Deterministic quantum state transfer and remote entanglement using microwave photons.

Sharing information coherently between nodes of a quantum network is fundamental to distributed quantum information processing. In this scheme, the computation is divided into subroutines and performed on several smaller quantum registers that are connected by classical and quantum channels 1 . A direct quantum channel, which connects nodes deterministically rather than probabilistically, achieves larger entanglement rates between nodes and is advantageous for distributed fault-tolerant quantum computation 2 . Here we implement deterministic state-transfer and entanglement protocols between two superconducting qubits fabricated on separate chips. Superconducting circuits 3 constitute a universal quantum node 4 that is capable of sending, receiving, storing and processing quantum information5-8. Our implementation is based on an all-microwave cavity-assisted Raman process 9 , which entangles or transfers the qubit state of a transmon-type artificial atom 10 with a time-symmetric itinerant single photon. We transfer qubit states by absorbing these itinerant photons at the receiving node, with a probability of 98.1 ± 0.1 per cent, achieving a transfer-process fidelity of 80.02 ± 0.07 per cent for a protocol duration of only 180 nanoseconds. We also prepare remote entanglement on demand with a fidelity as high as 78.9 ± 0.1 per cent at a rate of 50 kilohertz. Our results are in excellent agreement with numerical simulations based on a master-equation description of the system. This deterministic protocol has the potential to be used for quantum computing distributed across different nodes of a cryogenic network.

Microwave Quantum Link between Superconducting Circuits Housed in Spatially Separated Cryogenic Systems.

Superconducting circuits are a strong contender for realizing quantum computing systems and are also successfully used to study quantum optics and hybrid quantum systems. However, their cryogenic operation temperatures and the current lack of coherence-preserving microwave-to-optical conversion solutions have hindered the realization of superconducting quantum networks spanning different cryogenic systems or larger distances. Here, we report the successful operation of a cryogenic waveguide coherently linking transmon qubits located in two dilution refrigerators separated by a physical distance of five meters. We transfer qubit states and generate entanglement on demand with average transfer and target state fidelities of 85.8% and 79.5%, respectively, between the two nodes of this elementary network. Cryogenic microwave links provide an opportunity to scale up systems for quantum computing and create local area superconducting quantum communication networks over length scales of at least tens of meters.

Fast and Unconditional All-Microwave Reset of a Superconducting Qubit.

Active qubit reset is a key operation in many quantum algorithms, and particularly in quantum error correction. Here, we experimentally demonstrate a reset scheme for a three-level transmon artificial atom coupled to a large bandwidth resonator. The reset protocol uses a microwave-induced interaction between the |f,0⟩ and |g,1⟩ states of the coupled transmon-resonator system, with |g⟩ and |f⟩ denoting the ground and second excited states of the transmon, and |0⟩ and |1⟩ the photon Fock states of the resonator. We characterize the reset process and demonstrate reinitialization of the transmon-resonator system to its ground state in less than 500 ns and with 0.2% residual excitation. Our protocol is of practical interest as it has no additional architectural requirements beyond those needed for fast and efficient single-shot readout of transmons, and does not require feedback.

Resection of bilateral massive Achilles tendon xanthomata with reconstruction using a flexor hallucis longus tendon transfer and Bosworth turndown flap: A case report and literature review.

Tumours of the Achilles tendon are rare. Reconstruction of the large defect following excision, however, is often a challenge and is sometimes a factor in deciding against operative treatment of a benign lesion. We report a case of excision of bilateral Achilles tendon xanthomata, with reconstruction using a flexor hallucis longus tendon transfer and Bosworth turndown flap.

The effect of ankle and hindfoot malalignment on foot mechanics in patients suffering from post-traumatic ankle osteoarthritis.

