Impact of Medical Education in Middle School, Directed by a Science Teacher and a Healthcare Professional, on Self-Medication and Care System Literacy. A Comparative Prospective Cohort Study.

Objectives:To assess the immediate and six-month follow-up effects of medical education simultaneously provided by a practitioner and a science teacher on middle school students regarding self-medication and knowledge of the healthcare system. Methods:Two groups were constituted: the learning group (L group), with students receiving an interactive medical education, and the control group (C group), which included students without medical education. Both groups were evaluated by using a six-multiple choice question (MCQ) evaluation form: three times for L group - just before the medical workshop (T0), immediately after the medical workshop (T1) and at six-month follow-up after the medical workshop (T2) - and only the evaluation at T0 for students in C group. Results:In L group (n=219), medical education improved all results of the evaluations related to self-medication skills (p<0.001) and knowledge of the healthcare medical system (p<0.001). Students retained their knowledge over time as no significant gap has been identified between T1 and T2 evaluations. Age, gender, grade and students' level did not have any impact on the results of L group. Students in L group had equivalent results to those in the C group (n=195) at T0 but the results increased at T1 (p<0.001) and T2 (p<0.001). Conclusion:Interactive medical education in middle school co-animated by a medical practitioner and a natural science teacher improves long-term teenagers' awareness of the current public health challenges.

3-D finite element model of the impaction of a press-fitted femoral stem under various biomechanical environments.

BACKGROUND: Uncemented femoral stem insertion into the bone is achieved by applying successive impacts on an inserter tool called "ancillary". Impact analysis has shown to be a promising technique to monitor the implant insertion and to improve its primary stability. METHOD: This study aims to provide a better understanding of the dynamic phenomena occurring between the hammer, the ancillary, the implant and the bone during femoral stem insertion, to validate the use of impact analyses for implant insertion monitoring. A dynamic 3-D finite element model of the femoral stem insertion via an impaction protocol is proposed. The influence of the trabecular bone Young's modulus (Et), the interference fit (IF), the friction coefficient at the bone-implant interface (µ) and the impact velocity (v0) on the implant insertion and on the impact force signal is evaluated. RESULTS: For all configurations, a decrease of the time difference between the two first peaks of the impact force signal is observed throughout the femoral stem insertion, up to a threshold value of 0.23 ms. The number of impacts required to reach this value depends on Et, v0 and IF and varies between 3 and 8 for the set of parameters considered herein. The bone-implant contact ratio reached after ten impacts varies between 60% and 98%, increases as a function of v0 and decreases as a function of IF, µ and Et. CONCLUSION: This study confirms the potential of an impact analyses-based method to monitor implant insertion and to retrieve bone-implant contact properties.

The comparative efficacy of nerve transfer versus tendon transfer in the management of radial palsy: A systematic review and meta-analysis.

Background: There is no clear census as to which operative technique provides better recovery for radial nerve injuries. Therefore, in this systematic review, we examined the functional recovery, patient-reported outcomes, and complications of tendon transfer (TT) and nerve transfer (NT). Methods: Five electronic databases were searched for studies (>10 cases per study) comparing NT and TT regardless of the study design (observational or experimental). Manual search was also conducted. The quality was assessed by the NIH tool. Outcomes included functional recovery, patient-reported outcomes (DASH score, satisfaction, and inability to return to work), and complications. The prevalence was pooled across studies using STATA software, and then, a subgroup analysis based on the intervention type. Results: Twenty-one studies (542 patients) were analyzed. Excellent recovery, assessed by the Bincaz scale, was higher in the TT group (29 % vs. 11 %) as well as failure to extend the fingers (49 % vs. 9 %). No significant difference was noted between both groups regarding DASH score (mean difference = -2.76; 95 % CI: -12.66: 6.93). Satisfaction was great in the TT group (89 %) with a limited proportion of patients unable to return to work (7 %). Complications were slightly higher in the TT group (8 % vs. 7 %) while 18 % of patients undergoing TT requiring revision surgery. Radial deviation was encountered in 18 % of patients in the TT group and 0 % in the NT group. The quality was good, fair, and poor in 2, 13, and 6, respectively. Conclusions: In radial nerve injuries, although tendon transfer may seem to provide better functional motor recovery than nerve transfer, it is associated with a higher rate of failure to extend the finger. Given the large confidence interval, the accuracy of this finding is questioned. However, a great proportion of those patients require revision surgery afterward. Additionally, tendon transfer is associated with a greater complication rate than nerve transfer, particularly radial deviation.

