High Risk of Neck-liner Impingement and Notching Observed with Thick Femoral Neck Implants in Ceramic-on-ceramic THA.

BACKGROUND: Recently, impingement between the femoral stem and ceramic liner, which appears as a notch in the stem neck on radiographs, has emerged as a new complication. However, the proportion of impingement, potential risk factors, and related complications are poorly elucidated. QUESTION/PURPOSES: In patients who underwent ceramic-on-ceramic (CoC) THA and had at least 10 years of follow-up, we asked: (1) What proportion had radiographic evidence of stem neck-ceramic liner impingement (notching of the stem), and what implant design, implantation factors, or complications such as ceramic fracture or metallosis are associated with impingement? (2) How common are the complications of noise and ceramic fracture? (3) What are the radiologic changes (including fixation of femoral and acetabular components, osteolysis, and heterotopic ossification) and clinical outcomes as determined by the modified Harris hip score (mHHS) for this cohort? (4) What is the survivorship with implant revision as the endpoint and with reoperation for any reason as the endpoint after CoC THA using a thick-neck stem design? METHODS: Between May 2003 and April 2010, 643 patients underwent primary THA at a tertiary referral hospital. After excluding patients with metal-on-polyethylene and with ceramic-on-polyethylene implants, 621 patients were considered eligible for this study. All patients received the same hemispherical titanium cup, a standard-length tapered titanium stem, and a CoC bearing. Of those, 19% (115) were lost to follow-up before 10 years, and 8% (50) were excluded because they died before the minimum follow-up duration of 10 years, leaving 73% (456) for analysis. Patients had a mean age of 50 ± 14 years and were followed for a median (range) of 13 years (10 to 17). The mean cup abduction was 38° ± 5°, and the mean cup anteversion was 26° ± 7°. To determine the proportion of patients with the neck-liner impingement, we analyzed the plain radiographs of every patient during follow-up to detect notches around the stem. The detection of stem neck notches on the radiographs was reliable (intraobserver reliability: κ = 0.963; p < 0.001 and interobserver reliability: κ = 0.975; p < 0.001). To evaluate factors related to notching, we compared the possible confounding factors including gender, age, BMI, implant position, neck length, and head diameter. Complications such as ceramic fracture, noise, dislocation, and periprosthetic joint infection were recorded. Noise was evaluated via interview and with the Hip Noise Assessment Questionnaire, which assessed the noise qualitatively. For clinical outcome, we assessed the mHHS, which includes pain and function scales (0 [worst] to 100 [best]), every visit. Tilting of at least 4° or migration of at least 4 mm was the criteria for cup loosening; subsidence more than 3 mm, any change in position, or a continuous radiolucent line greater than 2 mm was the criteria for stem loosening. To evaluate osteolysis, we performed CT scans in 57% (262 of 456) of patients. Kaplan-Meier survivorship analysis was performed using the endpoints of survivorship free from implant revision and survivorship free from reoperation for any cause. RESULTS: The proportion of stem neck notching was 11% (49 of 456). There were no differences in cup abduction and anteversion between hips with notches and those without notches. Notched hips were more likely to have 28-mm than 32-mm heads (90% [44 of 49] versus 70% [285 of 407]; odds ratio 3.77 [95% CI 1.46 to 9.73]; p = 0.004). None of the 49 notched hips had a ceramic head or liner fracture or evidence of metallosis. A ceramic head fracture was reported in 2% (9 of 456); all fractures occurred in 28-mm short neck heads. A ceramic liner fracture occurred in 0.2% (1 of 456), and noise was noted in 6% (27 of 456). Acetabular osteolysis developed in 2% (7 of 456). The mHHS was 91 ± 12 points at the final follow-up. The survivorship free from implant revision was 97% (95% CI 96% to 99%), and the survivorship free from reoperation for any cause was 96% (95% CI 95% to 98%) at 13 years. CONCLUSION: The proportion of stems with neck-ceramic liner impingement and ceramic component fracture were unacceptably high after the use of a thick-neck stem design, especially when a 28-mm head was used. We have discontinued the use of this stem design and we recommend that such stems should not be used when CoC bearings are used. As these findings might be generalized to other bearing couples, further studies focused on polyethylene liner wear and local metallosis due to thick stem neck are warranted. LEVEL OF EVIDENCE: Level III, therapeutic study.

