Horn Of Meniscus Research Articles

Use of intravoxel incoherent motion diffusion-weighted imaging in identifying the vascular and avascular zones of human meniscus.

To investigate the hypothesis that the intravoxel incoherent motion (IVIM) diffusion-weighted imaging may depict microcirculation of meniscus and the perfusion changes in meniscal disorder. Fifty patients received diffusion-weighted MRI with multiple b-values ranging from 0 to 400 s/mm2 . The four horns of the menisci were divided into normal, degenerated, and torn groups. IVIM parameters including perfusion fraction (f), pseudo-diffusion coefficient (D*), true diffusion coefficient (D), and the product of f and D* (f D*) of normal meniscal red zone and white zone were derived and compared for microcirculation changes of normal, degenerated, and torn posterior horn of the medial meniscus (PMM). The parameters between red and white zones among the groups were compared. Significant differences were considered when P < 0.05. Mean f and fD* were significantly higher in the red zone than those in the white zone for the normal four meniscal horns (P < 0.05), whereas D* (P = 0.882, 0.011, 0.593, and 0.33) and D (P = 0.186, 0.099, 0.767, and 0.041) did not significantly differ between the two zones. Among the normal, degenerated, and torn PMM, f was observed to be lower in the red zone of torn horns as compared to the normal horns (P = 0.013). D*, fD*, and D did not exhibit statistically significant difference among different groups (P = 0.353, 0.661, and 0.327, respectively). This hypothesis driven work shows that IVIM imaging is able to depict microcirculation of meniscus and the perfusion changes in meniscal disorder. 3 J. Magn. Reson. Imaging 2017;45:1090-1096.

EXPRESSION OF COLLAGEN TYPE I IN UNALTERED AND OSTEOARTHRITIC MENISCI OF KNEE JOINT.

Knee osteoarthritis is a progressive degenerative disease which affects meniscal tissue. The aim of this study was to determine the differences in collagen type I expression in macroscopically unaltered and osteoarthritic menisci, and correlate the expression with the grade of macroscopic damage, age and body mass index of patients, preoperative condition of anterior cruciate ligament, angulation and knee contracture. The control group consisted of 10 macroscopically unaltered menisci, while the experimental group had 35 osteoarthritic menisci. Besides macroscopic grading of meniscal damage, the analysis of collagen type I expression was determined by immunohistochemical staining with the corresponding antibody using semiquantitative scale scores and quantitative parameters: intensity of expression and stained area size. The results of semiquantitative evaluation showed a statistically significant decrease in collagen type I expression in osteoarthritic menisci, which correlated with an increase in macroscopic damage grade. The results of quantitative evaluation did not show a statistically significant decrease in the expression. In posterior meniscal horns, a more intense collagen type I expression was seen in the women, as well as a positive correlation of quantitatively evaluated expression with body mass index. Collagen type I expression in the anterior horns was significantly lower in varus alignment. In the semiquantitative evaluation, collagen type I expression in osteoarthritic menisci was significantly lower compared to macroscopically unchanged menisci. The decrease in the expression level correlates with the increase in the grade of macroscopic meniscal damage. There was no statistically significant difference in the quantitative evaluation of expression.

Arthroscopic Meniscal Allograft Transplantation With Soft-Tissue Fixation Through Bone Tunnels

Meniscal allograft transplantation improves clinical outcomes for patients with symptomatic meniscus-deficient knees. We describe an established arthroscopic technique for meniscal allograft transplantation without the need for bone fixation of the meniscal horns. After preparation of the meniscal bed, the meniscus is parachuted into the knee through a silicone cannula and the meniscal horns are fixed with sutures through bone tunnels. The body of the meniscus is then fixed with a combination of all-inside and inside-out sutures. This technique is reliable and reproducible and has clinical outcomes comparable with those of bone plug fixation techniques.

