GPT-based chatbot tools are still unreliable in the management of prosthetic joint infections.

BACKGROUND: Artificial intelligence chatbot tools responses might discern patterns and correlations that may elude human observation, leading to more accurate and timely interventions. However, their reliability to answer healthcare-related questions is still debated. This study aimed to assess the performance of the three versions of GPT-based chatbots about prosthetic joint infections (PJI). METHODS: Thirty questions concerning the diagnosis and treatment of hip and knee PJIs, stratified by a priori established difficulty, were generated by a team of experts, and administered to ChatGPT 3.5, BingChat, and ChatGPT 4.0. Responses were rated by three orthopedic surgeons and two infectious diseases physicians using a five-point Likert-like scale with numerical values to quantify the quality of responses. Inter-rater reliability was assessed by interclass correlation statistics. RESULTS: Responses averaged "good-to-very good" for all chatbots examined, both in diagnosis and treatment, with no significant differences according to the difficulty of the questions. However, BingChat ratings were significantly lower in the treatment setting (p = 0.025), particularly in terms of accuracy (p = 0.02) and completeness (p = 0.004). Agreement in ratings among examiners appeared to be very poor. CONCLUSIONS: On average, the quality of responses is rated positively by experts, but with ratings that frequently may vary widely. This currently suggests that AI chatbot tools are still unreliable in the management of PJI.

Reconstruction of the pelvic ring in iliac or iliosacral resections: allograft or autograft?

BACKGROUND: The necessity to reconstruct the pelvic ring after an iliac or iliosacral resection is still debated. Different reconstructive techniques are available, including autologous and homologous graft and custom-made prosthesis. The aim of this study was to evaluate the functional outcome and complications of patients who underwent resection of iliac bone and part of the sacrum for primary bone tumour and reconstruction with an allograft or autograft. METHODS: We retrospectively evaluated 18 patients (10 males and 8 female) with a mean age of 28 years (range 9-56) who were operated between 1992 and 2015. Six patients were reconstructed with an autograft (Group A) and 12 patients with an allograft (Group B). All complications were recorded. At final follow-up, patients with the original reconstruction still in site were functionally evaluated with MSTS Score. RESULTS: Mean follow-up time was 107 months (range 4-221). Two patients (11.1%) had an external hemipelvectomy for local recurrence, and 3 patients died of the disease. Mean MSTS Score was comparable between the two groups 21.7 (range 20-25) in Group A and 19.9 (range 4-28) in Group B. Patients with partial sacral resection had an increased risk of local recurrence and lower MSTS Score [15.5 (range 7-20) vs. 22.2 (range 4-28)]. CONCLUSIONS: Biological reconstruction of pelvic ring with autologous or homologous bone graft gives acceptable functional results. However, the decision on how to reconstruct the pelvic ring after iliac resection should be taken on a patient-by-patient basis.

Preoperative surgical risk stratification in osteosarcoma based on the proximity to the major vessels.

AIMS: The aim of this study was to determine the risk of local recurrence and survival in patients with osteosarcoma based on the proximity of the tumour to the major vessels. PATIENTS AND METHODS: A total of 226 patients with high-grade non-metastatic osteosarcoma in the limbs were investigated. Median age at diagnosis was 15 years (4 to 67) with the ratio of male to female patients being 1.5:1. The most common site of the tumour was the femur (n = 103) followed by tibia (n = 66). The vascular proximity was categorized based on the preoperative MRI after neoadjuvant chemotherapy into four types: type 1 > 5 mm; type 2 ≤ 5 mm, > 0 mm; type 3 attached; type 4 surrounded. RESULTS: Limb salvage rate based on the proximity type was 92%, 88%, 51%, and 0% for types 1 to 4, respectively, and the overall survival at five years was 82%, 77%, 57%, and 67%, respectively (p < 0.001). Local recurrence rate in patients with limb-salvage surgery was 7%, 8%, and 22% for the types 1 to 3, respectively (p = 0.041), and local recurrence at the perivascular area was observed in 1% and 4% for type 2 and 3, respectively. The mean microscopic margin to the major vessels was 6.9 mm, 3.0 mm, and 1.4 mm for types 1 to 3, respectively. In type 3, local recurrence-free survival with limb salvage was significantly poorer compared with amputation (p = 0.025), while the latter offered no overall survival benefit. In this group of patients, factors such as good response to chemotherapy or limited vascular attachment to less than half circumference or longitudinal 10 mm reduced the risk of local recurrence. CONCLUSION: The proximity of osteosarcoma to major blood vessels is a poor prognostic factor for local control and survival. Amputation offers better local control for tumours attached to the blood vessels but does not improve survival. Limb salvage surgery offers similar local control if the tumour attachment to blood vessels is limited. Cite this article: Bone Joint J 2019;101-B:1024-1031.

