Meniscal injuries in skeletally immature children with tibial eminence fractures. Systematic review of literature.

PURPOSE: Although the mechanisms of injury are similar to ACL rupture in adults, publications dealing with meniscal lesions resulting from fractures of the intercondylar eminence in children are much rarer. The main objective was to measure the frequency of meniscal lesions associated with tibial eminence fractures in children. The second question was to determine whether there is any available evidence on association between meniscal tears diagnostic method, and frequencies of total lesions, total meniscal lesions, and total entrapments. METHODS: A comprehensive literature search was performed using PubMed and Scopus. Articles were eligible for inclusion if they reported data on intercondylar tibial fracture, or tibial spine fracture, or tibial eminence fracture, or intercondylar eminence fracture. Article selection was performed in accordance with the PRISMA guidelines. RESULTS: In total, 789 studies were identified by the literature search. At the end of the process, 26 studies were included in the final review. This systematic review identified 18.1% rate of meniscal tears and 20.1% rate of meniscal or IML entrapments during intercondylar eminence fractures. Proportion of total entrapments was significantly different between groups (17.8% in the arthroscopy group vs. 6.2% in the MRI group; p < .0001). Also, we found 20.9% of total associated lesions in the arthroscopy group vs. 26.1% in the MRI group (p = .06). CONCLUSION: Although incidence of meniscal injuries in children tibial eminence fractures is lower than that in adults ACL rupture, pediatric meniscal tears and entrapments need to be systematically searched. MRI does not appear to provide additional information about the entrapment risk if arthroscopy treatment is performed. However, pretreatment MRI provides important informations about concomitant injuries, such as meniscal tears, and should be mandatory if orthopaedic treatment is retained. MRI modalities have yet to be specified to improve the diagnosis of soft tissues entrapments. STUDY DESIGN: Systematic review of the literature REGISTRATION: PROSPERO N° CRD42021258384.

Litigation in arthroscopic surgery: a 20-year analysis of legal actions in France.

PURPOSE: The main objective of this study was to identify the epidemiological characteristics of litigation following arthroscopic procedures, performed in private practice and public hospitals in France. The secondary objective was to establish a risk profile for medical malpractice lawsuits after arthroscopic surgery. METHODS: All court decisions related to arthroscopic surgery between 1994 and 2020 were collected and reviewed cases from the two main French legal databases (Legifrance and Doctrine). Data were retrospectively collected and included: gender, joint and defendant's specialty involved, reason behind the lawsuit, initial indication and the type of arthroscopic procedure performed. The final verdicts as well as the indemnity awarded to the plaintiff (if any) were recorded. RESULTS: One-hundred eighty cases met the inclusion criteria of the study and were analyzed: 58 cases were before administrative courts and 122 were before civil courts. An orthopaedic surgeon was involved alone or in solidum in 45.6% of cases (82/180), followed by anesthesiologists in 5.6% (10/180). The private surgery center or public hospital were implicated in 63.9% (115/180) of cases. The 2 most common joints involved in litigation following arthroscopic surgery were the knee (82.2%, n = 148) and the shoulder (11.1%, n = 20). The main reasons behind the lawsuit were related to postoperative infection in 78/180 cases and to a musculoskeletal complication in 45/180 cases (25%). A failure to inform was also reported in 34/180 cases (18.9%). Of the 180 cases, 122 cases (67.8%) resulted in a verdict for the plaintiff. The average indemnity award for the plaintiff was 77.984 euros [2.282-1.117.667]. A verdict for the plaintiff was significantly associated with postoperative infection or a wrong-side surgery, while technical error and musculoskeletal complications were more significantly likely to result in a verdict in favor of the defendant (p = 0.003). CONCLUSION: This study evaluated and mapped lawsuits following after arthroscopic surgery in France over a period of more than 20 years. The main joint involved in lawsuits was knee. The main causes of lawsuits following arthroscopic surgery were related to postoperative infection, musculoskeletal complications and failure to inform. LEVEL OF EVIDENCE: Level IV.

Talar Dislocation: Is Reimplantation a Safe Procedure?

