Covering of wound infection in hip arthroplasty with local cutaneous flaps.

Total hip arthroplasty is a very common procedure to treat osteoarthritis. One of the complication is the infection which occurs in about 1% of the cases. The manifestation of infection can be poor wound healing with dehiscence and exposition of bone or prosthetic components. Hip arthroplasty infections are difficult to treat. It required an associated multidisciplinary approach with infectiology, orthopedic and plastic surgeries. The study included five patients with hip wound dehiscence after total hip arthroplasty. Coverage after orthopedic surgery was provided by local cutaneous flap. These cutaneous flaps were either a deep inferior epigastric perforator flap (DIEP) or a transposition flap. The orthopedic and the plastic treatment were done at the same time. Two deep inferior epigastric flaps were performed for patients with a deep defect with bone or prosthesis exposure. Four transposition flaps were done in three patients with wound dehiscence but without direct contact with the prosthesis. Three transposition flaps were done from the abdominal wall and one from the posterior thigh. The mean follow up was 18 months, ranging from 10 to 24months. After healing, there was no recurrence of the infection. In all cases, the coverage was obtained. The prosthesis was salvage and the gait was possible. Cutaneous flaps are easy and safe to cover the hip. They are reliable flaps even in patients with multiple co-morbidities. They do not cause sequelae on the recipient site. This study is the first about cutaneous flap for covering hip defects in hip arthroplasty infections.

Intramuscular stimulation vs sham needling for the treatment of chronic midportion Achilles tendinopathy: A randomized controlled clinical trial.

BACKGROUND: The insertion of filiform needles intramuscularly (a.k.a. intramuscular stimulation/dry needling) has been suggested as a possible treatment for various painful musculoskeletal conditions. Our aim was to answer the question, is intramuscular stimulation more effective than sham intramuscular stimulation/dry needling for the treatment of Achilles tendinopathy? METHODS: 52 participants with persistent midportion Achilles tendinopathy began and 46 completed one of three treatment protocols which were randomly assigned: (G3) a 12-week rehabilitation program of progressive tendon loading plus intramuscular stimulation (n = 25), (G2) the same rehabilitation program but with sham intramuscular stimulation (n = 19), or (G1) a reference group of rehabilitation program alone (as an additional control) (n = 8). The a priori primary outcome measure was change in VISA-A score at 12 weeks-VISA-A was also measured at 6 weeks, and at 6 and 12 months. Secondary outcome measures include the proportion of patients who rated themselves as much or very much improved (%), dorsiflexion range of motion (degrees), and tendon thickness (mm). RESULTS: The study retention was 94% at 12 weeks and 88% at 1 year. VISA-A score improved in all three groups over time (p<0.0001), with no significant difference among the three groups in VISA-A score at the start of the study (mean ± SD: G3 59 ± 13, G2 57 ± 17, G1 56 ± 22), at 12 weeks (G3 76 ± 14, G2 76 ± 15, G1 82 ± 11) or at any other timepoint. The percentage of patients who rated themselves as much or very much improved (i.e. treatment success) was not different after 12 weeks (G3 70%, G2 89%, G1 86% p = 0.94), or at 26 (p = 0.62) or 52 weeks (p = 0.71). No clinically significant effects of intervention group were observed in any of the secondary outcome measures. CONCLUSION: The addition of intramuscular stimulation to standard rehabilitation for Achilles tendinopathy did not result in any improvement over the expected clinical benefit achieved with exercise-based rehabilitation alone.

Mapping the stochastic sequence of individual ligand-receptor binding events to cellular activation: T cells act on the rare events.

T cell receptor (TCR) binding to agonist peptide major histocompatibility complex (pMHC) triggers signaling events that initiate T cell responses. This system is remarkably sensitive, requiring only a few binding events to successfully activate a cellular response. On average, activating pMHC ligands exhibit mean dwell times of at least a few seconds when bound to the TCR. However, a T cell accumulates pMHC-TCR interactions as a stochastic series of discrete, single-molecule binding events whose individual dwell times are broadly distributed. With activation occurring in response to only a handful of such binding events, individual cells are unlikely to experience the average binding time. Here, we mapped the ensemble of pMHC-TCR binding events in space and time while simultaneously monitoring cellular activation. Our findings revealed that T cell activation hinges on rare, long-dwell time binding events that are an order of magnitude longer than the average agonist pMHC-TCR dwell time. Furthermore, we observed that short pMHC-TCR binding events that were spatially correlated and temporally sequential led to cellular activation. These observations indicate that T cell antigen discrimination likely occurs by sensing the tail end of the pMHC-TCR binding dwell time distribution rather than its average properties.

