Massive hip prostheses ensheated by allografts

Summary Massive reconstuction prostheses have been widely used with excellent short- and mid-term functional results but follow-up shows that they often cause mechanical problems in young subjects related to the metallurgic failure of the prosthesis and defective muscle reattachment to its metal components. Allografts offer much more reliable functional results because of their ability to adapt at a new site and more immediately because they permit rapid muscular reattachment, even though some uncertainties remain as to the extent of revascularisation of the grafts and their incorporation into the skeleton. These techniques of cuffed prostheses are naturally mainly indicated in oncology for tumoral excision, but also in cases of reconstructive surgery of the upper end of the femur quite apart from any tumoral or traumatic lesion. These possibilities of bony reconstruction are clearly important since revisional prosthetic surgery is increasingly common, especially at the hip, where patients are often seen with major bone defects following multiple successive procedures. Reconstruction prostheses cuffed by bank bone add to the patient's bone stock and restore the initial surgical conditions. The use of such prostheses is the subject of many current studies, relating to study of the biology of bony allografts, the optimal shape of the prosthesis and the modes of its fixation within the bone.     

Replacement of prostheses of the hip

In view of the widespread insertion of total hip prostheses, in recent years loosening of such prostheses requiring operative revision has become increasingly frequent. Simultaneous bone resorption defects in the acetabulum and the femur pose a particular problem. Attrition of the polyethylene obviously plays an important part in this process, its effects becoming apparent after 15-20 years. When a total prosthesis is replaced every effort should be made to reproduce the normal anatomical situation as nearly as possible. In particular, the bone defects should not be filled up with massive implants or with bone cement, but should be reconstructed with bone transplants. Mechanical protection in the form of internal fixation is necessary for the larger bone transplants; if this is not provided they may not take properly. When there are defects in the acetabulum corticospongious bone chips taken from femoral heads are used in the vast majority of cases. For larger defects in the femur, large allogeneic transplants of cortical bone taken from cadavers and applied to the defects in the form of a cuff following sterilization with gamma irradiation have given very positive results in recent years.     

Reconstruction of the failed femoral component and proximal femoral bone loss in revision hip surgery

Advances in implant technology and surgical techniques have greatly improved the results of femoral stem revision in total hip arthroplasty. The 10-year results obtained with extensively coated noncemented revision stems parallel those obtained with cemented stems revised by using contemporary techniques. Proximal femoral bone loss is an important consideration when planning and performing revision arthroplasty. Proximal femoral bone defects can be managed with either metal or bone. Insignificant defects can be reconstructed by using primary hip arthroplasty techniques. Proximal femoral replacement prostheses are best restricted to sedentary elderly patients. Cortical strut grafts can be used reliably to reconstruct noncircumferential segmental defects. Calcar allografts are associated with unacceptably high rates of resorption. Proximal femoral allografts with either noncemented or cemented long-stem prostheses have the potential advantage of biologic soft-tissue attachment and restoration of bone stock. Impaction allografting with cement is indicated for cavitary defects and may also restore bone stock.     

Bone allografts in orthopedic surgery: current concepts

In the last decade, indications for bone allografting in orthopedic surgery have progressively increased, related to, on the one part, treatment of benign or malignant tumors, but, on another (major) part, to treatment of major bone defects due to loosening of hip or knee total prostheses. In France, legislation and control concerning donated human tissues, safety precautions, and the uses for human tissues have been greatly modified over the last few years. The authors describe the various obligations implicated by these activities and the consequences for tissue banks and surgeons; They describe different processes for bone inactivation and their action on allograft mechanical properties, or the biological capability for integration to the host bone. The authors then discuss different current techniques for bone stock reconstruction and the results in prosthetic or tumoral surgery, as well as their consequences on current surgical indications. In conclusion, they emphasize the optimal conditions for the success of allografts in orthopedic use: stability of the host bone-graft junction, vitality of the bone support, and a favourable mode of constraint of the graft, which have to be protected by osteosynthesis, but should not, however, miss partial bearing.     

