Large-diameter Head Research Articles

Fractures of a Single Design of Highly Cross-Linked Polyethylene Acetabular Liners: An Analysis of Voluntary Reports to the United States Food and Drug Administration

Polyethylene liner fracture is a risk associated with the use of highly cross-linked UHMWPE. We performed a review of the voluntary reports of fractured liners to the US Food and Drug Administration to determine if any risk factors could be identified. There have been 74 reports of fractured Trilogy, Longevity liners to the US Food and Drug Administration since 1999. Most cases utilized small acetabular shells (≤54mm) combined with large diameter heads (≥36mm). Liners less than 7mm thick at the weight bearing or 4.8mm thick at the rim should be used with caution. At revision surgery, malpositioned shells should be revised and the use of a thin liner should be avoided.

Hip resurfacing arthroplasty versus large-diameter head metal-on-metal total hip arthroplasty: comparison of three Designs from the Finnish Arthroplasty Register

Large headed metal-on-metal total hip arthroplasty may produce more metal ions than hip resurfacing arthroplasty. Increased metal-ion levels may be associated with higher revision rates due to adverse reaction to metal debris. The purpose of our study was to compare the survivorship of three hip resurfacing arthroplasty designs with their analogous cementless large-diameter head metal-on-metal total hip arthroplasties. Based on data obtained from the Finnish Arthroplasty Register, the revision risks of three metal-on-metal hip resurfacing arthroplasty/total hip arthroplasty design couples performed during 2001-2011 were analyzed using the Cox regression model. In the Cox regression analysis for compared design pairs adjusted for age, gender, operated side, head size, diagnosis, and implant, there was no statistically significant difference in revision risk between ReCap hip resurfacing arthroplasty and Bimetric/ReCap total hip arthroplasty (risk ratio = 1.43, confidence interval = 0.95-2.14, p = 0.09) or between Birmingham hip resurfacing arthroplasty and Synergy/Birmingham hip resurfacing total hip arthroplasty (risk ratio = 1.35, confidence interval = 0.75-2.43, p = 0.31). However, the revision risk of Corail and Summit/articular surface replacement total hip arthroplasty (ASR HRA) was significantly increased compared to ASR HRA. (risk ratio = 0.73, confidence interval = 0.54-0.98, p = 0.04). We conclude that the short-term revision risk of large headed metal-on-metal total hip arthroplasties was not increased compared to analogous hip resurfacing arthroplasties in two out of three devices studied at a nationwide level. There may be implant-related factors having an effect on the success of single manufacturer devices. However, more information on the incidence of adverse soft-tissue reactions in these patient cohorts is needed.

Femoral taperosis

A modular femoral head-neck junction has practical advantages in total hip replacement. Taper fretting and corrosion have so far been an infrequent cause of revision. The role of design and manufacturing variables continues to be debated. Over the past decade several changes in technology and clinical practice might result in an increase in clinically significant taper fretting and corrosion. Those factors include an increased usage of large diameter (36 mm) heads, reduced femoral neck and taper dimensions, greater variability in taper assembly with smaller incision surgery, and higher taper stresses due to increased patient weight and/or physical activity. Additional studies are needed to determine the role of taper assembly compared with design, manufacturing and other implant variables.

Early Failure of Metal-on-Metal Large-Diameter Head Total Hip Arthroplasty Revised with a Dual-Mobility Bearing: A Case Report.

Riviere, Charles MD1; Lavigne, Martin MD, MSc, FRCS1; Alghamdi, Ahmed MD, FRCS1; Vendittoli, Pascal-André MD, MSc, FRCS1 Author Information

Effect of head contact on the rim of the cup on the offset loading and torque in hip joint replacement

Head contact on the rim of the cup causes stress concentration and consequently increased wear. The head contact on the rim of the cup may in addition cause an offset load and torque on the cup. The head-rim contact resulting from microseparation or subluxation has been investigated. An analytical model has been developed to calculate the offset loading and resultant torque on the cup as a function of the translational displacement of the head under simplified loading condition of the hip joint at heel strike during a walking cycle. The magnitude of the torque on the cup was found to increase with the increasing translational displacement, larger diameter heads, eccentric cups, and the coefficient of friction of the contact. The effects of cup inclination, cup rim radius, and cup coverage angle on the magnitude of the torque were found to be relatively small with a maximum variation in the torque magnitude being lower than 20%. This study has shown an increased torque due to the head loading on the rim of the cup, and this may contribute to the incidence of cup loosening. Particularly, metal-on-metal hip joints with larger head diameters may produce the highest offset loading torque.

