Factors associated with postoperative acute kidney injury after hip fractures in elderly patients.

OBJECTIVES: Acute kidney injury (AKI) is a rare but serious complication after hip fractures. The aim of this study was to evaluate the incidence and the risk factors of postoperative AKI after hip fractures. METHODS: From January 2011 to December 2016, 550 patients who underwent surgery of hip fractures at our institution were retrospectively reviewed. AKI was defined and classified by AKI Network (AKIN) Classification/Staging System. The incidence, mortality, and risk factors of postoperative AKI were investigated. Receiver operating characteristic curve analysis was conducted to evaluate the ability of markers in predicting AKI. RESULTS: The incidence of postoperative AKI was 4.4% (25 cases). The mean onset of postoperative AKI was 8.0 ± 5.3 days and recovered after 7.0 ± 4.2 days after the occurrence of AKI. Of 25 patients with AKI, 6 patients (24.0%) died within 1 year after surgery. The independent risk factors for postoperative AKI are the estimated blood loss (EBL) (odds ratio (OR) 1.64; 95% confidence interval (CI) 1.33-2.58; p < 0.01) and postoperative level of albumin (OR 1.77; 95% CI 1.52-2.74; p < 0.01). The cutoff value of the serum albumin was <2.8 g/dL with a sensitivity of 88.0% and a specificity of 77.1%. The cutoff value of EBL was <766.5 mL with a sensitivity of 84.0% and a specificity of 66.3%. CONCLUSION: Postoperative AKI after hip fractures had low incidences (4.4%) but high mortality (24.0%). The postoperative AKI was correlated with blood loss and low postoperative albumin levels.

Outcomes of U-Blade Lag Screw for Cephalomedullary Fixation of Unstable Trochanteric Femur Fractures: A Case Control Study.

BACKGROUND: Unstable trochanteric femur fractures in elderly patients with osteoporosis are still challenging. Gamma3 nail with the U-blade lag screw (U-blade gamma nail) has been developed to improve mechanical stability of proximal femoral fragment. This study aimed to compare the clinical and radiologic outcomes of U-blade gamma nail to proximal femoral nail antirotation (PFNA), and standard Gamma3 nail (gamma nail) for unstable trochanteric femur fractures. METHODS: A retrospective matched-pair case study was performed with U-blade gamma nail, PFNA, and gamma nail. During 2012-2018, 970 patients with unstable trochanteric femur fractures were reviewed. Matching criteria were set as follows: 1) sex; 2) age (± 3 years); 3) body mass index (± 2 kg/m2); 4) bone mineral density (± 1 T-score in femur neck). Finally, a total of 159 patients were enrolled. We assessed the tip-apex distance (TAD), neck shaft angle, and hip screw sliding distance using plain radiographs. Also, we evaluated the clinical outcomes with Koval's grade and fixation failure during 2 years. RESULTS: The mean postoperative TAD was not significantly different among the 3 groups (p = 0.519). However, the change in the TAD at 1 year (p = 0.027) and 2 years (p = 0.008) after surgery was significantly smaller in U-blade gamma nail group compared with PFNA and gamma nail group. The hip screw sliding distance at 1 year (p = 0.004) and 2 years (p = 0.001) after surgery was significantly smaller in U-blade gamma nail group compared with PFNA and gamma nail group. However, there was no significant difference of Koval's grade and fixation failure among the 3 groups (p = 0.535). CONCLUSION: U-blade gamma nail showed favorable radiologic results in terms of the change in the hip screw position. However, U-blade gamma nail was not superior to PFNA and gamma nail in clinical outcomes.

Is the Oral Chemical Prophylaxis Necessary for the Prevention of Venous Thromboembolism after Joint Arthroplasty in a Korean Population?

