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Accuracy of implant positioning and precise reconstruction of leg alignment offers the best way to achieve good long-term results in total knee arthroplasty. Computer instrumentation was developed to improve the final position of the component and restore the mechanical axis. Current navigation systems use either optical or electromagnetic tracking. The advantage of the Electromagnetic (EM) navigation system is that no line-of-sight issues are present. However, special iron-free instruments are required. This report analyzes the postoperative radiological results of 32 knees treated using an EM system. All the measurements were recorded using software able to subtend angles automatically by five physicians, three radiologist and two orthopedic residents not involved with the surgery. Each radiograph was measured three times, in random order, and at delayed intervals. We found an ideal alignment for the mechanical axis (180+/-3 degrees ) in 30 out of 32 cases, whereas all the patients achieved a value of 90 degrees +/-3 degrees for both femoral and tibial frontal component angles. An apparently over-corrected implant position for the sagittal femoral component was reported, with a mean value of 11.2 degrees +/-3.6. The mean position of the tibial component was 90.6 degrees +/-2.8; just four measurements were outside of the +/-3 degrees of the desired value. EM is safe and there were no complications related to this system. An almost perfect correlation was found between the mechanical axis value of the EM navigation system (179.8 degrees +/-1.8) and the median value of the all reviewers (180.3 degrees +/-1.9) with a difference of 0.5 degrees .

Thermal ablation with radiofrequency (RF) is gaining increasing attention for the treatment of musculoskeletal lesions. This treatment offers several advantages compared to other methods: reduced invasiveness, low cost, and short hospitalisation time. In June 2001 we began using RF thermal ablation on osteoid osteomas (OO) in the appendicular and axial skeleton. Later, we also treated local benign and/or malignant tumors, some surgical recurrences, and some secondary localizations. Altogether we have performed over 270 procedures, mainly on OO. The experience we have gained has led us to think that the indication for this treatment can be extended to other thermosensitive lesions.

The serine/threonine protein kinase C (PKC) family was first identified as intracellular receptor(s) for the tumor promoting agents phorbol esters. Thirty years after the discovery of PKC, the role of specific PKC isoforms has been described in relationship with an altered pattern of expression in different types of cancer and a good number of small molecule inhibitors (inhibitory peptides, antisense oligonucleotides or natural compounds) targeting PKC are now available. Despite all these achievements and a huge amount of basic research studies on the biochemical regulation of PKC, there has been a delay in clinical trials with drugs targeting PKC function. This delay is easily explained taking into account the extreme biological complexity of the PKC family of isoforms and the incomplete understanding of the specific role of each PKC isozyme in different types of cancers. Some of the difficulties in developing pharmacological compounds selectively tuning the different PKCs have started to be overcome. In this review, the growing evidences of the role of the PKC isoforms α, βII, δ, ε, ζ and ι is in promoting or counteracting tumor progression will be discussed in relationship with promising therapeutic perspectives.

Objective: Bone marrow derived cell transplantation (BMDCT) has been recently suggested as a possible surgical technique to repair osteochondral lesions. To date, no qualitative MRI studies have evaluated its efficacy. The aim of our study is to investigate the validity of MRI T2-mapping sequence in characterizing the reparative tissue obtained and its ability to correlate with clinical results. Methods and materials: 20 patients with an osteochondral lesion of the talus underwent BMDCT and were evaluated at 2 years follow up using MRI T2-mapping sequence. 20 healthy volunteers were recruited as controls. MRI images were acquired using a protocol suggested by the International Cartilage Repair Society, MOCART scoring system and T2 mapping. Results were then correlated with AOFAS clinical score. Results: AOFAS score increased from 66.8 ± 14.5 pre-operatively to 91.2 ± 8.3 (p < 0.0005) at 2 years follow-up. T2-relaxation time value of 35-45 ms was derived from healthy ankles evaluation and assumed as normal hyaline cartilage value and used as a control. Regenerated tissue with a T2-relaxation time value comparable to hyaline cartilage was found in all the cases treated, covering a mean of 78% of the repaired lesion area. A high clinical score was related directly to isointense signal in DPFSE fat sat (p = 0.05), and percentage of regenerated hyaline cartilage (p = 0.05), inversely to the percentage of regenerated fibrocartilage. Lesion's depth negatively related to the integrity of the repaired tissue's surface (tau = -0.523, p = 0.007), and to the percentage of regenerated hyaline cartilage (rho = -0.546, p = 0.013). Conclusions: Because of its ability to detect cartilage's quality and to correlate to the clinical score, MRI T2-mapping sequence integrated with Mocart score represent a valid, non-invasive technique for qualitative cartilage assessment after regenerative surgical procedures.

