Meniscal Substitution: A Literature Review

With the increased awareness that meniscectomy results in degenerative changes in the knee joint, research is now aimed at substituting the meniscus that had been previously removed. Surgical attempts at replacing the meniscus include the use of autografts, allografts, and artificial synthetic prosthesis. This paper will review the available literature regarding each type of meniscal substitute. Surgical procedures, results, and considerations relating to the different substitutes will be examined. While studies indicate that meniscal transplantation is technically feasible, the long-term results are unknown. More research is necessary to determine if meniscal substitutes can survive for a prolonged time and function to prevent further degenerative changes from occurring

Anterior Cruciate Ligament injury, Patient Variables, Outcomes and Knee Osteoarthritis

The ruptured anterior cruciate ligament (ACL) leads to immediate symptoms that severely affect the individual and receives great attention among the scientific community, yet there is still no consensus on the optional form of treatment. An ACL injury is also a well known high risk factor for the development of knee osteoarthritis (OA) some decades later. Knee OA development after an ACL injury is multi-factorial. All patient variables must be further explored before better guidelines on ACL injury treatment can be issued. I studied 100 patients with an acute complete ACL tear over 15 years and evaluated the outcome after a primary non-surgical treatment algorithm based on early neuromuscular knee rehabilitation by a physical therapist and initial activity restrictions. Patients had less radiographic knee OA than in historical retrospective studies, and still had very small subjective symptoms. When OA was present, a concomitant meniscal injury treated by means of partial meniscectomy was the most important risk factor. Another cohort of 29 ACL-injured patients were examined with delayed gadolinium-enhanced MRI of cartilage (dGEMRIC) to estimate cartilage GAG content, as a proxy for cartilage integrity. Results indicated knee cartilage GAG changes 2 years after an ACL injury. Patients who had sustained a meniscectomy, or had a BMI > 25 kg/m2, had the most impaired cartilage quality, which supports the contention that this method can detect a cartilage matrix change that may be indicative of increased risk of OA. The data presented can help medical staff in decision-making when treating the ACL-injured patient

Long-term outcome of meniscus and cruciate ligament stabilization in the injured knee.

De lange termijn resultaten van meniscale suturen en voorste kruisband reconstructies worden geëvalueerd. Meniscale suturen in stabiele knieën geven de beste resultaten. De kans op het ontwikkelen van vroegtijdige degeneratieve veranderingen (arthrose) is 4 maal hoger bij meniscus herstel in instabiele knieën (vorste kruisband deficient) tov. meniscus herstel in stabierle knieën

Functional Outcomes of Anterior Cruciate Ligament Reconstruction Surgery

Anterior cruciate ligament (ACL) is one of the most common sports injuries with a reported yearly incidence rate of over two million injuries worldwide. The main aim of this thesis is to investigate various aspects related to the functional outcomes of ACLR through a series of clinical studies. Ethical approval was sought and granted by the North of Scotland Research Ethics Service. A systematic review was conducted to investigate the outcome measures used in Level I and II clinical ACLR studies. The review showed wide variability in the outcome measures utilised with no consensus on the ideal outcome instrument or combination of instruments to report the outcome of ACLR. Five-year results from the UK National Ligament Registry (NLR) were analysed with review for limitations of registry data and future recommendations. The data analysed provided a comprehensive review for the demographics, surgical techniques and functional outcomes of ACLR surgery across the UK. NLR data is limited by multiple factors including high rate of incomplete data, duplication of data, poor patient compliance and lack of validation of the data. A study was conducted to examine the hypothesis that patients with ACLR do not return to their pre-injury functional status at two years postoperatively. The study showed significant improvement in patient symptoms postoperatively compare to their post-injury scores, but the majority of patients failed to achieve their pre-injury functional outcome scores at 2 years postoperatively. In a comparative study, the anteromedial portal (AM) technique in femoral tunnel drilling was compared with the trans-tibial (TT) technique with respect to radiological and functional outcomes. The hypothesis was that AM portal produces better functional outcomes compared with TT technique. We found that the AM portal achieved a more anatomical position of the graft but there was no difference between the two techniques in functional outcome at 2 years postoperatively. However, ACLR with the AM portal technique had higher graft failure rate compared with the TT technique. The medium- term outcome of all-inside meniscal repairs was investigated in a longitudinal study. Meniscal repairs with concomitant ACLR had a lower failure rate compared with isolated meniscal repairs. This indicates that surgeons should have a low threshold for repairing meniscal tear during ACLR surgery. The healing response technique was studied in a selected group of patients with complete proximal ACL tears. This technique yielded good functional outcome for most of the patients at 2 years postoperative follow up. The studies included in this thesis provides substantial information for surgeons treating patients with ACL injuries. It provides a platform for further research studies investigating the outcomes of ACLR surgery

Cartilage adaptation after anterior cruciate ligament injury and reconstruction: implications for clinical management and research? A systematic review of longitudinal MRI studies