BACKGROUND: Ankle and hindfoot malalignment is a common finding in patients suffering from post-traumatic ankle osteoarthritis. However, no studies have addressed the effect of concomitant foot deformities on intrinsic foot kinematics and kinetics. Therefore, the objective of this study was to investigate the effect of ankle and hindfoot malalignment on the kinematics and kinetics of multiple joints in the foot and ankle complex in patients suffering from post-traumatic ankle osteoarthritis. METHODS: Twenty-nine subjects with post-traumatic ankle osteoarthritis participated in this study. Standardized weight-bearing radiographs were obtained preoperatively to categorize patients as having cavus, planus or neutral ankle and hindfoot alignment, based on 4 X-ray measurements. All patients underwent standard gait assessment. A 4-segment foot model was used to estimate intrinsic foot joint kinematics and kinetics during gait. Statistical parametric mapping was used to compare foot kinematics and kinetics between groups. FINDINGS: There were 3 key findings regarding overall foot function in the 3 groups of post-traumatic ankle osteoarthritis: (i) altered frontal and transverse plane inter-segmental angles and moments of the Shank-Calcaneus and Calcaneus-Midfoot joints in the cavus compared to the planus group; (ii) in cavus OA group, Midfoot-Metatarsus joint abduction sought to compensate the varus inclination of the ankle joint; (iii) there were no significant differences in inter-segmental angles and moments between the planus and neutral OA groups. INTERPRETATION: Future studies should integrate assessment of concomitant foot and ankle deformities in post-traumatic ankle osteoarthritis, to provide additional insight into associated mechanical deficits and compensation mechanisms during gait.

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.

Magnetic field reversals, polar wander, and core-mantle coupling.

True polar wander, the shifting of the entire mantle relative to the earth's spin axis, has been reanalyzed. Over the last 200 million years, true polar wander has been fast (approximately 5 centimeters per year) most of the time, except for a remarkable standstill from 170 to 110 million years ago. This standstill correlates with a decrease in the reversal frequency of the geomagnetic field and episodes of continental breakup. Conversely, true polar wander is high when reversal frequency increases. It is proposed that intermittent convection modulates the thickness of a thermal boundary layer at the base of the mantle and consequently the core-to-mantle heat flux. Emission of hot thermals from the boundary layer leads to increases in mantle convection and true polar wander. In conjunction, cold thermals released from a boundary layer at the top of the liquid core eventually lead to reversals. Changes in the locations of subduction zones may also affect true polar wander. Exceptional volcanism and mass extinctions at the Cretaceous-Tertiary and Permo-Triassic boundaries may be related to thermals released after two unusually long periods with no magnetic reversals. These environmental catastrophes may therefore be a consequence of thermal and chemical couplings in the earth's multilayer heat engine rather than have an extraterrestrial cause.

[Hallux valgus surgery in 2005. Conventional, mini-invasive or percutaneous surgery? Uni- or bilateral? Hospitalisation or one-day surgery?]. / La chirurgie de l'hallux valgus en 2005. Chirurgie conventionnelle, mini-invasive ou percutanée ? Uni- ou bilatérale ? Hospitalisation ou ambulatoire ?

There remains a good deal of controversy concerning forefoot surgery. Certain concepts such as conventional procedures, minimally invasive surgery, or percutaneous surgery are promoted because of their specific advantages including rapid recovery and compatibility with a short hospital stay or even outpatient surgery. Nevertheless, in 2005 many questions remain unanswered and highly variable practices have been basically founded on personal experience rather than scientific evidence. In addition, financial and lobbying pressure appears to have an influence on our choices, affecting the freedom of our therapeutic decision-making. Developed over a long period, conventional surgery has proven reliability, reproducibility and adaptability. Procedures termed minimally invasive are defined by the limited incision. Percutaneous surgery is not less invasive than other procedures; the techniques are performed under indirect visual control and often assisted with more or less sophisticated radioscopic techniques depending on the surgeon's own experience. In our opinion, percutaneous surgery should be considered as a new concept based on rapid and functional results. Patients often raise the question of a bilateral procedure. For hallux valgus, there is no consensus on whether unilateral or bilateral procedures are better, the best solution depending on postoperative weight bearing and thus on the technique employed. From a cost expenditures point of view, bilateral procedures have an impact. For the advantages in terms of macroeconomy for professional incapacity, the question is less univocal for healthcare authorities. Advances in perioperative anesthesia and analgesia have enabled a broader approach to ambulatory surgery. Outpatient surgery appears to have benefits in terms of organization and economics. Variables studied were as follows: duration of hospital stay, postoperative edema, number of days of sick leave and preoperative and early and late postoperative pain. Patients who underwent minimally invasive procedures had a significantly shorter hospital stay compared with three other groups. For bilateral procedures, hospital stay on average was longer than in the two other groups. There was no correlation between postoperative edema and pain or between the degree of edema at 15 days and two months. Mean sick leave was 54.6 days. This was significantly shorter for percutaneous procedures compared with conventional surgery or minimally invasive techniques. Preoperative pain was noted four to five on the Visual Analogue Scale (VAS). There was no significant difference between the different groups as a function of the type of surgery performed. Statistically, there is very little difference in the short term between the different techniques. A much longer study would be necessary to obtain evidence to guide our practices. While there is certainly no reason to condemn one method or another, surgeons must be careful about the promises given to patients which are generally based on personal experience but not necessarily supported by rigorous scientific data.

