Showing papers in "Clinical Orthopaedics and Related Research in 2009"

Future young patient demand for primary and revision joint replacement: national projections from 2010 to 2030.

Abstract: Previous projections of total joint replacement (TJR) volume have not quantified demand for TJR surgery in young patients (< 65 years old). We developed projections for demand of TJR for the young patient population in the United States. The Nationwide Inpatient Sample was used to identify primary and revision TJRs between 1993 and 2006, as a function of age, gender, race, and census region. Surgery prevalence was modeled using Poisson regression, allowing for different rates for each population subgroup over time. If the historical growth trajectory of joint replacement surgeries continues, demand for primary THA and TKA among patients less than 65 years old was projected to exceed 50% of THA and TKA patients of all ages by 2011 and 2016, respectively. Patients less than 65 years old were projected to exceed 50% of the revision TKA patient population by 2011. This study underscores the major contribution that young patients may play in the future demand for primary and revision TJR surgery.

Etiology of Ankle Osteoarthritis

Abstract: The purpose of this study was to evaluate the distribution rate of etiologies leading to ankle arthritis and to quantify and compare the important clinical and radiologic variables among these etiologic groups. We evaluated data from 390 patients (406 ankles) who consulted our center because of painful end-stage ankle osteoarthritis (OA) by using medical history, physical examination, and radiography. Posttraumatic ankle OA was seen in 78% of the cases (n = 318), secondary arthritis in 13% (n = 52), and primary OA in 9% (n = 36). The average American Orthopaedic Foot and Ankle Society (AOFAS) hindfoot score was 38 points (range, 0–74 points), range of motion was 22° (range, 0°−65°), and visual analog scale for pain was 6.8 (range, 2–10). Patients with posttraumatic end-stage ankle OA were younger than patients with primary OA. The average tibiotalar alignment was 88° (range, 51°–116°) and did not differ between the etiologic groups. Our study showed trauma is the main cause of ankle OA and primary OA is rare. In the majority of patients with ankle OA the average tibiotalar alignment is varus regardless of the underlying etiology. Level of Evidence: Level IV, prognostic study. See the Guidelines for Authors for a complete description of levels of evidence.

Are Current Measurements of Lower Extremity Muscle Architecture Accurate

Abstract: Skeletal muscle architecture is defined as the arrangement of fibers in a muscle and functionally defines performance capacity. Architectural values are used to model muscle-joint behavior and to make surgical decisions. The two most extensively used human lower extremity data sets consist of five total specimens of unknown size, gender, and age. Therefore, it is critically important to generate a high-fidelity human lower extremity muscle architecture data set. We disassembled 27 muscles from 21 human lower extremities to characterize muscle fiber length and physiologic cross-sectional area, which define the excursion and force-generating capacities of a muscle. Based on their architectural features, the soleus, gluteus medius, and vastus lateralis are the strongest muscles, whereas the sartorius, gracilis, and semitendinosus have the largest excursion. The plantarflexors, knee extensors, and hip adductors are the strongest muscle groups acting at each joint, whereas the hip adductors and hip extensors have the largest excursion. Contrary to previous assertions, two-joint muscles do not necessarily have longer fibers than single-joint muscles as seen by the similarity of knee flexor and extensor fiber lengths. These high-resolution data will facilitate the development of more accurate musculoskeletal models and challenge existing theories of muscle design; we believe they will aid in surgical decision making.

Clinical presentation of patients with symptomatic anterior hip impingement.

Abstract: Femoroacetabular impingement (FAI) is considered a cause of labrochondral disease and secondary osteoarthritis. Nevertheless, the clinical syndrome associated with FAI is not fully characterized. We determined the clinical history, functional status, activity status, and physical examination findings that characterize FAI. We prospectively evaluated 51 patients (52 hips) with symptomatic FAI. Evaluation of the clinical history, physical exam, and previous treatments was performed. Patients completed demographic and validated hip questionnaires (Baecke et al., SF-12, Modified Harris hip, and UCLA activity score). The average patient age was 35 years and 57% were male. Symptom onset was commonly insidious (65%) and activity-related. Pain occurred predominantly in the groin (83%). The mean time from symptom onset to definitive diagnosis was 3.1 years. Patients were evaluated by an average 4.2 healthcare providers prior to diagnosis and inaccurate diagnoses were common. Thirteen percent had unsuccessful surgery at another anatomic site. On exam, 88% of the hips were painful with the anterior impingement test. Hip flexion and internal rotation in flexion were limited to an average 97° and 9°, respectively. The patients were relatively active, yet demonstrated restrictions of function and overall health. These data may facilitate diagnosis of this disorder.

