The influence of virtual reality simulation on surgical residents' heart rate during an assessment of arthroscopic technical skills: A prospective, paired observational study.

HYPOTHESIS: To demonstrate that a virtual reality (VR) simulation training program reduces heart rate variability during an assessment of surgical trainees' technical skills in arthroscopy. STUDY DESIGN: Prospective observational matched study. MATERIALS & METHODS: Thirty-six orthopaedic surgery residents, new to arthroscopy, received standard training in arthroscopic knee surgery, supplemented by additional monthly training for 6months on a VR simulator for 16 of them. At inclusion, the 2 groups (VR and NON-VR) answered a questionnaire and performed a meniscectomy on a VR simulator. After 6months of training, two independent trainers blinded to the inclusion arms evaluated the technical skills of the two groups during meniscectomies on a model and on an anatomical subject. Heart rate variability (HRV) was measured using a wireless heart rate monitor during baseline, VR training, and assessment. RESULTS: After removing incomplete data, the analysis focused on 10 VR residents matched at inclusion with 10 NON-VR residents. The VR group had a significantly lower heart rate at the final assessment (p=0.02) and lower overall HRV (p=0.05). The low/high frequency ratio (LF/HF) was not significantly different between the groups (1.84 vs 2.05, p=0.66) but the before-after training comparison showed a greater decrease in this ratio in the VR group compared to the NON-VR group -0.76 (-41%) vs -0.08 (-4%). CONCLUSION: This study demonstrates a significant difference in heart rate variability between trained residents versus untrained residents during the final assessment of their technical skills at 6months. It appears that improving stress management should be an integral part of training programs in arthroscopic surgery. CLINICAL INTEREST: VR simulators in arthroscopy could improve non-technical skills such as heart rate variability, from the perspective of accountability. LEVEL OF EVIDENCE: III.

All the menisco-ligamentary structures of the medial plane play a significant role in controlling anterior tibial translation and tibial rotation of the knee. Cadaveric study of 29 knees with the Dyneelax® laximeter.

Purpose: This study aimed to determine the respective roles of the anterior cruciate ligament (ACL) and the different components of the medial plane in the control of anterior tibial translation and internal and external tibial rotation. Methods: Twenty-nine fresh lower limbs, disarticulated at the hip, were tested in the anatomy laboratory. The following structures were isolated: the ACL, the anteromedial retinaculum (AMR), the medial collateral ligament (superficial and deep MCL), the posterior medial capsule (PMC) and the posterior horn of the medial meniscus (PHMM). The lower limb was positioned at 30° of flexion on the Dyneelax® laximeter (0.1 mm and 0.1° accuracies) and underwent anterior loads up to 200 N and internal and external tibial rotations sectioned from front to back. and the knee was then retested. The results were presented as relative gains in translation and rotations for each structure. Student's t test and Wilcoxon tests were used. Results: The relative gains in translation for the ACL, AMR, superficial MCL, deep MCL, PMC and PHMM, respectively, were 42.9%, 6.7%, 7.4%, 6%, 7.5% and 11.6%. The relative gains in internal rotation for ACL, AMR, superficial MCL, deep MCL, PMC and PHMM, respectively, were 13%, 6.9%, 4.6%, 3.9%, 13% and 8%. The relative gains in external rotation for ACL, AMR, superficial MCL, deep MCL, PMC and medial meniscus, respectively, were 8.9%, 6%, 9.7%, 13.8%,11.2% and 8.5%. All the relative gains in translation, internal and external rotations were significant at each step of transection (p < 0.01). Conclusions: The ligamentous structures of the medial plane constitute a functional unit in which each component has a specific passive contribution. This study highlights the importance of recognising the extent of the medial ligament tears and performing a medial side anatomic and individual reconstruction and a suture of a ramp lesion, in addition to an ACL surgery.

Virtual reality simulation training improve diagnostic knee arthroscopy and meniscectomy skills: a prospective transfer validity study.

