Ceramic Bearings with Titanium Adapter Sleeves Implanted During Revision Hip Arthroplasty Show Minimal Fretting or Corrosion: a Retrieval Analysis

Are Corrosion and Material Loss a Threat for Titanium-Titanium Tapers in Total Hip Arthroplasty Modular Acetabular Components?

BACKGROUND

Extensive research has reported on fretting corrosion and material loss for a variety of metal taper interfaces in orthopedic devices. For modular acetabular shell-liner constructs, the interfaces studied thus far have consisted of mixed-metal pairings, and the risk of fretting corrosion and material loss for the all-titanium (Ti) shell-liner taper junction in one ceramic-on-ceramic (COC) design remains poorly understood. We asked: do Ti shell-liner taper interfaces in COC total hip arthroplasty devices show in vivo evidence of (1) fretting and/or corrosion, and (2) quantifiable potential material loss?

METHODS

We examined 22 shell-liner pairs and 22 single liners from retrieved COC components. The taper interface surfaces were assessed for fretting corrosion using a semiquantitative scoring method and imaged with scanning electron microscopy. A subcohort of components was measured with a coordinate measuring machine, and volumetric material loss and maximum wear depth were calculated.

RESULTS

Fretting corrosion at the taper interfaces was minimal to mild for 95% of liners and 100% of shells. Imaging revealed fretting marks within a band of corrosion on some implants and evidence of corrosion not in the proximity of mechanical damage. Estimated material loss ranged from 0.2 to 1.3 mm3 for liners, and 0.5 to 1.1 mm3 for shells. Maximum wear depth for all components was 0.03 mm or less.

CONCLUSIONS

Our results indicate that, compared to other taper junctions in total joint arthroplasty, the risk of corrosion and material loss may be minimal for Ti shell-liner interfaces.

New Ceramic Heads With Titanium Sleeves on Retained Femoral Components: Results of Over 500 Revision Total Hip Arthroplasties

BACKGROUND

Ceramic heads are frequently combined with titanium sleeves in revision total hip arthroplasties (THAs), ostensibly to protect the ceramic head from existing damage to the retained trunnion. Although widely adopted, data on the performance and safety of this construct are minimal. The purpose of this study was to describe implant survivorships, radiographic results, and clinical outcomes of patients who underwent revision THA with a ceramic head and titanium sleeve on a retained femoral component.

METHODS

We identified 516 revision THAs with femoral component retention (328 acetabular-only revisions and 188 bearing surface exchanges) treated with a new ceramic head and titanium sleeve between 2000 and 2020. Mean age at revision was 64 years, 56% were women, and mean body mass index was 30. The indications for revision THA were adverse local tissue reaction (25%), acetabular loosening (24%), dislocation (17%), infection (5%), and other (29%). Kaplan-Meier survivorships were analyzed, radiographs reviewed, and Harris Hip Scores evaluated. Mean follow-up was 4 years (range, 2 to 10).

RESULTS

There were no reoperations or failures for ceramic head fracture, taper corrosion, or head/sleeve disengagement. The 10-year survivorship free of any re-revision was 85%. Indications for the 57 re-revisions included dislocation (33), infection (13), acetabular component loosening (7), periprosthetic fracture (2), psoas impingement (1), and sciatic nerve irritation (1). The 10-year survivorship free of any reoperation was 82%. There were an additional 14 reoperations. Radiographically, 1.9% had progressive femoral radiolucent lines, and 4.7% had progressive acetabular radiolucent lines. Mean Harris Hip Score was 81 at 2 years.

CONCLUSIONS

New ceramic heads with titanium sleeves in revision THAs with retained femoral components were durable and reliable with no cases of ceramic head fracture or taper complications at mean 4-year follow-up, including those revised for adverse local tissue reaction.

LEVEL OF EVIDENCE

IV.