Predicted loading on the menisci during gait: The effect of horn laxity

Radiographic measurements have established a link between meniscus extrusion and meniscus degeneration as well as with knee osteoarthritis. The presented work combines medical imaging with motion capture data from two healthy female subjects to create subject specific knee models that predict tibio-menisco-femoral contact forces and ligament forces during muscle driven simulations of barefoot gait. The developed computational models were used to explore the relationship between the extent of meniscal extrusion and biomechanical function by altering the laxity of the meniscal horn attachments during gait. The extrusion distance increased as laxity increased and the amount of contact force transferred through the menisci during gait decreased rapidly as the meniscal attachments became more lax. Horn attachment lengths that were 20% longer than MRI attachment lengths resulted in an almost complete loss of force transfer through the menisci during the gait cycle. Relatively small changes (2–3mm) in the lengths at which horn bundles first become taut, manifested in large changes in the capacity of the tissue to transmit forces. As meniscal horn attachment laxity increased from 80% to 120% of the MRI measured horn distance, medial meniscus extrusion increased 3.9mm for the first subject and 2.7mm for the second subject. For the same horn laxity changes, the percent of medial tibiofemoral contact force transmitted through the medial meniscus during early stance decreased from 51% to 8% and from 36% to 14% for the two subjects. The results of our study show that increased meniscal extrusion occurs with increased laxity of the meniscal tibia attachments and this increased laxity results in loss of meniscal function.

Induction of fiber alignment and mechanical anisotropy in tissue engineered menisci with mechanical anchoring

This study investigated the effect of mechanical anchoring on the development of fiber organization and anisotropy in anatomically shaped tissue engineered menisci. Bovine meniscal fibrochondrocytes were mixed with collagen and injected into molds designed to produce meniscus implants with 12mm extensions at each horn. After a day of static culture, 10 and 20mg/ml collagen menisci were either clamped or unclamped and cultured for up to 8 weeks. Clamped menisci were anchored in culture trays throughout culture to mimic the native meniscus horn attachment sites, restrict contraction circumferentially, and encourage circumferential alignment. Clamped menisci retained their size and shape, and by 8 weeks developed circumferential and radial fiber organization that resembled native meniscus. Clamping also increased collagen accumulation and improved mechanical properties compared to unclamped menisci. Enhanced organization in clamped menisci was further reflected in the development of anisotropic tensile properties, with 2–3 fold higher circumferential moduli compared to radial moduli, a similar ratio to native meniscus. Ten and 20mg/ml clamped menisci had similar levels of organization, with 20mg/ml menisci producing larger diameter fibers and significantly better mechanical properties. Collectively, these data demonstrate the benefit of using bio-inspired mechanical boundary conditions to drive the formation of a highly organized collagen fiber network.

Different patterns of lateral meniscus root tears in ACL injuries: application of a differentiated classification system.

Posterior lateral meniscus root tears (PLMRTs) affect the intra-articular pressure distribution in the lateral compartment of the knee. The biomechanical consequences of these injuries are significantly influenced by the integrity of the meniscofemoral ligaments (MFLs). A newly introduced arthroscopic classification system for PLMRTs that takes MFL integrity into account has not yet been clinically applied but may be useful in selecting the optimal method of PLMRT repair. Prospective ACL reconstruction data were collected. Concomitant injuries of the lateral meniscus posterior horn were classified according to their shape and MFL status. The classifications were: type 1, avulsion of the root; type 2, radial tear of the lateral meniscus posterior horn close to the root with an intact MFL; and type 3, complete detachment of the posterior meniscus horn. Between January 2011 and May 2012, 228 consecutive ACL reconstructions were included. Lateral and medial meniscus tears were identified in 38.2% (n = 87) and 44.7% (n = 102), respectively. Of the 87 lateral meniscus tears, 32 cases had PLMRTs; the overall prevalence of PLMRTs was 14% (n = 32). Two medial meniscus root tears were detected. All PLMRTs were classified according to the classification system described above, and the fixation procedure was adapted to the type of meniscus tear. The PLMRT tear is a common injury among patients undergoing ACL repair and can be arthroscopically classified into three different types. Medial meniscus root tears are rare in association with ACL tears. The PLMRT classification presented here may help to estimate the injury's impact on the lateral compartment and to identify the optimal treatment. These tears should not be overlooked, and the treatment strategy should be chosen with respect to the type of root tear. IV.

