Femoral revision with the modular ZMR stem. Clinical and x-rays results at medium term follow-up

A retrospective review was conducted to evaluate the medium-term results of the ZMR modular revision taper stem. From March 1999 to December 2002, 65 consecutive hip revision surgeries were performed mostly for aseptic loosening. Femoral bone stock defects were classified according to AAOS\u2019s criteria and consisted mainly in type II and type III. A Wagner osteotomy was performed in 25 cases to remove primary implants that were cemented in 35 cases. Mean post-operative follow-up was 69 months (range, 36 to 91months). Clinical assessment at follow-up showed a significantly improved mean Harris Hip Score from 42 points preoperatively to 81 points postoperatively, while the x-ray examination did show a satisfactory distal integration of the stem in all cases and satisfactory reconstitution of the femoral bone stock in 47% of cases. The average subsidence of the stem at follow-up was under one millimeter. According to the data leg length discrepancy exceeding 15 millimeters caused significantly higher functional impairment and more pain

Lateral parapatellar approach in primary total knee arthroplasty of the valgus knee

Background Anatomic and pathological characteristics of the valgus knee deformity represent a challenging issue for the implant of a total knee arthroplasty. The surgical approach in such cases should allow a direct ad easy exposure of the joint, easy lateral soft tissue balancing and adequate patellar tracking. Materials and Methods Twenty-four total knee arthroplasties were implanted in valgus knees between January 2002 and September 2005. A mean preoperative valgus deformity of 18\ub0 was assessed on standing x-rays. Four posterior stabilized, eighteen posterior stabilized rotating platform prosthesis and two superstabilized prosthesis were implanted in 21 patients. The surgical approach has been in all cases a lateral parapatellectomy. Follow-up assessments were obtained for all patients at a mean 23 months. They consisted of a Knee Society Score and a Patellar Score evaluation, standing AP and lateral radiograms and skyline x-rays obtained at a flection of 45\ub0. Results A mean preoperative Knee Society Clinical Score of 32,7 points (range, -4 to 64 points) significantly improved at follow-up to an average 88,8 points (range, 57 to 99 points; p<0,05). The Knee Society Function Score significantly increased from a preoperative mean score of 32,7 points (range, -20 to 75 points) to an average followup score of 81,2 points (range, 30 to 100 points; p<0.05). The Patella Score revealed absence of anterior pain in all cases but one that reported severe pain. A satisfactory patello-femoral alignement of 4.7\ub0 (range, 1\ub0 to 10\ub0) was obtained at last follow-up x-rays. One intraoperative condilar fracture occured and was treated with a single screw. Discussion The lateral approach of valgus knees led to satisfactory results in primary total knee arthroplasties in a percentage of cases comparable or superior to those presented in literature for different approaches. In addition, lateral release is performed as a part of the approach itself, allows preservation of the blood supplies of the extensor apparatus and an optimal patellar tracking in most cases. Conclusions In conclusion, the lateral approach for a primary total knee arthroplasty could be recommended in valgus knees affected by osteoarthritis because as it proved to be effective in achieving a satisfactory implant positioning and functional outcome while reporting minor complications

Treatment of periprosthetic femoral fractures with distal fixation modular revision stems

Background Late periprosthetic fractures of the femur are the third most frequently reported cause of surgery after total hip artroplasty. Revision total hip artroplasty can be difficult, especially when poor bone stock is encountered. The aim of this study was to examine the results of late periprosthetic fractures complicated with primary implant loosening performed with distal fixation modular revision stem. Methods From November 1999 to May 2006, 16 late periprosthetic fractures were treated with distal-fixation, modular, straight stem. There were 13 females (82%) and 3 males (18%) whose mean age at surgery was 76.7 years (range, 48 to 95 years). Femoral revision surgery was performed with the Revitan (2 cases) and ZMR (14 cases) to get a stable distal primary fixation. X-rays were assessed accordingly to the Vancouver classification: there were 3 type B2 and 13 type B3 fractures. Mean post-operative follow-up was 52 months (range, 10 to 88 months). At the time of the last follow-up visit 4 patients already passed away, all of them for causes unrelated to the procedure. The clinical outcome was monitored with the Harris Hip Score, subjective VAS, pain and satisfaction evaluation. Standard AP and lateral x-rays of the hip were obtained at each follow-up visit. Leg-length discrepancy was also investigated as a factor possibly affecting outcome. Complications included one septic loosening that was treated with a two-stage revision. Results All the patients but one were finally able to walk and had minimal to no pain at all. A satisfactory functional outcome was achieved with an average 76 (range, 25 to 100) Harris Hip Scores points. The subjective pain and satisfaction scores were respectively 2.4 and 7.8 points. As far as radiograms are concerned, all the sixteen femur did show a good healing of the fracture, with no secondary stem subsidence. Discussion Generally, considering the severity of an event such as a periprosthetic late fracture in an elderly patient, results were satisfactory. The average Harris Hip Score and subjective satisfaction would have been even higher if one patient wouldn\u2019t have been so much disappointed because of her severe leg-length discrepancy, dependent on the acetabular side. From a surgical point of view, the employed devices proved to be handy in bridging the fracture with distal fixation while adequately stabilizing it. Conclusions According to the reported results, straight modular-revison stems provide an adequate treatment option of Vancouver type B3 and in selected cases of B2 type periprosthetic femoral fracture

