After a few years from its introduction, the limits of the THA became evident, mainly due to high rates of mobilization for polyethylene wear and to the release of metal ions from MOM and MOP couplings. Ceramic bearings were thus introduced in surgery to obtain lower levels of friction and wear. These issues have now been well recognized by several studies, which show that ceramic-on-ceramic joint has the lowest wear rate among various articulations and that ceramic particles induce less macrophage reaction and decrease cytokine secretion, allowing to have little periprosthetic osteolysis. After the first results in the late 70′s and early 80′s, the mechanical reliability was improved due to the manufacturers' efforts to reduce the ceramic fragility evolving average grain microstructure and lowering the degree of impurity. Betterment and standardization of production have led to 3rd generation alumina, Biolox Forte in 1994, that achieved a lower incidence of fracture. The purpose of our study has been to assess long-term follow-up results of alumina-on-alumina 3rd generation ceramic total hip cementless arthroplasty performed at our institution from January 1995 to December 2000. We prospectively followed more than 200 patients operated of THA for primary or secondary hip osteoarthritis analyzing clinical and radiographs features. In this period, the total hip replacement were performed by a single surgeon, who is the senior author (A.T.) in our Institution. All patients were clinically examined to confirm the diagnosis and all of them were checked with a standard plain radiographs in two projections and, when necessary, the radiographic examination was completed by CT scans. The same prosthesis was used in all patients, a 3rd generation alumina COC articulation, composed of a hemispherical titanium alloy cup and a 28-mm alumina ceramic femoral head. The modular ceramic head was fixed to a 12/14 taper cone. Proximally plasma-spray hydroxyapatite coated Ti alloy stems completes the implant features. Modular necks were used in retro or anteversion and varus or valgus offset, allowing changes in neck-shaft angle and giving a perfect intraoperative stability. Clinical assessment was performed using the Merle-D'Aubigne and Postel hip score. Each patient was assessed before surgery, after 30 days, afterwards at 4 months and annually after surgery. The mode of femoral component fixation was radiographically classified as bone ingrowth fixation, stable fibrous fixation or unstable fixation, according to the criteria Engh-Bobyn. Osteolysis was evaluated on the femoral side at each Gruen zone. Osteolysis on the acetabular side was evaluated by DeLee and Chanley zone. Our study has concluded that cementless modular hip arthroplasty with 3rd generation ceramic-on-ceramic bearing, with a 13 to 18 years follow-up, shows an excellent survivorship, in particular for the very low volume release of microparticles during friction, which consequently reduction of cytokine release, thus diminishing the risk of periprosthetic osteolysis and loosening of implant components.
The aim of this study was to evaluate blood metal ion levels, leucocyte profiles, and serum cytokines in patients with a total hip arthroplasty (THA) involving modular dual-mobility components. A total of 39 patients were recruited, with clinical follow-up of up to two years. Outcome was assessed using the Harris Hip Score (HHS, the 12-Item Short-Form Health Survey (SF-12), the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), and a visual analogue scale (VAS) for pain. Blood concentrations of cobalt (Co), chromium (Cr), and serum cytokines were measured. Subpopulations of leucocytes were analyzed by flow cytometry.Aims
Patients and Methods
A 70-year-old man with an uncemented metal-on-polyethylene
total hip prosthesis underwent revision arthroplasty 33 months later
because of pain, swelling and recurrent dislocation. There appeared
to be corrosion and metal release from the prosthetic head, resulting
in pseudotumour formation and severe local soft-tissue destruction.
The corrosion occurred at the junction between the titanium-molybdenum-zirconium-iron
taper and the cobalt-chrome-molybdenum head, but the mechanism was unproven.