Arthroscopic Repair of Separation of Anterior Intermeniscal Ligament

Objectives:Aim of this article is to present and discuss a patient with separation of anterior intermeniscal ligament which was repaired arthroscopically.Methods:Anterior intermeniscal ligament (AIML) (transverse geniculate ligament or anterior transvers ligament) is an intraarticular structure connecting anterior convex edge of lateral meniscle to anterior tip of medial meniscle; limits anterior movement of menisci during extension and prevents pressure application of condylar surfaces onto menisci; and also limits anterior-posterior separation of anterior horn of medial meniscus during low degrees of flexion. AIML was found in 69 to 94 percent in different studies.Results:A thirty-eight year-old female patient referred our clinic with complaints of pain in right knee for a year that responds to pain killers, increasing with climbing stairs and decreasing with rest. Synovium origined mass was seen on MRI with contrast applied after an intraarticular mass seen on MRI. She undervent surgery and the mass in the medial of joint space considered as pigmented villonodular sinovitis was resected arthroscopically. During arthroscopy, separation of anterior marge of AIML and elevation of anterior horns of both medial and lateral were noticed. Using no 1 PDS suture AIML was pulled downwards from anterior marge and fixed. After fixation AIML and anterior horns of menisci replaced on tibial plateu again.Conclusion:As injuries of AIML which has an important role at stabilization of menisci during knee motions are seen very rarely, freuquency of AIML was reported 9.75 percent in a cadaver study and 75 percent of them was accompanied by medial meniscal tear. We could not find any other clinical study reporting AIML injury in the literature. As we apply arthroscopical intervention in order to resect intraarticular mass considered as pigmented villonodular synovitis, anterior separation of AIML and elevation of anterior horn of both menisci were noticed coincidentally and then were repaired. As the arthroscopical evaluation due to injuries of intraarticular structures is performed, AIML should also be evaluated, if necessary, repair should be performed in order to obtain stabilization of anterior horns of menisci.

Releasing the circumferential fixation of the medial meniscus does not affect its kinematics.

Meniscal functioning depends on the fixation between the meniscal horns and the surrounding tissues. It is unknown, however, whether the integration between the outer circumference of the medial meniscus and the knee capsule/medial collateral ligament also influences the biomechanical behavior of the meniscus. Therefore, we aimed to determine whether detaching and resuturing the circumferential fixation of the medial meniscus influence its kinematic pattern. Human cadaveric knee joints were flexed (0°-30°-60°-90°) in a knee loading rig, in neutral orientation and under internal and external tibial torques. Roentgen stereophotogrammetric analysis was used to determine the motion of the meniscus in anteroposterior (AP) and mediolateral (ML) directions. Three fixation conditions were evaluated: (I) intact, (II) detached and (III) resutured. Detaching and resuturing the circumferential fixation did not alter the meniscal motion pattern in either the AP or ML direction. Applying an additional internal tibial torque caused the medial meniscus to move slightly anteriorly, and an external torque caused a little posterior translation with respect to the neutral situation. These patterns did not change when the circumferential fixation condition was altered. This study demonstrated that the motion pattern of the medial meniscus is independent of its fixation to the knee capsule and medial collateral ligament. The outcomes of this study can be deployed to design the fixation strategy of a permanent meniscus prosthesis. As peripheral fixation is a complicated step during meniscal replacement, the surgical procedure is considerably simplified when non-resorbable implants do not require circumferential fixation.

The effect of medial meniscal horn injury on knee stability.

This study investigated the effect of damage of the posterior and anterior horns of the medial meniscus on knee stability. Twenty fresh-frozen porcine knees were divided into two groups (anterior horn and posterior horn injury). Each group was tested in three states: intact medial meniscus, posterior or anterior horn of medial meniscus resection and total medial meniscectomy. A robotic testing system was used to test anterior tibial translation (ATT) at 30° (full extension), 60° and 90° of knee flexion with an external anterior tibial load of 89 N, internal rotation (IR) and external rotation (ER) at 30° and 60° of knee flexion under a 4 N m tibial rotation torque. In response to an IR torque, there was a significant difference between the state of intact medial meniscus and anterior and posterior horn damage, except for anterior horn resection at 60° of knee flexion. In response to an ER torque, there were no significant differences between the state of intact meniscus and horn damage except for anterior horn resection at 30° of knee flexion. Meniscal damage had no significant effect on ATT. The results indicated that the posterior horn was more important in controlling the IR stability than the anterior horn with knee flexion, and the anterior horn was more important in controlling the ER stability than the posterior horn at full knee extension in the anterior cruciate ligament-intact knee. These findings further the understanding of the mechanisms, the prevention of injuries and rehabilitation of meniscal horn injury in clinical practice.

