Aims. We aimed to evaluate the utility of . 68. Ga-citrate positron emission tomography (PET)/CT in the differentiation of periprosthetic joint infection (PJI) and aseptic loosening (AL), and compare it with . 99m. Tc-methylene bisphosphonates (. 99m. Tc-MDP) bone scan. Methods. We studied 39 patients with suspected PJI or AL. These patients underwent . 68. Ga-citrate PET/CT, . 99m. Tc-MDP three-phase bone scan and single-photon emission CT (SPECT)/CT. PET/CT was performed at ten minutes and 60 minutes after injection, respectively. Images were evaluated by three nuclear medicine doctors based on: 1) visual analysis of the three methods based on tracer uptake model, and PET images attenuation-corrected with CT and those not attenuation-corrected with CT were analyzed, respectively; and 2) semi-quantitative analysis of PET/CT: maximum standardized uptake value (SUVmax) of lesions, SUVmax of the lesion/SUVmean of the normal bone, and SUVmax of the lesion/SUVmean of the normal muscle. The final diagnosis was based on the clinical and intraoperative findings, and histopathological and microbiological examinations. Results. Overall, 23 and 16 patients were diagnosed with PJI and AL, respectively. The sensitivity and specificity of three-phase bone scan and SPECT/CT were 100% and 62.5%, 82.6%, and 100%, respectively. Attenuation correction (AC) at 60 minutes and non-AC at 60 minutes of PET/CT had the same highest sensitivity and specificity (91.3% and 100%), and AC at 60 minutes combined with SPECT/CT could improve the diagnostic efficiency (sensitivity = 95.7%). Diagnostic efficacy of the SUVmax was low (area under the curve (AUC) of ten minutes and 60 minutes was 0.814 and 0.806, respectively), and SUVmax of the lesion/SUVmean of the normal bone at 60 minutes was the best semi-quantitative parameter (AUC = 0.969). Conclusion. 68. Ga-citrate showed the potential to differentiate PJI from AL, and visual analysis based on uptake pattern of tracer was reliable. The visual analysis method of AC at 60 minutes, combined with . 99m. Tc-MDP SPECT/CT, could improve the sensitivity from 91.3% to 95.7%. In addition, a major limitation of our study was that it had a limited sample size, and more detailed studies with a larger sample size are warranted. Cite this article: Bone Joint Res 2022;11(6):398–408

We evaluated 100 consecutive patients with a suspected scaphoid fracture but without evidence of a fracture on plain radiographs using MRI within 24 hours of injury, and bone scintigraphy three to five days after injury. The reference standard for a true radiologically-occult scaphoid fracture was either a diagnosis of fracture on both MRI and bone scintigraphy, or, in the case of discrepancy, clinical and/or radiological evidence of a fracture. MRI revealed 16 scaphoid and 24 other fractures. Bone scintigraphy showed 28 scaphoid and 40 other fractures. According to the reference standard there were 20 scaphoid fractures. MRI was falsely negative for scaphoid fracture in four patients and bone scintigraphy falsely positive in eight. MRI had a sensitivity of 80% and a specificity of 100%. Bone scintigraphy had a sensitivity of 100% and a specificity of 90%. This study did not confirm that early, short-sequence MRI was superior to bone scintigraphy for the diagnosis of a suspected scaphoid fracture. Bone scintigraphy remains a highly sensitive and reasonably specific investigation for the diagnosis of an occult scaphoid fracture

We evaluated triple-phase bone scintigraphy in the differential diagnosis of peri-prosthetic infection in 46 patients with a total hip replacement or bipolar hemiarthroplasty who were due for revision surgery. There were 18 men and 28 women, with a mean age at operation of 64.6 years (28 to 81). We defined peri-prosthetic infection as an increased uptake of radioisotope in all the phases of triple-phase bone scintigraphy and validated these results against the histological and/or microbiology results in every case. The positive and negative predictive values for the presence of infection were 83% and 93%, respectively. The diagnostic sensitivity was 88% and the specificity was 90%. This study indicates that triple-phase bone scintigraphy is a useful tool in the detection of peri-prosthetic infection and offers a cost-effective method of screening

