Novel 3D printed integral customized acetabular prosthesis for anatomical rotation center restoration in hip arthroplasty for developmental dysplasia of the hip crowe type III: A Case Report.

RATIONALE: Exact restoration of the rotation center in total hip arthroplasty (THA) is technically challenging in patients with end-stage osteoarthritis due to developmental dysplasia of the hip (DDH), especially in the Crowe type II and III procedures. The technical difficulty is attributable to the complex acetabular changes. In this study, a novel 3-dimensional (3D) printed integral customized acetabular prosthesis for anatomical rotation restoration in THA for DDH Crowe type III was developed using patient-specific Computer-aided design and additive manufacturing (AM) methods. PATIENT CONCERNS: A 69-year-old female patient had developed left hip joint pain and restricted movement for 40 years; the symptoms had increased in the past 5 months. Pain, limited motion of the left hip joint, and lower limb length discrepancy were noted during physical examination. DIAGNOSIS: The patient was diagnosed with left hip end-stage osteoarthritis secondary to DDH (Crowe type III). INTERVENTION: A 3D printed acetabulum model was manufactured and a simulated operation was performed to improve the accuracy of reconstruction of the rotation center and bone defect. A 3D printed titanium alloy integral customized acetabular prosthesis was designed according to the result of simulated operation. The integral customized prothesis was implanted subsequently via the posterolateral approach. Radiography of the pelvis and Harris score assessment were performed during the perioperative period as well as at the 6- and 12-month follow-up. OUTCOMES: The 3D printed integral customized acetabular prosthesis matched precisely with the reamed acetabulum. The rotation center was restored and the bone defect was exactly reconstructed. There were no signs of prosthetic loosening at the 12-month follow-up. The Harris score gradually improved during the follow-up period. LESSONS: Satisfactory results of hip rotation restoration and bone defect reconstruction could be achieved by using 3D printed integral customized acetabular prosthesis, which provides a promising way to reconstruct the acetabulum in patients with DDH anatomically and rapidly for THA.

Periprosthetic proximal femoral fractures in cemented and uncemented stems according to Vancouver classification: observation of a new fracture pattern.

BACKGROUND: Periprosthetic fractures are increasingly encountered in hip arthroplasty. The Vancouver classification system is widely used. Little knowledge exists regarding the association of the Vancouver classification with either cemented or uncemented stems. The aim was to analyse a series of fractures and determine associations. METHODS: A series of consecutive patients over 8 years was identified including only post-operative fractures of primary hip arthroplasties. Baseline and radiographic characteristics were recorded including the type of stem fixation (cemented or uncemented) and Vancouver classification. Statistical analysis was performed to determine the association of the Vancouver classification between cemented and uncemented stems. RESULTS: A total of 172 patients were identified (84 cemented stems, 88 uncemented stems). There were 30 Vancouver A fractures (12 cemented vs.18 uncemented, p > 0.05), 125 Vancouver B fractures (63 cemented vs. 62 uncemented, p > 0.05) and 17 Vancouver C fractures (9 cemented vs. 8 uncemented, p > 0.05). The Vancouver B2 fracture occurred most frequently (N = 95; 44 cemented vs. 51 uncemented, p > 0.05) and consists of four distinct fracture patterns: the previously described comminuted 'burst', clamshell and spiral patterns and the newly observed 'reverse' clamshell. The burst and spiral fracture patterns are significantly associated with cemented stems, and the clamshell pattern is significantly associated with uncemented stems. CONCLUSIONS: Vancouver A, B and C fractures occur equally in cemented and uncemented stems. Awareness of four distinct Vancouver B2 fracture patterns, including the newly observed reverse clamshell, will aid surgeons in predicting stem instability.

The 10-year outcomes of the ASR XL Acetabular System: a single-center experience from China.

