The added value of the visual analysis of DWI in post-surgery follow-up of soft tissue sarcoma of the extremities: do we really need ADC?

INTRODUCTION: MRI has a fundamental role in the follow-up of soft tissue sarcomas (STSs). However, the differentiation of recurrences/residual disease from post-surgical changes is a complex task, with a central role for the radiologist. MATERIALS AND METHODS: We retrospectively evaluated 64 post-surgery MRI for extremities STSs. MR protocol included DWI (b = 0, 1000). Two radiologists were asked to consensually evaluate: presence/absence of tumoral nodules, lesion conspicuity, imaging diagnostic confidence, ADC values, and DWI overall image quality. The gold standard was histology or MR follow-up. RESULTS: Thirty-seven lesions in 29/64 patients were confirmed as local recurrence or residual disease (n = 16 ≤ 1 cm) with 1 MR false positive. On DWI, the conspicuity of the proved tumor lesions resulted excellent in 29/37, good in 3/37 and low in 5/37, higher than conventional imaging. A statistically significant higher diagnostic confidence of DWI compared to conventional imaging (p < 0.001) and DCE (p = 0.009) was observed. In the 37 histologically confirmed lesions, mean ADC value was 1.31 × 10-9 m2/s. Overall scar tissues mean ADC was 1.70 × 10-9 m2/s. DWI quality resulted adequate in 81% and unsatisfactory in 5%. CONCLUSIONS: In this highly heterogeneous group of tumors, the role of ADC seems to be limited. Based on our experience, looking at DWI images makes the lesions promptly and easily detectable. This technique gives less deceptive findings making the reader more confident in detecting/excluding tumoral tissue; the main drawback is the image quality and the lack of standardization.

Identification of New Potential Prognostic and Predictive Markers in High-Grade Osteosarcoma Using Whole Exome Sequencing.

Conventional high-grade osteosarcoma (OS) is the most common primary cancer of bone and it typically affects the extremities of adolescents. OS has a complex karyotype, and molecular mechanisms related to carcinogenesis, progression and resistance to therapy are still largely unknown. For this reason, the current standard of care is associated with considerable adverse effects. In this study, our aim was to identify gene alterations in OS patients using whole exome sequencing (WES) to find new potential prognostic biomarkers and therapeutic targets. We performed WES on formalin-fixed paraffin-embedded (FFPE) biopsy materials collected from 19 patients affected by conventional high-grade OS. The clinical and genetic data were analyzed according to response to therapy, presence of metastasis and disease status. By comparing good and poor responders to neoadjuvant therapy, we detected a clear prevalence of mutations in the ARID1A, CREBBP, BRCA2 and RAD50 genes in poor responders that negatively influence the progression-free survival time. Moreover, higher tumor mutational burden values correlated with worse prognosis. The identification of mutations in ARID1A, CREBBP, BRCA2 and RAD50 may support the use of a more specific therapy for tumors harboring these alterations. In particular, BRCA2 and RAD50 are involved in homologous recombination repair, and could thus be used as specific therapy targets of inhibitors of the enzyme Poly ADP Ribose Polymerase (PARP). Finally, tumor mutational burden is found to be a potential prognostic marker for OS.

Synovial sarcomas: A single surgeon experience of 130 cases.

BACKGROUND: Synovial sarcoma is a rare malignant tumor that generally requires a multidisciplinary therapeutic approach. In this study we report the experience of a single surgeon, evaluating surgical and oncological outcomes of the cases he treated through his 30 years carrier. METHODS: We enrolled patients treated surgically between 1988 and 2018. Surgical and medical treatments, as well as surgical and oncological results, were investigated. RESULTS: One hundred and thirty cases were included. Surgical resection was carried out achieving wide margins in 90% of the cases. At their latest follow-up, 76 patients were continuously disease free, 16 were no evidence of disease, and other 16 were alive with disease. Twenty cases were dead of disease and two dead of other causes. Twenty-five patients (19%) had local recurrence of synovial sarcoma through their postoperative intercourse. Thirty-seven patients (28%) were diagnosed with at least a metastasis during their follow-up. The global survival of our population, at each patient's latest follow-up, was 82%. Cases with tumor size above 5 cm had a significantly higher risk to develop metastasis (p = 0.002). CONCLUSIONS: Synovial sarcoma is a threatening disease and represents a challenge for oncological physicians and surgeons. Early diagnosis and multidisciplinary approach are mandatory to limit the spread of synovial sarcomas, maximizing the effectiveness of surgery and the other treatments.