Assessment of patient-reported outcomes (PROs): treatment satisfaction, medication adherence, and quality of life (QoL) and the associated factors in postmenopausal osteoporosis (PMO) patients in Korea.

Patient-reported outcomes (PROs) provide practical guides for treatment; however, studies that have evaluated PROs of women in Korea with postmenopausal osteoporosis (PMO) are lacking. This cross-sectional, multi-center (29 nationwide hospitals) study, performed from March 2013 to July 2014, aimed to assess PROs related to treatment satisfaction, medication adherence, and quality of life (QoL) in Korean PMO women using osteoporosis medication for prevention/treatment. Patient demographics, clinical characteristics, treatment patterns, PROs, and experience using medication were collected. The 14-item Treatment Satisfaction Questionnaire for Medication (TSQM) (score-range, 0-100; domains: effectiveness, side effects, convenience, global satisfaction), Osteoporosis-Specific Morisky Medication Adherence Scale (OS-MMAS) (score-range, 0-8), and EuroQol-5 dimensions questionnaire (index score range, - 0.22 to 1.0; EuroQol visual analog scale score range, 0-100) were used. To investigate factors associated with PROs, linear (treatment satisfaction/QoL) or logistic (medication adherence) regression analyses were conducted. A total of 1804 patients (age, 62 years) were investigated; 60.1% used bisphosphonate, with the majority (67.2%) using weekly medication, 27.8% used daily hormone replacement therapy, and 12.1% used daily selective estrogen receptor modulator. Several patients reported gastrointestinal (GI) events (31.6%) and dental visits due to problems (24.1%) while using medication. Factors associated with the highest OS-MMAS domain scores were convenience and global satisfaction. GI events were associated with non-adherence. TSQM scores for effectiveness, side effects, and GI risk factors were significantly associated with QoL. Our study elaborately assessed the factors associated with PROs of Korean PMO women. Based on our findings, appropriate treatment-related adjustments such as frequency/choice of medications and GI risk management may improve PROs.

A 3-Dimensional Analysis of Nasal Cavity Volume After Maxillary Le Fort I Osteotomy.

PURPOSE: Two- and 3-dimensional studies on changes of the pharyngeal airway after a Le Fort I osteotomy have been conducted, but there are few studies on the change of nasal structure. The nasal cavity is the first passage through which air enters during respiration. Movement of the maxilla by Le Fort I osteotomy affects the shape of the nasal cavity and the shape of other parts of the airway. This study compared preoperative and postoperative changes of the nasal cavity volume after a maxillary Le Fort I osteotomy. MATERIALS AND METHODS: Pre- and postoperative computed tomograms of 32 patients were assessed for nasal cavity volume according to the direction of maxillary movement. RESULTS: Thirty-two patients (22 men and 10 women) were classified according to the direction of maxillary movement: maxillary impaction (group I; 8 men and 6 women) and maxillary impaction and advancement (group II; 14 men and 4 women). Nasal cavity volume was markedly decreased after the Le Fort I osteotomy in groups I and II. Group I showed a positive correlation between the ratio of impaction and the ratio of volume difference. Group II showed no correlation between the ratio of impaction or advancement and the ratio of volume difference. CONCLUSION: Impaction and advancement of the maxilla decreased nasal volume.

Effect of Inner Taper Angle of Acetabular Metal Shell on the Malseating and Dissociation Force of Ceramic Liner.

