Hnf1b renal expression directed by a distal enhancer responsive to Pax8.

Xenopus provides a simple and efficient model system to study nephrogenesis and explore the mechanisms causing renal developmental defects in human. Hnf1b (hepatocyte nuclear factor 1 homeobox b), a gene whose mutations are the most commonly identified genetic cause of developmental kidney disease, is required for the acquisition of a proximo-intermediate nephron segment in Xenopus as well as in mouse. Genetic networks involved in Hnf1b expression during kidney development remain poorly understood. We decided to explore the transcriptional regulation of Hnf1b in the developing Xenopus pronephros and mammalian renal cells. Using phylogenetic footprinting, we identified an evolutionary conserved sequence (CNS1) located several kilobases (kb) upstream the Hnf1b transcription start and harboring epigenomic marks characteristics of a distal enhancer in embryonic and adult renal cells in mammals. By means of functional expression assays in Xenopus and mammalian renal cell lines we showed that CNS1 displays enhancer activity in renal tissue. Using CRISPR/cas9 editing in Xenopus tropicalis, we demonstrated the in vivo functional relevance of CNS1 in driving hnf1b expression in the pronephros. We further showed the importance of Pax8-CNS1 interaction for CNS1 enhancer activity allowing us to conclude that Hnf1b is a direct target of Pax8. Our work identified for the first time a Hnf1b renal specific enhancer and may open important perspectives into the diagnosis for congenital kidney anomalies in human, as well as modeling HNF1B-related diseases.

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.

Diabetic Foot Management: How Could a Procedural Pathway Improve the Surgical Outcome?

INTRODUCTION: Diabetic foot ulcer is the main aetiology for non-traumatic amputation, which is a major public health care concern. A multidisciplinary approach in the management of this pathology has been shown to improve the surgical outcome. However, there are little data available on the tools we can use to pursue this multidisciplinary approach. The main goal of this cross-sectional study was to find out whether the implementation of a specific management pathway could improve the treatment outcome in the treatment of diabetic foot. MATERIALS AND METHODS: From 2012 to 2014, we consecutively recruited patients with diabetic foot referred to Orthopaedic surgery department of our university for surgical opinion. A specific diabetic foot pathway was introduced in 2013. One group of patients who were treated with previous method were evaluated retrospectively. Another group of patients who were treated after implementation of the pathway were evaluated prospectively. We compared treatment outcome between the two groups. RESULTS: We included 51 patients. Amputation rate was similar both the groups: 74% in the retrospective group not using the new pathway versus 73% in a prospective group that used the new pathway. Revision surgery was 39% in the retrospective group and 14% in the prospective group (p=0.05). CONCLUSION: We recommend the use of this simple and cost-effective pathway to guide the interdisciplinary management of diabetic foot. A prospective study with more subjects would provide a better overview of this management pathway.

Diabetic Foot Management: How Could a Procedural Pathway Improve the Surgical Outcome?

@#Introduction: Diabetic foot ulcer is the main aetiology for non-traumatic amputation, which is a major public health care concern. A multidisciplinary approach in the management of this pathology has been shown to improve the surgical outcome. However, there are little data available on the tools we can use to pursue this multidisciplinary approach. The main goal of this cross-sectional study was to find out whether the implementation of a specific management pathway could improve the treatment outcome in the treatment of diabetic foot. Materials and Methods: From 2012 to 2014, we consecutively recruited patients with diabetic foot referred to Orthopaedic surgery department of our university for surgical opinion. A specific diabetic foot pathway was introduced in 2013. One group of patients who were treated with previous method were evaluated retrospectively. Another group of patients who were treated after implementation of the pathway were evaluated prospectively. We compared treatment outcome between the two groups. Results: We included 51 patients. Amputation rate was similar both the groups: 74% in the retrospective group not using the new pathway versus 73% in a prospective group that used the new pathway. Revision surgery was 39% in the retrospective group and 14% in the prospective group (p=0.05). Conclusion: We recommend the use of this simple and costeffective pathway to guide the interdisciplinary management of diabetic foot. A prospective study with more subjects would provide a better overview of this management pathway.

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 ß-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 ß-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 ß-lactam should be reconsidered, especially when a two-stage exchange is planned.

Poor outcomes of fusion with Trabecular Metal implants after failed total ankle replacement: Early results in 11 patients.

