We sought to determine the short to medium-term clinical and radiographic outcomes using a short stem in young adults with a proximal femoral deformity (PFD).

We prospectively studied 31 patients (35 hips) with PFDs treated with an uncemented primary THA using a short stem with cervicometaphyseal fixation between 2011–2018. There were 19 male (23 hips) and 12 female (12 hips) patients, with a mean BMI of 26.7±4.1 kg/m². Twelve cases had a previous surgical procedure, and six of them were failed childhood osteotomies. Mean age of the series was 44±12 years, mean follow-up was 81±27 months and no patients were lost to follow-up. PFDs were categorized according to a modified Berry´s classification. Average preoperative leg-length discrepancy (LLD) was −16.3 mm (−50 to 2).

At a mean time of 81 months of follow-up, survival rate was 97% taking revision of the stem for any reason and 100% for aseptic loosening as endpoints. No additional femoral osteotomy was required in any case. Average surgical time was 66 minutes (45 to 100). There was a significant improvement in the mHHS score when comparing preoperative and postoperative values (47.3±10.6 vs. 92.3±3.7, p=0.0001). Postoperative LLD was in average 1 mm (−9 to 18) (p=0.0001). According to Engh's criteria, all stems were classified as stable without signs of loosening. Postoperative complications included 1 pulmonary embolism, 1 neurogenic sciatic pain, 1 transient sciatic nerve palsy that recovered completely after six months, and 2 acute periprosthetic joint infections. One patient suffered a Vancouver B2 periprosthetic femoral fracture 45 days after surgery and was revised with a modular distally fixed uncemented fluted stem.

A type 2B short stem evidenced promising outcomes at short to medium-term follow up in young adult patients with PFDs, avoiding the need for corrective osteotomies and a revision stem.

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.

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.

Background: Infection diagnosis in THA remains difficult in some cases. Intraoperative analysis of frozen sections is related to the high sensitivity, specificity, positive predictive value, negative predictive value and accuracy. However, it is a technically demanding procedure and is not a universally accepted method. In the present study, we compared interleukin-6 (IL6) serum level with the erythrocyte sedimentation rate (ESR), the level of C-reactive protein (CRP) and the analysis of frozen sections of intraoperative specimens (FS).

Materials: Sixty-nine patients with a THA needing a reoperation due to a suspected infection or another aseptic failure were studied. Patients with chronic inflam-matory diseases, antibiotic treatment prior to surgery, Paget’s diseases and immunodeficiency syndromes were excluded from the study. The mean age at the time of the operation was 68 years old (range: 39 to 91). ESR, CRP and the serum level of IL6 were measured in blood samples before surgery. The cut-off levels were: ESR: ≥ 32 mm/hr, CRP: ≥ 3.2 mg/dl and interleukin-6 ≥ 12 pg/ml. Intraoperatively, samples of tissues were taken to be analyzed immediately on FS, to be routinely processed at the moment and to be referred for bacteriological cultures and histological study.

Results: Eleven (16%) of the 69 hips were infected. ESR showed a sensitivity of 0.72 (0.41 to 1.00), a specificity of 0.86 (0.76 to 0.95), a positive predictive value of 0.50 (0.22 to 0.77), and a negative predictive value of 0.94 (0.84 to 1.00).CRP showed a sensitivity of 0.72 (0.41 to 1.00), a specificity of 0.91 (0.83 to 0.99), a positive predictive value of 0.61 (0.31 to 0.91), and a negative predictive value of 0.94 (0.87 to 1.00). IL6 showed a sensitivity of 0.36 (0.30 to 0.69), a specificity of 0.94 (0.88 to 1.00), a positive predictive value of 0.57 (0.13 to 1.00), and a negative predictive value of 0.88 (0.80 to 0.97). The evaluation of the FS showed a sensitivity of 0.81 (0.54 to 1.00), a specificity of 0.98 (0.94 to 1.00), a positive predictive value of 0.90 (0.66 to 1.00), and a negative predictive value of 0.96 (0.91 to 1.00).The combination of CRP and IL6 identified all patients with deep infection of the implant and showed a sensitivity of 0.57 (0.13 to 1.00), a specificity of 1.00 (0.99 to 1.00), a positive predictive value of 1.00 (0.87 to 1.00), and a negative predictive value of 0.94 (0.87 to 1.00).