Experimental model in vivo for quantitative assessment of bone resorption inhibition.

Quantitative assessment of bone resorption inhibition in vivo is not easily accomplished; methods relying on a count of osteoclasts are questionable, and histomorphometric evaluation of the bone mass presents several technical problems as well. The authors developed a simple method to measure the inhibition of bone resorption by study of the proximal tibial metaphysis of growing rats: the height of the perichondrial bone ring was taken as an index of the balance between osteoblastic and osteoclastic activity because any agent that inhibits osteoclasts (without interference with osteoblasts) produces an increase in the height of this anatomical structure. Since the ring is well demarcated by surrounding tissues, its height can be measured with accuracy and used for quantitative assessment of bone resorption inhibition. This model was tested with salmon calcitonin, and it provides evidence in vivo that this hormone inhibits osteoclastic bone resorption

Acetabular revision surgery in the presence of severe bone loss: surgical technique and early results with modular porous tantalum augments and cups

Subject: In the presence of minimal acetabular bone loss most revision procedures can be done with the use of an uncemented hemispheric device with or without morselized allograft. The use of modular porous tantalum augments and cups has been recently introduced to address more severe bone deficiencies. The purpose of this study is to describe the surgical technique and early clinical results obtained with trabecular metal acetabular augments in cases of acetabular revision with severe bone loss. Materials and Methods: Since November 2003 seven acetabular revisions have been done by means of TMT\uae augments and cups: the primary indication for acetabular revision was aseptic loosening in five patients and septic loosening in two patients. According to Paprosky classification the acetabular bone defects were classified as follows: 2B in two hips, 2C in one hip, 3A in two hips and 3B in three hips. In two cases it was the first surgical hip replacement procedure. Five cases were multiple revisions. Results: At an average follow-up of 24 months no implant had evidence of loosening or migration. No dislocations occurred. Discussions and Conclusions: Augments provide mechanical support to hemispheric cups of various dimensions. This surgical technique avoids the use of structural allograft, helps to restore the center of hip rotation and increases contact area between the implant and the host bone for biological fixation. Longer follow-up is required to verify survival of these implants and potential mechanical and biologic complications related to use of this modular TMT\uae system

Frailty and post-operative delirium influence on functional status in patients with hip fracture: the GIOG 2.0 study

Background: This study analyzes the effect of frailty and Post-Operative Delirium (POD) on the functional status at hospital discharge and at 4-month follow-up in patients with hip fracture (HF). Methods: Multicenter prospective observational study of older patients with HF admitted to 12 Italian Orthogeriatric centers (July 2019-August 2022). POD was assessed using the 4AT. A 26-item Frailty Index (FI) was created using data collected on admission. The outcome measures were Cumulated Ambulation Score (CAS) ≤ 2 at discharge and a telephone-administered CAS ≤ 2 after 4&nbsp;months. Poisson regression models were used to assess the effect of frailty and POD on outcomes. Results: 984 patients (median age 84&nbsp;years, IQR = 79–89) were recruited: 480 (48.7%) were frail at admission, 311 (31.6%) developed POD, and 158 (15.6%) had both frailty and POD. In a robust Poisson regression, frailty alone (Relative Risk, RR = 1.56, 95% Confidence Intervals, CI 1.19–2.04, p = 0.001) and its combination with POD (RR = 2.57, 95% CI 2.02–3.26, p &lt; 0.001) were associated with poor functional status at discharge. At 4-month follow-up, the combination of frailty with POD (RR 3.65, 95% CI 1.85–7.2, p &lt; 0.001) increased the risk of poor outcome more than frailty alone (RR 2.38, 95% CI 1.21–4.66, p &lt; 0.001). Conclusions: POD development exacerbates the negative effect that frailty exerts on functional outcomes in HF patients