Chondrosarcoma (CHS) is the third most frequent primary malignant tumour of bone exceeded only by myeloma and osteosarcoma. It usually occurs in the trunk bones (pelvic girdle, shoulder, ribs) followed by the femur and humerus and is very rare in the spine accounting for about 5% of all CHSs. The majority of patients affected are over 50 years old. We report a case of a 22-year-old woman with a 2-month history of pain on the right side of the upper thoracic spine. Complete imaging work-up with radiographs, CT, MRI and digital subtraction angiography showed an osteolytic lesion of the right transverse process of T5 with extension into the ipsilateral rib and enhancing extracompartmental tissue involving the paraspinal muscles. Both CT-guided core needle biopsy and excisional biopsy were consistent with grade I central CHS with myxoid change and focal areas of Grade II CHS.

Background: There is great interest in the use of bone substitutes to improve bone repair. We compared the osteogenic potential of lyophilized bone chips combined with platelet gel, or with platelet gel and bone marrow stromal cells, with that of lyophilized bone chips alone in the healing of a high tibial osteotomy. Methods: A prospective, randomized, controlled study was performed, and a standardized clinical model was applied. Thirty-three patients undergoing high tibial osteotomy to treat genu varum were enrolled and assigned to three groups. During the osteotomy, lyophilized bone chips with platelet gel were implanted into eleven patients (Group A), lyophilized bone chips with platelet gel and bone marrow stromal cells were implanted in twelve patients (Group B), and lyophilized bone chips without gel were placed in ten patients as controls (Group C). Six weeks after surgery, computed tomography-guided biopsies of the grafted areas were performed and the specimens were analyzed by histomorphometry. Clinical and radiographic evaluation was performed at six weeks, twelve weeks, six months, and one year after surgery. Results: Histomorphometry at six weeks showed significantly increased osteoblasts and osteoid areas in both Group A (p = 0.006 and p = 0.03, respectively) and Group B (p = 0.009 and p = 0.001) in comparison with controls, as well as increased bone apposition on the chips (p = 0.007 and p = 0.001, respectively), which was greater in Group B than in Group A (p < 0.05). Group B showed significantly higher revascularization than the controls (p = 0.004). Radiographs revealed a significantly higher rate of osseointegration in Groups A and B than in the controls at six weeks (p < 0.005 and p < 0.0001, respectively). At the final evaluation at one year, the osseointegration was still better in Groups A and B than in Group C; however, all patients had complete clinical and functional evidence of healing. Conclusions: Adding a platelet gel or a platelet gel combined with bone marrow stromal cells to lyophilized bone chips increases the osteogenetic potential of the lyophilized bone chips and may be a useful tool in the treatment of patients with massive bone loss. Level of Evidence: Therapeutic Level I. See Instructions to Authors for a complete description of levels of evidence.

The diagnosis of osteoid osteoma is usually not difficult. In typical forms of the disease, with diaphyseal localization, the clinical course and radiographic findings are so typical that diagnosis may be considered certain even when there is no histological confirmation. In some localizations, nonetheless, such as in the cancellous or short bones, or when the lesion involves a joint, diagnosis may be difficult, uncertain and late. Between January 1991 and April 1997 a total of 91 patients who had been diagnosed as having osteoid osteoma were submitted to computed tomography. Of these patients, there were 34 females, and 57 males, and age ranged from a minimum of 2 to a maximum of 69 years. Localizations are reported in Table I. For the purposes of our study, several cases with atypical features have been selected from these. We found it interesting to emphasize the importance of a correct diagnostic procedure with the purpose of accurately identifying the lesion.