Ceramic-on-Ceramic or Metal-on-Polyethylene: The Bearing of Choice after Ceramic Component Fracture in Total Hip Arthroplasty along with Concise Follow-Up of the Previous Cohort

OBJECTIVE

We previously reported the questionable result of reoperation using metal-on-polyethylene (MoP) bearing after the fracture of the ceramic component. After the report, we abandoned the use of MoP; instead, we used ceramic-on-ceramic (CoC) bearing. This report aimed to present the outcome of reoperation to CoC bearing after ceramic component failures along with the longer-term outcome of the previously reported cohort with an MoP bearing.

RESULTS

The mean follow-up of the MoP cohort was extended from 4.3 years to 8.8 years. Metallosis had occurred in three of nine patients of the previous cohort, which all required re-reoperations. Two hips from 11 patients with revision to CoC had re-reoperations due to ceramic liner fracture and non-union of the osteotomized fragment, respectively. No metallosis and wear occurred in the cohort revised with CoC articulation. Otherwise, there were no adverse changes in radiographs and no impairment in functions.

METHODS

We conducted an extended prospective evaluation of a previous cohort consisting of six head fractures and three liner fractures. In this cohort, the patients underwent a bearing change to metal-on-polyethylene. Additionally, we retrospectively analyzed 11 cases of third-generation ceramic bearing fractures, comprising nine head fractures and two liner fractures. These cases were subsequently treated with a bearing change to fourth-generation CoC. We assessed clinical and radiological outcomes, including complication rates, in both groups.

CONCLUSION

We recommend the latest CoC as the bearing of choice in reoperation after the fracture of ceramic components. In the case of an MoP bearing after the ceramic component fracture, the risk of metallosis seemed high in the early postoperative period.

Surface Analysis of Ti-Alloy Micro-Grooved 12/14 Tapers Assembled to Non-Sleeved and Sleeved Ceramic Heads: A Comparative Study of Retrieved Hip Prostheses

Ti6Al4V titanium alloy (Ti-alloy) sleeved ceramic heads have become widely used in revision surgery when the hip stem is left in situ. This solution guarantees a new junction between the bore of the ceramic head and the Ti-alloy sleeve, regardless of any possible, slight surface damage to the Ti-alloy taper of the stem. However, this solution introduces an additional Ti-alloy/Ti-alloy interface pairing, which is potentially susceptible to mechanically assisted crevice corrosion. This study evaluated both qualitatively and quantitatively the damage that occurred in vivo on Ti-alloy micro-grooved 12/14 tapers of (i) primary implants with non-sleeved ceramic heads (Group 1), (ii) secondary implants with non-sleeved ceramic heads (Group 2), and (iii) secondary implants with sleeved ceramic heads (Group 3). A total of 45 explants-15 for each group, including short-, medium- and long-neck heads-underwent optical evaluation for surface damage (Goldberg scoring), surface roughness analysis, and SEM/EDX analysis. The Goldberg scores did not reveal different patterns in the tapers' surface damage; surface damage was classified as absent or mild (surface damage score ≤2) in 94%, another 94%, and 92% of the analysed regions for Group 1, Group 2, and Group 3, respectively. Small but significant differences in morphological changes occurred in the tapers of the three groups: reductions no greater than a few percentage points in median values of roughness parameters were found in Group 1 and Group 2, while negligible changes were found in Group 3. SEM/EDX analysis revealed little (i.e., a slight increase in the oxygen content) to undetectable changes in the chemical composition on the Ti-alloy surface independently of the group. These results suggest that the Ti-alloy/Ti-alloy sleeve/taper junction is only mildly susceptible to mechanically assisted crevice corrosion. Assembling a sleeved ceramic head, with variable neck lengths up to a "long-neck", to a Ti-alloy micro-grooved 12/14 taper of a stem left in situ does not seem to increase the risk of revision due to trunnionosis, as long as junction stability (i.e., the proper seating of the sleeved ceramic head on the 12/14 taper) is achieved intraoperatively.

