Editorial Commentary: Meniscal Allograft Transplantation Results in Both Pain Relief and Chondroprotection.

Meniscal allograft transplantation (MAT) effectively alleviates symptoms of the meniscus deficiency. Thus, MAT is a widely accepted and recommended treatment for individuals with unicompartmental pain due to meniscus deficiency. Long-term follow-up studies have indicated that MAT yields favorable clinical outcomes, demonstrating high survivorship and low rates of serious complications. In addition, the ability of MAT to function akin to the native meniscus and shield the knee cartilage from osteoarthritis has been a subject of ongoing investigation, and recent direct magnetic resonance imaging evidence shows long-term chondroprotection following MAT. Cartilage lesions worsen during the meniscus deficiency period. Consequently, delaying MAT until patients become more symptomatic may lead to poor outcomes and low graft survivorship due to concomitant cartilage lesions. These findings prompt a reevaluation of the purpose and timing of MAT decisions for meniscectomy patients, suggesting a more proactive approach to recommending MAT, particularly for patients at high risk of postmeniscectomy syndrome and osteoarthritis progression.

Editorial Commentary: Early Clinical Results Are Promising for Meniscus Centralization as an Augment to Medial Meniscus Root Repair.

Meniscal root tears remain a common problem, with devastating biomechanical and clinical consequences. Thankfully, numerous techniques have been developed to repair the symptomatic meniscal root tear. However, rates of conversion to arthroplasty are reported to be 21% to 33% at 10 years, and persistent extrusion of the meniscus at follow-up is a known limitation of current root repair techniques. There is also growing evidence that some medial meniscal root tears may be an effect of meniscal extrusion, rather than the cause of it. In that vein, failure to correct extrusion may be a key mechanism of clinical and radiographic failure despite successful meniscus root repair. Techniques that "centralize" the meniscus (such as centralization with anchors at the tibial rim, meniscotibial ligament repair, deep medial collateral ligament repair, or circumferential suture augmentation of the meniscus) may improve patient outcomes by better correcting meniscal extrusion. Indications could be extrusion greater than 3 mm and documented extrusion before the root tear.

Hypermobile lateral meniscus: A systematic review of current treatment options.

PURPOSE: The reliable data on the incidence of hypermobile lateral meniscus (HLM) and its clinical manifestations, diagnostic methods and therapeutic approaches are limited. This systematic study aimed to review available treatment options for HLM and the outcomes of each approach. METHODS: A systematic search was performed in four electronic databases (PubMed, EMBASE, Scopus, Web of Science) to identify studies in which arthroscopically confirmed cases of HLM were treated surgically or nonsurgically, and the required data comprising study characteristics, patient data, treatment approaches and outcome measures were extracted from eligible studies. RESULTS: Twenty studies with a total of 212 patients (138 males and 74 females) and 219 knees were included. The most frequently reported symptoms were locking sensations, knee pain, giving way and snapping. Treatments used by the studies were: radiofrequency energy in two studies; arthroscopic partial meniscectomy in one study; open surgery in two studies; and arthroscopic meniscal repair in 17 studies. Eleven studies used an all-inside repair method and an inside-out meniscal repair was reported in eight studies. Three studies reported the usage of posterior arthroscopy for therapeutic or diagnostic approaches. Evaluation of symptom resolution was the main outcome measurement for which almost all of the studies stated relief of symptoms after intervention. CONCLUSION: Despite the lack of definite consensus about the most appropriate intervention for HLM, therapeutic preference was directed towards arthroscopic all-inside and inside-out repair techniques. Although the surgeon's decision remains the key factor in choosing the most suitable treatment option for each individual, posterior arthroscopic meniscal repair may be considered as a better option for HLM treatment according to the findings of this review. LEVEL OF EVIDENCE: Level IV.

Editorial Commentary: Early Anterior Cruciate Ligament Reconstruction Decreases the Risk of Developing Irreparable Meniscus Tears in Female Athletes.

