MRI-based Zero Echo Time and Black Bone Pseudo-CT Compared with Whole-Body CT to Detect Osteolytic Lesions in Multiple Myeloma.

Background MRI is highly sensitive for assessing bone marrow involvement in multiple myeloma (MM) but does not enable detection of osteolysis. Purpose To assess the diagnostic accuracy, repeatability, and reproducibility of pseudo-CT MRI sequences (zero echo time [ZTE], gradient-echo black bone [BB]) in detecting osteolytic lesions in MM using whole-body CT as the reference standard. Materials and Methods In this prospective study, consecutive patients were enrolled in our academic hospital between June 2021 and December 2022. Inclusion criteria were newly diagnosed MM, monoclonal gammopathy of undetermined significance at high risk for MM, or suspicion of progressive MM. Participants underwent ZTE and BB sequences covering the lumbar spine, pelvis, and proximal femurs as part of 3-T whole-body MRI examinations, as well as clinically indicated fluorine 18 fluorodeoxyglucose PET/CT examination within 1 month that included optimized whole-body CT. Ten bone regions and two scores (categorical score = presence/absence of osteolytic lesion; semiquantitative score = osteolytic lesion count) were assessed by three radiologists (two experienced and one unfamiliar with pseudo-CT reading) on the ZTE, BB, and whole-body CT images. The accuracy, repeatability, and reproducibility of categorical scores (according to Gwet agreement coefficients AC1 and AC2) and differences in semiquantitative scores were assessed at the per-sequence, per-region, and per-patient levels. Results A total of 47 participants (mean age, 67 years ± 11 [SD]; 27 male) were included. In experienced readers, BB and ZTE had the same high accuracy (98%) in the per-patient analysis, while BB accuracy ranged 83%-100% and ZTE accuracy ranged 74%-94% in the per-region analysis. An increase of false-negative (FN) findings in the spine ranging from +17% up to +23%, according to the lumbar vertebra, was observed using ZTE (P < .013). Regardless of the region (except coxal bones), differences in the BB score minus the ZTE score were positively skewed (P < .021). Regardless of the sequence or region, repeatability was very good (AC1 ≥0.87 for all), while reproducibility was at least good (AC2 ≥0.63 for all). Conclusion Both MRI-based ZTE and BB pseudo-CT sequences of the lumbar spine, pelvis, and femurs demonstrated high diagnostic accuracy in detecting osteolytic lesions in MM. Compared with BB, the ZTE sequence yielded more FN findings in the spine. ClinicalTrials.gov Identifier: NCT05381077 Published under a CC BY 4.0 license. Supplemental material is available for this article.

[Long-term computed tomographic osteolytic analysis of highly cross-linked polyethylene prosthesis after total hip arthroplasty].

