Metaphyseal Stem Extension Improves Tibial Stability in Cementless Total Knee Arthroplasty.

BACKGROUND: The goal was to determine if the addition of a metaphyseal stem extension limits micromotion of a cementless tibial component during cyclic loading in primary total knee arthroplasty. The hypothesis tested was that the use of a 50-mm stem extension on a cementless tibial component would limit motion compared with an identical cementless component without a stem extension. METHODS: The study used 3 variations of a tibial component from the same total knee arthroplasty system. Group 1 consisted of a cementless tibial component without a stem extension. Group 2 used the same cementless component as group 1, but with the addition of a short 50-mm stem. Group 3 consisted of a cemented tibial component without a stem extension to serve as a "control" (gold standard). The tibial specimens were implanted into a synthetic bone model and tested using a physiological medial-lateral 60/40 load distribution for 5000 cycles. RESULTS: The results demonstrated a significant decrease in motion at the anterior region of the cementless stem extension (group 2) components compared with the cementless with no stem extension (group 1). The cementless with stem extension (group 2) demonstrated similar results at all cycles to the cemented (group 3) components at the anterior region. CONCLUSION: The addition of a short metaphyseal stem (50mm) to a keel plus 4-peg tibial component design provides a significant reduction in micromotion during cyclic loading of a cementless tibial baseplate in a synthetic foam bone model, similar to a cemented implant.

Archaeology and art in context: Excavations at the Gunu Site Complex, Northwest Kimberley, Western Australia.

The Kimberley region of Western Australia is one of the largest and most diverse rock art provenances in the world, with a complex stylistic sequence spanning at least 16 ka, culminating in the modern art-making of the Wunumbal people. The Gunu Site Complex, in the remote Mitchell River region of the northwest Kimberley, is one of many local expressions of the Kimberley rock art sequence. Here we report excavations at two sites in this complex: Gunu Rock, a sand sheet adjacent to rock art panels; and Gunu Cave, a floor deposit within an extensive rockshelter. Excavations at Gunu Rock provide evidence for two phases of occupation, the first from 7-8 to 2.7 ka, and the second from 1064 cal BP. Excavations at Gunu Rock provide evidence for occupation from the end of the second phase to the recent past. Stone for tools in the early phase were procured from a variety of sources, but quartz crystal reduction dominated the second occupation phase. Small quartz crystals were reduced by freehand percussion to provide small flake tools and blanks for manufacturing small points called nguni by the Wunambal people today. Quartz crystals were prominent in historic ritual practices associated with the Wanjina belief system. Complex methods of making bifacially-thinned and pressure flaked quartzite projectile points emerged after 2.7 ka. Ochre pigments were common in both occupation phases, but evidence for occupation contemporaneous with the putative age of the oldest rock art styles was not discovered in the excavations. Our results show that developing a complete understanding of rock art production and local occupation patterns requires paired excavations inside and outside of the rockshelters that dominate the Kimberley.

Last appearance of Homo erectus at Ngandong, Java, 117,000-108,000 years ago.

Homo erectus is the founding early hominin species of Island Southeast Asia, and reached Java (Indonesia) more than 1.5 million years ago1,2. Twelve H. erectus calvaria (skull caps) and two tibiae (lower leg bones) were discovered from a bone bed located about 20 m above the Solo River at Ngandong (Central Java) between 1931 and 19333,4, and are of the youngest, most-advanced form of H. erectus5-8. Despite the importance of the Ngandong fossils, the relationship between the fossils, terrace fill and ages have been heavily debated9-14. Here, to resolve the age of the Ngandong evidence, we use Bayesian modelling of 52 radiometric age estimates to establish-to our knowledge-the first robust chronology at regional, valley and local scales. We used uranium-series dating of speleothems to constrain regional landscape evolution; luminescence, 40argon/39argon (40Ar/39Ar) and uranium-series dating to constrain the sequence of terrace evolution; and applied uranium-series and uranium series-electron-spin resonance (US-ESR) dating to non-human fossils to directly date our re-excavation of Ngandong5,15. We show that at least by 500 thousand years ago (ka) the Solo River was diverted into the Kendeng Hills, and that it formed the Solo terrace sequence between 316 and 31 ka and the Ngandong terrace between about 140 and 92 ka. Non-human fossils recovered during the re-excavation of Ngandong date to between 109 and 106 ka (uranium-series minimum)16 and 134 and 118 ka (US-ESR), with modelled ages of 117 to 108 thousand years (kyr) for the H. erectus bone bed, which accumulated during flood conditions3,17. These results negate the extreme ages that have been proposed for the site and solidify Ngandong as the last known occurrence of this long-lived species.

