Bone scan usefulness in patients with painful hip or knee prosthesis: 10 situations that can cause pain,other than loosening and infection

In recent years, with the higher median life expectancy, the number of hip and knee replacements has increased. Clinical examination and morphological studies are essential to evaluate patients with a painful arthroplasty. Nuclear medicine examinations also play an important role, their main usefulness being the exclusion of prosthesis complications. Nevertheless, conventional examinations, namely bone scan and white blood cell scintigraphy, can also identify complications, such as loosening and infection. This study describes the normal and pathologic patterns of a bone scan and exemplifies ten common situations that can cause pain in patients with hip or knee arthroplasty, other than loosening and infection, which can be disclosed on a bone scintigraphy. The ten situations that should be considered and looked for when analysing a bone scan are: referred pain, patellofemoral pain syndrome, fractures, fissures, abscess/haematoma, bone insert behaviour, heterotopic ossification, greater trochanter pseudarthrosis, osteoarthritis extension in a knee with an unicompartmental prosthesis, and systemic disease with bone involvement.     

骨扫描在跟痛症诊疗中的临床意义

目的：探讨同位素骨扫描对跟痛症诊断及治疗的临床意义。方法：对４８例跟痛症患者进行了双足骨扫描及Ｘ线摄片检查，并用２５例无症状者作为对照，对治愈的８例患者跟踪观察。结果：发现骨扫描诊断阳性率高达９８％，而放射学发现有骨刺者仅为５４％，治疗后症状消失的患者骨扫描复查也转阴性，而骨刺仍然存在。结论：跟痛症不是由于骨刺所致，故Ｘ线检查帮助不大，而同位素骨扫描在跟痛症的诊断及疗效的评估中有较大的临床意义     

Bone scan index: A new biomarker of bone metastasis in patients with prostate cancer

Bone scintigraphy is one of the first‐line imaging modalities for the screening and follow up of bone metastasis in patients with prostate cancer. The amount (%) of bone metastasis can be calculated using a bone scan index thanks to recent advances in quantitative bone scintigraphy. Since an artificial neural network was applied for hot‐spot characterization and quantitation, the bone scan index has become a simple, reproducible and practical means of quantifying bone metastasis. The bone scan index is presently considered as an imaging biomarker of bone metastasis. The present article summarizes the principles and application of bone scan index using dedicated software (EXINI bone in Europe and North America; BONENAVI in Japan), and the advantages and cautions of using the bone scan index. The bone scan index could serve as a practical marker with which to monitor disease progression and treatment effects in multicenter studies, and to manage prostate and other types of cancer in the clinical setting.     

Penetration of the iliac bone as a modified tunneling option for graft infection in the groin

A graft infection is one of the most fatal complications after surgical treatment for arteriosclerosis obliterans. Although both redo arterial revascularization for limb salvage and prevention of recurrent infection are necessary for the treatment of an infected prosthetic graft, surgical strategy is extremely troublesome and challenging. We successfully performed the extra-anatomic bypass by penetrating an iliac bone, in 3 cases. The anterior aspect of iliac crest was exposed through pararectal retroperitoneal incision. The hole in the iliac bone can be easily made by an electric scalpel. In performing redo arterial revascularization for the prosthetic vascular graft infection, reconstructing the extra-anatomic bypass by penetrating an iliac bone is one of the most advantageous treatments. This surgical strategy can help to select the flexible bypassed route, isolate the infected site, and completely eradicate its area of infection for wound healing.     

Autologous granulocyte scanning of painful prosthetic joints

To detect sepsis in the painful joint, autologous granulocytes labelled with indium-111 were used to scan 60 patients with 74 prosthetic joints. All 18 patients with confirmed sepsis had positive scans, that is, migration of granulocytes into the region of the prosthesis. Of the 22 sterile arthroplasties 20 had negative scans. In 34 cases there was good correlation between the clinical impression and the result of the scan. We suggest that indium granulocyte scintigraphy is a reliable method of detecting an infected prosthesis.     

