Early results of autologous chondrocyte implantation in the talus

Autologous chondrocyte implantation (ACI) has been used most commonly as a treatment for cartilage defects in the knee and there are few studies of its use in other joints. We describe ten patients with an osteochondral lesion of the talus who underwent ACI using cartilage taken from the knee and were prospectively reviewed with a mean follow-up of 23 months. In nine patients the satisfaction score was 'pleased' or 'extremely pleased', which was sustained at four years. The mean Mazur ankle score increased by 23 points at a mean follow-up of 23 months. The Lysholm knee score returned to the pre-operative level at one year in three patients, with the remaining seven showing a reduction of 15% at 12 months, suggesting donor-site morbidity. Nine patients underwent arthroscopic examination at one year and all were shown to have filled defects and stable cartilage. Biopsies taken from graft sites showed mostly fibrocartilage with some hyaline cartilage. The short-term results of ACI for osteochondral lesions of the talus are good despite some morbidity at the donor site.     

Molecular markers in the evaluation of autologous chondrocyte implantation

Purpose: With the help of molecular markers, it has become possible to quantify cartilage repair and degradation in joints. In this study, we attempt to determine whether or not molecular markers in synovial fluid can be helpful in defining the repair process following autologous chondrocyte implantation (ACI). Type of Study: As part of a prospective clinical pilot study, 17 patients were evaluated before, as well as 6 weeks, 3, 6, and 12 months after the ACI. A synovial analysis was performed and molecular markers for bone and cartilage metabolism were determined. Methods: A number of parameters, including pyridinium crosslink (PY), deoxypyridinolin (DPD), n-telopeptide (NTX) from type I collagen, MMP-1, MMP-3; TIMP-1, PICP, proteoglycan, and YKL-40 were analyzed. The levels were referenced to the total protein concentration of the synovial fluid. The synovial analyses were compared with clinical parameters (Larson score) and magnetic resonance imaging (MRI) examinations. Results: The analysis of the data revealed differing trends for the various synovial markers over time. The most remarkable marker was found to be DPD, which increased continuously between surgery and week 12, only to disappear after the repair process had ceased 1 year after surgery. All molecular markers for cartilage degradation increased initially after surgery and dropped off below the original levels 3 to 6 months later. Conclusions: The evaluation revealed that the determination of marker levels can provide valuable information regarding the metabolism of bone and cartilage in a joint. They seem to provide a method for monitoring the repair process associated with the various treatment forms for chondral lesions.Arthroscopy: The Journal of Arthroscopic and Related Surgery, Vol 19, No 4 (April), 2003: pp 397–403     

Treatment of full-thickness chondral defects with autologous chondrocyte implantation

Autologous chondrocyte implantation (ACI) is a reproducible treatment option for large full-thickness symptomatic chondral injuries with appropriate knowledge of technique and patient selection. It provides a cellular repair that offers a high percentage of good to excellent clinical results over a long follow-up period. It is applicable over a wide range of chondral injuries from simple to more complex lesions. It is essential that the intra-articular environment be as close to normal as possible for successful cartilage repair. Coexisting knee pathology must be aggressively treated. ACI does have a prolonged postoperative rehabilitation course necessitated by the biologic nature of the repair, and patients must be able to comply with the rehabilitation and temporary restrictions required for a successful outcome.     

Reoperation after autologous chondrocyte implantation. Indications and findings

We have reviewed 22 patients from a total of 135 treated by autologous chondrocyte implantation (ACI) who had undergone further surgery for pain in the knee and mechanical symptoms after a mean of 10.5 months. There were 31 grafted lesions. At operation the findings included lifting (24/31) and detachment (3/31) of periosteal patches for which arthroscopic shaving was performed. Chondroplasty was undertaken on two new lesions, another required an ACI and a further patient required trimming of a meniscus. The mechanical symptoms resolved within two weeks. At the last review, two to 14 months from reoperation; 68% had improved, and 86% had normal or nearly normal IKDC scores. Of the 31 lesions, 30 (97%) had normal or nearly normal visual repair scores. Biopsy showed good integration with subchondral bone and the marginal interface in all specimens, most of which showed hyaline or hyaline-like cartilage (70%). Troublesome mechanical symptoms required surgery in 13% of ACI-treated patients and were attributed to periosteal extrusion. Simple arthroscopic debridement was curative.     

