HISTOLOGICAL FEATURES OF PSEUDOTUMOR AFTER SMALL HEAD DIAMETER METAL-ON-METAL TOTAL HIP ARTHROPLASTY.

The pathologic aspects of periprosthetic tissues in failed second-generation metal-on-metal (MoM) resurfacing hip arthroplasties have been widely described in terms of necrosis and inflammation. To our knowledge little data are reported on the association of this lesion with the use of small head diameter (less than 32 mm). In this study we present a small series of pseudo-tumor in small head metal-on-metal total hip arthroplasty focusing our attention on the histologic aspects of the harvested pathologic tissue. The histological examination of our cases showed a presence of lymphocytic infiltrate suggesting a delayed hypersensitivity reaction to metal of type IV (ALVAL) but different to each other in terms of the prevalence of the cellular component. If macrophages are predominant, the pathogenetic mechanism seems to be the reaction against metallic particle. On the other hand, if granulocytes are predominant, it is possible to consider a hypersensitivity reaction. Our observation suggests that the evidence of Pseudotumor in case of small-head metal-on-metal arthroplasty should be considered with the same properties of big-head and therefore these patients should be followed scrupulously.

Anatomic reinsertion of the distal biceps tendon rupture through a single anterior approach: extensile or mini-invasive approach? A retrospective study at mean 45-month follow-up.

PURPOSE: To evaluate and compare clinical results and complication rate of a standard and mini-invasive reconstruction technique for distal biceps tendon rupture. METHODS: Twenty-eight cases of biceps tendon rupture were evaluated at mean 45-month follow-up. A standard anterior approach was used in 19 cases, and a less invasive anterior approach was used in nine cases. Suture anchors were used for tendon reconstruction in all cases. Elbow range of motion (ROM), subjective strength recovery, time to return to work and sports activities, and complications were recorded. Disability of the Arm, Shoulder and Hand Score (DASH) the Oxford Elbow Score (OES), and the Mayo Elbow Performance Score (MEPS) were obtained for all patients. RESULTS: Mean ROM recovery was almost complete. Mean subjective strength recovery allowed full return to sports and work in 93 % of cases, within mean 3-month postoperative. Mean DASH, OES, and MEPS scores were good. The clinically relevant complications rate was 17.8 %, all associated with the standard extensile approach group (Group A). Asymptomatic heterotopic ossifications were detected in four cases (14.3 %), not affecting functional recovery. CONCLUSIONS: Clinical results and complications rate of anatomical reconstruction of the distal biceps tendon rupture were comparable to the literature. Comparison between Group A and B showed no significant differences in terms of ROM, and OES and MEPS scores. Strength recovery, time to return to sports and work, and DASH score showed a positive trend in Group B. The clinically relevant complications rate was 0 % in Group B and 26 % in Group A.

The great beauty: a neuroaesthetic study by neuroelectric imaging during the observation of the real Michelangelo's Moses sculpture.

Recent studies have been showed as the perception of real or displayed masterpieces by ancient or modern painters generate stable neuroelectrical correlates in humans. In this study, we collected the neuroelectrical brain activity correlated with the observation of the real sculpture of Michelangelo's Moses within the church where it is actually installed in a group of healthy subjects. In addition to the cerebral activity also the heart rate (HR) and the galvanic skin response (GSR) were collected simultaneously, to assess the emotional engage of the investigated population. The Moses sculpture was observed by the group from three different point of views, each one revealing different details of the sculpture. In addition, in each location the light conditions related to the specific observation of the sculpture were explicitly changed. Results showed that cerebral activity of the subjects varied significantly across the three different views and for light condition against no light condition (p<;0.04). Furthermore, the emotional engage estimated on the whole population is higher for a point of observation in which the Mose's face is directed toward the eyes of the observers (p<;0.02). Finally, the cerebral appreciation of the investigated group was found maximum from a perspective in which all the details of the sculpture could be easily grab by the eyes. Results suggested how the perception of the sculpture depends critically by the point of view of the observers and how such point of view can produce separate emotional and cerebral responses.

An electroencephalographic Peak Density Function to detect memorization during the observation of TV commercials.