Cephalhematoma infected by Escherichia coli presenting as an extensive scalp abscess

Cephalhematoma is normally a self-limiting condition affecting 1%–2% of live births, especially following instrumental forceps delivery. The sub-periosteal bleed is characteristically limited by the cranial sutures. Although benign in most instances, this condition may, in a small proportion of cases, be complicated by hyperbilirubinemia or scalp infection. We describe a case of cephalhematoma in a newborn infant infected with Escherichia coli resulting in an extensive deep seated scalp abscess. The infection was also systemic causing E. coli septicemia and initial assessment assumed local extension including bone and meningeal to cause skull osteomyelitis and meningitis respectively. Further investigations and multiple-modality imaging with ultrasound, CT scan and bone scintigraphy outlined the involvement as limited to the scalp, resulting in a shorter antibiotic treatment period and earlier discharge from hospital. The infant recovered well with parenteral antibiotics, saucerization of the abscess and a later skin grafting procedure.     

SPECT Bone scintigraphy of benign and malignant lesions of the spine

70 patients were examined with planar and SPECT bone scintigraphy. SPECT proved to be superior over planar bone scanning for imaging of traumatic, inflammatory, and malignant bone lesions. SPECT provides three-dimensional information and, therefore, delineates the exact location and extension of lesions. It also has a higher sensitivity than planar bone scintigraphy.The three-dimensional bone scan generates complementary diagnostic information which often facilitates an adequate therapy protocol.     

Endovascular native vessel recanalization to maintain limb perfusion after infected prosthetic vascular graft excision

Prosthetic vascular graft infection is an uncommon yet serious condition. Traditional management has included debridement, excision of the infected graft, and revascularization as needed. We report on two cases in which limb viability was maintained by using endovascular native vessel recanalization after excision of infected prosthetic grafts. This approach was successful in maintaining adequate limb perfusion in both cases. Endovascular native vessel recanalization should be considered as an option to maintain limb viability after excision of infected prosthetic vascular grafts, especially when autogenous conduit is lacking or limitation of the extent of surgery is desirable.     

Investigation of computed tomographic scan concurrent criterion validity in doubtful scaphoid fracture of the wrist

BACKGROUND: Rapid diagnosis of scaphoid bone fracture in the wrist is important so that appropriate treatment can be started. If a fracture is clinically suspected without being visible on radiography, further investigation has to be conducted to reveal a fracture or to rule it out. The objective of this study was to investigate the validity of computed tomographic (CT) scanning and bone scintigraphy compared with the clinical fracture rate during follow-up of 1 year for examining patients with a suspected scaphoid fracture. METHODS: Bone scintigraphy and CT scanning were performed in 29 patients with persistent clinical suspicion of a scaphoid bone fracture 5 to 10 days after trauma. RESULTS: The sensitivity, specificity, and positive and negative predictive values of the CT scan were 100%. The sensitivity, specificity, and positive and negative predictive values of bone scintigraphy were 78%, 90%, 78%, and 90%, respectively. Seven patients showed a fracture on both CT scanning and bone scintigraphy. Eighteen patients showed no fracture on both CT scanning and bone scintigraphy. A false-positive bone scintigram showed up in two patients and a false-negative bone scintigram in another two patients. CONCLUSION: CT scanning is a rapid, simple, valid method for demonstrating or ruling out a scaphoid fracture and is superior to bone scintigraphy.     

Bone scan in the evaluation of cementless hip prostheses

The authors report the data obtained in a bone scan study conducted in 15 patients with cementless total hip arthroplasty. The study was conducted a minimum of 6 months and a maximum of 46 months postsurgery. Contrary to what occurs for cemented prostheses, we used bone scan not as a diagnostic aid for complications, but in order to evaluate the osteogenetic response of the bone to a cementless prosthetic implant. Zonal bone scan high uptake revealed specific areas of overloading, or, when localized in the para-articular region, they anticipated the presence of ossifications before they became visible radiographically. Bone scan was also useful in monitoring the incorporation and remodelling phases of the auto and/or homoplastic bone grafts used.     

