Introduction. Reinforcement ring with allograft bone is commonly used for acetabular reconstruction of bone defects because it can achieve stable initial fixation of the prosthesis. It is not clear whether the allograft bone can function as a viable host bone and provide long-standing structural support. The purpose of this study was to assess to long-term survival of the reinforcement rings and allograft bone incorporation after acetabular revisions. Methods. We retrospectively reviewed 39 hips (37 patients) who underwent reconstruction of the acetabulum with a Ganz reinforcement ring and allograft bone in revision total hip arthroplasty. There were 18 females and 19 males with a mean age of 55.9 years (35–74 years). The minimum postoperative follow-up period was 10 years (10∼17 years). We assessed the acetabular bone defect using the Paprosky's classification. We determined the rates of loosening of the acetabular reconstructions, time to aseptic loosening, integration of the allograft bone, resorption of the allograft bone, and survival rate. Aseptic loosening of the acetabular component was defined as a change in the cup migration of more than 5 mm or a change in the inclination angle of more than 5° or breakage of the acetabular component at the time of the follow-up. Graft integration was defined as trabecular remodelling crossing the graft-host interface. Resorption of the allograft bone was classified as minor (<1/3), moderate (1/3–1/2) or severe (>1/2). Kaplan-Meier survivorship analysis was performed for aseptic loosening of the acetabular component. The results. The acetabular bone defects were classified as follows: 8 type II hips (4 type IIB, 4 type IIC), and 31 type III hips (17 type IIIA, 14 type IIIB). Fourteen (35.9%) of 39 hips was defined as aseptic loosening of an acetabular component. Loosening was more frequent in type IIIB (57.1%) than in type IIIA hips (29.4%). Mean time to aseptic loosening of the acetabular reconstructions was 6.3 years in type IIIA and from 5 years in type IIIB defects, respectively. Allograft bone incorporation was satisfactory in 66.7% of hips. There was minor bone resorption in 14.3% and moderate bone resorption in 10.2%. In 9 hips (23.1%), severe resorption of the allograft bone was observed and early component loosening was observed in these cases. The survival rate of acetabular component at 10 years of follow-up was 63.6% (95% confidence interval, 49–77%) with aseptic loosening as endpoints. Conclusions. The long-term survival rate of acetabular revision using the reinforcement ring and allograft bone in the reconstruction of severe acetabular bone defects was unsatisfactorily low due to loosening of acetabular components. Because of unfavorable graft incorporation into a host bone, an alternative component and structural support may be employed in the reconstruction of severe acetabular bone defects

Introduction. To report the short to medium term results of acetabular reconstruction using reinforcement/reconstruction ring, morcellised femoral head allograft and cemented metal on metal cup. Methods. Single centre retrospective study of 6 consecutive patients who underwent acetabular reconstruction for revision hip surgery. The acetabulum was reconstructed using morcellised femoral head allograft and reinforcement or reconstruction ring fixed with screws. The Birmingham cup – designed for cementless fixation, was cemented into the ring in all cases. The uncemented Echelon stem with metal on metal modular head was used for reconstructing the femur. Data from our previous in-vitro study had shown good pull out strength of a cemented Birmingham cup. Results. There were 2 men and 4 women with a mean age of 75 years(57-83). Revision was performed for aseptic loosening in 2, septic loosening in 2 and peri-prosthetic fracture with loosening in 2 patients. All patients were reviewed clinically and radiographically at a mean of 36 months follow-up(range 24 - 42 months). Revision was not necessary in any patient for failure of acetabular or femoral fixation. However, 1 patient had revision to a proximal femoral replacement and constrained cup for recurrent infection and osteomyelitis at 24 months. This patient was excluded from the final analysis. The mean Harris hip score at last follow up was 79(range 70-89). Radiographic analysis revealed good graft incorporation and no signs of loosening or cup/ring migration. No dislocations or metal ion problems were recorded in this series. Conclusions. To the best our knowledge, this is the first series using cemented metal on metal cups within a reinforcement/reconstruction ring for revision hip arthroplasty. Excellent cemented fixation of the cup, manufactured for cementless fixation, was obtained at surgery with no evidence of loosening, and no dislocations at minimum 24 months follow up

