Management of Meniscus Pathology with Concomitant Anterior Cruciate Ligament Injury.

PURPOSE OF REVIEW: The purpose of this review is to summarize current clinical knowledge on the prevalence and types of meniscus pathology seen with concomitant anterior cruciate ligament (ACL) injury, as well as surgical techniques, clinical outcomes, and rehabilitation following operative management of these pathologies. RECENT FINDINGS: Meniscus pathology with concomitant ACL injury is relatively common, with reports of meniscus pathology identified in 21-64% of operative ACL injuries. These concomitant injuries have been associated with increased age and body mass index. Lateral meniscus pathology is more common in acute ACL injury, while medial meniscus pathology is more typical in chronic ACL deficiency. Meniscus tear patterns associated with concomitant ACL injury include meniscus root tears, lateral meniscus oblique radial tears of the posterior horn (14%), and ramp lesions of the medial meniscus (8-24%). These meniscal pathologies with concomitant ACL injury are associated with increased rotational laxity and meniscal extrusion. There is a paucity of comparative studies to determine the optimal meniscus repair technique, as well as rehabilitation protocol, depending on specific tear pattern, location, and ACL reconstruction technique. There has been a substantial increase in recent publications demonstrating the importance of meniscus repair at the time of ACL repair or reconstruction to restore knee biomechanics and reduce the risk of progressive osteoarthritic degeneration. Through these studies, there has been a growing understanding of the meniscus tear patterns commonly identified or nearly missed during ACL reconstruction. Surgical management of meniscal pathology with concomitant ACL injury implements the same principles as utilized in the setting of isolated meniscus repair alone: anatomic reduction, biologic preparation and augmentation, and circumferential compression. Advances in repair techniques have demonstrated promising clinical outcomes, and the ability to restore and preserve the meniscus in pathologies previously deemed irreparable. Further research to determine the optimal surgical technique for specific tear patterns, as well as rehabilitation protocols for meniscus pathology with concomitant ACL injury, is warranted.

Repair of radial tears of the lateral meniscus on a stable knee: Results at a minimum follow-up of 2 years.

INTRODUCTION: In younger patients, meniscal repair is recommended for isolated lateral meniscus tears that are most often due to acute trauma. But there is little published data on the outcomes of repairing this specific type of lesion. The goal of this study was to evaluate the clinical outcomes, report the failure rate of repairing radial tears of the lateral meniscus in stable knees and determine the risk factors for failure. MATERIALS AND METHODS: All patients who had a stable knee and underwent arthroscopic repair of a radial lateral meniscus tear between April 2013 and December 2019 were reviewed retrospectively. Failure was defined as revision surgery for recurrence of symptoms (pain, locking) with intraoperative confirmation that the meniscus did not heal. The following data were collected: demographics (age, sex, BMI), time to surgery, clinical outcome scores (Tegner, Lysholm, IKDC), surgical details (repair technique, lesion zone, number of sutures). RESULTS: Thirty patients were included having a mean age of 20.1years (14-31). The follow-up ranged from 24 to 110months (mean 66.8±25.2). An all-inside repair was done in 6 patients (20%); an outside-in technique was done in 17 patients (57%) and a combination of all-inside and outside-in was done in 7 patients (23%). Four patients (13%) had a recurrence of their symptoms later on, while participating in sports. All the recurrences were at the initial tear site. The time to revision surgery was 16, 19, 24 and 37months in these four patients (mean 24±9). All the other patients were able to resume sports at their pre-injury level. Significant improvement in the IKDC, Lysholm and Tegner functional scores were found between the preoperative and postoperative assessments. No statistically significant risk factors for failure were identified. DISCUSSION: The functional healing rate after repair of a radial lateral meniscus tear in a stable knee was 86% at a mean follow-up of 5years, with the surgical technique having no impact on the long-term result. Most of the failures occurred within 2years of the repair procedure. We recommend repairing these tears as they have considerable healing potential. LEVEL OF EVIDENCE: IV; retrospective observational cohort study.

Outcomes of Lateral Meniscal Oblique Radial Tear Repair Compared With Intact Meniscus After ACL Reconstruction: A Cohort Study.

