In developmental dysplasia of the hip (DDH), a bone defect is often observed superior to the acetabulum after the reconstruction at the level of the true acetabulum during total hip replacement (THR). However, the essential amount of uncemented acetabular component coverage required for a satisfactory outcome remains controversial. The purpose of this study was to assess the stability and function of acetabular components with a lack of coverage > 30% (31% to 50%). A total of 760 DDH patients underwent THR with acetabular reconstruction at the level of the true floor. Lack of coverage above the acetabular component of > 30% occurred in 56 patients. Intra-operatively, autogenous morcellised bone grafts were used to fill the uncovered portion. Other than two screws inserted through the acetabular shell, no additional structural supports were used in these hips. In all, four patients were lost to follow-up. Therefore, 52 patients (52 hips, 41 women and 11 men) with a mean age of 60.1 years (42 to 78) were available for this study at a mean of 4.8 years (3 to 7). There were no instances of prosthesis revision or marked loosening during the follow-up. The Harris hip score improved from a mean of 40.7 points (. sd. 12.2) pre-operatively to 91.1 (. sd. 5.0) at the last follow-up. Radiological analysis with medical imaging software allowed us to calculate the extent of the uncoverage in terms of the uncovered arc of the implant as viewed on the anteroposterior pelvic radiograph. From this we propose that up to 17 mm of lateral undercoverage in the presence of a stable initial implantation in the presence of bone autografting, with an inclination angle of the acetabular component between 40° and 55°, is acceptable. This represents undercoverage of ≤ 50%. Cite this article: Bone Joint J 2013;95-B:1178–83

We followed the first 354 consecutive implantations of a cementless, double-tapered straight femoral stem in 326 patients. Follow-up was at a mean of 12 years (10 to 15). The mean age of the patients was 57 years (13 to 81). At follow-up, 56 patients (59 hips) had died, and eight (eight hips) had been lost to follow-up. Twenty-five hips underwent femoral revision, eight for infection, three for periprosthetic fracture and 14 for aseptic loosening. The overall survival was 92% at 12 years (95% CI 88 to 95). Survival with femoral revision for aseptic loosening as an endpoint was 95% (95% CI 92 to 98). The median Harris hip score at follow-up was 84 points (23 to 100). Radiolucent lines (< 2 mm) in Gruen zones 1 and 7 were present in 38 (16%) and 34 hips (14%), respectively. Radiolucencies in zones 2 to 6 were found in five hips (2%). The results for mid- to long-term survival with this femoral component are encouraging and compare with those achieved in primary cemented total hip arthroplasty. The high rate of loosening of the cup and the high rate of pain are, however, a source of concern

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Preoperative diagnosis is important for revision surgery after prosthetic joint infection (PJI). The purpose of our study was to determine whether reverse transcription-quantitative polymerase chain reaction (RT-qPCR), which is used to detect bacterial ribosomal RNA (rRNA) preoperatively, can reveal PJI in low volumes of aspirated fluid.

The treatment of substantial proximal femoral bone loss in young patients with developmental dysplasia of the hip (DDH) is challenging. We retrospectively analysed the outcome of 28 patients (30 hips) with DDH who underwent revision total hip replacement (THR) in the presence of a deficient proximal femur, which was reconstructed with an allograft prosthetic composite. The mean follow-up was 15 years (8.5 to 25.5). The mean number of previous THRs was three (1 to 8). The mean age at primary THR and at the index reconstruction was 41 years (18 to 61) and 58.1 years (32 to 72), respectively. The indication for revision included mechanical loosening in 24 hips, infection in three and peri-prosthetic fracture in three. Six patients required removal and replacement of the allograft prosthetic composite, five for mechanical loosening and one for infection. The survivorship at ten, 15 and 20 years was 93% (95% confidence interval (CI) 91 to 100), 75.5% (95% CI 60 to 95) and 75.5% (95% CI 60 to 95), respectively, with 25, eight, and four patients at risk, respectively. Additionally, two junctional nonunions between the allograft and host femur required bone grafting and plating. An allograft prosthetic composite affords a good long-term outcome in the management of proximal femoral bone loss in revision THR in patients with DDH, while preserving distal host bone

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The use of frozen tumour-bearing autograft combined with a vascularized fibular graft (VFG) represents a new technique for biological reconstruction of massive bone defect. We have compared the clinical outcomes between this technique and Capanna reconstruction.