Intramedullary Nails Yield Superior Results Compared With Plate Fixation When Using the Masquelet Technique in the Femur and Tibia.

OBJECTIVES: To determine the optimal fixation method [intramedullary nail (IMN) vs. plate fixation (PF)] for treating critical bone defects with the induced membrane technique, also known as the Masquelet technique. DESIGN: Retrospective cohort study. SETTING: Four Level 1 Academic Trauma Centers. PATIENTS/PARTICIPANTS: All patients with critical bone defects treated with the induced membrane technique, or Masquelet technique, between January 1, 2005, and January 31, 2018. INTERVENTION: Operative treatment with a temporary cement spacer to induce membrane formation, followed by spacer removal and bone grafting at 6-8 weeks. MAIN OUTCOME MEASUREMENTS: Time to union, number/reason for reoperations, time to full weight-bearing, and any complications. RESULTS: One hundred twenty-one patients (56 tibias and 65 femurs) were treated with a mean follow-up of 22 months (range 12-148 months). IMN was used in 57 patients and plates in 64 patients. Multiple grafting procedures were required in 10.5% (6/57) of those with IMN and 28.1% (18/64) of those with PF (P = 0.015). Reoperation for all causes occurred in 17.5% (10/57) with IMN and 46.9% (30/64) with PF (P = 0.001). Average time to weight-bearing occurred at 2.44 versus 4.63 months for those treated with IMN and plates, respectively (P = 0.002). The multivariable adjusted analysis showed that PF is 6.4 times more likely to require multiple grafting procedures (P = 0.017) and 7.7 times more likely to require reoperation (P = 0.003) for all causes compared with IMN." CONCLUSIONS: This is the largest study to date evaluating the Masquelet technique for critical size defects in the femur and tibia. Our results indicate that patients treated with IMN had faster union, fewer grafting procedures, and fewer reoperations for all causes than those treated with plates, with differences more evident in the femur. The authors believe this is a result of both the development of an intramedullary canal and circumferential stress on the graft with early weight-bearing when using an IMN, as opposed to a certain degree of stress shielding and delayed weight-bearing when using PF. We, therefore, recommend the use of an IMN whenever possible as the preferred method of fixation for tibial and femoral defects when using the Masquelet technique. LEVEL OF EVIDENCE: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Extreme Nailing: Is It Safe to Allow Immediate Weightbearing After Intramedullary Nail Fixation of Extra-articular Distal Tibial Fractures (OTA/AO 43-A)?

OBJECTIVES: To determine whether immediate weightbearing after intramedullary (IM) fixation of extra-articular distal tibial fractures (OTA/AO 43-A) results in a change in alignment before healing. DESIGN: Retrospective review. SETTING: Level 1 trauma center. INTERVENTION: IM nailing of distal tibial fractures. PATIENTS/PARTICIPANTS: Fifty-three patients with 54 fractures, all of whom could bear weight as tolerated postoperatively. Eighteen fractures were OTA/AO 43-A1, 20 OTA/AO 43-A2, and 16 OTA/AO 43-A3; 20 fractures were open. MAIN OUTCOME MEASUREMENTS: Change in fracture alignment or loss of position. RESULTS: Average change from initial angulation at final follow-up was 0.52 ± 1.49 degrees of valgus and 0.48 ± 3.14 degrees of extension. Final alignment was excellent in 14, acceptable in 28, and poor in 12; 2 fractures went from acceptable initial alignment to poor final alignment; and 2 fractures went from excellent to acceptable alignment. Seven fractures had an improvement in alignment over time. Two fractures required free-flap coverage and 4 required staged grafting because of bone loss. Ten fractures had an unplanned return to the operating room (5 for infected nonunion requiring implant exchange, 3 for infection requiring debridement without implant revision, and 2 for aseptic nonunion). No patient had revision for implant failure. CONCLUSIONS: Immediate weightbearing after IM fixation of extra-articular distal tibial fractures (OTA/AO 43-A) led to minimal change in alignment and seems to be safe for most patients. Complications were consistent with those reported in previous non-weightbearing cohorts. LEVEL OF EVIDENCE: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Outcomes of fixation for periprosthetic tibia fractures around and below total knee arthroplasty.

