gms | German Medical Science

Deutscher Kongress für Orthopädie und Unfallchirurgie (DKOU 2019)

22. - 25.10.2019, Berlin

The Intricate Microchannel Structure of the Human Femoral Head

Meeting Abstract

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  • presenting/speaker Shahed Taheri - Universitätsmedizin Göttingen, Klinik f. Unfallchirurgie, Orthopädie u. Plast. Chirurgie, Göttingen, Germany
  • Lina Jochim - Universitätsmedizin Göttingen, Klinik f. Unfallchirurgie, Orthopädie u. Plast. Chirurgie, Göttingen, Germany
  • Arndt F Schilling - Universitätsmedizin Göttingen, Klinik f. Unfallchirurgie, Orthopädie u. Plast. Chirurgie, Göttingen, Germany

Deutscher Kongress für Orthopädie und Unfallchirurgie (DKOU 2019). Berlin, 22.-25.10.2019. Düsseldorf: German Medical Science GMS Publishing House; 2019. DocAB41-399

doi: 10.3205/19dkou334, urn:nbn:de:0183-19dkou3345

Veröffentlicht: 22. Oktober 2019

© 2019 Taheri et al.
Dieser Artikel ist ein Open-Access-Artikel und steht unter den Lizenzbedingungen der Creative Commons Attribution 4.0 License (Namensnennung). Lizenz-Angaben siehe



Objectives: The presence of a subchondral channel-like microstructure that provides a direct link between articular cartilage (AC) and deeper trabecular bone has been confirmed in a handful of classic literature. Referred to as „defects“ or „breaks", they are not yet three-dimensionally visualized or characterized, despite their potential importance in understanding osteoarthritis (OA) pathophysiology. Here, we demonstrate the intricate 3D microstructure of the subchondral bone (SCB) channels in healthy human femoral head, and their region-dependent pattern. The microchannels are quantified in terms of average number (Ch.N), thickness (Ch.Th), as well as their correlation to the cartilage thickness.

Methods: Human femurs from the anatomical gift program of the Medizinische Hochschule Hannover (MHH) were kindly donated to us. They were independently graded by three orthopaedic surgeons according to the Outerbridge classification system, and subsequently, five healthy female joints were selected (age-range:40-60). 44 measuring points were systematically defined on each sample. Cylindrical specimens (n=220, D=2.00 mm) were then drilled out from each sample and scanned using a high-definition micro-CT system (µCT 50, SCANCO Medical AG; voxel size=1.2 µm, source voltage=90 kVp, intensity=88 µA). The SCB channels were segmented and analyzed using appropriate evaluation scripts and threshold setting. 5-m thick sagittal sections of hip joints were incubated with primary antibodies against CD31 (ab28364, Abcam, 1:100), and von Willebrand Factor (vWF, Dako, 1:200), and then processed for immunohistochemical staining using standard protocols. Statistical evaluation was carried out using SPSS package (IBM SPSS, version 25.0). The significance threshold (p) was set at 0.05.

Results and conclusion: The data were categorized into three groups based on the contact area of the femoral head with the acetabulum: load-bearing region (LBR), partial contact (PC) and non-load-bearing region (NLBR). The microchannels were abundant and small (Ch.N = 34.2±11.3 1/mm; Ch.Th = 26±16 µm) on the LBR, perpendicularly connecting SCB's surface to deeper trabecular spacing, while scarce and significantly thicker on the NLBR of the femoral head (p<0.01). The PC showed a combination of thick and small channels. The mean AC thickness (LBR: 696±209 µm, PC: 575±162 µm, NLBR: 315±124 µm) was positively correlated with the number of microchannels (Pearson's r=0.43; p<0.01). Immunohistochemistry results demonstrated positive expression for vWF inside microchannels, a specific marker for endothelial cells.

Our results demonstrate that an intricate microchannel structure exists in the subchondral bone of the human femoral head. The number, width, and distribution pattern of the channels is strongly region-dependent. The positive correlation of microchannel numbers with AC thickness in healthy femurs suggests that they might play a role in the nutrition of AC.