PURPOSE: Venous thromboembolism (VTE) is a serious complication that may occur after a major orthopedic surgery. The aim of the present study was to determine the necessity of a chemical thromboprophylactic agent (rivaroxaban [RXB]) by analyzing the prevalence of VTE in Korean arthroplasty patients who received RXB for prophylaxis compared with those who did not receive RXB. MATERIALS AND METHODS: A total of 2,603 patients who underwent knee or hip arthroplasty between 1996 and 2017 were prospectively evaluated. Of these, 1,608 patients underwent surgery before January 2010 and were not administered any type of prophylaxis after surgery; the remaining 995 underwent surgery after 2010 and received oral RXB once daily for 5-13 days from the day after hemovac drain removal to postoperative day 14. RESULTS: The primary study outcome was the prevalence of VTE, pulmonary embolism or death during follow up. The overall incidence of VTE was 1.69% (n=44); of these, 12 occurred in the RXB group and 32 in the non-prophylactic group. The odds ratio of VTE in the RXB group was 0.61. However, the statistical power of the study was 0.313 due to the low incidence of VTE. CONCLUSION: Treatment with oral chemical prophylaxis decreased the incidence of VTE after knee or hip arthroplasty in a Korean population. Furthermore, no serious complications occurred after administering oral RXB, which, coupled with its convenience, suggests oral RXB offers an attractive alternative to other agents. However, we recommend that further studies, including a multicenter study, be conducted to achieve adequate statistical power.

Long-Term Results of Hip Arthroplasty Using Extensive Porous-Coated Stem-A Minimum Follow-Up of 15 Years.

INTRODUCTION: We report the clinical and radiographic results of hip arthroplasty using extensive porous-coated stems over 15 years in Korea. METHODS: This retrospective study included 210 patients (268 hips) who underwent total hip arthroplasties (232 hips) and bipolar hemiarthroplasties (36 hips) between June 1996 and December 2002 for avascular necrosis of the femoral head, hip fracture, or osteoarthritis, after excluding those who died or were lost to follow-up. One senior author (K.H.M.) evaluated Harris Hip Score (HHS); limping gait; and leg length discrepancy, and 3 independent reviewers assessed the radiographic findings, including the level of stress shielding, Dorr classification, subsidence and loosening of femoral stem, heterotopic ossification (Brooker classification), osteolysis of acetabulum, wear rate of the polyethylene liner, component loosening, and revision rate. RESULTS: The mean follow-up duration was 16.9 years and average age at operation was 50.9 years. The HHS improved at the last follow-up. Stress shielding was grade 1 in 185 hips, grade 2 in 35 hips, grade 3 in 37 hips, and grade 4 in 11 hips. Femoral stem subsidence was <3 mm in 4 hips and >3 mm in 6 hips. Femoral stems with stable bony ingrowth were observed in 258 hips, fibrous stable femoral stems in 4 hips, and unstable femoral stems in 6 hips. Heterotopic ossification was class 1 in12 and class 2 in 4 hips. Revision surgery was performed for periprosthetic osteolysis of cup (45 hips), recurrent dislocation (1), unstable femoral stem (1), and infection (1). The Kaplan-Meier survivorship at the 15-year follow-up was 86.2%. The survivorship of femoral stem at 15 years was 99.3%, and if including impending revision due to unstable femoral stem was 97.1%. DISSCUSSION: This study has all the limitations inherent with a retrospective design. However, a large number of patients in this cohort operated on by a single surgeon and a long-term follow-up are some of the potential advantages of the current study. CONCLUSIONS: At the 15-year follow-up, extensive porous-coated stem showed relatively good survivorship even in geriatric patients (Dorr type C).

Clinical outcomes and survival rate of cementless modular distal fixation femoral stem for revision hip arthroplasty: A minimum 6-year follow-up.