Improving the Endoprosthesis Design and the Postoperative Therapy as a Means of Reducing Complications Risks after Total Hip Arthroplasty

One of the most high-tech, efficient and reliable surgical procedures is Total Hip Arthroplasty (THA). Due to the increase in average life expectancy, it is especially relevant for older people suffering from chronic joint disease, allowing them to return to an active lifestyle. However, the rejuvenation of such a severe joint disease as osteoarthritis requires the search for new solutions that increase the lifespan of a Total Hip Replacement (THR). Current trends in the development of this area are primarily focused on the creation of new materials used in THR and methods for their processing that meet the requirements of biocompatibility, long-term strength, wear resistance and the absence of an immune system response aimed at rejection. This study is devoted to the substantiation of one of the possible approaches to increase the reliability and durability of THR, based on the improvement of the implant design and postoperative rehabilitation technology, potentially reducing the risk of complications in the postoperative period.

Catastrophic intraoperative failure of a ceramic femoral head

Approximately 17 years after a primary metal-on-metal total hip arthroplasty, a 59-year-old female developed pain, swelling, and weakness in her right hip accompanied by laboratory findings and imaging suggestive of an adverse local tissue reaction. Acetabular revision was performed to upsize the femoral head and improve hip stability. Upon impaction of the new, non-option ceramic femoral head onto the unsleeved retained stem, the head split into two pieces without fragmentation. The surgery was completed using a cobalt-chromium head, which was impacted without issue onto the stem’s taper. Although BIOLOX delta femoral heads do not require titanium sleeves, we believe that careful consideration should be given to their use in revision total hip arthroplasty with ceramic heads, regardless of the extent of trunnion damage noted intraoperatively.

Assessing Taper Geometry, Head Size, Head Material, and Their Interactions in Taper Fretting Corrosion of Retrieved Total Hip Arthroplasty Implants

BACKGROUND

Decreased fretting and corrosion damage at the taper interface of retrieved ceramic-on-polyethylene total hip arthroplasty (THA) implants has been consistently reported; however, resultant fretting corrosion as a function of femoral head size and taper geometry has not been definitively explained.

METHODS

Eight cohorts were defined from 157 retrieved THA implants based on femoral head composition (n = 95, zirconia-toughened alumina, ZTA vs n = 62, cobalt-chromium alloy, CoCr), head size (n = 56, 32mm vs n = 101, 36mm), and taper geometry (n = 84, 12/14 vs n = 73, V40). THA implants were evaluated and graded for taper fretting and corrosion. Data were statistically analyzed, including via a 2³ factorial modeling.

RESULTS

Factorial-based analysis indicated the significant factors related to both resultant (summed) fretting and corrosion damage were head material and taper geometry; head material-taper geometry interaction was also a significant factor in resultant corrosion damage. Lower rates of moderate-to-severe fretting and corrosion damage were exhibited on ZTA heads (ZTA = 13%, CoCr = 38%), smaller heads (32mm = 18%, 36mm = 26%), and 12/14 tapers (12/14 = 13%, V40 = 35%). ZTA+32mm heads demonstrated the lowest rates of moderate-to-severe fretting and corrosion damage (12/14 = 2%, V40 = 7%), whereas CoCr heads with V40 tapers demonstrated the greatest rates of moderate-to-severe damage (32mm = 47%, 36mm = 59%).

CONCLUSION

In this series, retrieved implants with ZTA, 32-mm heads paired with 12/14 tapers exhibited lower rates of moderate-to-severe damage. Factorial analysis showed head material, taper geometry, and their interactions were the most significant factors associated with resultant damage grades. Isolating implant features may provide additional information regarding factors leading to fretting and corrosion damage in THA.

LEVEL OF EVIDENCE

IV (case series).

