Intraoperative Load Sensing in Total Knee Arthroplasty Leads to a Functional but Not Clinical Difference: A Comparative, Gait Analysis Evaluation.

INTRODUCTION: Although Total Knee Arthroplasty (TKA) is a successful procedure, a significant number of patients are still unsatisfied, reporting instability at the mid-flexion range (Mid-Flexion Instability-MFI). To avoid this complication, many innovations, including load sensors (LS), have been introduced. The intraoperative use of LS may facilitate the balance of the knee during the entire range of motion to avoid MFI postoperatively. The objective of this study was to perform a Gait Analysis (GA) evaluation of a series of patients who underwent primary TKA using a single LS technology. METHODS: The authors matched and compared two groups of patients treated with the same posterior stabilized TKA design. In Group A, 10 knees were intraoperatively balanced with LS technology, while 10 knees (Group B) underwent standard TKA. The correct TKA alignment was preoperatively determined aiming for a mechanical alignment. Clinical evaluation was performed according to the WOMAC, Knee Society Score (KSS) and Forgotten Joint Score, while functional evaluation was performed using a state-of-the-art GA platform. RESULTS: We reported excellent clinical results in both groups without any statistical difference in patient reported outcome measurements (PROMs); from a functional standpoint, several GA space-time parameters were closer to normal in the sensor group when compared to the standard group, but a statistically significant difference was not reached. CONCLUSIONS: Gait Analysis represents a valid method to evaluate TKA kinematics. This study, with its limitations, showed that pressure sensitive technology represents a valid aid for surgeons aiming to improve the postoperative stability of TKA; however, other factors (i.e., level of intra-articular constraint and alignment) may play a major role in reproducing the normal knee biomechanics.

Preventive bilateral femoral nailing in atypical femoral fracture non responder to anabolic therapy: case report and mini-review.

Currently bisphosphonates are the main antiresorptive medications used in osteoporosis. However, a prolonged use of these drugs is associated to an increased risk of atypical femoral fractures, especially in patients suffering from others predisposing clinical conditions. This report describes a case of a woman presenting bilateral impending femoral fracture initially treated with bisphosphonates suspension and intramedullary nailing of right femur. Despite anabolic therapy, the patient presented progression of incomplete contralateral femoral fracture which required a second surgical treatment.

Use of a Plasma-Sprayed Titanium-Hydroxyapatite Femoral Stem in Hip Arthroplasty in Patients Older than 70 Years. Is Cementless Fixation a Reliable Option in the Elderly?

BACKGROUND: Although cementless implants are increasing in popularity, the use of cementless femoral stems for total hip arthroplasty (THA) and hip hemiarthroplasty (HH) in elderly patients remains controversial. The aim of this study was to report the outcomes of a cementless stem used in a large multicentric cohort of elderly patients receiving elective THA and HH for displaced femoral neck fracture. METHODS: A total of 293 patients (301 hips) aged 70 years or older (mean age, 78 years; range, 70-93) who received the same cementless plasma-sprayed porous titanium-hydroxyapatite stem were retrospectively evaluated after primary THA and HH to investigate stem survival, complications, and clinical and radiographic results. RESULTS: Cumulative stem survival was 98.5% (95% CI, 96.4-99.4%; 91 hips at risks) with revision due to any reason as the end-point at 10-year follow-up (mean 8.6 years, range 4-12). No stem was revised due to aseptic loosening. The mean Forgotten Joint Score was 98.7. Radiographically, the implants showed complete osseointegration, with slight stress-shieling signs in less than 10% of the hips. CONCLUSION: The use of cementless stems was proven to be a reliable and versatile option even in elderly patients for elective THA and HH for femoral neck fracture.

Bibliometric trend analysis in a decade of European Orthopaedic literature.

