Factors associated with unsuccessful return-to-work following work-related upper extremity injury.

BACKGROUND: Returning to work following occupational injury is a key outcome for both workers' compensation boards and injured workers. Predictive factors for returning remain unclear. AIMS: To describe factors associated with unsuccessful return-to-work (RTW) in a hand injury population to identify target areas through which occupational rehabilitation programmes can help injured workers achieve successful RTW outcomes. METHODS: Demographic data, functional, pain and psychosocial scores were recorded for injured workers discharged between April 2011 and September 2015 from a multidisciplinary upper extremity treatment programme. The primary outcome of RTW status was assessed at programme discharge. Bivariate analyses and multivariable logistic regression were used to identify factors associated with being unable to RTW. RESULTS: Of 872 participants who met the inclusion criteria, 65% were male and the mean age was 46 (standard deviation [SD] 11) years. In unadjusted bivariate analyses, the group with an unsuccessful RTW outcome had higher mean baseline pain, catastrophizing and QuickDASH scores; a higher baseline prevalence of depression, and reported a high level of pain more frequently than those who were working at discharge. In the adjusted logistic regression model, not working at baseline, higher QuickDASH score and presence of depression at baseline were independently associated with unsuccessful work status outcome. CONCLUSIONS: Negative baseline work status, greater self-reported functional disability and presence of depression were associated with greater odds of unsuccessful RTW following a workplace upper extremity injury. Integrating mental healthcare provision with occupational rehabilitation is a potential programmatic approach to improve RTW.

Use of digital images to aid in the decision-making for acute upper extremity trauma referral.

UNLABELLED: This study evaluated the use of digital smartphone images in the decision-making for acute upper extremity trauma referrals. Surgeons (n = 15) were presented with ten upper limb trauma scenarios for consideration of immediate transfer. Based on verbal history and with additional images, participants were asked questions regarding diagnosis, injured tissues, recommended management and diagnostic and treatment confidence. Statistical analyses evaluated confidence level changes and relationships between confidence levels and independent variables. Confidence levels for diagnosis and treatment were increased with the provision of smartphone images, and this was statistically significant. The decision to transfer was changed in 22%. The photographs were more useful for amputation versus non-amputation injuries (diagnosis and treatment) and hand versus forearm injuries (diagnosis), and these differences reached statistical significance. Smartphone digital images were shown to be useful for decision-making in acute upper extremity trauma referrals. This improved communication may have implications for health cost savings and patient burden by minimizing unnecessary acute transfers. LEVEL OF EVIDENCE: Diagnostic Level III.

Fluid dynamics in bioreactor design: considerations for the theoretical and practical approach.

The following chapter summarizes principles of fluid dynamics in bioreactor design with a focus on mammalian cell-culture systems.

The osteogenic potential of pseudoarthrosis tissue and bone from human scaphoid non-unions.

Scaphoid fractures have the highest prevalence of non-union in the human body, but little is known about the osteogenic potential of cells at the pseudoarthrosis. It was our goal to determine whether cells isolated from non-unions could be stimulated to differentiate into osteoblasts and produce bone in vitro. Fifteen human scaphoid non-unions were excised during surgery and bone from either side of the non-union and the fibrocartilagenous central regions were harvested. Osteoblastic populations were subcultured from these. The number of bone nodules (colonies of osteoblast cells that produced bone) from all three regions was similar to the number of nodules derived from iliac bone cultures from the same patients. Treatment of cells with rhBMP-2 resulted in a 3- to 10-fold increase in bone nodule formation in vitro from cells derived from the non-unions. These data demonstrate that cells at the pseudoarthrosis have osteogenic capability and can be stimulated by rhBMP-2, possibly increasing the ability to heal.

Endothelin-1 down-regulates the expression of vascular endothelial growth factor-A associated with osteoprogenitor proliferation and differentiation.

Endothelin-1 (ET-1) is implicated in the signaling between vascular endothelial cells (VECs) and osteoblasts during bone development, remodeling and repair. Vascular endothelial growth factor (VEGF) also plays an important role in these intercellular interactions. Our objectives were to identify which specific VEGF isoforms were produced during osteoblastic proliferation and differentiation and to determine the effects of ET-1 on VEGF mRNA and protein production by osteoblastic cells. Semiquantitative reverse transcription polymerase chain reaction (RT-PCR) and ELISA were used to evaluate VEGF mRNA isoform expression and protein synthesis at different stages of ET-1-induced osteoblastic differentiation in fetal rat calvaria (FRC) osteoblastic cells. Three VEGF mRNA isoforms were identified corresponding to VEGF(120), VEGF(164) and VEGF(188). Predominant isoforms VEGF(120) and VEGF(164) had a bimodal expression that increased in the early proliferation and late mineralization phases. ET-1 stimulated osteoblastic proliferation and differentiation, but surprisingly, ET-1 down-regulated VEGF mRNA and protein expression and sustained the down-regulation over time in long-term cultures. Time course studies showed that ET-1 inhibited VEGF mRNA expression after incubation for 3 h in 7- and 14-day FRC cell cultures. Similarly, ET-1 inhibited VEGF protein secretion by 5.8- and 2.8-fold in 7- and 14-day FRC cells, respectively. VEGF-A protein secretion was inhibited by ET-1 in a dose-dependent manner with a maximal effect at 10(-7) M. This study supports a novel inhibitory role for ET-1 on VEGF synthesis in osteoblastic cells as a feedback mechanism in the temporal and spatial coupling of angiogenesis to bone formation and resorption.