INTRODUCTION: One of the reasons for revision of total ankle replacement (TAR) implants is loosening due to subchondral cysts. Reconstruction and fusion of the ankle is often the first choice for revision procedures due to the large bone defects, which are typically filled with autograft and/or allograft. Filling the defect with a trabecular metal tantalum implant is a potential alternative given the biomechanical properties of this component. HYPOTHESIS: Using tantalum as a spacer provides primary stability and contributes to fusion of the ankle joint after removal of failed TAR implants. METHODS: Eleven patients underwent arthrodesis an average of 6.9 years after TAR. The mean height of the bone defect was 32mm. It was filled with a specially designed quadrangular implant (Trabecular Metal™, Zimmer/Biomet) combined with an iliac crest graft. Ten patients underwent tibio-talo-calcaneal (TTC) arthrodesis fixed with an angled retrograde nail and one patient underwent talocrural arthrodesis fixed with two plates (anterolateral and anteromedial). The clinical, functional (AOFAS and SF36 scores) and radiological (plain X-rays and CT scan) outcomes were determined. RESULTS: At a mean follow-up of 19.3 months, the mean total AOFAS score was 56 (21-78) and the mean SF36 score was 60.5 (19-84). One patient was lost to follow-up and four patients still had pain. The tantalum implant was integrated in six patients. Five patients achieved fusion of the subtalar joint and 8 achieved fusion of the talocrural joint. Three patients required surgical revision. DISCUSSION: Our hypothesis was not confirmed. The clinical outcomes after more than 1 year of follow-up are disappointing, as was the large number of nonunion cases and the lack of tantalum integration. These technical failures can be explained by insufficient construct stability and/or insufficient implant porosity. LEVEL OF EVIDENCE: IV (retrospective cohort study).

Long-term survivorship of the Corail™ standard stem.

INTRODUCTION: The Corail™ stem, which was first introduced in 1986, has since been modified twice: first to make the neck thinner and then to change the location of the laser markings. The survival and complications of the first-generation straight, titanium, hydroxyapatite-coated stem are known; however, there is little specific information about the latest-generation stem. This led us to conduct a retrospective study to determine the: (1) long-term survival; (2) clinical and radiographic outcomes; (3) complications; and (4) risk factors for revision of the newest Corail™ stem. HYPOTHESIS: The newest Corail™ AMT (Articul/EZE™ Mini Taper) standard stem has comparable survival to prior models. PATIENTS AND METHODS: This single-center, retrospective study included 133 patients (140 hips), who underwent primary total hip arthroplasty (THA), between January and December 2004, in which a Corail™ Standard stem was implanted using a posterolateral approach. Patients who underwent revision THA, THA due to femoral neck fracture or who received lateralized (offset) stems were excluded. The mean age at the time of THA was 69±13 years [35-92] in 85 men (61%) and 55 women (39%) who had a mean BMI of 27kg/m2±11 [16-39]. At the latest follow-up, 32 patients (32 hips) had died and 8 patients (8 hips) had less than 3 years' follow-up, thus were not included in the clinical evaluation. The Merle d'Aubigné (PMA) score was collected. The stem's survivorship was calculated using the Kaplan-Meier method with revision for aseptic loosening and revision or implant removal for any reason as the end-points. The Cox model was used to analyze risk factors for revision. The mean follow-up was 10±3 years [3-12]. RESULTS: The PMA score was 12±2.6 [5-17] preoperatively and 16±2.7 [7-18] at the last follow-up (P<0.00001). Eighteen complications (12.8%) were recorded at the last follow-up. There were 15 early complications: 6 dislocations, 5 calcar fractures (4 treated by wire cerclage and 1 by stem change plus wire cerclage), 2 greater trochanter fractures (treated non-surgically) and 2 cases of sciatic nerve palsy. There were 3 late complications: 2 cases of iliopsoas irritation and 1 ceramic insert fracture. Stem survival for surgical revision due to aseptic loosening was 98% (95% CI: [0.96-1]). At 12 years, 95% of stems had not been revised or removed (95% CI: [0.92-0.99]). Being less than 58 years of age at the time of surgery was the only risk factor significantly associated with stem revision for any reason (P=0.04). CONCLUSION: Survival of the Corail™ Standard stem is similar to that of previous generation stems. The changes made in this stem solved the neck failure problem and did not induce new complications. LEVEL OF EVIDENCE: Level IV (retrospective 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.

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.

Cementless lateralized stems in primary THA: Mid-term survival and risk factors for failure in 172 stems.

