A prospective randomized clinical study of mosaic osteochondral autologous transplantation versus microfracture for the treatment of osteochondral defects in the knee joint in young athletes

The microfracture technique for the treatment of full-thickness articular cartilage lesions of the knee: midterm results

PURPOSE

The purpose of this study was to determine the effectiveness of the microfracture technique in the treatment of full-thickness articular cartilage lesions of the knee.

METHODS

In this study the midterm results of 90 patients (47 women and 43 men) with focal full-thickness articular cartilage lesions who had been managed with the microfracture technique are presented. The mean age of our patients was 34.5 years (range, 20 to 58), and 51 right and 39 left knees were treated. All of the articular lesions involved medial femoral condyles.

RESULTS

On the basis of follow-up at a mean of 68 months (range, 24 to 108 months), mean improvements in Lysholm knee scores (from 54.2 to 84.6 points), Tegner activity scale scores (from 2.6 to 5.2 points), and Oxford knee interrogation scores (from 23.1 to 44.8 points) were observed (P < .0001). Moreover, there was a strong and significant correlation between functional results and age younger than 35 years, size of defect less than 2 cm(2), non-weight-bearing surface, and body mass index lower than 25 kg/m(2), respectively (P < .001).

CONCLUSIONS

According to our midterm results, the microfracture technique is quite effective with regard to the improvement of daily activities with a favorable impact on pain relief and better functional results. Furthermore, we found that there was a correlation between functional results and age, size of defect, location of defect, and body mass index as prognostic parameters.

LEVEL OF EVIDENCE

Level IV, therapeutic case series.

[Therapy of articular cartilage lesions]

Lesions of adult articular cartilage do not heal or regenerate. They give rise to the development of osteoarthritis, and surgical treatment is necessary before the initiation of joint degeneration. Various treatment modalities ranging from microfracture to autologous mosaicplasty and autologous chondrocyte transplantation are available. Commonly they are distinguished by the presence or absence of cell transplantation. The treatment choice depends on size, depth, and location of the lesion; therefore exact classification is mandatory. The surgical procedure aims to reconstruct a physiological distribution of the biomechanical forces by surface restoration. Additional joint pathologies such as mechanical axis deviation, meniscal defects, and ligament insufficiencies threaten the surgical success and must be addressed simultaneously.

Innovations in osteosynthesis and fracture care

Over the years giant steps have been made in the evolution of fracture fixation and the overall clinical care of patients. Better understanding of the physiological response to injury, bone biology, biomechanics and implants has led to early mobilisation of patients. A significant reduction in complications during the pre-operative and post-operative phases has also been observed, producing better functional results. A number of innovations have contributed to these improved outcomes and this article reports on the advances made in osteosynthesis and fracture care.

Magnetic resonance imaging and clinical evaluation of patellar resurfacing with press-fit osteochondral autograft plugs

BACKGROUND

Autologous osteochondral transplantation (AOT) has been successfully used in the femoral condyle and trochlea and is an attractive treatment option for full-thickness patellar cartilage lesions.

HYPOTHESIS

Patients treated with AOT for the repair of symptomatic, isolated patellar cartilage lesions will demonstrate improvement in functional outcomes and postoperative magnetic resonance imaging appearance.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

Between 2002 and 2006, patients with focal patellar cartilage lesions treated with AOT were prospectively followed. The mean age at the time of surgery was 30 years. Clinical assessment was performed with the International Knee Documentation Committee (IKDC), activities of daily living of the Knee Outcome Survey (ADL), and Short Form-36 (SF-36) at baseline and most recent follow-up. Magnetic resonance imaging was used to evaluate the cartilage repair morphologic characteristics in 14 cases.

