The effect of platelet-rich plasma on osteochondral defects treated with mosaicplasty

Purpose

This study investigated the efficacy of platelet-rich plasma (PRP) on articular surfaces on which the mosaicplasty technique was performed. Our hypothesis was that PRP can accelerate the osseointegration process and enhance the quality of articular integrity after the mosaicplasty procedure.

Methods

Standard defects were created in the femoral groove of both patellofemoral joints of 12 New Zealand rabbits. PRP solution was placed inside the defect before fixation of the osteochondral autografts and injected inside the involved joint after capsular closure of the tested knees. The contralateral knees served as the control sides. The animals were euthanized three or six weeks after mosaicplasty, and both limbs were assessed according to Pineda’s histological grading scale. Significance level was set at p ≤ 0.05 a priori, and the Mann–Whitney U test was used for statistical analysis.

Results

Histologic findings at the interface between the transferred autograft and the original cartilage revealed better integration of the adjacent surfaces in the mosaicplasty with PRP group three weeks after the procedure; the difference was significant (p < 0.05). However, no significant difference in the transition zone was observed between the groups six weeks after the experiment (p = 0.59).

Conclusions

Our animal model showed that adjunctive use of PRP produced a better healing response and resulted in superior histological scores after three weeks compared with the mosaicplasty-only procedure. Interpretation of our results is important in terms of rapid return to previous activity levels. Thus, application of PRP can represent a valid therapeutic option for improving the efficacy of mosaicplasty by stimulating the local healing response.     

骨软骨镶嵌成形术修复骨软骨复合缺损的比较研究

目的观察采用骨软骨镶嵌成形术（Mosaicplasty）修复膝关节中等和大面积骨软骨复合缺损的效果,为临床应用提供理论依据。方法24只成年山羊随机分成3组（n=8）。中等面积缺损组在股骨内髁制造直径6mm缺损,植入直径2mm骨软骨柱修复;大面积缺损组于股骨内髁制造9mm直径缺损,以直径3mm骨软骨柱修复;对照组于股骨内髁制造直径6mm缺损后不修复。自股骨髁间窝和滑车沟两侧非负重区用自制Mosaicplasty器械钻取骨软骨柱,推出器嵌入缺损处镶嵌填满。术后4、8、16及24周处死动物,取修复骨软骨组织行大体观察、HE及甲苯胺蓝染色。术后24周,取大面积缺损组和对照组膝关节摄X线片,观察骨软骨缺损修复情况,并分别取修复组织及正常软骨组织行蛋白聚糖（glycosaminogly cans,GAG）含量测定。结果中等面积缺损组术后4周,移植的骨软骨柱与基底部骨床结合牢固;8-24周软骨层之间以及与正常软骨间界限仍清晰。大面积缺损组术后4周,移植的骨软骨柱与基底骨床结合牢固,部分骨软骨柱被压入骨床内;8-24周压陷程度加重,与股骨髁相对关节面的部分软骨被磨损。对照组24周缺损仍无明显修复迹象,与股骨髁相对关节面的软骨磨损剥脱。组织学观察结果类似大体观察,术后24周中等及大面积缺损组软骨柱间均有缝隙存在,大面积缺损组毗邻软骨细胞稀疏肥大。术后24周,X线片可见大面积缺损组软骨下骨愈合良好,而对照组仍可见骨质缺损,与股骨髁相对关节面的软骨局部骨质硬化;软骨GAG含量测定显示正常软骨和大面积缺损组修复组织间差异无统计学意义（P〉0.05）;前两者与对照组修复组织比较,差异均有统计学差异（P〈0.05）。结论Mosaicplasty可修复中等面积骨软骨复合缺损,但无法有效修复大面积缺损,效果有待改进。     

Potential healing benefit of an osteoperiosteal bone plug from the proximal tibia on a mosaicplasty donor-site defect in the knee