BACKGROUND: The revision rate of articular surface replacement (ASR) implants continues to rise in China because of metal debris. However, there are few reports on the clinical results of ASR implants with prolonged follow-up time in China. This study investigated the clinical outcomes and the risk factors of revision surgery in patients with ASR implants. METHODS: In total, 74 patients (74 hips) who underwent primary total hip arthroplasty (THA) with ASR implants over the past 4 to 10 years were retrospectively analyzed. Relevant clinical, radiographic, and biochemical data were examined. RESULTS: The average follow-up time was 88.46 (range 23-114) months, and the ASR implants of 18 hips (24.3%) were revised. Patients who received revision surgery had worse joint function with significantly lower Harris Hip Score and Western Ontario and McMaster Universities index than non-revision patients (61.11 ± 6.68 vs 85.30 ± 9.16, p < 0.001; 61.00 ± 3.83 vs 79.04 ± 14.49, p < 0.001; respectively). Higher acetabular abduction angle and serum Co and Cr concentration were significantly relevant to worse joint function as measured by HSS (p = 0.018, 0.009, 0.043, respectively). ROC curve analysis was applied to categorize the optimal cutoff values of acetabular abduction angle and serum Cr and Co concentration for revision surgery, which were settled as 47.80°, 98.44 µg/L, and 6.95 µg/L, respectively. Overall survival of the prostheses with high acetabular abduction angle (> 47.80°, HR = 70.145, 95% CI 1.558-3158.213, p = 0.029), high serum Cr concentration (98.44 µg/L, HR = 58.956, 95% CI 1.294-2685.203, p = 0.036), and high serum Co concentration (> 6.95 µg/L, HR = 179.511, 95% CI 2.360-13656.941, p = 0.019) decreased significantly than the lower groups. CONCLUSIONS: Evaluation of the DePuy ASR XL articulation demonstrated increased rates of revision following a longer follow-up period. High acetabular abduction angle and serum Cr and Co concentration correlated with worse clinical outcomes and high revision rate. Therefore, we advocate that patients with DePuy ASR XL implants be followed up more closely than those with other implants, especially with high acetabular abduction angle and serum Cr or Co concentration.

Prospective 5-year study with 96 short curved Fitmore™ hip stems shows a high incidence of cortical hypertrophy with no clinical relevance.

BACKGROUND: An increased occurrence of cortical hypertrophy (CH) was observed 1-2 years after implanting short curved Fitmore hip stems. There are no published data about either the clinical relevance or the progression of CH over the long term. METHODS: Ninety-six primary total hip arthroplasties were performed between 2008 and 2010 using the Fitmore hip stem. Clinical and radiological parameters were recorded preoperatively and at 1, 2, 3, and 5 year follow-up. RESULTS: CH appeared mainly on antero-posterior radiographs in Gruen Zones 2, 3, 5, and 6. After 1 year, the diameter was 10 ± 2 mm and remained constant thereafter. The CH rate after 1 year was 69% and after 5 years 71%. Subsidence after 1 year was 1.6 ± 1.55 mm and 1.93 ± 1.72 mm after 5 years. Cortical thinning was 46% after 1 year and 56% after 5 years, mainly in Gruen Zones 7 and 8. In the first year radiolucencies were found in 51% in all Gruen Zones, and in 20% after 5 years. Patient, implant, and surgical factors did not correlate with radiological outcomes except that larger stems had more CH. After 5 years, the Harris Hip Score had improved from 59 to 94 and the Oxford Hip Score from 22 to 41. Radiographic parameters, notably CH, were not associated with clinical outcomes except that cortical thinning correlated with lower outcome scores. CONCLUSIONS: CH correlated neither with clinical outcome nor with patient, surgical or implant factors, except for a positive correlation with stem size. The Fitmore hip stems settled within the first year to a stable fixation and then remained almost unchanged. However, cortical thinning is common in Gruen Zone 7 and 8 meaning that there is stress-shielding.

Cementless short-stem total hip arthroplasty in the elderly patient - is it a safe option?: a prospective multicentre observational study.