Total or complete dislocation of the talus is a triple dislocation of the tibiotalar, talocalcaneal, and talonavicular joints. It is a rare injury and is considered to be 1 of the most disabling ankle injuries. In light of the literature, there is a lack of consensus on their surgical treatment. The primary objective of this retrospective case series was to assess the long-term clinical and radiological outcomes of 5 patients who underwent talar reimplantation for total talar dislocation. From 2005 to 2011, 5 patients were admitted in emergency care unit with a total talar dislocation. The talar dislocation was surgically reduced and stabilized by a temporary internal fixation. Patients were reviewed with a mean follow-up of 60 months (48-70 months). Clinical and radiological evaluations were performed at the last follow-up. Despite 3 opened-dislocation (60%), none had infection. Three patients obtained subnormal biomechanical function with an American Orthopedic Foot and Ankle Score of 60 to 70/100. Two others patients (40%) underwent a secondary ankle arthrodesis because of avascular necrosis of the talus. Signs of necrosis appeared at 15 months and 24 months. Talar reimplantation should be attempted despite the risk of avascular necrosis: restoration of the talus in the ankle maintains normal hindfoot anatomy and preserves bone stock for future function or a subsequent surgical procedure. Patients should be informed of the risk of secondary surgery. Opened-dislocation seems to be a major risk factor of avascular necrosis, and surgeon must take care to keep soft tissues attached.

Pyoderma gangrenosum after orthopaedic or traumatologic surgery: a systematic revue of the literature.

INTRODUCTION: Pyoderma gangrenosum (PG) is a neutrophilic dermatosis characterised by a painful ulceration mimicking infection of the operative site. To this day, there is still no general agreement on the medical and surgical treatment of PG. This systematic review of the literature aims to summarise recent studies about post-operative PG in orthopaedic surgery to improve its medical and surgical management. METHOD: In April 2017, we carried out an exhaustive review of the literature in MEDLINE, PubMed and Cochrane databases. Key words were pyoderma gangrenosum, orthopaedic surgery, and surgical wound infection. We identified 183 articles. After excluding articles reporting idiopathic PG, cases secondary to non-orthopaedic surgery, and cases about other subtypes of dermatosis, 30 studies were identified. We only included articles reporting PG after orthopaedic or trauma surgery. RESULTS: Thirty-one cases of PG have been reported, 58% (18) of which were in women, whose mean age was 56.5 years. Clinical signs were constant, the most frequently affected site was lower limbs [77.4% (24)] and delay of symptom onset was two to 17 days. Systemic corticosteroid therapy was systematic, polyvalent immunoglobulins were used in two cases and immunosuppressive drugs in one. Negative pressure therapy was used in seven cases and hyperbaric oxygen in three. DISCUSSION: Delayed diagnosis leads to one or more surgical revisions, which could have been avoided by using early and adapted medical treatment. Early onset of a painful and infected ulcer at the operating site in a patient at risk of PG is an indicator that dermatologist advice is recommended before surgical debridement. Surgical revision, outside the inflammatory phase and/or covered by a systemic corticosteroid therapy, does not lead to PG relapse. LEVEL OF EVIDENCE: IV: Systematic revue of the literature.

Three-dimensional Frankfort horizontal plane for 3D cephalometry: a comparative assessment of conventional versus novel landmarks and horizontal planes.