Sagittal correction after short percutaneous fixation for thoracolumbar compression fractures: comparison of the combination of SpineJack® kyphoplasty and fractured vertebra screw fixation.

PURPOSE: The aim of this study was to compare two percutaneous pedicle fixations for the treatment of thoracolumbar fractures: one associating a jack kyphoplasty (SpineCut) and the other using intermediate screws (Trident). METHODS: All adult patients treated for single-level Magerl/AO type A thoracolumbar traumatic fractures in four orthopaedic departments, with SpineCut or Trident, with a one year minimum follow-up, were retrospectively included. Neurological disorders and osteoporotic fractures were not included. The following data were collected: age, sex, Magerl/AO type, type of surgery, and complications. Radiological parameters were analyzed on pre-operative CT scan, and on standing X-rays before discharge, at three months and one year post-operative: vertebral wedge angle (VWA), regional kyphosis angle (RKA), and traumatic regional angulation (TRA: difference between RKA and physiological values for each vertebra). RESULTS: Eighty patients were included, with 42 patients in SpineCut group and 38 in Trident group. Mean age was 41 ± 15.7 years. TRA correction did not differ between the groups: respectively 11.2 ± 8.1° in SpineCut versus 10.2 ± 9.1° in Trident group (p = 0.52). TRA loss of correction between early post-operative and three months was statistically higher in Trident group: -4 ± 5.1° versus -1.5 ± 3.8° (p = 0.03). After 3 months, TRA correction loss was comparable between the groups. Multivariate analysis demonstrated that pre-operative VWA was the only factor significantly associated with early TRA correction loss (p = 0.01). VWA correction and loss of correction did not differ significantly between the groups. No complications were observed. CONCLUSION: Percutaneous pedicle fixations of traumatic thoracolumbar fractures associating jack kyphoplasty and intermediate screws are both safe and efficient techniques.

Early injection of autologous bone marrow concentrates decreases infection risk and improves healing of acute severe open tibial fractures.

INTRODUCTION: Open fractures are at risk of nonunion; surgeons are reluctant to propose early standard bone grafting after open fractures, preferring to wait in order to adequately assess the facture status of infection. Bone marrow contains mesenchymal stem cells (MSCs) and granulocyte and macrophage precursors identified in vitro as colony forming units-granulocyte macrophage (CFU-GM), both of which have a prophylactic action against infection. We therefore tested the hypothesis that early injection of bone marrow concentrate would be useful in these fractures. METHODS: We evaluated a series of 231 patients who had received early percutaneous implantation of bone marrow concentrate (BMC) to treat open fractures (with gap less than 10 mm) that were Gustilo-Anderson Type II or III. The results were compared with those of 67 control (no early graft) patients and with those of 76 patients treated with an early, standard of care, iliac bone graft. All patients were treated with external fixation and were considered to have an aseptic fracture at the time of early grafting, but the actual status of infection was re-assessed at the time of grafting by histology and/or analysis of the aspirate. The bone marrow graft contained after concentration 49,758 ±â€¯21,642 CFU-GM-derived colonies/cc and 9400 ±â€¯1435 MSCs/cc which represents an important increase compared to the level of CFU-GM cells and MSCs present in a standard auto-graft. Healing was evaluated at 9 months. RESULTS: The rate of unsuspected infections was higher than 15% in the 3 groups. Bone union and removal of external fixation was achieved at 9 months by 50.7% of patients in the Control Group, by 86.8% of patients in the group with a standard bone graft, and by 87.4% of patients in the bone marrow group. A 90% risk reduction (p = 0.005) in the need for an invasive standard bone graft to treat a nonunion and in the risk of infection was observed when bone marrow was proposed as early injection to the treatment of type II or type-III tibial fractures. CONCLUSION: Bone marrow concentrate for early grafting in open fractures with limited gap was efficient for healing while decreasing infection.

Spinal metastases from thyroid cancer: Some prognostic factors.

