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Abstract Introduction Several cases of tibial post breakage are reported in the literature. To the best of our knowledge, only three cases of NexGen knee prosthesis (Zimmer, Warsaw, Indiana, USA) tibial post failure have been reported. Case presentation In November 1999, a 63-year-old Caucasian woman from Italy with a history of symptomatic left knee osteoarthritis underwent a total knee arthroplasty. In March 2008, while rising from a chair, she felt a sudden pain and instability in her left knee. She reported a fracture of the polyethylene post of the tibial insert. No malposition or malalignment of either the femoral or tibial components were identified. The polyethylene tibial insert was studied under light microscopy and scanning electron microscopy. The fracture was also noted to have occurred without any notable polyethylene wear. Conclusion Scanning electron microscopy revealed two different damage patterns that could be explained with a two-stage rupture of our patient's polyethylene post. This could have been caused by a non-optimal ligamentous balancing during first implant surgery. Her knee probably developed a varus instability that weakened the post, and then a posterior anterior stress finally broke the polyethylene.

Purpose: To present the 2-year results of the use of the lateral Collagen Meniscus Implant (CMI) for the treatment of irreparable lateral meniscal lesions or partial lateral meniscal defects, to investigate the potential predictors of clinical results, and to monitor device safety., Methods: Forty-three patients with a mean age of 30.1 ± 12.0 years were clinically evaluated 24 months after treatment of partial lateral meniscal defects with the CMI (Ivy Sports Medicine, Gräfelfing, Germany). We used the Lysholm score, the Tegner Activity Scale, a visual analog scale for pain (during strenuous activity, during routine activity, and at rest), a functional questionnaire, and a satisfaction questionnaire for the evaluation. All demographic and surgical parameters were used for multiple regression analysis to find outcome predictors. Serious adverse events and reoperations were monitored., Results: All clinical scores significantly improved from preoperatively to final evaluation at 24.2 ± 1.9 months' follow-up. The Lysholm score improved significantly from 64.3 ± 18.4 preoperatively to 93.2 ± 7.2 at final follow-up (P = .0001). Functional improvement was detected from 6 months after surgery, whereas strenuous activities and knee swelling reached optimal results after 12 months. The highest pain ratings experienced during strenuous activity, during routine activity, and at rest significantly improved from 59 ± 29, 29 ± 25, and 20 ± 25, respectively, preoperatively to 14 ± 18, 3 ± 5, and 2 ± 6, respectively, at 2 years' follow-up (P = .0001). At final follow-up, 58% of patients reported activity levels similar to their preinjury values whereas 95% of patients reported that they were satisfied with the procedure. A higher body mass index, the presence of concomitant procedures, and a chronic injury pattern seemed to negatively affect the final outcomes. Serious adverse events with a known or unknown relation to the scaffold, such as pain, swelling, and scaffold resorption, were reported in 6% of patients, leading to CMI explantation, debridement, or synovectomy., Conclusions: The lateral CMI scaffold could be considered a potentially effective and safe procedure to treat both irreparable lateral meniscal tears and post-meniscectomy syndrome in appropriately selected patients. Chronic injury, high body mass index, and concomitant procedures have been shown to negatively affect the short-term results; however, the results appeared to slowly improve through the 24-month follow-up period. Thus patience is needed when evaluating the expectations for and results of the described procedure., Level of Evidence: Level IV, therapeutic case series., (Copyright © 2015 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.)

Purpose: to evaluate the safety and effectiveness of the polyurethane meniscal scaffold through clinical examination, MRI and arthroscopic second look, over a minimum two-year follow-up., Methods: between 2009 and 2011, 19 patients underwent meniscal scaffold implantation in our department (medial meniscus in 16 cases lateral meniscus in two cases, and bilateral in one case). All the patients were clinically evaluated preoperatively, and at 6, 12, and 24 months after surgery using Lysholm score, Tegner score, and VAS. Ten patients were studied with MRI, and nine patients were evaluated arthroscopically., Results: no adverse reactions to the implant were observed. The clinical scores showed a significant improvement at 6 months and increased progressively over time. On MRI studies, the implants showed a clear hyperintense signal, sometimes irregular, and the chondral surface was preserved in all cases. At arthroscopic second look in the first months after surgery, the scaffold size was unchanged and the scaffold appeared light yellowish in color and well integrated into the surrounding tissues. At arthroscopic second look at 12 and 24 months the scaffold was found to have an irregular morphology and to be slightly reduced in size., Conclusions: polyurethane meniscal scaffold is a good alternative to a collagen scaffold, but a longer follow-up is needed to evaluate the scaffold degradation and chondral coverage., Level of Evidence: level IV, therapeutic case series.

We report and discuss the use of and rationale for tissue engineering techniques in a 40-year-old sportsman who suffered simultaneous anterior cruciate ligament (ACL) rupture, irreparable medial meniscal tear, and chondral lesion of the medial femoral condyle. A 2-step treatment was adopted to address all lesions. The first procedures consisted of ACL reconstruction and collagen meniscus implant (CMI), followed 6 months later by autologous chondrocyte implantation on a collagen membrane (MACI). A CMI biopsy was performed 6 months after implantation. Histologic and ultrastructural analysis documented scaffold invasion by cells and newly synthesized connective tissue. At 2-year follow up, the clinical and functional results were good and magnetic resonance imaging showed integration of the meniscal and cartilage implants. In this patient, each lesion needed to be addressed to achieve an optimal outcome. The primary goal was to restore normal joint biomechanics by performing CMI and ACL reconstruction. MACI was an adequate solution for the management of the large (5 cm(2)) chondral defect.