Center of Experimental Orthopaedics, Saarland University Medical Center and Saarland University, Homburg/Saar, Germany.
Departments of Anesthesia and Surgery, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA.
Am J Sports Med. 2022 Aug;50(10):2669-2679. doi: 10.1177/03635465221104775. Epub 2022 Jul 14.
Subchondral drilling is an established marrow stimulation technique for small cartilage defects, but whether drilling is required at all and if the drill hole density affects repair remains unclear.
Osteochondral repair is improved when the subchondral bone is perforated by a higher number of drill holes per unit area, and drilling is superior to defect debridement alone.
Controlled laboratory study.
Rectangular full-thickness chondral defects (4 × 8 mm) were created in the trochlea of adult sheep (N = 16), debrided down to the subchondral bone plate without further treatment as controls (no treatment; n = 7) or treated with either 2 or 6 (n = 7 each) subchondral drill holes (diameter, 1.0 mm; depth, 10.0 mm). Osteochondral repair was assessed at 6 months postoperatively by standardized (semi-)quantitative macroscopic, histological, immunohistochemical, biochemical, and micro-computed tomography analyses.
Compared with defect debridement alone, histological overall cartilaginous repair tissue quality ( = .025) and the macroscopic aspect of the adjacent cartilage (≤ .032) were improved after both drilling densities. Only drilling with 6 holes increased type 2 collagen content in the repair tissue compared with controls ( = .038). After debridement, bone mineral density was significantly decreased in the subchondral bone plate (≤ .015) and the subarticular spongiosa (≤ .041) compared with both drilling groups. Debridement also significantly increased intralesional osteophyte sectional area compared with drilling (≤ .034). No other differences in osteochondral repair existed between subchondral drilling with 6 or 2 drill holes.
Subchondral drilling independent of drill hole density significantly improves structural cartilage repair compared with sole defect debridement of full-thickness cartilage defects in sheep after 6 months. Subchondral drilling also leads to a better reconstitution of the subchondral bone compartment below the defects. Simultaneously, drilling reduced the formation of intralesional osteophytes caused by osseous overgrowth compared with debridement.
These results have important clinical implications, as they support subchondral drilling independent of drill hole number but discourage debridement alone for the treatment of small cartilage defects. Clinical studies are warranted to further quantify the effects of subchondral drilling in similar settings.
骨下钻孔是一种成熟的用于治疗小范围软骨缺损的骨髓刺激技术，但仍不清楚是否需要进行钻孔，以及钻孔密度是否会影响修复效果。
通过增加单位面积的骨下钻孔数量，可以改善软骨下骨的骨软骨修复，并且钻孔优于单纯的病灶清创术。
对照实验研究。
在成年绵羊的滑车处制造全层（4×8mm）矩形软骨缺损（N=16），不进行进一步处理作为对照（无处理；n=7）或用 2 或 6 个（n=7）骨下钻头（直径 1.0mm，深度 10.0mm）进行处理。术后 6 个月，通过标准化（半）定量宏观、组织学、免疫组织化学、生物化学和微计算机断层扫描分析评估骨软骨修复情况。
与单纯清创术相比，两种钻孔密度均能提高组织学整体软骨修复组织质量（P=.025）和相邻软骨的宏观外观（P≤.032）。只有 6 个孔的钻孔术可增加修复组织中的 II 型胶原含量，与对照组相比有统计学差异（P=.038）。清创术后，与两个钻孔组相比，软骨下骨板（P≤.015）和软骨下松质骨（P≤.041）的骨矿物质密度明显降低。清创术还导致病灶内骨赘的截面积明显大于钻孔术（P≤.034）。在绵羊全层软骨缺损 6 个月后，与单独钻孔相比，亚软骨钻孔的密度对骨软骨修复无显著影响。亚软骨钻孔还导致缺损下方的软骨下骨腔更好地重建。同时，与清创术相比，钻孔术减少了由于骨质过度生长而引起的病灶内骨赘的形成。
与单纯清创术相比，6 个月后，在绵羊全层软骨缺损中，亚软骨钻孔术独立于钻孔密度，可显著改善结构软骨修复效果。此外，亚软骨钻孔术还可以更好地重建缺损下方的软骨下骨。同时，与清创术相比，钻孔术减少了由于骨质过度生长而引起的病灶内骨赘的形成。
这些结果具有重要的临床意义，因为它们支持亚软骨钻孔术独立于钻孔数量，但不支持单独清创术用于治疗小范围软骨缺损。有必要进行临床研究来进一步量化类似情况下亚软骨钻孔术的效果。