A comparison of metal/metal and ceramic/metal taper-trunnion modular connections in explanted total hip replacements

Corrosion and wear are commonly found at the taper-trunnion connection of modular total hip arthroplasty (THA) explanted devices. While metal/metal (M/M) modular taper-trunnion connections exhibit more wear/corrosion than ceramic/metal (C/M) modular taper-trunnion connections, damage is present in both, regardless of material. This study used a combination of assessment techniques including clinical data, visual scoring assessment, optical imaging, profilometry, and x-ray photoelectron microscopy (XPS), to investigate wear mechanisms and damage features at the modular taper-trunnion connection of 10 M/M and 8 C/M explanted THAs. No correlation was found between any demographic variable and corrosion wear and assessment scores. All assessment techniques demonstrated that the stem trunnions had more damage than head tapers for both explant groups and agreed that C/M explants had less corrosion and wear compared to M/M explants. However, visual assessment scores differed between assessment techniques when evaluating the tapers and trunnions within the two groups. Profilometry showed an increase (p <.05) in surface roughness for stem trunnions compared to head tapers for both explant groups. X-ray photoelectron spectroscopy performed on deposits from two M/M explants found chromium and molybdenum carbides beneath the surface while chromium sulfate and aged bone mineral were found on the surface suggesting that the debris is a result of corrosion rather than wear. These results indicate that taper-trunnion damage is more prevalent for M/M explants, but C/M explants are still susceptible to damage. More comprehensive analysis of damage is necessary to better understand the origins of taper-trunnion damage.

lsolated acetabular revisions of articular surface replacement (ASR) XL implants with highly porous titanium cups and Delta bearings

INTRODUCTION

Articular surface replacement (ASR) XL implants exhibit higher-than-expected revision rates, blood ion concentrations and soft tissue lesions, making revisions troublesome and potentially unsatisfying. Appropriate techniques and outcomes in ASR XL revisions are rarely documented. The aims of this study were the assessments of pre-revision data, post-revision clinical and radiographic outcomes and ion levels in isolated acetabular ASR XL revisions performed using highly porous titanium cups and Delta ceramic articulations.

METHODS

18 isolated acetabular ASR XL revisions in 16 patients were performed using Ti-Por cups (Adler Ortho, Milan, Italy) and Delta bearings (CeramTec, Plochingen, Germany). Pre-revision demographic, clinical, radiological and implant-related features were assessed. Clinical and radiographic parameters (cup positioning, osseointegration) after revisions were evaluated at a minimum follow-up of 5 years. Ion concentrations in blood and urine were collected in pre-revision setting and 1 year after revision.

RESULTS

4 complications occurred in 3 different revisions (16.7%), 1 dislocation, 2 infections, 1 psoas impingement. No re-revision was performed at 5 years (1 scheduled arthroscopy). Good clinical outcomes were achieved (HHS score: 88.3 ± 9.2). All the cups showed reassuring signs of osseointegration (>3 parameters). Blood ion concentrations significantly decreased: patients with Co blood ion concentration over the threshold (7 μg/l) decreased from 76.5% to 0%. No pre-revision or intraoperative data influenced the revision outcomes.

CONCLUSIONS

Highly porous titanium cups and Delta ceramic articulations provided reliable mid-term clinical and radiographic outcomes in isolated acetabular ASR XL revisions. Ion concentrations significantly decreased. Multicentre prospective controlled studies are required to confirm these preliminary outcomes.

In Vivo Corrosion of Sleeved Ceramic Femoral Heads: A Retrieval Study

BACKGROUND

The purpose of this study was to evaluate a series of retrieved sleeved ceramic femoral heads used in total hip arthroplasty (THA) and determine qualitative and quantitative damage and corrosion patterns.

METHODS

An IRB-approved implant retrieval database was utilized to identify all sleeved ceramic femoral heads collected from 1995 to 2004. There were 16 implants with an average duration of in situ of 70 months (range, 13-241 months). The femoral stem was known in 14 cases and was titanium alloy in each of those cases. None were revised for metal-related complications. Ten implants (63%) were from primary THAs, and 6 (38%) were from revision THAs. Damage and corrosion were qualitatively graded using a modified Goldberg method. A quantitative assessment was performed with a coordinate measurement machine (CMM).

