Meta-analysis of the Incidence and Risk Factors for Squeaking after Primary Ceramic-on-ceramic Total Hip Arthroplasty in Asian Patients / 대한고관절학회지

PURPOSE: The purpose of this study was to assess the squeaking incidence and risk factors after primary ceramic-on-ceramic total hip arthroplasty (THA) in Asian patients using meta-analysis. MATERIALS AND METHODS: We performed a meta-analysis of published data on the squeaking incidence and risk factors from 2000 to 2013. Eight studies in Asians were analyzed for both squeaking incidence and risk factors and 25 studies in Western patients were analyzed for squeaking incidence. The data collected were: patient factors, surgical factors and implantation factors. RESULTS: The overall incidence of hip squeaking was 2.7% in Asians and 3.1% in Westerners. This difference was not statistically significant. The only significant risk factor was an increase in the acetabular cup abduction angle. Of the factors, the cup abduction angle was the only significant risk factor for the occurrence rate of squeaking, and the occurrence rate tended to increase with increasing angle. CONCLUSION: The incidence of squeaking in Asians after primary ceramic-on-ceramic THA is 2.7% and is similar to that in Westerners. The increased cup abduction angle is associated with squeaking; therefore, surgeons should be careful not to implant the cup at a too steep abduction angle.

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.

Ceramic-on-Ceramic Total Hip Arthroplasty: Minimum of Six-Year Follow-up Study

BACKGROUND: This study examines the clinical and radiologic results of ceramic-on-ceramic total hip arthroplasties with regard to wear, osteolysis, and fracture of the ceramic after a minimum follow-up of six years. METHODS: We evaluated the results of a consecutive series of 148 primary ceramic-on-ceramic total hip arthroplasties that had been performed between May 2001 and October 2005 in 142 patients. The mean age was 57.2 years (range, 23 to 81 years). The mean follow-up period was 7.8 years (range, 6.1 to 10.1 years). Preoperative diagnosis was avascular necrosis in 77 hips (52%), degenerative arthritis in 36 hips (24.3%), femur neck fracture in 18 hips (12.2%), rheumatoid arthritis in 15 hips (10.1%), and septic hip sequelae in 2 hips (1.4%). Clinical results were evaluated with the Harris hip score, and the presence of postoperative groin or thigh pain. Radiologic analysis was done with special attention in terms of wear, periprosthetic osteolysis, and ceramic failures. RESULTS: The mean Harris hip score improved from 58.3 (range, 10 to 73) to 92.5 (range, 79 to 100) on the latest follow-up evaluation. At final follow-up, groin pain was found in 4 hips (2.7%), and thigh pain was found in 6 hips (4.1%). Radiologically, all femoral stems demonstrated stable fixations without loosening. Radiolucent lines were observed around the stem in 25 hips (16.9%), and around the cup in 4 hips (2.7%). Endosteal new bone formation was observed around the stem in 95 hips (64.2%) and around the cup in 88 hips (59.5%). No osteolysis was observed around the stem and cup. There were 2 hips (1.4%) of inclination changes of acetabular cup, 2 hips (1.4%) of hip dislocation, 1 hip (0.7%) of ceramic head fracture, and 1 hip (0.7%) of squeaking. The Kaplan-Meier survival rate of the prostheses was 98.1% at postoperative 7.8 years. CONCLUSIONS: The ceramic-on-ceramic total hip arthroplasty produced excellent clinical results and implant survival rates with no detectable osteolysis on a minimum six-year follow-up study. The ceramic-on-ceramic couplings could be a reasonable option of primary total hip arthroplasty for variable indications.

