Tolerance and microbiological efficacy of cefepime or piperacillin/tazobactam in combination with vancomycin as empirical antimicrobial therapy of prosthetic joint infection: a propensity-matched cohort study

BACKGROUND

The use of piperacillin/tazobactam with vancomycin as empirical antimicrobial therapy (EAT) for prosthetic joint infection (PJI) has been associated with an increased risk of acute kidney injury (AKI), leading us to propose cefepime as an alternative since 2017 in our reference centre.

OBJECTIVES

To compare microbiological efficacy and tolerance of these two EAT strategies.

METHODS

All adult patients with PJI empirically treated with vancomycin+cefepime (n = 89) were enrolled in a prospective observational study and matched with vancomycin+piperacillin/tazobactam-treated historical controls (n = 89) according to a propensity score including age, baseline renal function and concomitant use of other nephrotoxic agents. The two groups were compared using Kaplan-Meier curve analysis, and non-parametric tests regarding the proportion of efficacious empirical regimen and the incidence of empirical therapy-related adverse events (AE).

RESULTS

Among 146 (82.0%) documented infections, the EAT was considered efficacious in 77 (98.7%) and 65 (98.5%) of the piperacillin/tazobactam- and cefepime-treated patients, respectively (P = 1.000). The rate of AE, particularly AKI, was significantly higher in the vancomycin+piperacillin/tazobactam group [n = 27 (30.3%) for all AE and 23 (25.8%) for AKI] compared with the vancomycin+cefepime [n = 13 (14.6%) and 6 (6.7%)] group (P = 0.019 and <0.001, respectively), leading to premature EAT discontinuation in 20 (22.5%) and 5 (5.6%) patients (P = 0.002). The two groups were not significantly different regarding their comorbidities, and AKI incidence was not related to vancomycin plasma overexposure.

CONCLUSIONS

Based on the susceptibility profile of bacterial isolates from included patients, microbiological efficacy of both strategies was expected to be similar, but vancomycin + cefepime was associated with a significantly lower incidence of AKI.

Microbiologic epidemiology depending on time to occurrence of prosthetic joint infection: a prospective cohort study

OBJECTIVES

The high microbiologic diversity encountered in prosthetic joint infection (PJI) makes the choice of empirical antimicrobial therapies challenging, especially in cases of implant retention or one-stage exchange. Despite the risk of dysbiosis and toxicity, the combination of vancomycin with a broad-spectrum β-lactam is currently recommended in all cases, even if Gram-negative bacilli (GNB) might be less represented in late PJI. In this context, this study aimed to describe the microbiologic epidemiology of PJI according to the chronology of infection.

METHODS

This prospective cohort study (2011-2016) evaluated the microbiologic aetiology of 567 PJI according to time of occurrence from prosthesis implantation-early (<3 months), delayed (3-12 months) and late (>12 months)-as well as mechanism of acquisition.

RESULTS

Initial microbiologic documentation (n = 511; 90.1%) disclosed 164 (28.9%) Staphylococcus aureus (including 26 (16.1%) methicillin-resistant S. aureus), 162 (28.6%) coagulase-negative staphylococci (including 81 (59.1%) methicillin-resistant coagulase-negative staphylococci), 80 (14.1%) Enterobacteriaceae, 74 (13.1%) streptococci and 60 (10.6%) Cutibacterium acnes. Considering nonhaematogenous late PJI (n = 182), Enterobacteriaceae (n = 7; 3.8%) were less represented than in the first year after implantation (n = 56; 17.2%; p <0.001), without difference regarding nonfermenting GNB (4.6% and 2.7%, respectively). The prevalence of anaerobes (n = 40; 21.9%; including 32 (80.0%) C. acnes) was higher in late PJI (p <0.001). Consequently, a broad-spectrum β-lactam might be useful in 12 patients (6.6%) with late PJI only compared to 66 patients (20.3%) with early/delayed PJI (p <0.001).

CONCLUSIONS

Considering the minority amount of GNB in late postoperative PJI, the empirical use of a broad-spectrum β-lactam should be reconsidered, especially when a two-stage exchange is planned.

What are the risk factors for dislocation in primary total hip arthroplasty? A multicenter case-control study of 128 unstable and 438 stable hips

INTRODUCTION

Dislocation after total hip arthroplasty (THA) is a leading reason for surgical revision. The risk factors for dislocation are controversial, particularly those related to the patient and to the surgical procedure itself. The differences in opinion on the impact of these factors stem from the fact they are often evaluated using retrospective studies or in limited patient populations. This led us to carry out a prospective case-control study on a large population to determine: 1) the risk factors for dislocation after THA, 2) the features of these dislocations, and 3) the contribution of patient-related factors and surgery-related factors.

HYPOTHESIS

Risk factors for dislocation related to the patient and procedure can be identified using a large case-control study.

PATIENTS AND METHODS

A multicenter, prospective case-control study was performed between January 1 and December 31, 2013. Four patients with stable THAs were matched to each patient with a dislocated THA. This led to 566 primary THA cases being included: 128 unstable, 438 stable. The primary matching factors were sex, age, initial diagnosis, surgical approach, implantation date and type of implants (bearing size, standard or dual-mobility cup).