SummaryObjectiveTo summarize the current evidence of magnetic resonance imaging (MRI)-measured cartilage adaptations following anterior cruciate ligament (ACL) reconstruction and of the potential factors that might influence these changes, including the effect of treatment on the course of cartilage change (i.e., surgical vs non-surgical treatment).MethodsA literature search was conducted in seven electronic databases extracting 12 full-text articles. These articles reported on in vivo MRI-related cartilage longitudinal follow-up after ACL injury and reconstruction in “young” adults. Eligibility and methodological quality was rated by two independent reviewers. A best-evidence synthesis was performed for reported factors influencing cartilage changes.ResultsMethodological quality was heterogenous amongst articles (i.e., score range: 31.6–78.9%). Macroscopic changes were detectable as from 2 years follow-up next to or preceded by ultra-structural and functional (i.e., contact-deformation) changes, both in the lateral and medial compartment. Moderate-to-strong evidence was presented for meniscal lesion or meniscectomy, presence of bone marrow lesions (BMLs), time from injury, and persisting altered biomechanics, possibly affecting cartilage change after ACL reconstruction. First-year morphological change was more aggravated in ACL reconstruction compared to non-surgical treatment.ConclusionIn view of osteoarthritis (OA) prevention after ACL reconstruction, careful attention should be paid to the rehabilitation process and to the decision on when to allow return to sports. These decisions should also consider cartilage fragility and functional adaptations after surgery. In this respect, the first years following surgery are of paramount importance for prevention or treatment strategies that aim at impediment of further matrix deterioration. Considering the low number of studies and the methodological caveats, more research is needed

Tensile Mechanics of the Knee Meniscus in the Context of Cracks: Failure and Fracture Mechanisms, Strain Concentrations, and the Effect of Specimen Shape

Knee meniscus tears (cracks) are a major cause of knee dysfunction and osteoarthritis, but little is known about how they grow or what effects they have on meniscus mechanics. The objective of this work was to investigate the mechanics and failure of crack-free and cracked meniscus in uniaxial tension, with specific attention to failure mechanisms (fracture and bulk rupture) and local strain concentrations. A finite element model was used to find a test configuration likely to cause fracture and crack propagation. Center cracks with a 45° crack–fiber angle were selected for producing large fiber stresses, and 90° edge cracks were selected for producing large inter-fiber shear stresses. The circumferential and radial tensile mechanics of the meniscus were quantified using ex vivo tensile testing. A fiber recruitment model was fitted to the test data, and a method was developed to quantify the inflection (yield) point and modulus based on the shape of the stress–strain curve. Comparison of tensile test specimen shapes showed that an expanded tab specimen shape produces more rapid and complete fiber recruitment, lesser yield strain, and greater peak stress (strength) than rectangle specimens, and, likely, dogbone specimens. Mechanical effects of meniscus cracks were quantified by comparing cracked and crack-free specimens in circumferential and radial tension. The cracks did not cause a decrease in peak stress, indicating fracture did not occur. However, significantly greater longitudinal strain and shear strain was found near the crack tip for circumferential tension specimens. In radial tension specimens, all strain field components were greater near the crack tip. Failure tended to proceed along fascicle boundaries. Circumferential specimens failed by widespread interdigitating fiber pull-out, which also caused crack deflection. Radial specimens failed by necking and fiber rotation. These data demonstrate the remarkable fracture toughness of the meniscus, but increased near-tip strain may cause sub-failure damage and dysfunction. These results provide functional targets for interventions to repair or regenerate the meniscus

Minimizing the risk of graft failure after anterior cruciate ligament reconstruction in athletes. A narrative review of the current evidence

Anterior cruciate ligament (ACL) tear is one of the most common sport-related injuries and the request for ACL reconstructions is increasing nowadays. Unfortunately, ACL graft failures are reported in up to 34.2% in athletes, representing a traumatic and career-threatening event. It can be convenient to understand the various risk factors for ACL failure, in order to properly inform the patients about the expected outcomes and to minimize the chance of poor results. In literature, a multitude of studies have been performed on the failure risks after ACL reconstruction, but the huge amount of data may generate much confusion. The aim of this review is to resume the data collected from literature on the risk of graft failure after ACL reconstruction in athletes, focusing on the following three key points: individuate the predisposing factors to ACL reconstruction failure, analyze surgical aspects which may have significant impact on outcomes, highlight the current criteria regarding safe return to sport after ACL reconstruction

Modern approach in a meniscal injury treatment

Meniscal injuries are one of the most common pathologies in the orthopedic clinic. It is an injury which occurs in abnormal knee movement or as a form of a degenerative process over years. The types of meniscal injury are various in means of severity, patient history, clinical presentation and patient age. Discoveries in the meniscal biomechanics proposed great changes for the general health of the knee joint and advancement in the treatment. Meniscal pathology is better understood and the progress in diagnostics and treatment allows preservation of the knee from developing symptoms and secondary osteoarthritic changes. It was not long ago that any suspicion of a meniscal lesion led to open meniscectomy, which in most cases was total. Magnetic resonance imaging in the second part of the 20th century made revolutionary progress in classification and lesion analysis. Arthroscopy allowed less invasive treatment options and has rapidly replaced open total to arthroscopic partial meniscectomy with parallel development of meniscal tissue sparing treatments coordinately to statistical results. New promising options raised in development of various techniques of meniscal repair and transplantation. Meniscal repair shows promising results in its ever-evolving techniques including inside-out, outside-in and all inside. In the 1990s began the era of meniscal replacement as a modern possibility in treating meniscal pathologies. Increased improvements in graft fixation and extended indications for meniscus allografting have widened the demand for meniscal allografts