PURPOSE: Limited data exist on the actual transfer of skills learned using a virtual reality (VR) simulator for arthroscopy training because studies mainly focused on VR performance improvement and not on transfer to real word (transfer validity). The purpose of this single-blinded, controlled trial was to objectively investigate transfer validity in the context of initial knee arthroscopy training. METHODS: For this study, 36 junior resident orthopaedic surgeons (postgraduate year one and year two) without prior experience in arthroscopic surgery were enrolled to receive standard knee arthroscopy surgery training (NON-VR group) or standard training plus training on a hybrid virtual reality knee arthroscopy simulator (1 h/month) (VR group). At inclusion, all participants completed a questionnaire on their current arthroscopic technical skills. After 6 months of training, both groups performed three exercises that were evaluated independently by two blinded trainers: i) arthroscopic partial meniscectomy on a bench-top knee simulator; ii) supervised diagnostic knee arthroscopy on a cadaveric knee; and iii) supervised knee partial meniscectomy on a cadaveric knee. Training level was determined with the Arthroscopic Surgical Skill Evaluation Tool (ASSET) score. RESULTS: Overall, performance (ASSET scores) was better in the VR group than NON-VR group (difference in the global scores: p < 0.001, in bench-top meniscectomy scores: p = 0.03, in diagnostic knee arthroscopy on a cadaveric knee scores: p = 0.04, and in partial meniscectomy on a cadaveric knee scores: p = 0.02). Subgroup analysis by postgraduate year showed that the year-one NON-VR subgroup performed worse than the other subgroups, regardless of the exercise. CONCLUSION: This study showed the transferability of the technical skills acquired by novice residents on a hybrid virtual reality simulator to the bench-top and cadaveric models. Surgical skill acquired with a VR arthroscopy surgical simulator might safely improve arthroscopy competences in the operating room, also helping to standardise resident training and follow their progress.

Construction and validation of a functional diagnostic score in anterior cruciate ligament ruptures of the knee in the immediate post-traumatic period. Preliminary results of a multicenter prospective study.

INTRODUCTION: Knee ligament injuries are frequent and their number is constantly increasing with the development of sports activities. Dynamic knee maneuvers usually make it possible to diagnose anterior cruciate ligament (ACL) injuries but they remain difficult to perform in the early post-traumatic phase. This leads to the almost systematic use of MRI scans, many of which turn out to be superfluous. The aim of this study was to construct a screening score based solely on history-taking, in order to help diagnose ACL injuries, and to define thresholds that could help inform recommendations for MRI usage. The hypothesis was that this score could distinguish a population of patients with a ruptured ACL from a population of patients with other knee injuries. MATERIAL AND METHODS: This prospective multicenter study included 166 patients. Patients were included if they were between 18 and 55 years of age, with knee trauma that had occurred in the last 10 days, and without a bone fracture on standard radiographs. They were excluded if the trauma required immediate surgical management and if they had a history of knee trauma. The screening score was completed by the physician. The score included the following items: assessment of pain, immediate post-traumatic functional impairment, notion of a "pop", feeling of instability and presence of a swelling. An MRI was systematically performed and the patient consulted a referring physician to compare the initial score with the diagnosis. RESULTS: Eighty-six patients had an injured ACL and 80 had a healthy ACL. Two thresholds could be identified. For a score lower than 4, the risk of an ACL injury was low with a sensitivity of 96% and a negative predictive value of 87%. For a score above 8, the ACL injury was highly probable with a specificity of 88% and a positive predictive value of 83%. DISCUSSION/CONCLUSION: The score was able to distinguish a population of patients with a ruptured ACL from a population of patients with other knee injuries. These preliminary results confirm that the selected items are relevant and that the score can help improve the diagnostic orientation of patients with recent knee trauma. Increasing the sample size in combination with an analysis of influencing factors will determine whether the performance of this score can be refined. LEVEL OF EVIDENCE: II prospective multicenter study.

A recurrent prosthetic joint infection caused by Erysipelothrix rhusiopathiae: case report and literature review.

Prosthetic knee joint infection caused by Erysipelothrix rhusiopathiae is uncommon and only one case of recurrent infection has previously been described. Here, we describe the case of a 77-year-old male patient who was admitted to the teaching hospital of Rennes (France) with bilateral and nocturnal gonalgia evolving for 1 month. He had bilateral knee prosthesis 10 years ago, and a history of large B-cell lymphoma in remission. A diagnosis of infective endocarditis, with prosthetic knee infection, was made, with positive cultures of synovial fluids and blood; colonies of E. rhusiopathiae were identified by MALDI-TOF MS. Initial treatment involved debridement, implant retention surgery and intravenous amoxicillin (12 g day-1) for 6 weeks with gentamicin 3 mg kg-1 day-1 added for the first 4 days. One year later, a second episode of E. rhusiopathiae infection occurred, suggesting a recurrence or reinfection due to the same bacterial species. The patient was finally cured after a two-stage exchange with a cemented articulated spacer and a 3 month course of amoxicillin (12 g day-1, iv). Different characteristics of E. rhusiopathiae infection were discussed, with a review of all cases of prosthetic joint infections caused by Erysipelothrix species. This case highlights the need for a long-term survey of patients, and a good knowledge of their environment to avoid any risk of reinfection.