Background: Recently, the posterior horn lateral meniscal oblique radial tear (LMORT) was identified in 12% of acute anterior cruciate ligament (ACL) injuries. However, patient-reported outcomes for repair of this relatively common tear have not been reported. Purpose: To determine the minimum 2-year functional outcomes after LMORT repair at the time of ACL reconstruction (ACLR) compared to a matched cohort of patients who underwent isolated ACLR (iACLR). Study Design: Cohort study; Level of evidence, 3. Methods: Included were 100 patients (mean age at surgery, 21 years; range, 13-45 years) who underwent primary ACLR between 2010 and 2018. The mean follow-up period was 4.1 ± 2.0 years (range, 2.0-9.2 years). A total of 50 patients with surgically repaired LMORT type 3 or type 4 lesions, defined as partial or complete tears >10 mm from the root (LMORT group) were matched 1:1 based on age, date of surgery, and graft choice with 50 patients who underwent iACLR (iACLR group). The postoperative outcomes were compared between groups using the International Knee Documentation Committee subjective score (sIKDC) and the Tegner activity scale. An updated medical history was obtained via the electronic medical record to determine any subsequent complications and reoperations. Results: There was 1 ACL graft failure in each group as well as 5 (10%) reoperations per group. None of the patients in the LMORT group necessitated a lateral meniscal revision repair or partial meniscectomy. The LMORT and iACLR groups reported comparable sIKDC scores (92.5 ± 6.8 vs 91.9 ± 8.2, respectively; P = .712) as well as Tegner scores (6.7 ± 1.8 vs 6.6 ± 1.8, respectively; P = .910) at final follow-up. No failures of the LMORT repairs were reported. Conclusion: The study findings demonstrated that reoperations, graft failure rates, patient-reported outcomes, and patient activity levels at ≥2 years after type 3 and 4 LMORT repairs at the time of ACLR compared favorably with those of a matched cohort of patients who underwent iACLR with intact meniscus.

Clinical outcomes after repair of an isolated radial tear in the middle segment of the lateral meniscus - All-inside suture repair vs trans-capsular suture repair.

Background/objective: For radial tears, all-inside suture (AIS) repair was clearly biomechanically superior, compared to conventional trans-capsular suture (TCS) repairs. However, clinical comparative studies of these two repairs techniques have not to be performed. Therefore, the aim of this study was to compare the clinical outcomes after AIS repair and TCS repairs for isolated radial tear at middle segment of lateral meniscus (RTMLM) in stable knees of young athletes. Methods: Twenty-six athletes (mean age, 19.1 years) underwent AIS repair with the double horizontal suture technique, using SutureLasso™ (Arthrex, Naples, FL) for isolated RTMLM (AIS group), and 20 athletes (mean age, 19.0 years) underwent inside-out repair, one of TCS repairs, with tie-grip suture technique (TCS group). All athletes were assessed for preoperative and two-year postoperative Knee injury and Osteoarthritis Outcome Score (KOOS). At six-month after repair, the lateral meniscal extrusion on mid-coronal plane on MRI and healing status on second-look arthroscopy were also evaluated in all patients. Results: In both groups, KOOS improved to either good or excellent postoperatively, while complete healing was found in only 23 and 25% at second-look arthroscopy. We identified no group-dependent differences in KOOS or healing status on arthroscopy. However, a close examination of failure rates revealed significant lower rates in AIS group relative to that of TCS group (p = 0.048). Moreover, the change from preoperative to postoperative lateral meniscal extrusion in AIS group was significantly smaller than that in TCS group (p = 0.038). Conclusions: AIS and TCS repairs for RTMLM were comparable in providing satisfactory clinical results with low rates of complete healing on arthroscopy. However, AIS repair could have lower failure rate of healing on arthroscopy and minimize postoperative lateral meniscal extrusion more effectively than TCS repair on MRI.

Meniscus Radial Tears: Current Concepts on Management and Repair Techniques.