BACKGROUND: Malseating of ceramic liner appeared as a matter of concern in multibearing metal, although multibearing cup can be coupled with hard liners as well as polyethylene liner. In this metal shell, the inner taper angle should be 10° for the modularity, while standard metal shells for ceramic liner have an inner taper angle of 18°. However, there has been no study in the effect of taper angle to the risk of malseating. We evaluated whether the taper angle of metal shell might affect the malseating of ceramic liner, and dissociation force of ceramic liner from metal shell. METHODS: Three surgeons manually inserted ceramic liners into two designs of metal shell with different tapers angles (10° and 18°). We compared malseating rates of ceramic liners and push-out strengths, which means dissociation force of the ceramic liner from the metal shell, between these two metal shell designs. RESULTS: The malseating rates in 10° metal shell were higher than those in 18° metal shell (23.3% vs 0%, P < .05). The mean dissociation force (1148.8 ± 46.7 N) in 10° taper cup was higher than that (389.7 ± 108.3 N) in 18° taper cup (P < .01). CONCLUSION: Our results suggest that surgeon should be cautious about malseating of ceramic liner when using multi-bearing metal shell with inner taper angle of 10°. CLINICAL RELEVANCE: When surgeon use multi-bearing metal shell with inner taper angle of 10°, our results suggest that surgeon should be cautious about malseating of ceramic liner.

Incidence and Risk Period of Periprosthetic Femoral Fracture After Cementless Bipolar Hemiarthroplasty in Elderly Patients.

BACKGROUND: The purpose of this study was to investigate the periprosthetic femoral fracture (PFF) after cementless bipolar hemiarthroplasty incidence, noting fracture types and the results of treatment in elderly patients. METHODS: We retrospectively reviewed 1563 elderly patients (1177 women and 386 men) who underwent cementless bipolar hemiarthroplasty for femoral neck fracture (1061 patients) or intertrochanteric fracture (502 patients). The type of fracture was classified according to the Vancouver classification. The average age was 79.6 years (range, 65-103 years). Clinical and radiologic evaluations were performed and Kaplan-Meier survivorship was analyzed. RESULTS: Thirty-seven PFFs (2.4%) occurred during a mean follow-up of 44.4 months. Two-thirds of PFFs (67%) occurred within 1 year. Most PFFs (22/27), which occurred within 2 years, were Vancouver type B fractures. After that, type A fractures were predominant (7/9). Based on Kaplan-Meier survivorship with PFF as the end point, the incidence rate was 1.7% (95% confidence interval [CI] = 1.6%-1.8%) at 12 months, 2.2% (95% CI = 2.1%-2.3%) at 36 months, and 3.8 % (95% CI = 3.6%-4.0%) at 144 months postoperatively. CONCLUSION: After cementless bipolar hemiarthroplasty in elderly patients, a caution should be paid to prevent PFF particularly during 1-year postoperatively.

Postoperative Deep Infection After Cemented Versus Cementless Total Hip Arthroplasty: A Meta-Analysis.

Periprosthetic joint infection (PJI) is a serious complication of total hip arthroplasty (THA). The objective of this meta-analysis was to compare the PJI rate between cemented and cementless THAs. Eight clinical studies (2 randomized controlled trials and 6 observational studies) were available for the analysis. Meta-analysis (with a fixed-effects model) and subgroup analysis were performed by research design and meta-regression was performed by continuous moderator. The overall incidence of PJI was 0.4% (357/84,200). The incidence was 0.5% (310/67,531) in cemented group, and 0.3% (47/16,669) in cementless group (P=0.008). The meta-analysis revealed that the use of cement in THA was associated with an increased risk of PJI (odds ratio 1.53; 95% confidence interval 1.120 to 2.100; P=0.008).

Third-generation alumina-on-alumina total hip arthroplasty: 14 to 16-year follow-up study.

Ceramic-on-ceramic articulation has the lowest wear with little osteolysis. However, the wear and osteolysis in long-term follow-up are not known. Another concern is ceramic fracture, which might occur after repeated stress during a long period. Ninety hips (76 patients with a mean age of 47 years) that underwent cementless total hip arthroplasty using third-generation ceramic-on-ceramic articulation were followed for 14-16 years. At final follow-up, there was no measurable ceramic wear and no periprosthetic osteolysis was identified. No ceramic fracture occurred during the follow-up. One hip was revised because of late infection. All prostheses were bone-ingrown. Two patients experienced a grinding sensation. However, no patient had squeak. The mean Harris hip score at the final evaluation was 89 points and the survival rate was 98.9%.

