The use of monoblock tapered stems has shown very good results in hip revision surgery, particularly in case of severe proximal femur bone deficiency. However a too valgus neck, a short offset, may result in a high risk of dislocation. In addiction monoblock stems make the control of limb length difficult, and potentially increase the risk of subsidence or intraoperative fracture. Different types of modular tapered stems with distal fixation have been developed to allow a more user-friendly restoration of limb-lenght discrepancy and an indipendent proximal control of offset and anti-retroversion. We assessed 64 hip revisions performed on 63 patients (mean age 62 years). Indication for treatment was: aseptic loosening (42 cases) septic loosening (18 cases) and periprosthetic fracture (4 cases). According to Paprosky classification, femoral defects were staged as type I (2 cases), type II (20 cases), type IIIA (25 cases) and type IIIB (13 cases); periprosthetic fractures were all type B2 according to the Vancouver classification. In all cases we used a Restoration® Modular (Striker, Orthopaedics) cone-conical uncemented stem implanted by a lateral approach, with a trans-femoral osteotomy in 19 cases. A preventive cerclage cable was used in 10 patients in case of very thin cortex. We used the minimum size stem in most of the cases. Mean follow-up was 20 months (range 6–36). Short-term complications included hip dislocation (1 case), recurrent infection (1 case), stem subsidence > 5 mm (1 case). Mean Harris Hip Score improved from 43 to 81.9 (t test p< 0.0005), while limb lenght discrepancy improved in 97% of cases with symmetry in 76%. The use of modular revision stems is an effective alternative in hip revision surgery that ensures good primary stability, while modularity enables the implant to be tailored to the patient, allowing restoration of the limb length and correct muscular balancing

The surgeon’s dilemma when faced with bone loss during hip replacement surgery is to try and leave more bone than he finds and risk the complications of bone grafting or use more cement or a bigger prosthesis and postpone and complicate later reconstructions. It is however a fact that good cement or prosthesis build up is better than a bad allograft. Types of allograft include bulk allograft, small fragment allograft and demineralized bone matrix. The author had in recent years done more and more mixed allografts in combination with bone graft substitutes and the present favourite is calcium sulphate pellets. Slooff believes that fresh frozen small fragments are the best, but in South Africa allografts are gamma radiated and although fears existed that gamma radiation could be detrimental to the biological response 2.5MRad dose seems to eliminate risk of infection and keep its biological properties. One of the arguments against bulk allograft is the slow and superficial incorporation and the risk of late collapse. More recently immunological response as a factor in a late failure has come to the fore. Clinical experience of up to 22 year follow up with these various types of bone grafts is discussed and representative cases shown. Where morsellized bone is used in combination with a supporting ring of cages or pressfit cups it is important that 50% of host bone contact with the metal is achieved and allograft filling up the rest as the prosthesis or cage resting on an allograft can easily fail when compression of the allograft occurring during weight bearing. Femoral struct grafts are used, where the concave side is filled with the mixed allograft and makes excellent biological plates when femoral shaft defects or peri-prosthetic fractures are treated, and full incorporation takes place. In conclusion allografts are very useful in hip revision surgery provided certain principles are adhered to

Aim

Periprosthetic joint infection (PJI) is a devastating complication in revision total hip arthroplasty (THA). As preoperative diagnosis can be difficult, some patients who undergo planned aseptic revision surgery might have positive intraoperative cultures and later be classified as infected. In this retrospective study we analyzed the influence of intraoperative positive cultures and possible underlying risk factors in patients undergoing planned aseptic THA revision.

