Alexandra Carrer

Hospital readmission after spine fusion for adult spinal deformity.

Study Design. Retrospective cohort study. Objective. To assess the rate, causes, and risk factors of unplanned hospital readmission after spine fusion for the treatment of adult spinal deformity. Summary of Background Data. Hospital readmissions in the elderly are common, and with increasing emphasis on the quality of health care, readmission rates are used to assess hospital performance. Spine surgery has seen rapidly increased utilization during the past 2 decades. Surgical treatments of complex spinal deformity are known to have higher rates of complications than other types of spine surgery. However, there are no reports describing the rates and causes of hospital readmission after deformity surgery. Methods. Patients were identified at a single institution from 2006 through 2011 that received a spine fusion for the treatment of adult spinal deformity. All hospital readmissions within 90 days of discharge were reviewed for cause. Unplanned readmission rates were calculated via Kaplan-Meier failure analysis. Rates were compared across patients receiving different lengths of spine fusion (short: 2–3 vertebra, medium: 4–8, long: 9 or more). Risk factors were assessed using a Cox proportional hazards multivariate model. Results. Eight hundred thirty-six patients were enrolled (111 short, 402 medium, and 323 long fusions). The overall unplanned readmission rate was 8.4% at 30 days and 12.3% at 90 days. Patients with long spine fusion had higher rates of readmission than patients with medium or short length fusions. Surgical site infection accounted for 45.6% of readmissions. Risk factors for readmission include longer fusion length, higher patient severity of illness, and specific medical comorbidities. Conclusion. Unplanned hospital readmissions after spine fusion for adult spinal deformity are common, and are most often due to surgical site infection. Patient medical comorbidities are an important part of assessing risk and can be used by providers and patients to better assess individual risk prior to treatment. Level of Evidence: 3

Hospital readmission rates after surgical treatment of primary and metastatic tumors of the spine.

Study Design. Retrospective cohort study. Objective. This study aimed to identify the rates and causes of unplanned hospital readmission at 30 days and 1 year after surgical treatment of primary and metastatic spinal tumors. Summary of Background Data. Primary spine tumors and non–spine tumors metastatic to the spine can represent complex problems for surgical treatment, but surgical intervention can provide significant patients with significant improvements in quality of life. However, recent emphasis on decreasing the cost of health care has led to a focus on quality measures such as hospital readmission rates. Methods. At a large referral spine center between 2005 and 2011, 197 patients with primary (n = 33) or metastatic (n = 164) tumors of the spine were enrolled. Hospital readmissions within 1 year were reviewed. Kaplan-Meier analysis was performed to estimate unplanned hospital readmission rates, and risk factors were evaluated using a Cox proportional hazards model. Results. Unplanned hospital readmission rates were 6.1% and 16.8% at 30 days for primary and metastatic tumors (P = 0.126), respectively, and 27.5% and 37.8% at 1 year (P = 0.262). Metastatic tumors with aggressive biology (i.e., lung, osteosarcoma, stomach, bladder, esophagus, pancreas) caused higher rates of readmission than other types of metastatic tumors. One-third of readmissions were due to recurrent disease, whereas 23.3% were due to surgical complications and 43.3% due to medical complications. Numerous medical comorbidities increased the risk of unplanned hospital readmission. Conclusion. Unplanned hospital readmissions after surgical intervention for spine tumors are common, and patients with aggressive metastatic tumors are at increased risk. In addition, comorbid medical problems are important risk factors that increase the chance that a patient will require hospital readmission within 1 year. Level of Evidence: 3

Progressive Gorham disease of the forearm.

