Showing papers in "The Iowa orthopaedic journal in 2011"

Proximal junctional kyphosis in adult reconstructive spine surgery results from incomplete restoration of the lumbar lordosis relative to the magnitude of the thoracic kyphosis.

Abstract: Background PROXIMAL JUNCTIONAL KYPHOSIS (PJK) IS DEFINED AS: 1) Proximal junction sagittal Cobb angle >≥10°, and 2) Proximal junction sagittal Cobb angle of at least 10° greater than the pre-operative measurement PJK is a common complication which develops in 39% of adults following surgery for spinal deformity. The pathogenesis, risk factors and prevention of this complication are unclear. Methods Of 54 consecutive adults treated with spinal deformity surgery (age≥59.3±10.1 years), 19 of 54 (35%) developed PJK. The average follow-up was 26.8 months (range 12 - 42). Radiographic parameters were measured at the pre-operative, early postoperative (4-6 weeks), and final follow-up visits. Sagittal alignment was measured by the ratio between the C7-plumbline and the sacral-femoral distance. Binary logistic regression model with predictor variables included: Age, BMI, C7-plumbline, and whether lumbar lordosis, thoracic kyphosis and sacral slope were present Results Patients who developed PJK and those without PJK presented with comparable age, BMI, pelvic incidence and sagittal imbalance before surgery. They also presented with comparable sacral slope and lumbar lordosis. The average magnitude of thoracic kyphosis was significantly larger than the lumbar lordosis in the proximal junctional kyphosis group, both at baseline and in the early postoperative period, as represented by [(-lumbar )lordosis - (thoracic kyphosis)]; no- PJK versus PJK; 6.6°±23.2° versus -6.6°±14.2°; p≥0.012. This was not effectively addressed with surgery in the PJK group [(-LL-TK): 6.2°±13.1° vs. -5.2°±9.6°; p≥0.004]. This group also presented with signs of pelvic retroversion with a sacral slope of 29.3°±8.2° pre-operatively that was unchanged after surgery (30.4°±8.5° postoperatively). Logistic regression determined that the magnitude of thoracic kyphosis and sagittal balance (C7-plumbline) was the most important predictor of proximal junctional kyphosis. Conclusions Proximal junctional kyphosis developed in those patients where the thoracic kyphosis remained greater in magnitude relative to the lumbar lordosis, and where the sagittal balance seemed corrected, but part of thise correction was secondary to pelvic retroversion. Level of evidence Prognostic case-control study - Level III.

Reliability of various observers in determining common radiographic parameters of adult hip structural anatomy.

Abstract: Background Radiographic evaluation of the hip is extremely important in the diagnosis and treatment decisionmaking process for pre-arthritic hip disease. Many different radiographic measurements have been described as indicators of underlying structural hip deformity. The purpose of this study was to determine the interobserver and intraobserver reliability of various musculoskeletal physicians in performing selected measurements of adult structural hip anatomy. Methods A blinded review of 45 sets of radiographs from patients with developmental dysplasia, femoro-acetabular impingement, and normal anatomy was performed. Data points included the lateral center-edge angle (LCEA), vertical-center-anterior angle (VCA), head-neck offset ratio (UNO), alpha angle, Tonnis angle, Tonnis osteoarthritis grade and a radiographic diagnosis. One orthopaedic fellow, two orthopaedic residents, and two attending musculoskeletal physiatrists analyzed radiographs on two separate occasions. One sports medicine orthopaedic attending physician completed a single analysis of the image sets. Intraobserver and interobserver reliability was established using intra-class correlation coefficients (ICC) for continuous variables. Agreement regarding categorical variables was performed using the kappa coefficient Results Excellent intraobserver reliability was found for the following: LCEA (ICC = 0.88), VCA (0.88), Tonnis angle (0.83), HNO on the frog lateral (0.78), alpha angle on the frog lateral (0.76), HNO on the cross-table lateral (0.75), and angle alpha on the cross-table lateral (0.76). Intraobserver reliability for osteoarthritis grade was poor (weighted kappa = 0.57). For all data points, interobserver reliability was considerably worse, with 95% confidence intervals spanning below 0.55. Conclusions While the described measurements of adult structural hip anatomy provide excellent reliability for a given reader, these measurements are less reliable across readers. Taken in isolation, these measurements, as performed by observers with varied clinical experience and clinical backgrounds, are limited in determining a consistent radiographic diagnosis.

