Cementless Total Hip Arthroplasty Using the COREN Hip System: A Minimum Five-Year Follow-up Study / 대한고관절학회지

PURPOSE: This study presents the clinical and radiological outcomes of cementless total hip arthroplasty using the COREN hip system after a minimum duration of follow-up of 5 years. MATERIALS AND METHODS: We evaluated the results of a consecutive series of the first 200 primary total hip arthroplasties that had been performed in our hospital in 169 patients between February 2007 and April 2011. Six patients (6 hips) had died within 5 years, and 12 patients (13 hips) had been lost to follow-up, leaving a total of 151 patients (181 hips) available for the study. All patients were evaluated clinically and radiologically with special attention to thigh pain, implant fixation, radiolucent line and osteolysis around implants. RESULTS: The mean Harris hip score improved from 59.4 preoperatively to 97.2 postoperatively. No patient complained of thigh pain. All implants demonstrated radiographic evidence of stable fixation by bone ingrowth without any change in position. No implant was loose radiographically or was revised. Eleven hips (7.7%) had a radiolucent line around the femoral stem. Focal osteolytic area was detected in 3 cases (2.1%). An osteolytic lesion was stabilized in 1 case and further observation was needed in 2 cases in which the lesions were detected several years after surgery. Stress shielding was observed in 80.3% of cases (first degree, 35.9%; second degree, 44.4%); there were no cases of third or fourth degree stress shielding. One case was complicated by bacterial infection and repeated dislocation. CONCLUSION: Mid-term results of total hip arthroplasty using the COREN hip system are very encouraging clinically and radiologically.

Early Results after Treatment of Femoral Neck Fractures with Total Hip Arthroplasty Using Cementless Fiber Metal Taper(R) Stem in Elderly Patients / 대한정형외과학회잡지

PURPOSE: The purpose of this study was to evaluate the early results of clinicoradiological outcomes after cementless total hip arthroplasty (THA) for displaced femoral neck fracture in elderly patients. MATERIALS AND METHODS: A total of 44 cementless THA procedures performed between January 2008 and January 2012 for displaced femoral neck fracture in patients older than 65 years of age were enrolled in this study and all patients presented normal cognitive ability preoperatively and were followed for more than two years after surgery. We evaluate the clinical and radiological results. The mean age was 72 years (range 65-81 years), 34 patients were female, and 10 patients were male. The mean follow-up period was 30.7 months. RESULTS: Clinically, at the last follow-up, the mean Harris hip score was 96.5 points. Walking ability was recovered postoperatively in 79.5% of cases (35 cases), and activities of daily living were achieved in 66% of cases (29 cases). Radiographically, none of the acetabular cups showed evidence of migration, loosening, or osteolysis. All cases showed excellent or good fixation postoperatively and stable bony fixation of the femoral stem, with the exception of one case, who presented with a periprosthetic fracture during follow-up. There were no cases of osteolysis, significant alignment change or progressive subsidence. Postoperative dislocation occurred in two cases (4.5%), but no re-dislocations were observed after closed reduction. CONCLUSION: Short-term outcomes proved to be satisfactory in elderly patients older than 65 years of age, who presented with normal cognitive ability preoperatively, undergoing cementless THA for displaced femoral neck fractures.

Cementless Total Hip Arthroplasty Using the Conical Femoral Stem / 대한정형외과학회잡지

PURPOSE: The purpose of this study is to evaluate the clinical and radiological results of cementless total hip arthroplasty using a conical stem. MATERIALS AND METHODS: From June 2005 to December 2007, total hip arthroplasty using the conical stem was performed in 47 patients and 51 hips. The most common causes for total hip arthroplaty were osteonecrosis of the femoral head in 32 cases. The mean follow-up period was 74.3 months (range: 62-93 months) and the mean age was 51.2 years (range: 36-84 years). The clinical evaluation included the Harris hip score, the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score, and pain on the inguinal area or thigh. Radiographic evaluation was performed for determination of the fixation status of the implant, the radiolucent line, subsidence, loosening and heterotopic ossification around the acetabular cup and the femoral stem. RESULTS: At the most recent follow-up, the mean Harris hip score was 94.1 points and the WOMAC score was 11.3 points. Radiologically, bone ongrowth was seen in all cases without migration of acetabular cup, femoral stem, changing of the position, subsidence and loosening. Complications included two cases of posterior dislocation, one case of heterotopic ossification, and one case of deep vein thrombosis. CONCLUSION: Cementless total hip arthroplasty using the conical femoral stem shows good clinical and radiologic results in treatment of osteonecrosis of the femoral head with normal canal flare index and femur neck fracture with stove pipe type.