RESULTS

Among the 16 retrieved implants, 1 (6%) demonstrated severe Grade 4 corrosion, 5 (31%) had moderate Grade 3 corrosion, 5 (31%) had mild Grade 2 corrosion, and 5 (31%) had no visible corrosion at the inner sleeve that interfaces with the stem trunnion. The only case of grade 4 corrosion occurred in the only head-sleeve in the study that was not factory assembled and was mated with a titanium molybdenum zirconium ferrous (TMZF) alloy stem. The mean maximum linear corrosion depth at the taper interface, as measured by the CMM, was 7.7 microns (range, 0.9-32.9 microns).

CONCLUSION

This study is the first to quantify corrosion at the titanium interface of sleeved ceramic femoral heads. Potentially clinically significant damage and corrosion patterns were observed in a few failed retrievals; however, the majority of cases demonstrated minimal or no damage.

Evaluation of pull-off strength and seating displacement of sleeved ceramic revision heads in modular hip arthroplasty

Corrosion in revision total hip arthroplasty can be mitigated using a ceramic head on a well-fixed in situ stem, but concerns of their early failure because of any surface defects on in situ stem necessitates the use of a titanium sleeve, which furnishes a factory-finish surface. These sleeves are manufactured in different sizes allowing neck-length adjustment. The strength of the taper junction of non-sleeved primary heads is well-investigated, but the influence of an interposed titanium sleeve on achieving a secure taper lock is unclear. Therefore, this study aimed to investigate the pull-off strength and seating displacement of revision ceramic heads and titanium taper sleeves. Two different head diameters and two different taper adapter sleeve offset lengths were mated with trunnions at two different impaction forces. The seating displacement and pull-off force was recorded for each specimen. Profilometry of the grooved outer surfaces of the sleeve and trunnion was done before and after testing to analyze the change in surface roughness. The influence of head diameter, sleeve offset, and impaction force on seating displacement and pull-off force was analyzed using analysis of covariance. Pull-off forces for 6 kN assembly force were approximately three times those for 2 kN. The head diameter did not have a significant effect on the measured parameters. Compared with short offset length sleeves, extra-long increased seating displacement by 31% and reduced pull-off forces by 15%. While sleeves of different offset lengths permit control of neck length, surgeons must be careful of the impact of this choice on the stability of implant. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 38:1523-1528, 2020.

Taper fretting corrosion with Stryker Anato stem after hip replacement

We report a case of head-neck taper fretting corrosion in a patient who had a total hip replacement with a noncemented Stryker Anato femoral stem and a V40 metal head with a Stryker Tritanium hemispherical socket with a highly cross-linked polyethylene liner (metal on polyethylene) (Stryker, Mahwah, NJ, USA). A 57-year-old man presented with early-onset hip pain after right total hip arthroplasty. Workup was negative for infection. Metal artifact reduction sequence MRI revealed an encapsulated fluid mass. Metal ion cobalt level was elevated at 6 ppb. The patient underwent right revision total hip arthroplasty with excellent results at 1-year follow-up.

Adapter sleeves are essential for ceramic heads in hip revision surgery

BACKGROUND

Removing a head during isolated acetabular revision surgery can cause damage to the stem taper surface from extraction tool contact. Implanting a ceramic head on the damaged stem taper might elevate the fracture risk, which can be mitigated with the use of titanium adapter sleeves. The aim of this study was to investigate whether the improved fracture strength of modern generation ceramic heads allows the direct implantation on damaged stem tapers without an adapter sleeve.

METHODS

Finite element models of taper junctions with and without adapter sleeve were generated. Different stem taper damages were modelled to investigate the influence on the ceramic head fracture load under axial compression.

FINDINGS

Heads without adapter sleeves exhibited slightly higher or equal fracture strengths compared with sleeved heads for most scenarios. However, a small metal elevation on the stem taper caused a drastic decrease of the fracture strength if no adapter sleeve was used (-96%). The sleeved head was not influenced by the metal elevation damage.