Instant 99mTc-ciprofloxacin scintigraphy for the diagnosis of osteomyelitis in the diabetic foot

BACKGROUND: The diagnosis of osteomyelitis of the foot in patients with diabetes mellitus remains a challenge. This study was conducted to evaluate bone infections using scintigraphy with instantly prepared single-vial kit, radio-labeled ciprofloxacin (Diagnobact TM) in comparison to a bacterial culture taken from the involved site. METHODS: Twenty-five patients with type 2 diabetes mellitus having foot ulcers, including six with superficial ulcers and positive 99mTc-methylene diphosphonate (MDP) bone scan as a control, were subjected to 99mTc-ciprofloxacin scan and subsequent bacteriological culture. RESULTS: 99mTc-ciprofloxacin scan was positive in 13 patients and negative in 12 patients, including the six with superficial ulcers. Bacterial culture was positive in 18 patients and negative in seven, including one with osteomyelitis on bone biopsy only. 99mTc-ciprofloxacin scan showed "true positive" results in 12, "true negative" in six, "false positive" in one, and "false negative" in six. The specificity and sensitivity of the test were 66.7% and 85.7%, respectively. The positive and negative predictive values and an accuracy of 92.8%, 50% and 72%, respectively. Staphylococcus aureus and Escherichia coli were the most frequently isolated organisms. CONCLUSION: 99mTc-ciprofloxacin is a sensitive and specific marker to diagnose bone infection in patients with diabetes mellitus, but care must be taken in case of fastidious organisms and ciprofloxacin-resistant bacterial flora in which false results may be obtained.     

Aortic and peripheral prosthetic graft infection: differential management and causes of mortality

This report of 25 patients with prosthetic graft infection has compared the diagnosis, management, and outcome in 14 patients with infected aortic grafts with 11 patients with infected peripheral grafts (two axillofemorofemoral, five femorofemoral, five femoropopliteal, and one femoral interposition). Peripheral graft infection had a significantly shorter interval to diagnosis compared with aortic graft infection. Total graft removal combined with either autogenous revascularization or extraanatomic bypass using prosthetic graft was performed in all 14 patients with infected aortic grafts. Management of peripheral graft infection consisted of total graft removal in eight patients (four with autogenous revascularization and two with amputation) and partial graft removal in three patients (two with amputation). Mortality and amputation rates for infected aortic grafts were 43 percent and 25 percent, respectively compared with 36 percent and 27 percent for infected peripheral grafts. Recommendations for management of the infected aortic prosthetic graft include total graft removal, but methods and timing of revascularization are dependent on the specific features of the individual case. However, preferred management for the infected peripheral prosthetic graft includes total graft removal and, if indicated, revascularization using autogenous tissue.     

Persistent infection associated with residual cement after resection arthroplasty of the hip

BACKGROUND: The danger of residual bone cement after resection of infected prosthetic components is controversial. PATIENTS AND METHODS: We analyzed 10 patients with infected total hip prosthesis who had been treated previously with resection arthroplasty and antibiotics and who had persistent infection with residual cement. In 9 patients, surgical debridement with resection of all the PMMA was performed, and adequate intravenous antibiotics were administered. 1 patient refused surgical treatment, but accepted antibiotics. RESULTS: At an average of 4 (1-18) years of follow-up, 8 patients had no signs or symptoms of recurrent infection. 1 severely immunodeficient patient died 2 years after the removal of residual cement, for reasons other than his hip. The patient who refused surgical treatment continues to have an active sinus 4 years after first consultation. INTERPRETATION: Residual cement may be responsible for chronic infection. At resection arthroplasty, as part of the treatment of an infected hip arthroplasty, all devitalized or foreign material must be removed.     

Fifteen minutes bone scintigraphy in patients with clinically suspected scaphoid fracture and normal x-rays

Occult fractures of the scaphoid bone occur frequently and may lead to non-union. The use of three-phase bone scintigraphy in patients with normal x-rays of the scaphoid after carpal injury is widely advocated.In this study, 40 patients with negative radiographs but clinically suspected scaphoid fracture, all had rapid bone scintigraphy with images taken 15 min after intravenous injection of 99 m-Technetium Hydroxymethylene diphosphonate. The scan was performed approximately 2 weeks after the trauma. We found 8 fractures of the scaphoid bone and 13 fractures of other carpal bones. In 5 cases the images were inconclusive. At follow-up 6 months to 2 years later we found no patients with non-union.We find this rapid version of the bone scan useful as a second line investigation for continuing wrist pain following trauma in the presence of normal radiography. This can result in a reduction in both time and costs required for the diagnostic process. If the results are inconclusive we recommend a delayed image. CT or MRI could also be considered. In rare cases a wrist arthroscopy may be considered.     