[Results of self-centering patellofemoral prosthesis: a retrospective study of 57 implants]. / Résultats de la prothèse fémoropatellaire autocentrique: à propos d'une série continue de 57 prothèses.

PURPOSE OF THE STUDY: The aim of this retrospective analysis was to report results obtained with a self-centering patellofemoral prosthesis. We wanted to determine whether self-centering still has indications for the treatment of patellofemoral osteoarthritis. MATERIAL AND METHODS: This was a continuous series of 57 knees operated on since 1986 in the same center for implantation of a self-centering patellofemoral prosthesis (Medinov then Depuy). Eight patients died and four were lost to follow-up. Two knees were excluded from the analysis after revision with a PFP. We report here the outcome of 43 prostheses at mean follow-up of six years two months (range 78 months to 15 years). The IKS score (200 points) and the ADL scale (in %) were recorded. The position of the prosthesis was assessed on plain X-rays. Mean age at implantation was 67.2 years. The main reasons for surgery were osteoarthritis secondary to dysplasia (60%) and primary disease (31.1%). RESULTS: At last follow-up, the IKS score was 157.2 points (range 76-195). The mean ADL score was 74.1/100 (48.8-96.3). The IKS evaluation showed good outcome in 66.7% of knees. The ADL scale gave a less satisfactory outcome: 57.7% good outcome for this scale which takes into account all knee functions for activities of daily life. Outcome was better among patients with trochlear dysplasia. Eleven patients (24.4%) had had revision surgery for total knee arthroplasty. Preoperatively, the trochlear angle was smaller in revision cases (p=0.023). In these patients, the first prosthesis was more anterior (p=0.004) with a greater horizontal axis (p=0.015). DISCUSSION: Our outcomes were less satisfactory than the average results in the literature. It must be noted however, that the concept of a good outcome depends on the scale used for assessment. We found in our series a 10% difference between the ADL scale and the IKS score. Independently of the assessment scale used, outcome was better in knees with osteoarthritis secondary to dysplasia. An analysis of the X-ray findings disclosed technical errors leading to failure. The outcome of patellofemoral prosthesis depends essentially on two factors: technical precision and patient selection. CONCLUSION: In light of these findings, we have come to limit still further the rare indications for patellofemoral prostheses. The typical indication is isolated advanced patellofemoral osteoarthritis secondary to patellofemoral dysplasia unresponsive to medical treatment in patients aged 50-70 years. Revision with a total knee arthroplasty required changing the patellar insert if worn. We have not had any particular problem with revision total knee arthroplasty after patellofemoral prosthesis.

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).

[Anterior cruciate ligament revision: analysis and results from a series of 74 cases]. / Les reprises de ligamentoplastie du ligament croisé antérieur: analyse et résultats d'une série de 74 cas.