Long-term stability of total hip arthroplasty (THA) depends on the integration between osseous tissue and the biomaterial implant. Integrity of the osseous tissue requires the contribution of mesenchymal stem cells and their continuous differentiation into an osteoblastic phenotype. Some studies, like Wang ML et al., show that chronic exposure to titanium and zirconium oxide wear debris may contribute to decreased bone formation at the bone/implant interface by reducing the population of viable human mesenchymal stem cells (hMSCs) and compromising their differentiation into functional osteoblasts. On the basis of our good experience in the use of Exeter technique in revision surgery of THA, two years ago we started to utilize bone grafts mixed with growth factors in order to improve grafts incorporation and implant fixation. At the moment we are studying the use of hMSCs during hip revision surgery, employing polyethylene cup to reduce the possible titanium and zirconium oxide debris. hMSCs are obtained with MarrowsStim Concentration Kit (Biomet Biologics Europe) by 60 ml of patient’s bone marrow. Clinical outcomes and quality of life are evaluated on the basis of Harris Hip Score, Womac score and SF-36 score, while bone graft incorporation features are assessed with post operative computed tomography (CT) examination and further CT controls at two, four and eight months after surgery

Introduction. The Kaplan Meier estimator is widely used in orthopedics. In situations where another event prevents the occurrence of the event of interest, the Kaplan Meier estimator is not appropriate and a competing risks model has to be applied. We questioned how much bias is introduced by erroneous use of the Kaplan Meier estimator instead of a competing risks model in a hip revision surgery cohort. Methods. In our previously published cohort study, 62 acetabular revisions (58 patients) were performed between January 1979 and March 1986. Twenty to twenty-five years after surgery, no patients were lost to follow-up. Thirteen patients underwent revision surgery. During the 20 to 25 years follow-up, 30 patients (33 acetabular revisions) died of causes unrelated to their hip surgery. Results. In the data set analyzed, the Kaplan Meier method overestimates the probability of implant failure by 6.7%, 13.8%,26.8%,48.6% at 5, 10, 15 and 20 years respectively. Discussion. We have performed two different analyses for a hip revision surgery cohort and discussed the use of a competing risks model. Ignoring competing risks leads to biased estimations of the probability of having future revision surgery. Therefore we recommended the use of a competing risks model whenever there are competing risks present

INTRODUCTION

Trabecular Titanium is an open-cell regular structure composed by hexagonal cells of controlled pore, manufactured by Electron Beam Melting (EBM) technology, that allows moulding of cellular solid structures. The Lima Delta TT revision cups are One and Revision, which is characterized by a caudal hook and fins. Both allow internal modularity and cranial TT augments.

The aim of this prospective study is to evaluate the short to medium-term clinical and radiographic outcomes of acetabular revision cups in TT.

The constant increase in number of hip revisions during last years has lead to a consequent increase even in fracturative events of the femoral shaft. The treatment of these kind of fractures have to be considered like the one for « pathologic fractures », due to periprosthetic or pericemental osteolysis that occurs in prosthesis’ mobilization, reducing drastically the bone resistance.

We use to divide these fractures primarily in two groups:

Pathologic Fractures, occurring before revision surgery.

Surgical solutions are different, according to fracture’s level and severity. TYPE 1 Fracture limited to trochanteric region TYPE 2 Fracture not exceeding stem length TYPE 3 Fracture line from shaft to distal part of the stem TYPE 4 Fracture line completely under femoral stem TYPE 5 Plurifragmentary fracture

For 1st group, surgical solution is to stabilize trochanteric region with dynamic wiring. For 2nd group, plate with both screws and dynamic wires are indicated. The fractures of last three groups are successfully treated with cementless long stem prosthesese, eventually associated with plate. In summary, the modern techniques of revision surgery associated with systems of cement removal (ultra-sounds and re-cementing procedures) have permitted to decrease the number of periprosthetic fractures. We think that the use of last generation models of cementless modular stem for revision, associated with dynamometric wiring, always allows brilliantly solving this complex surgical problem.

Introduction and purpose: The ARC-2F cup used in this study is made of a rough titanium alloy with HA coating. It is a hemispherical cup fixed by means of a thread and screws. The study analyzes the cup’s long term clinical and radiological performance.

