THA FOR DEVELOPMENTAL HIP DYSPLASIA,Daniel J. Berry, MD Mayo Clinic Rochester, MN, USA,THA FOR DYSPLASIA Problem to Overcome on Acetabulum,Problem: Lateral acetabular bone deficiency of varying severity,THA FOR DYSPLASIA/LOW DDH,ACETABULAR RECONSTRUCTION,THA FOR DYSPLASIA/LOW DDH Acetabular Reconstruction,General Principles: Uncemented socket Optimize cup stability on host bone Dont let bone deficiency dictate cup position,THA FOR DYSPLASIA/LOW DDH Acetabular Reconstruction,Key Point: Use supplemental screws Avoid pressfit fixation alone without screws in deficient acetabulum,THA FOR DYSPLASIA/LOW DDH Acetabular Reconstruction,Technique of arthroplasty is determined by severity of antero-lateral acetabular bone loss,THA FOR DYSPLASIA/LOW DDH Acetabular Reconstruction,Mild Lateral Deficiency: Routine acetabular reconstruction (uncemented) Slight medialization of cup if necessary Accept slight lateral uncoverage,THA FOR DYSPLASIA/LOW DDH Acetabular Reconstruction,Moderate Lateral Deficiency: Medialize hip center to medial wall Accept some lateral uncoverage (1.5 cm of cup) Accept slight elevation of hip center,Marked Lateral Deficiency: Options: Medialize through medial wall High hip center Lateral bulk autogenous femoral head graft,THA FOR DYSPLASIA/LOW DDH Acetabular Reconstruction,MANAGEMENT OF THE DYSPLASTIC HIP Acetabular Reconstruction,My preference: Medialize to (but not through) medial wall Accept slight elevation of hip center Lateral fem head graft if needed High hip center only in rare cases,10 yrs, bone restored,FEMORAL HEAD AUTOGRAFTS Slight Extra work, Extra Risk They do bank bone for future,THA IN DEVELOPMENTAL DYSPLASIA Acetabular Reconstruction,High Dislocation False Acetabulum Not thick or wide enough for cup fixation True Acetabulum Thicker bone Posterior column: best bone,THA IN DEVELOPMENTAL DYSPLASIA,Acetabulum: Reconstruct at anatomic center Small cup, 22 m head No graft (usually) Technical tips: - open socket with burr - ream in reverse,THA FOR DYSPLASIA/LOW DDH Conclusions,Acetabular reconstruction in hip dysplasia: Uncemented cup Supplemental screws Judicious medialization Structural graft only when necessary,THA FOR DEVELOPMENTAL HIP DYSPLASIA: THE FEMORAL SIDE,Daniel J. Berry, MD Mayo Clinic Rochester MN,THA FOR DYSPLASIA Problems to Overcome on Femoral Side,Problems to overcome: Femoral anatomy: Abnormal neck shaft angle and anteversion Leg length: Variable discrepancy,THA FOR DYSPLASIA Problems to Overcome,Femoral Deformity: The amount of femoral deformity does not always correlate with level of acetabular dysplasia,THA FOR DYSPLASIA Femoral Reconstruction,Femoral Reconstruction options: Cemented DDH stem Uncemented stem-monoblock prox coated-monoblock ext coated-modular stem,THA FOR DYSPLASIA Femoral Reconstruction,Cemented Femur: DDH stems, cement help manage abnormal proximal anatomy But.cemented fixation less desirable in mostly young patients,Uncemented Preferred In Most young patients,Prox coated,Fully coated,Modular,THA FOR DYSPLASIA Femoral Reconstruction,Monoblock Proximally Coated Stem: Good only if mild deformity Not good (poor fit, anteversion problems, fracture) if more deformity,THA FOR DYSPLASIA Femoral Reconstruction,THA FOR DYSPLASIA Femoral Reconstruction,Fully Coated Uncemented Stems: Allow more adjustment for anteversion Special stems accommodate valgus neck ? Extensively coated less desirable in young patients,THA FOR DYSPLASIA Femoral Reconstruction,THA FOR DYSPLASIA Femoral Reconstruction,Modular Uncemented Stems: Proximally coated Allow version adjustment Require surgeon familiarity,THA FOR DYSPLASIA Femoral Reconstruction,THA FOR HIGH DISLOCATION,Acetabular reconstruction at anatomic center with small cup Need to shorten femur to reduce hip, minimize sciatic nerve stretch,THA FOR HIGH DISLOCATION,Traditional method: Trochanteric Osteotomy, Proximal Shortening, cemented stem Disadvantages: trochanteric healing problems proximal femur becomes a straight tube,THA FOR DYSPLASIA High Dislocation,Newer method: Subtrochanteric Shortening Osteotomy Elegant Maintains proximal femoral anatomy Allows uncemented femur Avoids trochanteric problems,THA FOR DYSPLASIA High Dislocation,Subtroch shortening osteotomy: Post approach Osteotomize femur, translate anteriorly Place cup Shorten femur Place uncemented stem Stem with beads or flutes: fixes osteotomy,THA FOR HIP DYSPLASIA Sciatic Nerve,Lengthening: how much is safe? No definite guidelines but beware when over 2 cm Flex knee post op to relax nerve,THA FOR DYSPLASIA Conclusions,Great operation: dramatic restoration of pain and improved function for most patients New methods and implants: better function and better durability,