Cementless bipolar hemiarthroplasty using a micro-arc oxidation coated stem in patients with displaced femoral neck fractures.

Femoral stem fixation for displaced femoral neck fractures in osteoporotic patients is an ongoing debate. We evaluated the outcome of 136 cementless bipolar hemiarthroplasty using a Micro-arc oxidation (MAO) coated stem. All patients survived the procedure and were discharged from the hospital. Thirty- and 90-day mortality rates were 0.7% and 2.2%, respectively. Ninety-eight hips were followed for a minimum of 2years (mean, 44months) postoperatively. Three stems were revised because of a periprosthetic fracture. Although cortical stress shielding around the stem was observed in 3 hips, there was no loosening or osteolysis. Cementless bipolar hemiarthroplasty using a MAO-coated stem is a useful and safe option to treat displaced femoral neck fractures.

Midterm results of large diameter Biolox forte ceramic head on delta ceramic liner articulation in total hip arthroplasty.

Seventy-nine patients (94 hips), who underwent cementless alumina-on-alumina total hip arthroplasty (THA) with the use of a 36-mm delta ceramic liner-on-alumina ceramic femoral head, were followed for an average of 6.5years (range, 5-7.7years). All acetabular and femoral components were bone-ingrown and neither pelvic nor femoral osteolysis was identified until the latest follow-up. The survivorship with revision surgery as an endpoint was 97.9% (95% confidence interval=100%-95%). Ceramic related complications such as fracture and squeaking did not occur in any patient. The mid-term results of cementless THA with this type of ceramic articulation are encouraging.

Revision of ceramic head fracture after third generation ceramic-on-ceramic total hip arthroplasty.

We performed 24 revisions of fractures of third generation ceramic heads. The stem was not changed in 20 revisions; a new ceramic-on-ceramic bearing was used in four and a metal-on-polyethylene bearing in 16. The stem was changed in four revisions; a new ceramic-on-ceramic bearing was used in three and a metal-on-polyethylene bearing in one. During the follow-up of 57.5 months, complications occurred in five hips among the 20 stem retained revisions: a fracture of the new ceramic head in two, metallosis with pseudocyst in two, and femoral osteolysis with stem loosening in one. However, there were no complications in the four revisions where the stem was changed. Revision surgery after ceramic head fracture shows high rates of early complications. We recommend stem revision in cases of THA failure due to fracture of a modern ceramic head.

Retaining well-fixed cementless stem in the treatment of infected hip arthroplasty.

BACKGROUND AND PURPOSE: Two-stage reconstruction, reimplantation after removal of an infected prosthesis, has been considered to be the gold standard for treatment of infected hip arthroplasty. However, during the removal of a well-fixed femoral stem, the proximal femur can be damaged and a sequestrum can be formed, which might lead to chronic osteomyelitis and difficulty in reimplantation. We wanted to determine whether infection after hip arthroplasty can be treated without removal of a well-fixed stem. METHODS: We treated 19 patients who had an infection after hip replacement, but a well-fixed cementless stem, with 2-stage reconstruction. At the first stage, we removed the acetabular cup, the liner and the head, but not the stem. We then implanted a cup of cement spacer. After control of infection, we reimplanted the acetabular component and head. RESULTS: 2 patients did not undergo second-stage reconstruction because they were satisfied with the pain relief and the activity that they had with the cement-spacer implantation. The remaining 17 patients underwent the second-stage of the reconstruction using cementless arthroplasty. At a mean follow-up time of 4 (2-8) years, 15 of the patients had no recurrence of infection, with satisfactory clinical and radiographic outcome. INTERPRETATION: This second-stage reconstruction after retention of the stem could be an alternative treatment option for periprosthetic infection with a well-fixed stem.