Minimum Seven-year Follow-up of Cementless Total Hip Arthroplasty with the COREN Hip System / 대한고관절학회지

PURPOSE: We previously reported results of a mean 3.2-year follow-up of the COREN hip system, which is the first total hip prosthesis developed in Korea. The aim of this prospective study was to update the previous report with regard to the hip function and radiographic implant performance. MATERIALS AND METHODS: Between 2003 and 2004, a consecutive series of 68 primary, cementless, total hip prostheses (COREN) were implanted in 57 patients(68 hips) and followed up for a minimum of 7 years. Sixty-three of the 68 hips were available for clinical scoring and radiographic analysis. RESULTS: The mean Harris hip and WOMAC scores were improved from 48.1 and 54.7, preoperatively, to 96.4 and 22.1 at the final follow-up. The mean patient activity increased from 3.1, preoperatively, to 8.2 at the final follow-up. All hips showed stable bony ingrowth on the radiographs. No hips showed evidence of osteolysis or prosthesis loosening, and no revision was required during the follow-up. A Periprosthetic fracture (Vancouver type B1) was encountered in one hip 4.7 years after surgery, which was treated by reoperation. CONCLUSION: This study shows that the COREN hip system produces excellent mid-term results in cementless hip arthroplasty.

Ceramic on Ceramic Cementless Total Hip Arthroplasty with a 36 mm Diameter Femoral Head: More than Three Years Follow up / 대한고관절학회지

PURPOSE: The purpose of this study was to analyze the results for clinical outcome and radiologic assessment of ceramic on ceramic cementless total hip arthroplasty using a 36 mm diameter femoral head. MATERIALS AND METHODS: This study included a group of 40 patients of 43 cases who underwent ceramic on ceramic cementless total hip arthroplasty using a 36 mm diameter femoral head. The age range of this group was 28 to 82(mean 56); we monitored them over a period of 5.3 years(3-7.5 years). This clinical evaluation process included monitoring the degree of pain, range of motion, and the Harris hip score after three years since the surgery was performed. Radiographic evaluation and complication were confirmed as well. RESULTS: The preoperative Harris hip score increased from 43.4(21-57) to 88.1(81-95) after the surgery. The average motion range of hip was 113degrees flexion, 30degrees abduction, 24degrees adduction, 36degrees external rotation, and 12degrees internal rotation. Subjective pain was zero or minimal in all cases. Among the complications, dislocation occurred in only one case by a fall from a height and was reduced by closed reduction. There was no occurrence of ceramic fracture, even though infection occurred in one hip. CONCLUSION: The clinical outcome and radiologic assessment of the ceramic on ceramic cementless total hip arthroplasty using a 36 mm diameter femoral head showed a satisfactory result at three-year follow-up. Longer-term follow up is needed for further assessment.