The concept of Femoroacetabular impingement: Current status and future perspectives

Abstract: Femoroacetabular impingement (FAI) is a recently proposed mechanism causing abnormal contact stresses and potential joint damage around the hip. In the majority of cases, a bony deformity or spatial malorientation of the femoral head or head/neck junction, acetabulum, or both cause FAI. Supraphysiologic motion or high impact might cause FAI even with very mild bony alterations. FAI became of interest to the medical field when (1) evidence began to emerge suggesting that FAI may initiate osteoarthritis of the hip and when (2) adolescents and active adults with groin pain and imaging evidence of FAI were successfully treated addressing the causes of FAI. With an increased recognition and acceptance of FAI as a damage mechanism of the hip, defined standards of assessment and treatment need to be developed and established to provide high accuracy and precision in diagnosis. Early recognition of FAI followed by subsequent behavioral modification (profession, sports, etc) or even surgery may reduce the rate of OA due to FAI.

Combined Anteversion Technique for Total Hip Arthroplasty

Abstract: Combined cup and stem anteversion in THA based on femoral anteversion has been suggested as a method to compensate for abnormal femoral anteversion. We investigated the combined anteversion technique using computer navigation. In 47 THAs, the surgeon first estimated the femoral broach anteversion and validated the position by computer navigation. The broach was then measured with navigation. The navigation screen was blocked while the surgeon estimated the anteversion of the broach. This provided two estimates of stem anteversion. The navigated stem anteversion was validated by postoperative CT scans. All cups were implanted using navigation alone. We determined precision (the reproducibility) and bias (how close the average test number is to the true value) of the stem position. Comparing the surgeon estimate to navigation anteversion, the precision of the surgeon was 16.8° and bias was 0.2°; comparing the navigation of the stem to postoperative CT anteversion, the precision was 4.8° and bias was 0.2°, meaning navigation is accurate. Combined anteversion by postoperative CT scan was 37.6° ± 7° (standard deviation) (range, 19°–50°). The combined anteversion with computer navigation was within the safe zone of 25° to 50° for 45 of 47 (96%) hips. Femoral stem anteversion had a wide variability. Level of Evidence: Level II, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.

Arthroscopic Femoroplasty in the Management of Cam-type Femoroacetabular Impingement

Abstract: Cam-type femoroacetabular impingement is a recognized cause of intraarticular pathology and secondary osteoarthritis in young adults. Arthroscopy is reportedly useful to treat selected hip abnormalities and has been proposed as a method of correcting underlying impingement. We report the outcomes of arthroscopic management of cam-type femoroacetabular impingement. We prospectively assessed all 200 patients (207 hips) who underwent arthroscopic correction of cam impingement from December 2003 to October 2007, using a modified Harris hip score. The minimum followup was 12 months (mean, 16 months; range, 12–24 months); no patients were lost to followup. The average age was 33 years with 138 men and 62 women. One hundred and fifty-eight patients (163 hips) underwent correction of cam impingement (femoroplasty) alone while 42 patients (44 hips) underwent concomitant correction of pincer impingement. The average increase in Harris hip score was 20 points; 0.5% converted to THA. We had a 1.5% complication rate. The short-term outcomes of arthroscopic treatment of cam-type femoroacetabular impingement are comparable to published reports for open methods with the advantage of a less invasive approach.

Radiographic Evaluation of the Hip has Limited Reliability

Abstract: Radiographic evaluation provides essential information regarding the diagnosis and treatment of musculoskeletal disorders. We evaluated the ability of hip specialists to reliably identify important radiographic features and to make a diagnosis based on plain radiographs alone. Five hip specialists and one fellow performed a blinded radiographic review of 25 control hips, 25 hips with developmental dysplasia (DDH), and 27 with femoroacetabular impingement (FAI). On two separate occasions, readers assessed acetabular version, inclination and depth, position of the femoral head center, head sphericity, head-neck offset, Tonnis grade, and joint congruency. Observers made a diagnosis categorizing each hip as normal, dysplastic, FAI, or combined DDH and FAI (features of both). Reliability was determined using Cohen’s kappa coefficient. Intraobserver values were highest for acetabular inclination (κ = 0.72) and determination of femoral head center position (κ = 0.77). Interobserver reliability values were highest for acetabular inclination (κ = 0.61) and Tonnis osteoarthritis grade (κ = 0.59). All other measurements, including diagnosis, had kappa values less than 0.55. We concluded many of the standard radiographic parameters used to diagnose DDH and/or FAI are not reproducible. Accordingly, a more clear set of definitions and measurements must be developed to allow for more reliable diagnosis of early hip disease. Level of Evidence: Level III, diagnostic study. See the guidelines for authors for a complete description of the levels of evidence.

