Introduction: Early mortality associated with unstable pelvic ring injuries is often secondary to continuous pelvic bleeding. Hemostatic measures such as pelvic binders or external fixation may help to control low pressure bleeding from lacerated veins or broad fracture surfaces, while control of high pressure arterial bleeding may require embolization.

Purpose: Evaluate our experience with the control of hemorrhagic shock associated with pelvic ring injuries during initial patient management.

Methods: From January 2003 until December 2006, all [105] patients admitted to our level I trauma center with a pelvic or an acetabular fracture were prospectively entered into our polytrauma data base. Of 105 patients, 67 were classified with a type B or C pelvic fracture. All these patients received a pelvic strap belt by the paramedic team at the scene of the accident. Pelvic fractures were diagnosed on the initial anteroposterior pelvic radiograph and computed tomography. From this initial group of 67 patients, we identified 38 as unstable requiring blood transfusion and intensive care monitoring. The results and survival rate were evaluated according to the initial sequence of surgical procedures and the patients were divided into 3 groups, X,Y, and Z Follow-up physical examination and radiographs was performed for all survivors at an average of 10 months post-injury (range, 6 months to 3 years).

Results: The average age of the 38 patients was 38.6 years (range, 24–51 years) and their average ISS was 53 (range 21–75).All were injured in a high velocity motor vehicle accident or a fall from a height. The patients were managed in the emergency department by a multidisciplinary team according A.T.L.S. guidelines. Of the 38 patients, five died shortly after arrival in the emergency department despite resuscitation efforts. Within the first 24 hours, pelvic stabilization was performed in 27 patients with either an anterior external fixator frame (n=13), pelvic clamp (n=11) or primary open reduction internal fixation (n=3). In group X, of 19 patients initially treated with external fixation and eventual arterial embolization without laparotomy, 18 (94 %) survived. In group Y, there were 8 patients treated by external fixation, eventual arterial embolization and laparotomy, and 7 (87 %) survived. In group Z, all 6 patients in whom a scratch laparotomy with packing prior to any skeletal fixation was attempted,no patient survived ! All survivors underwent definitive open reduction and plate and screw fixation, with an average ICU stay of 10 days (3–15).

Conclusion: This study shows that optimal control of bleeding associated with pelvic ring injuries is achieved by initial skeletal fixation prior to any other surgical procedures. Immediate laparotomy was associated with a high rate of intraoperative death due to the failure to control bleeding.

Objective: Dislocation is a well known complication after total hip arthroplasty (THA), and the second cause of revision surgery. Our objective was to assess the effect of a pre-operative patient education session on the occurrence of hip dislocation within 6 months after primary THA.

Methods: Between 1998 and 2007 we conducted a prospective cohort study at the University Hospital Department of Orthopaedic Surgery including all primary THAs performed via a transgluteal approach and with use of a 28mm diameter head. The preoperative education session was introduced in June 2002 and included advice on muscle strengthening exercises and postoperative restrictions of range of motion as means of preventing dislocation. Main outcome was the incidence of dislocation within 6 months of surgery. The following potentially confounding factors were assessed: age, sex, body mass index, number of co-morbidities, presence of a neurological disorder, history of alcohol abuse, American Society of Anaesthesiologists (ASA) score, diagnosis (primary or secondary osteoarthritis), previous surgery of the hip, surgeon experience, preoperative functional status, pain level, and motion (Harris Hip Score), preoperative general health status (SF-12), and private or public health care insurance (as proxy for socioeconomic status). Multivariable logistic regression was used for adjustment.

Results: 597 patients who underwent 656 THAs between June 2002 and June 2007 participated in the education session, while 1641 patients who underwent 1945 procedures did not. Forty-six dislocations occurred over the study period, 5 (0.8%) in participants and 41 (2.1%) in non-participants (risk difference 1.3%; 95% CI 0.4; 2.3), with the time interval between surgery and dislocation being significantly shorter among participants (0.2 vs. 1.2 months, p=0.016). Preoperative counselling of 77 patients allowed for preventing one dislocation (number needed to treat). Non-participants had a 2.8 times higher risk of dislocation than participants (unadjusted odds ratio 2.80, 95% CI 1.10; 7.13). Adjustment for age, sex, co-morbidities and prior surgery did not change the results (adjusted odds ratio 2.79, 95% CI 1.09; 7.15).

