Cup migration and bone graft resorption are some of the limitations after acetabular impaction bone grafting (IBG) technique in revision hip surgery when used for large segmental defects. We asked whether the use of a metallic mesh may decrease the appearance of this complication. We compared the appearance of loosening in patients with a bone defect 3A or 3B according to Paprosky. We assessed 204 hips operated with IBG and a cemented cup according to Slooff et al between 1997 and 2004. There were 100 hips with a preoperative bone defect of 3A and 104 with a 3B. We used 142 medial and/or rim metallic meshes for uncontained defects. The mean follow-up for unrevised cups was 10.4 years. We detemined postoperative radiological cup position and acetabular reconstruction of the hip center according to Ranawat in both groups. We assessed the appearance of radiological loosening and resorption of the graft.Background
Materials and Methods
Dislocation is one of the most important complications after primary total hip replacement (THR). The low incidence of this finding makes it difficult to analyse the possible risk factors. The surgical technique can also influence this rate through cup position or an adequate reconstruction of the hip. We assessed the demographic data and radiological reconstruction of the hip related to the appearance of dislocation after primary THR. 1414 uncemented THRs were recorded from our Local Joint Registry. The mean age of the patients was 60.1 years old (range, 14 to 95), and the mean weight was 73.3 kg (42 to 121). There were 733 men and 974 patients were classified with an activity level of 4 or 5 according to Devane. The most frequent diagnosis was primary osteoarthritis, 795 hips, followed by avascular necrosis 207 hips. An alumina-on-alumina THR was implanted in 703 hips and a metal-on-polyethylene THR in 711 hips. A femoral head size of 28 mm was used in 708 hips and 32 mm in 704. Radiological cup position was assessed using the acetabular abduction angle, the height of the center of the hip, and the horizontal distance of the cup. Cup anteversion was measured according to Widmer and the reconstruction of the center of rotation of the hip according to Ranawat. The radiographic reconstruction of the abductor mechanism was measured using two variables: the lever arm and the height of the greater trochanter.Introduction
Material and Methods
Between 1999 and 2001, 90 patients underwent
total hip replacement using the same uncemented acetabular and femoral
components with a 28 mm metallic femoral head but with prospective
randomisation of the acetabular liner to either Durasul highly cross-linked
polyethylene or nitrogen-sterilised Sulene polyethylene. We assessed
83 patients at a minimum follow-up of ten years. Linear penetration
of the femoral head was estimated at six weeks, six and 12 months
and annually thereafter, using the Dorr method, given the non-spherical
shape of the acetabular component. There was no loosening of any component; only one hip in the
Sulene group showed proximal femoral osteolysis. The mean penetration
of the femoral head at six weeks was 0.08 mm (0.02 to 0.15) for
the Durasul group and 0.16 mm (0.05 to 0.28) for the Sulene group
(p = 0.001). The mean yearly linear penetration was 64.8% lower
for the Durasul group at 0.05 mm/year ( Cite this article:
Proper cup positioning is a critical component in the success of total hip arthroplasty surgery. A multicenter study has been initiated to study a new type of highly cross-linked polyethylene. This study provides a unique opportunity to a review the acetabular cup placement of over 500 patients implanted in the past 2 years from 13 medical centers from the U.S., Mexico, and Europe. 482 patients have received primary total hip arthroplasty using components from a single manufacturer in 5 centers in the US and Mexico and 7 centers in Europe. The acetabular anteversion and inclination were measured in post-operative radiographs. An acceptable window of cup position is defined at 5–25° of anteversion and 30–45° of inclination.Introduction
Methods
We report the results of 79 patients (81 hips)
who underwent impaction grafting at revision hip replacement using the
Exeter femoral stem. Their mean age was 64 years (31 to 83). According
to the Endoklinik classification, 20 hips had a type 2 bone defect,
40 had type 3, and 21 had type 4. The mean follow-up for unrevised
stems was 10.4 years (5 to 17). There were 12 re-operations due to intra- and post-operative
fractures, infection (one hip) and aseptic loosening (one hip).
All re-operations affected type 3 (6 hips) and 4 (6 hips) bone defects.
The survival rate for re-operation for any cause was 100% for type
2, 81.2% (95% confidence interval (CI) 67.1 to 95.3) for type 3,
and 70.8% (95% CI 51.1 to 90.5) for type 4 defects at 14 years.
The survival rate with further revision for aseptic loosening as
the end point was 98.6% (95% CI 95.8 to 100). The final clinical
score was higher for patients with type 2 bone defects than type
4 regarding pain, function and range of movement. Limp was most
frequent in the type 4 group (p <
0.001). The mean subsidence
of the stem was 2.3 mm ( The impacted bone grafting technique has good clinical results
in femoral revision. However, major bone defects affect clinical
outcome and also result in more operative complications.