BACKGROUND: Spinal metastases (SpMs) from thyroid cancers (TC) significantly reduce quality of life by causing pain, neurological deficits in addition to increasing mortality. Moreover, prognosis factors including surgery remain debated. METHODS: Data were stored in a prospective French national multicenter database of patients treated for SpM between January 2014 and 2017. Fifty-one consecutive patients affected by TC with 173 secondary SpM were included. RESULTS: Mean overall survival (OS) time for all patients from the diagnosis of a thyroid SpM event was 9.1 years (SD 8.7 months). The 1-year, 5-year and 10-year survival estimates were 94% (SD 3.3), 83.8.0% (SD 5.2), and 74.5% (SD 9.9). The median period of time between primary thyroid tumor diagnosis and the SpM event was 31.4 months (SD 71.6). In univariate analysis, good ECOG-PS (status 0 and 1) (p < 0.0001), ambulatory status (Frankel score) (p < 0.0001) and no epidural involvement (p = 0.01), were associated with longer survival, whereas cancer subtype (p = 0.436) and spine surgery showed no association (p = 0.937). Cox multivariate proportional hazard model only identified good ECOG-PS: 0 [HR: 0.3, 95% CI 0.1-0.941; p < 0.0001], 1 [HR: 0.8, 95% CI 0.04-2.124; p = 0.001] and ambulatory neurological status: Frankel E [HR: 0.262, 95% CI 0.048-1.443; p = 0.02] to be independent predictors of better survival. CONCLUSION: For cases presenting SpM from TC, we highlighted that the only prognostic factors were the progression of the cancer (ECOG-PS) and the clinical neurological impact of the SpM (Frankel status). Surgery should be discussed mainly for stabilization and neurological decompression.

Surgical Treatment of a Symptomatic Diaphyseal Tibiofibular Synostosis in a Professional Rugby Player: A Case Report and Literature Review.

CONTEXT: Diaphyseal tibiofibular synostosis (DTS) is a rare pathology with unknown origin especially occurring in intensive sport athletes. No therapeutic guideline has been well established in the literature. CASE PRESENTATION: A rare case of DTS in a 26-year-old professional rugby player has been described. A 5-month exhaustive conservative treatment including physiotherapy and oral medication has been achieved but failed. Management and Outcomes: Following the conservative treatment failure, the DTS has been widely removed including the adjacent interosseous membrane, and the patient could return to competition at the same level after 5 months of convalescence. No recurrence has been revealed at a 35-month follow-up at least. CONCLUSION: In accordance with the literature data and even if the pathophysiology remains obscure, resection of DTS seems to be the adapted treatment to allow and to reduce professional athletes' recovery time at the same sport level. The resection including a part of the tibiofibular interosseous membrane could avoid the occurrence of recurrence. Conservative treatment should be reserved for senior patients with a low sport activity.

Long-Term Results of Anterior-Only Lumbar Interbody Fusions in Rheumatoid Arthritis Patients: Comparative Retrospective Cohort Study.

OBJECTIVE: Rheumatoid arthritis (RA) is a risk factor of lumbar spine surgical failure. The interest of anterior lumbar fusion in this context remains unknown. This retrospective study aimed to compare the outcome of anterior-only fusions between RA patients and non-RA (NRA) patients to treat lumbar spine degenerative disorders. METHODS: NRA and RA groups including anterior-only fusion were compared. Clinical data (Visual Analog Scale score axial back pain scale, the Oswestry Disability Index, and a questionnaire of satisfaction regarding the surgical result); radiologic data (bone fusion, sagittal balance analysis); and adverse events were assessed using repeated measure 1-way analysis of variance. RESULTS: The mean follow-up was 9.5 years (95% confidence interval [7.1-12.2]) for the RA group (n = 13) and 9.4 years (95% confidence interval [8.7-10.3]) for the NRA group (n = 36). Anterior fusion improved clinical outcome without any effect of RA (Visual Analog Scale score axial back pain scale; P < 0.001/Oswestry Disability Index; P = 0.01). The presence of RA influenced neither the satisfaction as the regards the surgical result nor spine balance nor bone fusion. Context of RA increased the surgical revision rate (10 patients [76.9%] for RA group vs. 3 patients [8.8%] for the NRA group; P = 0.001) because of the occurrence of an adjacent segment disease needing surgical revision (P = 0.028), especially the occurrence of intervertebral frontal dislocation (P = 0.02). CONCLUSIONS: As noticed for posterior-only fusion, the anterior lumbar approach in RA patients does not seem to avoid the occurrence of an adjacent segment disease.

Are spine metastasis survival scoring systems outdated and do they underestimate life expectancy? Caution in surgical recommendation guidance.