Cementless Total Hip Arthroplasty in Dysplastic Hips

PURPOSE: To evaluate the clinical and radiological results after cementless total hip arthroplasty in dysplastic hips. MATERIALS AND METHODS: This study included 36 cases that underwent total hip arthroplasty using a cementless prosthesis in our hospital from July 1990 to May 2008. The average time of of follow-up was 103.7 months. In total, 27 cases about 24 patients were women, and 8 cases about 7 patients were men. The average age at the time of operation was 55.7 years(29-80 years). In total, 26 cases were Crowe type I and 8 cases were Crowe type II. One case was Crowe type IV. Acetabular cup angles and the contact ratio between the acetabular cup and the host bone were measured, and the grafting bone was observed for absorption in the follow-up radiographs. Revision of components was defined as a failure. RESULTS: Harris hip score was improved from 55.1 points pre-operatively to 86.1 points in the last follow-up. Revision was done in 12 cases(33.3%). Altogether, 10 cases revised the acetabular cup for osteolysis and polyethylene wear and 2 cases exchanged a polyethylene liner for only liner wear. CONCLUSION: Total hip arthroplasty in the dysplastic hip using a cementless acetabular cup, not a hydroxyapatite-coated acetabular cup, showed good clinical and radiological results when the contact ratio between acetabular cup and bone was above 70%.

Useful Method for Neutral Positioning of the Femoral Stem in Cementless Total Hip Arthroplasty / 대한고관절학회지

PURPOSE: The aim of this study was to evaluate the usefulness of a method for positioning the femoral stem in neutral position refer to the measured value of "lateral distance" in pre-operative templating and the femoral stem position post-operatively. MATERIALS AND METHODS: A total of 81 hips in 76 patients underwent cementless total hip arthroplasty between March 2008 and April 2012 using the C2 stem (Lima Corporate S.P.A, Udine, Italy). We measured the perpendicular distance from the lateral outermost part of the greater trochanter to the lateral outermost part of the femoral stem (lateral distance, LD) in pre-operative templating. We aimed to insert the femoral stem in neutral position by comparing LD measured intra-operatively. We evaluated the position of the femoral stem on post-operative plain radiography. We compared the result of post-operative re-measurement of the LD with that of pre-operative measurement. RESULTS: In all of the 81 cases, the femoral stem was inserted in neutral position, defined as the femoral stem position within 3degreesvalgus or varus. The average angle of the inserted femoral stem was 1.20degrees(0.003-2.85degrees). LD measured in preoperative templating was 15.6 mm(10-21.5 mm), and it showed no correlation ratio with LD; LD re-measured post-operatively was 15.9 mm(10.3-23.5 mm) (P=0.781). CONCLUSION: Measuring LD pre-operatively and using the value intra-operatively is an effective method for insertion of the femoral stem in neutral position.

The Results of Cementless Total Hip Arthroplasty for Primary Osteoarthritis Compared with Avascular Necrosis of the Femoral Head

PURPOSE: Cementless total hip arthroplasty was performed to treat primary osteoarthritis of the hip and avascular necrosis of the femoral head. The clinical and radiological results of the acetabular cups and femoral stems were compared. MATERIALS AND METHODS: The subjects were 84 cases who underwent primary cementless total hip arthroplasty from March 1992 to May 2001. The 84 cases were followed up for at least eight years. The patients were divided into the following two groups: group (A), 38 cases of degenerative osteoarthritis of the hip; and group (B), 46 cases of avascular necrosis of the hip. The clinical evaluation was conducted based on the Harris Hip Score (HHS). A radiological assessment was performed to determine if osteolysis or acetabular loosening had occurred. The results were analyzed statistically. RESULTS: The postoperative HHS of groups A and B at the final follow-up were 92.1 and 91.2, respectively (p=0.483). The radiological results revealed 9 and 15 cases of acetabular osteolysis (p=0.671) and 1 and 3 cases of vertical migration of the acetabular cups in the group A and B, respectively. Eight and 7 complications (p=0.572) were encountered in group A and B, respectively. Among these, 4 and 5 cases of revisional total hip arthroplasty were performed in group A and B, respectively. The results of survival analysis were similar in the two groups (p=0.969). CONCLUSION: The clinical and radiological features of the acetabular cups and stems were similar in the two groups. Nevertheless, further studies will be needed due to the high rate of polyethylene liner wear and osteolysis around the acetabular cups or femoral stems.

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.