INTRODUCTION: The incidence of periprosthetic fractures after total knee arthroplasty (TKA) is rising due to an increasing number of TKAs performed annually and the growing elderly population. Like periprosthetic fractures of the distal femur, periprosthetic tibia fractures are primarily treated with operative fixation; however, there is limited scientific literature that has reported outcomes of periprosthetic tibia fractures treated with modern plating techniques. To our knowledge, this is the largest series of non-intraoperative periprosthetic tibia fractures treated with open reduction internal fixation (ORIF) ever reported. METHODS: Retrospective chart review of 4557 operatively treated tibia fractures with ORIF over a 16-year period at two Level 1 Trauma Centers. RESULTS: 38 patients with an average follow-up of 15.3 months (range 3-24) were identified. 11 (28.9%) fractures were in the proximal tibia (four with extension into the plateau (Felix 1A) and seven adjacent to the tibial stem (Felix 2A)), six (15.8%) in the midshaft/diaphysis (Felix 3A), and 21 (55.3%) in the distal 1/3rd (metaphysis, Felix 3A). 76.3% (29/38) of fractures united by 6 months following the index procedure, leaving 9 nonunions. The overall re-operation rate was 31.6% (12/38). There were no significant differences in rates of union (p = 1.00), reoperation (p = 0.66), superficial infection (p = 0.66), or deep infection (p = 0.31) in patients treated with single versus dual plating. CONCLUSION: Periprosthetic tibia fractures are difficult to treat and have a high risk of nonunion and reoperation even with modern plating techniques. Most patients can be treated to union with operative fixation and do not require revision arthroplasty, if the components are stable initially. We recommend dual plating for fractures in the proximal third, and either single plating or nailing for fractures in the middle and distal thirds depending on bone quality, implant positioning, and fracture morphology.

Safety and efficacy of a two-screw cephalomedullary nail for intertrochanteric femur fracture fixation: a retrospective case series in 264 patients.

INTRODUCTION: Recent advances have led to the design of a new cephalomedullary nail, which aims to decrease the risk of failures in patients with intertrochanteric hip fractures by allowing for insertion of two interdigitating screws into the head segment. The goal of this study is to evaluate the safety and efficacy of this two-screw cephalomedullary nailing system. PATIENTS/PARTICIPANTS: Patients 18 years of age and older who underwent intramedullary nailing of their intertrochanteric femoral fracture using the InterTAN nailing system (Smith and Nephew, Memphis, TN) from 2012 to 2016 were included in this retrospective study which was performed at two urban certified level-1 trauma centers and one urban certified level-3 trauma center. The study data was collected through a retrospective chart review and review of the existing radiographic studies. Primary outcome measure was mechanical hardware failure and screw cutout. Secondary outcome measures included nonunion, malunion, medical and surgical complications. RESULTS: A total of 264 patients were included in this analysis. Two patients (0.75%) were found to have a screw cut out requiring revision surgery. Two other revision surgeries were performed for malrotation (n = 1) and malunion (n = 1). Other implant-related complications occurred in 19 cases (7.9%), which included broken distal screws (n = 9), distal screw loosening (n = 8), and loose lag screws (n = 2). There was a total of 10 (3.8%) surgical wound complications, including four deep and six superficial infections. DISCUSSION: This modified cephalomedullary nail is a reliable, safe, and effective implant for management of intertrochanteric hip fractures. Surgical treatment of patients with intertrochanteric hip fractures can be performed in a safe fashion using this implant.

