Introduction

The Corail stem is a fully HA coated tapered implant that has demonstrated long-term success. On the NJR it has become one of the most commonly used implants in the UK. The aim of our study was to document our experience of the revision of this implant together highlighting some important technical considerations.

Summary

162 patient cohort with serial Metal Artefact Reduction Sequence MRI scans. Patients with normal initial scans can be followed up at 1 year. Those with abnormal scans should be followed up at a shorter interval of 6 months.

Aim

To determine the outcome, the need for revision surgery, quality of life (QOL) of patients and the financial implications of instability following successful closed reduction of dislocation after primary total hip arthroplasty (THA).

Aim: To determine the outcome and need for subsequent surgery in patients following successful closed reduction of dislocation after primary total hip arthroplasty (THA) and the financial implications of re-operation.

Methods: Data was retrospectively obtained from radiographs and patient case notes for all dislocated primary hip replacements presenting to the University Hospital of Wales from January 2000 till November 2005. Records were analysed with a minimum of 1 year follow-up to determine the outcome and need for subsequent surgery following successful closed reduction of dislocation after primary THA. Factors studied include age at primary surgery, indications, components, approach, head size, duration since surgery and direction of dislocation

Results: Over the 6 year study period, 98 patients presented with 100 first time dislocated primary total hip replacements. All the dislocations underwent successful closed reduction. 62 (62%) hips re-dislocated more that once. At minimum follow up of 1 year, 7 patients had died and were excluded from the final study group. Of the remaining 93 hips, 46 patients have had no further surgery. 44 THA’s have undergone revision procedures and 3 are waiting to have revision surgery (51% in total). Of those who have undergone revision surgery, 7 hips re-dislocated since and 3 of those needed further re-revision.

Discussion: Dislocation following primary THA remains a problem with varying dislocation rates quoted in the literature. In our series, 51% of patients presenting with dislocation required revision surgery. All patients in this series had 28 mm or smaller femoral heads. The financial impact of the burden of revision surgery continues to increase. In this series in isolation the cost of revision surgery totalled greater that £500,000.

Aim: To investigate the outcome following revision total hip arthroplasty (THA) using 36 mm and 40 mm modular femoral heads.

Methods: Details were retrieved from our arthroplasty database regarding all revision THAs done in our unit using 36 mm and 40 mm femoral heads. Follow-up information was obtained from patient records and telephone conversation.

Results: The cohort considered totalled 107 revision THAs, 93 using a 36 mm head and 14 using a 40 mm head. All received either highly cross-linked UHMWPE liners or metal on metal liners. The indications for revisions were recurrent instability in eight, periprosthetic fracture in 11, second stage revision in 24, fracture of the femoral stem in one and aseptic loosening in the remaining 63. At a minimum follow up of one year, information was not available for five but they did not have any record of dislocation. Out of the remaining 102 patients, dislocation occurred in 4 hips (3.9%). None of the revisions done with 40 mm head dislocated. In two of the dislocations, the initial indication for revision THA was recurrent instability and if they are excluded, the dislocation rate was 1.96%.

Discussion: Dislocation and the sequalae of recurrent instability remains a significant problem following revision THA and the existing literature varies greatly in the quoted dislocation rates. We believe that the use of 36 mm and 40 mm femoral heads in our unit has been a major factor in low (3.6%) dislocation rate following revision THA. To date there have been no problems encountered resulting from the use of highly cross-linked UHMWPE.

Introduction: We report our experience with the ZMR Hip System (Zimmer Inc.). The system accommodates a number of femoral fixation philosophies including spline, porous and taper stem options. The tapered stem is designed to achieve a distal wedge fit and also allow bone on-growth via the corundumized titanium alloy surface. The modular mid-stem junction allows a selection of body designs to be selected providing significant intra-operative flexibility and version adjustment.

Method: This study considers 64 cases performed in 63 patients with a mean age at the time of surgery of 70 years (range 55–89) utilising the taper stem design. The indication for revision surgery was aseptic loosening in 33 patients (Paprosky types II – 12, IIIA-10, IIIB-11) 22 peri-prosthetic fractures (Vancouver types B2-15, B3-7), 8 for infection and 4 patients with instability.

Results: The cohort had a minimum three-year follow-up with a mean of 50 months (range 36–72) and clinical assessment included Oxford score and thigh pain assessment. Engh’s criteria was utilised in the radiological evaluation when considering femoral component fixation. Femoral stem subsidence and femoral bone stock were also appraised on serial follow-up radiographs.

Discussion: The survival rate at follow-up with stem revision being the end point was 100%. When re-operation for any reason and radiological loosing are considered as the end point the survival rate was 95%.

Conclusion: We conclude excellent medium term results with the use of a cementless modular taper stem in challenging femoral revision surgery.