RESULTS

The patients with unstable THAs were 67±12 [37-73]years old on average; there were 61 women (48%) and 67 men (52%). Hip osteoarthritis (OA) was the main reason for the THA procedure in 71% (91/128) of the unstable group. The dislocation was posterior in 84 cases and anterior in 44 cases. The dislocation occurred within 3 months of the primary surgery in 48 cases (38%), 3 to 12 months after in 23 cases (18%), 1 to 5years after in 20 cases (16%), 5 to 10years after in 17 cases (13%) and more than 10years later in 20 cases. The dislocation recurred within 6 months of the initial dislocation in 23 of the 128 cases (18%). The risk factors for instability were a high ASA score with an odds ratio (OR) of 1.93 (95% CI: 1.4-2.6), neurological disability (cognitive, motor or psychiatric disorders) with an OR of 3.9 (95% CI: 2.15-7.1), history of spinal disease (lumbar stenosis, spinal fusion, discectomy, scoliosis and injury sequelae) with an OR of 1.89 (95% CI: 1.0-3.6), unrepaired joint capsule (all approaches) with an OR of 4.1 (95% CI: 2.3-7.37), unrepaired joint capsule (posterior approach) with an OR of 6.0 (95% CI: 2.2-15.9), and cup inclination outside Lewinnek's safe zone (30°-50°) with OR of 2.4 (95% CI: 1.4-4.0).

DISCUSSION

This large comparative study isolated important patient-related factors for dislocation that surgeons must be aware of. We also found evidence that implanting the cup in 30° to 50° inclination has a major impact on preventing dislocation.

LEVEL OF EVIDENCE

Level III; case-control study.

Can a target zone safer than Lewinnek's safe zone be defined to prevent instability of total hip arthroplasties? Case-control study of 56 dislocated THA and 93 matched controls

BACKGROUND

Various factors contribute to instability of total hip arthroplasty (THA), with implant orientation being a major contributor. We performed a case-control study with computed tomography (CT) data to determine whether: 1) orientation contributes to THA instability and 2) a safer target zone for stability than Lewinnek's classic safe zone can be defined.

MATERIAL AND METHODS

We included prospectively 363 cases of THA dislocation that occurred during the calendar 2013 year in 24 participating hospitals. Of the 128 dislocations that occurred in patients who underwent THA at these centers, 56 (24 anterior, 32 posterior) had CT scans, thus were included in the analysis. The control group was matched 4:1 based on implant type, year of implantation, age, sex, bearing types and THA indication. Of the 428 matched control THA cases, 93 had CT scans. In all, the CT scans from 149 cases (56 unstable, 93 stable) were analyzed to determine the acetabular cup's inclination and anteversion, and the femoral stem's anteversion.

RESULTS

In the unstable THA group, cup inclination was 46.9°±7.4°, cup anteversion was 20.4°±10.8° and stem anteversion was 14.2°±9.9°. In the stable THA group, cup inclination was 44.9°±5.3° (P=0.057), cup anteversion was 22.1°±5.1° (P=0.009) and stem anteversion was 13.4°±4.4° (P=0.362). The optimal total anteversion (cup+stem) of 40-60° was achieved in 16.5% of unstable THA cases and 13.9% of stable THA cases, thus this parameter does not predict stability (odds ratio [OR] of 0.40, P=0.144). The cup was positioned in Lewinnek's safe zone in 44.6% of patients in the unstable group and 68.2% of those in the stable group (OR 3.74, P=0.003). A target zone defined as 40-50° inclination and 15-30° anteversion was better able to distinguish between unstable cases (23.2%) and stable cases (71.6%) resulting in an OR of 13.91 (P<0.001).

DISCUSSION

Implant positioning was the only risk factor for instability found in this study. Moreover, our findings reinforce the theory put forward by other authors that Lewinnek's safe zone is not specific enough to differentiate between stable and unstable THA implantations. The target zone for acetabular cups proposed here (40-50° inclination and 15°-30° anteversion) is related to a lower risk of instability. This orientation can be used as a guide, but must be combined with other technical elements to optimize stability. By balancing stability and biomechanics, the 40-50° inclination and 15°-30° anteversion target zone redefines the optimal positioning window.

LEVEL OF EVIDENCE

III case-control study.

Similar levels of pain are reported in forefoot surgery after management as a day case and admission for 48 hours

While many forefoot procedures may be performed as a day case, there are no specific guidelines as to which procedures are suitable. This study assessed the early post-operative pain after forefoot surgery performed a day case, compared with conventional inpatient management.

A total of 317 consecutive operations performed by a single surgeon were included in the study. Those eligible according to the criteria of the French Society of Anaesthesia (SFAR) were managed as day cases (127; 40%), while the remainder were managed as inpatients.

The groups were comparable in terms of gender, body mass index and smoking status, although the mean age of the inpatients was higher (p < 0.001) and they had higher mean American Society of Anaesthesiologists scores (p = 0.002). The most severe daily pain was on the first post-operative day, but the levels of pain were similar in the two groups; (4.2/10, sd 2.5 for day cases, 4.4/10, sd 2.4 for inpatients; p = 0.53). Overall, 28 (9%) of patients who had their surgery as a day case and 34 (11%) of inpatients reported extreme pain (≥ 8/10). There were more day case patients rather than inpatients that declared their pain disappeared seven days after the surgery (p = 0.02). One day-case patient with excessive bleeding was admitted post-operatively.

Apart from the most complicated cases, forefoot surgery can safely be performed as a day case without an increased risk of pain, or complications compared with management as an inpatient.

Cite this article: Bone Joint J 2015;97-B:1645–50.

Compared fixation and survival of 280 lateralised vs 527 standard cementless stems after two years (1-7)

BACKGROUND

Restoring the native hip anatomy increases hip prosthesis survival, whereas increased femoral lateralisation creates high torque stresses that may alter prosthesis fixation. After finding lucent lines around cementless lateralised stems (Corail™, DePuy Synthes, St Priest, France) in several patients, we evaluated the effects of lateralisation in a large case-series. The objective of our study was to compare lateralised vs standard stems of identical design in terms of radiological osteo-integration and survival.

