Reliability of the Harris Hip limping sub-score in patients undergoing total hip arthroplasty.

PURPOSE: In patients undergoing total hip arthroplasty, limping is a significant symptom, often assessed with the limping sub-score of the Harris Hip Score. However, the reliability of this sub-score has not been specifically investigated. The purpose of this study is to investigate the intra- and inter-rater reliability of this sub-score. METHODS: Thirty patients undergoing THA were recruited and performed a gait analysis before surgery and three months after surgery. In addition, 30 asymptomatic participants were included. In total, 90 visits were analysed in this study. The HHS limping sub-score was assessed for each visit using a video (front and back view side-by-side) of a ten metre walk at a self-selected speed. Two orthopaedic surgeons evaluated the limping of each video in two different grading sessions with a one week delay. To avoid recall bias, the patient's number identity was randomized and different for each grading session and each rater. The weighted Cohen's Kappa coefficient was used to quantify the intra- and inter-reliability. The reliability of three components was studied: the presence of limping, its severity, and the compensation type. RESULTS: For all components, the agreement for intra-rater reliability ranged from moderate to strong and from none to moderate for the inter-rater reliability. CONCLUSION: These results do not encourage the use of HHS-limping sub-score for data involving different raters in both clinical and research contexts. It calls for improved consensus on limping definitions or the creation of objective measures.

Radiographic signs and hip pain 5 years after THA with a cemented stem predict future revision for aseptic loosening: a prospective cohort study.

BACKGROUND AND PURPOSE: We aimed to evaluate the long-term predictive value of radiographic abnormality and/or hip pain assessed 5 years following primary total hip arthroplasty (THA) and the occurrence of revision for aseptic loosening between 5 and 25 years postoperatively. PATIENTS AND METHODS: We included all primary THAs performed between 1996 and 2011 (same uncemented cup, polyethylene-ceramic bearing, 28 mm head, cemented stem) and prospectively enrolled in the institutional registry, for whom baseline and follow-up radiographs were available. At 5 years radiographically we assessed femoral osteolysis and/or stem migration. Pain was evaluated with the Harris Hip pain subscore. Kaplan-Meier survival and Cox regression analyses were performed. RESULTS: 1,317 primary THAs were included. 25 THAs (2%) were revised for aseptic stem loosening. Any abnormal radiographic sign at 5 years was present in 191 THAs (14%). Occasional hip pain was reported by 20% and slight to severe pain by 12% of patients at 5 years. In patients < 60 years, 10 of the 12 later revised for aseptic stem loosening had abnormal radiographs at 5 years vs. 5 of the 13 later revised in those ≥ 60 years. Hazard ratios (HR) were 34 (95% confidence interval [CI] 7-155) in younger vs. 4 (CI 1-11) in the older group. HR for association of hip pain at 5 years with future revision was 3 (CI 1-5). CONCLUSION: The presence of abnormal radiographic signs 5 years after THA was strongly associated with later revision for aseptic stem loosening, especially in patients < 60 years. The association between pain at 5 years and future revision was much weaker.

[Customized 3D cutting guides : what applications in orthopedic surgery ?] / Guides de coupes 3D sur mesure : quelles applications en chirurgie orthopédique?

3D printing is a technology that has been evolving rapidly over the past twenty years. It is an additive manufacturing process which allows the creation of objects without geometry restrictions. This process has applications in orthopaedic surgery through personalized cutting guides and implants which offer the possibility to treat complex pathologies such as tumoral surgery, architectural defects of the acetabulum and malunions. Although their use cannot be recommended for routine knee and hip prosthetic surgery, their value in high tibial osteotomies seems promising. Despite its high cost, this technology is of growing interest in orthopaedic surgery.

L'impression 3D est une technologie en évolution rapide depuis une vingtaine d'année. Il s'agit d'un procédé de fabrication par addition de matière permettant la réalisation d'objets sans limitation de forme. Ce procédé trouve des applications en orthopédie pour l'obtention de guides de coupes et d'implants sur mesure offrant la possibilité de traiter des pathologies complexes comme la chirurgie tumorale, les défauts architecturaux de l'acétabulum et les cals vicieux. Si leur utilisation ne peut être recommandée de façon routinière pour la chirurgie prothétique de genou et de hanche, leur intérêt dans les ostéotomies du tibia semble prometteur. Bien que d'un coût élevé, cette technologie trouve un intérêt croissant en chirurgie orthopédique.

