The purpose of this study was to perform morphological and molecular analyses of articular cartilage from a 14-year-old boy with unusual cartilage lesions, patella alta and trochlea dysplasia in both knee joints and c...The purpose of this study was to perform morphological and molecular analyses of articular cartilage from a 14-year-old boy with unusual cartilage lesions, patella alta and trochlea dysplasia in both knee joints and clinically examine two family members (sister, mother), also affected in their knee joints. Biopsies from the boy’s patella were used for: histological examination, Transmission Electron Microscopy (TEM) and DNA sequencing of the COL2A1 gene including Multiplex Ligation-dependent Probe Amplification (MLPA), for detection of DNA deletions and duplications. Clinical and radiological examination showed patella alta and trochlea dysplasia for the brother (type D), sister (type A) and mother (type A) with Insall-Salvati ratios of 1.50, 1.46 and 1.3. Light Microscopy (LM) of biopsies from the patient showed rhomboid chondrocytes in lacuna with deposition of protein aggregates in the ECM. TEM revealed abnormal type II collagen fibrils in aggregates and chondrocytes with abnormal matrix accumulation in rough Endoplasmic Reticulum (rER). Immunostaining showed that type II collagen was deposited intracellularly and in protein aggregates, together with type I collagen, indicating alterations in chondrocyte function and turnover of these molecules. DNA sequencing of 54 exons including extended DNA analysis with MLPA was non-conclusive. Conclusions: We suggest that patella alta and trochlea dysplasia for this patient is associated with collagen accumulation in chondrocytes, abnormal type II collagen heterofibrils in the ECM, cell death and cartilage with subnormal strength and increased risk of premature patellofemoral arthritis. A family with these disorders suggests that phenotype might be transmitted as an autosomal dominant trait.展开更多
Patellofemoral instability(PI)is the disruption of the patella’s relationship with the trochlear groove as a result of abnormal movement of the patella.To identify the presence of PI,conventional radiographs(anteropo...Patellofemoral instability(PI)is the disruption of the patella’s relationship with the trochlear groove as a result of abnormal movement of the patella.To identify the presence of PI,conventional radiographs(anteroposterior,lateral,and axial or skyline views),magnetic resonance imaging,and computed tomography are used.In this study,we examined four main instability factors:Trochlear dysplasia,patella alta,tibial tuberosity–trochlear groove distance,and patellar tilt.We also briefly review some of the other assessment methods used in the quantitative and qualitative assessment of the patellofemoral joint,such as patellar size and shape,lateral trochlear inclination,trochlear depth,trochlear angle,and sulcus angle,in cases of PI.In addition,we reviewed the evaluation of coronal alignment,femoral anteversion,and tibial torsion.Possible causes of error that can be made when evaluating these factors are examined.PI is a multi-factorial problem.Many problems affecting bone structure and muscles morphologically and functionally can cause this condition.It is necessary to understand normal anatomy and biomechanics to make more accurate radiological measurements and to identify causes.Knowing the possible causes of measurement errors that may occur during radiological measurements and avoiding these pitfalls can provide a more reliable road map for treatment.This determines whether the disease will be treated medically and with rehabilitation or surgery without causing further complications.展开更多
基金financially supported by Interface Biotech A/S,Horsholm,Denmark.
文摘The purpose of this study was to perform morphological and molecular analyses of articular cartilage from a 14-year-old boy with unusual cartilage lesions, patella alta and trochlea dysplasia in both knee joints and clinically examine two family members (sister, mother), also affected in their knee joints. Biopsies from the boy’s patella were used for: histological examination, Transmission Electron Microscopy (TEM) and DNA sequencing of the COL2A1 gene including Multiplex Ligation-dependent Probe Amplification (MLPA), for detection of DNA deletions and duplications. Clinical and radiological examination showed patella alta and trochlea dysplasia for the brother (type D), sister (type A) and mother (type A) with Insall-Salvati ratios of 1.50, 1.46 and 1.3. Light Microscopy (LM) of biopsies from the patient showed rhomboid chondrocytes in lacuna with deposition of protein aggregates in the ECM. TEM revealed abnormal type II collagen fibrils in aggregates and chondrocytes with abnormal matrix accumulation in rough Endoplasmic Reticulum (rER). Immunostaining showed that type II collagen was deposited intracellularly and in protein aggregates, together with type I collagen, indicating alterations in chondrocyte function and turnover of these molecules. DNA sequencing of 54 exons including extended DNA analysis with MLPA was non-conclusive. Conclusions: We suggest that patella alta and trochlea dysplasia for this patient is associated with collagen accumulation in chondrocytes, abnormal type II collagen heterofibrils in the ECM, cell death and cartilage with subnormal strength and increased risk of premature patellofemoral arthritis. A family with these disorders suggests that phenotype might be transmitted as an autosomal dominant trait.
文摘Patellofemoral instability(PI)is the disruption of the patella’s relationship with the trochlear groove as a result of abnormal movement of the patella.To identify the presence of PI,conventional radiographs(anteroposterior,lateral,and axial or skyline views),magnetic resonance imaging,and computed tomography are used.In this study,we examined four main instability factors:Trochlear dysplasia,patella alta,tibial tuberosity–trochlear groove distance,and patellar tilt.We also briefly review some of the other assessment methods used in the quantitative and qualitative assessment of the patellofemoral joint,such as patellar size and shape,lateral trochlear inclination,trochlear depth,trochlear angle,and sulcus angle,in cases of PI.In addition,we reviewed the evaluation of coronal alignment,femoral anteversion,and tibial torsion.Possible causes of error that can be made when evaluating these factors are examined.PI is a multi-factorial problem.Many problems affecting bone structure and muscles morphologically and functionally can cause this condition.It is necessary to understand normal anatomy and biomechanics to make more accurate radiological measurements and to identify causes.Knowing the possible causes of measurement errors that may occur during radiological measurements and avoiding these pitfalls can provide a more reliable road map for treatment.This determines whether the disease will be treated medically and with rehabilitation or surgery without causing further complications.