Schwannomas of the peroneal nerves: Clinical and functional results of surgical treatment.

OBJECTIVES: Peroneal nerves Schwannomas are rare benign tumors. Literature is still poor of studies about clinical and functional outcomes after surgical treatment. We evaluated the pre-operative presentation of the disease and assessed clinical and functional outcomes after surgery. METHODS: We collected all the cases of peroneal nerves' neurinoma treated surgically between June 2016 and June 2020. We analyzed each patients' personal data and carried out accurate clinical examinations before and after surgery. MRI was performed both pre-operatively and post-operatively. RESULTS: We reported 9 cases of peroneal nerves schwannomas: five arising from the common peroneal nerve and four arising from the deep or superficial branches alone. Their mean size was 22.6 mm. Each patient showed sensation deficits before surgery; pre-operative MRC score was 4.2. Pre-Operative MSTS and LEFS scores were 23.6 and 64.4. Surgery was successful in each case. No local recurrence nor major complication occurred. Tumor size was significantly associated with both diagnostic delay and development of pre-operative deficits. Surgery was proven to be globally successful: post-operative evaluations highlighted a marked reduction of neurological signs and overall functional limitations. CONCLUSIONS: Surgical treatment at early stages of the disease represents a reliable and relatively safe therapeutic option.

Analysis of Biomechanical Differences Between Condylar Constrained Knee and Rotating Hinged Implants: A Numerical Study.

BACKGROUND: Different levels of constraint for total knee arthroplasty can be considered for revision surgeries. While prior studies have assessed the clinical impact and patient outcomes of condylar constrained knee (CCK) and rotating hinged (RTH) implants, nowadays little is known about the biomechanical effects induced by different levels of constraint on bone stress and implant micromotions. METHODS: CCK and RTH implant models were analyzed using a previously validated numerical model. Each system was investigated during a squat and a lunge motor task. The force in the joint, the bone and implant stresses, and micromotions in this latter were analyzed and compared among designs. RESULTS: Different activities induced similar bone stress distributions in both implants. The RTH implant induces mostly high stress compared to the CCK implant, especially in the region close to tip of the stem. However, in the proximal tibia, the stresses achieved with the CCK implant is higher than the one calculated for the RTH design, due to the presence of the post-cam system. Accordingly, the condylar constrained design shows higher implant micromotions due to the greater torsional constraint. CONCLUSION: Different levels of constraint in revision arthroplasty were always associated with different biomechanical outputs. RTH implants are characterized by higher tibial stress especially in the region close to the stem tip; condylar implants, instead, increase the proximal tibial stress and therefore implant micromotions, as a result of the presence of the post-cam mechanism. Surgeons will have to consider these findings to guarantee the best outcome for the patient and the related change in the bone stress and implant fixation induced by different levels of constrain in a total knee arthroplasty.

One-Step Reconstruction with Custom-made 3D-printed Scapular Prosthesis After Partial or Total Scapulectomy.

En bloc scapulectomy with covering muscles was historically considered the only procedure available for surgical treatment of bone and soft tissue tumors of the scapula. When possible, reconstruction with scapular allograft is the gold standard, and gives satisfactory functional, cosmetic, and oncological outcomes. While good results have recently been reported with 3D-printed prostheses for reconstruction of bone loss, there is little information available in the medical literature regarding scapula reconstruction with a 3D-printed prosthesis. Between 2016 and 2018, we performed four scapular resections (two total and two involving the superior 1/3) followed by reconstruction with a 3D-printed prosthesis made of a porous titanium alloy (Ti-6Al-4V, diameter between 100 and 400 mm), using computer-aided design (CAD) and patient-specific implants (PSI) with previously acquired CT-MR fusion images. At 2 years follow-up, the patients with partial scapulectomy had an MSTS score of 76%, no local or systemic recurrence, good clinical results and no pain. At 1 year 6 months follow-up, the patients with total scapulectomy had an MSTS score of 46%, no local or systemic recurrence, fair clinical results and no pain. Thus, custom-made 3D-printed prostheses appear to be valuable in orthopedic surgery. However, a larger cohort and longer-term analysis are needed to evaluate the scapular 3D-printed prosthesis as a reliable reconstruction technique.