[What surgical treatment for femoro-acetabular impingement?] / Quelle prise en charge chirurgicale pour le conflit fémoro-acétabulaire ?

Femoroacetabular impingement (FAI) is a frequent cause of hip pain in young people and athletes. It requires a complete work-up, including X-rays, hip arthro-MRI and CT coxometry with measurement of femoral torsion. The surgical management of CFA must be adapted to the morphological anomalies of the femur (cam), acetabulum (pincer) and femoral torsional disorders. Most CFA can be treated by hip arthroscopy, with correction of the cam and suture of the labrum. Some CFA with a bulky or posterior cam require surgical hip dislocation. A femoral rotation or derotation osteotomy can correct an associated torsional disorder. In cases of marked retroversion of the acetabulum, anteverting periacetabular osteotomy can reorient the acetabulum.

Le conflit fémoro-acétabulaire (CFA) est une cause fréquente de douleurs de hanche chez le sujet jeune et l'athlète. Il nécessite un bilan par radiographie, arthro-IRM de hanche, coxométrie scanographique avec torsions fémorales. La prise en charge chirurgicale du CFA doit être adaptée en fonction des anomalies morphologiques du fémur (came), du cotyle (pince) et des troubles torsionnels du fémur. La majorité des CFA peuvent être traitées par arthroscopie de hanche avec correction de la came et suture du labrum. Certains CFA avec une came volumineuse ou postérieure nécessitent une prise en charge par luxation chirurgicale de hanche. Une ostéotomie fémorale de rotation ou dérotation peut corriger un trouble torsionnel associé. En cas de rétroversion marquée du cotyle, une ostéotomie périacétabulaire d'antéversion permet de réorienter le cotyle.

High-energy blunt pelvic ring injury incidence and polytrauma caseload in a single level I trauma center during COVID-19 related pseudo-lockdown measures: a retrospective cohort study based on a prospective registry.

BACKGROUND: Pelvic ring injuries are potentially lethal lesions associated with polytrauma patients and need an efficient trauma team for their management. The purpose of this study was to evaluate the incidence of high-energy blunt pelvic ring injuries and the absolute number of polytrauma patients in a single level I trauma center during the 2020 pseudo-lockdown period related to the Coronavirus pandemic, and to compare it with corresponding periods in 2014-2019 in order to better understand the need of organized and dedicated personnel and infrastructures. METHODS: This retrospective cohort study was based on data prospectively recorded into the institutional Severely Injured Patients' Registry. Data were obtained for each year period (January 1st to December 31st) and corresponding pseudo-lockdown period (March 16th to June 19th). High-energy blunt pelvic ring injuries inclusion criteria were: (1) Registry entry between January 1st, 2014 and December 31st, 2020; (2) age ≥ 16 years old; and (3) pelvic ring injury presence. Corresponding exclusion criteria were: (1) death before admission; (2) transfer from another institution > 24 h after trauma; (3) penetrating, blast, burn and electrical injuries, drownings; (4) patients living outside the defined institution's catchment area; and (5) any document attesting the patient's will to not participate in any study. Polytrauma patients inclusion criteria were: (1) Registry entry between January 1st, 2014 and December 31st, 2020; (2) age ≥ 16 years old; and (3) Injury Severity Score ≥ 16. Corresponding exclusion criteria were: (1) death before admission; (2) transfer from another institution > 24 h after trauma; and (3) any document attesting the patient's will to not participate in any study. Categorical variables were reported using proportions and continuous variables using medians and interquartile ranges. Because data were exhaustive for the authors' level I trauma center, no inferential statistics were computed. RESULTS: The incidence of high-energy blunt pelvic ring injuries and the absolute number of polytrauma patients remained within range of previous years despite pseudo-lockdown measures. CONCLUSIONS: These observations bring better knowledge about pseudo-lockdown's impact on trauma and may help for future health strategy planning by pointing out the importance of maintaining the activity of level I trauma centers in terms of personnel and infrastructures.

Extensive skin necrosis following total hip arthroplasty performed through the direct anterior approach.