To assess the efficacy of percutaneous CT-guided biopsy in the diagnosis and therapeutic planning of neoplastic and flogistic diseases of the pelvis.From July 1990 to December 1999 193 patients (113 males, 80 females: mean age 49, standard deviation 16) were submitted to CT-guided percutaneous biopsy of the pelvic region; 117 biopsies (61%) were performed at iliac, pubic and ischial segments and 76 (39%) at sacral region; 107 patients were admitted to the hospital and 86 were in clinic. Needles were 8 G (4 mm), 10 to 15 cm long. Approach to pelvic lesions was performed according to the specific site. Lesions of the lateral pelvic region have always been approached through the lateral surgical incision according to Enneking. Lesions of the posterior pelvic region have always been approached by the introduction of the needle along the posterior surgical incision according to Enneking. Lesions of the anterior region have always been approached through the anterior surgical incision according to Enneking. From July 1990 to May 1997 pelvic percutaneous biopsies have been carried out with a CT Sytec 3000. From May 1997 to December 1999 the device was replaced by a High Speed CTi. The introduction of spiral CT allowed reduction of performance mean time from 45 minutes (standard deviation 15) to 30 minutes (standard deviation 10).In 154 patients (80%) we observed a neoplastic, inflammatory or not classified degeneration. In 8 patients (4%) the retrieved material ended to be inadequate for a diagnosis. In 31 patients (16%) no disease was revealed at the histological examination. Such patients with negative histological examination have been kept under clinical and radiological control in the following period in order to verify the manifestation or the presence of an alteration previously not observed. On 31-3-2000 none of them had been submitted to a new percutaneous biopsy of the pelvic region. The overall mean accuracy has been 96% considering the negative patients as really negative. In 5 cases (2.6%) we have had complications represented by pain at the introduction and penetration site of the needle.The choice of the needle, the approach to the lesion and the position of the patient are conditioned by the site of the tumor, its extension, the distance skin-neoplastic disease and by the respect of the incision lines of Enneking, in order not to complicate the job of the orthopaedic surgeon spreading tumoral cells outside the chosen surgical approach. The mean time of the procedure is 30 minutes (standard deviation 10). There are no absolute contraindications to percutaneous biopsy except the suspect or the presence of an hydatideal cyst. The risks have to be compared with those correlated with alternative methods or with the more concerning risk of a missed diagnosis. Complications in the literature range from 0% to 10%, the incidence varying according to the location; pain is the most frequent complication. Altogether the most negative event, although not a true complication, is the retrieval of an inadequate sample: the only drawback of percutaneous biopsy in comparison with incisional biopsy. The accuracy rate of percutaneous biopsy varies in relation to the involved anatomical region, to the pathological process, to the experience of the user, to the amount of the retrieved tissue and to the cooperation of the patient. Our experience shows that, in selected patients, percutaneous biopsy is a virtually safe and almost painless procedure which saves the patient from a surgical procedure in regional or general anestesia as for an incisional biopsy, and allows immediate planning and scheduling of a correct therapy for primitive or secondary neoplastic lesions.