Total hip arthroplasty for developmental dysplasia of the hip (DDH) remains a difficult and challenging problem. How to reconstruct acetabular deficiencies has become increasingly important. One of the major causes inducing loosening of acetabular reinforcement ring with hook (Ganz ring) is insufficient initial stability. In this study, three-dimensional finite element models of the pelvis with different degrees of bone defect and acetabular components were developed to investigate the effects of the number of screws, screw insert position (Fig. 1), and bone graf quality on the initial stability under the peak load during normal walking. The size of pelvic bone defect, the number of screws and the position of screws were varied, according to clinical experience, to assess the change of initial stability of the Ganz ring. The Ganz ring was placed in the true acetabulum and the acetabular cup was cemented into the Ganz ring with 45 degrees abduction and 15 degrees of screws. The Insert position, nodes on the sacroiliac joint and the pubic symphysis were fixed in all degrees of freedom as the boundary condition. The peak load during normal walking condition was applied to the center of the femoral head (Fig. 2). According to the Crowe classification, as the degree of acetabular dysplasia was increased, the relative micromotion between the Ganz ring and pelvis was also increased. The peak micromotion increased as the stiffness of bone graft decreased. Increasing the numbers of screws, the relative micromotion tended to be reduced and varied the screw insertion position that affects the relative micromotion in the Ganz ring-pelvic interface (Fig. 3). This study showed that increasing the number of inserted screws can reduce the relative micromotion. Both the insert position and graft bone property affect the stability of the Ganz ring while the insert position has a greater impact. The current study is designed to lay the foundation for a biomechanical rationale that will support the choice of treatment

Instability and aseptic loosening are the two main complications after revision total hip arthroplasty (rTHA). Dual-mobility (DM) cups were shown to counteract implant instability during rTHA. To our knowledge, no study evaluated the 10-year outcomes of rTHA using DM cups, cemented into a metal reinforcement ring, in cases of severe acetabular bone loss. We hypothesized that using a DM cup cemented into a metal ring is a reliable technique for rTHA at 10 years, with few revisions for acetabular loosening and/or instability. This is a retrospective study of 77 rTHA cases with severe acetabular bone loss (Paprosky ≥ 2C) treated exclusively with a DM cup (NOVAE STICK; SERF, DÉCINES-CHARPIEU, FRANCE) cemented into a cage (Kerboull cross, Burch-Schneider, or ARM rings). Clinical scores and radiological assessments were performed preoperatively and at the last follow-up. The main endpoints were revision surgery for aseptic loosening or recurring dislocation. With a mean follow-up of 10.7 years [2.1-16.2], 3 patients were reoperated because of aseptic acetabular loosening (3.9%) at 9.6 years [7-12]. Seven patients (9.45%) dislocated their hip implant, only 1 suffered from chronic instability (1.3%). Cup survivorship was 96.1% at 10 years. No sign of progressive radiolucent lines were found and bone graft integration was satisfactory for 91% of the patients. The use of a DM cup cemented into a metal ring during rTHA with complex acetabular bone loss was associated with low revision rates for either acetabular loosening or chronic instability at 10 years. That's why we also recommend DM cup for all high risk of dislocation situations

