50 years ago, prosthetic replacement of the hip joint ushered in a new epoch in orthopaedics. Total hip replacement made it possible to remove a severely diseased, painful hip and restore normal function and a normal quality of life to the afflicted patient. The early results of total hip replacement are almost all spectacular and hip replacement has become the most successful type of orthopaedic surgery. These good results using an approach that was technically relatively simple resulted in a temptation to implant prosthetic hip joints with ever increasing frequency in ever younger patients. This led to the emergence of new problems, which were not so clearly recognised at the outset: it emerged that the stability of prosthetic hip joints was of limited duration. This had the following consequence: If a total hip prosthesis is implanted in an elderly person whose remaining life-expectancy is shorter than the longevity of the prosthesis, hip replacement is a life-long solution. We can therefore say that, for a patient who has only 10 to 15 years left to live, their hip problem is solved by total hip replacement. For young people, who still have a long life expectancy in front of them, it is different. They will experience failure of the artificial joint and require further surgery. The commonest and most important type of failure in total hip prostheses is aseptic loosening, which is associated with resorption of bone at the site of the prosthesis. The cause of this phenomenon has only gradually been recognised in the course of the years. Initially, the unanimous opinion was that the methacrylate cement, used to fix the components of the prosthesis in the bone, was the definitive cause of aseptic loosening because fissures and fractures of the cement were almost always found during surgical revision of loosened joints. There was talk of "cement disease" and great efforts were made to improve the quality of the cement and the cementing technique. Moreover, even today, there is no established answer to the question whether, over the course of many years, cement ages and becomes friable, a process that may have major implications for young patients. For this reason, ways of reliably fixing the prosthesis in the bone without methacrylate cement were also explored at the same time. Valuable pioneering work in this field was carried out with uncemented dental implants made of titanium and with a roughened surface. With these implants, the phenomenon of osseointegration, i.e. the deposition of bone directly on the roughened metal surface without any intervening connective tissue, was observed. This phenomenon has also been utilised successfully in hip prostheses: if artificial hips made of titanium alloy with a coarse-blasted surface and with a high primary mechanical stability are placed in the bone, osseointegration also occurs. In parallel with this development, Willert, from Göttingen, identified the most important cause of loosening of the prosthesis: he established that, when an artificial joint articulates, very fine particles of polyethylene are eroded from the prosthetic cup when the surfaces of the joint glide over one another and that these are only partially removed by the lymphatic system. A large proportion of the particles accumulates in the artificial joint and in the gap between the prosthesis and the bone, giving rise to foreign body granulomata, which resorb bone thus leading to loosening. The number of eroded particles is considerable. In 1998, Patricia Campbell, from Los Angeles, showed that 470,000 particles per step were produced from an articulation between a metal head and a polyethylene cup. This huge number gives an indication how small these particles are, since the linear erosion of the polyethylene surface only amounts to about 0.1 to 0.2 mm a year. This relatively recent recognition of "particle disease" has led to the investigation of other materials, which produce fewer erosion particles, for artificial joint articulations. Three possible options are available today, but it is not yet possible to decide for certain which of them is superior to the others: the longest experience has been with metal/metal articulation with articulatory pairings of cobalt/chromium/molybdenum alloy. In recent years, ceramic/ceramic articulations of aluminium oxide-ceramic and pairings of ceramic with highly crosslinked polyethylene have also been used. With these modern articulations, particle erosion can be reduced about 200 fold. If the erosion particles are an important cause of loosening of the prosthesis, it is reasonable to expect that, with these new joint pairings, the durability of an artificial joint can be substantially prolonged. The cone prosthesis described here has been developed on the basis of the knowledge and experience of the last 20 years. The conical anchoring of the stem, involving the placing of a conical implant in the conically reamed medullary cavity, results in continuous contact between the stem of the prosthesis and the bone, with a high degree of primary stability. The sharp longitudinal ribs on the stem, which cut a little into the bone, provide a high degree of rotational stability. In the case of conical fixation, the mechanical transmission of force varies with the diameter of the stem: the weight bearing surface of a cone in relation to its length is greater where the stem has a larger diameter than at the tip of the stem where the diameter is smaller. Therefore, for geometrical reasons, the conical fixation of the stem results in a transmission of force that is predominantly proximal and avoids proximal stress protection. The round cross-section permits free adjustment of the angle of anteversion and avoids any forced rotation as a result of bony deformity, which is very important in the case of dysplastic hips.
- MeSH
- cementování MeSH
- dospělí MeSH
- kyčelní protézy * MeSH
- lidé středního věku MeSH
- lidé MeSH
- mladiství MeSH
- náhrada kyčelního kloubu MeSH
- protézy - design MeSH
- selhání protézy MeSH
- senioři MeSH
- slitiny MeSH
- titan * MeSH
- Check Tag
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- mladiství MeSH
- mužské pohlaví MeSH
- senioři MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- slitiny MeSH
- Ti-6Al-7Nb alloy MeSH Prohlížeč
- titan * MeSH
- Klíčová slova
- HIP/fracture and dislocation *,
- MeSH
- dislokace kloubu * MeSH
- dítě MeSH
- fraktury kyčle * MeSH
- kojenec MeSH
- kyčel * MeSH
- lidé MeSH
- vývojová kyčelní dysplazie * MeSH
- Check Tag
- dítě MeSH
- kojenec MeSH
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- Klíčová slova
- HIP/abnormalities *,
- MeSH
- kyčel abnormality MeSH
- lidé MeSH
- vývojová kyčelní dysplazie * MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
Various surgical treatments for osteoarthritis (OA) secondary to hip dysplasia have been reported in the literature. According to the position of the arthroplasty cup, generally they could be divided into two groups: the primary rotational center (PRC) group and the high hip center (HHC) group. Some surgeons prefer the HHC technique. Without doubt it is less demanding, but several concerns exist against the long-term stability. When restoring the PRC, since the dysplastic acetabulum is usually shallower and underdeveloped, bone grafts or other biosynthetic materials are usually needed for the ideal fixation. The source of grafts is quite wide. For example, they could be autologous (femoral head, iliac crest) or homologous (allografts), bulky or morselized. Medial wall protrusion technique, as well as other materials like oblong cup, porous titanium and tantalum augments, 3D printed implants could also be an option. Except these, reports are also divided into cemented and cementless techniques. Therefore, no technique is perfect and clinical results so far are quite variable. We think it's necessary to compare the pros and cons between each other. Key words:hip dysplasia, total hip replacement, cup position, secondary osteoarthritis.