HYPOTHESIS

Lateralised stems, despite being used only when indicated by the anatomical parameters, carry a higher risk of impaired osteo-integration.

MATERIALS AND METHODS

A retrospective study was conducted in 807 primary total hip arthroplasties (THAs) performed between 2006 and 2010 in 798 patients with a mean age of 65 ± 14.2 years. Lateralised stems were used in 280 cases (Corail High Offset KHO, n = 169; and Corail coxa vara KLA, n = 111 cases) and standard stems in 527 cases (Corail KA). Mean follow-up was 2.3 years (range, 1-7 years). The clinical evaluation included determination of the Postel-Merle d'Aubigné (PMA) score. Bone fixation and stability of the implants were assessed by determining the Engh and Massin score and the ARA score on the radiographs at last follow-up. Femoral, acetabular and global offset values were determined before and after THA. Nobles's Canal Flare Index was computed. Survival was estimated using the Kaplan-Meier method with surgical revision for aseptic loosening as the end-point.

RESULTS

The PMA score improved from 12 (10-15) pre-operatively to 17.7 (14-18) (P < 0.05). After THA, in the lateralised stem group, femoral offset was restored in 217 (77%) hips and the mean change vs the pre-operative offset value was -2 mm; in the standard stem group, femoral offset was restored in 440 (83.5%) hips and the mean change was +1 mm. The Engh and Massin score values were similar in the standard stem and lateralised stem groups (24.4 ± 2.2 and 22.6 ± 2.4, respectively, NS). Revision for aseptic loosening was required in 5 patients with lateralised stems (3 KHO and 2 KLA) versus none of the patients with standard stems. There were no cases of excessive femoral offset and the mean change in offset was -2.3mm (-5.3 to -1.1). Noble's index was increased (4.27 ± 0.5 for the loosened lateralised stems, 3.65 ± 0.8 for the well-fixed lateralised stems and 3.82 ± 0.6 for the standard stems), with no significant difference across groups. Overall survival after 3.5 years of follow-up was 94.6% (95% confidence interval, 88.4-100%) with lateralised stems and 100% with standard stems (P < 0.05).

DISCUSSION

The risk of aseptic loosening was significantly higher with the lateralised stem (5/280, 1.8%) than with the standard stem (n = 0). Our findings indicate a need for careful preparation to obtain primary fixation of lateralised stems.

LEVEL OF EVIDENCE

III, retrospective case-control study.

Comparison of quality of life following total ankle arthroplasty and ankle arthrodesis: Retrospective study of 54 cases

INTRODUCTION

The benefit of ankle arthroplasty compared to arthrodesis continues to be debated, but the quality of life after these two interventions has rarely been assessed. We conducted a case-control study to compare quality of life and functional and athletic ability.

HYPOTHESIS

Functional results, athletic ability, and quality of life after total ankle arthroplasty (TAA) are better than after ankle arthrodesis.

MATERIAL AND METHODS

Two continuous series of 59 TAAs and 46 arthrodeses (operated on between 1997 and 2009) were evaluated retrospectively using a questionnaire including the functional items of the AOFAS score, the Foot Function Index (FFI) score, the Foot Ankle Ability Measure (FAAM), and the SF-36.

RESULTS

Eighty-three responses (79% of the overall series) were matched in two groups: 32 TAAs [age at the intervention, 51.4years (range, 21-63years); follow-up, 52.2months (range, 30-146months); age at revision, 55.8years (range, 26-67years); BMI, 27.7 (range, 21.7-36.7)] and 22 arthrodeses [age at intervention, 50.1years (range, 24-72years); follow-up 57.9months (range, 12-147months); age at revision 54.9 years (range, 31-75years); BMI, 26.8 (range, 17.6-37)] (NS on all items between the two groups). The pain results were better after TAA, but with no statistically significant difference: AOFAS pain, (/40) 28.1±8.2 vs. 24.5±9.6; FFI pain, 16.6±18.8 vs. 24.3±21.5. The overall FFI score (/100) was better (P=0.048) after TAA (16.2±16.5 vs. 24.8±18.2). The overall mean athletic level compared to the state prior to the injury was relatively low in both groups, but significantly (p=0.007) higher in the TAA group: FAAM sports score (/100), 49.5±24.4 vs. 29.8±26.2. The quality-of-life scores, SF-36 physical health, mental health, and general health were not significantly different after TAA and arthrodesis: mental health score, 63.1±14.7 vs. 57.8±21.5; physical health score, 61.3±17.8 vs. 53.7±23.9, overall score, 63.2±16.4 vs. 55.9±23.5.

DISCUSSION

Very few publications describe activities and quality of life after TAA and arthrodesis. Despite weaknesses, this comparative study demonstrates a tendency toward better functional results after TAA than after ankle arthrodesis, without the difference between the two groups being very significant. On the other hand, there was no difference in terms of quality of life. After the doubts raised by publications on severe periprosthetic osteolysis at the intermediate term with certain TAA models, these results encourage pursuit of implantation and development of TAA.

LEVEL OF PROOF

Comparative retrospective. Level III study.

Autologous chondrocyte implantation for traumatic full-thickness cartilage defects of the knee in 14 patients: 6-year functional outcomes

BACKGROUND

Autologous chondrocyte implantation (ACI) was introduced in 1987 in Sweden by Brittberg and Peterson for the treatment of severe chondral defects of the knee. Here, our objective was to evaluate mid-term outcomes of ACI in young athletic patients with deep chondral defects of the knee after trauma.