BACKGROUND: Due to its bone preserving philosophy, short-stem total hip arthroplasty (THA) has primarily been recommended for young and active patients. However, there may be benefits for elderly patients given a less invasive operative technique due to the short curved implant design. The purpose of this study was to compare the clinical and radiological outcomes as well as perioperative complications of a calcar-guided short stem between a young (< 60 years) and a geriatric (> 75 years) population. METHODS: Data were collected in a total of 5 centers, and 400 short-stems were included as part of a prospective multicentre observational study between 2010 and 2014 with a mean follow-up of 49.2 months. Preoperative femur morphology was analysed using the Dorr classification. Clinical and radiological outcomes were assessed in both groups as well as perioperative complications, rates and reasons for stem revision. RESULTS: No differences were found for the mean visual analogue scale (VAS) values of rest pain, load pain, and satisfaction, whereas Harris Hip Score (HHS) was slightly better in the young group. Comparing both groups, none of the radiological parameters that were assessed (stress-shielding, cortical hypertrophy, radiolucency, osteolysis) reached differences of statistical significance. While in young patients aseptic loosening is the main cause of implant failure, in the elderly group particularly postoperative periprosthetic fractures due to accidental fall have to be considered to be of high risk. The incidence of periprosthetic fractures was found to be 0% in Dorr type A femurs, whereas in Dorr types B and C fractures occurred in 2.1 and 22.2% respectively. CONCLUSIONS: Advanced age alone is not necessarily to be considered as contra-indications for calcar-guided short-stem THA, although further follow-up is needed. However, markedly reduced bone quality with femur morphology of Dorr type C seems to be associated with increased risk for postoperative periprosthetic fractures, thus indication should be limited to Dorr types A and B. TRIAL REGISTRATION: German Clinical Trials Register; DRKS00012634 , 07.07.2017 (retrospectively registered).

To withhold or to implement bisphosphonate after cementless hip arthroplasty: a dilemma in elderly hip fracture patients.

BACKGROUND: Prior studies reported ambivalent effects of bisphosphonates on the fixation of cementless stem in hip arthroplasty patients. To set up the postoperative guide of bisphosphonate use after cementless hip arthroplasty, we investigated whether zoledronate has beneficial or negative effects in the stem migration and walking ability after cementless hemi-arthroplasty in elderly patients, who were operated due to femoral neck fracture. METHODS: We compared 59 patients (zoledronate group), who received zoledronate after cementless hemi-arthroplasty, and 66 patients (control group), who did not receive that agent. We evaluated stem subsidence, cortical porosis around the stem, and walking ability with the use of Koval's categories at 2-year follow-up. RESULTS: No patient had more than 2 mm of stem subsidence in both groups. One patient in the control group had cortical porosis around the stem, but none in the zoledronate group. There were no significant differences in the postoperative Koval scores (p = 0.769) and in the proportion of walking recovery to pre-fracture status (p = 0.695) between the two groups. CONCLUSION: We did not find neither beneficial nor negative effect of this agent in terms of stem fixation and walking ability. Zoledronate can be used after cementless hemi-arthroplasty to manage the osteoporosis in elderly patients.

Pigmented villonodular synovitis does not influence the outcome following cementless total hip arthroplasty using ceramic-on-ceramic articulation: a case-control study with middle-term follow-up.

