Treatments of avascular osteonecrosis of the hip: Current treatments.

Conservative treatments for aseptic osteonecrosis of the femoral head have their ancestor in the core decompression of the femoral neck, recommended by Ficat. Due to inconsistent results, this treatment has been optimized by either vascularized fibular grafting, or by injecting autologous stem cells into the necrotic zone. The French promoters have published long-term results, showing efficacy in the early stages of the disease, where the femoral head has not yet lost its sphericity. Over the last 10years, comparative studies, sometimes randomized, opposing them to simple core decompression, have been published by non-promoters, confirming the possibility of stabilization or even regression of necrosis area. But these techniques are not easy to implement. Cell therapy requires treatment of marrow samples by centrifugation to obtain a pellet with a high concentration of haematopoietic cells. The now proven long-term efficacy as well as the safety of this technique make it the method of choice for treating young patients detected at the sub-radiological stage by MRI. Unfortunately, many are seen late with detached cephalic cartilage or collapsed femoral head and have no other option than total hip arthroplasty. This technique is very reliable. With alumina ceramics, results of more than 20years show the absence of wear and osteolysis, although other complications such as instability or periprosthetic fractures may occur in these young and active patients.

[Treatment switch in diabetic macular edema: Literature review and management algorithm]. / Les switchs de traitement dans l'œdème maculaire diabétique : revue de la littérature et algorithme de prise en charge.

Initial management of diabetic macular edema (DME) is well-defined, but there is a lack of national or international consensus for patients who do not respond or respond only partially to these treatments. Several studies, mostly retrospective, have assessed medication switches, but currently, the literature contains no randomized studies. The goal of this article is to present an algorithm for switching medications, which can be proposed to DME patients treated with anti-VEGF agents, as defined by a group of French retina experts, supported by the existing literature on the subject. After initiation of an anti-VEGF treatment for DME, the response is usually assessed after 5 monthly injections. A partial anatomical response (reduction of central retinal thickness between 10 and 20%), seen in 30 to 40% of patients, is associated with a favorable visual prognosis according to randomized studies. Continuation of the anti-VEGF injections after the induction phase is thus possible. If the response remains incomplete after 3 additional anti-VEGF injections, a complete ophthalmologic examination should be performed, and a switch to another therapeutic class (corticosteroids) may be proposed in the absence of contraindications. If a complete non-response is seen initially (reduction of central retinal thickness<10%), the switch is proposed immediately after the induction phase.

Emergence and multiple reassortments of French 2015-2016 highly pathogenic H5 avian influenza viruses.

From November 2015 to August 2016, 81 outbreaks of highly pathogenic (HP) H5 avian influenza virus were detected in poultry farms from South-Western France. These viruses were mainly detected in farms raising waterfowl, but also in chicken or guinea fowl flocks, and did not induce severe signs in waterfowl although they did meet the HP criteria. Three different types of neuraminidases (N1, N2 and N9) were associated with the HP H5 gene. Full genomes sequences of 24 H5HP and 6 LP viruses that circulated in the same period were obtained by next generation sequencing, from direct field samples or after virus isolation in SPF embryonated eggs. Phylogenetic analyses of the eight viral segments confirmed that they were all related to the avian Eurasian lineage. In addition, analyses of the "Time of the Most Recent Common Ancestor" showed that the common ancestor of the H5HP sequences from South-Western France could date back to early 2014 (±1 year). This pre-dated the first detection of H5 HP in poultry farms and was consistent with a silent circulation of these viruses for several months. Finally, the phylogenetic study of the different segments showed that several phylogenetic groups could be established. Twelve genotypes of H5HP were detected implying that at least eleven reassortment events did occur after the H5HP cleavage site emerged. This indicates that a large number of co-infections with both highly pathogenic H5 and other avian influenza viruses must have occurred, a finding that lends further support to prolonged silent circulation.

Early worsening of diabetic retinopathy after rapid improvement of blood glucose control in patients with diabetes.

