An assessment of the postcranial skeleton of the Paracolobus mutiwa (Primates: Colobinae) specimen KNM-WT 16827 from Lomekwi, West Turkana, Kenya

The earliest most complete skeleton of Theropithecus

The interosseous membrane affects load distribution in the forearm

In this case report, we describe an alternative surgical procedure to treat proximal radius and ulnar nonunion in a toy breed dog. A 14-month-old, Maltese cross-breed dog was referred after previous treatment with external and internal fixation had failed, resulting in a nonunion of a fracture of the proximal radius and ulna with the proximal radius fragment too small and friable to be used for fixation. A craniomedial approach was made to debride the radius nonunion site and a second approach to the lateral aspect of the ulna was made. The fracture was realigned and a titanium locking plate was applied in bridging fashion, fixed to the proximal ulnar fragment with three locking screws in the most proximal plate holes, a fourth screw was inserted in the mid-shaft of the distal ulnar fragment and three locking screws were inserted in the distal most holes of the plate through the distal ulna to engage the distal radial fragment. A recombinant bone morphogenetic protein 2 graft was inserted into the radius and ulna fracture sites. The dog had a successful clinical and radiographic outcome with bridging of the defect 4 weeks postoperatively and complete callus formation 8 weeks postoperatively. Implants have undergone dynamization and then removal. Use of a locking plate as an internal fixator achieving fixation of the proximal ulna and distal radius can be considered an option for the treatment of proximal radioulnar nonunions with a small proximal radial fragment.

Olecranon fractures are relatively common injuries, accounting for approximately 10% of upper extremity fractures in adults [26]. These fractures may result from a direct blow to the proximal ulna, or indirectly, via the forceful contraction of the triceps against resistance (typically, during a fall onto an outstretched hand). Less commonly, the olecranon may fracture when the elbow is hyperextended, as the bone is impacted against the olecranon fossa of the distal humerus. For unstable injuries, operative fixation typically is required. Even after recovery, loss of ROM is not uncommon. This article provides an overview of olecranon fractures in adults; therefore, discussion of olecranon fractures in skeletally immature patients is beyond the scope of this article.

The proximal and distal femur epiphyses of mice are both weight-bearing structures derived from chondrocytes but differ in development. Mineralization at the distal epiphysis occurs in an osteoblast-rich secondary ossification center (SOC), while the chondrocytes of the proximal femur head (FH), in particular, are directly mineralized. Thyroid hormone (TH) plays important roles in distal knee SOC formation, but whether TH also affects proximal FH development remains unexplored. Here, we found that TH controls chondrocyte maturation and mineralization at the FH in vivo through studies in thyroid stimulating hormone receptor (Tshr-/-) hypothyroid mice by X-ray, histology, transcriptional profiling, and immunofluorescence staining. Both in vivo and in vitro studies conducted in ATDC5 chondrocyte progenitors concur that TH regulates expression of genes that modulate mineralization (Ibsp, Bglap2, Dmp1, Spp1, and Alpl). Our work also delineates differences in prominent transcription factor regulation of genes involved in the different mechanisms leading to proximal FH cartilage calcification and endochondral ossification at the distal femur. The information on the molecular pathways contributing to postnatal cartilage calcification can provide insights on therapeutic strategies to treat pathological calcification that occurs in soft tissues such as aorta, kidney, and articular cartilage.

New radiocarbon dates for terminal Pleistocene and early Holocene settlements in West Turkana, northern Kenya

Middle Pliocene hominin distribution patterns in Eastern Africa

Wide margin excision followed by tibialisation of fibula and ankle arthrodesis as novel surgical technique in giant cell tumor patient

Summary: Vascularized fibular epiphyseal transfer (VFET) offers a functional advantage in pediatric limb salvage due to the preservation of growth potential and an articular surface for remodeling. This review summarizes the available evidence on the clinical characteristics and outcomes of pediatric reconstruction applying VFET at different recipient sites and with varying techniques. VFET was used to reconstruct the proximal humerus, distal radius or ulna, proximal femur, distal fibula, calcaneus, and mandible. Although most often harvested on the anterior tibial artery, VFET has also been performed using the peroneal artery, the inferior lateral genicular artery, and a dual pedicle. Recipient site flap inset most often involved fixation with plates and/or screws as well as soft tissue reconstruction using a retained slip of biceps femoris tendon. Outcomes included limb growth, range of motion, and strength. The most common reported complications were bone flap fracture and peroneal nerve palsy. The anterior tibial artery was the most applied pedicle with reliable limb growth, but with the added risk of postoperative peroneal palsy. Bone flap fracture most often occurred at the proximal humerus and femur recipient sites. Plate fixation and the combined use of allograft had lower instances of bone flap fracture. This review highlights how the anticipated dynamic growth and remodeling this free flap offers in the long term must be weighed against its complexity and potential complications.