Gorhams-Stout disease is a rare but potentially debilitating disease consisting of massive bone osteolysis and bone resorption associated with vascular proliferation and increased osteoclastic activity. Although it can present in a wide variety of forms, it typically involves bones formed by intramembranous ossification such as the skull, pelvis, and scapula. It can occur spontaneously or after trauma. Most cases are monofocal and resolved spontaneously, although there are reports of multifocal and rapidly progressing disease. It typically presents as disuse muscle atrophy or pathologic fracture during the second through fourth decades of life, yet it has also been reported in childhood and in the elderly. The etiology of Gorhams disease remains to be fully elucidated. Gorham attributed the origin of the disease to uncontrolled proliferation of small vessels eating away bone tissue. Other authors attribute the cause of the disease to increased osteoclastic activity mediated by elevated cytokine levels and increased osteoclastic differentiation. Treatment is not established and focuses at stopping osteoclastic activity and angiogenic proliferation. Radiation therapy, chemotherapy, bone grafting, and antiresorptives medications have all been used with different degrees of success. In an effort to further characterize this elusive disease, we report on an unusual presentation of a patient with Gorhams disease of the radius spreading to the ulna and then the proximal humerus with a 13-year follow-up. To our knowledge this is the first report in the literature of a saltatory type of Gorhams disease spreading from bone to bone across a joint.

Fresh-frozen osteochondral allograft reconstruction of a severely fractured talus. A case report.

Talar fractures constitute <1% of all fractures1 and are associated with a high rate of morbidity due to the limited vascularity of the talus and frequent substantial posttraumatic loss of function. Especially challenging are comminuted talar fractures for which reduction and internal fixation is implausible and a tibiotalar and/or subtalar arthrodesis is performed at the cost of joint mobility and hindfoot anatomy. The use of autologous bone-tissue allografts (from the iliac crest or femoral head) to treat talar neck and body fractures has been reported. However, these allograft procedures have been accompanied by primary fusion of one or more of the seven articular surfaces of the talus, most commonly the talocalcaneal, talonavicular, and talotibial joints, leading to considerable loss of function2-4. The use of whole-bone fresh-frozen allografts in the foot has only been reported for the treatment of bone tumors. Muscolo et al. reported on the use of whole fresh-frozen calcaneal allografts for the treatment of chondrosarcoma and giant-cell tumor of the calcaneus5. We are unaware of any previous reports on the use of bulk allografts as an alternative to subtalar arthrodesis for the treatment of severely comminuted fractures of the talus. In an attempt to minimize loss of function, we reconstructed a severely comminuted talar fracture with use of a portion of a fresh-frozen osteochondral talar allograft. We report our results after twenty-nine months of follow-up. The patient was informed that data concerning this case would be submitted for publication. Afifty-year-old man fell from a height of 16 ft (4.9 m). He complained of pain in the back and in the right ankle. Radiographs demonstrated a comminuted fracture of the posteroinferior aspect of the right talus. The fracture involved the posterior aspect of the talar …

The increased prevalence of cervical spondylosis in patients with adult thoracolumbar spinal deformity.

Study Design: Retrospective cohort study. Objective: To assess the concomitance of cervical spondylosis and thoracolumbar spinal deformity. Summary of Background Data: Patients with degenerative cervical spine disease have higher rates of degeneration in the lumbar spine. In addition, degenerative cervical spine changes have been observed in adult patients with thoracolumbar spinal deformities. However, to the best of our knowledge, there have been no studies quantifying the association between cervical spondylosis and thoracolumbar spinal deformity in adult patients. Methods: Patients seen by a spine surgeon or spine specialist at a single institution were assessed for cervical spondylosis and/or thoracolumbar spinal deformity using an administrative claims database. Spinal radiographic utilization and surgical intervention were used to infer severity of spinal disease. The relative prevalence of each spinal diagnosis was assessed in patients with and without the other diagnosis. Results: A total of 47,560 patients were included in this study. Cervical spondylosis occurred in 13.1% overall, but was found in 31.0% of patients with thoracolumbar spinal deformity (OR=3.27, P<0.0001). Similarly, thoracolumbar spinal deformity was found in 10.7% of patients overall, but was increased at 23.5% in patients with cervical spondylosis (OR=3.26, P<0.0001). In addition, increasing severity of disease was associated with an increased likelihood of the other spinal diagnosis. Patients with both diagnoses were more likely to undergo both cervical (OR=3.23, P<0.0001) and thoracolumbar (OR=4.14, P<0.0001) spine fusion. Conclusions: Patients with cervical spondylosis or thoracolumbar spinal deformity had significantly higher rates of the other spinal diagnosis. This correlation was increased with increased severity of disease. Patients with both diagnoses were significantly more likely to have received a spine fusion. Further research is warranted to establish the cause of this correlation. Clinicians should use this information to both screen and counsel patients who present for cervical spondylosis or thoracolumbar spinal deformity.

