• aseptic loosening
• periprosthetic fracture
• radiolucency line
• revision surgery
• total hip arthroplasty

• The Science and Technology Planning Project of Huaihua, China, NO.2021R3117 and The Scientific and Technological Innovation Platform of Huaihua, China, No. 2022F2701

In response to an ageing global population, the primary hip and knee arthroplasty rate continues to increase. Although an effective treatment, up to 25% patients may require revision arthroplasty during their lifetime, commonly due to periprosthetic loosening. Revision procedures are associated with significantly increased healthcare costs; therefore, timely and accurate diagnostics are critical for clinicians and patients. Loosening, which may be septic or aseptic, remains a challenge and requires thorough clinical examination and multimodal imaging evaluation. Plain radiographs remain an essential diagnostic tool but advanced imaging modalities such as computed tomography, magnetic resonance imaging and nuclear medicine are playing an increasingly important role. This comprehensive review, through outlining the available radiological modalities, their respective strengths and weaknesses and the pertinent imaging findings, may help radiologists and orthopaedic surgeons make more informed decisions in the management of periprosthetic loosening.

• Periprosthetic loosening
• Total hip replacement
• Total knee replacement
• Diagnostic radiology
• Aseptic loosening

• ALTR (adverse local tissue reaction)
• ARMD (adverse reaction to metal debris)
• AUC
• Appropriateness Criteria
• appropriate use criteria
• metal artifact reduction
• total hip arthroplasty imaging
• total hip prosthesis complications

• Humans
• Arthroplasty, Replacement, Hip/adverse effects
• Magnetic Resonance Imaging/methods
• Pain
• Radiography
• Radionuclide Imaging
• Societies, Medical
• United States

• Arthroplasty
• Bone defect
• Femoral
• Hip
• Revision

• Humans
• Arthroplasty, Replacement, Hip
• Retrospective Studies
• Reproducibility of Results
• Femur/surgery
• Radiography
• Hip Prosthesis
• Reoperation

• Universitätsklinikum Bonn (8930)

• computed tomography
• digital tomosynthesis
• magnetic resonance imaging
• metal artifact reduction

Hip arthroplasty is a frequently used procedure with high success rates. Its main indications are primary or secondary advanced osteoarthritis, due to acute fracture, osteonecrosis of the femoral head, and hip dysplasia. The goals of HA are to reduce pain and restore normal hip biomechanics, allowing a return to the patient’s normal activities. To reach those goals, the size of implants must suit, and their positioning must meet, quality criteria, which can be determined by preoperative imaging. Moreover, mechanical complications can be influenced by implant size and position, and could be avoided by precise preoperative templating. Templating used to rely on standard radiographs, but recently the use of EOS^® imaging and CT has been growing, given the 3D approach provided by these methods. However, there is no consensus on the optimal imaging work-up, which may have an impact on the outcomes of the procedure. This article reviews the current principles of templating, the various imaging techniques used for it, as well as their advantages and drawbacks, and their expected results.

• 3D parameters
• CT
• arthroplasty
• hip
• radiographs

• aseptic loosening
• diagnosis
• radiographic findings
• revision total hip arthroplasty
• subsidence

Hip arthroplasty (HA) is a frequently used procedure with high success rates, but 7% to 27% of the patients complain of persistent postsurgical pain 1 to 4 years post-operation. HA complications depend on the post-operative delay, the type of material used, the patient’s characteristics, and the surgical approach. Radiographs are still the first imaging modality used for routine follow-up, in asymptomatic and painful cases. CT and MRI used to suffer from metallic artifacts but are nowadays central in HA complications diagnosis, both having their advantages and drawbacks. Additionally, there is no consensus on the optimal imaging workup for HA complication diagnosis, which may have an impact on patient management. After a brief reminder about the different types of prostheses, this article reviews their normal and pathologic appearance, according to each imaging modality, keeping in mind that few abnormalities might be present, not anyone requiring treatment, depending on the clinical scenario. A diagnostic imaging workup is also discussed, to aid the therapist in his imaging studies prescription and the radiologist in their practical aspects.

Digital tomosynthesis (DTS) is a new imaging technique derived from radiography, and its usefulness has been gradually reported in the field of orthopedic diagnosis in recent years. A fully hydroxyapatite (HA)-coated stem, which is used for total hip arthroplasty (THA), is a type of cementless stem that has been widely used recently and reported to have good results. However, stem loosening on plain radiographs is difficult to determine in some cases due to cancellous condensation around the stem. In this retrospective cross-sectional study, we compared the results of plain radiography versus DTS to evaluate the imaging findings after THA using a fully HA-coated stem. Twenty joints each in the 3 y and 1 y postoperative groups underwent plain radiography and DTS. On DTS, bone formation around the stem was confirmed in all cases; however, this formation was not reproducible on plain radiography, and there were cases in which the reaction could not be confirmed or cases with cancellous condensation resembling reactive lines. This reaction was not reproducible on plain radiographs, and in some cases, the reaction could not be confirmed, or there were cases with cancellous condensation that resembled reactive lines. Therefore, DTS was useful in the diagnosis of bone formation around the implant.