Correction: A reassessment of the early archaeological record at Leang Burung 2, a Late Pleistocene rock-shelter site on the Indonesian island of Sulawesi.

[This corrects the article DOI: 10.1371/journal.pone.0193025.].

A reassessment of the early archaeological record at Leang Burung 2, a Late Pleistocene rock-shelter site on the Indonesian island of Sulawesi.

This paper presents a reassessment of the archaeological record at Leang Burung 2, a key early human occupation site in the Late Pleistocene of Southeast Asia. Excavated originally by Ian Glover in 1975, this limestone rock-shelter in the Maros karsts of Sulawesi, Indonesia, has long held significance in our understanding of early human dispersals into 'Wallacea', the vast zone of oceanic islands between continental Asia and Australia. We present new stratigraphic information and dating evidence from Leang Burung 2 collected during the course of our excavations at this site in 2007 and 2011-13. Our findings suggest that the classic Late Pleistocene modern human occupation sequence identified previously at Leang Burung 2, and proposed to span around 31,000 to 19,000 conventional 14C years BP (~35-24 ka cal BP), may actually represent an amalgam of reworked archaeological materials. Sources for cultural materials of mixed ages comprise breccias from the rear wall of the rock-shelter-remnants of older, eroded deposits dated to 35-23 ka cal BP-and cultural remains of early Holocene antiquity. Below the upper levels affected by the mass loss of Late Pleistocene deposits, our deep-trench excavations uncovered evidence for an earlier hominin presence at the site. These findings include fossils of now-extinct proboscideans and other 'megafauna' in stratified context, as well as a cobble-based stone artifact technology comparable to that produced by late Middle Pleistocene hominins elsewhere on Sulawesi.

Proximal ingrowth coating decreases risk of loosening following uncemented shoulder arthroplasty using mini-stem humeral components and lesser tuberosity osteotomy.

BACKGROUND: Mini-stem humeral component (MSHC) use during total shoulder arthroplasty (TSA) provides bone preservation and ease of revision. MSHCs rely solely on proximal metaphyseal fixation; some early reports have demonstrated an unacceptably high rate of early loosening. To our knowledge, no study analyzing the effect of proximal porous coating on MSHCs has been performed. METHODS: We performed a retrospective review of consecutive patients who underwent anatomic TSA using coated or uncoated MSHCs with minimum 2-year follow-up. Postoperative radiographs were assessed for risk of or frank stem loosening, subsidence, and presence of radiolucencies. Range of motion, outcome scores (visual analog scale pain, American Shoulder and Elbow Surgeons, and Single Assessment Numeric Evaluation), and any complications were noted. RESULTS: We analyzed 68 shoulders with a mean follow-up of 27.3 months (range, 24-50 months). Of these, 34 had proximal coating and 34 were uncoated. In the coated group, no stems loosened, 1 (2.9%) subsided, and 7 (20.6%) developed radiolucencies. In the uncoated group, 1 stem (2.9%) became aseptically loose (requiring revision after 26 months), 7 (20.6%) were judged at risk of loosening (2 because of subsidence), and 15 (44.1%) developed radiolucencies. There was also an increased risk of proximal medial humeral radiolucencies among uncoated MSHCs. There were no significant differences in final range of motion or outcome scores. CONCLUSION: MSHC use is appropriate for TSA, achieving desired pain relief and functional improvement. Overall, component loosening appears uncommon at early follow-up; however, uncoated stems appear to be at greater risk of loosening and developing radiolucencies. Selecting an MSHC with proximal porous coating may decrease the risk of implant-related complications.

Obese Patients Have Fewer Wound Complications Following Fixation of Ankle Fractures.

