Papers by Keyword: Total Hip Arthroplasty (THA)

Abstract: In ceramic-on-ceramic total hip arthroplasty (THA), modular acetabular component with a sandwich insertion was developed and evaluated mid-term clinical results. 35 hips had undergone cementless ceramic-on-ceramic THA with sandwich cup (Kyocera, Kyoto, Japan). The mean duration of follow-up was 5 years. 6 hips had undergone component revisions. The reasons for revision included infection in 1 hip, dislocation with loosening in 2 hips, alumina liner fractures in 2 hips, and cup dissociation in 1 hip. All femoral and acetabular components showed no loosening in the unrevised hips at the time of the last follow-up. None of the 29 unrevised hips had osteolysis.

Abstract: Limitation in liner and head options available to the surgeon may be the most practical disadvantage of alumina-on-alumina total hip arthroplasty (THA). This may be more problematic in the revision THA. We evaluated the results of 57 revision THAs (average, 46.2 years old) performed with a contemporary alumina-on-alumina bearing surface after a 5-year minimum follow-up (average, 67 months; range, 60-85 months). A third generation alumina-on-alumina bearing (BIOLOX® forte, CeramTec AG) and a cementless PLASMACUP®-BiCONTACT® hip revision system (AESCULAP AG & Co.) had been used in all patients. Alumina bearing was chosen for a relatively young active patient in whom an acetabular bone defect was not severe and an extremely long neck of artificial head was not required for the restoration of hip joint mechanics. The average Harris hip score improved from 65.0 points to 88.9 points. No implant loosened, no stem or cup was re-revised, and no additional reoperations were required. Ceramic wear was undetectable in 14 hips where differentiation of the femoral head from the cup was possible on radiographs and no osteolysis was observed. During the follow-up period, no hip demonstrated signs of infection or ceramic failure. Short-term results of revision THAs performed with analumina-on-alumina bearing are encouraging. We believe that physiological age and activity level of a patient, severity of acetabular bone loss, and availability of alumina head and liner options required for the restoration of proper limb length and joint stability should be considered to choose this alumina bearing surface during the revision THA.

Abstract: 29 cases of primary total hip arthroplasty (THA) using interface bioactive bone cement technique (IBBC) combined with third generation cementing technique were evaluated clinically and radiologically. The present study includes 2 men 2 cases and 24 women 27 cases with an average age at operation of 63 years old (ranging 42 to 81). Mean postoperative follow up period was 17.3 months (ranging 12 to 23 months). Pre- and postoperative (1 year) evaluation using Japan Orthopaedic Association (JOA) hip score were 36.0, and 85.0 points, respectively. Postoperative cementing grade using Barrack’s classification was A in every case. At one year, radiolucent line at bone-cement interface was not observed, except one case of rheumatoid arthritis patient at zone 3 (Delee and Charnley) in the acetabular side. Neither osteolysis nor loosening was observed in every case. No major complications, such as infection, dislocation, pulmonary embolization, were observed. The present study revealed excellent short-term result was obtained by IBBC technique combined with third generation cementing technique for primary THAs.

Abstract: The Omnifit-HA femoral stem component has shown excellent results in early clinical studies. This is an independent prospective study of the outcome of a ydroxyapatite-coated femoral component implanted by one surgeon with an intermediate-term follow up. The senior author performed 103 consecutive uncemented total hip arthroplasties in 96 patients from July 1991 to December 1996. The components implanted were the Omnifit-HA femoral stem and the Omnifit PSL porous-coated acetabular shell. The mean age at the time of the index procedure was 52 years old (range, 27–78) and male:female ratio was 54:42. Three patients were deceased and four patients were lost to follow-up. The mean follow up was 10.3 years (range, 7.3–12.7 years). Clinical and radiographic evaluations were performed by an independent observer. The average preoperative and postoperative Harris Hip Scores were 55 and 92, respectively. The overall survivorship of the Omnifit-HA stem was 100% with no femoral revisions. The survivorship of the Omnifit PSL cup was 89.7% with 4 acetabular revisions for aseptic loosening and 6 polyethelene liner exchanges for osteolysis or late instability. The mean polyethylene wear rate was 0.24 mm per year. This long-term follow up shows that the use of circumferentially coated hydroxyapatite stems can protect against the migration of wear debris along the femoral stem.

