Article
Improved method of 2D preoperative templating of total hip arthroplasty for developmental dysplastic hip
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Authors
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Tetiana Zub
- Dnipropetrovsk medical academy, Dnipro, Ukraine
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Serhii Panchenko
- PSACEA, Dnipro, Ukraine
| Published: | October 26, 2021 |
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Outline
Text
Objectives: Total hip arthroplasty (THA) is the only alternative for treatment of neglected cases of developmental dysplastic hip (DDH). Changes in bone and soft tissue anatomy require for preoperative preparing, e.g. precise preoperative templating of artificial join implantation.
The purpose of the work was to estimate the efficacy of 2D preoperative templating in patients with DDH using two template lists by matching of planned and set components.
Methods: 83 cementless THAs in 66 patients with DDH were performed with 2D preoperative templating. Anteroposterior and lateral X-Rays of hips were used and 2 template lists were used: the 1st one without setting of artificial joint and the 2nd one with imitation of setting. Position of acetabular cup planned with recovery of true rotation center. Cut of femoral neck planned 10 mm over little trochanter if it was possibly and femoral stem was fitted to femoral canal. The length of femoral head was determined by evalution of leg length discrepancy on template list.
Four degrees of components' alignment were picked out: complete match (by type, by size), match by type with difference in 1 size, match by type with difference in 2 sizes, complete mismatch (different types or more then 3 sizes in difference).
Results and Conclusion: Complete match for 3 components was found in 26.5% of cases.
Acetabular cups. Complete mismatch was found in 4.8% of cases, match by type with difference in 1 size - in 18.1% and in difference in 2 sizes - in 4.8%, complete match - in 74.1% of cases.
Femoral stems. Tapered stems with square cross-section with standard and narrow proximal part with standard and valgus neck-shaft angle and conical cementless femoral stems were used. Complete mismatch was found in 8.4% of cases, match by type with difference in 1 size - in 18.1% and in difference in 2 sizes - in 2.4%, complete match - in 71.1% of cases.
Modular heads. Very long, long, neutral and short heads were used. Complete mismatch (difference in 3 sizes) was found in 2.4% of cases, match by type with difference in 1 size - in 8.4% and in difference in 2 sizes - in 42.2%, complete match - in 47.0% of cases.
The reason for mismatch of acetabular component was excessive subchondral sclerosis which made surgeons to use threaded cups instead of press-fit cups. Incorrect X-Rays because of hip joint stiffness might lead to underestimation of proximal femur deformation. The level of femoral neck cut could make influence both on type and size of femoral stem and modular head. Soft tissues stiffness was the reason for setting of shorter modular heads than planned ones.
DDH is a difficult condition for preoperative planning and surgery but using of 2 template list for 2D templating had given results resemble to ones when researchers used 3D templating for such a diagnosis.
