Combined Anteversion Technique in Total Hip Arthroplasty for Crowe IV Developmental Dysplasia of the Hip

Cheng

Feng

et al. 2020

Section: Methodsmentioning

confidence: 99%

Crowe Type IV Hip Dysplasia Treated by THA Comebined with Osteotomy to Balance Functional Leg Length Discrepancy: A Prospective Observational Study

Cheng

Feng

et al. 2020

“…Because type IV dysplasia hips have substantial anteversion of the acetabulum and femur, combined anteversion of the limb under 55° (20°–25° and 15°–20° for the cup and stem, respectively) is used to avoid postoperative dislocation. Following this principle, in a series of 16 type IV dysplasia hip cases, Zhu and colleagues set the cup anteversion according to the native acetabular anteversion to enable preferable cup coverage. Following subtrochanteric osteotomy, they rotated the proximal femur backward to maintain appropriate combined anteversion.…”

Section: Direct Anterior Approach Total Hip Arthroplastymentioning

confidence: 99%

“…After THA, the mean femur, acetabular, and combined anterversion extents were 17.9° ± 2.9°, 31.2° ± 2.5°, and 49.2° ± 2.6°. No dislocations occurred during 12 months of follow up. The main complications that occur following application of an anatomic hip center technique are summarized in Table .…”

Section: Direct Anterior Approach Total Hip Arthroplastymentioning

confidence: 99%

Total Hip Arthroplasty for Crowe Type IV Hip Dysplasia: Surgical Techniques and Postoperative Complications

Han

et al. 2019

Total hip arthroplasty (THA) of Crowe type IV developmental dysplasia of the hip (DDH) is challenging. Although traditional (lateral, posterolateral, and posterior) THA approaches have been used with great anatomic success, they damage periarticular muscles, which are already quite weak in type IV DDH. The recently developed direct anterior approach (DAA) can provide an inter‐nerve and inter‐muscle approach for THA of type IV dysplasia hips. However, femur exposure with the DAA could be difficult during surgery and it is hard to apply femoral shortening osteotomy. THA techniques used for type IV DDH include anatomic hip center techniques (true acetabular reconstruction) and high hip center techniques, wherein an acetabulum is reconstructed above the original one. Although anatomic construction of the hip center is considered “the gold standard” treatment, it is impossible if the anatomical acetabular is too small and shallow. Procedures used to support type IV DDH reduction with anatomic hip center techniques include greater trochanter osteotomy, lesser trochanter osteotomy, and subtrochanteric osteotomy. However, these techniques have yet to be standardized, and it is unclear which is best for type IV DDH. One‐state and two‐state non‐osteotomy reduction techniques have also been introduced to treat type IV DDH. Potential complications of THA performed in patients with type IV DDH include leg length discrepancy (LLD), peri‐operative femur fracture, nonunion of the osteotomy site, and nerve injury. It is worth noting that nowadays an increasing number of Crowe type IV DDH patients are more sensitive to postoperative LLD.

“…A larger combined anteversion will increase the rate of postoperative dislocation. An appropriate method to deal with overdeveloped acetabular anteversion in DDH is to control the combined anteversion under 55°. Even with highly deformed acetabula of Crowe IV, it is also a useful method to prevent postoperative dislocation.…”

Section: Confirmation Of Acetabular Positionmentioning

confidence: 99%

“…The preoperative acetabular anteversion can be measured in CT scans (Fig. ). The angle between the transverse axis of the knee joint and the transverse axis of the femoral neck in CT forms the femoral anteversion (Fig.…”

Section: Confirmation Of Acetabular Positionmentioning

confidence: 99%

Preoperative Planning for Total Hip Arthroplasty for Neglected Developmental Dysplasia of the Hip

Cheng

et al. 2019

Developmental dysplasia of the hip (DDH) is accompanied by morphological alterations on both the acetabular and the femoral side. Total hip arthroplasty (THA) provides effective treatment in cases of neglected DDH but requires elaborate preoperative planning. To determine the morphological changes resulting from the dysplasia, the anatomic acetabular position, the height of the femur head dislocation, the height of the femur head dislocation, and the combined anteversion must all be established. In addition, a vital and complicated process of strategizing leg length balance must be conducted in cases of severe DDH. Each type of leg length discrepancy (LLD), including bony and functional and anatomical LLD, should be evaluated in the context of the presence or absence of a fixed pelvic tilt. Moreover, with severe unilateral dislocated hips, a more inferior change in the original rotational center of the hip must be accounted for. Due to these multiple morphological changes, the accurate size of the prosthesis and the cup position are difficult to predict. In comparison with other methods, CT scan‐based 3‐dimensional templating provides the best accuracy. Despite the presence of anatomic alterations, various types of acetabular and femoral prostheses have been developed to treat hip dysplasia. Both cemented and cementless cups are used in DDH cases. In DDH accompanied by insufficient acetabular bone stock, a cemented cup combined with bone graft provides a reliable treatment. Monoblock stems can be used when the combined anteversion is less than 55°, and a modular stem system when this parameter is greater than 55°. Customized stems can be designed for DDH coupled with severe proximal femoral distortion. A ceramic‐on‐ceramic bearing is considered optimal for young DDH patients.