Aims

The primary outcome was investigating differences in wear, as measured by femoral head penetration, between cross-linked vitamin E-diffused polyethylene (vE-PE) and cross-linked polyethylene (XLPE) acetabular component liners and between 32 and 36 mm head sizes at the ten-year follow-up. Secondary outcomes included acetabular component migration and patient-reported outcome measures (PROMs) such as the EuroQol five-dimension questionnaire, 36-Item Short-Form Health Survey, Harris Hip Score, and University of California, Los Angeles Activity Scale (UCLA).

Aims

The most frequent indication for revision surgery in total hip arthroplasty (THA) is aseptic loosening. Aseptic loosening is associated with polyethylene liner wear, and wear may be reduced by using vitamin E-doped liners. The primary objective of this study was to compare proximal femoral head penetration into the liner between a) two cross-linked polyethylene (XLPE) liners (vitamin E-doped (vE-PE)) versus standard XLPE liners, and b) two modular femoral head diameters (32 mm and 36 mm).

Summary

Despite high revision rates, the mean two year migration of the ASR^TM cup is within an acceptable threshold. Slightly higher migration rates found for the M2a- Magnum™ Porous Coated Acetabular Component but longer follow up is needed to establish if this implant is at risk.

Radiostereometric analysis (RSA) can detect early micromovement in unstable implant designs which are likely subsequently to have a high failure rate. In 2010, the Articular Surface Replacement (ASR) was withdrawn because of a high failure rate. In 19 ASR femoral components, the mean micromovement over the first two years after implantation was 0.107 mm (sd 0.513) laterally, 0.055 mm (sd 0.204) distally and 0.150 mm (sd 0.413) anteriorly. The mean backward tilt around the x-axis was -0.08° (sd 1.088), mean internal rotation was 0.165° (sd 0.924) and mean varus tilt 0.238° (sd 0.420). The baseline to two-year varus tilt was statistically significant from zero movement, but there was no significant movement from one year onwards.

We conclude that the ASR femoral component achieves initial stability and that early migration is not the mode of failure for this resurfacing arthroplasty.

Introduction

Metal on metal articulations produce chromium (Cr) and cobalt (Co) debris, particularly when the articulations are worn in. High levels in the peripheral blood are indicative of excess wear and may cause adverse effects. The present RCT investigates metal ion levels and the relationship of Co, Cr ions and lymphocyte counts during the running-in period.

Background

The treatment of femoral neck fracture with internal fixation (IF) is recommended in younger patients and has compared to arthroplasty the advantage of retaining the femoral head. A big problem with osteosynthesis is though failure. Finding predictors for fixation failure is still an ongoing process and osteoporosis has been suggested as a predictor.

It is accepted that resurfacing hip replacement preserves the bone mineral density (BMD) of the femur better than total hip replacement (THR). However, no studies have investigated any possible difference on the acetabular side.

Between April 2007 and March 2009, 39 patients were randomised into two groups to receive either a resurfacing or a THR and were followed for two years. One patient’s resurfacing subsequently failed, leaving 19 patients in each group.

Resurfaced replacements maintained proximal femoral BMD and, compared with THR, had an increased bone mineral density in Gruen zones 2, 3, 6, and particularly zone 7, with a gain of 7.5% (95% confidence interval (CI) 2.6 to 12.5) compared with a loss of 14.6% (95% CI 7.6 to 21.6). Resurfacing replacements maintained the BMD of the medial femoral neck and increased that in the lateral zones between 12.8% (95% CI 4.3 to 21.4) and 25.9% (95% CI 7.1 to 44.6).

On the acetabular side, BMD was similar in every zone at each point in time. The mean BMD of all acetabular regions in the resurfaced group was reduced to 96.2% (95% CI 93.7 to 98.6) and for the total hip replacement group to 97.6% (95% CI 93.7 to 101.5) (p = 0.4863). A mean total loss of 3.7% (95% CI 1.0 to 6.5) and 4.9% (95% CI 0.8 to 9.0) of BMD was found above the acetabular component in W1 and 10.2% (95% CI 0.9 to 19.4) and 9.1% (95% CI 3.8 to 14.4) medial to the implant in W2 for resurfaced replacements and THRs respectively. Resurfacing resulted in a mean loss of BMD of 6.7% (95% CI 0.7 to 12.7) in W3 but the BMD inferior to the acetabular component was maintained in both groups.

