IMPORTANCE: Failure of bone fracture healing occurs in 5% to 10% of all patients. Nonunion risk is associated with the severity of injury and with the surgical treatment technique, yet progression to ...nonunion is not fully explained by these risk factors. OBJECTIVE: To test a hypothesis that fracture characteristics and patient-related risk factors assessable by the clinician at patient presentation can indicate the probability of fracture nonunion. DESIGN, SETTING, AND PARTICIPANTS: An inception cohort study in a large payer database of patients with fracture in the United States was conducted using patient-level health claims for medical and drug expenses compiled for approximately 90.1 million patients in calendar year 2011.The final database collated demographic descriptors, treatment procedures as per Current Procedural Terminology codes; comorbidities as per International Classification of Diseases, Ninth Revision codes; and drug prescriptions as per National Drug Code Directory codes. Logistic regression was used to calculate odds ratios (ORs) for variables associated with nonunion. Data analysis was performed from January 1, 2011, to December 31, 2012, EXPOSURES: Continuous enrollment in the database was required for 12 months after fracture to allow sufficient time to capture a nonunion diagnosis. RESULTS: The final analysis of 309 330 fractures in 18 bones included 178 952 women (57.9%); mean (SD) age was 44.48 (13.68) years. The nonunion rate was 4.9%. Elevated nonunion risk was associated with severe fracture (eg, open fracture, multiple fractures), high body mass index, smoking, and alcoholism. Women experienced more fractures, but men were more prone to nonunion. The nonunion rate also varied with fracture location: scaphoid, tibia plus fibula, and femur were most likely to be nonunion. The ORs for nonunion fractures were significantly increased for risk factors, including number of fractures (OR, 2.65; 95% CI, 2.34-2.99), use of nonsteroidal anti-inflammatory drugs plus opioids (OR, 1.84; 95% CI, 1.73-1.95), operative treatment (OR, 1.78; 95% CI, 1.69-1.86), open fracture (OR, 1.66; 95% CI, 1.55-1.77), anticoagulant use (OR, 1.58; 95% CI, 1.51-1.66), osteoarthritis with rheumatoid arthritis (OR, 1.58; 95% CI, 1.38-1.82), anticonvulsant use with benzodiazepines (OR, 1.49; 95% CI, 1.36-1.62), opioid use (OR, 1.43; 95% CI, 1.34-1.52), diabetes (OR, 1.40; 95% CI, 1.21-1.61), high-energy injury (OR, 1.38; 95% CI, 1.27-1.49), anticonvulsant use (OR, 1.37; 95% CI, 1.31-1.43), osteoporosis (OR, 1.24; 95% CI, 1.14-1.34), male gender (OR, 1.21; 95% CI, 1.16-1.25), insulin use (OR, 1.21; 95% CI, 1.10-1.31), smoking (OR, 1.20; 95% CI, 1.14-1.26), benzodiazepine use (OR, 1.20; 95% CI, 1.10-1.31), obesity (OR, 1.19; 95% CI, 1.12-1.25), antibiotic use (OR, 1.17; 95% CI, 1.13-1.21), osteoporosis medication use (OR, 1.17; 95% CI, 1.08-1.26), vitamin D deficiency (OR, 1.14; 95% CI, 1.05-1.22), diuretic use (OR, 1.13; 95% CI, 1.07-1.18), and renal insufficiency (OR, 1.11; 95% CI, 1.04-1.17) (multivariate P < .001 for all). CONCLUSIONS AND RELEVANCE: The probability of fracture nonunion can be based on patient-specific risk factors at presentation. Risk of nonunion is a function of fracture severity, fracture location, disease comorbidity, and medication use.
Background:
Posttraumatic osteoarthritis (PTOA) after anterior cruciate ligament (ACL) reconstruction ultimately translates into a large economic effect on the health care system owing to the young ...ages of this population.
Purpose/Hypothesis:
The purposes were to perform a meta-analysis to determine the prevalence of osteoarthritis after an ACL reconstruction, examining the effects of length of time after surgery, preoperative time interval from injury to surgery, and patient age at the time of surgery. It was hypothesized that the prevalence of PTOA increased with time from surgery and that increased time from injury to surgery and age were also risk factors for the development of PTOA.