Conductivity response of amorphous oxide interfaces to pulsed light illumination.

Two-dimensional electron gases (2DEGs) formed at oxide interfaces show a large variety of functional properties of major physical interest. Here, the peculiar electric transport behavior of the 2DEG formed at the LGO/STO oxide interface is studied under the application of light pulses of different amplitude, duration, and repetition rate, and by varying the sample temperature from 8 to 300 K. The experimental results evidence a persistent photoconductivity, intimately related to the complex physics of this system. These findings suggest the possibility of using the oxide interfaces for advanced applications as, for example, energy conversion or information storage.

Angiosarcoma around total hip arthroplasty: case series and review of the literature.

BACKGROUND: Angiosarcoma (AS) is a rare and malignant tumor which mainly arises in the skin and superficial soft tissue and less frequently in deep soft tissue and bones. Some cases of AS are described in association with vascular and orthopedic devices. Nonetheless, only a few cases of AS around THA are reported in the literature. MATERIALS AND METHODS: We describe five cases of AS arising around total hip arthroplasty who received surgery at our institution (Istituto Ortopedico Rizzoli, Bologna, Italy), and we report the cases described in literature. RESULTS: Foreign bodies such as polyethylene were demonstrated to have a carcinogenic role in animals, but reports of similar cases in humans are rare. Nevertheless, osteolysis induced by wear particles of polyethylene is a frequent event and could induce to desist form considering other more rare causes of osteolysis such as AS. This could be the reason why the diagnosis in several cases was significantly delayed. Common features of these cases could be helpful for doing a prompt diagnosis. The initial presentation is suggestive for septic or aseptic loosening with a massive osteolysis around the cup and/or the stem associated with peculiar aspects as bleeding and loss of weight. Frequently, needle biopsy is negative because foreign-body reaction might have "covered" the most relevant condition of epithelioid AS. CONCLUSIONS: In conclusion in a patient who presents with uncontrollable bleeding, loss of weight and massive osteolysis, AS must be actually considered as possible diagnosis.

Histology and grading are important prognostic factors in synovial sarcoma.

INTRODUCTION: The diagnosis of synovial sarcoma (SS) is currently based on clinical, morphological, immunohistochemical and cytogenetic data. Some of these factors such as grade and histology, specific translocations (SS18-SSX1 vs. SS18-SSX2) and the reduced expression of INI1, were proposed as prognostic variables. The aim of this study was to verify whether histological (grading and histology) and molecular (type of SSX translocation and INI1 expression) characteristics of SS influence the prognosis of the disease. MATERIAL AND METHODS: We retrospectively evaluated 196 patients affected by SS of the extremities treated at our Institution (Istituto Ortopedico Rizzoli, Bologna, Italy). All cases were histologically revised and tumor grade was assessed according to the FNLCC system. Tissue specimens were retrospectively evaluated to check for SS18-SSX fusion type and INI1 expression. RESULTS: Most SS were monophasic, 28% were biphasic. Eighty tumors (41%) were grade 3. Sixty percent harbored SSX1 translocation, 40% SSX2; 51% maintained the expression of INI1. Sarcoma specific survival (OS) was 56.6% at 5 years and 46.9% at 10 years. Prognosis was worse in those patients monophasic SS (p = 0.011) as in those with a grade 3 tumors (p = 0.083). No correlation was found neither between SSX fusion type nor INI1 expression and survival. LR-free survival was 78.9% at 5 years and 75.9% at 10 years. A higher LR rate was observed in tumors with SSX2 translocation and (p = 0.049) in grade 3 SS (0 = 0.028). DISCUSSION: Our data confirm that not all cases of SS present the same severe outcome. High-risk patients identified on the basis of these parameters may qualify for an aggressive treatment approach.