PURPOSE OF THE STUDY: In the development of cementless total hip arthroplasty wear, loosening as well as stress shielding are considered as major issues. New results in literature specify survivorship of THA over 97%. Consequently the implant loosening and wear especially can be considered as almost solved. Therefore, it is essential to use bone preserving primary implants that allow for a physiological load transfer and cause no or only slight stress shielding at the proximal femur. The MAYO conservative hip stem with a wedge design ensuring immediate primary fixation of the stem with metaphyseal load transfer. MATERIAL AND METHODS: A retrospective study was performed to review the first consecutive 316 MAYO conservative hip stems implanted at the Martin-Luther-University of Halle-Wittenberg (Germany). 85.4% (270 MAYO stems) were radiographic analysed and classified according to the HHS. RESULTS: The mean HHS improved from 44.79 preoperatively to 93.58 postoperatively. 1.85% (5 MAYO stems) had to be replaced because of aseptic loosening. Furthermore the DEXA scans revealed the metaphyseal load transfer with increased bone density in the calcar region. CONCLUSION: As especially younger patients will require one or more hip revision procedures during the course of their life due to their life due to their age and activity level. These patients should receive a primary implant with proximal load transfer. Only these implants can avoid stress shielding of the proximal femur. The minimally invasive implantation of these implants can also ensure an enhanced periprosthetic bone density an optimized postoperative rehabilitation phase.
- MeSH
- kyčelní kloub diagnostické zobrazování MeSH
- kyčelní protézy * MeSH
- lidé MeSH
- náhrada kyčelního kloubu * MeSH
- rentgendiagnostika MeSH
- selhání protézy MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- Klíčová slova
- HIP/abnormalities *, HIP/fracture and dislocation *,
- MeSH
- dítě MeSH
- fraktury kyčle * MeSH
- kojenec MeSH
- kyčel abnormality MeSH
- lidé MeSH
- vývojová kyčelní dysplazie * MeSH
- Check Tag
- dítě MeSH
- kojenec MeSH
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
PURPOSE OF THE STUDY The literature is conflicting as to whether the high hip center (HHC) reconstruction in total hip arthroplasty (THA) is an ideal option for patients with severe developmental dysplasia of the hip (DDH). This study aimed to compare the mid-term functional and radiographic outcomes of THA using HHC versus anatomical hip center (AHC) technique in Crowe types II and III DDH. Our hypothesis was that there may be no differences in terms of functional and radiographic outcomes between patients who underwent THA using HHC or AHC. MATERIAL AND METHODS Fifty-seven patients who underwent a primary THA due to Crowe type-II or type-III DDH were retrospectively reviewed and included. Patients were divided into two groups as per the hip center reconstruction: Group A (AHC technique) and group H (HHC technique). A cementless cup was inserted in 25 hips (19 female, 6 male; mean age = 51 years, age range = 28-67)) at near-AHC in group A and 32 hips (22 female, 10 male; mean age = 53 years, age range = 29-68) at HHC position in group H. To assess clinical status, the Harris Hip Score (HHS) was used at the final follow-up. In radiographical assessment, component loosening and osseointegration of the acetabular cup were examined on follow-up radiographs. Complications were also recorded. RESULTS The mean follow-up was 41 months (range, 25-84) in group A and 40 months (range, 24-86) in group H. The mean HHS was 83 (range, 74-91) in group A and 83.6 (range, 73-94) in group H (p = 0.741). Osteolysis was determined in three patients from each group. The other 51 cups demonstrated a minimum of one radiographic sign of osseointegration. Although the overall complication rate was higher in group A (64%) than in group H (46%), this difference reached no statistical significance (p = 0.11). CONCLUSIONS The HHC technique using cementless acetabular fixation seems to be a valuable alternative option to AHC technique in cases of Crowe types II and III DDH. Key words: High hip center; anatomical hip center; center of rotation; total hip arthroplasty; dysplastic hip; developmental dysplasia of the hip; Crowe type II; Crowe Type III.
- MeSH
- dospělí MeSH
- kyčelní protézy * MeSH
- lidé středního věku MeSH
- lidé MeSH
- náhrada kyčelního kloubu * metody MeSH
- následné studie MeSH
- retrospektivní studie MeSH
- senioři MeSH
- výsledek terapie MeSH
- vývojová dysplazie kyčelního kloubu * chirurgie MeSH
- vývojová kyčelní dysplazie * diagnostické zobrazování chirurgie MeSH
- Check Tag
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- mužské pohlaví MeSH
- senioři MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