RESULTS

Twenty-two patients met the study criteria with a mean follow-up of 28.7 months (range, 17.7-57.8 months). The mean patellar lesion size was 165.6 +/- 127.8 mm(2), and the mean size of the donor plug was 9.7 +/- 1.1 mm in diameter with 1.8 +/- 1.4 plugs/defect. The mean preoperative IKDC score was 47.2 +/- 14.0 and improved to 74.4 +/- 12.3 (P = .028). The mean preoperative ADL score was 60.1 +/- 16.9 and increased to 84.7 +/- 8.3 (P = .022). The mean SF-36 also demonstrated an improvement, from 64.0 +/- 14.8 at baseline to 79.4 +/- 15.4 (P = .059). Nine patients underwent concomitant distal realignment and demonstrated improvement between preoperative and postoperative outcomes scores, but these differences were not statistically significant. Magnetic resonance imaging appearance demonstrated that all plugs demonstrated good (67%-100%) cartilage fill, 64% with fissures < 2 mm at the articular cartilage interface, 71% with complete trabecular incorporation, and 71% with flush plug appearance.

CONCLUSION

Patellar AOT is an effective treatment for focal patellar chondral lesions, with significant improvement in clinical follow-up. This study suggests that patients with patellar malalignment may represent a subset of patients who have a poor prognostic outlook compared with patients with normal alignment.

Cartilage T2 assessment at 3-T MR imaging: in vivo differentiation of normal hyaline cartilage from reparative tissue after two cartilage repair procedures--initial experience

PURPOSE

To prospectively compare cartilage T2 values after microfracture therapy (MFX) and matrix-associated autologous chondrocyte transplantation (MACT) repair procedures.

MATERIALS AND METHODS

The study had institutional review board approval by the ethics committee of the Medical University of Vienna; informed consent was obtained. Twenty patients who underwent MFX or MACT (10 in each group) were enrolled. For comparability, patients of each group were matched by mean age (MFX, 40.0 years +/- 15.4 [standard deviation]; MACT, 41.0 years +/- 8.9) and postoperative interval (MFX, 28.6 months +/- 5.2; MACT, 27.4 months +/- 13.1). Magnetic resonance (MR) imaging was performed with a 3-T MR imager, and T2 maps were calculated from a multiecho spin-echo measurement. Global, as well as zonal, quantitative T2 values were calculated within the cartilage repair area and within cartilage sites determined to be morphologically normal articular cartilage. Additionally, with consideration of the zonal organization, global regions of interest were subdivided into deep and superficial areas. Differences between cartilage sites and groups were calculated by using a three-way analysis of variance.

RESULTS

Quantitative T2 assessment of normal native hyaline cartilage showed similar results for all patients and a significant trend of increasing T2 values from deep to superficial zones (P < .05). In cartilage repair areas after MFX, global mean T2 was significantly reduced (P < .05), whereas after MACT, mean T2 was not reduced (P > or = .05). For zonal variation, repair tissue after MFX showed no significant trend between different depths (P > or = .05), in contrast to repair tissue after MACT, in which a significant increase from deep to superficial zones (P < .05) could be observed.

CONCLUSION

Quantitative T2 mapping seems to reflect differences in repair tissues formed after two surgical cartilage repair procedures. (c) RSNA, 2008.

Articular cartilage defects in the knee--basics, therapies and results

Full-thickness defects of the articular cartilage in the knee joint have lower regenerative properties than chondral lesions of the ankle. In order to avoid early osteoarthritis, symptomatic articular cartilage defects in younger patients should undergo biological reconstruction as soon as possible. Various surgical procedures are available to biologically resurface the articular joint line. Numerous animal experiments and clinical studies have shown that early biological reconstruction of circumscribed cartilage defects in the knee is superior to conservative or delayed surgical treatment. This superiority refers not only to defect healing but also to the elimination of changes following secondary osteoarthritis. The various surgical procedures can be differentiated by the range of indications and the final outcome. Additional malalignment, meniscus tears and/or ligament instabilities should be treated simultaneously with the cartilage resurfacing. The mid- and long-term results of the various current techniques are promising, but further modifications and improvements are needed.

Autologous osteochondral grafting--technique and long-term results

BACKGROUND

Efficacious treatment of chondral and osteochondral defects of weightbearing articular surfaces is a daily challenge in musculoskeletal care. Autogenous osteochondral transplantation represents a possible solution for creating hyaline or hyaline-like repair in the affected area that has a noninflammatory pathoorigin. This paper discusses the experimental background and over 15 years of clinical experience with autologous osteochondral mosaicplasty.