Purpose The purpose of this bibliometric study was to summarize European orthopedic literature produced by EFORT memberships between 2009 and 2019 and to identify the 100 most cited articles, analyzing the characteristics that made them so interesting for the orthopedic scientific world. Method A search of the literature was conducted using Clarivate Analytics Web of Science in the subject category "orthopaedics"; then the results were summarized using Web of Science tools. Results A total of 160.375 articles were found: most of these were produced by England. In particular the most prolific institution was the University of London. Analyzing in detail the 100 most cited publications emerged that most of them were review published in journal with high impact factor (Q1). The University of Oxford was the institution with the greatest number of contributions (13%). The most cited topics were osteoarthritis (24%), followed by orthopedic basic science (22%). Biomaterials was the most common topic by ordering the 100 analyzed articles according to "usage count", a recent indicator of the level of interest in a specific item. Conclusion This bibliometric study can be useful to identify topics of interest for future scientific research and to outline the features that make some publications more interesting than others.

Mesangiogenic Progenitor Cells Are Tissue Specific and Cannot Be Isolated From Adipose Tissue or Umbilical Cord Blood.

Mesangiogenic progenitor cells (MPCs) have been isolated from human bone marrow (BM) mononuclear cells. They attracted particular attention for the ability to differentiate into exponentially growing mesenchymal stromal cells while retaining endothelial differentiative potential. MPC power to couple mesengenesis and angiogenesis highlights their tissue regenerative potential and clinical value, with particular reference to musculoskeletal tissues regeneration. BM and adipose tissue represent the most promising adult multipotent cell sources for bone and cartilage repair, although discussion is still open on their respective profitability. Culture determinants, as well as tissues of origin, appeared to strongly affect the regenerative potential of cell preparations, making reliable methods for cell isolation and growth a prerequisite to obtain cell-based medicinal products. Our group had established a definite consistent protocol for MPC culture, and here, we present data showing MPCs to be tissue specific.

Operating procedures for electrochemotherapy in bone metastases: Results from a multicenter prospective study on 102 patients.

INTRODUCTION: Bone metastases are frequent in patients with cancer. Electrochemotherapy (ECT) is a minimally invasive treatment. Preclinical and clinical studies supported the use of ECT in patients with metastatic bone disease (MBD). The purposes of this multicentre study are to confirm the safety and efficacy of ECT, and to identify appropriate operating procedures in different MBD conditions. MATERIALS AND METHODS: 102 patients were treated in 11 Centres and recorded in the REINBONE registry (a shared database protected by security passwords): clinical and radiological information, ECT session, adverse events, response, quality of life indicators and duration of follow-up were registered. RESULTS: 105 ECT sessions were performed (one ECT session in 99 patients, two ECT sessions in 3 patients). 24 patients (23.5%) received a programmed intramedullary nail after ECT, during the same surgical procedure. Mean follow-up was 5.9 ± 5.1 months (range 1.5-52). The response to treatment by RECIST criteria was 40.4% objective responses, 50.6% stable disease and 9% progressive disease. According to PERCIST criteria the response was: 31.4% OR; 51.7% SD, 16.9% PD with no significant differences between the 2 criteria. Diagnosis of breast cancer and ECOG values 0-1 were significantly associated to objective response. A significant decrease in pain intensity and significant better quality of life was observed after ECT session at follow-up. CONCLUSION: The results are encouraging on pain and tumour local control. ECT proved to be an effective and safe treatment for MBD and it should be considered as an alternative treatment as well as in combination with radiation therapy.

Synthetic Bone Grafting in Aseptic Loosening of Acetabular Cup: Good Clinical and Radiological Outcomes in Contained Bone Defects at Medium-Term Follow Up.