These results suggest that the ability of a resurfacing hip replacement to preserve BMD only applies to the femoral side.

Introduction: Recently there has been increasing interest in postoperative pain treatment by use of wound infil-tration with local anaesthetics. The technique has been reported effective following hip and knee arthroplasty. We hypothesized that repeated installations of intraar-ticular local anaesthetic in patients with femoral neck fracture would give pain relief without side effects and reduced opioid usage.

Material and Methods: 33 patients undergoing osteo-synthesis with two Hook Pins were randomized into 2 groups in a double-blinded study (Clinical Trials.gov id: NCT00529425). In group A (Active) 19 patients received 1 peroperative (30 ml=200 mg) and 6 postoperative (10 ml=100 mg) bolus instillations of ropivacaine through an intraarticular catheter which was removed after 48 hours. In group B (placebo) 14 patients were injected with the same volume of saline water. The need for opioid rescue analgesia standardized to mg equivalent of oxyco-done and pain measured on a 5 point scale were recorded during the intervention period of two days after surgery.

Results: No significant difference in consumption of rescue analgesia was found between the groups on day one and two: Group A (16.7 mg and 15 mg, both median values) opposed to group B (10 mg and 7.5 mg, both median values), (P=0.51 and P=0.36 Mann-Whitney). Testing for insufficient use of rescue analgesia by comparing the number of pain scores exceeding a defined limit of tolerable pain showed no difference between the groups on day 1 and 2 (P=0.31 and P=0.45). Comparing the maximum pain score we found no significant difference between the groups on day 1 (P=0.41). Although not significant, the maximum pain score was higher in group A on day 2 (P=0.051). There was no difference between the median pain score on day 1 (P=0,78) but on day 2 the median pain score was significantly higher in group A (P=0,03).

Conclusion: Repeated intraarticular application of ropi-vacaine provides no reduction in opioid requirements or pain after osteosynthesis of femoral neck fracture. This suggests that the technique has no clinically relevant analgesic effect in this category of patients.

Background: Dysplasia of the hip is associated with hip pain and development of secondary osteoarthrosis. An early intervention by a PAO is both a pain relieving treatment and it prolongs or eliminates the development of osteoarthrosis. Different surgical approaches have been used to perform the PAO. We have compared a modified iliofemoral (MI) approach and the ilioinguinal (II) approach on acetabular reorientation, perioperative variables and clinical outcome.

Patients and Method: We included 90 PAO’s performed on 75 patients with symptomatic hip dysplasia operated between February 2003 and July 2006 at Odense University Hospital. The variables in this study are center edge (CE) and acetabular roof angle (AA), Harris Hip score (HHS), WOMAC, pain (VAS), satisfaction with surgery, level of activity, quality of life (EQ5D), peri-operative blood loss, operating time and neurovascular complications.

Results: The MI approach was used in 71 PAO’s and the II in 19 PAO’s. Overall, patients had a significantly better result after the PAO compared to before with regard to HHS, pain and WOMAC, EQ5D. Reorientation measured on pre- and post-operative CE- and AA-angles showed no significant difference between the two groups. Operating time proved the MI approach significantly faster then the II-approach (p< 0.05). The intraoperative blood loss and pre-operative Hb-conc. was equal in the two groups. However, there was a significant lower postoperative Hb-conc. using the II-approach. The II group had one case of arterial thrombosis and none in the MI group. In both groups, half the patients had dysaesthesia related to the lateral cutaneous femoral nerve.

There were no significant differences between the two approaches with regard to pre- and post-operative HHS, WOMAC, patient satisfaction, level of activity and EQ5D

Conclusion: Although the II approach offers better access to the pubic bone, we did not find any difference in reorientation of the acetabular fragment. Both groups improved significantly in clinical outcome and quality of life. We find the MI approach safer than the II, as no arterial thrombosis was seen in that group.

Introduction: The purpose of this prospective randomized is to compare a resorbable versus a non resorbable CR regarding restrictor migration and cementation quality in cemented THA.

Materials and Methods: 91 patients were randomized to either a resorbable Imset(Aesculap) or a non-resorbable Hardinge (De Puy) CR.