The pathomechanical etiology of post-traumatic osteoarthritis following intraarticular fractures

Abstract: Many intra-articular fracture patients eventually experience significant functional deficits, pain, and stiffness from post-traumatic osteoarthritis (PTOA). Over the last several decades, continued refinement of surgical reconstruction techniques has failed to markedly improve patient outcomes. New treatment paradigms are needed - ideally, bio/pharmaceutical. Progress in that direction has been impeded because the pathomechanical etiology of PTOA development is poorly understood. In particular, the relative roles and pathomechanisms of acute joint injury (from the initial trauma) versus chronic contact stress elevation (from residual incongruity) are unknown, primarily because there have been no objective methods for reliably quantifying either of these insult entities. Over the past decade, novel enabling technologies have been developed that provide objective biomechanical indices of injury severity and of chronic contact stress challenge to fractured joint surfaces. The severity of the initial joint injury is indexed primarily on the basis of the energy released in fracture, obtained from validated digital image analysis of CT scans. Chronic contact stress elevations are indexed by patient-specific finite element stress analysis, using models derived from post-reduction CT scans. These new measures, conceived in the laboratory, have been taken through the stage of validation, and then have been applied in studies of intra-articular fracture patients, to relate these biomechanical indices of cartilage insult to the incidence and severity of PTOA This body of work has provided a novel framework for developing and testing new approaches to forestall PTOA following intra-articular fractures.

The course of the distal saphenous nerve: a cadaveric investigation and clinical implications.

Abstract: Introduction Injury to the saphenous nerve at the ankle has been described as a complication resulting from incision and dissection over the distal tibia and medial malleolus. However, the exact course and location of the distal saphenous nerve is not well described in the literature. The purpose of this study was to determine the distal limit of the saphenous nerve and its anatomic relationship to commonly identified orthopaedic landmarks and surgical incisions.

Chondrosarcoma of the spine: a series of 16 cases and a review of the literature

Abstract: Only a few major studies of chondrosarcoma of the mobile spine have been reported. These studies have shown that spinal chondrosarcomas require complete surgical resection and are notoriously resistant to chemotherapy and radiation. We present 16 cases of chondrosarcoma of the mobile spine diagnosed at a median age of 54.5 (range 20 - 79) years. Diagnosis and treatment studies were based on both CT scans and MRI. Fifteen of our 16 patients had low-grade (grade 1-2) chondrosarcomas. All patients were treated with surgical resection. Fourteen patients had total resection while two patients had subtotal resection. The two patients who had subtotal resection died of their disease. Five of the fourteen patients who had total resection also died. The mean interval to death was 3.6 years. This study confirms that although chondrosarcomas of the spine are low grade, they are dangerous neoplasms. Even with complete resection, they have a high rate of recurrence and metastasis.

Concomitant infection and local metal reaction in patients undergoing revision of metal on metal total hip arthroplasty.

Abstract: Total hip arthroplasty (THA) with conventional polyethylene bearings is traditionally the standard operative treatment for endstage arthritis of the hip. This design has excellent survivorship in most populations, with a low occurrence of infection and other associated complications. Due to concern over increased wear in younger, more active populations, other bearing surfaces have been evaluated, particularly metal-on-metal with wear rates theorized to be lower than conventional THA. Unique to metal-on-metal THA, however, is the possibility of local soft tissue reactions that can mimic infection, making proper diagnosis and treatment difficult. We present a case series of nine hips in eight patients undergoing revision of metal-on-metal THA for local soft tissue reactions, three of which were also found to be concomitantly infected. The laboratory and hip aspirate data described show significant overlap between the infected and non-infected cases. Care must be taken when evaluating patients with failed metal-on-metal THA as there may be an increased incidence of co-infection in this group of patients.

Open pelvic fractures: the University of Tennessee Medical Center at Knoxville experience over ten years.