Background. There are many difficulties during performing total hip replacement in high riding DDH. These difficulties include:. In Acetabular part: bony defect in antero lateral acetabular wall/finding true centre of rotation/shallowness of true acetabulum/hypertrophied and thick capsular obstacle between true and false acetabulum. In Femoral part: small diameter femoral shaft/excessive ante version/posterior placement of greater trochanter. anatomic changes in soft tissue & neurovascular around the hip including: adductor muscle contracture/shortening of abductor muscles/risk of sciatic nerve injury following lengthening of the limb after reduction in true acetabulum/vascular injury. The purpose of this lecture is how to manage above problems with using reinforcement ring (ARR) for reconstruction of true acetabulum and step cut L fashion proximal femoral neck shortening osteotomy in a single stage operation. Method. 23 surgeries in 19 patients, including 18 female and one male were performed by me from Jan. 1997 till Dec. 2009. Six patients had bilateral hip dislocation, but till now only four of them had bilateral stepped operation. Left hip was involved in 15 cases (65.2%). The average age was 40 years old. All hips were high riding DDH according to both hartofillokides and crowe classification. Reconstruction of true acetabulum was performed with aid of reinforcement ring and bone graft from femoral head in all cases. Trochantric osteotomy was done in all, followed by fixation with wire in 22 cases which needed two revisions due to symptomatic non union (9%). Hooked plate was use in one case for trochantric fixation. Due to high riding femur, it was necessary to performed femoral shortening in neck area as a step cut L fashion. In two patient, one with bilateral involvement, after excessive limb lengthening following trial reduction, it was necessary to performed concomitant supracondylar femoral shortening. (3 cases = 13%). 22 mm cup & miniature muller DDH stem were used in 18 cases (78.26%). In 5 cases, one bilaterally, non cemented stem and 28 mm cemented cup in ring were used. Primary adductor tenotomy was performed in 9 cases. Secondary adductor tenotomy needed in 2 cases (totally = 47.82%). Repair of iatrogenic femoral artery tear after traction injury with retractor, occurred in 2 cases (8.69%). All patients evaluate retrospectively. Average follow up month is 68.7. Results. One case of left acetabular component revision due to painful bony absorption in infero medial part of ring with poor inclination wad done, after 2 years of primary operation. Know after 13 years she has had early signs of stem loosening in the same side. Another acetabular component revision following traumatic dislodgment of cup and cement from ring was performed after 13 months from primary operation. Again she had poor implant inclination. So revision rate is 8.69%. (One case will need revision in near future, so the revision rate will increase to 13%) Radiological wires breakage which were used for greater trochanteric fixation, could be seen in 11 cases (47.82%), but only two of them with functional impairment needed to re-fixation with Menen plate(18.18% of trochanteric non union). Average limb lengthening after operation is 4.3 Cm (2-7 Cm). Only one case of transient Sciatic nerve paresis had happened for 2 months followed by complete recovery. Two case of secondary adductor tenotomy wre done, one after traumatic dislocation of prosthesis with pubic fracture, and the other one after restriction of hip abduction. The average Harris hip score from 23 pre -operatively has been increase to 85.38. (The pre op. scores were 12.625 – 40.775/The post op. scores were 64.92 – 96). No post operative infection was seen. Discussion. This is a midterm follow up survey, but 7 cases have more than 9 years follow up with only one stem loosening (11% long term loosening rate). It is a challenging procedure for performing joint replacement in high riding DDH, if so using reinforcement ring with graft for true acetabulum reconstruction and getting primary proximal femoral shortening in a step cut L fashion around the lesser trochanteric region would be a worthy procedure. In high riding DDH due to hypoplasia of lesser trochanter, there is not a significant difference in bone resistance and it is possible to get shortening in this area without fearing of deco promising bony stability. The average shortening is 3 Cm. In specific cases with more severe contracture for preventing neuro-vascular complication, concomitant shortening osteotomy in supracondylar area is recommended. Although greater trochanter fibrous union has produced less functional impairment, but a better technique should be considered. Distal and lateral advancement of osteotomised greater trochanter lead to better abductor muscle performance and less limp. Adductor tenotmy has a great importance in contracted soft tissue, so in any case with abduction limitation it should be performed