BACKGROUND: Pigmented villonodular synovitis (PVNS) is a relatively rare, locally aggressive, and potentially recurrent synovial disease of large joints. The purpose of this study was to investigate (1) the disease recurrence rate and (2) the treatment outcomes including Harris hip scores, complications, and revision following cementless total hip arthroplasty (THA) with ceramic-on-ceramic (CoC) articulation in patients with PVNS. METHODS: Twenty-two patients (14 females and 8 males) with histologically confirmed PVNS underwent cementless THA using CoC bearings between 2000 and 2013. Three patients with less than 5-year follow-up were excluded. The mean age was 35.2 years (range, 22-58 years) with a mean follow-up of 8.6 years (range, 6.9-10.8 years). A control group was matched in a 2:1 ratio with the PVNS group for age, sex, body mass index (BMI), year of surgery, and American Society of Anesthesiologists score (ASA). Postoperative outcome variables included disease recurrence, Harris Hip Scores (HHS) at the latest follow-up, complications (dislocation, squeaking, ceramic fracture), and any-cause revision. A Kaplan-Meier implant survivorship curve with 95% confidence interval (CI) of the two groups was generated. RESULTS: No recurrence of PVNS was noted in the follow-up period. The HSS in the PVNS group was 92.6 ± 5.5, which was similar to the control group (93.4 ± 4.6, p = 0.584) at the last follow-up visit. No patients sustained dislocation, osteolysis, or any ceramic fracture within the study duration. One patient in the PVNS group had a complication of squeaking, but did not require revision. Another patient in the PVNS group underwent revision surgery due to aseptic loosening. There was no significant difference in revision rates between the two groups (p = 1.000). The implant survivorship free of any revision was 90.0% (95% CI, 73.2% to 100%) in the PVNS group and 92.5% (95% CI, 82.6% to 100%) in the control group at 10 years (p = 0.99). CONCLUSIONS: For young and active patients with end-stage PVNS of the hips, cementless THA using CoC bearing has similar functional outcome scores, a low complication rate, and similar implant survivorship compared to the control group.

Total Hip Arthroplasty in Young Patients in The Netherlands: Trend Analysis of >19,000 Primary Hip Replacements in the Dutch Arthroplasty Register.

BACKGROUND: Total hip arthroplasty (THA) is one of the most successful interventions in medical care. Because of shifting trends in THA and failure rates being higher in younger patients, we aimed to assess trends in implant fixation, bearing type, head diameter, and surgical approach in patients younger than 55 years in the Netherlands using data from the Dutch Arthroplasty Register. METHODS: Trends in the method of implant fixation, bearing type, head diameter, and surgical approach were analyzed over year of surgery (2007-2016) and over age groups (<25, 25-29, 30-34, 35-39, 40-44, 45-49, and 50-54 years). RESULTS: Between 2007 and 2016, a total of 19,915 primary THAs were performed in patients <55 years. Osteoarthritis was the most prevalent diagnosis (66.1%). Uncemented fixation was used in 79.5% of all performed THAs. The use of 32-mm head diameters increased (from 32.6% in 2007 to 50.1% in 2016), where an increasing trend toward the use of ceramic-on-polyethylene as most frequently used bearing type was present (from 37.5% in 2007 to 53.8% in 2016). The posterolateral surgical approach was the most frequently used approach; however, the anterior approach is used increasingly (0.1% in 2007 to 21.1% in 2016). Ceramic-on-polyethylene bearing surfaces, 32-mm head diameters, and the anterior approach were most commonly used in patients between 50 and 54 years. CONCLUSION: There was a clear preference for uncemented fixation in young patients. In head diameter, bearing type, and surgical approach, clear trends were visible. Characteristics of THA in young patients were subject to changing perspectives.

Total Hip Arthroplasty Bearing Surface Trends in the United States From 2007 to 2014: The Rise of Ceramic on Polyethylene.

BACKGROUND: Wear of the bearing surface is a critical element in determining the longevity of a total hip arthroplasty (THA). Over the past decade, concerns related to modern metal-on-metal (MoM) bearings and corrosion at the femoral head-neck interface have influenced surgeon selection of bearing surfaces. The purpose of this study is to analyze trends in THA bearing surface selection from 2007 through 2014 using a large national database. METHODS: The Nationwide Inpatient Sample database was used to extract bearing surface data from patients who underwent a primary THA between 2007 and 2014. Patients were grouped by bearing surface type: metal-on-polyethylene (MoP), ceramic-on-polyethylene (CoP), MoM, and ceramic-on-ceramic (CoC) bearings. Descriptive statistics were employed to describe trends. Univariate and multivariate analyses were performed to identify differences between bearing surface groups. RESULTS: During the study period, 2,460,640 THA discharges were identified, of which 1,059,825 (43.1%) had bearing surface data. A total of 496,713 (46.9%) MoP, 307,907 (29.1%) CoP, 210,381 (19.9%) MoM, and 44,823 (4.2%) CoC cases were identified. MoM utilization peaked in 2008 representing 40.1% of THAs implanted that year and steadily declined to 4.0% in 2014. From 2007 to 2014, the use of CoP bearing surfaces increased from 11.1% of cases in 2007 to 50.8% of cases in 2014. In 2014, CoP utilization surpassed MoP which represented 42.1% of bearing surfaces that year. CONCLUSION: During the study period, MoM bearing surfaces decreased precipitously, while CoP surpassed MoP as the most popular bearing surface used in a THA.

