Lazertinib is an oral, third-generation, epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI) for the treatment of non-small cell lung cancer (NSCLC). This case report presents a rare instance of small cell carcinoma transformation in pancreatic metastasis in a patient with EGFR-mutated NSCLC undergoing treatment with lazertinib. Small cell carcinoma transformation indicates a mechanism of treatment resistance, and tissue biopsy is essential to confirm this. When isolated progression of a lesion is suspected during TKI therapy in EGFR-mutated NSCLC, histological evaluation is necessary to confirm the transformation for the treatment strategy.

Lazertinib is an oral, third-generation, epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI) for the treatment of non-small cell lung cancer (NSCLC). This case report presents a rare instance of small cell carcinoma transformation in pancreatic metastasis in a patient with EGFR-mutated NSCLC undergoing treatment with lazertinib. Small cell carcinoma transformation indicates a mechanism of treatment resistance, and tissue biopsy is essential to confirm this. When isolated progression of a lesion is suspected during TKI therapy in EGFR-mutated NSCLC, histological evaluation is necessary to confirm the transformation for the treatment strategy.

Background: Volar plate fixation for distal radial fractures is the most common cause of closed rupture of the flexor pollicis longus tendon (FPL). For treating a closed FPL rupture, transferring the fourth flexor digitorum superficialis or a tendon graft from the palmaris longus (PL) can be performed. This study reports the results of tendon grafting using the PL in closed FPL rupture and discusses the provision of optimal tendon tension. Methods: This retrospective study included 11 out of 20 patients who underwent PL tendon graft for closed FPL rupture between 2013 and 2022, with a follow-up period of more than 12 months. There were 4 men and 7 women, with an average age of 62 years. The average period from the date of rupture to surgery was 39 days. Ruptures occurred due to volar plate fixation in 7 cases, without a specific cause in 2 cases, and after a steroid injection for trigger thumb in 2 cases. The rupture site was in zone 2 in 4 cases and zone 5 in 7 cases. The mean follow-up period was 59 months. Optimal tension for the grafted tendon was determined by comparing the intraoperative angles of the interphalangeal (IP) and metacarpophalangeal (MCP) joints with the angles of the same joints at the final follow-up. Results: At the final follow-up, the mean IP joint motion was 61.0°, which was 81.5% of the contralateral side. The average range of motion of the MCP joint was 43.6°, which was 80.0% of the contralateral side. The pinch power was 90.8% of the contralateral side. Cases with > 70° IP joint motion were those in which the IP joint angle was > 45° during surgery. Moreover, the greater the flexion of the IP and MCP joints intraoperatively, the better the range of motion of the IP joints. Conclusions Tendon grafting using the PL is recommended as an effective surgical method to achieve 81.5% of contralateral IP joint motion in cases of closed FPL tendon rupture. Over-tensioning of the tendon graft with IP Joint flexion more than 45° during surgery is recommended.

Background: Several studies have investigated the morphological risk factors contributing to posterior cruciate ligament (PCL) injury. However, no study has focused on the injury patterns of intrasubstance tears or tibial avulsion fractures in relation to morphologies and regional bone quality. This study aimed to investigate the impact of the knee morphology and regional bone quality of the proximal tibia on the PCL injury pattern. Methods: This retrospective study compared the radiological features of 76 patients with PCL injuries (PI group) and 76 matched patients with normal PCL (control group). The PI group was divided into 2 subgroups: PCL avulsion fracture (PAF subgroup; n = 43) and PCL intrasubstance tear (PIT subgroup; n = 33). Measurements included the coronal notch width index, coronal tibial slope, medial and lateral posterior tibial slopes, and medial tibial depth. Three Hounsfield unit average measurements were taken from the proximal tibia around the PCL insertion site to create a summative measure of overall bone quality. Results: The medial tibial depth and coronal notch width index were significantly lower in the PI group than those in the control group (medial tibial depth: 2.04 ± 0.77 vs. 3.02 ± 1.04, p = 0.017; coronal notch width index: 0.21 ± 0.03 vs. 0.24 ± 0.03, p = 0.041). In the subgroup analysis, medial tibial depth and Hounsfield unit were significantly lower in the PAF subgroup than in the PIT subgroup (medial tibial depth: 1.74 ± 0.66 vs. 2.43 ± 0.77, p = 0.008, Hounsfield unit: 89.48 ± 31.73 vs. 120.15 ± 29.24, p = 0.004). Binary logistic regression analysis showed that medial tibial depth (odds ratio [OR], 0.161; p < 0.001) and Hounsfield unit (OR, 0.950;p < 0.001) were independent risk factors for PCL tibial avulsion fractures. Conclusions Lower notch width index and medial tibial depth are associated with PCL injuries. Shallower medial tibial depth and lower Hounsfield unit measurements around the PCL insertion site were associated with an increased incidence of PCL avulsion fractures. These findings may assist clinicians in identifying patients at risk of distinct PCL injury patterns.

