The noisy ceramic hip: is component malpositioning the cause?

Ceramic-on-Ceramic Total Hip Arthroplasty Using a Double Tapered, Proximally Coated Stem: 15 to 24-year Clinical and Radiologic Follow-Up

BACKGROUND

Total hip arthroplasty implant choice profoundly affects survivorship, complications, and failure modes. This study evaluates the long-term (average 18 year) outcomes of ceramic-on-ceramic hip arthroplasty using uncemented shells and stems. Despite an impressive 20-year cumulative percent revision of 5.9%, the hydroxyapatite proximally coated femoral components evaluated in this study have seen declining use since 2003.

METHODS

A review of 349 consecutive total hip arthroplasties from 1999 to 2007 was matched to 272 cases with registry data. A survivorship analysis included 274 hips (Group A) after excluding patients lost to follow-up and navigated cases. Group B comprised 135 patients who had complete datasets spanning a minimum of 15 years.

RESULTS

Kaplan-Meier analysis identified a 95.6% survivorship plateau at 16 to 24 years, with no significant impact from age, sex, component size, or original pathology. In Group B, EuroQol-5 Dimensions-5 Levels (EQ5D5L) scores indicated favorable outcomes in mobility, self-care, activities, pain/discomfort, and anxiety/depression, with an EQ5D visual analog score mean of 79.24. Functional scores, including the Harris Hip Score, Oxford Hip Score, and Forgotten Joint Score, showed positive outcomes. Radiologic assessments revealed no osteolysis or loose components, with a mean Engh score of 21.69. Dorr classification identified bone quality variations. Better Engh scores corresponded to higher levels of patient satisfaction. Age at surgery was correlated with better functional scores, while sex influenced various outcomes.

CONCLUSIONS

This comprehensive study, spanning an average of 18.23 years, combined multiple patient-reported outcome measures with extensive clinical and radiologic follow-up. It reported a notably high survivorship rate for this implant combination but highlighted the declining use of the hydroxyapatite proximally coated femoral stem used in this study, potentially facing withdrawal risks in Australia.

LEVEL OF EVIDENCE

Therapeutic Level IV.

Protective effect of sevoflurane on lung function of elderly chronic obstructive pulmonary disease patients undergoing total hip arthroplasty

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is a common respiratory disorder that affects the elderly population and increases the risk of postoperative pulmonary complications (PPCs) after major surgeries. Sevoflurane is a volatile anesthetic that has been shown to have anti-inflammatory and antioxidant properties and attenuate lung injury in animal models.

AIM

To evaluate the protective effect of sevoflurane on the lung function of elderly COPD patients undergoing total hip arthroplasty (THA).

METHODS

In this randomized controlled trial, we randomly assigned 120 elderly patients with COPD, who were scheduled for THA, to receive either sevoflurane (sevoflurane group) or propofol (propofol group) as the maintenance anesthetic. The primary outcome was the incidence of PPCs within seven days after surgery. The secondary outcomes were changes in the lung function parameters, inflammatory markers, oxidative stress markers, and postoperative pain scores.

RESULTS

The results showed that the incidence of PPCs was significantly lower in the sevoflurane group than in the propofol group (10% vs 25%, P = 0.02). Furthermore, the decline in the forced expiratory volume in 1 s, forced vital capacity, and peak expiratory flow was significantly lesser in the sevoflurane group than in the propofol group at 24 h and 48 h after surgery (P < 0.05). The interleukin-6, tumor necrosis factor-alpha, malondialdehyde, and 8-hydroxy-2 α-deoxyguanosine levels were significantly lower in the sevoflurane group than in the propofol group at 24 h after surgery (P < 0.05). The sevoflurane group showed significantly lower postoperative pain scores than the propofol group at 6 h, 12 h, and 24 h after surgery (P < 0.05).

CONCLUSION

Sevoflurane protects the lung function of elderly COPD patients undergoing THA under general anesthesia by reducing the incidence of PPCs, attenuating inflammatory and oxidative stress responses, and alleviating postoperative pain.

A Nomogram That Characterizes a Patient's Odds of Developing Squeaking After Fourth-generation Ceramic-on-ceramic THA

BACKGROUND

Although ceramic-on-ceramic (CoC) bearings result in the lowest wear rate of any bearing combination, postoperative squeaking remains worrisome. However, data concerning squeaking in long-term follow-up studies are still lacking, especially for fourth-generation CoC THA.

QUESTIONS/PURPOSES

(1) After keeping the prosthesis in place for 10 years, what percentage of patients treated with fourth-generation CoC THA implants report squeaking, and are there points in time when squeaking occurs more frequently? (2) What are the characteristics, association with hip function, and factors associated with squeaking? (3) Can we create a nomogram that characterizes a patient's odds of experiencing squeaking based on the factors associated with it?

METHODS

Between January 2009 and December 2011, 1050 patients received primary THAs at our institution, 97% (1017) of whom received fourth-generation CoC THAs because this was the preferred bearing during this period. Of the 1017 eligible patients, 5% (54) underwent THAs performed by low-volume surgeons, 3% (30) were implanted with cemented prostheses, 2% (22) died, 1% (10) were immobile, 1% (six) underwent revision surgery, and 17% (169) were lost to follow-up before 10 years, leaving 726 patients for analysis here at a mean of 11 ± 1 years. In the study cohort, 64% (464) were male and 36% (262) were female, with a mean age of 44 ± 13 years at primary THA. We extracted data about articular noise from follow-up records in our institutional database and used a newly developed questionnaire to ascertain the percentage of patients who reported squeaking at the latest follow-up interval. Although not validated, the questionnaire was modeled on previous studies on this topic. The longitudinal pattern for squeaking was explored to find timepoints when squeaking occurs more frequently. Based on the questionnaire data, we calculated the percentages of frequent, reproducible, and avoidable squeaking. Hip function was evaluated with the Harris Hip Score and WOMAC score and compared between the squeaking and nonsqueaking groups. Factors associated with squeaking, which were examined in a multivariate analysis, were used to develop a nomogram.

RESULTS

At 10 years, 16% (116 of 726) of patients reported squeaking. Two squeaking peaks were determined, at 0 to 1 year and 8 to 10 years. Frequent, reproducible, and avoidable squeaking accounted for 42% (36 of 86), 20% (17 of 86), and 41% (35 of 86), respectively. The mean Harris Hip Score (93 ± 4 versus 94 ± 5; p = 0.81) and WOMAC score (16 ± 13 versus 15 ± 13; p = 0.23) did not differ between patients with squeaking and those without. After controlling for potential confounding variables such as etiology and head offset, we found that patients younger than 46 years (odds ratio 2.5 [95% confidence interval 1.5 to 5.0]; p < 0. 001), those who were male (OR 2.0 [95% CI 1.1 to 3.5]; p = 0.04), those having a total flexion and extension arc of less than 50° (OR 2.0 [95% CI 1.2 to 3.3]; p = 0.02), and those with the Corail hip implant (OR 4.1 [95% CI 2.1 to 7.7]; p < 0. 001) were more likely to report squeaking. We created a nomogram that can be used at the point of care that can help clinicians identify patients at a higher risk of experiencing squeaking; this nomogram had good performance (area under the receiver operating characteristic curve of 77%).

CONCLUSION

As a potential late complication, squeaking after fourth-generation CoC THA is of concern and may be related to increased stripe wear. We recommend that surgeons use this nomogram to assess the odds of squeaking before selecting a bearing, especially in patients at high risk, to facilitate shared decision-making and improve patient satisfaction. Future external validation of the model is still needed to enhance its applicability.Level of Evidence Level III, therapeutic study.

Damage analysis of retrieved BioloxⓇdelta components used in hard and soft bearings

This retrieval study included 43 Biolox delta explants (18 CoC, 25 CoP). Implants were examined macroscopically, whereby damage was evaluated using a semi quantitative scoring system. Confocal microscopy was used to examine wear related damage patterns of the articulating surfaces. Scanning electron microscopy (SEM) with energy-dispersive X-ray spectroscopy (EDS) was used to analyze wear marks on the implant surface and wear debris in periprosthetic tissue samples. Raman spectroscopy and X-ray diffraction (XRD) were used to quantify monoclinic zirconia fractions. On all components, in vivo wear resulted predominantly in different damage patterns caused by metal transfer. In CoC bearings stripe wear was additionally detected, and some implants underwent severe damage due to component breakage. The wear scores were higher for CoC components, with no differences between the scores for CoC heads and liners. Wear features caused comparable roughening on implants from CoC and CoP bearings. SEM studies demonstrated that most wear marks were caused by metal debris released from implant components. Grain pull-out was observed in stripe wear regions. Monoclinic phase shift was observed in a similar quantity on components from CoP and CoC bearings. The increase of monoclinic zirconia content around metal deposits was minimal and was more pronounced in areas of stripe wear. The results of this study indicate, that ZTA components in general undergo minimal wear in both, CoC and CoP bearings, however, it is more pronounced in the former. Metal deposits, as the most common wear feature, have no significant effect on monoclinic phase transition. STATEMENT OF SIGNIFICANCE: In this paper, we classify all damage patterns macroscopically according to an established scoring system and assess them regarding surface roughness (confocal microscopy) and monoclinic phase content (Raman spectroscopy) in order to derive the severity for patients. We compare hard-hard and hard-soft bearings and relate damage patterns with metal transfer based on SEM/EDS examinations. Furthermore, we work out correlations between patient-specific data, cause of revision and the physical condition of each individual sample Our cohort consists of 43 Biolox delta retrievals, a comparatively large quantity. In addition, we address current topics such as metal transfer and, based on the classification of damage patterns, provide incentives and/or meaningful focal points for further research.