Restoring bone loss is one of the major challenges when facing hip revision surgery. To eliminate the risk of disease transmission and antigenicity of allografts and donor-morbidity of autografts, the use of synthetic bioceramics has become popular in the last decade. Our study investigated the effectiveness of impaction bone grafting (IBG) of contained acetabular defects (Paprosky 2 and 3a) using a porous ceramic-based hydroxyapatite bone substitute (Engipore, provided by Finceramica Faenza S.p.A., Faenza, Italy) mixed with a low percentage of autologous bone (obtained from reaming when available). We retrospectively assessed 36 patients who underwent acetabular revision using IBG using a porous ceramic-based hydroxyapatite bone substitute with cementless implants with a mean follow-up of 4.4 years. We evaluated, at regular intervals, patients clinically (using the Hip Harris Score and Oxford Score) and radiologically to evaluate the rate of incorporation of the graft, the presence of radiolucent lines or migrations of the cup. Clinical scores significantly improved (WOMAC improved from 49.7-67.30, and the HSS from 56-89). The rate of implants' survival was 100% at our medium follow-up (4.4 years). We reported five cases of minor migration of the cup, and radiolucent lines were visible in seven patients at the last-follow up. The graft was well-incorporated in all patients. The results presented in this study suggest the HA bone substitute is an effective and safe bone graft when facing hip revision surgery; thus, longer follow-up studies are required.

Lessons learnt from COVID 19: An Italian multicentric epidemiological study of orthopaedic and trauma services.

INTRODUCTION: The Pandemic caused by the SARS-CoV-2 has put a strain on the most of health systems all over the world. Many hospitals had to re-organize to deal with the emergency, so that the non-core activities have been suspended or cancelled, raising management problems. The aim of this multicentre study is to report the epidemiological orthopaedic and traumatological data between COVID and pre-COVID era and to analyse patients' needs and their management. METHODS: We reported and compared traumatological and elective orthopaedic surgeries performed in three of the main hospital centres in Tuscany during COVID (March 2020) and pre-COVID (March 2019) era. We also reported the epidemiological data about the number of orthopaedic first aid visits at the main hub, analysing the main differences. For each centre, we reported the number, diagnosis, co-morbidities, treatment, hospital course, complications and outcomes of confirmed COVID 19 patients. We also indicated what kind of PPE were used by medical staff and patients at any visit. RESULTS: The scheduled surgery drastically decreased in all the centres and the most of procedures were carried out for tumours, infections and implant mobilizations during the COVID time, delaying all the other ones. Trauma activities slightly decreased between the two time points: proximal femur fractures continued to engage our hospitals at the same pre-COVID volumes, while minor traumas drastically decreased. We report a decrease of 70.95% in orthopaedic first aid, with first-aid-visits/hospitalization ratio of 13.8 in the pre-COVID time vs 5.8 in the COVID time. A total of 5 confirmed COVID patients were treated for fractures and 4 of them healed without complications. We report just one case of death among COVID patients. All the medical staff members have worn the PPE and no one have developed COVID symptoms. CONCLUSIONS: The COVID-19 raised many important issues, such as the optimal management of patients requiring the treatment of conventional diseases during a pandemic. The flow of patients changes from one area to another during a pandemic and an integrated approach within the same geographical area could be useful to better allocate resources and manage the patients' needs. The preventive measures put in place in our country seem to work, but this first experience with COVID-19 crisis highlighted the chronic problems of our health system and we believe that we have to "learn the lesson" to be better prepared in the future.

Which role for synthetic ligaments in the reconstruction of patellar tendon chronic rupture after TKA? Mid-term outcomes using LARS ligament.