Failure of dual radius hydroxyapatite-coated acetabular cups

<p>Abstract</p> <p>Introduction</p> <p>Many kind of hydroxyapatite-coated cups were used, with favorable results in short term studies; it was supposed that its use could improve osteointegration of the cup, enhancing thus stability and survivorship. The purpose of this study is to analyze the long term behavior of the hemispheric HA coated, Dual Radius Osteonics cup and to discuss the way of failure through the exam of the revised components and of both periacetabular and osteolysis tissue.</p> <p>Materials and Methods</p> <p>Between 1994 and 1997, at the Department of Orthopedic Sciences of the Insubria University, using the posterolateral approach, were implanted 276 Dual Radius Osteonics^®in 256 patients, with mean age of 63 years.</p> <p>Results</p> <p>At a mean follow-up of 10 years (range 8–12 years), 183 cups in 165 patients, were available for clinical and radiographical evaluation. 22 Cups among the 183 were revised (11%). The cause of revision was aseptic loosening in 17 cases, septic loosening in one case, periprosthetic fracture in another case, osteolysis and polyethylene wear in two cases and, finally, recurrent dislocations in the last one. In the remaining patients, mean HHS increased from a preoperative value of 50,15 to a postoperative value of 92,69. The mean polyethylene wear was 1,25 mm (min. 0,08, max. 3,9 mm), with a mean annual wear of 0,17 mm. The mean acetabular migration on the two axis was 1,6 mm and 1,8 mm. Peri-acetabular osteolysis were recorded in 89% of the implants (163 cases). The cumulative survivorship (revision as endpoint) at the time was 88,9%.</p> <p>Conclusion</p> <p>Our study confirms the bad behavior of this type of cup probably related to the design, to the method of HA fixation. The observations carried out on the revised cup confirm these hypotheses but did not clarify if the third body wear could be a further problem. Another interesting aspect is the high incidence of osteolysis, which are often asymptomatic becoming a problem for the surgeon as the patient refuses the possibility of a revision.</p

Overhaul and Installation of the ICARUS-T600 Liquid Argon TPC Electronics for the FNAL Short Baseline Neutrino Program

The ICARUS T600 liquid argon (LAr) time projection chamber (TPC) underwent a major overhaul at CERN in 2016-2017 to prepare for the operation at FNAL in the Short Baseline Neutrino (SBN) program. This included a major upgrade of the photo-multiplier system and of the TPC wire read-out electronics. The full TPC wire read-out electronics together with the new wire biasing and interconnection scheme are described. The design of a new signal feed-through flange is also a fundamental piece of this overhaul whose major feature is the integration of all electronics components onto the signal flange. Initial functionality tests of the full TPC electronics chain installed in the T600 detector at FNAL are also described

Lactate released by inflammatory bone marrow neutrophils induces their mobilization via endothelial GPR81 signaling.

Neutrophils provide first line of host defense against bacterial infections utilizing glycolysis for their effector functions. How glycolysis and its major byproduct lactate are triggered in bone marrow (BM) neutrophils and their contribution to neutrophil mobilization in acute inflammation is not clear. Here we report that bacterial lipopolysaccharides (LPS) or Salmonella Typhimurium triggers lactate release by increasing glycolysis, NADPH-oxidase-mediated reactive oxygen species and HIF-1α levels in BM neutrophils. Increased release of BM lactate preferentially promotes neutrophil mobilization by reducing endothelial VE-Cadherin expression, increasing BM vascular permeability via endothelial lactate-receptor GPR81 signaling. GPR81-/- mice mobilize reduced levels of neutrophils in response to LPS, unless rescued by VE-Cadherin disrupting antibodies. Lactate administration also induces release of the BM neutrophil mobilizers G-CSF, CXCL1 and CXCL2, indicating that this metabolite drives neutrophil mobilization via multiple pathways. Our study reveals a metabolic crosstalk between lactate-producing neutrophils and BM endothelium, which controls neutrophil mobilization under bacterial infection