INTERPRETATION

Adapter sleeves are essential to ensure patient safety and prosthesis longevity whenever implanting ceramic heads on used stem tapers.

Diagnosis and management of implant debris-associated inflammation

Introduction: Total joint replacement is one of the most common, safe, and efficacious operations in all of surgery. However, one major long-standing and unresolved issue is the adverse biological reaction to byproducts of wear from the bearing surfaces and modular articulations. These inflammatory reactions are mediated by the innate and adaptive immune systems.Areas covered: We review the etiology and pathophysiology of implant debris-associated inflammation, the clinical presentation and detailed work-up of these cases, and the principles and outcomes of non-operative and operative management. Furthermore, we suggest future strategies for prevention and novel treatments of implant-related adverse biological reactions.Expert opinion: The generation of byproducts from joint replacements is inevitable, due to repetitive loading of the implants. A clear understanding of the relevant biological principles, clinical presentations, investigative measures and treatments for implant-associated inflammatory reactions and periprosthetic osteolysis will help identify and treat patients with this issue earlier and more effectively. Although progressive implant-associated osteolysis is currently a condition that is treated surgically, with further research, it is hoped that non-operative biological interventions could prolong the lifetime of joint replacements that are otherwise functional and still salvageable.

Registry study on failure incidence in 1,127 revised hip implants with stem trunnion re-use after 10 years of follow-up: limited influence of an adapter sleeve

Background and purpose - Little is known about the role of retained trunnions in revision hip arthroplasties, i.e., when only the femoral head is substituted. Wear (fretting corrosion) and ceramic head fractures are 2 poorly understood concerns related to use, and the role of adapter sleeves has not been defined. In this registry study we assessed the influence of sleeve interposition on re-revision rates in revision hip arthroplasties with retained stems. Confounding factors (demographics, implant-related features) and failures were also analyzed. Patients and methods - We conducted a registry study on 1,127 revised implants (retained trunnion and head exchange). In 26% of implants an adapter sleeve was interposed; in 74% no adapter sleeve was implanted. Demographic and implant-related features were investigated including a descriptive analysis of failures. Results - The mean follow-up of revised implants with and without the use of an adapter sleeve was 3.3 and 5.1 years, respectively. The implant survival without an adapter sleeve was significantly higher, 98.4% (95% CI 96.9-99.8) vs. 95.2% (CI 93.2-96.6) with an adapter sleeve at 5 years. No re-revisions due to adverse local tissue reactions or ceramic head fractures were reported. In order to overcome the different distribution of head materials and head sizes in the two cohorts, only Delta balls were investigated. Interpretation - Adapter sleeve interposition had a minor influence on the revision rates. No adverse local tissue reactions or head fractures occurred.

Do oxidized zirconium heads decrease tribocorrosion in total hip arthroplasty? A study of retrieved components

AIMS

The aim of this study was to evaluate fretting and corrosion in retrieved oxidized zirconium (OxZr; OXINIUM, Smith & Nephew, Memphis, Tennessee) femoral heads and compare the results with those from a matched cohort of cobalt-chromium (CoCr) femoral heads.

PATIENTS AND METHODS

A total of 28 OxZr femoral heads were retrieved during revision total hip arthroplasty (THA) and matched to 28 retrieved CoCr heads according to patient demographics. The mean age at index was 56 years (46 to 83) in the OxZr group and 70 years (46 to 92) in the CoCr group. Fretting and corrosion scores of the female taper of the heads were measured according to the modified Goldberg scoring method.

RESULTS

The OxZr-retrieved femoral heads showed significantly lower mean corrosion scores than the CoCr heads (1.3 (1 to 2.75) vs 2.1 (1 to 4); p < 0.01). Mean fretting scores were also significantly lower in the OxZr cohort when compared with the CoCr cohort (1.3 (1 to 2) vs 1.5 (1 to 2.25); p = 0.02). OxZr heads had more damage in the proximal region compared with the distal region of the head. Location had no impact on damage of CoCr heads. A trend towards increased corrosion in large heads was seen only in the CoCr heads, although this was not statistically significant.