There has been a substantial increase in the participation of women in sports since the passage of Title IX in 1972. With increased participation has come a rise in athletic injuries, including anterior cruciate ligament (ACL) tears. Numerous factors (modifiable and nonmodifiable) contribute to the 2 to 8 times increased risk of ACL tears in female compared with male athletes. The sports with the greatest risk of ACL injury include cutting sports such as soccer (1.1% per season), basketball (0.9% per season), volleyball, and lacrosse. In addition, female patients have a 33.7% greater risk of a subsequent contralateral ACL tear. Approximately 70% of ACL tears are the result of noncontact injuries. Numerous factors contribute to the increased risk of ACL tears in female athletes, including nonmodifiable (hormonal fluctuations, sex differences in knee geometry) and modifiable risk factors (neuromuscular control). Injury-prevention programs focus on modifiable risk factors and have been shown to be incredibly effective, decreasing the risk of ACL tears up to 50%. ACL tears commonly are associated with meniscus tears, including medial meniscus ramp and lateral posterior root lesions; therefore, thorough assessment is critical to identify this pathology. Early ACL reconstruction (i.e., <12 months following injury) increases the likelihood of being able to repair meniscus tears. Given the much greater risk of ACL tears and lower rate of return to sport in female athletes, this group warrants special attention to identify and treat these injuries earlier and subsequently improve overall outcomes.

The first-generation anatomical medial meniscus prosthesis led to unsatisfactory results: a first-in-human study.

PURPOSE: The purpose of this first-in-human study was to evaluate the effect of a polycarbonate anatomical meniscus prosthesis system, including the surgical procedure, on knee pain and describe potential adverse events in patients with post-meniscectomy pain syndrome. METHODS: Eleven patients with post-meniscectomy pain syndrome and limited underlying cartilage damage were enrolled in the study. Five received a medial polycarbonate urethane meniscus prosthesis which was clicked onto 2 titanium screws fixated at the native horn attachments on the tibia. The KOOS score was planned to be collected at baseline and at 3, 6, 12 and 24 months following the intervention including radiographs at 6, 12 and 24 months. MRI scans were repeated after 12 and 24 months. RESULTS: The surgical technique to select an appropriately sized implant and correct positioning of the fixation screws and meniscus prosthesis onto the tibia was demonstrated to be feasible and reproducible. Inclusion stopped after 5 patients because of serious adverse device-related events. All patients reported knee joint stiffness and slight effusion in their knee at 6 months follow-up. In 3 patients the implant was removed because of implant failure and in 1 patient the implant was removed because of persistent pain and extension limitation. In none of the patients did the KOOS score improve in the first 6 months after surgery. However, in the patient who still has the implant in situ, PROMs started to improve 1 year after surgery and this improvement continued through 2 years of follow-up. The KOOS Pain, symptoms and ADL were close to the maximal 100 points. KOOS QoL and sport did improve but remained suboptimal. CONCLUSION: This first version of the meniscus prosthesis led to impaired knee function and failed in four out of five patients. The patients where the prosthesis was removed were salvable and the PROMs returned to pre-study levels. The results in the patient where the device is still in place are promising. LEVEL OF EVIDENCE: Level II.

Arthroscopic centralization reduces extrusion of the medial meniscus with posterior root defect in the ACL reconstructed knee.

PURPOSE: The purpose of this study was to evaluate the effects of arthroscopic meniscal centralization reinforcement for a medial meniscus (MM) posterior root defect on knee kinematics and meniscal extrusion in the anterior cruciate ligament reconstructed (ACLR) knee. The hypothesis was that the medial meniscus centralization would reduce extrusion and anterior laxity in ACLR knee with a medical meniscal defect. METHODS: Fourteen fresh-frozen human cadaveric knees were tested using a six-degrees-of-freedom robotic system under the following loading conditions: (a) an 89.0 N anterior tibial load, (b) 5.0 Nm internal and external rotational torques, (c) a 10.0 Nm valgus and varus loadings, and (d) a combined 7.0 Nm valgus moment and then a 5.0 Nm internal rotation torque as a static simulated pivot shift. The tested knee states included: (1) anatomic single-bundle cruciate ligament reconstruction with intact medial meniscus (MM Intact), (2) anatomic single-bundle cruciate ligament reconstruction with medial meniscus posterior root defect (MM Defect), (3) Anatomic single-bundle cruciate ligament reconstruction with medial meniscus arthroscopic centralization (MM Centralization). Medial meniscus arthroscopic centralization was performed using 1.4 mm anchors with #2 suture. The MM extrusion (MME) was measured using ultrasound under unloaded and varus loading conditions at 0° and 30° of flexion. RESULTS: Anterior tibial translation (ATT) increased significantly with MM posterior root defect compared to MM intact at all flexion angles. With MM centralization, ATT was not significantly different from the intact meniscus at 15° and 30° of flexion. Meniscus extrusion increased significantly with the root defect compared to intact meniscus and decreased significantly with meniscal centralization compared to the root defect at both flexion angles. CONCLUSIONS: In ACL reconstruction, cases involving irreparable medial meniscal posterior root tears, applying arthroscopic centralization for avoiding the meniscal extrusion should be considered. Clinically, in ACL reconstruction cases with irreparable medial meniscal posterior root tears, applying arthroscopic meniscal centralization for avoiding the meniscal extrusion should be considered. Meniscal centralization decreases the extrusion of the MM and offers improvements in knee laxity.