Objective: To analyze the occurrence of osteolysis in total hip arthroplasty (THA) with highly cross-linked polyethylene prosthesis during a follow-up of more than 15 years. Methods: The clinical data of 84 patients (105 hips) treated with THA in the Affiliated Hospital of Kanazawa Medical University in Japan between June 2000 and April 2004 and met the selection criteria was retrospectively analyzed. There were 7 males and 77 females, aged from 41 to 75 years, with an average of 56.4 years. There were 94 hips with secondary hip osteoarthritis, 4 hips after pelvic osteotomy, 2 hips with primary hip osteoarthritis, 2 hips with traumatic hip osteoarthritis, 2 hips with osteonecrosis of the femoral head, and 1 hip with rheumatoid arthritis. According to Crowe classification, there were 79 hips of type Ⅰ, 19 hips of type Ⅱ, 6 hips of type Ⅲ, and 1 hip of type Ⅳ. The highly cross-linked polyethylene acetabular liner combined with a 26 mm zirconia femoral head were used in all patients. X-ray films were taken after operation to analyze the radiation transmission and osteolysis around the acetabular prosthesis. The vertical distance (the distance between the teardrop line at the lower edge of the pelvis and the perpendicular line of the hip rotation center), the horizontal distance (the horizontal distance between the hip rotation center and the interteardrop line and the vertical line at the lower edge of the teardrop), and the acetabular cup anteversion angle were measured at last follow-up. The acetabular and femoral osteolysis was analyzed by CT scan and three-dimensional multiplanar reconstruction (3D-MPR). Combined with X-ray film and CT results, osteolysis was evaluated according to the Narkbunnam score. Results: Deep vein thrombosis of lower limbs occurred in 2 cases. All patients were followed up 15-18 years, with an average of 15.9 years. One hip dislocation and 1 periprosthetic fracture occurred postoperatively, and no acetabular loosening or prosthetic lining ruptures occurred. Except for 1 patient who had a radiolucent line in the acetabulum after operation, the other 83 patients did not show any radiolucent line in the acetabulum or the femur. None of the patients underwent hip revision. X-ray films at last follow-up showed an acetabular cup anteversion angle of -10°-39°, with an average of 22°; a vertical distance of 3.5-47.1 mm, with an average of 24.6 mm; and a horizontal distance of 22.6-48.1 mm, with an average of 31.7 mm. There was no acetabular or femoral osteolysis in all patients on X-ray films and CT 3D-MPR images at last follow-up, and the Narkbunnam score was 0 in any region. Conclusion: Highly cross-linked polyethylene prosthesis does not increase the risk of long-term complications such as osteolysis after THA.

An Incidental Detection of Breast Cancer Osteolytic Bone Metastasis Using a 99m Tc-TRODAT-1 SPECT Scan.

ABSTRACT: This report presents a case of suspected Parkinson disease in a 76-year-old woman with a history of slurred speech, general weakness, unstable gait, and bradykinesia for months. A 99m Tc-TRODAT-1 SPECT scan revealed a symmetrically decreased bilateral nigrostriatal system, including bilateral putamen and caudate nuclei. The scintigraphic findings may reflect normal aging or atypical parkinsonism. The bilateral frontal bones and left temporal bone exhibited increased uptake of 99m Tc-TRODAT-1, and previous 99m Tc-MDP bone scan and CT images were reviewed. Osteolytic lesions at the corresponding site indicated bone metastasis from breast cancer.

[28-year-old male patient with headaches on the left side and facial pain]. / 28-jähriger Patient mit in den Kiefer ausstrahlenden ­Kopfschmerzen temporal links.

INTRODUCTION: A 28-year-old male suffers for two weeks from new-onset very severe headache located on his left temple radiating to his jaw. He also complains about left sided retroorbital pain and chewing aggravated symptoms. In addition, nausea and emesis in the mornings during the past six months were reported. Clinical examination revealed tender swelling over the left temple, but laboratory results showed no signs of inflammation, normal electrolytes, kidney and liver values. A CT-scan revealed a circumscriptive osteolytic lesion in the left os temporale.

Metal hypersensitivity in trapeziometacarpal arthroplasty: A systematic pattern of progression.

Metal hypersensitivity is a rare and often underestimated complication, as shown by the small number of published studies, particularly concerning the upper limbs and the hand. However, the increase in the annual number of trapeziometacarpal arthroplasties underlines the importance of better understanding of this problem. We performed a study based on data from the revision of trapeziometacarpal prostheses to assess the incidence of this complication and to define a sequence of radiological changes to detect metal hypersensitivity. This single-center retrospective study included 37 patients operated on between January 2014 and November 2023 for revision of trapeziometacarpal prosthesis. Ten (27%) had no clearly identified cause of failure. For these 10 patients, we analyzed clinical data and postoperative X-rays. In the 11 revision arthroplasties, 2 patients had no symptoms or radiographic signs suggestive of allergy. Six patients had a-posteriori diagnosis established by allergy testing, which also identified 2 additional patients, for a total of 8 patients (21% of the initial cohort). In these cases, there was systematic metaphyseal osteolysis of the first metacarpal between 15 days and 1 month after implantation. Clinically, most patients had an asymptomatic period of 2 weeks to 1 month before onset of symptoms and osteolysis, often accompanied by local inflammation. This study found a reproducible pattern of progression, characterized by the appearance of radiographic signs of osteolysis in the first month, followed by clinical deterioration. Although this course is strongly suggestive of a metal hypersensitivity, it is crucial not to exclude the possibility of an infectious cause, which should always be considered.

