Paolo Bulgheroni

Autologous chondrocyte implantation using a bilayer collagen membrane: A preliminary report

Purpose. To present preliminary clinical experience with Matrix-induced autologous chondrocyte implantation, a new tissue-engineering technique for treatment of deep cartilage defects, in which autologous chondrocytes are seeded on a tridimensional scaffold provided by a bilayer type I–III collagen membrane. Methods. From December 1999 to January 2001, 13 patients underwent implantation procedure for deep cartilage defects. Age of patients ranged from 18 to 49 years (mean age, 35 years). The mean defect size was 3.5 cm2 (range, 2.0–4.5 cm2). Clinical and functional evaluation were performed using various score systems for the ankle and the knee, and magnetic resonance imaging was performed at 6 and 12 months postoperatively. Membrane structure and cellular population were investigated by light microscopy, scanning electron microscopy, and electrophoresis before implantation. Results. The mean follow-up was 6.5 months (range, 2–15 months). No complications were observed in the postoperative period. The 6 patients with a minimum follow-up of 6 months showed an improvement in clinical and functional status after surgery. Magnetic resonance images showed the presence of hyaline-like cartilage at the site of implantation; there was evidence of chondroblasts and type II collagen inside the seeded membrane. Conclusion. Matrix-induced autologous chondrocyte implantation offers several advantages with respect to the traditional cultured cell procedure. These include technical simplicity, short operating time, minimal invasiveness, and easier access to difficult sites. It appears to be a reliable method for the repair of deep cartilage defects.

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.

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.

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.

Two stage fracture of a polyethylene post in a 9-year-old posterior-stabilized knee prosthesis: a case report

IntroductionSeveral 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 presentationIn 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.ConclusionScanning electron microscopy revealed two different damage patterns that could be explained with a two-stage rupture of our patients 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.

Osteochondritis dissecans of the entire femoral trochlea.

Juvenile osteochondritis dissecans (JOCD) is a term used to describe the separation of an articular cartilage and subchondral bone segment from the remaining articular surface in skeletally immature children. Maximum incidence is between the ages of 10 and 20 years. It is found more frequently in children who are athletes and is twice as common in boys as it is in girls. This condition most commonly affects the knee joint, with approximately 85% of lesions occurring in the medial femoral condyle and 15% of lesions occurring in the lateral femoral condyle. There are very few cases reported in the literature that involve the patellofemoral joint. The patella is more frequently affected, whereas osteochondritis dissecans of the trochlea femuri was first described by Axhausen in 1912. Review of the literature reveals few reported JOCD cases of either the lateral or the medial femoral trochlear groove. We report a rare case of JOCD involving the entire femoral trochlea and its management.

Short-term evaluation of collagen meniscus implants by MRI and morphological analysis

Abstract Meniscectomy can lead to degenerative joint changes in the knee. Collagen meniscus implantation is a tissue engineering technique designed to stimulate regeneration of meniscal tissue in case of irreparable tears or previous meniscectomy. The implant is composed of type I collagen derived from bovine Achilles tendon and enriched with glycosaminoglycans. Previous clinical trials demonstrated satisfactory medium-term results in patients who received a collagen meniscus implant (CMI). In this study, CMI structure was analysed by light microscopy and scanning electronic microscopy (SEM). The same morphological studies were performed on two implant biopsies, obtained from two patients who underwent a second arthroscopic look six months after implantation. The evolution of the implant was also investigated by magnetic resonance imaging, 6 and 12 months postoperatively. CMI presented a multilamellar structure, with inner lacunae allowing tissue ingrowth. The lamellae were made of collagen fibrils, randomly oriented and preserving the typical 64-nm period. At second arthroscopic look, the implant appeared in continuity to the native residual meniscus and parameniscus, and showed good consistency and stability at probing. The biopsy specimens demonstrated invasion of the scaffold by connective tissue and blood vessels. The newly synthesised collagen fibrils were clearly distinguishable from the scaffold ones. No phagocytomacrophagic cells nor inflammatory reactions were observed inside the implant. MRI findings confirmed CMI biocompatibility and highlighted the evolution of the integration process with time. The data achieved in this study support the hypothesis that CMI stimulates regeneration of meniscal-like tissue, which could prevent the development of degenerative changes after meniscectomy.

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.