PURPOSE OF REVIEW: This review provides a historical perspective on the approach to radial tears and collates the currently available evidence on repair techniques, rehabilitation, and outcomes following the treatment of meniscus radial tears. RECENT FINDINGS: Recent literature shows that the repair of meniscus radial tears reports improved patient-reported outcome scores with high return to function and activity. However, no single technique nor construct was proven better than the other. Various methods of repairing radial tears can be employed, with biomechanical research supporting all-inside double vertical sutures, the addition of vertical "rip-stop" mattress sutures, and transtibial pullout augmentation. To ensure proper healing before undergoing physical therapy, it is crucial to abstain from weight-bearing and deep knee flexion for the first 6 weeks after surgery. Despite considerable heterogeneity in surgical techniques and rehabilitation protocols found in the current literature, studies reporting on radial repairs report positive results, with high healing rates and improved patient-reported outcomes.

The Lateral Meniscus Oblique Radial Tear (LMORT).

PURPOSE OF REVIEW: The lateral meniscus oblique radial tear (LMORT) of the posterior horn is a relatively new term for one of the more common types of lateral meniscal tears found in patients with acute anterior cruciate ligament (ACL) injuries. Given the importance of anatomical reduction and preservation of the lateral meniscus to maintain normal knee stability and slow the progression of early-onset osteoarthritis, LMORT classification and treatment guidelines have been formulated. This article provides a review of the prevalence, classification, biomechanics, surgical repair techniques, and outcomes related to LMORT injuries. RECENT FINDINGS: Current research demonstrates favorable clinical results when LMORTs are surgically treated based on recent evidence. Biomechanically, repair of the higher grade 3 and 4 LMORT lesions have led to comparable results when compared to an intact lateral meniscus, and superior results when compared to partial meniscectomy and untreated tears. Ongoing research is aimed to determine the difference between LMORT repairs compared to intact lateral menisci at the time of ACL surgery regarding comparable patient outcomes. LMORT lesions are common tears of the lateral meniscus that should be treated surgically based on tear type at the time of ACL surgery. The benefit of doing so has already been demonstrated biomechanically.

Isolated radial tears of the lateral meniscus midbody: a case series of professional athletes treated with outside-in repair.

PURPOSE: The main aim of the study is to assess clinical and functional outcomes of arthroscopic outside-in repair of isolated radial tears of the midbody of lateral meniscus in professional athletes and to evaluate the return to the sport activity after surgery. METHODS: A retrospective data collection on professional athletes with isolated complete lesion of the midbody of lateral meniscus, treated with arthroscopic outside-in repair was carried out. Outcome measures included functional assessment, Limb Symmetry Index (LSI) and Hamstring Quadriceps Ratio (HQR) and Lysholm score collected before surgery and at 4-month follow-up. Data on return to sport practice and re-injury were also retrieved. RESULTS: Fourteen patients satisfied the selection criteria. Full return to professional sport activity (Tegner 10) was registered in the 86% of the cohort at 4 months after the surgery. Functional testing of the athletes showed a return of the LSI and HQR to the pre-surgical condition, demonstrating a full recovery of the functional ability and muscle strength. Similarly, clinical evaluation through Lysholm score showed an improvement, reaching an average of 97.7 points at 4 months follow-up. CONCLUSION: A good functional recovery and a high rate of return to play has been observed in a population of professional athletes, at 4 months after outside-in repair.

Posterior Horn Lateral Meniscal Oblique Radial Tear in Acute Anterior Cruciate Ligament Reconstruction Incidence and Outcomes After All-Inside Repair: Clinical and Second-Look Arthroscopic Evaluation.

