Results of Hip Arthroplasty Using a COREN Stem at a Minimum of Ten Years / 대한고관절학회지

Purpose@#We report on the 10-year clinical hip function and radiologic outcomes of patients who underwent hip arthroplasty using a COREN stem. @*Materials and Methods@#A consecutive series of 224 primary cementless hip arthroplasty implantations were performed using a COREN stem between 2009 and 2011; among these, evaluation of 128 hips was performed during a minimum follow-up period of 10 years. The mean age of patients was 65.4 years (range, 40-82 years) and the mean duration of follow-up was 10.8 years (range, 10-12 years). Evaluation of clinical hip function and radiologic implant outcomes was performed according to clinical score, thigh pain, and radiologic analysis. @*Results@#Dramatic improvement of the mean Harris hip score (HHS) from 59.4 preoperatively to 93.5 was observed at the final follow-up (P≤0.01). Stable fixation was demonstrated for all implants with no change in position except for one case of Vancouver type B2 periprosthetic femur fracture. A radiolucent line (RLL) was observed in 16 hips (12.5%). Thigh pain was observed in only two hips (1.6%) at the final follow-up. There were no cases of osteolysis around the stem. The survival rate for the COREN stem was 97.7%. @*Conclusion@#Good long-term survival with excellent clinical and radiological outcomes can be achieved using the COREN femoral stem regardless of Dorr type.

Clinical and Radiological Outcomes of Rectangular Tapered Cementless Stem According to Proximal Femoral Geometry in Elderly Asian Patients / 대한고관절학회지

PURPOSE: A retrospective analysis of mid- to long-term clinical and radiological outcomes of Korean patients over 60 years of age who underwent hip arthroplasty using a cementless rectangular tapered stem according to Dorr proximal femur geography. MATERIALS AND METHODS: From January 2007 to December 2013, 107 patients (112 hips) underwent hip arthroplasty using the C2 stem. The mean age of patients was 77.4 years (range, 60–91 years) and the mean follow-up duration was 91.1 months (range, 60–116 months). All patients were evaluated clinically and radiologically with special attention to Dorr femoral bone classification, implant fixation, radiolucent line (RLL), and thigh pain. RESULTS: All implants demonstrated radiographic evidence of stable fixation by bone ingrowth without any change in position. The mean Harris hip score improved from 65.5±16.0 (preoperative) to 90.5±15.9 (final follow-up) (P<0.001). Incidence of RLLs, stress shielding, and thigh pain was highest in patients with Dorr type A (RLL, P=0.021; stress shielding, P=0.030; thigh pain, P<0.001). One stem revision was performed due to deep infection. The Kaplan–Meier survival rate of the femoral stem was 97.6%. CONCLUSION: The overall survival rate of the C2 stems was greater than 97%; there were no significant differences in survival of the C2 stem according to the Dorr classification. The incidences of RLL of thigh pain and RLL were significantly different among Dorr classifications and (highest in patients with Dorr type A).

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

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.

Prognostic Factors and Clinical Outcomes after Treatment of Periprosthetic Femoral Fractures Using a Cable-plate / 대한고관절학회지

PURPOSE: To analyze prognostic factors for the treatment of periprosthetic femoral fractures (PFFs) using the cable-plate construct. MATERIALS AND METHODS: A retrospective review of a consecutive series of 41 PFFs treated by osteosynthesis using the cable-plate system. The mean age of patients was 67.3±12.1 years (range, 42-86 years) and the mean follow-up period was 31.5±11.6 months (range, 12–58 months). Fresh frozen cortical strut allografts were leveraged in three cases for additional stability. Prognostic factors that may potentially affect clinical outcomes were analyzed. RESULTS: At the time of final follow-up, fracture union was obtained in 29 hips (70.7%; Group I) after an average of 13.5 weeks (range, 12–24 weeks). Healing failure after surgical treatment was observed in 12 cases (29.3%; Group II), including delayed union (n=10) cases and nonunion (n=2). Factors significantly associated with fracture union included fracture pattern (P=0.040), plate overlap percentage to stem length (P<0.001) and T-score at the preoperative bone mineral density (P=0.011). Transverse-type fractures around or just distal to a well-fixed femoral stem were observed in six cases (50.0%) of Group II. CONCLUSION: The cable-plate osteosynthesis of PFFs should be performed with caution in transverse-type fractures or in cases with severe osteoporosis. Fixation with sufficient plate overlap to stem length may be critical to prevent healing failure.