Lazertinib is an oral, third-generation, epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI) for the treatment of non-small cell lung cancer (NSCLC). This case report presents a rare instance of small cell carcinoma transformation in pancreatic metastasis in a patient with EGFR-mutated NSCLC undergoing treatment with lazertinib. Small cell carcinoma transformation indicates a mechanism of treatment resistance, and tissue biopsy is essential to confirm this. When isolated progression of a lesion is suspected during TKI therapy in EGFR-mutated NSCLC, histological evaluation is necessary to confirm the transformation for the treatment strategy.

Background: Volar plate fixation for distal radial fractures is the most common cause of closed rupture of the flexor pollicis longus tendon (FPL). For treating a closed FPL rupture, transferring the fourth flexor digitorum superficialis or a tendon graft from the palmaris longus (PL) can be performed. This study reports the results of tendon grafting using the PL in closed FPL rupture and discusses the provision of optimal tendon tension. Methods: This retrospective study included 11 out of 20 patients who underwent PL tendon graft for closed FPL rupture between 2013 and 2022, with a follow-up period of more than 12 months. There were 4 men and 7 women, with an average age of 62 years. The average period from the date of rupture to surgery was 39 days. Ruptures occurred due to volar plate fixation in 7 cases, without a specific cause in 2 cases, and after a steroid injection for trigger thumb in 2 cases. The rupture site was in zone 2 in 4 cases and zone 5 in 7 cases. The mean follow-up period was 59 months. Optimal tension for the grafted tendon was determined by comparing the intraoperative angles of the interphalangeal (IP) and metacarpophalangeal (MCP) joints with the angles of the same joints at the final follow-up. Results: At the final follow-up, the mean IP joint motion was 61.0°, which was 81.5% of the contralateral side. The average range of motion of the MCP joint was 43.6°, which was 80.0% of the contralateral side. The pinch power was 90.8% of the contralateral side. Cases with > 70° IP joint motion were those in which the IP joint angle was > 45° during surgery. Moreover, the greater the flexion of the IP and MCP joints intraoperatively, the better the range of motion of the IP joints. Conclusions Tendon grafting using the PL is recommended as an effective surgical method to achieve 81.5% of contralateral IP joint motion in cases of closed FPL tendon rupture. Over-tensioning of the tendon graft with IP Joint flexion more than 45° during surgery is recommended.

Background: Several studies have investigated the morphological risk factors contributing to posterior cruciate ligament (PCL) injury. However, no study has focused on the injury patterns of intrasubstance tears or tibial avulsion fractures in relation to morphologies and regional bone quality. This study aimed to investigate the impact of the knee morphology and regional bone quality of the proximal tibia on the PCL injury pattern. Methods: This retrospective study compared the radiological features of 76 patients with PCL injuries (PI group) and 76 matched patients with normal PCL (control group). The PI group was divided into 2 subgroups: PCL avulsion fracture (PAF subgroup; n = 43) and PCL intrasubstance tear (PIT subgroup; n = 33). Measurements included the coronal notch width index, coronal tibial slope, medial and lateral posterior tibial slopes, and medial tibial depth. Three Hounsfield unit average measurements were taken from the proximal tibia around the PCL insertion site to create a summative measure of overall bone quality. Results: The medial tibial depth and coronal notch width index were significantly lower in the PI group than those in the control group (medial tibial depth: 2.04 ± 0.77 vs. 3.02 ± 1.04, p = 0.017; coronal notch width index: 0.21 ± 0.03 vs. 0.24 ± 0.03, p = 0.041). In the subgroup analysis, medial tibial depth and Hounsfield unit were significantly lower in the PAF subgroup than in the PIT subgroup (medial tibial depth: 1.74 ± 0.66 vs. 2.43 ± 0.77, p = 0.008, Hounsfield unit: 89.48 ± 31.73 vs. 120.15 ± 29.24, p = 0.004). Binary logistic regression analysis showed that medial tibial depth (odds ratio [OR], 0.161; p < 0.001) and Hounsfield unit (OR, 0.950;p < 0.001) were independent risk factors for PCL tibial avulsion fractures. Conclusions Lower notch width index and medial tibial depth are associated with PCL injuries. Shallower medial tibial depth and lower Hounsfield unit measurements around the PCL insertion site were associated with an increased incidence of PCL avulsion fractures. These findings may assist clinicians in identifying patients at risk of distinct PCL injury patterns.