Incidence of and risk for osteonecrosis of the jaw in Korean osteoporosis patients treated with bisphosphonates: A nationwide cohort-study.

PURPOSE: To estimate the incidence of osteonecrosis of the jaw (ONJ) in patients treated with bisphosphonates (BPs) and to identify clinical risk factors that increase the risk for ONJ in Korean osteoporosis patients. METHODS: We used data acquired from the Korean National Health Insurance Service. Among 2,140,149 participants with osteoporosis in 2012, we selected 164,926 new BP users and 164,926 age- and sex-matched control subjects. The control group included only patients with no prescriptions for BPs between January 1, 2011, and December 31, 2016. Participants were followed for 4 years. RESULTS: Over the 4-year follow-up period, the cumulative incidence rates of ONJ were 20.9 and 6.9 per 100,000 person-years in the BP and control groups, respectively. The BP group had an increased risk for ONJ compared to the control group after adjusting for multiple variables (hazard ratio [HR] 3.72, 95% CI 2.70-5.11). Advanced age (≥70 years), comorbid diseases such as diabetes, hypertension, and rheumatoid arthritis (RA) were independent risk factors for the development of ONJ. In addition, tooth extraction (HR 9.85), gingivitis, and periodontal disease (HR 4.78) were strongly associated with ONJ. CONCLUSIONS: ONJ incidence was 21 per 100,000 person-years in osteoporosis patients receiving bisphosphonates. Clinical factors including advanced age, diabetes, RA, dental disease, as well as BP use were significantly associated with ONJ.

Bipolar hemiarthroplasty using microarc oxidation-coated cementless stem in patients with unstable intertrochanteric fracture.

PURPOSE: Treatment for an unstable intertrochanteric fracture in elderly patients is challenging. Bipolar hemiarthroplasty (HA) using microarc oxidation (MAO) coating has been a treatment option alternative to internal fixation. However, the outcome of bipolar HA using MAO-coated stem in these patients is unknown. METHODS: From July 2007 to April 2016, 234 (older than 65 years) patients (234 hips) who were diagnosed as having unstable intertrochanteric fractures were treated with bipolar HA using a fully MAO-coated standard-length rectangular cementless stem. During the arthroplasty, the greater trochanteric and the medial fracture fragments were attached to the stem and fixed with two to three 16-gauge wires. Forty-eight patients (48 hips) died within postoperative 2 years. The remaining 186 patients (186 hips) were followed up for a mean of 4.3 (range 2-10) years. RESULTS: With the exception of 4 patients who died during hospitalization, 176 of 230 ( 76.5%) patients could ambulate independently with or without an assistive device at the time of hospital discharge. Venous thromboembolism occurred in seven patients (3.0%). One hip dislocated due to a fall 1 month after the arthroplasty. Periprosthetic femoral fracture occurred in four patients and periprosthetic acetabular fracture in one patient. One patient had periprosthetic of acute pyelonephritis. There was no focal osteolysis around the femoral stem. CONCLUSION: The result of cementless HA using MAO-coated stem enabled early ambulation in most (76.5%) of elderly patients with unstable intertrochanteric fractures and the results were encouraging.

Contemporary ceramic total hip arthroplasty in patients with cerebral palsy: does it work?

BACKGROUND: Adult patients with cerebral palsy (CP), who have advanced degenerative arthritis of the hip, have been treated with resection arthroplasty and arthrodesis. Although total hip arthroplasty (THA) has also been used as one of the alternative options, there are few studies on contemporary bearings used in THA. Therefore, we evaluated the results of the contemporary ceramic-on-ceramic THA in adult patients with CP. METHODS: From January 2005 to December 2007, five adult CP patients (5 hips) underwent THA using contemporary ceramic-on-ceramic bearings. All patients were able to stand or ambulate with intermittent use of assistive devices at home. We retrospectively reviewed the series to determine the results of THA in terms of pain relief, improved function, and durability of prosthesis. RESULTS: There were 3 men and 2 women with a mean age of 35.9 years. All patients had pain relief without decline in mobility postoperatively. One hip was dislocated, which was treated successfully with closed reduction and an abduction brace for 2 months. There was no ceramic fracture, loosening, or osteolysis during the mean follow-up of 6.8 years (range, 5.8 to 8.3 years). CONCLUSIONS: Cementless THA using contemporary ceramic-on-ceramic bearings is a useful option for the treatment of advanced degenerative arthritis of the hip in ambulatory adults with CP.