THU0193 White Meniscus Sign is Associated with Degeneration of Cartilage in Pre-Radiographic Osteoarthritis

BackgroundOsteoarthritis (OA) is a heterogeneous disease characterized by joint degeneration including the progressive loss of hyaline articular cartilage. One of the challenges in diagnosis and management of OA is the...

Bone Plug Versus Suture-Only Fixation of Meniscal Grafts

Background: Meniscus allograft transplantation (MAT) is primarily undertaken to relieve the symptoms associated with meniscal deficiencies. However, its ability to restore normal knee joint contact mechanics under physiological loads is still unclear. Purpose: To quantify the dynamic contact mechanics associated with 2 commonly used fixation techniques in MAT of the medial compartment: transosseous suture fixation via bone plugs and suture-only fixation at the horns. Study Design: Controlled laboratory study. Methods: Physiological loads to mimic gait were applied across 7 human cadaveric knees on a simulator. A sensor placed on the medial tibial plateau recorded dynamic contact stresses under the following conditions: (1) intact meniscus, (2) MAT using transosseous suture fixation via bone plugs at the anterior and posterior horns, (3) MAT using suture-only fixation, and (4) total medial meniscectomy. A “remove-replace” procedure was performed to place the same autograft for both MAT conditions to minimize the variability in graft size, geometry, and material property and to isolate the effects of the fixation technique. Contact stress, contact area, and weighted center of contact stress (WCoCS) were quantified on the medial plateau throughout the stance phase. Results: Knee joint contact mechanics were sensitive to the meniscal condition primarily during the first half of the gait cycle. After meniscectomy, the mean peak contact stress increased from 4.2 ± 1.2 MPa to 6.2 ± 1.0 MPa (P = .04), and the mean contact area decreased from 546 ± 132 mm2 to 192 ± 122 mm2 (P = .01) compared with the intact meniscus during early stance (14% of the gait cycle). After MAT, the mean contact stress significantly decreased with bone plug fixation (5.0 ± 0.7 MPa) but not with suture-only fixation (5.9 ± 0.7 MPa). Both fixation techniques partially restored the contact area, but bone plug fixation restored it closer to the intact condition. The location of WCoCS in the central cartilage region (not covered by the meniscus) shifted peripherally throughout the stance phase. Bone plug fixation exhibited correction to this peripheral offset, but suture-only fixation did not. Conclusion: Under dynamic loading, transosseous fixation at the meniscal horns provides superior load distribution at the involved knee compartment after meniscal transplantation compared with suture-only fixation. Particular attention should be directed to the ability of medial MAT to function during the early stance phase. Clinical Relevance: Transosseous fixation via bone plugs provides superior load distribution of a transplanted meniscal allograft compared with suture fixation alone at time zero.

The Biomechanical Effect of a Lateral Meniscus Posterior Root Tear With and Without Damage to the Meniscofemoral Ligament: Efficacy of Different Repair Techniques

To evaluate the effect of the meniscofemoral ligament (MFL) in maintaining lateral-compartment contact pressures after injury to the posterior root of the lateral meniscus, and to measure the ability to restore intra-articular loads to normal by repairing the posterior root to the tibia after transection of the posterior root and the MFL. Ten human cadaveric knee joints were axially loaded to 100N. A digital pressure sensor measured the contact pressure in the lateral compartment. Five different conditions were tested: intact, after release of the posterior root of the lateral meniscus, after transection of the MFL along with release of the posterior root, refixation of the posterior root of the lateral meniscus to the tibia using an anatomic transosseous tunnel, and refixation of the root of the lateral meniscus using a tibial anterior cruciate ligament (ACL) tunnel. After transection of the posterior lateral meniscus root, the contact pressure did not increase significantly. The additional transection of the MFL led to a significant increase in the contact pressure. Anatomic fixation of the meniscus posterior horn reduced the femorotibial pressure to nearly pre-sectioning values. The reattachment of the meniscus posterior horn through a tibial ACL tunnel was equivalent to an anatomic fixation. In the case of a root tear of the lateral meniscus, the MFL maintains meniscus function and stabilizes the pressure in the lateral compartment. A complete detachment of the posterior meniscus horn (MFL and root tear) leads to an increase in the intra-articular pressure. A root repair normalizes the pressure down to normal values. The tibial ACL tunnel is suitable to perform the repair and to lead out the suture. In the case of a complete detachment of the meniscus posterior horn, fixation of the posterior root is necessary to restore the meniscus function and to guarantee an equal pressure distribution in the lateral compartment. It can be combined with an ACL reconstruction.