AIM: To review the frequency, importance of and risk factors for "early worsening of diabetic retinopathy" (EWDR) after rapid improvement of blood glucose in patients with diabetes. METHODS: This was a systematic review of key references (PubMed 1980-2016) and the current international recommendations for the above-mentioned topics. RESULTS: EWDR has been described during intensive treatment (IT) in patients with uncontrolled type 1 or 2 diabetes, and after pancreas transplantation or bariatric surgery. EWDR arises in 10-20% of patients within 3-6 months after abrupt improvement of glucose control, and in nearly two times that proportion in patients with advanced baseline diabetic retinopathy (DR). While EWDR is often transient and predominantly driven by the development of cotton-wool spots and intraretinal microvascular abnormalities in patients with no or minimal DR, it can lead to irreversible retinal damage in patients with advanced DR before IT. Its identified risk factors include higher baseline levels and larger magnitudes of reduction of HbA1c, longer diabetes durations and previous severity of DR. CONCLUSION: Intensive diabetes treatment inducing a rapid fall in glucose should prompt vigilance and caution, particularly in patients with long-term and uncontrolled diabetes and DR prior to IT. Careful retinal examination should be performed in all patients before initiating IT; however, in patients with severe non-proliferative or proliferative DR, panretinal photocoagulation therapy should be performed promptly. During the year following IT, quarterly eye monitoring is required in patients at high risk of EWDR (long-term uncontrolled diabetes, previous advanced DR), whereas follow-up every 6 months can be applied in patients with short-term diabetes and no/minimal DR before IT. To date, there is no evidence that controlling the speed or magnitude of HbA1c decreases will reduce the risk of EWDR in patients with diabetes.

Efficacy of 0.2 µg/day fluocinolone acetonide implant (ILUVIEN) in eyes with diabetic macular edema and prior vitrectomy.

PurposeLimited data are available on the efficacy of the 0.2 µg/day fluocinolone acetonide (FAc) implant in eyes with prior vitrectomy. Here, we present a collection of 26 vitrectomized eyes treated with the 0.2 µg/day FAc implant.MethodsRetrospective study involving six centers from four European countries analyzing the safety and efficacy data from patients (26 eyes from 25 patients) with DME and a prior vitrectomy that had been treated with one 0.2 µg/day FAc implant.ResultsPrior intravitreal therapies included anti-VEGF (mean, 3.8 injections) and steroids (mean, 1.9 injections). Pars plana vitrectomy (PPV) was performed in these eyes primarily for abnormalities of vitreoretinal interface, followed by proliferative diabetic retinopathy and vitreous hemorrhage. The 0.2 µg/day FAc implant was injected 24.2 months, on average, after PPV and the mean duration of follow-up after injection was 255 days (range, 90 to 759 days). The mean change in BCVA was +11.7 ETDRS letters (range, -19 to +40 letters; P<0.0004) and the mean change in central foveal thickness (CFT) was -233.5 µm (range, -678 to 274 µm; P<0.0001). The mean change in IOP from baseline at the last visit was +1.4 mm Hg (range, -9 to +8 mm Hg; P=0.0090). Eight eyes initiated or continued IOP lowering medications.ConclusionsThese data suggest the 0.2 µg/day FAc implant is effective in vitrectomized patients with an acceptable safety profile. Further studies are still required to confirm the current findings and to assess the effect of the 0.2 µg/day FAc implant over a longer period of follow-up.

How does total knee replacement technique influence polyethylene wear?