Background: To assess the reproducibility of landmarks in three dimensions that determine the Frankfort horizontal plane (FH) as well as two new landmarks, and to evaluate the angular differences of newly introduced planes to the FH. Methods: Three-dimensional (3D) surface models were created from CBCT scans of 26 dry human skulls. Porion (Po), orbitale (Or), internal acoustic foramen (IAF), and zygomatico-maxillary suture (ZyMS) were indicated in the software by three observers twice with a 4-week interval. Angles between two FHs (FH 1: Or-R, Or-L, mid-Po; FH 2: Po-R, Po-L, mid-Or) and between FHs and new planes (Plane 1-6) were measured. Coordinates were exported to a spreadsheet. A statistical analysis was performed to define the landmark reproducibility and 3D angles. Results: Intra- and inter-observer landmark reproducibility showed mean difference more than 1 mm for x-coordinates of all landmarks except IAF. IAF showed significantly better reproducibility than other landmarks (P < 0.0018). The mean angular difference between FH 1 and FH 2 was 0.7 degrees. Plane 3, connecting Or-R, Or-L and mid-IAF, and Plane 4, connecting Po-R, Po-L and mid-ZyMS, both showed an angular difference of less than 1 degree when compared to FHs. Conclusions: This study revealed poor reproducibility of the traditional FH landmarks on the x-axis and good reproducibility of a new landmark tested to replace Po, the IAF. Yet, Or showed superior results compared to ZyMS. The potential of using new horizontal planes was demonstrated. Future studies should focus on identification of a valid alternative for Or and ZyMS and on clinical implementation of the findings.

Three-Dimensional Evaluation of Maxillary Sinus Septa for Implant Placement.

BACKGROUND: The aim of our study was to investigate, in 3 dimensions, the maxillary sinus septa as an alternative site for dental implant placement to avoid sinus lift procedures. MATERIAL AND METHODS: We selected 100 dentate and 100 edentate patients with the presence of a maxillary sinus septum by reviewing a larger cone beam computer tomography (CBCT) database from the Department of Oral and Maxillofacial Surgery at Cliniques Universitaires Saint Luc in Bruxelles, Belgium. Three-dimensional reconstructions of 200 maxillary sinus septa were performed using Maxilim software. Ten measurements (length, lateral height, and thickness of the middle and medial region of the septum) were performed by 1 observer, 2 times, with an interval of 1 week between measurements. The angle between the septum and the maxillary plane was also measured. Finally, localization and orientation were assessed for each septum. RESULTS: There was no statistically significant difference between the 2 intraobserver measurements (p>0.05). Student's t-test was used to compare means. Middle height was the only measurement for which there was a difference between edentate and dentate patients (p=0.0095, edentate mean < dentate mean). The location of the septa observed in our study groups demonstrated greater prevalence in the posterior region than in the anterior and middle regions. For the spatial orientation of the septum, we found that most septa (81.2% in dentate patients, 53% in edentate patients) were oblique. CONCLUSIONS: Three-dimensional evaluation of maxillary sinus septa using 3D CBCT imaging showed that the sinus septum could offer an alternative site for implant placement in the maxillary sinus.

A new mandible-specific landmark reference system for three-dimensional cephalometry using cone-beam computed tomography.

OBJECTIVES: To develop a novel 3D landmark reference system that is specific for mandibular midline cephalometric landmarks and to assess its repeatability and reproducibility. METHODS: Cone-beam computed tomography (CBCT) scans (3D Accuitomo® 170) were performed on 26 dry human skulls. The CBCT data were exported into DICOM files and imported to Maxilim® software to create 3D surface models. Two observers identified five landmarks to create a specific mid-sagittal mandibular plane: two mandibular foramina, two molar landmarks and one interincisive landmark. On this mid-sagittal mandibular plane, four mandibular cephalometric landmarks were marked: Point B, Pogonion, Gnathion and Menton. All observations were repeated by the two observers after an interval of 4 weeks. The coordinates (x, y, z) of each landmark were exported, and statistical analyses were performed to evaluate inter- and intra-rater precision. RESULTS: The intra-observer median precision in locating all landmarks ranged between 0.17 and 0.61mm. The intra-observer repeatability was generally good with a precision under 1mm in more than 50 per cent. The overall median inter-observer precision was 0.26-2.30mm. The mandibular foramina showed the best inter-observer reproducibility. The general inter-observer reproducibility was moderate to good, except for Pogonion and Point B. LIMITATIONS: Dry human skulls may not represent anatomical conditions found in living patients, thus the system should be validated using patients' data. CONCLUSION: The novel reference system offered good precision and generally good to moderate repeatability and reproducibility for mandibular midline cephalometric landmark identification in three dimensions. These findings will be useful for further improvement of 3D cephalometric systems.