Microbiology and antibiotics after second-stage revision of periprosthetic joint infections: A two-year follow-up cohort.

BACKGROUND: Optimal duration of antimicrobial regimen after reimplantation of two-stage procedures for periprosthetic joint infection (PJI) is poorly standardized. The aim of this study was to assess the characteristics of reimplantation microbiology with 6 weeks (2nd stage positive culture) or 10 days (2nd stage negative culture) of antibiotics in patients with complex chronic PJI and factors associated with microbiology at reimplantation. PATIENTS AND METHODS: We performed a retrospective single-center study including all consecutive complex PJI recipients managed by two-stage surgery in a referral centre, from 2015 to 2018. Outcome was assessed at a minimum 2-year follow-up. Logistic regression analysis was performed to assess predictors of reimplantation microbiology. RESULTS: Fifty patients (median age 69 [62-77] years) were included. PJI predominantly involved the hip (48%). The most common microorganisms were Staphylococcus aureus (36%), and coagulase-negative staphylococci (24%). At the second stage, reimplantation microbiology was positive for 10 patients (20%). Documentation was obtained within 48hours. With median follow-up of 41 [30-50] months after reimplantation, treatment failure occurred in 4 patients (8%). Using log-rank to compare Kaplan-Meier survival curves, no difference in the probability of treatment failure was found according to reimplantation microbiology (P=0.34). After adjustment, relapse was not associated with positive reimplantation microbiology (P=0.53). CONCLUSIONS: In this work, positive microbiology at reimplantation did not predict treatment failure. Rapid growth at post-reimplantation suggests that antibiotic use should not exceed 10 days when cultures are negative. Additional studies are needed to determine the optimal duration of antibiotic therapy in case of negative microbiology.

High-level judo practice after hip resurfacing.

BACKGROUND AND HYPOTHESIS: The ability to participate in sports after hip arthroplasty is increasingly being requested by patients. The possibilities of participating in sports such as judo after hip arthroplasty have not been explored sufficiently even though these sports are associated with a high risk of loosening, dislocation or revision. The aim of this study was to evaluate the return to judo after hip resurfacing arthroplasty (HRA) in terms of time and level of practice in an expert population and to determine the surgical complication rate. MATERIALS AND METHODS: This was a retrospective observational study of all licensed judo practitioners at an expert level (≥black belt 3rd Dan) who underwent HRA. Patients filled out a sport-specific questionnaire that captured their level of judo practice (international, national, regional, recreational), type of practice (teaching, technical recreational, competitive recreational), dan grade, weekly volume of practice and time elapsed after surgery before resuming judo. The features of the return to judo were analyzed (technical, ground, combat). RESULTS: Sixty-seven HRA were implanted in 60 patients: 11 were international judokas, 3 were national, 8 were regional and 38 were recreational. The case series consisted of 18 patients who were 3rd Dan, 18 were 4th Dan, 7 were 5th Dan, 5 were 6th Dan and 12 were 7th Dan. The average follow-up was 65.3 months (range 9.9-11.9). All the clinical scores pointed to clinically and statistically significant improvement. Of the 60 patients, 53 had resumed judo at the final assessment (90%) after a mean of 4 months (2-7) for technical judo, 6 months (3-10) for ground judo and 7 months (3-12) for combat judo. Of those who did not resume their judo practice, 3 patients voluntarily changed sports, 2 had psychological apprehension and 2 had residual groin pain. The weekly volume of practice preoperatively was 0.9hours (0-5) and postoperatively it reached 5hours (2-18) (P<0.001). CONCLUSION: HRA in a population of high-level judokas allows for return to sport practice without short-term complications such as fracture, dislocation or loosening. LEVEL OF EVIDENCE: III.