INTRODUCTION: Increasing the femoral offset when performing total hip arthroplasty (THA) theoretically increases the stresses and risks of the stem not integrating itself into bone. But this concept has not been validated for cementless stems; this led us to conduct a retrospective study to determine: (1) the risk factors for the occurrence of symptomatic femoral radiological abnormalities, (2) the incidence of these abnormal radiological findings, (3) the revision rate for aseptic non-integration of a cementless lateralized stem. HYPOTHESIS: Young patients with significant femoral canal flare and a small cementless lateralized stem have a higher risk of abnormal osseointegration. MATERIAL AND METHODS: We analyzed retrospectively 172 consecutive lateralized stems (KHO, Corail™ product line) implanted during primary THA between 2006 and 2012 in 157 patients (mean age 68years±12.6 (20-95), 89% men). Radiographs were used to evaluate osseointegration scores, offset restoration and the Noble index. Kaplan-Meier survival analysis was performed using "symptomatic femoral radiological abnormalities" and "revision for aseptic stem non-integration" as endpoints. RESULTS: The mean follow-up was 5.9years±2.7 (range, 2-12.4years). Being more than 70years of age (HR=0.7, 95% CI: [0.3-0.9], P=0.004) and having a larger stem (HR=0.6, 95% CI: [0.4-0.9], P=0.03) were protective against symptomatic femoral radiological abnormalities, while increasing the postoperative femoral offset (HR=1.1, 95% CI: [1.01-1.2], P=0.02) was deleterious. The survival free of "symptomatic femoral radiological abnormalities" was 93% (95% CI: 89-97) at 5years and 84% (95% CI: 75-95) at 8years. The survival free of "revision for aseptic stem non-integration" was 98% (95% CI: 96.8-100) at 5years and 97% (95% CI: 95.2-100) at 8years. DISCUSSION: In this study, the risk factors for symptomatic radiological abnormalities were being less than 70years of age, having a small lateralized stem and restoring a large femoral offset. Lateralized stems used in this study had a 10% rate of symptomatic radiological abnormalities and a 4% rate of revision for aseptic non-integration. LEVEL OF EVIDENCE: IV, retrospective study.

Cementless Corail™ femoral stems with laser neck etching: Long-term survival, rupture rate and risk factors in 295 stems.

INTRODUCTION: Implant neck fracture involving a non-modular femoral stem is rare in primary total hip arthroplasty (THA). Occasional cases have been reported following laser etching of the Corail(tm) stem, but risk factors have not been precisely determined. We therefore performed a retrospective study on a series of Corail(tm) stems with laser neck etching, in order to: (1) determine the exact implant neck fracture rate at 10 years, and (2) identify associated risk factors. HYPOTHESIS: Laser etching increases the rate of implant neck fracture. MATERIALS AND METHODS: Between October 2002 and December 2003, 295 THAs were consecutively performed using the Corail(tm) stem with laser neck etching, in 286 patients: 151 male (53%), 135 female (47%); mean age, 63 years (range, 18-89 years); mean weight, 73kg (range, 45-120kg). Stems were standard in 240 cases (81%) and lateralized in 55 (19%). The main assessment criterion was stem replacement for implant neck fracture. RESULTS: At a mean 10 years' follow-up (range, 1-11 years), 11 patients were lost to follow-up (4%) and 35 had died (12%) (with stem in situ). Overall 10-year stem survival was 91% (95% CI: [87-94%]). Sixteen patients (5.4%) underwent revision surgery for implant neck fracture, 6 (2%) bone and joint infection and in 4 cases (1.3%) the stem was replaced preventively for fracture risk suspected during a revision procedure on the cup. All fractures were of the fatigue type, implicating implant neck laser etching. Mean time to fracture was 4.5 years (range, 1.4-9.8 years). Risk factors comprised: weight>80kg (P=0.002) (OR=5.7; 95% CI: 1.9-17), age<60 years (P=0.02) (OR=3.4; 95% CI: 1.2-9.6), male gender (P=0.01) (OR=14.8; 95% CI: 1.9-113) and lateralized stem (P<0.001) (OR=6.5, 95% CI: 2.3-18). CONCLUSION: The present 5.4% fracture rate was higher than in registry data (<1%). Fracture mechanisms involved excessive stress in an area under tension, leading to fatigue fracture. Male gender, high weight and young age were risk factors, as in the literature for fatigue fracture. Location and depth of laser etching induced fatigue fracture. The study demonstrated that laser etching creates an area of weakness in the implant neck and should therefore be eschewed in this part of the femoral stem. LEVEL OF EVIDENCE: IV, retrospective study.

Similar levels of pain are reported in forefoot surgery after management as a day case and admission for 48 hours: A continuous prospective study of 317 patients.

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.

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.

Does arthrodesis of the first metatarsophalangeal joint correct the intermetatarsal M1M2 angle? Analysis of a continuous series of 208 arthrodeses fixed with plates.

