Paper #68 - ISHA Annual Scientific Meeting 2016

Outcome of Hip Arthroplasty Following Failed Hip Arthroscopy - A Case-Control Study

Simon Parker, BSc, MBBS, MRCS, Reading, Berkshire UNITED KINGDOM
George Grammatopolous, BSc, MBBS, DPhil, Reading UNITED KINGDOM
Owain Lloyd Ioan Davies, MA, MBBChir, MRCS, Bangor UNITED KINGDOM
Thomas C.B. Pollard, MD, FRCS (Tr & Orth), Reading UNITED KINGDOM
Antonio (Tony) Andrade, MB BS, FRCS (Tr & Orth), Reading, Berkshire UNITED KINGDOM

Royal Berkshire Hospital, Reading, Berkshire, UNITED KINGDOM

FDA Status Not Applicable

Summary: This case-control matched study aimed to identify the effect of previous hip arthroscopy on the outcome of subsequent hip arthroplasty, and has demonstrated that equivalent outcomes can be achieved in both patient groups, with no demonstrable difference in range of movement measurements, functional outcome measures, complication rate, or 7-year implant survival rate.

Abstract:
Background
Hip arthroscopy is increasingly being used in joint preservation surgery with clear benefits in the treatment of pre-arthritic conditions and early arthritis. With increasing use and evolving indications, the number of patients requiring subsequent hip arthroplasty will inevitably also rise. Currently, however, little evidence exists as to the impact of hip arthroscopy on outcomes of a subsequent hip arthroplasty. The aim of this case-control matched study was to identify the effect of previous hip arthroscopy on the outcome of subsequent hip arthroplasty.

Patients & Methods
A retrospective review of a prospectively collected patient database identified 31 patients/hips, defined as cases, who have received a hip arthroplasty [19 Total Hip Arthroplasties (THAs) and 12 Hip Resurfacing Arthroplasties (HRAs)] following prior ipsilateral hip arthroscopy under the care of the senior author.
Outcome was compared with a group of controls, comprising of hip arthroplasties (n= 62) that had been performed by the senior author’s team on patients/hips that had had no previous hip arthroscopies, over the same time-period. Controls were matched for age (p=0.7), gender (p=0.3) and prosthesis-type (p=0.9).
Outcome measures studied included pre- and post-operative range of movement (flexion, extension, abduction, adduction, internal/external rotation), pre- and post-operative Harris Hip (HHS) and Oxford Hip (OHS) Scores, complication rates and implant survivorship. A physiotherapist in a dedicated clinic made all assessments.

Results
The mean age of the cases was 47.5 (SD: 9) years of age and most patients were female (70%). The mean length of follow-up was 5.5 (1 – 11) years. Flexion improved from 80° (SD:20) pre-operatively to 105° (SD: 15) post-operatively, similarly abduction (23° Vs 43°) and internal rotation (9° Vs 32°) improved significantly following arthroplasty. On average the HHS improved from 54 (SD:14) to 93 (SD: 15) and the OHS improved from 28 (SD: 8) to 40 (SD: 10). The complication rate was 16%, most commonly being adverse reaction to metal debris (ARMD) (n=8, 9%, all in resurfacing arthroplasties), followed by dislocation (n=2). To-date 9 revisions have taken place; 8 for ARMD and 1 for leg-length discrepancy. The 7-yr implant survival is 78% for HRA and 98% for THA.

There was no difference in the pre- or post-operative range of movement along any axis between the two groups (p=0.1 – 0.6). Similarly, there was no difference in pre- or post- operative functional outcome measures (HHS, or OHS) between the groups. There were no differences in the complication rate (p=0.7), or the 7-year implant-survival rates between the groups (p=0.3).

Conclusion
This study demonstrates that equivalent outcomes can be achieved for hip arthroplasty in patients with failed hip arthroscopy. There was no demonstrable difference in range of movement measurements, despite the ‘cases’ having had a previous procedure and scarred soft-tissue envelope.