Return to football training and competition after lockdown caused by the COVID-19 pandemic: medical recommendations.

The lockdown caused by the COVID-19 pandemic represents a great unknown regarding the physiological changes induced in elite football players. Although it will differ from country to country, the return to sport for professional football players will follow a forced lockdown never experienced and longer than the normal annual season break. Moreover, in addition to an obvious decrease in performance, the lockdown will possibly lead to an increase of the injury risk. In fact, preseason is always a period with a specific football injury epidemiology, with an increase in the incidence and prevalence of overuse injuries. Therefore, it seems appropriate to recommend that specific training and injury prevention programmes be developed, with careful load monitoring. Training sessions should include specific aerobic, resistance, speed and flexibility training programmes. The aerobic, resistance and speed training should respect some specific phases based on the progressiveness of the training load and the consequent physiological adaptation response. These different phases, based on the current evidence found in the literature, are described in their practical details. Moreover, injury prevention exercises should be incorporated, especially focusing on overuse injuries such as tendon and muscle lesions. The aim of this paper is to provide practical recommendations for the preparation of training sessions for professional footballers returning to sport after the lockdown.

Medical recommendations for home-confined footballers' training during the COVID-19 pandemic: from evidence to practical application.

In early 2020, the world is facing a global emergency called COVID-19. Many professional footballers around the world are home confined. The maintenance of physical capacity is a fundamental requirement for the athlete, so the training sessions must be adapted to this unique situation. Specific recommendations must be followed concerning the type of training, its intensity, the precautions that have to be followed to avoid the possibility of contagion, and the restrictions in accordance with the presence of any symptoms. This article analyses the available scientific evidence in order to recommend a practical approach.

Implications of monocular vision for racing drivers.

We performed two experiments to investigate how monocular vision and a monocular generalized reduction in vision (MRV) impact driving performance during racing. A total of 75 visually normal students or professional racing drivers, were recruited for the two experiments. Driving performance was evaluated under three visual conditions: normal vision, simulated monocularity and simulated monocular reduction in vision. During the driving scenario, the drivers had to detect and react to the sudden intrusion of an opponent's racing car into their trajectory when entering a turn. Generalized Linear Mixed Models (GLMMs) and ANOVA were then used to explore how monocular vision and monocular reduction in vision affect drivers' performance (crash and reaction time) while confronting them with critical situations. The results show that drivers under monocular condition are from 2.1 (95% CI 1.11-4.11, p = .024) to 6.5 (95% CI 3.91-11.13; p = .0001) times more likely to collide with target vehicles compared with their baseline (binocular) condition, depending on the driving situation. Furthermore, there was an average increase in reaction time from 64 ms (p = .029) to 126 ms (p = .015) under monocular condition, depending on the critical driving situation configuration. This study objectively demonstrates that monocularity has a significant impact on driving performance and safety during car racing, whereas performance under monocular reduction in vision conditions is less affected.

Accelerated Achilles tendon healing by PDGF gene delivery with mesoporous silica nanoparticles.

We report the ability of amino- and carboxyl-modified MCM-41 mesoporous silica nanoparticles (MSN) to deliver gene in vivo in rat Achilles tendons, despite their inefficiency to transfect primary tenocytes in culture. We show that luciferase activity lasted for at least 2 weeks in tendons injected with these MSN and a plasmid DNA (pDNA) encoding the luciferase reporter gene. By contrast, in tendons injected with naked plasmid, the luciferase expression decreased as a function of time and became hardly detectable after 2 weeks. Interestingly, there were neither signs of inflammation nor necrosis in tendon, kidney, heart and liver of rat weekly injected with pDNA/MSN formulation during 1.5 months. Our main data concern the acceleration of Achilles tendons healing by PDGF-B gene transfer using MSN. Biomechanical properties and histological analyses clearly indicate that tendons treated with MSN and PDGF gene healed significantly faster than untreated tendons and those treated with pPDGF alone.

Circumferential arthrodesis using PEEK cages at the lumbar spine.

