Objectives

The Oxford hip score (OHS) is a 12-item questionnaire designed and developed to assess function and pain from the perspective of patients who are undergoing total hip replacement (THR). The OHS has been shown to be consistent, reliable, valid and sensitive to clinical change following THR. It has been translated into different languages, but no adequately translated, adapted and validated Danish language version exists.

Background

For bone grafting procedures, the use of autologous bone is considered the gold standard, as it is has a better healing capacity compared to other alternatives as allograft and synthetic bone substitutes. However, as there are several drawbacks related to autografting (infection, nerve- or vascular damage, chronic pain problems, abdominal herniation), there has been a targeted effort to improve the healing capacities of synthetic bone substitutes.

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.

Introduction: Revision rate after THA in the younger age groups is still unacceptable high and might up to 20% after 10 years. The aim of this investigation is to evaluate risk factors for later revision in patients younger than 50 years at surgery based on the NARA database (Nordic Arthroplasty Register Association).

Materials and Methods: 14,610 primary THA from Denmark, Sweden, and Norway, operated from 1995 to 2007, were included. 49.4% was males, the diagnosis was idiopathic osteoarthrosis (OA) in 46%, childhood disease in 26%, inflammatory arthritis (IA) in 12%, non-traumatic osteonecrosis in 9% and fracture in 6%. 49% of the THA’s were uncemented, 27% cemented, 14% hybrid, and 8% were inverse hybrid THA’s. Cox multiple regression, adjusted for diagnose, age, gender, calendar year and surgical approach, was used to calculate prosthesis survival with any revision as end-point. RR= relative risk (CI= confidence interval).

Results: The overall 10-year survival was 83%. There was no difference between gender (RR=0.94 (0.82–1.07)). IA had a 37% reduced risk of revision compared with OA (RR=0.67 (0.54–0.84)), whereas there was no difference between childhood disease and primary osteoarthrosis. Overall, cemented, uncemented and reverse hybrid THA had a better survival than hybrid THA. Hybrid THA had 24% increased risk compared with cemented (RR=1.24 (1.04–1.49)). There were no difference between cementless and cemented (RR=1.07 (0.92–1.26)). Interestingly, the inverse THA had lower revision rate than cemented THA in men (RR=0.50 (0.25–0.99)). The risk for revision due to aseptic loosening was lowest in cementless THA and reduced to RR=0.55 (0.44–0.69) compared with cemented THA.

Discussion: and Conclusion: Choice of prosthetic concept for younger patients is still of debate. The present study including only patients younger than 50 years of age, showed that overall cemented, uncemented and reverse hybrid THA, had better survival than traditional hybrid. The risk for revision due to aseptic loosening was higher in cemented than cementless THA.

Introduction: There is an increasing interest in surface replacement arthroplasty (SRA) as an alternative to conventional THA (cTHA) in young and active patients. However, there has been considerable variability in reported outcomes. National joint registry reports have shown increased revision rates compared to cTHA. We analysed outcome measured as non-septic revision rate within two years for SRA in the NARA data base (Nordic Arthroplasty Register Association).

Materials and Methods: 1638 SRA and 163802 cTHA with age up to 73 years and a non-fracture diagnosis, operated from 1995 to 2007, were compared using Cox multiple regression including age, gender, diagnosis, nation and prosthesis type with cTHA divided into cemented, uncemented, hybrid and reversed hybrid fixation. Men below 50 years of age (460 SRA and 7185 cTHA) were analysed as a subset. The SRA cohort with a mean follow-up 1,8 years was also analysed with the same method including age, gender, diagnosis, number of performed SRA per hospital and the four most commonly used prosthesis designs. In an additional analysis femoral head diameter was added, reducing the number of cases to 1552. results are presented as relative risk (RR) with 95 % confidence interval(CI).

Results: SRA had a more than twofold increased revision risk compared to cTHA, RR=2,50 (1,67–3,70), which increased to 3,63 (2,42–5,44) when compared with all cemented THA. In the subpopulation of men below 50 years of age, there was no difference between SRA and any of the cTHA cathegories. Within the SRA group RR was reduced by male gender, RR=0,46 (0,25–0,86), in hospital performing > 70 SRA (RR=0,26, 0,11–0,60) and with use of BHR (Birmingham Hip Resurfacing) compared to all other designs (RR=0,27, 0,12–0,61). The size of the femoral head diameter had no significant influence on the early revision rate.

Discussion and Conclusion: Surface replacement arthroplasty has an increased risk of early revision compared to conventional and cemented THA except for men below 50 years of age. There is a learning curve on the hospital level. Cases with secondary osteoarthritis were comparatively few and were mainly caused by pediatric hip disease. SRA might become an alternative for young men, but our follow up is too short to determine if this indication remains in the longer perspective.