Acetabular bone structure is not the same in all patients and can be defined by the radiolucent triangle superior to the acetabulum. We ask if the acetabular anatomy determines the initial cup fixation and screws use. We have assessed 205 hips in which a Cerafit cementless cup was implanted. According to Dorr et al., acetabulae were classified as type A, in which the radiolucent triangle had an isosceles shape (86 hips), type B, in which the triangle extended into the teardrop (90 hips), and type C which had a right-angle triangle (29 hips). The use of screws was decided at the time of surgery and according to cup stability, not acetabular anatomy. Avascular necrosis and inflammatory arthritis were the most frequent diagnoses in type A hips, osteoarthritis in type B, and dysplasia in type C. Women were more frequent in types A and C (p<
0.001). The use of screws was more frequent in women (p<
0.001) and in type A (34.9%) and type C hips (62.1%) than in type B hips (20.0%) (p<
0.001). The multivariate logistic regression model showed the acetabular type (p=0.11) and gender (p=0.003) as independent factors. Acetabular types A (OR=1.98, 95% CI: 0.922–4.208, p=0.075) and C (OR=5.09, 95% CI: 1.74–14.9, p=0.003) increase the risk for screw use. Men have a lower risk for screw use (OR=0.329, 95% CI: 0.16–0.68, p=0.003). Acetabular anatomy and gender determine the use of screws in cementless cups. Continued follow-up is necessary to determine if screws results in less loosening and osteolysis.
The biological response to implant-derived wear particles is recognized as one of the main factors involved in the development of periprosthetic osteolysis. Wear particles induce a foreign-body inflammatory response that results in the formation of a periprosthetic membrane and progresses over time to aseptic loosening and implant failure. Upon exposure to particles, macrophages and other cell types release inflammatory cytokines to the periprosthetic milieu such as inter-leukin-1 beta (IL-1 beta, tumor necrosis factor-alpha (TNF-alpha) and interleukin-6 (IL-6) which contribute to bone resorption. Heat shock proteins (HSP) are intra-cellular proteins involved in the maintenance of cellular homeostasis. The stress inducible form of the Hsp70 family protein, Hsp72, has been detected in circulation, acting as a factor capable of regulating pro-inflammatory cytokines secretion and it has been demonstrated that induces the production of pro-inflammatory cytokines via the CD14 and Toll-like receptor-mediated signal transduction pathway. We hypothesized that Hsp72 could be involved in the inflammatory response to wear particles. To this aim, we investigated Hsp72 and its receptor, CD14, in interfacial membrane specimens obtained from patients undergoing revision surgery for aseptic loosening of uncemented acetabular cups (n=7). Distribution of both proteins was assessed by immunofluorescence and examined by confocal laser scanning microscopy. Hsp72 was detected in the periprostehetic membranes, colocalizing with CD14. Explants of membranes were cultured in vitro and levels of Hsp72 and IL-6 were determined by ELISA after 24, 48 and 72 h (n=9). Cultured membranes released IL-6 to culture medium in a time-dependent manner (p<
0.05), while Hsp72 levels decreased during same observation period (p<
0.05). These data suggest that, rather than being produced by the periprosthetic tissue, Hsp72 might be recruited by CD14+ cells from extracellular fluids. In this regard, preliminary data indicated that soluble Hsp72 levels in sera from patients undergoing revision surgery due to aseptic loosening were significantly lower than those from age-matched control subjects (n=6; p<
0.001). To investigate the involvement of Hsp72 in the inflammatory response to wear particles, we used a cell culture model of THP-1 cells driven to the monocyte/macrophage differentiation pathway. These cells were exposed to titanium particles of phagocytosable sizes, either in the presence or absence of exogenously added Hsp72. results obtained to date indicate that Hsp72 is able to modulate the titanium-induced TNF-alpha, IL-1 beta and IL-6 secretion (p<
0.05). Altogether, our data suggest that Hsp72 could be a novel mediator involved in wear particles-induced osteolysis and prosthetic failure.