BACKGROUND: The term posterior horn lateral meniscal oblique radial tear (LMORT) has emerged to characterize the tear patterns of the lateral meniscus in many patients with acute anterior cruciate ligament (ACL) injury. There is a lack of data regarding the exact incidence according to the types of LMORT and clinical outcomes. PURPOSES: (1) To investigate the incidence of LMORT according to type in patients with acute ACL reconstruction (ACLR) and (2) to identify healing status after repair of LMORT via second-look arthroscopy and clinical outcomes. STUDY DESIGN: Case series; Level of evidence: 4. METHODS: Patients who underwent primary ACLR within 6 months of injury were retrospectively reviewed. The LMORT was classified into 4 types based on the severity and distance from the root: type 1 (partial tear <10 mm from the root), type 2 (complete tear <10 mm from the root), type 3 (partial tear >10 mm from the root), type 4a (complete tear >10 mm from the root), and type 4b (type 4a with longitudinal tear at the meniscocapsular junction). Only patients with LMORT were isolated, and the clinical outcomes were compared according to the healing status of LMORT in second-look arthroscopy. RESULTS: Of 635 patients with ACLR, LMORT was identified in 97 patients (15.3%), and type 4 LMORT accounted for the largest proportion (n = 62; 32.6%) of 190 lateral meniscal tears. In 79 patients with LMORT who satisfied the 2-year follow-up period, all patient-reported outcomes (PROs), including the Lysholm (preoperative, 64.1; postoperative, 88.2) and International Knee Documentation Committee subjective (preoperative, 50.5; postoperative, 82.9) scores, were significantly improved (P < .001) 31.8 months postoperatively. Of the 61 patients who underwent second-look arthroscopy, 49 (80.3%) were classified into the complete healing group. There was no significant difference in postoperative PROs between the complete and partial healing groups. CONCLUSION: The incidence of LMORT was 15.3% in patients with acute ACL injury, and type 4 LMORT was the most common type. Complete healing of LMORT was achieved in 80.3% of patients who underwent second-look arthroscopy, and the PROs were significantly improved postoperatively. Good clinical results can be achieved if the LMORT is repaired as much as possible during ACLR.

Spiral capsulorhexis technique with anterior chamber maintainer under continuous fluid pressure in intumescent cataracts and its clinical outcomes.

PURPOSE: To evaluate the efficacy of technique combining an anterior chamber maintainer (ACM) and spiral capsulorhexis under continuous fluid pressure in intumescent cataracts. METHODS: One hundred thirty-one eyes of 128 patients who underwent phacoemulsification and IOL implantation for intumescent white cataracts without a red reflex were included in the study. Group 1 consisted of 67 eyes of 65 patients who underwent spiral capsulorhexis with an ACM under continuous fluid pressure. Group 2 consisted of 64 eyes of 63 patients who underwent capsulorhexis after injection of viscoelastic material into the anterior chamber. Both groups were compared in terms of endothelial cell loss, intraoperative and postoperative complications. RESULTS: Progression to the periphery in the capsule not resulting in a radial tear was observed in 3 eyes in Group 1 and 11 eyes in Group 2 (P=0.019). While the type of radial tear known as the Argentinian flag sign was not observed in Group 1, it was observed in 8 eyes in Group 2 (P=0.003). Postoperative intraocular lens (IOL) decentration did not develop in any eye in group 1, but in 3 eyes in group 2 (P=0.11). CONCLUSION: The combination technique of an anterior chamber maintainer and spiral capsulorhexis provides a controlled and safe capsulorhexis and reduces intraoperative and postoperative complications in intumescent cataracts.

Medial meniscus extrusion and stage are related to the size of spontaneous osteonecrosis of the knee in patients who underwent high tibial osteotomy.

PURPOSE: Spontaneous osteonecrosis of the knee (SONK) causes acute atraumatic knee pain, and meniscus tears may be associated with the pathogenesis of SONK. The purpose of this study was to investigate the relationship of the type of meniscus tear and medial meniscus extrusion with SONK on the medial femoral condyle in patients who underwent surgical treatment with high tibial osteotomy due to severe knee pain. METHODS: We enrolled 98 patients with 102 knees who underwent medial opening wedge high tibial osteotomy (OWHTO) under the diagnosis of medial femoral condyle osteonecrosis at our hospital from December 2003 to January 2020. Based on the Koshino classification, cases of SONK were classified as stage 1-4. The relationships of demographic data, X-rays and MRI images, including femorotibial angle (FTA), meniscus tear type, and medial meniscus extrusion (MME), with the stage and volume of SONK were investigated. RESULTS: Ninety-eight patients (29 males and 69 females), with an average age at surgery of 69.2 ± 9.6 years and Body mass index(BMI) of 61.0 ± 17.6 kg/m2. In 102 cases of SONK, 11 knees, 18 knees, 46 knees, and 27 knees were classified as stage 1-4, respectively. The mean SONK volume was 2161.61 µm (range 95.67-7484.68 µm) on preoperative MRI. The preoperative FTA (mean 180.86°, range 172-187°) was not associated with the stage or volume of SONK. Meniscus tears were found in all cases of SONK and consisted of 2 degenerations, 2 horizontal tears, 0 vertical tears, 40 radial tears, 4 complex tears, and 54 medial meniscus posterior root tears (MMPRTs). In addition, 99% (101/102) of knees showed more than 3 mm of meniscus extrusion. Although the meniscus tear type was not associated with SONK stage, there was a high rate of tears that caused disruption of the hoop strain, such as MMPRTs (52.9%) or radial tears (39.2%). MME was significantly related to SONK volume (r = 0.387, p < 0.001). CONCLUSION: All patients with SONK had coexisting meniscus tears, most menisci had medial extrusion, and a positive correlation was observed between MME and SONK volume.