Conclusion: In this study, we obtained similar results combining CRP and IL6 as with the analysis of the frozen sections, which has been in the past our first option to determine whether a THA is infected or not. IL6 and CRP may be used as a valuable routine diagnostic tool in revision THA.

Containment of bone defects is one of the main requisites for using the bone impaction grafting technique. When the proximal femur is absent, circumferential meshes in combination with impacted bone allografts and long stems could be an alternative method. However, the initial stability of this femoral stems has not been evaluated and we were not able to find any series in the literature that includes a group of patients treated with this method.

This study has two purposes: one is to analyze the initial resistance in vitro to axial and rotational forces of a fresh frozen bovine model with a complete loss of the proximal femur reconstructed with a circumferential metal mesh containing impacted bone allografts and a long polished cemented stem. The second is to present the short-term clinical and radiographic evaluation in a group of patients with massive bone loss of the proximal femur that were reconstructed with this method.

Four femurs with an 8 cm proximal bone defect were reconstructed with a circumferential metal mesh, impacted bone grafts and a cemented long stem (group 1). Results were compared with 4 cases presenting an intact proximal femur in which the same stem was implanted (group 2).

Thirteen patients with complete massive proximal femoral bone defects (average 12 cm long) were reconstructed with a circumferential metal mesh, impacted bone allografts and a long cemented stem (average 217 cm long).

Failure mode was characterized by subsidence under axial load in group one at 617 kg and by periprosthetic fracture in control group at 1335 kg. Under rotational load, group 1 femurs failed at the cement interface at an average of 79 kg and the intact femurs presented a fracture at an average of 260 kg.

At 25 months follow-up, 6 patients had to be reoperated. We observed 2 fractures of the metal mesh at 31 and 48 months in cases reconstructed with a Charnley stem that did not by pass the mesh. Three patients presented one dislocation that needed open reduction in 2 cases. Two acute deep infections were treated with debridement, antibiotics and component retention.

This model presented a 50% resistance to axial load and 30% resistance to rotational load compared to an intact femur with the same implant. However, this resistance is by far higher than the physiologic load occurring in a normal femur during gait.

Although the incidence of complications in this patients was high, this was related to the complexity of the cases. Failures of the system were not observed except in the 2 cases presenting technical defects.

This experimental initial stability and early clinical as well as radiographic results encourage the use of circumferential meshes to contain impacted bone allografts combined with long cemented stems in complex revision hip surgery.

Acetabular bone stock loss represents one of the main challenges in revision hip surgery.

We present 149 consecutive aseptic acetabular reconstructions with impacted bone allograft technique and a cemented cup followed clinically and radiographically for an average of 52 months (range 24–156 months). Patients requiering reinforcement rings were not included in this series. Seven reconstructions in six patients were lost to follow-up.

The average postoperative Merle DAubigne and Postel score was 5.7 points for pain, 4.5 points for mobility and 5.2 points for gait. Radiographic analysis evidenced incorporation of the grafts in all but in four cups with more than 5 mm migration, demonstrating radiographic failure. All of these patients presented clinical failure as well. Non progressive radiolucent lines were observed in 29 non symptomatic patients. mainly in Zone 1 according to De Lee and Charnley. Six patients were reoperated (4.5%), 3 of them because of deep infection and 3 patients for aseptic failure related to massive segmental and cavitary defects. Overall survival rate of the acetabular reconstruction was 95.8% (CI 95%:92.3–99.1). When infected cases were excluded, this rate was 98%.

Providing precise indications, acetabular reconstruction with impacted morsellized bone allografts and cemented cups is an excellent biologic reconstructive technique in patients with bone stock deficiency