Materials and methods: 51 cups were studied in 49 patients. Mean follow-up was 9 years and 10 months (min. 7– max. 13). The patients’ mean age was 62.2 years, 27 were female and 22 were male. The preop diagnosis was: cup movement in 25 uncemented cups and 16 cemented ones; 8 cups with partial protrusions and 2 infections. 19.6% had segmentary bone defects, 37.3% had cavitary bone defects and 43.1% had a combination of the two, according to the AAOS classification. An autologous graft (either freeze-dried or of bank origin) was used in 72.5% of cases. Use was made of the Johnston et al. clinical and radiological protocol and of Merle D’Aubigne’s score.

Results: 76.5% of patients had no pain, 60.8% of results were excellent, 29.4% good, 7.8% fair and 2% poor. A total of 50 cups were osseointegrated; there had been two migrations in the first three months and 1 cup had moved, but no cups had to be re-revised. The number of radiolucent lines was maximal in the V zone (5.9%) – this includes the displaced cup. As regards complications, there were three dislocations and 5.9% of patients presented with pelvic osteolysis.

Conclusions: Use of the ARC-2F cup leads to excellent results in revision surgery since it is conducive to good primary fixation and a degree of osseointegration with is not lost in the long-term.

Introduction Recent publications have confirmed that as many as one in four retrieved femoral heads can be significantly contaminated with potential pathogens. Reports from the Centre for Disease Control in Atlanta, Georgia have described fatal outcomes from the unwanted transmission of bacterial disease with inadequately processed allograft materials. Surgeons requesting non terminally sterilised bone refer to theoretical biological and biomechanical deleterious effects of gamma irradiation. This study examines the accuracy of those claims.

Methods We have investigated the effects of varying levels of gamma irradiation (0kG, 15kG and 25kG) on the biological competence of morsellised allograft bone and its associated biomechanical impaction qualities. The biological study has used an in vivo model (nude rat) to quantify the effects of gamma irradiation on osteoinduction and osteoconduction. An in vitro impaction routine has been used to measure compaction, impaction and stiffness in the allograft product.

Results There were no statistical differences in the biomechanical or biological properties of the 0kG and 15kG specimens (P< 0.05). Gamma irradiation at the 25kG level resulted in an allograft product of higher biomechanical stiffness, unchanged osteoinductivity and slightly lower osteoconductivity (P< 0.05).

Conclusion Terminal gamma irradiation of 15kG reduces the risk of bacterial transmission with allograft products. It does not alter the efficacy of the allograft at biological and biomechanical levels. Gamma irradiation represents the mainstay of sterilisation of musculoskeletal allograft materials. Australian practices appear to be leading an international trend.

In relation to the conduct of this study, one or more the authors have received, or are likely to receive direct material benefits.

Acetabular revision in patients with bone deficiency is often difficult because of the poor quality and quantity of the acetabular bone stock. The purpose of this study was to evaluate the midterm clinical and radiographic outcomes of acetabular revision with use of an impaction bone-grafting technique and a cemented polyethylene cup.

Results: thirty consecutive acetabular revisions were performed with impaction bone-grafting and use of a cemented cup in twenty-eight patients with bone deficiency. The average age at the revision was sixty-eight years. The minimum duration of follow-up of all reconstructions that were still functioning or that were followed until the time of death was three years (mean, 8.1 years; range, three to fifteen years). The acetabular bone defects were classified as cavitary in fifteen hips and as combined segmental-cavitary in fifteen hips according to AAOS classification.

One hip had a repeat revision. Radiographic analysis that had not been revised showed loosening in four hips. All these four hips were treated by bulk bone graft covering more than 50% of cups. Kaplan-Meier analysis demonstrated a prosthetic survival rate, with aseptic loosening as the end point, of 72% at fourteen years and, with revision as the endpoint, of 100% at ten years and 83% at fourteen years.

Impaction bone-grafting was an excellent option to manage acetabular revision surgery. However, excessive bulk bonegraft should not be used.

Background:

Massive acetabular defects remain an unresolved challenge in revision arthroplasty surgery of the hip. We report on 7 patients treated with custom made acetabular components to manage these massive boney defects.

Between July 2000 and December 2002, 263 consecutive patients across 5 surgical centers underwent to a revision surgery of a failed acetabular component in which TM acetabular components were used.

