Limits...
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

Macroscopic images of the india ink stained cartilage surfaces.(a-d) femur condyles and (e-h) tibia plateaus. Figs a-d show the presence of femoral condyle cartilage fibrillation in all experimental groups (white arrows), while Figs e-f show focal india ink staining of the central tibia plateau for all groups (black arrows). The femur and tibia of the implant group (a and e) showed more extensive ink staining than the other groups.
© Copyright Policy
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4507942&req=5

pone.0133138.g005: Macroscopic images of the india ink stained cartilage surfaces.(a-d) femur condyles and (e-h) tibia plateaus. Figs a-d show the presence of femoral condyle cartilage fibrillation in all experimental groups (white arrows), while Figs e-f show focal india ink staining of the central tibia plateau for all groups (black arrows). The femur and tibia of the implant group (a and e) showed more extensive ink staining than the other groups.

Mentions: Signs of cartilage degeneration were present in all operated as well as in all non-operated joints. All femoral condyles showed marked fibrillation along the mediolateral axis, which was most pronounced on the inner aspect of the medial condyle (Fig 5a–5d). This resulted in highly similar macroscopic femoral cartilage scores for all groups (Median (IQR): Implant: 2.00 (0.00); Implant-control: 2.00 (0.00); Sham: 2.00 (0.75); Sham-control: 2.00 (0.00)). A majority of the joints of the implant group showed damage patterns along the anteroposterior axis on the medial femur condyles (Fig 5a). The cartilage covering the central region of the medial tibia plateau was also damaged in all groups (Fig 5e–5h). The medial tibia plateau of the implant group showed additional fibrillation. In two animals of the implant group cartilage erosions down to the subchondral bone were found. However, the location of these chondral defects corresponded to the location of the malpositioned bone tunnels. The median (IQR) macroscopic scores for the tibial cartilage were: Implant: 3.00 (0.75); Implant-control: 2.00 (1.00); Sham: 1.25 (0.88); Sham-control: 2.00 (0.00)). Significant differences were found between the scores of the implant and sham, and implant and sham-control groups (p = 0.004 and p = 0.012 respectively).


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)

Macroscopic images of the india ink stained cartilage surfaces.(a-d) femur condyles and (e-h) tibia plateaus. Figs a-d show the presence of femoral condyle cartilage fibrillation in all experimental groups (white arrows), while Figs e-f show focal india ink staining of the central tibia plateau for all groups (black arrows). The femur and tibia of the implant group (a and e) showed more extensive ink staining than the other groups.
© Copyright Policy
Related In: Results  -  Collection

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

pone.0133138.g005: Macroscopic images of the india ink stained cartilage surfaces.(a-d) femur condyles and (e-h) tibia plateaus. Figs a-d show the presence of femoral condyle cartilage fibrillation in all experimental groups (white arrows), while Figs e-f show focal india ink staining of the central tibia plateau for all groups (black arrows). The femur and tibia of the implant group (a and e) showed more extensive ink staining than the other groups.
Mentions: Signs of cartilage degeneration were present in all operated as well as in all non-operated joints. All femoral condyles showed marked fibrillation along the mediolateral axis, which was most pronounced on the inner aspect of the medial condyle (Fig 5a–5d). This resulted in highly similar macroscopic femoral cartilage scores for all groups (Median (IQR): Implant: 2.00 (0.00); Implant-control: 2.00 (0.00); Sham: 2.00 (0.75); Sham-control: 2.00 (0.00)). A majority of the joints of the implant group showed damage patterns along the anteroposterior axis on the medial femur condyles (Fig 5a). The cartilage covering the central region of the medial tibia plateau was also damaged in all groups (Fig 5e–5h). The medial tibia plateau of the implant group showed additional fibrillation. In two animals of the implant group cartilage erosions down to the subchondral bone were found. However, the location of these chondral defects corresponded to the location of the malpositioned bone tunnels. The median (IQR) macroscopic scores for the tibial cartilage were: Implant: 3.00 (0.75); Implant-control: 2.00 (1.00); Sham: 1.25 (0.88); Sham-control: 2.00 (0.00)). Significant differences were found between the scores of the implant and sham, and implant and sham-control groups (p = 0.004 and p = 0.012 respectively).

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