Abstract: Introduction Open fractures of the pelvis remain a devastating injury with a high mortality and morbidity. Such injuries require an aggressive treatment plan and the coordination of trauma and orthopaedic surgeons to achieve the best outcomes. We report our experience at the University of Tennessee Medical Center at Knoxville with open pelvic fractures over the last ten years.

Arthroscopic subacromial decompression: acromioplasty versus bursectomy alone--does it really matter? A systematic review.

Abstract: Background Subacromial impingement is a common disorder mat in some cases results in surgical management. Arthroscopic subacromial bursectomy alone or in combination with acromioplasty are treatment options when non-operative measures fail.

Predictive measures of a resident's performance on written orthopaedic board scores

Abstract: OBJECTIVE Residency programs are continually attempting to predict the performance of both current and potential residents. Previous studies have supported the use of USMLE Steps 1 and 2 as predictors of Orthopaedic In-Training Examination (OITE) and eventual American Board of Orthopaedic Surgery success, while others show no significant correlation. A strong performance on OITE examinations does correlate with strong residency performance, and some believe OITE scores are good predictors of future written board success. The current study was designed to examine potential differences in resident assessment measures and their predictive value for written boards. DESIGN/METHODS A retrospective review of resident performance data was performed for the past 10 years. Personalized information was removed by the residency coordinator. USMLE Step 1, USMLE Step 2, Orthopaedic In-Training Examination (from first to fifth years of training), and written orthopaedic specialty board scores were collected. Subsequently, the residents were separated into two groups, those scoring above the 35(th) percentile on written boards and those scoring below. Data were analyzed using correlation and regression analyses to compare and contrast the scores across all tests. RESULTS A significant difference was seen between the groups in regard to USMLE scores for both Step 1 and 2. Also, a significant difference was found between OITE scores for both the second and fifth years. Positive correlations were found for USMLE Step 1, Step 2, OITE 2 and OITE 5 when compared to performance on written boards. One resident initially failed written boards, but passed on the second attempt This resident consistently scored in the 20(th) and 30(th) percentiles on the in-training examinations. CONCLUSIONS USMLE Step 1 and 2 scores along with OITE scores are helpful in gauging an orthopaedic resident's performance on written boards. Lower USMLE scores along with consistently low OITE scores likely identify residents at risk of failing their written boards. Close monitoring of the annual OITE scores is recommended and may be useful to identify struggling residents. Future work involving multiple institutions is warranted and would ensure applicability of our findings to other orthopedic residency programs.

The Ponseti method in Latin America: initial impact and barriers to its diffusion and implementation.

Abstract: The Ponseti method for correcting clubfoot is a safe, effective, and minimally invasive treatment that has recently been implemented in Latin America. This study evaluates the initial impact and unique barriers to the diffusion of the Ponseti method throughout this region. Structured interviews were conducted with 30 physicians practicing the Ponseti method in three socioeconomically diverse countries: Chile, Peru and Guatemala. Since learning the Ponseti method, these physicians have treated approximately 1,740 clubfoot patients, with an estimated 1,705 (98%) patients treated using the Ponseti method, and 35 (2%) patients treated using surgical techniques. The barriers were classified into the following themes: physician education, health care system of the country, culture and beliefs of patients, physical distance and transport, financial barriers for patients, and parental compliance with the method. The results yielded several common barriers throughout Latin America including lack of physician education, physical distance to the treatment centers, and financial barriers for patients. Information from this study can be used to inform, and to implement and evaluate specific strategies to improve the diffusion of the Ponseti method for treating clubfoot throughout Latin America.