Protrusio acetabuli can be either primary or secondary. Primary or idiopathic protrusio is a rare condition of unknown etiology. Secondary protrusio may be associated with rheumatoid arthritis, ankylosing spondylitis, osteoarthritis, osteomalacia, trauma and Paget's disease. Challenges in surgery include: lack of bone stock, deficient medial support to the cup, difficulty in dislocating the femoral head, and medialization of the hip joint center. Several surgical techniques have been described: use of cement alone without bone graft; morselised impacted autograft or allograft with a cemented cup; metal cages, reinforcement rings, and solid grafts. We describe our technique of impaction grafting using autologous bone and a cementless porous-coated hemispherical cup without the use of acetabular rings or cages in patients with an average age of 46 years. Protrusion was graded depending on distance of medial wall from Kohler's line as mild (1–5 mm medial), moderate (6–15 mm medial) and severe if it was more than 15 mm medial to the Kohler's line. All patients were operated in the lateral position using a modified Hardinge's anterolateral approach. Adductor tenotomy may be required in cases of severely stiff hips. After careful dislocation of the femoral head, it was sectioned in situ into slivers to facilitate obtaining the graft. The periphery was reamed and care was taken to preserve the membrane lining the floor of the defect. Morselised graft was impacted with hemispherical impactors and the trial cup 1–2 mm larger than the last reamer placed in the desired position. The final socket was then inserted. Femoral preparation was performed in routine fashion. The mean pre-operative Harris Hip Score of 52 improved to 85 points at a mean follow up of 4 years. The average acetabular inclination angle was 42 degrees. Our results have shown incorporation of the graft in all cases. There was no evidence of progression of the protrusio or cup loosening in any of the cases. Thus far, our hips have not shown osteolytic lesions. The technique described is a satisfactory biological solution of restoring bone stock particularly in young and middle-aged patients

The orthopaedic surgeon is often consulted to manage pathologic fractures due to metastatic disease, even though he or she may not be an orthopaedic oncologist. A good understanding of the principles of management of metastatic disease is therefore important. The skeleton remains a common site for metastasis, and certain cancers have a predilection for bone, namely, tumors of the breast, prostate, lung, thyroid, and kidney. Myeloma and lymphoma also often involve bone. The proximal femur and pelvis are most commonly affected, so we will focus on those anatomic sites. The patient may present with pain and impending fracture, or with actual fracture. Careful preoperative medical optimization is recommended. If the lesion is solitary, or the primary is unknown, the diagnosis must be made by a full workup and biopsy before definitive treatment is planned. For patients with known metastasis (the most common situation), the options for treatment of pathologic lesions of the proximal femur generally center on internal fixation versus prosthetic replacement. Patients with breast or prostate metastasis can live for several years after pathologic fracture, so constructs must be relatively durable. If fixation is chosen, it must be stable enough to allow full weight bearing, since the overwhelming majority of pathologic fractures will never heal. In general, long constructs are chosen to protect the entire length of the bone. Nails should protect the femoral neck as well, so cephalomedullary devices are typically chosen. Megaprostheses can be useful in situations where bony destruction precludes stable internal fixation. Postoperative radiation is recommended after wound healing. Acetabular involvement typically requires reinforcement rings or cement augmentation with the Harrington technique. Careful multi-disciplinary medical management is recommended to minimise complications