PURPOSE: Revision hip arthroplasty is a very challenging procedure. Use of a modular distal fixation stem is one of the available options for revision arthroplasty in patients with proximal femoral bone deficiency. The purpose of this study was to evaluate mid- to long-term outcomes of cementless modular distal fixation femoral stem implantation in revision hip surgery. METHODS: Clinical and radiological findings, complications, and stem survival rate were analyzed for 46 patients (48 hips) who underwent revision hip arthroplasty using a cementless modular distal fixation femoral stem. The mean patient age was 58.8 years (range 31-82 years) and the mean follow-up period was 95 months (72-122 months). The preoperative diagnoses were aseptic loosening (36 hips), infection (4 hips), ceramic fracture (4 hips), and femoral periprosthetic fracture (4 hips). RESULTS: The mean Harris hip score improved from 56.6 preoperatively to 88.2 postoperatively at the last follow-up. All hips showed stable osteointegration and firm fixation. Complications involved four hips (8.3%); there was one case each of periprosthetic fracture, delayed union of osteotomy site, femoral perforation, and infection. One stem re-revision was performed for deep infection of the femoral side. The Kaplan-Meier survival rate was 97.6% at the final follow-up. CONCLUSION: Revision hip arthroplasty using a cementless modular distal fixation femoral stem showed satisfactory initial firm fixation and mid- to long-term survival rate. Complications can be minimized by careful surgical planning and meticulous procedure.

Clinical efficiency of bone marrow mesenchymal stem cell implantation for osteonecrosis of the femoral head: a matched pair control study with simple core decompression.

BACKGROUND: To date, several trials have reported the use of mesenchymal stem cell (MSC) implantation for osteonecrosis of the femoral head (ONFH). However, the clinical outcomes have not been conclusive. This study compared the clinical and radiological results of bone marrow mesenchymal stem cell (BMMSC) implantation with traditional simple core decompression (CD) using a matched pair case-control design. METHODS: We retrospectively reviewed 100 patients with ONFH (106 hips) who had been treated by CD alone (50 patients, 53 hips) and CD + BMMSC implantation (50 patients, 53 hips) between February 2004 and October 2014. We assessed the total hip replacement arthroplasty (THA) conversion rate and ARCO (Association Research Circulation Osseous) stage progression. Survivor rate analysis was performed using the Kaplan-Meier method, and an additional THA was defined as the primary endpoints. RESULTS: The mean follow-up period was 4.28 years. There was a difference in the THA conversion rate between the CD (49%) and CD + BMMSC groups (28.3%) (p = 0.028). ARCO stage progression was noted in 20 of 53 hips (37.7%) in the CD group and 19 of 53 hips (35.8%) in the CD + BMMSC group. Among collapsed cases (ARCO stages III and IV), there was no difference in clinical failure rate between the two groups. Conversely, in the pre-collapse cases (ARCO stages I and II), only 6 of 30 hips (20%) progressed to clinical failure in the CD + BMMSC group, whereas 15 of 30 hips (50%) progressed to clinical failure in the CD group (p = 0.014). Kaplan-Meier survival analysis showed a significant difference in the time to failure between the two groups up to 10-year follow-up (log-rank test p = 0.031). There was no significant difference in terms of age (p = 0.87) and gender (p = 0.51) when comparing THA conversion rates between groups. No complication was noted. CONCLUSIONS: These results suggest that implantation of MSCs into the femoral head at an early stage of ONFH lowers the THA conversion rate. However, ARCO stage progression is not affected by this treatment. TRIAL REGISTRATION: Retrospectively registered.

Long-term clinical outcome of two-stage revision surgery for infected hip arthroplasty using cement spacer: Culture negative versus culture positive.

INTRODUCTION: Periprosthetic joint infection (PJI) is a terrible complication after hip arthroplasty. Clinical feature of culture-negative PJI (CN-PJI) has not been well studied till now. In our study, we retrospectively analyzed long-term clinical results after two-stage revision arthroplasty using an antibiotic-impregnated cement spacer for CN-PJI. The purpose of this study is to investigate the clinical features and prognosis of CN-PJI after hip arthroplasty and to compare these with those of culture-positive PJI (CP-PJI). METHODS: We retrospectively reviewed 15 CN-PJI cases and 70 CP-PJI cases following hip arthroplasty. The average follow-up period was 7.4 years (5-11.7 years). The demographics, laboratory findings, the time interval between antibiotic-impregnated cement spacer insertion and revision arthroplasty, and recurrence of infection were analyzed. RESULTS: The CN-PJI group showed a significantly higher incidence of prior antibiotic use ( p = 0.004) and lower serum C-reactive protein (CRP) level ( p = 0.001) than the CP-PJI group. Normalized time interval of CRP level in CN-PJI was shorter than that of CP-PJI group. The mean interval time for two-stage exchange arthroplasty was also significantly lower ( p = 0.049) in the CN-PJI group than the CP-PJI group. There was no case of treatment failure or major complication in CN-PJI group. CONCLUSION: The CN-PJI group after total hip arthroplasty could be treated successfully by two-stage exchange arthroplasty without any complications. Clinical course and prognosis of CN-PJI group was also better compared with that of CP-PJI group. Therefore, culture negativity of PJI cannot be always a poor prognostic factor for the treatment.