Conclusion: Preoperative patient education reduced the dislocation risk within 6 months after THA, and particularly after the patient had returned home. Other peri-operative benefits from patient education have been reported and should be considered in a cost-effectiveness analysis.

Objectives: The aim of this study was to quantify bone microarchitecture within the glenoid fossa of the scapula.

High-resolution micro-computed tomography ([mu]CT) imaging have been instrumental in providing true quantitative and qualitative three-dimensional data on baseline bone morphology

Materials and Methods: 25 fresh-frozen human cadaveric shoulders were analysed. The mean age of the specimens was 66 years. All scapulae were inspected for normal anatomic landmarks.

The glenoids were cut at the glenoid neck and at the base of the coracoid process.

The total, trabecular, and cortical BMDs of the 5 regions of the glenoids were determined by use of peripheral quantitative computed tomography (pQCT) (Xtrem Ct;Scanco, Zurich, Ch) Each glenoid was fixed horizontally in a custom-made jig, and axial pQCT scans (pixel size,1536/1536; slice thickness 80 microns), perpendicular to the articular surface, were obtained at the level of each area. From the resulting binarized three-dimensional reconstruction, Scanco software was used to calculate the bone volume per tissue volume; mean trabecular separation; mean trabecular number, connectivity density.

Results: The total BMD of the posterior and superior glenoid were significantly higher than those of the anterior and inferior glenoid. Trabecular BMD of the posterior glenoid was significantly higher than that of the anterior glenoid, and cortical BMD of the superior glenoid was significantly higher than that of the inferior glenoid.

The mean total BMD in different regions of 20 glenoid specimens ranged from 0,243 to 0,489 g/cm2. The center of the glenoid was surprisingly poor in trabecular structures as we found a bony gap at 8 mm of distance from the articular surface.

Conclusions and clinical relevance: Although the specimen age was quite high in our material, we believe aging does not affect our study as shoulders prosthesis are generally performed on old patients.

In the future, component design should use areas of stronger subchondral bone. Posterior and superior bone area could be another alternative for fixation in decreasing glenoid-loosening rates. As the inferior center of the glenoid is an area devoided of trabecular bone, center-keel design component doesn’t seem to be the best choice.

Purpose of the study: This was an analysis of long-term outcome of 260 consecutive total hip arthroplasty (THA) procedures performed with a press-fit CLS-Spotorno cup. This easy-to-position cup preserves bone stock if revision should be needed.

Material and methods: From January 1990 to December 1994, 260 THA were implanted with a CLS-Spotorno cup in 221 patients. The clinical and radiological outcome was assessed with minimal ten years follow-up. Mean age at operation was 63 years (range 26–82 years). Sixty eight patients (68 hips) died before ten years follow-up. Five patients (five hips) could not be transported for review and four patients (four hips) were lost to follow-up. This study thus concerned 183 Spotorno cups (70.3%) in 144 patients (65.1%) who were reviewed clinically at 120–166 months follow-up. One hundred twenty-five patients agreed to undergo a radiological work-up. X-rays were analyzed by several independent operators. Two hundred sixty prostheses were implanted by two senior surgeons using the transgluteal approach. The Harris score and the De-Lee-Charnley radiological assessment as well as the Kaplan-Meier survival curve were determined.

Results: Seven cups were revised (3.8%): three because of aseptic loosening, two during stem revision because of polyethylene wear, and two for recurrent dislocation. Radiographically, four cups (2.2%) had migrated and there was a lucent line adjacent to the cup in at least one of the three De-Lee-Charnley zones for 23 cups (12.5%). There were no cup wing fractures. The mean Harris score for 144 patients (183 hips) was 90 points (range 37–100) at last follow-up. Outcome was considered excellent for 123 hips (67%), good for 34 (18.5%), fair for 20 and mediocre for five. The Kaplan-Meier 10-year survival with revision as the end point was 99% (CI: 94.8–99.8%).

Discussion: The 10-year survival of CLS-Spotorno cups is excellent with a low rate of revision. These results can be tempered by the radiological findings, although the lucent lines were already visible on the 12-month x-rays with no visible progression.

Conclusion: This cup provides excellent long-term results with a survival curve comparable to other press-fit cups. It is easy to position and revise.