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.

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.

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.

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.

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.

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.

Densitometric evaluation of periprosthetic bone remodeling.

The application of Dual-energy X-ray absorptiometry (DEXA) in orthopaedic surgery gradually has been extended from the study of osteoporosis to different areas of interest like the study of the relation between bone and prosthetic implants. Aim of this review is to analyze changes that occur in periprosthetic bone after the implantation of a total hip arthroplasty (THA) or a total knee arthroplasty (TKA). In THA the pattern of adaptive bone remodeling with different cementless femoral stems varies and it appears to be strictly related to the design and more specifically to where the femoral stem is fixed on bone. Short stems with metaphyseal fixation allow the maintenance of a more physiologic load transfer to the proximal femur decreasing the entity of bone loss. Femoral bone loss after TKA seems to be related to the stress shielding induced by the implants while tibial bone remodeling seems to be related to postoperative changes in knee alignment (varus/valgus) and consequently in tibial load transfer. After both THA and TKA stress shielding seems to be an inevitable phenomenon that occurs mainly in the first year after surgery.

Proximal Femur Megaprostheses in Orthopedic Oncology: Evaluation of a Standardized Post-operative Rehabilitation Protocol.

Background: Reconstructions of the proximal femur after massive resections represent one of the main challenges in orthopedic oncology. Among the possible treatments, megaprostheses represent one of the most used and reliable reconstructive approaches. Although literature about their outcomes has flourished through the last decades, a consensus rehabilitative treatment is still far from being established. Materials and methods: We evaluated the functional results of all our oncologic cases treated between 2016 and 2022 that could follow our standardized post-operative rehabilitative approach, consisting in progressive hip mobilization and early weight-bearing. Results: Twenty-two cases were included in our study. On average, their hospitalization lasted 15.1 days. The seated position was achieved on average within 3.7 days after surgery, the standing position reached 5.4 after surgery, while assisted deambulation was started 6.4 days after surgery. After a mean post-operative follow-up of 44.0 months, our patients' mean MSTS score was 23.2 (10-30). Our data suggested a statistically significant inverse linear correlation between post-operative functionality and patients' age, resection length, and the start of deambulation. Conclusions: A correct rehabilitation, focused on early mobilization and progressive weight-bearing, is crucial to maximize patients' post-operative functional outcomes.

Knee Extensor Apparatus Reconstruction with Allograft after Patellar Resection: A Case Report.

Background: The extensor apparatus of the knee can be thought of a chain that transmits the muscular strength developed by the quadriceps muscles to the proximal tibia. This complex is essential to allow the extension of the tibia over the femur, being essential to provide knee mobility and stability. In case of lesions which irreparably damage the patella, such as a locally aggressive bone tumor, it is necessary to restore both the apparatus' anatomical continuity and its strength. Case report: A 39-years-old Caucasian man with a history of lung carcinoma developed atraumatic swelling and soreness in his left knee. Imaging evidence reported a degeneration of the left patella. We performed an en bloc resection of the patella and the nearby soft tissues of the extensor apparatus. The resulting gap was fulfilled with a massive allograft consisting of a quadriceps tendon, a patella and a patellar ligament. No complication or local recurrences were observed. At the patient's latest follow-up, he did not have any extension lag and quadriceps strength was completely restored. Conclusion: Massive allografts can represent a reliable alternative for the reconstruction of the patella and the knee extensor apparatus in orthopedic oncology.

Clinical and functional results after total scapulectomy in orthopedic oncology: are custom-made scapular prostheses better than humeral suspension?

Background: In orthopedic oncology, total scapulectomy is necessary to allow a wide resection of extended malignancies of the scapula and scapular girdle. Scapular reconstruction is challenging even for the most experienced surgeon. This paper reports our experience with total scapular resections, followed by humeral suspension or custom-made prostheses. Methods: In this retrospective study, we evaluated all the oncologic patients treated in our institution between 2016 and 2023 with total scapulectomy and consequential reconstruction using humeral suspension or a custom-made prosthesis. Only cases suffering from malignant bone tumors were included. The postoperative functionality of the treated limbs was assessed using the Musculoskeletal Tumor Society (MSTS) scoring scale. Complications and local recurrences were also recorded. Results: Nine patients were enrolled. Five had custom-made implants, and four had humeral suspensions. The mean postoperative MSTS score of patients treated with custom-made prostheses was 24.0 (22-26). Globally, our cohort's mean MSTS score was 19.1 (9-26). Patients with custom-made prostheses had significantly better functional outcomes (MSTS 24 vs 13) and similar complication rates (40% vs 50%) than those who received humeral suspensions. Conclusion: Our outcomes suggest that, when feasible, custom-made scapular prostheses can represent a reliable reconstructive option after total scapulectomy for malignant scapular tumors.