INTRODUCTION: First-ray metatarsophalangeal arthrodesis is a classic surgical procedure in the treatment of severe hallux valgus, hallux rigidus, revision surgery, and inflammatory arthritis. The objective of this study was to verify if metatarsophalangeal plate arthrodesis could correct the M1M2 intermetatarsal angle. MATERIAL AND METHODS: This prospective and continuous series (June 2007 to March 2011) included 208 patients (48% severe and/or arthritic hallux valgus, 18% hallux rigidus, 16% rheumatoid forefoot, 13% surgical revision of the first ray, 5% hallux varus), with a mean age of 62.4±9.9 years (range, 19-87 years). All the patients were operated on by a senior surgeon with the same technique: spherical avivement of the joint surfaces using reamers, osteosynthesis with an anatomic plate (Fyxis-Biotech™) in Ti.6Al.4 V alloy prebent to 5° with a phalangeal arm to receive an oblique metatarsophalangeal screw in compression, in addition to four 2.7-mm nonlocking dorsal screws. The full-scale preoperative and intraoperative angle measurements were taken on AP and lateral X-rays of the weightbearing foot, as related to the etiology and the severity of the preoperative metatarsus varus (M1M2<15°, M1M2 15-19°, M1M2≥20°). The statistical analysis was done using the StatView software. RESULTS: The mean follow-up was 18.6±12.4 months (range, 2-76 months). Nearly all of the arthrodesis patients (97%) achieved bone union, and 5% of the plates were removed. The M1P1 angle decreased from 33.8±19.7° (range, -45° to -67°) preoperatively to 13.3±5.3° (range, 0-32°) at the last follow-up, and the M1M2 angle from 14.2±5.4°(range, 0-26°) to 6.5±2.3° (range, 0-12°). The preoperative M1M2 angle was <15° in 97 patients, 15-19° for 78 patients, and ≥20° for the 33 others; at the last follow-up it was 5.8±2.1° (range, 0-10°), 6.7±2.2° (0-10°), and 8.1±2.4° (3-12°), respectively. No correction of the metatarsus varus was demonstrated in relation to etiology. The M1M2 angle was >10° in only two patients (one case of rheumatoid arthritis and one case of severe hallux valgus): 0.9%. DISCUSSION: These results show that isolated metatarsophalangeal arthrodesis of the first ray can correct metatarsus varus even in substantial deformations in any etiology. LEVEL OF PROOF: Level II cohort 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.

Dual mobility retentive acetabular liners and wear: surface analysis of 40 retrieved polyethylene implants.

PURPOSE OF THE STUDY: Dual mobility systems with retentive acetabular liners have been used in clinical practice for total hip arthroplasty since 1976. The dual mobility system preserves a wide range of motion while providing greater stability. This study measured wear on the concave and convex surfaces of 40 retrieved polyethylene liners, to evaluate the advantages of this system in relation to wear. MATERIAL AND METHODS: Forty polyethylene inserts that had been removed due to infection or mechanical failure after a mean 8 years were analyzed. The mean age of patients at arthroplasty was 46 years old. Macroscopic analysis was followed by surface analysis with direct measurement of changes in the curvature radii. The internal concave surface was measured in three dimensions using a 4-mm stylus (BNH 706). External convexity was measured by lateral projection. The estimated error was ± 5 µm for both measurement methods. Manufacturers' tolerance for these implants was approximately 50 µm. Linear wear and wear volume was determined by comparing the measured dimensions with the theoretical dimensions of new liners. RESULTS: Macroscopically, all of the pieces studied had lost the initial machined grooves on the convex surface; 40% of the pieces showed visible wear of the retentive collar. Mean annual convex surface wear was 9 µm (SD 9µm) and 73 µm (SD 69 µm) for the concave surface. Mean total wear, which was the sum of the wear on the convex and concave surfaces was 82 µm (SD 72 µm). Wear volume was 28.9 mm(3)/yr for the convex surface (SD 27.6) and 25.5 for the concave surface (SD 23.2) with a mean annual total wear volume of 54.3 mm(3)/yr (SD 39.6). DISCUSSION: Total wear in the 40 dual mobility liners that had functioned in vivo was similar to that reported in metal-polyethylene bearings with 22.2mm femoral heads. The results of wear in both the convex and concave surfaces show that wear with the dual mobility system was not increased compared to conventional metal-polyethylene bearings, while providing better retention and greater stability. CONCLUSION: The use of dual mobility acetabular liners is an attractive solution when a metal-polyethylene bearing is needed. The increased joint stability is not associated with increased wear.

Histologic study of periprosthetic osteolytic lesions after AES total ankle replacement. A 22 case series.