PURPOSE OF THE STUDY: This was a retrospective series of patients who underwent revision ligamentoplasty of the anterior cruciate ligament (ACL). We wanted to assess the functional outcome after this type of surgery and search for potential prognostic factors. MATERIAL AND METHODS: The series included 74 patients, mean age 34 years (range 21-59 years). The initial ligamentoplasty was performed with a synthetic ligament (n=16), an autograft (n=57) or an allograft (n=1). Differential laxity (KT-1000 maximal manual) was 7 +/- 2.5 mm. Anterior drawer was measured on the stress x-rays in 20 degrees flexion: medial 8 +/- 4.7 mm, lateral 8.3 +/- 4.9 mm. Mean time to revision surgery was 78 months. Reconstruction was performed arthroscopically in 69 knees. The implant used for the revision reconstruction was an autograft: patellar tendon (n=42), quadriceps tendon (n=15), hamstring tendon (n=13), patellar tendon and quadriceps tendon (MacInJones) (n=3), fascia lata (n=1). A meniscal tear was noted in 24 knees and a cartilage lesion in 35. RESULTS: Outcome was assessed at mean 21.2 months follow-up. The mean IKDC function score was 71.7 (range 21.8-100). 78% of patients considered their knee normal or nearly normal and 88% presented a positive Lachmann. Mean differential laxity measured with KT-1000 (maximal manual) was 2 +/- 1.7 mm. Stress x-rays revealed a mean differential laxity measured at 3.7 +/- 2.3 mm medially and 6.3 +/- 4.3 mm laterally. The presence of a meniscal lesion favored osteoarthritic degradation. Presence of chondral lesions altered the functional outcome significantly and limited resumption of sports activities. An initial repair using a synthetic ligament affected the functional outcome after revision surgery and favored or aggravated chondral lesions. DISCUSSION: The clinical results we have obtained with revision ACL ligamentoplasty are comparable to previous series reported in the literature. The functional outcome is not as good as after first-intention repair, especially if the initial plasty was done with a synthetic ligament and the knee presented meniscal or cartilage damage.

Metatarsalgia.

The causes of metatarsalgia are classified as primary, secondary, and iatrogenic. Anatomical and biomechanical considerations separate "static" from "propulsive" forms of metatarsalgia. The physical examination should be combined with an assessment of weight-bearing radiographs and, if needed, of ultrasound or magnetic resonance imaging scans. The first-line treatment is conservative (stretching exercises, footwear modification, insoles, and lesion debridement). Soft-tissue surgical procedures (gastrocnemius muscle recession, tendon transfer, and plantar plate repair) should also be considered. Among the various types of metatarsal osteotomy, the Weil procedure is reliable. Percutaneous methods are being developed but require evaluation. A treatment algorithm can be developed based on whether the hallux is normal or abnormal. Metatarsalgia due to inflammatory disease requires a specific treatment strategy.

IL-33 is induced in undifferentiated, non-dividing esophageal epithelial cells in eosinophilic esophagitis.

The molecular and cellular etiology of eosinophilic esophagitis (EoE), an emerging tissue-specific allergic disease, involves dysregulated gene expression in esophageal epithelial cells. Herein, we assessed the esophageal expression of IL-33, an epithelium-derived alarmin cytokine, in patients with EoE. IL-33 protein was markedly overexpressed within the nuclei of a subpopulation of basal layer esophageal epithelial cells in patients with active EoE compared to control individuals. IL-33 exhibited dynamic expression as levels normalized upon EoE remission. IL-33-positive basal epithelial cells expressed E-cadherin and the undifferentiated epithelial cell markers keratin 5 and 14 but not the differentiation marker keratin 4. Moreover, the IL-33-positive epithelial cells expressed the epithelial progenitor markers p75 and p63 and lacked the proliferation markers Ki67 and phospho-histone H3. Additionally, the IL-33-positive cells had low expression of PCNA. IL-33 expression was detected in ex vivo-cultured primary esophageal epithelial cells in a subpopulation of cells lacking expression of proliferation markers. Collectively, we report that IL-33 expression is induced in an undifferentiated, non-dividing esophageal epithelial cell population in patients with active EoE.

[Risks of pulmonary vein isolation by radiofrequency for the treatment of paroxysmal atrial fibrillation: a single centre experience of the first 200 patients]. / Risques liés a l'isolement par radiofréquence des veines pulmonaires pour le traitement de la fibrillation auriculaire paroxystique: expérience monocentrique des 200 premiers patients.

The authors report the initial experience of an electrophysiological laboratory starting ablation for atrial fibrillation, a promising technique which is not yet widely practiced because of the risks related to the procedure. The incidence of severe complications (tamponade, pulmonary vein stenosis, ischaemic events) did not appear to be different in the first 100 procedures compared with the next 100 procedures: 3% in the two groups. The selection of patients, strict perioperative management and the initial support by confirmed operators seem to be the factors which minimise the complications rate of the procedure.

[Iliopsoas bursal distension revealing complication of total hip arthroplasty: five cases]. / Masse inguinale révélatrice d'une complication d'une arthroplastie totale de hanche: A propos de 5 cas.

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.

[Congenital club foot: treatment in childhood, outcome and problems in adulthood]. / Le pied bot varus equin: traitement chez l'enfant et devenir a l'age adulte.