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 purposes of this study are to investigate the inter-relationship between Stulberg class and radiographic hip osteoarthritis (OA) in patients with Legg-Calvé-Perthes disease (LCP) and to determine whether LCP patients develop hip OA more often than sex- and age-matched individuals.

Material and Methods: 167 LCP patients presented to our institution from 1941 to 1962. All patients were treated conservatively by a Thomas splint. Retrospectively medical records and radiographs were retrieved.

At follow-up weight-bearing AP pelvis radiographs were obtained. OA was present when the minimum joint space width was < 2.0 mm. Radiographs of sex- and age-matched controls were obtained from The Copenhagen City Heart Study.

The following criteria for exclusion were applied:

insufficient or missing radiographs

52 patients (55 hips) were enrolled in the study and 115 patients (136 hips) were excluded. Mean age for men at follow-up was 53 years and for women 55 years.

Results: In the LCP group four hips of 50 hips had OA compared to one hip of 107 hips in the control group. One patient out of 41 in Stulberg class I/II had OA compared to three out of nine in Stulberg class III/IV/V.

Conclusion: LCP patients have a significant higher risk of having hip OA compared to a sex- and age-matched control group, p=0.04 [OR=8.5 (CI=0.8–428.8)]. Patients in Stulberg class III, IV or V have a significantly increases risk of hip OA compared to patients in Stulberg class I or II, p=0.03 [OR=13.7 (CI 1.9–97.1)].

Introduction: Up to now comparisons and pooling of data between the Scandinavian arthroplasty registers have been restrained by use of separate and incompatible data systems.

Purpose: To create a common Scandinavian database for hip arthroplasties and to compare demographics and results between the Scandinavian countries.

Materials and methods: For this study we selected primary total hip prostheses (THR) from 1995–2006. A common code set was made, and after de-identification of the patients’ identity, including deletion of the national civil registration numbers, Denmark, Sweden, and Norway delivered data. Kaplan-Meier and Cox multiple regression, with adjustment for diagnosis, age, and gender, were used to calculate prosthesis survival, with any revision as end-point.

Results: 280,201 operations were included (Denmark 69,242, Sweden 140,821, Norway 70,138). Female patients constituted 60% in Denmark and Sweden and 70% in Norway. In Denmark, Sweden, and Norway childhood disease constituted 3.1%, 1.8%, and 8.7% respectively. The posterior approach was used in 91% of cases in Denmark, 60% in Sweden, and 24% in Norway. Cemented THRs were applied in 46% of patients in Denmark, 89% in Sweden, and in 79% in Norway. Resurfacing hips constituted 0.5% or less in all countries.

9,596 of the 280,201 primary THRs, had been revised. Ten-years survival was 91.9% (95% CI: 91.5 – 92.3) in Denmark, 93.9% (95% CI: 93.6–94.1) in Sweden, and 92.6% (95% CI: 92.3–93.0) in Norway.

In Sweden and Norway 23% of revisions were due to dislocation, compared to 34% in Denmark. Replacement of only cup or liner constituted 29% of the revisions in Sweden, 33% in Norway, and 44% in Denmark.

Conclusion: This unique database is now functioning, and has showed differences among the countries concerning demographics, prosthesis fixation, prosthesis survival, and reasons for revisions. The large number of THRs in this database significantly enhances our perspectives for future research, especially in diagnostic- and treatment groups with too small numbers in each separate

Introduction: Microdialysis can detect ischemia in soft tissue. In a previous study we have shown the development of ischemia in the femoral head removed from patients undergoing total hip replacement.

This study also raised some methodological questions that this study tries to answer.

What is happening in the dead space around the catheter in the drill canal? And is there an equilibrium period after the insertion of the catheter.

Methods and materials:

Ex vivo study: in 5 syringes with 5 ml human blood a microdialysis catheter was inserted and microdialysis performed over 3 hours.

Results:

Ex vivo: the microdialysis results showed that lactate kept a steady level and glucose and glycerol all fell, pyruvate fell but leveled out. The lactate/pyruvate ratio increased from 13(4) to 32(6) (p< 0.001).

Conclusion: The ex vivo study showed a clear washout pattern, and is different from what we see in bone.

The in vivo study indicates that an equilibrium period is necessary or that a reference measurement in healthy bone must be used when performing short measurements in bone.