In knee prostheses, wear is inherent to the tribology of the imperfectly congruent surfaces, one in chromium-cobalt alloy, the other in polyethylene. It is a multifactorial phenomenon, involving the properties of the respective materials and implant design, but also implant functioning, as determined by the implantation technique. There are still dark corners in the implantation charge book, especially concerning minimal insert thickness, the adjustment of tibiofemoral alignment and ligament balance. A review of the literature revealed consensus regarding minimal insert thickness (8mm), tibiofemoral alignment (to be kept within 5° on either side of the neutral axis) and ligament balance (identical collateral ligament tension in both extension and flexion spaces). Finer adjustment seems desirable. Tibiofemoral alignment is probably customizable according to individual patient morphology and weight. The rotational alignment of the components should allow harmonious patellar engagement. Classic ligament balance rules underestimate sagittal laxity, which needs checking to prevent paradoxical movement accelerating polymer delamination. Navigation techniques or specific ancillaries can help optimize implant component alignment. Control of sagittal laxity may require specific adaptation, notably in the flexion space. Improved implantation technique could postpone wear onset until beyond the 10th or even 20th postoperative year, barring material failure for other reasons.

Internal fixation of intra-capsular proximal femoral fractures in patients older than 80 years: Still relevant? Multivariate analysis of a prospective multicentre cohort.

BACKGROUND: Arthroplasty is now widely used to treat intra-capsular proximal femoral fractures (PFFs) in older patients, even when there is little or no displacement. However, whether arthroplasty is associated with lower mortality and complication rates in non-displaced or mildly displaced PFFs is unknown. The objectives of this prospective study were: (1) to evaluate early mortality rates with the two treatment methods, (2) to identify risk factors for complications, (3) and to identify predictors of functional decline. HYPOTHESIS: Arthroplasty and internal fixation produce similar outcomes in non-displaced fractures of patients older than 80 years with PFFs. MATERIAL AND METHODS: This multicentre prospective study included consecutive patients older than 80 years who were managed for intra-capsular PFFs at eight centres in 2014. Biometric data and geriatric assessment scores (Parker Mobility Score, Katz Index of Independence, and Mini-Nutritional Assessment [MNA] score) were collected before and 6 months after surgery. Independent risk factors were sought by multivariate analysis. We included 418 females and 124 males with a mean age of 87±4years. The distribution of Garden stages was stage I, n=56; stage II, n=33; stage III, n=130; and stage IV, n=323. Arthroplasty was performed in 494 patients and internal fixation in 48 patients with non-displaced intra-capsular PFFs. RESULTS: Mortality after 6 months was 16.4% overall, with no significant difference between the two groups. By multivariate analysis, two factors were significantly associated with higher mortality, namely, male gender (odds ratio [OR], 3.24; 95% confidence interval [95% CI], 2.0-5.84; P<0.0001) and high ASA score (OR, 1.56; 95% CI, 1.07-2.26; P=0.019). Two factors were independently associated with lower mortality, with 75% predictive value, namely, high haematocrit (OR, 0.8; 95% CI, 0.7-0.9; P=0.001) and better Parker score (OR, 0.5; 95% CI, 0.3-0.8; P=0.01). The cut-off values associated with a significant risk increase were 2 for the Parker score (OR, 1.8; 95% CI, 1.1-2.3; P=0.001) and 37% for the haematocrit (OR, 3.3; 95% CI, 1.9-5.5; P=0.02). Complications occurred in 5.5% of patients. Surgical site infections were seen in 1.4% of patients, all of whom had had arthroplasty. Blood loss was significantly greater with arthroplasty (311±197mL versus 201±165mL, P<0.0002). Dependency worsened in 39% of patients, and 31% of patients lost self-sufficiency. A higher preoperative Parker score was associated with a lower risk of high postoperative dependency (OR, 0.86; 95% CI, 0.76-0.97; P=0.014). DISCUSSION: Neither treatment method was associated with decreased mortality or better function after intra-capsular PFFs in patients older than 80 years. Early mortality rates were consistent with previous reports. Among the risk factors identified in this study, age, preoperative self-sufficiency, and gender are not amenable to modification, in contrast to haematocrit and blood loss. CONCLUSION: Internal fixation remains warranted in patients older than 80 years with non-displaced intra-capsular PFFs. LEVEL OF EVIDENCE: III, prospective case-control study.

Wear products of total hip arthroplasty: The case of polyethylene.