PURPOSE OF THE SYMPOSIUM: Treatment of idiopathic talipes varus, or congenital clubfoot, is designed to re-align the foot to alleviate pain and allow plantigrade weight bearing with adequate joint motion despite the subnormal radiographic presentation. This symposium was held to review current management practices for congenital clubfoot in children and to analyze outcome in adults in order to propose the most appropriate therapeutic solutions. MANAGEMENT OF CONGENITAL CLUBFOOT IN CHILDREN: Idiopathic talipes varus can be suspected from the fetal ultrasound. Parents should be given precise information concerning proposed treatment after birth. Deviations must be assessed in the newborn then revised regularly using objective scales during and after the end of treatment. This enables a better apprehension of the evolution in comparison with the severity of the initial deformation. Conservative treatment is proposed by many teams: a functional approach (rehabilitation and minimal use of orthetic material) or the Ponseti method (progressive correction using casts associated with percutaneous tenotomy of the calcaneal tendon) are currently preferred. If such methods are insufficient or unsuccessful, surgery may be performed as needed at about 8 to 11 months to achieve posteromedial release. Good results are obtained in 80% of patients who generally present minimal residual deformations (adduction of the forefoot, minimal calcaneal varus, residual medial rotation, limitation of dorsal flexion), which must be followed regularly through growth. The difficulty is to distinguish acceptable from non-acceptable deformation. At the end of the growth phase, severe articular sequelae are rare (stiff joint, recurrence of initial deformation, overcorrection) but difficult to correct surgically: osteotomy, tendon transfer, double arthrodesis, Ilizarov fixator. Gait analysis is essential to quantify function and obtain an objective assessment of the impact on higher joints, providing valuable guidance for surgical correction. OUTCOME IN ADULTHOOD: There have been very few studies evaluating the long-term functional outcome after treatment during childhood. According to two studies presented at this symposium (Brussels, Lausanne), results have been generally good but with subnormal radiographs irrespective of the type of treatment or how early treatment started in childhood. Hypoplasia of the talar dome is a constant finding and is correlated with limitation of dorsal flexion of the ankle joint. A small degree under-correction is often observed but well tolerated while overcorrection is generally less well tolerated. Functional outcome depends highly on preservation of subtalar joint motion. There have been no reports on the results of treatment of sequelae in adults. Most problems (pain, stiffness, osteoarthritis) are observed in the mid or rear foot. Indications for conservative surgery (osteotomy) of the mid or rear foot are rare compared with indications for combined arthrodesis. Talocrural decompensation is a turning point observed in the adult. Management at this point is difficult: fusion of the ankle worsens the situation by increasing the stress on the forefoot and aggravating the disability; implantation of an ankle prosthesis is technically difficult and remains to be fully developed. Treatment of the dorsal bunion of the great toe may require tendon transfer and/or fusion. CONCLUSION: A child born with clubfoot will never have a normal foot in adulthood. Sequelae present at the end of growth will intensify during adult life; under-correction is easier to treat in adulthood than overcorrection. The most difficult problems in adulthood are: neglected clubfoot, over correction, and degradation of the talocrural joint.

[Analysis of meniscal lesions accompanying anterior cruciate ligament tears: A retrospective analysis of 156 patients]. / Lésions méniscales constatées lors de la reconstruction du ligament croisé antérieur: siège et nature dans une série continue de 156 patients.

PURPOSE OF THE STUDY: The purpose of this retrospective study of a continuous series was to document preferential types and localizations of meniscal lesions accompanying anterior cruciate ligament tears and to demonstrate the relationships between meniscal lesions, patient age and time from trauma to surgery. MATERIAL AND METHODS: One hundred fifty-six patients with no history of meniscal lesions underwent ligamentoplasty in 2003. All procedures were performed by the same operator. The time from trauma to surgery was 31.6 months on average. This was a retrospective continuous series using data from detailed operative reports. RESULTS: An isolated lesion of the medial meniscus was observed in 25.6% of cases. There was an isolated lesion of the lateral meniscus in 21.8% and lesions of both menisci in 9%. The most frequent injury was a longitudinal fissuration, for both menisci. Patient age and time from trauma to surgery were statistically correlated with presence of a medial lesion. There was no statistical relationship for the lateral meniscus nor for type of meniscal injury. DISCUSSION: The proportion of lesions to the lateral meniscus appeared to be unaffected by age or time to surgery after trauma, suggesting that lateral meniscal lesions occurred at the time of the initial curciate injury. On the contrary, the incidence of medial lesions increased with time and patient age, confirming the important role of the medial meniscus to block anterior displacement of the knee. We thus recommend early repair of anterior cruciate ligament tears in order to avoid medial meniscectomy which would increase with increasing time from injury to surgery and thus affect the postoperative outcome.