"Stop & drop"- a modified "stop & chop" phacoemulsification technique for cataract surgery.

PURPOSE: To introduce a novel technique termed "stop and drop" for creating the first crack in the initial hemi-nucleus, eliminating the need to slip a chopper under the anterior capsular rim during horizontal chopping, hence lowering the risk of capsular or zonular damage. METHODS: Placing a blunt chopper tip on the upper surface of the hemisection proximal to the capsular edge and pressing it downward to initiate a crack in a pinching manoeuvre. Once a crack has formed, the chopper can slide to the side, widening the crack and assisting the phaco needle to pull out the first fragment. RESULTS: The technique was used in over 100 cases of cataracts successfully. No radial tear, posterior capsule rupture or zonulolysis occurred. CONCLUSIONS: "Stop and drop" is an effective and safe technique for performing phacoemulsification. It is not suitable for soft nuclei where the chopper will likely "cheese-wire" through the nuclear material.

Radial tears in the anterior third of the lateral meniscus are frequently combined with horizontal tears.

INTRODUCTION: Radial tears of the lateral meniscus are often located in the junction of the middle and posterior third or posterior tibial attachment. However, we observed that a few cases of radial tears occurred in the anterior third of the lateral meniscus, and in many cases, they were accompanied by horizontal tears. HYPOTHESIS: Radial tears are more frequently accompanied by horizontal tears in the anterior third of the lateral meniscus than in other regions. MATERIAL AND METHODS: From July 2006 to May 2019, patients who underwent arthroscopic surgery for radial tears of the lateral meniscus were included. Patients with radial tears in the anterior third of the lateral meniscus were classified into the anterior group and those with radial tears in the middle and posterior third were classified into the comparison group. Magnetic resonance imaging and arthroscopic findings were reviewed to evaluate whether radial tears were accompanied by other types of tears, especially horizontal tears. The incidence of complex tears between the two groups was compared. RESULTS: Eighty knees in 79 patients were included. The mean age at the time of surgery was 44.1±16.9 years. The anterior group included 30 knees, and 19 (63.3%) of those also had horizontal tears. In the anterior group, all complex tears were accompanied by horizontal tears, and no other types of accompanying tears were observed. The comparison group included 50 knees, and 16 (32%) of those also had other types of tears. Of the 16 complex tears, 14 had horizontal tears and 2 had longitudinal tears. The incidence of complex tear was significantly higher in the anterior group than in the comparison group (p<.001). CONCLUSION: Radial tears occurring at the anterior third of the lateral meniscus are frequently accompanied by a horizontal tear. It is important to be aware and predict the occurrence of such characteristic tears and to do proper surgical procedures. LEVEL OF PROOF: IV; Cross-sectional study.

Kinematic Analysis of Lateral Meniscal Oblique Radial Tears in the Anterior Cruciate Ligament-Deficient Knee.