HYPOTHESIS

ACI is effective in filling full-thickness chondral defects of the knee.

PATIENTS AND METHODS

We prospectively monitored 14 patients, with International Cartilage Repair Society grade III or IV lesions, who underwent ACI between 2001 and 2006. Standard evaluation measurements were used. Mean age at surgery was 37.7 years (range, 30-45). A history of surgery on the same knee was noted in ten (67%) patients. The defect was on the medial femoral condyle in 11 patients, lateral femoral condyle in two patients, and both femoral condyles in one patient. Mean defect surface area after debridement was 2.1cm(2) (1-6.3).

RESULTS

After a mean follow-up of six years, improvements were noted in 12 (86%) patients, with an International Knee Documentation Committee (IKDC) score increase from 40 (27.6-65.5) to 60.2 (35.6-89.6) (P=0.003) and a Brittberg-Perterson score decrease from 54.4 (11.8-98.2) to 32.9 (0-83.9) (P=0.02), between the preoperative assessment and last follow-up. The visual analogic scale pain score decreased from 66.3 (44-89) to 23.2 (0-77) (P=0.0006). In two (14%) patients, no improvements were detectable at last follow-up. The remaining 12 patients were satisfied and able to resume sporting activities, albeit at a less strenuous level. Two ACI-specific complications occurred, namely, periosteal hypertrophy treated with debridement in one patient and transplant delamination in another.

DISCUSSION

Our findings are consistent with previous reports but cover a longer follow-up period. Although the outcomes are promising, longer follow-ups are needed to confirm the long-term effectiveness of ACI.

LEVEL OF EVIDENCE

IV, prospective therapeutic study.

Distal osteotomy of the lateral metatarsals: a series of 72 cases comparing the Weil osteotomy and the DMMO percutaneous osteotomy

INTRODUCTION

A Weil osteotomy with internal fixation can match the preoperative plan by precisely setting the metatarsal length; however 10 to 30% of patients end up experiencing postoperative stiffness. A percutaneous distal metatarsal mini-invasive osteotomy (DMMO) is a purely extra-articular technique; metatarsal length is set automatically upon weight bearing of the foot. The goal of this study was to compare these two osteotomy techniques when performed on the three or four most lateral metatarsals.

HYPOTHESIS

A DMMO will result in better joint motion than a Weil osteotomy.

PATIENTS AND METHODS

This was a retrospective, single center, single surgeon study with 72 patients. Group 1 consisted of 39 patients operated by the DMMO technique. Group 2 consisted of 33 patients operated by the standard Weil osteotomy technique. In some cases, a procedure on the first ray (Scarf or fusion) was also performed. The age, gender and procedures on the first ray were comparable for both groups. Patients were evaluated with clinical (AOFAS score) and radiological outcomes (Maestro criteria) at 3 and 12 months minimum follow-up.

RESULTS

Sixty-seven patients were seen again with an average follow-up of 14.8 months (range 12-24). The postoperative AOFAS score was comparable in both groups (86.5 and 85.3, respectively). The joint range of motion was comparable in both groups. Static problems (oedema, metatarsalgia, hyperkeratosis and dislocation) were comparable at the last follow-up. The metatarsalgia recurred in four patients from group 1 and five patients from group 2. After 3 months, oedema and metatarsalgia were significantly greater in group 1. Radiological measurements (M1P1angle, M1M2angle and Maestro criteria) were comparable. Metatarsal head recoil was identical between each ray in group 1. At the last follow-up, all the osteotomy sites had achieved union.

DISCUSSION AND CONCLUSION

The results of static metatarsalgia treatment were comparable when using a DMMO or Weil osteotomy. However the DMMO had longer postoperative recovery, notably because of oedema. The percutaneous DMMO technique did not improve joint range of motion.

LEVEL OF EVIDENCE

III, comparative retrospective study.

Patella osteochondritis dissecans end stage: The osteochondral mosaicplasty option

INTRODUCTION

Patellar damage during osteochondritis dissecans of the knee is rare. There were two objectives to this study: evaluate the functional results of surgical treatment by mosaicplasty in this disease as well as evaluate articular surface reconstruction and cylindrical bone plugs incorporation.

MATERIALS AND METHODS

Six consecutive cases of patella osteochondritis dissecans in young athletes were treated using mosaicplasty by the same senior surgeon between 2002 and 2007. All these cases presented ICRS stage IV osteochondritis dissecans with an empty defect lesion. The average age at diagnosis was 20.5 ± 9.2 years old. The pre- and post-operative clinical evaluation was based on the IKDC subjective knee evaluation, the Lysholm and Tegner scores, CT arthrography and MRI.

RESULTS

Evaluation of the functional results of surgical treatment at a mean follow-up of 26 months showed an average IKDC subjective evaluation score of 66.3, a Lysholm score of 85 and a Tegner score of 5.7 (37.2, 58.3 and 3.5 respectively before surgery). The radiological evaluation showed articular surface reconstruction with satisfying congruency and good incorporation of the graft into the bone at the receptor site, except in one patient in whom a 5mm diameter cartilage defect and a loose body were identified.

DISCUSSION

Osteochondral grafting with the mosaicplasty technique has been shown to be effective and give satisfying functional results. The problem of the per-operative cylindrical bone plugs choice requires to be addressed during the procedure course itself, according to the patella lesion location.