Preoperative diagnosis of prosthetic joint infection

Making pre-operative diagnosis of intermediate and low-grade infections of prosthetic joint infection (PJI) is demanding and requires both clinical experience and good knowledge of diagnostic test performance. It is also necessary to know the rules of working with diagnostic tests based on the expected change in pre-test probability of PJI or the diagnostic odds ratio. This also requires a multi-modal approach with a rational combination of relevant tests because none of them can have both 100% sensitivity and 100% specificity. Suspicion of a developing PJI should be aroused by relevant information present in the patient s medical history and confirmed by clinical examination. Patients with an increased starting PJI probability, i.e. after taking the medical history and clinical examination, should be examined for the erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) levels (screening tests). When both of these tests are positive and no other alternative explanation for their increase is plausible, then the post-test probability of PJI is significantly increased (up to 70%). Under such conditions the diagnosis is made definitive by positive results of synovial fluid analysis (leukocyte count, percentage of neutrophils and lymphocytes, IL-1, IL-6) or an increased IL-6 serum levels. On the other hand, when both ESR and CRP are negative, the post-test probability of PJI is significantly decreased and no further examination for the presence of infection is usually necessary. In case of inconsistent results of ESR and CRP or if there is a high suspicion of joint infection regardless of these test results, joint fluid aspiration (cytology, IL-1, IL-6) and IL-6 serum levels should be assessed. In this situation scintigraphy imaging (three-phase bone scan combined with labelled leukocytes or anti-granulocyte antibodies) can also support or exclude the diagnosis. In low-grade infections or after previous administration of antibiotics it is recommended to repeat the above-mentioned laboratory tests and joint aspiration after at least a two-week interval without antibiotics. Key words: Total joint arthroplasty, prosthetic joint infection, preoperative diagnosis, pre-test probability, post-test probability, algorithm.     

Rekonstruktion vs. Amputation: Entscheidungsfindung bei der chronischen Osteitis

The decision on reconstruction or amputation of a chronically infected limb is difficult and depends on various factors.Apart from the local bone and soft tissue conditions, the age of the patient, specific associated diseases, and psychosocial environment are also of great importance in making an appropriate decision on treatment. The introduction of callus distraction has considerably improved bone and soft tissue reconstruction, thus relegating the complexity of local infections to minor importance compared to the impact of associated cardiovascular and metabolic diseases.The previously established classifications of posttraumatic osteomyelitis for judging the expected therapeutic necessities and outcome now have only limited value. It is therefore appropriate to provide detailed information and explanations to the patient before any therapeutic procedure concerning the duration of treatment, possible complications as well as the expected functional outcome of the reconstructive procedures. It is important to weigh the outcome of a time-consuming reconstructive procedure against the advantages and disadvantages of an amputation and its subsequent prosthetic management.     

Added value of SPECT/CT in patients suspected of having bone infection: preliminary results