BACKGROUND: Lateral meniscal oblique radial tears (LMORT) occur frequently in conjunction with anterior cruciate ligament (ACL) disruption and are anatomically distinct from meniscus root tears. HYPOTHESIS/PURPOSE: The purpose of this study was to characterize the effects of LMORT types 3 (LMORT3) and 4 (LMORT4) lesions on joint stability and meniscal extrusion in ACL-deficient knees. Our hypothesis was that both lesions would promote significant increases in anterior translation and meniscal extrusion, with the LMORT4 lesion having a greater effect. STUDY DESIGN: Controlled laboratory study. METHODS: Two matched pairs of cadaveric knees (n = 4) were used to optimize the testing sequence. Additional cadaveric knees with LMORT3 (n = 8) and LMORT4 (n = 8) lesions created after ACL transection underwent robotic kinematic testing for anterior drawer and pivot-shift simulations with associated ultrasound-measured meniscal extrusion at clinically relevant knee flexion angles. RESULTS: Optimization testing showed no differences on the effect of LMORT4 lesions for anterior translation and lateral meniscal extrusion with ACL-intact versus ACL-deficient knees. ACL deficiency and LMORT3 and LMORT4 lesions with ACL deficiency were associated with significantly greater anterior translation compared with ACL-intact state for both anterior drawer and pivot-shift testing at all flexion angles (P < .001). ACL deficiency with either LMORT3 or LMORT4 lesion was associated with significantly greater anterior translation than was ACL deficiency only (P < .005) for anterior drawer testing at 90° of flexion. Meniscal extrusion was greater with LMORT3 and LMORT4 lesions compared with ACL deficiency only (P < .05) for anterior drawer at 60° of flexion and for pivot shift at 15° of flexion. The LMORT4 lesion demonstrated increased anterior translation for anterior drawer (P = .003) at 60° of flexion (12%) as well as for pivot shift at 15° of flexion (7%) and 30° of flexion (13%) (P < .005) compared with ACL deficiency only. CONCLUSION: In this cadaveric model, the addition of an LMORT3 or LMORT4 lesion increased anterior laxity for both the anterior drawer and the pivot shift when compared with an isolated ACL tear. Lateral meniscal extrusion was also exacerbated by these LMORT lesions. CLINICAL RELEVANCE: LMORT lesions, distinct from meniscus root tears, occur frequently in conjunction with ACL tears. This study characterized the biomechanical consequences of LMORT3 and LMORT4 lesions on joint stability and meniscal function, highlighting the importance of diagnosing and treating LMORT lesions at the time of ACL reconstruction.

Extrusion of the medial meniscus is a potential predisposing factor for post-arthroscopy osteonecrosis of the knee.

BACKGROUND: Post-arthroscopic osteonecrosis of the knee (PAONK) is a rare condition. No studies have analyzed the relationship between the meniscus extrusion and PAONK. The purpose of this retrospective study is to test a hypothesis that the degree of the medial meniscus (MM) extrusion might be significantly greater in the knees with PAONK than in the matched control knees both before and after the meniscectomy. METHODS: Ten knees with PAONK were detected out of a total of 876 knees which had undergone arthroscopic partial meniscectomy of the MM. Ten matched control knees were randomly selected out of the remaining 866 knees without PAONK. The clinical data of these 20 patients were retrospectively collected from the medical records. To evaluate the location of the menisci on the joint line, Extrusion width and Inner width were defined on a coronal section of magnetic resonance imaging (MRI). The intra- and inter-rater reliability was evaluated by calculating the intra- and inter-class coefficients. Statistical comparisons between the 2 groups were made using the 3 non-parametric tests. RESULTS: Before the meniscectomy, the Extrusion width of the MM (mean 4.7 ± 1.4 mm) was significantly greater than that (3.0 ± 1.3 mm) in the Control group (P = 0.0195). In the MRI taken in a range from 3 to 50 weeks after the meniscectomy, the Extrusion width of the MM (5.9 ± 1.1 mm) in the PAONK group was significantly greater than that (3.4 ± 1.4 mm) in the Control group (P = 0.0009), and the Inner width of the MM (0.6 ± 1.7 mm) in the PAONK group was significantly less than that (3.9 ± 1.0 mm) in the Control group (P = 0.0001). CONCLUSION: A significant relationship was found between the degree of the MM extrusion and the onset of PAONK. This study suggested that the extrusion of the MM is a potential predisposing factor for PAONK.

Lateral meniscus "PASTA injury": Partial-thickness radial tear of the lateral meniscus: A case report.