Outcomes following ankle fracture surgery have been well studied; however, factors associated with surgical wound healing specifically are less clear. We aimed to study the relationship between wound healing and body mass index, as well as other variables following surgical treatment of ankle fractures. There were 127 consecutive, isolated, closed, malleolar ankle fractures treated with open reduction and internal fixation at a level-1 trauma center from 2008 to 2012. Patient, injury, and treatment variables were recorded and clinical records were reviewed to identify wound complications. There were 6 major and 18 minor wound complications. The overall rate of wound complication of any type was significantly lower in obese patients at 11.7% (7/60) compared with 25.4% (17/67, P < .05) in nonobese patients. When controlling for other variables obesity was associated with a significantly lower risk of developing a wound complication (OR 0.267, 95% CI 0.087-0.822), as was low energy mechanism (OR 0.246, 95% CI 0.067-0.906). No other covariates tested were associated with an increased risk of a wound infection. Ankle anatomy may present a unique situation whereby obesity may be protective against wound complications. Further studies are needed to confirm this clinical observation, and to demonstrate the mechanism through which this may occur. LEVELS OF EVIDENCE: Therapeutic, Level IV: Retrospective.

Into the Past: A Step Towards a Robust Kimberley Rock Art Chronology.

The recent establishment of a minimum age estimate of 39.9 ka for the origin of rock art in Sulawesi has challenged claims that Western Europe was the locus for the production of the world's earliest art assemblages. Tantalising excavated evidence found across northern Australian suggests that Australia too contains a wealth of ancient art. However, the dating of rock art itself remains the greatest obstacle to be addressed if the significance of Australian assemblages are to be recognised on the world stage. A recent archaeological project in the northwest Kimberley trialled three dating techniques in order to establish chronological markers for the proposed, regional, relative stylistic sequence. Applications using optically-stimulated luminescence (OSL) provided nine minimum age estimates for fossilised mudwasp nests overlying a range of rock art styles, while Accelerator Mass Spectrometry radiocarbon (AMS 14C) results provided an additional four. Results confirm that at least one phase of the northwest Kimberley rock art assemblage is Pleistocene in origin. A complete motif located on the ceiling of a rockshelter returned a minimum age estimate of 16 ± 1 ka. Further, our results demonstrate the inherent problems in relying solely on stylistic classifications to order rock art assemblages into temporal sequences. An earlier than expected minimum age estimate for one style and a maximum age estimate for another together illustrate that the Holocene Kimberley rock art sequence is likely to be far more complex than generally accepted with different styles produced contemporaneously well into the last few millennia. It is evident that reliance on techniques that produce minimum age estimates means that many more dating programs will need to be undertaken before the stylistic sequence can be securely dated.

Does Screw Configuration or Fibular Osteotomy Decrease Healing Time in Exchange Tibial Nailing?

OBJECTIVES: This multicenter study was designed to evaluate whether tibia fracture nonunions treated with exchange nailing proceed to union faster with dynamically- versus statically-locked nails, or with fibular osteotomy versus no fibular osteotomy. DESIGN: Retrospective, chart-review, multicenter study. SETTING: Multicenter review of 6 level 1 trauma centers. PATIENTS/PARTICIPANTS: Patients who had a tibia fracture treated with an intramedullary nail that progressed to nonunion, and were subsequently treated with exchange nailing, were identified. All patients that met inclusion criteria and subsequently progressed to union were included in the study. INTERVENTION: Patients underwent tibial exchange nailing to repair nonunions, with screws in either a dynamically- or statically-locked configuration with or without fibular osteotomy. MAIN OUTCOME MEASURES: The primary outcome measure was a comparison of time to healing of tibial nonunion comparing different screw configurations and fibular osteotomy. RESULTS: Fifty-two patients underwent an exchange nail procedure and their outcomes were used for the primary analysis. Patients with dynamically-locked nails proceeded to union 7.9 months after revision surgery compared with 7.3 months for those with statically-locked nails, but this was not statistically significant (P = 0.68). Patients with fibular osteotomy proceeded to union 2.9 months faster than those without fibular osteotomy, and this trended toward significance (P = 0.067). Obese patients healed on average 8.8 months after surgery compared with 6.8 months for nonobese patients (P = 0.27). Closed fractures healed after 6.4 months compared with 7.7 months for open fractures (P = 0.40). CONCLUSIONS: There was no significant difference in time to union between patients who had a dynamic screw configuration compared with a static screw configuration for their exchange nail. Patients who underwent fibular osteotomy proceeded to union faster than those without an osteotomy. LEVEL OF EVIDENCE: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Homo floresiensis-like fossils from the early Middle Pleistocene of Flores.

