Bone regeneration represents a complex process, of which basic biologic principles have been evolutionarily conserved over a broad range of different species. Bone represents one of few tissues that can heal without forming a fibrous scar and, as such, resembles a unique form of tissue regeneration. Despite a tremendous improvement in surgical techniques in the past decades, impaired bone regeneration including non-unions still affect a significant number of patients with fractures. As impaired bone regeneration is associated with high socio-economic implications, it is an essential clinical need to gain a full understanding of the pathophysiology and identify novel treatment approaches. This review focuses on the clinical implications of impaired bone regeneration, including currently available treatment options. Moreover, recent advances in the understanding of fracture healing are discussed, which have resulted in the identification and development of novel therapeutic approaches for affected patients.

Soft-tissue sarcomas (STS) are a rare subtype of soft-tissue mass and are frequently misinterpreted as benign lesions. Magnetic resonance imaging (MRI) is the primary recommended type of diagnostics. To assess the quality of primary radiology reports, we investigated whether recommended MRI report elements were included in compliance with European Society of Musculoskeletal Radiology (ESSR) guidelines. A total of 1107 patients were evaluated retrospectively, and 126 radiological reports on patients with malignant STS were assessed for ESSR quality criteria. One or more required sequences or planes were missing in 67% of the reports. In all 126 cases, the report recognized the mass as anomalous (100%). Sixty-eight percent of the reports mentioned signs of malignancy. The majority of reports (n = 109, 87%) articulated a suspected diagnosis, 32 of which showed a mismatch with the final diagnosis (25%). Thirty-two percent of the reports had a misinterpretation of the masses as benign. Benign misinterpretations were more common in masses smaller than 5 cm (65% vs. 27%). Thirty percent of the reports suggested tissue biopsy and 6% recommended referral to a sarcoma center. MRI reports showed frequent deviations from ESSR guidelines, and protocol guidelines were not routinely met. Deviations from standard protocol and reporting guidelines could put patients at risk for inadequate therapy.

Surgical therapy of bone metastases is becoming increasingly important due to prolonged life expectancy and improved oncological treatment options. In a mostly palliative approach, it is necessary to identify those patients who might benefit from surgery. The shorter the remaining lifetime, the more restricted the indication and the less radical the intervention should be. The aim of this study was to evaluate the postoperative outcomes and prognostic factors for survival of patients with surgically treated bone metastases. We retrospectively included 140 patients who underwent surgery for 151 bone metastases in the extremities and pelvis at our hospital between 2010 and 2020. We examined patient demographics, surgical procedures, 30-day complications, local tumour progression, and reoperations. Survival was calculated using Kaplan-Meier analysis. Prognostic factors were investigated by univariate analysis using the log-rank test and multivariate analysis using the Cox regression hazard model. In 138 patients, the median survival time was 12.3 months. The overall survival rates at one, two, three and five years were 52.3%, 37.6%, 28.0%, and 18.0%, respectively. In univariate analysis, lung cancer, renal cell carcinoma, pathological fracture, visceral metastasis and multiple bone metastases were significantly associated with prognosis. No significant influence was determined for gender, age, location of bone metastasis, type of surgical procedure and time between diagnosis of primary tumour and surgery for bone metastasis. Multivariate analysis confirmed that pathological fracture, visceral metastasis and lung cancer were negative prognostic variables in terms of survival. Within 30 days, the incidence of complications was 25.0% and mortality was 9.3%. The most common complications were urinary tract infections (5.0%), pneumonia (4.3%), and delirium (2.9%). Local tumour progression occurred in 12 patients (8.7%) and five reoperations (3.6%) were performed. There were no significant differences between patients treated with endoprosthetic replacement (n = 47) and those treated with internal fixation (n = 91) in terms of 30-day complications and mortality as well as local tumour progression. Survival of patients after surgery for bone metastases in the extremities or pelvis is very limited. The presence of a pathological fracture, visceral metastasis and lung cancer were independent prognostic factors for poor survival. Both internal fixation and endoprosthetic replacement achieved similar outcomes.

Introduction: Osteoid osteoma (OO) is a common benign bone tumor. OO is observed most frequently in the long bones, especially in the tibia and femur. When occurring in the bones of the hand, OO can be a diagnostic and therapeutic challenge. The aim of this study was to provide a systematic review of occurrence, symptoms, diagnosis and treatment options regarding OO in hand bones. Materials and methods: We performed a systematic review of the literature. All studies from the online databases PubMed and SpringerLink, which reported cases of osteoid osteomas in the bones of the hand, were included. By summarizing the literature, we evaluated the localization within the hand as well as diagnostic and therapeutic options. Results: We included 133 studies reporting 401 cases. OO was mostly common in the phalanges. The diagnosis was mostly made by CT (computed tomography) scan. Most of the OO were treated surgically by open curettage or en bloc resection. Conclusions: Osteoid osteomas in the bones of the hand are rare and a delayed diagnosis is common. In cases of pain combined with particular symptoms such as nail hypertrophy and swelling OO should be considered. Of the most used imaging methods, CT scans have the highest sensitivity.

Lipomatous tumors are among the most common soft tissue tumors (STTs). Magnetic resonance imaging (MRI) is a state-of-the-art diagnostic tool used to differentiate and characterize STTs. Radiological misjudgment can lead to incorrect treatment. This was a single-center retrospective study. Two hundred and forty lipomatous tumors were included. MRI diagnoses were categorized as benign, intermediate, or malignant and were compared with histological diagnoses. Tumor volumes were measured by MRI and from surgical specimens. The tumor was correctly categorized 73.3% of the time. A total of 21.7% of tumors were categorized as more malignant in MRI reports than they were by histology, and vice versa for 5.0% of tumors. Volume measured by MRI was not different from actual tumor size in pathology. Atypical lipomatous tumors (ALTs) and liposarcomas (LPSs) were larger when compared with lipomata and occurred in older patients. Based on the MRI-suspected tumor entity, surgical treatment can be planned. Large lipomatous tumors in elderly patients are more likely to be ALTs. However, a safe threshold size or volume for ALTs cannot be determined.

Intramuscular myxomas (IMMs) are benign tumors. Evidence regarding diagnostic and therapeutic pathways is rare, and guidelines do not exist due to their low incidence. The aim of this study was a retrospective analysis at a university cancer center and the interdisciplinary re-evaluation of the individual diagnostic and therapeutic procedures. Overall, 38 patients were included in the study. IMMs occurred mostly in middle-aged women. At the time of first consultation, 57.9% had few symptoms or were asymptomatic. In 92.1% of the cases, the tumor was localized in the extremities. The lower extremity was affected in 73.7%. The average size of IMMs was 5.0 cm. The proximally located tumors in the gluteus, thighs, and upper arms were significantly larger (p = 0.02) than the distally-located tumors in the forearms and lower legs. An MRI was performed in 97.4%. Based on imaging, an IMM was suspected in 5.6% by radiologists and in 54.1% by musculoskeletal surgeons. An incision biopsy was performed in 68.4% and led in 100.0% to the right histopathological diagnosis. In total, 89.5% of IMMs were resected. Postoperative complications requiring revision occurred in 8.8%. Recurrences or degenerations of IMMs were not reported in any of these cases.