Ulnar nerve component to innervation of thumb carpometacarpal joint

Abstract: Purpose Thumb carpometacarpal (CMC) joint arthritis is one of the most common problems addressed by hand surgeons. The gold standard of treatment for thumb CMC joint arthritis is trapeziectomy, ligament reconstruction and tendon interposition. Denervation of the thumb CMC joint is not currently used to treat arthritis in this joint due to the failure of the procedure to yield significant symptomatic relief. The failure of denervation is puzzling, given that past anatomic studies show the radial nerve is the major innervation of the thumb CMC joint with the lateral antebrachial nerve and the median nerve also innervating this joint. Although no anatomic study has ever shown that the ulnar nerve innervates the CMC joint, due to both the failure of denervation and the success of arthroscopic thermal ablation, we suspect that previous anatomic studies may have overlooked innervation of the thumb CMC joint via the ulnar nerve. Methods We dissected 19 formalin-preserved cadaveric hand-to-mid-forearm specimens. The radial, median and ulnar nerves were identified in the proximal forearm and then followed distally. Any branch heading toward the radial side of the hand were followed to see if they innervated the thumb CMC joint. Results Eleven specimens (58%) had superficial radial nerve innervation to the thumb CMC joint. Nine specimens (47%) had median nerve innervation from the motor branch. Nine specimens (47%) had ulnar nerve innervation from the motor branch. Conclusions We believe this is the first study to demonstrate that the ulnar nerve innervates the thumb CMC joint This finding may explain the poor results seen in earlier attempts at denervation of the thumb CMC, but the more favorable results with techniques such as arthroscopy with thermal ablation.

Gluteal compartment syndrome and superior gluteal artery injury as a result of simple hip dislocation: a case report.

Abstract: Gluteal compartment syndrome as a result of hematoma from a ruptured superior gluteal artery is exceedingly rare; to date, one similar case in a pelvic fracture model has been reported. We report a case of acute gluteal compartment syndrome from a ruptured superior gluteal artery resulting from a simple posterior hip dislocation in an otherwise healthy young male. Timely surgical exploration, evacuation of the hematoma, and achievement of hemostasis allowed for an excellent outcome at follow-up. We review the gluteal compartments as well as treatment protocols for this injury.

A randomized, prospective study comparing intertrochanteric hip fracture fixation with the dynamic hip screw and the dynamic helical hip system in a community practice.

Abstract: Objective To evaluate the clinical performance of the Dynamic Helical Hip System (DHHS) spiral blade relative to the Dynamic Hip Screw (DHS) lag screw.

Demographic and comorbid disparities based on payer type in a total joint arthroplasty cohort: implications in a changing health care arena

Abstract: INTRODUCTION The purpose of this study was to compare differences in demographic, functional, access to care, and comorbidity data between a Medicaid and Iowa Care (state Medicaid) insured patient cohort and Medicare and a Commercial Payer patient cohort undergoing lower extremity total joint arthroplasty (TJA). MATERIAL & METHODS A retrospective review of 874 primary TKAs and THAs by a single surgeon at an academic institution between January, 2004 and June, 2008 was performed. Data on the primary insurance payer was used to stratify the cohort into two groups; Medicaid and Iowa Care (state Medicaid) insured and Medicare and commercial payer. Demographic, functional, access to care, and comorbidity data obtained from a standard preoperative survey were compared. RESULTS Of 874 primary TKAs and THAs, 18.3 % of patients were Medicaid and Iowa Care insured, while 81.7 % were insured by Medicare and commercial payer. Average age was 53.7 and 62.3 respectively, while average BMI was 35.2 and 32.9 respectively. The Medicaid and Iowa Care group was found to be 3 times more likely to smoke tobacco (25.2% v. 8.3%). Preoperative WOMAC Function scores were 33.9 and 46.8, respectively. Self reported diabetes was used as a general surrogate for health comorbidities and occurred in 12.3 % and 11.5%, respectively. Distance traveled was used as a general surrogate for access to care with averages of 92.5 miles and 62.8 miles, respectively. CONCLUSION The Medicaid and Iowa Care (state Medicaid) group had significantly higher rates of smoking, were significantly younger, and had significantly lower WOMAC scores (p<0.05) preoperatively. BMI comparison showed a trend to greater obesity in the Medicaid and Iowa Care cohort (p=0.056). Diabetes rates were comparable between the two cohorts. Medicaid and Iowa Care patients traveled 29.7 miles farther, suggesting they had less access to local orthopaedic care. There are major differences in comorbidities and patient demographics between payer types.

Cervical laminoplasty construct stability: an experimental and finite element investigation.