METHODS

Several series of animal studies and subsequent clinical practice of over 1,000 mosaicplasty patients were assessed to confirm the survival of transplanted hyaline cartilage and fibrocartilage filling of donor sites located on relatively less weightbearing surfaces, as well as donor-site disturbances and morbidity. Histological evaluations of dog and horse implantations as well as several series of clinical evaluations in the human material are summarized in this paper. Clinical scores, different types of imaging techniques, second-look arthroscopies, histological examination of biopsy samples, and cartilage stiffness measurements were used to evaluate the clinical outcomes and quality of the transplanted cartilage.

RESULTS

Analysis of clinical scores has shown good to excellent results in 92% of patients with femoral condylar implantations, 87% of tibial resurfacements, 74% of patellar and/or trochlear mosaicplasties and 93% of talar procedures. Longterm donor-site complaints measured by the Bandi score were minor and present only in 3% of patients. 81 out of the 98 control arthroscopies represented congruent and good gliding surfaces and histologically proven survival of the transplanted hyaline cartilage as well as fibrocartilage covering of the donor sites. Complications in the entire patient group were four deep infections and four deep venous thromboses. In nearly 8% of the cases excessive intraarticular bleeding was observed in the early postoperative period, as a minor complication of the procedure. Multicentric, comparative, prospective evaluation of 413 arthroscopic resurfacing procedures (mosaicplasty, Pridie drilling, abrasion arthroplasty and microfracture cases in homogenised subgroups) demonstrated that mosaicplasty resulted in favourable clinical outcome in the long-term follow-up compared to other three techniques. Durability of the early results was confirmed in long-term evaluations both of the femoral condylar implantations and talar mosaicplasties.

CONCLUSIONS

According to our encouraging results in this increasingly large series, supported by similar findings from other centres, it seems that autologous osteochondral mosaicplasty may be an alternative for small and medium-sized focal chondral and osteochondral defects of weightbearing surfaces of the knee and other weightbearing synovial joints.

Treatment of focal articular cartilage defects in the knee: a systematic review

We asked whether autologous chondrocyte implantation or osteochondral autograft transfer yields better clinical outcomes compared with one another or with traditional abrasive techniques for treatment of isolated articular cartilage defects and whether lesion size influences this clinical outcome. We performed a literature search and identified five randomized, controlled trials and one prospective comparative trial evaluating these treatment techniques in 421 patients. The operative procedures included autologous chondrocyte implantation, osteochondral autograft transfer, matrix-induced autologous chondrocyte implantation, and microfracture. Minimum followup was 1 year (mean, 1.7 years; range, 1-3 years). All studies documented greater than 95% followup for clinical outcome measures. No technique consistently had superior results compared with the others. Outcomes for microfracture tended to be worse in larger lesions. All studies reported improvement in clinical outcome measures in all treatment groups when compared with preoperative assessment; however, no control (nonoperative) groups were used in any of the studies. A large prospective trial investigating these techniques with the addition of a control group would be the best way to definitively address the clinical questions.

LEVEL OF EVIDENCE

Level II, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.

Arthroscopic autologous osteochondral grafting for cartilage defects of the knee: prospective study results at a minimum 7-year follow-up

BACKGROUND

Articular cartilage lesions, with their inherent limited healing potential, remain a challenging problem for orthopaedic surgeons. Various approaches have been proposed to treat these lesions; nevertheless, opinions on indications and clinical efficacy of these techniques are still controversial.

PURPOSE

To evaluate the outcome of osteochondral autografts for treatment of femoral condyle cartilage lesions at a medium-to long-term follow-up.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

We prospectively evaluated 30 patients (mean age, 29.3 years) with full-thickness knee chondral lesions (<2.5 cm(2)) treated with arthroscopic autologous osteochondral transplantation. Thirteen patients underwent previous surgery, while 17 patients were operated on for the first time. In 19 patients, associated procedures were performed. All patients were evaluated at 2- and 7-year follow-up. The International Cartilage Repair Society form, Tegner score, and magnetic resonance imaging were used for clinical evaluation.