CONCLUSION

Retrieval analysis of OxZr femoral heads showed a decreased amount of fretting and corrosion compared with CoCr femoral heads. OxZr seems to be effective at reducing taper damage. Cite this article: Bone Joint J 2019;101-B:386-389.

Impact of stem taper damage on the fracture strength of ceramic heads with adapter sleeves

BACKGROUND

Using a new ceramic head with a titanium adapter sleeve offers the possibility of maintaining a well fixed stem when conducting cup revision of a total hip arthroplasty. The aim of this study is to test the impact of stem taper damage on the fracture strength of sleeved ceramic heads.

METHODS

Pristine zirconia-toughened alumina heads with titanium adapter sleeves (BIOLOX®OPTION System) were tested on damaged Ti-4Al-6V stem tapers in accordance with ISO7206-10. Four distinctive damage types classified as intolerable by the manufacture were investigated, representing various reductions in contact area between the stem taper and sleeve taper as well as damage incurred from previous ceramic head fracture.

FINDINGS

The largest reduction in fracture strength occurred for a loss of contact for the entire length of the stem taper. Nonetheless, the fracture strength in all investigated cases was several times higher than that defined by the FDA standards.

INTERPRETATION

The use of a titanium sleeve recreates a uniform contact situation between the ceramic head and the outer sleeve taper in situations of damaged stem tapers. For the investigated damage types a high fracture strength of the ceramic head was maintained. This study supports the clinical use for sleeved ceramic heads in instances of greater damages of stem tapers than previously defined in order to spare patients from stem removal.

Management of the Implant With Taper Corrosion: What to Change and What to Change It to?

Management of implant corrosion remains a challenge for the revision arthroplasty surgeon. Our field continues to gain insight in to how to manage this clinical scenario but there are still gaps in what is known to be considered to be the standard of care. There is a significant amount of effort going in to determining the best means of managing this issue but more work is needed. There is no doubt more studies are needed to further delineate the appropriate treatment algorithms for this clinical problem.

Adapter Sleeves Are Not Needed to Reduce the Risk of Fracture of a New Ceramic Head Implanted on a Well-Fixed Stem

The purpose of this study was to assess (1) the prevalence of the fracture of ceramic heads implanted on used trunnions of well-fixed stems without using a titanium adapter sleeve; (2) the prevalence of trunnionosis secondary to fretting and/or corrosion at the trunnion of the well-fixed stem; and (3) clinical and radiographic results and the survival rate of the revised acetabular components. Eighty-eight patients (100 hips) underwent isolated revision of the acetabular components for polyethylene wear and osteolysis of the acetabulum. The study group consisted of 70 men and 18 women with a mean age of 52.8 years (range, 31-54 years) when the primary total hip arthroplasty was performed. Evidence of fretting and corrosion of the trunnion of all prostheses was examined macroscopically using a magnifying lens. Degree of fretting and corrosion of the trunnion was assessed using a 4-point scoring technique. A new 36-mm alumina delta ceramic head was implanted on the trunnion of a well-fixed stem without using a titanium adapter sleeve in all hips. The mean follow-up after revision of the acetabular component was 12.8 years (range, 10-14 years). Among the 100 new ceramic heads implanted on a well-fixed stem, no fracture of the ceramic head occurred at a mean follow-up of 12.8 years. The median fretting and corrosion scores for the trunnions were 1.5±1.1 and 1.3±0.9 points, respectively. The mean Harris hip score at the final follow-up was 89±15 points (range, 63-100 points). Survivorship of the revised acetabular components at 14 years was 95% (95% confidence interval, 87.6%-98.6%). [Orthopedics. 2018; 41(3):158-163.].