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Evaluation of Single-Impact-Induced Cartilage Degeneration by Optical Coherence Tomography.

de Bont F, Brill N, Schmitt R, Tingart M, Rath B, Pufe T, Jahr H, Nebelung S - Biomed Res Int (2015)

Bottom Line: OCT images were assessed qualitatively (DJD classification) and quantitatively using established parameters (OII, Optical Irregularity Index; OHI, Optical Homogeneity Index; OAI, Optical Attenuation Index) and compared to corresponding histological sections.While OAI and OHI scores were not significantly changed in response to low- or moderate-impact energies, high-impact energies significantly increased mean DJD grades (histology and OCT) and OII scores.In conclusion, OCT-based parameterization and quantification are able to reliably detect loss of cartilage surface integrity after high-energy traumatic insults and hold potential to be used for clinical screening of early osteoarthritis.

View Article: PubMed Central - PubMed

Affiliation: Department of Orthopaedics, Aachen University Hospital, 52074 Aachen, Germany.

ABSTRACT
Posttraumatic osteoarthritis constitutes a major cause of disability in our increasingly elderly population. Unfortunately, current imaging modalities are too insensitive to detect early degenerative changes of this disease. Optical coherence tomography (OCT) is a promising nondestructive imaging technique that allows surface and subsurface imaging of cartilage, at near-histological resolution, and is principally applicable in vivo during arthroscopy. Thirty-four macroscopically normal human cartilage-bone samples obtained from total joint replacements were subjected to standardized single impacts in vitro (range: 0.25 J to 0.98 J). 3D OCT measurements of impact area and adjacent tissue were performed prior to impaction, directly after impaction, and 1, 4, and 8 days later. OCT images were assessed qualitatively (DJD classification) and quantitatively using established parameters (OII, Optical Irregularity Index; OHI, Optical Homogeneity Index; OAI, Optical Attenuation Index) and compared to corresponding histological sections. While OAI and OHI scores were not significantly changed in response to low- or moderate-impact energies, high-impact energies significantly increased mean DJD grades (histology and OCT) and OII scores. In conclusion, OCT-based parameterization and quantification are able to reliably detect loss of cartilage surface integrity after high-energy traumatic insults and hold potential to be used for clinical screening of early osteoarthritis.

No MeSH data available.


Related in: MedlinePlus

(a) Top view of a representative cartilage sample to illustrate the standardized scan area. Tissue marking dye spots at the 12, 6, and 9 o'clock positions indicate the midsagittal plane (between 12 and 6 o'clock) and its perpendicular plane, while the intersection point between both planes is the sample centre point (1; white spot). From here, 3D OCT scanning was performed parallel to the midsagittal plane in an area of 10 × 10 mm (length × width) towards the sample periphery as indicated by 9 o'clock dot (2; parallel lines within box). Thus, the impact area itself (3; centered on the centre point) and the immediate adjacent concentric tissue were scanned. (b) Corresponding histological section demonstrating the topography of the sample centre point (1) and the scan area (2) in relation to the radius of the impact area (3). Note the absence of subchondral cancellous bone which had been removed to leave only compact bone attached. Safranin O, 1.6x magnification.
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fig1: (a) Top view of a representative cartilage sample to illustrate the standardized scan area. Tissue marking dye spots at the 12, 6, and 9 o'clock positions indicate the midsagittal plane (between 12 and 6 o'clock) and its perpendicular plane, while the intersection point between both planes is the sample centre point (1; white spot). From here, 3D OCT scanning was performed parallel to the midsagittal plane in an area of 10 × 10 mm (length × width) towards the sample periphery as indicated by 9 o'clock dot (2; parallel lines within box). Thus, the impact area itself (3; centered on the centre point) and the immediate adjacent concentric tissue were scanned. (b) Corresponding histological section demonstrating the topography of the sample centre point (1) and the scan area (2) in relation to the radius of the impact area (3). Note the absence of subchondral cancellous bone which had been removed to leave only compact bone attached. Safranin O, 1.6x magnification.