BACKGROUND AND AIM OF THE WORK: Patellar tendon rupture is a rare complication after Total Knee Arthroplasty (TKA) which often requires surgical treatment. Patients with chronic lesions or tendon degenerations showed good results when treated using autografts or allografts, but these techniques showed poor outcomes at long-term follow-up (FU). Moreover, allografts have high costs and limited availability, not to mention the increased risk of immune reactions and infections. Recently, the use of synthetic ligaments for patellar tendon reconstruction has taken hold with encouraging results. We report our experience in the treatment of patellar tendon ruptures after TKA using the Ligament Advanced Reinforcement System-LARS®. METHODS: Clinical evaluation was performed using the Knee Society Score and recording extensor lag. Instrumental evaluation was performed using ultrasound imaging to assess patellar tendon thickness and using conventional x-rays to assess prosthesis' mobilization signs and patella's height. RESULTS: At the final FU, 6 knees were included in our study. Patient's mean age was 66.7. Patellar tendon reconstruction occurred after a mean time of 4 months from the previous surgery. The mean FU was 44,2 months. The mean Knee Score was 63.3 and the mean Function Score was 35. In 4 knees the extensor lag was < 10° while in 2 knees it was > 20°. The mean ISI was 1.16, while the average increment in tendon thickness was 127.12%. CONCLUSIONS: In our opinion, synthetic ligaments can be successfully employed for the reconstruction of patellar tendon breakage after TKA and rTKA in selected patients, in order to quickly return them to their activity of daily living.

Septic femoral shaft non-union treated by one-step surgery using a custom-made intramedullary antibiotic cement-coated carbon nail: case report and focus on surgical technique.

Background and aim of the work: In the orthopaedic and traumatological fields septic non-unions represent a severe complication, hard to manage and treat. Traditionally, the surgical technique consists in to two sequential steps: debridement with administration of local and systemic antibiotics associated with temporary stabilization of the fracture and subsequent reconstruction of bone and soft tissues. Recently, the use of some devices to treat septic non-union by one-step surgery have been introduced with encouraging resultsMethods: We reported our experience with a case treated by one-step procedure using a custom-made intramedullary antibiotic cement-coated carbon nail. We reviewed the literature and described the surgical technique employed in this case. Results: At 6 months from surgery the patient was able to perform full weight-bearing and carry out the normal activities of daily living. Serum inflammatory markers normalized and radiographic controls showed the presence of a mechanically good bone callus at the non-union site. The bone resection carried out determined a limb length discrepancy of 3 cm, that was corrected through a temporary shoe lift, currently well tolerated. The patient regained full ROM of the right knee. Conclusion: Intramedullary antibiotic cement-coated nail associated with systemic antibiotic therapy proved to be an effective treatment to control the infection and provide immediate stability at the septic non-union/fracture site, allowing a rapid functional recovery. It represents a valid option especially in patients who refuse external devices or surgical additional procedures, as in our case. (www.actabiomedica.it).

Carbon/PEEK nails: a case-control study of 22 cases.

BACKGROUND: Interest around carbon/PEEK plates and nails has been raising. The elastic modulus close to the bone, the high load-carrying capacity and radiolucency make CFR/PEEK materials a potential breakthrough. In the literature, there are abundant data about CFR/PEEK plates in the treatment of proximal humerus, distal radius and distal fibula fractures. In patients affected by bone metastasis, CFR/PEEK nails were proved effective and safe with 12 months of follow-up. Very little is known about performances of CFR/PEEK nails in patients affected by other pathologies. PURPOSES: The aim of the study was to evaluate safety and efficacy of CFR/PEEK nails in the treatment of various pathological conditions. It was also investigated whatever radiolucency of this nails could lead to a more objective evaluation of bone callus or disease site. PATIENTS AND METHODS: In the study group were included 20 patients (22 bone segments) who underwent CFR/PEEK nail implantation (eight humerus, one tibia, nine femur and four knee arthrodesis). They were affected by pathological fractures, and in four cases, they required an arthrodesis of the knee. They were retrospectively evaluated considering nail failures and bone callus or disease progression (RUSH scores). Mean follow-up time was 11 months (min 6.8-max 20.3). In the control group were included patients treated with titanium nails in the same institution for the same pathologies. An interclass correlation coefficient (ICC) analysis was performed in both groups considering RUSH scores by two expert surgeon from two institution to assess whether radiolucency could lead to a more objective evaluation of disease or bone callus site. RESULTS: The ICC of mean values between RUSH scores was 0.882 (IC 95%: 0.702-0.953) in the CFR/PEEK group, while it was 0.778 (IC 95%: 0.41-0.91) in the titanium group. Observers' evaluation showed a significantly higher obscuration by titanium nails than by CFR/PEEK nails. No osteosynthesis failures were reported in both groups. CONCLUSIONS: Our results confirm the safety of CFR/PEEK nails in the short-medium term. The radiolucency of these materials led our observers to perform more objective evaluations of bone callus formation or disease progression compared to the titanium group given the higher ICC. LEVEL OF EVIDENCE: III Case-control therapeutic study.