3D Ultrasound Spine Image Selection Using Convolution Learning-to-Rank Algorithm.

3D Ultrasound imaging has become an important means of scoliosis assessment as it is a real-time, cost-effective and radiation-free imaging technique. However, the coronal images from different depths of a 3D ultrasound image have different imaging definitions. So there is a need to select the coronal image that would give the best image definition. Also, manual selection of coronal images is time-consuming and limited to the discretion and capability of the assessor. Therefore, in this paper, we have developed a convolution learning-to-rank algorithm to select the best ultrasound images automatically using raw ultrasound images. The ranking is done based on the curve angle of the spinal cord. Firstly, we approached the image selection problem as a ranking problem; ranked based on probability of an image to be a good image. Here, we use the RankNet, a pairwise learning-to-rank method, to rank the images automatically. Secondly, we replaced the backbone of the RankNet, which is the traditional artificial neural network (ANN), with convolution neural network (CNN) to improve the feature extracting ability for the successive iterations. The experimental result shows that the proposed convolutional RankNet achieves the perfect accuracy of 100% while conventional DenseNet achieved 35% only. This proves that the convolutional RankNet is more suitable to highlight the best quality of ultrasound image from multiple mediocre ones.

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.

Agreement between pre-operative and intra-operative bacteriological samples in 85 chronic peri-prosthetic infections.

BACKGROUND: Whether pre-operative microbiological sampling contributes to the management of chronic peri-prosthetic infection remains controversial. We assessed agreement between the results of pre-operative and intra-operative samples in patients undergoing single-stage prosthesis exchange to treat chronic peri-prosthetic infection. HYPOTHESIS: Agreement between pre-operative and intra-operative samples exceeds 75% in patients undergoing single-stage exchange of a hip or knee prosthesis to treat chronic peri-prosthetic infection. MATERIAL AND METHODS: This single-centre retrospective study included 85 single-stage prosthesis exchange procedures in 82 patients with chronic peri-prosthetic infection at the hip or knee. Agreement between pre-operative and intra-operative sample results was evaluated. Changes to the initial antibiotic regimen made based on the intra-operative sample results were recorded. RESULTS: Of 149 pre-operative samples, 109 yielded positive cultures, in 75/85 cases. Of 452 intra-operative samples, 354 yielded positive cultures, in 85/85 cases. Agreement was complete in 54 (63%) cases and partial in 9 (11%) cases; there was no agreement in the remaining 22 (26%) cases. The complete agreement rate was significantly lower than 75% (P=0.01). The initial antibiotic regimen was inadequate in a single case. DISCUSSION: Pre-operative sampling may contribute to the diagnosis of peri-prosthetic infection but is neither necessary nor sufficient to confirm the diagnosis and identify the causative agent. The spectrum of the initial antibiotic regimen cannot be safely narrowed based on the pre-operative sample results. We suggest the routine prescription of a probabilistic broad-spectrum antibiotic regimen immediately after the prosthesis exchange, even when a pathogen was identified before surgery. LEVEL OF EVIDENCE: IV, retrospective study.

Experimental validation of the GNRB® for measuring anterior tibial translation.

INTRODUCTION: The objective of this study was to validate the technique used to measure anterior tibial translation in cadaver knees using the GNRB® device by comparing it with the gold standard, the OrthoPilot® navigation system. HYPOTHESIS: Simultaneous measurement of anterior tibial translation by the GNRB® and the OrthoPilot® in the chosen experimental conditions will result in significant differences between devices. MATERIAL AND METHODS: Five fresh frozen cadavers were used. The knee was placed in 20° flexion. Four calibrated posterior-anterior forces (134N to 250N) were applied. For each applied force, the anterior tibial translation was measured simultaneously by both devices. Two conditions were analyzed: anterior cruciate ligament (ACL) intact and ACL transected. The primary criterion was anterior tibial translation at 250N. The measurements were compared using a paired Student's t-test and the correlation coefficient was calculated. Agreement between the two methods was determined using Bland-Altman plots. Consistency of the measurements was determined by calculating the intraclass correlation coefficient. RESULTS: For all applied forces and ligament conditions, the mean difference between the GNRB® and the navigation system was 0.1±1.7mm (n.s). Out of the 80 measurements taken, the difference between devices was less than ±2mm in 66 cases (82%). There was a strong correlation, good agreement and high consistency between the two measurement methods. DISCUSSION: The differences between the measurements taken by the GNRB® and the navigation system were small and likely have no clinical impact. We recommend using the GNRB® to evaluate anterior knee laxity. LEVEL OF EVIDENCE: II controlled laboratory study.