RESULTS

The International Cartilage Repair Society objective evaluation showed 76.7% of patients had good or excellent results at 7-year follow-up, and International Knee Documentation Committee subjective score significantly improved from preoperative (34.8) to 7-year follow-up (71.8). The Tegner evaluation showed a significant improvement after the surgery at 2- and 7-year follow-up (from 2.9 to 6.2 and 5.6, respectively); however, we noticed reduced sports activity from 2- to 7-year follow-up. Magnetic resonance imaging evaluation showed good integration of the graft in the host bone and complete maintenance of the grafted cartilage in more than 60% of cases.

CONCLUSION

The results of this technique at medium- to long-term follow-up are encouraging. This arthroscopic 1-step surgery appears to be a valid solution for treatment of small, grade III to IV cartilage defects.

[A new technique for transcrestal sinus floor elevation with press-fit bone cylinders (dowel lift): short communication of the first in vitro results]

The minimally invasive sinus floor elevation as first described by Summers is limited in augmentation volume, whereas a more invasive approach is required for the technique of Tatum for larger bone defects. We developed a new technique for the transcrestal elevation of the sinus floor with bone dowels using a press-fit technique (dowel lift). We present the technique with first in vitro results in a fresh, unpreserved, human cadaver.

Fixation of unstable osteochondritis dissecans lesions of the knee using arthroscopic autogenous osteochondral grafting (mosaicplasty)

PURPOSE

A number of surgical techniques have been described for the operative fixation of an unstable osteochondritis dissecans (OCD) lesion in the knee that has failed appropriate nonoperative management. However, no one technique has been universally successful. We report the results of a new fixation technique for unstable OCD lesions using arthroscopic autogenous osteochondral grafting (mosaicplasty).

METHODS

Twenty patients with OCD lesions (16 International Cartilage Repair Society [ICRS] OCD type II, 3 ICRS OCD type III, and 1 ICRS OCD type IV) who had failed an appropriate course of nonoperative management underwent autogenous osteochondral grafting. The OCD lesions were assessed arthroscopically and then fixed in situ by using multiple 4.5-mm osteochondral dowel grafts harvested from the edges of the femoral trochlea. The lesion was initially fixed with an osteochondral graft passing through the center of the fragment and then stabilized by using further grafts inserted around its periphery.

RESULTS

Preoperative International Knee Documentation Committee scores assessed 5 patients as nearly normal, 8 as abnormal, and 7 as severely abnormal. At the 18-month follow-up, all of the knees were scored as normal. The average preoperative visual analog pain score out of 10 was 8.3, which was reduced to 0.8 at 6 months and to 0 at 1 year after surgery. Serial magnetic resonance imaging scans showed healing of the bony part of the lesion in all of the knees 6 months after surgery and continuous articular cartilage healing at 9 months.

CONCLUSIONS

Autogenous osteochondral grafting of unstable OCD lesions in the knee is a reliable and minimally invasive technique that provides a stable biologic fixation using autogenous bone graft and has few complications.

LEVEL OF EVIDENCE

Level IV, therapeutic case series.

Gene therapy for articular cartilage repair

Articular cartilage serves as the gliding surface of joints. It is susceptible to damage from trauma and from degenerative diseases. Restoration of damaged articular cartilage may be achievable through the use of cell-regulatory molecules that augment the reparative activities of the cells, inhibit the cells' degradative activities, or both. A variety of such molecules have been identified. These include insulin-like growth factor I, fibroblast growth factor 2, bone morphogenetic proteins 2, 4, and 7, and interleukin-1 receptor antagonist. It is now possible to transfer the genes encoding such molecules into articular cartilage and synovial lining cells. Although preliminary, data from in-vitro and in-vivo studies suggest that gene therapy can deliver such potentially therapeutic agents to protect existing cartilage and to build new cartilage.