Abstract: Hydroxyapatite (HA) coatings for femoral stems have been successful in short- to intermediate-term follow up. However, the outcomes of HA-coated cups have not been as successful as comparable non-HA-coated designs. This has been attributed to component design and to poor quality HA-coating processes. This is a clinical outcome study of a newer generation acetabular design with an improved plasma-sprayed HA-coat. Ninety consecutive primary total hip replacements implanted with a HA-coated metal-backed cup were prospectively followed up for 2–5 years after surgery. Mean age was 69 years, male:female ratio was 36:47; mean-weight was 77 kg. Polyethylene wear was measured on digitized images. Component position, component migration, and implant-bone interface radiolucent lines were analyzed by computerized image analysis. Hip-scores improved from preoperative mean 59(±12) to a final follow-up mean of 91(±12). One hip was revised for recurrent dislocation. No hips were revised for aseptic loosening. Mean acetabular abduction angle was 46°(±8.5) and anteversion was 18°(±8.7). Incomplete lucent lines were noted on early postoperative radiographs in 5% of the cases. With ongoing follow up radiolucent line thickness decreased by mean 13% and radiolucent line density increased by 11%. No cup had complete continuous radiolucent lines or lysis. Mean polyethylene linear and volumetric wear rates were 0.14(± 0.15) mm/year and 73(± 70) mm3/year respectively. Wear rates were higher in males (p<0.03). No other factor (age, body weight, cup abduction or anteversion angle) correlated significantly with wear rate. This study presents encouraging short-term results. The improvement in radiolucent lines suggests a beneficial effect of the HA-coat on bone ingrowth. None of the cups loosened or migrated. Wear rates were comparable to published reports of successful non-HA-coated cups. Long-term follow up is ongoing to corroborate these early findings.

Abstract: Alumina ceramic is an excellent material for biologic implantation. Decreased particulate wear debris should increase implant longevity. The purpose of this study is to examine clinical and radiological results of ceramic-on-ceramic hip implants compared to cobalt chrome on polyethylene. Four cementless systems were compared, three alumina-on-alumina bearing systems: System I, porous coated cup; System II, hydroxyapatite-coated cup; Trident system, hydroxyapatite-coated cup with metal sleeve backing on ceramic cup liner; and System III (control), porous-coated cup with polyethylene and cobalt chromium bearing system. Patients were randomized to receive System I, II, or III. Trident patients were not randomized. Examinations are performed at 6 months, 1 year and yearly thereafter including x-rays, clinical exam and Harris Hip Score (HHS). Minimum 24-month followup was performed in 562 ceramic hips and 154 control hips. Age, height, weight, gender and diagnosis were similar in all groups. HHS was rated good/excellent by 95 percent of ceramic hips and 97 percent of control hips. Radiographic results demonstrated radiolucency in Femoral Gruen Zone 1 in 3.8 percent (18/474) of ceramic hips and in 8 percent (10/128) of control hips. Unstable acetabular components were reported in none of ceramic hips and in 3.2 percent (5/154) of control hips. Revision was performed in 7 (1.2 percent) ceramic hips, none due to failure of ceramic materials, and in 9 (5.8 percent) control hips. Alumina ceramic materials show promise, but continued evaluation of long-term clinical results is needed.

Abstract: Polyethylene wears of 22.225 mm diameter alumina and zirconia femoral heads in cemented total hip arthroplasty (THA) were compared at mean follow-up of five years. Ninety-six primary cemented K-MAX THA in eighty-seven patients were observed, forty-six hips with alumina heads and fifty-one hips with zirconia heads. Both of the mean linear wear rate and the mean volumetric wear rate of the polyethylene against zirconia were significantly higher that those of alumina (p<0.01, p<0.01, respectively). The monoclinic phase content and roughness rose up on the surfaces of two retrieved zirconia heads from revision surgeries. This was supposed as the differences of thermal conductivity between alumina and zirconia, for which local temperature was higher in zirconia head, leading to the phase transformation and lower-temperature aging degeneration (LTAD) of zirconia head surface.