Inpatient mortality after primary total hip arthroplasty: analysis from the National Inpatient Sample database.

Although inpatient mortality rates following total hip arthroplasty are low, understanding factors that influence inpatient mortality rates is important. Discharge data from the 2007-2008 HCUP Nationwide Inpatient Sample database were used in this study. Patients were identified based on whether they were admitted for a primary total hip arthroplasty and grouped based on their mortality status. All hip and acetabular fracture patients were excluded. Discharge data revealed 508,150 primary total hip arthroplasties with an inpatient mortality rate of 0.13%. The most significant pre-operative predictors of inpatient mortality were increasing age, weekend admission, increased Charlson co-mobidity score, Medicare payer status, race and a Southern hospital region. The two most significant complications post-operatively leading to increased mortality were pulmonary and cardiovascular complications.

Rural vs. urban utilization of total joint arthroplasty.

The purpose of this study was to analyze the association between patient demographics and hospital demographics on utilization of total joint arthroplasty in rural and urban populations from the National Inpatient Sample database. Any patient that was discharged after a primary total hip or primary total knee arthroplasty was included in this study. Results showed that rural patients living in a Northeastern hospital region compared to West, less than 65 years of age, females, Blacks and Hispanics were less likely to undergo total joint arthroplasty compared to their urban counterparts. Rural patient were more likely to undergo total joint arthroplasty compared to their urban counterparts if they were in the Midwest and had Medicare as their primary payer provider.

WITHDRAWN: Inpatient Mortality After Primary Total Hip Arthroplasty: Analysis From The National Inpatient Sample Database.

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Evaluation of a novel, nonspanning external fixator for treatment of unstable extra-articular fractures of the distal radius: biomechanical comparison with a volar locking plate.

PURPOSE: To compare the stability of a novel, nonspanning external fixator with a standard volar locked plate for treatment of unstable distal radius fractures. METHODS: A simulated, unstable, extra- articular distal radius fracture was created in six matched pairs of fresh frozen human distal radii. One of each pair was treated with a nonspanning external fixator [Mirza Cross Pin Fixator (CPX), A.M. Surgical Inc. Smithtown, NY] and the other was treated with a volar locked plate [Distal Volar Radial Plate (DVR), Hand Innovations, Miami, FL]. Each specimen was axially loaded in central, dorsal, and volar locations, loaded in cantilever bending in volar to dorsal, dorsal to volar, and radial to ulnar directions and loaded in torsion. Load-displacement curves were generated to determine the construct stiffness for each loading schema, with comparisons made between the two treatment groups. Specimens were then cyclically loaded with 50 N axial loads applied for 1,000 and 10,000 cycles. Measurement of construct stiffness was repeated and comparisons made both between the two treatments and within treatments to their precycling stiffness. RESULTS: There was no significant difference in the mechanical stiffness of the nonspanning external fixator and the volar locking plate after axial loading in any of the loading modalities. Cyclic loads of 1,000 and 10,000 cycles resulted in no significant difference in construct stiffness between the nonspanning external fixator and volar locked plate. However, the nonspanning external fixator demonstrated decreasing stiffness after cyclic loading with 10,000 cycles (p < 0.02). CONCLUSION: This study demonstrated no significant difference in the mechanical stiffness of the CPX nonspanning external fixator and volar locked plate in a cadaveric fracture model. Both constructs appear to be biomechanically equivalent in this experimental model; however, this is only one factor in the choice of fixation device for the management of unstable distal radius fractures.

Percutaneous acetabuloplasty: a cadaveric study.

Periacetabular osteolysis is a common etiology of prosthesis failure in patients who undergo total hip arthroplasty. These lesions are treated by open and, more recently, percutaneous techniques. The purpose of this study was to determine the relevant surface anatomy and bony landmarks in establishing percutaneous access to periacetabular regions and identifying critical at-risk structures in establishing access. Percutaneous access to the periacetabular region was established superiorly, anteroinferiorly, and posteroinferiorly by using 5 L5-to-mid thigh fixed cadaver pelvises with latex-injected vessels using threaded guidewires. Dissection was completed to identify structures at risk, with the distance from the wires recorded to the nearest millimeter. C-arm position for the optimal visualization and placement of guidewires was recorded. Average distance from the pin and the at-risk structures ranged from 11.2 to 38.7 mm. All 3 approaches allowed for safe percutaneous access to the periacetabular regions without injuring significant anatomical structures. This study established safe starting points and orientation for guidewires and radiograph projections associated with percutaneous access to the periacetabular regions. The findings in this study will be useful for developing minimally invasive approaches to these regions for the treatment of osteolytic lesions of diverse etiology. However, a biomechanical evaluation of the impact of these bony channels on the strength of pelvis under physiological and unanticipated loading must be performed before this technique can be safely translated to clinical practice.

Arthroscopically treated intraarticular osteoid osteoma in the ankle--a report of 3 cases.

We present 3 cases of arthroscopically treated intraarticular osteoid osteoma of the ankle. Emphasis is on the high index of suspicion for this lesion, the appropriate imaging modality and the efficacy of arthroscopic excision of these tumors with superficial location in the talus and tibial plafond.