Protrusio acetabuli can be either primary or secondary. Primary or idiopathic protrusio is a rare condition of unknown etiology. Secondary protrusio may be associated with rheumatoid arthritis, ankylosing spondylitis, osteoarthritis, osteomalacia, trauma and Paget's disease. Challenges in surgery include lack of bone stock, deficient medial support to the cup, difficulty in dislocating the femoral head, and medialisation of the hip joint center. Several surgical techniques have been described: use of cement alone without bone graft; morsellised impacted autograft or allograft with a cemented cup; metal cages, reinforcement rings, and solid grafts. We describe our technique of impaction grafting using autologous bone and a cementless porous-coated hemispherical cup without the use of acetabular rings or cages in patients with an average age of 46 years. Protrusion was graded depending on distance of medial wall from Kohler's line as mild (1–5mm medial), moderate (6–15mm medial) and severe if it was more than 15mm medial to the Kohler's line. All patients were operated in the lateral position using a modified Hardinge's anterolateral approach. Adductor tenotomy may be required in cases of severely stiff hips. After careful dislocation of the femoral head, it was sectioned in situ into slivers to facilitate obtaining the graft. The periphery was reamed and care was taken to preserve the membrane lining the floor of the defect. Morsellised graft was impacted with hemispherical impactors and the trial cup 1–2mm larger than the last reamer placed in the desired position. The final socket was then inserted. Femoral preparation was performed in routine fashion. The mean preoperative Harris hip score of 52 improved to 85 points at a mean follow up of 4 years. The average acetabular inclination angle was 42 degrees. Our results have shown incorporation of the graft in all cases. There was no evidence of progression of the protrusio or cup loosening in any of the cases. Thus far, our hips have not shown osteolytic lesions. The technique described is a satisfactory biological solution of restoring bone stock particularly in young and middle-aged patients

Acetabular protrusio occurs from migration of the femoral head medial to Kohler's line. This occurs in inflammatory arthritis, osteoarthritis with coxa vara deformities, previous acetabular fracture, and in metabolic bone diseases such as osteomalacia, Paget's disease, Marfan's syndrome, and osteogenesis imperfecta. Total hip replacement in this situation is difficult due to the requirement to place the acetabular component opening at the level of the normal rim or the patient will be at risk for component-on-component or bone-on-bone impingement, resulting in dislocation or component loosening. The deficient medial wall doesn't resist cup subsidence and the deficient peripheral rim may provide poor initial cup stability. Many management options have been described including using cement, bulk bone graft, and particulate graft to support the cup medially, and use of a reinforcement ring cage to provide better rim support. Gates reported on a series of 36 primary total hip replacements with acetabular protrusio treated with cemented cups and medial particulate autograft with a mean follow-up of 12.8 years with 6 definitively loose, 3 probably loose, and 22 possibly loose. The technique that provides initial porous cup stability and potential for long-term biological fixation is preferred. Mullaji and Shetty reported 90% good and excellent results and no loosening or migration at a mean 4.2 years in 30 primary total hips with acetabular protrusio treated with oversized porous cups for rim support and medial particulate bone grafting. Forty percent of their cases had protrusio greater than 15 mm medial to Kohler's line. Hansen and Ries also reported no revisions using this same technique in 19 revision total hips with an average follow-up of 2.8 years. However, they emphasised that this technique should only be used if the peripheral rim is intact, and if inadequate, to use a reconstruction cage. In revision total hips with large medial acetabular defects this is more likely to be the case. However, use of a reconstruction cage doesn't provide biological fixation. Ilyas reported a 15.1% loosening rate using cages for revisions with medial defects at a follow-up of 6 years. I have alternatively used a porous protrusio shell when rim support is poor and the medial defect is greater than 10 mm. The technique is to perform a cylindrical peripheral ream and a medial hemispherical ream. This provides greater host bone to shell contact for stability and greater biological fixation, and fills much of the medial defect. I used this technique in 43 cases with an average follow-up of 3.7 years. There were no revisions, no apparent cup migrations, and no progressive component bone radiolucencies. For primary total hips with protrusio, when good rim support can be achieved with a few millimeters of peripheral over-ream, a standard porous cup and medial particulate autografting is preferred. However, in many primary cases with greater than 10 mm of protrusio, the peripheral rim may be significantly stress shielded and thus, may have poor rim support unless the rim is significantly over-reamed. Because of my excellent results using protrusio shells in revision cases, I will consider also using a protrusio shell in primary total hips in elderly patients with >10 mm of protrusio. I have experience in 10 primary cases with an average follow-up of 4.1 years. One failed for infection. The other 9 have been successful with no apparent cup migration and no progressive component bone radiolucencies

