Osteoporosis Diagnosis, Management, and Referral Practice After Fragility Fractures.

PURPOSE OF REVIEW: The purpose of this manuscript is to review the current diagnosis, management, and referral practices of patients with osteoporosis after a fragility fracture from the orthopedic surgeon's perspective. RECENT FINDINGS: Effective treatments are available for osteoporosis that significantly decrease the risk of additional fractures. Despite recommendations for improved post-fragility fracture osteoporosis management, the rate of diagnosis and treatment is still unacceptably low. Patients sustaining a low-energy fracture should be evaluated for osteoporosis with discussion of beginning pharmacological treatment. Antiresorptive and anabolic agents are available treatment options. Fracture Liaison Services can help to coordinate the care of these patients and improve the rate of diagnosis and initiation of therapy. Dartmouth-Hitchcock is working to improve the bone health for our patients utilizing a multidisciplinary team-based approach. This process is intended to lead to increased recognition of osteoporosis within our institution and close the capture gap between hospital discharge and initiation of osteoporosis pharmacotherapy.

Visualization of the Cervicothoracic Junction With EOS Imaging Is Superior to Conventional Lateral Cervical Radiographs.

STUDY DESIGN: Single-center retrospective review. OBJECTIVES: The cervicothoracic junction (CTJ) is typically difficult to visualize using traditional radiographs. Whole-body stereoradiography (EOS) allows for imaging of the entire axial skeleton in a weightbearing position without parallax error and with lower radiation doses. In this study we sought to compare the visibility of the vertebra of the CTJ on lateral EOS images to that of conventional cervical lateral radiographs. METHODS: Two fellowship-trained spine surgeons evaluated the images of 50 patients who had both lateral cervical radiographs and EOS images acquired within a 12-month period. The number of visible cortices of the vertebral bodies of C6-T2 were scored 0-4. Patient body mass index and the presence of spondylolisthesis >2 mm at each level was recorded. The incidence of insufficient visibility to detect spondylolisthesis at each level was also calculated for both modalities. RESULTS: On average, there were more visible cortices with EOS versus XR at T1 and T2, whereas visible cortices were equal at C6 and C7. Patient body mass index was inversely correlated with cortical visibility on XR at T2 and on EOS at T1 and T2. There was a significant difference in the incidence of insufficient visibility to detect spondylolisthesis on EOS versus XR at C7-T1 and T1-2, but not at C6-7. CONCLUSIONS: EOS imaging is superior at imaging the vertebra of the CTJ. EOS imaging deserves further consideration as a diagnostic tool in the evaluation of patients with cervical deformity given its ability to produce high-quality images of the CTJ with less radiation exposure.

Liner dissociation leading to catastrophic failure of an Oxinium femoral head.

Oxinium is an alternative bearing surface designed to emulate the superior wear and scratch properties of ceramic femoral heads in total hip arthroplasty while minimizing the risk for brittle fracturing. However, recent studies have indicated that hip dislocation following total hip arthroplasty may be a risk factor for catastrophic failure of the femoral head. Here, we report on a novel case of a catastrophic Oxinium head and polyethylene liner failure in the absence of previous hip dislocation or trauma and review the probable failure mechanism. This report underscores the need to be vigilant about proper acetabular cup and liner seating, particularly in the setting of Oxinium femoral head use. In the event of Oxinium head failure, metallosis may compromise stabilizing soft tissues including the abductors. Dual-mobility articulation, which was successful in this case, is one option to consider when the risk for chronic redislocation is elevated.

Physician-Specific Variability in Spine Fusion Patients.

BACKGROUND: It is often assumed that each surgeon's patient population is similar to that of his or her peers. Differences in patient characteristics naturally may lead to diverse outcomes. To date, the variability of individual surgeons' patient populations has not been adequately characterized. The purpose of this study is to describe the variation in physician-specific patient characteristics among surgeons performing spine fusion surgery at a large, urban academic medical center. METHODS: We analyzed administrative data from a single institution for spine fusion surgery from 2009 to 2013. There were 6585 primary and 362 revision cases of spine fusion performed within this time period. Variability between surgeons and their respective patient populations was compared using descriptive statistics. RESULTS: The mean annual percentage of primary fusion patients with diabetes mellitus ranged from 0 to 16.17% (mean ± SD, 7.79% ± 3.96%) but constituted anywhere from 0 to 41.58% (mean ± SD, 8.15% ± 12.09%) of revision fusions. The mean annual percentage of primary fusion patients who were obese ranged from 0 to 9% (mean ± SD, 2.95% ± 2.7%), and 0 to 25% in revision cases (mean ± SD, 3.43% ± 6.43%). The annual mean percentage of patients with American Society of Anesthesiologists (ASA) scores greater than 3 ranged from 8.8% to 44.43% (mean ± SD, 20.42% ± 8.85%) in primary fusions and 0 to 100% (mean ± SD, 32.79% ± 23.47%) in revision fusions. CONCLUSION: There was a large amount of variability among surgeons' patient populations when looking at characteristics such as obesity, diabetes, and ASA scores >3. These factors have been shown to impact patient outcomes. The variability in the patient populations of individual surgeons' practices even within the same medical center must be taken into account when evaluating physician specific outcomes and quality of care.