Which is the Best Activity Rating Scale for Patients Undergoing Total Joint Arthroplasty

Abstract: We compared the metric properties of the University of California, Los Angeles (UCLA) activity scale, the Tegner score, and the Activity Rating Scale for assessment of activity levels in 105 patients undergoing THA (48 women; mean age, 63.4 years) and 100 patients undergoing TKA (61 women; mean age, 66.5 years). We assessed construct validity by correlating these scales with the International Physical Activity Questionnaire and different traditional patient self-reporting outcome measures. Test-retest reliability, feasibility, and floor and ceiling effects also were determined. The UCLA scale showed the strongest correlations with the other measures (r = −0.35 to 0.56 for THA; r = −0.55 to 0.23 for TKA) and was the only scale that discriminated between insufficiently and sufficiently active patients undergoing THA and TKA. The UCLA scale had the best reliability, provided the highest completion rate, and showed no floor effects. It seems to be the most appropriate scale for assessment of physical activity levels in patients undergoing total joint arthroplasty.

Update on clubfoot: etiology and treatment.

Abstract: Although clubfoot is one of the most common congenital abnormalities affecting the lower limb, it remains a challenge not only to understand its genetic origins but also to provide effective long-term treatment. This review provides an update on the etiology of clubfoot as well as current treatment strategies. Understanding the exact genetic etiology of clubfoot may eventually be helpful in determining both prognosis and the selection of appropriate treatment methods in individual patients. The primary treatment goal is to provide long-term correction with a foot that is fully functional and pain-free. To achieve this, a combination of approaches that applies the strengths of several methods (Ponseti method and French method) may be needed. Avoidance of extensive soft-tissue release operations in the primary treatment should be a priority, and the use of surgery for clubfoot correction should be limited to an “a la carte” mode and only after failed conservative methods. Level of Evidence: Level V, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

Multimodal pain management after total hip and knee arthroplasty at the Ranawat Orthopaedic Center.

Abstract: Improvements in pain management techniques in the last decade have had a major impact on the practice of total hip and knee arthroplasty (THA and TKA). Although there are a number of treatment options for postoperative pain, a gold standard has not been established. However, there appears to be a shift towards multimodal approaches using regional anesthesia to minimize narcotic consumption and to avoid narcotic-related side effects. Over the last 10 years, we have used intravenous patient-controlled analgesia (PCA), femoral nerve block (FNB), and continuous epidural infusions for 24 and 48 hours with and without FNB. Unfortunately, all of these techniques had shortcomings, not the least of which was suboptimal pain control and unwanted side effects. Our practice has currently evolved to using a multimodal protocol that emphasizes local periarticular injections while minimizing the use of parenteral narcotics. Multimodal protocols after THA and TKA have been a substantial advance; they provide better pain control and patient satisfaction, lower overall narcotic consumption, reduce hospital stay, and improve function while minimizing complications. Although no pain protocol is ideal, it is clear that patients should have optimum pain control after TKA and THA for enhanced satisfaction and function.

Acetabular polyethylene wear and acetabular inclination and femoral offset.