Abstract: STUDY DESIGN Experimental and finite element investigation of cervical laminoplasty. OBJECTIVE To determine the stability of the construct post cervical laminoplasty. SUMMARY OF BACKGROUND DATA Cervical laminoplasty is a widely used technique to widen the spinal canal dimensions without permanently removing the dorsal elements of the cervical spine. Although various laminoplasty procedures have been developed recently, the use of mini-plates to hold the lamina open and prevent restenosis of the spinal cord is a fairly new method and has not been thoroughly investigated. METHODS Biomechanical compression tests and finite element analyses were performed in this study. Sixteen cervical vertebrae (C3 - C6) were isolated from six cadaveric cervical spines (age at death 68 to 91 years; mean 85 years) and were used for compression tests. Out of the 16 vertebrae, four were without any surgical intervention and the remaining 12 were implanted with one of the two laminoplasty plates: open door (OD) graft. Each vertebra was randomly assigned to one of the three groups: OD plate (6), graft plate (6) or intact vertebrae (4). The intact and implanted vertebrae were potted and loaded to failure. Cross-head displacements and the corresponding reaction force throughout the test were recorded to determine the failure loads. A finite element model of the C5 cervical vertebra was created to accommodate the laminoplasty implants. Experimental loading and boundary conditions were simulated and the stress distribution in the lamina was predicted in response to the compressive loads. RESULTS A substantial increase in the sagittal canal diameter (27%-33%) and the spinal canal area (31.2%-47%) was observed at all levels. The strength of the implanted specimens was considerably decreased (by six to eight times) as compared to the intact specimens. CONCLUSION Experimentally obtained data can be combined with mathematical models, such as finite element models, to accurately predict the biomechanical behavior (stresses and strains) of implants and the posterior bone which may not be possible by the use of any other method.

Integrating carthage-specific t1rho mri into knee clinic diagnostic imaging

Abstract: With a rise in post-traumatic osteoarthritis, OA no longer is considered just a disease of aging. The ‘gold standard’ for OA diagnosis has long been planar radiographs for visualizing osteophytes, joint space narrowing and sclerotic changes. A typical magnetic resonance imaging (MRI) protocol will acquire proton density, T1, T2, and fat suppressed images that give a comprehensive picture of morphologic changes associated with injury and subsequent degenerative processes. However, the earliest events of cartilage degeneration occur within the tissue, before measureable changes in morphology. MRI methods have been proposed to display and quantify changes in composition and integrity of such elements of cartilage extracellular matrix as collagen and proteoglycan (PG) content in vivo. T1ρ the spin-lattice relaxation time in the rotating frame, has come to the forefront for visualizing water proton-PG interactions in articular cartilage. The purpose of this T1ρ MRI study was to define an objective femoral condyle-specific registration method, in which zone-dependent cartilage compositional changes could be assessed from the bone outward through the existing cartilage, at pre-ACL reconstruction and subsequent follow-up times, when the loss of thickness to surface-down cartilage erosion might occur later in the OA pathogenesis. Additionally, this study explores the effects of reducing the number of spin-lock times on the absolute T1ρ relaxation times; a major parameter in expanding T1ρ coverage to the whole joint while satisfying clinical imaging time and specific absorption rate (SAR) safety constraints. The developed image analysis tools serve as the first step toward quantitative functional assessment of cartilage health with noninvasive T1ρ MRI, which has the potential to become an important new tool for the early diagnosis of cartilage degeneration following ACL trauma.

Ponseti Brasil: a national program to eradicate neglected clubfoot - preliminary results.

Abstract: BACKGROUND After hearing about the reproducible and excellent results of the Ponseti method for clubfoot treatment, a group of Brazilian orthopaedic surgeons organized and participated in a standardized national program to teach the Ponseti technique in 21 different cities across Brazil. METHODS A total of 21 Ponseti symposiums were organized in a standard fashion from January, 2007 to December, 2008. They consisted of a two-day program with lectures, hands-on cast application, and discussion of local clinical cases presented by orthopaedic surgeons. Thirteen Brazilian orthopaedic surgeons, who had been trained by the University of Iowa or centers recognized by them, taught the method. Financial support for travel was provided by an English charity: La Vida (Vital Investment for Developing Aid in Latin America). The physicians who attended the symposiums answered questionnaires before and after the training. RESULTS About 7% of the 8000 orthopaedic surgeons in Brazil (556 orthopaedic surgeons) were trained. These orthopaedic surgeons stated that they had treated about 4905 babies in the previous year via other methods, including extensive surgery. Seventeen percent of the surgeons did not know about the Ponseti technique at the start of the symposium. Eighty-eight percent reported they felt able to treat children with the Ponseti technique after the symposium. Ninety-four percent of respondents reported that the symposium changed their way of treating clubfoot CONCLUSIONS These Ponseti symposiums brought about an exchange of medical information and empowered the participants. This program is a good educational tool which can be used in eradicating neglected clubfoot in Brazil.