Aim: Isotope bone scan has become a part of the routine workup for a painful arthroplasty. A retrospective analysis was performed to analyse the significance of isotope bone scan results in the management of painful arthroplasty. Methods and Materials: The study group included all the 58 consecutive patients who underwent an isotope bone scan for a painful arthroplasty over a one year period. The data collected included: age, sex, date and nature of primary arthroplasty, inflammatory markers, indication, date and result of the bone scan, and the final outcome. Results: The primary arthroplasty was a TKR (29 patients) and THR (29 patients). The average duration between primary arthroplasty and the bone scan was 44.3 months (Range 5 – 195 months). The duration was less than 1 year for 6 patients. The average age of the patients was 62 years. The male: female ratio was 31:27. 4 of the arthroplasties were uncemented and 54 were cemented. The bone scan results were normal in 32 patients, unclear in 17 patients and abnormal in 9 patients. There was no statistical correlation found between the inflammatory markers and the results of the bone scan. Discussion: The results of the bone scan made a significant contribution in the management decision of the patient in 8 of the patients and served to reassure the patient/surgeon in most of the rest 50. In 6 patients it was performed within a year of the primary arthroplasty, during which period the results are not very specific. An isotope bone scan involves a significant radiation exposure to the patient as well utilization of time and resources, hence always ask the million dollar question: “Is it going to alter my management plan”

Aim: Isotope bone scan has become a part of the routine workup for a painful arthroplasty. A retrospective analysis was performed to analyse the significance of isotope bone scan results in the management of painful arthroplasty. Methods and Materials: The study group included all the 58 consecutive patients who underwent an isotope bone scan for a painful arthroplasty over a one year period. The data collected included: age, sex, date and nature of primary arthroplasty, inflammatory markers, indication, date and result of the bone scan, and the final outcome. Results: The primary arthroplasty was a TKR (29 patients) and THR (29 patients). The average duration between primary arthroplasty and the bone scan was 44.3 months (Range 5 – 195 months). The duration was less than 1 year for 6 patients. The average age of the patients was 62 years. The male: female ratio was 31:27. 4 of the arthroplasties were uncemented and 54 were cemented. The bone scan results were normal in 32 patients, unclear in 17 patients and abnormal in 9 patients. There was no statistical correlation found between the inflammatory markers and the results of the bone scan. Discussion: The results of the bone scan made a significant contribution in the management decision of the patient in 8 of the patients and served to reassure the patient/surgeon in most of the rest 50. In 6 patients it was performed within a year of the primary arthroplasty, during which period the results are not very specific. An isotope bone scan involves a significant radiation exposure to the patient as well utilization of time and resources, hence always ask the million dollar question: “Is it going to alter my management plan”

We reviewed the plain radiographs, bone scans and hip aspiration results of 54 patients with painful hip arthroplasties which had been explored surgically, to compare the results of the investigations with the operative findings. For acetabular loosening, the sensitivity and specificity of bone scanning were 87% and 95%, with an accuracy of 90%: for serial plain radiography sensitivity was 95%, specificity 100% and accuracy 97%. For femoral component loosening, bone scan sensitivity was 85%, specificity 100% and accuracy 89%: the sensitivity of plain radiography was 100%, with specificity 92% and accuracy 98%. Technetium bone scanning did not provide additional information with regard to loosening and is not necessary in the routine investigation of a painful hip arthroplasty. Serial pain radiography is the most effective method of detecting loosening, and bone scanning is useful only when radiography is inconclusive with regard to loosening or infection

In 66 patients with back pain and suspected spondylolysis, the results of bone scintigraphy have been correlated with operative findings and clinical follow-up. Although bone scintigraphy is of little value for primary diagnosis, it helps to distinguish between those patients with established non-union of the defect, and those in whom healing is still progressing and who may benefit from immobilisation. We also found that increased uptake on the contralateral side to a unilateral spondylolysis is suggestive of impending fracture