Publication rate of studies presented at the French Arthroscopic Society Meeting in 2014.

INTRODUCTION: Publication rates for studies reported at French Arthroscopic Society (Société francophone d'arthroscopie, SFA) meetings are not known. A comprehensive search of podium presentations to the 2014 SFA meeting was performed, assessing: (1) publication rate for meeting abstracts, and (2) bibliometric parameters including journal Impact Factor. HYPOTHESIS: The full-text publication rate for abstracts accepted for the 2014 French Arthroscopic Society (SFA) meeting was around 47.1%: i.e., the rate reported for the 2013 meeting of the French Society of Orthopedic Surgery and Traumatology (SoFCOT). MATERIAL AND METHODS: Bibliometric analysis of all abstracts accepted for the 2014 SFA annual meeting was undertaken by the Junior French Arthroscopic Society (SFA Junior), who collated the podium presentations. Reported studies were retrospective in 43 cases (54%) and prospective in 36 (46%). They consisted in clinical studies in 52/79 cases (66%), experimental studies in 4 (5%), cadaver or animal studies in 13 (16.5%), epidemiological studies in 8 (10%), a case report in 1 (1.2%) and a literature review in 1 (1.2%). Thirty-two (40.5%) concerned the shoulder and 31 (39%) the knee. Publication was checked on systematic PubMed-Medline search of authors' names. Articles found on PubMed-Medline were downloaded into the SIGAPS scientific publication search, management and analysis system database. Journal impact factor and SIGAPS category (A to E) were obtained, as were number of citations and h-index. This was a descriptive study, assessing numbers; results were reported as number and percentage. RESULTS: Overall publication rate was 31/79 (39.2%): 20/31 clinical studies (64.5%), 6 cadaver studies (19.4%), 3 epidemiology studies (9.7%), 1 experimental study (3.2%) and 1 literature review (3.2%). Mean 2014 SFA meeting-to-publication time was 18.7 months [range, -2 to 60 months]. Journal SIGAPS categories were A for 4 articles (13.3%), B for 13 (43.3%), C for 3 (10%), D for 9 (30%), with no E category articles but 1 article (3.3%) without SIGAPS category. CONCLUSION: The publication rate for abstracts accepted for report to the 2014 SFA annual meeting was lower than for the 2013 SoFCOT meeting. The high level of the journals in question testified to the quality of the studies reported at the SFA meeting. LEVEL OF EVIDENCE: IV, retrospective study.

Virtual reality simulator improves the acquisition of basic arthroscopy skills in first-year orthopedic surgery residents.

INTRODUCTION: Arthroscopy training using a virtual reality (VR) simulator is said to improve the training of orthopedic surgery residents, although it has never been evaluated in a large representative population of first-year residents. HYPOTHESIS: We hypothesized that first-year residents who train on a VR simulator would improve their basic arthroscopy skills more than residents who use other training methods. The primary aim was to compare various arthroscopy-learning techniques after 6 months of training. POPULATION AND METHODS: The study population consisted of 107 first-year residents who were tested twice on a VR arthroscopy simulator (December 2017 and June 2018). The residents were divided into three groups: no specific arthroscopy training (A), non-specific and one-off arthroscopy training (B), 6 months of VR arthroscopy simulator training (C). During the testing, they had to perform the Periscoping exercise (orientation of angled scope) and the Catch the Stars Glenohumeral exercise (extraction of loose bodies). The parameters analyzed were time (s), camera alignment relative to horizontal (%), camera path length (cm) and grasper path length (cm). RESULTS: After 6 months, there was a significant difference between groups during the Periscoping exercise in the time (A: 137.8 s; B: 126.7 s; C: 92.2 s) (p<0.0001), camera alignment (A: 93%; B: 98%; C: 97%) (p=0.0028), camera path length (A: 116.9cm; B: 112.5cm; C: 67.3cm) (p<0.0001) and during the Catch the Stars Glenohumeral exercise in the time (A: 112.2 s; B: 103 s; C: 61.4 s) (p<0.0001), camera path length (A: 46.3cm; B: 40.9cm; C: 32.9cm) (p<0.0153) and grasper path length (A: 146.4cm; B: 142.2cm; C: 95.8cm) (p<0.0001). DISCUSSION: The residents who participated in the VR arthroscopy simulator training program for 6 months had better results when performing practical exercises and standard arthroscopy tasks than those who did not receive any training or only received only one-off training. Their final performance indicated technical mastery that the other residents had not achieved. LEVEL OF EVIDENCE: II, Prospective, comparative, non-randomized study.