Impact of residual disease after "unplanned excision" of primary localized adult soft tissue sarcoma of the extremities: evaluation of 452 cases at a single Institution.

BACKGROUND: Soft tissue sarcomas are often inappropriately excised; it is, however, still a matter of debate whether the presence of residual disease in the re-excision specimen can affect patients' prognosis. The aim of this study is to investigate the impact of re-excision after unplanned surgery of primary soft tissue sarcomas (STS) of the extremities. PATIENTS AND METHODS: We retrospectively evaluated 452 adults with grade 2-3, localized STS (349 primary and 103 unplanned excisions). RESULTS: In the re-excision group, a full 43% of the patients had residual tumor. The re-excision group achieved a significantly better outcome in terms of sarcoma-specific survival (SS) (p = 0.002), local recurrence (LR) (p = 0.004) and distant metastasis (DM) (p = 0.028). Residual tumor was associated with a higher risk of DM (p = 0.005). CONCLUSION: We confirm that unplanned surgery does not compromise patients' prognosis; scar re-excision guarantees at least the same SS, LR and DM rates compared to STS primarily treated in a referral center. Routine use of radiation therapy after re-excision could improve local control. Distant metastases seem to be negatively affected by the presence of residual tumor, and therefore, the use of CT in deep and large STS is suggested. The main goal is to avoid unplanned surgery by referring suspected lumps (especially deep, large, increasing in size) to a specialist center.

Minimally-invasive treatment of calcaneal fractures: A review of the literature and our experience.

The optimal treatment of calcaneal fractures (CF) is currently controversial and is still under debate. It is well established that conservative treatment of these fractures is associated with poor results. Several surgical techniques are described in the literature; however, there is no consensus on which of these is more effective. The main goals of surgery are to restore the subtalar joint congruence, and calcaneal width, height, shape and alignment, thus avoiding medial and lateral impingement and enabling the patient to resume a normal lifestyle. ORIF is the most popular technique for these fractures, but it is associated with high rates of wound complications, hardware failure and infections. Several minimally-invasive techniques have been developed recently for the treatment of CF, with the common aim to be as simple, effective and inexpensive as possible and to reduce surgical times, complications and length of hospital stay.

Surgical margins do not affect prognosis in high grade myxofibrosarcoma.

INTRODUCTION: Myxofibrosarcoma (MFS) is one of the most common soft tissue sarcomas (STS) in elderly patients and it primarily affects the extremities. The aim of this retrospective analysis is to understand the natural history of MFS and whether adequate treatment influence prognosis. PATIENTS AND METHODS: We reviewed 129 adult patients with primary, localized, FNCLCC grade 3 MFS of the extremities operated at Istituto Ortopedico Rizzoli, Bologna. Sarcoma specific survival (SS), local recurrence (LR) and distant metastasis (DM) were analyzed. RESULTS: Among excised MFS (119), 106 (89.9%) had R0 margins, 13 (10.1%) R1 margins. No significant correlation between margins adequacy and tumor depth, location and size was found. Estimated SS was 73.2% at 5 years and 66.3% at 10 years, with a better SS in superficial MFS (p = 0.011). Local recurred MFS had a worse SS (p = 0.049). Local recurrence-free rate was 74.3% at 5 and 10 years. Even if not significant, a better outcome in term of LR was observed in superficial MFS and R0 margins. Distant metastasis-free survival was 75.6% at 5 years and 72.9% at 10 years, with a better outcome in superficial MFS (p = 0.012). DISCUSSION: Myxofibrosarcoma remain a debated entity with specific behavior features. Myxofibrosarcoma tends to local recur due to its infiltrative grow pattern making difficult to achieve "safe margins". To date, surgical margins as classified for other STS are not predictive of LR and patients' survival. Tumor grade and depth are still the most important prognostic factors.