Endothelin-1 promotes osteoprogenitor proliferation and differentiation in fetal rat calvarial cell cultures.

Endothelin-1 (ET-1), a peptide produced by vascular endothelial cells, has been suggested to be one of the signaling factors between vascular and osteoblastic cells during bone growth and remodeling. The osteoinductive effects of ET-1 were tested on fetal rat calvaria which have the ability to form bone nodules in culture. ET-1 (10(-10) to 10(-6) M) dose-dependently increased cell proliferation. The effect of ET-1 (10(-8) M) on proliferation was greater than that of dexamethasone (Dex; 10(-8) M). ET-1 also increased the number of bone nodules by 146% over untreated cells, which coincided with a 3.1-fold increase in alkaline phosphatase activity. Limiting dilution assays showed that ET-1 treatment increased the number of osteoprogenitors (CFU-AP and CFU-OB) beyond what would be expected by a proliferative effect alone, indicating that ET-1 also stimulated osteoblast differentiation. Osteocalcin mRNA expression was upregulated as shown by Northern blot analysis. Using cDNA microarray analysis, ET-1 treatment resulted in an expression profile that included an upregulation of 163 genes and expressed sequence tags. Simultaneous addition of ET-1 and Dex to the medium further increased the number of bone nodules and alkaline phosphatase activity over either treatment alone. Our results show that ET-1 promotes both osteoblastic proliferation and differentiation and that the effects of ET-1 and Dex on differentiation are cooperative.

Osseous anatomy of the scapula.

Detailed anatomy and morphometry of the scapula were obtained to provide information for surgical procedures such as hardware fixation, drill hole placement, arthroscopic portal placement, and prosthetic positioning. Twenty-six measurements were made in 15 pairs of scapulas from cadavers. The average length of the scapulas from the superior to the inferior angle was 155 +/- 16 mm (mean +/- standard deviation). The thickness of the medial border 1 cm from the edge was 4 +/- 1 mm. The superior border was sharp and thin, and the suprascapular notch was present as a foramen in two scapulas. The distance from the base of the suprascapular notch to the superior rim of the glenoid was 32 +/- 3 mm. The length of the spine from the medial edge of the scapula to the lateral edge of the acromion was 134 +/- 12 mm. The anteroposterior width of the spine at 1 and 4 cm from the medial edge was 7 +/- 1 and 18 +/- 3 mm, respectively; the width at the lateral edge (spinoglenoid notch) was 46 +/- 6 mm. The acromion measured 48 +/- 5 mm x 22 +/- 4 mm and was 9 +/- 1 mm thick. The acromial shape was flat in 23%, curved in 63%, and hooked in 14% of scapulas. The distance from the glenoid to the acromion was 16 +/- 2 mm. The glenoid dimensions were 29 +/- 3 mm (anteroposterior) x 36 +/- 4 mm (superoinferior) and faced posterior by 8 +/- 4 degrees. Anteroposterior thickness of the head of the scapula 1 cm from the surface was 22 +/- 4 mm. The thickness of the coracoid was 11 +/- 1 mm. The average length of the coracoacromial ligament was 27 +/- 5 mm. Scapulas from male cadavers were significantly larger than scapulas from female cadavers in 19 measurements.

Anatomy and functional significance of the long extensors to the fingers and thumb.

Intrinsic and extrinsic hand muscles power finger extension. These two muscle groups have different anatomy that allows complimentary function at the interphalangeal joints and opposing function at the metacarpophalangeal joints. Independent extension of each finger is not possible because of anatomic constraints including the juncturae tendinum and intertendinous fascia between the extrinsic extensor tendons on the dorsum of the hand. Anatomic variations of the extrinsic extensor tendons are frequent and knowledge is important when assessing the traumatized or diseased hand.

The dorsal aponeurosis, intrinsic, hypothenar, and thenar musculature of the hand.