BACKGROUND: Total hip arthroplasty is a widely performed surgical procedure, which enables patients to regain mobility, alleviates pain, and improves overall quality of life. Periarticular multimodal drug infiltration (PAI) is increasingly being used as an effective postoperative pain management, decreasing the systemic consumption of opioids. Extensive postoperative skin necrosis without a deep joint infection as a complication of total hip arthroplasty with PAI has not yet been described. CASE PRESENTATION: A 71-year-old patient who underwent total hip arthroplasty of the right hip for primary osteoarthritis through the Direct Anterior Approach presented postoperatively a large area of necrotic skin at the incision. Joint infection was excluded. An extensive debridement was performed and the tissue defect was reconstructed by a pedicled anterolateral thigh flap. The skin maintained a satisfactory appearance at 1 year postoperatively, and the hip was pain-free with restored ranges of motion. The patient was able to walk with no support and without limitation. CONCLUSION: We address the possible risk factors, discuss the use of epinephrine in PAI and explore possible treatment options for such a complication.

[Dislocation after total hip arthroplasty : how to avoid it ?] / Luxations de prothèse de hanche : comment les éviter ?

Dislocation after hip replacement is a complication that can have dramatic consequences for the patient. The purpose of this article is to review the different parameters influencing stability and how to reduce this risk. The approach, the diameter of the femoral head, and the use of dual-mobility acetabular cups have led to a drastic reduction in the rate of dislocation, particularly in patients at risk, in cases of imbalance of the spino-pelvic complex, or in cases of revision surgery. The inclusion of patients in dedicated clinical pathways and participation in preoperative education sessions also contribute to the reduction of dislocation risk.

La luxation après prothèse de hanche est une complication qui peut avoir des conséquences dramatiques pour le patient. Cet article a pour but de revoir les différents paramètres influençant la stabilité prothétique et pouvant diminuer ce risque. La voie d'abord, le diamètre de la tête fémorale et l'usage de cotyles à double mobilité ont permis une diminution drastique du taux de luxation, en particulier chez les patients à risque, en cas de déséquilibre du complexe spino-pelvien ou en cas de reprise chirurgicale. L'inclusion des patients dans des itinéraires cliniques dédiés et la participation à des séances d'information préopératoire participent également à la réduction du risque de luxation.

Reliability of the pelvis and femur anatomical landmarks and geometry with the EOS system before and after total hip arthroplasty.

Bi-plane X-ray provides 3D measurements of the lower limb based on the identification of anatomical landmarks in sagittal and frontal X-rays. In clinical practice, such measurements involve multiple operators and sessions. This study aimed at evaluating the reliability of anatomical landmarks identification and geometric parameters of the pelvis and femur measured with bi-plane X-rays before and after total hip arthroplasty (THA). Twenty-eight patients undergoing primary THA were selected retrospectively. Two operators performed three reconstructions for each patient before and after THA. Intraclass correlation (ICC) and smallest detectable change (SDC) were computed for intra-operator, inter-operator, and test-retest conditions. Most anatomical landmark positions had good to excellent SDC (< 5 mm) apart from the centre of the sacral slope, greater trochanter, and anterior superior iliac spines (up to 7.1, 16.9, and 21.5 mm respectively). Geometric parameters had moderate to excellent SDC, apart from femoral and stem torsion, pelvic incidence, and APP inclination with poor SDC (9-12°). The sagittal view had significantly higher measurement errors than the frontal view. Test-retest and inter-operator conditions had no significant differences suggesting a low influence of patient posture. Osteoarthritis and the presence of implants did not seem to influence reliability and measurement error. This study could be used as a reference when assessing lower limb structure with bi-plane X-rays.

Acetabular Peri-Prosthetic Fractures-A Narrative Review.

Acetabular peri-prosthetic fractures are rare but their incidence is rising due to the increased prevalence of total hip arthroplasty, the increasing life expectancy and the growing functional demand of an ageing population, the incidence of primary total hip arthroplasty is increasing. They are either intra-operative or post-operative and have various aetiologies. Several factors such as implant stability, bone loss, remaining bone stock, fracture pattern, timing, age and co-morbidities of the patients must be considered for adequate treatment. To date, the literature on this subject has been sparse and no universally recognized treatment algorithm exists. Their rarity makes them a little-known entity and their surgical management represents a challenge for most orthopaedic surgeons. This review aims to present an update on epidemiology, the diagnostic work up, existing classification systems, surgical approaches and therapeutic options for acetabular peri-prosthetic fractures.