Advantage of minimal anterior knee pain and long-term survivorship of cemented single radius posterior-stabilized total knee arthroplasty without patella resurfacing.

BACKGROUND: The single radius total knee prosthesis was introduced with the advantage of reduced patellar symptoms; however, there is no long-term follow-up study of the same. The purpose of this study was to determine the survival rate of single radius posterior-stabilized total knee arthroplasty and patellofemoral complication rates in a consecutive series. METHODS: Seventy-one patients (103 knees) who underwent arthroplasty without patellar resurfacing using a single radius posterior-stabilized total knee prosthesis were followed up for a minimum 10 years. Clinical evaluation using Knee Society knee and function scores and radiologic evaluation were performed at regular intervals. Anterior knee pain as well as patellofemoral complications were evaluated with a simple questionnaire. The Kaplan-Meier product-limit method was used to estimate survival. RESULTS: Seventeen patients (23 knees) were excluded due to death (12 knees) or lost to follow-up (11 knees). Of the 80 knees enrolled, all femoral components and 78 tibial components were well fixed without loosening at final follow-up. Two revisions were performed because of tibial component loosening and periprosthetic joint infection. One patient with tibial component loosening refused to have revision surgery. No obvious tibial insert polyethylene wear was observed. The survivorships at 132 months were 96.7% using revision or pending revision as end points. Anterior knee pain was present in 6 patients (6 knees, 7.5%) at the latest follow-up. No patellofemoral complication requiring revision was encountered. CONCLUSIONS: The single radius posterior-stabilized total knee prosthesis demonstrated an excellent minimum 10-year survivorship. The low rates of implant loosening and 7.5% of anterior knee pain as a patellofemoral complication are comparable with those reported for other modern total knee prosthesis.

Current trends of stem use in hemiarthroplasty for femoral neck fracture in South Korea.

BACKGROUND: Hemiarthroplasty is a common operation to treat femoral neck fracture in elderly patients. The choice of whether to use cemented stem or cementless stem in hemiarthroplasty has been controversial in clinical practice. However, recent trends regarding stem choice in South Korea are not known or documented. In this study, we assessed the trends of stem fixation in hemiarthroplasty for femoral neck fractures in South Korea. METHODS: Data of patients with femoral neck fractures, who were operated on between the years of 2007 and 2011 and were ≥ 50 years old at the time of operation, were obtained from the Health Insurance Review and Assessment Service. All new visits or admissions to clinics or hospitals for femoral neck fractures were identified using the International Classification of Disease Tenth Revision diagnostic code (S720). The trends in the utilization of cemented and cementless hemiarthroplasty were then analyzed. RESULTS: The proportion of cementless hemiarthroplasty increased from 42.7% of all surgical procedures in 2007 to 61.4% of all surgical procedures in 2011 (p < 0.001), while the use of cemented hemiarthroplasty demonstrated a corresponding decrease. CONCLUSIONS: There was a current trends towards using cementless stems in hemiarthroplasty for femoral neck fractures in South Korea.

Alumina-on-alumina total hip arthroplasty: a concise follow-up, at a minimum of ten years, of a previous report.