Kinematics of a cementless mobile bearing posterior cruciate ligament-retaining total knee arthroplasty

Mobile bearing (MB) total knee arthroplasty (TKA) was developed to provide low contact stress and unconstrained joint motion. We studied a consecutive series of 41 knees with mobile-bearing, posterior cruciate-retaining (CR) TKAs to determine if kinematics resembled normal knees or if kinematics changed over time. Patients were studied at 3 and 21 months average follow-up with weight-bearing radiographs at full extension, 30 degrees flexion and maximum flexion. Shape-matching techniques were used to measure TKA kinematics. Implant hyperextension, maximum flexion and total ROM increased with follow-up. Tibial rotation and condylar translations did not change with time. The medial condyle did not translate from extension to 30 degrees, but translated 5 mm anteriorly from 30 degrees to maximum flexion. Lateral condylar translation was 3 mm posterior from extension to 30 degrees, with no translation from 30 degrees to maximum flexion. Tibiofemoral kinematics in CR-MB-TKAs were stable over time, but did not replicate motions observed in healthy knees. The mobile tibial insert showed rotation and translation at both follow-up examinations, but the patterns of translation were not predictable.

Comparative study of knee anterior cruciate ligament reconstruction with or without fluoroscopic assistance: a prospective study of 73 cases

INTRODUCTION

Correct placement of both tibial and femoral tunnels is one of the main factors for a favorable clinical outcome after anterior cruciate ligament (ACL) reconstruction. We used an original system of computer assisted surgery (CAS). The system, based on fluoroscopic guidance combined with special graphical software of image analyzing, showed to the surgeon, before drilling, the recommended placement of tibial and femoral tunnel centers. We compared the first anatomical and clinical results of this procedure to the usual one single incision technique.

MATERIALS AND METHODS

We conducted a prospective study on 73 patients; 37 patients were operated on with CAS and 36 without CAS, by the same senior surgeon. The mean age was 27 years for both groups. Every patient was reviewed at an average of 2.2 years (range 1-4.5) by an independent observer, using IKDC scoring system, KT-1000, and passive stress radiographs.

RESULTS

Time between ACL rupture and reconstruction averaged 30 months for both groups. CAS needed 9.3 min extra surgery time. Clinical evaluation was graded from A to C as per the IKDC scoring system: 67.6% A, 29.7% B, 2.7% C with CAS; and 60% A, 37.1% B, 2.9% C without CAS. IKDC subjective knee evaluation score averaged 89.7 with CAS and 89.5 without CAS. Pre operative KT-1000 maxi manual differential laxity averaged 7. At revision time, all the patients after CAS had a differential laxity less than 2 and 97.7% without CAS. Stress X-rays differential laxity averaged 2.4 mm with CAS and 3 mm without CAS. The area of dispersion of the tunnels' center was smaller on the femoral side using the CAS method. There was no statistically significant difference between both groups using IKDC score, KT-1000 and passive stress radiographs.

CONCLUSIONS

The CAS method provided a more accurate and reproducible tunnels placement without clinical significant effect.

[Survival of cementless dual mobility sockets: ten-year follow-up]

PURPOSE OF THE STUDY

We report a retrospective series of 106 total hip prosthesis with ten years follow-up. The purpose of this study was to analyze survival of cementless dual mobility sockets.

MATERIAL AND METHODS

The series included 90 consecutive patients with 106 first-intention total hip prosthesis, all with cementless dual mobility sockets. All prosthesis (Novae-1 socket and Profil-1 stem, Serf) were implanted within a 6-month period. The stainless steal socket was coated with alumina and had two short anchorage studs and a superior mooring screw and a polyethylene retentive liner. The stem had a 22.2 mm chromium cobalt head. The main indication for arthroplasty was degenerative joint disease. Mean age at implantation was 56 years (range 23-87). All patients were seen for physical examination and x-rays every two or three years. We noted cup survival at ten years (actuarial method), defining surgical revision for cup replacement due to an aseptic cause as the endpoint.

RESULTS

Twelve patients died during the 10-year follow-up and one was lost to follow-up. The Postel-Merle d'Aubligné score improved from 7.1 preoperatively to 15.8 at ten years. There were two isolated acetabular loosenings, two intra-prosthetic dislocations due to advanced wear of the polyethylene insert. The overall survival rate of the socket was 94.6% at ten years. There were no episodes of prosthetic instability in this series.

DISCUSSION

This study demonstrates the good ten-year survival of the dual mobility socket, comparable to that of conventional prostheses. The absence of any case of prosthetic instability in this series confirms the good short-term and long-term stability of the dual mobility socket. Intraprosthetic dislocation, due to loss of the polyethylene retaining ring is the main limitation of this method. The incidence was however low (2% at ten years) and treatment was not a problem. We recommend using the dual-mobility socket as the first-intention implant for patients with a high risk of post-operative instability, but also recommend it for all patients aged over 70 years since instability is the leading cause of surgical revision after this age.

Masse inguinale révélatrice d’une complication d’une arthroplastie totale de hanche

The iliopsoas bursa is situated immediately anterior to the hip joint. Communication can develop between a hip prosthesis and the iliopsoas bursa leading to distension and formation of an inguinal mass revealing complication of total hip arthroplasty. We report five clinical cases. The five patients with a total hip arthroplasty developed a mass in the Scarpa triangle which correlated with defective prosthesis function. We chose not to dissect the cystic mass but to treat the intra-articular cause. Symptoms resolved after the intervention in all cases. This rare condition should be envisioned if an inguinal mass develops or has a functional impact, particularly on the lymphovenous circulation. Anatomic relations can be distinguished with computed tomography. Prosthetic complications include infection, loosening or wear. The work-up should include search for infection and standard x-rays of the hip joint. Before surgery, duplex Doppler should be performed systematically to search for a thromboembolic complication.

