Proximity of the Ulnar Neurovascular Structures in Endoscopic Carpal Tunnel Release Surgery: A Cadaveric Study.

PURPOSE: To evaluate the proximity of the ulnar neurovascular structures to the endoscopic blade during endoscopic carpal tunnel release (CTR). METHODS: Ten fresh-frozen cadaver hands were used to perform endoscopic CTR using devices from two manufacturers. The skin was excised from the palm, and the endoscopic carpal tunnel blade was deployed at the distal edge of the transverse carpal ligament (TCL). The blade's proximity to the ulnar neurovascular bundle, deep ulnar motor branch, superficial palmar arch, and median nerve was recorded. Following release of the TCL, the device was turned ulnar to the maximal extent to determine if direct injury to the ulnar neurovascular bundle was possible. RESULTS: The average longitudinal distance from the end of the TCL to the superficial palmar arch was 13.3 mm (range, 8.4-20.9) and to the ulnar motor branch was 10.8 mm (range, 4.0-15.0). The average transverse distance from the end of the TCL to the ulnar neurovascular bundle was 5.9 mm (range, 3.1-7.8) and to the median nerve was 3.3 mm (range, 0-6.5). In two of our specimens, the median nerve subluxated volarly over the cutting device. When placing the blade at the distal edge of the TCL, injury to the deep motor branch of the ulnar nerve, ulnar neurovascular bundle, or superficial palmar arch was not possible in any specimens using the tested devices, even when turning the blade directly toward these structures. CONCLUSIONS: There is a low likelihood of direct injury to the ulnar neurovascular bundle during endoscopic CTR. CLINICAL RELEVANCE: These results suggest that injury to the ulnar neurovascular bundle is unlikely during endoscopic CTR if the distal aspect of the transverse carpal ligament can be clearly identified prior to release. Control of the median nerve is also important to prevent subluxation over the cutting device.

Radial Head Arthroplasty for Fracture: Implant Survivorship and Outcomes at Mean Follow-up of 8 Years.

PURPOSE: The purpose of this study was to evaluate implant survivorship and clinical outcomes following radial head arthroplasty for fracture at long-term follow-ups. METHODS: A retrospective analysis was conducted on adult patients who underwent primary uncemented radial head arthroplasty for radial head or neck fractures between 2012 and 2015. Medical records were reviewed to collect information regarding demographics, injury characteristics, reoperations, and revisions requiring implant removal. A bivariate analysis was conducted to identify potential risk factors for reoperation. A Kaplan-Meier curve was created to determine implant survival rates. Eligible patients were contacted to confirm any reoperations and obtain Quick Disability of the Arm, Shoulder, and Hand scores at long-term follow-ups. RESULTS: A total of 89 patients were eligible for analysis and assessed at a mean of 97 months after surgery (range, 81-128). Reoperation rate was 16% (14 of 89 patients), including 5% of patients requiring implant removal or revision. However, 93% of reoperations occurred within the first 12 months of the index surgery. Fracture dislocations of the elbow had a higher rate of reoperation. A Kaplan-Meier curve demonstrated an implant survival rate of 96% at 10-year follow-up. Of the patients who responded, the mean Quick Disability of the Arm, Shoulder, and Hand score was 8.7 ± 10.3, with none requiring additional reoperations or revisions. There were otherwise similar outcome scores among patients requiring reoperation versus those who did not. CONCLUSIONS: Although radial head arthroplasty for fractures has a high potential for reoperation within the first year, survival rates with uncemented implants remain high at 10 years, and patients report excellent Quick Disability of the Arm, Shoulder, and Hand scores at long-term follow-ups, despite any need for reoperation. Fractures with associated elbow dislocation may be at a higher risk for reoperation, and it is important to provide this prognostic information to patients who are likely to require arthroplasty for more extensive injuries. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic IV.

Development of adiposity among Ju/'Hoansi Hunter-Gatherers.

OBJECTIVES: To characterize the development of childhood adiposity among the Ju'/Hoansi, a well-known hunter-gather group, to compare our results to U.S. references and to recently published results from Savanna Pume' foragers of Venezuela, with the goal of expanding our understanding of adipose development among human hunter-gatherers. METHODS: Triceps, subscapular, and abdominal skinfolds, along with height and weight from ~120 Ju'/Hoansi girls and ~103 boys, ages 0 to 24 years, collected in 1967-1969 were analyzed using best-fit polynomial models and penalized spines to characterize age-specific patterns of adiposity and their relationship to changes in height and weight. RESULTS: Overall, Ju/'Hoansi boys and girls exhibit small skinfolds with a decline in adiposity from 3 to 10 years, with no consistent differences among the three skinfolds. Increases in adiposity during adolescence precede peak height and weight velocities. Adiposity declines during young adulthood for girls and remains largely constant for boys. DISCUSSION: Compared to U.S. standards, the Ju/'Hoansi show a strikingly different pattern of adipose development, including the lack of an adiposity rebound at the onset of middle childhood, and clear increases in adiposity only at adolescence. These findings are consistent with published results from the Savanna Pumé hunter-gatherers of Venezuela, a group with a very different selective history, suggesting that the adiposity rebound does not characterize hunter-gathering populations more generally. Similar analyses in other subsistence populations are called for to confirm our results, and help distinguish the impact of specific environmental and dietary factors on adipose development.

Body composition, age and fertility among free-ranging female rhesus macaques (Macaca mulatta).

The relationship of morphometric measures and birth status among 93 females on Cayo Santiago trapped during the 2001 and 2002 seasons was assessed. The proportion of females giving birth differed between the two seasons (0.58 vs. 0.38; P = 0.006) with a prominent decline among older females. Most morphometric measures increased from adolescent to adult groups, but bicep circumference showed a significant decrease among adults. When controlled for age differences, females with infants during the 2002 season exhibited greater bicep circumference, but no difference in abdominal fat than those without. Members of the socially dominant group did not have a higher rate of birth in either 2001 or 2002, despite being significantly longer and weighing more than those of the subordinate group. Abdominal skinfold and bicep circumference were significant predictors of birth status during the 2002 season, controlling for age group, social group membership, and parity in the previous year. Bicep circumference was also a significant predictor of birth status for the 2001 birth season. These findings suggest that individual variation in body composition among females of Cayo Santiago is associated with differences in fertility.

Population variation in age-related decline in male salivary testosterone.

BACKGROUND: Age-related declines in free and bioavailable testosterone are frequently reported for Western populations, but interpopulation variation in this pattern has not previously been investigated. METHODS: Salivary testosterone was measured using a consistently applied protocol on morning samples collected from men in four populations (USA, Congo, Nepal, and Paraguay) representing different geographical, ecological, and cultural settings. RESULTS: Mean testosterone levels varied significantly between the four populations. The mean testosterone differences between populations were greatest for young men (aged 15-30 years) and insignificant for older men (aged 45-60 years). The slope of age-related decline in testosterone was significant in the USA and Congolese participants, but not in the Nepalese or Paraguayan participants. CONCLUSIONS: Age patterns of testosterone decline vary between populations primarily as a result of variation in the peak levels attained in young adulthood. The potential consequences of this variation for other aspects of male health deserve investigation.