Quantifying the effects of extensor mechanism medializatlon procedures using MRI: a cadaver-based study.

Abstract: Background Patellofemoral joint kinematics are dependent on a variety of anatomical features. One of the most common causes of patellar instability is malalignment of the quadriceps extensor mechanism. The Southwick-Fulkerson osteotomy focuses on correcting malalignment of the quadriceps extensor mechanism through medialization of the tibial tubercle. MRI, in conjunction with established patellofemoral indices, allows quantitative evaluation of the patellofemoral joint during active quadriceps extension both pre- and postoperatively.

Cervical synovial cyst: case report.

Abstract: A 47-year-old female school teacher with a six-week history of left-sided scapular and arm pain is presented. We report her evaluation and treatment Although lumbar degenerative synovial cysts have been reported over 200 times in the literature,6 cervical synovial cysts are much more rare. This case reports a cervicothoracic junction degenerative synovial cyst presenting as radiculopathy.

Digital soft tissue trauma: a concise primer of soft tissue reconstruction of traumatic hand injuries

Abstract: Soft tissue reconstruction after digital injury can be challenging for hand surgery specialists and non-specialists alike given the number of reconstructive options, some of which employ microvascular techniques. Stable, mobile, and sensate digits with an adequate soft tissue envelope are the ultimate goals of soft tissue reconstruction of the hand.1 The purpose of this primer is to provide an overview of non-microvascular reconstruction techniques for digital injuries that can be employed by orthopaedic surgeons. We will also show some examples of more advanced options that are available for those injuries that may not be able to be treated by standard techniques.

Assessment of walking pattern pre and post peri-acetabular osteotomy

Abstract: Background Adult hip dysplasia (AHD) is a common etiology of hip pain in the young adult. Patients with adult hip dysplasia may present with hip pain and early degenerative changes resulting from elevated cumulative hip-contact stress. While there are numerous studies using radiographic parameters coupled with general and disease-specific health status measures to demonstrate that periacetabular osteotomy improves the orientation of the acetabulum, decreases pain and improves function, to our knowledge there is only one study that utilized gait analysis to demonstrate an objective functional alteration. The purpose of the present study was to prospectively evaluate the walking pattern and assess the activity level of patients undergoing periacetabular osteotomy for symptomatic adult hip dysplasia.

Conical, radiographic, and patient-reported results of surface replacing proximal interphalangeal joint arthroplasty of the hand.

Abstract: The purpose of this study was to evaluate the one-year clinical, radiologic and patient-reported results of surface-replacing proximal interphalangeal joint arthroplasty (SR-PIP) of the hand. Fifteen patients with 18 joints underwent the procedure, and nine patients with 11 joints had follow-up of at least one year's duration. Of these joints, six had a diagnosis of osteoarthritis with no history of trauma, three had post-traumatic arthritis, one had psoriatic arthritis, and one had erosive arthritis. The mean clinical follow-up was at 3.3 years, and the mean radiographic follow-up was at 3.1 years. The average post-operative gain in range of motion at the PIP joint was 28 degrees and was statistically significant. Six patients completed self-reported questionnaires at a mean of 4.8 years post-operatively. The mean Disabilities of the Arm, Shoulder and Hand (DASH) score post-operatively was 17, and the Michigan Hand Questionnaire (MHQ) score for overall satisfaction was 70. There were three complications but only one reoperation. Seven of 11 joints showed some evidence of subsidence on follow-up radiographic examination. However, no joints were revised sec-ondary to loosening. Longer follow-up is needed to determine if this observable radiologic subsidence leads to symptomatic loosening of the implant