[Value of percutaneous core needle biopsy in the investigation of a suspected bone tumor]

PURPOSE

To Determine the value of percutaneous core needle biopsy in the investigation of a suspected bone neoplasm.

MATERIAL AND METHODS

We performed a retrospective study of 91 core needle biopsies performed between May 1995 and October 2001. Patients were excluded if they had a known primary carcinoma or if an infection was suspected by clinical, physical or laboratory findings. The results were correlated to the analysis of the surgical piece or, for the 28 patients who did not undergo surgery, to the clinical evolution over more than 12 months.

RESULTS

The final diagnosis was metastasis in 29 cases, primary bone tumor in 36 cases and benign lesions in 25 cases. Sensitivity was 92.3% and specificity was 97.4%. For primary malignant bone tumors, results respected histology features and grade in 79.2%. In cases of mistake, because of the correlation of these results to the clinical and radiological context, the treatment of the bony malignant lesions were adapted in 95.8% of cases. Only one major complication was reported in these 91 biopsies.

CONCLUSION

First intention core needle biopsy, confronted with radio-clinical context seems to have a place in the evaluation of bone lesions when a tumor is suspected. This technique, less expensive than an open biopsy and with fewer complications, is best performed as part of a multidisciplinary approach with the surgeon's collaboration.

[Iliopsoas impingement in 12 patients with a total hip arthroplasty]

PURPOSE OF THE STUDY

We report 12 cases of iliopsoas impingement, an under-recognized cause of hip pain in total hip arthroplasty patients.

MATERIAL AND METHODS

Between January 1998 and October 2000, we diagnosed 12 cases of iliopsoas impingement among 280 total hip arthroplasty patients with hip pain (4.3%). Our population was composed of 9 women and 3 men aged 62 to 80 years (mean 72 years). Nine patients had a first intention arthroplasty and 3 had a revision prosthesis. Delay from implantation to diagnosis of impingement ranged from 6 months to 5 years. Common cases of pain after hip arthroplasty, infection, loosening, were ruled out in all cases. A standard x-ray series including an AP view of the pelvis, an AP view of the hip and a surgical false-lateral view of the hip as well as a CT scan were obtained when iliopsoas impingement was suspected. The CT series extended from the lower part of the acetabulum through the fixation screws.

RESULTS

Pain had been observed immediately after implantation in 10 cases (83%) and in 2 cases (17%) 3 to 5 years later. These patients did not have to use crutches when pain started to develop. Pain projected anteriorly and was always exaggerated when moving from the sitting position to the upright position and when going up stairs. In one patient, palpation revealed a mass in the groin that corresponded to a massive iliopsoas bursitis. Two non-pathognomonic physical signs were found in all cases: groin pain induced by active flexion against force in the lateral reclining position and at hip extension, and pain in the dorsal reclining position at deflexion of the hip, starting at 45 degrees. The standard AP views showed evidence of defective anteversion of 4 press fit cups, 1 off-centered screwed cup and 3 oversized cups. The CT scan demonstrated that the impingement involved the anterior border of the cup applied against the iliopsoas tendon in 8 cases either due to anterior uncovering in a dysplasic hip or anterior cup overhang. In 4 cases the cup fixation screws protruded anteriorly in front of the ilion and came in contact with the posterior aspect of the iliopsoas muscle. A bursitis had developed in 50% of the cases.

DISCUSSION

When infection and loosening have been ruled out, hip pain after total hip arthroplasty would suggest a possible impingement of the acetebular component on the iliopsoas muscle due to defective anteversion or centering, the use of oversized cups, and/or the use of fixation screws. We emphasize the importance of a correct position for the cup to avoid an overhanging anterior border and discuss the use of screwed cups for primary total hip arthroplasty and of oversized cups for revision procedures.

[Surgical treatment of acetabular fractures: outcome in a series of 60 consecutive cases]

PURPOSE OF THE STUDY

The aim of this study was to analyze clinical and radiographic results after surgical treatment of acetabular fractures.

MATERIAL AND METHODS

We reviewed 60 consecutive fractures of the acetabulum with loss of joint congruency at mean 5-years follow-up after treatment. There were 49 men and 11 women, mean age 41 years. According to the R.O. grading, the fractures were: 22 class A (33.3%) including 17 type A1, 23 class B (38%) including 10 type B1a2, 14 class C (23.3%) and 1 unclassifiable. Eight of the patients had associated pelvic injury, 40 had hip dislocations and 9 had sciatic nerve injury. Ten femoral head fractures were discovered during the surgical procedure. Three surgical approaches were used: 1) Kocher Langenbeck approach (28 cases), 2) Mears and Rubash triradiate approach (8 cases), 3) extended iliofemoral approach (22 cases), 4) other approaches (2 cases). Anteroposterior and 45 degrees oblique view of the pelvis were obtained for all patients following admission. Computerized tomography scans were performed in all cases. Fracture displacement and congruency of the femoral head with the roof were documented according to the SOFCOT radiographic criteria. The quality of reduction was assessed using the Matta criteria and the Duquennoy and Senegas criteria. Clinical outcome was assessed at follow-up using the Postel-Merle-d'Aubigné score.

RESULTS

Anatomic reduction was achieved in 62% of the cases (1 mm or less displacement on all views) and congruency of the femoral head with the roof was excellent in 73% of the cases. Clinical outcome was satisfactory in 80% (excellent or good). Operative complications included significant ectopic bone in 21, and in 2 others sciatic nerve palsy that had resolved at 1 year follow-up. Three patients developed avascular necrosis of the femoral head.