Multiple postnatal craniofacial anomalies are characterized by conditional loss of polycystic kidney disease 2 (Pkd2).

Polycystin 2 (Pkd2), which belongs to the transient receptor potential family, plays a critical role in development. Pkd2 is mainly localized in the primary cilia, which also function as mechanoreceptors in many cells that influence multiple biological processes including Ca(2+) influx, chemical activity and signalling pathways. Mutations in many cilia proteins result in craniofacial abnormalities. Orofacial tissues constantly receive mechanical forces and are known to develop and grow through intricate signalling pathways. Here we investigate the role of Pkd2, whose role remains unclear in craniofacial development and growth. In order to determine the role of Pkd2 in craniofacial development, we located expression in craniofacial tissues and analysed mice with conditional deletion of Pkd2 in neural crest-derived cells, using Wnt1Cre mice. Pkd2 mutants showed many signs of mechanical trauma such as fractured molar roots, distorted incisors, alveolar bone loss and compressed temporomandibular joints, in addition to abnormal skull shapes. Significantly, mutants showed no indication of any of these phenotypes at embryonic stages when heads perceive no significant mechanical stress in utero. The results suggest that Pkd2 is likely to play a critical role in craniofacial growth as a mechanoreceptor. Pkd2 is also identified as one of the genes responsible for autosomal dominant polycystic kidney disease (ADPKD). Since facial anomalies have never been identified in ADPKD patients, we carried out three-dimensional photography of patient faces and analysed these using dense surface modelling. This analysis revealed specific characteristics of ADPKD patient faces, some of which correlated with those of the mutant mice.

Zoledronic acid inhibits pulmonary metastasis dissemination in a preclinical model of Ewing's sarcoma via inhibition of cell migration.

BACKGROUND: Ewing's sarcoma (ES) is the second most frequent primitive malignant bone tumor in adolescents with a very poor prognosis for high risk patients, mainly when lung metastases are detected (overall survival <15% at 5 years). Zoledronic acid (ZA) is a potent inhibitor of bone resorption which induces osteoclast apoptosis. Our previous studies showed a strong therapeutic potential of ZA as it inhibits ES cell growth in vitro and ES primary tumor growth in vivo in a mouse model developed in bone site. However, no data are available on lung metastasis. Therefore, the aim of this study was to determine the effect of ZA on ES cell invasion and metastatic properties. METHODS: Invasion assays were performed in vitro in Boyden's chambers covered with Matrigel. Matrix Metalloproteinase (MMP) activity was analyzed by zymography in ES cell culture supernatant. In vivo, a relevant model of spontaneous lung metastases which disseminate from primary ES tumor was induced by the orthotopic injection of 106 human ES cells in the tibia medullar cavity of nude mice. The effect of ZA (50 µg/kg, 3x/week) was studied over a 4-week period. Lung metastases were observed macroscopically at autopsy and analysed by histology. RESULTS: ZA induced a strong inhibition of ES cell invasion, probably due to down regulation of MMP-2 and -9 activities as analyzed by zymography. In vivo, ZA inhibits the dissemination of spontaneous lung metastases from a primary ES tumor but had no effect on the growth of established lung metastases. CONCLUSION: These results suggest that ZA could be used early in the treatment of ES to inhibit bone tumor growth but also to prevent the early metastatic events to the lungs.

Oversized cups as a major risk factor of postoperative pain after total hip arthroplasty.

After total hip arthroplasty (THA) some patients have persistent postoperative pain (POP). Some of these POP are anterior and are caused by an anterior iliopsoas impingement (AIPI). We have hypothesized that oversized implanted cups could be responsible for POP and especially AIPI. We screened 237 patients who had a primary THA and compared the size difference (ΔS) between the native femoral head and the implanted cup, in patients with and without POP. Median ΔS was 2 mm [-6; 11 mm] and patients with POP had a significantly increased ΔS (P < 0.0001). The threshold above which pain was significantly more frequent was ΔS ≥ 6 mm. Odds ratio was 14.4 for POP and 26 for AIPI pain when ΔS ≥ 6 mm.

