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Background: The increasing number of THAs in younger patients will inevitably result in an increase of revision procedures. However, there is little evidence about the outcome of revision procedures in this patient group. Therefore, we updated a previous study conducted 5 years ago about the outcome of revision procedures in patients younger than 55 years., Questions/purposes: We sought to provide a concise update on the previously reported (1) long-term failure rate as defined by repeat revision, (2) clinical outcome as defined by the Oxford Hip score and the Harris Hip score, and (3) radiographic outcome of cemented revision THA performed with impaction bone grafting on both the acetabular and femoral sides in one surgery in patients younger than 55 years old., Methods: Between 1991 and 2007, we performed 86 complete THA revisions in patients younger than 55 years. In 38% (33 of 86) of revisions, bone impaction grafting was used on both the acetabular and femoral side because of acetabular and femoral bone stock loss. Mean age at time of revision was 46 ± 8 years. No patient was lost to follow-up, but six patients died during follow-up, including three since 2015. Still, the hips of all 33 patients were included in analysis at a mean of 17 ± 5 years. Failure was calculated using competing risk analysis. For clinical outcome, we assessed the Harris Hip score and the Oxford Hip score from our longitudinally maintained institutional database. Radiographic analysis was performed to evaluate radiographic loosening, defined as radiolucencies ≥ 2 mm in all zones or ≥ 5 mm migration for both components. The acetabular component was also considered loose with tilting ≥ 5°., Results: The 15-year failure rate of revision THA was 27% (95% CI 13 to 44) for re-revision of any component for any reason and 10% (95% CI 3 to 25) for re-revision of any component for aseptic loosening. The mean Harris Hip score increased from 55 ± 18 preoperatively to 74 ± 22 at latest follow-up. Eight cups were considered radiographically loose, seven of which were re-revised. No stems were considered radiographically loose. Failure rate with endpoint radiographic loosening at 15 years was 23% (95% CI 10 to 39)., Conclusion: We found that impaction bone grafting with a cemented cup and a cemented stem is a valuable biological revision technique that results in a stable and durable solution, after one or even multiple previous revision THAs. Although current implants may prove sufficient in most cases, they do not promote bone stock preservation. We believe that in young patients with bone stock loss, impaction bone grafting can be used as long as the defect can be contained adequately with a metal mesh and viable bone bed is available for revascularization., Level of Evidence: Level IV, therapeutic study., Competing Interests: Each author certifies that neither he, nor any member of his immediate family, has funding or commercial associations (consultancies, stock ownership, equity interest, patent/licensing arrangements, etc.) that might pose a conflict of interest in connection with the submitted article. All ICMJE Conflict of Interest Forms for authors and Clinical Orthopaedics and Related Research® editors and board members are on file with the publication and can be viewed on request., (Copyright © 2020 by the Association of Bone and Joint Surgeons.)

