Bone integration in acetabular revision hip arthroplasty using equine-derived bone grafts: a retrospective study.

PURPOSE: During the last decade, total hip arthroplasty has become a common procedure performed in young patients, as well as elderly ones. This has led to an increase in total hip arthroplasty revisions. Loosening of primary components with associated bone loss represents the major cause of total hip arthroplasty revision. This study evaluates the safety and performance of an enzyme-deantigenic equine-derived bone graft material in acetabular defect reconstruction. METHODS: Records of 55 patients who were treated for Paprosky type II or III acetabular bone defects with arthroplasty revisions using equine-derived bone and followed for an average of 34 months (range from 24 to 48 months) were analyzed. RESULTS: Of the 55 revisions, 49 (89%) were regarded as successful, showing good osteointegration without signs of mobilization. Failures included six cases (11%) of mobilization: five cases of aseptic mobilization (9.1% of revisions, 83% of failures) and one case of septic mobilization (1.9% of revisions, 17% of failures). These results are consistent with those of studies having a similar follow-up period for allografts used in combination with trabecular metal components. CONCLUSIONS: Results of the present study suggest that enzyme-treated equine-derived bone grafts may be a valid alternative to autogenous and homologous bone grafts in total hip arthroplasty revision.

Clinical and instrumental evaluation of two different regimens of tranexamic acid in total hip arthroplasty: a single-centre, prospective, randomized study with 80 patients.

PURPOSE: The use of tranexamic acid (TXA) in total hip arthroplasty (THA) can significantly reduce blood losses with many clinical and economical advantages. However, no consensus has been reached regarding the optimal regimen for TXA administration. The aim of this study is to analyse and compare the haemostatic effect of two different intravenous (IV) regimens of TXA. MATERIALS AND METHODS: We planned a single-centre, prospective, randomized study including 80 patients who underwent primary unilateral minimally invasive THA because of a hip osteoarthritic degeneration. We divided patients into two groups: the G10 group received two IV doses of 10 mg/kg of TXA, and the G20 group received two doses of 20 mg/kg. RESULTS: No significant differences in mean minimum levels of Hb and HcT stratified by days after surgery were uncovered between the two groups despite the use of two different dosages of TXA. Also the mean blood volume loss was statistically similar between two groups. No differences were also observed regarding the occurrence of adverse effects. CONCLUSIONS: In two IV bolus regimens of TXA administration, the use of a dose of 10 or 20 mg/kg provides statistically similar results in blood loss sparing. Therefore, the use of two 10 mg/kg doses could be considered more advisable in order to reduce the potential thromboembolic risks related to this drug.

The kinetics of remodeling of a calcium sulfate/calcium phosphate bioceramic.

In the last years considerable research and development activity have been expended to find new ceramic bone substitutes for the treatment of bone defects. However in many cases the drawback of synthethic bone substitutes are the slow graft incorporation and remodelling into the host bone. The purpose of this study was to analyze the kinetics of resorption and new bone formation of new calcium sulfate (CaSO4)/calcium phosphate (CaPO4) bioceramic engineered to enhance its bone forming properties. We prospectively evaluated the results of a series of 15 hips with osteonecrosis of the femoral head (ONFH) treated at with core decompression and injection of the CaSO4/CaPO4 composite. In all hips, a quantitative computed tomography (QTC) scan was taken within one week after the surgery, at 12 months, 2 years and finally with a minimum of 4 years follow-up. The mean HU in the immediate post-operative period was 1445 (Range 1388-1602); At one year the mean HU strongly decrease at 556.6 HU (P < 0.01); The mean HU at 2 years follow-up further decreased to 475.1. The mean HU at 4 years was unchanged. The quantitative and qualitative CT scan data of this series indicates that the CaSO4-CaPO4 ceramic composite resorbs over a narrow timeframe and the gradual resorption of the graft within the defect provides an ideal environment for the direct new bone growth that propagates across the defect.

A steroid-induced bilateral avascular necrosis of the femoral head in an underage patient affected by multiple sclerosis.

Patients affected by Multiple Sclerosis are often treated by pulsed intravenous corticosteroids to manage acute relapses with positive outcomes. The intravenous administration is frequently associated to avascular necrosis of several bones, particularly the femur. The present report regards a case of an underage MS patient with a bilateral ANFH secondary to pulsed administrations of steroids, managed by a conservative approach on a hip, and by a novel surgical technique on the contralateral side.

A novel technique to preserve range of motion in two-stage revision of infected total knee arthroplasty.

