Subchondral Drilling Independent of Drill Hole Number Improves Articular Cartilage Repair and Reduces Subchondral Bone Alterations Compared With Debridement in Adult Sheep.

BACKGROUND: 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. HYPOTHESES: 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. STUDY DESIGN: Controlled laboratory study. METHODS: 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. RESULTS: Compared with defect debridement alone, histological overall cartilaginous repair tissue quality (P = .025) and the macroscopic aspect of the adjacent cartilage (P≤ .032) were improved after both drilling densities. Only drilling with 6 holes increased type 2 collagen content in the repair tissue compared with controls (P = .038). After debridement, bone mineral density was significantly decreased in the subchondral bone plate (P≤ .015) and the subarticular spongiosa (P≤ .041) compared with both drilling groups. Debridement also significantly increased intralesional osteophyte sectional area compared with drilling (P≤ .034). No other differences in osteochondral repair existed between subchondral drilling with 6 or 2 drill holes. CONCLUSION: 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. CLINICAL RELEVANCE: 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.

Evidence in surgical training - a review.

The first residency programs for surgical training were introduced in Germany in the late 1880s and adopted in 1889 by William Halsted in the United States [Cameron JL. William Stewart Halsted. Our surgical heritage. Ann Surg 1997;225:445-58.]. Since then, surgical education has evolved from a sheer volume of exposure to structured curricula, and at the moment, due to work time restrictions, surgical education is discussed on an international level. The reported effect of limited working hours on operative case volume has been variable [McKendy KM, Watanabe Y, Lee L, Bilgic E, Enani G, Feldman LS, et al. Perioperative feedback in surgical training: a systematic review. Am J Surg 2017;214:117-26.]. Experienced surgeons fear that residents do not have sufficient exposure to standard procedures. This may reduce the residents' responsibility for the treatment of the patient and even lead to a reduced autonomy at the end of the residency. Surgical education does not only require learning the technical skills but also human factors as well as interdisciplinary and interprofessional handling. When analyzing international surgical curricula, major differences even between countries of the European Union with more or less strict curricula can be found. Thus far, there is no study that analyzes the educational program of different countries, so there is no evidence which educational system is superior. There is also little evidence to distinguish the good from the average surgeon or the junior surgeons' progress during his residency training. Although some evaluation tools are already available, the lack of resources of most teaching hospitals often results in not using these tools as long it is not mandatory by a governmental program. Because of decreased working hours, increasing hospital costs, and increasing jurisdictional restrictions, teaching hospitals and teachers will have to change their sentiments and focus on their way of surgical education before governmental regulations will emerge leading to more regulation in surgical education. Some learning tools such as simulation, electronic learning, augmented reality, or virtual reality for a timely, sufficient and up to date surgical education. However, research and evidence for existing and novel learning tools will have to increase in the next years to allow surgical education for the future generation of surgeons around the world.