Usual interbody cages at the lumbar spine are made of titanium or carbon fiber-polyetheretherketone (PEEK). Pure PEEK cages have more recently been proposed for its lower elasticity modulus. The goal of our study was to investigate a series of patients with circumferential fixation using anterior PEEK cages for degenerative lumbar spine disorders with a specific interest in the local lordosis. Fifty-seven consecutive patients aged 54.6 years (29 to 75) were reviewed. The level of arthrodesis varied from L2L3 to L5S1. The clinical status and the radiologic variations in local lordosis at the level of arthrodesis were measured. Decrease in lordosis at follow-up was tested in a multivariate analysis regarding age, obesity, spinal level, bone graft amount, type of posterior instrumentation, postoperative lordosis increase, and cage height. The average follow-up was 5.7 years (4 to 8). Clinical outcomes were excellent or good in 49 cases. Fusion was definite in 56 cases. Although 47 patients had no change in lordosis after surgery, 10 cases showed lordosis increase (8.2 degrees; 5 to 12). At follow-up, local lordosis decreased in 13 cases (5.6 degrees; 4 to 8). The linear model was significant (P<0.001; R=0.590) showing that loss in lordosis was related with postoperative lordosis increase (P=0.01), cage height (P<0.001), posterior instrumentation rigidity (P=0.026), age (P=0.047), and low level (P=0.013). Lumbar circumferential arthrodesis using PEEK cages provided good clinical results and fusion rate. However, lordosis correction was not maintained at follow-up, especially at lower levels, using high cages, in older patients, and when associated with a rigid primary posterior instrumentation. Regarding the last point, this is likely that the order of the instrumentation (posterior first, then anterior) played a role in the loss of lordosis in case of rigid posterior fixation.

Wedge osteotomy for treating post-traumatic kyphosis at thoracolumbar and lumbar levels.

Local post-traumatic kyphosis may impair spinal sagittal balance and result in severe disability. The goal of this study is to evaluate posterior closing wedge osteotomy at the level of injury, by comparing thoracolumbar (T12-L1) and lumbar (L2-4) spinal levels. Thirteen consecutive patients had surgery in an average 13 months after the initial injury. There were 8 thoracolumbar and 5 lumbar deformities. Nine patients already had posterior fixation. Eight patients had preoperative neurological deficits. Sagittal correction was assessed in terms of regional angulation (RA) and effective regional deformity (ERD), which was defined as the difference between the actual RA and the physiological RA for the level. The average follow up was 2.1 years. The average RA passed from 43.8 degrees (31 to 55) to 2.2 degrees (-5 to 7) after surgery. It was 5.3 degrees (-4 to 12), at follow-up. RA and surgical correction were not significantly different between thoracolumbar and lumbar groups. The average ERD was 47.2 degrees (24 to 66) preoperatively and 8.6 degrees (-5 to 37) at follow-up. The ERD passed from 41.8 degrees (24 to 54) to 0.5 degrees (-5 to 6) in the thoracolumbar group, and from 55.8 degrees (50 to 66) to 21.6 degrees (17 to 37) in the lumbar group. The ERD was significantly different initially (P=0.014) and after surgery (P=0.06). The anatomical result was complete in the thoracolumbar group, because the correction of the deformity at this level does not require more than correction of the vertebral body kyphosis. On the contrary, due to adjacent disc damage, the technique did not fully restore the physiological regional lordosis at lower levels.

Evaluation of the 96/4 PLDLLA polymer resorbable lumbar interbody cage in a long term animal model.

Arthrodesis using interbody cages has demonstrated high fusion rates. However, permanent cages are exposed to stress-shielding, corrosion, and may require explanation when necessary. Polylactic acid (PLA) bioresorbable cages are developed for avoiding these problems, but significant tissue reaction has been reported with 70/30 PLDLLA in some preclinical animal studies. The objective was to evaluate 96/4 PLDLLA cages in a sheep model over 3 years. Sixteen sheeps underwent one level anterior lumbar interbody fusion using 96/4 PLDLLA cages, filled and surrounded with cancellous bone graft from the iliac crest. Six groups of three animals were killed after 3, 6, 9, 12, 24, and 36 months. Harvested lumbar spine had radiographic, MRI, and CT evaluation and histological analysis. Histological results: cage swelling and slight signs of fragmentation associated to fibrocartilaginous tissue apposition at 3 months; bone remodeling around the cage with direct apposition of the mineralization front at 6 months; active cage degradation and complete fusion around the cage at 9 months; cage fragmentation and partial replacement by bone tissue at 12 months; bone bridges in and around the cage at 24 months; full resorption and intervertebral fusion at 36 months. Radiological results: partial arthrodesis at 3 months; definite peripheral arthrodesis at 6 months; similar aspect at 9 months; significant cage resorption at 12 months; definite inner and outer fusion at 24 months; complete cage resorption and calcification at the location of the cage at 36 months confirmed histological observations. Radiographic, CT scan, MRI, and histological data were consistent for showing progressive resorption of 96/4 PLDLLA, interbody fusion, and bone remodeling, with no significant signs of local intolerance reaction. These results are promising and suggest further development of 96/4 PLDLLA cages.