PURPOSE: Two-stage revision represents the gold standard in the treatment of infected total knee arthroplasty. Different techniques have been proposed, mostly not preserving range of motion. An articulated antibiotic-loaded cement spacer made in association with two unicompartmental implants has been used as an alternative to a static spacer in an effort to retain as much movement as possible between the stages in young, high-demand patients with preserved ROM. METHODS: We evaluated nine consecutive patients with a mean age of 66.5 years. The second stage was performed after lab tests returned to normal and culture proved negative. Mean follow-up was 4.6 years. RESULTS: Mean ROM from a preoperative value of 105.6° was 103.5° after the first stage, and improved to 110.0° after the definitive implant. Mean Knee Society score was 27.6 preoperatively improving to 86.4 points postoperatively. WOMAC score showed that six patients were very satisfied with the overall result of their reimplanted knee, three subjects were somewhat satisfied. No recurrence of infection, no significant radiolucent lines or osteolysis were recorded at clinical and radiological follow-up and the patients were satisfied with the outcome. CONCLUSIONS: Results indicated that this technique may ensure the advantages of a static spacer, but allow a greater ROM and better functional recovery. It may be considered as a viable option in selected cases even though the higher costs of two unicompartmental implants should be considered in the light of other aspects, such as prolonged hospital stay and rehabilitation in revision of infected total knee arthroplasty.

Growth factors in the treatment of early osteoarthritis.

Regenerative medicine is the science that studies the regeneration of biological tissues obtained through use of cells, with the aid of support structures and with biomolecules such as growth factors. As regards the growth factors the PRP, or the platelet-rich plasma, obtained from a withdrawal of autologous blood, concentrating the platelets, represents a safe, economical, easy to prepare and easy to apply source of growth factors. Numerous growth factors are in fact within the platelets and in particular a large number of them have a specific activity on neo-proliferation, on cartilage regeneration and in particular also an antiapoptotic effect on chondroblasts: - The PDGF which regulates the secretion and synthesis of collagen;- The EGF that causes cellular proliferation, endothelial chemotaxis and angiogenesis;- The VEGF that increases angiogenesis and vascular permeability;- The TGF-beta that stimulates the proliferation of undifferentiated MSC, stimulates chemotaxis of endothelial cells and angiogenesis;- The bFGF that promotes the growth and differentiation of chondrocytes and osteoblasts stimulates mitogenesis of mesenchymal cells, chondrocytes and osteoblasts. These properties have led to the development of studies that evaluated the efficacy of treatment of infiltrations in the knee and hip with platelet-derived growth factors. Regarding the knee it was demonstrated that in patients with moderate degree of gonarthrosis, the PRP is able to significantly reduce the pain and improve joint function, both on placebo and towards infiltrations with hyaluronic acid. The success of the treatment was proportional to the age of and inversely proportional to the severity of osteoarthritis according to Kellgren and Lawrence classification. The possibility of infiltrations guided with ultrasound into the hip led us to extend the indications also to hip arthrosis, as already showed by Sanchez. Even in coxarthrosis preliminary results at 6 and 12 months show that a cycle of 3 infiltrations of PRP has significantly decreased the pain and increased range of motion and joint function.

Hip arthrosis and surgical intervention: what and when?

Osteoarthritis of the hip is a common pathology and involves forms of disability and need for treatments that affect the quality of life of patients and their families, and in general of the whole society. It should be considered as such degenerative joint disease is increasing as the increase in life expectancy and musculoskeletal trauma, the latter responsible for secondary forms of osteoarthritis. The treatment of osteoarthritis of the hip has changed a lot over the years, since the earlier diagnosis and, before, with prevention through proper lifestyle. More in-depth knowledge of the biology of the tissues involved, first of all hyaline cartilage, has lead to non-surgical treatments such as infiltration with hyaluronic acid (viscosupplementation) and autologous growth factors derived from platelets (platelet rich plasma). Surgical therapy with prosthetic replacement is finally a choice to share with the patient based on pain and functional limitation, bearing in mind always the best technology and tribology and the possibility of less invasive surgical access, while recognizing that there are not still eternal prosthesis. Of particular importance then is the age of the patient. There are also other types of surgery (hip arthroscopy, forage) for other pathologies of the hip which can be resolutive, or, in a sense, can delay the arrival to the prosthetic replacement. We will discuss below the decision-making process that leads the surgeon with the patient to the surgery option.

A dual-mobility cup reduces risk of dislocation in isolated acetabular revisions.