Background: Developmental dysplasia of the hip (DDH) is a common cause of secondary osteoarthritis (OA) in younger patients, and when end-stage OA develops, a THA can provide a solution. Different options have been developed to reconstruct these defects, one of which is impaction bone grafting combined with a cemented cup. To determine the true value of a specific technique, it is important to evaluate patients at a long-term followup. As there are no long-term studies, to our knowledge, on THA in patients with DDH using impaction bone grafting with a cemented cup, we present the results of this technique at a mean of 15 years in patients with previous DDH., Questions/purposes: We wished to determine (1) the long-term probability of cup revision at a minimum followup of 15 years for cemented acetabular impaction bone grafting in patients with DDH; (2) the radiographic appearance of the bone graft and radiographic signs of implant loosening; and (3) the complications and pre- and postoperative Harris hip scores with cemented THA combined with impaction bone grafting in patients with previous DDH., Methods: Between January 1984 and December 1995 we performed 28 acetabular impaction bone grafting procedures for secondary OA believed to be caused by DDH in 22 patients; four patients died before 15 years, leaving 24 hips in 18 patients for retrospective analysis at a minimum of 15 years (mean, 20 years; range, 16-29 years). The diagnosis of DDH was made according to preoperative radiographs and intraoperative findings. All grades of dysplasia were included; five patients had Crowe Group I, eight had Group II, nine had Group III, and two had Group IV DDH. No patients were lost to followup. In all cases the acetabular defects were combined cavitary and segmental. Owing to the high number of deaths, we performed a competing-risk analysis to determine the probability of cup revision surgery., Results: The competing-risk analysis showed cumulative incidences at 15 and 20 years, with endpoint revision for any reason of 7% (95% CI, 0%-17%), whereas this was 4% (95% CI, 0%-11%) with endpoint revision of the cup for aseptic loosening. Three revision surgeries were performed. Two cup revisions were performed for aseptic loosening at 12 and 26 years. Another cup revision was performed owing to sciatic nerve problems at 2 years. A stable radiographic appearance of the graft was seen in 19 of the 25 unrevised hips. Four hips showed acetabular radiolucent lines and two showed acetabular osteolysis. None of the unrevised cups showed migration or radiographic failure. Postoperative complications included a pulmonary embolus and a superficial wound infection. The Harris hip score improved from 37 (range, 9-72) preoperatively to 83 (range, 42-99) at latest followup., Conclusions: Cemented primary THA with the use of impaction bone grafting shows satisfying long-term results in patients with previous DDH. For future research it is important to evaluate this technique in a larger cohort with a long-term followup. Other techniques also should be evaluated at long-term followup to be able to compare different techniques in this important and specific patient group., Level of Evidence: Level IV, therapeutic study.

Background: The increasing number of total hip arthroplasties (THAs) performed in younger patients will inevitably generate larger numbers of revision procedures for this specific group of patients. Unfortunately, no satisfying revision method with acceptable survivorship 10 years after revision has been described for these patients so far., Questions/purposes: The purposes of this study were to (1) analyze the clinical outcome; (2) complication rate; (3) survivorship; and (4) radiographic outcome of cemented revision THA performed with impaction bone grafting (IBG) on both the acetabular and femoral sides in one surgery in patients younger than 55 years old., Methods: During the period 1991 to 2007, 86 complete THA revisions were performed at our institution in patients younger than 55 years. In 34 of these 86 revisions (40%), IBG was used on both the acetabular and femoral sides in 33 patients. Mean patient age at revision surgery was 46.4 years (SD 7.6). No patient was lost to followup, but three patients died during followup. None of the deaths were related to the revision surgery. The mean followup for the surviving hips was 11.7 years (SD 4.6). We also analyzed complication rate., Results: The mean Harris hip score improved from 55 (SD 18) preoperatively to 80 points (SD 16) at latest followup (p = 0.009). Six hips underwent a rerevision (18%): in four patients, both components were rerevised; and in two hips, only the cup was revised. Patient 10-year survival rate with the endpoint of rerevision for any component for any reason was 87% (95% confidence interval [CI], 67%-95%) and with the endpoint of rerevision for aseptic loosening, the survival rate was 97% (95% CI, 80%-100%). In total six cups were considered radiographically loose, of which four were rerevised. Three stems were radiographically loose, of which none was rerevised., Conclusions: IBG is a valuable biological revision technique that may restore bone stock in younger patients. Bone stock reconstruction is important, because these patients likely will outlive their revision implants. Bone reconstruction with impaction grafting may facilitate future revisions., Level of Evidence: Level IV, therapeutic study.

Background: Loosening of acetabular components often leads to bony defects. Management of extensive acetabular bone loss in hip revision arthroplasty can be a tremendous challenge., Questions/purposes: We asked whether a reconstruction with impacted bone grafts will provide a durable and pain-free function in extensive acetabular defects. We specifically determined the (1) survival rates with the end point of revision for any reason, aseptic revision, and radiographic loosening; (2) visual analog scale (VAS) pain score, Harris hip score (HHS), and the Oxford Hip Questionnaire score (OHQS); (3) number of repeat revisions; (4) complications; and (5) radiographic loosening, wear, and radiolucencies., Patients and Methods: We retrospectively followed 25 patients (27 hips) with extensive acetabular defects. No patient was lost to followup. Two patients died during followup. Minimum followup was 3 years (mean, 8.8 years; range, 3-14.1 years)., Results: Three patients (three hips) underwent repeat revision surgery and another two patients (two hips) had radiographically loose hips. The 10-year survival rate was 88% (95% confidence interval, 74.2%-100%) with the end point acetabular revision for any reason and 95% (95% confidence interval, 86.0%-100%) with the end point acetabular revision for aseptic loosening. The mean HHSs were 55 points before surgery and 72 points postoperatively., Conclusions: Acetabular reconstruction with impaction bone grafting and a cemented cup is a reliable technique with a 10-year survival rate of 88% in patients with extensive acetabular deficiencies., Level of Evidence: Level IV, case series. See the Guidelines for Authors for a complete description of levels of evidence.