Persistent pain alters AMPA receptor subunit levels in the nucleus accumbens.

BACKGROUND: A variety of pain conditions have been found to be associated with depressed mood in clinical studies. Depression-like behaviors have also been described in animal models of persistent or chronic pain. In rodent chronic neuropathic pain models, elevated levels of GluA1 subunits of α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors in the nucleus accumbens (NAc) have been found to inhibit depressive symptoms. However, the effect of reversible post-surgical pain or inflammatory pain on affective behaviors such as depression has not been well characterized in animal models. Neither is it known what time frame is required to elicit AMPA receptor subunit changes in the NAc in various pain conditions. RESULTS: In this study, we compared behavioral and biochemical changes in three pain models: the paw incision (PI) model for post-incisional pain, the Complete Freund's Adjuvant (CFA) model for persistent but reversible inflammatory pain, and the spared nerve injury (SNI) model for chronic postoperative neuropathic pain. In all three models, rats developed depressive symptoms that were concurrent with the presentation of sensory allodynia. GluA1 levels at the synapses of the NAc, however, differed in these three models. The level of GluA1 subunits of AMPA-type receptors at NAc synapses was not altered in the PI model. GluA1 levels were elevated in the CFA model after a period (7 d) of persistent pain, leading to the formation of GluA2-lacking AMPA receptors. As pain symptoms began to resolve, however, GluA1 levels returned to baseline. Meanwhile, in the SNI model, in which pain persisted beyond 14 days, GluA1 levels began to rise after pain became persistent and remained elevated. In addition, we found that blocking GluA2-lacking AMPA receptors in the NAc further decreased the depressive symptoms only in persistent pain models. CONCLUSION: Our study shows that while both short-term and persistent pain can trigger depression-like behaviors, GluA1 upregulation in the NAc likely represents a unique adaptive response to minimize depressive symptoms in persistent pain states.

AMPAkines have novel analgesic properties in rat models of persistent neuropathic and inflammatory pain.

BACKGROUND: Novel analgesics that do not suppress the respiratory drive are urgently needed. Glutamate signaling through α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors plays important roles in central pain circuits. AMPAkines augment AMPA receptor function and have been shown to stimulate the respiratory drive to oppose opioid-induced hypoventilation. However, their role in chronic pain states remains unknown. METHODS: The authors studied AMPAkines (CX546 and CX516) in rat spared nerve injury (SNI) model of neuropathic pain and Complete Freund's Adjuvant (CFA) model of inflammatory pain. They measured the effect of AMPAkines on mechanical and cold allodynia. They also evaluated their effect on depressive symptoms of pain using the forced swim test, as time of immobility on this test has been used as a measure for behavioral despair, a feature of depression. RESULTS: The authors found that CX546, compared with dimethyl sulfoxide (DMSO) control, reduced both mechanical and sensory allodynia in SNI (DMSO group, n = 9; CX546 group, n = 11) and CFA models (both DMSO and CX546 groups, n = 9). They found that CX546, compared with control, also reduced depressive symptoms of pain by decreasing immobility on the forced swim test in both SNI (both DMSO and CX546 groups, n = 8) and CFA models (both DMSO and CX546 groups, n = 10). Finally, they found that CX516, compared with control, also reduced mechanical and cold allodynia in the SNI model (both DMSO and CX516 groups, n = 10). CONCLUSIONS: AMPAkines alleviate pain hypersensitivity as well as depression-like behavior associated with long-lasting nerve injury and inflammatory insult.

A single subanesthetic dose of ketamine relieves depression-like behaviors induced by neuropathic pain in rats.

BACKGROUND: Chronic pain is associated with depression. In rodents, pain is often assessed by sensory hypersensitivity, which does not sufficiently measure affective responses. Low-dose ketamine has been used to treat both pain and depression, but it is not clear whether ketamine can relieve depression associated with chronic pain and whether this antidepressant effect depends on its antinociceptive properties. METHODS: The authors examined whether the spared nerve injury model of neuropathic pain induces depressive behavior in rats, using sucrose preference test and forced swim test, and tested whether a subanesthetic dose of ketamine treats spared nerve injury-induced depression. RESULTS: Spared nerve injury-treated rats, compared with control rats, showed decreased sucrose preference (0.719 ± 0.068 (mean ± SEM) vs. 0.946 ± 0.010) and enhanced immobility in the forced swim test (107.3 ± 14.6s vs. 56.2 ± 12.5s). Further, sham-operated rats demonstrated depressive behaviors in the acute postoperative period (0.790 ± 0.062 on postoperative day 2). A single subanesthetic dose of ketamine (10 mg/kg) did not alter spared nerve injury-induced hypersensitivity; however, it treated spared nerve injury-associated depression-like behaviors (0.896 ± 0.020 for ketamine vs. 0.663 ± 0.080 for control rats 1 day after administration; 0.858 ± 0.017 for ketamine vs. 0.683 ± 0.077 for control rats 5 days after administration). CONCLUSIONS: Chronic neuropathic pain leads to depression-like behaviors. The postoperative period also confers vulnerability to depression, possibly due to acute pain. Sucrose preference test and forced swim test may be used to compliment sensory tests for assessment of pain in animal studies. Low-dose ketamine can treat depression-like behaviors induced by chronic neuropathic pain.