Uncontrolled Hemorrhage in Insulin-dependent Diabetic Rats

OBJECTIVES Diabetes mellitus (DM) is a known risk factor for higher morbidity and mortality after trauma. The authors tested the hypothesis that there is a difference in the response to uncontrolled hemorrhage between normal euglycemic rats and insulin-dependent diabetic rats. METHODS Thirty-one adult male Sprague-Dawley rats were used in this study. Fifteen streptozocin (STZ)-injected rats became diabetic (DM+) 2 weeks after treatment. Sixteen rats served as nondiabetic controls (DM-). All rats were anesthetized with Althesin and their femoral arteries were catheterized via cutdown, allowing continuous monitoring of vital signs. Sixteen (eight DM-, eight DM+) rats underwent uncontrolled hemorrhage by 75% tail amputation. Fifteen (eight DM-, seven DM+) rats served as non-hemorrhage controls. The mean arterial pressure (MAP), lactate, and cumulative hemorrhage volume per 100 g were measured pre-hemorrhage and then every 15 minutes post-hemorrhage for 2 hours. Data were reported as mean +/- standard deviation. Interval data were analyzed by analysis of variance (two tails, alpha = 0.05). RESULTS Pre-hemorrhage glucose was significantly higher (p < 0.001) in the DM+ (357.9 +/- 22.2 mg/dL) versus DM- (125.7 +/- 9.7 mg/dL) rats. At baseline, there was no significant difference in weight, MAP, or lactate between DM+ and DM- rats. Body-weight-adjusted mean cumulative hemorrhage volume was significantly greater (p < 0.04) in diabetic rats (2.52 +/- 0.15 cm(3)/100 g body weight) than the nondiabetic rats (1.86 +/- 0.25 cm(3)/100 g body weight). CONCLUSIONS Compared to nondiabetic rats, diabetic rats suffered a greater blood loss after the same uncontrolled vascular injury.

Influences of structural properties of the distal tibia on the compressive strength of interlocking screws for intramedullary nails

Intramedullary (IM) nailing procedures for tibia fractures present the advantages of protecting the surrounding soft tissues at the distal tibia metaphysis. The current nails offer the options of putting a maximum of 3 screws distally. Locking the nail distally raises some valuable questions which are, to date, unanswered in literature. Following a previous work done at our lab on artificial sawbones, we expanded the study on cadaveric human bones in order to simulate, as much as possible, the mechanical behavior of in vivo applications. Our goal was to determine the most biomechanically stable configuration of distal locking screws for the treatment of distal metaphyseal tibia fractures with IM nails and, more importantly, the most efficient way to use surgical time and resources. Our results showed that a configuration with three locking screws could provide higher load carrying capacity than the two screws although not statistically significant. This work was also conducted to assess the impact of gender, age, cortical thickness, and cancellous bone density on the load carrying capacity of the bone samples.

Biomechanical Testing of the Compressive Strength of Various Distal Locking Screw Options for Intramedullary Nails in the Treatment of Tibia Fractures

Treatment of distal third tibia fractures remains challenging. New intramedullary nails provide torsional stability by using distal interlocking screws. In this study we attempted to determine the most biomechanically stable number and configuration of distal locking screws. The distal part of human cadaveric tibia bones was nailed using a tibial nail (Stryker T2). Distal locking was performed in three different configurations: (a) Group I: 2 screws in the medio-lateral (ML) direction, (b) Group II: 1 ML screw and 1 Screw in the antero-posterior (AP) direction, and (c) Group III: 2 ML screws and 1 AP screw. The specimens were then mounted onto a mechanical testing machine (Instron) and tested in compression. The load carrying capacity of the samples from Group III with these locking screws was higher than Group I & II, although this difference was not statistically significant.Copyright