CT assessment of the axial deviation of the femoral and tibial prosthetic components in total knee arthroplasty.January to July 1999, seventeen patients, 10 males and 7 females, mean age 66 years (standard deviation +/- 4) were examined after total knee arthroplasty. Exclusion criteria were prosthesis loosening and severe (equal or superior to 7 degrees) varus or valgus deviation. All patients were examined with knee radiography in the standing position completed by axial projections of patella and by CT scanning. We used a modification of Berger technique and carried out comparative CT scans extended lower limbs and acquisitions perpendicular to the mechanical axis of the knee, from the femoral supracondylar region down to the plane crossing the distal end of the tibial prosthetic component. Reference lines were then drawn electronically on given scanning planes to reckon the axial deviation of the femoral and tibial prosthetic components.Six patients, one female and 5 males, with normal rotational values of femoral and tibial prosthetic components presented no clinical symptoms. Eight patients, 4 females and 4 males, with abnormal values presented the following clinical symptoms: medial impingement, (incomplete) dislocation patella, and lateral instability. One female patient with a normal rotational value of femoral prosthetic component and an altered value of tibial prosthetic component presented medial impingement. Finally two patients, one female and one male, were absolutely asymptomatic although the rotational values of the two prosthetic components were beyond the normal range.Total knee arthroplasty is presently a standard treatment for many conditions involving this joint. There are several possible postoperative complications, namely fractures, dislocations (a)septic loosening and femoropatellar instability. The latter condition is the most frequent complication among implant failures and is caused by bad orientation of the femoral and tibial components on frontal and axial planes. We measured the orientation of the prosthetic components introducing a CT procedure which modifies the uniarticular with four scans introduced by Berger. The new method uses Berger's parameters and the CT study of both joints by means of Helical CT. With a single examination lasting less than 4 minutes and with the patient in a more comfortable position, we can obtain: 1) comparative and simultaneous assessment of the contralateral joint; 2) several scans to better define Berger's parameters and to accomplish measurement of the rotational deviation with higher precision and markedly decreasing the error margin. The analysis of the results confirms the international literature findings and especially the fundamental importance in positioning both prosthetic components within normal values, as emphasized by the relationship between the clinical symptoms and the rotational degree of the femoral and tibial prosthetic components.

Proximal carpal instability is a painful condition characterized by early or late loss of radioulnar joint (RUJ) congruence not affecting the normal bone alignment of the two carpal rows. The joint incongruence or (incomplete) dislocation which leads to proximal instability is caused by many traumatic and nontraumatic events. The diagnosis of (incomplete) dislocation of the distal RUJ may be extremely difficult to make at conventional radiography because such injuries can be seen only when the lateral joint projection is perfect; otherwise the diagnosis is not reliable. CT is the only imaging tool diagnosing the grade of distal RUJ congruence independent of the examination technique.We studied the radiocarpal complex conditions leading to proximal instability at the Rizzoli Orthopedic Institute from December, 1995, through December, 1997. In all, 389 cases were seen, 376 from trauma and 13 of nontraumatic origin. Each injury was studied with conventional radiography, CT, and MRI. Radiography was performed in two projections, namely the posteroanterior one with hand extension and the lateral one with the forearm in neutral position and the elbow bent at 90 degrees; the projections were repeated whenever a cast brace was applied. Unenhanced CT was performed for comparison with the patient prone and the forearm and wrist in prone and neutral position, as well as with the patient, forearm and wrist supine. Three criteria of electronic image processing were adopted for the RUJ studies in the 3 projections: radioulnar lines, congruence, and epicenter. MRI was always performed after conventional radiography and CT. Only the involved radiocarpal region was studied; coronal, axial and sagittal images were acquired with T2-weighted GE and T1-weighted SE sequences.Proximal instability was found in 17 of 389 patients; it was early in 13 and late in 4 of them. The comparison of radiographic and CT results showed that the former method is unreliable, with 53% false negatives. Pain, a cast brace, congenital or acquired deformities of distal radius and ulna and patient mispositioning by the radiology technician can change the rotation of the forearm, wrist and hand and make a perfect laterolateral projection in neutral position unfeasible, which affects the radiographic diagnosis. Conversely, CT showed its extreme efficacy in assessing the distal RUJ congruence with no false negatives independent of the RUJ rotation and of instability type and grade.Conventional radiography is a poorly reliable tool for the diagnosis of joint incongruence and its grade. In contrast, CT can diagnose a RUJ (incomplete) dislocation easily and unquestionably, thanks to its axial capabilities, even when adequate radiographic studies would be unfeasible. If the anteroposterior projection of the radiocarpal complex shows a congenital or acquired deformity of distal radius, the lateral projection can be skipped and a CT scan in prone, neutral and supine position performed. The 3 CT criteria quantify incongruence type and grade, and also demonstrate the position of maximum incongruence and its decrease by position. The comparative study of the radiocarpal region makes CT a very useful and valuable tool in congenital instability because its allows the assessment of contralateral radioulnar congruence too. MRI is very useful in the diagnosis of injury or degeneration of the fibrocartilage complex, namely in patients with no bone changes at conventional radiography.