We previously reported the five-to-six-year results of the use of third-generation alumina-on-alumina bearings in a consecutive series of 100 primary cementless total hip arthroplasties. This report presents the longer-term outcomes of these same bearings, at a minimum of ten years postoperatively. Eighty-six of eighty-eight hips available for the study retained the original bearings at the time of the latest follow-up. Thirteen hips were associated with noise, and six hips demonstrated fretting of the femoral neck on radiographs. Two hips required a change of the bearings because of a ceramic head fracture. The ten-year survival rate of the alumina-on-alumina total hip prostheses, with revision of any implant for any reason as the end point, was 99.0%. On the basis of those results, we concluded that the rate of survival of primary cementless total hip prostheses with third-generation alumina-on-alumina bearings is excellent at ten years. However, the risk of ceramic fracture, noise, and impingement between the metal neck and the ceramic liner should be a concern to surgeons, and patients should be informed of these risks before surgery.

THA using an anatomic stem in patients with femoral head osteonecrosis.

Treating young patients with femoral head osteonecrosis (ON) remains challenging. Anatomic stems were introduced in the 1980s and 1990s to improve the proximal canal fit in an attempt to enhance long-term implant survival, an important aspect of treating young patients. We began using one design in 1993 and asked three questions to confirm whether the design criteria improved outcomes in patients with ON: (1) What is the long term survivorship of these implants?; (2) What is the amount and rate of wear?; and (3) What is the incidence of osteolysis? We retrospectively reviewed 56 patients (69 hips) who underwent THA for femoral head ON with a cementless anatomic stem proximally coated with hydroxyapatite. Four patients (four hips) were lost to followup and 16 patients (19 hips) died. In the remaining 36 patients (46 hips) the minimum followup was 10 years (mean, 11.2 years; range, 10-13 years). The mean age at operation was 48.6 years. The average Harris hip score at last followup was 87 points. Worst-case survivorship was 58.1% at 13 years and best-case was 93.3%. The average linear wear of the polyethylene liner was 2.02 mm and the average annual wear was 0.18 mm per year. Thirty-seven hips (80%) had femoral osteolysis and 14 (30%) had acetabular osteolysis. One patient who had extensive femoral osteolysis and stem loosening was revised at 11.2 years postoperatively. The high rates of polyethylene wear and osteolysis are of concern.

Ceramic liner fracture after cementless alumina-on-alumina total hip arthroplasty.

Advances in technology have reduced the risk of fracture of ceramic total hip arthroplasty implants, but concerns remain about fracture of both components. We retrospectively reviewed 133 patients (157 hips) who had cementless alumina-on-alumina total hip arthroplasties with a sandwich-type acetabular component. Six patients (seven hips) died and five patients (six hips) were interviewed by telephone (95% followup). The 122 patients (144 hips) examined had a minimum followup of 36 months (average, 45 months; range, 36-68 months). All acetabular cups and femoral stems were radiographically stable at the last followup. Five hips in five patients (3.5%) were revised because of ceramic liner fractures. Ceramic liner fractures occurred at a mean of 35 months (range, 24-48 months) postoperatively. Acetabular cups in the fracture group (n = 5) were more anteverted than those in the nonfracture group (n = 139). In three patients the fracture apparently occurred during squatting, resulting in hyperflexion and wide hip abduction. Early ceramic liner fracture was associated with impingement associated with excessive anteversion of the acetabular cup in Korean patients who habitually squat.

Cementless alumina-on-alumina total hip arthroplasty in patients younger than 50 years: a 5-year minimum follow-up study.

Sixty-seven patients (78 hips) who were younger than 50 years underwent cementless total hip arthroplasty using a porous-coated acetabular cup, an alumina liner, a 28-mm alumina head, and a proximally porous-coated femoral stem. One patient (1 hip) died and 2 patients (3 hips) were lost to follow-up. The remaining 64 patients (74 hips) were followed for 5 to 6 years. Their mean age at the index operation was 37 years. The mean Harris hip score was 94 points at the time of final follow-up. Four patients (4 hips) had mild thigh pain. All acetabular and femoral components were bone-ingrown, and neither pelvic nor femoral osteolysis was identified. No fracture of the ceramic liner or head was identified. Wear of the ceramic components was undetectable in 27 hips in which measurement was possible.