Smaller Iatrogenic Defects Created by Inside-Out Compared With All-Inside Meniscus Repair Devices in Human Cadaveric Model.

PURPOSE: (1) To investigate the pattern and diameter of the iatrogenic defect that meniscal repair devices impose on meniscal tissue and (2) to determine whether repair-induced defect patterns or diameters differ across devices. METHODS: Sixty-one fresh frozen human cadaveric menisci were used (n = 9; eliminated). All-inside devices (n = 9) included ULTRA FAST-FIX, FAST-FIX 360, Depuy Mitek 0° and 12° TRUESPAN, ConMed Sequent, Zimmer Biomet JuggerStitch, Stryker IvyAIR, Arthrex FiberStitch and Meniscal Cinch II. Inside-out needles (n = 4) included ConMed HiFi, Depuy Mitek ORTHOCORD, Arthrex-2-0 FiberWire, and Stryker SharpShooter. Following India Ink staining, implant devices were inserted into cadaveric menisci. Samples were fixed in formalin solution and imaged with a high-resolution camera. Defects were classified by qualitative evaluation. Defect and needle diameter were quantified with software assistance. Statistical analysis was performed using analysis of variance testing. RESULTS: We analyzed 644 iatrogenic defects with mean defect diameter of 1.96 mm (standard deviation 0.86). For all-inside devices, defect patterns (n = 436) were 15.6% linear, 38.1% semilunar, 46.3% stellate, while inside-out devices (n = 208) were 95.7% stellate, 4.3% linear, and 0.0% semilunar. All-inside devices had mean defect diameter of 2.46 mm, while inside-out meniscus needles had mean 0.90 mm defect diameter (P < .001). FasT-FIX 360, ULTRA-FAST-FIX, and Arthrex Meniscal Cinch II induced smaller diameter defects than other all-inside devices (F = 20.2, P < .05). Strong positive correlation was found comparing outer needle diameter and mean defect diameters across all devices (R2 = 0.9447). CONCLUSIONS: Needles utilized in meniscal implant systems produce the following basic defect patterns: stellate (62.3%), semilunar (25.8%), and linear (11.9%). A strong positive correlation was found between mean defect size and outer needle diameter across all devices. Inside-out double-armed flexible needles produced significantly smaller defects than all-inside devices. Of the all-inside devices, ULTRA FAST-FIX, FAST-FIX 360, and Arthrex Meniscal Cinch II produced smaller defects on average. CLINICAL RELEVANCE: While the true clinical impact of these findings cannot be drawn from the present study, this investigation provides necessary context to better understand reported similarities and differences in healing rates and outcomes between inside-out and all-inside repair techniques.

Acetabular labral reconstruction with medial meniscal allograft: preliminary results of a new surgical technique.

PURPOSE: Reconstruction of the acetabular labrum during femoroacetabular impingement (FAI) surgery is accepted when the labrum is deficient and irreparable. Here we describe a novel technique using fresh-frozen medial meniscal allograft for labral reconstruction during surgical hip dislocation for correction of pincer FAI due to acetabular overcoverage. METHODS: The results from seven hips (six patients) that underwent this procedure with 1 year minimum follow-up, and radiographs are presented. RESULTS: Six of the seven hips had improvements in pain, hip flexion, hip abduction, and Merle d'Aubigné-Postel scores. Only one patient with pre-existing osteoarthritis underwent reoperation with conversion to total hip arthroplasty. All digastric trochanteric osteotomies healed, and there were no cases of femoral head osteonecrosis or progression of Tönnis grades. CONCLUSIONS: The medial meniscus is a morphologically and clinically suitable option for labral reconstruction and effectively restores the hip fluid seal.

Platelet-rich plasma (PRP) augmentation does not result in more favourable outcomes in arthroscopic meniscal repair: a meta-analysis.