Synthetic prostheses used in surgery to repair abdominal wall defects (excluding groin hernias). Characteristics, in situ behaviour and applications]

This study is an updating on synthetic prostheses used today to repair incisional hernias, eviscerations and abdominal wall defects due to a severe infection or a parietal excision of malignant tumours. The present prostheses are the fruits of the constantly developing plastic industry. Their characteristics and types (mesh or patch), together with the materials they are made of, are studied taking this development into account. The tissular reactions caused by prostheses are different depending on whether the material they are made of is an absorbable one or not. Published data on animal experimentation are largely used in this part of the study. A significant part is also allocated to the pathobiology of prostheses infection on which is based prevention of risk infection in the surgical practice. A synthetic prostheses has to be chosen depending on its characteristics and the tissular reactions it generates. In a septic environment, only absorbable prostheses can be used without risk. As for incisional hernias, which allows the authors to refer to their own expérience, the choice also depends on both the surgeon's own conception of the treatment and its purpose. The defect recovery after parietal excision of malignant tumours is eased by the use of a synthetic prostheses. In the future, synthetic prostheses will be even more used than today in the repair of abdominal wall. A present, the materials they are made of keep on being developed.     

Massive autoclaved allografts and autografts for limb salvage surgery A1-8 year follow-up of 23 patients

We performed 23 reconstructions with bone grafts autoclaved at 135 °C for 10 minutes for extensive bone defects after tumor resection. In 15 cases, the resected specimens were autoclaved and used as autografts. In 7 cases, allografts obtained from amputated extremities or cadavers were autoclaved and immediately stored at -80 °C prior to their use. A combination of the two was used in 1 case. The grafts were used in combination with prostheses or other forms of internal fixation. The mean follow-up was 49 (14-98) months. Incorporation of the host-graft junction was observed radiographically after a mean of 11 (6-17) months in all cases. No recurrence due to the autoclaved bone was observed. However, 10 patients suffered complications, including infection, bone resorption, fracture and loosening of the prosthesis. In terms of Mankin's evaluation of bone grafts, 12 patients were evaluated as good or excellent. We conclude that despite the complications, autoclaved autografts and allografts are viable options for reconstruction in many countries because of the difficulty of obtaining large quantities of fresh frozen allografts.     

Proximally porous-coated ingrowth prostheses: limits of use

Callaghan has suggested that the most important factor in obtaining optimal results after total hip arthroplasty may be the ability to determine when to use cemented or cementless fixation. This article has presented the indications and relative contraindications for use of proximally porous-coated prostheses. Midterm results suggest that with appropriate patient selection, excellent clinical results can be achieved with currently available proximally porous-coated prostheses. Use of proximally coated prostheses is indicated for primary total hip arthroplasty in patients aged >70 years with good bone stock. Relative contraindications are based on interference with bone ingrowth or with the ability to achieve a congruent fit, both of which preclude establishment of rigid initial stability. These conditions include metabolic bone disease such as osteoporosis, osteomalacia, Gaucher's disease, sickle cell disorders, and Paget's disease; significant anatomical distortion, as seen in developmental dysplasia of the hip with anteversion, prior osteotomy, or intertrochanteric fracture; Dorr type C bone; and current treatment with radiation, chemotherapy, indomethacin, or diphosphonates. The same relative contraindications to use are applicable in revision situations. Further, proximally porous-coated prostheses should not be used for revision arthroplasty in the setting of massive bone loss, limited life expectancy, or inability to participate in protected weight bearing. These devices may be used successfully in revision arthroplasty when the hip has minimal or moderate bone loss, and occasionally in the setting of severe bone loss. As further information is revealed through the long-term (10-20 years) results of proximally coated prostheses, further refinements and knowledge of the indications and contraindications for the use of these prostheses will be revealed.     