Extraction of total knee arthroplasty intramedullary stem extensions.

Intramedullary stem extensions will need to be extracted during total knee arthroplasty (TKA) revisions, especially repeated ones. These stems have various designs and lengths, can be straight or offset, cemented (partially or totally) or cementless, smooth or rough. This diversity adds to the difficult of extracting them, which the surgeon must anticipate before starting the revision procedure. Porous metaphyseal metal components (cones, sleeves) are being used increasingly during revision TKA. They pose specific extraction challenges and complicate the extraction of the stems with which they are often associated. The maneuvers used during extraction have a direct impact on the subsequent joint reconstruction methods. These procedures are always long and difficult, with an increased risk of bone-related complications (perforation, fracture) or infection. They must always be carried out at specialized centers by experienced surgeons. The reasons for re-revision are the same as those for TKA revision, mainly aseptic loosening, instability and infection-only the latter requires that all components be removed. The local conditions are often unfavorable: epiphyseal-metaphyseal bone defect, thin cortices, osteoporosis, and in some cases, stiffness. The type of implant to extract and its characteristics must be identified beforehand in case special instruments are needed. An imaging workup is done to specify the relationship of the stem with bone, quality of its fixation, bone lesions and gaps between stem and bone, knowing that extraction is harder when the gaps are smaller. A combination of extended radiolucent lines, purely metaphyseal fixation, and a thin smooth stem may mean that intramedullary extraction is feasible. The extensor mechanism must be released to achieve sufficient exposure. If a tibial tubercle osteotomy is needed, it must be sized to match the extraction. After disassembly of femoral and tibial components-which can be challenging-the epiphyseal components must be released. High performance instruments for cement extraction and metal cutting are essential. Other than simple cases (loosened or partially fixed implants), intramedullary extraction can be dangerous especially when the stem extension is well-fixed, whether cemented or not. A diaphyseal window may be sufficient, but in most cases, an extended osteotomy is needed. This includes detaching the tibial tubercle at the tibia. At the femur, this may require an anterior midline window, an anterior extended ostéotomy or an anterolateral oblique distal femoral osteotomy with fibrous hinge. The extraction of metaphyseal porous components is difficult. Their connection with the bone must be broken - which can be long and risky - before the associated stem is removed. While it is easier to extract when the stem can be removed first, it is not always feasible. Reconstruction depends intimately on the methods used to extract the existing implants. Any diaphyseal discontinuity must be bridged (long stem or plate). The extent of the resulting bone defect after extraction drives the revision methods, which are simplified by using porous metaphyseal metal components and shorter stems when possible.

Does performing outpatient total hip arthroplasty contribute to early complications and readmissions? Retrospective case-control study of 50 patients.

INTRODUCTION: Advances in anesthesia and surgical practices have allowed total hip arthroplasty to be performed as an outpatient procedure. The aim of this study was to demonstrate its feasibility in a selected population compared to a group of inpatients by analyzing the cumulative length of hospital stay, complications and readmissions. PATIENTS AND METHODS: This was a retrospective, single-surgeon study of continuous adult patients between October 2016 and May 2018 who underwent primary total hip arthroplasty (THA) and were eligible to undergo this procedure either as an inpatient or outpatient based on their health and comprehension level. Two groups of patients were set up. The outpatient group was given a preoperative treatment education session. The same anesthesia protocol and surgical technique was used in both groups. RESULTS: Fifty outpatients were compared to 77 inpatients. In the outpatient group, the patients were significantly younger, had a greater walking distance and were predominantly male. The two groups were comparable in terms of functional and medical criteria. The mean cumulative hospital stay was 1.2days in the outpatient group with one discharge failure because of nausea and vomiting, versus 5.1days in the inpatient group (p<0.0001). There were three complications in each group (p=1.00). There were three readmissions in the outpatient group and four in the inpatient group (p=1.00) that were of similar length (p=0.86). There was no difference in the mean number of additional office visits over this period between the two groups. CONCLUSION: Outpatient THA procedures can be done reliably and safely in France in a carefully selected population without increasing the complication rate or readmission rate. Expanding this practice requires implementing specific anesthesia and surgery protocols, along with close perioperative monitoring to help manage risk. LEVEL OF EVIDENCE: IV (retrospective cohort study).