BACKGROUND: The efficacy and safety of platelet-rich plasma (PRP) augmentation for arthroscopic meniscal repair is controversial. This meta-analysis compared arthroscopic meniscal repair performed in isolation or augmented with PRP. METHODS: The present study was conducted according to PRISMA 2020 guidelines. Pubmed, Web of Science, Google Scholar and Embase were accessed in August 2021. All the clinical trials which compared arthroscopic meniscal repair performed in isolation or augmented with PRP were included. RESULTS: Eight hundred thirty-seven patients were included: 38% (318 of 837 patients) were women; the mean age of the patients was 35.6 (range, 20.8-64.3) years; the mean follow-up was 26.2 (range, 6-54) months. Similarity was found in analogue scale (VAS) (P = 0.5) and Lysholm (P = 0.9), and International Knee Documentation Committee (IKDC) scores (P = 0.9). Similarity was found in the rate of failure (P = 0.4) and rate of revision (P = 0.07). CONCLUSION: The current published scientific evidence does not support PRP augmentation for arthroscopic meniscal repair.

Huge intrameniscal cyst successfully treated by open debridement and combined arthroscopic and open repair: a case report.

BACKGROUND: Meniscal cysts are not uncommon in clinical practice, with reported incidence rates varying from 1 to 22%. Most meniscal cysts are parameniscal cysts, which are created by extravasation of synovial fluid through the meniscal tear into the adjacent soft tissue. In contrast, intrameniscal cysts in which the fluid collects in the meniscus are very rare. We encountered a teenager with a huge intrameniscal cyst accompanied by a small vertical meniscal tear in the red-white zone of the upper surface of the medial meniscus. A literature search revealed no information regarding the appropriate treatment methods and results for this type of lesion. CASE PRESENTATION: A 14-year-old boy presented to our outpatient clinic because of right knee pain that had been present for the previous 2 months. The patient participated in Hapkido, but had no specific trauma history. Magnetic resonance imaging revealed a huge intrameniscal cyst located in the central parenchyma of the posteromedial corner of the medial meniscus. In addition, one sagittal slice on MRI revealed a vertical tear in the red-white zone of the upper surface of the medial meniscus. The presence of such a tear accompanied by a huge intrameniscal cyst is very unusual. The patient was treated via arthroscopic inside-out meniscal suture repair and open cystic debridement with additional meniscocapsular suturing. During 4 years of magnetic resonance imaging follow-up, the lesion has completely disappeared and the meniscus has successfully recovered its normal form. CONCLUSIONS: Our treatment method may be considered as the first choice for young patients who require surgical treatment for large intrameniscal cysts with accompanying small vertical meniscal tears.

The modified cross-suture technique for unilateral pulled-out anchor during all-inside meniscal repair.

BACKGROUND: Meniscal repair has received increasing attention, but for inexperienced doctors, unilateral suture anchor pulling out may occur during all-inside meniscal repair, and the treatment outcome may be affected. When the errors happened intraoperatively, how to minimize the loss under guaranteeing of treatment effectiveness is a topic worth studying. PURPOSE: To explore the practicability and effectiveness of the modified cross-suture method for arthroscopic remediation of unilateral suture anchor pulling out of an all-inside meniscal repair system. METHODS: From May 2014 to May 2017, 28 patients diagnosed with injuries of the meniscus and anterior cruciate ligaments (ACL) from the First Department of Orthopaedics of the Second Affiliated Hospital of Xi'an Jiaotong University were enrolled in the study as the observation group, including 18 males and 10 females with an average age of 25.5 ± 2.3 years (range 18-42 years). All patients underwent ACL reconstruction concurrently. All meniscus injuries were repaired with an all-inside meniscal repair technique, and 1-3 needles of unilateral suture anchor pulling out occurred intraoperatively. The modified cross-suture method was used to remedy the error of anchor pulling out and to eventually complete an effective repair. Another 30 patients who underwent ACL reconstruction and all-inside meniscal concurrently without unilateral suture anchor pulling out, including 20 males and 10 females with an average age of 26.3 ± 1.9 years (range 19-45 years), were enrolled as the control group. During postoperative follow-up, range of motion, Lachman test and pivot shift test were performed during the physical examination. The clinical healing of the meniscus was evaluated according to the Barrett standard. The meniscus healing status was also confirmed with magnetic resonance imaging (MRI). The function of the knee joint was evaluated according to the IKDC, Lysholm and Tegner scores. RESULTS: Twenty-five patients in the observation group and 28 patients in the control group completed the follow-up, with an average follow-up of 18.4 ± 5.2 months. All operations were performed by the same surgeon. At the follow-up 1 year after the operation, the average knee ROM of the two groups was 125.2 ± 4.3 degrees and 124.7 ± 3.8 degrees, the clinical healing rate of the meniscus of the two groups was 92.0% (23/25) and 92.9% (26/28), the MRI healing rate of the menniscus of the two groups was 72.0% (18/25) and 71.4% (20/28), and the IKDC, Lysholm and Tegner scores of the two groups were 90.52 ± 2.8, 89.17 ± 3.1, and 6.81 ± 1.7 and 91.42 ± 1.9, 90.32 ± 3.4, and 7.02 ± 1.4, respectively. The differences were not statistically significant (P > 0.05). CONCLUSIONS: The modified cross-suture method is practicable and effective for arthroscopic remediation of unilateral suture anchor pulling out in an all-inside meniscal repair system.