Reduced Infection Rate After Aseptic Revision Total Knee Arthroplasty With Extended Oral Antibiotic Protocol.

BACKGROUND: The optimal postoperative antibiotic duration has not been determined for aseptic revision total knee arthroplasty (R-TKA) where the risk of periprosthetic joint infection (PJI) is 3%-7.5%. This study compared PJI rates in aseptic R-TKA performed with extended oral antibiotic prophylaxis (EOAP) to published rates. METHODS: Aseptic R-TKAs consecutively performed between 2013 and 2017 at a tertiary care referral center in the American Midwest were retrospectively reviewed. All patients were administered intravenous antibiotics while hospitalized and discharged on 7-day oral antibiotic prophylaxis. Infection rates and antibiotic-related complications were assessed. RESULTS: Sixty-seven percent of the 176 analysis patients were female, with an average age of 64 years and body mass index of 35 kg/m2. Instability and aseptic loosening comprised 86% of revision diagnoses. Overall, 87.5% of intraoperative cultures were negative, and the remainder were single positive cultures considered contaminants. PJI rates were 0% at 90 days, 1.8% (95% confidence interval 0.4%-5.3%) at 1 year, and 2.2% (95% confidence interval 0.6%-5.7%) at mean follow-up of approximately 3 years (range, 7-65 months). CONCLUSION: EOAP after aseptic R-TKA resulted in a PJI rate equivalent to primary TKA, representing a 2- to-4-fold decrease compared with published aseptic R-TKA infection rates. Further study on the benefits and costs of EOAP after aseptic R-TKA is encouraged.

Association between open tibia fractures and acute compartment syndrome: A retrospective cohort study.

BACKGROUND: Studies on the association of open tibia fractures and acute compartment syndrome (ACS) show confusing results, with some papers highlighting a positive association, and others failing to do so. The aim of this study was to determine if an open tibia fracture is at increased risk of ACS occurrence, when compared to a closed fracture. HYPOTHESIS: Skin injury in the setting of an open tibia fracture does not prevent from ACS occurrence, because the energy transmitted to the limb during trauma may lead to soft tissue lesions, including skin lacerations and ACS. PATIENTS AND METHODS: In total, 711 consecutive adult patients (mean age 44.6 years; 65.8% males) sustaining 725 tibia fractures between 01.01.2005 and 31.12.2009 were included in this retrospective study. The outcome measure was ACS. The following variables were assessed: soft tissue condition, age, sex, low- vs. high-energy injury, type of fracture, associated contiguous skeletal injury. A logistic regression model was used and adjustment was performed for age and sex. RESULTS: ACS occurred in 10.4% of proximal intra-articular fractures, 10.4% of extra-articular fractures and 3.3% of distal intra-articular fractures, and in 8.7% of closed fractures, 7.8% of open Gustilo 1 fractures and 13.3% of open Gustilo 2 and 3 fractures. Open lesions were not associated with ACS when tibia fractures were considered as a whole. When stratifying by types of fractures, open Gustilo 2 and 3 lesions were associated with ACS in proximal intra-articular fractures (p=0.048). There was no association with closed or any type of open lesions for extra-articular fractures. There were not enough ACS cases among distal intra-articular fractures to draw conclusions. DISCUSSION: As ACS may occur with any type of open tibia fractures, clinicians should not be wrongly reassured by an open fracture, assuming that the wound would relieve the pressure inside the muscle compartments. There is a weak association between open Gustilo 2 and 3 lesions and ACS in proximal intra-articular fractures only. These findings are important for surgeons treating these injuries, especially by intubated, sedated or obtunded patients. LEVEL OF EVIDENCE: III; retrospective diagnostic study.

[Lessons learned from 25 years of an institutional hip and knee arthroplasty registry]. / Leçons apprises par 25 ans d'un registre institutionnel des prothèses de hanche et de genou.

