Minimum 10-Year Clinical Outcome of Lateral Collagen Meniscal Implants for the Replacement of Partial Lateral Meniscal Defects: Further Results From a Prospective Multicenter Study.

BACKGROUND: The collagen meniscal implant (CMI) is a biologic scaffold aimed at replacing partial meniscal defects. The long-term results of lateral meniscal replacement have never been investigated. PURPOSE: To document the clinical outcomes and failures of lateral CMI implantation for partial lateral meniscal defect at a minimum 10-year follow-up. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: This study included 24 consecutive patients who underwent lateral CMI implantation for partial lateral meniscal defects between April 2006 and September 2009 and who were part of a previous study with a 2-year follow-up. Outcome measures at the latest follow-up included the Lysholm score, Knee injury and Osteoarthritis Outcome Score, visual analog scale (VAS) for pain, Tegner activity level, and EuroQol 5-Dimensions score. Data regarding complications and failures were collected, and patients were asked about their satisfaction with the procedure. RESULTS: Included in the final analysis were 19 patients (16 male, 3 female) with a mean age at surgery of 37.1 ± 12.6 years and a mean follow-up of 12.4 ± 1.5 years (range, 10-14 years). Five failures (26%) were reported: 1 CMI removal because of implant breakage and 4 joint replacements (2 unicompartmental knee arthroplasties and 2 total knee arthroplasties). The implant survival rate was 96% at 2 years, 85% at 5 years, 85% at 10 years, 77% at 12 years, and 64% at 14 years. Lysholm scores at the final follow-up were rated as "excellent" in 36% (5 of 14 nonfailures), "good" in 43% (6 of 14), and "fair" in 21% (3 of 14). The VAS score was 3.1 ± 3.1, with only 16% (3 of 19 patients) reporting that they were pain-free; the median Tegner score was 3 (interquartile range, 2-5). All clinical scores decreased from the 2-year follow-up; however, with the exception of the Tegner score, they remained significantly higher compared with the preoperative status. Overall, 79% of patients were willing to undergo the same procedure. CONCLUSION: Lateral CMI implantation for partial lateral meniscal defects provided good long-term results, with a 10-year survival rate of 85% and a 14-year survival rate of 64%. At the final follow-up, 58% of the patients had "good" or "excellent" Lysholm scores. However, there was a general decrease in outcome scores between the short- and the long-term follow-up.

Polyurethane Meniscal Scaffold for the Treatment of Partial Meniscal Deficiency: 5-Year Follow-up Outcomes: A European Multicentric Study.

BACKGROUND: A biodegradable polyurethane scaffold was developed to treat patients with the challenging clinical condition of painful partial meniscal defects. HYPOTHESIS: The use of an acellular polyurethane scaffold in patients with symptomatic partial meniscal defects would result in both midterm pain relief and improved function. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: A total of 155 patients with symptomatic partial meniscal defects (101 medial and 54 lateral) were implanted with a polyurethane scaffold in a prospective, single-arm, multicentric study with a minimum 5-year follow-up. Clinical outcomes were measured with the visual analog scale for pain, International Knee Documentation Committee subjective knee evaluation form, Lysholm knee scale, and Knee injury and Osteoarthritis Outcome Score at baseline and at 2- and 5-year follow-ups. Magnetic resonance imaging (MRI) was used to evaluate the knee joint, meniscal implant, and meniscal extrusion. Kaplan-Meier survival analysis was also performed. Removal of the scaffold, conversion to a meniscal transplant, and unicompartmental/total knee arthroplasty were used as endpoints. RESULTS: Eighteen patients were lost to follow-up (11.6%). The patients who were included in this study showed significant clinical improvement after surgery as indicated by the different outcome measures (P = .01). However, the clinical improvement tended to stabilize between 2 and 5 years of follow-up. MRI scans of the scaffolds in 56 patients showed a smaller-sized implant in the majority of the cases when compared with the native meniscus with an irregular surface at the 5-year follow-up. During the follow-up period, 87.6% of the implants survived in this study. At 5 years of follow-up, 87.9% of the medial scaffolds were still functioning versus 86.9% of the lateral scaffolds. In total, 23 treatments had failed: 10 removed scaffolds because of breakage, 7 conversions to meniscal allograft transplantation, 4 conversions to unicompartmental knee arthroplasty, and 2 conversions to total knee arthroplasty. CONCLUSION: The polyurethane meniscal implant was able to improve knee joint function and reduce pain in patients with segmental meniscal deficiency over 5 years after implantation. The MRI appearance of this scaffold was different from the original meniscal tissue at the midterm follow-up. The treatment survival rates of 87.9% of the medial scaffolds and 86.9% of the lateral scaffolds in the present study compared favorably with those published concerning meniscal allograft transplantation after total meniscectomy.