Cementless Total Hip Arthroplasty with Fourth Generation Ceramic-on-Ceramic Articulation: Minimum Two Years of Follow-up / 대한고관절학회지

PURPOSE: The purpose of this study is to report clinical and radiographic results over a period of two 2 years after cementless total hip arthroplasty (THA) with fourth generation ceramic-on-ceramic articulation. MATERIALS AND METHODS: We studied 22 patients, 23 cases which were followed up for two years among 25 patients, 26 patients who underwent cementless THA with the fourth generation ceramic between April 2009 and December 2009. The average age of the patients was 55.9 years old(22 to 72 years old), and the average follow-up duration was 28 months(24 to 32 months). A clinical evaluation was performed using the Harris hip score (HHS), and radiologic evaluation was based on acetabular cups and osteolysis of the femoral stems, instability, distance, angle, and so on. RESULTS: HHS showed an increase, from 54 for before-surgical treatment, to 91 at the last follow-up. Inguinal pain was observed in one case, and femoral pain was observed in two cases. Stable fixation was achieved in all cases, and no instability, osteolysis, or movement of acetabular cups and femoral stems was observed. CONCLUSION: Clinical and radiological short-term results for use ofthe fourth generation ceramic-on-ceramic cementless THA have favorable so far. Further follow-up study should be performed for evaluation of the long-term results.

Ceramic on Ceramic Total Hip Arthroplasty: The Results of a Minimum 10-Years Follow up

PURPOSE: We wanted to evaluate the clinical and radiographic results of ceramic on ceramic bearing cementless total hip arthroplasty with a minimum of 10-years follow up. MATERIALS AND METHODS: This study was performed on 44 patients and 51 hips, and the patients were recruited among the patients who underwent ceramic-ceramic type cementless total hip arthroplasty from August 1998 to February 2000 and they were available for 10-years or longer follow up. The gender ratio was 28 males and 16 females, and the mean age at the time of surgery was 49 years (range: 26~77 years). Regarding the causality of disease, osteonecrosis was noted in 36 cases, degenerative arthritis was noted in 4 cases, acetabular dysplasia was noted in 4 cases and septic or tuberculous hip sequelae was noted in 7 cases. The clinical evaluation was performed according to the Harris hip score, and for the radiological evaluation of the femoral component, we assessed the degree of subsidence and the presence of periprosthetic osteolysis, endosteal new bone formation and cortical hypertrophy, and the final fixation state of the implant. In the cases with an acetabular cup osteoscleostic line in the vicinity of the acetabular cup, endosteal new bone formation, acetabular osteolysis and the vertical migration as well as the horizontal migration of the acetubular cup were assessed. RESULTS: Regarding the clinical outcomes, the Harris hip score was improved from an average 59 points to 93 points at the final follow up. For the radiological results, osteolysis was not detected in the acetabular and femoral components, the subsidence of femoral stem was not beyond 2 mm on average and significant subsidence was not detected. In regard to complications, linear fracture during surgery was noted in 6 cases and postoperative hip dislocation was noted in 1 case. A ceramic head fracture occurred in one case and a ceramic liner fracture occurred in 2 cases. CONCLUSION: This type of articulation is a promising option at a minimum of 10-years follow up of 51 hips that underwent ceramic-ceramic bearing cementless total hip arthroplasty. However, our results demonstrated that surgeons should be aware of the potential risks of ceramic fracture when using ceramic-on-ceramic bearing surfaces. Additional longer-term follow-up is necessary.

Ceramic-on-Ceramic Bearing Total Hip Arthroplasty: Five-Year Midterm Follow-up Results