Nowadays, there is a growing interest in measuring the impact of advertisements through the estimation of cerebral reactions. Several techniques and methods are used and discussed in the consumer neuroscience. In such a context, the present paper provides a novel method to estimate the level of memorization occurred in subjects during the observation of TV commercials. In particular, the present work introduce the Peak Density Function (PDF) as an electroencephalographic (EEG) time-varying variable which is correlated with the cerebral events of memorization of TV commercials. The analysis has been performed on the EEG activity recorded on twenty healthy subjects during the exposition to several advertisements. After the EEG recordings, an interview has been performed to obtain the information about the memorized scenes for all the video clips watched by the subjects. Such information has been put in correlation with the occurrence of transient peaks of EEG synchronization in the theta band, by computing the PDF. The present results show that the increase of PDF is positively correlated, scene by scene, (R=0.46, p<;0.01) with the spontaneous recall of subjects. This technology could be of help for marketers to overcome the drawbacks of the standard marketing tools (e.g., interviews, focus groups) when analyzing the impact of advertisements.

Differences in the perceived music pleasantness between monolateral cochlear implanted and normal hearing children assessed by EEG.

The perception of the music in cochlear implanted (CI) patients is an important aspect of their quality of life. In fact, the pleasantness of the music perception by such CI patients can be analyzed through a particular analysis of EEG rhythms. Studies on healthy subjects show that exists a particular frontal asymmetry of the EEG alpha rhythm which can be correlated with pleasantness of the perceived stimuli (approach-withdrawal theory). In particular, here we describe differences between EEG activities estimated in the alpha frequency band for a monolateral CI group of children and a normal hearing one during the fruition of a musical cartoon. The results of the present analysis showed that the alpha EEG asymmetry patterns related to the normal hearing group refers to a higher pleasantness perception when compared to the cerebral activity of the monolateral CI patients. In fact, the present results support the statement that a monolateral CI group could perceive the music in a less pleasant way when compared to normal hearing children.

Neuroelectric brain imaging during a real visit of a fine arts gallery: a neuroaesthetic study of XVII century Dutch painters.

Neuroaesthetic is a scientific discipline founded more than a decade ago and it refers to the study of the neural bases of beauty perception in art. The aim of this paper is to investigate the neuroelectrical correlates of brain activity of the observation of real paintings showed in a national fine arts gallery (Scuderie del Quirinale) in Rome, Italy. In fact, the present study was designed to examine how motivational factors as indexed by EEG asymmetry over the prefrontal cortex (relative activity of the left and right hemispheres) could be related to the experience of viewing a series of figurative paintings. The fine arts gallery was visited by a group of 25 subjects during an exhibition of the XVII century Dutch painters. Results suggested a strict correlation of the estimated EEG asymmetry with the verbal pleasantness scores reported by the subjects (p<0,05) and an inverse correlation of the perceived pleasantness with the observed painting's surface dimensions (p<0,002).

Frontal EEG theta changes assess the training improvements of novices in flight simulation tasks.

The aim of the study is to analyze the variation of the EEG power spectra in theta band when a novice starts to learn a new task. In particular, the goal is to find out the differences from the beginning of the training to the session in which the performance level is good enough for considering him/her able to complete the task without any problems. While the novices were engaged in the flight simulation tasks we recorded the brain activity by using high resolution EEG techniques as well as neurophysiologic variables such as heart rate (HR) and eye blinks rate (EBR). Results show clear changes in the EEG power spectra in theta band over the frontal brain areas, either over the left, the midline and the right side, during the learning process of the task. These results are also supported by the autonomic signals of HR and EBR, by the performances' trends and by the questionnaires for the evaluation of the perceived workload level.

Bone marrow aspirate and bone allograft to treat acetabular bone defects in revision total hip arthroplasty: preliminary report.

OBJECTIVES: The safety and effectiveness of autologous mesenchymal cells for treating bone defects in humans is still uncertain. The present study presents a new technique consisting of allogeneic bone grafting enriched with bone marrow concentrate to treat acetabular bone defects resulting from aseptic loosening of the acetabular cup after total hip replacement. PATIENTS AND METHODS: Five adult patients were included in the study. Prior to surgery, patients were tested for antibodies to common pathogens. Treatment consisted of bone allogeneic scaffold seeded with bone marrow mesenchymal cells harvested from the iliac crest and concentrated using an FDA-cleared device. Clinical and radiographic follow-up was performed at 1, 3, 6, and 12 months after surgery. To assess viability, morphology, and the immunophenotype, bone marrow nucleated cells were cultured in vitro, then tested for sterility and evaluated for the possible replication of adventitious viruses. RESULTS: In 4 of 5 patients, both clinical and radiographic healing of the bone defect together with bone graft integration was observed at the mean time of 3.5 months. Mean follow-up was 2 years. One patient failed to respond. No post-operative complications were observed. Bone marrow nucleated cells were enriched 3.8-fold by a single concentration step. Enriched cells were free of microbial contamination. The immunophenotype of adherent cells was compatible with that of mesenchymal stem cells. No viral reactivation was observed. CONCLUSIONS: Allogeneic bone scaffold enriched with concentrated autologous bone marrow cells obtained from the iliac crest, may represent a good alternative to treat acetabular bone defects observed in revision hip arthroplasty.