Bilateral Idiopathic Chondrolysis of the Hip in an Adult: A Case Report and Review of the Literature / 대한고관절학회지

Idiopathic chondrolysis of the hip usually develops in adolescents and is a disease characterized by gradual degenerative changes of the hyaline cartilage surrounding the head of the femur. It eventually decreases the hip joint space and causes limitations in the hip joint range of motion due to pain. The authors had experienced an unusual case of bilateral idiopathic chondrolysis of the hip in an 54 year-old male; thus, we report the treatment results and literature reviews in this case report.

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.

Cementless Revision Total Hip Arthroplasty with Ceramic Articulation / 대한고관절학회지

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? / 대한고관절학회지

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.

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

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.

Long-Term Clinical Outcome of Two Stage Revision Surgery for Infected Hip Arthroplasty Using Cement Spacer / 대한정형외과학회잡지

PURPOSE: We retrospectively analyzed long-term clinical results after two-stage revision arthroplasty using an antibiotic-impregnated cement spacer for infected total hip arthroplasty. MATERIALS AND METHODS: Twenty-six hips (group 1: cup exchanged, group 2: cup and stem exchanged) were enrolled in this study. The mean follow-up period was 7.4 years (5 to 11 years). We analyzed the laboratory findings, the time interval between antibiotic-impregnated cement spacer insertion and revision arthroplasty, Harris hip score, Oxford hip score, radiologic changes, and recurrence of infection. RESULTS: Revision hip arthroplasty was performed at 7.5 weeks on average (group 1: 7.2 weeks, group 2: 7.7 weeks) after implant removal and cement spacer insertion. In group 1, Harris hip score was 51.1 points preoperatively, 84.4 points at six months, 89.3 points in at one year, 91.8 points at three years, and 89.8 points at five years. In group 2, the Harris hip score was 49.8 points preoperatively, 78.1 points at six months, 83.7 points at one year, 90.3 points at three years, and 88.7 points at five years. Recurrence of infection developed in one hip in each group. CONCLUSION: Ninety-two percent of infected hips were eradicated with two-stage revision arthroplasty using an antibiotic-impregnated cement spacer for infected hip arthroplasty at minimum five-year follow-up. When the infection was limited to the hip joint and the stem was fixed well, two-stage revision with stem retained could be a good treatment option.

Clinical Characteristics of Methicillin-resistant Staphylococcus aureus Infection for Chronic Periprosthetic Hip and Knee Infection / 대한고관절학회지

PURPOSE: Deep infection after hip and knee arthroplasty is a serious complication and is difficult to treat due to its toxicity. The aims of our study were to find out the differences of methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-sensitive Staphylococcus aureus (MSSA) infection after hip and knee arthroplasty focusing on clinical course and laboratory findings. MATERIALS AND METHODS: We retrospectively reviewed 61 staphylococcal infection cases after hip and knee arthroplasty (MSSA in 25 patients, MRSA in 36 patients). Vital signs, laboratory tests, microbiology and clinical courses were analyzed. The average follow-up period was 3.8 years (range, 2 to 10.1 years). RESULTS: At initial visit, MRSA group showed significant higher erythrocyte sedimentation rate, C-reactive protein (CRP) and neutrophil percentage. The average duration for the normalization of CRP was longer in MRSA group (MRSA: 36.7+/-25.1 days, MSSA: 24.7+/-13.6 days; P=0.008). The mean interval between staging operation was longer in MRSA group (MRSA: mean 8.7 weeks [range, 6.4 to 21.4 weeks], MSSA: mean 6.8 weeks [range, 6 to 13.1 weeks]; P=0.012). MRSA group (13.9%) revealed higher recurrence rate than MSSA group (4%). Two patients (5.6%) from MRSA group expired by sepsis. One limb amputation (2.7%) was carried out in MRSA group. CONCLUSION: MRSA infection after arthroplasty showed more toxic serologic parameter and poorer prognosis. Aggressive treatment should be considered for MRSA infection following arthroplasty.