BACKGROUND: Isolated acetabular revisions using standard cups are at risk of dislocation. The introduction of a nonconstrained dual-mobility cup was designed to improve prosthetic stability without increasing loosening rates, but it is unclear whether the risk of dislocation is reduced. QUESTIONS/PURPOSES: We therefore determined: (1) if the rate of dislocation in isolated acetabular revisions is lower with a dual-mobility cup, (2) implant survival, (3) patient function, and (4) radiographic incidence of migration, loosening, and osteolysis. METHODS: We prospectively followed 33 selected patients who underwent isolated acetabular revisions with a minimum of 2 years' followup (mean, 3 years; range, 2-5 years). In 24 patients a stainless steel dual-mobility cup was cemented into an antiprotrusio cage, whereas in nine we used a hyaluronan dual-mobility revision cup with a foramen hook and superior and posterior flanges screw fixations. We determined Harris hip (HHS) and WOMAC scores and examined radiographs for migration, loosening, and osteolysis. RESULTS: There were no dislocations. Survivorship rates of the femoral and acetabular components were 97% at 5 years; the rerevision rate for any reason was 3%. At last followup, the mean HHS increased from 48 points preoperatively to 86 points. No patients had progressive osteolysis, component migration, or loosening on radiographs. CONCLUSION: In this select group of isolated acetabular revisions, our data suggest the use of a dual-mobility cup reduced the risk of dislocation without increasing loosening from 2 to 5 years. LEVEL OF EVIDENCE: Level IV, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.

The use of an injectable calcium sulphate/calcium phosphate bioceramic in the treatment of osteonecrosis of the femoral head.

PURPOSE: The purpose of our study is to describe the rationale, the surgical technique and the early clinical and radiographic results of the treatment of patients with early stage osteonecrosis of the femoral head (ONFH) by performing: core decompression, injection of autologous bone marrow concentrate and the use of a new composite injectable bone substitute (PRO-DENSE(®)), as a mechanical supplementation associated with decompression. METHODS: The study included 37 hips (31 patients, 14 females, 17 males; mean age 43.9 years, range 24-56 years) with stages IC-IIIA ONFH. The outcome was determined by the changes in the Harris hip score (HHS), by progression in radiographic stages and by the need for hip replacement. The mean follow-up was 20.6 months (range 12-32 months). RESULTS: At final follow-up the mean HHS increased from 68 points pre-operatively to 86 points post-operatively. The radiological results showed that 29 hips (78.4 %) improved or had no further collapse. The overall clinical success rate of the procedure was 86.5 %, with three conversions to THA, and a failure rate of only 3.3 % in the pre-collapse group. CONCLUSIONS: We are encouraged by these early results using core decompression, injection of the autologous bone marrow concentrate and backfilling the defect with an injectable bioceramic for the treatment of early stages of ONFH; as far as a conclusion can be drawn from the current data, this treatment seems to relieve hip pain and prevent the progression of ONFH in the majority of the cases.

Long-term survival of a flat-on-flat total condylar knee arthroplasty fixed with a hybrid cementing technique for tibial components.

PURPOSE: Total knee arthroplasty is one of the most successful procedures of modern orthopedics. Several implants have been proposed over the years with different designs, kinematics, and cementing techniques, with good results. The aim of the study was to assess the clinical and radiographic long-term follow-up of a series of patients undergoing total knee replacement that used a specific design of knee implant with cemented femoral and patellar components, and a hybrid fixation technique for tibial trays that used a cemented base plate and press-fit keels. METHODS: A total of 145 implants in 135 patients were studied with clinical and radiologic evaluations. The mean follow-up was 17.1 years. RESULTS: Seven failures for aseptic loosening and four failures for infection were registered. Twenty-nine implants showed nonprogressive radiolucencies, mostly at a single component, which did not need revision. The overall survivorship at the mean follow-up of 15 years considering aseptic loosening as the endpoint was 92.1%. CONCLUSIONS: The authors confirm the good rates of success and the long-term survival of this specific implant and the effectiveness of the tibial hybrid cementing technique, which is still debated among researchers.

Advances in the surgical treatment of fragility fractures of the upper femur.

Fragility fractures typically occur in elderly patients. They are related to osteoporosis, because of the weakening of the bone structure, and are the result of low-energy injuries and often involve the metaphyseal segments of bone. The fracture of the upper extremity of the femur are one of the most typical of the elderly patients. They may be intracapsular (femoral neck fractures) or extracapsular (intertrochanteric fractures). Each kind of fracture can be treated in several ways: the intracapsular fracture can be treated with screws, unipolar or bipolar hemiarthroplasty or even with total arthroplasty. The extracapsular fractures instead can be treated with sliding hip screw, intramedullary nail, femoral neck screws, helical blade or primary arthroplasty. What must be remembered is that osteoporotic bone has distinct morphologic characteristics that influence its biomechanical properties and therefore the choices and techniques for internal fixation. Therefore only a complete understanding of the biology of the osteoporotic bone will lead to a good quality of the treatment of the fragility fractures.