Cementless Total Hip Arthroplasty with Large Diameter Metal-on-Metal Heads: Short-Term Survivorship of 8059 Hips from the Finnish Arthroplasty Register

Population-based register data from the National Joint Register of Australia and England and Wales have revealed that the mid-term outcome of cementless large diameter head metal-on-metal total hip arthroplasty is inferior to that of conventional cemented metal-on-polyethylene total hip arthroplasty. The aim of this study was to compare the results of cementless large diameter head metal-on-metal total hip arthroplasty with conventional cemented arthroplasty in Finland. The second aim of this study was to compare the cementless large diameter head metal-on-metal models with each other. Based on the data extracted from the Finnish Arthroplasty Register, the risk of revision of 8059 cementless large diameter head metal-on-metal total hip arthroplasties performed during 2002-2009 was analyzed using Cox regression model. The revision risk of these hips was compared to that of 16,978 cemented metal-on-polyethylene total hip arthroplasties performed during the same time period. In the Cox regression analysis, there was no difference in revision risks between cementless large diameter head metal-on-metal total hip arthroplasty and cemented metal-on-polyethylene total hip arthroplasty (relative risk = 0.90, confidence interval = 0.74-1.10, p = 0.3). However, in female patients aged 55 years or above, cementless large diameter head metal-on-metal total hip replacements showed a significantly increased risk of revision as compared to cemented total hip replacements (relative risk = 1.33, confidence interval = 1.04-1.70). Compared to the reference implant in this study (cementless Synergy stem combined with Birmingham Hip Resurfacing [BHR] cup), the CementLess Spotorno (CLS) stem combined with Durom cup had a 2.9-fold (95% confidence interval = 1.17-6.90) increased risk of revision. We found that cementless large diameter head metal-on-metal total hip arthroplasty had short-term survivorship compared with cemented total hip arthroplasty at a nation-wide level. However, in female patients aged 55 years or above, cementless large diameter head metal-on-metal total hip arthroplasty showed inferior results. Furthermore, implant design had an influence on revision rates. Longer follow-up time is needed to assess the success of large diameter head metal-on-metal total hip arthroplasty.

Avascular Necrosis of the Femoral Head in a Patient with Poliomyelitis Treated by THA with a Large-diameter Metal Head - A Case Report -

Avascular Necrosis of the Femoral Head in a Patient with Poliomyelitis Treated by THA with a Large-diameter Metal Head - A Case Report -

Does Choice of Head Size and Neck Geometry Affect Stem Migration in Modular Large-Diameter Metal-on-Metal Total Hip Arthroplasty? A Preliminary Analysis

Due to their theoretical advantages, hip systems combining modular necks and large diameter femoral heads have gradually gained popularity. However, among others, concerns regarding changes in the load transfer patterns were raised. Recent stress analyses have indeed shown that the use of modular necks and big femoral heads causes significant changes in the strain distribution along the femur. Our original hypothesis was that these changes may affect early distal migration of a modular stem. We examined the effect of head diameter and neck geometry on migration at two years of follow-up in a case series of 116 patients (125 hips), who have undergone primary Metal-on-Metal total hip arthroplasty with the modular grit-blasted Profemur®E stem combined with large-diameter heads (>36 mm). We found that choice of neck geometry and head diameter has no effect on stem migration. A multivariate regression analysis including the potential confounding variables of the body mass index, bone quality, canal fill and stem positioning revealed only a negative correlation between subsidence and canal fill in midstem area. Statistical analysis, despite its limitations, did not confirm our hypothesis that choice of neck geometry and/or head diameter affects early distal migration of a modular stem. However, the importance of correct stem sizing was revealed.