Background: A general increase in total number of primary total hip arthroplasty (THA) has been observed in Denmark from 3.828 in 1995 to 7.645 in 2006. During the same period the number of pa-tients treated at private clinics has also increased. To our knowledge no studies, comparing patient characteristics and treatment quality between public and private hospitals, have been published.

We compared patients’ characteristics and outcome following THA in private and public hos-pitals.

Materials and Methods: We used data from the Danish Hip Arthroplasty Registry to identify 69 249 primary THA’ies performed between 1 January 1995 to 31 December 2006.

To detect eventual difference in patient characteristics- age, gender, diagnosis leading to THA, Carlson’s comorbidity score and Charnley category were evaluated.

We matched 3 658 cases operated in private with 3 658 controllers operated in public hospitals on propensity score. Scoring parameters were age, gender, diagnosis leading to THA, Carlson’s comorbidity score, Charnley category, operating time, type of anesthesia and type of prosthesis.

We used multivariate logistic regression on propensity score matched data to assess association between type of hospital and outcome by computing relative risks and 95% Confidence Interval (CI). Outcomes were perioperative complications, readmission within 3 months, re-operation within 2 years, implant failure after 5 years, and mortality within 3 months of surgery.

Results: Private hospitals operated on older females, patients with primary osteoarthritis and low comorbidity and Charnley category 1.

Patients in private and propensity matched controls from public hospitals showed no differences in age, gender, diagnosis leading to THA, Carlson’s comorbidity score, Charnley category, operating time, type of anesthesia and type of prosthesis (p-value < 0,0001).

Based on matched data, private hospitals had lower relative risk for perioperative complications (0.39, 0.26–0.60), reoperations (0.59, 0.41–0.83) and readmissions (0.57, 0.42–0.77) compared with public. There was no difference in mortality or implant failure.

Discussion and Conclusions: We had no data on surgeon, general health and socioeconomic status of the patients. In addition, reported data from private clinics have not been validated in contrast to public hospitals

We found significant difference between patient characteristics operated at public versus private hospitals. No difference was evident regarding mortality and implant failure but for complications, reoperations and readmissions between private and public hospitals.

Introduction: NSAID’s are routinely used as either pain-killer or in prevention of heterotopic bone formation (HBF) after total hip replacement (THR). Experimental animal studies have in two decades shown NSAID’s to influence bone remodelling, and thereby also to reduce fixation and bone healing round non-cemented implants. Clinical studies have, however, non been able to demonstrate these observations, too. This may be due a low power in such studies with only few observations. The present study present results from The Danish Hip Arthroplasty Register (DHR) on the effect of NSAID’s to revision of cemented implants due aseptic loosening.

Materials and Methods: DHR was established January 1, 1995 and covers all Danish clinics. All report both primary and revision cases to a central database. Every Danish citizen have an unique civil register number - making it possible to follow both primary and revision cases and to investigate survival due various circumstances. Cox’s regression analysis to estimate the relative risks (RR) of revision and data are presented with 95% confidence intervals.

Results: During the period 1995–2006 total 64.725 primary THR’s were recorded in DHR. Of these 8.531 cases had prophylactic NSAID after surgery in prevention of HBF. Total 409 hips (4.8%) of this population undergoing revision THR had been treated with NSAID’s after surgery. In contrast, 2.536 (4.3%) undergoing revision in the population had no NSAID’s. Overall the risk for revision for any reason was reduced for patients treated with NSAID’s (RR = 0.88 (0.79–0.98) p=0.02). This was even more significant in revision due to aseptic loosening (RR = 0.76 (0.64–0.90) p< 0.01). Subgroup analysis showed that the reduction was in the cemented THR (RR = 0.82 (0.70–0.95) p=0.01) with a further more significant sign in revision due aseptic loosening (RR = 0.69 (0.55–0.87) p< 0.01). In contrast there was no differences in cementless THR neither in revision for any reason (RR = 1.19 (0.86–1.63) p=0.30) nor for aseptic loosening (RR = 1.72 (0.87–3.43) p=0.12).

Discussion and Conclusion: The present investigation from the DHR is a good example of what can be evaluated from a register, and never possibly concluded from standard clinical studies. The results demonstrate that NSAID’s administrated in order to prevent HBF after primary THR surprisingly did not increase the risk of revision in non-cemented implants, but in contrast did reduce the risk for revision in cemented THR. The reason for this reduction is speculated, and be relate to the phenomenon that NSAID’s did not only influence the osteoblastic activity, but also the osteoclasts and thereby prevent early postoperative bone degradation after cemented THR where heat from the bone-cement may impose devascu-larisation of vital bone near the implant.