Protrusio acetabuli can be either primary or secondary. Primary or idiopathic protrusio is a rare condition of unknown etiology. Secondary protrusio may be associated with Rheumatoid Arthritis, Ankylosing spondylitis, osteoarthritis, osteomalacia, trauma and Paget's disease. Challenges in surgery include lack of bone stock, deficient medial support to the cup, difficulty in dislocating the femoral head, and medialisation of the hip joint centre. Several surgical techniques have been described: use of cement alone without bone graft; morsellised impacted autograft or allograft with a cemented cup; metal cages, reinforcement rings, and solid grafts. We describe our technique of impaction grafting using autologous bone and a cementless porous-coated hemispherical cup without the use of acetabular rings or cages in patients with an average age of 46 years. Protrusion was graded depending on distance of medial wall from Kohler's line as mild (1–5 mm medial), moderate (6–15 mm medial) and severe if it was more than 15 mm medial to the Kohler's line. All patients were operated in the lateral position using a modified Hardinge's anterolateral approach. Adductor tenotomy may be required in cases of severely stiff hips. After careful dislocation of the femoral head, it was sectioned in situ into slivers to facilitate obtaining the graft. The periphery was reamed and care was taken to preserve the membrane lining the floor of the defect. Morsellised graft was impacted with hemispherical impactors and the trial cup 1–2 mm larger than the last reamer placed in the desired position. The final socket was then inserted. Femoral preparation was performed in routine fashion. The mean pre-operative Harris hip score of 52 improved to 85 points at a mean follow up of 4 years. The average acetabular inclination angle was 42 degrees. Our results have shown incorporation of the graft in all cases. There was no evidence of progression of the protrusio or cup loosening in any of the cases. Thus far, our hips have not shown osteolytic lesions. The technique described is a satisfactory biological solution of restoring bone stock particularly in young and middle-aged patients

Introduction. This study was performed to evaluate the minimum 5-year clinical and radiological results of liner cementation into a stable acetabular shell using a metal-inlay, polyethylene liner during revision total hip arthroplasty (THA). Methods. Sixty-six hips (63 patients) that underwent revision THA using a metal-inlay polyethylene liner cementation were included. The causes of revision were; polyethylene wear in 37 cases, femoral stem loosening in 20 cases, ceramic head fracture in 4 cases, and recurrent dislocation in 5 cases. Clinical results were graded at final follow-up using Harris hip scores, and radiographs were evaluated to determine acetabular component inclination, the stabilities of acetabular and femoral components, correction of hip centers, and the progression of osteolysis. Results. The average follow-up was 87.3 months (range 60.1∼134.3). Mean Harris hip scores improved from 64 preoperatively to 87.6 at final follow-up. Seven cases (10.6%) of dislocations occurred after revision surgery and 2 cases (3.0%) underwent acetabular revision or soft tissue augmentation. One cemented liner (1.5%) was dislodged and acetabular revision was performed using an acetabular reinforcement ring and a morselized bone graft. Two cases (3.0%) developed an infection and both underwent debridement and prosthesis with antibiotic-loaded acrylic cement (PROSTALAC) and intravenous antibiotics. Radiographic evaluations revealed osteolytic progression in the acetabular cup in 3 cases and osteolytic progression at the femoral stem in 7 cases, but none of these 10 cases underwent revision of the acetabular or femoral component. No cases of metallosis, metallic hypersensitivity, or cancer were encountered. Conclusion. This study shows that liner cementation into a stable metal shell provides relatively good clinical results. This technique offers lower surgical morbidity, a short operation time, and rapid patient recovery. Summary. Good clinical and radiologic outcomes were obtained at more than 5-years after liner cementation into a stable acetabular shell using a metal-inlay polyethylene liner during revision THA