DISCUSSION

Clinical outcome depends on the quality of the reduction. Class C and class B fractures with roof injury should thus be treated by large surgical exposure. The triradiate approach increases the incidence of ectopic bone. The higher incidence of ectopic bone in patients treated by osteotomy of the trochanter compared with patients without osteotomy of the trochanter was significant (p<0.05). Avascular necrosis of the femoral head was associated with delayed reduction (66% of the cases).

CONCLUSION

Our good clinical results are encouraging; we are pursuing the use of surgical treatment for displaced acetabular fractures. Clinical outcome depends on the use of the appropriate surgical approach.

[Vascular risk and total hip arthroplasty]

PURPOSE OF THE STUDY

Though exceptional, there is a real risk of vascular complications during total hip arthroplasty procedures. The gravity of these iatrogenic accidents results from their high mortality (7%) and possible functional sequelae (19%).

MATERIAL AND METHOD

We report a retrospective multicenter study of 14 vascular complications, six of which occurred during revision surgery for total hip arthroplasty. We assessed risk factors and identified situations of major risk related to acetabular revision: intrapelvic dislocation, protrusion with no bony barrier, and presence of intrapelvic foreign bodies. We advocate the retroperitoneal approach for acetabular revision in case of intrapelvic dislocation or anomalous vessel size or trajectory on the preoperative arteriography. This approach allows ablation of the implants under visual control of the iliac vessels.

RESULTS AND DISCUSSION

A careful preoperative work-up is essential to avoid arterial or venous injury. A perfect knowledge of the vessel trajectories and their projection on the acetabulum is crucial. Indeed, such vascular complications are never expected and transform a well-programmed functional procedure into an emergency procedure with the inherent risks. We recall that such accidents may be expressed well after closing and the importance of careful surveillance before, during and after the surgical procedure.

[Unstable pelvic ring fracture: osteosynthesis of the posterior lesion by percutaneous sacroiliac fixation]

PURPOSE OF THE STUDY

We report our experience with percutaneous sacroiliac screwing for unstable pelvic ring fracture.

MATERIAL AND METHODS

Twenty unstable pelvic ring fractures with sacroiliac disjunction (9 cases), trans-sacral fracture (9 cases), or bilateral posterior fractures (5 cases) were managed with percutaneous sacroiliac fixation using 1 or 2 screws. There was also pubic disjunction in 7 cases, managed by osteosynthesis in 5 cases. No fixation of fractures of one or both of the obturator rings, present in 13 cases, was attempted. The posterior screwing was performed under fluoroscopic guidance in 15 cases and computed tomographic guidance in 5.

RESULTS

There were no infectious or neurological complications. Radiographically, anatomic reduction of the posterior fracture was achieved in 10 cases. A vertical ascension persisted in 4 patients and a rotation in 6. Radiographic results were correlated with delay to surgery: correction of the vertical displacement was achieved in 80% of the patients operated before five days and in 55% of the others. Two patients experienced a secondary displacement. There was no cases of nonunion of either the anterior or posterior fracture. Follow-up was available for 14 patients (2 patients died and follow-up was too short for 4). The mean Majeed score was 92/100 and none of the patients experienced anterior pain. Three patients had moderate pain in the sacroiliac area.

DISCUSSION

The ventral position appears to be best adapted for percutaneous sacroiliac screwing but can be contraindicated by concomitant lesions. We prefer fluoroscopic guidance for these emergency procedures. Two views, ascending and descending, appear sufficient. The better stability provided by two screws can be achieved under computed tomographic guidance without risk of neurovascular damage.

CONCLUSION

Percutaneous sacroiliac screwing is a good management strategy for unstable pelvic ring fractures with little risk of morbidity.

Locating the center of rotation of the hip

In prosthetic surgery of the hip joint it is essential to recenter the hip to recreate the leverage of the gluteus medius muscle. Determination of the center of rotation of the hip is difficult if both hip joints have been destroyed. On the basis of 70 frontal radiographs of the hip in the standing position, the authors measured the position of the center of the femoral head in relation to Köhler's line and the TD line joining the two radiological Us ("tear-drops"). On the same radiograph they defined the horizontal and vertical indices. The descriptive analysis of these parameters stresses the influence of sex on the coordinates of the center of rotation of the hip. The authors demonstrated the statistical correlations between the coordinates of this center of rotation of the joint and certain horizontal and vertical indices. It emerged that knowledge of these indices suffices to define the theoretic position of the center of rotation. The method is compared with other principles set out in the literature. The procedure has a clinical application in the context of preoperative planning of prosthetic reconstruction of the acetabulum, whenever it is destroyed bilaterally (after trauma, in congenital dislocation or acetabular loosening, etc).

[An unusual anomaly : cervical spondylolysis in an adult]

A case of spondylolysis with exceptional involvement of the cervical spine is reported. The lesion turned out to be a defect in the pars interarticularis of a cervical vertebra. Such cases generally involve the sixth vertebra. Spondylolysis is asymptomatic more often than not. Positive diagnosis is supported by an analysis of the anatomic structures on radiographs and CT-scans. Differential diagnoses include congenital lesion (articular dysplasia) is always found, there is no argument allowing the assertion that cervical spondylolysis is a congenital condition rather than secondary to stress fractures.