Lumbar spinal stenosis treatment with Aperius perclid interspinous system.

PURPOSE: The purpose of this study is to report clinical outcome and imaging changes of percutaneous Aperius stand-alone implant in patients with degenerative lumbar spinal stenosis and neurogenic intermittent claudication, which did not respond to conservative treatment. METHOD: Between January 2008 and July 2010, 37 patients (20 males and 17 females) with mean age of 64.3 years underwent surgery for the onset of claudicatio spinalis with Aperius PercLID interspinous device (Medtronic). In all patients, the diagnosis was: foraminal stenosis, in one case (2.7 %) it was associated to a degenerative anterior listhesis (I grade), in three cases (8.1 %) it was associated to an intraforaminal disc herniation. The mean follow-up was of 18 months (range 2-35 months). The patients were evaluated through the Oswestry disability index, Zurich Claudication Questionnaire (ZCQ), VAS scales. In all cases were obtained preoperative and in postoperative radiographs and magnetic resonance imaging. RESULTS: The VAS score decreased significantly after surgery: the patients presented a mean VAS of seven preoperatively and two postoperatively (p < 0.001). The ZCQ score significantly decreased postoperatively, with an average reduction of 21.89 % (p < 0.001). The ODI score as well showed a significant reduction postoperatively of an average 26.09 % (p < 0.001). CONCLUSION: Despite of the brief follow up, the preliminary results are encouraging, showing a significantly decrease of the disability parameters, a marked improvement of the function with the vanishing of the claudicatio spinalis and the following increase of the free interval during the walk. Aperius PercLID system seems to offer an alternative to the traditional decompression surgery.

The use of a preformed spacer in two-stage revision of infected hip arthroplasties.

Two-stage revision with the use of an antibiotic-loaded cement spacer has spread widely as a successful treatment for THA infection. Between 1999 and 2008, 28 patients with infected THA were treated with two-stage implant revision using a preformed spacer. The spacer was left in situ for 5.5 months (range 1-13 months), and the patients were allowed to walk with partial weight bearing. At a mean follow-up of 53 months (range 18-106 months), recurrence of infection was observed in only one patient. Complications were observed in five patients: three spacer dislocations, one distal femoral fracture occurred during stem removal, and one femoral artery pseudo-aneurysm. The mean HHS increased from 43 points (range 13-77) to 82 points (range 35-96). Though small prospective studies are reported in literature, good eradication rate and good functional outcomes encourage for the use of an antibiotic-loaded cement spacer. The industrial production ensures procedure standardization, well-defined physical and chemical properties to the device and eliminates time necessary to intraoperatory manufacturing.

Management of distal radius fractures: treatment protocol and functional results.

Distal radius fractures are the most frequent lesions encountered during clinical practice. The treatment is controversial and still debated in the literature. For a correct management of these lesions many authors recently emphasised the importance of anatomical reduction, a stable fixation and early joint mobilisation. We report our experience in the daily management of these lesions. The fractures are evaluated considering fracture type, fracture reduction criteria, adequacy of reduction criteria and overall fracture stability. The best treatment option must be decided in accordance to the type of fracture, the extent of metaphyseal comminution, the quality of the bone and the medical condition of the patient.

Application of bone morphogenetic proteins to femoral non-unions: a 4-year multicentre experience.

Fracture non-unions often complicate orthopaedic trauma. BMPs (bone morphogenetic proteins) are currently considered the most appealing osteoinductive agents. Applications of BMP-7 since January 2004 were prospectively recorded in a multicentre registry of aseptic femoral non-unions. The study included 30 patients who had undergone a median of 1 revision operation before BMP-7 application and who were followed up for a median 24 months. In 23/30 cases the application of BMP-7 was combined with revision of the fixation, and in 12 it was combined also with autograft. Non-union healing was verified in 26/30 cases in a median period of 6 months. No adverse events were associated with BMP-7 application. Our case series supports the safety and efficacy of BMP-7 in femoral non-unions. Multicentre networks and systematic, long-term follow-up of patients may improve understanding of this promising osteoinductive bone substitute.