We present a series of 35 patients (19 men and
16 women) with a mean age of 64 years (36.7 to 75.9), who underwent
total hip replacement using the ESKA dual-modular short stem with
metal on-polyethylene bearing surfaces. This implant has a modular
neck section in addition to the modular head. Of these patients,
three presented with increasing post-operative pain due to pseudotumour
formation that resulted from corrosion at the modular neck-stem
junction. These patients underwent further surgery and aseptic lymphocytic
vaculitis associated lesions were demonstrated on histological analysis. Retrieval analysis of two modular necks showed corrosion at the
neck-stem taper. Blood cobalt and chromium levels were measured
at a mean of nine months (3 to 28) following surgery. These were
compared with the levels in seven control patients (three men and
four women) with a mean age of 53.4 years (32.1 to 64.1), who had
an identical prosthesis and articulation but with a prosthesis that
had no modularity at neck-stem junction. The mean blood levels of
cobalt in the study group were raised at 50.75 nmol/l (5 to 145)
compared with 5.6 nmol/l (2 to 13) in control patients. Corrosion at neck-stem tapers has been identified as an important
source of metal ion release and pseudotumour formation requiring
revision surgery. Finite element modelling of the dual modular stem
demonstrated high stresses at the modular stem-neck junction. Dual
modular cobalt-chrome hip prostheses should be used with caution
due to these concerns.
Introduction. Dual modular hip prostheses were introduced to optimize the individual and intra-surgical adaptation of the implant design to the native anatomics und biomechanics of the hip. The downside of a modular implant design with an additional modular interface is the potential susceptibility to fretting, crevice corrosion and wear [1–2]. The purpose of this study was to characterize the metal ion release of a modular hip implant system with different modular junctions and material combinations in consideration of the corrosive physiological environment. Methods. One design of a dual
Introduction: The double threaded Cone Modular Hip Replacement System has been used in 114 patients as a primary prosthesis in over three years. No patient has been lost to follow up and all patients have been assessed postoperatively for the Harris Hip Score, Pain Score, Dexa analysis as well as plain X-rays. Method: 114 patients requiring primary hip replacement were entered into a prospective clinical trial over a three year period. The Harris Hip Score, Pain Score and Dexa analysis (Luna 2000 program) and X-rays were assessed at six weeks, three months, six months, twelve months, two years and three years and results were compared with the preoperative figures. Length of hospital stay, discharge details (home or rehabilitation unit) and physiotherapy assessment of time to independent stair climbing was prospectively assessed. Results: The Dexa analysis indicates a loss of bone at two years at Gruen’s zones one and seven of 25% and at zones two and six of approximately 20% with no increase or loss of bone in zones three, four and five. The Harris Hip Scores and Pain Scores show a significant improvement comparing preoperative with postoperative results in this series. One patient required revision of the femoral neck component for recurrent dislocation and three patients have significant rotational thigh pain due to varus implantation of the stem (the pilot has since been shortened and the diameter reduced by 1mm). Conclusion: The double threaded cone shaped
Introduction: while modularity that permits independent fitting of the diaphysis, metaphysis, length, offset, and version may greatly facilitate reconstruction and ultimate clinical performance, potential generation of metallic wear debris due to fretting at the modular interface is a concern. Materials and methods: serum titanium was analyzed using inductively coupled plasma sector field mass spectrometry. titanium levels were analyzed preoperatively and at 1-year follow-up in patients treated with the acumatch. ?. m-series prosthesis, which has a three-piece modular femoral stem and preopera-tively, at 1-year and 2-year follow-up in patients treated with the versys nonmodular femoral stem. Results: Pre-operative mean serum titanium levels were not significantly different in patients receiving the modular Acumatch (0.25 ppb) or the nonmodular Versys (0.21 ppb) femoral stems. Titanium level in the Acumatch group was significantly higher at 1 year (2.56 ppb; range: 0.65–5.62) than those obtained for the Versys group at 1 year (1.86 ppb: range: 1.08–2.65) or 2 year (1.46 ppb: range: 1.12–2.02) post-operatively (P<
0.05). Titanium levels were significantly increased at each follow-up in both the Acumatch and Versys groups when compared to pre-operative levels (P<
0.001). Discussion/ Conclusion: Serum titanium levels were significantly increased in patients treated with the highly
The June 2014 Hip &
Pelvis Roundup360 looks at: Modular femoral necks: early signs are not good; is corrosion to blame for modular neck failures; metal-on-metal is not quite a closed book; no excess failures in fixation of displaced femoral neck fractures; noise no problem in hip replacement; heterotopic ossification after hip arthroscopy: are NSAIDs the answer?; thrombotic and bleeding events surprisingly low in total joint replacement; and the elephant in the room: complications and surgical volume.