Cementless Total Hip Arthroplasty Using Dual Offset Titanium Tapered Stem: At Least 7-Year Follow-Up / 대한정형외과학회잡지

PURPOSE: The purpose of current study is to evaluate the midterm results of cementless primary total hip arthroplasty (THA) using a dual offset titanium tapered stem. MATERIALS AND METHODS: A retrospective analysis of 102 cases (84 patients), with a minimum of 7-year clinical follow-up, was performed. All of the cases consisted of patients who underwent primary cementless THA, using a dual offset titanium tapered stem in The Catholic University of Korea, Bucheon St. Mary's Hospital between July 2004 and May 2009. Clinical results were analyzed via the Harris hip score, level of thigh pain, squeaking around hip joint, and complication rate. Radiologic results were examined with stability and location of inserted prosthesis, hypertrophy of femoral cortex, and osteolysis. RESULTS: Out of the 102 cases (84 patients; 47 males and 37 females), with the mean age of 55.9 years (range, 27–79 years) and mean follow-up period of 99.2 months (range, 84–132 months). The mean Harris hip score was 53.8 preoperatively (range, 26–75) and improved to 93.5 postoperatively (range, 74–100) (p=0.000). All of the cases gained stable bony fixation on the final follow-up, including 2 cases of intra-operative proximal femur fracture. Calcar remodeling was observed in 94 cases, however, they were irrelevant with stem stability. Cortical hypertrophy of femur was seen in 12 cases and thigh pain in 4 cases; nonetheless, they were not relevant (p=0.067). There was 1 case of squeaking sound during joint movement. Hip dislocation occurred in 1 case early after the procedure, but the event was due to excessive anteversion of the acetabular cup, in which a revisional replacement procedure of the acetabular cup was conducted. No sign of ceramic breakage was observed. There were 2 cases of heterotrophic ossification. CONCLUSION: Results from a 7-year follow-up of cementless THA using dual offset titanium tapered stem were encouraging in both clinical and radiologic evaluations.

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.

Hip Arthroplasty Using Collarless Polished Tapered Stem: Minimum 2 Years Follow-up Results

PURPOSE: This study evaluated the clinical and radiologic results of total hip arthroplasty and bipolar hemiarthroplasty using collarless polished tapered femoral stem. MATERIALS AND METHODS: We retrospectively reviewed the results of 33 patients who underwent THA and BHA using cemented CPT femoral stem from November 2006 to April 2009. The mean follow-up period was 33 months. The clinical results were evaluated with a Harris Hip Score (HSS), and radiographic results were assessed with cement grade, osteolysis, loosening, stress shielding and subsidence methods. RESULTS: Mean HSS improved with 91 points. Postoperative cement grade was A in 14 cases, B in 14 cases, C1 in 5 cases and D in none. Aseptic loosening was not found, while focal radiolucency in zone 8 was found. 70% of stems showed grade 1 and 2 stress shielding according to Engh's criteria. Subsidence of the femoral stem was less than 1 mm in 32 cases, and was 1.47 mm in another case. Ectopic ossification was observed in 13 cases, class I in 11 cases, and class II in 2 cases, using Brooker's classification. CONCLUSION: This study showed the good clinical and radiographic results of THA and BHA with a cemented CPT femoral stem at the mid-term follow-up. However, a long-term follow-up study will be needed to evaluate the more precise clinical and radiographic outcomes.

Total Hip Replacement Arthroplasty with the Mallory-Head System : Minimum 8-Year Follow-up Results

PURPOSE: The purpose of this study was to assess the clinical and radiographic results of total hip arthroplasty with using the double tapered Mallory-Head system. MATERIALS AND METHODS: The clinical and radiographic results of a consecutive series of 81 total hip replacements in 75 patients were reviewed at eight to twelve years (average: 9.8 years) postoperatively. The underlying diseases were avascular necrosis in 46 hips (57%), osteoarthritis in 12 hips (15%), RA in 9 hips (11%) and others. The clinical result was evaluated on the basis of the modified Harris hip score and the modified Merle d'Aubigne-Postel score. A radiographic analysis was also performed. RESULTS: The average modified Harris hip score was improved from preoperative 56 points to postoperative 92 points. The average modified Merle d'Aubigne-Postel score was 15 points at the latest follow up, and 55 hips (68%) were classified as having clinical grades of excellent or good results. One acetabular component was revised because of loosening, and one was revised because of recurrent dislocation. CONCLUSION: The clinical and radiological evaluations of the total hip replacements using the Mallory-Head system showed good results.

Cementless Total Hip Arthroplasty Using a Tapered Femoral Component / 대한정형외과학회잡지

PURPOSE: We investigated the results of cementless total hip arthroplasty using a tapered titanium-alloy stem. MATERIALS AND METHODS: We followed 72 hips in 60 patients who underwent total hip arthroplasty and received the using Mallory-Head femoral component for a mean of 9.1 years. The most common disease was avascular necrosis (56 hips; 77.7%). Their mean age was 50.1 years at the time operation. We analysed the clinical results by the Merle d'Aubigne and Postel scoring system and the radiographic outcome according to Engh's criteria. RESULTS: The mean hip score was 16.4 at the last followup. An excellent or good clinical result was obtained in 62 hips (86.1%). Thigh pain was present in 3 hips (4.1%), and femoral osteolysis was observed in 8 hips (11.1%), which did not progress to the distal part. Two femoral components were revised for loosening and for periprosthetic fracture. Thus, 69 stems survived at the last follow up. Sixty-six hips (91.7%) had fixation by bone ingrowth, and three (4.1%) showed stable fibrous fixation. CONCLUSION: These results shows that excellent fixation can be obtained by using a tapered titanium alloy femoral component by medium-term followup.

Biomechanical Analysis of Proximal Fitting-Distal Filling Stem and Proximal Fitting- Distal Tapered Stem in Cementless Hip Prosthesis: A 3 Dimensional Finite Element Study / 대한정형외과학회잡지

PURPOSE: This study was undertaken to compare the initial micromotion and stress shielding of a "fit and fill" stem to a "proximal fitting and distal tapered" stem in the early postoperative period using the load simulating single leg stance and stair climbing. MATERIALS AND METHODS: Using the data from 3-D human CT scan, authors developed two types of 3-dimensional finite element total hip replacement model of proximal femur, which were inserted with a "fit and fill" stem and a "proximal fitting and distal tapered" stem. The constructions of stems were based on the OmnifitTM stem (about 13,000 element & 20,000 nodes). We compared micromotion, maximal principal stress and strain energy of each stems. RESULTS: The results indicate that micromotion in a fit and fill stem were slightly lower than that of a tapered stem, especially in stair climbing over that in the single leg stance. The maximum principal stress on the cortex of femur was slightly higher in a tapered stem in the case of single leg stance, and 2 times higher in the case of stair climbing. Strain energy also was much higher in a tapered stem in both single leg stance and stair climbing gait. CONCLUSION: These findings indicate that a tapered stem design could provide more favorable biomechanical benefits rather than a fit & fill stem after cementless total hip replacement.