Purpose of the study: Coxofemoral conflicts can sometimes lead to early degenerative disease in young patients. Open surgery for surgical dislocation with joint cleaning had provided promising short- and mid-term results. Arthroscopy of the hip joint is a less invasive alternative. The purpose of this work was to compare prospectively the outcome achieved with open surgical or arthroscopic treatment of coxofemoral conflicts after a minimum follow-up of two years.

Material and methods: Sixty-three patients, mean age 30 years (range 19–54) with arthroMRI-proven coxofemoral conflict were evaluated two years after treatment. Surgical dislocation was used for 31 patients and arthroscopy for 32. Clinical outcome was assessed on the basis of WOMAC scores noted preoperatively, postoperatively and at two years follow-up. Complications were noted.

Results: Results were similar in the two groups at two years: preoperative WOMAC score: 65/100 (41–95) pour open dislocation, 57/100 (15–96) for arthroscopy; postoperative WOMAC score at two years: 79/100 (41–99) for open dislocation, 84/100 (50–99) for arthroscopy. The rate of patient satisfaction was similar: (open dislocation: 75% and arthroscopy: 82%). Complications: open dislocation : 3 case of POA including 1 Brooker stage III and one 1 case of ossifying myositis of the thigh; arthroscopy: 2 case of hematoma (spontaneous resolution) and 1 case of transient irritation (48 h) of the lateral femoral cutaneous nerve. Surgical revisions at two years: open dislocation: one total hip arthroplasty at 15 months and one resection of ossification (POA) at 15 months; arthroscopy: two total hip arthroplasties at 5 and 15 months.

Discussion: The results obtained with the two methods are encouraging at two years. A satisfaction rate of 80% can be expected.

Conclusion: Arthroscopy appears to be the more advantageous alternative for young patients since it is less invasive and provides similar results at two years.

Purpose of the study: Coxofemoral conflicts can sometimes lead to early degenerative disease in young patients. Hip arthroscopy is a less invasive alternative which can remove all of the coxofemoral conflicts. Like open surgery, a purely arthroscopic technique enables all the necessary corrections, even involving the rim. Arthroscopy has provides promising short- and mid-term results. The purpose of this work was to present the surgical technique, its drawbacks and complications, and present suggestions for improvement.

Material and methods: Fifty-one patients, mean age 31 years (range 15–54 years) underwent purely arthroscopic treatment of coxofemoral conflicts between February 2001 and November 2003. Prospective follow-up was at least six months. The type of conflict and the corresponding corrections were noted. The Pre- and postoperative WOMAC scores were used for clinical assessment. Complications were noted as well as means for avoiding them.

Results: The operative technique, the potential dangers, and suggestions for successful arthroscopy are presented. The clinical outcome with at least six months follow-up was: hip R/L: 21/31. Head and acetabular correction: 46 cases. Head correction alone (head/neck offset): 5 cases. Preoperative WOMAC score: 59/100 (15–99). Postoperative WOMAC score: 85/100 (49–99). Complications: spontaneously resolutive hematoma (n=2), transient (48h) irritation of the lateral femoral cutaneous nerve (n=1).

Discussion: Purely arthroscopic correction of a coxofemoral conflict is as safe as the open surgical technique. The arthroscopic method provides very promising short- and mid-term results with no major complications. The lower morbidity with this technique enables ambulatory treatment with shorter recovery time.

Purpose of the study: Revision total hip arthroplasty (rTHA) is associated with higher mortality than primary total hip arthroplasty (pTHA). The functional outcome after rTHA is globally satisfactory but less so than with primary implantation. Nevertheless, data are scarce. Patients undergoing revision procedures are older and have more co-morbid conditions. In this context, we evaluated quality-of-life and patient satisfaction five years after implantation, comparing rTHA versus pTHA. We analyzed the impact of age, obesity, and co-morbid conditions.

Material and methods: The study cohort included all patients undergoing pTHA (n=471) OR rTHA (n=124) in our unit between 1996 and 2000. Five years postoperatively, we noted the Harris hip score (HHS) and patient satisfaction, assessed on a visual analog scale (VAS) from 1 to 10.