Introduction Autologous osteochondral transplantation is a popular treatment for articular cartilage lesions in the knee joint. The donor defect is commonly left empty and remains a matter of concern.Materials and methods In 20 knees of 10 goats, we created a standardised donor defect in the knee. In the control group the defects were left empty, whereas in two other groups a bone plug from the proximal tibia was press-fitted into the defect with or without a covering periosteal layer.Results Histological evaluation after 8 and 16 weeks showed that relatively rapid osteoclastic resorption of the bone plug occurred. Defects were mainly filled with fibrous tissue, and collapse of the adjacent bone and cartilage was visible, especially when the defects were left empty. Occasionally, some consolidation of the graft to the host bone could be detected, and in some samples periosteal chondrogenesis was present.Conclusion Our findings suggest that transplantation of a tibial bone plug with covering periosteum to the donor defect in a cartilage transplantation procedure does not have any additional value in an attempt to minimise the damage at the donor site. The observed resorption of the bone plug and the collapse of the adjacent joint margin remain a matter of concern with this technique.     

The effect of overlapping on the primary stability of osteochondral grafts in mosaicplasty

Our goal was to determine the primary stability of overlapping osteochondral grafts used in mosaicplasty by studying the effect of overlapping in an ex vivo model. Osteochondral grafts, 10 mm in diameter, were transplanted from the trochlea of cow femurs to the weight-bearing area of the lateral femoral condyle with 0, 15, or 30% overlap. The grafts were pushed in with a probe at a rate of 2 mm/min, and load (N)-displacement (mm) curves were recorded. In Group I (control, 0% overlap), insertion 1 and 2 mm below the cartilage level could be reached at 572.3 +/- 273.6 and 999.3 +/- 427.6 N, respectively. In Group II (15% overlap), insertion 1 and 2 mm below the cartilage level could be reached at 263.6 +/- 91.7 and 746.6 +/- 88.0 N, respectively. In Group III (30% overlap), insertion 1 and 2 mm below the cartilage level could be reached at 179.4 +/- 31.2 and 657.0 +/- 106.5 N, respectively. The loads that were necessary to produce a 1-mm dent in the grafts were significantly different between Groups I and II and Groups I and III (p < 0.05). These results suggest that stability may be reduced by graft overlapping in mosaicplasty surgery. The results of this ex vivo animal study contribute to a more complete understanding of the primary stability of osteochondral grafts in an overlapping position as well as postoperative protocols.     

The present state of treatments for articular cartilage defects in the knee

INTRODUCTION

Chondral and osteochondral lesions of the knee are notoriously difficult to treat due to the poor healing capacity of articular cartilage and the hostile environment of moving joints, ultimately causing disabling pain and early osteoarthritis. There are many different reconstructive techniques used currently but few are proven to be of value. However, some have been shown to produce a better repair with hyaline-like cartilage rather than fibrocartilage.

METHODS

A systematic search of all available online databases including PubMed, MEDLINE® and Embase™ was undertaken using several keywords. All the multiple treatment options and methods available were considered. These were summarised and the evidence for and against them was scrutinised.

RESULTS

A total of 460 articles were identified after cross-referencing the database searches using the keywords. These revealed that autologous and matrix assisted chondrocyte implantation demonstrated both ‘good to excellent’ histological results and significant improvement in clinical outcomes.

CONCLUSIONS

Autologous and matrix assisted chondrocyte implantation have been shown to treat symptomatic lesions successfully with significant histological and clinical improvement. There is, however, still a need for further randomised clinical trials, perfecting the type of scaffold and the use of adjuncts such as growth factors. A list of recommendations for treatment and the potential future trends of managing these lesions are given.     