Although the technique of autogenous acetabular bone grafting has been widely used to augment containment of the acetabulum in total hip arthroplasty (THA) for developmental dysplasia, the role of this technique in improving long-term results remains controversial. We present the long-term results of cemented THA with acetabular bone grafting in 112 patients (133 hips) in order to clarify the factors which affect the outcome. The mean follow-up was for 12.3 years (8 to 24). Kaplan-Meier survivorship analysis predicted a rate of survival of the acetabular component at 15 years of 96% (95% confidence interval (CI) 92 to 99) with revision for aseptic loosening as the endpoint, and of 75% (95% CI 65 to 85) when radiological loosening was used. Parametric survivorship analysis using the Cox proportional-hazards model indicated that trochanteric nonunion, lateral placement of the socket, and delayed trabecular reorientation of the bone graft were risk factors for loosening of the acetabular component. Our findings have shown that autologous acetabular bone grafting is of value for long-term success provided that the risk factors are reduced

We have made a retrospective review of 185 cemented Charnley total hip arthroplasties performed between 1970 and 1974 to determine the relationships between radiological variables and failure of the femoral and acetabular components. We measured the acetabular wear, the orientation of the cup, the thickness and consistency of acetabular and femoral cement mantles, radiolucency and femoral alignment. The mean follow-up was for 11.7 years. Femoral loosening was demonstrable radiologically in 15 hips (8.1%), ten (5.4%) of which were revised during the period of follow-up. Only when the first postoperative radiograph showed a thin cement mantle in Gruen zone 5 was there a significant association with failure of the femoral component. There were 12 loose acetabular components (6.5%), nine (4.8%) of which were revised. When the initial radiograph after operation showed radiolucency in DeLee and Charnley zone 1, the incidence of acetabular loosening was 28.21%. If such radiolucency was not present, the incidence of acetabular loosening was only 0.69%. Our findings emphasise the importance of careful cementing

We describe a technique for the diagnosis of loosening of the femoral component of the Oxford Unicompartmental Knee Replacement using accurately aligned lateral radiographs in extension and flexion. If gaps are present between the component and cement on one radiograph and not on the other, the component is loose

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To establish the utility of adding the laboratory-based synovial alpha-defensin immunoassay to the traditional diagnostic work-up of a prosthetic joint infection (PJI).

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We evaluated a large database with mechanical failure of a single uncemented modular femoral component, used in revision hip arthroplasty, as the end point and compared them to a control group treated with the same implant. Patient- and implant-specific risk factors for implant failure were analyzed.

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Biofilm formation is intrinsic to prosthetic joint infection (PJI). In the current study, we evaluated the effects of silver-containing hydroxyapatite (Ag-HA) coating and vancomycin (VCM) on methicillin-resistant Staphylococcus aureus (MRSA) biofilm formation.

We retrospectively reviewed 44 consecutive patients (50 hips) who underwent acetabular re-revision after a failed previous revision that had been performed using structural or morcellised allograft bone, with a cage or ring for uncontained defects. Of the 50 previous revisions, 41 cages and nine rings were used with allografts for 14 minor-column and 36 major-column defects. We routinely assessed the size of the acetabular bone defect at the time of revision and re-revision surgery. This allowed us to assess whether host bone stock was restored. We also assessed the outcome of re-revision surgery in these circumstances by means of radiological characteristics, rates of failure and modes of failure. We subsequently investigated the factors that may affect the potential for the restoration of bone stock and the durability of the re-revision reconstruction using multivariate analysis. At the time of re-revision, there were ten host acetabula with no significant defects, 14 with contained defects, nine with minor-column, seven with major-column defects and ten with pelvic discontinuity. When bone defects at re-revision were compared with those at the previous revision, there was restoration of bone stock in 31 hips, deterioration of bone stock in nine and remained unchanged in ten. This was a significant improvement (p <  0.001). Morselised allografting at the index revision was not associated with the restoration of bone stock. . In 17 hips (34%), re-revision was possible using a simple acetabular component without allograft, augments, rings or cages. There were 47 patients with a mean follow-up of 70 months (6 to 146) available for survival analysis. Within this group, the successful cases had a minimum follow-up of two years after re-revision. There were 22 clinical or radiological failures (46.7%), 18 of which were due to aseptic loosening. The five and ten year Kaplan–Meier survival rate was 75% (95% CI, 60 to 86) and 56% (95% CI, 40 to 70) respectively with aseptic loosening as the endpoint. The rate of aseptic loosening was higher for hips with pelvic discontinuity (p = 0.049) and less when the allograft had been in place for longer periods (p = 0.040). . The use of a cage or ring over structural allograft bone for massive uncontained defects in acetabular revision can restore host bone stock and facilitate subsequent re-revision surgery to a certain extent. Cite this article: Bone Joint J 2014;96-B:319–24

Total knee arthroplasty (TKA) is known to lead to a reduction in periprosthetic bone mineral density (BMD). In theory, this may lead to migration, instability and aseptic loosening of the prosthetic components. Bisphosphonates inhibit bone resorption and may reduce this loss in BMD. We hypothesised that treatment with bisphosphonates and calcium would lead to improved BMD and clinical outcomes compared with treatment with calcium supplementation alone following TKA. A total of 26 patients, (nine male and 17 female, mean age 67 years) were prospectively randomised into two study groups: alendronate and calcium (bisphosphonate group, n = 14) or calcium only (control group, n = 12). Dual energy X-ray absorptiometry (DEXA) measurements were performed post-operatively, and at three months, six months, one, two, four, and seven years post-operatively. . Mean femoral metaphyseal BMD was significantly higher in the bisphosphonate group compared with controls, up to four years following surgery in some areas of the femur (p = 0.045). BMD was observed to increase in the lateral tibial metaphysis in the bisphosphonate group until seven years (p = 0.002), and was significantly higher than that observed in the control group throughout (p = 0.024). There were no significant differences between the groups in the central femoral metaphyseal, tibial medial metaphyseal or diaphyseal regions of interest (ROI) of either the femur or tibia. Bisphosphonate treatment after TKA may be of benefit for patients with poor bone quality. However, further studies with a larger number of patients are necessary to assess whether this is clinically beneficial. Cite this article: Bone Joint J 2015;97-B:337–45