Mentions: Upon informed patient consent and institutional ethical review board approval (AZ EK 157/13), human articular cartilage-bone samples were obtained from total knee replacement surgeries (n = 11 patients; 7 males, 4 females; age 72.0 ± 5.0 years). All patients underwent total knee replacement at our institution due to primary OA of the knee as determined both clinically and radiographically. After sterile excision, cartilage-bone samples were collected in sterile DMEM medium (Gibco-BRL, Gaithersburg, USA) containing 100 U/mL penicillin (Gibco), 100 μg/mL gentamycin (Gibco), and 1.25 U/mL amphotericin B (Gibco) and immediately transferred to the laboratory. Macroscopically, samples were graded according to the Outerbridge classification [23]. For standardization, only cartilage samples graded Outerbridge grade 0, that is, without any signs of degeneration, were used for the present study. Moreover, only samples obtained from the femoral condyles (9/25 [medial/lateral]) were included. Samples were cut to standard size (length × width: 20 × 20 mm) with the surface as plain as possible, while the subchondral bone was trimmed to the subchondral lamella; that is, all cancellous bone was removed until only compact bone was left. It is of note that the thickness of the subchondral bone plate as determined on histological sections was variable ranging from 0.10 to 0.75 mm. Tissue marking dye (Polysciences, Warrington, USA) outside the impact area was applied for future reference. More specifically, two spots at opposing sample sides marked the midsagittal imaging plane (0°), while its orthogonal plane (90°) was defined by a third spot on another sample side (Figure 1). The intersection of these two planes indicated the sample center point. Thirty-four samples were thus prepared and assessed macroscopically, of which 32 were included in the impaction versus nonimpaction study design (see Section 2.2) and thus transferred to 12-well plates filled with 3 mL/well of the DMEM medium as above. Two samples underwent histological processing immediately after preparation for preimpact histological standardization.


Evaluation of Single-Impact-Induced Cartilage Degeneration by Optical Coherence Tomography.

de Bont F, Brill N, Schmitt R, Tingart M, Rath B, Pufe T, Jahr H, Nebelung S - Biomed Res Int (2015)

(a) Top view of a representative cartilage sample to illustrate the standardized scan area. Tissue marking dye spots at the 12, 6, and 9 o'clock positions indicate the midsagittal plane (between 12 and 6 o'clock) and its perpendicular plane, while the intersection point between both planes is the sample centre point (1; white spot). From here, 3D OCT scanning was performed parallel to the midsagittal plane in an area of 10 × 10 mm (length × width) towards the sample periphery as indicated by 9 o'clock dot (2; parallel lines within box). Thus, the impact area itself (3; centered on the centre point) and the immediate adjacent concentric tissue were scanned. (b) Corresponding histological section demonstrating the topography of the sample centre point (1) and the scan area (2) in relation to the radius of the impact area (3). Note the absence of subchondral cancellous bone which had been removed to leave only compact bone attached. Safranin O, 1.6x magnification.
© Copyright Policy - open-access
Related In: Results  -  Collection