There were 150 women and 113 men with a mean age of 69.5 years.

The indication for acetabular revision was aseptic loosening in 186 cases (70.7%)

Clinical evaluations were performed using the Harris hip score, the WOMAC and UCLA activity scale.

Implant and screw position, polyethylene wear, radiolucent lines, gaps, and osteolysis were assessed. Preoperatively, acetabular bone deficiency was categorized using the classification of Paprosky et al.

Statistical analysis was performed using nonparametric correlations. Standard life table was constructed, and the survival rate was calculated by means of Kaplan-Meier method.

The overall mean follow-up was 73.6 months (range, 60–84 months), and no patient was lost to follow-up.

The preoperative HHS rating improved from a mean of 43.6 ± 11.4 before revision, to a mean of 82.1 ± 10.7.

None of the patients was re-revised for loosening. The cumulative prosthesis survival was 99.2% at 5 years.

There was no correlation found between the various degrees of acetabular bony defect and the magnitude of clinical results (independent of pre-revision Paprosky grade). The use of component augments allowed us to minimize the volume of morsellized allograft used for defect repair.

TM acetabular component demonstrates promising midterm results similar to those reported by other authors.

Acetabular loosening is often dangerous because the patient is pain free for several years. The following bone loss may represent the biggest challenge in revision surgery.

Object of this study is to evaluate the use of an iliac stem cup (Link®) associated with impacted bone grafts in acetabular loosening and CDH.

We performed 25 implants in loosening (13 grade 2 and 12 grade 3 of Paprosky): average age was 68 years old in 16 female and 9 male. Mean follow up was 22 months.

We used bone grafts in 17 cases. In 1 case we cemented the Mcminn cup because of poor initial stability with no complication at 18 months.

We noted radiolucency lines < 2 mm. in 1 case and bone resorption in 2 cases. The complications were: malpositioning of the stem (1%), sacroiliac pain (4%), superficial infection (2%) and DVT (1%).

In conclusion, we can affirm that McMinn cup, despite a demanding surgical technique, represents a valid alternative to acetabular revision surgery because of the good initial stability, the respect of loading lines and besides it allows the use of pressurized bone chips.

Revision THA is guaranteed to throw some light on the question of longevity of implants. This study takes a fresh look at the materials that we have used in 30 years of joint replacement.

We studied four consecutive revision arthroplasties performed in one week. Patient 1 was a 55-year-old woman who in 1994 received a titanium-backed acetabular cup with virgin HDP insert and an alumina femoral head on a titanium stem. Polyethylene osteolysis was obvious and histological assessment confirmed the presence of polyethylene granulomata. Patient 2 was a 28-year-old man who had bilateral ceramic-on-ceramic hip replacements 18 and 19 years previously. The prosthesis on the left became loose and showed a typical alumina-ceramic problem. Patient 3 was a 51-year-old woman with stage-III polyethylene disease after 19 years. Substantial granulomata were seen on histological sections. Patient 4, a 52-year-old woman, had received a gamma cross-linked cup and stainless steel head 22 years previously. She presented with dislocation but no tribological problems. There was no wear and interfaces were perfect.

These four cases highlight the importance of proper selection of tribological materials. Polyethylene disease was an important cause of medium-term or late failure and acrylic debris was only a secondary problem. Literature reports on titanium metallosis seem over-rated, but titanium performance is questionable with cement. Finally, cross-linking of ultra-high molecular weight polyethylene is a simple, cheap and effective way of enhancing long-term performance in joint replacement surgery.

Acetabular loosening is often dangerous because the patient is pain free for several years. The subsequent bone loss may represent the greatest challenge in revision surgery. The extension of the bone loss may be small or wide, but it could also be associated with several defects. Usually, the most affected district is the dome, especially because the cup leans to migrate proximally. The object of this study is to evaluate the use of an iliac stem cup (Link®) associated with impacted bone grafts in acetabular loosening and congenital hip dysplasia (CDH).