Among the bearing surfaces involved in a total hip arthroplasty, ultra-high molecular weight polyethylene (UHMWPE) is the weak link. It is submitted to the friction of a harder bearing, producing wear particles, which, in turn, initiate an inflammatory reaction ultimately leading to osteolysis. This kind of bone deterioration sometimes turns out to an aggressive granuloma and may provoke implant loosening. Wear resistance of UHMWPE depends on its molecular weight and crystallinity. Some steps of the manufacturing process were improved to optimize its tribological properties and to slow down degradation resulting from mechanical (abrasion) and chemical (oxidation) phenomena. Its preparation and conservation must be performed in an inert atmosphere, i.e. without ambient oxygen. Its resistance to abrasion depends on its cross-linking degree. Its cross-linking rate was observed to increase proportionally to the irradiation doses, improving its wear resistance. However, its mechanical properties are impaired and moreover, it becomes oxidation sensitive. It is therefore necessary to submit it to a thermal treatment to eliminate free radicals that were produced during irradiation. More recently impregnation by vitamin E, a powerful anti-oxidant product, was proposed to preserve the polymer from in vivo oxidation while maintaining its mechanical properties. We raised the hypothesis that last-generation UHMWPE could offer the same wear resistance as the most performing bearings (ceramic-on-ceramic). Recent clinical results confirm the tribological performance of highly crosslinked UHMWPE in vivo. However, it remains to be seen whether this excellent wear resistance would persist under eccentric load such as edge loading, and if, in the long run, this kind of bearing proves capable of reducing the risk of osteolysis in young and active patients.

Is arthroplasty preferable to internal fixation for the treatment of extracapsular fracture of the upper femur in the elderly?

INTRODUCTION: Although internal fixation is the reference treatment for extracapsular fracture of the upper femur, indications for arthroplasty are broadening, especially in unstable comminutive fracture in fragile bone. The present study hypothesis was that arthroplasty reduces early mortality and morbidity and provides better recovery of autonomy in over-80 year-old patients than does internal fixation. MATERIAL AND METHODS: A prospective multicenter study was conducted on 8 sites. Internal fixation was systematically used in 5 centers; arthroplasty was used systematically in 1 center, and reserved for unstable fracture in 2 centers. A total of 697 patients aged over 80 years (mean age, 85±5 years), presenting with extracapsular fracture, were included; 521 were treated by internal fixation and 176 by arthroplasty. Results were studied on multivariate analysis of ASA score, blood loss, transfusion, and also of treatment modality as an independent factor for early (first 6 months) mortality and morbidity (mechanical, general and nutritional complications) and functional outcome (autonomy and dependence). RESULTS: Overall mortality was 19.2%. Autonomy deteriorated in 56% of patients alive at 6 months and dependence worsened in 44%. Two percent of those managed by internal fixation underwent revision for disassembly (n=8) or infection (n=1). Eight percent of those managed by arthroplasty underwent revision for dislocation (n=4), implant loosening (n=3) or infection (n=7). On univariate analysis, mortality was higher in the arthroplasty group (25%) than with internal fixation (17%; P=0.002), as were blood loss (425±286mL versus 333±223mL; P<0.0001), transfusion rate (61% versus 32%; P<0.0001) and infection (4% versus 0.2%; P<0.001). On multivariate analysis, however, treatment modality no longer showed impact on mortality or on morbidity and autonomy at 6 months. Nutritional status was better conserved at 6 months following arthroplasty, but dependence worsened. Poor preoperative autonomy, ASA score, and nutritional status and time to treatment were independent factors for mortality. Transfusion, associated with onset of mechanical complications, significantly increased dependence. CONCLUSION: Type of treatment had little impact on mortality, morbidity or functional outcome. Differences seemed more related to preoperative functional and nutritional status. LEVEL OF EVIDENCE: III, prospective case-control study.

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.

Arthroscopic treatment of acute acromioclavicular dislocations using a double button device: Clinical and MRI results.