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fig1: (a) Top view of a representative cartilage sample to illustrate the standardized scan area. Tissue marking dye spots at the 12, 6, and 9 o'clock positions indicate the midsagittal plane (between 12 and 6 o'clock) and its perpendicular plane, while the intersection point between both planes is the sample centre point (1; white spot). From here, 3D OCT scanning was performed parallel to the midsagittal plane in an area of 10 × 10 mm (length × width) towards the sample periphery as indicated by 9 o'clock dot (2; parallel lines within box). Thus, the impact area itself (3; centered on the centre point) and the immediate adjacent concentric tissue were scanned. (b) Corresponding histological section demonstrating the topography of the sample centre point (1) and the scan area (2) in relation to the radius of the impact area (3). Note the absence of subchondral cancellous bone which had been removed to leave only compact bone attached. Safranin O, 1.6x magnification.
Mentions: Upon informed patient consent and institutional ethical review board approval (AZ EK 157/13), human articular cartilage-bone samples were obtained from total knee replacement surgeries (n = 11 patients; 7 males, 4 females; age 72.0 ± 5.0 years). All patients underwent total knee replacement at our institution due to primary OA of the knee as determined both clinically and radiographically. After sterile excision, cartilage-bone samples were collected in sterile DMEM medium (Gibco-BRL, Gaithersburg, USA) containing 100 U/mL penicillin (Gibco), 100 μg/mL gentamycin (Gibco), and 1.25 U/mL amphotericin B (Gibco) and immediately transferred to the laboratory. Macroscopically, samples were graded according to the Outerbridge classification [23]. For standardization, only cartilage samples graded Outerbridge grade 0, that is, without any signs of degeneration, were used for the present study. Moreover, only samples obtained from the femoral condyles (9/25 [medial/lateral]) were included. Samples were cut to standard size (length × width: 20 × 20 mm) with the surface as plain as possible, while the subchondral bone was trimmed to the subchondral lamella; that is, all cancellous bone was removed until only compact bone was left. It is of note that the thickness of the subchondral bone plate as determined on histological sections was variable ranging from 0.10 to 0.75 mm. Tissue marking dye (Polysciences, Warrington, USA) outside the impact area was applied for future reference. More specifically, two spots at opposing sample sides marked the midsagittal imaging plane (0°), while its orthogonal plane (90°) was defined by a third spot on another sample side (Figure 1). The intersection of these two planes indicated the sample center point. Thirty-four samples were thus prepared and assessed macroscopically, of which 32 were included in the impaction versus nonimpaction study design (see Section 2.2) and thus transferred to 12-well plates filled with 3 mL/well of the DMEM medium as above. Two samples underwent histological processing immediately after preparation for preimpact histological standardization.

Bottom Line: OCT images were assessed qualitatively (DJD classification) and quantitatively using established parameters (OII, Optical Irregularity Index; OHI, Optical Homogeneity Index; OAI, Optical Attenuation Index) and compared to corresponding histological sections.While OAI and OHI scores were not significantly changed in response to low- or moderate-impact energies, high-impact energies significantly increased mean DJD grades (histology and OCT) and OII scores.In conclusion, OCT-based parameterization and quantification are able to reliably detect loss of cartilage surface integrity after high-energy traumatic insults and hold potential to be used for clinical screening of early osteoarthritis.

View Article: PubMed Central - PubMed

Affiliation: Department of Orthopaedics, Aachen University Hospital, 52074 Aachen, Germany.

ABSTRACT
Posttraumatic osteoarthritis constitutes a major cause of disability in our increasingly elderly population. Unfortunately, current imaging modalities are too insensitive to detect early degenerative changes of this disease. Optical coherence tomography (OCT) is a promising nondestructive imaging technique that allows surface and subsurface imaging of cartilage, at near-histological resolution, and is principally applicable in vivo during arthroscopy. Thirty-four macroscopically normal human cartilage-bone samples obtained from total joint replacements were subjected to standardized single impacts in vitro (range: 0.25 J to 0.98 J). 3D OCT measurements of impact area and adjacent tissue were performed prior to impaction, directly after impaction, and 1, 4, and 8 days later. OCT images were assessed qualitatively (DJD classification) and quantitatively using established parameters (OII, Optical Irregularity Index; OHI, Optical Homogeneity Index; OAI, Optical Attenuation Index) and compared to corresponding histological sections. While OAI and OHI scores were not significantly changed in response to low- or moderate-impact energies, high-impact energies significantly increased mean DJD grades (histology and OCT) and OII scores. In conclusion, OCT-based parameterization and quantification are able to reliably detect loss of cartilage surface integrity after high-energy traumatic insults and hold potential to be used for clinical screening of early osteoarthritis.

No MeSH data available.


Related in: MedlinePlus