Results: The rTHA patients were older (72 yeras versus 68 years, p=0.004), more frequently obese (BMI30: 33% versus 19%, p=0.003) and presented more co-morbid conditions involving medical ( 2: 46% versus 21%, p< 0.001) and orthopedic ( 2: 13% versus 7%, p=0.053) problems. Five years after surgery, quality-of-life and patient satisfaction were much lower after rTHA than after pTHA (HHS < 70; 31% versus 9%, p< 0.001; satisfaction score 8: 68% versus 85%, p< 0.001). Adjustment for the preoprative status (ASA, medical and orthopedic comorbidity, BMI, gender, age) attenuated these differences which nevertheless remained significant [non-adjusted HHS difference: 11.5 (95%CI: 7.4–15.7); adjusted difference: 8.8 (95%CI: 5.5–12.1)]. In both groups, a low HHS was associated with BMI ≥ 30, poor preoperative function, 2 joints affected, elderly age. Obesity was associated with even poorer results after rTHA than after pTHA (non-adjusted difference, p=0.026).

Discussion: Quality-of-life and patient satisfaction at five years were clearly poorer after rTHA than after pTHA. This is in agreement with data in the literature. The difference is explained in particular by greater patient age and more associated comorbidities for rTHA. Obesity is a prognostic factor which is more unfavorable after rTHA than after pTHA.

Conclusion: Considering the risks and benefits of revision surgery, it is important to recognize not only the surgical factors but also the characteristic features of the patients.

We examined whether a selective cyclooxygenase-2 (COX-2) inhibitor (celecoxib) was as effective as a non-selective inhibitor (ibuprofen) for the prevention of heterotopic ossification following total hip replacement. A total of 250 patients were randomised to receive celecoxib (200 mg b/d) or ibuprofen (400 mg t.d.s) for ten days after surgery. Anteroposterior radiographs of the pelvis were examined for heterotopic ossification three months after surgery. Of the 250 patients, 240 were available for assessment. Heterotopic ossification was more common in the ibuprofen group (none 40.7% (50), Brooker class I 46.3% (57), classes II and III 13.0% (16)) than in the celecoxib group (none 59.0% (69), Brooker class I 35.9% (42), classes II and III 5.1% (6), p = 0.002). Celecoxib was more effective than ibuprofen in preventing heterotopic bone formation after total hip replacement.

Objective: To evaluate the outcome of open reduction and internal fixation of displaced proximal humerus fractures using a new locking plate.

Design: Prospective.

Setting: Level I university center.

Patients: Twenty-eight women and 22 men (mean age, 62.9 ± 19.l years). Twenty-nine patients were 65 years of age or older (mean age, 76.8 years). Fractures were classified according to AO/OTA as 11-A2 (n=3), A3 (n=12), B1 (n=4), B2 (n=18), B3 (n=1), C1 (n=1), and C2 (n=11). Mean follow-up was 19.8 months (range, 12 to 39 months).

Intervention: Open reduction and internal fixation with a proximal humerus locking plate.

Main Outcome Measurements: Raw and adjusted (sex and age) Constant score.

Results: Forty patients were available for follow-up. The mean raw Constant score was 66.6 (adjusted, 82.0). In patients under 65, the raw Constant score was 78.2 (adjusted score, 86.7). In patients over 65, the raw Constant score was 56.1 (adjusted score, 77.8). An excellent or good result was found in 72.5% overall. There was no secondary loss of position or implant cut-out. Seven patients (17.5%) developed avascular necrosis (AVN), 6 in C2 fractures in the older group. Their mean adjusted score was 60.7, as compared to 86.6 ± in those without AVN (p = 0.001).

Conclusions: The outcome was equally good in the younger and older age groups of patients, except in those who developed avascular necrosis. While the latter might be due to the nature of the fracture, it is also possible that surgical technique plays a role.

Introduction One of the most difficult aspects of shoulder arthroplasty is retroversion. The ideal angle is about 30 of posterior rotation of humeral head with regard to the frontal plane so that the humeral head squarely faces the glenoid surface in the resting position. The axis, lateral epicondyle- medial epicondyle is often taken as reference and serves as landmark in many arthroplasty instrumentation. [1,2]

Clinical experience has shown that estimating a 30 angle in space is definitely not easy even with the help of diverse goniometers.

Methods Each operator has to put 3 prostheses with a 30 degrees retroversion according to the position of the forearm so we had proceeded to 52 putting of prostheses .

The measures were made by taking into account of the humerus axis, the plan of condyles and angle of inclination of the collar, given by the angle of cutting. Three barycentres of the three humeral sections have determined the humeral axis. The condylar axis is determined from the 2 barycentres of the digitalized points on the anterior articular condylar surfaces. These 2 axis determine the frontal plane on which a reference mark R(x, y, z) is attached with Z lined up with the humeral shaft and X lined up on the condyles. Different angles could then be determined.