A 10- to 12-year follow-up study of delta ceramic-on-ceramic total hip arthroplasty

BACKGROUND

We previously reported five-to-seven-year results of total hip arthroplasty (THA) with the use of delta ceramic-on-ceramic (CoC) bearing. We conducted an extension study with a CT scan at a minimum of 10 years after surgery.

METHODS

From March 2009 to March 2011, 273 patients (310 hips) received cementless THA with delta CoC bearing, porous-coated cup and hydroxyapatite-coated stem. In this extended study, 252 patients (144 men and 108 women) (288 hips) with a mean age of 49.7 years (16-83) at surgery were followed for a mean of 10.4 years (10-12) with CT scans in 133 hips (46.2%, 133/288). Clinical and radiographic evaluations were made at each follow-up and Kaplan-Meier survival analysis was performed with revision and reoperation as endpoints.

RESULTS

There were no more ceramic fractures. Compared to mid-term results, the incidence of squeaking and RLLs increased to 3.1% (9/288) and 19.4% (56/288), respectively. The RLL progressed to focal osteolysis in 3 hips (5.4%, 3/56). No hip had detectable wear or prosthetic loosening. Two hips were reoperated due to periprosthetic joint infection and periprosthetic femoral fracture in each. The survivorship decreased to 98.3% (96.7-99.9%) at 12 years.

CONCLUSION

During the extended follow-up, no additional ceramic fracture occurred, and the incidence of squeak increased by 0.7%. The long-term survivorship of Delta CoC THA was encouraging. However, focal osteolysis occurred around the hydroxyapatite-coated stem in 1% (3/288).

LEVEL OF EVIDENCE

II (Prospective cohort study).

Primary Total Hip Arthroplasty with Ceramic-on-Ceramic Articulations: Analysis of a Single-center Series of 1,083 Hips at a Minimum of 10-Year Follow-Up

BACKGROUND

There are limited long-term results of using ceramic-on-ceramic bearings (COC) in total hip arthroplasty (THA) in a large number of patient cohorts. The purpose of this study was to evaluate the minimum 10-year clinical and radiological outcomes and survivorship in a single surgeon series of CoC-THA.

METHODS

Among the 1,039 patients (1,391 hips) who underwent primary THA at our institution between 2008 and 2011, 49 patients (69 hips) experienced paralysis or death, and 194 patients (239 hips, 19%) were lost to follow-up. The remaining 796 patients (1,083 hips) were assessed at a mean of 11 years (range, 10 to 13 years) using the modified Harris hip score (mHHS), the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), and a questionnaire on articular noises. Survival analysis was used to estimate the survivorship. Radiological evaluation was performed on 869 hips at the final follow-up.

RESULTS

Survivorship at 11 years was 98.3% for revision or aseptic loosening, and 98.2% for re-operation. At the final follow-up, the mean mHHS and WOMAC scores were 93 (range, 12 to 100) and 14.4 (range, 3 to 66), respectively. There were 131 (12%) hips experienced squeaking, but no patient required revision. No fracture of the ceramic was observed. Radiological evaluation at the final follow-up revealed that three (0.3%) hips exhibited loosening, two (0.2%) had femoral osteolysis, 81(9.3%) acquired radiolucencies, and 35 (4%) showed heterotopic ossification.

CONCLUSION

This ceramic-on-ceramic bearing for THA had a high survivorship and excellent functional outcomes for at least 10 years.

Robotic-assisted versus manual total hip arthroplasty in obese patients: a retrospective case-control study

Aims

The objective of this study was to evaluate the accuracy of acetabular cup positioning in the obese patients when using robotic-assisted technology during total hip arthroplasty (THA).

Methods

Data were retrospectively collected from patients who underwent primary (THA) with a body mass index (BMI) ≥ 28 kg/m² and ≥ 1 year of follow-up between January 2018 and December 2019. Their demographics, diagnosis, acetabular cup positioning, American Society of Anesthesiologists (ASA) score, Harris Hip Score (HHS), and Forgotten Joint Score (FJS) at the final follow-up were recorded for analysis.

Results

There were no statistically significant differences between the two groups in height, weight, BMI, ASA score, or preoperative Harris Hip Score (HHS). Also, there was no difference in inclination angle between the two groups (R-THA: 41.29° ± 3.04°; manual THA (M-THA): 40.47° ± 5.46°; P = 0.312). However, the mean anteversion angle was greater in the R-THA group (20.71° ± 1.98° vs. 19.08° ± 4.04°; P < 0.001). Compared to M-THA, R-THA more frequently achieved an acetabular cup angle within 5° of the target (anteversion, 98.1% vs. 78.1% P = 0.001; inclination, 88.5% vs. 53.1%, P < 0.001). The R-THA group was more advantageous in restoring the hip center of rotation (COR) and leg length difference (LLD). There was no statistical difference in postoperative HHS (P = 0.404) or FJS (P = 0.497) between the two groups.

Conclusions

Compared to manual technique, robotic-assisted technique provided more precise acetabular cup positioning and better leg length restoration for obese patients. The robotic-assisted technique was more advantageous in recovering the center of rotation position and achieved a higher proportion of the acetabular cup placed in the target safety zone. Further studies are needed to confirm the clinical outcomes of surgeries in obese patients using robotic-assisted technology.

Third and fourth generation ceramic-on-ceramic total hip arthroplasty at a minimum of ten years

BACKGROUND

Ceramic on Ceramic bearings in Total Hip Arthroplasty (THA) afford a low friction coefficient, low wear rates and extreme hardness. Significant complications include hip squeak, ceramic fracture and poor polyethylene performance in revision procedures due to imbedding of abrasive microscopic ceramic fragments. We report on the results of this bearing at a minimum of 10 years.

METHODS

A single-centre retrospective review of 449 THAs was performed. Primary outcome measures included aseptic revision and all-cause revision rates at a minimum of 10 years post operatively. Evaluation of functionality was performed with WOMAC and SF-36 scores which were performed pre-operatively and at intervals of 6 months, one year, 2 years, 5 years and 10 years post operatively.

RESULTS

There was a 6.2% (n = 28) all-cause and 5.3% (n = 24) aseptic revision rate for ceramic on ceramic total hip arthroplasty at minimum of 10 years with a mean time to revision 4.8 years (range 2 months-11.6 years). Notably, there were 2 revisions for ceramic head fracture, one for ceramic liner fracture, 3 for aseptic loosening and 3 revisions for squeaking. Pain of unknown origin was the most common reason for revision. There was an improvement in postoperative WOMAC scores from a mean of 59.8 (range 15-95) pre-operatively to a mean of 15.6 (range 0-78) at 10 years.

CONCLUSION

This study showed good functional outcomes but high revision rates for CoC THA at a minimum of 10 years. Our rates of ceramic fracture were consistent with other studies.

Toward long-live ceramic on ceramic hip joints: In vitro investigation of squeaking of coated hip joint with layer-by-layer reinforced PVA coatings

This study attempts to find a promising solution for the squeaking of ceramic on ceramic (COC) bearing surfaces by introducing reinforced poly(vinylalcohol) (PVA) layer-by-layer coatings on the bearing surface of Stryker Trident femoral head. A customized hip simulator was established to provide a realistic simulation of the normal gait (flexion–extension) of the hip joint, and to examine squeaking for coated and uncoated femoral heads. Different characterization techniques were employed to study the coatings’ structure. The PVA macromolecules were successfully cross-linked via epichlorohydrin agent, and chemically bonded onto the surface, forming a superior reinforced PVA coating on the femoral head’s surface. These coatings play a dominant role in increasing the pre-squeaking age of the hip joint due to reduction in hard-on-hard contact and femoral head liner clearance with their good viscoelastic properties. Which cause, damping friction-induced vibrations. This improvement resembles novel-type, long-life, and stable hip joint biomaterials with distinguished and promising pre-squeaking age.