Abstract: Restoration of femoral offset and acetabular inclination may have an effect on polyethylene (PE) wear in THA. We therefore assessed the effect of femoral offset and acetabular inclination (angle) on acetabular conventional (not highly cross-linked) PE wear in uncemented THA. We prospectively followed 43 uncemented THAs for a minimum of 49 months (mean, 64 months; range, 49–88 months). Radiographs were assessed for femoral offset, acetabular inclination, and conventional PE wear. The mean (± standard deviation) linear wear rate in all THAs was 0.14 mm/year (± 0.01 mm/year) and the mean volumetric wear rate was 53.1 mm3/year (± 5.5 mm3/year). In THAs with an acetabular angle less than 45°, the mean wear was 0.12 mm/year (± 0.01 mm/year) compared with 0.18 mm/year (± 0.02 mm/year) in those with a reconstructed acetabular angle greater than 45°. Reproduction of a reconstructed femoral offset to within 5 mm of the native femoral offset was associated with a reduction in conventional PE wear (0.12 mm/year versus 0.16 mm/year). Careful placement of the acetabular component to ensure an acetabular angle less than 45° in the reconstructed hip allows for reduced conventional PE wear. Level of Evidence: Level II, prospective study. See Guidelines for Authors for a complete description of levels of evidence.

One-step Bone Marrow-derived Cell Transplantation in Talar Osteochondral Lesions

Abstract: The ideal treatment of osteochondral lesions is debatable. Although autologous chondrocyte implantation provides pain relief, the need for two operations and high costs has prompted a search for alternatives. Bone marrow-derived cells may represent the future in osteochondral repair. Using a device to concentrate bone marrow-derived cells and collagen powder or hyaluronic acid membrane as scaffolds for cell support and platelet gel, a one-step arthroscopic technique was developed for cartilage repair. We performed an in vitro preclinical study to verify the capability of bone marrow-derived cells to differentiate into chondrogenic and osteogenic lineages and to be supported onto scaffolds. In a prospective clinical study, we investigated the ability of this technique to repair talar osteochondral lesions in 48 patients. Minimum followup was 24 months (mean, 29 months; range, 24–35 months). Clinical results were evaluated using the American Orthopaedic Foot and Ankle Society (AOFAS) score and the influence of scaffold type, lesion area, previous surgeries, and lesion depth was considered. MRI and histologic evaluation were performed. The AOFAS score improved from 64.4 ± 14.5 to 91.4 ± 7.7. Histologic evaluation showed regenerated tissue in various degrees of remodeling although none showed entirely hyaline cartilage. These data suggest the one-step technique is an alternative for cartilage repair, permitting improved functional scores and overcoming the drawbacks of previous techniques. Level of Evidence: Level IV, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

Capital Realignment for Moderate and Severe SCFE Using a Modified Dunn Procedure

Abstract: Moderate to severe slipped capital femoral epiphysis leads to premature osteoarthritis resulting from femoroacetabular impingement. We believe surgical correction at the site of deformity through capital reorientation is the best procedure to fully correct the deformity but has traditionally been associated with high rates of osteonecrosis. We describe a modified capital reorientation procedure performed through a surgical dislocation approach. We followed 40 patients for a minimum of 1 year and 3 years from two institutions. No patient developed osteonecrosis or chondrolysis. Slip angle was corrected to 4 degrees to 8 degrees and the mean alpha angle after correction was 40.6 degrees. Articular cartilage damage, full-thickness loss, and delamination were observed at the time of surgery, especially in the stable slips. This technique appears to have an acceptable complication rate and appears reproducible for full correction of moderate to severe slipped capital femoral epiphyses with open physes.

Periacetabular osteotomy: a systematic literature review.

Abstract: The Bernese periacetabular osteotomy is commonly used to treat symptomatic acetabular dysplasia. Although periacetabular osteotomy is becoming a more common surgical intervention to relieve pain and improve function, the strength of clinical evidence to support this procedure for these goals is not well defined in the literature. We therefore performed a systematic review of the literature to define the level of evidence for periacetabular osteotomy, to determine deformity correction, clinical results, and to determine complications associated with the procedure. Thirteen studies met our inclusion criteria. Eleven studies were Level IV, one was Level III, and one was Level II. Radiographic deformity correction was consistent and improvement in hip function was noted in all studies. Most studies did not correlate radiographic and clinic outcomes. Clinical failures were commonly associated with moderate to severe preoperative osteoarthritis and conversion to THA was reported in 0% to 17% of cases. Major complications were noted in 6% to 37% of the procedures. These data indicate periacetabular osteotomy provides pain relief and improved hip function in most patients over short- to midterm followup. The current evidence is primarily Level IV.

