Effects Of Meniscectomy Research Articles

Effect of 1.5 mm biter-width meniscectomy on cadaveric knee pressure, peak pressure, force, and contact area

This study investigated the immediate biomechanical effects of a biter-width partial medial meniscectomy. Small tears on the free edge of the meniscus are occasionally discovered during arthroscopic knee procedures. Removal of these tears often requires no more width than that of a biter from the edge. While past cadaveric partial meniscectomy studies have reported on the effects of meniscectomies from resection of one-third to three-quarters of meniscal width, the biomechanical sequelae of substantially smaller meniscectomies remain unknown. This study was performed to determine how single-biter-width meniscectomies affect the pressure distribution and peak pressure on the tibial plateau, as these parameters are correlated with increased likelihood of development of osteoarthritis. Eight cadaveric knees were instrumented with a thin-film pressure sensor underneath the menisci while retaining the major ligaments and most of the capsule. Knees were loaded to 1000 N at angles of flexion of 0, 15, 30, and 45 in normal tibio-femoral angles and in 7° of varus. Pressure, peak pressure, force and contact area were recorded. Afterwards, biter-width meniscectomies were performed, and measures repeated. There were significant changes in contact area at most flexion and tibio-femoral angles. There were no changes in the amount of force that was transmitted through the medial compartment. The overall pressure on the tibial plateau did not change in most knee conditions and peak pressure did not change significantly in any condition. The changes in contact area were consistent with our expectations. Similarly, the lack of change in force was also expected. However, the lack of significant changes in pressure and peak pressure represent findings indicating that a biter sized meniscectomy may have clinically insignificant effects on biomechanics.

Vertical Tears of the Lateral Meniscus: Effects on In Vitro Tibiofemoral Joint Mechanics.

Background:Lateral meniscal tears are often seen with acute anterior cruciate ligament (ACL) injury and may be left in situ, repaired, or treated with meniscectomy. Clinical studies have shown good outcomes with vertical tears left in situ and poor outcomes following meniscectomy. However, clinically relevant studies are needed to establish a biomechanical foundation for treatment of these tears, particularly regarding the effects of meniscectomy.Purpose:To compare tibiofemoral joint mechanics following vertical lateral meniscal tears and meniscectomies. We hypothesized that a peripheral vertical tear of the lateral meniscus would alter joint mechanics, increasing contact pressure and area, and that more drastic effects would be seen following meniscectomy, at higher knee flexion angles, and with increased loads.Study Design:Controlled laboratory study.Methods:Ten fresh-frozen cadaveric knees (average age, 55 ± 12 years) were tested with 5 lateral meniscus states: intact, short vertical tear, extended vertical tear, posterior horn partial meniscectomy (rim intact), and posterior horn subtotal meniscectomy (rim excised). The specimens were loaded axially at knee flexion angles of 0°, 30°, and 60°, and musculotendinous forces were applied, simulating a 2-legged squat. Intra-articular contact pressures were measured using pressure-sensitive Fuji film. Kinematic data were acquired through digitization of fiducial markers.Results:Vertical tears did not cause a significant change in contact pressure or area. Partial meniscectomy increased maximum contact pressures in the lateral compartment at 30° and 60° from 5.3 MPa to 7.2 MPa and 7.6 MPa, respectively (P = .02, P = .007). Subtotal meniscectomy (8.4 MPa) significantly increased contact pressure compared with partial meniscectomy (7.6 MPa) at 60° (P = .04). Both meniscectomy states significantly increased contact pressures with increasing flexion from 0° to 60° (P < .001, P < .001).Conclusion:Vertical tears of the lateral meniscus during a simulated 2-legged squat did not significantly change contact pressures and areas compared with an intact meniscus. However, treating these tears with partial and complete meniscectomy significantly increased maximum contact pressures.Clinical Relevance:Biomechanical evidence supports treating vertical lateral meniscus tears with meniscal-sparing techniques as opposed to meniscectomy, which may lead to progressive degenerative joint disease from altered joint biomechanics.

(i) Basics of orthopaedic biomechanics

Abstract An outline of the basic principles of orthopaedic biomechanics is presented. Joint moments, muscle moment arms, in vivo forces, contact stresses and joint stability are all discussed with recent clinical examples to demonstrate their importance. These clinical examples focus on the hip and the knee and include: the effects of femoral offset and reducing the abductor moment arm on hip arthroplasty, how the knee adduction moment causes an asymmetric load distribution between the condyles, the magnitude of in vivo forces and their implications for wear, the consequences of meniscectomy on cartilage contact stresses, extreme contact stresses caused by edge loading in hip replacements, the effect of femoral head size and capsular repair in total hip replacement stability, knee medial rotation and the role of the anterior cruciate ligament in joint stability.

Inside-out meniscus repair

The long-term adverse effects of meniscectomy reported by many investigators has led to a treatment philosophy of meniscal repair and preservation whenever possible. Meniscal repair should allow a successful return by most patients to an active lifestyle with a decreased risk of developing osteoarthritis. Many different techniques of meniscal repair have been developed. The inside-out arthroscopic-assisted meniscal repair, developed by Henning, features: 1) meniscal and meniscosynovial abrasion to promote vascular healing, 2) cannulated suture-needle delivery system for suture placement, and 3) a posteromedial or lateral skin incision for needle retrieval to avoid neurovascular complications. The inside-out arthroscopic-assisted technique has been reproducible with an acceptable complication rate. It is time consuming and technically demanding, but offers considerable advantages over excision for ultimate knee function. The purpose of this chapter is to describe the indication, operative technique, postoperative rehabilitation and results of inside-out meniscal repair.