Have the frequency of and reasons for revision total knee arthroplasty changed since 2000? Comparison of two cohorts from the same hospital: 255 cases (2013-2016) and 68 cases (1991-1998).

INTRODUCTION: The number of total knee arthroplasty (TKA) revisions is expected to increase 601% in the United States between 2005 and 2030. This type of information is not available in France, and the last national study on this topic was done in 2000. This led us to perform a comparative study to determine if 1) the frequency of TKA revisions has increased and 2) the reasons for reoperation have changed relative to data gathered in 2000 at a single hospital in France. HYPOTHESIS: The frequency of TKA revision has increased between the two studies, performed 15 years apart. MATERIAL AND METHODS: In this retrospective observational single-center study (January 2013 to December 2016), all patients with a TKA who were reoperated with or without any component change were included. This cohort was compared to our historical cohort defined in 2000 of 68 TKA reoperations between January 1991 and January 1998. The reasons for revision were determined by consulting computerized patient records to find the disease history, clinical examinations, imaging findings, laboratory tests and the surgery report. Cases due to periprosthetic fractures, infection and skin-related complications were excluded in order to be consistent with the indications of the historical cohort. RESULTS: Between 2013 and 2016, 349 TKA revisions were performed, and 255 met the inclusion criteria. Note that the historical cohort had 68 cases. The mean time elapsed between the primary TKA and revision procedure was 5.3 years [34 days to 31 years]. Eight reasons for reoperation were identified. Aseptic loosening (85 cases (33.3%)), stiffness (70 cases (27.5%)), tibiofemoral laxity (39 cases (15.3%)) and patellar complications (34 cases (13.3%)) were the four most common reasons for reoperation. The frequency has changed over time: relative to 2000, the annual frequency increased by a factor of 6.5. The reasons have also changed over time: there was an increase in revisions for aseptic loosening (33.3% vs. 23.5%), stiffness (27.5% vs. 20.6%) and knee joint laxity (15.3% vs. 10.3%). Conversely, there was a reduction in revisions for patellar complications (13.3% vs. 26.5%), unexplained pain (0.4% vs. 8.8%) and patellar clunk syndrome (1.2% vs. 4.4%). DISCUSSION: The number of TKA revisions has increased by a factor of 6.5, with aseptic loosening still being the most common reason. The number of revisions performed for stiffness and knee joint laxity have increased. Fewer revisions are being done for unexplained pain because surgeons are now better able to determine the cause of TKA-related pain. There were fewer patella-related complications because of technical progress. The data generated from our single-center study are consistent with current published data. LEVEL OF EVIDENCE: II, comparative study.

Acetabular reconstruction using porous metallic material in complex revision total hip arthroplasty: A systematic review.

Bone defects during acetabular revision of total hip arthroplasty raise a problem of primary fixation and of durable reconstruction. Bone graft with direct cemented fixation or in a reinforcement cage was long considered to be the gold standard; however, failures were reported after 10 years' follow-up, especially in segmental defect of the roof or pelvic discontinuity. In such cases, metallic materials were proposed, to ensure primary fixation by a roughness effect with added screws, and especially to avoid failure due to bone resorption in the medium term. We report a systematic literature analysis, addressing the following questions: (1) What materials are available and can be used with dual mobility (DM) designs? Apart from Trabecular Metal™ (TM), in which a DM cup can be cemented for sizes≥56mm, 4 other porous metals are available (Tritanium™, Trabecular Titanium™, Conceloc™, Regenerex™ and Gription™) although only the first 3 can be associated to DM. (2) Can the cost of these materials be estimated and compared to allograft with reinforcement cage? Considering simply the cost of the implant itself, compared to reconstruction by graft+cage+cemented cup (€2100), TM incurs an extra cost of €534, but with €1434 not covered by the French healthcare insurance. The cost of custom implants (apart from hemi-pelvis) ranges between €4200 and €8500, with only €4749 cover. (3) Do metallic materials ensure better survival than allograft+cage, according to severity of bone loss? Metallic reconstruction is claimed (with a low level of evidence) to reduce the risk of iterative loosening, but with a higher rate of dislocation, probably due to the lack of DM in many series. (4) What are the advantages and drawbacks of modular and custom metallic reconstructions? Modular reconstructions do not require 3D preoperative planning, but incur the risks of complications inherent to modularity. Custom implants can deal with more extensive defects, but require 5 to 8 weeks' production and are difficult to implant for the larger ones and/or when revision is limited to the acetabulum. (5) In what indications are these materials irreplaceable? Prior failure of allograft+cage in Paprosky type III defect with or without pelvic discontinuity shows the greatest benefit from metallic reconstruction, conditional on certain technical tricks. Only reconstructions using TM have more than 10 years' follow-up; other materials will need close monitoring. Failures in allograft with reinforcement cages occurred after about 10 years, and TM will need longer follow-up to prove its effectiveness. The high risk of dislocation should enable DM to be used, especially for small-diameter metallic reconstructions.