Since 1996, the Geneva Arthroplasty Registry at the University Hospitals of Geneva (HUG) has been collecting, archiving and disseminating relevant high-quality information on primary total hip and knee arthroplasties and revision procedures performed at the Division of Orthopaedics and Traumatology. Patients are followed throughout their lifetime with the prosthesis. The registry has been essential to better understand and subsequently improve the care of patients with hip and knee replacements. It will continue to fulfil its mission and to work towards an even more effective transfer of the knowledge obtained to all stakeholders and as well as towards its implementation.

Depuis 1996, le registre genevois des arthroplasties aux HUG recueille, archive et diffuse des informations pertinentes de haute qualité concernant les arthroplasties primaires de la hanche et du genou ainsi que les procédures de révision réalisées au Service de chirurgie orthopédique et traumatologie de l'appareil moteur. Les patients sont suivis pendant toute leur vie avec la prothèse. Le registre a été essentiel pour mieux comprendre et ensuite améliorer la prise en charge de patients avec arthroplastie de hanche et de genou. Il continuera à remplir sa mission et à assurer une transmission encore plus efficace des connaissances obtenues vers tous les groupes concernés (stakeholders) et à leur implémentation.

[Giant cell tumor of bone]. / Tumeur à cellules géantes de l'os.

Giant cell tumor is a benign epiphyseo-metaphyseal bone tumor affecting the young patient. It is characterized by an extensive osteolysis, a high potential for recurrence, a risk of malignant transformation and pulmonary metastases. Curettage and cavity filling is the most common treatment, even in the case of a pathological fracture. A wide resection with prosthetic reconstruction must sometimes be considered. Better knowledge of the role of RANK-L in the pathophysiology of these tumors has led to clinical trials involving denosumab. Treatment with denosumab is suggested for inoperable lesions, or for aggressive lesions, in particular of the spine, pelvis, and sacrum before en bloc resection.

La tumeur à cellules géantes est une tumeur osseuse bénigne épiphysométaphysaire touchant le sujet jeune. Elle est caractérisée par une ostéolyse parfois extensive, un potentiel de récidive élevé, un risque de transformation maligne et de métastases pulmonaires. Le curetage-comblement est le traitement de choix, y compris en cas de fracture pathologique. Une résection plus large avec reconstruction prothétique doit parfois être envisagée. La meilleure connaissance du rôle de RANK-L dans la physiopathologie de ces tumeurs a conduit à des essais cliniques impliquant le dénosumab. Un traitement par celui-ci est proposé pour les lésions inopérables ou agressives, notamment du rachis, du pelvis et du sacrum, avant une résection en bloc.

Clinical and radiographic predictors of acute compartment syndrome in the treatment of tibial shaft fractures: a retrospective cohort study.

BACKGROUND: The purpose of this study was to evaluate the association between epidemiological, clinical and radiographic factors of patients with tibial shaft fractures and the occurrence of acute compartment syndrome. METHODS: 270 consecutive adult patients sustaining 273 tibial shaft fractures between January 2005 and December 2009 were included in this retrospective cohort study. The outcome measure was acute compartment syndrome. Patient-related (age, sex), fracture-related (high- vs. low-energy injury, isolated trauma vs. polytrauma, closed vs. open fracture) and radiological parameters (AO/OTA classification, presence or absence of a noncontiguous tibial plateau or pilon fracture, distance from the centre of the tibial fracture to the talar dome, distance between tibial and fibular fracture if associated, and angulation, translation and over-riding of main tibial fragments) were evaluated regarding their potential association with acute compartment syndrome. Univariate analysis was performed and each covariate was adjusted for age and sex. Finally, a multivariable logistic regression model was built, and odds ratios and 95% confidence intervals were obtained. Statistical significance was defined as p < 0.05. RESULTS: Acute compartment syndrome developed in 31 (11.4%) cases. In the multivariable regression model, four covariates remained statistically significantly associated with acute compartment syndrome: polytrauma, closed fracture, associated tibial plateau or pilon fracture and distance from the centre of the tibial fracture to the talar dome ≥15 cm. CONCLUSIONS: One radiological parameter related to the occurrence of acute compartment syndrome has been highlighted in this study, namely a longer distance from the centre of the tibial fracture to the talar dome, meaning a more proximal fracture. This observation may be useful when clinical findings are difficult to assess (doubtful clinical signs, obtunded, sedated or intubated patients). However, larger studies are mandatory to confirm and refine the prediction of acute compartment syndrome occurrence. Radiographic signs of significant displacement were not found to be correlated to acute compartment syndrome development. Finally, the higher rate of acute compartment syndrome occurring in tibial shaft fractures associated to other musculoskeletal, thoraco-abdominal or cranio-cerebral injuries must raise the level of suspicion of any surgeon managing multiply injured patients.