A new technique for the transcrestal sinus floor elevation and alveolar ridge augmentation with press-fit bone cylinders: a technical note

BACKGROUND

The minimally invasive sinus floor elevation as first described by Summers is limited in the volume of augmentation that is possible. In contrast, the more invasive approach is the sinuslift of Tatum which is indicated for greater bone deficiencies. Therefore, a new technique was developed for transcrestal elevation of the sinus floor and alveolar ridge augmentation with bone dowels in press-fit technique.

MATERIALS & METHODS

The crestal cortical bone is cut with a hollow grinder followed by an indirect sinus floor elevation with a plunger. The cylindrical defect is then filled with a cylindrical bone transplant with the press-fit technique.

RESULTS

The method was tested in ten fresh porcine skulls and was successful when applied subsequently in two fresh human cadavers (both female, age 60 and 92 years). This was followed by the insertion of another cylinder in overlapping mosaic manner with the dowel-lift technique in the left maxilla in one cadaver. A sinoscopy of the second cadaver experiment showed no perforation of the maxillary sinus membrane. The result was convincing.

CONCLUSION

A new method for transcrestal elevation of the maxillary sinus floor and alveolar ridge augmentation with bone cylinders in press-fit technique was developed. The operation combines the minimally invasive approach of Summers with a large augmentation volume otherwise requiring the direct technique of Tatum. These results should encourage further preclinical experiments.

Gelenkerhaltende chirurgische Therapie der Gonarthrose im mittleren Lebensalter

Several treatment options for the osteoarthritis of the knee in middle-aged patients to preserve the joint are available. Arthroscopic debridement is still a valuable treatment when detailed indications are considered. Microfracture procedure showed good and excellent results primarily at a follow-up of 2 years. Cartilage defects up to 4 cm2 should be treated by the mosaic-type osteochondral autologous transplantation. Autologous chondrocyte implantation (ACI) should be discussed when larger defects are presented in the younger patient. Existing osteoarthritis, ACI is not recommended. Up till now, there was no significant difference in outcomes comparing ACI and mosaicplasty or microfracture. Basic for successful surgical cartilage repair is a stable joint with a normal limb. An eventual additional osteotomy of the knee should be considered based on a standing, three-joint radiograph in every patient.

Cartilage regeneration in the rabbit nasal septum

OBJECTIVE

Rhinoplasty frequently includes harvesting of nasal septal cartilage. The objective of this prospective basic investigation is to determine whether cartilage can regenerate after submucosal resection (SMR) of the nasal septum in the rabbit. Neocartilage formation has not heretofore been described in this model.

METHODS

By lateral rhinotomy, SMR was performed on 17 rabbits followed by reapproximation of the perichondrium. After 7 months, septi were fixed, sectioned, and examined histologically. Findings were photographed and data tabulated according to location and extent.

RESULTS

Sites of matrix-secreting isogenous chondrocyte islands were identified between the perichondrial flaps of every animal, principally in the anterior inferior septum. The width of the islands averaged 190 microm, and the mean neocartilage height was found to be 840 microm. The newly formed cartilage consisted of chondrocytes within chondrons and was comparable in shape and structure to native septal cartilage.

CONCLUSIONS

After SMR, rabbit cartilage tissue can regenerate and form matrix within the potential space created by surgery. The surrounding stem cell-rich perichondrium may be the site of origin for these chondrocytes. These findings suggest that after SMR of the human nasal septum, it may be possible for new cartilage tissue to develop provided the mucosa is well approximated. This biologic effect may be enhanced by insertion of cytokine-rich tissue scaffolds that exploit the native ability of septal perichondrium to regenerate and repair cartilage tissue.