Study Design:
Meta-analysis.
Methods:
A meta-analysis of the prevalence of radiographic PTOA after ACL reconstruction was performed of studies with a minimum of 5 years’ follow-up, with a level of evidence of 1, 2, or 3. The presence of osteoarthritis was defined according to knee radiographs evaluated with classification based on Kellgren and Lawrence, Ahlbäck, International Knee Documentation Committee, or the Osteoarthritis Research Society International. Metaregression models quantified the relationship between radiographic PTOA prevalence and the mean time from injury to surgery, mean patient age at time of surgery, and mean postoperative follow-up time.
Results:
Thirty-eight studies (4108 patients) were included. Longer postsurgical follow-up time was significantly positively associated with a higher proportion of PTOA development. The model-estimated proportion of PTOA (95% CI) at 5, 10, and 20 years after surgery was 11.3% (6.4%-19.1%), 20.6% (14.9%-27.7%), and 51.6% (29.1%-73.5%), respectively. Increased chronicity of the ACL tear before surgery and increased patient age were also associated with a higher likelihood of PTOA development.
Conclusion:
The prevalence of osteoarthritis after an ACL reconstruction significantly increased with time. Longer chronicity of ACL tear and older age at the time of surgery were significantly positively correlated with the development of osteoarthritis. A timely referral and treatment of symptomatic patients are vital to diminish the occurrence of PTOA.
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Abstract
Surface energy budgets of high-latitude permafrost systems are poorly represented in Earth system models (ESMs), yet permafrost is rapidly degrading and these dynamics are critical to future ...carbon-climate feedback predictions. A potentially important factor in permafrost degradation neglected so far by ESMs is heat transfer from precipitation, although increases in soil temperature and thaw depth have been observed following increases in precipitation. Using observations and a mechanistic ecosystem model, we show here that increases in precipitation hasten active layer development beyond that caused by surface air warming across the North Slope of Alaska (NSA) under recent and 21st century climate (RCP8.5). Modeled active layer depth (ALD) in simulations that allow precipitation heat transfer agreed very well with observations from 28 Circumpolar Active Layer Monitoring sites (R
2
= 0.63; RMSE = 10 cm). Simulations that ignored precipitation heat transfer resulted in lower spatially-averaged soil temperatures and a 39 cm shallower ALD by 2100 across the NSA. The results from our sensitivity analysis show that projected increases in 21st century precipitation deepen the active layer by enhancing precipitation heat transfer and ground thermal conductivity, suggesting that precipitation is as important an environmental control on permafrost degradation as surface air temperature. We conclude that ESMs that do not account for precipitation heat transfer likely underestimate ALD rates of change, and thus likely predict biased ecosystem responses.
Background:
Ramp lesions were initially defined as a tear of the peripheral attachment of the posterior horn of the medial meniscus at the meniscocapsular junction. The separate biomechanical roles ...of the meniscocapsular and meniscotibial attachments of the posterior medial meniscus have not been fully delineated.
Purpose:
To evaluate the biomechanical effects of meniscocapsular and meniscotibial lesions of the posterior medial meniscus in anterior cruciate ligament (ACL)–deficient and ACL-reconstructed knees and the effect of repair of ramp lesions.
Study Design:
Controlled laboratory study.
Methods:
Twelve matched pairs of human cadaveric knees were evaluated with a 6 degrees of freedom robotic system. All knees were subjected to an 88-N anterior tibial load, internal and external rotation torques of 5 N·m, and a simulated pivot-shift test of 10-N valgus force coupled with 5-N·m internal rotation. The paired knees were randomized to the cutting of either the meniscocapsular or the meniscotibial attachments after ACL reconstruction (ACLR). Eight comparisons of interest were chosen before data analysis was conducted. Data from the intact state were compared with data from the subsequent states. The following states were tested: intact (n = 24), ACL deficient (n = 24), ACL deficient with a meniscocapsular lesion (n = 12), ACL deficient with a meniscotibial lesion (n = 12), ACL deficient with both meniscocapsular and meniscotibial lesions (n = 24), ACLR with both meniscocapsular and meniscotibial lesions (n = 16), and ACLR with repair of both meniscocapsular and meniscotibial lesions (n = 16). All states were compared with the previous states. For the repair and reconstruction states, only the specimens that underwent repair were compared with their intact and sectioned states, thus excluding the specimens that did not undergo repair.