[Axial lower limb alignment and knee geometry in patients with osteoarthritis of the knee]. / Analyse segmentaire de la déformation frontale dans les gonarthroses fémoro-tibiales latéralisées.

PURPOSE OF THE STUDY: We conducted a retrospective radiographic study to identify and quantify medial and lateral misalignments in candidates for total knee arthroplasty. MATERIAL AND METHODS: We studied a discontinuous series of 101 patients (164 knees) among candidates for total knee arthroplasty seen between 1990 and 2002. We selected a random sample for study. Exclusion criteria were any history of fracture, surgical treatment, rheumatoid disease, or congenital disorder. A first group of 136 genu varum knees was identified in 82 patients (mean age 72 years, mean weight 79 kg). A second group of 28 genu valgum knees was identified in 19 patients (mean age 67 years, mean weight 71 kg). The standard radiograms were digitalized for semi-automatic measurements using the Metros software. We recorded overall deformation, femoral valgus, tibial varus, HKA angle, HKS angle (mechanical/anatomic axis of the femur) and angle C (horizontal inclination of the ankle to the ground). All measures were compared between each other for each patient to search for relations. RESULTS: In the genu varum group (136 knees), mean overall deformation was 9 degrees , mainly due to tibial misalignment (5.5 degrees ) with a 1 degrees femoral valgus component. The HKS angle was 6.3 degrees , and lateral joint gap 4.3 degrees ; the C angle was 4 degrees . Overall varus followed tibial varus (p<0.01). Ankle inclination followed tibial varus (p<0.01). In the genu valgum group (28 knees), overall deformation was 4.2 degrees , mainly due to femoral misalignment (5.6 degrees) with 1 degrees tibial varus and a medial joint gap of 2 degrees . The HKS angle was 4.7 degrees and the mean C angle -4 degrees . Overall valgus was related to femoral valgus (p<0.001). Tibial varus was greater with greater femoral valgus (p<0.01). In both groups, the HKS angle was smaller with greater femoral valgus. DISCUSSION: Semi-automatic measurements on digitalized films enabled excellent reproducibility. Causes of error were related to limb rotation at acquisition. This study showed that genu varum worsens because of tibial wear followed by ligament distension, while for genu valgum, worsening predominantly results from femoral wear. The ankle joint line was nearly horizontal in one-third of the limbs, even when there was a major misalignment of the lower limb. The HKS angle was quite variable in both morphotypes, but was smaller with greater femoral valgus in both groups. CONCLUSION: Measuring all components involved in medial and lateral knee misalignment is very useful for understanding the morphotype of each individual knee before performing osteotomy or implanting a knee prosthesis.

[One-stage reconstruction of the two cruciate ligaments with a single autogenous graft from the extensor system: techniques and results of 25 chronic cases]. / Reconstruction simultanée des 2 ligaments croisés par un transplant autogène unique: technique et résultats à propos de 25 laxités chroniques.