Background/Aims: The prognostic value of serial 18F-fluorodeoxyglucose positron emission tomography/computed tomography ( 18F-FDG PET/CT) for patients with borderline resectable or locally advanced pancreatic cancer who undergo conversion surgery or continue chemotherapy without surgery has not been well-established. Methods: A retrospective analysis of patients with pancreatic ductal adenocarcinoma was conducted at Seoul National University Bundang Hospital between March 2013 and February 2022.Patients underwent PET/CT at baseline and subsequent radiologic evaluations following chemotherapy. Changes in the maximum standardized uptake value (SUVmax), mean standardized uptake value (SUVmean), metabolic tumor volume, and total lesion glycolysis were analyzed.Based on their treatment regimens, patients were stratified into the conversion surgery group or nonconversion surgery group. Survival outcomes and various clinical factors were assessed. Results: Among 121 patients, 52 underwent conversion surgery, and 69 continued to receive chemotherapy without surgery. A significant reduction in the SUVmax was correlated with prolonged recurrence-free survival and overall survival in the conversion surgery group. Confirmation of a pathologic response indicated a significant association between reductions in the SUVmax and positive outcomes. Reductions in the metabolic tumor volume and total lesion glycolysis were associated with improved progression-free survival and overall survival in the nonconversion surgery group. Conclusions Serial PET/CT scans demonstrated prognostic value in pancreatic ductal adenocarcinoma patients, revealing distinct correlations in the conversion surgery group and nonconversion surgery group.

Purpose: Commonly used surgical approaches for internal plate fixation of transcondylar distal humeral fractures may require ulnar nerve release or anterior transposition, and extensive surgical dissection can cause triceps weakness. This study reports the surgical technique and clinical outcomes of a medial and lateral approach for dual-plate fixation of transcondylar distal humeral fractures without ulnar nerve release or extensive surgical dissection. Methods: Sixteen patients (mean age, 81.25 years; range, 70–95 years) who underwent plate fixation using a medial and lateral approach for distal humeral transcondylar fractures were retrospectively reviewed. An anatomical distal humerus parallel or orthogonal locking plate was used for internal fixation. Ulnar nerve release was not performed in any patients. Surgical outcomes were evaluated 1 year postoperatively based on the level of pain, elbow range of motion, the Mayo elbow performance score, and postoperative complications. Results: The mean visual analog scale score was 0.47. The mean range of motion of the elbow joint was 13.8° for extension and 131.8° for flexion. The Mayo Elbow Performance Score was excellent in nine patients and good in seven. Bone union was achieved in all patients. There were no complications such as ulnar neuropathy, heterotopic ossification, or infection. Conclusion In transcondylar distal humeral fracture in older adults, a medial and lateral approach with dual anatomical locking plate fixation is recommended as a surgical technique that has the advantage of enabling rigid fixation without necessitating ulnar nerve release and extensive surgical dissection. Nonetheless, further research should be conducted.

Lazertinib is an oral, third-generation, epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI) for the treatment of non-small cell lung cancer (NSCLC). This case report presents a rare instance of small cell carcinoma transformation in pancreatic metastasis in a patient with EGFR-mutated NSCLC undergoing treatment with lazertinib. Small cell carcinoma transformation indicates a mechanism of treatment resistance, and tissue biopsy is essential to confirm this. When isolated progression of a lesion is suspected during TKI therapy in EGFR-mutated NSCLC, histological evaluation is necessary to confirm the transformation for the treatment strategy.