Avoiding Injury to the Popliteal Neurovascular Bundle in All-Inside Suturing of the Posterior Horn of the Lateral Meniscus: A Magnetic Resonance Imaging Assessment of Portal Selection and Safety.

PURPOSE: We assessed the risk of injury to the popliteal neurovascular bundle (PNVB) while suturing the posterior horn of the lateral meniscus (PHLM). METHODS: We simulated all-inside suturing of the PHLM using magnetic resonance imaging of 60 knees. Lines were drawn from the medial and the lateral edges of the patellar tendon to the PHLM at increasing distances from the posterior cruciate ligament (PCL) to simulate suturing device trajectory. Distance from each line to the PNVB was measured (d). A similar analysis was performed using lines drawn from 1 cm medial and 1 cm lateral to the patellar tendon. We compared the average "d" at increasing distances from the PCL, between the different simulated portal entry points. We have also analyzed the association between different demographic characteristics and the shortest distance from the PVNB to the PHLM. RESULTS: Of 1200 measurements performed, the simulated suturing trajectory transected the PNVB 343 times (28.6%). At 0 mm from the PCL, the safest portal was the 1-cm lateral portal (P < .001), with an average "d" of 2.7 mm. At 3 mm, 6 mm, 9 mm, and 12 mm from the PCL, the safest portal was the 1-cm medial portal (P < .001), with average "d" of 3.8 mm, 6.9 mm, 10.1 mm, and 13.5 mm, respectively. Average distance between the PHLM and the PNVB was 7.8 mm. Shorter distance between the PHLM and the PNVB was associated with younger age and female sex (P = .014 and .001, respectively). CONCLUSIONS: All-inside suturing of the PHLM at 0 mm from the PCL is safer with a more lateral portal. Beyond 3 mm from the PCL, a more medial portal carries a lower risk to the PNVB. Young and female patients have a shorter distance between the PHLM and the PNVB, suggesting a greater risk for injury to the PNVB. Careful preoperative magnetic resonance imaging assessment may assist in safer portal selection when planning repair of the PHLM. CLINICAL RELEVANCE: This study describes a magnetic resonance imaging-based risk assessment for injury of the PVNB while suturing the PHLM. It allows the orthopaedic surgeon a better understanding of the anatomic relationship between the popliteal neurovascular bundle and the lateral meniscus and can assist in portal selection and safety.

Widening of the popliteal hiatus on magnetic resonance imaging leads to recurrent subluxation of the lateral meniscus.

PURPOSE: This study was undertaken to elucidate the clinical significance of widening of the popliteal hiatus on magnetic resonance imaging (MRI), and to document the clinical results and technical aspects of arthroscopic repair of this finding. METHODS: Included are 82 knees after arthroscopic surgery, divided according to arthroscopic diagnosis into group A, hypermobility of lateral meniscus, 8 knees; group B, tear of the anterior horn of the lateral meniscus, 32 knees; and group C, no abnormality of the lateral meniscus, 36 knees with medial meniscal tears and 6 with other conditions. Popliteal hiatus diameter was measured and the popliteal hiatus/lateral tibial plateau (LTP) ratio was calculated on preoperative sagittal and coronal MRI. At arthroscopy, the widened popliteal hiatus in group A was tightened anteriorly by outside-in or all-inside suture and posteriorly with all-inside suture. Outcomes were evaluated with MRI, Lysholm, Tegner and VAS scores. RESULTS: The preoperative diameter of the popliteal hiatus and the popliteal hiatus/LTP ratio were significantly larger in group A than in groups B and C (p < 0.05) on both views. Threshold popliteal hiatus/LTP values of 0.16 and 0.18 on the sagittal and coronal views demonstrated diagnostic discrimination, and these values were significantly reduced after arthroscopy in Group A. Lysholm and Tegner scores were improved after tightening of the popliteal hiatus, while VAS scores reduced (all p < 0.05). CONCLUSION: Widening of the popliteal hiatus on MRI may lead to recurrent subluxation of the lateral meniscus. Arthroscopic anterior and posterior tightening of the popliteal hiatus was a safe and effective treatment. LEVEL OF EVIDENCE: II.