[Total hip arthroplasty. Risk factors and prevention of iatrogenic vascular complications]

Vascular injuries during orthopaedic hip surgery are rare. However, they must always be feared because they threaten life and limb. We present 11 vascular injuries observed over a 12-year period. Seven women and 4 men, treated by elective surgery, presented 14 vascular injuries (6 arterial, 5 venous and 3 prosthetic vascular graft). Four injuries occurred during revision procedures. They were all operated as an emergency for ischaemic syndrome (6 cases) and/or haemorrhage (7 cases). Four patients (37%) died and 4 developed sequelae, various directly attributable to the vascular injury. In the light of these cases, we tried to determine the various mechanisms of the injury and the orthopedic and vascular risk factors. Preoperative detection and well defined therapeutic rules are very important for the prevention of these severe vascular accidents.

Morphometry of the talocrural joint

Based on two orthogonal radiologic views, the authors present a morphometric study of the talocrural joint. In 50 normal subjects, 10 parameters were measured and divided into 3 groups: the distal tibial joint surface parameters, the malleolar parameters and the talar parameters. These parameters were treated in both a descriptive and a correlative analysis. If the talocrural joint is a hinge joint whose talar articular surface can be simplified and classed as a cylinder segment, it is possible to calculate its curve radius. Then the correlative analysis allows to define the talar parameters and the corresponding parameters of the distal tibial joint surface. The malleolar parameters are independent factors. This study is the first morphologic analysis to serve as a basis for an ankle arthroplasty.

Anatomical basis for the choice of the femoral implant in the total hip arthroplasty

There is within the population a considerable variation in the endosteal canal anatomy of the proximal extremity of the femur. This anatomical variation might jeopardize the result of the total hip arthroplasty when the surgeon uses a cementless femoral shaft. Indeed, if the secondary fixation of an implant stays under the dependency of many parameters, one has to obtain before anything else a very good primary stability, obtained by the morphological appropriateness of the bone-implant. The authors propose to define the cementless indications, as regards total hip arthroplasty, defining two radio-anatomical parameters: the Cortico-Medullary Index and the Femoral Flare Index.

Acetabular anatomy and the relationship with pelvic vascular structures. Implications in hip surgery

Most direct vascular trauma occurring during hip surgery results from injury to pelvic vascular structures which are not visible during the procedures of reaming, drilling holes or the fixation of screws. In this study, 5 pelves of fresh cadavers were injected with a radiopaque mixture and were visualised with a scanner according to 5 predetermined sections. Bone depth of the acetabulum was measured in each section. A calculation was made describing the minimal distance separating the inner cortex from the principal pelvic vessels. After an anatomic dissection of each pelvis, the relationship between the vessels and screws of the fixation cup, implanted identically on the quadranted acetabulum, was observed. The screws placed in the anterior and inferior quadrants and the center of the acetabulum endangered the external iliac v. and a. and the obturator pedicle. The depth of the periacetabular bone was greater in the superior and posterior quadrants. The inferior gluteal, pudendal and superior gluteal aa. were more than ten mm from the posterior wall. Conversely, the external iliac and obturator pedicles came in contact with the osseous surface on which they lay. A projection of the vessels on the acetabulum was made, and the reproducible character of the acetabular-quadrant system was verified. The superior quadrant offers all the characteristics of a vascular safe zone. A knowledge of these anatomic relationships explain vascular trauma in pelvic fractures and helps to prevent vascular injury in hip surgery.

[Total hip arthroplasty - The choice of the femoral component: cemented or uncemented?]

The shape of the femoral canal is variable, much more variable than most contemporary designs of femoral components would suggest or can accomodate. Several studies have demonstrated the clinical importance of a close match between the dimensions of the femur and the implanted prosthesis. The clinical significance ofbone implant proximal fit has been noted for cementless mode fixation. A practical consequence of the variability of the proximal endosteal canal is that different femoral components may be needed for all the patients of the population. For the autors, the choice of the technique (cement or cementless), and the choice of the optimal femoral stem (standard or custom-made implant) depends on two radiologic parameters: I.C.M. and I.E.F.; these parameters are defined and analysed.

[Preliminary and multidisciplinary study of three Coptic mummies of the Testut-Latarjet museum at Lyon]

In 1901 Albert Gayet raked up from Antinoe three mummies exhibited to day at the Anatomy Museum of Lyon. The study of the three mummies was made in detail as to their dress, anthropometric and scannographic findings. The clothes were characteristic of coptic civilization. The radiographic date gave a life span of around 40 years. The X-ray imagery shows the remains of cerebral and visceral organs. The sexual criteria are thought to be those of two women and undetermined for the child. Later, several investigations like endoscopic autopsy, tooth microscopy and chromosomic map will be necessary.

The upper end of the femur: dimensions of the endosteal canal

Based on a prospective study of 30 right or left femurs removed in a continuous series in the anatomy department, a study was made of the dimensions of the endosteal canal of the upper end of the femur. The femora were analysed by means of 12 CT scans below the lesser trochanter. The sections were numbered and the dimensional parameters calculated by computer, using an original plan. The results were subjected to descriptive and correlative analysis. From these dimensional findings it appeared that the anatomy of the upper end of the femur is not random; morphotypic models exist and the laws of a normal model are regulated by a mathematical equation.

[Analysis of restraint of the femur head. Experimental study of allograft of cold bone and autoclaved bone to kill the HIV virus]

The retrovirus S.I.A.D. grown in marrow bone and iatrogenic infections may be possible after bone graft in following total hip arthroplasties. Previous investigators proposed several methods to kill the virus, but without bacteriological safety. They found 20 to 55% of loss on mechanical properties. The present study reports the response of autoclaved femoral heads compression testing on material machine Model 1026 Instron. The stress response of marrow bone to stains showed a classic peak and with linear regression study we saw a relationship between autoclaved bone and cold bone. The cortical bone resists to strains highly 12% of load.