Can the presence of an infection be predicted before a revision total hip arthroplasty? Preliminary study to establish an infection score.

INTRODUCTION: The diagnosis of periprosthetic joint infection can be challenging, in part because there is no universal diagnostic test. Current recommendations include several diagnostic criteria, and are mainly based on the results of deep microbiological samples; however, these only provide a diagnosis after surgery. A predictive infection score would improve the management of revision arthroplasty cases. The purpose of this study was to define a composite infection score using standard clinical, radiological and laboratory data that can be used to predict whether an infection is present before a total hip arthroplasty (THA) revision procedure. HYPOTHESIS: The infection score will make it possible to differentiate correctly between infected and non-infected patients in 75% of cases. MATERIAL AND METHODS: One hundred and four records from patients who underwent THA revision for any reason were analysed retrospectively: 43 with infection and 61 without infection. There were 54 men and 50 women with an average age of 70±12 years (range 30-90). A univariate analysis was performed to look for individual discriminating factors between the data in the medical records of infected and non-infected patients. A multivariate analysis subsequently integrated these factors together. A composite score was defined and its diagnostic effectiveness was evaluated as the percentage of correctly classified records, along with its sensitivity and specificity. RESULTS: The score consisted of the following individually weighed factors: body mass index, presence of diabetes, mechanical complication, wound healing disturbance and fever. This composite infection score was able to distinguish correctly between the infected patients (positive score) and non-infected patients (negative score) in 78% of cases; the sensitivity was 57% and the specificity 93%. DISCUSSION: Once this score is evaluated prospectively, it could be an important tool for defining the medical - surgical strategy during THA revision, no matter the reason for revision. LEVEL OF EVIDENCE: Level IV - retrospective study.

May one-stage exchange for Candida albicans peri-prosthetic infection be successful?

UNLABELLED: Fungal infection of a total joint arthroplasty has a low incidence but is generally considered as more difficult to cure than bacterial infection. As for bacterial infection, two-stage exchange is considered as the gold standard of treatment. We report two cases of one-stage total joint exchange for fungal peri-prosthetic infection with Candida albicans, where the responsible pathogens was only identified on intraoperative samples. This situation can be considered as a one-stage exchange for fungal peri-prosthetic infection without preoperative identification of the responsible organism, which is considered as having a poor prognosis. Both cases were free of infection after two years. One-stage revision has several potential advantages over two-stage revision, including shorter hospital stay and rehabilitation, no interim period with significant functional impairment, shorter antibiotic treatment, better functional outcome and probably lower costs. We suggest that one-stage revision for C. albicans peri-prosthetic infection may be successful even without preoperative fungal identification. LEVEL OF EVIDENCE: Level IV-Historical cases.

Infection recurrence factors in one- and two-stage total knee prosthesis exchanges.

PURPOSE: Revision of infected total knee replacements (TKR) is usually delayed for a period in which the joint space is filled with an antibiotic-loaded acrylic spacer. In contrast, one-stage re-implantation supposes immediate re-implantation. Formal comparisons between the two methods are scarce. A retrospective multi-centre study was conducted to investigate the effects of surgery type (one-stage vs. two-stage) on cure rates. It was hypothesised that this parameter would not influence the results. METHOD: All infected TKR, treated consecutively between 2005 and 2010 by senior surgeons working in six referral hospitals, were included retrospectively. Two hundred and eighty-five patients, undergoing one-stage or two-stage TKR, with more than 2-year follow-up (clinical and radiological) were eligible for data collection and analysis. Of them, 108 underwent one-stage and 177 received two-stage TKR. Failure was defined as infection recurrence or persistence of the same or unknown pathogens. Factors linked with infection recurrence were analysed by uni- and multi-variate logistic regression with random intercept. RESULTS: Factors associated with infection recurrence were fistulae (odds ratio (OR) 3.4 [1.2-10.2], p = 0.03), infection by gram-negative bacteria (OR 3.3 [1.0-10.6], p = 0.05), and two-stage surgery with static spacers (OR 4.4 [1.1-17.9], p = 0.04). Gender and type of surgery interacted (p = 0.05). In men (133 patients), type of surgery showed no significant linkage with infection recurrence. In women (152 patients), two-stage surgery with static spacers was associated independently with infection recurrence (OR 5.9 [1.5-23.6], p = 0.01). Among patients without infection recurrence, International Knee Society scores were similar between those undergoing one-stage or two-stage exchanges. CONCLUSION: Two-stage procedures offered less benefit to female patients. It suggests that one-stage procedures are preferable, because they offer greater comfort without increasing the risk of recurrence. Routine one-stage procedures may be a reasonable option in the treatment of infected TKR. LEVEL OF EVIDENCE: III.