Long-Term Results of Alumina Ceramic-On-Ceramic Bearings in Cementless Total Hip Arthroplasty: A 20-Year Minimum Follow-Up

BACKGROUND

Alumina ceramic-on-ceramic bearings are used in total hip arthroplasty (THA) because of their wear-resistant and inert properties. In this study, we assessed the clinical and radiographic outcomes of patients undergoing primary cementless ceramic-on-ceramic THA at a minimum follow-up of 20 years.

METHODS

A series of 301 consecutive primary THAs in 283 patients were assessed. Clinically, patients were assessed with the modified Harris Hip Score (HHS) and pain questionnaires. Anteroposterior radiographs of the pelvis and lateral radiographs of the hip were used to radiologically assess the implant. Patients were classified as lost to follow-up if they could not be contacted on multiple occasions or did not wish to participate further in this study.

RESULTS

At twenty years after operation, 60 patients had died of a cause unrelated to surgery, 16 had experienced complications requiring reoperation, and 100 hips had both clinical assessments and radiographs at a minimum of 20 years of follow-up. The average HHS improved from 56.1 (range: 17-89) before THA to 92.5 (range: 63-100) at the latest follow-up. The classification of the HHS was good or excellent in 96.4% of patients. Only 1.8% of patients still had moderate residual pain at the thigh or groin. Radiographically, all patients demonstrated bony ingrowth but no clinical symptoms of loosening. The overall survival rate of the implants was 94.2% at 20 years with revision for any reason as the end point.

CONCLUSION

Long-Term follow-up in our series showed excellent implant survival, excellent functional outcomes, and minimal late complications. There was no significant radiographic evidence of failure at a minimum of 20 years after THA.

LEVEL OF EVIDENCE

Therapeutic Level IV.

Long-Term Results of Delta Ceramic-on-Ceramic Total Hip Arthroplasty

Background

Ceramic-on-ceramic (COC) bearings in total hip arthroplasty (THA) have long been considered the coupling with the lowest overall wear. However, concerns about complications such as ceramic breakage and noise, combined with the improved performance of polyethylene, have limited its use in the United States. This postapproval follow-up reports long-term (10 years) results of Delta COC in THA patients primarily enrolled in an Investigational Device Exemption study.

Methods

Patients received Delta COC THA in a prospective multicenter study with either 28-mm (N = 105 hips in 104 patients) or 36-mm (N = 81) articulations. Annual clinical and radiographic evaluations were performed for years 5 to 10, and study patients were asked about hip noises and reproducibility.

Results

There have been 4 additional reports of noise in 4 patients (COC 28, n = 3; COC 36, n = 1). The cumulative incidence rate for squeaking or noise at 10 years is 5.9% for COC 28 and 13.5% for COC 36. There have been 2 additional reports of dislocation in 2 patients (COC 28, n = 1; COC 36, n = 1). The cumulative incidence rate for dislocation at 10 years is 3.7% for COC 28 and 3.5% for COC 36. At 10 years, there were greater than 40 hips available for follow-up. At mean 10-year follow-up, there were a total of 3 ceramic liner fractures, but none since the previous report. There were no revisions in the 28-mm cohort, and 2 revisions in the 36-mm cohort (1 for recurrent dislocation and 1 for pain and noise). Overall Kaplan-Meier survivorship was 95.96% at 10.5 years (28 mm: 97.68% at 10.2 years; 36 mm: 94.11% at 10.4 years.)

Conclusions

At 10-year follow-up, we report excellent results in regard to survivorship, with one patient revised for pain with associated squeaking.

No Difference in Dislocation Rates Comparing Large Diameter Jumbo Femoral Heads and Dual-Mobility Bearings in Revision Total Hip Arthroplasty

BACKGROUND

Dual-mobility (DM) bearings reduce instability in revision total hip arthroplasty (THA); however, DM bearings are costly and reports of corrosion have recently emerged. Furthermore, no study has compared DM to standard bearings with large diameter femoral heads ≥40-mm. This study's purpose was to compare postoperative dislocation rates of standard and DM bearings with large femoral heads after revision THA.

METHODS

A retrospective review of 301 consecutive revision THAs was performed. The mean follow-up was 37.1 months. To isolate the effect of the double articulation, standard and DM bearings with femoral heads ≥40-mm were compared. Outcomes were postoperative dislocation and reoperation within 90 days.

RESULTS

The cohort consisted of 182 standard bearings and 75 DM bearings. There were no differences in revision indication comparing standard and DM bearings (P = .258). Overall dislocation rate was 8.6% (22 of 257). The dislocation rate was 5.7% for standard bearings with ≥40-mm femoral heads compared with 6.9% in DM bearings with ≥40-mm femoral heads (P = 1.000). In multivariate analysis, lower body mass index (odds ratio 1.72), female sex (odds ratio 2.01), and decreased outer femoral head diameter-to-cup component size ratio (odds ratio 1.64) were predictors of postoperative dislocation regardless of bearing type.

CONCLUSION

This study showed no difference in dislocation rates between standard and DM bearings when comparing similar femoral head diameters of ≥40-mm used in revision THAs. Considering the cost and potential deleterious issues associated with additional interfaces, DM bearings should be used judiciously considering similar results may be achieved with single-articulation bearings using large femoral heads.

LEVEL OF EVIDENCE

Level III.

Squeaking Is Common and Increases Over Time Among Patients With Long-term Follow-up After Ceramic-on-ceramic THA

BACKGROUND

Ceramic-on-ceramic (CoC) is a durable bearing with excellent wear characteristics, but squeaking remains a concern. The proportion of patients who report squeaking varies widely between studies performed at short- and mid-term follow-up.

QUESTIONS/PURPOSES

(1) What proportion of patients treated with CoC THA bearings report squeaking at a minimum of 10 years of follow-up? (2) Are patient, implant, or radiographic factors associated with squeaking? (3) Are THAs that squeak more likely to be revised than those that do not? (4) Are patient-reported functional outcome scores lower between THAs that squeak and THAs that do not squeak at long-term follow-up?

METHODS

Between January 1, 2003 and August 31, 2008 a total of 80 patients received THAs with third-generation alumina-on-alumina bearings at one center. Of the original 80 patients, 1% (1 of 80) had died, and 21% (17 of 80) were lost to follow-up before 10 years, leaving 62 patients for analysis at a median (range) of 14 years (11 to 16). Ceramic-on-ceramic THA represented 23% (80 of 343) of all primary THAs performed during the study period. Ceramic-on-ceramic THA was used preferentially in patients younger than 50 years of age. The mean (range) age of patients in the cohort was 44 ± 11 years (18 to 65). Sixty-eight percent (42 of 62) were men. Two separate manufacturers' implants were included. There were uncemented acetabular and femoral components included in this study. All CoC bearings were third-generation alumina-on-alumina. Squeaking was determined through a mailed questionnaire or telephone interview. The 10-question survey developed by the researchers queried patients whether audible "squeaking" could be heard from their hip replacement. Patients were asked to write in their description of the noise to distinguish squeaking from other noises not relevant to the current study. Implant information, component position, and patient demographics were obtained via chart review and postoperative radiographs reviewed by one of the investigators not involved with the index operative procedure. Using revision for any reason as an endpoint, a Kaplan-Meier analysis was performed to compare survivorship between THAs that squeaked versus those that did not. Patient-reported outcomes were surveyed using the Hip Disability and Osteoarthritis Outcome Score for Joint Replacement (HOOS JR), which comprises six items regarding patient pain and function, raw summed scores range from 0 (perfect hip health) to 24 (total hip disability).

RESULTS

Squeaking was self-reported by 53% (33 of 62) of patients in this group. Squeaking was more common in patients who received the titanium-molybdenum-zirconium-iron stem than in patients with the titanium-aluminum-vanadium stem (63% [29 of 46] versus 31% [4 of 13]; odds ratio 3.8 [95% CI 1.02 to 14.4]; p = 0.046). We found no differences in the likelihood a patient would report squeaking based on component position, component size, patient age, sex, or BMI. Ten-year survivorship free from revision was not lower in patients who reported squeaking (91% [95% CI 74 to 97] versus 90% [95% CI 71 to 96]; p = 0.69). Patient-reported outcome scores (HOOS JR) were not lower in those who reported squeaking (3 ± 3 [95% CI 1.5 to 4.0] versus 3 ± 5 [95% CI 1.5 to 5.5]; p = 0.59).

CONCLUSION

At long-term follow-up, we found that CoC bearing squeaking in patients who underwent THA is more common than previously reported. Survivorship was lower than expected in this cohort, and most revisions in this series were for squeaking. Although implant-dependent, surgeons should counsel patients about the potential for squeaking in CoC THA, which may occur years after index procedure.

LEVEL OF EVIDENCE

Level III, therapeutic study.