New diagnostic tools for prosthetic joint infection.

The diagnosis of peri-prosthetic bone and joint infections relies on converging information from clinical, laboratory and imaging assessments. Clinical findings alone may suffice: a sinus tract is a major criterion that establishes the diagnosis of infection. Identifying the causative organism is crucial and requires the early collection of high-quality samples from sites in contact with the prosthetic material. The bacteriological samples may be obtained by aspiration or open surgery. Imaging techniques have undergone remarkable improvements over the last two decades. Ultrasonography can be performed early and can be used to guide a needle biopsy if appropriate. Computed tomography or magnetic resonance imaging shows the extent of bone and/or soft-tissue involvement, provided effective artefact-suppression techniques are applied. Nuclear medicine methods have an undefined place in the diagnostic strategy and their possible role must be evaluated during a multidisciplinary discussion. The array of new laboratory methods introduced in recent years includes microbiological culture techniques, molecular biology tests, antigen and antibody assays and tests for immune markers in blood and/or joint fluid. When the first-line investigations fail to provide a definitive diagnosis, a multidisciplinary discussion at a referral centre for complex osteo-articular infections makes a major contribution to defining the subsequent diagnostic strategy. This lecture focusses on the following six questions: does the clinical assessment still have diagnostic relevance? What is the diagnostic contribution of imaging studies? Must the infection be documented pre-operatively and if so, how? Which microbiological techniques should be used? Which non-microbiological investigations help to diagnosis peri-prosthetic bone and joint infections? What role do referral centres for complex bone and joint infections play in the diagnostic strategy?

Are spinoglenoid ganglion cysts early markers of glenohumeral arthritis?

HYPOTHESIS: The objective of this study was to improve our understanding of the pathogenesis and symptoms of ganglion cysts (GCs) in the spinoglenoid notch. Two hypotheses were tested: (1) the labral tears responsible for these cysts are mainly degenerative and nontraumatic, (2) spinoglenoid cysts are early magnetic resonance image (MRI) markers of eccentric posterior glenoid wear. MATERIALS AND METHODS: This was a descriptive diagnostic study. Patients were included when a spinoglenoid cyst was discovered after complaints of pain in the posterosuperior aspect of the shoulder. MRI and arthroscopy were used to classify the glenoid GC and characterize the glenohumeral joint. The GCs were classified into 1 of 3 types: GC0 (isolated cyst), GC1 (cyst and associated labral lesion), and GC2 (cyst and associated labral and cartilage lesion). RESULTS: Twenty patients (average age, 43 years) were included between 2000 and 2014. There were 7 GC0, 8 GC1, and 5 GC2 type cysts. Isolated labral tears (GC1) were always located posteriorly, without anterior extension or glenoid detachment. The humeral subluxation index was above 55% in 75% of shoulders, including all of the type GC2 shoulders. The 5 GC2 shoulders had type B1, B2, or C glenoids. CONCLUSIONS: The management of paraglenoid labral cysts must go beyond addressing the suprascapular nerve compression related to traumatic labral detachment, and surgeons should look automatically for associated degenerative joint damage. The diagnosis of GCs should be supplemented by humeral subluxation index measurement on computed tomography scan or MRI, and the patient should be informed that joint-related posterior shoulder pain might persist in cases of GC1 and GC2. LEVEL OF EVIDENCE: Basic Science Study; Anatomy; Imaging and In Vivo.