INTRODUCTION: Arthroscopic treatment of acute grade 3 and 4 acromioclavicular dislocation is controversial, due to the risk of recurrence and of postoperative reduction defect. The purpose of the present study was to investigate whether the healing of the acromioclavicular (AC) and coracoclavicular (CC) ligaments and the accurate 3D positioning parameters of the AC joint using MRI were correlated with satisfactory functional outcome. MATERIAL: Thirty-nine patients were enrolled from 2009 to 2011 and managed arthroscopically by CC lacing using a double-button device. METHODS: Clinical assessment included the Shoulder and Hand (QuickDash) score, Constant-Murley score and visual analog scale (VAS) for residual pain. Time and rate to return to work and return to sport were assessed according to type of sport and work. Postoperative complications were recorded. Radiological examination consisted of anteroposterior clavicle and lateral axillary radiographs. AC ligament healing and 3D joint congruency were assessed on MRI and correlated to the clinical results. RESULTS: Mean patient age was 35.7 years (range, 20-55). Mean follow-up was 42.3±10.6 months (range, 24-60). At final follow-up, mean QuickDash score, Constant score and VAS were respectively 1.7±4 (range, 0-11), 94.7±7.3 (range, 82-100) and 0.5±1.4 (range, 0-2). Thirty-five (90%) patients were able to resume work, including heavy manual labor, and sport. Radiology found accurate 3D joint congruency in 34 patients (87%) and CC and AC ligament healing in 36 (93%). Complications included reduction loss at 6 weeks in 3 patients, requiring surgical stabilization. Satisfactory functional results were associated with accurate AC joint congruency in the coronal and axial planes (P<0.05) and good AC and CC ligament healing (P<0.04). An initial 25% reduction defect in the coronal plane was not associated with poor functional results (P=0.07). CONCLUSION: Arthroscopic treatment by CC lacing satisfactorily restored ligament and joint anatomy in the present series. These satisfactory anatomic results correlated with good clinical outcome encourage continuing with this technique. LEVEL OF EVIDENCE: Level IV, therapeutic case series.

Critical analysis of experimental models of periprosthetic joint infection.

INTRODUCTION: Because the extreme diversity of clinical situations makes formal clinical trials difficult to carry out, animal models of periprosthetic infection in orthopaedics are needed to understand the aetiology and pathology of these infections, and to test new treatment methods. These experimental models must reproduce the features of the infections encountered in clinical practice. One of the model variables is the method of inoculation: local (intra-articular), intravenous or intra-arterial. Another is the timing of the inoculation: intra-operative or postoperative. Together, these options simulate the different contamination methods: direct, by proximity or blood-borne. However, the chosen inoculation route can also affect the infection rate and severity in the various models, and in some cases do not accurately reproduce the postoperative infections encountered clinically. HYPOTHESIS: The direct inoculation method is the most effective for inducing a local infection on a foreign body in a joint, and the least iatrogenic. METHODS: A critical analysis of published studies was carried out to evaluate each model against three endpoints, according to the type of inoculation. The primary endpoint was the infection rate, which should be as close as possible to 100%. The secondary endpoints were the mortality rate and rate of spontaneous healing, both of which should be as low as possible. Twenty-one articles were reviewed. RESULTS: Intra-articular and intra-medullary inoculations had induction rates between 70 and 100%; intra-arterial inoculations had an induction rate of 100%, while intravenous inoculation had a rate of 47 to 77%. The mortality rates were lower with the intra-articular and intramedullary inoculations (5 to 23%) than for the intra-arterial inoculations (37%) and intravenous inoculations (28 to 56%). The spontaneous healing rate was 0 to 30% for intra-articular and intramedullary inoculations, 30 to 53% for intravenous inoculations and 0% for intra-arterial inoculations. CONCLUSION: Direct inoculation methods are most effective at reproducing chronic periprosthetic joints infections, without putting the animal's life at risk or allowing for spontaneous healing. The simulation of blood-borne infections is more random.

No improvement in the post-TKA infection prognosis when the implant is not reimplanted: Retrospective multicentre study of 72 cases.