Bony morphology of the knee and non-traumatic meniscal tears: is there a role for meniscal impingement?

Meniscal tears are an important cause of morbidity. The aim of this study was to examine the relationship between non-traumatic meniscal tears and the intrinsic bony morphology of the knee. A retrospective analysis of 160 knee MRI scans in 150 patients was carried out who met the following criteria: (a) age between 20 and 45 years, (b) no history of knee trauma, surgery, infection, metabolic bone disease, and (c) no collateral or cruciate ligamentous injury. The medial tibial slope (MTS), lateral tibial slope (LTS), medial tibial plateau depth (MTPD), and medial and lateral femoral condylar offset ratios were calculated. The anterior horn, body, and posterior horn of the menisci were graded as 0 (no tear), 1 and 2 (degenerative changes), or 3 (definitive tear). One-way ANOVA and linear regression was used for statistical analysis. In patients with grade 3 tears of the posterior horn of the medial meniscus, there was a significant association with shallower MTS (p < 0.05), smaller medial femoral offset ratio (p < 0.05) and smaller lateral femoral offset ratio (p < 0.05). Patients with grade 3 tears of anterior horn of the lateral meniscus had a significant association with shallower LTS (p < 0.05). No significant association was seen between MTPD and meniscal tears. Our results suggest an association between bony morphology of the knee and non-traumatic meniscal tears. Shallower MTS and LTS may result in impingement of posterior horn of medial meniscus and anterior horn of lateral meniscus, respectively. Future kinematic studies will be needed to help confirm our findings.

Treatment of patients with knee cartilage injury combined with lesions of the anterior crucial ligament and meniscus

Purpose: to study the possibility to use rational arthroscopic tactics of treatment and duration of rehabilitation of patients with injured knee cartilage combined with the anterior cruciate ligament (ACL) and menisci lesions on the basis of retrospective analysis of 735 knee joint surgeries with using of arthroscopic methods.Methods: combined injury of the joint cartilage of different severity was diagnosed in 519 patients (71.7 %), primary ACL lesion was observed in 221 patients. Meniscectomy was performed in 514 patients. In 106 patients with menisci and ACL lesions posttraumatic changes in joint cartilage of different severity according to Outerbridge were detected. In accordance with this patients were categorised into 4 groups. The 5th group (control) contains patients with ACL and meniscus lesions without any changes in joint cartilage. Patients with menisci lesions in 97% of cases underwent partial resection of the injured part, and just in 3% (cases of paracapsular injuries) meniscus suturing was performed. In 91% patients meniscus posterior horn lesions were revealed, in 6% - injuries of the meniscus body, and just in 3% of all meniscus lesions anterior horn of meniscus was injured.Results: for restoration of ACL injured were used tendons of semitendinous and gracilis muscles. In postoperative period we recommended offloading of the operated lower extremity depend on changes in joint cartilage but not longer than 6 months after surgery. Thus in case of changes in cartilage of the first grade no other manipulations on cartilage except restoration of intraarticular structures were performed. In cases of changes in cartilage of the second and third grades we performed vaporization of its injured parts, in cases of the fourth grade osteoperforation of the defected segments was done.Conclusions: it was confirmed that arthroscopy is the «gold standard» in diagnostics and treatment of injured structures of knee joint enabling visualisation of the degree and depth of joint cartilage changes, determining of indications for appropriate treatment, performing of medicinal manipulations, planning adequate comprehensive postoperative therapy and rehabilitation. Intraoperative tactics of treatment of patients with combined ACL, meniscus and joint cartilage lesion depends on severity of cartilage changes. Duration of postoperative rehabilitation increased with the growth of severity of joint cartilage changes. Therefore, combination of arthroscopic treatment of injured joint cartilage injury of ІІІ-ІV grades and proper rehabilitation in young patients now remains the most relevant and requires further study and improvement.