Introduction. In the case of bipolar hemiarthroplasty, surgeons are often faced with only migration of outer head and severe osteolysis in acetabulum without loosening of femoral component. There has been much debate regarding the merits of removing or retaining stable femoral components in such cases. The purpose of this study was to determine whether revision of an isolated acetabular component without the removal of a well-fixed femoral component [Fig. 1] could be successfully performed. Materials and methods. Thirty-four hips of 33 patients who were followed up for a minimum of 1 year were examined. There were 29 women and 4 men. The average time from primary operation to revision surgery was 12.5 years (range, 0.0 to 17.9 years), and the average follow-up time after revision was 5 years (range, 1.1 to 15.2 years). The average age of the patients at the time of the index revision was sixty-four years (range, thirty-two to seventy-eight years). The reason for acetabular revision was migration of outer head in twenty-eight hips, disassembly of bipolar cup in four hips and recurrent dislocation in two hips. Of the thirty-four femoral components, twenty-seven were cementless and seven were cemented. In nine hips, we performed bone grafting to osteolysis of the proximal femur around the stem. Acetabular components were revised to an acetabular reinforcement ring with a cemented cup in 26 hips, to cementless acetabular components in 8 hips, and to cemented cup in 1 hip. Results. The average Japan Orthopaedic Association hip score improved from 50.7 to 86.1 points after revision surgery. One femoral component (3%) was revised because of periprosthetic fracture, three years after the index acetabular revision and eighteen years after the initial bipolar hemiarthroplasty. Radiographic evaluation of the thirty-three femoral components that were not revised demonstrated no evidence of loosening or subsidence. There were no dislocation or deep infection. Thirty-three (97%) of the acetabular components were judged to be stable at the final follow-up. A nonprogressive radiolucent line of less than 2 mm was observed in one case. Conclusion. We recommend that isolated acetabular revision be considered in cases of failed bipolar hemiarthroplasty with a well-fixed femoral component

Purpose. Complete wear-out of Polyethylene (PE) liner results in severe metallosis following articulation of the artificial head with the acetabular metal shell. We postulated that an adverse response can be led to surrounding bone tissue and new implant after revision surgery because the amount of PE wear particle is substantial and the metal particles are infiltrated in this catastrophic condition. We evaluated clinical characteristics and the survival rate of revision total hip arthroplasty (THA) performed in patients with severe metallosis following failure of PE liner. Materials and Methods. Between January 1996 and August 2004, severe metallosis following complete wear-out of PE liner were identified during revision THA in 28 hips of 28 patients. One patient had died at 7 days after surgery and 3 patients could not be reached at 5 year follow-up. Twenty-four hips of 24 patients (average age, 47.5 years) were followed for at least 6.5 years (average, 11.3 years; range, 6.5–15.9 years) and were evaluated. The mean time interval between prior surgery and the index revision surgery was 9.6 years (range, 4.0–14.3 years). The indications for revision surgery were osteolysis around well-fixed cup and stem in 22 hips and osteolysis with aseptic loosening of the cup in 2 hips. Bubble sign was observed on preoperative radiograph in 10 hips. Total revision, cup revision, and solitary bearing change were performed in 13, 10, and one hip respectively. A cementless implant was used in 23 hips and acetabular reinforcement ring was used in one. Clinical evaluation was performed using Harris hip scores and Kaplan-Meier survival analysis was performed. Multivariate analysis was performed with age, gender, BMI, bone defect type, existence