Computed tomography-based structural rigidity analysis can assess tumor- and treatment-induced changes in rat bones with metastatic lesions.

BACKGROUND: Breast cancer (BrCa) is a predominant malignancy, with metastasis occurring in one in eight patients, nearly half of which target the bone, leading to serious complications such as pain, fractures, and compromised mobility. Structural rigidity, crucial for bone strength, becomes compromised with osteolytic lesions, highlighting the vulnerability and increased fracture risk in affected areas. Historically, two-dimensional radiographs have been employed to predict these fracture risks; however, their limitations in capturing the three-dimensional structural and material changes in bone have raised concerns. Recent advances in CT-based Structural Rigidity Analysis (CTRA), offer a promising, more accurate non-invasive 3D approach. This study aims to assess the efficacy of CTRA in monitoring osteolytic lesions' progression and response to therapy, suggesting its potential superiority over existing methodologies in guiding treatment strategies. METHODS: Twenty-seven female nude rats underwent femoral intra-medullary inoculation with MDA-MB-231 human breast cancer cells or saline control. They were divided into Control, Cancer Control, Ibandronate, and Paclitaxel groups. Osteolytic progression was monitored weekly using biplanar radiography, quantitative computed tomography (QCT), and dual-energy X-ray absorptiometry (DEXA). CTRA was employed to predict fracture risk, normalized using the contralateral femur. Statistical analyses, including Kruskal-Wallis and ANOVA, assessed differences in outcomes among groups and over time. RESULTS: Biplanar radiographs showed treatment benefits over time; however, only certain time-specific differences between the Control and other treatment groups were discernible. Notably, observer subjectivity in X-ray scoring became evident, with significant inter-operator variations. DEXA measurements for metaphyseal Bone Mineral Content (BMC) did not exhibit notable differences between groups. Although diaphyseal BMC highlighted some variance, it did not reveal significant differences between treatments at specific time points, suggesting a limited ability for DEXA to differentiate between treatment effects. In contrast, the CTRA consistently demonstrated variations across different treatments, effectively capturing bone rigidity changes over time, and the axial- (EA), bending- (EI), and torsional rigidity (GJ) outcomes from the CTRA method successfully distinguished differences among treatments at specific time points. CONCLUSION: Traditional approaches, such as biplanar radiographs and DEXA, have exhibited inherent limitations, notably observer bias and time-specific inefficacies. Our study accentuates the capability of CTRA in capturing real-time, progressive changes in bone structure, with the potential to predict fractures more accurately and provide a more objective analysis. Ultimately, this innovative approach may bridge the existing gap in clinical guidelines, ushering in enhanced Clinical Decision Support Tool (CDST) for both surgical and non-surgical treatments.

Mid-term clinical radiological results of the constrained condylar knee prosthesis in total knee revision.

INTRODUCTION: The aim of the present study is to analyze the clinical-radiological outcomes of patients undergoing knee prosthesis revision surgery using constrained condylar prosthesis (LCCK; Zimmer-Biomet). MATERIAL AND METHODS: Retrospective study of 89 patients operated on between the years 2008 and 2020 with a minimum of 2 years of follow-up. Clinical outcomes were evaluated using the WOMAC Index score and KOOS scales. Radiological results (radiolucent lines, osteolysis, and cortical hypertrophy) were evaluated by two independent observers. Implant survival was analyzed using the Kaplan-Meier method. RESULTS: At the end of follow-up, a mean WOMAC Index score of 78.67 and KOOS score of 68.8 were obtained. Radiolucent lines (both non-progressive and progressive) were detected in 83.3% of the patients in the sample. Areas of osteolysis > 5 mm around the components were present in 6.75%. Cortical hypertrophy was seen around the femoral stem in 20.3% of cases, around the tibial stem in 20.3% and around both components in 6.76%. No statistically significant relationship was found between the presence of radiolucent lines, osteolysis or cortical hypertrophy with functional results. Implant survival was 88.1% at 13 years. CONCLUSION: The present study shows high survival of LCCK prosthesis in revision surgery. The progressive radiolucencies, were associated with worst clinical outcome.