Improvement in bone homeostasis following autologous chondrocyte implantation of the knee

This retrospective review and clinical follow-up demonstrates the effectiveness of autologous chondrocyte implantation of the knee. From September 1995 to June 2001, 24 patients with average follow-up of 26.5 months were evaluated. The mean Lysholm score improved from 43.58 before surgery to 71.42 at most recent follow-up, the modified Cincinnati knee score for overall clinician evaluation improved from 2.96 to 6.92, and the mean modified Cincinnati knee score for overall patient evaluation improved from 3.21 to 6.13 at P <.05. Seventy-nine percent of patients responded that they would have the same knee surgery again and 83% rated the results of their knee surgery as good to excellent. Limited radionuclide bone scans with single photon emission computed tomography were completed in 11 of the patients to assess the physiology and homeostasis of subchondral bone adjacent to treated articular cartilage defects. A trend was identified suggesting improvement in subchondral bone scores at a mean of 29.6-months follow-up compared to preoperative bone scan assessment. There also was a trend towards greatest improvement correlating with the patients with the best clinical scores. The results of this study suggest that autologous chondrocyte implantation of the knee can be successful in improving pain and function in patients with articular cartilage defects.     

Cell manipulation in autologous chondrocyte implantation: from research to cleanroom

In the field of orthopaedics, autologous chondrocyte implantation is a technique currently used for the regeneration of damaged articular cartilage. There is evidence of the neo-formation of tissue displaying characteristics similar to hyaline cartilage. In vitro chondrocyte manipulation is a crucial phase of this therapeutic treatment consisting of different steps: cell isolation from a cartilage biopsy, expansion in monolayer culture and growth onto a three-dimensional biomaterial to implant in the damaged area. To minimise the risk of in vitro cell contamination, the manipulation must be performed in a controlled environment such as a cleanroom. Moreover, the choice of reagents and raw material suitable for clinical use in humans and the translation of research protocols into standardised production processes are important. In this study we describe the preliminary results obtained by the development of chondrocyte manipulation protocols (isolation and monolayer expansion) in cleanrooms for the application of autologous implantation.     

自体软骨细胞移植术治疗关节软骨损伤的研究进展

关节软骨再生能力非常有限。目前临床上治疗关节软骨损伤常采用自体软骨细胞移植术(autologous chondrocyte implantation,ACI),其临床效果已得到肯定,但仍不十分理想。随着软骨细胞体外培养、软骨组织工程等相关学科及技术的发展,自体软骨细胞移植术已得到很大改进。然而,要达到理想的透明软骨组织完全修复关节软骨缺损仍有差距。本文从ACI技术的临床效果、软骨细胞体外培养、软骨组织工程、组织学评价和移植后软骨细胞示踪五个方面进行综述。     

Autologous chondrocyte implantation versus matrix-induced autologous chondrocyte implantation for osteochondral defects of the knee: a prospective, randomised study

Autologous chondrocyte implantation (ACI) is used widely as a treatment for symptomatic chondral and osteochondral defects of the knee. Variations of the original periosteum-cover technique include the use of porcine-derived type I/type III collagen as a cover (ACI-C) and matrix-induced autologous chondrocyte implantation (MACI) using a collagen bilayer seeded with chondrocytes. We have performed a prospective, randomised comparison of ACI-C and MACI for the treatment of symptomatic chondral defects of the knee in 91 patients, of whom 44 received ACI-C and 47 MACI grafts. Both treatments resulted in improvement of the clinical score after one year. The mean modified Cincinnati knee score increased by 17.6 in the ACI-C group and 19.6 in the MACI group (p = 0.32). Arthroscopic assessments performed after one year showed a good to excellent International Cartilage Repair Society score in 79.2% of ACI-C and 66.6% of MACI grafts. Hyaline-like cartilage or hyaline-like cartilage with fibrocartilage was found in the biopsies of 43.9% of the ACI-C and 36.4% of the MACI grafts after one year. The rate of hypertrophy of the graft was 9% (4 of 44) in the ACI-C group and 6% (3 of 47) in the MACI group. The frequency of re-operation was 9% in each group. We conclude that the clinical, arthroscopic and histological outcomes are comparable for both ACI-C and MACI. While MACI is technically attractive, further long-term studies are required before the technique is widely adopted.     