INTRODUCTION: We report a relatively rare case of partial-thickness radial tear in the inferior surface of lateral meniscus, while the superior surface is intact. This situation was similar to PASTA rotator cuff tear. Meanwhile, there is a full-thickness radial tear in the edge. CASE PRESENTATION: A 17-year-old boy twisted the left knee while playing basketball. Magnetic resonance imaging (MRI) revealed radial tear of the lateral meniscus. During arthroscopy, it was found that there was a full-thickness radial tear of about 2 mm located in the edge. Partial meniscectomy was performed to treat radial meniscal tear located in the white area. After that, we found that the superior surface of the lateral meniscus was intact. However, in the inferior surface of the lateral meniscus, partial-thickness radial tear was found extending to red zone. We used FASTFIX (Smith & Nephew) for all-inside suture. As of three months after this surgery, the patient recovered smoothly. DISCUSSION: Suspect that the force acts on a special position of meniscus and the thickness of the meniscus is uneven. Thus, it leads to partial-thickness radial tear in the inferior-surface, while the superior surface is intact. CONCLUSION: Partial-thickness radial tears in the inferior surface of lateral meniscus are relatively rare. This situation was similar to PASTA rotator cuff tear. Because the superior surface of the meniscus is intact, it may results in misdiagnosis. It's easy to ignore the inferior surface injury.

Bony injury associated with ramp lesion and a double meniscal injury - A hidden terrible triad of the posteromedial knee.

Ramp lesions are important injuries that are difficult to detect on MRI and pose a challenge to diagnose on arthroscopy since they require inspection of the posteromedial compartment. No bony injury has been reported in the literature as an associated injury with the ramp lesion. We report a rare case of complete ramp tear of the posterior capsule-meniscal junction associated with fracture of the rim of the posterior medial tibial plateau and a double injury to the posterior medial meniscus forming a terrible triad with poor prognosis. This report has implications on the classifications of ramp lesions, posterior root injuries of the medial meniscus and meniscal tears as fracture of the rim adds a new dimension to these injuries.

Different effects of the lateral meniscus complete radial tear on the load distribution and transmission functions depending on the tear site.

PURPOSE: To compare the effect of the lateral meniscus (LM) complete radial tear at different tear sites on the load distribution and transmission functions. METHODS: A compressive load of 300 N was applied to the intact porcine knees (n = 30) at 15°, 30°, 60°, 90°, and 120° of flexion. The LM complete radial tears were created at the middle portion (group M), the posterior portion (group P), or the posterior root (group R) (n = 10, each group), and the same loading procedure was followed. Finally, the recorded three-dimensional paths were reproduced on the LM-removed knees. The peak contact pressure (contact area) in the lateral compartment and the calculated in situ force of the LM under the principle of superposition were compared among the four groups (intact, group M, group P, and group R). RESULTS: At all the flexion angles, the peak contact pressure (contact area) was significantly higher (lower) after creating the LM complete radial tear as compared to that in the intact state (p < 0.01). At 120° of flexion, group R represented the highest peak contact pressure (lowest contact area), followed by group P and group M (p < 0.05). The results of the in situ force carried by the LM were similar to those of the tibiofemoral contact mechanics. CONCLUSION: The detrimental effect of the LM complete radial tear on the load distribution and transmission functions was greatest in the posterior root tear, followed by the posterior portion tear and the middle portion tear in the deep-flexed position. Complete radial tars of the meniscus, especially at the posterior root, should be repaired to restore the biomechanical function.

Biomechanical comparison of vertical suture techniques for repairing radial meniscus tear.

PURPOSE: The aim of this study was to (1) develop suture techniques in repairing radial meniscal tear; (2) to compare the biomechanical properties of the proposed repair techniques with the conventional double horizontal technique. METHODS: Thirty-six fresh-frozen porcine medial menisci were randomly assigned into four groups and a complete tear was made at the midline of each meniscus. The menisci were subsequently repaired using four different repair techniques: double vertical (DV), double vertical cross (DVX), hybrid composing one vertical and one horizontal stitch, and conventional double horizontal (DH) suture technique with suturing parallel to the tibia plateau. The conventional double horizontal group was the control. The repaired menisci were subjected to cyclic loading followed by the load to failure testing. Gap formation and strength were measured, stiffness was calculated, and mode of failure was recorded. RESULTS: Group differences in gap formation were not statistically significant at 100 cycles (p = .42), 300 cycles (p = .68), and 500 cycles (p = .70). A trend was found toward higher load to failure in DVX (276.8 N, p < .001), DV (241.5 N, p < .001), and Hybrid (237.6 N, p < .001) compared with DH (148.5 N). Stiffness was also higher in DVX (60.7 N/mm, p < .001), DV (55.3 N/mm, p < .01), and Hybrid (52.1 N/mm, p < .01), than DH group (30.5 N/mm). Tissue failure was the only failure mode observed in all specimens. CONCLUSION: Our two proposed vertical suture techniques, as well as the double vertical technique, had superior biomechanical properties than the conventional technique as demonstrated by higher stiffness and higher strength.