Post-arthroscopy septic arthritis: Current data and practical recommendations.

Septic arthritis develops after less than 1% of all arthroscopy procedures. The clinical symptoms may resemble those seen after uncomplicated arthroscopy, raising diagnostic challenges. The diagnosis rests on emergent joint aspiration with microscopic smear examination and prolonged culturing on specific media. Urgent therapeutic measures must be taken, including abundant arthroscopic lavage, synovectomy, and the concomitant administration of two effective antibiotics for at least 6 weeks. Preservation of implants or transplants is increasingly accepted, and repeated joint lavage is a component of the treatment strategy. After knee arthroscopy, infection is the most common complication; most cases occur after cruciate ligament reconstruction, and staphylococci are the predominant causative organisms. Emergent synovectomy with transplant preservation and appropriate antibiotic therapy ensures eradication of the infection in 85% of cases, with no adverse effect on final functional outcomes. After shoulder arthroscopy, infection is 10 times less common than neurological complications and occurs mainly after rotator cuff repair procedures; the diagnosis may be difficult and delayed if Propionibacterium acnes is the causative organism. The update presented here is based on both a literature review and a practice survey. The findings have been used to develop practical recommendations aimed at improving the management of post-arthroscopy infections, which are exceedingly rare but can induce devastating functional impairments.

Validation of the French version of two on high-activity knee questionnaires.

INTRODUCTION: Self-administered quality-of-life questionnaires are valuable evaluation tools in orthopedic surgery. The conventional questionnaires are limited by a substantial ceiling effect. We wished to validate a French translation of two English questionnaires for high-activity patients: the High-Activity Arthroplasty Score (HAAS) and the Activity Scale for Arthroplasty Patients (ASAP). One hundred patients operated on for knee replacement were selected. The answers to both questionnaires were analyzed and compared to the Oxford Knee Score (OKS) and to the scoring system of the American Knee Society (AKS). HYPOTHESIS: There is no correlation between the results of both high-activity questionnaires and of the two conventional scoring systems. RESULTS: All questions were easily understood. The mean scores of the HAAS and ASAP questionnaires were 8.2±3.0 and 30.7±9.6, respectively. The distributions were not considered normal. There was no floor effect, but there was a limited ceiling effect (0% and 14%, respectively). The internal coherence of both questionnaires was satisfactory. There was a significant correlation between the high-activity scores and the conventional scores. DISCUSSION: Both high-activity questionnaires in our French translation can potentially measure the overall function of a patient after knee replacement as accurately as the index English version. It is self-administered, easy to use, can collect patients' answers by postage mailing, and involves no ceiling effect. All these points should allow its routine use for evaluation after knee replacement. The HAAS evaluation seems to be superior to the ASAP evaluation. LEVEL OF EVIDENCE: Case-control study, level III.

Postoperative pain control by intra-articular local anesthesia versus femoral nerve block following total knee arthroplasty: impact on discharge.

INTRODUCTION: The goal of this retrospective study was to compare pain control following total knee arthroplasty (TKA) on a perioperative protocol of local anesthesia (LA) versus the more classical femoral nerve block (FNB) technique. HYPOTHESIS: Fitness for discharge would be achieved earlier using the LA protocol. MATERIALS: Ninety-eight consecutive TKA patients operated on by a single surgeon were included with no selection criteria. In the study group (49 patients), 200 mL ropivacaine 5% was injected into the surgical wound and an intra-articular catheter was fitted to provide continuous infusion of 20 mL/h ropivacaine for 24h. The control group (49 patients) received ropivacaine FNB. Discharge fitness (independent walking, knee flexion>90°, quadricipital control, pain on VAS≤3) and hospital stay were assessed. RESULTS: Discharge fitness was achieved significantly earlier in the study group (4.2±2.6 versus 6.7±3.2 days; P=0.0003), with significantly shorter mean hospital stay (6.1±3.4 versus 8.8±3.5 days; P=0.0002). The complications rate did not differ between study and control groups. DISCUSSION: Although retrospective, this study indicates that the LA protocol improves management of post-TKA pain and accelerates rehabilitation, thereby, reducing hospital stay. The acceleration effect may be due to the absence of quadriceps inhibition. LEVEL OF EVIDENCE: Level III - Case control study.