The evolutionary origin of Homo floresiensis, a diminutive hominin species previously known only by skeletal remains from Liang Bua in western Flores, Indonesia, has been intensively debated. It is a matter of controversy whether this primitive form, dated to the Late Pleistocene, evolved from early Asian Homo erectus and represents a unique and striking case of evolutionary reversal in hominin body and brain size within an insular environment. The alternative hypothesis is that H. floresiensis derived from an older, smaller-brained member of our genus, such as Homo habilis, or perhaps even late Australopithecus, signalling a hitherto undocumented dispersal of hominins from Africa into eastern Asia by two million years ago (2 Ma). Here we describe hominin fossils excavated in 2014 from an early Middle Pleistocene site (Mata Menge) in the So'a Basin of central Flores. These specimens comprise a mandible fragment and six isolated teeth belonging to at least three small-jawed and small-toothed individuals. Dating to ~0.7 Ma, these fossils now constitute the oldest hominin remains from Flores. The Mata Menge mandible and teeth are similar in dimensions and morphological characteristics to those of H. floresiensis from Liang Bua. The exception is the mandibular first molar, which retains a more primitive condition. Notably, the Mata Menge mandible and molar are even smaller in size than those of the two existing H. floresiensis individuals from Liang Bua. The Mata Menge fossils are derived compared with Australopithecus and H. habilis, and so tend to support the view that H. floresiensis is a dwarfed descendent of early Asian H. erectus. Our findings suggest that hominins on Flores had acquired extremely small body size and other morphological traits specific to H. floresiensis at an unexpectedly early time.

Age and context of the oldest known hominin fossils from Flores.

Recent excavations at the early Middle Pleistocene site of Mata Menge in the So'a Basin of central Flores, Indonesia, have yielded hominin fossils attributed to a population ancestral to Late Pleistocene Homo floresiensis. Here we describe the age and context of the Mata Menge hominin specimens and associated archaeological findings. The fluvial sandstone layer from which the in situ fossils were excavated in 2014 was deposited in a small valley stream around 700 thousand years ago, as indicated by (40)Ar/(39)Ar and fission track dates on stratigraphically bracketing volcanic ash and pyroclastic density current deposits, in combination with coupled uranium-series and electron spin resonance dating of fossil teeth. Palaeoenvironmental data indicate a relatively dry climate in the So'a Basin during the early Middle Pleistocene, while various lines of evidence suggest the hominins inhabited a savannah-like open grassland habitat with a wetland component. The hominin fossils occur alongside the remains of an insular fauna and a simple stone technology that is markedly similar to that associated with Late Pleistocene H. floresiensis.

Revised stratigraphy and chronology for Homo floresiensis at Liang Bua in Indonesia.

Homo floresiensis, a primitive hominin species discovered in Late Pleistocene sediments at Liang Bua (Flores, Indonesia), has generated wide interest and scientific debate. A major reason this taxon is controversial is because the H. floresiensis-bearing deposits, which include associated stone artefacts and remains of other extinct endemic fauna, were dated to between about 95 and 12 thousand calendar years (kyr) ago. These ages suggested that H. floresiensis survived until long after modern humans reached Australia by ~50 kyr ago. Here we report new stratigraphic and chronological evidence from Liang Bua that does not support the ages inferred previously for the H. floresiensis holotype (LB1), ~18 thousand calibrated radiocarbon years before present (kyr cal. BP), or the time of last appearance of this species (about 17 or 13-11 kyr cal. BP). Instead, the skeletal remains of H. floresiensis and the deposits containing them are dated to between about 100 and 60 kyr ago, whereas stone artefacts attributable to this species range from about 190 to 50 kyr in age. Whether H. floresiensis survived after 50 kyr ago--potentially encountering modern humans on Flores or other hominins dispersing through southeast Asia, such as Denisovans--is an open question.

Earliest hominin occupation of Sulawesi, Indonesia.