OBJECTIVE: Survival scoring systems for spine metastasis (SPM) were designed to help surgical practice. The authors sought to validate the prognostic accuracy of the main preoperative scoring systems for SPM. METHODS: It was hypothesized that true patient survival in SPM was better than that predicted using prognosis scores. To investigate this hypothesis, the authors designed a French national retrospective study of a prospectively collected multicenter database involving 739 patients treated for SPM between 2014 and 2017. RESULTS: In this series, the median survival time for all patients from an SPM diagnosis was 17.03 ± 1.5 months. Sensitivity and specificity were estimated using the area under the curve (AUC). The AUC of Tomita's prognosis score was the lowest and poorest (0.4 ± 0.023, range 0.35-0.44), whereas the AUC of the Tokuhashi score was the highest (0.825). The Lei score presented an AUC of 0.686 ± 0.022 (range 0.64-0.7), and the Rades score showed a weaker AUC (0.583 ± 0.020, range 0.54-0.63). Differences among AUCs were all statistically significant (p < 0.001). The modified Bauer score and the Rades score had the highest rate of agreement in predicting survival, with a weighted Cohen's kappa of 0.54 and 0.41, respectively, indicating a moderate agreement. The revised Tokuhashi and Lei scores had a fair rate of agreement (weighted Cohen's kappa = 0.24 and 0.22, respectively). The van der Linden and Tomita scores demonstrated the worst performance, with only a "slight" rate of agreement (weighted Cohen's kappa = 0.19 and 0.16, respectively) between what was predicted and the actual survival. CONCLUSIONS: The use of prognostic scoring systems in the estimation of survival in patients with SPM has become obsolete and therefore underestimates survival. Surgical treatment decisions should no longer be based on survival estimations alone but must also take into account patient symptoms, spinal instability, and quality of life.

Determinants of the primary stability of cementless acetabular cup implants: A 3D finite element study.

Primary stability of cementless implants is crucial for the surgical success and long-term stability. However, primary stability is difficult to quantify in vivo and the biomechanical phenomena occurring during the press-fit insertion of an acetabular cup (AC) implant are still poorly understood. The aim of this study is to investigate the influence of the cortical and trabecular bone Young's moduli Ec and Et, the interference fit IF and the sliding friction coefficient of the bone-implant interface µ on the primary stability of an AC implant. For each parameter combination, the insertion of the AC implant into the hip cavity and consequent pull-out are simulated with a 3D finite element model of a human hemi-pelvis. The primary stability is assessed by determining the polar gap and the maximum pull-out force. The polar gap increases along with all considered parameters. The pull-out force shows a continuous increase with Ec and Et and a non-linear variation as a function of µ and IF is obtained. For µ > 0.6 and IF > 1.4 mm the primary stability decreases, and a combination of smaller µ and IF lead to a better fixation. Based on the patient's bone stiffness, optimal combinations of µ and IF can be identified. The results are in good qualitative agreement with previous studies and provide a better understanding of the determinants of the AC implant primary stability. They suggest a guideline for the optimal choice of implant surface roughness and IF based on the patient's bone quality.

Ankle osteonecrosis in fifty-one children and adolescent's leukemia survivors: a prospective randomized study on percutaneous mesenchymal stem cells treatment.

PURPOSE: Corticoid treatment associated with haematologic treatments can lead to ankle osteonecrosis in children's survivors of acute leukemia (ALL). Based on the efficiency of mesenchymal stem cells (MSCs) in hip osteonecrosis, we performed an evaluation of this treatment in 51 children and adolescents who had symptomatic ankle osteonecrosis after therapy for haematologic cancer. MATERIAL AND METHODS: The 51 patients had a total of 79 osteonecrosis sites on MRI, with 29 talus sites, 18 metaphyseal tibia sites, 12 epiphyseal tibia sites, eight calcaneus sites, six fibula sites, four navicular sites, and two cuboid sites. In this prospective randomized trial, 37 ankles were addressed for cell therapy, 37 others for core decompression alone, and 20 were considered as a control group without treatment. We analyzed the outcome of this treatment osteonecrosis, the number and characteristics of bone marrow mesenchymal cells (MSCs) that could be transplanted, and the risks of tumorigenesis in these patients with haematologic cancers. The patients were operated on over a period of ten years from 2000 to 2010 and were monitored through December 31, 2019. RESULTS: Despite a normal systemic blood cells count, MSCs in the iliac crest (counted as CFU-F) were in low number (1021 MSCs/mL; range 314-3015) and were of host origin after even allogeneic bone marrow transplantation. Better clinical outcomes (pain, foot and ankle deformity) and osteonecrosis repair on MRI with absence of collapse were obtained in ankles that received cell therapy as compared with those with core decompression alone or those without initial surgery. No tumour was found on MRI at the sites of injection and this study found no increased risk of recurrence or of new cancer in this population after an average follow-up of 15 years. CONCLUSIONS: These results suggest that autologous MSCs can improve the quality of life of leukemia survivors with ankle osteonecrosis.