Results:
Cutting the meniscocapsular and meniscotibial attachments of the posterior horn of the medial meniscus significantly increased anterior tibial translation in ACL-deficient knees at 30° (P ≤ .020) and 90° (P < .005). Cutting both the meniscocapsular and meniscotibial attachments increased tibial internal (all P > .004) and external (all P < .001) rotation at all flexion angles in ACL-reconstructed knees. Reconstruction of the ACL in the presence of meniscocapsular and meniscotibial tears restored anterior tibial translation (P > .053) but did not restore internal rotation (P < .002), external rotation (P < .002), and the pivot shift (P < .05). To restore the pivot shift, an ACLR and a concurrent repair of the meniscocapsular and meniscotibial lesions were both necessary. Repairing the meniscocapsular and meniscotibial lesions after ACLR did not restore internal rotation and external rotation at angles >30°.
Conclusion:
Meniscocapsular and meniscotibial lesions of the posterior horn of the medial meniscus increased knee anterior tibial translation, internal and external rotation, and the pivot shift in ACL-deficient knees. The pivot shift was not restored with an isolated ACLR but was restored when performed concomitantly with a meniscocapsular and meniscotibial repair. However, the effect of this change was minimal; although statistical significance was found, the overall clinical significance remains unclear. The ramp lesion repair used in this study failed to restore internal rotation and external rotation at higher knee flexion angles. Further studies should examine improved meniscus repair techniques for root tears combined with ACLRs.
Clinical Relevance:
Meniscal ramp lesions should be repaired at the time of ACLR to avoid continued knee instability (anterior tibial translation) and to eliminate the pivot-shift phenomenon.
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Previous research suggests that various types of childhood maltreatment frequently co-occur and confer risk for multiple psychiatric diagnoses. This non-specific pattern of risk may mean that ...childhood maltreatment increases vulnerability to numerous specific psychiatric disorders through diverse, specific mechanisms or that childhood maltreatment engenders a generalised liability to dimensions of psychopathology. Although these competing explanations have different implications for intervention, they have never been evaluated empirically.
We used a latent variable approach to estimate the associations of childhood maltreatment with underlying dimensions of internalising and externalising psychopathology and with specific disorders after accounting for the latent dimensions. We also examined gender differences in these associations.
Data were drawn from a nationally representative survey of 34 653 US adults. Lifetime DSM-IV psychiatric disorders were assessed using the AUDADIS-IV. Physical, sexual and emotional abuse and neglect were assessed using validated measures. Analyses controlled for other childhood adversities and sociodemographics.
The effects were fully mediated through the latent liability dimensions, with an impact on underlying liability levels to internalising and externalising psychopathology rather than specific psychiatric disorders. Important gender differences emerged with physical abuse associated only with externalising liability in men, and only with internalising liability in women. Neglect was not significantly associated with latent liability levels.
The association between childhood maltreatment and common psychiatric disorders operates through latent liabilities to experience internalising and externalising psychopathology, indicating that the prevention of maltreatment may have a wide range of benefits in reducing the prevalence of many common mental disorders. Different forms of abuse have gender-specific consequences for the expression of internalising and externalising psychopathology, suggesting gender-specific aetiological pathways between maltreatment and psychopathology.
Background:
Anterior cruciate ligament (ACL) tears are one of the most common injuries among athletes. However, the ability to fully restore rotational stability with ACL reconstruction (ACLR) ...remains a challenge, as evidenced by the persistence of rotational instability in up to 25% of patients after surgery. Advocacy for reconstruction of the anterolateral ligament (ALL) is rapidly increasing because some biomechanical studies have reported that the ALL is a significant contributor to internal rotational stability of the knee.
Hypothesis/Purpose:
The purpose of this study was to assess the effect of ALL reconstruction (ALLR) graft fixation angle on knee joint kinematics in the clinically relevant setting of a concomitant ACLR and to determine the optimal ALLR graft fixation angle. It was hypothesized that all fixation angles would significantly reduce rotational laxity compared with the sectioned ALL state.