Sulawesi is the largest and oldest island within Wallacea, a vast zone of oceanic islands separating continental Asia from the Pleistocene landmass of Australia and Papua (Sahul). By one million years ago an unknown hominin lineage had colonized Flores immediately to the south, and by about 50 thousand years ago, modern humans (Homo sapiens) had crossed to Sahul. On the basis of position, oceanic currents and biogeographical context, Sulawesi probably played a pivotal part in these dispersals. Uranium-series dating of speleothem deposits associated with rock art in the limestone karst region of Maros in southwest Sulawesi has revealed that humans were living on the island at least 40 thousand years ago (ref. 5). Here we report new excavations at Talepu in the Walanae Basin northeast of Maros, where in situ stone artefacts associated with fossil remains of megafauna (Bubalus sp., Stegodon and Celebochoerus) have been recovered from stratified deposits that accumulated from before 200 thousand years ago until about 100 thousand years ago. Our findings suggest that Sulawesi, like Flores, was host to a long-established population of archaic hominins, the ancestral origins and taxonomic status of which remain elusive.

Acute Management of Open Fractures: An Evidence-Based Review.

Open fractures are complex injuries associated with high morbidity and mortality. Despite advances made in fracture care and infection prevention, open fractures remain a therapeutic challenge with varying levels of evidence to support some of the most commonly used practices. Additionally, a significant number of studies on this topic have focused on open tibial fractures. A systematic approach to evaluation and management should begin as soon as immediate life-threatening conditions have been stabilized. The Gustilo classification is arguably the most widely used method for characterizing open fractures. A first-generation cephalosporin should be administered as soon as possible. The optimal duration of antibiotics has not been well defined, but they should be continued for 24 hours. There is inconclusive evidence to support either extending the duration or broadening the antibiotic prophylaxis for type Gustilo type III wounds. Urgent surgical irrigation and debridement remains the mainstay of infection eradication, although questions persist regarding the optimal irrigation solution, volume, and delivery pressure. Wound sampling has a poor predictive value in determining subsequent infections. Early wound closure is recommended to minimize the risk of infection and cannot be substituted by negative-pressure wound therapy. Antibiotic-impregnated devices can be important adjuncts to systemic antibiotics in highly contaminated or comminuted injuries. Multiple fixation techniques are available, each having advantages and disadvantages. It is extremely important to maintain a high index of suspicion for compartment syndrome, especially in the setting of high-energy trauma.

Hot Topics in Biomechanics: Hip Fracture Fixation.

Geriatric hip fractures continue to increase in frequency as the population ages, and intertrochanteric femur fractures are a significant part of these injuries. Plate fixation for intertrochanteric fractures of the proximal femur has been in use for many years, and application of the sliding hip screw has also been a mainstay of treatment. Recent data suggest there may be a benefit to using implants that add rotational stability to the proximal intertrochanteric fragment. Although preliminary data are promising, there is need for improved investigation to demonstrate the benefit of these new implant designs. In this era of increasing emphasis on cost, quality, and value, better data are needed to help clinicians determine the best therapy for their patients.

Shoulder arthroplasty in the patient with metal hypersensitivity.

BACKGROUND: The in vivo effects of metal hypersensitivity remain a topic of much debate. At the core of this debate is the possible, although still hotly contested, link between metal hypersensitivity and poorly functioning or failing implants. There are multiple studies on this topic in the hip and knee arthroplasty literature, but the applicability of this experience to shoulder arthroplasty remains unclear. Although how often metal hypersensitivity affects shoulder arthroplasty patients remains uncertain, a multitude of case reports have implicated metallic implants as a source of local and systemic allergic reactions. We recommend a cautious approach to patients with a history of metal hypersensitivity, including a careful evaluation of suspected metal hypersensitivities in all patients undergoing shoulder arthroplasty. If available, we recommend a metallic implant with low to no nickel content in patients with metal hypersensitivity. Given the large and increasing, number of total shoulder arthroplasty procedures and the high percentage of the population having a known or suspected metal hypersensitivity, this review is intended to guide and educate the shoulder surgeon in the evaluation and treatment of this patient population and to point out the areas where evidence-based recommendations are lacking.