Extra-articular hip resection with maintenance of pelvic continuity in malignant tumours of the proximal femur with articular invasion.

INTRODUCTION: Extra-articular hip resection may be necessary in cases of malignant tumour of the pelvic bone or of the proximal femur invading the hip joint. When the tumour is in the proximal femur, it is possible to resect the acetabulum en bloc by performing a periacetabular osteotomy, but this creates a discontinuity in the pelvic ring with difficult reconstruction and diminished function. Several techniques described recently seek to be as sparing as possible on the pelvic bone by preserving the posterior column or both columns in order to facilitate reconstruction and improve function. However, these still require complex reconstructions and can necessitate intra-pelvic dissection. TECHNIQUE: We describe here an extra-articular hip resection technique for tumours of the proximal femur invading the joint, with maintenance of pelvic continuity by preserving both columns and the quadrilateral plate of the acetabulum, without intra-pelvic dissection, that can be performed on patients in whom the medial wall of the acetabulum is thick enough. Our preliminary assessments have included studies on dry bone and imaging analyses. The technique was first tested on a single cadaver pelvis (encompassing 2 hips) and subsequently performed on a patient with a pathological fracture of the femoral neck due to osteosarcoma secondary to Paget's disease. CONCLUSIONS: Further clinical applications are essential to evaluate the overall effectiveness, safety and impact on patient functionality of this experimental technique.

Drugs targeting the bone microenvironment: new therapeutic tools in Ewing's sarcoma?

INTRODUCTION: Ewing's sarcoma (ES) is the second most frequent malignant primary bone tumour in children, adolescents and young adults. The overall survival is 60 - 70% at 5 years but still very poor for patients with metastases, disease relapse or for those not responding to chemotherapy. For these high risk patients, new therapeutic approaches are needed beyond conventional therapies (chemotherapy, surgery and radiation) such as targeted therapies. AREAS COVERED: Transcriptomic and genomic analyses in ES have revealed alterations in genes that control signalling pathways involved in many other cancer types. To set up more specific approaches, it is reasonable to think that the particular microenvironment of these bone tumours is essential for their initiation and progression, including in ES. To support this hypothesis, preclinical studies using drugs targeting bone cells (bisphosphonate zoledronate, anti-receptor activator of NF-κB ligand strategies) showed promising results in animal models. This review will discuss the new targeted therapeutic options in ES, focusing more particularly on the ones modulating the bone microenvironment. EXPERT OPINION: Targeting the microenvironment represents a new option for patients with ES. The proof-of-concept has been demonstrated in preclinical studies using relevant animal models, especially for zoledronate, which induced a strong inhibition of tumour progression in an orthotopic bone model.

Effect of adding bone marrow to ceramic graft materials with different interconnectivities in lumbar arthrodesis : quantification of bone formation.

INTRODUCTION: Combining bone marrow (BM) with graft materials can stimulate bone healing. However, bone growth is not quantified in most studies, and the influence of the rate of interconnectivity of ceramics loaded with bone marrow has not yet been quantified. Here, a rabbit model of posterolateral intertransverse arthrodesis was used to quantify the effect of adding BM to partially (PIC) or totally (TIC) interconnected ceramics. MATERIALS AND METHODS: A single lumbar level was grafted on two sides with TIC (n = 12) or PIC (n = 18). The ceramic was loaded with 1.5 ml of BM on one side (chosen at random). The fusion rate was assessed by manual palpation test. Bone formation was quantified on scanning electron microscopy images and by dual-energy X-ray absorptiometry. RESULTS: At week 6, bone formation with TIC was twice as high as that with PIC. When BM was added, 35.1 and 87.8 % more bone formation was observed in the TIC and PIC, respectively. In ceramics loaded with BM, the bone mineral density was significantly higher than that in ceramics alone. CONCLUSIONS: Differences in interconnectivity within the family of biphasic ceramics should be taken into account when applying them clinically. BM increased bone formation regardless of the type of ceramic employed.

Prognostic and therapeutic interest of a new classification in inferior hip dislocation: a systematic review of the literature.