Study Design:
Controlled laboratory study.
Methods:
Ten nonpaired fresh-frozen human cadaveric knees underwent a full kinematic assessment in each of the following states: (1) intact; (2) anatomic single-bundle (SB) ACLR with intact ALL; (3) anatomic SB ACLR with sectioned ALL; (4) anatomic SB ACLR with 7 anatomic ALLR states using graft fixation angles of 0°, 15°, 30°, 45°, 60°, 75°, and 90°; and (5) sectioned ACL and ALL. Internal rotation during a 5-N·m internal rotation torque and anterior translation during an 88-N anterior load were recorded at 15° flexion intervals between 0° and 120°. Axial plane translation and internal rotation during a simulated pivot-shift test (combined 5-N·m internal rotation and 10-N·m valgus torques) were recorded between 0° and 60°. Kinematic changes were measured and compared with the intact state for all reconstructed and sectioned states.
Results:
Anatomic ALLR at all graft fixation angles significantly overconstrained internal rotation of the knee joint beyond 30° of flexion and at 45° and 60° during the pivot-shift test. Furthermore, there were no significant knee kinematic differences between any tested graft fixation angles during anterior drawer, pivot-shift, and internal rotation tests.
Conclusion:
Anatomic ALLR in conjunction with an ACLR significantly reduced rotatory laxity of the knee beyond 30° of knee flexion. However, ALLR, regardless of fixation angle, resulted in significant overconstraint of the knee.
Clinical Relevance:
ALLR at any fixation angle overconstrained native joint kinematics and should be performed with careful consideration. Further investigation into the application and target population for ALLR is strongly recommended.
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Abstract
Vegetation composition shifts, and in particular, shrub expansion across the Arctic tundra are some of the most important and widely observed responses of high-latitude ecosystems to rapid ...climate warming. These changes in vegetation potentially alter ecosystem carbon balances by affecting a complex set of soil–plant–atmosphere interactions. In this review, we synthesize the literature on (a) observed shrub expansion, (b) key climatic and environmental controls and mechanisms that affect shrub expansion, (c) impacts of shrub expansion on ecosystem carbon balance, and (d) research gaps and future directions to improve process representations in land models. A broad range of evidence, including
in-situ
observations, warming experiments, and remotely sensed vegetation indices have shown increases in growth and abundance of woody plants, particularly tall deciduous shrubs, and advancing shrublines across the circumpolar Arctic. This recent shrub expansion is affected by several interacting factors including climate warming, accelerated nutrient cycling, changing disturbance regimes, and local variation in topography and hydrology. Under warmer conditions, tall deciduous shrubs can be more competitive than other plant functional types in tundra ecosystems because of their taller maximum canopy heights and often dense canopy structure. Competitive abilities of tall deciduous shrubs vs herbaceous plants are also controlled by variation in traits that affect carbon and nutrient investments and retention strategies in leaves, stems, and roots. Overall, shrub expansion may affect tundra carbon balances by enhancing ecosystem carbon uptake and altering ecosystem respiration, and through complex feedback mechanisms that affect snowpack dynamics, permafrost degradation, surface energy balance, and litter inputs. Observed and projected tall deciduous shrub expansion and the subsequent effects on surface energy and carbon balances may alter feedbacks to the climate system. Land models, including those integrated in Earth System Models, need to account for differences in plant traits that control competitive interactions to accurately predict decadal- to centennial-scale tundra vegetation and carbon dynamics.
BACKGROUND:Platelet-rich plasma (PRP) is a blood-derived preparation whose use has grown exponentially in orthopaedic practice. However, there remains an unclear understanding of the biological ...properties and effects of PRP on musculoskeletal healing. Heterogeneous processing methods, unstandardized nomenclature, and ambiguous classifications make comparison among studies challenging. A comprehensive assessment of orthopaedic clinical PRP trials is key to unraveling the biological complexity of PRP, while improving standardized communication. Toward this goal, we performed a systematic review of the PRP preparation protocols and PRP composition utilized in clinical trials for the treatment of musculoskeletal diseases.