Meniscus repairs in the adolescent population-safe and reliable outcomes: a systematic review.

PURPOSE: The purpose of this study was to determine the outcomes of meniscus repair in the adolescent population, including: (1) failure and reoperation rates, (2) clinical and functional results, and (3) activity-related outcomes including return to sport. METHODS: Two authors independently searched MEDLINE, Cochrane Central Register of Controlled Trials & Cochrane Library, and CINHAL databases for literature related to meniscus repair in an adolescent population according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. No meta-analysis was performed in this qualitative systematic review. RESULTS: Thirteen studies, including no Level I, one Level II, one Level III, and eleven Level IV studies yielded 466 patients with 503 meniscus repairs. All defined meniscal re-tear as a primary endpoint, with a reported failure rate ranging from 0 to 42% at a follow-up ranging from 22 to 211 months. There were a total of 93 failed repairs. IKDC scores were reported in four studies with a mean improvement ranging from 24 to 42 (P < 0.001). Mean post-operative Lysholm scores were reported in seven studies, ranging from 85 to 96. Additionally, four of those studies provided mean pre-operative Lysholm scores, ranging from 56 to 79, with statistically significant mean score improvements ranging from 17 to 31. Mean post-operative Tegner Activity scores were reported in nine studies, with mean values ranging from 6.2 to 8. CONCLUSION: This systematic review demonstrates that both subjective and clinical outcomes, including failure rate, Lysholm, IKDC, and Tegner activity scale scores, are good to excellent following meniscal repair in the adolescent population. Further investigations should aim to isolate tear type, location, surgical technique, concomitant procedures, and rehabilitation protocols to overall rate of failure and clinical and functional outcomes. LEVEL OF EVIDENCE: IV.

Degenerative tears of the posterior horn of the medial meniscus: correlation between MRI findings and outcome following intra-articular steroid/bupivacaine injection of the knee.

AIM: To evaluate the response of symptomatic degenerative tears of the posterior horn of the medial meniscus to guided intra-articular knee steroid/bupivacaine injection and to correlate clinical outcomes with preprocedural findings at magnetic resonance imaging (MRI). MATERIALS AND METHODS: Sixty patients who had clinical and MRI evidence of a symptomatic degenerative tear of the posterior horn of the medial meniscus, isolated or accompanied by additional features of degenerative arthritis, who had failed conservative approaches (physiotherapy, non-steroidal anti-inflammatories, and 3 months rest/knee bracing) were included in the study. Patients underwent intra-articular knee steroid/bupivacaine injection and were followed clinically for a minimum of 6 months. Preprocedural MRI findings were correlated with duration of symptoms, clinical response to injection (recorded as complete, partial or no response) and duration of response to injection. RESULTS: Forty-nine of 60 patients (82%) reported an improvement in symptoms following guided intra-articular knee steroid/bupivacaine injection (complete: 25 patients (42%), partial: 24 (40%) patients). Improvement was sustained in 32 of 60 patients (53%) at follow-up. Thirteen of 18 patients (72%) who had an isolated degenerative tear of the posterior horn of the medial meniscus recorded a complete resolution of symptoms. This was sustained at follow-up in 10 patients (56%). CONCLUSION: Intra-articular steroid/bupivacaine knee joint injection reduced pain symptoms in the majority of patients (81.7%) with degenerative tears of the posterior horn of the medial meniscus, usually with a sustained response. Preprocedural MRI appearances correlate with response to injection. Patients with isolated tears are more likely to have a favourable outcome.

Can we predict the clinical outcome of arthroscopic partial meniscectomy? A systematic review.