PURPOSE: We believe that cemented femoral stems will relieve the stiffness of ceramic-based bearings, resulting in reduced complication of ceramic-on-ceramic bearing total hip arthroplasty (THA). The purpose of this study was to evaluate the midterm effect of ceramic-on-ceramic bearing THA using cemented femoral stems. MATERIALS AND METHODS: We studied 32cases (30 patients) of THA using ceramic-on-ceramic bearing cemented femoral stems and 33 cases (31 patients) of THA using ceramic-on-ceramic bearing cementless femoral stems. All total hip arthroplasties were performed between January 2004 and December 2005 and were followed up for more than 5 years. The clinical results and radiographic results were evaluated. RESULTS: The mean HHS improved from points pre-operatively to points at the last follow-up in both the cemented and cementless stem groups (P<0.05). The mean WOMAC score also improved from points pre-operatively to points at the last follow-up in both the cemented and cementless stem groups (P<0.05). But no statistically significant difference was noted between the cemented and cementless stem groups in HHS and WOMAC scores (P=0.304, P=0.769). There were 3 patients with a sense of discomfort on ambulation and 5 patients with thigh pain in the cementless stem group and no cases in the cemented stem group. There was no instance of acetabular loosening in either group. Subsidenc of the cemented femoral stem was less than 1mm in 30 cases and less than 2 mm in 2 cases. All cementless femoral stems acquired firm bony union. CONCLUSION: Midterm results showed no statistical links between ceramicon-ceramic-bearing THA using cemented femoral stems or cementless femoral stems.

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.

Cementless Total Hip Arthroplasty Using a Ceramic on Ceramic Bearing Surfaces in Patients 60 or More Years Old

PURPOSE: To investigate clinical and radiographic results for cementless total hip arthroplasty (THA) using ceramic-on-ceramic articulation in patients over 60 years old. MATERIALS AND METHODS: Between May 2000 and February 2007, we analyzed 44 THAs that used ceramic-on-ceramic articulation in 34 patients aged 60 or older. The mean follow-up duration was 3.2 years; the mean age was 66.8 years. Clinical and radiographic evaluations were carried out. Risk factors for dislocation were evaluated. RESULTS: Final Harris hip scores increased to an average of 90 points from an average of 51 points preoperatively. Radiographic findings demonstrated that fixations around the stems and the acetabular cups were stable. There was no aseptic loosening and osteolysis around the implants. There were 10 cases of posterior dislocation within 3 months postoperatively. Two revisions were done, one due to a recurrent dislocation and one to a ceramic head fracture. Risk factors for dislocation were ASA score, cup anteversion angle and total anteversion angle. CONCLUSION: Cementless THAs using ceramic-on-ceramic articulation for patients aged sixty or more elicits good clinical and radiographic results. Because of the high rate of early dislocation and damage to the ceramic, we call attention to the position of the implants and postoperative management in elderly, debilitated patients.

Cementless Total Hip Arthroplasty with Alumina Ceramic-on-Ceramic Articulation

PURPOSE: We wanted to evaluate the clinical and radiological results of total hip arthroplasty using a ceramic-on-ceramic articulation. MATERIALS AND METHODS: From March 2004 to February 2006, total hip arthroplasty was performed in 21 patients and 31 hips. The mean follow up period was 56 months (range: 48~72 months). The causes for the AVN were alcohol in 12 cases, idiopathic in 10 cases, steroid in 6 cases and post-traumatic in 3 cases. The clinical results were evaluated using the Harris hip score and according to the pain on the inguinal area or thigh. The radiographic evaluation was performed to determine the level of osteolysis and instability around the acetabular cup and femoral stem, the position of the femoral stem and the wear of the articular surface. RESULTS: At the most recent follow-up, the mean Harris hip score was 93 points with no inguinal or thigh pain. The complications included one case of peroneal nerve palsy, one case of ceramic head fracture, two cases of noise in the joint, two cases of posterior dislocation and two patients died because of complication related to liver cirrhosis. Radiologically, bone ingrowth was noted in all the cases with no migration of the acetabular component and femoral stem, changing of the position or osteolysis. CONCLUSION: Total hip arthroplasty with ceramic on ceramic articulation shows satisfactory results at an average of 56 months follow up. There was bone ingrowth in all cases except for one ceramic head fracture. Further follow-up study should be performed to evaluate the long-term results.