Ceramic on Ceramic Cementless Total Hip Arthroplasty Using a Large Diameter Head / 대한정형외과학회잡지

PURPOSE: The authors evaluated the clinical and radiological results of ceramic on ceramic articulation cementless total hip arthroplasty using a large diameter head. MATERIALS AND METHODS: Seventy-two hips were followed for more than 2 years after ceramic on ceramic articulation cementless total hip arthroplasty using a 36 mm diameter head. The mean patient age was 62 years (range: 50-85), and the mean follow-up period was 35.3 months (range: 25-53). The Harris hip score, the postoperative inguinal pain and the thigh pain were analyzed clinically. The radiological results were assessed using various radiological indices. RESULTS: The mean Harris hip score improved from preoperative 57.5 points to postoperative 94.8 points. The postoperative mean flexion of hip was 109degrees (range: 100degrees-125degrees), external rotation was 42degrees (range: 35degrees-49degrees) and abduction was 35degrees (range: 30degrees-45degrees). There was one case of inguinal pain. Radiologically, all the stems demonstrated stable fixation without progressive subsidence of the stem or significant change in the cup obliquity. A radiolucent line was observed around the stem in 4 cases (5.6%) and around the cup in 2 cases (2.8%). Endosteal new bone formation was observed around the stem in 28 cases (38.9%) and around the cup in 26 cases (36.1%). There was no osteolysis around the stem or the cup. CONCLUSION: The short-term results of ceramic on ceramic cementless total hip arthroplasty using a large diameter head demonstrated satisfactory results.

The Clinical and Radiologic Results of Total Hip Arthroplasty with an AML Hip Prosthesis: Minimum 7 Years' Follow-up Study

PURPOSE: To evaluate the long-term results (minimum 7 Years'follow-up) of cementless total hip arthroplasty using an Anatomic Locking Medullary (AML) hip prosthesis. MATERIALS AND METHODS: Fifty-one patients (57 hips) underwent total hip arthroplasty between January 1995 and July 2002. They were followed up for a minimum of seven years (7.1 to 14.6) after the initial operation. The mean age of the patients was 56.8 years. The radiographs were reviewed and the clinical results were evaluated. RESULTS: The mean Harris hip score improved from 52.4 points preoperatively to 88.2 points postoperatively. Of the 40 hips showing a good press-fit, 29 hips (72.5%) exhibited bone ingrowth fixation. Of the remaining 17 hips with a poorer press-fit, 7 hips (35.3%) showed bone ingrowth fixation and 6 hips (35.3%) had unstable fixation. Of the 36 hips showing bone ingrowth fixation, 28 hips (77.8%) exhibited stress mediated bone resorption. On the last follow-up radiographic examination, osteolysis occurred around the femoral stem and acetabular cup in 21 (36.8%) and 6 (10.5%) hips, respectively. CONCLUSION: The results of cementless AML total hip arthroplasty were acceptable up to 7 years but polyethylene wear and osteolysis should be followed carefully over the long term.

Short Term Results of Cementless Total Hip Arthroplasty with Subtrochanteric Shortening Osteotomy in Severe Dysplasia of Hip

PURPOSE: This study examined the clinical, functional and radiological results of total hip arthroplasty with subtrochanteric shortening osteotomy in severe dysplasia of hip. MATERIALS AND METHODS: Seventeen cases of severe dysplasia of the hip, which were treated with total hip arthroplasty with subtrochanteric shortening osteotomy from August 1997 to September 2004, were evaluated. The mean follow-up duration was 52.9 months (range: 26~106). Harris hip score (HHS), leg length discrepancy (LLD) and complication were assessed clinically. Gait analysis (7 cases) and Cybex study (8 cases) for the abductor muscle power were assessed functionally. Bony union and stability around the osteotomy site of the femoral and acetabular components was assessed radiologically. RESULTS: The mean HHS improved from 65.1 (range: 23~87) points preoperatively to 88.2 (range: 72~100) points at the last follow-up. The mean LLD improved from 3.7 (range: 1~7) cm preoperatively to 1.6 (range: 0.5~3.3) cm postoperatively. All cases showed complete bony union of the allograft in the acetabulum and osteotomy site at a mean time of 6 months postoperatively. Gait analysis improved in all cases but there was some limping gait remaining. On the Cybex study, 6 out of 8 cases showed improved abductor muscle peak toque, postoperatively. CONCLUSION: A cementless total hip arthroplasty with subtrochanteric shortening osteotomy is believed to be a useful treatment for severe dysplasia of hip. Despite the improving HHS, the abductor power can be decreased. In these points, gait analysis and the Cybex study are helpful on the follow-up.