Carpal instability is a painful posttraumatic syndrome with early or late loss of the normal alignment of the carpal bones, which can be caused by a variety of injuries, from minor sprain to major fracture-dislocation of the carpal-wrist complex. If the trauma causing instability is a fracture, a severe dislocation or a fracture-dislocation, the radiographic diagnosis is not particularly difficult. The morphologic and dynamic complexity of the carpal region represents, instead, a major obstacle in the radiologic diagnosis of mild or moderate sprains because the morphologic alterations on standard static views are minimal or absent in these conditions.We reviewed 214 injuries causing posttraumatic carpal instability including both the cases classified by the Data Analysis Center of the Istituto Ortopedico Rizzoli as carpal dislocations and fracture-dislocations from January, 1975, to July, 1996, and the more recent cases directly observed at our Casualty Clinic. In the former cases, we reviewed only the available images, while our patients were examined with comparative standard and under stress or dynamic views.Of 214 lesions causing posttraumatic carpal instability, 43 along the great arch were classified as severe because they were easily detectable on standard films and 171 along the small arch were classified as mild because slight/no abnormalities were detected on standard static views. Only dynamic imaging showed posttraumatic carpal instability demonstrating the integrity of the ligaments and of the carpal hinges, as well as gaps or asymmetry not detected on static views.We suggest the systematic use of dynamic imaging in the cases where static findings are negative or poor, in the patients with a painful wrist after an apparently minor sprain. Missed or delayed diagnoses are thus reduced, as well as the consequent joint incongruity and/or chronic subluxation which may severely impair these patients.

The authors analysed the patterns of recurrence of osteosarcoma of the extremities treated between 1959 and 1989 either with surgery alone (1959-71) or with combined surgery and adjuvant (1972-82) or neoadjuvant chemotherapy (1983-89). In a total of 452 patients with recurrent osteosarcoma, the initial site of metastasis was the lung in 88% of cases independently of the type of treatment received. The mean period of onset of pulmonary metastasis differed according to the type of treatment performed: 8 months for patients treated with surgery alone; 15.9 months for those treated with adjuvant chemotherapy and 20.3 months for patients treated with neoadjuvant chemotherapy. The incidence of metastases appearing within 12 months of FU was 87%, 56% and 21% respectively. In a most recent and effective neoadjuvant protocol (66% DFS), the incidence of recurrence owing to pulmonary metastasis during the first year of FU was 2% and as much as 75% of all recurrences were concentrated in the following 18 months. Surgery for pulmonary metastasis in patients undergoing chemotherapy was performed in 54 cases with secondary healing in 14 (26%). On the basis of these results the authors suggest a scheme of radiological follow-up for patients with osteosarcoma of the extremities treated with neoadjuvant chemotherapy with intensified controls (every 2 months) during the period with the highest risk of recurrence (13-20 months) and four-monthly controls during the first year and after 31 months of FU. In order to increase the efficacy of FU controls during the high-risk period, the a. propose using CT controls instead of chest X-rays at months 14, 20 and 26.

The use of percutaneous spinal biopsy (PSB) is on the increase in the field of interventional radiology. From July 1990 to December 1992 in the Department of Radiology in the Istituto Ortopedico Rizzoli, 74 patients (50 men and 24 women, mean age: 47 years old) underwent CT-guided spinal biopsy. This study was aimed at evaluating the diagnostic capabilities and accuracy of CT-guided percutaneous biopsy, which is considered as a simple, reliable and definitive method for histopathologic diagnosis. In our case histories, the total average accuracy rate, which varies according to the involved segment and to the kind of lesion to be examined, was 86%; in 14% of cases the excised tissue proved insufficient for histologic diagnosis. By allowing the histopathologic diagnosis to be made, CT-guided PSB proves a valuable technique to plan the treatment of primary/secondary neoplastic lesions or of inflammatory and dysmetabolic processes.

Intraoperative ultrasonography was conducted in 20 patients; the technique of intraoperative ultrasonography for use in spinal surgery is described. The authors emphasize that this non-invasive method obtains real time images of considerable diagnostic importance, allowing for a significantly minor use of image intensifier, with a consequent reduction in doses for both the patient and the staff.