Cementless Total Hip Arthroplasty using Ceramic-on-ceramic Osteonics(R) System: Minimum 8-year Follow up Results / 대한정형외과학회잡지

PURPOSE: To evaluate the 8-year follow up results of the clinical and radiographic of the cementless total hip arthroplasty using the Osteonics(R) system with ceramic-on-ceramic articulation on a retrospective basis. MATERIALS AND METHODS: Between March 1999 and February 2000, 31 primary total hip arthroplasties were performed in 27 patients using the cementless Osteonics(R) system. The mean follow-up period was 101 months (96-107 months). The mean age at surgery was 56.5 years of age (28-62 years). Preoperative diagnoses were the following in the 27 patients: 5 cases of primary osteoarthritis, 15 cases of avascular necrosis, and 7 cases of secondary osteoarthritis. The clinical results were evaluated using the Harris hip score and radiographic evaluation was done in terms of the fixation of components, the prevalence of osteolysis, and wear of ceramics. RESULTS: The mean preoperative Harris hip score at was the most recent follow-up was 91. Complications were calcar fracture in 8 cases, posterior dislocation in 2 cases, continuous thigh pain in 2 cases, squeaking sound in 3 cases, and limping gait lasting at least 1-year post operation in 6 cases. All cases had fixation by bony ingrowth was and there was no migration of acetabular cups nor osteolysis. There was no loosening of the femoral stem. It was not possible to measure ceramic wear and there were no ceramic fractures. CONCLUSION: At the 8-year follow-up, results of the cementless total hip arthroplasty using the Osteonics(R) system with ceramic-on-ceramic articulation demonstrated favorable results of osseointegration of the components and unmeasurable ceramic wear. However, longer-term-follow up was necessary. We believe that further study is required to determine the high incidence of squeaking.

Total Hip Arthroplasty using a Ceramic on Ceramic Bearing Surfaces / 대한정형외과학회잡지

PURPOSE: To evaluate the clinical and radiological results of total hip arthroplasty using a ceramic on ceramic bearing surfaces. MATERIALS AND METHODS: From April 1999 to April 2005, 53 hips had total hip arthroplasty with a ceramic on ceramic bearing surfaces in our hospital. Causes of total hip arthroplasty were avascular necrosis of femoral head in 47 hips, osteoarthritis in 3 hips and ankylosing spondylitis in 3hips. We used three kinds of acetabular cup and two kinds of femoral stem in this study. Follow-up period was an average of 55months (24-92). Clinical results were evaluated with Harris hip score and squeak sound. Radiological results included liner wear rate, breakage of ceramic, component loosening and osteolysis. RESULTS: Mean Harris hip scores improved from 58 to 88.3. No breakage of ceramic liner or head occurred. No acetabular or femoral osteolysis was seen. Audible squeak sound or sensation was detected in 10 hips (18%). Revision was done in three cases (5.7%), the cause of one of them was acetabular cup loosening. CONCLUSION: Total hip arthroplasty with a ceramic on ceramic bearing surfaces showed satisfactory clinical and radiological results in an average of 4.6 years follow-up. However, we have to study causes and adverse effect of squeaking on the total hip arthroplasty.

Ceramic on Ceramic Hybrid Type Total Hip Arthroplasty in Patients with more than 65 years of Age -Minimum 5-year Follow-up Results