Cementless Total Hip Arthroplasty with Use of the COREN Hip System

PURPOSE: To report the results of a minimum three-year follow-up of cementless total hip arthroplasty using the COREN Hip System(R) (Corentec, Seoul, Korea), which is the first total hip prosthesis developed in Korea. MATERIALS & METHODS: A total of 57 patients (68 hips) who had undergone cementless total hip arthroplasty using the COREN Hip System(R) between July 2003 and March 2004 were analyzed clinically and radiographically after a minimum follow-up of three years after the index arthroplasty. RESULTS: The mean Harris hip score improved from 46 points preoperatively to 95 points at the one-year follow-up and to 99 points at the three-year follow-up. All the patients reported a good or excellent satisfaction with the results of surgery. All prostheses showed radiographic evidence of stable bony fixation, and no hips showed evidence of osteolysis or prosthesis loosening. During the follow-up period, there were no complications such as a deep infection, dislocation or ceramic fracture in any hip, and no revision surgery was required. CONCLUSION: The clinical and radiographic evaluations of Cementless total hip arthroplasty using the COREN Hip System(R) showed excellent outcomes after a minimum follow-up duration of three years.

Short-term Results of Cementless Ceramic-on-ceramic Articulation Total Hip Arthroplasty

PURPOSE: This study evaluated the short-term results of ceramic articulation total hip arthroplasty in cementless total hip arthroplasty. MATERIALS AND METHODS: 142 hips were followed-up for more than 2 years after cementless total hip arthroplasty using ceramic-on-ceramic articulation. The mean age and follow-up period was 58.3 years and 3.0 years, respectively. The Harris hip score and postoperative hip pain were analyzed clinically. The radiological results were assessed using various radiological indices. RESULTS: At the last follow-up, the Harris hip score improved from 58.1 points preoperatively to 93.2 points postoperatively. There were 4 cases (2.8%) of significant hip pain. Radiologically, all the stems demonstrated stable fixation. The inclination of the acetabular cup was changed significantly in 2 cases (1.4%), which were diagnosed as being loosened. A radiolucent line was observed around the stem in 9 cases (6.3%), and around the cup in 3 (2.1%). Endosteal new bone formation was observed around the stem in 50 cases (35%), and around the cup in 55 (38.5%). No osteolysis was observed around the stem and the cup. CONCLUSION: The short-term results of ceramic on ceramic articulation hip arthroplasty were excellent without osteolysis.

Cementless Acetabular Component Fixation with Circumferential Medial Wall Osteotomy in Severely Hypoplastic Acetabulum / 대한정형외과학회잡지

PURPOSE: To evaluate the results of the acetabular circumferential medial wall osteotomy in obtaining secure fixation of cementless hemispherical acetabular cup to the hypoplastic acetabulum. MATERIALS AND METHODS: Seventy-nine THAs with a circumferential acetabular medial wall osteotomy in the dysplastic acetabulum performed between 1987 to 1997 and followed up for more than 6 years were assessed. The indication of this technique was acetabular coverage that could not achieve more than 70% after cup fixation. In all cases, a cementless hemispherical acetabular cup was fixed in the true acetabulum. Additional procedures included soft tissue releases in 23 hips, a derotational femoral osteotomy in 10 hips, a structural bone graft in 7 hips and femoral shortening in 8 hips. Both clinical and radiographic parameters were evaluated. RESULTS: The Harris hip scores were improved from 68.4 to 92.2 postoperatively. Radiographic analysis revealed no aseptic loosening or radioluacent line, and showed stable bony fixation at the true acetabulum in all cases. 7 hips showed acetabular osteolysis. Two acetabular components were revised due to dissociation of the polyethylene liner and 4 polyethylene liners were exchanged because of severe wear or osteolysis. CONCLUSION: The circumferential acetabular medial wall osteotomy can provide appropriate positioning, sufficient coverage of the acetabular cup with a preservation of the medial wall thickness in cementless THA without additional bone grafting in the dysplastic acetabulum.