A report is presented on 5 cases of pneumothorax which occurred during chemotherapy in patients suffering from osteogenic sarcoma of the extremities. None of them presented radiographically detectable substitutive pulmonary lesions. It was hypothesised that the origin of pneumothorax was the necrosis produced by agents of a pulmonary micrometastasis.

Gluon scattering processes are studied in hadronic highp T events using data obtained with the Split Field Magnet detector (SFM) at the CERN ISR. The experimental set-up allowed the scanning of a wide range of parton energies and scattering angles. It is shown that for positive pions as trigger particles, the parton composition of the recoil jet is correlated with the polar angle and transverse momentum of the triggering pion. Over the kinematical region studied, the recoil jet originates predominantly from scatered gluons, with an increasing prevalence of the gluon component towards forward triggering angles. The variation of the momentum structure of the recoil jet with the trigger angle indicates that the fragmentation function of gluons is softer than that of quarks.

The authors report two recent cases of Fenton's syndrome, a very rare carpal fracture-dislocation. After some anatomico-physiopathological considerations and a review of the literature, a wider nosographic frame is proposed in which the entity of the dislocation of the head of the capitate bone is not essential. According to both the literature and the personal findings, the authors remark that this syndrome is always found in the presence of two morphological variants of the distal radioulnar joint. Finally, the authors stress the importance of a correct diagnosis of this lesion to avoid unnecessary attempts of reduction.

A variety of unique and very rare carpal dislocations are reported. According to personal findings, an extension of the descriptive classification of this pathology is proposed, utilizing also the X-ray files of the Rizzoli Orthopaedic Institute. Moreover, the radiographical features are evaluated which help choosing the treatment to be followed.

The angle of anteversion, assessed by the Dunlap technique, was determined in 30 patients suffering from primary osteoarthritis of the hip. This was compared with the same angle in 10 normal subjects. The patients with arthritis showed a statistically significant increase in the angle. This is considered by the authors to play a significant part in the pathogenesis of primary osteoarthritis of the hip.

Twelve patients who had undergone osteosynthesis with a metal plate combined with a frozen homoplastic bone graft for the treatment of fractures or pseudarthrosis were subjected to bone scintigraphy with 99 Tc MDP. This investigation showed the graft to be a site of early and specific accumulation of the tracer. This finding supports early colonization of the graft by vascular structures and osteoblastic cells. In view of the small number of cases studied and our incomplete knowledge of the metabolic processes involved these considerations must remain hypotheses but given the excellent clinical results obtained, the relationships between homoplastic bone and host bone merit further investigation.

Objective: The aim of the present study was to evaluate the reliability of scout CT (sCT) lateral radiograph, in terms of diagnostic accuracy and intra- and interobserver agreement in the detection of vertebral fractures (VFs). Methods: 300 CT examinations of the thoracic and/or lumbar spine were collected and independently analysed by 3 musculoskeletal radiologists in 2 different sessions. A semi-quantitative approach was used for VF assessment on sCT, and morphometric analysis was performed when a VF was suspected. Results of multiplanar sagittal CT reconstructions interpreted by the most expert radiologist were considered as gold standard. Arthrosiswas also scored.Only vertebral bodies assessable by both sCT and gold standard were considered for the analysis. Area under the receiver operating characteristic curve (AUROC), Cohen’s kappa statistic and linear-by-linear association were used for statistical analysis. Results: 1522 vertebrae were considered (130 males and 170 females; ages, 73.062.8 years). 73 of 1522 (4.8%) VFs were identified in 34/300 patients (11.3%). In the detection of VFs, the sensitivity and specificity of sCT were 98.7% and 99.7%, respectively. Accuracy (AUROC50.99260.008), as well as interobserver agreement (k50.96860.008), was excellent. Intra-observer agreement was perfect (k51.000). Performance of this method was independent of arthrosis, vertebral level and type and grade of VFs. Conclusion: sCT is a simple but very accurate method for the detection of VFs. It should be introduced as a spine evaluation tool for the detection of VFs in examinations that are performed for other diagnostic purposes. Advances in knowledge: sCT lateral radiograph is an accurate tool for the detection of VFs. This technique may be used with several advantages in clinical practice.