Can FDG-PET assess the response to chemotherapy and predict tissue necrosis in osteosarcoma and Ewing sarcoma?

INTRODUCTION: Osteosarcoma (OS) and Ewing sarcoma (ES) represent the pediatric population's most common malignant bone tumors. 18-Fluorodeoxyglucose positron emission tomography has been shown to be effective in both the diagnostic and staging phases of cancer treatment. In recent years, some studies have also explored the possibility that FDG-PET could have a prognostic role.

Outcomes of Long Bones Treated With Carbon-Fiber Nails for Oncologic Indications: International Multi-institutional Study.

BACKGROUND: Intramedullary nail fixation is commonly used for prophylactic stabilization of impending and fixation of complete pathological fractures of the long bones. However, metallic artifacts complicate imaging evaluation for bone healing or tumor progression and postoperative radiation planning. Carbon-fiber implants have gained popularity as an alternative, given their radiolucency and superior axial bending. This study evaluates incidences of mechanical and nonmechanical complications. METHODS: Adult patients (age 18 years and older) treated with carbon-fiber nails for impending/complete pathological long bone fractures secondary to metastases from 2013 to 2020 were analyzed for incidences and risk factors of mechanical and nonmechanical complications. Mechanical complications included aseptic screw loosening and structural failures of host bone and carbon-fiber implants. Deep infection and tumor progression were considered nonmechanical. Other complications/adverse events were also reported. RESULTS: A total of 239 patients were included; 47% were male, and 53% were female, with a median age of 68 (IQR, 59 to 75) years. Most common secondary metastases were related to breast cancer (19%), lung cancer (19%), multiple myeloma (18%), and sarcoma (13%). In total, 17 of 30 patients with metastatic sarcoma received palliative intramedullary nail fixation for impending/complete pathological fractures, and 13 of 30 received prophylactic nail stabilization of bone radiated preoperatively to manage juxta-osseous soft-tissue sarcomas, where partial resection of the periosteum or bone was necessary for negative margin resection. 33 (14%) patients had complications. Mechanical failures included 4 (1.7%) structural host bone failures, 7 (2.9%) implant structural failures, and 1 (0.4%) aseptic loosening of distal locking screws. Nonmechanical failures included 8 (3.3%) peri-implant infections and 15 (6.3%) tumor progressions with implant contamination. The 90-day and 1-year mortalities were 28% (61/239) and 53% (53/102), respectively. The literature reported comparable failure and mortality rates with conventional titanium treatment. CONCLUSIONS: Carbon-fiber implants might be an alternative for treating impending and sustained pathological fractures secondary to metastatic bone disease. The seemingly comparable complication profile warrants further cohort studies comparing carbon-fiber and titanium nail complications.

Computer tomography prototyping and virtual procedure simulation in difficult cases of hip replacement surgery.

Each year approximately 1 million total hip replacements (THR) are performed worldwide. A percentage of failure due to surgical approach and imprecise implant placement still exists. These result in several serious complications. We propose an approach to plan, to simulate, and to assist prosthesis implantation for difficult cases of THR based on 3-D virtual models, generated by segmenting patients' CT images, 3-D solid models, obtained by rapid prototyping (RP), and virtual procedure simulation. We carried out 8 THR with the aid of 3-D reconstruction and RP. After each procedure a questionnaire was submitted to the surgeon to assess the perceived added value of the technology. In all cases, the surgeon evaluated the 3-D model as useful in order to perform the planning. The clinical results showed a mean increase in the Harris Hip Score of about 42.5 points. The mean time of prototyping was 7.3 hours, (min 3.5 hours, max 9.3 hours). The mean surgery time was 65 minutes (min 50 minutes, max 88 minutes). Our study suggests that meticulous preoperative planning is necessary in front of a great aberration of the joint and in absence of normal anatomical landmarks, CT scan is mandatory, and 3-D reconstruction with solid model is useful.