Spine Metastasis in Elderly: Encouraging Results for Better Survival.

MINI: The incidence of spinal metastasis (SpM) is increasing, and life expectancy for patients with malignancy is also rising. The "elderly" represent a population with steady growth in SpM proportion. Bracing is associated with lower survival. We believe that surgery should be considered, regardless of the patient's age.

Multicentric prospective study. Through this study, we aimed to clarify and update the prognostic assessment of elderly with spine metastasis (SpM). The incidence SpM is rising, in parallel life expectancy is getting longer and the number of elderly patients presenting malignancy is increasing. Elderly patients with SpM constitute a growing heterogeneous population The patient data used in this study were obtained from a French national multicenter database of patients treated for SpM between 2014 and 2017. Two hundred and forty-three consecutive patients >70 years' old were diagnosed. Median overall survival (OS) time for elderly patients following the event of SpM was 16.3 months. First, we identified significantly worse survival prognostic factors for elderly patients with SpM: poor WHO status 3/4: (hazard ratio [HR]: 2.245, 95% confidence interval [CI] 1.899­2.655; P  < 0.0001), >80 years (HR: 1.758, 95% CI 1.117­2.765; P  = 0.015) no-ambulatory neurological status (Franckel A/B status [HR: 3.219, 95% CI 1.621­6.390; P  < 0.0001)], gastrointestinal cancer (HR: 3.530, 95% CI 1.75­7.1; P  < 0.0001), lung cancer (HR: 3.452, 95% CI 1.784­6.680; P  < 0.0001), orthopedic brace treatment (HR: 1.329; 95% CI 1.050­1.683; P  = 0.018), and epiduritis (HR: 1.52, 95% CI 1.041­2.22; P  = 0.03) were independently poor prognostic factors of survival. The only good prognosis factor identified was thyroid cancer (HR: 0.257, 95% CI 0.07­0.952; P  = 0.04). Prognosis factors concerning the survival of elderly patients seem to be the same as those for the general population such as primary cancer histology, neurological status, WHO status, and epiduritis. Age >80 years also appears to be an independently poor prognosis factor. Our data suggest that orthopedic brace treatment is also associated with lower survival. Level of Evidence: 2.

Spine metastasis in patients with prostate cancer: Survival prognosis assessment.

BACKGROUND: Patients presenting spine metastasis (SpM) from prostate cancer (PC) form a heterogeneous population, through this study, we aimed to clarify and update their prognostic assessment. METHODS: The patient data used in this study was obtained from a French national multicenter database of patients treated for PC with SpM between 2014 and 2017. A total of 72 patients and 365 SpM cases were diagnosed. RESULTS: The median overall survival time for all patients following the event of SpM was 28.8 months. First, we identified three significant survival prognostic factors of PC patients with SpM: good Eastern Cooperative Oncology Group/World Health Organization personnel status (Status 0 hazard ratio [HR]: 0.031, 95% confidence interval [CI]: 0.008-0.127; p < .0001) or (Status 1 HR: 0.163, 95% CI: 0.068-0.393; p < .0001) and SpM radiotherapy (HR: 2.923, 95% CI: 1.059-8.069; p < .0001). Secondly, the presence of osteolytic lesions of the spine (vs. osteoblastic) was found to represent an independent prognosis factor for longer survival [HR: 0.424, 95% CI: 0.216-0.830; p = .01]. Other factors including the number of SpM, surgery, extraspinal metastasis, synchrone metastasis, metastasis-free survival, and SpM recurrence were not identified as being prognostically relevant to the survival of patients with PC. CONCLUSION: Survival and our ability to estimate it in patients presenting PC with SpM have improved significantly. Therefore, we advocate the relevance of updating SpM prognostic scoring algorithms by incorporating data regarding the timeline of PC as well as the presence of osteolytic SpM to conceive treatments that are adapted to each patient.

