Project description:Meniscus tears of the knee are among the most common orthopedic knee injury. Specifically, tears of the posterior root can result in abnormal meniscal extrusion leading to decreased function and progressive osteoarthritis. Despite contemporary surgical treatments of posterior meniscus root tears, there is a low rate of healing and an incidence of residual meniscus extrusion approaching 30%, illustrating an inability to recapitulate native meniscus function. Here, we characterized the differential functional behavior of the medial and lateral meniscus during axial compression load and dynamic knee motion using a cadaveric model. We hypothesized essential differences in extrusion between the medial and lateral meniscus in response to axial compression and knee range of motion. We found no differences in the amount of meniscus extrusion between the medial and lateral meniscus with a competent posterior root (0.338mm vs. 0.235mm; p-value = 0.181). However, posterior root detachment resulted in a consistently increased meniscus extrusion for the medial meniscus compared to the lateral meniscus (2.233mm vs. 0.4705mm; p-value < 0.0001). Moreover, detachment of the posterior root of the medial meniscus resulted in an increase in extrusion at all angles of knee flexion and was most pronounced (4.00mm ± 1.26mm) at 30-degrees of knee flexion. In contrast, the maximum mean extrusion of the lateral meniscus was 1.65mm ± 0.97mm, occurring in full extension. Furthermore, only the medial meniscus extruded during dynamic knee flexion after posterior root detachment. Given the differential functional behaviors between the medial and lateral meniscus, these findings suggest that posterior root repair requires reducing overall meniscus extrusion and recapitulating the native functional responses specific to each meniscus.
Project description:Recurrent patellar dislocation has recently been treated with anatomic medial patellofemoral ligament (MPFL) reconstruction using a semitendinosus muscle tendon. Although it is necessary to add tension to fix the tendon graft without loading excess stress on the patellofemoral joint, adjustment of the tension can be difficult. To resolve this problem, we developed an MPFL reconstruction procedure using the ToggleLoc Fixation Device (Biomet, Warsaw, IN), in which the semitendinosus muscle tendon is folded and used as a double-bundle tendon graft and 2 bone tunnels and 1 bone tunnel are made on the patellar and femoral sides, respectively. The patellar side of the tendon graft is fixed with an EndoButton (Smith & Nephew, London, England), and the femoral side is fixed with the ToggleLoc. Stepless adjustment of tension of the tendon graft is possible by reducing the size of the loop of the ToggleLoc hung onto the tendon graft. It may be useful to position the patella in the center of the femoral sulcus by confirming the patellofemoral joint fitting. Stability can be confirmed by loading lateral stress on the patella in the extended knee joint. This procedure is less invasive because opening of the lateral side of the femur is not necessary, and it may be useful for MPFL reconstruction.
Project description:PurposeTo compare the degree of medial meniscal extrusion (MME) between knees with medial meniscus posterior root tear (MMPRT) and degenerative tears of the medial meniscus using ultrasonography (US) in different limb positions and to identify the findings characteristic of MMPRT.MethodsThe study group comprised 25 subjects with MMPRT (group RT), 25 subjects with degenerative medial meniscal tears (group D), and 25 knees with no abnormalities of the medial meniscus (MM) on magnetic resonance imaging (MRI) (group C) whose age was ≥40 years. MME was evaluated using US in the supine, figure-4, feet-dangling, and standing positions. The MME was evaluated by the actual measurement values and the relative values to the MME in the supine position. The differences in the MME among the 3 groups in each limb position were analyzed using one-way analysis of variance. P < .05 was considered significant.ResultsThe actual MME values were largest in group RT in all 4 limb positions. When changing the limb position from the supine to the figure-4, the actual MME increased from 3.8 ± 0.8 mm to 5.5 ± 1.3 mm in group RT, whereas it decreased from 3.4 ± 1.1 mm to 1.8 ± 1.2 mm in group D, showing the most significant difference in MME of the figure-4 position between the 2 groups (P < .001). In group RT, 88% of knees had the maximum MME in the figure-4 position. In group D, 60% of knees had the maximum MME in the standing position and only 2 knees (8%) had the maximum MME in the figure-4 position.ConclusionsThe increase in MME from the supine to the figure-4 position was a characteristic finding of MMPRT but not degenerative tears.Level of evidenceLevel III, case-control study.