Cochlear Implantation in Patients With Osteolytic Labyrinthitis: A Case Series.

OBJECTIVE: To describe the rare process of osteolytic labyrinthitis, previously referred to as labyrinthine sequestrum, which involves progressive obliteration of the bony and membranous labyrinth with eventual supplantation with soft tissue and, in some cases, bony sequestrum. PATIENTS: Three patients with diverse presentations of osteolytic labyrinthitis from two tertiary care academic medical centers. INTERVENTIONS: Case series report analyzing the relevant clinical, radiologic, pathologic, and surgical data on our patients with osteolytic labyrinthitis and comparing these index cases to the existing literature. MAIN OUTCOME MEASURES: We describe the varying image findings seen in osteolytic labyrinthitis on computed tomography and magnetic resonance imaging. Also, we report successful surgical intervention and hearing rehabilitation with cochlear implantation in patients with osteolytic labyrinthitis. RESULTS: Our three patients presented with profound sudden sensorineural hearing loss and vertigo consistent with labyrinthitis. None of the three patients had a history of chronic otitis media. Imaging workup revealed varying degrees of erosion to the otic capsule bone demonstrating the spectrum of disease seen in osteolytic labyrinthitis. Although two cases showed osteolytic changes to the semicircular canals and vestibule, the first case revealed frank bony sequestrum within the obliterated labyrinth. The three cases were taken for surgical debridement and cochlear implantation. CONCLUSIONS: We propose the new term, osteolytic labyrinthitis-previously referred to as labyrinthine sequestrum-to describe the rare spectrum of disease characterized by destruction of the osseous and membranous labyrinth and potential supplantation with bony sequestrum. Cochlear implantation is a viable option in selected patients with osteolytic labyrinthitis.

[Rare differential diagnosis of an osteolytic lesion of the mandible in a young adult]. / Seltene Differenzialdiagnose bei osteolytischer Läsion des Unterkiefers einer jungen Erwachsenen.

We report a rarely occurring hematologic neoplasm in a young adult. Hematologic neoplasms were first described in 2008 and are now included in both accepted tumor classification systems, i.e., International Consensus Classification and World Health Organization. This hematologic neoplasm shows a characteristic ALK positivity in immunohistochemical examination and correspondingly, ALK fusion genes in the molecular analysis. Pathologists should be aware of this entity, particularly as it is challenging to differentiate from other more frequent neoplasms of the same disease group or mesenchymal neoplasm with ALK aberration.

Multicentric carpotarsal osteolysis syndrome with variants of MAFB gene: a case report and literature review.

BACKGROUND: Multicentric carpotarsal osteolysis (MCTO) is a rare genetic disorder characterized by the progressive loss of bone in the hands, feet, and other skeletal structures. It presents with symptoms that may resemble those of juvenile idiopathic arthritis, making diagnosis challenging for clinicians. The identification of MAF BZIP Transcription Factor B (MAFB) mutations as significant contributors to MCTO represents a major breakthrough in our understanding of the pathogenesis of this rare skeletal disorder. CASE PRESENTATION: Our objective was to present the phenotype, treatment, and outcome of a patient with a variant of MAFB-induced MCTO to broaden the range of clinical features associated with MCTO and share our clinical experience for improved diagnosis and treatment. In our case, early MRI examination of the bones and whole exome sequencing enabled an early and accurate MCTO diagnosis, and timely Denosumab administration resulted in no deterioration. CONCLUSION: This suggests that MRI examination and whole exome sequencing should be considered when MCTO is suspected, and Denosumab might be an option in the treatment of MCTO.