“Trunionitis”: A Cause for Concern?

Large diameter heads (LDH) are connected to the stem by means of a Morse taper. An adapter sleeve may be also used to adjust the head offset intraoperatively and/or to change the bearing couple and size. This paper explains the effect of head diameter and friction coefficient on the frictional torque acting on the tapers. A greater frictional torque tends to increase the micromotion occurring with in the tapered junction. Other crucial parameters are those that determine the distance between the center of the head and the tapered junction engagement level (e.g. head offset, adapter sleeve). Caution must be paid in using LDH coupled to small tapered junction, with or without an adapter sleeve.

Fretting Corrosion and Trunnion Wear—Is it Also a Problem for Sleeved Ceramic Heads?

Some modular bearing systems with large diameter metal-on-metal articulation have exhibited higher than usual revisions due to corrosion and metal debris originating from modular metal connections. Large diameter ceramic-on-ceramic bearings exist, which use a titanium alloy adapter sleeve for fixing the ceramic ball head to the stem taper. This study addresses the issue of taper fretting and corrosion for large ceramic bearings with standard and a newly designed experimental setup. While large metal diameter heads have been shown to be a cause for failure of THA, our results demonstrate that large ceramic heads even with a metal adapter sleeve have no effect on corrosion of modular taper connections.

Large diameter heads

Large femoral heads have been used with increasing frequency over the last decade. The prime reason is likely the effect of large heads on stability. The larger head neck ratio, combined with the increased jump distance of larger heads result in a greater arc of impingement free motion, and greater resistance to dislocation in a provocative position. Multiple studies have demonstrated clear clinical efficacy in diminishing dislocation rates with the use of large femoral heads. With crosslinked polyethylene, wear has been shown to be equivalent between larger and smaller heads. However, the stability advantages of increasing diameter beyond 38 mm have not been clearly demonstrated. More importantly, recent data implicates large heads in the increasing prevalence of groin pain and psoas impingement. There are clear benefits with larger femoral head diameters, but the advantages of diameters beyond 38 mm have not yet been demonstrated clinically.

Mid-term results of large diameter heads on cross-linked polyethylene liners in total hip replacement.

Highly cross-linked polyethylene liners in total hip replacement (THR) have allowed the use of larger diameter femoral heads. Larger heads allow for increased range of motion, decreased implant impingement, and protection against dislocation. The purpose of this study is to assess the clinical and radiographic outcomes of patients with large femoral heads THR at 4 years postop. Study includes 28 patients who had a primary THR with a 36mm larger femoral head were retrospectively for minimum 4 years follow-up. All patients received a cementless acetabular shell and a highly cross-linked polyethylene liner with an inner diameter of 36mm. The median radiographic follow-up was 4 years (range 2.0-6.0), and patients were assessed clinically by Harris hip score. The mean follow-up is minimum 4 years (range 2-6 years) results in all operated patients showed marked improvement in Harris hip score from preoperative mean 49.1 to 89.9 at 4 years or more follow-up. The complications include superficial infection (n=2). No dislocation, or no osteolysis was seen in the pelvis or proximal femur, and no components failed due to aseptic loosening. There was no evidence of cup migration, screw breakage, or eccentric wear on the liner. The mid-term results in this series of patients with LDH using 36 mm femoral head articulating with highly cross linked polyethylene showed excellent clinical, and radiological results, in terms of, joint restoration that replicates the natural anatomy, optimized range of motion without impingement & reduced opportunity for postoperative dislocation.

