is of critical importance. Various grafts have been used so far, with autografts long considered the optimal solution for the treatment of ACL-deficient knees. Limited data are available on the long-term survivorship of synthetic grafts.Purpose:To compare the functional outcome and survivorship of ACL reconstructions performed using the LARS (ligament augmentation and reconstruction system) ligament and the ABC (active biosynthetic composite) purely polyester ligament.Study Design:Case series; Level of evidence, 4.Methods:The results of 72 patients who underwent primary arthroscopic ACL reconstruction with the LARS ligament and 31 cases with an ABC purely polyester ligament were reviewed. The mean follow-up periods for the LARS and ABC groups were 9.5 and 5.1 years, respectively. A survivorship analysis of the 2 synthetic grafts was performed using the Kaplan-Meier method with a log-rank test (Mantel-Cox, 95% CI). Lysholm, Tegner activity, Knee injury and Osteoarthritis Outcome Score (KOOS), and International Knee Documentation Committee (IKDC) scores as well as laxity measurements obtained using a KT-1000 arthrometer were recorded for all intact grafts, and a Mann-Whitney U test was used for comparison reasons.Results:The rupture rates for LARS and ABC grafts were 31% (95% CI, 20%-42%) and 42% (95% CI, 25%-59%), respectively. For intact grafts, the mean Lysholm score was good for both groups (90 for the LARS group and 89 for the ABC group), with the majority of patients returning to their preinjury level of activities, and the mean IKDC score was 90 for the LARS group and 86 for the ABC group.Conclusion:The rupture rates of both LARS and ABC grafts were both high. However, the LARS ligament provided significantly better survivorship compared with the ABC ligament at short- to midterm follow-up (95% CI).

Acute surgical management of traumatic knee dislocations — Average follow-up of 10 years

BackgroundTraumatic knee dislocations have been managed historically by means of either delayed reconstruction or non-operative methods. More recently, there has been a trend towards early reconstruction. There is no clear consensus in the literature as to how such patients should be managed and in what time frame. ObjectiveThe aim of this study was to establish the long-term outcome of patients who underwent acute surgical management of their traumatic knee dislocation. MethodsThirty-six patients with traumatic knee dislocations were treated by multi-ligament reconstruction. All surgical interventions occurred within 21days of presentation. The collateral ligament complexes were primarily repaired where possible and reconstructions were performed with either autograft, allograft or the ligament augmentation and reconstruction system (LARS) synthetic graft. ResultsThe mean time to surgery was 12days (1 to 21) with a mean follow-up of 10.1years (7 to 19). The International Knee Documentation Committee (IKDC) assessment demonstrates that 56% of patients went on to have “nearly normal” knee function and the average Tegner–Lysholm score of 80 (57 to 91), is consistent with good function. The Knee Outcome score (KOS) was 84% for Activities of Daily Living and 74% for Sports. ConclusionThis study demonstrates a high level of overall knee function following the acute surgical reconstruction of traumatic knee dislocations. Level of evidenceLevel 2B: Cohort Study with Outcome Measures.

Clinical and radiological results after coracoclavicular ligament reconstruction for type III acromioclavicular joint dislocation using three different techniques. A retrospective study

the purpose of this retrospective study was to present the outcomes of three different techniques for the treatment of type III acromioclavicular joint dislocations: arthroscopic TightRope (TR), arthroscopic GraftRope (GR), and open reconstruction of the coracoclavicular (CC) ligament using the Ligament Augmentation and Reconstruction System (LARS). eighteen patients underwent clinical and radiological evaluations after a mean follow-up time of 43 months. The following clinical outcome measures were considered: the Disability of the Arm, Shoulder and Hand outcome measure (DASH), the Nottingham Clavicle Score (NCS), and the Constant score (CS). On X-rays, the CC distance was measured. the median DASH score at follow-up was 12.5 in the TR group, 5 in the GR group, and 4.2 in the LARS group. The median NCS value was 88 in the TR group, 88 in the GR group, and 91 in the LARS group. The median CS was 100 in the TR group, 95 in the GR group, and 94.5 in the LARS group. The mean CC distance was 10.3 mm in the TR group, 13.8 in the GR group, and 16.6 in the LARS group. all three techniques proved to be reliable in providing good clinical outcomes, although none of the studied techniques demonstrated reliability in maintaining anatomical reduction after surgery. Level III, retrospective comparative study.

The biomechanics of biodegradable versus titanium interference screw fixation for anterior cruciate ligament augmentation and reconstruction.

The ligament augmentation and reconstruction system (LARS) is one of the options available for anterior cruciate ligament (ACL) reconstruction. To date, however, there are no published data regarding the biomechanical properties of LARS fixation for ACL reconstruction. The aim of this study was to investigate the biomechanical properties of various LARS interference-screw fixations. A total of 100 LARS ligaments were fixed in porcine femurs with five different interference screws (four biodegradable screws and one titanium interference screw) introduced from inside-out or extra-articularly outside-in. Each group consisted of ten specimens. The constructs were cyclically stretched and subsequently loaded until failure. We evaluated the maximum load before failure, elongation during cyclic loading, stiffness, and failure mode. Elongation during cyclical loading for all devices tested was significantly larger between the first and 20th cycles than between the 20th and 500th cycles (p < 0.05). Maximum failure load was not significantly lower for the biodegradable screws than for the titanium screws (p > 0.05). All specimens failed because of ligament pull-out from the bony tunnel. Our findings suggest that biomechanical secure fixation of the LARS for ACL reconstruction can be achieved using either biodegradable or titanium interference screws. The stability of fixation is independent of the approach, type of investigation, and type of fixation (extra-articular outside-in or intra-articular inside-out).

