Aims

There is a paucity of long-term studies analyzing risk factors for failure after single-stage revision for periprosthetic joint infection (PJI) following total hip arthroplasty (THA). We report the mid- to long-term septic and non-septic failure rate of single-stage revision for PJI after THA.

Aims

We aimed to compare the implant survival, complications, readmissions, and mortality of Vancouver B2 periprosthetic femoral fractures (PFFs) treated with internal fixation with that of B1 PFFs treated with internal fixation and B2 fractures treated with revision arthroplasty.

Aims

We aimed to report the mid- to long-term rates of septic and aseptic failure after two-stage revision surgery for periprosthetic joint infection (PJI) following total hip arthroplasty (THA).

Although there is some clinical evidence of ceramic bearings being associated with a lower infection rate after total hip arthroplasty (THA), available data remains controversial since this surface is usually reserved for young, healthy patients. Therefore, we investigated the influence of five commonly-used biomaterials on the adhesion potential of four biofilm-producing bacteria usually detected in infected THAs.

In this in-vitro research, we evaluated the ability of S. aureus, S. epidermidis ATCC 35984, E. coli ATCC 25922 and P. aeruginosa to adhere to the surface of solid biomaterials, including a 28mm cobalt-chromium metal head, a 28mm fourth-generation ceramic head, a 48mm fourth-generation ceramic insert, a 48mm highly-crossed linked polyethylene insert and a 52mm titanium porous-coated acetabular component. After an initial vortex step, a bacterial separation from the surface of each specimen was done until no remaining attached bacteria were observed by digital optical microscope. The colony-forming units were counted to determine the number of viable adherent bacteria and the bacterial density.

We found no differences on global bacterial adhesion between the different surfaces. E. coli presented the least adherence potential among the analysed pathogens (p<0.001). The combination of E. coli and S. epidermidis generated an antagonist effect over the adherence potential of S. epidermidis individually (58±4% vs. 48±5%; p=0.007). The combination of P. aeruginosa and S. aureus presented a trend to an increased adherence of P. aeruginosa independently, suggesting an agonist effect (71% vs. 62%; p=0.07).

In this study, ceramic bearings appeared not to be related to a lower bacterial adhesion than other biomaterials. However, different adhesive potentials among bacteria may play a major role on infection's inception.

Following a total hip arthroplasty (THA), early hospital readmission rates of 3–8% are considered as ‘acceptable’ in terms of medical care cost policies. Surprisingly, the impact of readmissions on mortality has not been priorly portrayed. Therefore, we aimed to analyse the mortality of unplanned readmissions after primary THA at a high-volume Argentinian center.

We prospectively analysed 90-day readmissions of 815 unilateral, elective THA patients operated between 2010–2014 whose medical insurance was the one offered by our institution. Mean follow-up was 51 months (range, 37–84). Median age was 69 (IQR, 62–77). We stratified our sample into readmitted and non-readmitted cohorts. Through a Cox proportional hazard model, we compared demographic characteristics, clinical comorbidities, surgical outcomes and laboratory values between both groups in order to determine association with mortality.

We found 37 (4.53%) readmissions at a median time of 40.44 days (IQR: 17.46–60.69). Factors associated with readmission were: hospital stay (p=0.00); surgical time (p=0.01); chronic renal insufficiency (p=0.03); ASA class 4 (p=0.00); morbid obesity (p=0.006); diabetes (p=0.04) and a high Charlson Index (p=0.00). Overall mortality rate of the series was 3.31% (27/815). Median time to mortality was 455.5 days (IQR: 297.58–1170.65). One-third (11/37) of the readmitted patients died, being sepsis non-related to the THA the most common cause of death. After adjusting for confounders, 90-day readmissions remained associated with mortality with an adjusted HR of 3.14 (CI95%: 1.05–9.36, p=0.04).

Unplanned readmissions were an independent risk factor for future mortality, increasing 3 times the risk of a decease eventuality.

Aims

The Corail stem has good long-term results. After four years of using this stem, we have detected a small group of patients who have presented with symptomatic metaphyseal debonding. The aim of this study was to quantify the incidence of this complication, to delineate the characteristics of patients presenting with this complication and to compare these patients with asymptomatic controls to determine any important predisposing factors.

Femoral offset restoration is related to low rates of wear and dislocation. Replication of the native hip anatomy improves prosthesis survival, whereas increasing the femoral offset elevates the torque stresses, thus inducing a risk of suboptimal stem fixation.

Although the Corail (DePuy Synthes, St Priest, France) uncemented stem has an excellent record of fixation, an unexpectedly number of aseptic loosenings has been noted in our institution.

We sought to characterize the clinical parameters observed in a group of patients who have experienced metaphyseal aseptic loosenings with the collarless version of the Corail uncemented femoral component; describe the radiographic findings in this group of patients; expose the intraoperative findings in the cases that needed revision surgery and to calculate a possible frequency of this complication.

We present a series of 15 metaphyseal debondings of the collarless version of the Corail uncemented stem in primary total hip arthroplasty. Eleven men and four woman with an average age of 60 years old (range: 42 to 81 years old) and a previous history of osteoarthritis presented with thigh pain and limping at an average of 33 months postoperative (range: 5 to 100 months). Seven cases presented a Dorr´s classification type A femur and 8 cases a type B femur. In 10 of the 15 cases a 36 mm ceramic on ceramic bearing surface was implanted and in 5 a 28 mm diameter ceramic on polyethylene pair. Radiographic assessment of the failures evidenced an increase in femoral offset of 6.2 mm in average (range: 0 to 17 mm). Nine of the 15 cases had a standard offset stem and 3 an extended offset stem. Leg length discrepancy was in average 2.4 mm (range: 0 to 8 mm). None of the failures presented a more than 2 mm subsidence. Alignment of these stems was in average 2.1 degrees of varus (range: 0 to 5 degrees).