In the sagittal plan (perpendicular in the humeral axis), the retroversion angles of the prosthesis and the angle of cutting are calculated.

Results The standard deviation of the retroversion angle of the prosthesis is 14,22 which is really too high. In fact, 4 prostheses were inserted with poor retroversion (17°, 17°, 18°, 4,4°) and 20 with excessive retroversion (max =65°). This retroversion angle is not dependant on the other factors (cut angle, inclination angle...) The implant height was not taken into account

Conclusions Only 28 of the prostheses were placed in the right orientation within 20° to 40° of retroversion angle. It shows the difficulties to place a shoulder prosthesis in good position.even in standard conditions and with the standard marks.

Purpose: Fracture of the lateral process of the talus is exceptional. Diagnosis may be missed in 50% of patients, the fracture often being confused with severe ankle sprain. Through the seventies, less than 60 cases were reported in the literature. We report a retrospective study of seven cases treated surgically between 1990 and 2001.

Material and methods: We examined the different mechanisms leading to fracture of the lateral process of the talus and propose a therapeutic algorithm. All patients were seen at follow-up consultations. We used the AOFAS hindfoot evaluation scale, radiographs (anteroposterior view of the ankle and 3/4 lateral view of the foot, Broden views). Outcome was scored excellent, fair, or poor. Mean patient age was 33 years (20–51). Mean follow-up was six years (1–12). The patients incurred the fracture during a snowboard accident (n=1), motocycle accidents (n=3), defenestration (n=1), and mountain climbing accidents (n=2). Fractures resulted from forced eversion in one patient and high-energy trauma in six. Fracture classification according to Hawkins was type 1 (n=4, type 2 (n=3), and type 3 (n=1). Time from the accident to diagnosis was less than 15 days except in one patient where the diagnosis was made ten months after the trauma. Associated lesions were subtalar dislocation (n=2), talar neck fracture (n=1), medial malleolar fracture (n=1), and open fracture of the first cuneiform (n=1). The procedure consisted in fixation of the fragments without resection in four cases, resection of small fragments and fixation of large fragments in two, and osteotomy of a deformed callus of the lateral process of the talus in one. Weight bearing was not allowed four six weeks except in one patient with subtalar dislocation whose calcaneotalar pin was withdrawn at eight weeks.

Results: Complications were one case of superficial infection which resolved with antibiotic treatment and two cases of subtalar osteoarthritis at more than ten years. The overall score was 85 on average. The outcome was excellent in six cases and poor in one.

Discussion: A review of the literature shows that fracture of the lateral process of the talus occurs in 1% of all ankle lesions. Five mechanisms have been described. The two most frequent are ankle inversion in dorsiflexion and high-energy trauma. The three other mechanisms are eversion, direct trauma and stress fracture. The consequences of inadequate treatment include: late healing, non-union, deformed callus (one case in our series), avascular necrosis, subtalar instability, and joint incongruency with risk of subtalar and/or talofibular osteoarthrosis. The appropriate treatment depends on the time of diagnosis, the size and nature of the fracture and the degree of displacement. The therapeutic algorithm used in Geneva is as follows: orthopaedic treatment (plaster resting boot for six weeks followed by physiotherapy) associated with close surveillance in the event of a fracture measuring less than 5 mm which is generally extra- articular. If the patient considers this treatment is insufficient, removal of the fragment can be proposed. For fractures measuring more than 1 cm, which are generally intra-articular, surgical treatment is needed if the fragment is displaced more than 2 mm. In the event of late diagnosis, it may be necessary to remove the fragment or perform subtalar arthrodesis, or as needed resection of a deformed callus. If the diagnosis is established early and appropriate treatment given, the results have been excellent at six years.

We have assessed the long-term results after operative and non-operative treatment of undisplaced and displaced calcaneal fractures.

At a mean of 6.5 years, we reviewed 70 patients with a calcaneal fracture who were divided into four groups: group 1, 18 patients with undisplaced fractures and a normal Böhler’s angle (BA) who had been treated non-operatively; group 2, 23 with intra-articular fractures and a BA < 10° who had been treated non-operatively; group 3, 13 with intra-articular fractures and a BA > 10° who had been treated surgically; and group 4, 16 with intra-articular fractures and a BA < 10° who had been treated surgically.

