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Short Term Evaluation of an Anatomically Shaped Polycarbonate Urethane Total Meniscus Replacement in a Goat Model.

Vrancken AC, Madej W, Hannink G, Verdonschot N, van Tienen TG, Buma P - PLoS ONE (2015)

Bottom Line: Since the treatment options for symptomatic total meniscectomy patients are still limited, an anatomically shaped, polycarbonate urethane (PCU), total meniscus replacement was developed.This study demonstrates that the novel, anatomically shaped PCU total meniscal replacement is biocompatible and resistant to three months of physiological loading.Evidently, redesigning the fixation method is necessary.

View Article: PubMed Central - PubMed

Affiliation: Radboud University Medical Center, Radboud Institute for Health Sciences, Orthopaedic Research Lab, Nijmegen, The Netherlands.

ABSTRACT

Purpose: Since the treatment options for symptomatic total meniscectomy patients are still limited, an anatomically shaped, polycarbonate urethane (PCU), total meniscus replacement was developed. This study evaluates the in vivo performance of the implant in a goat model, with a specific focus on the implant location in the joint, geometrical integrity of the implant and the effect of the implant on synovial membrane and articular cartilage histopathological condition.

Methods: The right medial meniscus of seven Saanen goats was replaced by the implant. Sham surgery (transection of the MCL, arthrotomy and MCL suturing) was performed in six animals. The contralateral knee joints of both groups served as control groups. After three months follow-up the following aspects of implant performance were evaluated: implant position, implant deformation and the histopathological condition of the synovium and cartilage.

Results: Implant geometry was well maintained during the three month implantation period. No signs of PCU wear were found and the implant did not induce an inflammatory response in the knee joint. In all animals, implant fixation was compromised due to suture breakage, wear or elongation, likely causing the increase in extrusion observed in the implant group. Both the femoral cartilage and tibial cartilage in direct contact with the implant showed increased damage compared to the sham and sham-control groups.

Conclusion: This study demonstrates that the novel, anatomically shaped PCU total meniscal replacement is biocompatible and resistant to three months of physiological loading. Failure of the fixation sutures may have increased implant mobility, which probably induced implant extrusion and potentially stimulated cartilage degeneration. Evidently, redesigning the fixation method is necessary. Future animal studies should evaluate the improved fixation method and compare implant performance to current treatment standards, such as allografts.

No MeSH data available.


Related in: MedlinePlus

Evaluation of implant deformation.a) A 3D model of the implant, illustrating the locations of the cross-sections through the anterior and posterior horn and mid regions. b) Projection of the implant onto the transverse plane, including the definitions of implant length and width. c) Example of a cross-section, including the definition of the cross-sectional area.
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pone.0133138.g003: Evaluation of implant deformation.a) A 3D model of the implant, illustrating the locations of the cross-sections through the anterior and posterior horn and mid regions. b) Projection of the implant onto the transverse plane, including the definitions of implant length and width. c) Example of a cross-section, including the definition of the cross-sectional area.

Mentions: All explanted prostheses were stored at room temperature in 0.15 M phosphate buffered saline for a minimum of four weeks. A non-implanted reference prosthesis was kept under similar conditions for four weeks. The implants were microCT scanned in air using the same settings as described in the ‘implant’ section of this paper. The images were segmented using Mimics software (v14.0, Materialise, Leuven, Belgium) and 3D models of the implant geometries were created. To be able to compare corresponding regions for each implant, the 3D models were aligned by a Hausdorff distance minimization algorithm [25]. Length and width of each implant were determined from the projection on to the transverse plane. As the horn geometry was potentially different for each implant, the horns were excluded from the analysis (Fig 3a and 3b). In addition, the height, width and area of cross-sections through the anterior and posterior horn and mid region of the implant were quantified (Fig 3b and 3c).


Short Term Evaluation of an Anatomically Shaped Polycarbonate Urethane Total Meniscus Replacement in a Goat Model.

Vrancken AC, Madej W, Hannink G, Verdonschot N, van Tienen TG, Buma P - PLoS ONE (2015)

Evaluation of implant deformation.a) A 3D model of the implant, illustrating the locations of the cross-sections through the anterior and posterior horn and mid regions. b) Projection of the implant onto the transverse plane, including the definitions of implant length and width. c) Example of a cross-section, including the definition of the cross-sectional area.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4507942&req=5

pone.0133138.g003: Evaluation of implant deformation.a) A 3D model of the implant, illustrating the locations of the cross-sections through the anterior and posterior horn and mid regions. b) Projection of the implant onto the transverse plane, including the definitions of implant length and width. c) Example of a cross-section, including the definition of the cross-sectional area.
Mentions: All explanted prostheses were stored at room temperature in 0.15 M phosphate buffered saline for a minimum of four weeks. A non-implanted reference prosthesis was kept under similar conditions for four weeks. The implants were microCT scanned in air using the same settings as described in the ‘implant’ section of this paper. The images were segmented using Mimics software (v14.0, Materialise, Leuven, Belgium) and 3D models of the implant geometries were created. To be able to compare corresponding regions for each implant, the 3D models were aligned by a Hausdorff distance minimization algorithm [25]. Length and width of each implant were determined from the projection on to the transverse plane. As the horn geometry was potentially different for each implant, the horns were excluded from the analysis (Fig 3a and 3b). In addition, the height, width and area of cross-sections through the anterior and posterior horn and mid region of the implant were quantified (Fig 3b and 3c).

Bottom Line: Since the treatment options for symptomatic total meniscectomy patients are still limited, an anatomically shaped, polycarbonate urethane (PCU), total meniscus replacement was developed.This study demonstrates that the novel, anatomically shaped PCU total meniscal replacement is biocompatible and resistant to three months of physiological loading.Evidently, redesigning the fixation method is necessary.

View Article: PubMed Central - PubMed

Affiliation: Radboud University Medical Center, Radboud Institute for Health Sciences, Orthopaedic Research Lab, Nijmegen, The Netherlands.

ABSTRACT

Purpose: Since the treatment options for symptomatic total meniscectomy patients are still limited, an anatomically shaped, polycarbonate urethane (PCU), total meniscus replacement was developed. This study evaluates the in vivo performance of the implant in a goat model, with a specific focus on the implant location in the joint, geometrical integrity of the implant and the effect of the implant on synovial membrane and articular cartilage histopathological condition.

Methods: The right medial meniscus of seven Saanen goats was replaced by the implant. Sham surgery (transection of the MCL, arthrotomy and MCL suturing) was performed in six animals. The contralateral knee joints of both groups served as control groups. After three months follow-up the following aspects of implant performance were evaluated: implant position, implant deformation and the histopathological condition of the synovium and cartilage.

Results: Implant geometry was well maintained during the three month implantation period. No signs of PCU wear were found and the implant did not induce an inflammatory response in the knee joint. In all animals, implant fixation was compromised due to suture breakage, wear or elongation, likely causing the increase in extrusion observed in the implant group. Both the femoral cartilage and tibial cartilage in direct contact with the implant showed increased damage compared to the sham and sham-control groups.

Conclusion: This study demonstrates that the novel, anatomically shaped PCU total meniscal replacement is biocompatible and resistant to three months of physiological loading. Failure of the fixation sutures may have increased implant mobility, which probably induced implant extrusion and potentially stimulated cartilage degeneration. Evidently, redesigning the fixation method is necessary. Future animal studies should evaluate the improved fixation method and compare implant performance to current treatment standards, such as allografts.

No MeSH data available.


Related in: MedlinePlus