The unstable total hip replacement.

BACKGROUND: Dislocation is one of the most common complications of total hip arthroplasty with a reported dislocation rate of 3.2%. Despite increased experience with hip replacement, the overall rate has not yet changed. The aim of this paper is to review the most recent literature published on this topic and indexed in Medline, in order to clarify the main risk factors, and to standardize a treatment protocol of such an important complication of prosthetic surgery. MATERIALS AND METHODS: Medline database was searched using key words: "hip dislocation", "hip instability" from 1980-2007. Studies were eligible for review and included if they met the following criteria: (1) publication in English, (2) clinical trials (3) review papers. RESULTS: The risk of first-time dislocation as a function of time after the surgery is not well understood. Most, but not all, series have demonstrated that the risk of dislocation is highest during the first few months after hip arthroplasty; however, first-time late dislocation can also occur many years after the procedure. Several risk factors were described, including the surgical approach, the diameter of the head, impingement, component malposition, insufficient abductor musculature. In addition, there are also many treatment options, such as long-term bracing after closed reduction, component reorientation, capsulorraphy, trochanteric advancement, increasing offset, exchange of the modular head and the polyethylene liner, insertion of constrained liner. CONCLUSION: Preventing hip dislocation is obviously the best strategy. Surgeons must take into account patient and surgical risk factors. For patients at high risk for dislocation the surgeon should accurately restore leg length and femoral offset; the use of larger femoral heads, posterior transosseous repair of the capsulotendinous envelope if posterior approach is chosen or the use of a lateral approach should be considered. Proper patient education and postoperative care are very important.

Analysis of bone ingrowth on a tantalum cup.

BACKGROUND: Trabecular Metal (TM) is a new highly porous material made of tantalum (Zimmer, Warsaw, Indiana, USA). Its three-dimensional structure is composed of a series of interconnected dodecahedron pores that are on average 550 microm in diameter. This size is considered optimal for bone ingrowth and is similar to trabecular bone. The elastic modulus of TM (3 GPa) is more similar to that of cancellous (0,1-1,5 GPa) or cortical (112-18 GPa) bone and is significantly less similar to that of Titanium (110 GPa) and Co-Cr alloys (220 GPa). These features enable bone apposition and remodeling. The purpose of the present study was to evaluate the histology of the bone-implant interface in a human specimen. MATERIALS AND METHODS: A highly porous tantalum cup (Zimmer, Warsaw, Indiana, USA) was removed for recurrent dislocations three years after implantation. In order to obtain a slice of the cup, two cuts were made on the centre using an Exakt cutting machine. Then the slice was embedded in a Technovit resin and a Hematoxylin-eosin stain was used to study the bone tissue. Bone ingrowth was calculated using a method based on simple calculations of planar geometry. RESULTS: The histological evaluation of the periprosthetic tissues revealed a typical chronic inflammation with few particles of polyethylene that were birefringent using polarized light. The quantitative evaluation of bone ingrowth revealed that more than 95% of voids were filled with bone. DISCUSSION: In the literature, a lot of studies focused on tantalum were carried on animal model. Up to now little information is available about the histology of the bone-tantalum interface in a human artificial joint. We had an opportunity to remove a well integrated cup hence this study. The histology confirmed the strong relationship between the structure of this material and bone. The morphometric analysis revealed a high percentage of bone ingrowth.

"Conus" uncemented stem in developmental hip dysplasia.

The purpose of this study was to evaluate 115 "Conus" uncemented stems at an average follow-up of 6 years (2-9 years). Seventeen patients were lost at follow-up for a final number of 98 stems in 75 patients. The clinical outcome of 71 hips (72%) was graded excellent, 25 (25%) were good, one (2%) fair and one (2%) poor. The average Harris Hip Score increased from 49.35 before operation to 96.30 at the time of the last follow-up. None of the stems implanted required a revision for aseptic or septic loosening. Cortical hypertrophy or radiolucencies were never seen in any of the stems evaluated. Heterotopic ossification was seen in one hip (1%). Modification of the calcar was observed in 29 hips (30%) and they consisted in a slight rounding off of the proximal medial edge of the cut femoral neck. These results encourage the use of this versatile stem which showed a good primary and secondary stability, with a good load distribution along the femur.