INTRODUCTION: For the surgeon and patient, permanent removal of an infected knee prosthesis is an unwelcome decision taken out of necessity because unfavourable local or general conditions may increase the likelihood of mechanical or infectious failure upon prosthesis reimplantation. The purpose of this study was to determine if permanent removal of an infected total knee arthroplasty (TKA) implant controls the infection and prevents above-the-knee amputation when reimplantation turns out to be too risky. It was hypothesized that removal without reimplantation contributes to eradicating the infection and helps to avoid amputation. PATIENTS AND METHODS: Seventy-two consecutive patients who underwent TKA removal between 2000 and 2010 at 14 hospitals were reviewed. The TKA removal was followed by knee fusion in 29 cases or implantation of a permanent cement spacer in 43 cases. RESULTS: If failure is defined as clinically obvious recurrence of the infection, the survival rate was 65 ± 5% at 2 years; 44% of patients had a recurrence of the infection, 8% had undergone amputation and 19% presented with nonunion at the last follow-up. The male gender and the presence of multiple co-morbidities were predisposing factors for failure. DISCUSSION: Control of the infection is not guaranteed upon TKA implant removal; the success rate is lower than in cases of two-stage reimplantation. The outcomes in this study are worse than those of other published studies. This is likely due to the heterogeneity in the patient population and treatments, along with the presence of co-morbidities. This treatment option should be the last recourse before amputation.

Control of paradoxical kinematics in posterior cruciate-retaining total knee arthroplasty by increasing posterior femoral offset.

PURPOSE: Balancing the posterior cruciate ligament (PCL) with posterior cruciate-retaining total knee replacement (PCR-TKR) aims to restore femoral rollback. In practice, paradoxical roll forward persists. The purpose of this study is to propose a technique for optimizing PCL tension. Because PCL function starts above 60° of flexion, we hypothesize that PCL balancing requires flexion gap tightening by oversizing the femoral component and increasing posterior condylar offset (PCO). METHODS: PCR-TKR was performed in 21 osteoarthritis patients with a gap-balancing technique. The femoral component was oversized if more than a 5-mm posterior drawer existed after tibial component implantation. Kinematics was recorded intra-operatively in two steps with dedicated navigation software (Praxim, La Tronche, Isère, France): antero-posterior (AP) displacements of condylo-tibial contact points were observed in native and implanted knees, with each knee serving as its own control. The absence of paradoxical displacements was verified once the final implants were inserted. RESULTS: Paradoxical medial condyle displacement (11 mm) persisted in a single case. On average, posterior displacement of the medial condyle decreased from 9 ± 9 to 1 ± 6 mm (p = 0.001) and that of the lateral condyle from 16 ± 14 to 6 ± 6 mm (p = 0.006). In the 0°-30° flexion interval, posterior displacement was 2 times less than before implantation for the medial condyle (p = 0.001), and 4 times less for the lateral condyle (p = 0.004). The course of the lateral condyle decreased from 2 ± 3 to 0 ± 4 mm in the 90°-120° flexion interval (p = 0.046). Six-month flexion was 124° ± 17°. CONCLUSION: Femoral component oversizing allows us to control paradoxical forward displacements in 95 % of cases. When balancing PCR prostheses, AP laxity should be taken into account. Increasing PCO appears to be a reliable technique for adjusting PCL balance. Thus, it may optimize extensor mechanism action and, subsequently, the functional results of PCR-TKR. LEVEL OF EVIDENCE: Diagnostic study, Level II.

Does the PFNA™ nail limit impaction in unstable intertrochanteric femoral fracture? A 115 case-control series.