AIM: We evaluated the contribution of SPECT/CT as an adjunct to combined three-phase bone scintigraphy (planar and SPECT) for diagnosing and localizing bone infection. Subsequently, the diagnostic performance of SPECT/CT was compared to visual fusion of SPECT with data of additional CT, X-ray, or MRI studies (SPECT + CT/X-ray/MRI). MATERIALS AND METHODS: Thirty-one patients suspected of bone infection, presenting pathological findings on triple-phase bone scintigraphy, underwent additional SPECT/CT. The SPECT/CT-technology combines the acquisition of SPECT and CT data with the same imaging device enabling perfect overlay of anatomical and functional images. (99m)Tc-DPD was used as radiopharmaceutical in all patients. For data analysis findings of bone scintigraphy (planar scans as well as SPECT) were categorized as positive, negative, or equivocal for the presence of osteomyelitis. In a second step, they were compared with SPECT/CT and SPECT + CT/X-ray/MRI with respect to localization and classification of lesions. Validation was achieved by surgery, biopsy, or by clinical follow up over at least 9 months including microbiological and radiological findings. RESULTS: Three-phase bone scan (incl. SPECT) correctly classified 7 lesions as positive and 11 lesions as negative for osteomyelitis. Six scans were interpreted false positive, two false negative, and five as equivocal. Rating the latter as positive for osteomyelitis, sensitivity of bone scan was (78%), specificity (50%). SPECT/CT was true positive in 7 patients, and true negative in 19. There were two false positive and two false negative findings, one scan was equivocal (sensitivity 78%, specificity 86%). Definition of anatomical localization of inflammatory foci was much easier by SPECT/CT due to better depiction of underlying anatomical details. SPECT + CT/X-ray/MRI yielded the highest sensitivity (100% compared to 78% of SPECT/CT), if equivocal findings (5/31 compared to 1/31 for SPECT/CT) are rated as true positive for osteomyelitis. Among radiological techniques, MRI (2 x FP) and CT (2 x FN) proved equal and expectedly superior to X-ray in delivering the correct diagnosis. CONCLUSION: SPECT/CT improves the diagnostic performance of three-phase bone scan for osteomyelitis by avoiding false positive or equivocal results. An additional benefit over visual fusion of SPECT with X-ray, CT, or MRI studies could not be confirmed in our study.     

Repair of a saccular aortic aneurysm with superficial femoral-popliteal vein in the presence of a pancreatic abscess

When one is faced with impending rupture, repair of an aortic aneurysm cannot be delayed. In the presence of coexisting intra-abdominal sepsis, traditional therapy would call for aneurysm exclusion and axillofemoral bypass grafting. Consequences of this choice of treatment include limited long-term graft patency and recurrent prosthetic infection. Autogenous deep veins from the lower extremities have demonstrated exceptional patency and resilience to infection when used to replace infected aortic grafts. We now report a case of concomitant open drainage of a pancreatic abscess and repair of a saccular abdominal aortic aneurysm using the superficial femoral-popliteal vein as a conduit.     

人造血管旁路术后移植物感染的外科治疗

为评价人造血管旁路术后移植物感染外科治疗的临床疗效,作者对１９８５年～１９９５年上海中山医院收诊的２５０例人造血管旁路术后发生移植物感染的８例进行分析。临床表现为移植物外露伴创口溢脓、大出血、移植物和／或远端肢体动脉搏动消失、远端肢体坏疽。移植物感染率３．２％。外科治疗包括：（１）移植物去除、清创引流术;（２）移植物去除、清创引流加截肢术;（３）移植物去除、清创引流加近远端动脉人造血管重建术;（４）单纯清创引流术。结果显示,８例中６例痊愈,２例因吻合口破裂出血死亡。作者认为移植物感染的危险因素有：（１）糖尿病;（２）继发血肿;（３）同一部位多次手术。外科积极处理较保守治疗愈后更好。     

Animal-Associated Bacteria, Erysipelotrix rhusiopathiae, as the Cause of Infection in a Total Hip Arthroplasty

Invasive infection with animal-associated bacteria, Erysipelotrix rhusiopathiae, is unusual and has, to our knowledge, never been described as the cause of infected total hip arthroplasty. We describe how an infected total hip arthroplasty caused by these bacteria is eradicated using standard surgical and antibiotic treatment. Before 2-stage revision surgery, the patient had persistent groin pain, elevated C-reactive protein, radiographic periprosthetic osteolysis, excessive intra-articular fluid, and periprosthetic activity accumulation on the white cell scan. The patient was treated with benzylpenicillin after confirmed sensitivity of E rhusiopathiae diagnosed by culture of five tissue samples and polymerase chain reaction of the prosthetic sonicate sample. Sixteen weeks after the last stage of revision surgery, there were no signs of reoccurring infection.