Risk factors for failure of revision total hip arthroplasty using a Kerboull-type acetabular reinforcement device.

BACKGROUND: The present study aimed to identify the risk factors associated with revision total hip arthroplasty (THA) failure using a Kerboull-type (KT) plate. METHODS: We analyzed 77 revision THAs using cemented acetabular components with a KT plate for aseptic loosening between May 2000 and March 2012. We examined the association of bone graft type, acetabular bone defects, age at the time of surgery, preoperative Japanese Orthopaedic Association (JOA) score, postoperative JOA hip score, and body mass index, with radiographic failure as the outcome. RESULTS: The 7.4-year radiographic failure survival rate was 81.6%. The survival rate was significantly different between the beta-tricalcium phosphate (ß-TCP) group and the bulk allograft group (p = 0.019). The survival curves were also significantly different between the ß-TCP group and bulk allograft group (p = 0.036). American Academy of Orthopaedic Surgeons type IV was significantly associated with radiographic failure (odds ratio [OR]: 15.5, 95% confidence interval [CI]: 1.4-175.4; p = 0.032). CONCLUSIONS: The midterm outcomes of revision THA indicate that type of bone graft and bone defect size may affect radiographic survival rate when using a KT plate.

Short stem total hip arthroplasty for osteonecrosis of the femoral head in patients 60 years or younger: a 3- to 10-year follow-up study.

BACKGROUND: In young patients with osteonecrosis of the femoral head (ONFH), short-stem total hip arthroplasty (THA) could allow a potential advantage in preserving metaphyseal bone-stock, when revision surgery might become necessary. However, only a few studies have evaluated the outcome of short-stem THAs in ONFH. We reviewed the prospectively collected data of a cementless partial neck-retaining short-stem with ceramic-on-ceramic bearings in ONFH patients. METHODS: Thirty patients (37 hips) younger than 60 years (mean age at surgery, 51.5 years) underwent THA with the NANOS® stem (Smith and Nephew, Marl, Germany) from January 2006 to December 2012. All patients received a 32-mm or 36 mm ceramic femoral head. Harris hip score, WOMAC and UCLA activity score were recorded. Postoperative radiographs were evaluated for bone-implant fixation and osteolysis. Further analysis correlated clinical findings with implants characteristics and patient demographics at mean 5.6 years' follow-up (range, 3-10 years). RESULTS: The clinical and functional results improved significantly (p < 0.001). At latest follow-up, mean HHS, WOMAC, and UCLA activity scores were 90 (range, 71-100), 94 (range, 76-100), and 6.3 (range, 4-10) points, respectively. The diameter of the femoral head did not influence the clinical outcome (p = 0.661). All hips showed bone ingrowth fixation of the acetabular and femoral components. No patients showed osteolysis. No revision for any reason was performed during the study period. CONCLUSIONS: The excellent clinical results and fixation pattern at mean 5.6 years' follow-up reveal this implant as a reliable option in advanced stage of ONFH either. Further investigations are crucial to determine the long-term durability and to assess whether the association of ceramic-on-ceramic bearings, can be useful to achieve longer survivorship and lower complications rates. TRIAL REGISTRATION: Registry number: ISRCTN 91336248 ; date of registration: 04/07/2017.