Knee prosthesis in 1990. Apropos of a 15 years' experience

Knee prostheses have been greatly refined over the past ten years. A range of prostheses with various designs are currently used. On the basis of their 15-year experience, the authors assess the role of the various prostheses. Among partial prostheses, the femoropatellar prosthesed have a restricted place and are reserved for isolate degenerative diseases of the femoropatellar joint without femorotibial involvement: 34 such prostheses have been used by the authors and the department of professor J.H. Aubriot in Caen. About 75% of the results are satisfactory, with a follow-up in time of more than 8 years in 6 of these cases. Single-compartment prostheses are used in degenerative disease on an angular deviation, condylar necrosis or post-traumatic lesions, as far as one compartment only is affected. The authors have inserted 115 "Lotus" uni-compartment prostheses at Saint-Louis hospital. 75.6% of these have very good or good results maintained in time, as 72% of the 32 prostheses still produce satisfactory results after 5 years or more. The greatest progress was made above all for total prostheses replacing all the compartments of the knee. Hinge prostheses now have only rare indications as first-intention prostheses due to the immediate vital risks and to the high percentage of suppuration and long-term loosening. Sliding prostheses have taken an increasingly dominant place. The authors used Insall's total condylar prostheses, which do not preserve the posterior cruciate ligament, until 1983. 45 prostheses were followed up for 1 to 10 years, showing 71% of very good or good results.(ABSTRACT TRUNCATED AT 250 WORDS)     

Fixation of Auricular Prostheses by Osseointegrated Implants

Placement of enosseous implants in the temporal bone may overcome the apparent disadvantages of skin adhesives and skinpockets for the fixation of auricular prostheses. The surgical procedure for placement of implants in the temporal bone and the results obtained in eight patients wearing implant-supported auricular prostheses are described. From the results of this study, it is obvious that osseointegrated implants have great advantages compared with skin adhesives and skinpockets to rehabilitate patients suffering from auricular defects. The major achievement of implant-supported auricular prostheses is the patients″ increased comfort and confidence wearing these types of prostheses.     

Some considerations on the use of heterologous prostheses in incisional hernias at risk of infection

Summary The authors report their experience in the use of heterologous prostheses in incisional hernias at risk of infection.45 out of 260 large incisional hernias (17.3%) were treated with nonabsorbable heterologous prostheses between January 1 1984 and January 1 1999. The literature shows a particular rigor in the treatment of incisional hernias, as in the French research by Chevrel and Flament [1990], where, in 1078 cases, the surgeons used autoplasty, relaxing techniques and, sometimes, absorbable prostheses, choosing to delay definitive treatment. The present authors deal with a series of cases treated with nonabsorbable prostheses. Even in incisional hernias at risk of infection, particularly with associated visceral surgery, the use of synthetic meshes has given encouraging results. The low incidence of suppurative complications, with neither removal of the patch nor recurrences in the short term, shows that this is a safe and definitive cure.     

Indications for cryopreserved allografts in tumoral pathology

Summary The use of preserved bone is not a recent technique and the first reported cases of fresh allografts date from the beginning of the 19th century; many authors have practised such procedures with results judged good in over 50% of the cases. However, bony reconstruction after surgical excision for tumors still raises certain problems, which are not entirely resolved. This is a study in relation to massive grafts used to replace diaphyseal fragments or articular surfaces. The use of prostheses ensheathed by bank bone is an intermediate solution combining firmness with articular stability and muscular reattachment to the periprosthetic bone. This technique should be used whenever the loss of bone substance renders revascularisation of the graft uncertain.     

Ceramic hip prostheses in young patients: a retrospective study of 74 patients

Zones of osteolysis occur in mobilized and in well-fixed prostheses with the classic ultrahigh molecular weight polyethylene-metal couple. However, since 1981 with the use of the ceramic couple in cemented hip prostheses in young patients, osteolysis has not been observed. The prostheses in patients with a longer followup do not show signs of wear in the bearing or signs of bone lysis in the well-fixed prostheses. Cementless prostheses with the same type of ceramic bearing have been used since 1990 in patients with more than 30 years of life expectancy, in an effort to eliminate loosening at the cement-bone interface. The cementless prostheses performed well with spot welds visible 3 months after the operation, which still are present at 7 years of followup. Lysis has not been observed behind the cup or around the stem. In the current series, head ruptures and accidents in the stem and neck junction produced by the modularity of the prostheses did not occur. The authors focus on the positive results shown by ceramic bearings and describe the results of 31 cemented, five hybrid, and 58 uncemented prostheses with ceramic bearings in patients younger than 50 years of age.     