[Cartilage repair in the knee joint]

Full thickness defects of the articular cartilage in the knee joint have lower regenerative properties compared to chondral lesions of the ankle. In order to avoid early osteoarthritis, symptomatic articular cartilage defects in younger patients should undergo biological reconstruction as early as possible. There are different surgical procedures available to achieve a biological resurfacing of the articular joint line. Numerous animal experiments and clinical studies have shown that early biological reconstruction of circumscribed cartilage defects in the knee is superior to a conservative or delayed operative treatment. This effect refers not only to the defect healing but also to the elimination of changes following secondary osteoarthritis. The different surgical procedures can be differentiated concerning the various indications and the final outcome. Additional malalignment, meniscus tears, and/or ligament instabilities should be treated simultaneously together with the cartilage resurfacing. The mid- and long-term results of the different current techniques are promising, but further modifications and improvements are needed.

Immature porcine knee cartilage lesions show good healing with or without autologous chondrocyte transplantation

OBJECTIVE

The purpose of this study was to find out how deep chondral lesions heal in growing animals spontaneously and after autologous chondrocyte transplantation.

METHODS

A 6mm deep chondral lesion was created in the knee joints of 57 immature pigs and repaired with autologous chondrocyte transplantation covered with periosteum or muscle fascia, with periosteum only, or left untreated. After 3 and 12 months, the repair tissue was evaluated with International Cartilage Repair Society (ICRS) macroscopic grading, modified O'Driscoll histological scoring, and staining for collagen type II and hyaluronan, and with toluidine blue and safranin-O staining for glycosaminoglycans. The repair tissue structure was also examined with quantitative polarized light microscopy and indentation analysis of the cartilage stiffness.

RESULTS

The ICRS grading indicated nearly normal repair tissue in 65% (10/17) after the autologous chondrocyte transplantation and 86% (7/8) after no repair at 3 months. At 1 year, the repair tissue was nearly normal in all cases in the spontaneous repair group and in 38% (3/8) in the chondrocyte transplantation group. In most cases, the cartilage repair tissue stained intensely for glycosaminoglycans and collagen type II indicating repair tissue with true constituents of articular cartilage. There was a statistical difference in the total histological scores at 3 months (P=0.028) with the best repair in the spontaneous repair group. A marked subchondral bone reaction, staining with toluidine blue and collagen type II, was seen in 65% of all animals.

CONCLUSIONS

The spontaneous repair ability of full thickness cartilage defects of immature pigs is significant and periosteum or autologous chondrocytes do not bring any additional benefits to the repair.

Autologous osteochondral mosaicplasty grafting

Successful management of chondral and osteochondral defects of the weight-bearing joint surfaces has always been a challenge for orthopedic surgeons and rehabilitation specialists. Autologous osteochondral mosaic transplantation technique is one of the recently evolved methods to create hyaline or hyaline-like repair tissue in the pathologic area. Clinical evaluation, various imaging techniques, arthroscopy (second look), histological examination of biopsy samples, and measurements of cartilage mechanical properties are used to evaluate the merits of outcomes and quality of the transplanted cartilage. According to our investigations, good to excellent results were achieved in more than 92% of patients treated with femoral condylar implantations, 87% of those treated with tibial resurfacing, 79% of those treated with patellar and/or trochlear mosaicplasties, and 94% of those treated with talar procedures. Long-term donor-site discrepancies, assessed with use of the Bandi Score, showed that patients had 3% morbidity after mosaicplasty. Sixty-nine of 89 patients who were followed up with a second-look arthroscopy showed congruent gliding surfaces, histological evidence of the survival of the transplanted hyaline cartilage, and fibrocartilage filling of the donor sites. In a series of 831 consecutive patients, very few complications have been observed. These included 4 deep infections and 36 painful postoperative intra-articular bleedings. On the basis of these results and those of other similar studies, autologous osteochondral mosaicplasty appears to be a promising alternative for the treatment of small- and medium-sized focal chondral and osteochondral defects of the weight-bearing surfaces of the knee and other weight-bearing synovial joints.

Autologous cartilage implantation for full thickness articular cartilage defects of the knee

BACKGROUND

Treatments for managing articular cartilage defects of the knee, including drilling and abrasion arthroplasty, are not always effective. When they are, long-term benefits may not be maintained and osteoarthritis may develop, resulting in the need for a total knee replacement. An alternative is the surgical implantation of healthy cartilage cells into damaged areas (autologous cartilage implantation).