The purpose of this study was to investigate the use of early post-operative bone scintigraphy to predict surgical outcome following vascularized fibular grafting (VFG) for osteonecrosis of the hip. Bone scans from one hundred and four hips (Steinberg stage I–IV) treated with VFG between 1994 and 2000 were retrospectively reviewed. Bone scan scores were significantly lower in the failed group (n=31) compared to the successful group (n=73), p=0.03. Logistic regression demonstrated that a higher bone scan score was associated with success, p=0.028, with an odds ratio of 3.08 (1.13–8.40). The purpose of this study was to investigate the use of bone scintigraphy to predict surgical outcome following vascularized fibular grafting (VFG) for osteonecrosis of the hip. Subjects with a higher bone scan score post-operatively had a three-fold higher chance of success than subjects with the lowest score. These results suggest that having a well perfused and viable graft in the early post-operative period improves the chances of a successful result. Single Photon Emission Computed Tomography images from one hundred and four hips (Steinberg I–IV) treated with VFG between 1994 and 2000 were retrospectively reviewed. Each scan was divided into three regions, the greater trochanter, neck, and head. The intensity at the graft in each region (axially and coronally) was compared to the intensity at the ipsilateral proximal femoral diaph-ysis and assigned a score: less than diaphysis (one), equal to (two), and greater than (three). Cumulative scores were obtained for each subject. Intraobserver variability was 0.93. Surgical failure was defined as conversion to or on the waiting list for total hip arthroplasty. Thirty percent of hips failed treatment (n=31, mean survival 34.9 months, range 5–98), while 70% were successful (n=73, mean follow-up 56.6 months, range 22–100). Bone scan scores were significantly lower in the failed group (mean 7.1, range 6–12) compared to the successful group (mean 8.5, range 6–18), p=0.03. Positive skewness (+1.7) was demonstrated as 64% of hips had a score of six while 36% had a score > 6 (range 8–18). Logistic regression demonstrated that a bone scan score > 6 was associated with success, p=0.028, with an odds ratio of 3.08 (1.13–8.40)

Introduction. Many surgeons assess biological activity of fracture nonunion by the presence or absence of callus using radiograph. However, it is difficult to assess biological activity only by radiographic appearance. Bone scintigraphy reflects blood supply and bone metabolism and is possibly useful to assess biological activity in nonunion cases. Hypothesis. We hypothesized that poor callus visualization did not always mean lack of biological activity. Materials & Methods. Retrospective assessment and comparison of radiographs and Tc-99m bone scintigraphy of 44 patients with uninfected nonunion was done. Results. Uptake was observed at or around the nonunion site in all cases. Three patterns of uptake were noted; Spot type (S): intense uniform uptake, Uneven type (U): uptake with distribution from cold to hot, and Cleft type (C): decreased uptake surrounded by significant uptake on both sides. All 9 cases of hypertrophic nonunion demonstrated the S type. In 21 cases of oligotrophic nonunion, there were 12 S, 5 U and 4 C. In 3 cases of comminuted nonunion, there were 1 U and 2 C. In 5 cases of defect nonunion, there were 1 U and 4 C. In 6 cases of atrophic nonunion, there were 2 U and 4 C. Discussion & Conclusions. Our results suggest that poor callus visualization does not always mean lack of biological activity. The distribution of uptake and the cleft with decreased uptake are helpful findings to assess the necessity of bone graft or other supplementation in nonunion surgery

Of 693 elderly patients admitted with suspected hip fractures, 43 had normal radiographs and were investigated by isotope bone scan. The 30 patients (70%) with normal scans were mobilised and none developed a fracture. All 13 of the patients with specific bone scan abnormalities were subsequently proved to have fractures, five of which became displaced. Clearly conventional radiography does not exclude fracture of the femoral neck in elderly patients; bone scanning is advisable in doubtful cases

