Symposium: 2014 International Hip Society Proceedings 21 articles
There are many factors that may affect the learning curve for total hip arthroplasty (THA) and surgical approach is one of these. There has been renewed interest in the direct anterior approach for THA with variable outcomes reported, but few studies have documented a surgeon’s individual learning curve when using this approach.
Uncemented acetabular components have demonstrated low revision rates and high patient satisfaction but with concerns regarding increased costs compared with monoblock cups. Some newer lower-cost uncemented monoblock options have become available in the last decade, but limited data are available on their performance.
Osteoarthritis may result from abnormal mechanics leading to biochemically mediated degradation of cartilage. In a dysplastic hip, the periacetabular osteotomy (PAO) is designed to normalize the mechanics and our initial analysis suggests that it may also alter the cartilage biochemical composition. Articular cartilage structure and biology vary with the depth from the articular surface including the concentration of glycosaminoglycans (GAG), which are the charge macromolecules that are rapidly turned over and are lost in early osteoarthritis. Delayed gadolinium-enhanced magnetic resonance imaging of cartilage (dGEMRIC) enables noninvasive measurement of cartilage GAG content. The dGEMRIC index represents an indirect measure of GAG concentration with lower values indicating less GAG content. GAG content can normally vary with mechanical loading; however, progressive loss of GAG is associated with osteoarthritis. By looking at the changes in amounts of GAG in response to a PAO at different depths of cartilage, we may gain further insights into the types of biologic events that are occurring in the joint after a PAO.
Oxidized Zirconium Head on Crosslinked Polyethylene Liner in Total Hip Arthroplasty: A 7- to 12-year In Vivo Comparative Wear Study
Osteolysis resulting from wear debris production from the bearing surfaces is a major factor limiting long-term survival of hip implants. Oxidized zirconium head on crosslinked polyethylene (XLPE) is a modern bearing coupling. However, midterm in vivo wear data of this coupling are not known.
THA Revisions Using Impaction Allografting With Mesh Is Durable for Medial but Not Lateral Acetabular Defects
Most acetabular revisions are managed with cementless hemispherical or elliptical metal implants relying on bone ingrowth. Nonetheless, loss of acetabular bone stock and inability to achieve secure component fixation represent challenges in the setting of revision total hip arthroplasty. Impaction bone grafting (IBG) using allograft represents one option for treatment of this problem. However, cup migration and bone graft resorption are limitations when IBG is used for large segmental defects, and the precise role of IBG as well as the use of mesh (and the kinds of defects for which mesh does not work well) in this setting remains unknown.
Women Demonstrate More Pain and Worse Function Before THA but Comparable Results 12 Months After Surgery
Many studies report differences in patient-reported outcome measures (PROMs) for men and women undergoing total hip arthroplasty (THA). Few studies have evaluated whether these are explained by corresponding differences in important preoperative factors.
Does Cup-cage Reconstruction With Oversized Cups Provide Initial Stability in THA for Osteoporotic Acetabular Fractures?
The incidence of acetabular fractures in osteoporotic patients is increasing. Immediate total hip arthroplasty (THA) has potential advantages, but achieving acetabular component stability is challenging and, at early followup, reported revision rates for loosening are high.
Do Alumina Matrix Composite Bearings Decrease Hip Noises and Bearing Fractures at a Minimum of 5 Years After THA?
Ceramic-on-ceramic bearing couples are theoretically attractive in total hip arthroplasty (THA) because of low wear, but concerns regarding ceramic fracture and squeaking have arisen. Improved material properties of newer alumina matrix composite (AMC) materials, known as Delta ceramics, may reduce these risks. In addition, the use of thinner liners and larger femoral heads may be helpful clinically to lower the rate of dislocation. However, limited short-term clinical results are available and intermediate-term effects are unclear.
Low Wear Rates Seen in THAs With Highly Crosslinked Polyethylene at 9 to 14 Years in Patients Younger Than Age 50 Years
Patients 50 years or younger are at high risk for wear-related complications of their total hip arthroplasty (THA) because of their generally higher levels of activity. Highly crosslinked polyethylene (HXLPE) is believed to be more durable for this population than conventional polyethylene because of its improved wear; however, limited information is available on the wear of HXLPE in this population, particularly the wear of HXLPE when it articulates with alternative bearings like Oxinium (Smith & Nephew, Memphis, TN, USA).
Do Oxidized Zirconium Femoral Heads Reduce Polyethylene Wear in Cemented THAs? A Blinded Randomized Clinical Trial
Charnley low-friction torque total hip arthroplasty (THA) remains the gold standard in THA. The main cause for failure is wear of the socket. Highly crosslinked polyethylene (HXLPE) has been associated with reduced wear rates. Also, oxidized zirconium has shown in vitro reduced wear rates. However, to our knowledge, there are no data comparing oxidized zirconium femoral heads with metal heads against HXLPE or ultrahigh-molecular-weight polyethylene (UHMWPE) when 22.25-mm bearings were used, which was the same size that performed so well in Charnley-type THAs.