Abdominal wall hernia surgery: prosthetic materials

Treatment of abdominal hernia has been revolutionised by using new prostheses. Reduction of tissue tension, elimination of wall defects and lowering of recurrences are the key aspects of the success of these devices. In Italy, prostheses are widely used. Marketing enquires show percentages of prosthesis use of over 80% for the treatment of primitive hernias and as much as 100% for recurrences. It is strongly recommended that randomised prospective studies be carried out in order to establish the advantages and disadvantages of the various techniques. Moreover, an international classification should be considered so that all surgeons can use the same language and compare their results.     

Custom made cranioplasty prostheses in porous hydroxy-apatite using 3D design techniques: 7 years experience in 25 patients

Summary Background. None of the materials currently used to reconstruct skull defects is fully satisfactory. Their biological and physical properties are very different to those of natural bone. Solid state, high porosity hydroxy-apatite (HA) seems to be a good support for bone regeneration within the prostheses, enabling integration of the heterologous material with low post-implant infective risk. Materials and methods. A model of the cranium of each patient was made in epoxy resin by stereolithography. The prosthesis was built on this model using a ceramic sintering process. In each case, an exact copy of the missing bone flap was obtained (curvature, dimensions, margins, irregularities and thickness). The porosity obtained is the same as that of the spongy bone of the skull with interconnected macropores (>150 μm) to promote osteoblast migration into the prosthetic core. In The Neurosurgery Division of Cesena, 26 cranioplasty prostheses have been implanted with this technique in 7 years (from 1998 to 2004). No particular criteria were pre-established, but the main indications for use of ceramic prostheses were complex and/or extended (surface >25 cm²) post-surgery craniolacuna and/or previous unsuccessful procedures due to rejection, infection or bone flap reabsorption. Results. Twenty-five patients were included in this study. A clinical check-up and 3D CT (mean follow-up 30 months, range 12–79) always showed an excellent aesthetic result. No cases of infection, rejection or spontaneous prosthesis fragmentation were found. The surgical procedure was simpler and shorter than for other described procedures. Conclusions. Bioceramic porous hydroxy-apatite prosthesis have been demonstrated as a valid alternative to traditional cranioplasty techniques both aesthetically and in terms of absence of infections/rejections. Principal limitations for the use of HA prostheses are the need for stereolithography process, the poor malleability of the material and the high cost.     

Early results after four years experience with the S.T.A.R. uncemented total ankle prosthesis

The first ankle prostheses appeared in 1973 as an alternative to ankle arthrodesis, which was until then the only valid solution for a painful degenerative, rheumatoid or posttraumatic ankle. Several designs followed, all with disappointing results. Low-constraint prostheses are now being used, with literature studies of 5 years follow-up. In this study, the authors have evaluated the results of 26 uncemented, hydroxyapatite-coated STAR prostheses, all implanted between January 1996 and December 1999, with an average follow-up of 15.8 months (range: 1.5 to 48 months). For evaluation, all patients filled out a questionnaire at three different moments in time, and all of them were clinically reviewed by one single observer. The Kofoed ankle score was used for clinical evaluation. All ankle prostheses were also radiographically reviewed, using a radiographic scoring system developed by the authors. Evaluation with the Kofoed ankle score showed 74% favourable results. When patients were asked to rate their satisfaction on a scale between 0 and 100, an average improvement of 50/100 was reached. Pain was the most important indication to surgery and is the only parameter that can be predictably influenced. The effects on motion and walking distance are less predictable. No major complications occurred and there were no revision operations. Should prosthetic failure occur, an arthrodesis can still be performed, as bone resection in the primary procedure has been minimal.     