The surgical technique requires a posterolateral approach, dedicated cannulated hardware tools to improve iliac stem positioning, intraoperative C-arm and bone grafts to enhance primary stability. We performed 21 implants in 18 cases of acetabular loosening (10 grade 2 and 8 grade 3 according to Paprosky) and three CDH: average age was 68 years old in 14 women and seven men. Mean follow-up was 21 months. We used bone grafts in 17 cases. In one case we cemented the McMinn cup because of poor initial stability with no complications at 18 months. We noted radiolucency lines < 2 mm in one case and bone resorption in two cases. Mean Harris Hip Score (HHS) was 60 preoperatively and 88 postoperatively. The complications were: malpositioning of the stem (1%), sacroiliac pain (4%), superficial infection (2%) and DVT (1%).

The primary cementless stability is achieved by the aid of an iliac palpator checked by fluoroscopy: the palpator works as a guide for the iliac stem to avoid malpositiong or wrong inclination. In addition, the dedicated cup trials could also function as an impactor for chips bone grafts in the so-called “impaction grafting technique”. In conclusion, we confirm that the McMinn cup, despite a demanding surgical technique, represents a valid alternative to acetabular revision surgery because of the good initial stability and the respect of loading lines and it also allows the use of pressurised bone chips. Furthermore, the hip centre is restored in acetabular loosening and CDH.

Introduction: The Arc2F is a cementless hemispheric threaded acetabular cup fabricated from titanium alloy (TI-6Al-4V) with a HA porous coating and dome holes for screws.

Materials and methods: We evaluated fifty one cups in forty nine patients under revision surgery. The average duration of follow-up was 9.8 years (range, 7–13 years). Mean age at time of revision surgery was 62.2 years (range, 41–76 years). 55.1% of the patients were women and 44.9% were men.

Preoperative diagnoses were: painful aseptic loosening in 41 cups (25 cementless and 16 cemented acetabular components), 8 acetabular protusio with unipolar hemiprosthesis and two cronic infections.

Acetabular bone deficiencies were classified as segmental in 19.6 %, cavitary in 37.3 % and combined in 43.1% according to the AAOS. Bone graft was used in 72.5 %.

Clinical and radiographic results were rated according to the Johnston et al and Merle D’Aubigne scores.

Results: The result was excellent in 60.8%, good in 29.4%, fair in 7.8%, and poor in 2%. At the time of the last follow-up, 76.5% were not painful.

The acetabular component was categorized as stable in 50 (98%), with two cases of migration in the first three months. Only one component was categorized as loose. No acetabular cup were removed or revised again.

Radiolucent lines were maximum in zone 5: 5.9% (Include the migrated component).

The most frequent complication was dislocation, which occurred in 3 hips (5.9%). Pelvic osteolysis was present in 5.9%.

Discussion: The Arc2F acetabular cup shows excellents results in revision surgery with a good primary fixation and long-term osseointegration.

This paper investigates the association between risk factors recorded prospectively before primary total hip arthroplasty (THA) and the risk for later revision surgery. The National Health Screening Service in Norway invited 56 818 people born between 1925 and 1942 to participate in an investigation of risk factors for cardiovascular disease and 92% participated. Matching these screening data with data from the Norwegian Arthroplasty Register about primary THA and revision THA, we identified 504 men and 834 women who had undergone primary THA at a mean age of 62 years. Of these, 75 and 94 were revised during follow-up. The mean age at screening was 49 years and the mean age at censoring was 68 years. The mean age of those who underwent revision THA was 57 years. Men had a 1.9 times higher risk of undergoing hip revision during follow-up (95% CI). For each year’s increase in age at primary THA, the risk of revision THA during follow-up decreased by 14% for men and 17% for women. Men who at screening had the highest level of physical leisure activities had 5.5 times the risk of later revision than those with the lowest level of physical activity (95% CI).

Men have a higher risk for revision THA. The older the patient, the lower the risk for revision. Men with intense physical activity in middle age are at increased risk of undergoing revision THA before they reach 70.