Giovanni Alfonso Borelli: The Precursor of Medial Pivot Concept in Knee Biomechanics.

A new philosophy of science and medicine had spread throughout the 17th-century Italy: the "Scientific Revolution." Giovanni Alfonso Borelli (1608-1679) was one of the most charismatic and brilliant scientists of his generation in Europe. He extended to biology the rigorous analytic methods developed by his indirect mentor Galileo in the field of mechanics. In his masterpiece " De Motu Animalium ," Borelli analyzed structure, motion, balance, and forces concerning almost all the principal joints of the human body, in static and dynamic situations. In particular, he accurately studied the anatomy and biomechanics of the knee joint. He sustained that femoral condyles shift backward during flexion, allowing a wider range of movement. Furthermore, he observed that, when the knee flexes, the lateral condyle moves backward more than the medial condyle: this concept is nowadays known as medial pivoting. The aim of this article is to describe the life and work of this important Italian scientist and to present his unrecognized contribution to modern knee biomechanics.

The difference in activity of daily living (ADL) and mortality in patients aged over 80 years with femoral neck fracture treated with hemiarthroplasty or osteosynthesis at 2 years of follow-up.

INTRODUCTION: Hip fractures are one of the major causes of morbidity and mortality in the elderly and outcomes following hip fracture have been the focus of several studies over recent decades. Among all types of fall-related injuries, hip fractures cause the greatest number of deaths, lead to severe health problems and reduce quality of life. Improving the outcome of hip fracture surgery has thus become one of the main areas of interest for orthopaedic surgeons. The aim of this study was to compare the difference in activity of daily living (ADL) and mortality between patients aged over 80 years with hip fracture treated with osteosynthesis versus prosthesis at 2 years of follow-up. MATERIALS AND METHODS: The data were collected on admission and during in-hospital stay. Information recorded on admission included: age, sex, type and mechanism of fracture, functional and cognitive status, comorbidity, and severity of illness. Prefracture functional status was measured. The follow-up was clinical and radiographical, or was by telephone for patients who were not able to come to the clinic. Patients aged over 80 years who underwent a single surgical procedure treated with intramedullary nail or hemiarthroplasty were included in the study. RESULTS: A total of 174 patients (45 male and 129 female) were included in the study. The two treatment groups were comparable for all preoperative parameters except for preoperative haemoglobin, which was an average of 1g/dl higher in the patients given hemiarthroplasty compared with those treated with intramedullary nail (t-test: p<0.05). The average observation period was 594.99days; the number of deaths was 62 of 164 contacted patients, and the survival rate at 2 years was 62.2%. There was increased mortality in patients who underwent hemiarthroplasty (Log-rank Mantel-Cox, p: 0,048). The difference in ADL between preoperative and follow-up is not statistically significant between the two groups. DISCUSSION: In the literature, there are few specific studies that consider these parameters in this population. However, these findings are consistent with the findings from other studies. CONCLUSION: Patients who received hemiarthroplasty have a higher mortality risk than those treated with intramedullary nail; there are no differences in ADL at follow-up.

Hydroxyapatite in total hip arthroplasty. Our experience with a plasma spray porous titanium alloy/hydroxyapatite double-coated cementless stem.