[Sport participation after hip and knee replacement]. / Peut-on faire du sport avec une prothèse de hanche ou de genou ?

Hip and knee replacement are among the most successful orthopaedic interventions in terms of satisfaction and they are now proposed to younger patients. Recommendations regarding return to sports are based on expert opinions and on the results of surveys performed among surgeons. Sports activities are classified as recommended, recommended with some level of experience, and discouraged. They take into account the risks associated with sports activities, but are not necessarily in line with the growing expectations of patients. This article addresses the risks related to return to sports, recommended sports, and the rate and appropriate timing of sport resumption. The main predictor remains the motivation of the patient and the pre-operative sporting level.

Le remplacement prothétique de la hanche ou du genou donne satisfaction à un grand nombre de patients, permettant aujourd'hui d'étendre les indications à des patients plus jeunes. Les recommandations concernant la reprise du sport reposent sur des avis d'experts et des enquêtes menées auprès de chirurgiens, et classent les activités en activités recommandées, recommandées avec un certain niveau d'expérience et déconseillées. Elles tiennent compte des risques liés à la pratique sportive, mais ne sont pas toujours en phase avec les attentes croissantes des patients. Cet article pose la question des risques associés à la reprise du sport après chirurgie, des sports recommandés ainsi que du taux et du délai de reprise. Le principal facteur prédictif de reprise du sport demeure la motivation du patient et le niveau sportif préopératoire.

Third-generation pure alumina and alumina matrix composites in total hip arthroplasty: What is the evidence?

Wear, corrosion and periprosthetic osteolysis are important causes of failure in joint arthroplasty, especially in young patients.Ceramic bearings, developed 40 years ago, are an increasingly popular choice in hip arthroplasty. New manufacturing procedures have increased the strength and reliability of ceramic materials and reduced the risk of complications.In recent decades, ceramics made of pure alumina have continuously improved, resulting in a surgical-grade material that fulfills clinical requirements.Despite the track record of safety and long-term results, third-generation pure alumina ceramics are being replaced in clinical practice by alumina matrix composites, which are composed of alumina and zirconium.In this review, the characteristics of both materials are discussed, and the long-term results with third-generation alumina-on-alumina bearings and the associated complications are compared with those of other available ceramics. Cite this article: EFORT Open Rev 2018;3:7-14. DOI: 10.1302/2058-5241.3.170034.

Clinical and radiographic predictors of acute compartment syndrome in the treatment of tibial plateau fractures: a retrospective cohort study.

BACKGROUND: The aim of the study was to evaluate the relation between demographic, injury-related, clinical and radiological factors of patients with tibial plateau fractures and the development of acute compartment syndrome. METHODS: All consecutive adult patients with intra-articular tibial plateau fractures admitted in our urban academic medical centre between January 2005 and December 2009 were included in this retrospective cohort study. The main outcome measurement was the development of acute compartment syndrome. RESULTS: The charts of 265 patients (mean age 48.6 years) sustaining 269 intra-articular tibial plateau fractures were retrospectively reviewed. Acute compartment syndrome occurred in 28 fractures (10.4%). Four patients presented bilateral tibial plateau fractures; of them, 2 had unilateral, but none had bilateral acute compartment syndrome. Non-contiguous tibia fracture or knee dislocation and higher AO/OTA classification (type 41-C) were statistically significantly associated with the development of acute compartment syndrome in multivariable regression analysis, while younger age (<45 years), male sex, higher Schatzker grade (IV-V-VI), higher tibial widening ratio (≥1.05) and higher femoral displacement ratio (≥0.08) were significantly associated in the analysis adjusted for age and sex. CONCLUSIONS: Two parameters related to the occurrence of ACS in tibial plateau fractures were highlighted in this study: the presence of a non-contiguous tibia fracture or knee dislocation, and higher AO/OTA classification. They may be especially useful when clinical findings are difficult to assess (doubtful clinical signs, obtunded, sedated or intubated patients), and should rise the suspicion level of the treating surgeon. In these cases, regular clinical examinations and/or intra-compartmental pressure measurements should be performed before and after surgery, even if acute compartment syndrome seemed unlikely during initial assessment. However, larger studies are mandatory to confirm and refine both factors in predicting the occurrence of acute compartment syndrome.