The intrinsic muscles of the hand consist of seven interossei and four lumbrical muscles. With the extrinsic long extensors, the intrinsic muscles act via the dorsal aponeurosis to control finger motion. The interossei also control finger abduction and adduction, and flexion of the metacarpophalangeal joints. The lumbricals are the main extensors of the interphalangeal joints. The complex structure of the dorsal aponeurosis allows coordination and individual joint motion. The muscles of the hypothenar and thenar eminences also insert into the dorsal aponeurosis and the skeleton of the small finger and thumb, respectively, and are responsible for the specialized motion. Knowledge of the anatomy is necessary for understanding the function in treating abnormalities and trauma to the intricate structures of the hand.

Scaphoid nonunion with avascular necrosis of the proximal pole. Treatment with a vascularized bone graft from the dorsum of the distal radius.

Scaphoid nonunion with avascular necrosis of the proximal pole remains a difficult problem. We have endeavoured to heal the fracture, restore scaphoid height and revascularize the proximal pole of the scaphoid by means of a vascularized dorsal interposition graft from the distal radius. The procedure has resulted in union of six of ten fractures. Fractures that healed had not been treated by a previous bone grafting procedure. Dissatisfaction was due to loss of motion in patients who had healed fractures, and pain in those patients with persistent non-unions.

Definitions and terminology of compartment syndrome and Volkmann's ischemic contracture of the upper extremity.

Increased tissue pressure within the confines of a nondistensible anatomic compartment increases venous pressure, causes vascular compression, decreases the arteriovenous gradient, and results in a compartment syndrome. The decreased blood flow and hypoxia result in cellular damage of muscles, nerves, and vascular endothelium. Richard von Volkmann's legacy has taught us that a patient's overall status must be monitored to follow the systemic determinants of peripheral blood flow and oxygen transport. Limbs must also be monitored with vigilance. A high index of suspicion must always be present, and compartment pressures can be measured directly to aid in clinical decision making regarding the status of a compartment. The remaining articles in this issue describe and explore von Volkmann's syndrome using the terms and concepts introduced here.

Crush syndrome of the upper extremity.

Crush syndrome is the severe systemic manifestation of prolonged muscle compression and compartment syndrome. Careful patient assessment, early diagnosis, and aggressive treatment are vital to prevent multiorgan failure and death. Medical management of systemic complications, along with operative procedures of fasciotomy and debridement, are indicated with accompanying compartment syndrome. Debridement of necrotic and nonviable tissue is necessary; significant risks of infection and hemorrhage remain until the wounds can be subsequently closed or covered with skin graft. Crush syndrome and muscle necrosis in a closed injury without compartment syndrome may be followed clinically until healing or demarcation of a gangrenous part occurs, providing the patient's general medical condition, including renal function, can be maintained. Fasciotomy and hyperbaric oxygen will not reverse necrosis of muscle in the absence of compartment syndrome and therefore do not affect outcome of the extremity. Overall, prognosis is improved by early diagnosis and treatment, but outcome of the crushed extremity is poor and Volkmann's contracture often results.

Retinoic acid responsiveness of cells and tissues in developing fetal limbs evaluated in a RAREhsplacZ transgenic mouse model.

Limb morphogenesis is a complex phenomenon in which retinoids play an important role. Abnormal maternal retinoid levels from high oral doses cause fetal malformations, including abnormalities of the musculoskeletal system. Our purpose was to identify the retinoid-responsive cells in bone and cartilage during limb development by using a transgenic line of mice containing a reporter gene insert consisting of a retinoic acid response element linked to an Escherichia coli beta-galactosidase gene. Transgenic fetuses from day 11.5 after conception to birth (day 20) were analyzed histologically. Retinoid-responsive cells and tissues were first seen in the limb bud at 12.5 days in the webs between the forming digits. The webs stained maximally at 14.5 days, after which staining intensity subsided. Staining in the muscles was detectable at 13.5 days, at a stage coinciding with myoblast fusion. Specific regions of perichondrium and periosteum also stained at this stage. Occasional staining was observed in individual chondroblasts in all chondrogenic regions, including hypertrophic chondroblasts and certain articular surfaces of developing joints. Staining of these tissues decreased in intensity in subsequent stages. Osteoclasts started to express beta-galactosidase at 15.5 days and continued to stain into maturity. Our results indicate that specific subsets of cells respond to retinoids at specific stages in the course of normal limb development. In hypertrophic chondrocytes and cells in the webs and joints that display such a response, retinoid-induced effects may be linked to cell death that occurs in these regions. Staining in muscle, perichondrium, and periosteum may reflect retinoid-induced effects associated with cell differentiation and growth. These results suggest that retinoids play a role in a variety of tissues, including bone and cartilage, at specific stages during morphogenesis.

Functional anatomy of the extensor tendons of the digits.