Purpose: This study examined the minimum five-year results of hybrid type total hip arthroplasty (THA) with ceramic-on-ceramic articulation and femoral stem fixation using cement in patients older than 65 years. Materials and Methods: From February 1999 to November 2002, a hybrid type THA with ceramic-on-ceramic articulation and femoral stem fixation using cement were performed in 47 patients (47 hips) older than 65 years of age. Among the 47 patients, 29 patients were followed up for more than 5 years. The mean age of these patients was 68.9 years (65~73years). The mean follow-up period was 74.6 months (61~107 months). The postoperative diagnosis included AVN of the femoral head in 21 hips, Osteoarthritis in 2 hips, rhematoid arhthritis in 1 hip, femoral neck fracture in 4 hips and Tuberculosis in 1 hip. The clinical results were analyzed retrospectively by the Harris hip score (HHS), hip and thigh pain, and radiologically by the level of osteolysis around acetabular cup and femoral stem, bone reabsorption by stress shielding, instability, acetabular and femoral stem anteversion, acetabular inclination and the femoral stem fixation site. Results: After surgery, the overall HHS improved from 56.3 +/- 1.4 to 92.3 +/- 1.1 points (p=0.013). Excellent and good results were obtained in 21 (72.4%) and 8 hips (27.6%), respectively. There was no case of thigh pain. Radiologically, there was no acetabular and femoral component osteolysis. Absorption by stress shielding was observed in 6 cases (20.7%) with an acetabular cup and 3 cases (10.3%) with a femoral stem. Bony stability was observed in all cases treated with an acetabular cup and possible loosening in 1 case (3.4%) treated with a femoral stem. Acetabular and femoral stem anteversion was 18.4degrees+/- 1.1 and 13.1degrees+/- 0.9 respectively. Acetabular inclination was 41.5degrees+/- 1.3. The femoral stem was inserted centrally in all cases. Complications included posterior dislocation of 1 hip (3.4%) and periprosthetic fracture of the femur in 1 hip (3.4%). There was no fracture of the ceramic component Conclusion: The mid-term results of hybrid type THA with ceramic-on-ceramic articulation and femoral stem fixation using cement were effective both clinically and radiologically in patients older than 65 years.

Results of Ceramic on Ceramic Bearing Total Hip Arthroplasty Using Cemented Femoral Stem and Cementless Femoral Stem

PURPOSE: The purpose of this study was to evaluate the results of ceramic-on-ceramic bearing primary total hip arthroplasty (THA) using cemented femoral stems and cementless femoral stems. MATERIALS AND METHODS: We studied 59 cases (52 patients) of THAs using ceramic-on-ceramic bearing cemented femoral stems and 64 cases (58 patients) of THAs using ceramic-on-ceramic bearing cementless femoral stems. All THAs were performed between January 2004 and February 2005 and were followed up for more than 3 years. The clinical results were evaluated using the Harris hip score (HHS), WOMAC score, sense of discomfort, and thigh pain. Radiographic results were assessed with serial radiographs. RESULTS: The mean HHS improved from 62.7 points preoperatively to 92.4 points at the last follow-up in the cemented stem group and improved from 61.5 points to 91.8 points in the cementless stem group (p>0.05). And mean WOMAC score improved from 37.9 points to 7.0 points in the cemented stem group and from 38.5 points to 12 points in the cementless stem group (p<0.05). There were 5 patients with a sense of discomfort and 9 patients with thigh pain in the cementless stem group and no cases in the cemented stem group. There were no instances of acetabular loosening in either group. Subsidence of the cemented femoral stem was less than 1 mm in 57 cases and less than 2 mm in 2 cases. All cementless femoral stems acquired firm bony union. CONCLUSION: Ceramic-on-ceramic bearing THA using a cemented stem showed clinical results superior to those achieved using a cementless stem. Cemented THA is thought to be good for complementing the problems caused by the hardness of ceramic-on-ceramic bearings.

Cementless Total Hip Arthroplasty using Ceramic-on-ceramic Summit(R) System: 3 years follow up