Risk of dislocation using large- vs. small-diameter femoral heads in total hip arthroplasty

BackgroundDislocation remains a difficult problem in total hip arthroplasty. Large-diameter femoral heads may lower the incidence of dislocation by enhancing the jump distance and decreasing impingement, but their performance against small-diameter heads has not been assessed. This study compared the mid-term radiographic and functional outcomes of two matched cohorts of patients undergoing total hip arthroplasty who had a high pre-operative risk for dislocation and who received either small-diameter (26- or 28-millimeters) or large-diameter (≥36-millimeters) femoral heads.MethodsAll patients who received large-diameter heads (≥36-millimeter) between 2002 and 2005, and who had pre-operative risk factors for dislocation, were identified in the institution’s joint registry. Forty-one patients (52 hips) who received large-diameter heads were identified, and these patients were matched to 48 patients (52 hips) in the registry who received small-diameter femoral heads.ResultsAt mean final follow-up of 62 months (range, 49 to 101 months), both groups achieved excellent functional outcomes as measured by Harris Hip scores, with slightly better final scores in the large-diameter group (90 vs. 83 points). No patient showed any radiographic signs of loosening. No patient dislocated in the large-diameter femoral head group; the smaller-diameter group had a greater rate of dislocation (3.8%, 2 out of 52).ConclusionsLarge-diameter femoral head articulations may reduce dislocation rates in patients who have a high pre-operative risk for dislocation while providing the same functional improvements and safety as small-diameter bearings.

Corrosion at the Cone/Taper Interface Leads to Failure of Large-diameter Metal-on-metal Total Hip Arthroplasties

Metal-on-metal (MoM) THAs have reduced wear rates compared with metal-on-polyethylene. However, elevated serum metal ion levels and pseudotumors have been reported in large MoM articulations. We therefore determined (1) if corrosion occurred at the cone/taper interface leading to instability in patients with large-diameter THAs; (2) how patients presented clinically and radiographically; (3) if adverse periprosthetic tissue reactions occurred; (4) whether metal was released from the implants into the periprosthetic tissues; and (5) if head size correlated with metal release. We reviewed 114 patients who had revisions of large-diameter head MoM articulations. Mean time of implantation was 46 months. To identify adverse reactions and particle load, tissues were stained by hematoxylin and eosin and CD3/CD20/CD68 antibodies. Periprosthetic tissues were analyzed for metal content and distribution in different regions. Electrochemical reactions between the stem and adapter were investigated by a minicell electrode. Electrochemical studies on the stem and the head adapter showed a risk for galvanic corrosion. Ninety-four percent of patients had instability at the cone/taper interface. All patients presented with early clinical symptoms; 59 patients had radiographic signs of loosening. One hundred four patients had foreign body reactions and necrosis. The largest amounts of metal released were titanium or iron. We found no correlation between head size and metal ion release. These findings suggest that in modular cone/taper connections, friction of the MoM articulations may cause failure of the cone/taper interface leading to galvanic corrosion and loosening. It is unclear whether the design of this MoM system provides sufficient stability at the taper.

Technique and results of endoscopic tenotomy in iliopsoas muscle tendinopathy secondary to total hip replacement: A series of 10 cases

There have been numerous recommendations for management of iliopsoas tendinopathy secondary to hip replacement: medical treatment, cup replacement, and open or arthroscopic tenotomy. We report on a series of 10 endoscopic iliopsoas tenotomies. Arthroplasty comprised five primary conventional total prostheses, two large head diameter metal-metal models, one resurfacing and one revision arthroplasty. All patients underwent clinical (PMA, WOMAC), imaging (X-ray, CT, scintigraphy) and biological assessment. Seven cases showed mechanical impingement (six involving the anterior edge of the cup, and one a cement fragment); the other three involved large femoral components (two large head diameter models, one resurfacing). Infiltration test was positive in eight cases out of nine. Endoscopic iliopsoas tenotomy for recurrence was performed in dorsal decubitus on an ordinary table, under fluoroscopy, using two approaches (inferior for the endoscope, superior for the instruments) converging on the lesser trochanter. There were no complications. At a mean 20 months' follow-up (range, 12-60 months), mean pain grade was 5.5 (4-6). Eight patients showed complete relief, and two partial relief (two atypical cases). Mean PMA score was 16.9 (15-18) and mean WOMAC score 84 (60-95). Muscle force was recovered at a mean 3.25 months (0.5-6). Eight patients were very satisfied, one satisfied and one moderately satisfied. This technique is much less heavy than implant replacement; postoperative course is shorter than for open tenotomy and the technique is simpler than arthroscopic tenotomy, with lower risk. Subsequent cup change, where necessary, is not compromised. IV, retrospective, case series.

