Dual Semitendinosus Allograft Reconstruction of Chronic Achilles Tendon Ruptures: Operative Technique and Outcomes.

BACKGROUND: Dual semitendinosus allograft reconstruction of chronic Achilles tendon ruptures has several potential benefits including superior tensile strength compared with a turndown construct and avoidance of the morbidity and operative time associated with autograft augmentation. We present a series of chronic Achilles tendon ruptures reconstructed with dual semitendinosus allograft. METHODS: We retrospectively reviewed the charts of patients aged 18 years and older who underwent reconstruction of chronic Achilles tendon ruptures using dual semitendinosus allograft. The primary outcome of this study was to evaluate the need for revision surgery. Secondary outcomes included patient-reported outcomes, for which Achilles Tendon Rupture Scores (ATRS) were collected at final follow-up. Nine patients with a mean age of 58.9 (range, 43-75) years met inclusion criteria. RESULTS: Median follow-up was 66 months (range, 27-121 months). One patient (11.1%) required revision reconstruction after sustaining graft failure 9.5 years after her index procedure, and 1 patient reported a poor ATRS score at the 27-month final follow-up despite an intact surgical repair. At final follow-up, no patient required the use of an assistive device for ambulation or a walking boot. The median ATRS at final follow-up was 93 (range, 30-100). DISCUSSION: Good clinical outcomes without rerupture were observed in 7 of 9 patients (77.8%) at short- to midterm follow-up, suggesting that dual semitendinosus allograft reconstruction is a viable option for the reconstruction of chronic Achilles tendon tears. LEVEL OF EVIDENCE: Level IV, case series.

Genetic counseling as preventive intervention: toward individual specification of transgenerational autism risk.

BACKGROUND: Although autism spectrum disorders (ASD) are among the most heritable of all neuropsychiatric syndromes, most affected children are born to unaffected parents. Recently, we reported an average increase of 3-5% over general population risk of ASD among offspring of adults who have first-degree relatives with ASD in a large epidemiologic family sample. A next essential step is to investigate whether there are measurable characteristics of individual parents placing them at higher or lower recurrence risk, as this information could allow more personalized genetic counseling. METHODS: We assembled what is to our knowledge the largest collection of data on the ability of four measurable characteristics of unaffected prospective parents to specify risk for autism among their offspring: (1) sub clinical autistic trait burden, (2) parental history of a sibling with ASD, (3) transmitted autosomal molecular genetic abnormalities, and (4) parental age. Leveraging phenotypic and genetic data in curated family cohorts, we evaluate the respective associations between these factors and child outcome when autism is present in the family in the parental generation. RESULTS: All four characteristics were associated with elevation in offspring risk; however, the magnitude of their predictive power-with the exception of isolated rare inherited pathogenic variants -does not yet reach a threshold that would typically be considered actionable for reproductive decision-making. CONCLUSIONS: Individual specification of risk to offspring of adults in ASD-affected families is not straightforwardly improved by ascertainment of parental phenotype, and it is not yet clear whether genomic screening of prospective parents in families affected by idiopathic ASD is warranted as a clinical standard. Systematic screening of affected family members for heritable pathogenic variants, including rare sex-linked mutations, will identify a subset of families with substantially elevated transmission risk. Polygenic risk scores are only weakly predictive at this time but steadily improving and ultimately may enable more robust prediction either singly or when combined with the risk variables examined in this study.

Genetic architecture of reciprocal social behavior in toddlers: Implications for heterogeneity in the early origins of autism spectrum disorder.

Impairment in reciprocal social behavior (RSB), an essential component of early social competence, clinically defines autism spectrum disorder (ASD). However, the behavioral and genetic architecture of RSB in toddlerhood, when ASD first emerges, has not been fully characterized. We analyzed data from a quantitative video-referenced rating of RSB (vrRSB) in two toddler samples: a community-based volunteer research registry (n = 1,563) and an ethnically diverse, longitudinal twin sample ascertained from two state birth registries (n = 714). Variation in RSB was continuously distributed, temporally stable, significantly associated with ASD risk at age 18 months, and only modestly explained by sociodemographic and medical factors (r2 = 9.4%). Five latent RSB factors were identified and corresponded to aspects of social communication or restricted repetitive behaviors, the two core ASD symptom domains. Quantitative genetic analyses indicated substantial heritability for all factors at age 24 months (h2 ≥ .61). Genetic influences strongly overlapped across all factors, with a social motivation factor showing evidence of newly-emerging genetic influences between the ages of 18 and 24 months. RSB constitutes a heritable, trait-like competency whose factorial and genetic structure is generalized across diverse populations, demonstrating its role as an early, enduring dimension of inherited variation in human social behavior. Substantially overlapping RSB domains, measurable when core ASD features arise and consolidate, may serve as markers of specific pathways to autism and anchors to inform determinants of autism's heterogeneity.