The anterior approach for the treatment of posterior osteochondral lesions of the talus: comparison of different surgical techniques

Introduction: Most of all osteochondral talar lesions are located in the middle and posterior area of the talar surface. Malleolar osteotomy is often used to access the defect but may be associated with malunion or secondary osteoarthritis. We present an alternative approach to the talus with temporary removal and replacement of a tibial bone block and compare it with other anterior approaches described in the literature. Patients and methods: Thirteen patients (5 males, 8 females) with an average age of 27.2 years and an osteochondral talar lesion were included in our study. All patients were previously operated on the same ankle. Ten lesions were caused by a sports injury. The average follow up was 45 months. The patients were evaluated before and after surgery using the ankle and hindfood score (AOFAS). For the analyses baseline clinical data were compared with follow up data using the Wilcoxon test. Results: The overall improvement between the preoperative and postoperative AOFAS scores was an average of 34.9 points (P=0.0002). No complications occurred at the site of the tibial bone block and the donor site at the talus. There were no patients with recurrence or an ankle osteoarthrosis in the follow up period. Conclusion: The removal of a tibial bone block and its subsequent replacement is a useful technique to access osteochondral talar lesions for osteochondral transplantation for which arthroscopic interventions have failed. The results are comparable to other anterior approaches described in the literature.An erratum to this article can be found at     

A 2-staged method for treatment of deep osteochondral lesions of the knee joint

We performed a 2-staged arthroscopic-assisted surgical procedure to treat a patient with a large osteochondral lesion of the knee joint. The osteochondral lesion was too comminuted to reattach; in addition, the underlying bony defect was too deep. In the first stage, autogenous cortical bone was used for grafting the bony defect along with screw fixation. The second stage consisted of screw removal and transplantation of autogenous osteochondral graft overlying the chondral defect. The osteochondral grafts were taken from the non–weight bearing areas of the same knee.Arthroscopy: The Journal of Arthroscopic and Related Surgery, Vol 17, No 9 (November-December), 2001: E35     

A comparison of open versus arthroscopic harvesting of osteochondral autografts

Osteochondral autograft transfer is a technique for treatment of traumatic and degenerative cartilage lesions. A graft in which the cartilage cap is oriented perpendicular to the long axis of the graft is ideal because it can both restore the cartilage tidemark and minimize articular step-off at the recipient site. This study determines if osteochondral harvest technique (arthroscopic versus mini-open) or donor site location affects suitable graft harvest. One hundred and twenty eight osteochondral grafts were harvested in 16 cadaver knees utilizing a 7 mm OATS chisel from four donor sites: lateral supracondylar ridge, lateral femoral condyle, lateral intercondylar notch and medial femoral condyle. Mini-open and arthroscopic harvesting techniques were equally employed. Radiographic methods were used to analyze graft perpendicularity. Statistical analysis comparing graft suitability based on technique and donor site location was performed. There were no statistically significant differences (p > 0.05) in graft suitability regardless of the technique used or donor site location. 69% of arthroscopic and 56% of mini-open graft harvest were considered suitable, possessing a cartilage cap and graft axis angle that would create less than 1 mm of articular incongruity. Incongruity results when the angle between the subchondral bone plug long axis and cartilage interface is greater than 74°. There is no difference in the quality of osteochondral grafts harvested from the knee regardless of technique or donor site used. Osteochondral graft diameter should be kept at or less than 7 mm because of the high percentage of unacceptable grafts with increasing chisel sizes.     

Osteochondral autografts transfer for post-traumatic osteochondral defect of the knee-2 to 5 years follow-up

The treatment of post-traumatic osteochondral defects of the weight-bearing surface of the knee in young active patients remains a significant challenge. We report the results of an osteochondral autograft transfer (OAT) in 18 patients (mean age 29 years) with post-traumatic focal osteochondral defects of the knee. Sixteen lesions were over the femoral condyle and two were over the tibial plateau. The average size of the lesion was 4.1 cm² (from 2.25 to 6 cm²), and the subchondral bone involved no more than 1 cm in depth. Osteochondral grafts were harvested from the non-weight-bearing area of the femoral condyle. Ten patients also had concomitant surgical procedures. The average follow-up was 42 months (from 24 to 64 months). All patients were evaluated by Lysholm and Tegner activity scores and plain radiographs. Nine patients had MRI, eight patients had second-look arthroscopy and two had a biopsy. Sixteen patients (89%) had good to excellent results, while two patients with lesion over the tibial surface had fair results. The biopsy revealed survival of hyaline cartilage. For small to medium osteochondral lesion over the femoral condyle of the knee in selected patients, osteochondral autografting yielded promising short to mid-term results.