Diffusion of innovation: enhancing the dissemination of the ponseti method in latin america through virtual forums

Abstract: This ethnographic study evaluated the use of low-bandwidth web-conferencing to enhance diffusion of a specific best practice, the Ponseti method to treat clubfoot, in three economically diverse countries in Latin America. A "Ponseti Virtual Forum" (PVF) was organized in Guatemala, Peru and Chile to examine the influences of economic level and telecommunication infrastructure on the effectiveness of tins approach. Across the three countries, a total of 14 different sites participated in the PVFs. Thirty-three Ponseti-trained practitioners were interviewed before and after each PVF, which included interactions with a Spanish-speaking Ponseti method expert. Semi-structured interviews, observations, and IP address data were triangulated and analyzed. The results demonstrated that 100% of the practitioners rated the sessions as very useful and that they would use this approach again. The largest obstacles to using PVFs were financial (7 out of 9 practitioners) in Guatemala; a lack of equipment and network access (6 out of 11) in Peru; and the organization and implementation of the conferences themselves (7 out of 9) in Chile. This study illustrates the usefulness of Ponseti Virtual Forums in Latin America. Health officials in Peru are currently developing a large-scale information session for traumatologists about the Ponseti method, while practitioners in Guatemala and Chile are organizing monthly scholarly meetings for physicians in remote areas. This initial feedback suggests that low-bandwidth web-conferencing can be an important vehicle for the dissemination of best practices, such as the Ponseti method, in developing countries.

Treatment of posttraumatic labral interposition with surgical hip dislocation and labral repair.

Abstract: We report a case of a 12-year-old male with delayed presentation of a spontaneous incongruous reduction of a hip dislocation due to labral-chondral acetabular rim fragment entrapment The patient was treated with a staged hip arthroscopy and subsequent surgical dislocation and open repair. At two-year follow-up, the patient had an excellent clinical and radiographic outcome.

Efficacy and cost-effectiveness of a blood salvage system in primary total knee arthroplasty—a retrospective match-controlled chart review

Abstract: We retrospectively reviewed the clinical and cost effectiveness of the OrthoPAT blood salvage system (Haemonetics Corp., Braintree, MA) following total knee arthroplasty (TKA). Two-hundred-and-two patients who received the OrthoPAT system were matched to 202 controls. A second match was performed for subjects weighing <75 kg. For all matched subjects, no significant difference in allogeneic blood transfusion (ABT) rate was found between the control and study groups (p=0.55). In the subjects <75 kg, use of the OrthoPAT system almost halved the incidence of ABT; however, in this small population the result was not statistically significant (p=0.10). Blood management costs for study patients were significantly higher than those of the control group in both the total matched pairs and those <75 kg (p< 0.0001 and p= 0.05, respectively).

Early spondylodiscitis presenting with single vertebral body involvement: a report of two cases.

Abstract: Infectious spondylodiscitis is an uncommon disease with increasing incidence that typically presents with abnormalities in two adjacent vertebral bodies and the intervening disk. We describe two cases that initially presented with imaging abnormalities in only a single vertebral body. Both patients had a history of lumbar back pain and elevated inflammatory markers, but the lack of classical spondylodiscitis imaging findings led to diagnostic delay and confusion. It is likely that the incidence of atypical presentations of spondy-lodiscitis will increase as the disease incidence increases and imaging is performed at an earlier stage. It is important to recognize the disease early because early diagnosis is the key to preventing serious complications like epidural abscess and spinal cord compression.

Comparison of hospital costs and duration of treatment with two different clubfoot protocols.

Abstract: In Brazil, clubfoot has traditionally been treated by serial manipulation and casting over a period of several months with the Kite technique. In most cases, complete correction was not achieved and posteromedial release was required.2,3 In 2003, the University Hospital at the University of Sao Paulo (Campus Universitary City) changed their clubfoot treatment protocol to the Ponseti technique.1,5,6,7 This was due to the dissemination of this technique in the medical literature. In 2004, the Ponseti technique was recognized by the Brazilian Orthopaedic Society Guidelines Book as a recommended way to treat clubfoot8 The authors retrospectively compared the hospital costs in the treatment of five consecutive patients with the previous protocol (Kite technique and posteromedial release) with the hospital costs for treatment of five consecutive patients with the new protocol (the Ponseti technique). The objective of this study was to compare direct hospital costs and duration of treatment from these two different protocols.