Background: Young patients with degenerative cartilage disease of the hip remain a challenge for the orthopaedic surgeon. Different treatment options are available of which uncemented hips are the most popular owing to long-term concerns about cemented implants. As an alternative, we have used a cemented hip design in combination with bone impaction grafting in patients with acetabular defects., Questions/purposes: We therefore determined the survival rates and radiological failures of cemented THA in patients younger than 30 years and reported clinical scores, complications and current state of the revised THAs., Methods: We retrospectively reviewed all 48 patients (69 hips) younger than 30 years at the time of surgery who had a primary cemented THA performed between 1988 and 2004. Acetabular defects were reconstructed using bone impaction grafting in 29 hips. Mean age at surgery was 24.6 years (range, 16-29 years). Revisions were documented, radiographs were analyzed, and the Kaplan-Meier method was used to determine survival for different end points. No patient was lost to followup, three patients (four hips) had died. Minimum followup was 2 years (mean, 8.4 years; range, 2-18 years)., Results: Eight hips were revised (three for infection and five for aseptic loosening) and one hip dislocated for which open reduction was necessary. One additional cup was considered a radiographic failure. The 10-year survival was 83% (95% confidence interval, 69%-92%) with revision for any reason as the end point and 90% (95% confidence interval, 77%-96%) with revision for aseptic loosening., Conclusions: We found a high survival rate of these cemented THA in young patients. In young patients with acetabular bone defects we recommend reconstruction using cemented implants with bone impaction grafting.

Unlabelled: Although uncemented cup implants frequently are used in young patients, we believe long-term survival rates of cups in these patients are somewhat disappointing, and therefore we have continued to use cemented cups in primary THA, even in young patients. However, in cases of acetabular bone stock defects, we also use bone impaction grafting. We prospectively followed 130 patients with 175 cemented cups; no patients were lost to followup. The mean age of the patients at surgery was 31 years (range, 16-39 years). An acetabular reconstruction with bone impaction grafting was performed in 84 hips (48%). The minimum followup was 2 years (average, 8.1 years; range, 2.0-18.5 years). Twenty-one of the 175 cups (12%) were revised at an average of 8.1 years (range, 2.0-18.5 years). Reasons for revision were infection (one early, seven late), recurrent dislocations (two), traumatic loosening (one), and aseptic loosening (10). The 10-year survival rate of all cemented cups with end point of revision for any cause was 85%. Survival with end point of aseptic loosening of all cups was 92%. Survival with end point of revision for aseptic loosening was 90% for the cups without impaction grafting and 95% for the cups with impaction grafting. We believe cemented acetabular cups in young patients have acceptable midterm survival; however, in the case of acetabular bone defects, we recommend reconstruction with impaction grafting., Level of Evidence: Level III, therapeutic study.