Subchondral bone or intra-articular injection of bone marrow concentrate mesenchymal stem cells in bilateral knee osteoarthritis: what better postpone knee arthroplasty at fifteen years? A randomized study.

PURPOSE: There is an increasing number of reports on the treatment of knee osteoarthritis (OA) using mesenchymal stem cells (MSCs). However, it is not known what would better drive osteoarthritis stabilization to postpone total knee arthroplasty (TKA): targeting the synovial fluid by injection or targeting on the subchondral bone with MSCs implantation. METHODS: A prospective randomized controlled clinical trial was carried out between 2000 and 2005 in 120 knees of 60 patients with painful bilateral knee osteoarthritis with a similar osteoarthritis grade. During the same anaesthesia, a bone marrow concentrate of 40 mL containing an average 5727 MSCs/mL (range 2740 to 7540) was divided in two equal parts: after randomization, one part (20 mL) was delivered to the subchondral bone of femur and tibia of one knee (subchondral group) and the other part was injected in the joint for the contralateral knee (intra-articular group). MSCs were counted as CFU-F (colony fibroblastic unit forming). Clinical outcomes of the patient (Knee Society score) were obtained along with radiological imaging outcomes (including MRIs) at two year follow-up. Subsequent revision surgeries were identified until the most recent follow-up (average of 15 years, range 13 to 18 years). RESULTS: At two year follow-up, clinical and imaging (MRI) improvement was higher on the side that received cells in the subchondral bone. At the most recent follow-up (15 years), among the 60 knees treated with subchondral cell therapy, the yearly arthroplasty incidence was 1.3% per knee-year; for the 60 knees with intra-articular cell therapy, the yearly arthroplasty incidence was higher (p = 0.01) with an incidence of 4.6% per knee-year. For the side with subchondral cell therapy, 12 (20%) of 60 knees underwent TKA, while 42 (70%) of 60 knees underwent TKA on the side with intra-articular cell therapy. Among the 18 patients who had no subsequent surgery on both sides, all preferred the knee with subchondral cell therapy. CONCLUSIONS: Implantation of MSCs in the subchondral bone of an osteoarthritic knee is more effective to postpone TKA than injection of the same intra-articular dose in the contralateral knee with the same grade of osteoarthritis.

Total hip arthroplasty for sickle cell osteonecrosis: guidelines for perioperative management.

The prognosis of sickle cell disease (SCD) has greatly improved in recent years, resulting in an increased number of patients reporting musculoskeletal complications such as osteonecrosis of the femoral head. Total hip arthroplasty (THA) can be utilized to alleviate the pain associated with this disease.Although it is well known that hip arthroplasty for avascular necrosis (AVN) in SCD may represent a challenge for the surgeon, complications are frequent, and no guidelines exist to prevent these complications. Because patients with SCD will frequently undergo THA, we thought it necessary to fulfil the need for guidance recommendations based on experience, evidence and agreement from the literature.For all these reasons this review proposes guidelines that provide clinicians with a document regarding management of patients with SCD in the period of time leading up to primary THA. The recommendations provide guidance that has been informed by the clinical expertise and experience of the authors and available literature.Although this is not a systematic review since some papers may have been published in languages other than English, our study population consisted of 5,868 patients, including 2,126 patients with SCD operated on for THA by the senior author in the same hospital during 40 years and 3,742 patients reported in the literature. Cite this article: EFORT Open Rev 2020;5:641-651. DOI: 10.1302/2058-5241.5.190073.

Ex vivo estimation of cementless femoral stem stability using an instrumented hammer.

BACKGROUND: The success of cementless hip arthroplasty depends on the primary stability of the femoral stem. It remains difficult to assess the optimal number of impacts to guarantee the femoral stem stability while avoiding bone fracture. The aim of this study is to validate a method using a hammer instrumented with a force sensor to monitor the insertion of femoral stem in bovine femoral samples. METHODS: Different cementless femoral stem were impacted into five bovine femur samples, leading to 99 configurations. Three methods were used to quantify the insertion endpoint: the impact hammer, video motion tracking and the surgeon proprioception. For each configuration, the number of impacts performed by the surgeon until he felt a correct insertion was noted Nsurg. The insertion depth E was measured through video motion tracking, and the impact number Nvid corresponding to the end of the insertion was estimated. Two indicators, noted I and D, were determined from the analysis of the time variation of the force, and the impact number Nd corresponding to a threshold reached in D variation was estimated. FINDINGS: The pullout force of the femoral stem was significantly correlated with I (R2 = 0.81). The values of Nsurg, Nvid and Nd were similar for all configurations. INTERPRETATION: The results validate the use of the impact hammer to assess the primary stability of the femoral stem and the moment when the surgeon should stop the impaction procedure for an optimal insertion, which could lead to the development of a decision support system.