Treatment of full-thickness chondral defects in the knee with autologous chondrocyte implantation

Autologous chondrocyte implantation (ACI) has now been performed for over a decade in the United States. ACI has been demonstrated as a reproducible treatment option for large, full-thickness, symptomatic chondral injuries of the knee. As clinical experience has expanded and indications broadened to more complex cartilage defects, it has become evident that aggressive treatment of coexisting knee pathology is essential for optimal results. This includes management of malalignment, ligamentous, and/or meniscal deficiency, and subchondral bone loss to make the intra-articular environment as ideal as possible for successful cartilage restoration. Additionally, refinements in the rehabilitation necessary for biologic cartilage repair have been made, based on better understanding of the maturation process of the repair cartilage, allowing for earlier initiation of knee range of motion, strengthening exercises, and weight bearing. These changes have enhanced the recovery for the patient and decreased the risk of motion deficits. This article will discuss patient selection for ACI, review ACI surgical technique, including management of coexisting knee pathology, present postoperative ACI rehabilitation guidelines, and summarize clinical outcomes after ACI.     

Arthroscopic implantation of a three dimensional scaffold for autologous chondrocyte transplantation

The arthroscopic M-ACT technique is applicable for defects at the femoral condyle up to 5 cm2. The size of the defect has to be assessed with a specific scaled, percutaneously inserted needle. Then an 8 mm water-stop-cannula is positioned in a suprameniscal portal. The chondrocyte seeded matrix is trimmed to size the defect. The scaffold is introduced in the joint through the cannula and placed into the defect with a blunt arthroscopic grasp instrument to prevent damage of the scaffold. Then a specific drill guide is inserted through an additional anteromedial portal to place it on the scaffold in a perpendicular angle. The position of the drill guide should not be changed during the next two steps. It may be helpful to hold the matrix in place with a probe inserted through the cannula. A 1.5 mm K-wire is drilled at least 16 mm into the subchondral bone. Then the biodegradable pin (length 16 mm) is placed in the drill guide and carefully hammered into the subchondral bone. The joint is flexed so that the drill guide can be placed on the posterior end of the scaffold. Another hole is drilled with the K-wire and a second pin is inserted. Finally the stability of the matrix is tested with a probe and the joint is mobilized.     

Outcome of combined autologous chondrocyte implantation and anterior cruciate ligament reconstruction

Background:

Instability of the knee joint, after anterior cruciate ligament (ACL) injury, is contraindication to osteochondral defect repair. This prospective study is to investigate the role of combined autologous chondrocyte implantation (ACI) with ACL reconstruction.

Materials and Methods:

Three independent groups of patients with previous ACL injuries undergoing ACI were identified and prospectively followed up. The first group had ACI in combination with ACL reconstruction (combined group); the 2^nd group consisted of individuals who had an ACI procedure having had a previously successful ACL reconstruction (ACL first group); and the third group included patients who had an ACI procedure to a clinically stable knee with documented nonreconstructed ACL disruption (No ACL group). Their outcomes were assessed using the modified cincinnati rating system, the Bentley functional (BF) rating system (BF) and a visual analog scale (VAS).

Results:

At a mean followup of 64.24 months for the ACL first group, 63 months for combined group and 78.33 months for the No ACL group; 60% of ACL first patients, 72.73% of combined group and 83.33% of the No ACL group felt their outcome was better following surgery. There was no significant difference demonstrated in BF and VAS between the combined and ACL first groups. Results revealed a significant affect of osteochondral defect size on outcome measures.

Conclusion:

The study confirms that ACI in combination with ACL reconstruction is a viable option with similar outcomes as those patients who have had the procedures staged.     

Surgical management of large talar osteochondral defects using autologous chondrocyte implantation

Background

Talar osteochondral lesions (OLT) occur frequently in ankle sprains and fractures. We hypothesize that matrix-induced autologous chondrocyte implantation (MACI) will have a low reoperation rate and high patient satisfaction rate in treating OLT less than 2.5 cm².