Hip resurfacing in patients under thirty years old: an attractive option for young and active patients

Metal-on-metal hip resurfacing is offered as an alternative to traditional hip arthroplasty for young, active adults with advanced osteoarthritis. The concept of hip resurfacing is considered very attractive for this specific population (hard-on-hard bearing component with a large femoral head limiting the risk of dislocation, and allowing femoral bone stock preservation). A prospective clinical trial was designed to investigate the outcome of hip resurfacing in young patients (under 30 years old). We studied 24 hips in 22 patients. Mean age at operation was 24.9 years (range 17.1-29.9). No patient was lost to follow-up. There was no revision at average follow-up of 50.6 months (44-59). Mean UCLA activity score improved from 5.5 (1-9) pre-operatively to 7.6 (1-10) postoperatively (p < 0.001). Mean Harris hip score increased from 43.9 (19-67) to 89.3 (55-100) (p < 0.001). Radiological analysis discerned no osteolysis and no implant migration. The absence of short-term complications, such as mechanical failure or dislocation, is encouraging and leads us to think that mid-term results will be satisfactory. Moreover, the specific advantages of hip resurfacing (bone stock preservation, excellent stability, low risk of dislocation, large-diameter head) make the procedure a very attractive option for young subjects.

Luxationen nach Hüftendoprothetik

Dislocations after total hip arthroplasties are one of the most common complications of the procedure. According to registers, recurrent hip dislocations account for up to 30 % of the indications for a revision operation. The incidence of a dislocation is influenced by indication-associated, patient-dependent and operation-specific risk factors. 50 % of the dislocations occur within the first 3 months which confirms the high relevance of operation-specific influencing factors. The diagnosis is almost always made with the help of computed tomography, as this is the only method to determine the three-dimensional relationship of the components. A dynamic fluoroscopic examination can verify an increased translation (reduced soft-tissue tension) and thus enables a functional examination to determine the mechanism of the dislocation. By means of a classification of dislocations into five types under consideration of the implant position, the sufficiency of the pelvitrochantar musculature, the presence of an impingement, the congruence of head and acetabular liner as well as combinations of these factors it is possible to plan an adequate therapy. From the therapeutic point of view the correct positioning of the stem and head is of decisive importance. In addition therapeutic success can be realized by using larger head diameters through to tripolar sockets, reconstruction of soft tissues and, last but not least, an adequate postoperative immobilization. Even so, this treatment is associated with a high rate of complications and in the literature failure rates of up to one third, i.e., the reoccurrence of a dislocation, are reported.

One-year prospective comparative study of three large-diameter metal-on-metal total hip prostheses: Serum metal ion levels and clinical outcomes

