Incidence, Degree, and Development of Graft Hypertrophy 24 Months after Matrix-Induced Autologous Chondrocyte Implantation: Association with Clinical Outcomes

Jay Ebert, A. Smith, M. Fallon, R. Butler, R. Nairn, W. Breidahl, David Wood

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    Abstract

    Background: Graft hypertrophy is a common occurrence after periosteal, collagen-covered and matrix-induced autologous chondrocyte implantation (MACI).

    Purpose/Hypothesis: The purpose of this study was to investigate the incidence, development, and degree of graft hypertrophy at 24 months after MACI. The hypothesis was that graft hypertrophy would not be associated with clinical outcome at 24 months.

    Study Design: Case series, Level of evidence, 4.

    Methods: This study was undertaken in 180 consecutive patients (113 male, 67 female) after MACI in the knee. All patients were assessed clinically using the Knee injury and Osteoarthritis Outcome Score (KOOS) and underwent magnetic resonance imaging (MRI) at 3, 12, and 24 months after surgery. The incidence of hypertrophy relevant to anatomic graft site was investigated, as was the progressive change in hypertrophic studies postoperatively. The degree of tissue overgrowth in hypertrophic cases was investigated, as was its association with patient clinical outcome at 24 months after surgery.

    Results: Of the 180 patients, 50 demonstrated a hypertrophic graft at 1 or more postoperative time points. This included 9 grafts (5.0%) at 3 months and 32 grafts (18.7%) at 12 months. At 24 months, 47 grafts (26.1%) - 43 (32.1%) tibiofemoral and 4 (8.7%) patellofemoral - were hypertrophic. Patients with hypertrophic grafts at 24 months (n = 47) were younger (P =.051), they had a lower body mass index (BMI; P =.069), and significantly fewer of them had patellofemoral grafts (P =.007) compared with patients who had grafts with full (100%) tissue infill (n = 61). There were no significant differences in any of the KOOS subscales between patients with graft hypertrophy or full (100%) tissue infill at 24 months after surgery, while the severity of graft hypertrophy was not associated with KOOS subscales at 24 months.

    Conclusion: Hypertrophic grafts after MACI were common and continued to develop through to 24 months after surgery. Hypertrophic growth was associated with being younger and having a lower BMI, was more common on the femoral condyles, and overall was not associated with clinical outcome at 24 months after surgery. However, further research with longer term follow-up is required to evaluate the effect of persistent hypertrophy on graft stability and to assess the use of early surgical intervention to prevent such failure.
    Original languageEnglish
    Pages (from-to)2208-2215
    JournalAmerican Journal of Sports Medicine
    Volume43
    Issue number9
    Early online dateJul 2015
    DOIs
    Publication statusPublished - Sep 2015

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    Chondrocytes
    Hypertrophy
    Transplants
    Incidence
    Knee Injuries
    Knee Osteoarthritis
    Thigh
    Knee
    Body Mass Index
    Collagen

    Cite this

    @article{acc0027e3ba84198b313a20574da82d7,
    title = "Incidence, Degree, and Development of Graft Hypertrophy 24 Months after Matrix-Induced Autologous Chondrocyte Implantation: Association with Clinical Outcomes",
    abstract = "Background: Graft hypertrophy is a common occurrence after periosteal, collagen-covered and matrix-induced autologous chondrocyte implantation (MACI). Purpose/Hypothesis: The purpose of this study was to investigate the incidence, development, and degree of graft hypertrophy at 24 months after MACI. The hypothesis was that graft hypertrophy would not be associated with clinical outcome at 24 months. Study Design: Case series, Level of evidence, 4.Methods: This study was undertaken in 180 consecutive patients (113 male, 67 female) after MACI in the knee. All patients were assessed clinically using the Knee injury and Osteoarthritis Outcome Score (KOOS) and underwent magnetic resonance imaging (MRI) at 3, 12, and 24 months after surgery. The incidence of hypertrophy relevant to anatomic graft site was investigated, as was the progressive change in hypertrophic studies postoperatively. The degree of tissue overgrowth in hypertrophic cases was investigated, as was its association with patient clinical outcome at 24 months after surgery. Results: Of the 180 patients, 50 demonstrated a hypertrophic graft at 1 or more postoperative time points. This included 9 grafts (5.0{\%}) at 3 months and 32 grafts (18.7{\%}) at 12 months. At 24 months, 47 grafts (26.1{\%}) - 43 (32.1{\%}) tibiofemoral and 4 (8.7{\%}) patellofemoral - were hypertrophic. Patients with hypertrophic grafts at 24 months (n = 47) were younger (P =.051), they had a lower body mass index (BMI; P =.069), and significantly fewer of them had patellofemoral grafts (P =.007) compared with patients who had grafts with full (100{\%}) tissue infill (n = 61). There were no significant differences in any of the KOOS subscales between patients with graft hypertrophy or full (100{\%}) tissue infill at 24 months after surgery, while the severity of graft hypertrophy was not associated with KOOS subscales at 24 months. Conclusion: Hypertrophic grafts after MACI were common and continued to develop through to 24 months after surgery. Hypertrophic growth was associated with being younger and having a lower BMI, was more common on the femoral condyles, and overall was not associated with clinical outcome at 24 months after surgery. However, further research with longer term follow-up is required to evaluate the effect of persistent hypertrophy on graft stability and to assess the use of early surgical intervention to prevent such failure.",
    author = "Jay Ebert and A. Smith and M. Fallon and R. Butler and R. Nairn and W. Breidahl and David Wood",
    year = "2015",
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    Incidence, Degree, and Development of Graft Hypertrophy 24 Months after Matrix-Induced Autologous Chondrocyte Implantation: Association with Clinical Outcomes. / Ebert, Jay; Smith, A.; Fallon, M.; Butler, R.; Nairn, R.; Breidahl, W.; Wood, David.