Introduction: Poor long-time results in patients with Legg-Calvé-Perthes disease (LCP) are most often due to degenerative hip disease. The purpose of this study was to investigate if patients with LCP have an increased rate of total hip replacement (THR) compared to sex- and age-matched persons.

Material and Methods: 167 LCP patients presented to our institution from 1941 to 1962. All patients were treated conservatively by a Thomas splint. Retrospectively medical records and radiographs were retrieved. Data from the Danish Hip Replacement Register and the Registries of the National Board of Health were collected to get information regarding the number of the patients who had a THR.

Radiographs of sex- and age-matched controls for the follow-up group were obtained from The Copenhagen City Heart Study.

The following criteria for exclusion were applied

emigrated persons,

135 patients (156 hips) were enrolled in this study and 32 patients (35 hips) were excluded.

Results: 20 hips out of 156 hips in patients with LCP have had a THR. Mean age at operation for the women was 50 years and 44 years for the men. None of the sex- and age-matched persons have had a THR.

Conclusion: LCP patients had a significantly higher risk of THR surgery compared to sex- and age-matched control persons, (p< 0.00 [OR= 49.0 (CI 8.2-infinite)]).

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.

Introduction: We studied the survival of primary total hip arthroplasty (THA) in patients undergoing surgery because of rheumatoid arthritis (RA) and compared our results to the survival of primary THA in patients undergoing surgery because of osteoarthritis (OA). Furthermore, we evaluated the effect of primary THA-survival in RA-patients concerning multiple confounders such as age, gender, comorbidity, and cemented/uncemented prosthesis.

Material and Methods: Using the Danish Hip Arthroplasty Register we gathered info concerning 1.302 primary THA’s in 1.106 RA-patients and 41.848 primary THA’s in 35.729 OA-patients. These patients underwent surgery from 1995 to 2004. Using the Cox regression model we estimated the relative risk (RR) for revision due to aseptic loosening, other reasons, and all reasons and adjusted for above mentioned confounders.

Results: The adjusted RR’s for cup-revision of primary THA’s in patients with RA (compared to OA) were 1.22 (aseptic loosening − 95% Confidence Interval (CI) 0.75–1.99), 0.90 (other causes for revision − 95% CI 0.61–1.32), and 1.00 (all revisions − 95% CI 0.74–1.35). For the stem the RR’s were 0.50 (aseptic loosening − 95% CI 0.25–0.99), 0.58 (other causes for revision − 95% CI 0.35–0.95), and 0.54 (all revisions − 95% CI 0.36–0.80). RR for all revisions (both cup and stem) was 0.83 (95% CI 0.64–1.09). The RAsubanalysis showed an increased RR (all revisions) for men compared to women (RR 2.60; 95% CI 1.19–5.66). No significant result concerning all revisions for age, comorbidity, and cemented/ uncemented prosthesis was found. The mean follow-up was 5,4 years for RA and 4,8 years for OA.

Conclusion: The survival of primary THA’s in RA could not be associated with any clearly overall increased risk of revision when compared to OA. However, male gender seems to be a risk factor for undergoing revision-THA in the RA-subgroup.

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.

There is a great need for suitable large animal models that closely resemble osteoporosis in humans, and that they have adequate bone size for bone prosthesis and biomaterial research. This study aimed to investigate effects of a 7 month glucocorticoid (GC) treatment alone without ovariectomy on the properties of sheep cancellous bone.

Eighteen female sheep were randomly allocated into 3 groups: group 1 (GC-1) received GC (0.60mg/kg/day methylprednisolone) 5 days weekly for 7 months; group 2 (GC-2) received the same treatment regime for 7 months, and further observed for 3 months without GC; and group 3 served as the control group, and left untreated for 7 months. The sheep received restricted diet.

After 7 months of GC treatment. Cancellous bone volume fraction of the 5th lumbar vertebra in the GC-1 group was reduced by −35%, trabecular thickness by −28%, and changed from typical plate structure to a combination of plate and rod structure with increased connectivity by 202%. Bone strength was reduced by 52%. Bone formation marker, serum osteocalcin of GC-1, was reduced by 71% at 7 months, but recovered with an increase of 45% at 10 month in the GC-2 group. Similar trends were also seen in the femur and tibia. At 10 months, the GC-2 group had microarchitectural and mechanical properties similar to the level of the control sheep.

We have demonstrated in this study that 7 month high-dose GC on bone density and microarchitecture are comparable with those observed in human after long-term GC treatment. Moreover, we have shown that the bone quality with regard to strength and microarchitecture recovers after 3 months further observation without GC. This suggests that a prolonged administration of GC is needed for long-term observation to keep osteopenic bone. The model will be useful in pre-clinical studies.

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.