Patterns of Meniscal Damage Associated with Acute ACL Rupture

Patterns of Meniscal Damage Associated with Acute ACL Rupture

The relationship between lateral meniscus shape and joint contact parameters in the knee: a study using data from the Osteoarthritis Initiative

IntroductionThe meniscus has an important role in force transmission across the knee, but a detailed three-dimensional (3D) morphometric shape analysis of the lateral meniscus to elucidate subject-specific function has not been conducted. The aim of this study was to perform 3D morphometric analyses of the lateral meniscus in order to correlate shape variables with anthropometric parameters, thereby gaining a better understanding of the relationship between lateral meniscus shape and its load-bearing function.MethodsThe lateral meniscus (LM) was manually segmented from magnetic resonance images randomly selected from the Osteoarthritis Initiative (OAI) non-exposed control subcohort. A 3D statistical shape model (SSM) was constructed to extract the principal morphological variations (PMV) of the lateral meniscus for 50 subjects (25 male and 25 female). Correlations between the principal morphological variations and anthropometric parameters were tested. Anthropometric parameters that were selected included height, weight, body mass index (BMI), femoral condyle width and axial rotation.ResultsThe first principal morphological variation (PMV) was found to correlate with height (r = 0.569), weight (r = 0.647), BMI (r = 0.376), and femoral condyle width (r = 0.622). The third PMV was found to correlate with height (r = 0.406), weight (r = 0.312), and femoral condyle width (r = 0.331). The percentage of the tibial plateau covered by the lateral meniscus decreases as anthropometric parameters relating to size of the subject increase. Furthermore, when the size of the subject increases, the posterior and anterior horns become proportionally longer and wider.ConclusionThe correlations discovered suggest that variations in meniscal shape can be at least partially explained by the levels of loads transmitted across the knee on a regular basis. Additionally, as the size of the subject increases and body weight rises, the coverage percentage of the meniscus is reduced, suggesting that there would be an increase in the load-bearing by the cartilage. However, this reduced coverage percentage is compensated by the proportionally wider and longer meniscal horn.

A new arthroscopic technique for lateral meniscal allograft transplantation: Cadaver feasibility study

The three prerequisites for a successful meniscal allograft are fixation, graft sizing and precise positioning. The goal of this study was to demonstrate that lateral meniscal allografts can be reliably positioned using a fully arthroscopic technique. This surgical technique is feasible and results in good positioning of the meniscal graft. Twelve fresh cadavers were used in the study. The meniscal graft implantation procedure was performed entirely by arthroscopy. The meniscal horns were fixed with screw-in suture anchors and the meniscal border was fixed to the capsule by arthroscopic meniscus-capsule sutures. The main outcome measure of good implant positioning was based on the distance between the implanted location of the posterior horn of the lateral meniscus (PHLM) and its original location. To accomplish this, aerial photographs of the tibial plateau were used to compare the insertion zones and to calculate the distance between them. These measurements were performed by two surgeons and then compared. Eleven of the 12 procedures (92%) were performed successfully. The posterior horn of the lateral meniscus was positioned an average of 4.3mm in the medial-lateral axis and 1.7 mm in the anterior-posterior axis away from its original location. Thus the position of the implanted PHLM was on average 4.6mm away from its original location. This fully arthroscopic technique is feasible. It offers the advantages associated with minimally-invasive surgery and results in good positioning of the posterior horn of the allograft. Two limitations of this study are that the size of the implant was not matched and the chosen fixation method was not subjected to biomechanical evaluation. The lack of a tibial tunnel will make it easier to combine this procedure with ACL reconstruction. In these conditions, the clinical application of this technique seems to be timely. IV - Controlled experimental study.