Cementless Total Hip Arthroplasty with Circumferentially Proximal Porous-Coated Femoral Stem -Minimum 10-Year Follow-up Results

Purpose: The results of a more than 10-year follow-up after total hip arthroplasties with circumferential and proximal porous-coated femoral stems were evaluated. Materials and Methods: Seventy-six patients (80 hips), who were operated on between Aug. 1991 and July 1994, were followed for more than 10 years after primary total hip arthroplasties using Multilock stems. The mean age at the time of the operations was 47.3 years old and the mean duration of follow-up was 12.3 years. The clinical results and radiological findings were evaluated. Results: The mean Harris hip scores improved from 54.7 points to 88.5 points at the time of the 10-year follow up. On the last follow-up radiograph, endosteal bone formation was observed in 70 hips (90%) and all femoral stems were biologically stable. Femoral osteolysis, which was linear in Gruen zone I and VII and mostly restricted to the proximal zones, was observed in 67 hips (84%), and no hip had distal osteolysis in the femur. There was no loosening, migration, or revisions of the stems. Conclusion: Total hip arthroplasties using circumferential and proximal porous coated Multilock femoral stems demonstrated stable osseous fixation and no distal osteolysis for a minimum 10-year follow-up; therefore, all stems were reported to have satisfactory outcomes. With improvement of cup design and liner wear, circumferential and proximal porous coating designs of femoral stems can be an alternative answer to mechanical failure due to aseptic loosening.

Short-term Results of Cementless Total Hip Arthroplasty Using Ceramic on Ceramic Articulation / 대한정형외과학회잡지

PURPOSE: The authors evaluated the clinical and radiological short-term results of ceramic on ceramic articulation of cementless total hip arthroplasty. MATERIALS AND METHODS: One hundred fourteen patients, with a total of 130 hips were followed for more than 2 years after cementless total hip arthroplasty using ceramic on ceramic articulation (Lima. SPH-C2). The mean age was 58 years, and the mean follow-up period was 3.0 years. The Harris hip score and postoperative hip pain were analyzed clinically. The radiological results were assessed using various radiological indices such as subsidence, cup inclination angle, radiolucent line, endosteal new bone formation and osteolysis. RESULTS: At last follow-up, the average Harris hip score improved from 57.5 points preoperatively to 93 points postoperatively. There were 4 cases (3.0%) of significant hip pain. Radiologically, all stems demonstrated stable fixation. The inclination of the acetabular cup was significantly changed in 4 cases (3%), and was diagnosed as loosened. A radiolucent line was observed around the stem in 5 cases (3.8%), and around the cup in 7 cases (5.4%). Endosteal new bone formation was observed around the stem in 47 cases (36.2%), and around the cup in 52 cases (40.0%). Osteolysis was not observed around the stem and the cup. CONCLUSION: With a minimum follow-up of 2 years, ceramic on ceramic articulation hip arthroplasty demonstrated excellent results on the stem side. However, 4 cases (3.0%) of cup loosening suggest that there is a fixation problem due to the design of the cup.