Surgery and postoperative regime were identical in the two groups.

CR-migration during cementation and stem insertion was calculated and the quality of cementation was evaluated on the post-operative X-ray according to the criteria by Barrack et Al(1)

Mean values are presented with 95% CI. An unpaired T-test was used to analyse the differences in CR migration and the quality of cementation quality.

Results: The mean CR-migration in the Imset group was 9.8mm(CI: 6.1mm-13.5mm) compared with 3.7mm (CI: 1.8mm-5.5mm) in the Hardinge group (P=0.042)

Regarding quality of cementation the mean value in the Imset group were 2.8 which was significantly better in the Hardinge group=2.1 (P=0.003)

Conclusion: The resorbable CR was associated with significantly greater migration and inferior quality of cementation compared with our standard non-resorbable restrictor.

Resurfacing THA is claimed to transfer stress naturally to the femur neck and preserve proximal femoral bone mass postoperatively. DXA is an established method in estimating BMD around a standard THA, but due to the anteversion of the femur neck, rotation could affect the size of the neck-regions and thereby the BMD measurements around a RTHA. To our knowledge, this is the first study to analyze the effects of hip rotation on BMD in the femoral neck around a RTHA.

We scanned the femoral neck of 15 patients twice in each position of 15° inward, 0° and 15° outward rotation, and analyzed BMD in a single and a six-region model. CVs were calculated for BMD in the same position as well as between different positions.

For double measurements in the same position we found mean CVs of 3.1% (range 2.5% – 3.7%) and 4.6% (range 2.2% – 8.6%) in the one- and six-region models, respectively. When the 15° outward position was excluded, the CVs decreased to 2.8% and 4.0%. With rotation, the mean CVs rose to 5.4% (range 3.2%–7.2%) and 11.8% (range 2.7% – 36.3%). This effect was most pronounced in the 6-region model, predominantly in the lateral and distal parts of the femoral neck, where the change was significantly different from the fixated position. For the single-region model 15° rotation could be allowed without compromising the precision.

We conclude that rotation adversely affects the precision of BMD measurements around a RTHA, but in the single-region model smaller rotations can be allowed.

With the hip fixated the six-region model produces low CVs, acceptable for longitudinal studies. For maximal topographical detail we prefer the six-region model and recommend that future longitudinal DXA studies, including RTHA, be performed standardised, Preferably, with the hip in the neutral or internal rotation.

Introduction: Periacetabular osteotomy (PAO) is a major orthopaedic surgical procedure which may be associated with a significant blood loss and complications. We have compared the perioperative blood loss and complications using two different approaches – The modified iliofemoral (MI) and ilioinguinal (II) for PAO.

MATERIALS AND Methods: 92 PAO’s in 80 patients (54 females; 26 males), with dysplastic hip joints, operated at Odense University Hospital with the Bernese method, between 2003 and Feb. 2006, using the MI or the II were included. The MI include no release of the tensor fascia lata, sartorius or rectus femoris.

The procedures were reviewed with primary focus on perioperative blood loss, length of surgery and neurovascular complications. Patients who underwent combined surgery of acetabulum and femur were excluded.

Data are presented as mean with 95% confidence interval (CI) in brackets.

Results: The MI approach was used in 65 and the II in 27 PAO’s. Average time for surgery in the MI group was 88 min (95% CI: 83–94) and in the II group 106 min (95% CI: 97–114), (P=0.0007). The intraoperative blood loss in the MI group was 571 ml (95% CI: 489–654) compared with 518 ml (95% CI: 387–649) in the II group (P=0.49). However, postoperatively, the hemoglobin concentration was 7.1 (95% CI: 6.9–7.3) in the MI group compared with 6.6 (95% CI: 6.1–6.8) in the II group (P=0.002).

The MI group had 1 case of major arterial bleeding, however no blood transfusion. The II group had 2 cases of arterial thrombosis and one transient sciatic nerve palsy. One patient received blood transfusion.

CONCLUSION: In this study, the MI approach was proved to be significantly faster than the II, however no significant difference was found in intraoperative blood loss, but the hemoglobin fell significantly less in the MI compared with the II group. The II approach was associated with 3 major complication compared with one in the MI.