We systematically reviewed the peer-reviewed literature to relate the survival of hybrid metal-on-metal hip resurfacing arthroplasty devices to a National Institute of Clinical Excellence (NICE) benchmark for choosing a primary total hip replacement, which is a survival rate of 90% at a follow-up of ten years. A total of 29 articles (10 621 resurfaced hips) met the inclusion criteria. The mean follow-up ranged from 0.6 to 10.5 years and the survival of the implant ranged from 84% to 100%. Of the 10 621 hips, 370 were revised (3.5%), with aseptic loosening as the most frequent mode of failure. None of the hip resurfacing arthroplasty implants used to date met the full ten-year NICE benchmark of survival. A total of 13 studies showed satisfactory survival compared with the three-year NICE benchmark

The use of short stems has become more popular with the increased interest in less invasive approaches for total hip arthroplasty. The curved broaches and stem can be inserted along a curved track to avoid the abductor attachments. Short stems have the potential of being more bone conserving by allowing for higher neck retention, maintenance of the medial greater trochanter, and preferential stress transfer to the proximal femur. An initial experience with 500 new short stems (Fitmore, Zimmer Orthopedics) stems used for total hip arthroplasty is reported. No stems have been revised for aseptic loosening

We analysed synovial fluid from 88 hips, 38 with osteoarthritis and 12 with well-functioning and 38 with loose hip prostheses. The levels of TNF-α, IL-1ß (71 hips) and IL-6 (45 hips) were measured using the ELISA technique. Joints with well-functioning or loose prostheses had significantly increased levels of TNF-α compared with those with osteoarthritis. Hips with aseptic loosening also had higher levels of IL-1ß but not of IL-6 compared with those without an implant. The levels of TNF-α and IL-1ß did not differ between hips with stable and loose prostheses. Higher levels of TNF-α were found in hips with bone resorption of type II and type III (Gustilo-Pasternak) compared with those with type-I loosening. The level of cytokines in joint fluid was not influenced by the time in situ of the implants or the age, gender or area of the osteolysis as measured on conventional radiographs. Our findings support the theory that macrophages in the joint capsule increase the production of TNF-α at an early phase probably because of particle load and in the absence of clinical loosening. Since TNF-α has an important role in the osteolytic process, the interfaces should be protected from penetration of joint fluid

We retrospectively reviewed 56 patients (71 hips) treated by total replacement for severe disability after pelvic irradiation. Symptoms were associated with various radiological lesions due to irradiation, including atraumatic femoral-neck fracture, osteonecrosis of the femoral head or of the acetabulum, and radiation osteitis of the whole pelvis. From 1970 to 1982 we used standard cemented components in 49 hips and had a high rate of acetabular loosening (52%) at a mean follow-up of 69 months. This was probably due to the mechanical insufficiency of irradiated periacetabular bone. From 1983 to 1990 we routinely used acetabular reinforcement rings. The rate of aseptic acetabular loosening in 22 hips at a mean follow-up of 40 months was 19%, but there were two septic loosenings emphasising the risk of infection in these patients. When total replacement is required for an irradiated hip, we recommend reinforcement of the acetabulum using a metallic ring, but there is still an increased risk of infection and in difficult cases such as severe acetabular destruction or soft-tissue or vascular injuries, a Girdlestone procedure may be indicated

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Complex displaced osteoporotic acetabular fractures in the elderly are associated with high levels of morbidity and mortality. Surgical options include either open reduction and internal fixation alone, or combined with total hip arthroplasty (THA). There remains a cohort of severely comorbid patients who are deemed unfit for extensive surgical reconstruction and are treated conservatively. We describe the results of a coned hemipelvis reconstruction and THA inserted via a posterior approach to the hip as the primary treatment for this severely high-risk cohort.

We reviewed the results of 545 consecutive total hip replacements using a cementless non-coated high-density polyethylene acetabular component combined with a cemented Muller stem at five to 10 years. In all, 421 patients (445 hips) were available for review, 118 by questionnaire and 303 by examination and radiography. Of these, 86% had a good or excellent result. We found a high rate of radiological loosening of the cup after the sixth year, and a high rate of clinical loosening after the eighth year. Loosening was commoner in women, in younger patients and where a smaller size of acetabulum had been used. Calcar resorption was significantly related to loosening of the acetabulum. Loosening appeared to be mainly due to polyethylene debris produced by micro-movement of the acetabulum against the bone, which had resulted in a giant cell foreign body reaction and subsequent bone erosion. We have abandoned the use of this prosthesis and suggest that direct contact between bone and polyethylene should be prevented by a coating of metal or some other material