Two-stage surgical procedure for treating pelvic malunions.

When surgically treated, pelvic-ring deformities due to post-traumatic malunions in adults usually require invasive three-stage (prone/supine/prone or supine/prone/supine) procedures. A standardised two-stage prone/supine procedure was developed by the authors. Technical points and first clinical results are presented. Malunuions related to Tile B and C types of fracture were successfully corrected.

Massive Gorham-Stout syndrome of the pelvis.

Gorham-Stout disease is defined as a spontaneous, massive, and nonfamilial idiopathic osteolysis. The diagnosis is based essentially on radiological and histological findings. Biopsy reviews always reveal excessive intraosseous nonmalignant proliferation of small vessels, which results in bone resorption and may extend to adjacent bones and soft tissues. These lesions are progressively replaced by extensive fibrosis. Since its first description in 1955, there is still controversy about its prognosis, etiology, and treatment. A case of Gorham-Stout disease, located on the right pelvis, is reported with 50 years of clinical and radiographic follow-up, in a man who has never been treated. To date, this is the longest documented case report of the disease and its rare natural history. It demonstrates that after a variable time of evolution, the massive osteolysis is able to undergo spontaneous arrest and that the lesions may remain stable during several decades. Besides, no reossification was observed, even after 37 years of disease quiescence. Based on a large review of the literature, the authors then discuss the prognosis, etiopathology, and different therapeutic options available to halt the progression of the osteolysis.

[Spinal cord trauma: epidemiology and pre-hospital management]. / Les lésions traumatiques de la moelle épinière: épidémiologie et prise en charge pré-hospitalière.

In France, about 2000 people suffer spinal cord injuries each year. Most patients are young men involved in road accidents and most have cervical lesions. Emergency pre-hospital care is crucial, as the lesions are potentially life-threatening and can have devastating functional consequences. The possibility of spinal cord trauma must always be kept in mind, and the spine must be immobilized. The initial neurological examination is extremely important. Initial medical care should target an average systolic blood pressure above 80 mmHg, ensure adequate ventilation, maintain the body temperature over 36 degrees C, and control hyperglycemia. The patient should be transported rapidly to a specialized spinal trauma unit.

Predictors of outcomes after posterior decompression and fusion in degenerative spondylolisthesis.

No consensus has been reached regarding surgical management of degenerative spondylolisthesis. The optimal type of surgical procedure and surgical indications have not been precisely defined. In order to screen for predictors of outcome, we retrospectively studied patient outcomes after posterior decompression and fusion for isolated lumbar degenerative spondylolisthesis. Twenty-four consecutive patients (age range 50-78 years) underwent primary surgery for isolated lumbar degenerative spondylolisthesis. The surgical procedure consisted of posterior decompression and pedicle screw instrumented fusion using autogeneous bone graft, with or without interbody fusion. Clinical and radiologic status were assessed using the Beaujon functional score and plain AP and lateral radiographs. A multivariate analysis was used to correlate the functional score increase with surgical procedure modifications and preoperative clinical and radiologic features in order to determine which of them led to better results. Eighteen patients completed the evaluation. Six others were lost to follow-up after a minimum of 0.87 years. Combining all the results, the mean follow-up was 2.87 years. The Beaujon score was improved in the 24 patients (P<0.001), and fusion was successful in all cases. Additional interbody fusion and preoperative leg pain were significantly correlated with larger score increase (P=0.016 and P=0.003). Posterior decompression and fusion is successful in treating lumbar degenerative spondylolisthesis. From this study, circumferential fusion improves the outcomes and leg pain is a fair indication for surgery.

