Stair Ascending and Descending in Hip Resurfacing and Large Head Total Hip Arthroplasty Patients

Large head total hip arthroplasty (THA) and hip resurfacing arthroplasty (HRA) are alternatives to standard THA that generally have head sizes larger than 36 mm. This study examined 20 patients (10 large head THA and 10 HRA), at an average of 18 months postoperatively, and 15 healthy control subjects during stair negotiation. Hip kinetic and kinematic variables and ground reaction forces were measured. The THA and HRA groups ascended the stairs with increased peak hip flexion angles and decreased hip extension angles as compared with controls. The operative groups also descended the stairs with decreased hip flexion moments. No differences between the operative groups were observed. Eighteen months postoperatively, patients with large head THA or HRA display abnormal flexion and extension during a physically-demanding task.     

Large Diameter Metal on Metal Articulations. Comparison of Total Hip Arthroplasty and Hip Resurfacing Arthroplasty

The use of large diameter metal bearing total hip arthroplasty (THA) and hip resurfacing arthroplasty (HRA) increased in popularity in the last decade. More recent literature has highlighted the effect of head size in patient outcomes. Data was obtained from the Australian Orthopaedic Association National Joint Replacement Registry (AOA-NJRR) to evaluate the Birmingham (MoM) bearing surface when used with THA and HRA. There is no difference in the overall rate of revision between the THA and HRA but head size has a significant effect on revision rate. The data show that small diameter metal bearings in HRA (below 50 mm) have a higher rate of revision than large diameter metal bearings in HRA (equal to and above 50 mm) (P < .001). Conversely the large diameter metal bearings in THA have a higher rate of revision than the small diameter metal bearings in THA (P = .027). The revision rate for large diameter HRA compared to small diameter THA is not significantly different P = .670. We recommend caution when choosing either a large diameter (≥ 50 mm) metal on metal THA or small diameter (< 50 mm) HRA.     

An Initial Experience with Hip Resurfacing Versus Cementless Total Hip Arthroplasty

Background

Hip resurfacing is an alternative to total hip arthroplasty.

Questions/Purpose

We aimed to compare an experienced hip surgeon’s initial clinical results of hip resurfacing with a new cementless total hip arthroplasty (THA).

Methods

The first 55 consecutive hip resurfacing arthroplasties were compared to 100 consecutive cementless THAs using a cylindrical tapered femoral stem. The learning curve between the two procedures was compared utilizing the incidence of reoperation, complications, Harris Hip Scores (HHS), and implant survivorship.

Results

The reoperation rate was significantly higher (p = 0.019) for hip resurfacing (14.5%) versus THA (4%). The overall complication rate between the two groups was not significantly different (p = 0.398). Preoperative HHS were similar between the two groups (p = 0.2). The final mean HHS was similar in both the resurfacing and THA groups (96 vs. 98.3, respectively, p < 0.65). Kaplan–Meier survival analysis with an endpoint of reoperation suggests complications occurred earlier in the resurfacing group versus the THA group (log-rank test, p = 0.007).

Conclusions

In comparison to our initial experience with a cementless THA stem, operative complications occur earlier and more often after hip resurfacing during the learning period. The clinical outcomes in both groups however are similar at 5 year follow-up.

Electronic supplementary material

The online version of this article (doi:10.1007/s11420-013-9333-0) contains supplementary material, which is available to authorized users.     

Metal Ion Levels in Total Hip Arthroplasty Versus Hip Resurfacing

Recent studies suggest that the tapered interface between stem and femoral head may be a substantial source of cobalt and chromium ion release after metal-on-metal (MOM) total hip arthroplasty (THA). This study compared patient ion levels after MOM hip resurfacing (HR) and MOM THA performed with identical acetabular components. 110 HRs were compared with 22 THAs. All had well-oriented components, unilateral implants, and serum ion studies beyond one year post-operatively. The HR group’s median cobalt value was 1.11 μg/L vs. 2.86 μg/L for the THA patients. The HR group’s median chromium value was 1.49 μg/L vs. 2.94 μg/L for THA. Significantly higher THA ion levels suggest a source of ions other than the MOM bearing itself.     

Trends in Total Hip Arthroplasty Implant Utilization in the United States

Total hip arthroplasty (THA) implant usage has evolved as experience has been gained with newer implant designs. The purpose of this study was to characterize trends in THA implant usage between 2001 and 2012. The Orthopedic Research Network, which includes 174 hospitals and ~ 105,000 THA, was used to evaluate trends in fixation, bearings, acetabular cup and liner, and femoral head usage. In 2012, 93% of THAs were cementless; 56% of THA bearings were metal-HXLPE; and 35% were ceramic-HXLPE. 99% of acetabular cups were modular. 61% of femoral heads were metal, 39% were ceramic, 51% were 36 mm, and 28% were 32 mm. THA implant usage trends favor cementless fixation, metal-on-polyethylene or ceramic-on-polyethylene bearings, modular acetabular cups, and large diameter femoral heads.     