The results were assessed by a clinical score considering pain, return to work, return to physical activity, change in shoe-wear and the requirement for subtalar arthrodesis.

Patients with undisplaced calcaneal fractures had a good outcome. Those with displaced fractures treated surgically who presented at follow-up with a BA > 10° had a satisfactory functional outcome and those with displaced fractures who had non-operative treatment had a poor outcome. The poorest outcome was consistently seen in patients who were treated operatively without restoration of BA. Open reduction and internal fixation of intra-articular calcaneal fractures can only be expected to benefit those patients in whom nearly anatomical reconstruction is obtained.

Aims: To describe the proþle of patients older than 65 years of age with a fracture of the upper extremity, and the consequence of such an injury. Methods: Retrospective cohort study of 667 patients presenting to the emergency department between January 1999 and December 2000 with a fracture of the upper extremity. Variables included sex, age, location of fracture (± additional fractures), treatment, length of stay (in hospital and convalescent care), and place of habitation before and after injury. Follow-up continued until patientsñ deþnitive residential status. Results: The majority of patients were women with fractures of the wrist and proximal humerus. 42% were treated and returned to their previous residence. 37% were admitted to the hospital, of whom 90% had an operation; 97% returned to their previous residence. 21% of patients did not require an operation, but were unable to function independently and were admitted directly to our Geriatrics Hospital. This group was signiþcantly older and more frequently sustained a fracture of the proximal humerus or 2 fractures. 20% required long-term placement. Conclusions: Fractures of the upper extremity in this age group are frequent. A particular subset of signiþcantly older patients are unable to function independently, thus requiring hospitalization, extended periods of convalescence, and a greater likelihood of a permanent change in habitation.

Aims: To determine the precision of conventional versus computer assisted techniques for positioning the acetab-ular component in total hip arthroplasty (THA). Methods: Using a lateral approach, 150 cups were placed by 10 different surgeons in 10 identical plastic pelvis models. Only the immediate operating þeld was visible. Preoperative planning was performed with a computerized tomographic scan. Fifty cups were placed free hand, 50 others with the standard cup ancillary, and the remaining 50 cups using computer-assisted orthopaedic surgery. The accuracy of cup abduction and ante-version was assessed with an electromagnetic system. Results: Using conventional techniques, free hand placement revealed a mean precision of cup anteversion and abduction of 10¡ [range: 5.5–14] and 3.5¡ [2.5–5] respectively. With the cup positioner, these angles measured 8¡ [5–10.5] and 4¡ [3–5.5] respectively, and using the computer assisted method, the mean cup anteversion precision was 1.5¡ [1–2] and mean cup abduction measured 2.5¡ [2–3.5]. Conclusions: Computer assisted cup placement is a very accurate and reproducible technique during THA. It is clearly more precise than either of the two traditional methods of cup positioning, even for well-trained surgeons.

Aims: The diagnosis of a prosthetic joint infection is difþcult, but crucial for appropriate treatment. Scintigraphy with speciþc markers for infection (labeled white cells or immunoglobulin-G) has been reported as a more reliable diagnostic tool than clinical assessment (fever, þstula), laboratory studies [polynuclear neutrophils blood count (PNC), erythrocyte rate sedimentation (ESR), and C-reactive protein (CRP)], and preoperative aspiration. Methods: In the þrst part of this study, we retrospectively reviewed 230 patients admitted with a suspected prosthetic joint infection and compared the validity of these different diagnostic tools. 209 patients had an infection. Results: Pain, fever, ESR, and PNC are unreliable for identifying occult infection. The presence of a þstula is inconstant, but when present is very reliable to detect infection. Our study revealed sensitivity, speciþcity, positive and negative predictive value as follows: CRP: 97%, 81%, 98%, 71% respectively; aspiration: 82%, 94%, 99%, 43% respectively, and labelled scintigraphy 74%, 76%, 91%, 44% respectively. In the second part, we reviewed 23 articles which included 1,722 prosthetic joints with preoperative evaluation of infection. Conclusions: Both our study and the literature review indicate that CRP and joint aspiration are the best tools to diagnose prosthetic joint infection.