Modular revision systems in total knee arthroplasty. Possibilities and techniques

This paper deals with surgical techniques in revision total knee arthroplasty. The principles of exploring the knee joint, removing the implant, and implanting modular revision systems using a three-step technique are described. The opportunities of modern revision systems for reconstruction of bone defects and ligament instabilities are demonstrated. By means of modularity, the implant can be adapted to individual specifications for bone quality, bone defects, and soft tissue conditions. Modular stems allow an additional diaphyseal load transfer. Uncontained bone defects are reconstructed by metal wedges and blocks. By using the range from cruciate-retaining to condylar-constrained systems, the different degrees of instability can be substituted with the least constrained prosthesis. Totally constrained hinge knee prostheses should be used only in extreme cases such as complete loss of collateral ligaments or inability to correct flexion-extension gap mismatches. The results with modular revision systems described in the literature are reviewed.     

Total knee arthroplasty for neuropathic (Charcot) joints

The clinical and radiographic results of 40 modern design condylar total knee arthroplasties (TKAs) in 29 patients with a confirmed diagnosis of Charcot joint were reviewed. The followup averaged 7.9 years (range, 2-15 years) for clinical and 6.4 years (range, 2-15) for radiographic surveillance. There was a significant improvement in Knee Society pain and function scores and ROM after knee arthroplasty. Extensive bone fragmentation and bone defect was present in 38 knees (95%). Metal wedge augments (10 knees, eight patient), autologous bone grafting (17 knees, 13 patients), and bone allografts (two knees, two patients) were used to reinforce the bony defects. Ligamentous instability necessitated the use of long stem components in 27 knees and rotating hinge prostheses in five knees. There were six reoperations for periprosthetic fracture (two knees, two patients), aseptic loosening (two knees, two patients), instability (one knee, one patient), and deep infection (one knee, one patient). Total knee arthroplasty may be offered to a select group of patients with end-stage neuropathic arthropathy. The basic principles of knee arthroplasty in restoring limb alignment, reinforcing bony defects by bone grafting or augmented prostheses, careful ligamentous balancing, and appropriate selection of constrained prostheses particularly are important in these patients. The technical challenges encountered during TKA in patients with neuropathic arthropathy, particularly in those with significant deformities, can require skills, implant systems, and methods usually reserved for complex revision arthroplasty.     

Proposal for a new classification of prostheses used in the repair of abdominal wall hernial defects

Research and development in new biomaterials is currently increasing. The greater use of prostheses for the repair of abdominal wall defects has meant that new designs incorporating novel materials are constantly emerging. Today's surgeon needs to be aware of these novel designs and become familiar with their use. In the present article, we classify the prostheses currently available on the market for the repair of abdominal wall defects, mostly hernias. The new classification scheme we propose takes into account the type of prosthesis, its components, and its ideal site of placement in the abdominal wall.     

Therapy of osteonecrosis. Basic principles and decision aids

The treatment of osteonecrosis of the femoral head involves a continuum based on a radiographic spectrum of disease. Core decompression or pharmacological agents can be utilized for the earliest small or medium-sized pre-collapsed lesions. For these types of lesions, osteotomy has been tried by various authors with moderate success. For small or medium lesions that are post-collapse, various bone grafting procedures have been used. This approach should be tempered with a look at the articular cartilage if this is damaged or the lesion is large. Limited femoral resurfacing can be used for hips that do not have acetabular involvement. If there is acetabular involvement, total hip replacement remains the treatment of choice. There are present innovations in total hip arthroplasty that hopefully will lead to increased longevity of these prostheses with newer polyethylenes as well as the use of ceramic and other types of interfaces. Another possible advance for this disease would be the use of metal on metal standard prostheses, as well as metal on metal resurfacing arthroplasties. In terms of a salvage of the femoral head, all of the different procedures--core decompression, osteotomy, bone grafting--can be enhanced by new advances in the development of the utilization of bioactive factors. These range from osteoinductive agents such as cytokines, angiogenic stimulating factors, and bone morphogenetic proteins. In addition, osteoconductive substances may be helpful and can be combined with osteoinductive substances. These bioactive factors are described in detail in another chapter of this issue. With the ushering in of the millennium, there is hope for better results with this disease.