Evaluation of the coracoclavicular reconstruction using LARS artificial ligament in acute acromioclavicular joint dislocation

The most appropriate procedure for surgical treatment of severe acromioclavicular (AC) joint dislocation was still not clear. The purpose of this study is to evaluate the outcomes of coracoclavicular (CC) reconstruction with ligament augmentation and reconstruction system (LARS) artificial ligaments for the treatment of acute complete AC joint dislocation. Twenty-four patients (16 male and 8 female, ages ranged from 21 to 45) with acute complete AC joint dislocations were treated with CC reconstruction using LARS artificial ligaments. All these dislocations were unstable injuries. Clinical evaluation was used by the Constant scores and VAS. The radiographic evaluation consisted of Zanca radiographs for bilateral AC joint and axillary radiographs for the injured shoulder. All patients had follow-up times of 36months (range 6-60). The Constant scores rose from 62.3±6.9 preoperatively to 94.5±9.3 at final evaluation (P<0.05). Preoperative VAS scores were 5.1±1.7, and the VAS scores at the last review were 0.7±1.4 (P<0.05). Follow-up radiographs showed anatomical reduction in 20 patients and slight loss of reduction in 4 patients. Calcification of CC ligament in 4 patients, degenerative change around the AC joint in 2 patient and clavicular osteolysis around screws in one patient were found. LARS artificial ligament for reconstruction of CC can provide immediate stability and allow early shoulder mobilization with good functional results and few complications. This procedure was an effective and safe method to treat grade III and more AC joint dislocations. IV.

ARTHROSCOPIC ANTERIOR CRUCIATE LIGAMENT RECONSTRUCTION WITH LARS ARTIFICIAL LIGAMENT: AN 8–15-YEAR FOLLOW-UP

The aim of this study was to evaluate the clinical results of anterior cruciate ligament (ACL) reconstruction with an artificial ligament of the Ligament Augmentation and Reconstruction System (LARS) via an 8–15-year follow-up. Between January 1996 and January 2003, 38 patients received arthroscopic anterior cruciate reconstruction with the LARS artificial ligament at the Show Chwan Memorial Hospital, Changhua, Taiwan. Among them, 28 cases were included in this study. Excluding two failure cases, 26 cases were involved in the statistical analysis of various clinical assessments. The mean follow-up period after reconstruction was 11.4 ± 1.9 years. Assessment of clinical results included physical examination, magnetic resonance imaging, radiography, KT-1000 arthrometer test for knee stability, range of motion measurement, Lysholm score, and Tegner scale activity evaluations. The outcomes showed that among these 28 follow-up patients, there were two failure cases. The survival rate of LARS ligament reconstruction in this long-term follow-up was 92.9%. Among the 26 clinical assessed cases, the stability of the knee joint was improved as the anterior translation displacement measured by arthrometer reduced from 7.0 ± 3.1 mm (range: 4–17 mm) pre-operatively to 1.7 ± 1.7 mm (range: 0–6 mm) post-operatively. The Lysholm score improved from 39.7 ± 11.5 pre-operatively to 85.9 ± 19.6 post-operatively. Tegner activity scale improved from 3.2 ± 1.5 pre-operatively to 5.4 ± 2.4 post-operatively. All three improvements have statistic significance as the p-values were less than 0.05. In conclusion, ruptured ACL reconstruction with LARS artificial ligament has a survival rate of 92.9% and complication rate of 28.6% in this 8–15-year follow-up.

The knee joint in sports medicine

The knee joint in sports medicine

PolyNaSS bioactivation of LARS artificial ligament promotes human ligament fibroblast colonisation in vitro

Introduction of a new generation of artificial ligaments for ACL reconstruction, the Ligament Augmentation and Reconstruction System (LARS), gives promising clinical results [1]. The current literature supports the use of LARS from short to medium term. To go even further to improve the biocompatibility of this biomaterial, poly(sodium styrene sulfonate) (polyNaSS) was grafted onto its surface. Studies using sheep animal model showed improvement of knee functionalities with this grafted artificial ligament and a better adhesion of human cell lines. To better understand this in vivo improvement of integration with the bioactivated artificial prosthesis, in vitro studies were leaded using human ligament fibroblasts. Human ligament fibroblasts isolated from human ruptured ACL were amplified and seeded onto poly(NaSS) grafted and non-grafted PET scaffold (Lars ligament) under standard culture conditions. Cellularized fibers were observed under scanning electron microscopy and histological and immunohistological studies were performed. Cells are localized around the grafted PET fibers of the bioactive ligament and penetrate in the scaffold. On ungrafted fibers, cells stay around the scaffold. On grafted fibers, collagen I appears strongly organized whereas is thin and dispersed on non grafted fibers. Finally, grafting altered localization of decorin. PolyNaSS grafting enhances human ligament fibroblast organisation in vitro in contact with biomaterial and improves collagen and decorin deposits around fibers.