Result of Surgical Treatment for the Femoral Head Fracture

PURPOSE: This study analyzed the clinical and radiological long-term follow-up results of patients with femoral head fracture who received surgical treatments. MATERIALS AND METHODS: Retrospective evaluation was performed for 20 patients with femoral head fracture who received surgical treatments between December 1997 and May 2010. According to Pipkin's classification, there were five type I, six type II, one type III, and eight type IV fractures. RESULTS: The average Merle d'Aubigne'-Postel score was 12.8 (12.80+/-3.53). According to surgical method, the score for the bony fragment excision group was 9.8 (9.83+/-2.79), and that for the open reduction and internal fixation group was 13.9 (13.92+/-3.07). Depending on Thompson-Epstein criteria, two patients were good, two were fair, and two were poor in the bony fragment excision group. Four patients were excellent, six were good, and three were poor in the open reduction and internal fixation group. CONCLUSION: Bony fragment excision should be performed with caution in patients with femoral head fracture. Considering fragment size, location, and presence of acetabular fracture, better outcome can be expected using the open reduction and internal fixation method in comparison with excision.

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.

Analysis of the Factors Involved in Failed Fixation in Elderly Intertrochanteric Femoral Fracture

PURPOSE: To analyze the causes of internal fixation failure in elderly intertrochanteric femoral fractures. MATERIALS AND METHODS: We retrospectively analyzed 93 intertrochanteric femoral fractures that were treated by internal fixation. The follow-up period was at least 24 months. The mean age was 73 years. We analyzed the classification of the fracture, screw position, reduction state of the fracture, and neck-shaft angle. RESULTS: Internal fixation failure occurred in 12 cases (12.9%). The causes of internal fixation failure were one case (1.0%) of head perforation, 7 cases (7.5%) of excessive slippage of a screw, and 4 cases (4.3%) of varus deformity. Significant factors infixation failure were displacement of the posterolateral fragment more than 8 mm in anteroposterior radiograph, anterior displacement of a fragment, or more than 20-degree angulation in lateral radiography. Thirty-three cases had a screw in the middle position and 4 of these cases (12.1%) had fixation failure. Notably, 14 cases had a screw in the posteromedial position and 6 of these cases had fixation failure (42.8%). CONCLUSION: Accurate reduction of the posteromedial fragment is essential in unstable intertrochanteric fracture and anterior displacement or angulation should be avoided to prevent fixation failure. The tip apex distance of the screw and central location of the screw in the femoral head is also an important factor.

Midterm Results of Total Hip Arthroplasty Using the VerSys Fiber Metal Tapered Femoral Stem / 대한고관절학회지

PURPOSE: We evaluated the clinical and radiological results of patients who received the cementless VerSys fiber metal tapered stem for total hip arthroplasty. MATERIALS AND METHODS: Thirty seven hip joint replacements(31 patients) were evaluated over a minimum four year period following the procedure with an average follow-up period of 56 months(48-96 months). The mean patient age was 47.9 years old. Clinical results were analyzed using Harris hip scores, incidence of thigh pain and radiographic analysis was used to assess fixation of the stem, stress shielding, cortical hypertrophy and radiolucent lines around the femoral stem. RESULTS: The average Harris hip score was 90.7 points(82-99 points). Thigh pain was noticed in 6 hips(16%). Proximal femoral bone resorption by stress shielding was observed in 32 hips(86.5%). Cortical hypertrophy was noticed in 16 hips(43.2%) and was statistically correlated with stress shielding of 2nd degree or more according to the Engh classification. Stable bone ingrowth at the last follow-up was seen in 36 hips(97.2%). CONCLUSION: Cementless total hip arthroplasty using the cementless VerSys fiber metal tapered stem demonstrated excellent midterm clinical results as well as excellent radiologic results for stable fixation and endosteal new bone formtion. However, long term follow-up evaluation will be required because of the high rates of proximal bone resorption by stress shielding.

