CONVERSION FROM FUSED TO TOTAL HIP ARTHROPLASTY BY PROF J.A.O MULIMBA

Problems of fused hip Social Sitting in transport vehicles Other activities of daily living Mobility Limited and awkward High incidence of low back pain Effect on Ipsilateral knee Effect on contralateral hip

What are the reasons of conversion Activity of daily living(ADL) Painful Pseudoarthrosis Back pain Ipsilateral knee pain Contralateral hip pain Whitehouse MR, Duncan CP. JBJs(Br) Nov 2013 Sept. 95-B: 11suppl,114-119

Things to check before surgery Leg length discrepancy Opposite hip Ipsilateral knee Patient expectations – Don’t promise heaven Note It has been reported in some series that post operative complications are many: Failure rate Increased dislocation Pain

Noted Complications in other series Nerve palsies – quite a large number. Heterotopic calcification. Reduced motion. Some required revision arthroplasty. Recurrence of pain in a few. Mean age 51 years. Sah AP, Estolk DM. Dislocation Rate After conversion JBJs (AM), 2008,90(3) 506-17

In this communication No of patients – 6 Gender -5 female, 1 male Age; 47 years 43 years 34 years 36 years 29 years 30 years Average age 36.5 years Reason for fusion - Infection 3 - Trauma 2 -Unknown 1

Reasons for wanting conversion ADL 5 Awkward gait 6 Pain opposite hip 1 LBP 2 Restoration of leg length 4 Note Most patients had more than one reason

Methodology All patients done under GA Patient in lateral position Used standard lateral approach Cut always very close to the pelvic end of neck Acetabulum created Femoral reaming with neck conservation Limited female acetabulum to 48 mm Fixed the acetabulum shell with 1 or 3 screws

Methodology cont; Used insert of 28mm inside diameter Femoral canal reamed to level easily achieved by standard reamer Femoral component equivalent to largest reamer used Used neck length closest to the correction of LLD Trial reduction was always made but failed The wound was closed ST pin was put at tibial tuberosity

Methodology Cont; Patient taken back to the ward Heavy traction applied for one week After one week patient taken back to the theatre Under general anaesthesia closed reduction tried – failed Wound opened , reduction easily achieved All reductions were stable Wound closed

Methodology cont; Following day check X-ray done Patient mobilized by physiotherapist All patients discharged within 1 week of second operation

Post Op Two patients had sciatic nerve palsy 1 male 1 female – recovered after almost a year Pts were slower in getting going Limping took much longer to disappear Two patients did not get leg length restored Not a single dislocation occurred *Shortest follow up so far – 2 years Only disappointment is failed LLD

Referrences: 1) Joshi AB, Markovic Ljubisa, Hardinge K, Murphy JCM. Conversion of fused hip to total hip arthroplasty, J.Bone J Surg AM; 2002: 84(8): 1335 – 1341. 2) Ciitings DJ, Courtney PM, Ashley, BS,et al Diagnosing infection in patients undergoing conversion of prior internal fixation to total hip arthroplasty. J.Arthr. 2017; 32: 241 – 245. 3) Newman JM,Webb MR, Klika AK, et al Quantifying Blood loss and Transfusion Risk After Primary Vs Conversion Total Hip Arthroplasty. J.Arthro. 2017; 32 (6): 1902 – 1909.

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