Safety of simultaneous versus staged bilateral opening-wedge high tibial osteotomy with locked plate and immediate weight bearing.

PURPOSE: With advances in technology and particularly locked screws, patients with high tibial osteotomy (HTO) are frequently allowed full weight bearing for a  unilateral procedure. We are aware of no reports comparing the safety of a simultaneous bilateral HTO with staged bilateral HTO. The purpose of this study was to retrospectively compare these two strategies. MATERIAL AND METHODS: Ninety patients were treated with bilateral HTO surgery for osteoarthritis from 2009 to 2013; they had opening-wedge HTO and fixed with the same plate fixation and locked screws. A comparison of the outcomes after simultaneous bilateral HTO (35 patients) and after sequential staged bilateral HTO (55 patients) was performed. We considered four measures of medical safety: hypotension, serious intra-operative adverse event, heterologous blood transfusion, and thrombophlebitis. We considered also four measures of orthopaedic safety: infection, patient's inability to walk full weight bearing, changes in correction, and nonunion. RESULTS: For the same duration of operation, the duration of anaesthesia and the time in the operating room were 35% longer for patients having a staged bilateral HTO. Blood loss was higher in patients undergoing simultaneous bilateral HTO compared with those who underwent a staged bilateral HTO. For patients undergoing simultaneous bilateral HTO, thrombophlebitis frequency and length of anticoagulation were lower than the sum of each event in the staged bilateral HTO. The patients with simultaneous bilateral HTO had a longer total period of time for crutches than patients with staged bilateral HTO. Patients in the simultaneous bilateral cohort did not develop an infection within one year as patients in the planned-stage cohort. The simultaneous bilateral cohort had a lower rate of delayed union than the planned-stage cohort did. CONCLUSION: On the basis of this analysis, simultaneous bilateral HTO is a reasonable treatment option. Individuals who undergo staged bilateral HTO face the risk of complications twice, in addition to two hospitalizations. Patients who undergo simultaneous bilateral HTO have a higher risk of blood transfusion.

A cadaveric validation of a method based on impact analysis to monitor the femoral stem insertion.

The success of cementless hip arthroplasty depends on the primary stability of the femoral stem (FS). It remains difficult to assess the optimal impaction energy to guarantee the FS stability while avoiding bone fracture. The aim of this study is to compare the results of a method based on the use of an instrumented hammer to determine the insertion endpoint of cementless FS in a cadaveric model with two other methods using i) the surgeon proprioception and ii) video motion tracking. Different FS were impacted in nine human cadaveric femurs. For each configuration, the number of impacts realized when the surgeon felt that the FS was correctly inserted was noted Nsurg. For each impact, the insertion depth E was measured and an indicator D was determined based on the time-variation of the force. The impact number Nvid (respectively Nd), corresponding to the end of the migration phase, was estimated analyzing the evolution of E (respectively D). The respective difference between Nsurg, Nvid and Nd was similar and lower than 3 for more than 85% of the configurations. The results allow a validation of the use of an impact hammer to assess the moment when the surgeon should stop the impaction, paving the way towards the development of a decision support system to assist the surgeon.

Risk factors of instrumentation failure and pseudarthrosis after stand-alone L5-S1 anterior lumbar interbody fusion: a retrospective cohort study.