NHS-PROSPERO REGISTRATION NUMBER: 42016048592 OBJECTIVE: In order to make a more evidence-based selection of patients who would benefit the most from arthroscopic partial meniscectomy (APM), knowledge of prognostic factors is essential. We conducted a systematic review of predictors for the clinical outcome following APM. DESIGN: Systematic review DATA SOURCES: Medline, Embase, Cochrane Central Register, Web of Science, SPORTDiscus, PubMed Publisher, Google Scholar INCLUSION CRITERIA: Report an association between factor(s) and clinical outcome; validated questionnaire; follow-up >1 year. EXCLUSION CRITERIA: <20 subjects; anterior cruciate ligament-deficient patients; discoid menisci; meniscus repair, transplantation or implants; total or open meniscectomy. METHODS: One reviewer extracted the data, two reviewers assessed the risk of bias and performed a best-evidence synthesis. RESULTS: Finally, 32 studies met the inclusion criteria. Moderate evidence was found, that the presence of radiological knee osteoarthritis at baseline and longer duration of symptoms (>1 year) are associated with worse clinical outcome following APM. In addition, resecting >50% of meniscal tissue and leaving a non-intact meniscal rim after meniscectomy are intra-articular predictive factors for worse clinical outcome. Moderate evidence was found that sex, onset of symptoms (acute or chronic), tear type or preoperative sport level are not predictors for clinical outcome. Conflicting evidence was found for the prognostic value of age, perioperative chondral damage, body mass index and leg alignment. SUMMARY/CONCLUSION: Long duration of symptoms (>1 year), radiological knee osteoarthritis and resecting >50% of meniscus are associated with a worse clinical outcome following APM. These prognostic factors should be considered in clinical decision making for patients with meniscal tears.

Are Outcomes After Meniscal Repair Age Dependent? A Systematic Review.

PURPOSE: To determine if the failure rate and functional outcome after arthroscopic meniscus suture repair are age dependent. METHODS: A systematic review was conducted using a computerized search of the electronic databases MEDLINE and ScienceDirect in adherence with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Extracted data from each included study were recorded on a standardized form. Studies were included if they (1) were English-language studies in peer-reviewed journals, (2) used a distinct age cut-off to evaluate outcome of meniscal surgery for those above and below the specified cut-off, and (3) used meniscal repairs using suture based technique with inside-out, outside-in, or all-inside techniques. Review papers, case reports, technique papers, non-English language publications, abstracts, and data on meniscal repairs using meniscal screws, arrows, or darts were excluded. RESULTS: 15 of 305 identified articles met the inclusion/exclusion criteria. There were 1,141 menisci treated in 1,063 patients. Seven and 8 studies met the inclusion/exclusion criteria for analysis for the age thresholds of 25 years and 30 years, respectively, demonstrating no difference in failure rates relative to age threshold. Four of 6 studies that met analysis criteria found no difference in failure rates above or below an age threshold of 35 years. No significant difference in failure in patients younger than 40 than patients older than 40 was found for 4 of the 5 studies in that arm of the review. CONCLUSIONS: Analysis of the composite data in this systematic review reveals that no significant difference exists when evaluating meniscal repair failure rate as a function of age above or below the given age thresholds. LEVEL OF EVIDENCE: Level IV, systematic review of level III and IV studies.

Polyurethane meniscal scaffolds lead to better clinical outcomes but worse articular cartilage status and greater absolute meniscal extrusion.