INTRODUCTION: Medium-term results for total ankle replacement (TAR) are in general satisfactory, but there is a high redo rate for periprosthetic osteolysis associated with the AES implant. HYPOTHESIS: Comparing radioclinical findings and histologic analysis of implant revision procedure specimens can account for the elevated rate of osteolysis associated with the AES TAR implant. MATERIAL AND METHOD: In a prospective series of 84 AES TAR implants (2003-2008), 25 underwent revision for osteolysis (including three undergoing revision twice) at a mean 59.8 months. Eight patients had hydroxyapatite (HA) coated models and the others had titanium-hydroxyapatite (Ti-HA) coatings. Radiographs were systematically analyzed on Besse's protocol and evolution was monitored on AOFAS scores. The 94 specimens taken for histologic analysis during revision were re-examined, focusing specifically on foreign bodies. RESULTS: Macroscopically, no metallosis or polyethylene wear was found at revision. AOFAS global and pain scores fell respectively from 89.7/100 at 1 year postoperatively to 72.9 before revision and from 32.5/40 to 20.6/40, although global scores were unchanged in 25% of patients. Radiologically, all patients showed tibial and talar osteolytic lesions, 45% showed cortical lysis and in 25% the implant had collapsed into the cysts. All specimens showed macrophagic granulomatous inflammatory reactions in contact with a foreign body; the cysts showed necrotic remodeling. Some of the foreign bodies could be identified on optical histologic examination with polyethylene in 95% of the specimens and metal in 60% (100% of HA-coated models and 33.3% of Ti-HA-coated models). Unidentifiable material was associated: a brownish pigment in Ti-HA-coated models (33.3%) and flakey bodies in 44.4% of the HA-coated models and 18.2% of the Ti-HA-coated models. DISCUSSION: The phenomenon of periprosthetic osteolysis is still poorly understood, although implant wear debris seems to be implicated. All the patients with HA-coated implants with modular tibial stem had metal particles in the tissue around the implant, although their exact nature could not be determined. The double-layer Ti-HA coating may induce delamination by fretting while the biological bone anchorage is forming. LEVEL OF EVIDENCE: Prospective cohort study - Level IV.

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.

Scarf osteotomy versus metatarsophalangeal arthrodesis in forefoot first ray disorders: comparison of functional outcomes.

INTRODUCTION: Scarf osteotomies of the first metatarsal and metatarsophalangeal arthrodesis are the two most frequent surgical forefoot reconstructive procedures. HYPOTHESIS: We compared functional results of isolated arthrodesis of the first metatarsophalangeal joint with an isolated Scarf osteotomy of the first metatarsal. MATERIALS AND METHODS: This was a retrospective, observational, continuous study of patients operated between 1993 and 2008. After patients who had undergone a procedure on the lateral rays, extremely elderly patients, lost to follow-up patients and those with incomplete questionnaires had been excluded, there remained two comparable groups of 25 patients. Mean age was 60 in the arthrodesis group [41-70] and 59.8 in the Scarf group [47-71]. The Scarf group included 25 hallux valgus (100%) compared to 16 hallux valgus (64%) and nine hallux rigidus (36%) in the arthrodesis group. Complications were recorded. Evaluation of functional results was based on the most recent functional or quality of life scores (AOFAS, FFI, FAAM, SF 36) and a questionnaire on physical and athletic ability. RESULTS: There was no significant difference in the rate of complications between the two groups. There was no difference in pain according to the AOFAS score with 35.6/40 (± 6.5) in the Scarf group and 34.5 (± 5.9) in the arthrodesis group. Global satisfaction was also similar between the Scarf and arthrodesis groups: 91.4% and 90% of very satisfied or satisfied patients, respectively. The FFI score was higher in the Scarf group than in the arthrodesis group: 8.6 (± 20.1) and 19.8 (± 17.7) respectively. Functional results were better in the Scarf group than in the arthrodesis group with a FAAM Daily Activity score of 80.2 (± 12.1) compared to 68 (± 7.2), a FAAM Sports Activity score of 29.7 (± 6.7) compared to 25.2 (± 7.6) and a FAAM Global Function score of 94% (± 10.8) compared to 87% (± 15.7), respectively. The Global SF36 score was higher in the Scarf group than in the arthrodesis group: 70.9% (± 14.1) and 62.3% (± 20.6) respectively, which was due to a higher Mental Health score in the Scarf group: 68.7% (± 14.2) and 60.4% (± 19.3) respectively. In the area of sports activities the Scarf group practiced more hiking than the arthrodesis group (74% versus 42% respectively). There was no difference for other activities. DISCUSSION AND CONCLUSION: This study provides detailed information on the level of physical and sports activities that are practiced following these procedures, so that the patient can be better informed.