Heterotopic ossification, osteolysis and implant failure following cervical total disc replacement with the M6-C™ artificial disc.

INTRODUCTION: A recent study reported a 34% mid-term revision rate after M6-C™ cervical total disc replacement (CTDR) for wear-related osteolysis. Here, we aim to investigate the prevalence, risk factors, and radiographic characteristics of periprosthetic bony changes and implant failure of the M6-C™ artificial disc. METHODS: We retrospectively analysed radiographic (conventional X-ray, CT scan) and clinical outcomes (EQ-5D-5L, Neck Disability Index (NDI), and Visual Analog Scale (VAS) for neck and arm pain) data collected during routine follow-up of patients who underwent CTDR with the M6-C™ between 2011 and 2015. RESULTS: In total, 85 patients underwent CTDR with the M6-C™. Follow-up data were available for 43 patients (54% female, mean age 44 years) with 50 implants and a mean follow-up of 8.1 years (6.5-11 years). Implant failure with the presence of severe osteolysis was identified in 5 (12%) patients who were all male (p = 0.016) and implanted at the C5/6 level (p = 0.11). All failed implants required revision surgery. The overall prevalence of osteolysis was 44% (22/50 implants) and 34% (17/50 implants) for significant heterotopic ossification. Patients with high-grade osteolysis showed higher VAS arm pain (p = 0.05) and lower EQ-5D-VAS health VAS (p = 0.03). CONCLUSION: We report a lower reoperation rate for failed M6-C™ implants than previously published, but confirmed that osteolysis and heterotopic ossification are common following CTDR with the M6-C™ and may be asymptomatic. Therefore, we strongly recommend ongoing clinical and radiographic monitoring after CTDR with the M6-C™, particularly for male patients implanted at the C5/6 level.

From breast cancer cell homing to the onset of early bone metastasis: The role of bone (re)modeling in early lesion formation.

Breast cancer often metastasizes to bone, causing osteolytic lesions. Structural and biophysical changes are rarely studied yet are hypothesized to influence metastasis. We developed a mouse model of early bone metastasis and multimodal imaging to quantify cancer cell homing, bone (re)modeling, and onset of metastasis. Using tissue clearing and three-dimensional (3D) light sheet fluorescence microscopy, we located enhanced green fluorescent protein-positive cancer cells and small clusters in intact bones and quantified their size and spatial distribution. We detected early bone lesions using in vivo microcomputed tomography (microCT)-based time-lapse morphometry and revealed altered bone (re)modeling in the absence of detectable lesions. With a new microCT image analysis tool, we tracked the growth of early lesions over time. We showed that cancer cells home in all bone compartments, while osteolytic lesions are only detected in the metaphysis, a region of high (re)modeling. Our study suggests that higher rates of (re)modeling act as a driver of lesion formation during early metastasis.

Comparison of osteolysis around 3 different cement restrictors in total hip arthroplasty.

BACKGROUND AND AIM: Several studies reported osteolysis around polyethylene glycol/polybutylene terephthalate (PEG/PBT) based femoral cement restrictors. Our goal was to evaluate and compare osteolysis around 3 different plug designs: the slow biodegradable PEG/PBT cement restrictor; the fast biodegradable gelatin cement restrictor; and the non-biodegradable polyethylene plug. PATIENTS AND METHODS: In a retrospective multicentre cohort study chart data were extracted of patients who received a total hip arthroplasty between 2008 and 2012. A total of 961 hips were included. Cortical ratio between inner and outer cortices at the centre of the plug was measured on routine postoperative follow-up moments. Median follow up of all 3 hospitals was 3.5 years (1.4-7.3). The primary outcome was evidence of osteolysis (i.e. the difference in cortical ratio [CR]) on anteroposterior (AP) radiographs at final follow-up. RESULTS: Progressive osteolysis was found around the PEG/PBT cement restrictor represented by a significantly increasing cortical ratio (ΔCR 0.067 (95% CI, 0.063-0.071). Distance from tip prosthesis to plug and size of the plug were found to be independent factors in predicting increased cortical ratio. CONCLUSIONS: Our multicentre cohort shows increase of cortical ratio around the PEG/PBT cement restrictor which progresses over time. Physicians should be aware of this fact and are advised to intensify follow-up of patients who received this cement restrictor.