    In: American Journal of Sports Medicine, Vol. 43, No. 9, 09.2015, p. 2208-2215.

    Research output: Contribution to journalArticle

    TY - JOUR

    T1 - Incidence, Degree, and Development of Graft Hypertrophy 24 Months after Matrix-Induced Autologous Chondrocyte Implantation: Association with Clinical Outcomes

    AU - Ebert, Jay

    AU - Smith, A.

    AU - Fallon, M.

    AU - Butler, R.

    AU - Nairn, R.

    AU - Breidahl, W.

    AU - Wood, David

    PY - 2015/9

    Y1 - 2015/9

    N2 - Background: Graft hypertrophy is a common occurrence after periosteal, collagen-covered and matrix-induced autologous chondrocyte implantation (MACI). Purpose/Hypothesis: The purpose of this study was to investigate the incidence, development, and degree of graft hypertrophy at 24 months after MACI. The hypothesis was that graft hypertrophy would not be associated with clinical outcome at 24 months. Study Design: Case series, Level of evidence, 4.Methods: This study was undertaken in 180 consecutive patients (113 male, 67 female) after MACI in the knee. All patients were assessed clinically using the Knee injury and Osteoarthritis Outcome Score (KOOS) and underwent magnetic resonance imaging (MRI) at 3, 12, and 24 months after surgery. The incidence of hypertrophy relevant to anatomic graft site was investigated, as was the progressive change in hypertrophic studies postoperatively. The degree of tissue overgrowth in hypertrophic cases was investigated, as was its association with patient clinical outcome at 24 months after surgery. Results: Of the 180 patients, 50 demonstrated a hypertrophic graft at 1 or more postoperative time points. This included 9 grafts (5.0%) at 3 months and 32 grafts (18.7%) at 12 months. At 24 months, 47 grafts (26.1%) - 43 (32.1%) tibiofemoral and 4 (8.7%) patellofemoral - were hypertrophic. Patients with hypertrophic grafts at 24 months (n = 47) were younger (P =.051), they had a lower body mass index (BMI; P =.069), and significantly fewer of them had patellofemoral grafts (P =.007) compared with patients who had grafts with full (100%) tissue infill (n = 61). There were no significant differences in any of the KOOS subscales between patients with graft hypertrophy or full (100%) tissue infill at 24 months after surgery, while the severity of graft hypertrophy was not associated with KOOS subscales at 24 months. Conclusion: Hypertrophic grafts after MACI were common and continued to develop through to 24 months after surgery. Hypertrophic growth was associated with being younger and having a lower BMI, was more common on the femoral condyles, and overall was not associated with clinical outcome at 24 months after surgery. However, further research with longer term follow-up is required to evaluate the effect of persistent hypertrophy on graft stability and to assess the use of early surgical intervention to prevent such failure.

    AB - Background: Graft hypertrophy is a common occurrence after periosteal, collagen-covered and matrix-induced autologous chondrocyte implantation (MACI). Purpose/Hypothesis: The purpose of this study was to investigate the incidence, development, and degree of graft hypertrophy at 24 months after MACI. The hypothesis was that graft hypertrophy would not be associated with clinical outcome at 24 months. Study Design: Case series, Level of evidence, 4.Methods: This study was undertaken in 180 consecutive patients (113 male, 67 female) after MACI in the knee. All patients were assessed clinically using the Knee injury and Osteoarthritis Outcome Score (KOOS) and underwent magnetic resonance imaging (MRI) at 3, 12, and 24 months after surgery. The incidence of hypertrophy relevant to anatomic graft site was investigated, as was the progressive change in hypertrophic studies postoperatively. The degree of tissue overgrowth in hypertrophic cases was investigated, as was its association with patient clinical outcome at 24 months after surgery. Results: Of the 180 patients, 50 demonstrated a hypertrophic graft at 1 or more postoperative time points. This included 9 grafts (5.0%) at 3 months and 32 grafts (18.7%) at 12 months. At 24 months, 47 grafts (26.1%) - 43 (32.1%) tibiofemoral and 4 (8.7%) patellofemoral - were hypertrophic. Patients with hypertrophic grafts at 24 months (n = 47) were younger (P =.051), they had a lower body mass index (BMI; P =.069), and significantly fewer of them had patellofemoral grafts (P =.007) compared with patients who had grafts with full (100%) tissue infill (n = 61). There were no significant differences in any of the KOOS subscales between patients with graft hypertrophy or full (100%) tissue infill at 24 months after surgery, while the severity of graft hypertrophy was not associated with KOOS subscales at 24 months. Conclusion: Hypertrophic grafts after MACI were common and continued to develop through to 24 months after surgery. Hypertrophic growth was associated with being younger and having a lower BMI, was more common on the femoral condyles, and overall was not associated with clinical outcome at 24 months after surgery. However, further research with longer term follow-up is required to evaluate the effect of persistent hypertrophy on graft stability and to assess the use of early surgical intervention to prevent such failure.

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    M3 - Article

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    JO - The American Journal of Sports Medicine

    JF - The American Journal of Sports Medicine

    SN - 0363-5465

    IS - 9

    ER -