Comparison of MRI Alpha Angle Measurement Planes in Femoroacetabular Impingement

Abstract: Insufficient femoral head-neck offset is common in femoroacetabular impingement (FAI) and reflected by the alpha angle, a validated measurement for quantifying this anatomic deformity in patients with FAI. We compared the alpha angle determined on magnetic resonance imaging (MRI) oblique axial plane images with the maximal alpha angle value obtained using radial images. The MRIs of 41 subjects with clinically suspected FAI were reviewed and alpha angle measurements were performed on both oblique axial plane images parallel to the long axis of the femoral neck and radial images obtained using the center of the femoral neck as the axis of rotation. The mean oblique axial plane and mean maximal radial alpha angle values were 53.4° and 70.5°, respectively. In 54% of subjects, the alpha angle was less than 55° on the conventional oblique axial plane image but 55° or greater on the radial plane images. Radial images yielded higher alpha angle values than oblique axial images. Patients with clinically suspected FAI may have a substantial contour abnormality that can be underestimated or missed if only oblique axial plane images are reviewed. Radial plane imaging should be considered in the MRI investigation of FAI.

Newer Anesthesia and Rehabilitation Protocols Enable Outpatient Hip Replacement in Selected Patients

Abstract: Advancements in the surgical approach, anesthetic technique, and the initiation of rapid rehabilitation protocols have decreased the duration of hospitalization and subsequent length of recovery following elective total hip arthroplasty. We assessed the feasibility and safety of outpatient total hip arthroplasty in 150 consectutive patients. A comprehensive perioperative anesthesia and rehabilitation protocol including preoperative teaching, regional anesthesia, and preemptive oral analgesia and antiemetic therapy was implemented around a minimally invasive surgical technique. A rapid rehabilitation pathway was started immediately after surgery and patients had the option of being discharged to home the day of surgery if standard discharge criteria were met. All 150 patients were discharged to home the day of surgery, at which time 131 patients were able to walk without assistive devices. Thirty-eight patients required some additional intervention outside the pathway to resolve nausea, hypotension, or sedation prior to discharge. There were no readmissions for pain, nausea, or hypotension yet there was one readmission for fracture and nine emergency room evaluations in the three month perioperative period. This anesthetic and rehabilitation protocol allowed outpatient total hip arthroplasty to be routinely performed in these consectutive patients undergoing primary total hip arthroplasty. With current reimbursement approaches the modest savings to the hospital in length of stay may be outweighed by the additional costs of personnel, thereby making this outpatient system more expensive to implement.

The Feasibility and Perioperative Complications of Outpatient Knee Arthroplasty

Abstract: The duration of hospitalization and subsequent length of recovery after elective knee arthroplasty have decreased. We hypothesized same-day discharge following either a unicompartmental (UKA) or total knee arthroplasty (TKA) in an unselected group of patients would not result in a higher perioperative complication rate than standard-length hospitalization when following a comprehensive perioperative clinical pathway, including preoperative teaching, regional anesthesia, preemptive oral analgesia, preemptive antiemetics, and a rapid rehabilitation protocol. We prospectively followed 111 of all 121 patients who had primary knee arthroplasty completed by noon and who agreed to be followed prospectively; 25 had UKA and 86 TKA. Of the 111 patients, 104 (94%, 24 with UKA and 80 with TKA) met discharge criteria and were discharged directly to home the day of surgery. Nausea requiring additional treatment before discharge was the most common reason for a delay in discharge. There were four (3.6%) readmissions (all with TKA) and one emergency room visit without readmission (in a patient with a TKA) within the first week after surgery, while there were four subsequent readmissions (3.6%) and one additional emergency room visit without readmission within three months of surgery, all among patients undergoing TKA. There were no deaths, cardiac events, or pulmonary complications during this study. Outpatient knee arthroplasty surgery is feasible in a large percentage of patients yet early readmissions may be decreased with a prolonged hospitalization.

Is Recovery Faster for Mobile-bearing Unicompartmental than Total Knee Arthroplasty?

Abstract: How does unicompartmental compare with total knee arthroplasty in durability, incidence of complications and manipulations, recovery, postoperative function, and return to sport and work? We matched 103 patients (115 knees) treated with a mobile-bearing unicompartmental device through July 2005 to a selected group of 103 patients (115 knees) treated with cruciate retaining total knee arthroplasty for bilaterality, age, gender and body mass index. Patients who underwent a unicompartmental surgery had better range of motion at discharge and shorter hospital stay than those who had a total knee arthroplasty (77° versus 67° and 1.4 versus 2.2 days). At 6 weeks, Knee Society functional scores and range of motion were higher for unicompartmental than total knees (63 versus 55 and 115° versus 110°). Patient-perceived Oxford scores were similar between groups (unicompartmental 5.4 versus total 4.1). Average times to return to work and sport were similar for both groups. Minimally invasive unicompartmental knee arthroplasty demonstrated better early ROM, shorter hospital stays, and improved functional scores. No advantage was seen in terms of return to work, return to sport, or Oxford scores. The data suggest minimally invasive unicompartmental arthroplasty using a rapid recovery protocol allows patients a faster return to a more functional level than total knee arthroplasty.