A bicentric approach evaluating the combination of a hemispheric cup with a novel ceramic head in total hip arthroplasty

Medical ceramics are frequently used biomaterials as a liner in total hip arthroplasty. Strong efforts have been made to improve material properties over the last decades. Alumina toughened zirconia ceramics seem to be promising alternatives to further reduce fracture rates and squeaking phenomena. To answer the question if alumina toughened zirconia ceramic liners in combination with a cementless, hemispheric cup are able to reduce squeaking phenomena and fracture rates, we initiated a bicentric, mid-term trial. Noise phenomena will be recorded using MONA Score (Melbourne Orthopaedic Noise Assessment). Functional outcome (Harris Hip Score, University of California-Los Angeles, Forgotten Joint Score, EQ-5D Score, Visual Analogue Scale) and radiographic parameters will serve as secondary parameters. The study has been set up for 5 years, with follow-ups after 6-14 weeks, 12, 24 and 60 months.

Natural history of noise and squeaking in cementless ceramic-on-ceramic total hip arthroplasty

Introduction

Ceramic-on-ceramic (COC) total hip arthroplasty (THA) was developed to reduce wear debris, and consequently the occurrence of osteolysis and aseptic loosening. The purpose of the present study was to determine the incidence and natural history of noise including squeaking after COC THA, and to clarify whether clinical outcomes and any demographic and implant-related factors are associated with noise from these ceramic bearings.

Methods

This was a retrospective observational study of 137 primary COC THAs between 2004 and 2009 at our institute. The Mean follow-up was for 10.5 years. All patients were followed up with an office visit to obtain information regarding noise, pain, and function. The correlations between the noise, and patient demographic, radiographic, and implant-related factors were evaluated.

Results

Noise developed in 30 hips (21.9%), specifically squeaking in 2 (1.5%) of the 137 hips during the follow-up period. Noise including squeaking was not associated with pain or functional outcomes. There was significant correlation between noise and cup anteversion, in that cup anteversion of patients with noise was smaller than that in those without noise. No significant correlation was found between noise and any other patient demographic including age, sex, height, body weight, or body mass index. Kaplan-Meier survivorship analysis with revision for any reason and an aseptic loosening of either component as the end point, revealed a cumulative survival rate at 10 years of 98.4% and 99.1% respectively.

Conclusion

The long-term clinical and radiographic outcome of cementless COC THA is excellent, but we should be vigilant for noise from COC bearings.

A Surgeon's handedness in direct anterior approach-hip replacement

BACKGROUND

The impact of handedness on clinical outcomes was easily overlooked in hip replacement. This study aimed to find whether the component positioning and hip function were affected by the handedness in total hip arthroplasty (THA) through direct anterior approach (DAA).

METHODS

Total 102 patients who underwent bilateral DAA-THAs simultaneously between May 2016 and November 2018 in our institute were reviewed. All surgeries were operated by one right-handed surgeon. Their demographic, cup positioning, stem alignment, femoral stem fit, Harris hip score (HHS), intraoperative and postoperative complications were used to evaluate the role of handedness in DAA.

RESULTS

The inclination of left cups was significantly larger than that of right cups (42.61 ± 7.32 vs 39.42 ± 7.19, p = 0.000). The stem fit of left femur was significantly larger than that of right femur (84.34 ± 4.83 vs 82.81 ± 6.07, p = 0.043). No significant differences in safe zone ratio, HHS and complications between bilateral hips were found.

CONCLUSIONS

A surgeon's handedness had significant impact on cup's inclination and femoral stem fit in DAA-THA. However, there were no significant differences of cup malpositioning, stem alignment, hip function scores and complications between bilateral DAA-THAs.

Robot-Assisted Total Hip Arthroplasty for Arthrodesed Hips

Background

Conversion of arthrodesed hips to total hip arthroplasty (THA) remains technically demanding. This study aims to evaluate the safety and efficacy of robot-assisted THA in arthrodesed hips.

Methods

We retrospectively analyzed 45 ankylosing spondylitis patients with hip arthrodesis in the Chinese PLA General Hospital between August 2018 and August 2019. All surgeries were carried out by one single surgeon. The patients were followed at 3 months after surgery. Gender, body mass index, angle of hip arthrodesis, operating time, intraoperative fluoroscopic times, postoperative length of hospitalization, cup positioning, postoperative leg length discrepancy, offset discrepancy, intraoperative and postoperative complications, and postoperative Harris Hip Score were collected for all patients.

Results

Twenty-two patients (35 hips) who underwent robot-assisted THA and 23 patients (37 hips) who underwent manual THA were enrolled in this study. There were no significant differences in demographics and arthrodesed angles between the two groups. The fluoroscopic times during manual THA were significantly higher than those during robot-assisted THA (2.16±1.61 vs 0.47±0.61, respectively, p=0.000). In the robotic group, the percentage of acetabular cups within the safe zone was significantly greater than in the manual group (94.29% vs 67.56%, respectively, p=0.042). For manual THA, the anteversions were significantly different between the left and right sides (21.14±7.86 vs 16.00±6.32, respectively, p=0.042); however, no such significant difference was found in robot-assisted THA.

Conclusion

Compared with manual THA for arthrodesed hips, robot-assisted THA had significant advantages in improving the frequency of achieving cup positioning within the target zone with diminished radiation dose and no increase in operating time.

Impact of surgeon handedness in manual and robot-assisted total hip arthroplasty

BACKGROUND

The purpose of this study was to examine whether surgeon handedness could affect cup positioning in manual total hip arthroplasty (THA), and whether robot could diminish or eliminate the impact of surgeon handedness on cup positioning in robot-assisted THA.

METHODS

Fifty-three patients who underwent bilateral robot-assisted THA and sixty-two patients who underwent bilateral manual THA between August 2018 and July 2019 in our institute were respectively analyzed in this study. When the difference between the bilateral anteversion and inclination was greater than 5°, the patient was regarded as having different cup positioning between bilateral THA. Their demographics, orientation of acetabular cup, and postoperative 3 month Harris hip score (HHS) were recorded for analysis.

RESULTS

There were no significant differences in the gender, age, BMI, diagnosis's composition, and preoperative and postoperative HHS between the robotic and manual group. Two left hips dislocated in the manual group. The anteversion of left hip was significantly larger than that of right hip (24.77 ± 10.44 vs 22.44 ± 8.67, p = 0.043) in the manual group. There were no significant differences of cup positioning between bilateral robot-assisted THA. The patients in manual group were significantly more likely to have different cup positioning between bilateral hips than those in robotic group (77% vs 45%, p = 0.000). More manual THA were located out of the target zone than robot-assisted THA (70% vs 48%, p = 0.001).

CONCLUSIONS

Surgeon's handedness showed a trend towards an impact on cup positioning in manual THA and robot might help surgeon eliminate the adverse impact. However, the impact of handedness on the clinical outcomes still needs further observation.

Component positioning and ceramic damage in cementless ceramic-on-ceramic total hip arthroplasty

BACKGROUND

In ceramic-on-ceramic (CoC) total hip arthroplasty (THA), component positioning demonstrated to influence the bearing damage: however the connection between angles and clinical outcomes at long-term follow-ups is currently lacking. Aims of this study were: the computer tomography (CT) assessment of component positioning in CoC THAs; the correlation analysis between positioning and ceramic damage; the identification of safe zones.

METHODS

91 consecutive post-operative CT scans including two types of CoC implants, with a mean follow-up of 12 ± 4.4 years, were evaluated. III generation (74.2%) and IV generation (25.8%) CoC surfaces were included. The angle measurements (cup abduction, anteversion, cup tilt, stem antetorsion, sacral slope) were automated using a CT-based software. The combined anteversion was assessed as well as the cup-neck position at -15°, 0°, 45° and 90° of flexion. Ceramic damage was diagnosed using synovial fluid analyses and radiological criteria.

RESULTS

63.7% of THAs was inside the cup abduction target 30°-45° and 68.1% was inside the cup anteversion target 5°-25°. 19 patients (20.9%) showed signs of ceramic damage. High cup abduction and high cup-neck 45° minimum angle (which stood for high abduction and extreme combined version) significantly correlated with ceramic damage. No demographical features apart III generation ceramic bearings influenced the results. No safe zones could be detected.

CONCLUSIONS

In CoC THA, no safe zones can be described. However it is important to avoid cup inclination over 45° and a combination of steep cup and extreme combined version.

The use of an Ossis custom 3D-printed tri-flanged acetabular implant for major bone loss: minimum 2-year follow-up

INTRODUCTION

Custom 3D-printed acetabular implants are a new technology used in hip surgery with ever-increasing frequency. They offer patient-specific implants to optimise filling of bone defects and implant-bone contact, without the need for excessive bone resection.

METHODS

This is a retrospective cohort study of 46 consecutive patients who underwent an Ossis unilateral custom 3D-printed acetabular implant. Clinical (Oxford Hip Score OHS-60), Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), Harris Hip Score (HHS) and radiological (restoration of biomechanical hip centre, osteointegration, wear, heterotrophic ossification) results were assessed.