Management of the First Patellar Dislocation: A Narrative Review.

First patellar dislocation is a common injury of the knee, involving often adolescents and the active population. The consequences of the first episode can be various and potentially disabling. Among these, acute patellar dislocation can often result in recurrent patellar instability. Recurrent patellar instability is certainly multifactorial but depends primarily on the injury of the medial patellofemoral ligament (MPFL), the major soft-tissue stabilizer of the patella. Some classifications are extremely useful in establishing the diagnosis and therapy in patellofemoral disease, in particular in terms of instability. Among those, Henri Dejour and WARPS (weak atraumatic risky anatomy pain and subluxation)/STAID (strong traumatic anatomy normal instability and dislocation) classifications are certainly the most frequently used. There is no clear agreement on the management of the first patellar dislocation. A conservative approach seems to be the first choice in most of cases, but the presence of patellar displacement or osteochondral fractures makes surgery mandatory at the beginning. In addition, there is no clear consensus on which surgical strategy should be used to approach first dislocation, in relation to the possible variation in location of the MPFL injury, and to the eventual presence of preexisting predisposing factors for patellar instability. MPFL reconstruction may theoretically be more reliable than repair, while there is no clear evidence available that osseous abnormality should be addressed after the first episode of patellar dislocation. A narrative review was conducted to report the etiology, the diagnosis and all the possible treatment options of the first patellar dislocation. Modern classifications of the patellofemoral instability were also presented.

Evolution of Osteochondritis Dissecans of the Lateral Femoral Condyle Combined with Discoid Meniscus.

The discoid meniscus is a rare anomaly of the knee that affects mostly the lateral meniscus and is often asymptomatic. The osteochondritis dissecans is a disorder of the subchondral bone and articular cartilage and occurs frequently associated with the discoid lateral meniscus. In the present case, we showed the evolution of this association related to surgical treatment. A patient with lateral knee pain and a magnetic resonance depicting a torn discoid lateral meniscus and osteochondritis dissecans of the lateral femoral condyle was treated with partial meniscectomy and meniscal sutures. After 1 year, the symptoms reappeared, and a new meniscal repair was performed to treat a bucket-handle tear, while cartilage was apparently intact. After 4 years, there was a new recurrence of symptoms, and the knee developed a valgus deformity. Cartilage was treated with microfractures, and a subsequent distal femoral osteotomy associated with lateral meniscal scaffold was performed. The patient was followed up clinically, with radiographs and magnetic resonance for 5 years with an improvement of the results up to 2 years and no signs of deterioration of results over time.

Comparative Study of Collagen versus Synthetic-Based Meniscal Scaffolds in Treating Meniscal Deficiency in Young Active Population.

