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A new measurement method in Graf technique: prediction of future acetabular development is possible in
Osman Y Yavuz1, Ismail Uras, Bulent A Tasbas
1*Fatih University Faculty of Medicine, Ankara, Turkey †Prishtine American Hospital, Pristine, Kosovo ‡Emsey Hospital, Istanbul §Koru Hospital, Ankara, Turkey.
Insights
A new ultrasound measurement, the gamma-angle, can predict hip development in infants. This tool helps avoid unnecessary follow-up and overtreatment for infants with immature hips (type IIa).
Area of Science:
- Pediatric Orthopedics
- Diagnostic Imaging
- Developmental Biology
Background:
- Universal ultrasound screening for hip dysplasia leads to overtreatment due to physiologically immature hips (type IIa).
- Predicting future acetabular development in type IIa hips is crucial to reduce unnecessary follow-up and interventions.
Purpose of the Study:
- To introduce and validate the gamma-angle as a novel ultrasound measurement for predicting acetabular development.
- To differentiate between type IIa hips that will normalize and those that will progress to dysplasia.
Main Methods:
- Described the gamma-angle measurement, assessing femoral head coverage by the acetabular roof.
- Retrospectively analyzed ultrasonographic findings of infants with developmental dysplasia of the hip and normal hips.
- Compared gamma-angle values in type IIa hips that normalized (Group 2) versus those that became dysplastic (Group 1).
Main Results:
- Type IIa hips that normalized (type I) had gamma-angles between 77 and 82 degrees.
- Type IIa hips that developed dysplasia had gamma-angles between 72 and 78 degrees.
- Gamma-angles >78 degrees predicted normalization, while <77 degrees predicted dysplasia.
Conclusions:
- The gamma-angle effectively assesses cartilage coverage of the femoral head, predicting future acetabular development.
- This new measurement can significantly decrease unnecessary follow-up and treatment for infants with immature hips.
- The gamma-angle offers a valuable tool for optimizing hip dysplasia screening protocols.
Background:
Universal ultrasound screening has led to overtreatment and higher follow-up rates than are found with clinical examination alone because of high incidence of physiologically immature hips (type IIa) in the first weeks of life. The ability to predict future acetabular development in physiologically immature hips (type IIa) would therefore help to reduce overtreatment and unnecessary follow-up.
Methods:
We described the γ-angle to assess the femoral head coverage by the acetabular roof, which is measured between the baseline defined by Graf and the cartilaginous edge line connecting the inferior point of the iliac bone (lower limb) to the medial corner of the acetabular labrum. We retrospectively analyzed ultrasonographic findings of infants with developmental dysplasia of the hip diagnosed in our hospital and infants with normal hips screened in our hospital. Group 1 (35 hips) consists of type IIa hips at initial examination and went on to develop into dysplastic hips at follow-up. Group 2 (279 hips) consists of type IIa hips at initial examination and went on to develop into normal hips (type I) at follow-up.
Results:
The γ-angles of type IIa hips that developed into type I hip at follow-up ranged between 77 and 82. The γ-angles of type IIa hips that developed into hip dysplasia ranged between 72 and 78. All type IIa hips that had γ-angles >78 degrees developed into normal hips. We also observed that all type IIa hips that had γ-angles <77 degrees developed into dysplasia.
Conclusions:
The amount of cartilage mass covering the femoral head, which is a part of the acetabular roof, can therefore provide information about future acetabular development. This paper describes a new method of measurement (the γ-angle) that assesses the extent of the cartilage coverage of the femoral head, which can predict acetabular development. Its use would decrease the rates of unnecessary follow-up and treatment.
Level Of Evidence:
Level II (development of diagnostic criteria on the basis of consecutive patients).
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