Cementless Total Hip Arthroplasty in Bony Ankylosed Hip / 대한정형외과학회잡지

PURPOSE: The purpose of the present retrospective study was to report the clinical and radiological results of 31 total hip arthroplasties of 28 patients with bony ankylosed hip. MATERIALS AND METHODS: Conversions to cementless total hip arthroplasty between August 1983 and May 1999 were reviewed after followups ranging from 3 years 1 month to 18 years. The mean age of the patients at the time of operation was 35.0 years. The mean duration of the ankylosis was 15 years 7 months. RESULTS: At the time of the last follow-up, the mean arc of flexion was 84.6 degrees. The mean Harris hip score improved from 47.7 to 84.9. There were no significant differences in clinical results according to the type and duration of ankylosis. Radiographs showed one acetabular loosening, six acetabular osteolysis and five femoral osteolysis. In cases of osteolysis, the average wear rate was 0.28 mm/year. CONCLUSION: The conversion of bony ankylosed hip to a cementless total hip arthroplasty revealed a favorable outcome, and the risk of failure was found to be unrelated to the type and the duration of ankylosis. However, since some patients show excessive wear with osteolysis, polyethylene liner wear will be of critical importance in terms of long-term results.

Cementless Total Hip Arthroplasty using Anatomically Designed Femoral Components / 대한정형외과학회잡지

PURPOSE: To evaluate the mid and long-term clinical and radiological results of cementless total hip arthroplasty using a stem of anatomic design, and to determine those factors that influence stem loosening. MATERIALS AND METHODS: We analyzed 102 hips (83 patients) managed with cementless total hip arthroplasty using the stem of anatomic design with an average of 6.2 years of follow-up Twelve hips showed radiological loosening of the femoral stem. We compared these 12 hips with 24 well-fixed hips. RESULTS: The Harris hip score was 90.1 an average (range: 70-100) and the incidence of thigh pain was 19.1% (21 hips) at the last followup. The rate of revision was 2.9% (three hips) for the femoral side. Twelve hips (11.7%) showed radiological loosening on the femoral side, namely, subsidence of the stem (five hips), change in the position of the stem (six hips), and extensive osteolysis (one hip). The two groups differed significantly in femur of the wear rate of polyethylene liner, osteolysis, and stem fill. CONCLUSION: Operation involving an anatomic prosthesis should be properly performed to fill the proximal part of femur, and the wear the bearing surface should be improved. Furthermore, the prevention of thigh pain should be considered in the design of anatomic femoral stem.

Natural Progress of Bone Scan after Cementless Hydroxyapatite-Coated Total Hip Arthroplasty / 대한정형외과학회잡지

PURPOSE: To observe the progress pattern of quantitative bone uptake in asymptomatic patients with uncomplicated cementless total hip arthroplasties. MATERIAL AND METHODS: A periprosthetic quantitative 99mTc-MDP scintiscan was performed in 62 asymptomatic patients (80 hips) and 10 unoperated normal control group (20 hips) . The patients were studied in eight groups (10 hips each time) at scheduled time intervals (1, 3, 6, 9, 12, 24, 36, and 48 months) . We calculated the comparative ratio of uptake in each of the periprosthetic zones to both sacroiliac joints and compared these results with the control group. RESULTS: The uptake ratio of all the periprosthetic areas (cup and stem areas) peaked at one month after the operations (p<0.05) , and a statistically significant decrease was shown between one and three months (p<0.05) . After three months, the activity was relatively uniform and stable. Bone uptake on the proximal femur in the normal unoperated control group indicated that bone uptake in the metaphyseal area was physiologically high (p<0.01) . Comparing this result with that of the patient group, bone uptake decreased much faster in the HA-coated metaphyseal area than in the non-coated diaphyseal area. DISCUSSION AND CONCLUSION: Previous studies of bone scan after cementless hip arthroplasties reported that bone uptake in the HA-coated metaphyseal area was higher and had longer stabilizing time than that in the non-coated diaphyseal area. And they claimed that evaluation of bone uptake was meaningless in the acetabular cup area. However, our measurement of bone uptake on the proximal femur in the normal unoperated control group indicated that bone uptake in the metaphyseal area was physiologically high. Comparing this result with that of the patient group, bone uptake decreased much faster in the HA-coated metaphyseal area than in the non-coated diaphyseal area. And when a quantitative bone scan of the acetabular cup area was performed and compared to normal acetabulum in the control group, we found that, unlike the claims of several previous studies, the bone scan does produce meaningful results.