• POLARSTEM
• digital tomosynthesis
• fully hydroxyapatite-coated stem
• surrounding bone formation

The aim of this study was to compare the diagnostic performances of digital tomosynthesis (DTS) and conventional radiography in detecting osteonecrosis of the femoral head (ONFH) using computed tomography (CT), as the reference standard and evaluate the diagnostic reproducibility of DTS.

Forty-five patients (24 male and 21 female; age range, 25–77 years) with clinically suspected ONFH underwent anteroposterior radiography, DTS, and CT. Two musculoskeletal radiologists independently evaluated the presence and type of ONFH. The diagnostic performance of radiography and DTS in detecting the presence of ONFH and determining the types of ONFH were evaluated. The interobserver and intraobserver reliabilities of each imaging modality were analyzed using Cohen's kappa.

DTS had higher sensitivity (89.4%–100% vs. 74.5%–76.6%) and specificity (97.3%–100% vs. 78.4%–83.8%) for ONFH detection than radiography. DTS showed higher performance than radiography in identifying the subtypes of ONFH with statistical significance in one reader (type 1, 100% vs. 30.8%, p = 0.004; type II, 97.1% vs. 73.5%, p = 0.008). The interobserver agreement was excellent for DTS and moderate for radiography (kappa of 0.86 vs. 0.57, respectively). The intraobserver agreement for DTS was higher than that of radiography (kappa of 0.96 vs. 0.69, respectively).

DTS showed higher diagnostic performance and reproducibility than radiography in detecting ONFH. DTS may be used as a first-line diagnostic modality instead of radiography for patients suspected of having ONFH.

• Agreement
• Digital tomosynthesis
• Femoral head
• Osteonecrosis
• Reproducibility

• biological fixation
• cementless tapered-wedge stem
• digital tomosynthesis
• spot welds
• total hip arthroplasty

• Digital radiography
• Sacroiliitis
• Spondylitis, Ankylosing
• Tomography, X-ray computed

• Cohort Studies
• Humans
• Magnetic Resonance Imaging
• New York
• Radiography
• Sacroiliitis/diagnostic imaging
• Spondylarthritis/diagnostic imaging

• Digital tomosynthesis
• Highly porous titanium cup
• Hip arthroplasty
• Radiolucent lines

To explore the clinical significance of digital tomographic fusion imaging in the diagnosis of avascular disease of the femoral head in adults.

Eighty-two adult patients with avascular necrosis of the femoral head confirmed by MRI in the department of orthopedics of our hospital were studied retrospectively. The related signs of adult avascular necrosis of the femoral head were diagnosed by digital tomographic fusion imaging, and the detection rates of digital X-ray (DR) and digital tomosynthesis (DTS) were compared to clarify the clinical value of digital tomographic fusion imaging in the diagnosis of adult avascular necrosis of the femoral head.

DTS detected DR and 78 cases identified 55 cases. Taking the results of CT/MRI as the gold standard, the sensitivity, specificity, positive predictive value, and negative predictive value of DR and DTS in the diagnosis of ANFH were calculated. There was a significant difference in the detection rate between the two methods (P < 0.05).

The digital tomographic fusion imaging technique has the advantages of high detection rate and excellent image quality, is economical, and is worth popularizing. For those with negative X-rays, DTS diagnosis and CT or/and MRI can avoid unnecessary CT and MRI examinations, which is helpful to reduce the waste of medical resources.

• Avascular necrosis of the femoral head
• Digital tomography fusion imaging

To compare tomosynthesis and computed tomography (CT) for evaluating bone plug integration after anterior cruciate ligament (ACL) reconstruction with a bone–patellar tendon–bone (BPTB) graft.

Data of consecutive adult patients who underwent ACL reconstruction with BPTB were analyzed. Bone integration between the bone plug and bone tunnel was evaluated by tomosynthesis and CT, which were both performed 3 months postoperatively. The obtained data for both modalities were reconstructed with slice thickness of 2 mm. Evaluation of bone integration were separately performed using coronal- and sagittal-reconstructed images for the femur and tibia. The ratio of bone integration between the reconstructed slices in which bone grafting was involved, for both tomosynthesis and CT, was investigated by 2 blinded examiners. The equivalence of tomosynthesis to CT was tested by comparing the bone integration ratio for both modalities. The accuracy of diagnosing bone union using tomosynthesis and CT was also investigated.

The diagnostic accuracy of tomosynthesis and CT exceeded 80%. Interobserver agreement of bone integration in the sagittal plane on the femoral side was 0.92 (intraclass correlation coefficient) for CT and 0.76 (intraclass correlation coefficient) for tomosynthesis.

Although it showed poor reliability, tomosynthesis was equivalent to CT in evaluating bone plug integration after ACL reconstruction with BPTB.

Level II, diagnostic study.

• Digital tomosynthesis
• Dynamic radiculography
• Lumbar foraminal stenosis
• Lumbar radiculopathy