Corrosion of a Fassier-Duval Telescopic Nail Causing Pain and Osteolysis: A Case Report.

CASE: A 15-year-old girl known with osteogenesis imperfecta presented with left femoral pain. She had been treated with multiple Fassier-Duval intramedullary nails, which were still in situ. Radiographic imaging demonstrated focal osteolysis and periosteal reaction at the telescopic junction of the rod in the distal femur. She underwent implant removal. Intraoperative sampling demonstrating acute sterile inflammation and presence of brownish colored particles consistent with metal debris and osteolysis. Explant analysis confirmed corrosion of the stainless-steel telescopic nail as the underlying cause. CONCLUSION: Osteolysis and periosteal reaction because of corrosion should be considered in conjunction with other more common causes of pain, such as fracture or infection, in patients treated with telescopic intramedullary nails.

Medication-related osteonecrosis of the lower jaw without osteolysis on computed tomography images.

INTRODUCTION: Surgery is the standard treatment for medication-related osteonecrosis of the jaw (MRONJ). This study reviewed patients with mandibular MRONJ who underwent surgical treatment, and in particular the characteristics of non-osteolytic MRONJ with no evidence of osteolysis on CT were described. MATERIALS AND METHODS: We conducted a retrospective study of patients with mandibular MRONJ who underwent surgery between January 2016 and September 2022. Various clinical and imaging factors regarding treatment outcomes were investigated and analyzed. Additionally, the disease course of non-osteolytic MRONJ was examined in detail. RESULTS: This study included 55 patients (66 surgeries) with a mean age of 74.7. The primary disease was osteoporosis (24 patients) and malignancy (31 patients); the type of antiresorptive agent was bisphosphonate (BP) in 21 patients and denosumab (DMB) in 26. BP was initially administered; however, it was changed to DMB in eight patients. Preoperatively, the cumulative cure rates for all 66 surgeries were 72.8% at 1 year and 77.3% at 2 years. Cure rates were significantly lower in patients with malignancy, those without osteolysis, and those who underwent sequestrum removal or marginal mandibulectomy than those with osteoporosis, osteolysis, and segmental mandibulectomy. Non-osteolytic MRONJ was observed in eight patients, all with malignancy and receiving high-dose DMB. Only two patients were cured after the initial surgery, and most patients ultimately underwent segmental mandibulectomy. CONCLUSIONS: Surgical treatment yielded good treatment outcomes in most patients with mandibular MRONJ; however, the cure rate was lower in patients with malignancy who showed no osteolysis on CT images.

Does previous arthroscopic Bankart repair influence coracoid graft osteolysis in Latarjet procedure? A case-control study with computed tomography scan data.