Revision surgery of the hip was performed on 114 hips using an extensively porous-coated femoral component. Of these, 95 hips (94 patients) had a mean follow-up of 10.2 years (5 to 17). No cortical struts were used and the cortical index and the femoral cortical width were measured at different levels. There were two revisions for aseptic loosening. Survivorship at 12 years for all causes of failure was 96.9% (95% confidence interval 93.5 to 100) in the best-case scenario. Fibrous or unstable fixation was associated with major bone defects. The cortical index (p = 0.045) and the lateral cortical thickness (p = 0.008) decreased at the proximal level over time while the medial cortex increased (p = 0.001) at the proximal and distal levels. An increase in the proximal medial cortex was found in patients with an extended transtrochanteric osteotomy (p = 0.026) and in those with components shorter than 25 cm (p = 0.008). The use of the extensively porous-coated femoral component can provide a solution for difficult cases in revision surgery. Radiological bony ingrowth is common. Although without clinical relevance at the end of follow-up, the thickness of the medial femoral cortex often increased while that of the lateral cortex decreased. In cases in which a shorter component was used and in those undertaken using an extended trochanteric osteotomy, there was a greater increase in thickness of the femoral cortex over time.
Cultures were polymicrobial in 22 cases and by Gram-positive in 55 (80.9%). Highly-resistant organisms: methicillin-resistant Staphylococcus (36 patients) and ESBL-producing Enterobacteriaceae (2 patients). “Problematic-treatment”: Enterococcus (6 patients), Pseudomonas (3 patients), non-fermenting Gram-negative (2), moulds (1). Oral antibiotic selection: according to bacterial sensitivity, biofilm and intracellular effectiveness. Protocolized surgery: two-stage exchange. Average follow-up: 4.7+/−2.7 years (1–11). Healing of infection is diagnosed if absence of clinical, serological and radiological signs of infection during the whole follow-up. Orthopaedic outcome is evaluated by HHS for hips and by KSCRS for knees.
Healing of infection: 59/68 patients (86.8%), 32/37 hips (86.5%) and 27/31 knees (87.1%). Infection not healed: 7/68 cases (10.3%) (4/37 hips, 3/31 knees) (5 by highly-resistant and 1 by “problematic-treatment” bacteria). There are no differences between hips and knees (p=0.55).
Statistically significant differences are not found when comparing subgroups according to Gram stain (p=0.43), multiple vs single bacteria (p=0.47 infective, p=0.71 orthopaedic), highly-resistant bacteria (p=0.2 infective, p=0.1/0.5 orthopaedic), or “problematic-treatment” (p=0.68).
A strong statistical correlation appears between infective and orthopedic results after late arthroplasty infections. With the number of cases presented significant differences in infective or in orthopaedic results are not found when comparing single vs. polymicrobial, gram-negative vs. gram-positive, high vs. low antimicrobial resistance and “problematic-treatment” infections.
We reviewed 111 hemispherical Duraloc series-500 acetabular components with a minimum follow-up of 12 years. The mean clinical and radiological follow-up was 13.4 years (12 to 15). A Profile hydroxyapatite-coated anatomical femoral component was used in each case. Six patients had a late dislocation, for whom the polyethylene liner was exchanged. Each acetabular component was well fixed and all femoral components showed signs of bone ingrowth. The mean rate of femoral head penetration was 0.10 mm/year (0.021 to 0.481). The probability of not developing femoral cortical hypertrophy and proximal osteopenia by 12 years was 80.2% (95% confidence interval, 72.7 to 87.6) and 77.5% (95% confidence interval, 69.7 to 85.2), respectively. Despite these good clinical results, further follow-up is needed to determine whether these prostheses will loosen with time.
Gestational age was 1st trimester (3 cases), 2nd trimester (5 cases), 3rd trimester (5 cases). 10 women were treated surgically, 8 before finishing gestation. Gestation ended as and induced abortion (3 cases, 1 due to fetal death and 2 due to teratogenic risk), and birth (10 cases, all alive, 50% eutocic). Only 3 babies needed type II or type III neonatal reanimation.
Ultra-high-molecular-weight polyethylene sterilised in the absence of air and highly cross-linked polyethylene have been used to avoid osteolysis and loosening in total hip replacement. Our prospective randomised study has assessed the results using two different polyethylenes associated with the same prosthetic design. We assessed 45 Allofit acetabular components with a Sulene-polyethylene liner of conventional polyethylene gamma sterilised with nitrogen and 45 Allofit acetabular components with a Durasul-polyethylene liner sterilised in ethylene oxide, both matched with an Alloclassic stem with a 28 mm modular femoral head. The prostheses were implanted between May 1999 and December 2001. The mean follow-up was for 66.3 months (60 to 92). The linear penetration of the femoral head was estimated at 6 weeks, at 6 and 12 months and annually thereafter from standardised digitised radiographs using image-analysis software. There was no loosening of any prosthetic component. There were no radiolucent lines or osteolysis. The mean rate of penetration calculated from regression analysis during the first five years was 38 μm/year (