Project description:PurposeTo verify the effectiveness of detecting medial meniscus posterior root tears (MMPRTs) using weight-bearing posterior-anterior (PA) radiographs.Materials and methodsTwenty-three patients were diagnosed with an MMPRT using magnetic resonance imaging (Group A), with 23 matched individuals forming the control group (Group B). The distance between medial tibial eminence and the lateral edge of the medial femoral condyle (MTE–MFC distance) and medial joint space (MJS) width were measured on weight-bearing PA radiographs, with the knee flexed at 45° (Rosenberg view). Absolute medial meniscus extrusion (MME) was measured on magnetic resonance images.ResultsThe MTE–MFC distance was greater and the MJS width was smaller in Group A than Group B (7.7?±?1.7?mm versus 6.0?±?1.24?mm and 3.2?±?0.8?mm versus 4.5?±?0.7?mm, respectively; P?<?0.05). The MTE–MFC distance and MJS width correlated with MME (r?=?0.603 and 0.579, respectively; P?<?0.05), and the extent of MME was greater in Group A than Group B (4.1?±?1.1?mm versus 1.8?±?1.5?mm, respectively; P?<?0.05).ConclusionsMMPRTs increase the MTE–MFC distance and decrease the MJS width, with these measurements correlating to the MME. Therefore, measurement of the MTE–MFC distance and MJS width on the Rosenberg view could be a useful preliminary method for the diagnosis of an MMPRT.Level of evidenceIV
Project description:BackgroundIntact meniscus roots are a prerequisite for normal meniscal function, including even distribution of compressive forces across the knee joint. An injury to the root disrupts the hoop strength of the meniscus and may lead to its extrusion and the development of osteoarthritis. A medial meniscus posterior root tear (MMPRT) is often thought to have a primary degenerative pathogenesis. However, there is mention of some cases of MMPRTs where the patients have a solely traumatic injury to a previously healthy meniscus.PurposeTo describe a subpopulation of patients with traumatic MMPRT.Study designSystematic review; Level of evidence, 5.MethodsThe Web of Science database (www.webofscience.com) was queried using the Medical Subject Headings term "medial root tear." Articles were reviewed, and those evaluated for MMPRTs in a degenerative meniscus were excluded. A total of 25 articles describing cases of acute traumatic causes were included in this study. For these articles, the patient characteristics, injury mechanisms, and concomitant injuries evaluated were recorded and pooled.ResultsThe search revealed 660 articles, and 25 were selected for inclusion. A total of 113 patients with a traumatic MMPRT were identified and included in this review. The study population had a mean age of 27.1 years and a high share of men (64%). Also, this review displays how most patients with traumatic MMPRTs also suffer concomitant injuries (68%).ConclusionThe findings in this review support our hypothesis that there is a unique subgroup with acute traumatic MMPRTs that have unique patient characteristics, injury mechanisms, and combined injuries, compared with previously published reviews on MMPRTs.
Project description:A complete radial tear of the meniscus posterior root, which can effectively cause a state of total meniscectomy via loss of hoop tension, requires that the torn root be repaired. Several methods have been used to repair medial meniscus posterior root tears, most of which are based on a simple stitch technique that is known to have stitch-holding strength. We applied a modified version of the Mason-Allen stitch technique, which is recognized as a method for rotator cuff repair surgery because its locking effect overcomes the potential weakness of simple stitches. This article introduces the medial meniscus posterior root tears repair procedure based on a modified Mason-Allen stitch technique in which 2 strands (i.e., 1 simple horizontal and 1 simple vertical stitch) are used.
Project description:We describe a surgical technique to repair medial meniscus posterior root tears through a transtibial pullout repair with a subcortical button for tibial fixation. This technique allows progressive tensioning of the repaired root without losing tension both during suturing of the knots above the button and after the procedure, owing to the specific button configuration.
Project description:Transtibial pullout suture (TPS) repair of posterior medial meniscus root (PMMR) tears was shown to achieve good clinical outcomes. The purpose of this study was to compare biomechanically, a novel technique designed to repair PMMR tears using tendon graft (TG) and conventional TPS repair. Twelve porcine tibiae (n = 6 each) TG group: flexor digitorum profundus tendon was passed through an incision in the root area, created 5 mm postero-medially along the edge of the attachment area. TPS group: a modified Mason-Allen suture was created using no. 2 FiberWire. The tendon grafts and sutures were threaded through the bone tunnel and then fixed to the anterolateral cortex of the tibia. The two groups underwent cyclic loading followed by a load-to-failure test. Displacements of the constructs after 100, 500, and 1000 loading cycles, and the maximum load, stiffness, and elongation at failure were recorded. The TG technique had significantly lower elongation and higher stiffness compared with the TPS. The maximum load of the TG group was significantly lower than that of the TPS group. Failure modes for all specimens were caused by the suture or graft cutting through the meniscus. Lesser elongation and higher stiffness of the constructs in TG technique over those in the standard TPS technique might be beneficial for postoperative biological healing between the meniscus and tibial plateau. However, a slower rehabilitation program might be necessary due to its relatively lower maximum failure load.
Project description:We describe an all-suture transosseous repair technique used in the management of rotator cuff tears by means of an all-suture anchor secured on the intra-articular side of the humeral calcar. The technique uses an anterior cruciate ligament guide to ensure accurate positioning of the tunnels, avoiding the articular cartilage and minimizing risk to the neurovascular structures. The distal end of the guide is inserted through a rotator interval portal and passed down to the axillary pouch. The proximal end of the guide is approximated to the greater tuberosity at the cuff footprint, and a complete transosseous tunnel is created with a 2.4-mm drill. An all-suture implant is inserted through this tunnel down to the calcar, and its deployment is visualized under arthroscopy. Gentle traction is applied to the anchor, resulting in a 4-mm concertina of the suture anchor that rests opposed to the medial cortex. The major advantage of this technique is the fixation strength gained from the biomechanically superior cortical bone of the calcar. Furthermore, this method permits greater preservation of bone surface area at the level of the footprint for a larger tendon-to-bone healing surface. This technique also provides an excellent alternative in revision situations.
Project description:The medial patellofemoral ligament (MPFL) is the primary soft-tissue stabilizer of the patellofemoral joint. Among the patellofemoral instability surgery options, MPFL reconstruction is the most preferred soft-tissue procedure. There is no gold-standard surgical treatment method in MPFL reconstruction, and many surgical methods have been described. We describe our surgical technique for MPFL reconstruction wherein the semitendinosus autograft is fixed to a single tunnel opened in the patella with a suspensory fixation device and only a single interference screw on the femoral side.