The good clinical outcomes and low wear obtained with 28-mm metal-on-metal implants for total hip replacement prompted the development of large-diameter heads that more closely replicated the normal hip anatomy, with the goal of improving prosthesis stability. However, the blood release of metal ions due to wear at the bearing surfaces and the high rate of groin pain seen with large-diameter implants are causing concern. To determine whether these events are related to the geometry and metal composition of the prosthesis components, we conducted a prospective study of clinical outcomes and serum chromium and cobalt levels 1 year after implantation of three different acetabular cups. Serum levels of metal ions are comparable with different types of large-diameter metal-on-metal total hip prostheses. We compared 24 Durom™ cups (D), 23 M2a Magnum™ cups (M2a), and 20 Conserve Total™ (C) cups regarding serum chromium and cobalt levels, Postel-Merle d'Aubigné (PMA) scores and Oxford Hip Scores (OHS), as well as radiographic cup orientation and position at 1-year follow-up. Mean age was 66 years (45-85 years), mean body mass index was 28 Kg/m(2) (18-45), patients were almost equally divided between males and females, and the reason for hip replacement was primary hip osteoarthritis in 65 patients and avascular necrosis in two. Metal ions were assayed in serum from blood drawn through non-metallic catheters, using mass spectrometry. Dislocation occurred in two patients (one D and one M2a) and revision to change the bearing couple was required in two patients in the D group. Serum cobalt levels in the C group were significantly higher (P=0. 0003) than in the two other groups (7.5 μg/L versus 2. 7 μg/L with D and 2. 2 μg/L with M2a). Clinical outcomes were better in the M2a group (PMA, 17.7 [16-18]; and OHS, 15.2 [12-30]; P<0.05). The PMA score and OHS were 17.5 (16-18) and 18.2 (12-42), respectively, with D; and 16.75 (10-18) and 22. 2 (12-42), respectively, with C cups. When all three cup models were pooled, serum ion levels were higher in patients with pain than without pain (chromium, 7.1 μg/L versus 2.1 μg/L [P=0.002], and cobalt, 8 μg/L versus 2.6 μg/L [P=0.0004]). Serum chrome and cobalt levels increased after metal-on-metal total hip replacement, and the increase was greater with large-diameter implants than previously reported with 28-mm implants. Persistent pain was significantly associated with higher metal ion levels, with a probable cobalt cut-off of about 8 μg/L. Differences in modular head-neck concepts may explain the observed variations.

Mid-Term Outcome of Total Hip Replacement Using the Posterior Approach for Displaced Femoral Neck Fractures

Treatment of displaced femoral neck fractures with total hip replacement (THR) in appropriately selected patients has become more widely accepted. The use of the posterior approach for THR remains controversial due to concerns regarding dislocation, the cause of which is multi-factorial. This study is a single surgeon series of 45 consecutive active, healthy patients (mean age 78 years) with displaced femoral neck fractures treated with THR through a posterior approach. Large diameter heads (32mm in 47%, ≥36mm in 48% of patients) and an anatomic posterior soft tissue repair were utilised to minimize the risk of dislocation. Outcomes were reported at a mean of 2 and 6 years. The mortality rate was 13% at 2 years and 40% at 6 years. All revision surgery (4.4%) was performed for dislocations which occurred in 6.7% of patients. Good VAS pain, OHS and SF-12 scores were reported both at 2 and 6 years. Patient satisfaction with the results of surgery was high.

Failure rates of stemmed metal-on-metal hip replacements: analysis of data from the National Joint Registry of England and Wales

Total hip replacement (THR) is extremely common. Some prostheses fail, particularly in younger patients, and need to be revised, most commonly for loosening secondary to wear or dislocation. Surgeons have tried to address these problems by implanting large diameter metal-on-metal bearing surfaces. Our aim was to assess if metal-on-metal bearing surfaces lead to increased implant survival compared with other bearing surfaces in stemmed THR and, additionally, if larger head sizes result in improved implant survival. We analysed the National Joint Registry of England and Wales for primary hip replacements (402,051, of which 31,171 were stemmed metal-on-metal) undertaken between 2003 and 2011. Our analysis was with a multivariable flexible parametric survival model to estimate the covariate-adjusted cumulative incidence of revision adjusting for the competing risk of death. Metal-on-metal THR failed at high rates. Failure was related to head size, with larger heads failing earlier (3·2% cumulative incidence of revision [95% CI 2·5-4·1] for 28 mm and 5·1% [4·2-6·2] for 52 mm head at 5 years in men aged 60 years). 5 year revision rates in younger women were 6·1% (5·2-7·2) for 46 mm metal-on-metal compared with 1·6% (1·3-2·1) for 28 mm metal-on-polyethylene. By contrast, for ceramic-on-ceramic articulations larger head sizes were associated with improved survival (5 year revision rate of 3·3% [2·6-4·1] with 28 mm and 2·0% [1·5-2·7] with 40 mm for men aged 60 years). Metal-on-metal stemmed articulations give poor implant survival compared with other options and should not be implanted. All patients with these bearings should be carefully monitored, particularly young women implanted with large diameter heads. Since large diameter ceramic-on-ceramic bearings seem to do well we support their continued use. National Joint Registry of England and Wales.