METHODS:A systematic review of the literature was performed from 2006 to 2016. Inclusion criteria were human clinical trials, English-language literature, and manuscripts that reported on the use of PRP in musculoskeletal/orthopaedic conditions. Basic-science articles, editorials, surveys, special topics, letters to the editor, personal correspondence, and nonorthopaedic applications (including cosmetic use or dental application studies) were excluded.
RESULTS:A total of 105 studies (in 104 articles) met the inclusion criteria for analysis. Of these studies, only 11 (10%) provided comprehensive reporting that included a clear description of the preparation protocol that could be used by subsequent investigators to repeat the method. Only 17 studies (16%) provided quantitative metrics on the composition of the final PRP product.
CONCLUSIONS:Reporting of PRP preparation protocols in clinical studies is highly inconsistent, and the majority of studies did not provide sufficient information to allow the protocol to be reproduced. Furthermore, the current reporting of PRP preparation and composition does not enable comparison of the PRP products being delivered to patients. A detailed, precise, and stepwise description of the PRP preparation protocol is required to allow comparison among studies and provide reproducibility.
In its largest outbreak, Ebola virus disease is spreading through Guinea, Liberia, Sierra Leone, and Nigeria. We sequenced 99 Ebola virus genomes from 78 patients in Sierra Leone to ~2000× coverage. ...We observed a rapid accumulation of interhost and intrahost genetic variation, allowing us to characterize patterns of viral transmission over the initial weeks of the epidemic. This West African variant likely diverged from central African lineages around 2004, crossed from Guinea to Sierra Leone in May 2014, and has exhibited sustained human-to-human transmission subsequently, with no evidence of additional zoonotic sources. Because many of the mutations alter protein sequences and other biologically meaningful targets, they should be monitored for impact on diagnostics, vaccines, and therapies critical to outbreak response.
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Background:
Posterior medial meniscal root tears have been reported to extrude with the meniscus becoming adhered posteromedially along the posterior capsule. While anatomic repair has been reported ...to restore tibiofemoral contact mechanics, it is unknown whether nonanatomic positioning of a meniscal root repair to a posteromedial location would restore the loading profile of the knee joint.
Purpose/Hypothesis:
The purpose of this study was to compare the tibiofemoral contact mechanics of a nonanatomic posterior medial meniscal tear with that of the intact knee or anatomic repair. It was hypothesized that a nonanatomic root repair would not restore the tibiofemoral contact pressures and areas to that of the intact or anatomic repair state.
Study Design:
Controlled laboratory study.
Methods:
Tibiofemoral contact mechanics were recorded in 6 male human cadaveric knee specimens (average age, 45.8 years) using pressure sensors. Each knee underwent 5 testing conditions for the posterior medial meniscal root: (1) intact knee; (2) root tear; (3) anatomic transtibial pull-out repair; (4) nonanatomic transtibial pull-out repair, placed 5 mm posteromedially along the edge of the articular cartilage; and (5) root tear concomitant with an ACL tear. Knees were loaded with a 1000-N axial compressive force at 4 flexion angles (0°, 30°, 60°, 90°), and contact area, mean contact pressure, and peak contact pressure were calculated.
Results:
Contact area was significantly lower after nonanatomic repair than for the intact knee at all flexion angles (mean = 44% reduction) and significantly higher for anatomic versus nonanatomic repair at all flexion angles (mean = 27% increase). At 0° and 90°, and when averaged across flexion angles, the nonanatomic repair significantly increased mean contact pressures in comparison to the intact knee or anatomic repair. When averaged across flexion angles, the peak contact pressures after nonanatomic repair were significantly higher than the intact knee but not the anatomic repair. In contrast, when averaged across all flexion angles, the anatomic repair resulted in a 17% reduction in contact area and corresponding increases in mean and peak contact pressures of 13% and 26%, respectively, compared with the intact knee.
Conclusion:
For most testing conditions, the nonanatomic repair did not restore the contact area or mean contact pressures to that of the intact knee or anatomic repair. However, the anatomic repair produced near-intact contact area and resulted in relatively minimal increases in mean and peak contact pressures compared with the intact knee.
Clinical Relevance:
Results emphasize the importance of ensuring an anatomic posterior medial meniscal root repair by releasing the extruded menisci from adhesions and the posteromedial capsule. Similar caution toward preventing displacement of the meniscal root repair construct should be emphasized.
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