Oxidized zirconium femoral component for TKA: a follow-up note of a previous report at a minimum of 10 years.

BACKGROUND: New bearing surfaces for total knee replacement have been described in an attempt to reduce polyethylene wear and secondary osteolysis and improve longevity of implants. Oxidized zirconium is a new material that combines the strength of a metal with the wear properties of a ceramic. However, there are no reports as to who documents the long term results. We report a 10 year follow-up note of a selected series of TKAs with an oxidized zirconium femoral component. METHODS: We prospectively follow 98 TKAs performed in 94 patients with an oxidized zirconium femoral component. Five patients (5 knees) had died and 6 (6 knees) were lost to follow-up at a minimum of 2 years (mean, 6.3 years; range, 2-9 years) after the operation. For the remaining 83 patients (87 knees), the minimum follow-up was 10 years (mean, 11.3 years; range, 10.0-12.6 years). In 51 cases (58.6%), a cruciate-retaining implant with a deep-dished, more conforming PE was used, and in 36 cases (41.4%), a posterior-stabilized design was used. The patellae were resurfaced in 32 cases (36.7%) and in 55 cases (63.3%) were left unresurfaced. RESULTS: Survivorship was 97.8% at 10 years postoperatively. Two knees were revised for aseptic loosening of the femoral component. No major complication was observed clinically or radiologically. Mean Knee Society score improved from 36 to 84 and functional score from 37 to 83. CONCLUSIONS: Oxidized zirconium femoral component in TKA performs well over the first 10 years following implantation, with excellent survival rates and good clinical and radiological outcomes. LEVEL OF EVIDENCE: Level IV, therapeutic study.

Long term results of percutaneous fixation of proximal humerus fractures.

BACKGROUND: Proximal humerus fracture in elderly osteoporotic patients usually leads to severe displaced and multifragmentary fractures. Associated comorbidities may limit surgical options and conservative treatment is commonly indicated, however, with variable results. In most cases, surgery is the treatment of choice in order to restore anatomical integrity, and allow early functional recovery. Several techniques were used over the years, each with specific indication. Percutaneous pinning after closed reduction, a mini-invasive technique and fixation by use of K-wires is not preferred commonly. We present our experience with this approach, focusing on its indications and advantages. PATIENTS AND METHODS: A study group of 41 consecutive patients with a mean age of 65.5 years were evaluated clinically (VAS, Constant-Murley score, range of motion), and with radiological analysis: 35 patients finally completed a minimum followup of 24 months. RESULTS: K-wires were removed after a mean interval of 4 weeks. Clinical and radiographic healing occurred in a mean time of 8.2 weeks in all fractures but one, with improvements in mean Constant-Murley score of 87.6 points, mean VAS of 2.3. In 33 patients, the reduction was considered satisfactory. In two cases, reduction was poor, but the patients however presented acceptable functional outcome. CONCLUSIONS: Percutaneous pinning may represent a suitable option of treatment for 2-or 3-part proximal humerus fractures in selected subjects.

New biomaterials for bone regeneration.

Bone-grafting techniques either with autografts or allografts still represent a challenge for reconstructive surgery.Allografts and autografts are the current strategies for filling bone defects and subsequent repair but each have drawbacks. Synthetic bone-graft substitutes, developed in an effort to overcome the inherent limitations of autograft and allograft, represent an alternative strategy. Synthetic bone graft substitutes have the goal of mimicking the physical and mechanical nature of native tissue and to promote osteoconduction for bone regeneration. In addition these substitutes are capable to release drugs or growth factors in a temporally and spatially manner. Some biomaterials are employed to design biomimetic scaffold such as natural and synthetic polymers, ceramics, metallics and composites.The purpose of this paper is to provide an overview of the main biomaterials used for bone reconstruction.

The use of autologous blood-derived growth factors in bone regeneration.

Platelet-rich plasma (PRP) is defined as a portion of the plasma fraction of autologous blood having platelet concentrations above baseline. When activated the platelets release growth factors that play an essential role in bone healing such as Platelet-derived Growth Factor, Transforming Growth Factor-ß, Vascular Endothelial Growth Factor and others.Multiple basic science and in vivo animal studies agree that PRP has a role in the stimulation of the healing cascade in ligament, tendon, muscle cartilage and in bone regeneration in the last years PRP had a widespread diffusion in the treatment of soft tissue and bone healing.The purpose of this review is to describe the biological properties of platelets and its factors, the methods used for producing PRP, to provide a background on the underlying basic science and an overview of evidence based medicine on clinical application of PRP in bone healing.