Background: The epidemiology of fractures of the distal humerus, proximal ulna and proximal radius has been individually studied. We sought to determine the epidemiological characteristics of all adult elbow fractures in our region, and look specifically for a relationship between their incidence and socioeconomic deprivation. Methods: We analyzed a prospectively collected trauma database from an institution serving a population of 545,000 adults. The demographic, injury and deprivation details for all patients suffering acute fractures of the distal humerus, proximal radius or proximal ulna were analyzed. Fractures were classified according to the AO, Mayo, Regan and Morrey, and modified Mason systems. Deprivation status was determined by using the Index of Multiple Deprivation. Results: We identified 405 elbow fractures in 382 patients, with an incidence of 7.4/10,000/yr. The incidence was higher in women, particularly in the elderly. In men the distribution was bimodal. Distal humerus, proximal ulna and proximal radius fractures displayed distinct epidemiological characteristics. A correlation was identified between increasing proximal forearm fracture incidence with increasing levels of deprivation. Conclusion: This report documents the current age-related incidence of these injuries and adds to the growing body of evidence that socioeconomic status influences the rate and patterns of skeletal injury in adults. Future work should examine whether the epidemiological characteristics of these injuries continue to change as our population demographics evolve over time

Reconstruction of the Interosseous Ligament Unloads Metallic Radial Head Arthroplasty and the Distal Ulna in Cadavers

Osteoporosis has been suggested as a risk factor for implant failure, but data supporting such a link are limited. A case-control study was designed to evaluate the association between osteoporosis and dental implant failure. Cases (n = 49) and controls (n = 49) were selected from a private practice. The following measures were collected for each patient: 1) peripheral dual-energy x-ray absorptiometry (pDEXA) bone measurements at the distal and proximal radius and ulna; 2) classification of bone quality and quantity at the time of implant placement; and 3) questionnaire data regarding potentially confounding variables. Generalized estimating equations were used to relate the likelihood of having at least one implant failure in an individual to osteoporosis measures. The results suggested that there was no association between pDEXA scores at the radius and ulna and the risk for implant failure. For every 1-unit increase in bone density as measured by pDEXA t-score at proximal and distal radius and ulna, the risk for a patient to lose at least one implant changed by +14% and -6%, respectively (odds ratio, 1.14; 95% confidence interval, 0.80-1.62 and odds ratio, 0.94; 95% confidence interval, 0.71-1.23). The simple visual assessment of local bone quality had a moderately sized relationship to implant failure. Implants placed in sites with thin cortical bone increased the chance for a patient to lose at least one implant by 130% when compared to implants placed in a thick cortical layer or compact bone (odds ratio, 2.3; 95% confidence interval, 1.0-5.4). This exploratory study suggests that a simple visual assessment of bone quality at the site of implant placement may be more informative regarding implant failure than pDEXA bone density measures obtained at peripheral bones. In order to determine whether peripheral osteoporosis measurements have a small or moderate association with implant loss, studies with larger sample sizes will be required.

We present a 79-year-old woman with a complex elbow fracture including a comminuted proximal ulna fracture, coronoid process fracture, and comminuted radial head fracture treated with primary total elbow arthroplasty (TEA). The patient completed an early therapy protocol and had complete healing. At 15 months postoperatively, she had full pronosupination and elbow arc of motion from 10 to 135° with no reported pain. Primary treatment of unstable, complex fractures of the proximal ulna and radius with TEA has not been previously reported in the literature. This case reports suggests that indications for primary TEA for traumatic elbow injuries in the elderly could be expanded.

Maelestes gobiensis Wible et al., 2007, is the second new eutherian mammal to be named from the rich Mongolian Late Cretaceous locality of Ukhaa Tolgod, Ukhaatherium nessovi Novacek et al., 1997, being the first. Maelestes is only the seventh Late Cretaceous eutherian known from the skull and the upper and lower dentitions, and the fifth known from some postcranial elements. The type and only known specimen, PSS-MAE 607, is described and illustrated in detail. The type is amended to include: an incomplete skull, left dentary, atlas, axis, last cervical and first 11 thoracic vertebrae, 11 partial ribs, incomplete scapula, clavicle, humerus, and proximal radius and ulna. An astragalus on a separate block was referred to Maelestes by Wible et al. (2007), but it is too large to belong to this taxon and is removed from the isotype. Several corrections and updates are made to the phylogenetic analysis of Wible et al. (2007). The original analysis and the one in this report include 408 morphological cha...

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