Unlabelled: Ceramic-on-ceramic bearings in THA are a popular alternative to overcome wear concerns in traditional metal-polyethylene bearings. However, squeaking is a potentially worrisome phenomenon in ceramic-on-ceramic THAs which we observed in some of our patients. We reviewed all 42 patients who underwent 43 ceramic-on-ceramic noncemented THAs during the time of the study. Squeaking, defined as a reproducible sound of squeaking, clicking, or grating, occurred in nine of 43 implants (20.9%). Standard radiographs were normal. We used CT imaging to determine cup anteversion and inclination angles, comparing the squeaking hips with those of a randomly selected control group, but found no differences. We then hypothesized specific design features (stem size, cup size, head size, and neck length of the head) would be risk factors for squeaking. We found a difference in neck length between squeaking and nonsqueaking implants. A neck length of -4 mm or shorter resulted in a relative risk of 5.56 (95% confidence interval, 1.14-27.01) for squeaking. We found a high incidence of squeaking in our population, and we believe this phenomenon is an underreported side effect of these types of bearings. A short neck length of the femoral implant was a risk factor for squeaking in ceramic-on-ceramic THA., Level of Evidence: Level III, therapeutic study.

Unlabelled: Acetabular bone loss hampers implantation of a total hip arthroplasty in patients with developmental dysplasia of the hip. The bone impaction grafting technique in combination with a cemented total hip can restore the bone stock in these patients, but do these reconstructions yield satisfying long-term results? We used this technique in 28 hips (22 consecutive patients). The degree of dislocation was graded preoperatively as Crowe I in five hips, Crowe II in eight hips, Crowe III in nine hips, and Crowe IV in four hips. We present the long-term results of this bone impaction grafting technique a minimum of 10 years after surgery. Two patients died before the minimum followup of 10 years, leaving 20 patients (26 hips). Two cups were revised, one cup for a sciatic nerve palsy (at 2 years) and the other for aseptic loosening after 12 years. The cumulative survival of the cup with revision for any reason as the end point was 96% at 10 years and 84% at 15 years. There were no femoral revisions during followup. The bone impaction grafting technique in combination with a cemented cup is an effective technique for developmental dysplasia of the hip with favorable long-term results., Level of Evidence: Level IV, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.

Bone impaction grafting has been advocated for reconstruction of femoral head osteonecrosis. However, bone grafts do not prevent the progression of collapse and subsequent disabling osteoarthritis in late-stage osteonecrosis. We hypothesized reconstruction of large subchondral defects with a mix of impacted morsellized cancellous bone grafts and calcium phosphate cement would afford mechanical stability allowing remodeling into new bone without femoral head collapse. In a pilot study we created a critically sized subchondral defect model in 15 goats following the trapdoor procedure. Defects were left empty (n = 3), filled with morsellized cancellous bone grafts (n = 6), or filled with a mixture of morsellized cancellous bone and calcium phosphate cement (n = 6). No defects collapsed by sacrifice at 12 weeks. Defects filled with morsellized cancellous bone showed complete incorporation and remodeling to a normal trabecular structure. In the morsellized cancellous bone/calcium phosphate cement group, most of the calcium phosphate cement was resorbed in 12 weeks and the mixture was largely replaced by fibrous or fatty marrow. Although the specific mixture did not confirm our hypothesis, we suspect a slower resorbing calcium phosphate cement remains a promising material to mix with morsellized cancellous bone to treat late stages of femoral head osteonecrosis.

A major concern in using growth factors in impaction grafting is the potential stimulation of the osteoclastic lineage. A solution would be using an osteoconductive material resistant to resorption and providing initial stability after reconstruction. Growth factors may promote bone formation in combination with such graft materials. We determined whether OP-1 would promote the incorporation of impacted morselized allografts and tricalcium phosphate/hydroxyapatite (TCP/HA) into host bone, whether bone formation would be preceded by an initial process of accelerated resorption, and whether the response to OP-1 remodeling/incorporation would be dose-related. We performed two bone chamber studies in goats to ascertain the early effects of OP-1 dose on resorption and incorporation of impacted morselized allografts and TCP/HA. After 4 weeks, the incorporation process of impacted morselized allografts and TCP/HA was not promoted by OP-1. We observed no signs of accelerated resorption preceding bone formation. An increase in OP-1 dose resulted in an inhibition of fibrous tissue formation but OP-1 did not promote bone formation. Early failures in impaction grafting, using mixes with OP-1, might be explained by the lack of fibrous tissue ingrowth and not by increased resorption and remodeling.