of bubble sign and type of revision surgery as variables to evaluate the association with osteolysis or loosening. Results. One patient who had died from an unrelated medical condition at 6.5 years had hip that were functioning well at the time of death. Average Harris hip score improved from 64.5 points preoperatively to 81.9 points at the last follow-up. Wear and osteolysis were detected at average 8.9 years (3.1–13.5 years) after revision in 14 hips. Acetabular cup was loosened in 9 hips. Re-revision of cup was performed in 5 hips and re-revision of both cup and stem was done in 2 hips. In another hip, cup removal and artificial neck cutting was performed due to severe bone loss following two times of cup re-revision. With radiographic evidence of osteolysis as the end point, the 15-year survival rate was 35.3% (95% confidence interval [CI], 11.6%–59.0%). With radiographic loosening of any implant as the end point, the 15-year survival rate was 54.0% (95% CI, 27.9%–80.1%). Multivariate analysis revealed no variable that had a significant association with osteolysis or loosening. Conclusion. The survival rate of revision THA in patients with metallosis following a failure of a PE liner was low. Substantial amount of PE wear debris and the infiltration of metallic wear particles in the periprosthetic tissues might lead to progressive bone loss and implant loosening after revision THA

Introduction. Conversion of immovable hip to a total hip arthroplasty provides a solution, improving function, reducing back and knee pain, and slowing degeneration of neighboring joints associated with hip dysfunction while the mobilization by total hip arthroplasty is rather uncommon and challenging surgery. Materials and methods. Since 1998 we have performed 28 uncemented total hip arthroplasties for arthrodesed or ankylotic Hip. Among them 25 hips in 24 patients (four males and 20 females) with minimum of six months follow-up were evaluated. Thirteen hips were arthrodesed and twelve hips were ankylotic. One patient had arthrodesed hip in one side and ankylotic one in the other side. The mean age at the surgery was 63 (42 to 80). Two patients were Jehovah's witnesses. All 13 arthrodeses had been performed at other hospitals due to developmental dysplasia (11 hips), tuberculous coxitis (one hip), and infection after osteotomy (one hip). The underlying disease for the ankylosis was tuberculous coxitis for one hip and dysplastic osteoarthritis for 12 hips. Spongiosa Metal Cup (GHE, ESKA Orthodynamics AG, Lübeck, Germany) was used for 21 hips (screw fixation was added for two hips), Alloclassic Cup (Zimmer GmbH, Winterthur, Switherland) for one hip, Bicon Plus Cup (Smith & Nephew AG, Rotkreuz, Switherland) for one hip, and Müller's Reinforcement Ring (Zimmer GmbH, Winterthur, Switherland) for two hips. The bearing couple was ceramic on ceramic (Biolox forte, Ceramtec AG, Prochingen, Germany) for 14 hips, ceramic on polyethylene for eight hips, and metal on metal for three hips. Spongiosa Metal Stem (GHE, ESKA Orthodynamics AG, Lübeck, Germany) was used for 15 hips, SL Plus Stems (Smith & Nephew AG, Rotkreuz, Switherland) for nine hips, and Alloclassic Stem (Zimmer GmbH, Winterthur, Switherland) for one hip. All surgeries were carried out through an anterolateral approach. Twelve hips required the adductor tenotomy against the stiffness. The average follow-up period was 3.7 (0.5 to 10.6) years. Result. The average total blood loss during total hip arthroplasty was 685 (150 to 2042) milliliters and the average operative time was 102 (64 to 178) minutes. A perforation occurred in one femur. In this patient a plate (used for the previous arthrodesis) was buried in the femoral cortex. Trochanteric fracture occurred in another hip. The average post-operative range of motion was 65 (35 to 100) degrees in flexion, 2 (−10 to 15) in extension, 18 (5 to 30) in abduction, 10 (5 to 20) in adduction, 25 (10 to 45) in external rotation, and 14 (−5 to 30) in internal rotation. We had no postoperative dislocation. One patient required one-stage revision because of the recurrent infection at three years after the primary total hip arthroplasty. In all other patients the implants were stable at the final follow-up. Conclusions. An immovable hip brings about a lot of inconveniences. Though the surgery involved technical difficulties, it provided a better quality of life for the patients. Mobilization by means of uncemented total hip arthroplasty can be carried out successfully for immovable hips