INTRODUCTION: Reported cases of inferior dislocation in the literature are found under several names (inferior, anteroinferior, obturator, or erecta), which may be source of confusion. The purpose of this comprehensive review of the literature is to collect as many cases of inferior dislocation as possible to determine better therapeutic strategies, outcome after reduction, complications, and prognostic factors. METHODS: In April 2020, a literature search was performed in Pubmed, Medline, Scopus, Cochrane, and Embase databases. The MeSH keywords were "OBTURATOR DISLOCATION HIP" or "ANTERIOR DISLOCATION HIP" or "INFERIOR DISLOCATION HIP." Authors independently selected articles that met the selection criteria, with no time limit. RESULTS: Out of the 97 articles selected, there were 119 cases of primary inferior hip dislocations. This review of the literature has allowed us to differentiate 3 radiographic subtypes of inferior dislocations, which correspond to 3 different anatomical positions of the femoral head: "obturator" dislocation, "proximal anterior-inferior" dislocation, and "distal anterior-inferior" dislocation. Our subtype classification yielded 39 obturator subtype inferior dislocations (32.8%), 66 proximal anteroinferior subtypes (55.4%), and 14 distal anteroinferior (11.8%). The obturator subtype is at risk of reduction failure and femoral neck fracture during the reduction manoeuver. CONCLUSIONS: Our study identified 3 subtypes with different prognosis, with obturator and distal anteroinferior dislocations having a poorer prognosis because of their pre- and post-reduction complications. We were unable to determine the correct manoeuver to reduce inferior dislocations without taking the risk of femoral neck fracture, but each of these subtypes may require a different manoeuver.

Detecting generative artificial intelligence in scientific articles: Evasion techniques and implications for scientific integrity.

BACKGROUND: Artificial intelligence (AI) tools, although beneficial for data collection and analysis, can also facilitate scientific fraud. AI detectors can help resolve this problem, but their effectiveness depends on their ability to track AI progress. In addition, many methods of evading AI detection exist and their constantly evolving sophistication can make the task more difficult. Thus, from an AI-generated text, we wanted to: (1) evaluate the AI detection sites on a text generated entirely by the AI, (2) test the methods described for evading AI detection, and (3) evaluate the effectiveness of these methods to evade AI detection on the sites tested previously. HYPOTHESIS: Not all AI detection tools are equally effective in detecting AI-generated text and some techniques used to evade АI detection can make an AI-produced text almost undetectable. MATERIALS AND METHODS: We created a text with ChatGPT-4 (Chat Gеnеrаtivе Prе-trained Transformer) and submitted it to 11 АI detection web tools (Оriginаlity, ZеrоGPT, Writеr, Cоpylеаks, Crоssplag, GPTZеrо, Sapling, Cоntеnt аt scаlе, Cоrrеctоr, Writеfull еt Quill), bеfоrе аnd аftеr applying strategies to minimise AI detection. The strategies used to minimize AI detection were the improvement of command messages in ChatPGT, the introduction of minor grammatical errors such as comma deletion, paraphrasing, and the substitution of Latin letters with similar Cyrillic letters (a and о) which is also a method used elsewhere to evade the detection of plagiarism. We have also tested the effectiveness of these tools in correctly identifying a scientific text written by a human in 1960. RESULTS: From the initial text generated by the AI, 7 of the 11 detectors concluded that the text was mainly written by humans. Subsequently, the introduction of simple modifications, such as the removal of commas or paraphrasing can effectively reduce AI detection and make the text appear human for all detectors. In addition, replacing certain Latin letters with Cyrillic letters can make an AI text completely undetectable. Finally, we observe that in a paradoxical way, certain sites detect a significant proportion of AI in a text written by a human in 1960. DISCUSSION: AI detectors have low efficiency, and simple modifications can allow even the most robust detectors to be easily bypassed. The rapid development of generative AI raises questions about the future of scientific writing but also about the detection of scientific fraud, such as data fabrication. LEVEL OF EVIDENCE: III Control case study.

A New Classification of the Morphology of Complete Ponticulus Posticus on Cone Beam Computed Tomography.