Hip Resurfacing Arthroplasty for Ankylosing Spondylitis

We compared the results of the metal-on-metal hip resurfacing with the ceramic-on-ceramic total hip arthroplasty (THA) in 2 groups. The preoperative and postoperative ranges of motion (ROMs) were recorded. At the latest follow-up, both of the groups make satisfactory clinical and radiographic results. There was no significant difference in Harris hip score of the 2 groups, but the ROM of the hips in hip resurfacing group was significantly wider than THA group (P < .01). Hip resurfacing has better ROM improvement than THA, with the same pain relief. Its high stability and low dislocation rate allow patients to do early function exercises, which is important for ankylosing spondylitis (AS) patients to avoid reankylosis. Hip resurfacing may be a reasonable option for young AS population.     

Changes in Bone Mineral Density of the Acetabulum and Proximal Femur After Total Hip Resurfacing Arthroplasty

Our aim was to investigate the changes in bone mineral density (BMD) of acetabulum and proximal femur after total hip resurfacing arthroplasty. A comparative study was carried out on 51 hips in 48 patients. Group A consisted of 25 patients (26 hips) who had undergone total hip resurfacing and group B consisted of 23 patients (25 hips) who had had large-diameter metal-on-metal total hip arthroplasty (THA). BMDs around the acetabulum and proximal femur were measured using dual-energy x-ray absorptiometry (DEXA) at 2 weeks, 6 months, 1 year and annually thereafter during the 3 years after surgery. At final follow-up, the acetabular net mean BMD decreased by 11% in group A and 10% in group B with no differences between two groups (P = .35). For the femoral side, in Gruen zone 1, the mean BMD increased by 4% in group A, whereas it decreased by 11% in group B (P = .029). In Gruen zone 7, the mean BMD increased by 8% at the final follow-up in group A, whereas it decreased by 13% in group B (P = .02). In both groups the mean BMD increased by 3% in Gruen zones 3, 4, 5, and 6. Stress-related bone loss of the acetabulum was comparable for MOM THA and resurfacing devices, but proximal femoral bone density increased in the resurfacing group and decreased in the THA group.     

Periacetabular Bone Mineral Density Changes After Resurfacing Hip Arthroplasty Versus Conventional Total Hip Arthroplasty. A Randomized Controlled DEXA Study

A randomized controlled trial was performed to evaluate acetabular bone mineral density (BMD) changes after hip resurfacing (RHA) versus an established conventional total hip arthroplasty (THA). A total of 71 patients were allocated randomly to receive either an RHA press-fit cobalt–chromium cup (n = 38) or a THA with a threaded titanium cup and polyethylene-metal-inlay insert (n = 33). The BMD in five separate periacetabular regions of interest (ROI) was prospectively quantified preoperative until 24 months. We conclude that, in contrast to our hypothesis, periacetabular BMD was better preserved after RHA than after placement of a conventional THA. Long term follow-up studies are necessary to see whether this benefit in bone preservation sustains over longer time periods and whether it is turned into clinical benefits at future revision surgery.     

Similar Improvement in Gait Parameters Following Direct Anterior & Posterior Approach Total Hip Arthroplasty

We compared gait parameters prior to, at 6 months and 1 year following total hip arthroplasty (THA) performed via direct anterior approach (DAA) and posterior approach (PA) by a single surgeon in 22 patients. A gait analysis system involving reflective markers, infrared cameras and a multicomponent force plate was utilized. Postoperatively, the study cohort demonstrated improvement in flexion/extension range of motion (ROM) (P = 0.001), peak flexion (P = 0.005) and extension (P = 0.002) moments with no differences between groups. Internal/external ROM improved significantly in the DAA group (P = 0.04) with no change in the PA group. THA performed via DAA and PA offers similar improvement in gait parameters with the exception of internal/external ROM which might be related to the release and repair of external rotators during PA THA.     

Perioperative Morbidity and Mortality Following Bilateral Total Hip Arthroplasty

There is concern about safety of bilateral total hip arthroplasty (THA).This study aims to compare in-hospital complication rates between unilateral, simultaneous and staged bilateral THAs. The Nationwide Inpatient Sample from 2002–2010 was used. Patients and complications were identified using ICD-9-CM codes. In multivariate analysis, bilateral THA had higher risk of systemic complications (Odds ratio (OR): 2.1, P < 0.001) compared to unilateral procedure, whereas no significant difference existed between simultaneous and staged bilateral THAs. The rate of local complications was higher in bilateral versus unilateral (4.96% versus 4.54%, P = 0.009) and in staged versus simultaneous bilateral THAs (OR: 1.75, P = 0.05). Bilateral THA increases risk of systemic complications compared to unilateral surgery and simultaneous bilateral THA appears to be safer than staging during one hospitalization.     