PURPOSE: Total hip arthroplasty could fail due to many factors and one of the most common is the aseptic loosening. In order to achieve an effective osseointegration and reduce risk of lossening, the use of cemented implant, contact porous bearing surface and organic coating were developed. Aim of this study was to evaluate clinical and radiological mid-term outcomes of a porous titanium alloy/hydroxyapatite double coating manufactured cementless femoral stem applied with "plasma spray" technique and to demonstrate the possibility to use this stem in different types of femoral canals. METHODS: Between January 2008 and December 2012, 240 consecutive primary total hip arthroplasties (THAs) were performed using a porous titanium alloy/hydroxyapatite double coating manufactured cementless femoral stem. 182 patients were examined: 136 were females (74.7%) and 46 males (25.2%); average age was 72 years old (ranging from 26 to 92 years old). For each patient, Harris Hip Scores (HHS) and Womac Scores were collected. All X-ray images were analyzed in order to demonstrate stem survival rate and subsidence. RESULTS: Harris Hip Score was good or excellent in 85% of the cases (average 90%) and mean WOMAC score was 97.5 (ranging from 73.4 to 100). No cases of early/late infection or periprosthetic fracture were noticed, with an excellent implant survival rate (100%) in a mean period of 40 months (ranging from 24 and 84 months). 5 cases presented acute implant dislocation, 2 due to wrong cup positioning in a dysplastic acetabulum and 3 after ground level fall. Dorr classification of femoral geometry was uses and the results were: 51 type A bone, 53 type B bone and 78 type C bone. Stem subsidence over 2 mm was considered as a risk factor of future implant loosening and was evidenced in 3 female patients with type C of Dorr classification. No radiolucencies signs around the proximally coated portion of stem or proximal reabsorption were visible during the radiographic follow-up. CONCLUSIONS: Concerning the use of porous titanium alloy/hydroxyapatite double coating, this study reported an excellent implant survival rate in a mid-term period with a rate of 1,64% of subsidence in patients with type C of femoral canal but with an optimal HHS and Womac Score results. Regarding this stem, primary stability is guaranteed by trapezoid shape of proximal region and tapering in frontal plane through press-fit technique. Radiological absence of pedestal has been accepted as sign of no excessive stress transmission to distal cortex due to its tapered diaphyseal region. Thanks to the reported data, Authors can consider this double coating a valid choice with an excellent medium-term survival and encouraging subsidence results. Further studies are needed to ensure these results can be replicated.

Prospective Randomized Controlled Trial of Two Different Intramedullary Nails for Pertrochanteric Fractures of the Femur.

The purpose of this prospective randomized trial was to assess whether an intramedullary nail is superior or not to another one in the treatment of pertrochanteric fractures. Eighty-one patients with a 31-A1 or A2 Arbeitsgemeinschaft für Osteosynthesefragen/Orthopaedic Trauma Association (AO/OTA) pertrochanteric fracture were randomly allocated to fixation with either the Gamma® or the ENDOVIS® nail. In order to estimate the functional outcome the Parker-Palmer mobility score, Barthel Index, and EuroQol-5D (EQ-5D) were used. All patients were followed up at 1, 3, 6, and 12 months postoperatively. There was no statistical difference in Parker mobility score between groups. The statistical analysis revealed that there was no significant difference between the two patient groups as far as the operating time, the amount of blood transfused, and the latest functional outcome. Both kinds of intramedullary nails used in our study provide effective methods of treatment for intertrochanteric fractures in elderly patients. Our data showed slightly worse results for the ENDOVIS nail compared with the Gamma nail, but this did not reach a statistical significance.

Case report: late subtrochanteric fracture post radiofrequency ablation of osteoid osteoma.

Osteoid osteoma is a benign tumor especially affecting young males generally treated with radiofrequency ablation. This is a non-invasive and safe procedure, major complications are very rare, most of them consisting in local skin burns. The present case shows a late subtrochanteric fracture in a young boy after CT guided termoablation of osteoid osteoma of proximal femur and short review of the literature.

Acromio-clavicular repair using two different techniques.

