Data from recent AOANJRR shows a higher incidence of acetabular revision for dislocation of THA in uncemented compared to cemented THA (RR 1.59). We hypothesized that a difference in accuracy of component placement may be a factor. We aimed to assess any difference in accuracy between these 2 types of THA.

Patients undergoing navigated THA were prospectively recruited. Choice of uncemented or cemented THA was based on individual surgeon’s routine practice and preference and no adjustments were made for this study. All THAs (Cemented Exeter-21 and uncemented Trident/Secur fit-20) were performed through a posterior approach.

Statistical analysis: the mean and 95% confidence intervals (or median and interquartile range (IQR) for non parametric data) for each measure in both groups. ANOVA and nonparametric Mann-Whitney U test (significance level 5%). Levene’s test for homogeneity, Comparison of frequencies with chi-squared test or Fishers Exact test. Bonferroni correction where necessary.

We demonstrated a significant difference in reproducibility between components. Four of 20 (20%) uncemented cups deviated from the target inclination by 5 degrees or more compared to none of 21 in the cemented group (p=0.048). Seven of the 20 (35%) of the uncemented cups deviated from the target version by 5 degrees or more compared to none of 21 in the cemented group (p=0.003). There was a significant difference between the groups with regard to deviation from planned leg length (p< 0.001). Deviation from target leg length of greater than 5mm was found in 36.4% of the uncemented cases as compared to 8.3% of the cemented cases although due to the small numbers this was not statistically significant (p=0.16).

Statistically significant reduced accuracy of cup placement is demonstrated with uncemented compared to cemented implants. It is harder to control implant positioning in uncemented implants than cemented implants.

Introduction Over recent years the techniques of femoral and acetabular impaction allografting with fresh frozen morsellised bone have become incressingly popular for revision total hip arthoplasty with osseous defects. In many centres lack of availability or legislation has required surgeons to explore alternatives to fresh frozen bone that may have different structural and biological properties. In this study we compare in vitro the load carrying capacity of irradiated morsellised bone against a control non-irradiated sample.

Methods Fresh frozen heads were divided in halves with one half irradiated at 25 kGy and the control half left non-irradiated. A custom-built pneumatic loading apparatus applied a force of 1200N at a cycle rate of 1Hz for a total of 1500 cylcles. This loading cycle was chosen to simulate the loads normally experienced by the human femur during walking gait. The reduction in height (subsidence) of each test specimen was measured and statistical analysis performed.

Results Results from each treatment group displayed similar patterns of subsidence, with an initial rapid rate of subsidence occurring up to 50 to 100 load cycles, followed by a more gradual, slower rate as the tests progressed. The results for each treatment (mean ± standard deviation) were −3.59 ± 0.91 mm and −2.98 ± 0.812 mm for the irradiated and non-irradiated groups, respectively (P+0.049). The irradiated specimens demonstrated an increased amount of subsidence compared to the non-irradiated specimens.

Conclusions This study has shown that gamma irradiation of morsellised bone allograft material decreases its load-carrying capacity, as expressed by an increase in subsidence due to an applied cyclic load. The ability for morsellised bone allograft material to bear applied loads in vivo is an important biomechanical parameter and one indicator of a successful clinical outcome. The clinical implications of this result are important when considering the most appropriate methods of treating human bone allograft material.

In relation to the conduct of this study, one or more of the authors is in receipt of a research grant from a commercial source.

Introduction We report the results of cancellous femoral impaction grafting with cement in revision hip arthroplasty in all patients from the above centre, who had their surgery more than five years previously.

Methods Up to December 1994, 226 hips underwent femoral impaction grafting in 207 patients. No deaths were attributable to the revision surgery. Thirty-three patients with 35 functioning hips died with less than five years follow-up. Only one patient was lost to follow-up. All other patients have had clinical review by two of the authors (BH and HE) and a combined panel undertook radiological review.

Results Two hips (one percent) became infected at the time of their revision surgery. Twelve stems underwent a further surgical procedure for aseptic failure; 10 for treatment of fracture and two for mechanical loosening in the absence of fracture. Survivorship with any femoral re-operation for any cause as the end point was 90.5% (confidence interval 82 to 98% (Peto equation)) at 10 to 11 years. Using femoral re-operation for symptomatic aseptic mechanical loosening as the endpoint the survivorship was 99.1% (CI= 96–100) at the same follow-up. The technique used in our centre has been modified since this series with an increased use of longer stems with impacted allograft. The technique used in Exeter has evolved and there has been an increased awareness of the fundamental importance of gaining stability of the implant within the graft at the time of surgery.

Conclusion These results provide evidence of a successful technique in the intermediate to long term.

In relation to the conduct of this study, one or more the authors have received, or are likely to receive direct material benefits.

Aims: This study reports the results of all patients from our centre who underwent femoral impaction grafting more then five years previously. As a consequence of our experience our technique has been modified and the indications for impaction grafting have become clearer. Methods: 226 hips underwent femoral impaction grafting in 207 patients. No deaths were attributable to the revision surgery. 33 patients with 35 functioning hips died with less than 5 years follow up. Only one patient was lost to follow-up. There were two (1%) acute infections. Twelve stems underwent a further surgical procedure for aseptic failure – 10 for treatment of femoral fracture and 2 for mechanical loosening in the absence of fracture. Results: Survivorship with any femoral re-operation for any cause as the end point is 90.5% (Confidence Interval 82–98%) at 10–11 years. Using femoral re-operation for symptomatic aseptic mechanical loosening as the endpoint the survivorship was 99.1% (Confidence Interval 96–100%) at the same follow-up. Conclusions: As a consequence of our experience in this series our technique has been modified with an increased use of longer stems with impacted allograft. Long stems are indicated when the host bone around a short stem is significantly compromised, in cases of severe bone stock loss, or when a fracture occurs.

To establish the efficacy of femoral impaction grafting in femoral reconstruction following sepsis, we identified and reviewed all cases of two stage hip revision for sepsis in which femoral impaction grafting was used in the second stage, performed in Exeter from 1989 until the end of 1998. All patients underwent a Girdlestone excisional arthroplasty, were prescribed local and systemic antibiotic treatment, and then subsequently underwent surgical reconstruction, using femoral impaction grafting.

These 53 cases represent a subgroup of our patients who had received a two-stage revision for infection during that period. The other patients did not require femoral grafting. 4 patients died within 24 months of surgery.

4 patients became reinfected (7.5%), and 1 patient underwent stem revision for a fracture below the tip of the stem at 10 months, leaving 44 patients with an average of 53 months follow up (range 24 to 122 months). These 44 patients all demonstrated improved clinical scores and satisfactory radiological outcomes.

Our clinical results reveal post-operative scores approaching those for primary arthroplasty. Our intermediate term results justify the use of fresh frozen allograft bone in the second stage of revisional hip surgery for its low incidence of reinfection and loosening, and potential to improve bone stock.