Range of motion and patient satisfaction with traditional and high-flexion rotating-platform knees.

Abstract: Although a high degree of flexion is necessary for some activities of daily living, most total knee arthroplasty implants are designed to provide only up to 120° of flexion. Some new designs claim to provide greater flexion. In this retrospective study, we evaluated the Sigma rotating-platform high-flex knee against the traditional Sigma rotating-platform knee (DePuy, Warsaw, IN). There were 153 knees evaluated. We matched the subjects primarily on preoperative flexion and had 64 matched pairs. We also evaluated the knees based on their preoperative flexion, either <120° or ≥120°. In comparing the two implants, there were no significant differences in the patients' overall satisfaction, flexion gained or lost, or the need for further surgery. This study was approved by an institutional review board.

Children hospitalized with lower extremity fractures in the United States in 2006: A population-based approach

Abstract: OBJECTIVE: The purpose of this study was to examine the demographic and hospitalization characteristics of children hospitalized with lower extremity fractures in the United States in 2006. METHODS: Children aged 0 to 20 years with a diagnosis of lower extremity fracture in the 2006 Healthcare Cost and Utilization Project Kids' Inpatient Database (KID) were included. Lower extremity fractures were defined by International Classification of Diseases, 9th Revision, Clinical Modification codes 820-829 under "Injury and Poisoning (800-999)." Patient demographic and hospitalization-related data were analyzed by chi-square testing and unbalanced analysis of variance. RESULTS: There were more boys than girls with lower extremity fractures and 53% had private insurance as their primary payer. About one half of the children were between the ages of 13 and 20 years, but all ages were represented from age 0 to 20. White children accounted for 56%. Urban hospitalizations accounted for 93% of cases and 66 percent of admissions were to teaching hospitals. All patients had an average length of stay (LOS) 4.04 days, and infant patients had the longest average LOS of 5.46 days. The average number of diagnoses per patient was 3.07, and the average number of procedures per patient was 2.21. The average charge per discharge was $35,236, and the oldest patients had the largest average charge of $41,907. The average number of comorbidities increased with increasing patient age. There was a 55.6% greater mortality risk in non-teaching hospitals than in teaching hospitals and there was at least ten times the mortality risk in rural hospitals than in urban hospitals. CONCLUSIONS: This study provides an understanding of the demographic and hospitalization characteristics of children with lower extremity fractures in the United States in 2006. This information may be useful in implementing measures to help prevent similar injuries in the future. Further research is required to determine causality of the associations found including increased mortality risk for this population at rural and non-teaching hospitals. Language: en

Mechanical behavior of carpal tunnel subsynovial connective tissue under compression.

Abstract: Subsynovial connective tissue (SSCT) is a fluid-permeated loose connective tissue that occupies the majority of the space in the carpal tunnel not occupied by the digital flexor tendons or the median nerve. It is arranged in layers around these more discrete structures, presumably to assist with tendon gliding. As a result of this arrangement, the compressive behavior and the fluid permeability of this tissue may substantially affect the stresses in the median nerve resulting from contact with its neighboring tendons or with the walls of the tunnel itself. These stresses may contribute to damage of the median nerve and the development of carpal tunnel syndrome. In this study, the fluid permeability and the compressive behavior of the SSCT were investigated to better understand the mechanics of this tissue and how it may mediate mechanical insult to the median nerve. A custom experimental apparatus was built to allow simultaneous measurement of tissue compression and fluid flow. Using Darcy's law, the average SSCT fluid permeability was 8.78×10(15) m(4)/Ns. The compressive behavior of the SSCT demonstrated time dependence, with an initial modulus of 395kPa gradually decreasing to a value of 285kPa. These baseline tissue data may serve as a mechanical norm (toward which pathological tissue might be returned, therapeutically) and may serve as essential properties to include in future mechanical models of the carpal tunnel.