PURPOSE: The aim of this study was to compare the effectiveness of 2 different meniscal scaffolds in treating patients with irreparable partial medial meniscal tear and patients complaining of pain in the medial compartment of the knee due to a previous partial medial meniscectomy. Based on previous studies, we hypothesized that both the scaffolds are effective in improving clinical outcomes in these patient populations. MATERIAL AND METHODS: Twenty-eight patients underwent collagen-based medial meniscus implantation (CMI-Menaflex) and 25 with a second-generation scaffold (Actifit). All patients were assessed with Lysholm, Tegner scale, and MRI evaluation-preoperatively, at 6 months, at 12 moths, and followed-up for a minimum of 2 years. Second look arthroscopy and concomitant biopsy were performed in 7 and 12 patients of CMI and Actifit groups, respectively. RESULTS: The CMI group at final follow-up showed improvement in Lysholm score from 58.4 ± 17.3 to 94.5 ± 6.0, while the Actifit group showed improvement from 67.0 ± 15.7 to 90.3 ± 13.1; the improvement was statistically significant in both the groups but intergroup difference was not statistically significant (P = 0.1061). Tegner Activity Scale score improved in both the groups, but intergroup difference was not statistically significant (P = 0.5918). MRI evaluation showed in situ scaffold and no progression of degenerative arthritis in both the groups at final follow-up. Histological evaluation showed more fibrous tissue with blood vessels in the CMI group and the Actift group showed avascular cartilaginous features. CONCLUSION: Both the scaffolds are effective in improving patients' symptoms and joint function at short-term follow-up.

Long-term outcomes of medial CMI implant versus partial medial meniscectomy in patients with concomitant ACL reconstruction.

PURPOSE: To compare the clinical, objective and radiographic long-term results of patients with anterior cruciate ligament (ACL) lesion and partial medial meniscus defects, treated with ACL reconstruction and partial medial meniscectomy or medial CMI implant. METHODS: Seventeen patients treated with combined ACL reconstruction and medial CMI and 17 patients treated with ACL reconstruction and partial medial meniscectomy were evaluated with mean follow-up 9.6 years with Lysholm, Tegner, objective and subjective International Knee Documentation Committee scores, and VAS for pain. Arthrometric evaluation was performed with KT 2000. Weigh-bearing radiographs, antero-posterior and Rosenberg view, were also performed and evaluated with Kellgren-Lawrence score, Ahlback score and joint space narrowing. RESULTS: Pre-operative demographic parameters and clinical scores between patients treated with CMI and partial medial meniscectomy revealed no significant differences. A significant improvement of all the clinical scores was detected in both groups from pre-operative status to final follow-up. No significant difference between groups were found for clinical and radiographic scores; however, the chronic subgroup of patients treated with CMI showed a significantly lower level of post-operative knee pain compared to patients treated with partial medial meniscectomy and the acute subgroup of medial CMI showed better arthrometric scores. CONCLUSION: Good long-term clinical results in terms of stability, subjective outcomes and objective evaluation were reported both for medial CMI implant and partial medial meniscectomy, combined with ACL reconstruction for the treatment of partial medial meniscus tears combined with ACL lesions. Chronic meniscal tears treated with medial CMI reported lower levels of post-operative pain compared to meniscectomy, while acute lesions treated with medial CMI showed less knee laxity. Therefore, the use of the collagen meniscus implant in the case of anterior knee instability with a meniscal defect appears justified and able to improve clinical outcomes in the long term. LEVEL OF EVIDENCE: Retrospective comparative study, Level III.

Posterolateral rotatory instability of the knee after arthroscopic subtotal lateral meniscectomy: a case report.

A 33-year-old Caucasian woman came to our attention complaining of lateral knee pain on the left side, severe external instability associated with varus malalignment, and difficulties in weight-bearing activities. The symptoms had appeared following two lateral meniscectomies on her discoid meniscus, performed elsewhere. The patient was initially submitted to an allograft meniscus transplantation exploiting the unloaded condition of lateral compartment and obtained pain relief. The posterolateral corner was reconstructed in combination with a valgus osteotomy to address the posterolateral rotatory instability. The follow-up assessment at two years after the last surgery showed no symptoms, maintenance of limb alignment and no evidence of joint degeneration.