The all-inside all-suture technique demonstrated better biomechanical behaviors in meniscus radial tear repair.

PURPOSE: The purpose of this study was to evaluate the effectiveness of three constructs and techniques for repair of radial tears of the meniscus. METHODS: Thirty fresh frozen porcine menisci were divided equally into three groups consisting of (1) inside-out repair group, (2) a commonly used all-inside suture with anchor hybrid repair construct (AISAH) (Meniscal Cinch™), and (3) an all-inside all-suture repair construct (AIAS) (Knee Scorpion™). Radial tears were created and repaired and then the menisci were secured to the materials testing machine. Both cyclic loading and load-to-failure testing were performed. The displacement, stiffness, response to cyclic loading, and mode of failure were recorded and analyzed statistically. RESULTS: The displacement after cyclic loading (DACL) of the Cinch repair construct group was significantly higher than that of the inside-out repair construct group (p = 0.000) and AIAS repair construct (p = 0.000). There was not a statistical difference of DACL between inside-out and AIAS groups (n.s.). The inside-out construct failed at a significantly higher load than the AISAH repair construct (p = 0.000) and AIAS construct (p = 0.006). The AIAS construct failed at a significantly higher load than the AISAH repair construct (p = 0.009). The AIAS had a higher stiffness than AISAH (p = 0.047). The AIAS had a higher load at 3 mm protrusion than AISAH (p = 0.034). CONCLUSION: The AIAS repair construct had better biomechanical behaviors than AISAH construct and inside-out repair technique. Inside-out sutures and AIAS repair construct had similar biomechanical responses to cyclic loading. The AIAS can be used for meniscus tear surgical repair with less damage to peri-meniscus tissues.

Lateral Meniscal Oblique Radial Tears Are Common With ACL Injury: A Classification System Based on Arthroscopic Tear Patterns in 600 Consecutive Patients.

BACKGROUND: Meniscal root tears and ramp lesions have been rigorously characterized in recent literature. However, one of the most common lateral meniscal injuries identified with an acute anterior cruciate ligament (ACL) disruption, a posterior horn lateral meniscal oblique radial tear (LMORT), has not been thoroughly described. PURPOSE: To determine the incidence of all meniscal tears and, more specifically, the incidence of posterior horn LMORTs in a multicenter cohort of consecutive, acute ACL reconstructions. Additionally, the authors aimed to develop a new classification system to help guide treatment of posterior horn LMORTs. STUDY DESIGN: Cross-sectional study; Level of evidence, 3. METHODS: A multicenter retrospective cohort design was used to analyze 200 consecutive cases of acute ACL reconstruction from each of 3 different surgeons, for a total of 600 patients. The operative notes and intraoperative photos were analyzed to determine the incidence and laterality of all meniscal tears. A classification system based on tear characterization was then used to categorize tear patterns into similar groups. RESULTS: A total of 396 (66%) of the 600 patients with acute ACL disruption had concomitant meniscal tears. Specifically, 187 (31%) had a lateral meniscal injury, 89 (15%) had a medial meniscal injury, and 122 (20%) had both medial and lateral meniscal injuries. The most common lateral meniscal tear was an LMORT; 71 (18%) patients with meniscal tears had a posterior horn LMORT. Overall, the incidence of ACL injury with a concomitant posterior horn LMORT was 12%. A classification was developed, which included type 1 tear (partial thickness <10 mm from the root attachment), type 2 tear (complete radial oblique tear that extended <10 mm from root), type 3 tear (incomplete LMORT that extended >10 mm from root), and type 4 tear (complete LMORT >10 mm from root). CONCLUSION: In 600 consecutive acute ACL reconstructions, the incidence of concomitant ACL injury with meniscal injury was 66%, and posterior horn LMORTs represented a large proportion of all meniscal tears (12%). A classification scheme was developed for posterior horn LMORTs to aid reporting and clinical decision making for these common tears.