Excellent Results and Minimal Complications of Total Hip Arthroplasty in Sickle Cell Hemoglobinopathy at Mid-Term Follow-Up Using Cementless Prosthetic Components

The purpose of this study was to compare the outcomes of cementless primary total hip arthroplasty (THA) in sickle cell patients compared to the remaining cohort of osteonecrosis patients who did not have this disease. Thirty-two sickle cell patients (42 hips) who had a mean age of 37 years and mean follow-up of 7.5 years (range, 5–11 years) were compared to 87 non-sickle cell osteonecrosis patients (102 hips) who had mean age of 43 years and mean follow-up of 7 years (range, 3–10.5 years). Outcomes evaluated included implant survivorship, Harris hip scores, complication rates, radiographic outcomes, and Short Form-(SF-36) health questionnaire. There were no significant differences in aseptic implant survivorship (95 vs. 97%), Harris hip scores (87 vs. 88 points), SF-36 score, or radiographic findings between the two patient cohorts. In light of these findings, we believe that the outcomes of THA improved in sickle cell patients with optimized medical management and the use of cementless prosthetic devices.     

Outcomes of Total Hip Arthroplasty in Spastic Patients

Patients with spasticity and hip arthritis can present challenges to treatment. This investigation evaluated the effectiveness and safety of THA in patients with upper motor neuron disease. Twenty-seven consecutive patients with history of cerebral palsy (CP) or acquired spasticity (AS) underwent 30 THAs for treatment of hip arthritis. They were followed for an average 2.5 years (range 2.1–12.1). Patients with CP were more likely to require hip adductor release and hip flexor lengthening at the time of THA. Statistically significant improvements were made in Harris Hip Scores, pain scores, range of motion, ambulatory status, and the use ambulatory-assistive devices. There were no dislocations in this group. Patients with spasticity can benefit from THA in terms of pain relief and improved mobility with relatively low complications.     

Higher Prevalence of Mixed or Solid Pseudotumors in Metal-on-Polyethylene Total Hip Arthroplasty Compared With Metal-on-Metal Total Hip Arthroplasty and Resurfacing Hip Arthroplasty

Background

Pseudotumors are a common finding in metal-on-metal (MoM) total hip arthroplasty (THA) and resurfacing hip arthroplasty (RHA). However, information on pseudotumors in metal-on-polyethylene (MoP) THA is limited.

Plain Radiographs Fail to Reflect Femoral Offset in Total Hip Arthroplasty

Successful biomechanical reconstruction is a major goal in total hip arthroplasty (THA). We measured leg length (LL), global (GO) and femoral offset (FO) change on anteroposterior pelvis radiographs and on three-dimensional computed-tomography (3D-CT) with fiducial landmarks after cementless THA on 18 hips of cadaveric specimens. Measurements on radiographs were performed twice by four examiners and showed high interobserver (mean CCC ≥ 0.79) and intraobserver agreements (mean ICC ≥ 0.88). Mean differences between radiographic and 3D-CT measurements were 1.0 (SD 2.0) mm for LL, 0.6 (SD 3.6) mm for GO and 1.4 (SD 5.2) mm for FO. 1% of radiographic LL-, 15% of GO- and 35% of FO measurements were outside a tolerance limit of 5 mm. Radiographs seem acceptable for measuring LL/GO change but fail to reflect FO change in THA.     

Does Prosthetic or Bony Impingement Occur More Often in Total Hip Arthroplasty: A Dynamic Preoperative Analysis

BackgroundImpingement is a leading cause for instability resulting in revision total hip arthroplasty (THA). Impingement can be prosthetic, bony, or soft tissue. The purpose of this study is to investigate, using a virtual simulation, whether bony or prosthetic impingement presents first in well-positioned THAs.MethodsTwenty-three patients requiring THA were planned for a ceramic-on-poly cementless construct using dynamic planning software. Cups were orientated at 45° inclination and 25° anteversion when standing. Femoral components and neck lengths were positioned to reproduce native anteversion and match contralateral leg length and offset. The type and location of impingement was then recorded with recreation of anterior and posterior impingement during standard and extreme ranges of motion (ROM).ResultsIn standard ROM, flexion produced both prosthetic and bony impingement and extension resulted in prosthetic impingement in models with lipped liners. In extreme ROM, anterior impingement was 78% bony in 32-mm articulations, and 88% bony in 36-mm articulations. Posterior impingement was 65% prosthetic in 32-mm articulations, and 55% prosthetic in 36-mm articulations. Dual mobility cups showed the greatest risk of posterior prosthetic impingement in hyperextension (74%).ConclusionIn standard ROM, both bony and prosthetic impingement occurred in flexion, while prosthetic impingement occurred in extension in models with lipped liners. In hyperextension, prosthetic impingement was more common than bony impingement, and was exclusively the cause of impingement when a lip was used. In flexion, impingement was primarily bony with the use of a 36-mm head. The risk of posterior prosthetic impingement was greatest with dual mobility cups.Level of Evidence3.     