Purpose: Heterotopic ossification is a recognised complication after total hip arthroplasty. Prevalence can reach 53%, particularly if prophylaxis is not given, leading to postoperative pain and limiting the functional prognosis. Non-steroidal antiinflammatory drugs have proven efficacy but also present the risk of gastroduodenal toxicity making postoperative administration hasardous. Recently, selective COX-2 inhibitors have been shown to have a similar antiinflammatory activity with a clear reduction in gastrointestinal disorders. We hypothesised that selective COX-2 inhibitors could be as effective as classical NSAID for the prevention of heterotopic ossifications.

Material and methods: This clinical trial was conducted according to a prospective randomised protocol comparing a group of patients given prophylaxis with Celecoxib (Celebrex®) and another group of patients given ibuprofen (Brufen®). All patients scheduled for total elective prostheses were radomised in a prospective manner to one of the two groups, either Celecoxib 200mg b.i.d. or ibuprofen 400mg t.i.d. for ten immediate postoperative days. Radiological assessment was performed by two independent investigators blinded to the study (an orthopaedic surgeon and a radiologist) who scored calcifications according to the Brooker classification (type I to IV) at three months after surgery. Reproducibility of radiogram reading was tested and analysed with a kappa test K=0.74).

Results: Two hundred ten patients were randomised and 73 have had their three-month radiograms. The Cele-coxib group included 37 patients: 24 with Brooker stage 0, eleven with stage 1, two with stage 2. The ibuprofren group included 42 patients, 15 with Brooker 0, 16 with Brooker 1; nine with Brooker 2 and two with Brooker 3. The statistical analysis will be performed at the end of this study (June 2002).

Discussion: The preliminary results show that Celecoxib appears to have the same efficacy as ipubrofen for the prevention of heterotopic ossification after total hip arthroplasty. There was a clear trend in favour of Celecoxib.

The aim of the study was to determine the precision of conventional versus computer-assisted techniques for positioning the acetabular component in total hip arthroplasty (THA).

Malposition of the acetabular component during THA increases the occurrence of impingement, reduces range of motion, and increases the risk of dislocation and long-term wear. To prevent malpositioned hip implants, an increasing number of computer assisted surgery systems have been described, but their accuracy is not well established.

Using a lateral approach, 150 cups were placed by 10 different surgeons in 10 identical plastic pelvis models. Only the immediate operating field was visible. Pre-operative planning was performed with a computerised tomography scan. Fifty cups were placed free hand, 50 others with the standard cup positioner, and the remaining 50 cups using computer-assisted orthopaedic surgery (Medivision). The accuracy of cup abduction and anteversion was assessed with an electromagnetic system (Fastrak™).

Using conventional techniques, free hand placement revealed a mean precision of cup anteversion and abduction of 10° [range 5.5 to 14] and 3.5° [2.5 to 5] respectively. With the cup positioner, these angles measured 8° [5 to 10.5] and 4° [3 to 5.5] respectively, and using the computer assisted method, the mean cup anteversion precision was 1.5° [1 to 2] and mean cup abduction measured 2.5° [2 to 3.5].

Computer assisted cup placement is a very accurate and reproducible technique during THA. It is clearly more precise than either of the two traditional methods of cup positioning, even for well-trained surgeons.

To determine the precision of conventional versus computer assisted techniques for positioning the acetabular component in total hip arthroplasty (THA).

Malposition of the acetabular component during THA increases the occurrence of impingement, reduces range of motion, and increases the risk of dislocation and long-term wear. To prevent malpositioned hip implants, an increasing number of computer assisted surgery systems have been described, but their accuracy is not well established.

Using a lateral approach, 150 cups were placed by 10 different surgeons in 10 identical plastic pelvis models. Only the immediate operating field was visible. Pre-operative planning was performed with a computerised tomography scan. Fifty cups were placed free hand, 50 others with the standard cup positioner, and the remaining 50 cups using computer-assisted orthopaedic surgery (Medivision). The accuracy of cup abduction and anteversion was assessed with an electromagnetic system (Fastrak™).

Using conventional techniques, free hand placement revealed a mean precision of cup anteversion and abduction of 10° (range 5.5 to 14) and 3.5° (2.5 to 5) respectively. With the cup positioner, these angles measured 8° (5 to 10.5) and 4° (3 to 5.5) respectively, and using the computer assisted method, the mean cup anteversion precision was 1.5° (1 to 2) and mean cup abduction measured 2.5° (2 to 3.5).

Computer assisted cup placement is a very accurate and reproducible technique during THA. It is clearly more precise than either of the two traditional methods of cup positioning, even for well-trained surgeons.