Distal femoral replacement with the MML system: a single center experience with an average follow-up of 86 months.

BACKGROUND: The aim of this study was to compare the functional outcomes and complication rates after distal femoral replacement (DFR) performed with the modular Munich-Luebeck (MML) modular prosthesis (ESKA/Orthodynamics, Luebeck, Germany) in patients being treated for malignant disease or failed total knee arthroplasty. METHODS: A retrospective review of patient charts and a functional investigation (involving Musculoskeletal Tumor Society Score [MSTS], American Knee Society Score [AKSS], Oxford Knee Score [OKS], Western Ontario and McMaster Universities Osteoarthritis Index [WOMAC], Toronto Extremity Salvage Score [TESS], the 12-Item Short-Form [SF-12] Health Survey, and a failure classification system developed by Henderson et al.) of DFR cases from 2002 to 2015 were conducted. The indications for DFR were malignant tumor resection in the femur (n = 20, group A) or failure of revision total knee arthroplasty without a history of malignant disease (n = 16, group B). RESULTS: One-hundred and twenty-nine patients were treated during the study period. Of these, 82 were analyzed for complications and implant-survival. Further, 36 patients were available for functional assessment after a mean follow-up of 86 months (range: 24-154). There were 75 complications in total. The overall failure rate for DFR was 64.6% (53/82 patients). The most common failure mechanisms were type III (mechanical failure), followed by type I (soft tissue) and type II (aseptic loosening). The mean MSTS score (out of 30) was 17 for group A and 12 for group B. All the clinical outcome scores revealed an age-dependent deterioration of function. CONCLUSION: DFR is an established procedure to restore distal femoral integrity. However, complication rates are high. Post-procedure functionality depends mainly on the patient's age at initial reconstruction.

Actualización en artroplastia total de cadera / No disponible

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Causas de cirugía de revisión en artroplastia total de cadera. Análisis epidemiológico retrospectivo / Causes for revision surgery in total hip replacement. A retrospective epidemiological analysis

Objetivo. Se pretende evaluar la incidencia de cada una de las causas de cirugía de revisión de artroplastia total de cadera en el periodo comprendido entre 2009 y 2013 con relación a diferentes variables. Material y métodos. Hemos analizado 127 cirugías de revisión de artroplastia total de cadera realizadas en 127 pacientes en nuestro centro durante dicho periodo. Se registraron parámetros como edad, sexo, fecha de artroplastia primaria, fecha de reemplazo de prótesis y causa principal de reintervención. Se consideraron rescate precoz aquellas reintervenciones realizadas antes de los 5 años tras la artroplastia primaria. Resultados. La causa de rescate más frecuente fue el aflojamiento 38 (30%) seguido de inestabilidad 30 (24%). En cuanto a la edad en el momento del rescate, se encontraron diferencias estadísticamente significativas: los pacientes con reintervención por fractura eran significativamente mayores. Se encontraron diferencias en cuanto a la edad en la primera cirugía: eran 7 años más jóvenes aquellos con rescates tardíos (63,40) con respecto a los precoces (70,21). Discusión. Hemos observado resultados similares a los de las demás series publicadas, excepto una mayor incidencia de inestabilidad en rescate precoz. Conclusiones. Este estudio demuestra el aflojamiento aséptico y la inestabilidad como causas más frecuentes de rescate en nuestro centro. La edad es un factor muy influyente en cuanto a la longevidad de la artroplastia primaria. Son mayores las complicaciones en pacientes en los cuales se implanta la artroplastia primaria de cadera a edad más avanzada (AU)

