Department of Orthopaedic Surgery, Teikyo University School of Medicine, Tokyo, Japan.
Department of Orthopedic Surgery, NYU Langone Health, New York, New York, USA.
Am J Sports Med. 2021 Dec;49(14):3876-3886. doi: 10.1177/03635465211052512. Epub 2021 Oct 28.
Biological adjuvants are used after a musculoskeletal injury to improve healing, decrease inflammation, and restore joint homeostasis. Work on 1 such adjuvant, platelet-rich plasma (PRP), has suggested a positive effect when introduced during cartilage repair. However, it remains unknown whether healing osteochondral injuries benefit from serial PRP injections.
To evaluate the effects of serial PRP injections versus a single PRP injection on reparative cartilaginous tissue, subchondral bone remodeling, and the expression of inflammatory cytokines in joint synovium.
Controlled laboratory study.
A total of 48 New Zealand White rabbits were randomly assigned to receive 1 (1P), 2 (2P), or 3 (3P) PRP injections. Cylindrical full-thickness cartilage defects (2.9 × 2.9 mm) with microdrillings (0.6-mm diameter) were created on the medial condyles of both knees. PRP was injected into the right knee after closure (groups 1P, 2P, and 3P), at 2 weeks after surgery (groups 2P and 3P), and at 4 weeks after surgery (group 3P). The left knees did not receive any PRP injections. A total of 6 rabbits in each group were euthanized at 3, 6, and 12 weeks postoperatively. Cartilage repair tissue was assessed using the Goebel macroscopic and modified International Cartilage Regeneration & Joint Preservation Society (ICRS) histological scoring systems. Subchondral bone remodeling was evaluated by micro-computed tomography analysis (micro-CT). Inflammatory cytokine levels were assessed by quantitative polymerase chain reaction.
No significant differences were found for the mean macroscopic score between the PRP groups at 12 weeks (control, 6.1 ± 3.3; group 1P, 3.4 ± 2.7; group 2P, 4.2 ± 2.9; group 3P, 0.7 ± 1.5). All PRP groups had a significantly higher mean modified ICRS histological score compared with the control group, but no significant difference was found among the PRP groups. No significant differences were seen in outcomes for the tested micro-CT parameters or cytokine expression levels.
Serial PRP injections conferred no apparent advantage over single injections according to evaluations of the macroscopic and histological appearance of the cartilaginous tissue, subchondral bone healing, and inflammatory cytokine expression levels in the synovium.
The use of PRP as a biological adjuvant to bone marrow stimulation for osteochondral lesions has the potential to enhance the quality of regenerative cartilaginous tissue. We recommend only a single PRP injection if the use of PRP is indicated by the operating surgeon as an adjuvant therapy for osteochondral lesions.
生物佐剂用于肌肉骨骼损伤后，可改善愈合、减少炎症并恢复关节内稳态。对一种这样的佐剂，富血小板血浆（PRP）的研究表明，在软骨修复时引入它具有积极作用。然而，尚不清楚连续 PRP 注射是否有益于骨软骨损伤的愈合。
评估连续 PRP 注射与单次 PRP 注射对修复性软骨组织、软骨下骨重塑以及关节滑膜中炎症细胞因子表达的影响。
对照实验室研究。
48 只新西兰白兔被随机分配接受 1（1P）、2（2P）或 3（3P）次 PRP 注射。在双侧膝关节的内侧髁上创建 2.9×2.9mm 的全层圆形软骨缺损，并进行微钻孔（0.6mm 直径）。在关闭后（1P、2P 和 3P 组）、手术后 2 周（2P 和 3P 组）和手术后 4 周（3P 组）将 PRP 注入右侧膝关节。左侧膝关节未接受任何 PRP 注射。每组各有 6 只兔子在手术后 3、6 和 12 周时被安乐死。使用 Goebel 宏观和改良的国际软骨再生与关节保存协会（ICRS）组织学评分系统评估软骨修复组织。通过微计算机断层扫描分析（micro-CT）评估软骨下骨重塑。通过定量聚合酶链反应评估炎症细胞因子水平。
在 12 周时，PRP 组的平均宏观评分与对照组之间没有显著差异（对照组为 6.1±3.3；1P 组为 3.4±2.7；2P 组为 4.2±2.9；3P 组为 0.7±1.5）。所有 PRP 组的改良 ICRS 组织学评分均明显高于对照组，但 PRP 组之间无显著差异。micro-CT 参数或细胞因子表达水平的测试结果无显著差异。
根据对软骨组织的宏观和组织学外观、软骨下骨愈合以及滑膜中炎症细胞因子表达水平的评估，连续 PRP 注射并未显示出明显优于单次注射的优势。
PRP 作为骨髓刺激的生物佐剂用于骨软骨病变具有提高再生软骨组织质量的潜力。如果手术医生建议将 PRP 作为骨软骨病变的辅助治疗，我们建议仅进行单次 PRP 注射。
