Impact of intraoperative fluoroscopic beam positioning relative to the hip and pelvis on perceived acetabular component position.

Background: Parallax is poorly understood and can mislead surgeons using intraoperative fluoroscopy (IF) to guide cup placement during anterior approach (AA) total hip arthroplasty. The purpose of this study was to examine how changes in fluoroscopic beam positioning in relation to the hip and pelvis affects the projected acetabular image. Methods: An acetabular component was positioned in an anatomic pelvis model in 45° and 20° of abduction and anteversion, respectively using a computer assisted cup targeting system. Fluoroscopic images were taken at various caudal and cranially directed angles with the fluoroscopic beam centered over the hip then pelvis. In each position, four independent observers measured the abduction and anteversion angles of the projected cup image using the same computer targeting system. Results: Cup abduction and anteversion measured 43.5° and 19.5° when IF was centered over the hip and 40.5 and 27.5° when centered over the pelvis in the neutral position. Increasing the caudal direction of the beam 20° increased the projected abduction/anteversion angles by approximately 7°/12° and 9°/16° when centered over the hip and pelvis respectively. Increasing the cranial direction of the beam 20° decreased the measured abduction/anteversion angles by roughly 4°/20° and 4°/24° when centered over the hip and pelvis, respectively. Conclusion: The projected image of the acetabular component can change dramatically depending on fluoroscopic beam position relative to the hip and pelvis. Recognizing the approximate direction and magnitude of change with differing fluoroscopy positions may help surgeons avoid cup malpositioning.

Carpal Tunnel Syndrome: An Update for the Primary Care Physician.

Carpal tunnel syndrome costs the United States billions of dollars each year. The majority of patients are industrial workers, females, and the elderly who first present to their primary care physicians. Therefore, it is essential that the primary care physician understand this syndrome in order to diagnose and direct treatment. Here we present a review of the anatomy, pathophysiology, diagnosis, and current treatment of carpal tunnel syndrome that is relevant for the treating primary care physician. In addition, we discuss the role of the primary care physician in the diagnosis, management, and treatment of carpal tunnel syndrome. The aim of this review is to improve the integrated care of those patients suffering from carpal tunnel syndrome.

Hip Offset and Leg Length Equalization in Direct Anterior Approach Total Hip Arthroplasty without Preoperative Templating.

The standard practice of preoperative templating may be less important for direct anterior approach (DAA) total hip arthroplasty (THA) with intraoperative fluoroscopy (IF). However, this has yet to be tested. The purpose of this retrospective review was to report the hip offset (HO) and leg length (LL) equalization accuracy following 304 consecutively performed DAA THA with IF and no preoperative templating. A supplemental fluoroscopic gridding tool was used to assess hip symmetry. Operative and fluoroscopic times were also documented to assess for surgical efficiency. The mean HO and LL difference was 3.5 ± 2.6 mm (range: 0.0-9.3) and 2.9 ± 2.2 mm (range: 0.0-9.9), respectively. Hip offset and LL equalization within 10 mm was achieved in all patients. The mean operative time for unilateral THA was 72.2 ± 12.0 minutes, and the mean fluoroscopy time per hip was 10.5 ± 4.5 seconds. These results suggest that for surgeons with adequate experience performing DAA THA with IF, preoperative templating may not be necessary to reliably and efficiently achieve clinically acceptable HO and LL.

The effect of patellar thickness on gait biomechanics following total knee arthroplasty.

BACKGROUND: Patella resurfacing is commonly performed during total knee arthroplasty; however, determining the appropriate patellar thickness remains a challenge. The purpose of this study was to evaluate the role of post-TKA patellar thickness on knee extensor strength and biomechanical joint loading forces during walking and stair negotiation. METHODS: Fifteen patients (21 knees) underwent gait analysis prior to TKA and post-TKA at six weeks, three months, six months, and one year. Knee extensor strength and biomechanics were collected during level walking and stair negotiation and analyzed using Pearson correlation coefficients. RESULTS: Knee extensor strength was positively correlated to patellar thickness at three months and one year post-TKA (p ≤ .05). During walking, no significant correlations were present. During stair ascent, there was a positive correlation between patellar thickness and peak knee flexion angle one year post-TKA (p ≤ .05). During stair descent, there was a positive correlation between patellar thickness and maximum vertical ground reaction forces at one year post-TKA (p ≤ .01). CONCLUSIONS: The loss of patellar thickness when compared to measured pre-resurfacing thickness was correlated with a decrease in knee extensor strength; however, changes in patellar thickness were not significantly correlated to biomechanical loading forces during walking. Increases in demand of activity increase the torque to the knee joint, which elicit increases in compensatory motions, likely reducing the extent to which differences in joint loading during stair negotiation may be attributable to changes in patellar thickness. Therefore, the effect of post-patellar thickness on patient function in primary TKA is limited.