RESULTS

Patient mean age was 68 years and follow-up was 38 months (minimum 24 months). 10 patients were excluded from the outcome analysis; 2 patients died, 1 required revision for deep infection and 7 were lost to follow-up. Of the 36 patients included, 21 had severe osteolysis. 7 were revised for infection, 3 for tumoural defects, 3 for metallosis, 1 for dysplasia and 1 for trauma (Paprosky 2a [n=6], 2b [n=2], 2c [n=5], 3a [n=6], 3b [n=11], pelvic dissociation [n=6]). OHS significantly improved postoperatively (16-8-48.4 p=0.027). Postoperative functional scores were good (WOMAC 98; HHS 79). The biomechanical hip centre was restored in all patients. 1 patient had early implant migration with subsequent stabilisation. 2 patients had radiographs concerning for failure of osteointegration. 1 patient had recurrent dislocations.

CONCLUSIONS

The mid-term results of the Ossis custom 3D-printed tri-flanged acetabular implant for the management of severe acetabular defects are encouraging. The improvement in functional scores and radiographic outcomes are comparable to similar designs. In addition, no cases have required revision for aseptic loosening.

Excellent results of large-diameter ceramic-on-ceramic bearings in total hip arthroplasty

Aims

This study reports the mid-term results of total hip arthroplasty (THA) performed using a monoblock acetabular component with a large-diameter head (LDH) ceramic-on-ceramic (CoC) bearing.

Patients and Methods

Of the 276 hips (246 patients) included in this study, 264 (96%) were reviewed at a mean of 67 months (48 to 79) postoperatively. Procedures were performed with a mini posterior approach. Clinical and radiological outcomes were recorded at regular intervals. A noise assessment questionnaire was completed at last follow-up.

Results

There were four re-operations (1%) including one early revision for insufficient primary fixation (0.4%). No hip dislocation was reported. The mean University of California, Los Angeles (UCLA) activity score, 12-Item Short-Form Health Survey (SF-12) Mental Component Summary (MCS) score, SF-12 Physical Component Summary (PCS) score, Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score, and Forgotten Joint Score (FJS) were 6.6 (2 to 10), 52.8 (25.5 to 65.7), 53.0 (27.2 to 66.5), 7.7 (0 to 63), and 88.5 (23 to 100), respectively. No signs of loosening or osteolysis were observed on radiological review. The incidence of squeaking was 23% (n = 51/225). Squeaking was significantly associated with larger head diameter (p < 0.001), younger age (p < 0.001), higher SF-12 PCS (p < 0.001), and UCLA scores (p < 0.001). Squeaking did not affect patient satisfaction, with 100% of the squeaking hips satisfied with the surgery.

Conclusion

LDH CoC THAs have demonstrated excellent functional outcomes at medium-term follow-up, with very low revision rate and no dislocations. The high incidence of squeaking did not affect patient satisfaction or function. LDH CoC with a monoblock acetabular component has the potential to provide long term implant survivorship with unrestricted activity, while avoiding implant impingement, liner fracture at insertion, and hip instability. Cite this article: Bone Joint J 2018;100-B:1434–41.

Clinical Outcomes and Bearing-Specific Complications Following Fourth-Generation Alumina Ceramic-on-Ceramic Total Hip Arthroplasty: A Single-Surgeon Series of 749 Hips at a Minimum of 5-Year Follow-Up

BACKGROUND

The purpose of this study is to evaluate the minimum 5-year outcomes and bearing-specific complications in a single surgeon series of fourth-generation alumina ceramic-on-ceramic total hip arthroplasties (THAs).

METHODS

We retrospectively analyzed 667 patients (749 hips) who underwent primary THAs by a single surgeon using fourth-generation alumina ceramic bearings. There were 315 men and 352 women with a mean age of 54.2 years. The surgeon used cementless prostheses with an identical design and BIOLOX Delta ceramics in all hips, using a 36-mm head in 472 hips (63%) and a 32-mm head in 227. The mean follow-up duration was 6.5 years (range, 5 to 8 years).

RESULTS

The mean Harris hip score improved from 45.6 points preoperatively to 91.3 points at final follow-up. All but 1 acetabular cup and all femoral stems were well fixed. No radiographic evidence of osteolysis was identified at final follow-up. There were 2 (0.3%) ceramic liner fractures and no ceramic head fractures. A total of 48 hips (6.4%) exhibited audible noise (29 clickings and 19 squeakings), but no patient required revision. Other complications were 1 dislocation, 1 deep infection, 3 iliopsoas tendonitis, and 6 periprosthetic femoral fractures. Kaplan-Meier survivorship for revision for any reason was 98.6% (95% confidence interval, 97.7-99.5) at 6.5 years.

CONCLUSION

Delta ceramic-on-ceramic THAs had a high rate of survivorship without radiographic evidence of osteolysis at 6.5-year follow-up. However, we found 0.3% ceramic liner fractures and 6.4% audible noises associated with the use of Delta ceramics.

Is the cup orientation different in bilateral total hip arthroplasty with right-handed surgeons using posterolateral approach?

Background

The impact of surgeon handedness on acetabular cup orientation in total hip arthroplasty (THA) is not well studied. The aim of our study is to investigate the difference of cup orientation in bilateral THA performed by right-handed surgeons using posterolateral approach and which cup could be fitter to Lewinneck’s safe zone.

Methods

The study consisted of 498 patients that underwent bilateral THA by three right-handed surgeons in our hospital. Postoperative acetabular cup anteversion and abduction on an anteroposterior pelvic radiograph were measured by Orthoview software (Orthoview LLC, Jacksonville, Florida). Furthermore, the percentage of cup placement within the safe zone was compared.

Results

The mean anteversion was 25.28 (25.28° ± 7.16°) in left THA and 22.01 (22.01° ± 6.35°) in right THA (p < 0.001). The mean abduction was 37.50 (37.50° ± 6.76°) in left THA and 38.59 (38.59° ± 6.84°) in right THA (p = 0.011). In the left side, the cup was positioned in Lewinnek’s safe zone in 52% for anteversion, 87% for abduction, and 46% for both anteversion and abduction. But the cup placement within Lewinnek’s safe zone was 71, 88, and 62% in the right side, respectively. There were significant differences in the percentage of acetabular cup placement within the safe zone for anteversion (p < 0.001) and for both anteversion and inclination (p < 0.001). Dislocation occurred in 7.0% (35/498) of cases in left THA and 3.2% (16/498) in right THA. The percentages of patients experiencing dislocation were significantly different between the two sides (p = 0.006).

Conclusions

This current study demonstrated that surgeon handedness is likely to be a contributing factor that affects cup inclination and anteversion in bilateral THA and that the placement of cup performed by dominant hands of surgeons is more accurate than that performed by non-dominant sides.

Increase in Benign Squeaking Rate at Five-Year Follow-Up: Results of a Large Diameter Ceramic-on-Ceramic Bearing in Total Hip Arthroplasty

BACKGROUND

Squeaking is an on-going complication with a variable incidence of 0.5%-20.7%. The mechanism of squeaking has not been understood completely and is most likely multifactorial in nature. Previously, we have reported on a squeaking rate of 7.3% at 2 years. Our current results show a substantial increase in the squeaking incidence from 7.3% to 17.4% with the DeltaMotion articulation at the 5-year follow-up.

METHODS

Two hundred six total hip arthroplasties with a large ceramic-on-ceramic bearing were performed on 195 patients by 2 senior authors. The minimum duration of follow-up was 5 years (range 5-6.2).

RESULTS

The mean Harris Hip Score remained stable at 91.7 at 5 years compared to 92 after 2 years. However, we observed an increase in the squeaking rate from 7.3% after 2 years to 17.4% after 5 years. As in previous studies, we did not find significant differences between the silent and squeaking group in relation to age, height, weight, and femoral head diameter. In contrast, others reported no significant differences regarding range of motion and gender between the silent and the squeaking hip group at 2 years of follow-up, whereas at 5 years, the squeaking group showed a significantly higher combined range of motion and a higher relative risk of squeaking in women compared to the silent group.

CONCLUSION

While large diameter ceramic bearings may produce squeaking, especially in female patients, our mid-term clinical results of a large ceramic-on-ceramic bearing in total hip arthroplasty are encouraging. Nevertheless, long-term follow-up is recommended.