Polyurethane scaffold for the treatment of partial meniscal tears. Clinical results with a minimum two-year follow-up.

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.

Arthroscopic collagen meniscus implantation for partial lateral meniscal defects: a 2-year minimum follow-up study.

BACKGROUND: Loss of knee meniscal tissue often leads to increased pain and decreased function. HYPOTHESIS: At a minimum 2-year follow-up, patients receiving a lateral collagen meniscus implant (CMI) would show improved knee function and decreased pain compared with their preoperative status. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: Twenty-four patients with irreparable lateral meniscal tears (n = 7) or previous partial lateral meniscectomy (n = 17) underwent arthroscopic lateral collagen meniscus implantation. Clinical evaluation was performed preoperatively, at 6 months, and at a minimum 2-year follow-up with Lysholm, visual analog scale (VAS) for pain, Tegner, objective International Knee Documentation Committee (IKDC), and EuroQol 5 dimensions (EQ-5D) scores. A magnetic resonance imaging (MRI) evaluation was performed preoperatively and at final follow-up using the modified Yulish score for cartilage and the Genovese score for implant size and signal intensity. RESULTS: All clinical scores significantly improved from preoperative evaluation to final follow-up. Average Lysholm scores improved from 64.0 ± 16.2 to 92.7 ± 13.8 (P < .0001), VAS for pain from 55.2 ± 29.4 to 19.5 ± 25.6 (P < .0001), Tegner from 3 (interquartile range, 2-4) to 5 (interquartile range, 4-7) (P = .0062), objective IKDC from 6A, 14B, 4C to 20A, 3B, 1D (P = .0002), and EQ-5D from 0.58 ± 0.28 to 0.89 ± 0.14 (P < .0001). Good to excellent (A + B) objective IKDC scores improved from 83% preoperatively to 96% at 2-year follow-up. The Tegner index (the percentage of the lost activity level that was regained as a result of the treatment intervention) was 47% at 6-month follow-up and 79% at 2-year follow-up: this improvement was statistically significant (P = .0062). The MRI evaluations for tibial and femoral modified Yulish scores for cartilage remained similar over the course of the study; 87.5% of implants were reduced in size, and in 3 cases (12.5%), they were completely resorbed; 50% of the implants had a slightly hyperintense signal (relative to the normal meniscus), and signal intensity changes suggested that full maturation had occurred in 37.5% at final follow-up (based on the Genovese scores). CONCLUSION: The lateral CMI demonstrated that it was safe in this population study, with decreased pain and improved knee function in 96% of patients with excellent/good Lysholm results in 87% of patients at a minimum 2-year follow-up. The MRI scans demonstrated a decreased implant size relative to a normal meniscus.

Follow-up of collagen meniscus implant patients: clinical, radiological, and magnetic resonance imaging results at 5 years.

This study investigated at medium term follow-up the clinical outcomes and any progression of knee osteoarthritis in a population of patients that underwent arthroscopic placement of a collagen meniscus implant. Thirty-four patients underwent arthroscopic placement of a collagen meniscus implant for a symptomatic deficiency of medial meniscal tissue. Follow-up evaluation included Lysholm II score and Tegner activity scores and MR arthrography of the knee at 2 and 5 years after surgery. Plain radiographs were also obtained at 5 years. Six patients were excluded. In eight cases arthroscopic second look evaluation was performed. Lysholm and Tegner activity scores at 2 and 5 years after surgery improved significantly compared to the preoperative score. These patients showed good to excellent clinical results after 5 years from a CMI placement. The chondral surfaces of the medial compartment had not degenerated further since placement of the CMI. MR signal had continued to mature between 2 and 5 years after implant, progressively decreasing signal intensity but in any case comparable to the low signal of a normal meniscus. In most of cases the CMI-new tissue complex had a slight reduction in size, compared to a normal medial meniscus, but the new tissue had no apparent negative effects.