Diagnostic accuracy of intra-articular C-reactive protein assay in periprosthetic knee joint infection--a preliminary study.

BACKGROUND: Periprosthetic joint infection often raises diagnostic challenges, as the published criteria are heterogeneous. New markers for predicting periprosthetic infection have been evaluated. Here, we assessed one of these markers, C-reactive protein (CRP), in joint fluid. HYPOTHESIS: We hypothesised that intra-articular CRP levels would perform better than serum CRP concentrations in diagnosing knee prosthesis infection. PATIENTS AND METHODS: We prospectively included 30 patients including 10 with native-knee effusions, 11 with prosthetic-knee aseptic effusions, and 11 with prosthetic-knee infection defined using 2011 Musculoskeletal Society criteria. Serum CRP was assayed using turbidimetry or nephelometry and intra-articular CRP using nephelometry. Appropriate statistical tests were performed to compare the three groups; P values < 0.05 were considered significant. RESULTS: Serum and intra-articular CRP levels were 5- to 16-fold higher in the group with periprosthetic infection than in the other two groups. Although the areas under the ROC curves were not significantly different, the likelihood ratios associated with the selected cut-offs suggested superiority of intra-articular CRP: a value > 2.78 mg/L suggested possible infection (100% sensitivity and 82% specificity) and a value > 5.37 mg/L probable infection (90% sensitivity and 91% specificity). DISCUSSION: Our findings suggest a possible role for intra-articular CRP assay in diagnosing knee prosthesis infection and perhaps periprosthetic infection at any site. LEVEL OF EVIDENCE: Level III, diagnostic study, development of a diagnostic criterion in consecutive patients comparatively to a reference standard.

Anterior knee laxity measurement using stress radiographs and the GNRB(®) system versus intraoperative navigation.

BACKGROUND: Anterior knee laxity measurement serves both to diagnose and to evaluate the severity of anterior cruciate ligament (ACL) damage. HYPOTHESIS: We tested the hypothesis that anterior laxity measurements of ACL-deficient knees obtained using the GNRB(®) system and stress radiographs differed from each other and from intraoperative navigation measurement taken as the reference standard. MATERIAL AND METHODS: Twenty-one patients with chronic ACL deficiency underwent arthroscopic ACL reconstruction. Anterior knee laxity was measured preoperatively using the GNRB(®) system without anaesthesia and anterior-drawer stress radiographs under anaesthesia then intraoperatively using a non-image-based navigation system. RESULTS: The three measurements differed significantly (P=0.05). A systematic measurement error of -3.7 mm occurred for both preoperative measurements versus the reference standard. No significant difference was found between the two preoperative measurements. DISCUSSION: The GNRB(®) system should be preferred over stress radiographs, as reliability is similar but no radiation exposure is required. Both preoperative measurement methods underestimate anterior laxity as measured intraoperatively using the navigation system. This systematic bias may be relevant to treatment decision-making. LEVEL OF EVIDENCE: II, development of a diagnostic criterion in consecutive patients versus a validated reference standard.

Simultaneous bilateral total knee arthroplasty. A multicenter feasibility study.

INTRODUCTION: The value and risk of simultaneous total knee arthroplasty (TKA) in patients with bilateral knee arthritis is a subject of debate. HYPOTHESES: The risk of complications following simultaneous bilateral TKA will be increased compared to the rates published in the literature for unilateral TKA, and the clinical and functional outcomes will be poorer in this particular group. MATERIALS AND METHODS: One hundred and twenty-three patients who underwent simultaneous bilateral TKA between 2005 and 2011 in five specialized, high volume centers were evaluated. The files were analyzed retrospectively after a mean 33 months of follow-up. RESULTS: The mean hospital stay was 11 days. Mean blood loss was 4.1g/dL. A postoperative transfusion was performed in 68 patients (55%), with a mean 3.1 units of blood. The mean global IKS score increased from 90 to 150 points. Eighty patients would agree to undergo simultaneous bilateral TKA again (65%), and 70 would recommend this procedure to others (57%). DISCUSSION: The hypothesis was not confirmed: the risk of complications was not increased compared to the generally accepted risk of a unilateral procedure. The risk of complications in this study was very similar to that published in the literature for the same therapeutic strategy. Therefore, there is no solid medical evidence to prevent recommending this strategy. The results of the participating centers suggest that this therapeutic approach should be continued in selected indications. LEVEL OF EVIDENCE: IV, retrospective study.