Metachronous multicentric giant-cell tumor of the bone in the lower limb. Case report and Ki-67 immunohistochemistry study.

Multicentric giant-cell tumors of the bone (GCTs) are rare. Little is known about the mechanisms by which these tumors spread and how 1% of GCT turn out to be multicentric. We report the case of a 19-year-old woman with metachronous multiple and recurrent GCTs that were unusual in their pattern of progression along the right lower limb over a 23-year period. Histology showed no evidence of malignant transformation. The treatment was repeated curettage and packing with cement. This did not permit a wide surgical margin, but avoided amputation and preserved full limb function. We tested the proliferation index marker Ki-67 in the tumor specimens. Ki-67 expression was limited to the mononuclear cell component of the tumors. The proliferation index was similar in each new tumor and higher in recurrences for each location. In this case, proliferation was initially low in the new tumor location, despite the time difference and independent from the initial clone evolution. Proliferation index increased in recurrent GCTs after marginal margin resection.

In situ gene transfer into animal tendons by injection of naked DNA and electrotransfer.

BACKGROUND: Degenerative or traumatic tendon injuries are extremely common but often heal poorly, not restoring the normal function of the injured tissues. Gene transfer could improve the repair process, by permitting local production of therapeutic substances, e.g. growth factors. METHODS AND RESULTS: Injection of a plasmid carrying the lacZ marker gene was performed into the Achilles tendons of rat and mouse, and the patellar tendons of rabbit. At 48 h, transduced cells were found in the injected zones of the tendons but represented a minority of the tendon cells. A kinetics study in rats permitted observation of a gradual decrease with time in the beta-gal-expressing cell number; at day 42 no more gene expression was detected. Noteworthy, no inflammatory reaction was observed. We then investigated whether electrotransfer could improve gene transfer efficacy in rat tendon by delivering in situ electric pulses after DNA injection. Gene transfer was improved at best by approximately 50% under certain electrical conditions (200 V for 10 ms or 1200 V for 100 micro s). Finally, multiple injections of plasmid permitted an increase in the number of transduced cells by approximately 400%. CONCLUSIONS: In situ injection of naked DNA into tendons is a very simple technique that permits delivery of genes with a duration of expression sufficient for clinical application aimed at modulating healing or restoration of a degenerative tendon. Despite a low transfer efficiency, this method should be compatible with clinical applications aimed at delivering therapeutic substances acting at low concentration.

Postoperative morphine consumption in the elderly patient.

BACKGROUND: It has been suggested that the dose of intravenous morphine used during postoperative titration is not modified by aging. The authors therefore studied morphine requirements in patients undergoing total hip replacement. METHODS: Intravenous morphine titration was administered as boluses, then subcutaneous morphine was administered every 4 h over 24 h. Pain was assessed by use of the visual analog scale (0 to 100), and the threshold required to administer morphine was 30. Young and elderly (> or =70 yr old) patients were compared. Data are mean +/- SD or odds ratio (OR) [95% CI]. RESULTS: Two hundred twenty-four patients (68%) were young and 105 (32%) were elderly. The initial visual analog scale was not significantly different between groups. The dose of intravenous morphine in the postanesthesia care unit was not significantly different between young and elderly patients (0.15 +/- 0.11 vs. 0.14 +/- 0.10 mg/kg, P = NS), in contrast to the dose of subcutaneous morphine (0.18 +/- 0.18 vs. 0.11 +/- 0.11 mg/kg, P < 0.001) in the ward. Only severe pain (visual analog scale of 70 or greater; OR, 10.5 [4.5-24.8]) was significantly associated with a high dose (greater than 0.15 mg/kg) of intravenous morphine, whereas severe pain (OR, 2.5 [1.6-4.0]), age less than 60 yr (OR, 2.3 [1.4-3.8]), and absence of a nonsteroidal antiinflammatory drug (OR, 1.9 [1.2-3.1]) were significantly associated with a high dose (greater than 0.12 mg/kg) of subcutaneous morphine. CONCLUSIONS: The dose of intravenous morphine during titration is not modified in elderly patients, in contrast to the dose administered subcutaneously over a prolonged period.