Topical administration of tranexamic acid in hip arthroplasty.

PURPOSE: The purpose of this study was to assess the efficacy of a newly designed topical administration of tranexamic acid (TXA) in reducing post-operative bleeding in total hip arthroplasty (THA) and bipolar hip hemiarthroplasty (BHA). METHODS: A consecutive series of 160 patients who underwent hip arthroplasty was enrolled in this study. Topical administration of TXA was done in group 1 (40 patients underwent THA and 40 BHA). We compared the amount of blood loss and rates of post-operative transfusion in group 1 with those of group 2 (40 cases of THA and 40 cases of BHA) in which TXA solution was not applied. RESULTS: The total amount of blood loss in THA group 1 and THA group 2 was 793 ± 50 mL and 1086 ± 73 mL, respectively (p = 0.001). The transfusion rates of THA group 1 and THA group 2 was 27.5 % and 50 %, respectively (p = 0.039). The transfusion rates of BHA group 1 and BHA group 2 was 45 % and 60 %, respectively (p = 0.179). The amounts of blood loss through the drainage tube were 186 ± 22 mL and 257 ± 24 mL in THA group 1 and THA group 2, respectively, and 101 ± 11 mL and 147 ± 16 mL in BHA group 1 and BHA group 2, respectively, showing statistical significance. No complications such as infection, deep vein thrombosis or cardiovascular disease were observed during the hospital stay and the last follow-up. CONCLUSION: Topical administration of TXA is an effective and safe method to reduce post-operative bleeding and transfusion rates in hip arthroplasty.

Osteosynthesis versus endoprosthesis for the treatment of femoral neck fracture in Asian elderly patients.

BACKGROUND: The purpose of this study was to compare the clinical results between osteosynthesis and endoprosthesis for femoral neck fractures in asian elderly patients, and to analysis the factors that may affect the failure of osteosynthesis. METHODS: A retrospective review of 382 hips over 65-year old with femoral neck fracture was done. Within non-displaced fracture group, 81 cases (56.6 %) underwent internal fixation (IF) and with 62 cases (43.3 %) having bipolar hemiarthroplasty (BPHA). As for displaced fracture group, 60 cases (25.1 %) underwent internal fixation (IF) with 179 cases (74.8 %) having BPHA. Average follow-up period for the patients was 36.8 months. Analysis was conducted on complications depending on fracture types and osteoporosis, and clinical evaluation was done on gait capability by using Koval walking ability. RESULTS: In non-displaced group, BPHA group showed statistically significant lower percentage of complications compared to IF group, but re-operation rate and the degradations of Koval score were no significant differences. In displaced group, complication, re-operation rate and the degradations of Koval score of BPHA group were statistically better than those of IF group. Association between osteoporosis and non-union is no statistically significant. CONCLUSIONS: Endoprosthetic replacement could be a primary option for displaced femoral neck fracture in elderly asian patients. The choice of surgical treatment methods of non-displaced fracture in elderly asian patients should be determined carefully considering the age and the presence of osteoporosis.

Clinical Results of Internal Fixation of Subcapital Femoral Neck Fractures.