Current concept in rotational laxity control and evaluation in ACL reconstruction.

Rotation combined with translation; compose the three-dimensional motion of the knee subluxation in anterior cruciate ligament deficient knee. The worldwide scientists were focused initially on the translation part of this complex 3D motion, but since the beginning of the century there was a large interest on knee rotational laxity study. Lot of paper reported new devices and results with an explosion since the beginning of the decade. The purpose of this review is to provide an extensive critical analysis of the literature and clarify the knowledge on this topic. We will start with a dismemberment of different rotational laxities reported: the rotation coupled with translation in 2D tests such as Lachman test and anterior drawer test; the rotational envelope considering the maximum internal external rotation; and the "active rotation" occurring in 3D Pivot-shift (PS) test. Then we will analyze the knee kinematics and the role of different anterior cruciate ligament (ACL) bundle on rotation. A review of different mechanical and radiological devices used to assess the different rotations on ACL deficient knees will be presented. Two groups will be analyzed, dynamic and static conditions of tests. Navigation will be described precisely; it was the starter of this recent interest in rotation studies. Opto electronic and electromagnetic navigation systems will be presented and analyzed. We will conclude with the last generation of rotational laxity assessment devices, using accelerometers, which are very promising.

The Oxford Knee Score: compared performance before and after knee replacement.

BACKGROUND: Self-administered quality-of-life questionnaires are now crucial to the evaluation of orthopaedic surgical patient-reported outcomes, as they reflect patient satisfaction. The Oxford Knee Score (OKS) is a validated instrument that is widely used to assess outcomes of knee osteoarthritis surgery. HYPOTHESIS: The relevance of the OKS (comprehension and relevance of the items and responses, and internal and external validity) and its discriminating performance measured based on the ceiling and floor threshold effects are better before than after knee replacement surgery. MATERIALS AND METHODS: We included 200 patients (100 scheduled for knee replacement and 100 having had knee replacement more than 1 year earlier). The OKS questionnaire was handed to each patient during the first surgeon visit or during a follow-up visit. The American Knee Society (AKS) score was determined simultaneously. RESULTS: The mean OKS was 43.7 (range, 21-56; SD, 6.9) before surgery and 20.5 (range, 12-45; SD, 5.6) after surgery. The floor effect was absent (0%) before surgery and substantial (33%) after surgery; a weak ceiling effect (7%) was noted before surgery and no ceiling effect after surgery. Internal consistency of the OKS was excellent. The OKS correlated negatively with the AKS knee and functional scores, both before and after surgery. DISCUSSION: The OKS is well-suited to the evaluation of knee function both before and after knee replacement surgery. Before surgery, the absence of substantial floor and ceiling effects lead to excellent discrimination. After surgery, the substantial floor effect limits the ability to discriminate among the best results. Efforts should be made to develop more demanding scoring systems. LEVEL OF EVIDENCE: Level 2. Exploratory cohort study with universally applied reference standards.

Validation of a French version of the Oxford knee questionnaire.

INTRODUCTION: Self-administered quality-of-life questionnaires are a valuable evaluation tool in orthopedic surgery to determine patient satisfaction. The Oxford knee questionnaire has been validated for osteoarthritic patients. The aim of this study was to validate a French version of this English form. One hundred patients waiting for knee replacement were selected. The answers to the questionnaire were analysed and compared to the clinical and functional International Knee Society score (IKS). HYPOTHESIS: There is negative correlation between the results of the Oxford knee questionnaire and the IKS score. RESULTS: None of the patients had difficulty understanding the questions. The mean Oxford knee score was 43.7 (range 21-56, SD 6.9). The distribution was considered normal. There was no floor effect (0%); there was a limited ceiling effect (7%). The internal consistency of the questionnaire was excellent. There was a negative correlation between the Oxford knee score and the IKS knee score, functional score and global score. DISCUSSION: Our results are very similar to the results from the normative English version of the knee questionnaire and to the results from translated questionnaires in other foreign languages. Our French adaptation of the Oxford knee questionnaire can be used to measure the global function of a patient before knee replacement as accurately as the original English version. It is self-administered, easy to use and patients can send their responses by post, which makes it a useful tool for the routine evaluation of patients before knee replacement.