Introduction: We state that preserving the hip might be optimum in treatment of patients with dislocated femoral fractures presuming that the fractures unite. In order to be able to choose the right treatment for the patient with a dislocated femoral neck fracture, we have hypothesized that lack of blood flow and development of ischemia might have influence on outcome of the osteosynthesis. In this study we have established microdialysis and laser Doppler measurements in patients with a dislocated femoral neck fractures.

Methods and materials: 14 patients with dislocated fractures of the femoral neck were osteosynthezised by using 2 cannulated screws. During the operation blood flow was measured with laser Doppler in order to detect pulsatile flow, and microdialysis was performed to detect ischemia. Both measurements were made in the femoral head and with the greater trochanter as control. The parameters measured were lactate, pyruvate, glycerol and glucose concentrations. Lactate/pyruvate ratio was calculated in order to estimate ischemia defined as a value over 25. Measurements were done after the fracture was reduced, and during osteosynthesis. Data are presented as mean with standard deviation (SD) in brackets.

Results: In all but one patient laser Doppler showed pulsatile flow in the greater trochanter, whereas 8 patients had flow in the femoral head. In the greater trochanter the mean lactate/pyruvate ratio was 11 (7.55), in the femoral heads the mean ratio was 27.99 (21.24) although 4 heads did not show ischemia (p=0.0004). The values for glucose in the trochanter and the femoral head are 2.47 mM(1.92) and 1.53 mM(1.37) respectively, and for glycerol 0.16 mM(0.09) and 0.25 mM(0.22). During the observation period two patients were reoperated, one with hemiarthroplasty 3 months after the osteosynthesis due to failure of the osteosynthesis; the patient had flow measured by laser Doppler and ischemia with microdialysis. One had a resection arthroplasty due to infection.

Conclusion: To our knowledge it is the first time that laser Doppler and microdialysis has been established in patients with dislocated femoral neck fractures. Further studies will have to evaluate whether laser Doppler and microdialysis in combination with fracture related parameters can predict failure of the osteosynthesis. This might enable us to establish a treatment algorithm to be used in the daily clinic.

Background: We examined the role of the geometry of acetabulum in the development of osteoarthritis in young men. Contrary to previous studies we evaluated the significance of the anterior, posterior and total coverage of the femoral head, the influence of the femoral neck and the consequence of acetabular retroversion on standardized x-rays.

Material and Methods: Men (n=78) aged 26–55 years (case-group) were selected from the Danish Hip Arthroplasty Register. This group was compared to a control-group (n=78) selected from men of the same age group received as trauma patients. Anterior/posterior pelvic radiographs were evaluated taking into account the degree of pelvic rotation and tilt.

Results: Femoral head coverage, femoral head-neck ratio and centre edge angle were significantly smaller in the case-group, acetabular index angle and modified ACM-angle were significantly bigger. Anterior, posterior and total coverage of femoral head showed no difference. The frequency of acetabular retroversion was greater among cases.

Interpretation: Osteoarthritis of young men is associated with a small superior acetabular coverage, a steep acetabular roof, a small acetabular depth, a thickened femoral neck and acetabular retroversion.

Introduction: The main problem using first generation Gamma-nail in the treatment of intertrochanteric fractures has been a high frequency of intra- and postoperative femoral fractures. The TGN was thought to represent an improvement in design and potentially a less invasive treatment.

Material and methods: 146 fractures were randomised prospectively to either DHS or TGN. The 2 groups were comparable regarding age, gender and fracture type (AO). Follow-up was carried out after 4 and 12 months.

Results: Average operation time in the TGN group was 63 min (SD=30min) and 48 min (SD=23) in the DHS group (p=0.0016). There was no difference in intra-operative blood loss, need for blood transfusion, length of hospital stay or mortality. Two femoral fractures occurred postoperatively in the TGN group. At follow-up 12 patients in the TGN and 6 patients in the DHS group had had a reoperation (p> 0.05). Six reoperations in the TGN group and 3 in the DHS group resulted in preservation of the hip joint. The remaining patients had an arthroplasty or a Girdlestone resection. Poor reduction and/or positioning of the implant was significantly correlated to the risk of reoperation (p< 0.001). Specific technical errors could be identified among 3 fractures in the TGN group leading to reoperation. Any correlation between fracture type and reoperation could not be demonstrated.

Conclusion: In this study operation time was significantly longer in the TGN group. Among other variables no significant differences could be demonstrated. In our department, with a high number of residents performing these operations, the DHS will continue to be the standard implant. Whether the TGN has a place in a subgroup of intertrochanteric fractures, operated by specialized surgeons, needs further investigation.