BACKGROUND: Subcapital femoral neck is known to cause many complications, such as avascular necrosis (AVN) of the femoral head or nonunion, compared with other femoral neck fractures. The purpose of this study was to analyze the incidence of AVN and fixation failures in patients treated with internal fixation using cannulated screws for the subcapital femoral neck fractures. METHODS: This study targeted a total of 84 cases of subcapital femoral neck fractures that underwent internal fixation using cannulated screws. The average follow-up time after surgery was 36.8 months (range, 24 to 148 months). RESULTS: Nine hips (10.7%) showing AVN of the femoral head and 6 hips (7.1%) showing fixation failures were observed. The factors affecting the incidence of AVN of the femoral head after sustaining fractures correlated well with fracture types in the Garden classification (p = 0.030). The factors affecting fixation failure were the degree of reduction (p = 0.001) measured by the Garden alignment index and firm fixation (p = 0.009) assessed using the technique of 3-point fixation through the inferomedial cortical bone of the femoral neck. CONCLUSIONS: The complication rates for subcapital femoral neck fractures were lower than those previously reported; hence, internal fixation could be a primary treatment option for these fractures.

The Usefulness of Three-dimensional Computed Tomography as an Assessment of Periacetabular Osteolysis in Revision Total Hip Arthroplasty.

PURPOSE: This study was performed to determine the usefulness of three-dimensional computed tomography (3D-CT) in measuring periacetabular osteolysis by comparing the real volume of osteolysis in revision surgery. MATERIALS AND METHODS: Twnety-three patients who had undergone revision surgery due to periacetabular osteolysis but not included septic osteolysis and implant loosening. The mean age of patients at the time of surgery was 55.2 years. And the mean time interval between the primary total hip arthroplasty and revision surgery was 13.3 years. We measured the polyethylene wear in plain radiographs using computer assisted vector wear analysis program, the volume of acetabular osteolytic lesions in high-resolution spiral CT scans using Rapidia 3D software version 2.8 algorithms before the revision surgery were performed. Intraoperative real osteolytic volume was calculated as the sum of the volumetric increments of the acetabular cup and impacted allo-cancellous bone volume. RESULTS: Strong correlation was found between the volume of acetabular osteolytic lesions measured on 3D-CT and intraoperative real osteolytic volume which was calculated as the sum of the volumetric increments of the acetabular cup and impacted allo-cancellous bone volume. CONCLUSION: 3D-CT is considered a useful method for assessing and measuring the volume of periacetabular osteolysis before revision surgery.

Cementless Revision Total Hip Arthroplasty with Ceramic Articulation.

PURPOSE: The results of ceramic-on-ceramic (CoC) bearing surfaces in primary total hip arthroplasty (THA) were well known. However, it was not known in revision THA. The purpose of this study is to report the results of revision THA with ceramic articulation. MATERIALS AND METHODS: A total of 112 revision THAs were evaluated. The mean age at the time of surgery was 51.6 years (27.7 to 84.2 years). The mean duration of the follow-up periods was 6.3 years (2.3 to 11.4 years). RESULTS: The Harris hip scores improved from an average of 56.2 at the index surgery to an average of 93.3 at the last follow-up (P<0.001). None of hips showed osteolysis or ceramic head fracture. One hip showed aseptic loosening in the acetabular component with squeaking that caused a re-revision. There were nine cases of dislocation. The survivorship at 5 years was 94.5% (95% confidence interval, 87.9% to 97.6%) with revision for any reason as the endpoint and 100% with femoral revision. CONCLUSION: The ceramic articulation is one of good bearing options for revision THA in patients with a long life expectancy.

Does the Time of Postoperative Bisphosphonate Administration Affect the Bone Union in Osteoporotic Intertrochanteric Fracture of Femur?