T2 Values of Posterior Horns of Knee Menisci in Asymptomatic Subjects

PurposeThe magnetic resonance (MR) T2 value of cartilage is a reliable indicator of tissue properties and therefore may be used as an objective diagnostic tool in early meniscal degeneration. The purpose of this study was to investigate age, gender, location, and zonal differences in MR T2 value of the posterior horns of knee menisci in asymptomatic subjects.MethodsSixty asymptomatic volunteers (30 men and 30 women) were enrolled and divided into three different age groups: 20–34, 35–49 and 50–70 years. The inclusion criteria were BMI<30 kg/cm2 , normalized Western Ontario and McMaster Universities (WOMAC) pain score of zero, and no evidence of meniscal and ligamentous abnormalities on routine knee MR imaging. The T2 values were measured on images acquired with a T2-weighted fat-suppressed turbo spin-echo sequence at 3T.ResultsThe mean T2 values in both medial and lateral menisci for the 20–34, 35–49, and 50–70 age groups were 9.94 msec±0.94, 10.73 msec±1.55, and 12.36 msec±2.27, respectively, for women and 9.17 msec±0.74, 9.64 msec±0.67, and 10.95 msec±1.33, respectively, for men. The T2 values were significantly higher in the 50–70 age group than the 20–34 age group (P<0.001) and in women than in men (P = 0.001, 0.004, and 0.049 for each respective age group). T2 values were significantly higher in medial menisci than in lateral menisci only in women age 50–70 (3.33 msec, P = 0.006) and in the white zone and red/white zone of the 50–70 and 35–49 age groups than that of the 20–34 age group (2.47, 1.02; 2.77, 1.16 msec, respectively, all P<0.01).ConclusionThe MR T2 values of the posterior meniscal horns increase with increasing age in women and are higher in women than in men. The age-related rise of T2 values appears to be more severe in medial menisci than in lateral menisci. Differences exist in the white zone and red/white zone.

Arthroscopic meniscal allograft transplantation with two tibia tunnels without bone plugs: evaluation of healing on MR arthrography and functional outcomes

Meniscal allograft transplantation seems to be a valid therapeutic option to restore the knee function and limit the development of osteoarthritis after menisectomy. No surgical technique has been shown to provide better results than others. The main objective of this study was to assess graft healing after arthroscopic meniscal allograft transplantation without bone plugs. This retrospective study included all patients who underwent arthroscopic meniscal allograft transplantation during 2005-2010. The meniscal horns were fixed through two tibia tunnels without bone plugs. The primary endpoint was graft healing according to Henning's criteria on MR arthrography (MRA) at 6-month follow-up. The secondary endpoints were the KOOS questionnaire, the IKDC score, measurement of the joint space and meniscal extrusion on both MRA at 6-month and MRI at last follow-up. The series included 22 patients, mean age 37 ± 7.5 years. The allograft was lateral in 20 cases and medial in 2 cases. The mean follow-up was 4.4 ± 1.6 years with one lost to follow-up. MR arthrography was performed in 14/21 patients at 6-months of follow-up: 8/14 (57.1%) had total graft healing, 2/14 (14.3%) partial healing and 4/14 (28.6%) no healing. At final follow-up, all functional scores had significantly improved. The average pre- and post-operative joint space thickness was similar. MRI showed meniscal extrusion in 75% of patients. The meniscal allograft transplantation without bone plugs effectively treats painful and functional sequellae of meniscectomies. The graft healed in most patients at 6-month follow-up. The long-term clinical relevance of meniscal extrusion has to be evaluated. Retrospective study, Level IV.

Results of Arthroscopic Partial Meniscectomy for Lateral Discoid Meniscus Tears Associated with New Technique

PurposeTo introduce and evaluate the clinical results of a new arthroscopic technique for partial meniscectomy of symptomatic lateral discoid meniscus using a knife.Materials and MethodsFrom March 2005 to October 2010, 60 knees of 58 patients underwent arthroscopic partial meniscectomies for lateral discoid meniscus. The average age was 28.9 years (range, 12 to 63 years), and average follow-up was 26 months (range, 8 to 72 years). In this procedure, using a No. 11 knife holder inserted through the high far anteromedial portal, a stab incision on the anterior meniscal horn and following piecemeal meniscal excision were made. Clinical results were assessed using the scale of Ikeuchi and Lysholm score.ResultsMeniscus shape was complete in 32 knees (53.3%) and incomplete in 28 knees (46.6%). The shape of tears in complete type lesions was horizontal cleavage in 17 knees (53.1%), flap or complex degenerated tears in 10 knees (31.2%) and radial tears in 5 knees (15.6%). Clinical results assessed using the scale of Ikeuchi were excellent in 38 (63.3%), good in 13 (21.6%), fair in 8 (13.3%) and poor in 1 knee (1.6%). The average Lysholm score was improved from 82.8 preoperatively to 95.4 postoperatively.ConclusionsOur new arthroscopic technique in lateral discoid partial meniscectomy suggests convenient methods and successful clinical results.