Complications of Arthroscopic Femoroacetabular Impingement Treatment: A Review

Abstract: Recent developments in hip arthroscopy techniques and technology have made it possible in many cases to avoid open surgical technique for treating pincer-type and cam-type femoroacetabular impingement and rather treating it arthroscopically. Early reports suggest favorable results using arthroscopic techniques. The frequency of complications reported for hip arthroscopy for all indications is generally less than 1.5%, suggesting the procedure is safe. Little information is available on complications directly related to the arthroscopic treatment of femoroacetabular impingement. Failure to recognize and treat or incompletely reshape impingement deformities may be the most frequent cause for a second hip arthroscopy and redebridement of the deformity. There has been no report of avascular necrosis related to the arthroscopic treatment of femoroacetabular impingement; only one femoral neck fracture after arthroscopic cam remodeling has been reported in a large series of patients. Other clinical concerns include hip dislocation secondary to extensive capsulotomies or overresection of the anterior acetabular rim in the case of pincer impingement.

Obese diabetic patients are at substantial risk for deep infection after primary TKA.

Abstract: We conducted a prospective study of 1214 consecutive primary TKAs to compare the deep prosthetic infection rate between obese and nonobese patients during the first 12 months after surgery. We also sought to determine whether patient or surgical variables such as comorbidities, age, gender, blood transfusion, use of surgical drains, and antibiotic-impregnated cement were predictors of subsequent prosthetic infection after primary TKA. The overall prosthetic infection rate was 1.5% (n = 18). The odds for a deep prosthetic infection were greater in patients with morbid obesity (odds ratio [OR], 8.96; 95% confidence interval, 1.59–50.63) and diabetes (OR, 6.87; 95% confidence interval, 2.42–19.56). Men were more likely to have a prosthetic infection develop than women (OR, 5.93; 95% confidence interval, 1.95–18.04) and the prosthetic infection rate was lower (OR, 0.24; 95% confidence interval, 0.06–0.95) in patients when a surgical drain was used. There were no prosthetic infections in patients with diabetes who were not obese. This compares with 11 prosthetic infections in patients who were obese and diabetic and four prosthetic infections in patients who were obese but not diabetic. Morbid obesity and obesity combined with diabetes are risk factors for periprosthetic infection after TKA.

Novel measurement technique of the tibial slope on conventional MRI.

Abstract: The posterior inclination of the tibial plateau, which is referred to as posterior tibial slope, is determined routinely on lateral radiographs. However, radiographically, it is not always possible to reliably recognize the lateral plateau, making a separate assessment of the medial and lateral plateaus difficult. We propose a technique to measure the plateaus separately by defining a tibial longitudinal axis on a conventional MRI. The medial plateau posterior tibial slope obtained from radiographs was compared with MR images in 100 consecutive patients with knee pain when ligament or meniscal injury was assumed. The posterior tibial slope on MRI correlated with those on radiographs. The mean posterior tibial slope was 3.4° smaller on MRI compared with radiographs (4.8° ± 2.4° versus 8.2° ± 2.8°, respectively). The reproducibility was slightly better on radiographs than MRI (± 0.9° versus ± 1.4°). Twenty-one of the 100 cases had more than a 5° difference (range, −8.7° to 8.9°) between the medial and lateral plateaus. The proposed technique allows measurement of the posterior tibial slope of the medial and lateral plateaus on a standard knee MRI. By using this novel measurement technique, a reliable assessment of the medial and lateral tibial plateaus is possible.