Squeaking in ceramic-on-ceramic hips: No evidence of contribution from the trunnion morse taper

Squeaking in ceramic-on-ceramic (CoC) total hip arthroplasty (THA) was investigated with an acoustic monitoring device to distinguish between squeaking emanating from the trunnion morse taper (TMT) connection versus the articular surface. 82 patients with implant problems scheduled for revision were selected and acoustic emissions (AE) with simple movements monitored. Five of these patients with CoC implants underwent surgery and their retrieved implant components were analyzed in vitro. In vivo recordings of all 82 patients found audible squeaks produce frequency content across the entire 0-50 kHz spectrum. Of the five CoC implants the in vivo peak frequency range of flexion/extension motions was 0.8 kHz and comparable to the range of in vitro testing (0.2 kHz). In vitro TMT connection motions were very large comparatively, producing a higher average peak frequency range of 22.5 kHz. All retrieved implants showed evidence of wear at the TMT connection. These findings suggest, the TMT connection does not directly cause audible squeaking. Wear occurring at this junction may contribute to debris which disrupt lubrication, increase friction, and produce noise. This observation supports current evidence suggesting that squeaking is from the bearing surface. Our findings are the first to demonstrate that in CoC THA the recordable noise of a hip squeak does not originate nor have contribution from the TMT connection. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:1793-1798, 2017.

Do Changes in the Production Process Affect the Outcome of Ceramic Liners: A 3-Year Follow-Up Study

BACKGROUND

In 2011, the current liner was withdrawn from the market because of the potential risk for liner fracture secondary to increased pressures used to assemble the metal locking ring. The present study provides a short-term follow-up of patients with this implant.

METHODS

We retrospectively evaluated 63 consecutive hips in 53 patients operated by a single surgeon using a recalled ceramic-on-ceramic bearing. There were 30 women and 23 men with an average age of 50.6 years (range 20.3-63.5 years). The mean follow-up was 36.8 months.

RESULTS

Six hips in 6 patients were revised (9.5%) because of a liner-fracture during the follow-up period. All liner fractures were identified on computer tomography imaging. Nine patients had self-reported episodes of squeaking (14.3%). All 6 patients that underwent revision surgery for liner fracture described squeaking before revision. There were no revisions for other causes. Two of the revised patients had a subsequent dislocation (33%).

CONCLUSION

The recalled ceramic liner lots have an increased liner fracture rate. Patients with mechanical symptoms or squeaking should undergo computer tomography to rule out liner facture.

Hip Squeaking after Ceramic-on-ceramic Total Hip Arthroplasty

Objective:

The present study aimed to review the characteristics and influencing factors of squeaking after ceramic-on-ceramic (CoC) total hip arthroplasty (THA) and to analyze the possible mechanisms of the audible noise.

Data Sources:

The data analyzed in this review were based on articles from PubMed and Web of Science.

Study Selection:

The articles selected for review were original articles and reviews found based on the following search terms: “total hip arthroplasty”, “ceramic-on-ceramic”, “hip squeaking”, and “hip noise.”

Results:

The mechanism of the squeaking remains unknown. The possible explanations included stripe wear, edge loading, a third body, fracture of the ceramic liner, and resonance of the prosthesis components. Squeaking occurrence is influenced by patient, surgical, and implant factors.

Conclusions:

Most studies indicated that squeaking after CoC THA was the consequence of increasing wear or impingement, caused by prosthesis design, patient characteristics, or surgical factors. However, as conflicts exist among different articles, the major reasons for the squeaking remain to be identified.

3rd generation alumina-on-alumina in modular hip prosthesis: 13 to 18 years follow-up results

INTRODUCTION

Ceramic-on-ceramic (CoC) couplings are alternative bearings surfaces that have been reported to reduce osteolysis, wear debris and aseptic loosening compared to the use of polyethylene. Early experiences with ceramics had poor results, but they have led to many improvements in the manufacture and design of subsequent implants.

METHODS

We analysed medical files of 300 CoC total hip arthroplasty (THA) with a modular neck performed during period 1995-2000 by a single surgeon for a minimum follow-up of 13 years, evaluating clinical and radiological outcome.

RESULTS

The mean clinical Merle d'Aubigne and Postel hip score at the final follow-up is 17.4, against a preoperative value of 11.4. Overall survivorship with an endpoint of revision is 93.2% (95% CI, 89.0%-97.3%) at 15 years, while considering only prosthesis failures related to aseptic loosening and ceramic breakage, survival rate at 15 years is 97.2% (95% CI, 94.8%-100%). We observed complications that led to revision surgery in 11 patients (4%) (periprosthetic fractures, liner ruptures, septic loosening of the implant, aseptic loosening of the cup, aseptic loosening of the stem). The occurrence of squeaking is low (1.6%, 4 cases) and we analysed the characteristics of these patients.

DISCUSSION

Our study shows an excellent long term survivorship of third generation alumina CoC THA. We reiterate the importance to have a stable implant to maximise the advantage of ceramic and to avoid complications.

Primary Total Hip Arthroplasty With Fourth-Generation Ceramic-on-Ceramic: Analysis of Complications in 939 Consecutive Cases Followed for 2-10 Years

BACKGROUND

Delta ceramics may be the bearing of choice for younger and active patients due to its improved toughness and wear characteristics, provided there is no risk of fracture. However, ceramic fracture is the most serious complication related to this type of bearing. Although millions of Delta ceramics have been implanted worldwide, short to midterm results have been scarcely reported in the literature. The purpose of this study was to report the complication rate at short to midterm follow-up associated with the bearing surface used in a series of primary total hip arthroplasties with Delta ceramic-on-ceramic bearings performed in a single institution.

METHODS

A total of 939 cases (880 patients) undergoing primary total hip arthroplasty with fourth-generation Delta ceramic-on-ceramic bearings were retrospectively reviewed. They were followed for an average of 5.3 years (2-10 years).

RESULTS

One hip experienced a liner fracture, 2 cups presented early loosening due to friction between the acetabular screw and the backside of the liner, one femoral ball head had a fracture; one case of squeaking was reported, which is impending revision. Considering revision or impending revision in relationship with the bearing surface as the end point, the mean survival rate was 99.3% (confidence interval 95%, 98.3%-99.7%) at 2-10 years.

CONCLUSION

This study showed a low rate of ceramic fracture compared with others; however, it was much higher than the complication rate presented by the manufacturers. The complications observed were directly related to technical errors that surgeons should avoid when using this type of surface.

Delayed diagnosis of catastrophic ceramic liner failure with resultant pelvic discontinuity and massive metallosis

With newer-generation ceramic components used in total hip arthroplasty, component fracture is a rare complication. However rare, when ceramic component fracture does occur, prompt identification and revision is necessary as delay can lead to dramatic failure with resultant metallosis as the extremely hard ceramic debris abrades remaining components. We present a case of a 70-year-old woman with ceramic liner fracture and an estimated 10-year delay in intervention with failure resulting in pelvic discontinuity and massive metallosis with associated cutaneous manifestation. She was treated with a complex revision and reconstruction and is 2 years postrevision without major complication.

Midterm analysis of the seleXys cup with ceramic inlay

Background

Ceramic-on-ceramic (CoC) articulations in total hip replacement (THR) has been accepted as giving reliable mid-term results; however recent studies have reported higher revision rates of some implants. This study analyses the nationwide results of the seleXys TPS cup and the Bionit2 liner (Mathys, Bettlach, Switzerland) with respect to implant survival, cause for revision and mortality rates compared to other CoC articulations using the same stem.

Methods

Utilising the New Zealand Joint Registry, we compared the seleXys TPS cup with Bionit2 liner used with an uncemented Twinsys femoral stem to every other uncemented CoC THR using the same stem. Multivariate analysis was used to determine the effects of patient age, gender, ASA score and implant head size on these rates.

Results

Between 2006 and 2013 a total of 1035 seleXys THRs were performed on 862 patients. The comparison group had 375 THRs on 280 patients. There were 77 revisions (1.4/100 component years) in the study group and two in the comparison group (0.12/100 component years). Overall hazards ratio for revision was 12.22 times higher and female gender was associated with an increased risk (hazards ratio 1.77). Causes for revision were disturbing noises (23.4%), acetabular loosening (20.8%), and fracture of the liner (18.2%). Mortality rates were not significantly different (P = .567).

Conclusions

The seleXys TPS cup with the Bionit2 ceramic inlay coupling has an unacceptably high failure rate. We recommend avoiding this implant coupling and would advise that patients treated with this implant need close clinical and radiological follow-up.

The damping effect of cement as a potential mitigation factor of squeaking in ceramic-on-ceramic total hip arthroplasty

Objectives

Studies reporting specifically on squeaking in total hip arthroplasty have focused on cementless, and not on hybrid, fixation. We hypothesised that the cement mantle of the femur might have a damping effect on the sound transmitted through the metal stem. The objective of this study was to test the effect of cement on sound propagation along different stem designs and under different fixation conditions.

Methods

An in vitro model for sound detection, composed of a mechanical suspension structure and a sound-registering electronic assembly, was designed. A pulse of sound in the audible range was propagated along bare stems and stems implanted in cadaveric bone femurs with and without cement. Two stems of different alloy and geometry were compared.