Standardized fluoroscopy-based technique to measure intraoperative cup anteversion.

Direct anterior approach (DAA) with the patient lying supine has facilitated the use of intraoperative fluoroscopy and allows for standardized positioning of the patient. The current study presents a new technique to measure acetabular component anteversion using intraoperative fluoroscopy. The current paper describes a mathematical formula to calculate true acetabular component anteversion based on the acetabular component abduction angle and the c-arm tilt angle (CaT). The CaT is determined by tilting the c-arm until an external pelvic oblique radiograph with the equatorial plane of the acetabular component perpendicular to the fluoroscopy receptor is obtained. CaT is determined by direct reading on the C-arm device. The technique was validated using a radiopaque synbone model comparing the described technique to computed tomography anteversion measurement. The experiment was repeated 25 times. The difference in anteversion between the two measuring techniques was on average 0.2° (range -3.0-3.1). The linear regression coefficients evaluating the agreement between the experimental and control methods were 0.99 (95%CI 0.88-1.10, p < 0.001) and 0.33 (95%CI -1.53-2.20, p = 0.713) for the slope and intercept, respectively. The current study confirms that the described three-step c-arm acetabular cup measuring technique can reproducibly and reliably assess acetabular component anteversion in the supine position, as compared to CT-imaging. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:2307-2312, 2017.

Clinical features of anaerobic orthopaedic infections.

Some patient populations and types of orthopaedic surgery could be at particular risk for anaerobic infections. In this retrospective cohort study of operated adult patients with infections from 2004 to 2014, we assessed obligate anaerobes and considered first clinical infection episodes. Anaerobes, isolated from intra-operative samples, were identified in 2.4% of 2740 surgical procedures, of which half (33/65; 51%) were anaerobic monomicrobial infections. Propionibacterium acnes, a penicillin and vancomycin susceptible pathogen, was the predominantly isolated anaerobe. By multivariate analysis, the presence of fracture fixation plates was the variable most strongly associated with anaerobic infection (odds ratio: 2.1, 95% CI: 1.3-3.5). Anaerobes were also associated with spondylodesis and polymicrobial infections. In contrast, it revealed less likely in native bone or prosthetic joint infections and was not related to prior antibiotic use. In conclusion, obligate anaerobes in our case series of orthopaedic infections were rare, and mostly encountered in infections related to trauma with open-fracture fixation devices rather than clean surgical site infection. Anaerobes were often co-pathogens, and cultures most frequently recovered P. acnes. These observations thus do not support changes in current practices such as broader anaerobe coverage for perioperative prophylaxis.

The Accuracy of Acetabular Component Position Using a Novel Method to Determine Anteversion.

BACKGROUND: This study compares the differences in acetabular component position, leg length discrepancy, and hip offset between the anterior and posterior approach. A novel method is applied to determine the acetabular anteversion using the C-arm tilt angle for the anterior approach. METHODS: Hundred consecutive anterior total hip arthroplasties were matched according to gender, body mass index, and age to a cohort of 100 primary total hip arthroplasties operated on through a posterior approach. Postoperative radiographs were analyzed to determine cup inclination, cup anteversion, leg length discrepancy, and hip offset. RESULTS: The mean inclination was 40.8° (range 33°-48°) and 45.1° (range 33°-55°) for the anterior and posterior approach, respectively. Using the new C-arm tilt plane technique, an average acetabular anteversion of 18.4° (range 11°-26°) was achieved with the anterior approach compared with 23.6° (range 8°-38°) with the posterior approach. Hundred percent cups in the anterior group and 81% in the posterior group fell within the safe zone (P < .001). There was no difference in the overall hip offset between the operated side and the contralateral side for the anterior (P = .074) and posterior (P = .919) group. There was no difference in leg length discrepancy between the 2 approaches (P = .259). CONCLUSION: Intraoperative fluoroscopy-assisted direct anterior approach was associated with improved acetabular component positioning. However, no benefit was shown with regards to restoration of hip offset or leg length.