The modified Burton-Pellegrini method for the treatment of trapeziometacarpal arthritis. Medium-term results.

An original modification in the Burton-Pellegrini technique was used to treat 20 cases of trapeziometacarpal arthritis between 1992 and 2001. A retrospective evaluation concerned 13 cases and was based on functional and radiographic criteria measuring the height of the column of the thumb at rest and under stress. Mean follow-up was 54.2 months (range 24-144). The height of the column of the thumb was decreased in relation to that of healthy hands and shortening under stress was significantly correlated with an increase in pain under stress (R2 = 44.7; p = 0.012). The observation of hyperextension of the MP (> 20 degrees) at follow-up was correlated with worse functional results. The method proposed has proven to be reliable, safe, capable of guaranteeing greater force as compared to other surgical methods described in the literature. The study emphasizes the need for a careful preoperative evaluation and possible treatment of MP joint hyperextension.

Radiographic evaluation of the hip rotation centre after total joint replacement in hip dysplasia.

A retrospective study was conducted to correlate the clinical result of joint replacement in dysplastic hips with the obtained modifications of the rotation centre. Sixty primary total hip arthroplasties were performed on 46 patients suffering from hip dysplasia at our institution. The radiographic evaluation of the hip rotation centre was performed using the method proposed by Pierchon. The clinical assessment was by Harris Hip Score. Our results revealed that it was possible to modify the position of the pathological rotational centre with a statistically significant difference (p<0.05) for both coordinates. The general clinical evaluation relates well to the radiological evaluation as the average HHS increased to 92.683 (p<0.05). The data from our study are in accordance with the most recent literature and confirm the importance of a suitable biomechanical position of the hip rotation centre in a distal and medial sense. (Hip International 2005; 15: 92-7).

Autologous chondrocyte implantation using a bilayer collagen membrane: a preliminary report.

OBJECTIVE: To present preliminary clinical experience with Matrix-induced autologous chondrocyte implantation, a new tissue-engineering technique for treatment of deep cartilage defects, in which autologous chondrocytes are seeded on a tridimensional scaffold provided by a bilayer type I-III collagen membrane. METHODS: From December 1999 to January 2001, 13 patients underwent implantation procedure for deep cartilage defects. Age of patients ranged from 18 to 49 years (mean age, 35 years). The mean defect size was 3.5 cm(2) (range, 2.0-4.5 cm(2)). Clinical and functional evaluation were performed using various score systems for the ankle and the knee, and magnetic resonance imaging was performed at 6 and 12 months postoperatively. Membrane structure and cellular population were investigated by light microscopy, scanning electron microscopy, and electrophoresis before implantation. RESULTS: The mean follow-up was 6.5 months (range, 2-15 months). No complications were observed in the postoperative period. The 6 patients with a minimum follow-up of 6 months showed an improvement in clinical and functional status after surgery. Magnetic resonance images showed the presence of hyaline-like cartilage at the site of implantation; there was evidence of chondroblasts and type II collagen inside the seeded membrane. CONCLUSION: Matrix-induced autologous chondrocyte implantation offers several advantages with respect to the traditional cultured cell procedure. These include technical simplicity, short operating time, minimal invasiveness, and easier access to difficult sites. It appears to be a reliable method for the repair of deep cartilage defects.

Stem revision: special implant versus primary device.

The purpose of hip revision surgery is to relieve pain and restore hip function, while improving hip biomechanics and bone stock. The entity of bone stock impairment due to lysis indicates to the surgeon which revision stem he would preferably choose. Modern literature has described several options for stem revision, ranging from primary cemented/less implants in the case of limited proximal bone defects, to special revision stems where a massive femoral bone stock impairment is present. There are many classifications of the femoral bone-stock loss in the literature but most authors seem to agree that the treatment of minimal proximal defects should be performed with primary implant stems. The need to bridge a bigger bony gap makes distal fixation a good deal. Two options are described for this purpose: the Wagner stem and modular stems. Wagner's concept consists of a distal fixation based on the interference of the straight tapered titanium alloy stem at the level of the femoral isthmus, while longitudinal fins provide rotational stability. A wide variety of modular stems was lately developed to prevent major complication associated to the Wagner's stem, but some new problems arose from proximal overfill of the canal, difficult in assembly and fretting corrosion. Early experience with the new ZMR taper (Zimmer, Warsaw, IN, USA) modular revision stem is reported.

Femoral revision with special stems.

None.