Objective. To determine the impact of each cause of revision surgery in total hip arthroplasty during the period 2009-2013. To analyse the relationship between these causes with different variables. Materials and methods. A study was conducted on 127 patients who had hip replacement revision surgery in our hospital during this period. Parameters, such as age, sex, date of primary arthroplasty, prosthetic replacement date, and main cause of the revision were recorded. Those revisions performed within 5 years after the primary arthroplasty were considered as early rescue. Results. The most common cause of rescue was aseptic loosening in 38 (30%) followed by instability in 30 (24%). In terms of age at the time of rescue, statistically significant differences were found, with it being significantly higher in patients re-operated for a fracture. Differences in age at first surgery were found to be 7 years younger than those with late rescue (63.40) with respect to early (70.21). Discussion. Similar results to ours have been observed in other published series, except for the higher incidence of instability in early rescue. Conclusions. This study demonstrates aseptic loosening and instability as the most frequent causes of revision surgery in our hospital. Age is a very influential factor in relation to longevity of primary arthroplasty. Complications were higher in when the primary hip replacement is implanted in older patients (AU)

Actualización sobre la revisión de las artroplastias totales de cadera / No disponible

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Actualización en artroscopia de cadera / No disponible

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Intermediate-term trends in serum levels of metal ions after hip resurfacing arthroplasty.

BACKGROUND: The potential risks associated with hip resurfacing arthroplasty (HRA) are controversial and underestimated. The aim of this study was to explore intermediate-term trends for the levels of cobalt (Co), chromium (Cr), and molybdenum (Mo) ions after HRA. METHODS: Forty patients who underwent HRA from October 2005 to December 2010 were recruited to this study. The serum levels of metal ions were examined preoperatively and 3, 12, 24, and 60 months after surgery. Trends and differences in levels of metal ions with respect to sex, operated side, and body mass index (BMI) were analyzed. RESULTS: There were no significant differences in levels of Cr, Co, and Mo at each time point with respect to sex, operated side, and BMI (p > 0.05). The postoperative levels of Cr, Co, and Mo ions were significantly higher than the preoperative levels across sex, operated side, and BMI groups. Postoperative levels of Cr, Co, and Mo peaked at 12, 24, and 60 months, respectively. Cr levels peaked earlier (at 12 months) in the overweight (BMI ≥25 kg/m(2)) group compared to the normal-weight group (BMI <25 kg/m(2)), Co levels (at 12 months) peaked in women compared to men, and Mo levels (at 3 months) peaked in the bilateral HRA group compared to the unilateral HRA group. CONCLUSIONS: Serum levels of Cr, Co, and Mo increased significantly after HRA. Cr levels peaked earlier in the overweight patients, Co levels peaked in women, and Mo levels peaked in patients who underwent bilateral HRA. However, there were no significant differences with respect to sex, operated side, and BMI.

Long-term durability of alumina ceramic heads in THA.

BACKGROUND: The optimal type of bearing for hip arthroplasty remains a matter of debate. Ceramic-on-polyethylene (CoP) bearings are frequently used in younger and more active patients to reduce wear and increase biocompatibility compared to Metal-on-Polyethylene (MoP) bearings. However, in comparison to metal heads, the fracture risk of ceramic heads is higher. In addition, ceramic head fractures pose a serious complication which often necessitates major revision surgery. To date, there are no long-term data (>20 years of follow-up) reporting fracture rates of the ceramic femoral heads in CoP bearings. The purpose of this research was to investigate long-term CoP fracture rate. METHODS: We evaluated the clinical and radiographic results of 348 cementless THAs treated with 2nd generation Biolox Al2O3 Ceramic-on-Polyethylene (CoP) bearings consecutively implanted between January 1985 and December 1989. The mean age at implantation was 57 years. The patients were followed for a minimum of 20 years. At the final 111 had died, and 5 were lost to follow-up. The cumulative incidence of ceramic head fractures in the long-term was estimated using a competing risk analysis. RESULTS: The cumulative incidence of ceramic head fracture after 22-years was estimated with a competing risk analysis at 0.29% after 22-years (SE = 2.09%; 95% - CI: 0.03-1.5%). The radiographic analysis revealed no impending failures at final follow-up. DISCUSSION/CONCLUSION: The fracture rate of second-generation ceramic heads using a CoP articulation remains very low into the third decade after cementless THA.