Proximal Femoral Anatomy in the Normal Human Population

Abstract: In this study, we developed a complete description of the morphology of the proximal femur. Then, using this framework, we (1) determined normal population means, standard deviations, and ranges; (2) established differences among subpopulations; and (3) showed correlations among the various measurements. To accomplish these objectives, we analyzed 375 adult femurs. Specimens were digitally photographed in standardized positions, measurements being obtained using ImageJ software. Three parameters of the head-neck relationship were assessed. Translation was examined through four raw offset measurements (anterior, posterior, superior, inferior) used to calculate anterior-posterior and superior-inferior ratios. Rotation was investigated through anteroposterior (AP) and lateral physeal angles. Concavity was examined using alpha, beta, gamma, and delta angles. Two parameters of the neck-shaft relationship were assessed, neck version and angle of inclination. Average anterior-posterior and superior-inferior ratios were 1.14 and 0.90. Average AP and lateral physeal angles were 74.33° and 81.83°, respectively. Averages for alpha, beta, gamma, and delta angles were 45.61°, 41.85°, 53.46°, and 42.95°, respectively. Average neck version and angle of inclination were 9.73° and 129.23°, respectively. Differences existed between males and females and between those younger and older than 50 years. Correlations were observed between translation and concavity, and translation and the neck-shaft relationships.

The Effect of Cam FAI on Hip and Pelvic Motion during Maximum Squat

Abstract: Femoroacetabular impingement (FAI) causes abnormal contact at the anterosuperior aspect of the acetabulum in activities requiring a large hip range of motion (ROM). We addressed the following questions in this study: (1) Does FAI affect the motions of the hip and pelvis during a maximal depth squat? (2) Does FAI decrease maximal normalized squat depth? We measured the effect of cam FAI on the 3-D motion of the hip and pelvis during a maximal depth squat as compared with a healthy control group. Fifteen participants diagnosed with cam FAI and 11 matched control participants performed unloaded squats while 3-D motion analysis was collected. Patients with FAI had no differences in hip motion during squatting but had decreased sagittal pelvic range of motion compared to the control group (14.7 ± 8.4° versus 24.2 ± 6.8°, respectively). The FAI group also could not squat as low as the control group (41.5 ± 12.5% versus 32.3 ± 6.8% of leg length, respectively), indicating the maximal depth squat may be useful as a diagnostic exercise. Limited sagittal pelvic ROM in FAI patients may contribute to their decreased squatting depth, and could represent a factor amongst others in the pathomechanics of FAI.

Femoroacetabular impingement treatment using arthroscopy and anterior approach.

Abstract: Femoroacetabular impingement (FAI) has been identified as a common cause of hip pain in young adults. However, treatment is not well standardized. We retrospectively reviewed 97 patients (100 hips) who underwent osteochondroplasty of the femoral head-neck for FAI using a mini-open anterior Hueter approach with arthroscopic assistance. The mean age of the patients was 33.4 years. The labrum was refixed in 40 hips, partially excised in 39 cases, completely excised in 14 cases, and left intact in seven. Six patients were lost to followup, leaving 91 (94 hips) with a minimum followup of 28.6 months (mean, 58.3 months; range, 28.6–104.4 months). We assessed patients clinically using the nonarthritic hip score (NAHS). One patient had a femoral neck fracture 3 weeks postoperatively. At the last followup, the mean NAHS score increased by 29.1 points (54.8 ± 12 preoperatively to 83.9 ± 16 points at last followup). Eleven hips developed osteoarthritis and subsequently had total hip arthroplasty. The best results were obtained in patients younger than 40 years old with a 0 Tonnis grade. Refixation of the labrum did not correlate with a higher NAHS score (87 ± 11 with refixation versus 82 ± 19 points without) at the last followup. The technique for FAI treatment allowed direct visualization of the anterior femoral head-neck junction while avoiding surgical dislocation, had a low complication rate, and improved functional scores.

Reverse total shoulder replacement: intraoperative and early postoperative complications.

Abstract: Reverse total shoulder arthroplasty is a treatment option for patients with symptomatic glenohumeral arthritis and a deficient rotator cuff. The reported complication rates vary from 0% to 68%. Given this variation, our purposes were to (1) determine the learning curve for the procedure, (2) identify complications and surgical pitfalls, and (3) compare our results with those of similar published series. We retrospectively reviewed 20 consecutive patients (mean age, 73 years; range, 45–88 years) who had reverse total shoulder arthroplasty by one surgeon, tabulating intraoperative and postoperative complications. Minimum followup was 3 months (average, 9 months; range, 3–21 months). The intraoperative complication rate for the first 10 patients was higher than that for the second 10 patients. There were 33 complications in 15 patients: 11 patients collectively had 22 intraoperative complications and eight patients collectively had 11 postoperative complications. At radiographic followup, 11 patients had scapular notching and nine patients had heterotopic ossification. Our complication rate was higher than published rates. Level of Evidence: Level II, prognostic study. See the Guidelines for Authors for a complete description of levels of evidence.