Acromio-clavicular joint (ACJ) injuries represent nearly half of all athletic shoulder injuries. Stability of this joint depends on the integrity of the acromio-clavicular and coracoclavicular ligaments. Although the traumatic acromioclavicular joint separation is a well-known topic, there are different classifications, diagnostic procedures, concepts of intervention, and a great variety of implants. In this paper, we present an overview of the recent literature about this issue and the results of a retrospective non-randomized study with 2 different techniques. At the first Orthopedic Department of University of Pisa, a retrospective study was performed starting from January 2007 to February 2011 in our electronic database. We selected patient treated with two different techniques (tight-rope(®) system and hook plate) by the same senior surgeon with experience in shoulder surgery. The mean Costant score was 90 for the tight-rope(®) system group and 75 for the hook plate group. At the final follow-up, most of the patients had returned to their preinjury level of activity. Two patients had a breakage of the fixating system. The above-mentioned techniques provided satisfactory results with no loss of reduction except in two cases. The use of the hook plate is useful in fracture-dislocation of ACJ, but this requires another surgery to remove it. On the contrary, the use of the tight-rope(®) system does not require a new surgery or use of expensive synthetic graft or a graft harvested from a distant donor site.

Custom-fit total knee arthroplasty: our initial experience with 30 knees.

We report our initial experience of total knee arthroplasty (TKA) using customized cutting block technology in 30 TKAs from December 2010 to September 2012. Customized blocks were generated for each of the knees using preoperative magnetic resonance imaging of knee and long-leg weight-bearing radiographs. At 30 days, long-leg radiographs were obtained to evaluate the coronal alignment. Twenty-six of the 30 knees had a mechanical axis restored to within 3° of neutral. We conclude that this technology can be safely used in most of the cases of osteoarthritis.

Clinical and radiological results over the medium term of isolated acetabular revision.

Acetabular cup loosening is associated with pain, reduced function, and instability of the implant. If such event happens while the femoral implant is in a satisfactory position and is well fixed to the bone, isolated acetabular revision surgery is indicated. The aim of this single-center retrospective study was to evaluate the clinical and radiological results over the medium term (12-month follow-up mean 36, max 60) of isolated acetabular revisions surgery using a porous hemispheric revision shell matched with a cemented all-poly cup and large diameter femoral head (>32). 33 patients were enrolled. We collect any relevant data from the clinical board. Routine clinical and radiographic examinations were performed preoperatively; the postoperative follow-up was made at 1, 3, and 6 months and yearly thereafter. At the last available follow-up, we report satisfactory improvement of functional scores in all the patients; 2 patients (6.1%) showed thigh pain and only 4 hips (12.11%) presented mild groin pain; all the femoral components are well fixed and there were no potential or pending rerevisions. With bias due to the follow-up and to the retrospective design of the study, we report clinical, functional, and radiological satisfactory results.

The dual radius hemispherical 'Trident" cup: results based on 150 consecutive cases.

INTRODUCTION: Initial stability with press-fit cups can be achieved in a number of ways based on the design of the cup. With line-to-line fit, screws fixation, press-fit of 1 to 2 mm which is obtained by an oversized hemispherical cup, initial stability can be achieved with the dual-radius press-fit cups, which have an equatorial diameter 1 to 2 mm greater than that of the polar diameter, to ensure a good press-fit and to provide adequate initial stability for bone ingrowth to occur reliably. METHODS: Between January 2002 and January 2008, 400 total hip replacements (THRs) were carried out. We examined the first 150 consecutive primary THRs. In all hips, the acetabular component was the dual radius Trident AD shell (Stryker Orthopaedics, Mahwah, New Jersey). RESULTS: The median duration of follow-up was 6,2 yrs (range, 5 to 7 yrs). The median post-operative Harris Hip Score for 150 hips was 90.5 (range, 51 to 98). At the time of the latest follow-up, there was a bony incorporation of all components; we found no definite evidence of radiographic loosening and no signs of radiolucency. CONCLUSION: According to the encouraging results of the present study we conclude that the Trident cup is a valid choice for acetabular replacement.