BACKGROUND: The Latarjet procedure is commonly performed in the treatment of recurrent shoulder instability and is also indicated as a salvage procedure for recurrence after failed arthroscopic Bankart repair. Although this procedure has shown success, there has been an increased awareness of complications in recent studies, especially graft osteolysis. Most relevant research has focused on the pathophysiology, incidence, or location of graft osteolysis or the risk factors for graft osteolysis; however, the data are limited to primary Latarjet procedures. This study aimed to investigate the effect of previous arthroscopic Bankart repair surgery on coracoid bone graft osteolysis in the Latarjet procedure. METHODS: This retrospective case-control study analyzed data from patients who underwent primary Latarjet procedures or revision Latarjet procedures following failed arthroscopic Bankart repair. Clinical outcome measures included range of motion, the Subjective Shoulder Value, and the Rowe score. Volumetric analysis of each transferred coracoid graft was performed using early postoperative and late postoperative computed tomography scan data, and the amount of graft osteolysis was then calculated as the percentage of volume reduction of each graft. RESULTS: A total of 32 patients who met the inclusion criteria were included in this study, with 24 patients in the primary Latarjet group (group I) and 8 patients in the revision Latarjet group (group II). The mean age of the patients was 32.5 ± 7.7 years, and the mean follow-up duration was 52.1 ± 8.9 months. Both study groups showed significant improvement in the Subjective Shoulder Value compared with baseline (P < .05). Comparison of postoperative clinical outcome measures showed no significant difference in any outcome parameter between the 2 study groups (P > .05). No recurrence was observed during the follow-up period. A positive apprehension sign was present in 6 patients (25%) in group I and 4 patients (50%) in group II (P > .05). Analysis of radiologic data revealed that all patients underwent some degree of graft osteolysis, with varying osteolysis ratios between 12% and 98%. The mean osteolysis ratio of the coracoid graft was 67.3% ± 22.6% in group I and 69.4% ± 25.6% in group II, with no significant difference between the 2 groups (P > .05). CONCLUSION: The findings of this study suggest that a considerable amount of coracoid graft osteolysis is observed after both primary Latarjet procedures and revision Latarjet procedures following failed arthroscopic Bankart repair. Previous arthroscopic Bankart repair did not seem to have a significant influence on the amount of graft osteolysis, and both primary and revision Latarjet procedures showed satisfactory clinical outcomes.

Factors affecting stress shielding and osteolysis after reverse shoulder arthroplasty: A multicenter study in a Japanese population.

BACKGROUND: Stress shielding and osteolysis around the humeral stem after reverse shoulder arthroplasty causes loosening and periprosthetic fractures and reduces bone stock during revision surgery. In Japanese patients, who have relatively small bodies, different characteristics may exist regarding the occurrence of these changes compared with the characteristics of Westerners, who have relatively larger frames. The purpose of this multicenter study was to investigate the incidence and clarify the predictors of stress shielding and osteolysis in Japanese individuals who underwent reverse shoulder arthroplasty. METHODS: The occurrence of stress shielding and osteolysis was investigated in 135 shoulders that had undergone reverse shoulder arthroplasty at least 2 years prior in five Japanese hospitals. During post-surgical follow-up, which was conducted every 3 months, the locations of the stress shielding occurrences, such as cortical thinning and osteopenia (which primarily occurred in zones 1, 2, and 7, where 1 is the greater tuberosity and 7 is the calcar part), spot weld, and condensation lines, were recorded. Cases without any abnormal findings on radiographs obtained up to ≥2 years after surgery were regarded as having no abnormalities. Finally, the predictors of cortical thinning and proximal humeral osteolysis were assessed using univariate and multivariate regression analyses. RESULTS: Cortical thinning and osteopenia occurred in 68 shoulders, a condensation line occurred in 37 shoulders, and spot weld occurred in 23 shoulders. In particular, greater tuberosity and calcar osteolysis occurred in 40 and 47 shoulders, respectively. Long stem, cementless stem, and a larger proximal filling ratio were independent predictors of cortical thinning and osteopenia, whereas a cementless stem, larger metaphysis diameter, and a larger proximal filling ratio were associated with proximal humeral osteolysis. CONCLUSIONS: The predictors of stress shielding and osteolysis included the use of long stems, cementless stems, larger proximal filling ratios, and larger metaphysis diameters. LEVEL OF EVIDENCE: retrospective comparative study (Level III).

Osteolysis After Augmented Scapholunate Ligament Reconstruction: A Report of 3 Cases.

CASE: Augmented scapholunate ligament reconstruction using polyether ether ketone anchors and ultra-high molecular weight polyethylene synthetic tape has the theoretical advantage of improved stability, avoidance of K-wire fixation, and the potential for earlier mobilization. We present 3 cases of scaphoid and lunate osteolysis/fragmentation, operative and histologic findings at reoperation, and the sequelae of this technique. CONCLUSION: If planning to use suture anchors and synthetic tapes in small carpal bones, we recommend advising patients about the risk of osteolysis and monitoring closely patients who complain of pain with motion after surgery.