PURPOSE: To prospectively evaluate the 3 years follow up clinical and radiographic results of uncemented total hip arthroplasty using the Summit(R) system with ceramic-on-ceramic articulation. MATERIALS AND METHODS: From January 2001 to December 2001, thirty-one primary total hip arthroplasties were performed on thirty-one patients using the Summit(R) system. The mean follow-up period was 3.3 years. The preoperative diagnoses were degenerative osteoarthritis in 18 cases, avascular necrosis in 10 cases, and a femoral neck fracture in 3 cases. The mean age at surgery was 67.4 years. The clinical results were evaluated using the Harris hip score. The radiographic evaluation was performed to determine the stability of the components, the prevalence of osteolysis and the amount of wear. RESULTS: The mean Harris hip score improved from 64.7 points preoperatively to 90.4 points at the most recent follow-up. The complications included two cases of dislocation, three cases of limping gait lasting for 1 year after surgery. Fixation by bone ingrowth was noted in all cases and there was no case of migration of the acetabular cup and osteolysis. There was no case in the varus position, sinking down, or a loosening of the femoral stem. On the final observation after surgery, the range of hip joint motion showed flexion of 120.7degreeson average (110degrees~150degrees), extension of 5degrees(0degrees~10degrees), internal rotation of 20.3degrees(15degrees~25degrees), external rotation of 33.7degrees(20degrees~40degrees), abduction of 29.4degrees(20degrees~40degrees), and adduction of 19.5degrees(15degrees~25degrees). CONCLUSION: Uncemented total hip arthroplasty using the Summit(R) system with ceramic-on-ceramic articulation showed excellent clinical and radiographic results in the range of motion and function.

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.

Total Hip Arthroplasty with Ceramic-on-Ceramic Articulation: Minimum 5-year Follow-up Results / 대한정형외과학회잡지

PURPOSE: To evaluate the medium-term clinical and radiographic results of uncemented total hip arthroplasty with ceramic-on-ceramic articulation. MATERIALS AND METHODS: From February 1999 to August 2000, fifty-two primary total hip arthroplasties were performed on forty-two patients using a ceramic-on-ceramic bearing implant. The mean follow-up period was 5.4 years (range, 5-6.6 years) and the mean age at surgery was 43.2 years (range, 19-66 years). The clinical results were evaluated using the Harris hip score. The radiographic evaluations were carried out in terms of the stability of the components, the prevalence of osteolysis and wear. RESULTS: At the most recent follow-up, the mean preoperative Harris hip score improved from 63 points (range, 26-93 points) to 97 points (range, 82-100 points). The Harris hip score showed excellent results in 49 hips (94%) and good results in 3 hips (6%). Fixation by bone ingrowth was noted in all cases and there was no case with osteolysis or a deep infection. Ceramic wear was not detectable on the plain radiograph. Complications included one case of dislocation, one case of a fracture of the ceramic femoral head and one case of an intraoperative periprosthetic proximal femoral crack. CONCLUSION: Ceramic-on-ceramic articulation showed excellent clinical and radiographic results in terms of wear, osteolysis and loosening. A further follow-up study should be performed to evaluate the long-term clinical and radiographic results with special focus on the fracture of the ceramic material.

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.

Two Potential Dangers Resulting from a Difficult Intraoperative Reduction of the Femoral Head in Alumina-on-Alumina Bearing Total Hip Arthroplasty / 대한정형외과학회잡지

PURPOSE: The aim of this study was to evaluate changes in the bearing surface of an alumina head and cup insert after difficult intraoperative reduction of the head. MATERIALS AND METHODS: In two consecutive cases, where the force required for reduction caused scratching on the edge of the acetabular metal shell and marginal cracking of the adjacent portion of the alumina insert, the reduced alumina head was dislocated and retrieved with the alumina cup insert. The changes of the bearing surface were evaluated by gross inspection and by scanning electron microscopy(SEM) and energy dispersive x-ray spectrometry (EDAX). RESULTS: In both cases, the scratched area of the alumina head was found to have discolored. SEM and EDXA showed the discoloration to be the result of metallic debris from the titanium alloy shell. The metallic debris that was transferred from the head also stained the bearing surface of the alumina insert. CONCLUSION: Metallic debris might increase bearing surface wear. If the cracked ceramic fragments from the cup insert are neglected, it is also possible that they could be trapped between bearing surfaces and increase wear.