Results

The magnitudes of the maximum amplitudes of the bare stem were in the range of 10.8 V to 11.8 V, whereas the amplitudes for the same stems with a cement mantle in a cadaveric bone decreased to 0.3 V to 0.7 V, implying a pulse-attenuation efficiency of greater than 97%. The same magnitude is close to 40% when the comparison is made against stems implanted in cadaveric bone femurs without cement.

Conclusion

The in vitro model presented here has shown that the cement had a remarkable effect on sound attenuation and a strong energy absorption in cement mantle and bone. The visco-elastic properties of cement can contribute to the dissipation of vibro-acoustic energy, thus preventing hip prostheses from squeaking. This could explain, at least in part, the lack of reports of squeaking when hybrid fixation is used.

Cite this article: F. J. Burgo, D. E. Mengelle, A. Ozols, C. Fernandez, C. M. Autorino. The damping effect of cement as a potential mitigation factor of squeaking in ceramic-on-ceramic total hip arthroplasty. Bone Joint Res 2016;5:531–537. DOI: 10.1302/2046-3758.511.BJR-2016-0058.R1.

High Reliability of Care in Orthopedic Surgery: Are We There Yet?

As health care reimbursement models shift from volume-based to value-based models, orthopedic surgeons must provide patients with highly reliable care, while consciously minimizing cost, maintaining quality, and providing timely interventions. An established means of achieving these goals is by implementing a highly reliable care model; however, before such a model can be initiated, a safety culture, robust improvement strategies, and committed leadership are needed. This article discusses interdependent and critical changes required to implement a highly reliable care system. Specific operative protocols now mandated are discussed as they pertain to high reliability of orthopedic care and elimination of wrong-site procedures.

Noise characteristics in ceramic-on-ceramic vs. metal-on-polyethylene total hip arthroplasty: a comparative study

INTRODUCTION

A comparison of noise in ceramic-on-ceramic (CoC) bearings and metal-on-polyethylene (MoP) bearings after total hip arthroplasty (THA) was undertaken. Noise associated with MoP implants is rarely reported and has not been linked to squeaking.

METHODS

A noise characterising hip questionnaire and Oxford Hip Score (OHS) was sent to 1,000 THA patients; there were 509 respondents 282 CoC and 227 MoP; mean age 63.7 years (range 45-92 years), mean follow up 33 months (range 6-156 months).

RESULTS

Of 282 repsondents 47 (17%) of the CoC patients reported noise compared to 19 (8%) of the MoP patients (p = 0.048); 9 CoC patients and 4 MoP patients reported squeaking. Overall, 27% patients with noise reported avoiding recreational activities because of it and patients with noisy hips scored on average 5 points less on the OHS (CoC: p = 0.04 and MoP: p = 0.007).

DISCUSSION

This is the first study to report squeaking from MoP THAs. The squeaking hip phenomenon is not exclusive to CoC THAs. Noisy hip implants may have social implications, and patients should be aware of this. We have shown a relationship between noise and a lower OHS. However, longer follow-up is needed to link noise to a poorly functioning implant.

Ceramic-on-ceramic bearings total hip arthroplasty in young patients

Background

The results of ceramic-on-ceramic (CoC) total hip arthroplasty (THA) in younger patients were not univocal. This study aims to evaluate the results of CoC bearing THA in patients younger than 50 years.

Methods

A total of 90 younger patients performed CoC THAs during March 2003 and May 2008 were included in this study. Hip function and activity were evaluated with Harris hip score and University of California Los Angeles activity score. We had discussed survival rates, radiological findings of component loosening or osteolysis, and ceramic-related complications in these patients.

Results

The mean Harris hip score increased from 46.3 ± 12.0 points (range, 28-70 points) before surgery to 92.5 ± 5.6 points (range, 78-100 points) at the final follow-up. The mean preoperative University of California Los Angeles activity score was 4.2 ± 1.1 points (range, 2-6 points), which improved to a mean of 7.2 ± 1.3 points (range, 4-10 points). At the time of the last follow-up, there was found to be 1 occurrence of hip dislocation, 1 squeaking, and 2 “sandwich” ceramic liners fractured during normal activity of daily living. No hips showed osteolysis or required revision for aseptic loosening. Kaplan-Meier survivorship with revision due to loosening or osteolysis was 100% and with revision due to ceramic fracture was 97.3% (95% confidence interval, 93.7%-100%) at a mean of 9.4 years.

Conclusions

This study with the use of CoC bearings THAs in younger patients have shown promising results and higher rate of survivorship without evidence of osteolysis.

A numerical model to reproduce squeaking of ceramic-on-ceramic total hip arthroplasty. Influence of design and material

BACKGROUND

Modern ceramic (CoC) bearings for hip arthroplasty (THA) have been used in younger patients who expect improved survivorship. However, audible squeaking produced by the implant is an annoying complication. Previous numerical simulations were not able to accurately reproduce in vitro and in vivo observations. Therefore, we developed a finite element model to: (1) reproduce in vitro squeaking and validate the model by comparing it with in vivo recordings, (2) determine why there are differences between in vivo and in vitro squeaking frequencies, (3) identify the stem's role in this squeaking, (4) predict which designs and materials are more likely to produce squeaking.

HYPOTHESIS

A CoC THA numerical model can be developed that reproduces the squeaking frequencies observed in vivo.

MATERIAL AND METHODS

Numerical methods (finite element analysis [ANSYS]) and experimental methods (using a non-lubricated simulated hip with a cementless 32mm CoC THA) were developed to reproduce squeaking. Numerical analysis was performed to identify the frequencies that cause vibrations perceived as an acoustic emission. The finite element analysis (FEA) model was enhanced by adjusting periprosthetic bone and soft tissue elements in order to reproduce the squeaking frequencies recorded in vivo. A numerical method (complex eigenvalue analysis) was used to find the acoustic frequencies of the squeaking noise. The frequencies obtained from the model and the hip simulator were compared to those recorded in vivo.

RESULTS

The numerical results were validated by experiments with the laboratory hip simulator. The frequencies obtained (mean 2790Hz with FEA, 2755Hz with simulator, decreasing to 1759Hz when bone and soft tissue were included in the FEA) were consistent with those of squeaking hips recorded in vivo (1521Hz). The cup and ceramic insert were the source of the vibration, but had little influence on the diffusion of the noise required to make the squeaking audible to the human ear. The FEA showed that diffusion of squeaking was due to an unstable vibration of the stem during frictional contact. The FEA predicted a higher rate of squeaking (at a lower coefficient of friction) when TZMF™ alloy is used instead of Ti6Al4V and when an anatomic press-fit stem is used instead of straight self-locking designs.

DISCUSSION

The current FEA model is reliable; it can be used to assess various stem designs and alloys to predict the different rates of squeaking that certain stems will likely produce.

LEVEL OF EVIDENCE

Level IV in vitro study.

Is a ceramic-on-ceramic bearing really superior to ceramic-on-polyethylene for primary total hip arthroplasty? A systematic review and meta-analysis of randomised controlled trials

INTRODUCTION

The outcomes of using a ceramic-on-ceramic (CoC) vs ceramic-on-polyethylene (CoP) bearing surface for primary total hip arthroplasty (THA) are much debated. We performed a systematic review and meta-analysis of randomised controlled trials (RCTs) to compare and evaluate the outcomes of these 2 bearing surfaces.

MATERIALS AND METHODS

Electronic databases (PubMed/Medline, CENTRAL, Embase and Web of Science) were systematically searched for RCTs investigating the association between bearing surfaces and outcomes following primary THA. Two investigators independently reviewed studies for eligibility, assessed the risk of bias, extracted and analysed the data.

RESULTS

In total, 13 RCTs including a total of 2,488 THAs were identified. The Harris Hip Score appeared to be similar between CoC and CoP THAs. The acetabular liner wear rate was lower in CoC than CoP THA, but the meta-analysis showed that the incidence of component-related noise and overall ceramic fracture in CoC group were 14.73 times and 6.02 times higher than CoP THA, respectively. There were no statistically significant differences in rates of radiolucent line formation (&gt;1 mm), osteolysis, loosening, revision with follow-up ≥ 5 years, intraoperative femoral fracture, dislocation, deep infection, deep venous thrombosis and leg length discrepancy between CoC and CoP THAs.

CONCLUSIONS

There appears to be no clear evidence favouring the use of either a CoC or CoP bearing surfaces in primary THA, further studies with high-quality and longer term follow-up to provide more evidence on this topic are still required.