PURPOSE: Implantation of polyurethane (PU) meniscal scaffolds has become a popular procedure to provide a scaffold for vessel ingrowth and meniscal tissue regeneration in patients with partial meniscal defects. However, it is unclear whether PU meniscal scaffolds lead to better clinical and magnetic resonance imaging (MRI) outcomes post-operatively. This meta-analysis compared the clinical and MRI outcomes in patients with partial meniscal defects treated with PU meniscal scaffolds. METHODS: This meta-analysis reviewed all studies that assessed Lysholm score, International Knee Documentation Committee (IKDC) score, visual analogue scale (VAS) for pain, Tegner score, Knee Injury and Osteoarthritis Outcomes Score (KOOS), articular cartilage (AC), absolute meniscal extrusion (AME), morphology and size (MS), signal intensity (SI) of meniscal implant, and interface of the implant-residual meniscus complex (IIRMC) in patients with partial meniscal defects treated with PU meniscal scaffolds. RESULTS: Eighteen studies were included in the meta-analysis. The proportion of patients who evaluated MS (OR 0.71, 95% CI 0.38-1.33; n.s.), SI (OR 1.07, 95% CI 0.53-2.18; n.s.), and IIRMC (OR 1.00, 95% CI 0.33-3.06; n.s.) did not differ significantly between baseline and final follow-up. However, AC (OR 0.31, 95% CI 0.11-0.84; P = 0.02) and AME (OR 0.05, 95% CI 0.01-0.18; P < 0.00001) worsened between baseline and final follow-up. Conversely, Lysholm score (95% CI -1.87 to -1.07; P < 0.00001), IKDC score (95% CI -2.19 to -1.08; P < 0.00001), VAS for pain (95% CI -2.29 to -1.07; P < 0.00001), Tegner score (95% CI -0.76 to -0.15; P = 0.003), and overall KOOS (95% CI -29.48 to -23.17; P < 0.00001) were significantly greater at final follow-up when compared to baseline. CONCLUSION: This meta-analysis found no significant differences in the tested MRI parameters, including MS, SI, and IIRMC. However, AC and AME worsened between baseline and final follow-up. Conversely, patients treated with PU meniscal scaffolds showed significant functional improvement and pain relief when compared with baseline scores. Thus, PU meniscal scaffolds appear to be a viable alternative for patients with partial meniscal defects, although further studies are needed to determine whether worsened AC and AME are clinically relevant. In particular, precise measurement of PU meniscal scaffolds in combination with thorough investigation of the baseline articular cartilage status and meniscal defect size may be effective for pain relief or functional improvement in patients with PU meniscal scaffold implantation. LEVEL OF EVIDENCE: III.

Arthroscopic meniscal surgery versus conservative management in patients aged 40 years and older: a meta-analysis.

INTRODUCTION: The efficacy of arthroscopic meniscus surgery in old aged patients remains controversial. The purpose of the present study was to review published studies comparing arthroscopic meniscal surgery with conservative management to treat meniscal injuries in patients 40 years of age and older. MATERIALS AND METHODS: Several electronic databases were queried for articles published until July 2017 that evaluated outcomes of arthroscopic meniscal surgery in patients aged 40 years and older. Data searches, extraction, analysis, and quality assessment were performed according to the Cochrane Collaboration guidelines, and the clinical outcomes were evaluated using various outcome values. The results are presented as the standard mean difference (SMD) for continuous outcomes with 95% confidence intervals (CIs). RESULTS: Nine randomized controlled trials (RCTs) were included. There were no significant differences in clinical outcomes such as relief in knee pain (SMD = 0.01, 95% CIs = - 0.15 to 0.18, I2 = 38%) and improved knee function (SMD = 0.01, 95% CIs = - 0.19 to 0.21, I2 = 57%) between arthroscopic meniscal surgery and conservative management for degenerative meniscal tears. CONCLUSIONS: The efficacy of arthroscopic surgery was not superior to conservative management in this type of patients. Therefore, arthroscopic meniscal surgery should not be recommended as a first choice of treatment for degenerative meniscal tears. In patients over 40 years of age, arthroscopic surgery should be cautiously considered for degenerative meniscal tears and only when there has not been a satisfactory response to conservative management.

Post-operative deformation and extrusion of the discoid lateral meniscus following a partial meniscectomy with repair.

PURPOSE: The purpose of this study was to investigate the morphology of the discoid lateral meniscus sequentially following a partial meniscectomy with repair using magnetic resonance imaging (MRI). METHODS: Nine patients with a symptomatic discoid lateral meniscus with a peripheral tear were enrolled in this study, and a partial meniscectomy with repair was performed arthroscopically. An MRI examination was performed 2 weeks after surgery (before weight bearing was permitted) and again 6 months after surgery (when sporting activities could resume). The width, height and distance of the discoid lateral meniscus were measured. The distance was defined as the distance between the edges of the discoid lateral meniscus and the tibia. RESULTS: The width of the anterior, middle and posterior segments significantly decreased from 2 weeks to 6 months after surgery. The height of the middle and posterior segments significantly increased from 2 weeks to 6 months after surgery, whereas the height of the anterior segment did not significantly change. The distance of the anterior, middle and posterior segments significantly decreased from 2 weeks to 6 months after surgery. CONCLUSION: The discoid lateral meniscus exhibited deformation and extrusion from 2 weeks to 6 months after a partial meniscectomy with repair. Therefore, the function of load transmission might not be maintained appropriately after surgery. LEVEL OF EVIDENCE: IV.