OBJECTIVE: L5-S1 stand-alone anterior lumbar interbody fusion (ALIF) is a reliable technique to treat symptomatic degenerative disc disease but remains controversial for treatment of isthmic spondylolisthesis. In the present study the authors aimed to identify risk factors of instrumentation failure and pseudarthrosis after stand-alone L5-S1 ALIF and to evaluate whether instrumentation failure influenced the rate of fusion. METHODS: The study included 64 patients (22 [34.4%] male and 42 [65.6%] female, mean age 46.4 years [range 21-65 years]) undergoing stand-alone L5-S1 ALIF using radiolucent anterior cages with Vertebridge plating fixation in each vertebral endplate. Clinical and radiographic data were reviewed, including age, sex, pelvic parameters, segmental sagittal angle (SSA), C7/sacro-femoral distance (SFD) ratio, C7 sagittal tilt, lumbar lordosis (LL), segmental LL, percentage of L5 slippage, L5-S1 disc angle, and posterior disc height ratio. Univariate and multivariate analyses were used to identify risk factors of instrumentation failure and pseudarthrosis. RESULTS: At a mean follow-up of 15.9 months (range 6.6-27.4 months), fusion had occurred in 57 patients (89.1%). Instrumentation failure was found in 12 patients (18.8%) and pseudarthrosis in 7 patients (10.9%). The following parameters influenced the occurrence of instrumentation failure: presence of isthmic spondylolisthesis (p < 0.001), spondylolisthesis grade (p < 0.001), use of an iliac crest bone autograft (p = 0.04), cage height (p = 0.03), pelvic incidence (PI) (p < 0.001), sacral slope (SS) (p < 0.001), SSA (p = 0.003), and LL (p < 0.001). Instrumentation failure was statistically linked to the occurrence of L5-S1 pseudarthrosis (p < 0.001). On multivariate analysis, no risk factors were found. CONCLUSIONS: L5-S1 isthmic spondylolisthesis and high PI seem to be risk factors for instrumentation failure in case of stand-alone L5-S1 ALIF, findings that support the necessity of adding percutaneous posterior pedicle screw instrumentation in these cases.

Vitamin D history part III: the "modern times"-new questions for orthopaedic practice: deficiency, cell therapy, osteomalacia, fractures, supplementation, infections.

PURPOSE: The nutritional basis for rickets was described between 1880 and 1915, at the same period of discovery of other "vital substances" or vitamins. In contrast, rickets could also be prevented or cured by sunshine. But as the capacity to produce vitamin D depends on exposure to ultraviolet B rays (UVB) from sunlight or artificial sources, vitamin D became one of the most frequently used "drugs" in the twentieth century to compensate for insufficient exposure to UVB of humans. Furthermore, as the understanding of vitamin D metabolism grew during the twentieth century, other concerns than rickets occurred for the orthopaedic surgeon: In recent history, deficiency is explored as being an associated factor of different bone pathologies as fracture or prosthetic infection. The aim of this review is to analyze these new data on vitamin D. MATERIALS AND METHODS: During the twentieth century, there were many concerns for the orthopaedic surgeon: sources and synthesis of vitamin D, regulation of the calcium deposition process for both children and adults, when vitamin D deficiency is observed, and what the best method of vitamin D supplementation is. As target genes regulated by vitamin D are not limited to those involved in mineral homeostasis, orthopedists recently discovered that vitamin D might prevent periprosthetic infection. RESULTS: The primary source (80%) of vitamin D is dermal synthesis related to the sun. Dietary sources (20%) of vitamin D are fat fishe, beef, liver, and eggs. Vitamin D is produced industrially to be used in fortified foods and supplements. Maintenance of skeletal calcium balance is mediated through vitamin D receptors. Progenitor cells, chondrocytes, osteoblasts, and osteoclasts contain these receptors which explains the role of vitamin D in cell therapy, in the prevention of rickets and osteomalacia. Despite fortified foods, the prevalence of deficiency remains endemic in north latitudes. However, the definition of vitamin D insufficiency or deficiency remains controversial. Vitamin D has been evaluated in patients undergoing fractures and elective orthopaedic procedures Although supplementation may not be able to prevent or cure all the orthopaedic pathologies, oral supplementation is able to improve the vitamin D levels of deficient patients. These vitamin D level improvements might be associated with better functional and clinical outcomes after some surgical procedures and improvement of immunity to decrease the risk of infection in arthroplasties. CONCLUSION: Vitamin D deficiency is frequent and concerns millions of people in the world. It is therefore normal to find hypovitaminosis in various orthopaedic populations including trauma and arthroplasties. However, we do not know exactly if this phenomenon only reflects the general prevalence of vitamin D deficiency or has an influence on the outcome of some pathologies on specific populations at risk. After the success of treatment of rickets, it is disappointing that we are still wondering in the twenty-first century whether supplementation of a substance synthetized millions of years ago by plankton and necessary for growth of all the animals may improve (or not) clinical and functional outcomes of a simple fracture in humans.