Pathways of load-induced cartilage damage causing cartilage degeneration in the knee after meniscectomy

Results of both clinical and animal studies show that meniscectomy often leads to osteoarthritic degenerative changes in articular cartilage. It is generally assumed that this process of cartilage degeneration is due to changes in mechanical loading after meniscectomy. It is, however, not known why and where this cartilage degeneration starts. Load induced cartilage damage is characterized as either type (1)—damage without disruption of the underlying bone or calcified cartilage layer—or type (2), subchondral fracture with or without damage to the overlying cartilage. We asked the question whether cartilage degeneration after meniscectomy is likely to be initiated by type (1) and/or type (2) cartilage damage. To investigate that we applied an axisymmetric biphasic finite element analysis model of the knee joint. In this model the articular cartilage layers of the tibial and the femoral condyles, the meniscus and the bone underlying the articular cartilage of the tibia plateau were included. The model was validated with data from clinical studies, in which the effects of meniscectomy on contact areas and pressures were measured. It was found that both the maximal values and the distributions of the shear stress in the articular cartilage changed after meniscectomy, and that these changes could lead to both type (1) and type (2) cartilage damage. Hence it likely that the cartilage degeneration seen after meniscectomy is initiated by both type (1) and type (2) cartilage damage.

Meniscopatia e postura.

The first aim of this work is not only to review the localised perspective of meniscopathy, concerned with the consequences of meniscectomy, but to also view it in a broader dimension, in the behavioural aspect--related to postural activity. The second aim is to establish the relationship between these two dimensions. Meniscopathies invariably lead to degenerative alterations of the knee joint--not sufficiently explained by the local factors--that result in a situation of osteoarthritis. Some investigators established that the osteoarthritis process should not be confined only to the mechanical responsibility, due to some studies that also confirm the existence of biochemical alterations. However, others have also shown that the nervous system (NS) is likely to influence the inflammatory manifestations through the unmyelinated afferent fibers and sympathetic efferent fibers of the joints. These fibers can interact with non-neural elements, releasing some mediators, such as P substance (PS) and norepinephrine (NE), which, by themselves, or through other substances, contribute to the exacerbation of the inflammatory process. In order to relate the facts above, this longitudinal study comprised the following approaches clinical: anthropometric; biotechnical; and posturographic. It was characterised by five moments of data collection, the periodicity of which is related to the time of the surgery: the first moment is before surgery, followed by the remaining four, at six-week intervals, the sample being composed of--15 male caucasians, aged between 20 and 30 years, working for the Air Force. These Subjects were divided into two groups, according to the amount of meniscus removed in the longitudinal direction. Group A--meniscectomy < 1/2 the longitudinal body, composed of 7 subjects, with an average age of 21.4 years; and Group B, meniscectomy > 1/2 the longitudinal body, composed of: 8 subjects, with an average age of 24.1 years. The statistical analysis contained a descriptive approach that was comprised of--the average, the standard deviation and the limits of variation or variation range--and an inferential approach--ANOVA-One Way. The error probability chosen was p < or = 0.05. The tendency to recover was shown from the 3rd moment onwards (12th week), muscular involution also being implied by an involution of orthostatic postural activity, which confirms the interdependence between muscular tonicity and postural activity. In what concerns metabolic alterations, there was no parallel evolution with the other variables since, when the signs of recovery of the latter were verified, the osteo-cartilaginous manifestations of destruction and reconstruction are more emphasised. On the other hand, the manifestations of postural activity reach their highest values before the manifestations protagonized by biochemical substances related to osteo-articular alterations. The accuracy of the posturographic tests for the diagnosis of deficiencies in what concerns of motor activity was shown, such as the inversion of the dislocation amplitudes on the YY' axis in relation to the XX', visible when the performance of the injured limb is evident, which leads us to admit that this fact is a consequence of meniscal pathology.

Effects of meniscectomy and anterior cruciate ligament transection on rabbit knee joint in-vitro mechanics and cartilage gross morphology

The effects of meniscectomy and anterior cruciate ligament transection on knee joint compression compliance, capacity of energy storage and cartilage gross morphology were studied in rabbits six and 12 weeks postoperatively. Joints with meniscectomy and intact ligaments at 12 weeks had a similar joint compression compliance as sham-operated joints with intact menisci, but had moderate unicompartmental osteoarthritis. Further, the capacity of energy storage of such a joint was reduced. Knees with anterior cruciate ligament transection had a higher joint compression compliance than knees with intact joint structures. Anterior cruciate ligament transection caused severe cartilage degeneration of both knee compartments at 6 weeks, but in knees with intact menisci the tibial cartilage was better preserved than in knees with meniscectomy. Synovitis was pronounced in anterior cruciate ligament transected knees. In conclusion, meniscectomy reduced the capacity of energy storage of the joint and was followed by moderate unicompartmental cartilage degeneration at 12 weeks. Anterior cruciate ligament transection especially when combined with meniscectomy led during a similar observation period to more dramatic effects on joint compression compliance and morphology.

Load-Bearing in the Ovine Medial Tibial Condyle: Effect of Meniscectomy

SummaryTotal removal of a knee joint meniscus is followed by osteoarthritis in many mammalian species. Altered load-bearing has been observed in the human knee following meniscectomy but less is known about biochemical effects of meniscectomy in other species. Using pressure sensitive paper in sheep knee (stifle) joints it was found that, for comparable loads, the load-bearing area on the medial tibial condyle was significantly reduced following medial meniscectomy. Also, for loads of between 50 N and 500 N applied to the whole joint, the slope of the regression of contact area against load was much smaller. Following medial meniscectomy, the ability to increase contact area as load increased was markedly reduced.The load bearing area on the medial tibial condyle was reduced following meniscectomy.