INTRODUCTION: Femoral neck shortening after dynamic fixation of extra-capsular fracture may impair functional results, but is rarely assessed. The present study measured impaction in stable and unstable fractures (on the Ender classification) treated by PFNA™ nail. The objectives were: 1) to validate the Ender classification to assess fracture stability; 2) to determine whether neck shortening and head purchase quality varied with stability; and 3) to determine the functional impact of femoral neck shortening. HYPOTHESIS: The study hypothesis was that the PFNA™ nail stabilizes unstable as well as stable fractures. MATERIALS AND METHODS: One hundred and fifteen consecutive patients, aged over 70 years, operated on for intertrochanteric fracture using the PFNA™ nail were followed up prospectively for 6 months. Multivariate analysis, including age, gender, assembly quality and body-mass index, was applied to assess the predictive power of the Ender classification with respect to femoral neck shortening. Secondly, patients were grouped according to stable versus unstable fracture (n=70 and 45, respectively), and impaction and femoral head purchase were assessed on a dedicated radiographic protocol. Functional results were assessed on Parker score. RESULTS: In the unstable fracture group, 3 assembly failures required revision by total hip replacement. Ender grade>2 was significantly predictive of>5mm neck shortening. Neck shortening was greater in unstable fracture: 8.1 ± 8.4mm (range, 4-32 mm), versus 2.5 ± 3.7 mm (range, 3-14 mm) (P=0.0004). Mean blade cut-through was 1.2 ± 2.9 mm (range, 1-12 mm) in unstable fracture, versus 0.3 ± 1.3 mm (range, 1-6mm) (P=0.02). Mean cut-out was 2.3 ± 6 mm (range, 2-21 mm) in unstable fracture, versus 0.5 ± 2.6 mm (range, 1-8mm) (P=0.03). Parker scores diminished comparably in the two groups, without significant difference at follow-up: 3.9 ± 2.6 (range, 0-9) in stable and 3.1 ± 1.9 (range, 0-8) in unstable fracture; reduction in Parker score showed no correlation with femoral neck shortening (r=0.013, P=0.88). DISCUSSION: The PFNA™ nail provides poorer stabilization of unstable compared to stable fracture. Femoral neck shortening should be taken into account in assessing internal fixation hardware perfomances. LEVEL OF EVIDENCE: Level III. Prospective case-control study.

Cruciate-sacrificing total knee arthroplasty and insert design: A radiologic study of sagittal laxity.

INTRODUCTION: Ultracongruent inserts avoid some of the drawbacks of central spine postero-stabilized inserts. However, early wear has been reported, and may be due to increased sagittal laxity. The principal objective of the present study was to compare sagittal laxity in rotating platform total knee replacements (TKR) according to insert design: ultracongruent versus central spine. The principal hypothesis was that insert design influences global sagittal laxity. MATERIAL AND METHODS: A retrospective comparative study recruited 3 consecutive series of patients treated for primary osteoarthritis of the knee, with a minimum 1 year's follow-up. The UC series comprised 35 knees in 34 patients, receiving a Total Knee Triathlon™ (Stryker Orthopaedics, Mahwah, NJ) TKR with ultracongruent insert, at a mean 2.0 years' follow-up. The UC+ series comprised 36 knees in 34 patients, receiving the BalanSys™ (Mathys Ltd, Bettlach, Switzerland) TKR with ultracongruent insert, at a mean 2.5 years' follow-up; in this model, the anterior edge of the insert is higher than in the UC series ("deep-dish" design). The PS series comprised 43 knees in 40 patients, receiving a Total Knee Triathlon™ (Stryker Orthopaedics, Mahwah, NJ) TKR with central spine posterior stabilization, at a mean 1.5 years' follow-up. The principal assessment criterion was sagittal laxity at 90° flexion as measured by the Telos Stress Device® (Metax GmbH, Hungen, Germany). RESULTS: Sagittal laxity did not significantly differ between the UC and UC+ series: mean 8.2mm (range: 0-19.5mm) and 8.4mm (4.5-15.8mm), respectively. Sagittal laxity in the PS series was significantly less: 1.4mm (0.2-3.9) (P<0.0001). CONCLUSION: Sagittal laxity was greater in ultracongruent than central spine posterior stabilized TKR. This anteroposterior movement may induce polyethylene wear. The ideal degree of sagittal laxity for ultracongruent inserts remains to be determined. LEVEL OF EVIDENCE: IV - retrospective study.