Reconstructing large loaded bone defects with ceramic bone graft extenders is tempting considering the expected future donor bone shortage. However, whether there are negative effects is unknown. Standardized large defects in the acetabulum of goats were created and subsequently reconstructed with metal mesh and impacted morselized cancellous bone grafts or a 50/50% volume mixture of tricalcium phosphate-hydroxyapatite granules and morselized cancellous bone grafts using the bone impaction grafting technique. Subsequently, a cemented total hip prosthesis was inserted. Clinically, no differences were observed between groups. Most of the morselized cancellous bone graft had been resorbed and incorporated into new bone after 15 weeks. The large tricalcium phosphate-hydroxyapatite granules were integrated, the smaller crushed tricalcium phosphate-hydroxyapatite granules were surrounded by osteoclasts or engulfed by macrophages and giant cells. The cement penetration into the reconstructive layer and the quality of the bone based on a semiquantitative score were similar in both groups. We found no suggestion of tricalcium-hydroxyapatite granule-induced third-body wear in this short-term followup study. No negative effects were observed in this study, and therefore, it seems reasonable to use tricalcium-hydroxyapatite granules in a 50/50% volume mix with morselized cancellous bone graft as a bone graft extender in acetabular revision surgery with the bone impaction grafting technique.

Unlabelled: The outcome of total hip arthroplasty after acetabular fracture is compromised. We studied if the bone impaction grafting technique could provide long-term prosthesis survival in deformed and irregular acetabula. We studied 20 hips in 20 patients (mean age, 53.3 years; range, 35-75 years) that were reconstructed with acetabular bone impaction grafting and a cemented total hip prosthesis after acetabular fracture. No patient was lost to followup. At review the mean followup was 9.5 years (range, 3-18 years) and the average Harris hip score was 93 (range, 62-100). During followup there were two cup revisions: one after 14.5 years for septic loosening, and one after 15.3 years for aseptic loosening. The Kaplan-Meier survival rate of the cup with end-point revision for any reason was 100% at 10 years and 80% (95% CI; range, 62-98%) after 15 years. With end-point cup revision for aseptic loosening the survival rate was 100% at 10 years. Acetabular bone impaction grafting with a cemented cup is a biologically attractive technique with good long-term survival used to reconstruct bone stock loss after posttraumatic arthritis. The complication and reoperation rate was low in this relatively young group of patients., Level of Evidence: Therapeutic study, Level IV (Case series--no, or historical control group). See the Guidelines for Authors for a complete description of levels of evidence.

Segmental defects can be reconstructed with a cortical strut or a metal wire mesh when using bone impaction grafting in the femur. We hypothesized that structural grafts would negatively influence revascularization of the underlying impacted grafts compared with an open wire mesh. A standardized large medial wall defect was reconstructed with a strut or a mesh in six goats per group. In all femurs impaction grafting was done in combination with a cemented collarless double-tapered highly polished Exeter stem. After 6 weeks the femurs were harvested. A high rate of periprosthetic fractures was observed (three of seven and two of six for the strut and mesh groups, respectively). Histologic analysis showed different revascularization and tissue ingrowth patterns for both reconstruction techniques. In the strut group, fibrous tissue ingrowth was limited to the edges of the defect. Medially behind the strut no or limited fibrous tissue ingrowth was found. In the mesh group, fibrous tissue and blood vessels penetrated the mesh and a superficial zone of revascularized grafts was observed. Although revascularization, concomitant graft resorption and bone incorporation may compromise the short-term stability of the stem after surgery, the long-term stability of the stem probably is best guaranteed by graft incorporation.