PURPOSE: This study was designed to investigate the effect of bisphosphonate administration starting time on bone healing and to identify the best administration time following surgical treatment of osteoporotic intertrochanteric fractures. MATERIALS AND METHODS: Two hundreds and eighty four patients (284 hips; 52 males, 232 females) who underwent surgery following osteoporotic intertrochanteric fracture from December 2002 to December 2012 were retrospectively analyzed. The average follow-up period was 68.4 months. The patients were divided into three groups according to the time of bisphosphonate administration after operation: 1 week (group A; n=102), 1 month (group B; n=89), and 3 months (group C; n=93). Koval scores and change of Koval scores 1 year after operation were used for clinical evaluation. For radiologic evaluation, the time of callus appearance across the fracture line on sagittal and coronal radiographs and the time to absence of pain during hip motion was judged as the time of bone union. RESULTS: Koval scores one year after surgery for groups A, B, and C were 2.44, 2.36, and 2.43 (P=0.895), respectively. The mean time of union was 12.4, 11.9, and 12.3 weeks after operation in the three groups (P=0.883), respectively. There were zero cases of nonunion. There were 3, 5, and 7 cases of fixative displacement in the three groups, respectively, but the distribution showed no significant difference (P>0.472). CONCLUSION: The initiating time of bisphosphonate administration following surgery does not affect the clinical outcomes in patients with osteoporotic intertrochanteric fracture.

Clinical results of auto-iliac cancellous bone grafts combined with implantation of autologous bone marrow cells for osteonecrosis of the femoral head: a minimum 5-year follow-up.

PURPOSE: There are no reports about bone graft and cell therapy for the osteonecrosis of femoral head (ONFH). We prospectively evaluated the clinical results of auto-iliac cancellous bone grafts combined with implantation of autologous bone marrow cells for ONFH. MATERIALS AND METHODS: Sixty-one hips in 52 patients with ONFH treated with bone graft and cell therapy were enrolled, and the average follow-up of the patients was 68 (60-88) months. Necrotic lesions were classified according to their size by the Steinberg method and location of necrosis. RESULTS: At the last follow-up, the percentage of excellent or good results was 80% (12/15 hips) in the small lesion group, 65% (17/26 hips) in the medium size group, and 28% (6/20 hips) in the large size group. The procedures were a clinical success in 4 of 5 hips (80%) of stage I, 23 of 35 hips (65.7%) of stage II, 7 of 18 hips (38.9%) of stage III, and 1 of 3 hips (33.3%) of stage IV grade, according to the Association Research Circulation Osseous grading system. Among the 20 cases with large sized necrotic lesions, 17 cases were laterally located and this group showed the worst outcomes, with 13 hips (76.5%) having bad or failed clinical results. CONCLUSION: The results of the present study suggested that patients who have a large sized lesion or medium sized laterally located lesion would not be good candidates for the head preserving procedure. However, for medium sized lesions, this procedure generated clinical results comparable to those of other head preserving procedures.

The natural history of asymptomatic osteonecrosis of the femoral head.

PURPOSE: To observe the natural history of asymptomatic osteonecrosis of the femoral head, and to analyse the associations between the subsequent development of symptoms, epidemiological risk factors and the character of the lesions. METHODS: Sixty-eight patients were diagnosed with asymptomatic osteonecrosis of the femoral head. The patients were classified based on the development of symptoms. Relations were sought between symptom development and epidemiological risk factors, and the size and location of the necrotic lesions. RESULTS: Thirty-eight patients developed symptoms (55.9%) at a mean 2.27 years after diagnosis. Symptoms developed in 18 of 28 patients with alcohol-related necrosis (64.3%), in eight of 14 patients with steroid-related necrosis (57.1%), and in 12 of 26 patients with idiopathic necrosis (46.2%). None of the following: gender, age, body mass index (BMI), smoking status, or cholesterol level, was found to be significantly associated with the development of symtoms in asymptomatic osteonecrosis of femoral head (ONFH). Duration and amount of exposure to steroid were not significantly associated with symptom development. In the groups of heavy alcohol drinkers, large necrotic lesions and laterally located lesions showed a higher prevalence of symptom development. CONCLUSION: Symptoms developed in 55.9% of asymptomatic osteonecrosis of the femoral head. Prevalence of symptom development was significantly higher in heavy alcohol drinkers and large-sized lateral lesions.