We prospectively studied 86 children to assess the value and accuracy of isotope bone scanning in the diagnosis of suspected acute haematogenous osteomyelitis and septic arthritis. The patients were scanned because of difficulty in localising the exact site of the pathology. Characteristic scan appearances were found. In osteomyelitis there was increased or decreased uptake extending beyond the confines of the joint capsule; in septic arthritis there was increased or decreased uptake on either side of the joint line, but largely limited to and uniform within the joint capsule. The bone-scan images were correlated with the final diagnosis in 34 sites of septic arthritis and in 62 sites of osteomyelitis. The overall accuracy of the bone scans was 81%. The predictive value for a positive scan to be correct was 100% for a cold scan and 82% for a hot scan. The main reason for a false-positive scan was contiguous soft-tissue infection. The predictive value for a negative scan to be correct was 63%. One reason for a false-negative scan was that the patient was in the transitional phase from cold to hot

Introduction: It is very important to evaluate the healing process in the femoral head after free vascularized fibular graft (VFG) in osteonecrosis of the femoral head (ONFH). Bone scintigraphy combined with a pinhole collimator, which is simple and not expensive, is used for very high resolution images of small organs, such as thyroid and certain skeletal regions. The purpose of this study was to assess the changes using pinhole bone scintigraphy in ONFH after VFG. Materials and Methods: Changes of Tc-99m-HDP pinhole bone scintigraphy were analyzed in 22 cases of ONFH which were treated with VFG and had satisfactory results in patient evaluations at least 2 years after surgery. Harris Hip Scores were 90 points or more; and femoral head collapse was less than 2 mm. Results: The results were: (1) At 1 week, the pinhole image showed no significant change in cold area but two linear RI uptakes corresponding to the fibular graft were noted. (2) At 3 months, localized hot uptakes just above the tip of the graft were observed in 17 cases (77.2%), and diffuse increased uptake surrounding the cold area were observed. (3) At 6 months, localized hot uptake were increased in size and replaced cold areas and delineated the shape of the superolateral aspect of the femoral head. (4) At 1 year, increased RI uptake of the superolateral aspect of the femoral head expanded medially in all cases. (5) After 2 years, cold areas faded away in 18 cases (81.8%). Discussion: In conclusion, the authors believe that the Tc-99m-HDP pinhole bone scintigraphy is an excellent method to delineate the healing process in ONFH after VFG

This paper reports the results of bone scans on 78 painful feet. Scanning helped in the diagnosis of persistent foot pain following injury and it enabled stress fractures, fractures of the sesamoids and subtalar arthritis to be diagnosed earlier. It reliably excluded bone infection and was useful as a screening test when radiographs were normal

The diagnosis of acute osteomyelitis is often very difficult during the first 24 to 48 hours. Bone scanning has been a useful adjunct in this diagnosis by demonstrating increased uptake in the area or areas of involvement. Occasionally the pathological area is "cold" on scanning, which may lead to a misdiagnosis. This paper presents three cases demonstrating this unusual finding

Radiopharmaceuticals have been successfully used to detect occult neoplasms and infective lesions. Bone scans using 99mTc-labelled methylene diphosphonate located osteoid osteomas accurately in a series of 30 symptomatic patients. A portable radiation detector system has been designed to help intra-operative localisation and facilitate complete excision of the lesions with minimal damage to normal tissue. A sodium iodide detector with a fibre-optic link was used at first, but a cadmium telluride system has provided a more durable, reliable and sensitive sterilisable probe

We performed single-photon-emission CT (SPECT) and planar bone scans to assess femoral head vascularity in ten patients with displaced intracapsular hip fracture. The heads were labelled with tetracycline and after excision at hemiarthroplasty were assessed for tetracycline uptake distribution by fluorescence under UV light. The four which had the greatest tetracycline uptake were normal on SPECT and planar imaging. In two cases the planar bone scans were normal although SPECT suggested avascularity thus giving false-negative results. Surgeons should be aware of this; SPECT may prove to be a more accurate method of assessing vascularity of the femoral head in fractures of the femoral neck