The objectives of this retrospective study were to measure the prevalence of complete ponticulus posticus (CPP), to propose a new classification based on two different shapes of CPP, to compare these shapes with age and gender, and to test two different methods of measurements of the diameters of CPP on cone beam computed tomography (CBCT). MATERIAL AND METHODS: We used 2012 CBCT scans from Planmeca Promax 3D Mid and Romexis 5.1 software tools to measure the height and width of the CPP, and we measured the surface of the CPP using an ellipse tool. We classified the CPP into "thin" and "thick" shape. RESULTS: the prevalence of CPP was 9.49% with 97 male and 94 female patients. The unilateral type was found in 131 patients, while the bilateral type was found in 60 patients. Intra-observer reliability was evaluated using the intraclass correlation coefficient (ICC). The ICC was 0.875 for height, 0.872 for width, and 0.885 for the ellipse area. Both methods present very good intra-observer reproducibility. The "thin" group tended to be older and significantly more related to female patients. The "thick" group was associated with younger male patients. CONCLUSIONS: the proposed classification of CPP may be used when reporting the CBCT large field of view. There is still a need to increase the knowledge on the atlas and on its main variant, such as complete PP.

Risk of simultaneous and delayed breakage of total hip replacement ceramic implants in patients with trauma induced periprosthetic fracture and acetabular shell loosening.

BACKGROUND: Ceramic implant breakage (CIB) in total hip replacement (THR) is a rare incident. A confusion exists between the fragile mechanical behaviour of ceramic materials (brittleness) and fragility in the common sense (easy to break), leading to the misconception that trauma is to blame for these breakages. Trauma has been reported as a cause of breakage by several authors and it is debated whether the burst force can be reached in one single trauma in-vivo. We did a retrospective investigation aiming to determine the risk of CIB associated with a major trauma defined as a periprosthetic femoral fracture (PPFF) or a traumatic loosening of the acetabular shell (TLAS) in ceramic-on-ceramic (CoC) THR. HYPOTHESIS: The impact forces responsible of PPFF and TLAS, which are probably the most important impact forces sustained by patients, are not sufficient to induce immediate or delayed CIB. MATERIAL AND METHODS: We conducted a retrospective study on 31 patients (62 ceramic implants, 31 acetabular liners and 31 femoral heads) with a PPFF or TLAS between January 2010 and January 2022. We reviewed the records and X-rays at the time of the major trauma and at the last follow-up. We searched for simultaneous CIB, and those occurring on the non-explanted ceramic implants at last follow up (delayed CIB). These major traumas occurred in 9 men and 22 women. Median age was 75 years old [20-97years old]. There were 28 PPFF and 3 TLAS. Mean time from THR to trauma was 91.2±67months [2.4-240months]. RESULTS: On X-rays and after intraoperative confirmation, we do not report any simultaneous CIB on the 62 ceramic implants. Treatment consisted of internal fixation for 20 patients with preservation of both ceramic implants for Vancouver A, B1 and C fractures, 8 stem revisions with preservation of acetabular liner for Vancouver B2 and B3 fractures and 3 acetabular shell revisions to dual mobility and ceramic head change for TLAS. Thus, a total of 48 ceramic implants remained implanted (28 acetabular liners and 20 femoral heads). At last follow-up after the index revision (median=36 months [6-100months]), no patient had a delayed CIB. DISCUSSION: Major trauma resulting in a PPFF or TLAS in patient withs a CoC THR did not result in simultaneous CIB. The impact forces during these traumas are not sufficient to induce immediate breakage of the ceramic implants. At a median 3years follow-up we found no delayed CIB. Because CIB is a rare event, longer follow up and larger cohort study is needed to determine if a single high impact trauma can initiate and favour the spread of a crack in the ceramic material leading to a breakage. Considering the high mechanical resistance of the ceramic implants and the absence of CIB during or after a major trauma in our study, patients with CoC bearings should not be restricted in their daily activity to prevent CIB. LEVEL OF EVIDENCE: IV, retrospective cohort study.