In a one-surgeon study the clinical and radiographic results of 30 cementless bipolar hip prostheses in 24 patients younger than 55 years were evaluated. Eleven noncoated prostheses (Noncoated Group) and 19 hydroxyapatite-coated prostheses (Hydroxyapatite Group) were compared after a mean followup of 10.4 years. The Harris hip score increased from a preoperative average of 41 points to 76 points at final followup (Noncoated Group, 70 points; Hydroxyapatite Group, 80 points). Thigh or groin pain was present in 15 patients (16 hips) (Noncoated Group, 55%; Hydroxyapatite Group, 53%). Radiographically, subsidence was the major problem at the noncoated prostheses (Noncoated Group, 91%; Hydroxyapatite Group, 5%), whereas osteolysis mainly was seen at the hydroxyapatite-coated prostheses (Noncoated Group, 18%; Hydroxyapatite Group, 89%). The obtained aseptic revision rate of 27% (Noncoated Group, 27%; Hydroxyapatite Group, 26%) is too high to use this implant in young patients. The large amounts of polyethylene wear debris generated by the bipolar system play an important role in this limited success. In the initially well-fixed hydroxyapatite-coated prostheses the sealing effect of a hydroxyapatite coating creates high concentrations of polyethylene in the limited joint space, resulting in massive proximal femoral osteolysis. Consequently, a hydroxyapatite coating introduces a new failure mechanism. Therefore, hydroxyapatite does not improve the outcome of a cementless bipolar hemiarthroplasty in the long-term.

Even in extensive osteonecrosis of the femoral head in younger patients, a femoral head-preserving method is preferable. We developed a new technique using the lateral approach as used in traditional core biopsy; the osteonecrotic lesion was removed and impacted bone grafts were used to regain sphericity and prevent collapse. In this prospective one surgeon study, we included 28 consecutive hips in 27 patients with extensive osteonecrotic lesions (ARCO classification Stage 2 [11 hips], Stage 3 [14 hips]; and Stage 4 [three hips]); 14 hips had preoperative collapse. The mean age of the patients was 33 years (range, 15-55 years). At a mean followup of 42 months (range, 24-119 months), eight hips (29%) were converted to a total hip arthroplasty (THA). Of the 20 reconstructions that were in situ, 18 were clinically successful (90%) and 70% were radiologically successful. Patients who were younger than 30 years at surgery had a radiologically significant better outcome, even patients with higher stages of osteonecrosis. Patients with preoperative collapse and use of corticosteroids had disappointing results. This method is attractive as a salvage procedure, is relatively simple and quick, and it does not interfere with an eventual future hip arthroplasty.

Bone defects in revision hip surgery can be reconstructed with impacted morselized bone grafts. Rinsing these trabecular allografts may enhance graft incorporation by washing out immunogenic factors present in blood, marrow, and fat. However, it has been proposed that impaction of the graft releases biologically active factors, which can provide sufficient activity to stimulate new bone formation. Rinsing before impaction could enhance bone allograft incorporation, but rinsing after impaction could diminish the incorporation process of impacted bone graft. To study the effect of rinsing and impaction of morselized bone grafts on bone ingrowth, a bone chamber study was done in goats. Autografts and allografts were divided into three treatment groups: (A) impacted; (B) rinsed and impacted; and (C) rinsed, impacted, rinsed, and impacted again. Ten goats received three bone chambers in each proximal tibia. The chambers were filled with either allograft or autograft, yielding six different implants per goat. After 6 weeks, histologic analyses were done and bone and tissue ingrowth were measured. New bone and total tissue ingrowth were higher in autografts than in allografts, especially in the nonrinsed group. With rinsing, total tissue ingrowth increased in the allograft group to approach that of autografts. Rinsing after impaction did not additionally alter bone ingrowth. The current findings show that incorporation of allografts can be improved by rinsing the grafts before impaction.

Animal studies have shown almost complete incorporation of impacted morselized bone grafts. To determine whether this also is true in humans, 24 acetabular bone biopsy specimens from 21 hips of 20 patients were examined. Biopsy specimens were obtained 3 months to 15 years after acetabular reconstruction in primary and revision total hip arthroplasties in combination with a cemented cup. Histologic examination showed rapid revascularization of the graft, directly followed by osteoclastic resorption and woven bone formation on the graft remnants. New bone also was formed on fibrin accumulations or without any scaffold in the fibrous stroma tissue that had invaded the graft. Thereafter the mixture of graft, new bone, and fibrin was remodeled completely into a new trabecular structure, with normal lamellar bone and only scarce remnants of graft material. Localized areas of nonincorporated bone graft surrounded by fibrous tissue remained, irrespective of the followup period. Large nonincorporated fragments of cartilage also were found, particularly in cases in which femoral head bone chips were produced by a bone mill. In general, impacted trabecular bone chips incorporate by a mechanism that is similar to that previously observed in animal studies. In some patients, however, areas of nonincorporated bone graft remained and long-term alterations were found, probably related to the loosening process.