Background. Bone lesions in Ewing's sarcoma (ES/PNET) have been traditionally diagnosed with bone Scan. PET-scan is emerging as a promising investigative modality for detection of metastatic lesions. In this prospective study, we compare the utility of both to detect the metastatic sites. Methods. One hundred and seventy five histologically proven cases of ESPNET from 2004-2009 were prospectively staged with bone scan and PET-scan with Breath- hold CT scan- thorax. The diagnostic value of PET-scan to pick up metastatic lesions was compared with bone scan. Results. The site of primary disease was axial in 62(35.4 %) patients, appendicular in 94(53.7 %) patients, and extraskeletal in 19 (10.8 %) patients. 24(13.7 %) patients were metastatic at presentation, while 151(86.2 %) patients had localized disease. In all patients with localized disease, bone scan did not detect any lesion other than that detected on PET-scan. In metastatic patients, PET-scan detected 12 patients with lymph node involvement which were not detected by bone scan, 10 patients were found to have lung metastasis by PET scan with breath-hold CT thorax, bony metastases were seen in two patients where the number and site of lesions were same in both PET and bone scan. In 19 patients with extraskeletal PNET, PET scan detected primary lesion in all while the bone scan was non-avid in any of these. Conclusion. PET- Scan was able to detect all the bony lesions picked up by bone scan at baseline in newly diagnosed patients of PNET/ES. Furthermore, PET-scan was able to detect extra-skeletal sites of metastases. We conclude that PET scan may obviate the need of bone scan in the diagnostic work up of patients with Ewing's sarcoma

Aim: In the present study we examine the role of bone scan with 99mTc-MIBI, following a positive 99mTc-MDP scan, in the work up to differentiate between malignant and benign bone lesions. Material and methods: Fifty-nine patients, with a positive 99mTc-MDP bone scan had further investigation of the affected area with the oncophilic radiopharmaceutical 99mTc-MIBI (15 mCi). The agent was administered IV and images were obtained (planar/SPECT) 20 min and 3 hours later. All patients had biopsy and CT/MRI imaging. The 99m Tc-MIBI images were estimated by 3 independent observers and every abnormal uptake, ranging from faint to intense, was considered positive. Results: 32 patients had benign bone lesions according to histology pathology; 28 of them (87.5%) had a negative 99mTc-MIBI scan (trauma, benign bone tumors). Four patients with benign bone lesions had positive 99mTc-MIBI (chronic osteomyelitis,osteochondroma, osteochondroblastoma, chondroblastoma). 27 patients had malignant bone tumors proven by biopsy; 25 of them (92.6%) had possitive 99mTc-MIBI scans (sarcomas and metastases) and 2 negative (chondrosarcoma, MFH). Conclusions: The 99mTc-MIBI scan in patients with positive 99mTc-MDP scan and a high index of suspicion for malignancy (either primary or metastatic) was found to have a high negative pedictive value (NPV=0.875) in excluding the presence of malignancy and a high positive pedictive value (PPV=0.926) in identifying patients with malignancy. The 99mTc-MIBI was positive in all patients with metastatic disease (PPV=1.00). We suggest the use of 99mTc-MIBI as a useful method in decision-making in cases with bone pathology

Scaphoid fractures are commonly seen fractures following distal radius fractures, yet its diagnosis can be difficult. The present study is to explore the diagnostic approach to suspected scaphoid fractures in a district general hospital in the UK. This is a retrospective study. 286 Suspected scaphoid injuries were seen in our Fracture clinics. 184/286 were known to have normal x-ray findings initially and repeat x-ray in 10 days time. They were all treated as a simple case of a sprained wrist. 40 Patients out of the remaining 102 patients were noted to have scaphoid fractures on follow up x-rays and accordingly treated with cast. The remaining 62 patients were considered for further imaging. 28/102 went for bone scan, which confirmed scaphoid fracture in 4/28 cases. It also picked up other degenerative pathology in 4/28 cases. The rest of the scans were normal. 22/102 Were sent for CT scan which identified the fracture in 20 cases. CT scans provided details about the configuration of fracture, level of healing etc. MRI was performed in 12/102 cases, which confirmed fracture in 2/12 cases and bone bruising in 2/12 cases. There is no consensus regarding the investigation of choice when a follow up scaphoid x-ray is inconclusive in diagnosing a possible scaphoid fracture. In this study we note that a bone scan does not offer much information. On the other hand MRI and CT investigations were useful. We recommend the use of an MRI investigation for a fresh injury, and a CT scan for fresh and old injuries