Cemented versus Uncemented Hemiarthroplasty for Displaced Femoral Neck Fractures

Abstract: Hemiarthroplasty is the most commonly used treatment for displaced femoral neck fractures in the elderly There is limited evidence in the literature of improved functional outcome with cemented implants, although serious cement-related complications have been reported We performed a randomized, controlled trial in patients 70 years and older comparing a cemented implant (112 hips) with an uncemented, hydroxyapatite-coated implant (108 hips), both with a bipolar head The mean Harris hip score showed equivalence between the groups, with 709 in the cemented group and 721 in the uncemented group after 3 months (mean difference, 12) and 789 and 798 after 12 months (mean difference, 09) In the uncemented group, the mean duration of surgery was 124 minutes shorter and the mean intraoperative blood loss was 89 mL less The Barthel Index and EQ-5D scores did not show any differences between the groups The rates of complications and mortality were similar between groups Both arthroplasties may be used with good results after displaced femoral neck fractures

An introduction to medical malpractice in the United States.

Abstract: Medical malpractice law in the United States is derived from English common law, and was developed by rulings in various state courts. Medical malpractice lawsuits are a relatively common occurrence in the United States. The legal system is designed to encourage extensive discovery and negotiations between adversarial parties with the goal of resolving the dispute without going to jury trial. The injured patient must show that the physician acted negligently in rendering care, and that such negligence resulted in injury. To do so, four legal elements must be proven: (1) a professional duty owed to the patient; (2) breach of such duty; (3) injury caused by the breach; and (4) resulting damages. Money damages, if awarded, typically take into account both actual economic loss and noneconomic loss, such as pain and suffering.

Periprosthetic infection due to resistant staphylococci: serious problems on the horizon.

Abstract: Prosthetic joint infections (PJI) caused by methicillin-resistant staphylococci represent a major therapeutic challenge We examined the effectiveness of surgical treatment in treating infection of total hip or knee arthroplasty caused by methicillin-resistant staphylococcal strains and the variables influencing treatment success One hundred and twenty-seven patients were treated at our institution between 1999 and 2006 There were 58 men and 69 women, with an average age of 66 years Patients were followed for a minimum of 2 years or until recurrence of infection Debridement and retention of the prosthesis was performed in 35 patients and resection arthroplasty in 92 Debridement controlled the infection in only 37% of cases whereas two-stage exchange arthroplasty controlled the infection in 75% of hips and 60% of knees Preexisting cardiac disease was associated with a higher likelihood of failure to control infection in all treatment groups Antibiotic-resistant Staphylococci continue to compromise treatment outcome of prosthetic joint infections, especially in patients with medical comorbidities New preventive and therapeutic strategies are needed

Why Revision Total Hip Arthroplasty Fails

Abstract: Current outcomes data on revision total hip arthroplasty focuses on specific implants and techniques rather than more general outcomes We therefore examined a large consecutive series of failed THAs undergoing revision to determine if survivorship and modes of failure differ in comparison to the current data We retrospectively reviewed the medical records of 1100 revision THAs The minimum followup was 2 years (mean, 6 years; range, 0–204 years) Eighty-seven percent of revision total hips required no further surgery; however, 141 hips (13%) underwent a second revision at a mean of 37 years (range, 0025–159 years) Seventy percent (98 hips) had a second revision for a diagnosis different from that of their index revision, while 30% (43 hips) had a second revision for the same diagnosis The most common reasons for failure were instability (49 of 141 hips, 35%), aseptic loosening (42 of 141 hips, 30%), osteolysis and/or wear (17 of 141 hips, 12%), infection (17 of 141 hips, 12%), miscellaneous (13 of 141 hips, 9%), and periprosthetic fracture (three of 141 hips, 2%) Survivorship for revision total hip arthroplasty using second revision as endpoint was 82% at 10 years Aseptic loosening and instability accounted for 65% of these failures Level of Evidence: Level IV, therapeutic (retrospective) study See the Guidelines for Authors for a complete description of levels of evidence