Hip resurfacing after iliofemoral distraction for type IV developmental dysplasia of the hip a case report / Artroplastía de resuperficialización de cadera posterior a distracción iliofemoral en displasia del desarrollo de la cadera tipo IV: reporte de un caso

Osteoarthritis secondary to developmental dysplasia of the hip is a surgical challenge because of the modified anatomy of the acetabulum which is deficient in its shape with poor bone quality, torsional deformities of the femur and the altered morphology of femoral head. Particularly in Crowe type III and IV, additional surgical challenges are present, such as limb-length discrepancy and adductor muscle contractures. This is a bilateral hip dysplasia case where bilateral hip replacement was indicated, on the left side with a resurfacing one and on the other side a two stage procedure using a iliofemoral external fixator to restore equal leg length with a lower risk of complications. This case report shows both the negative clinical outcome of the left and the excellent one of the right hip where the dysplasia was much more severe. Patient selection and implant positioning are crucial in determining long-term results.

La osteoartritis secundaria a displasia del desarrollo de la cadera es un reto quirúrgico debido a la anatomía modificada del acetábulo que es deficiente en su forma, con mala calidad del hueso, deformidades de torsión del fémur y la morfología alterada de la cabeza femoral; en particular en los tipos III y IV de Crowe, retos quirúrgicos adicionales están presentes, tales como dismetría y contracturas musculares de los aductores. En este caso de displasia de cadera bilateral se indicó el reemplazo bilateral, en el lado izquierdo con una prótesis de resuperficialización y en el otro lado se realizó un procedimiento de dos etapas utilizando un fijador externo iliofemoral para restaurar la longitud de la pierna con un menor riesgo de complicaciones. Este caso muestra tanto el resultado negativo de la cadera izquierda como el excelente resultado de la cadera derecha, donde la displasia fue mucho más grave. La selección del paciente y la colocación del implante son cruciales en la determinación de resultados a largo plazo.

Hip resurfacing after iliofemoral distraction for type IV developmental dysplasia of the hip a case report.

Osteoarthritis secondary to developmental dysplasia of the hip is a surgical challenge because of the modified anatomy of the acetabulum which is deficient in its shape with poor bone quality, torsional deformities of the femur and the altered morphology of femoral head. Particularly in Crowe type III and IV, additional surgical challenges are present, such as limb-length discrepancy and adductor muscle contractures. This is a bilateral hip dysplasia case where bilateral hip replacement was indicated, on the left side with a resurfacing one and on the other side a two stage procedure using a iliofemoral external fixator to restore equal leg length with a lower risk of complications. This case report shows both the negative clinical outcome of the left and the excellent one of the right hip where the dysplasia was much more severe. Patient selection and implant positioning are crucial in determining long-term results.

La osteoartritis secundaria a displasia del desarrollo de la cadera es un reto quirúrgico debido a la anatomía modificada del acetábulo que es deficiente en su forma, con mala calidad del hueso, deformidades de torsión del fémur y la morfología alterada de la cabeza femoral; en particular en los tipos III y IV de Crowe, retos quirúrgicos adicionales están presentes, tales como dismetría y contracturas musculares de los aductores. En este caso de displasia de cadera bilateral se indicó el reemplazo bilateral, en el lado izquierdo con una prótesis de resuperficialización y en el otro lado se realizó un procedimiento de dos etapas utilizando un fijador externo iliofemoral para restaurar la longitud de la pierna con un menor riesgo de complicaciones. Este caso muestra tanto el resultado negativo de la cadera izquierda como el excelente resultado de la cadera derecha, donde la displasia fue mucho más grave. La selección del paciente y la colocación del implante son cruciales en la determinación de resultados a largo plazo.