Aims: We wanted to investigate the association between risk factors recorded prospectively before primary hip replacement, and the risk for later revision hip surgery. Methods: During the years 1977–83 The National Health Screening Service in Norway conducted an investigation of risk factors for cardiovascular disease. 56,818 persons born 1925–42 were invited, and 92% participated. We matched these screening data with data from the Norwegian Arthroplasty Register concerning primary and revision hip arthroplasty. Results: We identified 504 men and 834 women who had received a primary total hip replacement after the screening. Of these 75 and 94 were revised during follow-up. Mean age at screening was 49 years; mean age at primary hip replacement was 62 years. Mean age at censoring was 68 years. Men vs women had a relative risk of 1.9 of undergoing hip revision during follow-up (95% CI 1.3–2.8). For each years increase in age at primary hip arthroplasty, the risk of revision surgery during follow-up decreased with 14% for men and 17% for women. Men who at screening had the highest level of physical activity during leisure had 5.5 times the risk of later revision, relative to those with the lowest level of physical activity (95% CI 1.0–31.9). Conclusions: Men have a higher risk for revision hip surgery. There is less risk of revision the older the patient is at primary hip arthroplasty. Men with intense physical activity at middle age are at increased risk of undergoing revision hip surgery before they are 70 years old.

Reasons for bone loss in septic hip prosthesis include osteolysis caused by the infection in itself and by the mechanical loosening, while implant removal and the necessary bone debridment usually ends in a even more severe bone loss.

In two stage revision surgery the use of a long stem antibiotic-loaded pre-formed cement spacer (Spacer G – Tecres s.r.l., Italy) appears particularly useful to allow mechanical stability and antibiotic local elution even in the presence of wide proximal femoral bone loss. After two months the revision is performed with non-cemented long stem modular implants (Profemur – Wright-Cremascoli) without the need for massive bone grafts. Recently we have also started using growth factors to stimulate bone stock reconstitution. In all the patients a double antibiotic therapy is administered after the first and second stage procedures for 6–8 weeks.

The results obtained (54 patients, follow-up 2 – 5 years) according to this protocol show the absence of infection recurrence, 10 cranial spacer dislocation, not treated, 2 revision prosthesis dislocations, that required open reduction, 1 transient femoral nerve palsy.

The described technique, used according to a proper protocol, allows to obtain good results, in the medium term follow-up.

Large studies have reported high dislocation rates (7 to 24%) following revision total hip arthroplasty (THA), particularly when the revision is undertaken in the presence of pre-existing instability. We retrospectively reviewed the clinical and radiographic outcome of 155 consecutive revision THA's that had been performed using an unconstrained dual-mobility acetabular implant. It features a mobile polyethylene liner articulating with both the prosthesis head and a metal acetabular cup, such that the liner acts as the femoral head in extreme positions. It can be implanted in either a press fit or cemented manner. Mean follow-up was 40 months (18–66) and average age 77 (42–89). Uncemented (n=122) and cemented (n=33) implants with a reinforcing cage, were used. Indications were aseptic loosening (n=113), recurrent instability (n=29), periprosthetic fracture (n=11) and sepsis (n=2). Three of the 155 cases (1.9%) dislocated within 6 weeks of surgery and were successfully managed with closed reduction. The 3 dislocations occurred in the groups revised for recurrent dislocation and periprosthetic fracture. There were no cases of recurrent dislocation and no revisions for implant failure. Despite a pantheon of options available, post-operative dislocation remains a challenge especially in patients with risk factors for instability. The use of large diameter heads is proven to improve stability but there are concerns regarding wear rates, metal toxicity and recurrent dislocation in the presence of abductor dysfunction. With constrained liners there are concerns regarding device failure and aseptic loosening due to implant overload. Our dislocation rates of 1.9% and survivorship to date compare favourably with alternative techniques and are also in line with studies from France using implants of a similar design. In our hands, where there are risk factors for dislocation, the use of a dual-mobility implant has been very effective at both restoring and maintaining stability in patients undergoing revision THA.