Are Ceramic-on-ceramic Bearings in Total Hip Arthroplasty Associated With Reduced Revision Risk for Late Dislocation?
Dislocation is a major complication after primary total hip arthroplasty (THA), but little is known about the potential relationships between bearing materials and risk of dislocation. Dislocation within the first year after surgery is typically related to either surgical error or patient inattention to precautions, but the reasons for dislocation after the first year are often unclear, and whether ceramic bearings are associated with an increased or decreased likelihood of late dislocation is controversial.
An Increased Iliocapsularis-to-rectus-femoris Ratio Is Suggestive for Instability in Borderline Hips
The iliocapsularis muscle is an anterior hip structure that appears to function as a stabilizer in normal hips. Previous studies have shown that the iliocapsularis is hypertrophied in developmental dysplasia of the hip (DDH). An easy MR-based measurement of the ratio of the size of the iliocapsularis to that of adjacent anatomical structures such as the rectus femoris muscle might be helpful in everyday clinical use.
Ceramic-on-ceramic THA Associated With Fewer Dislocations and Less Muscle Degeneration by Preserving Muscle Progenitors
Dislocation is a common complication after total hip arthroplasty (THA). Although the etiology of dislocation is multifactorial, longer-term changes in muscle such as atrophy may influence the risk of prosthetic dislocation. Biological differences in wear products generated by different bearing surfaces may influence differences in the appearance of periarticular muscle after THA; however, such bearing-associated differences to our knowledge have not been studied in vivo, and few studies have evaluated bearing-associated differences in dislocation risk.
Primary Ceramic-on-ceramic Total Hip Arthroplasty Using a 32-mm Ceramic Head With a Titanium-alloy Sleeve
Modern ceramic-on-ceramic bearings have become attractive alternatives to conventional polyethylene in total hip arthroplasty (THA) as a result of their low wear and minimal particle production. However, 28-mm heads in ceramic-on-ceramic bearing couples have been associated with ceramic fracture. To address these issues, 32-mm and larger ceramic heads with a titanium-alloy sleeve have been introduced, although limited data are available on their durability and clinical outcomes.
Combined anteversion is the sum of femoral and acetabular anteversion and represents their morphological relationship in the axial plane. Few studies have investigated the native combined anteversion in patients with symptomatic dysplastic hips.
Femoral head fractures are rare injuries; incongruency and instability are indications for surgical intervention. Anterior, posterior, and transtrochanteric surgical approaches have been proposed, but the exposure is limited with classical approaches. Surgical hip dislocation allows for a 360° view of the head and may facilitate a reduction in selected head fractures, but to our knowledge, few studies have reported on the results with this technique. We therefore report on the (1) quality of fracture reduction; (2) modified Harris hip score at a minimum of 2 years (mean, 6 years, range, 26–122 months); and (3) frequency of complications, including avascular necrosis (AVN), arthritis development, and heterotopic ossification, in a case series of patients with femoral head fractures treated with this approach.
Frequent Femoral Neck Osteolysis With Birmingham Mid-head Resection Resurfacing Arthroplasty in Young Patients
Mid-head resection total hip resurfacing arthroplasty was promoted as an alternative to traditional total hip resurfacing for patients with poor femoral head bone quality or abnormal femoral head morphology, because those patients are at high risk of failure with traditional total hip resurfacing. It is a large-headed metal-on-metal device that uses a short, bone-conserving stem. Good performance of the implant has been reported at short-term followup, but no information on the implant performance in the mid- or long-term is available.
Intraoperative Synovial C-reactive Protein Is as Useful as Frozen Section to Detect Periprosthetic Hip Infection
Synovial quantification of C-reactive protein (SCRP) has been recently published with high sensitivity and specificity in the diagnosis of periprosthetic joint infection. However, to our knowledge, no studies have compared the use of this test with intraoperative frozen section, which is considered by many to be the best intraoperative test now available.
Acetate Templating on Digital Images Is More Accurate Than Computer-based Templating for Total Hip Arthroplasty
Templating is an important aspect of preoperative planning for total hip arthroplasty and can help determine the size and positioning of the prosthesis. Historically, templating has been performed using acetate templates over printed radiographs. As a result of the increasing use of digital imaging, surgeons now either obtain additional printed radiographs solely for templating purposes or use specialized digital templating software, both of which carry additional cost.
Satisfying Outcomes Scores and Survivorship Achieved With Impaction Grafting for Revision THA in Young Patients
The increasing number of total hip arthroplasties (THAs) performed in younger patients will inevitably generate larger numbers of revision procedures for this specific group of patients. Unfortunately, no satisfying revision method with acceptable survivorship 10 years after revision has been described for these patients so far.