Acetabular bone stock loss compromises the outcome in primary and revision total hip arthroplasty. In 1979, a biologic method was introduced with tightly impacted cancellous allografts in combination with a cemented polyethylene cup for acetabular reconstruction. With this technique, it is possible to replace the loss of bone and to repair normal hip mechanics and hip function with a standard implant. Based on the authors' 20 years experience, a review of the long-term data is presented in primary total hip arthroplasty with preexisting acetabular bone stock loss, primary total hip arthroplasty in rheumatoid arthritis, patients who had bone impaction when younger than 50 years, and in acetabular revisions. The survival rate with revision of the cup for aseptic loosening as the end point was 94% at 10 to 17 years, 90% at 10 to 18 years, 91% at 10 to 17 years, and 92% at 10 to 15 years. From biopsy specimens from humans and histologic data in animal experiments the incorporation of these impacted bone chips was proven. The acetabular bone impaction technique using large morselized bone chips (range, 0.7-1 cm) and a cemented cup is a reliable technique with favorable long-term outcome.

Revision of a failed total joint replacement often demands bone grafting methods to restore deficient bone stock. However, impaired allograft incorporation can be the result of inadequate host or graft properties. The stimulation of bone healing with growth factors could provide a new approach to deal with this problem. The repeated sampling bone chamber was used in the goat to investigate the properties of bone allografts enriched with transforming growth factor-beta, recombinant human bone morphogenetic protein-2, and basic fibroblastic growth factor under unfavorable vascular and nonloaded conditions. Ten goats each had three bone chambers implanted in the medial proximal tibia. Different carrier allograft bone preparations were used for each growth factor based on convention and previously reported results. The period between implantation and chamber harvest was 8 weeks. The concentrations of the growth factors used was 0, 1, or 10 micrograms of transforming growth factor-beta 2, 0, 1, or 5 micrograms of bone morphogenetic protein-2, and 0, 40, 200 ng of basic fibroblastic growth factor. The specimens were analyzed histomorphometrically for the amount of soft tissue ingrowth, bone ingrowth, and the number of osteoclasts. In all specimens, a resorption front grew into the graft followed by fibrovascular tissue and, in some instances, bone. In the 5 micrograms of bone morphogenetic protein-2 specimens, larger amounts of soft tissue and woven bone were present, whereas in the specimens that received 10 micrograms of transforming growth factor-beta 2, there was a decrease in the amount of tissue and bone ingrowth. Two hundred nanograms of basic fibroblastic growth factor had a negative effect on soft tissue formation but increased the amount of vascular elements containing erythrocytes. The number of osteoclasts was higher in the 5-microgram bone recombinant human morphogenetic protein-2 specimens. In the clinical arena with absence of good perigraft vascularization and loading, bone morphogenetic protein-2 may have a strong stimulatory effect on bone graft incorporation.

Loosening of primary cemented and noncemented components of total hip arthroplasties always is accompanied by a loss of bone stock. There are several options for reconstruction of the acetabular and femoral defects. The authors' treatment of choice is a standardized cemented revision procedure with tight impaction of morsellized cancellous autograft or allograft chips in acetabular and femoral reconstructions. In this study, the clinical and radiographic evaluation of acetabular defects reconstructed with impacted morsellized allograft femoral heads was described. A cemented cup supplemented with morsellized cancellous grafts and wire meshes in cases of segmental defects was sufficiently stable to allow for complete graft consolidation. After a mean followup of 70 months of 88 hips, 4 cases of clinical failures (including 1 infection) and 6 cases of radiologic failure of the reconstructions were observed, resulting in a failure percentage of 11.4% after 5 years. Autografts and allografts were equally effective. Because the clinical success of the technique also was supported by the results of histologic and biomechanic studies in animals, the authors were encouraged to continue this technique, not only in the acetabulum, but also in the femur.