Squeaking and microcracks in a delta-delta ceramic coupling: pin-on-disc study

There is a rising concern about squeaking in ceramic-on-ceramic total hip arthroplasty (THA). In pin-on-disc testing of a delta-delta coupling, we reproduced squeaking and observed microcracks on worn surfaces. We used a pin-on-disc machine and made discs and pins by cutting delta ceramic to a diameter of 40 mm (D-D). Cross-linked polyethylene was used for a comparison disc (D-P). We performed the same test using another D-D coupling specimen to confirm reproducibility. Squeaking in the D-D specimen was reproduced in wet conditions, though it was not found in the D-P specimen. Fast Fourier transform analysis showed a peak frequency for squeaking of 2794 Hz. The noise occurred at about 6.6 km of sliding distance. Scanning electron microscopy revealed that the worn surface of the pin in D-D at 10.8 km of sliding distance had some microcracks. However, there was no obvious damage to the worn surface of the pin in D-P at the same sliding distance. We confirmed the reproducibility of these findings, obtaining similar results, including squeaking, from another D-D coupling specimen. Our findings show that squeaking may occur in THA using delta ceramic bearings even if implants are placed to avoid extra-articular impingement of the femoral neck. Although the clinical relevance of microcracks is unknown, they may affect long-term outcomes in THA using delta ceramic bearings.

Ceramic on ceramic arthroplasty of the hip

The leading indication for revision total hip arthroplasty (THA) remains aseptic loosening owing to wear. The younger, more active patients currently undergoing THA present unprecedented demands on the bearings. Ceramic-on-ceramic (CoC) bearings have consistently shown the lowest rates of wear. The recent advances, especially involving alumina/zirconia composite ceramic, have led to substantial improvements and good results in vitro.

Alumina/zirconia composite ceramics are extremely hard, scratch resistant and biocompatible. They offer a low co-efficient of friction and superior lubrication and lower rates of wear compared with other bearings. The major disadvantage is the risk of fracture of the ceramic. The new composite ceramic has reduced the risk of fracture of the femoral head to 0.002%. The risk of fracture of the liner is slightly higher (0.02%).

Assuming that the components are introduced without impingement, CoC bearings have major advantages over other bearings. Owing to the superior hardness, they produce less third body wear and are less vulnerable to intra-operative damage.

The improved tribology means that CoC bearings are an excellent choice for young, active patients requiring THA.

Cite this article: Bone Joint J 2016;98-B(1 Suppl A):14–17.

Review on squeaking hips

Squeaking is a well-recognized complication for hard-on-hard bearings. The nature of squeaking is not yet completely understood however it is considered a multifactorial phenomenon. Patient, implant, and surgical factors play a role in squeaking. It is believed that mechanisms damaging the fluid film lubrication in which these bearings function optimally have a critical role. Such mechanisms include edge loading, stripe wear, impingement, third body particles and ceramic fracture. The resonance of metallic parts can produce noise in the human audible range hence the implant metallurgic composition and design may play a role. Implant positioning can facilitate impingement and edge loading enhancing the occurrence of squeaking. The recent introduction of large heads (> 36 mm) 4^th generation ceramic-on-ceramic bearing may accentuate the conditions facilitating noise formation; however the current literature is insufficient. Clinically, squeaking may manifest in extreme hip positions or during normal gait cycle however it is rarely associated with pain. Evaluations of patients with squeaking include clinical and radiographic assessments. Computer tomography is recommended as it can better reveal ceramic breakage and implant malposition. The treatments for most squeaking patients include reassurance and activity modification. However for some, noise can be a problem, requiring further surgical intervention. In the occurrence of ceramic fracture, implant failure, extreme components malposition, instability and impingement, surgery should be advised. This review will aim to discuss the current literature regarding squeaking.

Midterm Results of Delta Ceramic-on-Ceramic Total Hip Arthroplasty

This study reports mid-term results of Delta ceramic on ceramic (COC) in total hip arthroplasty (THA). Subjects received Delta COC THA in a prospective multi-center study with either 28 mm (n=177) or 36 mm (n=168) articulations. Annual clinical and radiographic evaluations were performed, and patients were asked about hip noises. At mean 5.3-year follow-up there were 3 (0.9%) post-operative liner fractures. Nine revisions were performed (2 liner fracture, 4 stem loosening, 3 deep infection). Kaplan-Meier survivorship at 6 years was 96.9% (94.0-98.4). Twenty-six (7.5%) subjects reported squeaking, of whom none were revised. One (0.3%) subject could reproduce a sound in clinic. More patients reported squeaking with a 36 mm bearing (28 mm: 7/177, 36 mm: 19/168, P=0.013).

The case for ceramic-on-polyethylene as the preferred bearing for a young adult hip replacement

The optimum choice of bearing surfaces in total hip arthroplasty, particularly in the younger and more active patient, remains controversial. Despite several studies demonstrating good long-term results for the metal-on-polyethylene articulation, there has been a recent vogue towards the utilisation of hard-on-hard bearings for younger patients due, in part, to concerns regarding polyethylene induced osteolysis. However, well-documented complications concerning metal-on-metal bearings and the risk of fracture in ceramic-on-ceramic bearings have raised concerns regarding the principle of the hard-on-hard bearing in the active patient. With recent technological advancements in the manufacture of both polyethylene and alumina ceramics, the in vitro properties of each material with regards to strength and toughness have been significantly improved. In addition, ceramic femoral heads have consistently been shown to produce less in vivo polyethylene wear than similar sized metal heads. This paper aims to critically review the biomechanical, in vivo and clinical studies related to the use of the ceramic on polyethylene bearing, and highlights its potential use as the preferred bearing for a young adult hip replacement.

Factors affecting squeaking in metal on metal hip resurfacings

We reviewed 380 hip resurfacings cases between December 1999 and Dec 2012. 11 cases (2.89%) squeaked postoperatively. Mean follow-up was 88.6 months (19-130 months). Mean time to squeak was 11.3 months (3-22 months). Ten (91%) cases were male and nine (81%) cases had a Birmingham hip resurfacing. Cases were matched for age, gender, BMI and implant to three controls. Radiographs were analysed using EBRA (Einzel-Bild-Roentgen-Analysis, University of Innsbruck, Austria) software to evaluate cup orientation. There was no significant difference between the mean inclination angle of the cups (p = 0.26) or the mean anteversion angle (p = 0.29). There was no difference in serum cobalt (p = 0.20) or serum chromium (p = 0.45) levels at latest follow-up. Three of the 11 (27.3%) cases had revision surgery at a mean follow-up of 101 months (72-117 months). Squeaking was not influenced by patient demographic parameters and resolved in all cases that did not undergo revision surgery. Males with a resurfacing head size <50 mm had significantly increased odds of squeaking when compared to controls (odds ratio = 26.6; 95% CI = 1.2-573.3; p<0.05). Based on our findings, we do not recommend that squeaking on its own should be an indication for revision of hip resurfacing components.

Ceramic-on-ceramic versus ceramic-on-polyethylene bearing surfaces in total hip arthroplasty

The choice between ceramic-on-ceramic (COC) and ceramic-on-polyethylene (COP) in primary total hip arthroplasty (THA) remains controversial. The purpose of this study was to evaluate the reliability and durability of COC vs COP bearing surfaces in THA. Based on published randomized, controlled trials (RCTs) identified in PubMed, Embase, and the Cochrane Central Register of Controlled Trials, the authors performed a meta-analysis comparing the clinical and radiographic outcomes of COC with those of COP. Two investigators independently selected the studies and extracted the data. The methodological quality of each RCT was assessed using the Physiotherapy Evidence Database (PEDro) scale. Relative risks and 95% confidence intervals from each trial were pooled using random-effects or fixed-effects models depending on the heterogeneity of the included studies. Nine RCTs involving 1575 patients (1747 hips) met the predetermined inclusion criteria. Eight of 9 included RCTs had high methodological quality. The heterogeneity was not significant, and all the results were pooled using a fixed-effects model. The results demonstrated that COC significantly increased the risks of squeaking and total implant fracture compared with COP. No significant differences with respect to revision, osteolysis and radiolucent lines, loosening, dislocation, and deep infection were observed between the COC and COP bearing surfaces. This meta-analysis resulted in no sufficient evidence to identify any clinical or radiographic advantage of COC vs COP bearing surfaces in the short- to mid-term follow-up period. Long-term follow-up is required for further evaluation.

Squeaking in large diameter ceramic-on-ceramic bearings in total hip arthroplasty

We analyzed the results of 206 consecutive total hip arthroplasties performed using large diameter ceramic-on-ceramic bearings. At an average follow-up of 28months, the mean Harris Hip Score improved from 54 to 92. Fifteen (7.3%) hips were noted to squeak. There was no significant difference between silent and squeaking hips with regards to age, weight, height, BMI, range of movement, femoral head diameter, leg length, and offset or center of rotation. No correlation was present between incidence of squeaking and increasing cup inclination and anteversion. 5.2% of cups orientated within Lewinnek's safe zone squeaked. No hips required revision for squeaking. While large diameter ceramic bearings may produce squeaking, our early results of surgery using large head ceramic bearings are encouraging. However, long-term follow-up is required.