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Orthopaedic Proceedings
Vol. 101-B, Issue SUPP_4 | Pages 123 - 123
1 Apr 2019
Karia M Vishnu-Mohan S Boughton O Auvinet E Wozencroft R Clarke S Halewood C Cobb J
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Aims

Accurate and precise acetabular reaming is a requirement for the press-fit stability of cementless acetabular hip replacement components. The accuracy of reaming depends on the reamer, the reaming technique and the bone quality. Conventional reamers wear with use resulting in inaccurate reaming diameters, whilst the theoretical beneficial effect of ‘whirlwind’ reaming over straight reaming has not previously been documented. Our aim was to compare the accuracy and precision of single use additively-manufactured reamers with new conventional reamers and to compare the effect of different acetabular reaming techniques.

Materials and Methods

Forty composite bone models, half high-density and half low-density, were reamed with a new 61 mm conventional acetabular reamer using either straight or ‘whirlwind’ reaming techniques. This was repeated with a 61 mm single use additively-manufactured reamer. Reamed cavities were scanned using a 3D laser scanner with mean diameters of reamed cavities compared using the Mann-Whitney U test to determine any statistically significant differences between groups (p<0.05) [Fig. 1).


Orthopaedic Proceedings
Vol. 91-B, Issue SUPP_III | Pages 402 - 402
1 Sep 2009
Mohan S Box U Hodgkinson J
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Introduction: The purpose of this study was to review the results of revision total hip replacement, using cement, done by a single surgeon in a tertiary referral centre. 164 patients underwent revision hip surgery for aseptic loosening, infection or recurrent dislocation.

Methods: 95 patients had a one stage revision, 25 patients had two stage revisions and the remainder had either the stem or socket revised. 10 patients had application of a PLAD for recurrent dislocation. Structural and morselized bone grafting was carried out in patients with extensive bone loss. 46 patients had morselized impaction bone grafting to the acetabulum. The first hundred patients with revision of both components and minimum follow up of twelve months were reviewed. Patients were routinely followed up in the clinic and assessed using the Oxford Hip Score and Merle D’Abigne scores for pain, function and range of movements. Radiographs were assessed for any demarcation or loosening.

Results: The mean age at surgery was 69.99 years (36ys to 95yrs). The mean follow up was 25 months (12 to 60 months). There were 5 dislocations, 2 wound dehiscence, 3 DVT’s and 2 deep infections in the whole group. There were 2 dislocations, 2 DVT, 1 wound dehiscence and 1 infection in the study group. The preoperative scores were available for 83 patients and the average scores for pain, function and range of movements were 3.2, 2.8 and 1.6 respectively. The average scores at the latest follow up were 5.08, 4.2 and 4.0. The mean Oxford Hip scores were 26.65. X-rays showed no demarcation in the acetabulum in 88 patients and in the femur in 92 patients. The trochanter was united in 72 patients. In 13 patients the trochanter had migrated more than 1 cm.

Conclusion: Revision total hip replacement using cement has shown good results in the short term. Cemented revisions are safe, reliable and also cost effective.


Orthopaedic Proceedings
Vol. 91-B, Issue SUPP_III | Pages 406 - 406
1 Sep 2009
Karva A Board T Mohan S Porter M
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Introduction: Hip Resurfacing has increased in popularity, particularly in young, active patients. However, concerns remain regarding metal ion levels, hypersensitivity leading to aseptic lymphocytic-vasculitis-associated lesions(ALVAL) and AVN. The purpose of this study was to document our experience of revising resurfacing arthroplasty for ALVAL.

Methods: All patients undergoing conversion of hip resurfacing to total hip replacement at our institution were reviewed. The notes were reviewed for the reason for revision, the make of the implant, time interval between primary procedure and revision and final diagnosis. Radiographs were reviewed to assess for implant alignment, signs of loosening, neck thinning and AVN.

Results: Out of the 34 patients who had revision surgery 13 were revised for suspected ALVAL, with mean age of 58.8 years at a mean 42.9 months following primary surgery. Of the 13 resurfacings revisions 11 were Birmingham resurfacing and 1 each of Cormet and ASR resurfacing. Groin pain was the presenting complaint in all patients, 5 patients developed their symptoms immediately postoperatively whilst 8 developed symptoms at mean 28.25 months. Haematological investigations were non-diagnostic. Radiographs were normal in 4 patients, whilst 4 demonstrated a loose cup. Thinning of femoral neck and vertical cup alignment were present in 2 patients each while 1 patient had both vertical cup and thinning of femoral neck. All revisions were achieved with primary implants and all patients had immediate pain relief after surgery. Implants and tissue were sent for laboratory analysis. 3 patients had a confirmed histological diagnosis of ALVAL, the remaining cases had identical operative findings and are presumed ALVAL.

Discussion: ALVAL accounts for nearly 1/3 of all our revisions for failed resurfacing arthroplasty. Unexplained pain in patients with resurfacing arthroplasty should be considered for a diagnosis of ALVAL and investigated appropriately. Symptoms tend to resolve reliably following conversion to total hip arthroplasty.


Orthopaedic Proceedings
Vol. 91-B, Issue SUPP_III | Pages 407 - 407
1 Sep 2009
Mohan S Board T Fishwick J Jeffs V Porter M
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Introduction: The Birmingham Hip Resurfacing(BHR) has shown encouraging early to medium term results. It has tended to be used in patients wishing to achieve high functional activity. However there is little data available to support this notion. The purpose of the study was to report the functional levels of patients following BHR.

Methods: Since February 2000, 313 patients have undergone resurfacing by the senior author. Two hundred and sixty four patients with a minimum 12 month follow-up were assessed for functional activity using the modified UCLA activity score. Patients were asked to score their activity level during the pre-symptomatic period as well as pre-operatively and during follow-up.

Results: The mean age at surgery was 55.7 years. The mean follow-up period was 46.72 months. The revision rate for any reason was 3.8%. The mean pre-symptomatic, pre-operative, one year post-operative and final follow-up UCLA scores were 7.9, 3.7, 6.6 and 7.0 respectively. At one year 89% (235 patients) had improved by at least one activity grade from pre-operative levels and 35% (93 Patients) achieved functional scores the same as, or better than their pre-symptomatic levels. This increased to 45% at final follow-up. Of the 242 patients previously involved in moderate activity(UCLA> =5), 31% regained this activity level at one year, rising to 40% at last follow-up. Only 19% of the 180 patients participating in very active/impact sports(UCLA> =8) obtained these levels at one year, rising to 30% at last follow-up.

Conclusion: This is the first assessment of function after BHR comparing pre-symptomatic scores with those obtained during follow-up. Functional scores continue to improve beyond one year in all groups. Significant numbers of patients can achieve functional levels at least as good as before they developed symptoms from their hip, however, the proportion of patients achieving this goal reduces with increasing pre-symptomatic activity.