Usefulness of the Cementless Stem for the Treatment of Hip Fracture in Elderly Patients with Osteoporosis: Comparative Analysis between Cementless Stem and Cemented Stem

PURPOSE: We evaluated the usefulness of the cementless stem in treating hip fracture patients older than 70. MATERIALS AND METHODS: We studied elderly osteoporotic hip fractures in the neck and intertrochanter area who had received hip arthroplasty with over 2 years of follow up period. Among those, we analyzed the clinical and radiological results of hip arthroplasty with cemented stem (group 1) and hip arthroplasty with cementless stem (group 2). Each group was consists of fifty hips. RESULTS: The mean age at surgery was 75 years and mean follow-up period was 40 months (minimum 24 months). The admission period was 28.68+/-8.8 days for group 1 and 28.05+/-8.7 days for group 2 (p>0.05) and the average operation time was 87+/-21.2 minutes, and 80+/-17 minutes (p>0.05) and the total blood loss was 611+/-141.3 cc and 557+/-120.5 cc (p>0.05) respectively. There was no statistically significant difference in all aspects. One case of pulmonary embolism occurred in group 1. Stem loosening was not observed in both groups at the last follow-up radiologic study. CONCLUSION: The hip arthroplasty with cementless stem for the osteoporotic hip fractures showed a competent results clinically and radiologically in short term follow up as compared with the cemented stem.

Measurement of Necrotic Lesion in Osteonecrosis of Femoral Head

PURPOSE: The size of the necrotic lesion is known to be the most important prognostic factor in osteonecrosis of the femoral head (ONFH). We evaluated the accuracy and relationship of three different measuring methods of necrotic lesions for ONFH. MATERIALS AND METHODS: Sixty hips that had ONFH were measured on an MRI by two orthopaedic surgeons using Steinberg, Kim, and modified Kerboul methods. Based on the lesion size of the necrosis as measured with the computerized Steinberg method, the hips were divided into Group I (small lesion: less than 15%), Group II (medium lesion: 15~30%), and Group III (large lesion: more than 30%). Data of the Kim and modified Kerboul methods were reclassified by statistical analysis according to the groups classified by the Steinberg method. RESULTS: Average lesion size of Group I (16 hips) was 10.92%, the average size of Group II (33 hips) was 21.68%, and the average size of Group III (11 hips) was 36.80%. We established a new criteria of the Kim and modified Kerboul methods based on Steinberg. The Kim method was reclassified into Groups I (less than 18%), II (18~33%), and III (33% or more). And the modified Kerboul method was divided into Groups I (less than 200.6degrees), II (200.6~262.4degrees), and III (more than 262.4degrees) as well. CONCLUSION: New criteria for the Kim and modified Kerboul method would be a useful indicator for the prognosis and treatment plan in ONFH.

Diagnosing Symptomatic Accessory Tarsal Bones Using SPECT/CT / 대한족부족관절학회지

PURPOSE: This study was designed to analyze the usefulness of Single Photon Emission Computed Tomography/Computed Tomography (SPECT/CT) in diagnosing symptomatic accessory tarsal bones. MATERIALS AND METHODS: Twenty four feet (16 patients) with symptomatic accessory navicular and/or os trigonum, who agreed to take SPECT/CT, were included in this study. Fifteen feet had accessory navicular, five had os trigonum, and four had both. According to the uptake in the SPECT/CT, 11 feet were classified into high and 13 into low uptake groups. The low uptake group was treated non-operatively, while the high uptake group received operations when initial conservative management failed. A modified Kidner procedure was performed for accessory navicular and arthroscopic excision was done for os trigonum. After a mean follow-up of 6.8 (range, 3~13) months, the American Orthopaedic Foot and Ankle Society (AOFAS) score and the Visual Analogue Scale (VAS) for pain were compared. RESULTS: Patients in the high uptake group had a higher initial mean VAS score (7.0+/-0.8 vs 2.2+/-0.9, p<0.05) and a lower initial mean AOFAS score (45.9+/-9.2 vs 83.9+/-4.2, p<0.05) compared to the low uptake group. All patients in the low uptake group improved after non-operative treatment. Seven patients underwent operations and had a decreased VAS (1.6+/-0.5) and an increased AOFAS score (88.3+/-1.8) at the last follow-up. Four patients in the high uptake group demonstrated erratic symptoms. CONCLUSION: SPECT/CT can be a useful diagnostic tool and helpful in designing treatment plans for symptomatic accessory navicular and os trigonum.

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.