Total hip arthroplasty using S-ROM prosthesis for dysplastic hip.

PURPOSE: The purpose of this study was to evaluate the clinical and radiological results of total hip arthroplasty using a proximal modular femoral stem in patients who had secondary coxarthrosis associated with a dysplastic hip. MATERIALS AND METHODS: Forty-two patients (45 hips) with secondary coxarthrosis were evaluated after undergoing primary total hip arthroplasty using an S-ROM proximal modular femoral stem. The average follow-up was 80 months (range: 60 to 96 months). Clinical and radiological assessments were performed based on the Harris hip score and the radiological changes around the prosthesis. RESULTS: The average Harris hip score improved from 52.2 points to 88.5 points. All femoral stems showed stable fixation; there were 37 cases by bony ingrowth and 8 cases by stable fibrous ingrowth. Neither osteolysis nor progressive radiolucent lines around the femoral stem were found at the last follow-up. Forty-one hips (91.9%) revealed excellent or good clinical results at the most recent follow-up. CONCLUSION: For advanced secondary coxarthrosis, total hip arthroplasty with the use of the proximal modular femoral stem yielded good mid-term results with respect to the clinical and radiological criteria.

Long-term results of total hip arthroplasty with an extensively porous coated stem in patients younger than 45 years old.

PURPOSE: This study analyzed the long-term results of cementless total hip arthroplasty using an extensively porous coated stem in patients younger than 45 years old. MATERIALS AND METHODS: The clinical and radiographic results of 45 hips from 38 patients who underwent cementless total hip replacement arthroplasty with an AML prosthesis were reviewed retrospectively. The average follow-up was 12 years (range, 10-15 years). RESULTS: The average Harris hip score at the time of final follow-up was 87.3 (range 77-94) points. Forty two hips (93.3%) showed excellent and good clinical results. Osteolysis occurred around the stem in 20 hips (44.4%) and around the cup in 26 hips (57.8%). Stress-mediated femoral resorption was observed in 33 hips (73.3%) at 10 years. There was no incidence of resorption progressing after 5 years postoperatively. There was no stem loosening. Five hips were revised for osteolysis, cup loosening and polyethylene wear. CONCLUSION: The long term results of total hip arthroplasty using an extensively porous coated stem were acceptable, and there was no case involving the progression of proximal bone resorption.

Revision total hip arthroplasty using an extensively porous coated femoral stem.

BACKGROUND: To determine the benefit of an extensively porous coated femoral stem in patients receiving revision total hip arthroplasty. METHODS: This study reviewed the results of 35 patients who received a revision total hip arthroplasty with extensively porous coated femoral stem between August, 1996, and December, 2002. The mean follow-up period was 77.5 months. The clinical and radiological results were evaluated by the Harris hip score and serial roentgenographic findings. RESULTS: The preoperative and postoperative Harris hip score was 68.3 and 92.5, respectively. Radiographically, none of the acetabular components showed any evidence of migration, tilt, rotation, or shedding of metal particles. In addition, none of the femoral components showed evidence of subsidence, pedestal, or shedding of metal particles. Twenty-two hips had a mild stress shield and 2 hips had a moderate stress shield. The perioperative complications encountered were deep vein thrombosis (1 case), mild heterotopic ossification (4 cases), intraoperative periprosthetic fractures (1 case), and nonunion of the trochanteric osteotomy site (2 cases). CONCLUSIONS: Extensively porous coated femoral stems and acetabular components produce excellent clinical and radiological results in revision total hip arthroplasty.

Clustered localized pigmented villonodular synovitis.

The localized form of pigmented villonodular synovitis (PVNS) is a rare pathologic entity characterized by limited involvement of the synovium. In the knee joint, which is the most commonly affected joint, the disorder generally presents as a single nodular lesion, or rarely as 2 or 3 multiple nodular lesions into the joint. We report 2 cases of localized PVNS in which multiple nodules were clustered in a limited patella fat pad area. Clustered, multiple nodular lesions in a limited area suggested to us to consider a variant of localized forms.