Impact of the Covid-19 pandemic context on the microbiological epidemiology and management of flexor sheath phlegmons.

INTRODUCTION: The COVID-19 pandemic in France has recently modified the patients' lifestyles, as well as methods of medical and surgical management. This could explain subsequent changes to the microbiological spectrum, the severity, as well as the scalability of phlegmons of the flexor tendon sheath. The objective of this study was to construct an epidemiological and bacteriological inventory of these hand infections, and to compare the clinical and microbiological data, before and after the COVID-19 pandemic. HYPOTHESIS: The hypothesis of this work was that the phlegmons of the flexor tendon sheath presented specific microbiological characteristics in the tropical environment of our University Hospital Center, and that these characteristics could have changed with the recent introduction of hydro-alcoholic solution (HAS) associated to the COVID-19 pandemic. MATERIAL AND METHODS: The preoperative epidemiological data of our patients were collected between January 2016 and December 2020. The stage of severity, according to the classification of Michon, the use of hydro-alcoholic solution, as well as the early clinical evolution were collected. The cohort was then divided into two groups in order to compare the microbiological profiles, the management and the clinical evolution of patients in the pre-COVID period with those in the post-COVID period. RESULTS: A total of 199 patients were included, 154 patients in the pre-COVID period and 26 in the post-COVID period. We found a majority of MSSA (58.3%, N=105) and negative samples comprised 18.9% (N=34). No statistically significant difference was found between the two groups regarding the bacteriological results. The clinical course was judged to be favorable in 93.5% of cases in the pre-COVID group compared to 80.8% in the post-COVID group (p=0.046). The use of HAS (p<0.0001), as well as the initial stage of severity according to Michon, were significantly higher in group 2 (p=0.04). DISCUSSION: The COVID-19 pandemic has not shown any change in the microbiological spectrum, despite the now daily use of HAS in everyday life. The postoperative clinical evolution was significantly less favorable after the onset of COVID and could be explained by an increase in cases with a more advanced initial stage of severity. LEVEL OF EVIDENCE: IV, Observational epidemiological study.

Preoperative Planning for Reverse Shoulder Arthroplasty: Does the Clinical Range of Motion Match the Planned 3D Humeral Displacement?

INTRODUCTION: The functional outcome after reverse shoulder arthroplasty (RSA) is closely linked to how much the humerus shifts because of the implants. While two-dimensional (2D) angle measurements have been used to capture this shift, it can be measured in three dimensions (3D) as the arm change position (ACP). In a previous study, the ACP was measured using 3D preoperative planning software with the passive virtual shoulder range of motion obtained after RSA. The main objective of this study was to evaluate the relationship between the ACP and the actual active shoulder range of motion measured after RSA. The hypothesis was that the ACP and the active clinical range of motion are related such that the ACP is a reliable parameter to guide the preoperative planning of an RSA. The secondary objective was to assess the relationship between 2D and 3D humeral displacement measurements. MATERIALS AND METHODS: This prospective observational study enrolled 12 patients who underwent RSA and had a minimum follow-up of 2 years. The active range of motion in shoulder flexion, abduction, and internal and external rotation was measured. At the same time, ACP measurements were taken from a reconstructed postoperative CT scan, in addition to the radiographic measurements of humeral lateralization and distalization angles on AP views in neutral rotation. RESULTS: The mean humeral distalization induced by RSA was 33.3 mm (±3.8 mm). A non-statistically significant increase in shoulder flexion was observed for humeral distalization beyond 38 mm (R2 = 0.29, p = 0.07). This "threshold" effect of humeral distalization was also observed for the gains in abduction, as well as internal and external rotations, which seemed better with less than 38 mm or even 35 mm distalization. No statistical correlation was found between the 3D ACP measurements and 2D angle measurements. CONCLUSION: Excessive humeral distalization seems to be detrimental to joint mobility, especially shoulder flexion. Humeral lateralization and humeral anteriorization measured using the ACP seem to promote better shoulder range of motion, with no threshold effect. These findings could be evidence of tension in the soft tissues around the shoulder joint, which should be taken into consideration during preoperative planning.