OBJECTIVES

To determine the effectiveness of autologous cartilage implantation (ACI) in people with full thickness articular cartilage defects of the knee.

SEARCH STRATEGY

We searched the Cochrane Bone, Joint and Muscle Trauma Group Specialised Register (15 December 2005), the Cochrane Central Register of Controlled Trials (The Cochrane Library, Issue 3, 2005), MEDLINE (1966 to December 2005), CINAHL (1982 to December Week 2, 2004), EMBASE (1988 to 2005 Week 50), SPORTDiscus (1830 to January 2005) and the National Research Register Issue 3, 2005.

SELECTION CRITERIA

Randomised and quasi-randomised trials comparing ACI with any other type of treatment (including no treatment or placebo) for symptomatic cartilage defects of the medial or lateral femoral condyle, femoral trochlea or patella.

DATA COLLECTION AND ANALYSIS

Two review authors selected studies for inclusion independently. We assessed study quality based on adequacy of the randomisation process, adequacy of the allocation concealment process, potential for selection bias after allocation and level of masking. Data was not pooled due to clinical and methodological heterogeneity in the studies.

MAIN RESULTS

We included four randomised controlled trials (266 participants). One trial of ACI versus mosaicplasty reported statistically significant results for ACI at one year, but only in a post-hoc subgroup analysis of participants with medial condylar defects; 88% had excellent or good results with ACI versus 69% with mosaicplasty. A second trial of ACI versus mosaicplasty found no statistically significant difference in clinical outcomes at two years. There was no statistically significant difference in outcomes at two years in a trial comparing ACI with microfracture. In addition, one trial of matrix-guided ACI versus microfracture did not contain enough long-term results to reach definitive conclusions.

AUTHORS' CONCLUSIONS

The use of ACI and other chondral resurfacing techniques is becoming increasingly widespread. However, there is at present no evidence of significant difference between ACI and other interventions. Additional good quality randomised controlled trials with long-term functional outcomes are required.

Arthroscopic chondral osseous autograft transplantation (COR procedure) for femoral defects

PURPOSE

Localized, full-thickness articular cartilage defects of the femoral condyle are often found unexpectedly. An arthroscopic repair technique that transplants chondral osseous replacement plugs to fill the defect (the COR technique; Mitek Products, Westwood, MA) offers an immediate solution for these lesions. The purpose of this study was to review the clinical and radiographic results of femoral chondral osseous replacement for full-thickness articular cartilage lesions between 2.5 and 1.0 cm in diameter.

TYPE OF STUDY

Case series.

METHODS

A retrospective review of a consecutive series of patients from 2 centers treated for full-thickness femoral articular cartilage lesions using a chondral osseous autograft transplantation technique was performed. All knees were evaluated both preoperatively and postoperatively by physical examination, radiographs, and Lysholm and Tegner knee scores. Inclusion criteria were full-thickness femoral condyle defects greater than 1 cm and less than 2.5 cm in diameter, and a minimum 24-month follow-up. Exclusion criteria were associated tibial defects, patellar defects, or generalized arthritic change. Grafts harvested from the superior, lateral femoral notch were press-fit into drilled holes to fill the femoral defects.

RESULTS

Thirty-six patients met the inclusion criteria with an average follow-up of 48 months (range, 24 to 89 months). Their average age was 43 years and there were 20 men and 16 women. The medial femoral condyle was involved in 27 cases and the lateral femoral condyle in 9. The average Lysholm score increased from 44 preoperatively to 84 at follow-up. The average Tegner score at follow-up was 5. Repeat arthroscopy was performed in 14 patients and showed good incorporation of the grafts in all cases. Radiographic examinations revealed no arthritic changes at follow-up.

CONCLUSIONS

This technique successfully transplants chondral osseous grafts within the knee that remain viable. No radiographic arthritic changes were observed and the midterm clinical result was favorable for these patients. Further investigation of the long-term results is required.

LEVEL OF EVIDENCE

Level 4, no or historical control.