Effectiveness of Accelerated Recovery Performance for Post-ACL Reconstruction Rehabilitation.

Atrophy and protracted recovery of normal function of the ipsilateral quadriceps femoris muscle following anterior cruciate ligament reconstruction surgery is well documented. The Accelerated Recovery Performance trainer is a type of electrical stimulation device that delivers a high-pulse frequency via a direct current, making it unique from many other devices on the market. The purpose of the present study was to investigate the effects of the direct current (via the Accelerated Recovery Performance trainer protocol) on gains in thigh circumference following anterior cruciate ligament reconstruction. Twenty-five patients were enrolled following isolated anterior cruciate ligament reconstruction and randomly assigned to either an isometric rehabilitation protocol augmented with the Accelerated Recovery Performance trainer protocol (experimental group) or the isometric rehabilitation protocol alone (control group). The two groups participated in sixteen sessions of directed rehabilitation over a two-month time period. Patients were followed with serial thigh circumference measurements at 5, 10, 15, and 20 centimeters above the superior patellar pole. Comparison of the overall mean circumferential gains in thigh circumference of the involved leg demonstrated approximately 3:1 gains in the ARP group over the control group, demonstrating it to be superior to isometric rehabilitation alone with regards to gains in thigh girth. The Accelerated Recovery Performance trainer protocol should be considered for post-anterior cruciate ligament reconstruction rehabilitation in order to reverse disuse atrophy of the ipsilateral quadriceps femoris.

Addressing large tibial osseous defects in primary total knee arthroplasty using porous tantalum cones.

BACKGROUND: Tibial osseous defects can present a serious challenge in primary total knee arthroplasty. We describe a technique of using porous tantalum cones along with primary arthroplasty implants to address large tibial osseous defects in primary total knee arthroplasty and present the short-term results. METHODS: We present 17 cases (15 patients) in which primary total knee implants and porous tantalum cones were used to address large tibial bony defects. Clinical results were evaluated using Knee Society Scores, pre- and postoperative knee range of motion, and serial radiographs. RESULTS: At an average of 3.5 years of follow-up, all 17 knees had functioning implants with stable metaphyseal cones demonstrating radiographic evidence of osteointegration. At a minimum follow-up of two years, no patient had signs of osteolysis, instability, infection, or systemic complications. All 15 patients had excellent results with an average post-operative Knee Society Score of 94.6. Knee flexion improved by an average of 12.0° and knee extension improved to neutral in all patients. CONCLUSION: Primary total knee arthroplasty with porous tantalum cone augmentation produced excellent short-term results and should be considered an effective method for addressing large tibial osseous defects in primary total knee arthroplasty.

The Prevalence of Neck and Shoulder Symptoms and Associations with Comorbidities and Disability: The Johnston County Osteoarthritis Project.

OBJECTIVES: Neck and shoulder pain are common but underreported by older people, raising important questions of frequency, medical comorbidities, gender and racial disparities and functional impact associated with neck and shoulder symptoms in elders, which we examined in this analysis. METHODS: We performed a cross-sectional analysis in the community-based Johnston County Osteoarthritis Project, a cohort that is representative of the U.S. population, utilizing data from 1672 participants with a mean age of 68 years; 69% were white and 68% were women. Trained staff obtained data on participant-reported: symptoms, comorbidities, depression, and functional status; and performance-based functional assessments. Regression models of neck and shoulder symptoms and functional measures were adjusted for age, sex, race, and body mass index, and additionally for other joint symptoms and comorbidities. RESULTS: Symptoms of neck (8%), shoulder (13%) or both (13%) were reported by participants. Neck symptoms were most frequently reported by White women; shoulder symptoms were evenly distributed among race and gender subgroups. Neck and shoulder symptoms were associated with cancer, diabetes mellitus, depression, and lung, cardiovascular, and other musculoskeletal problems, as well as pain, aching or stiffness at other sites, and independently with self-reported and performance -based functional measures. CONCLUSIONS: These findings suggest that primary health care providers should inquire about neck and shoulder symptoms and address potential underlying causes to improve functional status and decrease disability in older people.