PURPOSE OF THE STUDY: Chronic tears of both cruciate ligaments are rarely encountered. Management practices have varied. One-stage reconstruction of both ligaments using arthroscopically implanted allografts was proposed starting in 1996 for such chronic laxity but only 44 cases have been reported in six papers mixed in with recent cases raising very different problems. Treatments using allografts or autogenous grafts or both implanted arthroscopically have often been combined with open surgery. We report a retrospective analysis of 25 knees treated with the same technique from 1983 to 2004: reconstruction with a single transplant taken from the extensor system. MATERIAL AND METHODS: A 30-cm lenght patella tendon-patella-quadriceps tendon graft was harvested. The patellar block was fixed in a hole drilled under the tibial spine, the patellar tendon replacing the posterior cruciate ligament and the quadriceps tendon passing through the lateral condyle and replacing the anterior cruciate ligament before implantation on Gerdy's tubercle, this also creating an extra-articular plasty with the same implant. Medial, lateral and posterior plasties were performed, depending on the radiographic assessment of laxity. Twenty-five knees with major laxity and instability were operated on, including 14 in two-stage operations. The differential anterior drawer was 10+/-3 mm medially and 9+/-5 mm laterally. The posterior drawer at 70 degrees was 15+/-4 mm medially and 10+/-6 degrees laterally. The total anteroposterior laxity of the medial compartment was 29 mm, it was 30 mm for the lateral compartment. Lateral laxity was considered major (>10 degrees ) in 17 knees and medial laxity in 7. Lateral and medial laxities were associated in eleven knees. Hyper-extension was very severe in five knees. RESULTS: Functional outcome at mean 6.5 years follow-up (range 1-21) was satisfactory (except in three knees) allowing renewed occupational activity. Resumption of sports activity was less marked and none of the knees was in IKDC class A, corroborating results in the literature. Anatomic outcome was assessed on the radiological drawer decrease which was modest, mean gain in the anterior drawer measuring 4 and 5 mm in the medial and lateral compartments and mean gain in the posterior drawer measuring 5 mm medially and 3 mm laterally. Peripheral laxity was corrected for best. DISCUSSION: Classically, one or other of the cruciate ligaments is repaired, sometimes both, but in a two-stage procedure associating two different methods and autogenous tendon grafts. One-stage reconstruction of both cruciate ligaments with a single autogenous graft and a wide approach has not led to any complications. One-stage reconstruction using this technique has several advantages: one anterior incision, single transplant which also enables lateral plasty, short immobilization time with rapid rehabilitation.

[Intra-articular reconstruction of the anterior cruciate ligament with and without extra-articular supplementation by quadricipital tendon plasty: seven-year follow-up]. / Influence d'une ligamentoplastie extra-articulaire latérale sur les résultats de la reconstruction du ligament croisé antérieur avec le ligament patellaire avec 7 ans de recul.

PURPOSE OF THE STUDY: Reconstruction of the anterior cruciate ligament (ACL) is a common procedure, but use of lateral reinforcement is still a subject of debate. The purpose of this study was to compare two randomized series of ACL reconstructions, one using an intra-articular method (patellar tendon autograft) and the other an intra- and extra-articular method (Mac-InJones). MATERIAL AND METHODS: From January 1995 to March 1998, 63 knees underwent surgery for ACL reconstruction. Inclusion criteria was significant medial differential laxity measured between 7 and 12 mm on passive dynamic x-rays as 20 degrees flexion. Group 1 (patellar tendon intra-articular reconstruction) included 34 patients (27.1+/-7.5 years) and group 2 (intra-articular reconstruction plus extra-articular quadircipital tendon plasty) included 29 patients (28.5+/-12 years). The IKDC score was determined for 72% of the knees in group 1 and 68% in group 2 at seven years follow-up on average (102 and 93 months respectively). Anterior laxity was measured radiographically and with KT-1000. The position of the tunnels was controlled using the Aglietti method. RESULTS: The subjective functional score was 83.6+/-3.5 in group 1 and 83.5+/-3.5 in group 2. The overall IKDC knee score classes for group 1 were 0% A, 52.4% B, 28.6% C, and 19% D and for group 2 were 5.5% group A, 50% group B, 33.3% group C, and 11.1% group D. In group 1, the pivot test was negative in 61.9% and noted stage 1 in 28.6% and stage 2 in 9.5%. In group 2, the pivot test was negative in 78.9% and noted stage 1 in 15.8% and stage 2 in 5.3%. The KT-1000 showed no difference in gain in laxity: 31% for group 1 and 27% for group 2. Similarly, radiographically there was no difference with a 43.9% gain in differential laxity for the medial compartment and 45.3% for the lateral compartment in group 1. In group 2 the corresponding values were 51.9% and 41.8%. The position of the tunnels was the same in the two groups. DISCUSSION: In a preliminary study with two years follow-up, the results in these two series were not significantly different. It was concluded that there was not clear advantage to adding the extra-articular lateral plasty. At the present 7-year follow-up, pivoting appears to be better controlled in the lateral plasty group (p=0.23), but with no significant difference for laxity for both knee compartments. The inclusion criteria would be different today and would be based on the laxity of the lateral compartment.