Relative Head Size Increase Using an Anatomic Dual Mobility Hip Prosthesis Compared to Traditional Hip Arthroplasty: Impact on Hip Stability

Smaller head sizes and head/cup ratios make cups smaller than 50 mm and larger than 58 mm, more prone to dislocation. Using computer modeling, we compared average head sizes and posterior horizontal dislocation distance (PHDD) in two 78-patient matched cohorts. Cup sizes were small (≤ 50 mm) or large (≥ 58 mm). The control cohort had conventional fixed bearing prostheses, while the experimental cohort had anatomical dual mobility (ADM) hip prostheses. ADM cups have larger average head sizes and PHDD than traditional fixed bearing prostheses by 11.5 mm and 80% for cups ≤ 50 mm, and 16.3 mm and 90% for cups ≥ 58 mm. Larger head sizes and increased head/cup ratio may allow the ADM prosthesis to reduce the incidence of dislocation.     

Utility of Synovial Fluid Aspirations in Failed Metal-On-Metal Total Hip Arthroplasty

White blood cell (WBC) count and neutrophil percentage from preoperative synovial fluid aspirations are used to help determine the presence or absence of periprosthetic joint infection (PJI) in failed total hip arthroplasty (THA). The clinical levels indicative of infection have not been delineated in metal-on-metal (MoM) bearings. We identified 39 patients who received a preoperative synovial fluid aspiration prior to MoM revision. Thirty-five of 39 cases were culture negative and 4 of 39 were culture positive. WBC count > 3000 cells/μL was 100% sensitive and 57.1% specific. Neutrophil percentage > 80% was 100% sensitive and 97.1% specific. Both CRP and ESR > 8.0 mg/L and > 22 mm/h, respectively were 75.0% sensitive and 67.6% specific. Our data suggest that synovial WBC count and serum ESR and CRP have poor predictive value in diagnosing PJI for failed MoM THA, whereas synovial neutrophil percentage is a highly accurate marker for diagnosing infection in this patient population.     

Application of Computed Tomography-Based Navigation for Revision Total Hip Arthroplasty

The usefulness of navigation systems for revision total hip arthroplasty (THA) remains unclear. The purpose of this study was to evaluate the accuracy of cup positioning using a navigation system in revision THA. Cup alignment of thirty revision cases was evaluated. Data were also compared with those of 30 navigated primary THA cases. In the revision THA group, mean difference in postoperative measurement from preoperative plan was 0.5 ± 4° (range, − 9° to 8°) for inclination and − 0.07° ± 5° (− 14° to 13°) for anteversion. Mean difference in postoperative measurement from intraoperative record was 0.7° ± 3° (− 5° to 8°) for inclination and − 0.7° ± 3° (− 12° to 5°) for anteversion. Compared with the primary THA group, none of these parameters were significantly different. This navigation system was useful even in revision THA.     

Cementless Total Hip Arthroplasty in Patients with Osteonecrosis After Kidney Transplantation

This study was to determine the mid- to long-term survivorship of cementless metal-on-metal THA in 52 patients (74 hips) who underwent THA for osteonecrosis of the femoral head with a cementless THA. The mean follow-up was 10.2 years. The mean age at operation was 42.1 years (range, 25–62 years). The survivorship analysis with revision as the end point estimated a 96.6% chance of THA survival during 16.4 years. The average Harris hip score at last follow-up was 89.2 points (range, 74–100). Two patients (two hips) required revision surgery for extensive acetabular osteolysis at 9 years and acetabular liner dissociation at 2 years. The survival rates of cementless THA in these patients are encouraging. However, the possibility of metallic wear related complications are raising concern.     

Chinese Patients' Satisfaction With Total Hip Arthroplasty: What Is Important and Dissatisfactory?

Through validated self-administered questionnaires, we conducted a retrospective investigation in 818 patients (1009 hips) who underwent primary THA, to collect data on overall satisfaction plus satisfaction and importance rating for 16 specific functions and issues. Overall, 8.1% patients were dissatisfied with the surgery. The top 3 important items are pain relief, squatting, and walking. The top 3 dissatisfactory items are jogging, squatting, and rising after squatting. The strongest risk factors for dissatisfaction with walking were pain (6.1 ×), muscle weakness(3.7 ×), and LLD (3.3 ×). The strongest risk factors for dissatisfaction with squatting were low postoperative HHS ROM (3.7 ×) and muscle weakness (2.6 ×). For Chinese patients, ROM, muscle strength and LLD are very important.