1. Dr.A.K.Venkatachalam MS Orth, DNB Orth, FRCS, M.Ch Orth Consultant Orthopedic surgeon Associate professor Chennai THR in mal-united acetabular fractures- role for short stem prostheses

2. THR in malunited acetabular fractures Introduction Acetabular fractures occur in young patients THR requires acetabular reconstruction, bone grafting and reconstruction Limb length discrepancy needs to be addressed-due to proximal femoral migration, protrusio, proximal femoral bone loss Possible to correct LLD on acetabular side with protrusio alone by auto graft, allograft, synthetic bone substitutes, metal Hence opportunity to preserve bone on femoral side Hence role for short stem femoral prostheses instead of THR.

3. THR in mal-united acetabular fractures Materials and methods Case1-25 year male, longstanding mal-united acetabular fracture with protrusio grade 3. Femoral side normal. Acetabular reconstruction with peripheral cup capture, bone grafting with morsellized femoral head autograft. Cup lateralized to anatomical center Short stem femoral prosthesis with ceramic on metal bearings Residual LLD- 1.5cm.

4. Malunited acetabular fractures Case 2- 42 year old male, transverse fracture acetabulum with ORIF. Acetabular reconstruction w/o bone grafting, short stem femoral and uncemented cup. Ceramic on metal bearings. No post op LLD. LLD

5. Mal-united acetabular fractures Case 3-47 year old female, transverse fracture acetabulum with absorption of femoral head, proximal & central migration with protrusio acetabuli THR –Acetabular reconstruction with peripheral cup placement, bone grafting. Femoral reconstruction with THR as head was partially resorbed. Metal on poly bearings No LLD post op

6. Mal-united acetabular fractures Case 4- 30 year old male, posterior wall & roof fracture, proximal femoral head migration. Pre op LLD of three inches THR with posterior wall & roof acetabular reconstruction with femoral head cortico-cancellous slice, Recon plate on acetabular side, conventional uncemented femur. Ceramic on ceramic bearings. No post op LLD. Post op sciatic N. palsy

7. Malunited acetabular fractures General pre op, op and post op issues with Hip replacement Discussion Myositis ossificans post op. Sciatic nerve palsy. Keep knee flexed during surgery. Limb length discrepancy. ? Retention / removal of previous metal ware. Hindrance during acetabular preparation from previous metal ware. May need screw cutting rather than removal. Bone graft required- femoral autograft, cryo allograft, Synthetic bone substitutes- Hydroxy apatite, Calcium sulphate Metal restrictors- trabecular metal, Augments, cages. Cement not preferred as most patients are young. Acetabular reconstruction with Jumbo cups, cages, augments, restrictors, recon plate, bone graft.

8. Hip replacement in neglected Acetabular fractures-Discussion THR has been standard procedure. Uncemented THR preferred as most patients are young. When gross LLD is present, due to combination of acetabular and femoral fractures, total hip replacement is procedure of choice If LLD is mainly due to acetabular protrusio and femoral anatomy is preserved, possible to do a short stem hip replacement. Hard on hard bearings preferred as most patients are young. Hard on cross linked poly in middle aged.

9. Malunited acetabular fractures Acetabular side issues Previous metal work- can be left alone if Myositis present, Other wise can be removed Pre op swabs for possible wound infection from previous metal ware Acetabular defects analysed by Paproski classification. Peripheral cup placement in protrusio. Cup should be lateralized. Jumbo cup used. Central bone grafting Peripheral bone grafting in posterior wall and roof fractures. Roof and wall reinforcement with metal & bone prior to hip replacement. Possible to use TM augments, but since most patients are young, bone graft preferred. Cup requires screw fixation rather than Mono block cups. Standard or multi hole shells depending on bone loss.

10. Malunited acetabular fractures Femoral side issues LLD may be present from long standing proximal and central migration of proximal femur Proximal femoral bone loss from AVN, Femoral head & neck bone deficiency due to fracture. Neck anatomy may be altered precluding short stem prostheses.

11. Malunited acetabular fractures Role & advantages of short stem femoral prostheses Conclusion Short stem prosthesis are possible when proximal femoral anatomy is preserved, minimal LLD( <2) Advantage is femoral bone preservation in carefully selected cases. Limb length < 1inch can be addressed with variable neck lengths in non modular and modular femoral prosthesis. Versatility of bearing combinations like ceramics, metal, poly. Femoral side conversion to primary THR in future eliminating or reducing need for a revision femoral implant. Increased cost of short stem prosthesis is a factor.