The complexity and intricacy of hand function are reflected by the anatomy. Extensor muscles have a relatively consistent architecture but also have notable anatomic variations of their tendons, particularly on the ulnar side of the hand. The extensor tendons, juncturae tendinum, intertendinous fascia, and soft tissue function as a plexiform construct to provide stability during power grip and allow for laxity in performing independent fine finger tasks. The greater independence of index finger motion relates to its two tendons, one (EDC-index) with a thin transverse juncturae tendinum, the other (EIP) without a junctural connection. It is also more independent because of a more mobile metatarsal, and because it is confined by only one web. The first dorsal interosseous also functions to rotate the index finger. The lumbrical to the index finger has only a single origin on the flexor profundus tendon. The elaborate tendon plexus on the dorsum of the hand is repeated in the complexity of the dorsal aponeurosis on the dorsum of the fingers. Finger motion is a balance of flexor muscles and intrinsics and extensor muscles that provides incredible versatility. This versatility and delicate balance of function is easily jeopardized by trauma and disease. The hand is among the most frequently injured parts of the body. An appreciation and understanding of its complex anatomy is of importance to hand assessment, repair, and reconstruction.

The altruistic medical researcher: gone and forgotten?

With increasing economic, political, and bureaucratic involvement in research, there is little focus on the medical researcher's idealistic and benevolent intentions. Benevolence is a pillar of ethical human-subjects research, and altruism is a form of benevolence that is difficult to quantify. It is interest in the welfare of others without personal benefit. This article examines the extent of altruism in medical research from philosophical, psychological, and practical points of view. With the emergence of experimental human trials in the first half of the century, the fame and recognition of physicians largely precluded altruistic motivation. From the philosophical perspective, altruism is at best an optional moral principle. It is not evident in ethical guidelines. In the scientific process, altruism can exist only in ethical and properly designed research. Egoism, scientific misconduct, and conflicts of interest undermine it; but altruism is also a potential solution for these problems. Research is not globally oriented and has an unjust distribution. In an evolutionary model, altruism cannot thrive due to its lack of rewards and feedback, particularly in the economic climate of today's science. Anonymity is decreasing, selfishness is increasing. Research has become an industry, and virtuous ideals are a romantic notion. If we use altruism as an indicator, then its rarity and fragility indicate research's unhealthy state.

Carpal tunnel syndrome.

CTS is a common upper extremity problem that has an increasing incidence and poorly understood causes. Radiographs and electrodiagnostic tests are helpful, but the diagnosis remains based on clinical symptoms and signs. The several sites of median nerve compression must be considered. Splinting and steroid injections are often effective. Carpal tunnel release is indicated in refractory or acute problems, and both open and endoscopic methods remain popular. Each has specific advantages.

Recurrent carpal tunnel syndrome.

Recurrent symptoms of CTS have been shown to occur in 0% to 19% of patients following CTR, with up to 12% requiring re-exploration. Common causes of recurrent CTS are incomplete release of the TCL, fibrous proliferation, or recurrent tenosynovitis. The prognosis for re-exploration is fair; improvement can be achieved in many cases, but prognosis is not as favorable as in primary CTR. The most predictable improvement seems to be in patients with CTS caused by granulomatous infections, in which proper surgery and medical therapy can usually result in a satisfactory outcome. For the heavily scarred carpal tunnel with fibrous proliferation, many operative options are available. These procedures include external nerve lysis and mobilization, followed by application of local muscle flaps, fat grafts, or vein wrapping. There appear to be higher recurrence rates and poorer outcomes in patients with occupation-related CTS.

Titanemia from total knee arthroplasty. A case resulting from a failed patellar component.

The subject of this case report is a patient with elevated serum levels of titanium (77 parts/billion [ppb]; normal, 3.3 ppb) and vanadium (0.38 ppb; normal, 0.17 ppb) resulting from excessive wear of a metal-backed patellar component in a total knee arthroplasty. The patellar component was worn through both its polyethylene and metal backing as a result of abnormal contact between the patellar and femoral components. Scanning electron microscopic examination of the ingrowth surface of the patellar component indicated that particle debonding occurred as a result of overloading of the sintered neck regions at the particle-substrate interface, suggesting a possible damage during initial insertion of the device, which may have predisposed it to loosening and abnormal contact with the femoral component. Wear particles resulted in staining of the tissues within the knee and an inflammatory and immune response in the synovium consisting of giant cells and T lymphocytes. The serum metal levels were reduced 22 weeks after replacing the patellar component; however, the titanium level was still slightly elevated (8 ppb).

Synovial osteochondromatosis of the distal radio-ulnar joint.

Synovial osteochondromatosis is an uncommon lesion characterized by cartilagenous and osseous metaplasia of joint synovium. It is typically monarticular, affecting large joints such as the knee and hip, although it has also been described in the ankle, elbow and shoulder. It is exceptionally rare in the hand, but has been reported involving the tenosynovium of the digits and the wrist. We report a rare case of synovial osteochondromatosis involving the distal radio-ulnar joint in a 16-year-old man.