Six cases were revised to a long cemented or uncemented stem, 2 cases were lost and 7 cases are awaiting revision surgery. Although the incidence of this complication was low (15 failures in 855 cases in 10 years = 1.75%), we are concerned about the real magnitude of this problem, as this mode of failure was observed up to 8 years after implantation.

Enhanced lateralization of the hip, independently of the type of stem, may have played a role in the infrequent early failures of this popular design. Routine use of “fine tunning” preoperative planning in order to avoid offset enhancement is strongly reccommended, as this was the only suspected factor that was present in almost all the failures we observed.

We determined the midterm survival, incidence of peri-prosthetic fracture and the enhancement of the width of the femur when combining struts and impacted bone allografts in 24 patients (25 hips) with severe femoral bone loss who underwent revision hip surgery. The pre-operative diagnosis was aseptic loosening in 16 hips, second-stage reconstruction in seven, peri-prosthetic fracture in one and stem fracture in one hip. A total of 14 hips presented with an Endoklinik grade 4 defect and 11 hips a grade 3 defect. The mean pre-operative Merle D’Aubigné and Postel score was 5.5 points (1 to 8).

The survivorship was 96% (95% confidence interval 72 to 98) at a mean of 54.5 months (36 to 109). The mean functional score was 17.3 points (16 to 18). One patient in which the strut did not completely bypass the femoral defect was further revised using a long cemented stem due to peri-prosthetic fracture at six months post-operatively. The mean subsidence of the stem was 1.6 mm (1 to 3). There was no evidence of osteolysis, resorption or radiolucencies during follow-up in any hip. Femoral width was enhanced by a mean of 41% (19% to 82%). A total of 24 hips had partial or complete bridging of the strut allografts.

This combined biological method was associated with a favourable survivorship, a low incidence of peri-prosthetic fracture and enhancement of the width of the femur in revision total hip replacement in patients with severe proximal femoral bone loss.

We reviewed the clinical and radiological results of 131 patients who underwent acetabular revision for aseptic loosening with impacted bone allograft and a cemented acetabular component. The mean follow-up was 51.7 months (24 to 156).

The mean post-operative Merle D’Aubigné and Postel scores were 5.7 points (4 to 6) for pain, 5.2 (3 to 6) for gait and 4.5 (2 to 6) for mobility. Radiological evaluation revealed migration greater than 5 mm in four acetabular components. Radiological failure matched clinical failure. Asymptomatic radiolucent lines were observed in 31 of 426 areas assessed (7%). Further revision was required in six patients (4.5%), this was due to infection in three and mechanical failure in three. The survival rate for the reconstruction was 95.8% (95% confidence interval 92.3 to 99.1) overall, and 98%, excluding revision due to sepsis.

Our study, from an independent centre, has reproduced the results of the originators of the method.

Bone allografts can store and release high levels of vancomycin. We present our results of a two-stage treatment for infected hip arthroplasty with acetabular and femoral impaction grafting using vancomycin-loaded allografts. We treated 29 patients (30 hips) by removal of the implants, meticulous debridement, parenteral antibiotic therapy and second-stage reconstruction using vancomycin-supplemented impacted bone allografts and a standard cemented Charnley femoral component. The mean follow-up was 32.4 months (24 to 60). Infection control was obtained in 29 cases (re-infection rate of 3.3%; 95% confidence interval 0.08 to 17) without evidence of progressive radiolucent lines, demarcation or graft resorption. One patient had a further infection ten months after revision caused by a different pathogen. Associated post-operative complications were one traumatic periprosthetic fracture at 14 months, a single dislocation in two hips and four displacements of the greater trochanter. Vancomycin-supplemented allografts restored bone stock and provided sound fixation with a low incidence of further infection.

Impacted morcellised bone allograft and a Charnley stem was used to revise 59 loose femoral components in 57 consecutive patients. Femoral bone loss was rated as Endo-Klinik grade 2 in nine patients, grade 3 in 41, and grade 4 in nine. The immediate postoperative radiographs and those taken at the most recent follow-up were compared for radiolucencies, subsidence and incorporation of the graft. One patient was lost to follow-up and two were not available for radiological analysis.

The mean clinical follow-up in 58 procedures was 56.7 months (24 to 144) and the mean radiological review of 56 reconstructions was 54.4 months (24 to 144). An intraoperative femoral fracture occurred in one patient (1.7%) and was successfully treated by strut grafting and cerclage wiring. Extrusion of cement through perforations or incomplete hoop fractures was detected in the postoperative radiographs of ten procedures (17%); none of these patients sustained a complete fracture. Three patients had dislocations (5%) and two (3.5%) developed painful subsidence of the stem which required a further revision. The latest follow-up radiographs in 56 reconstructions showed a well fixed stem and radiological healing of the graft in 52 (93%), and definite loosening in four (7%). Of these four, two were revised again and two were asymptomatic after a follow-up of 120 months each. The mean subsidence in the 52 successful revisions was 0.38 mm (0 to 4). Impaction allografting with a Charnley stem restored bone stock and provided adequate fixation of the stem in 93% of the hips. There was a low rate of rerevision (3.5%) and a low incidence of intraoperative and postoperative complications.