ObjectiveTo review the research progress on intra-articular screw penetration in proximal humeral fracture treated with locking plate. MethodsThe domestic and foreign literature about the proximal humeral fracture treated with locking plate was extensively reviewed. The incidence of screw penetration and risk factors were summarized from both primary and secondary screw penetrations, and the reasons of the intra-articular screw penetration and the technical solutions to avoid the penetration were analyzed. ResultsThe incidence of intra-articular screw penetration is about 11%-30%, which includes primary and secondary screw penetrations. The primary screw penetration is related to improper operation, inaccurate measurement, and “Steinmetz solid” effect, which results in inadequate fluoroscopy and blind zone. The secondary screw penetration is related to the loss of reduction and varus, collapse, and necrosis of the humeral head. The risk factors for intra-articular screw penetration include the bone mass density, the fracture type, the quality of fracture reduction, the applied location, number, and length of the plate and screws, and whether medial column buttress is restored. Improved fracture reduction, understanding the geometric distribution of screws, good intraoperative fluoroscopy, and reconstruction of medial column buttress stability are the key points for success. ConclusionThe risk of the intra-articular screw penetration in the proximal humeral fractures treated with locking plates is still high. Follow-up studies need to further clarify the cause and mechanism of screw penetration, and the risk factors that lead to screw penetration, in order to effectively prevent the occurrence of this complication.
Objective To analyze the causes and treatment of off target of the distal interlocking screws when short cephalomeduallry nails were installed through jig-guided targeting device, and to put forward the technical points to prevent off target. Methods Retrospective analysis of 9 patients with intertrochanteric fractures treated between July 2014 and June 2023 was conducted, in which off target occurred during the insertion of the distal interlocking screw by jig-guided targeting device in short cephalomedullary nailling (<24 cm). There were 1 male and 8 females, with an average age of 82.7 years (range, 73-94 years). There were 3 cases of type A1, 5 cases of type A2, and 1 case of type A3 according to 2018-AO/Orthopaedic Trauma Association (AO/OTA) fracture classification. As for the misaligned distal interlocking screw, six parameters were collected and analyzed, including the time of finding, the position, the type of passing through the cortical bone, the special circumstances during operation (such as the need to remove the intramedullary nail for reaming the diaphysis, hammering, etc.), the treatment, and the patient follow-up results. Results In the 9 patients, the off target of the distal interlocking screw was found in 7 cases during operation and in 2 cases after operation; the locking screw was located behind the nail in 7 cases and in front of the nail in 2 cases; the off target locking screw was passing tangentially in transcortical patern in 6 cases and in bicortical pattern through the medullary cavity in 3 cases. Three cases were attributed to the mismatch between the nail and the femur, two of which were attributed to the narrow femoral medullary cavity, one of which was attributed to the large anterolateral femoral bowing, and the other 6 cases were attributed to technical errors such as the loosening of the jig-guided targeting device, the tension of the fascia lata, and the blunt of the drill. In the 7 cases found during operation, the misaligned interlocking screw was removed first and the screw hole was left vacant, then in 2 cases, the interlocking screw was not used further; in 1 case, the distal dynamic hole was successfully inserted with a dynamic guide frame, and in 4 cases, the interlocking screw was successfully put after 2-3 attempts, leaving a large hole in the lateral cortex. No special treatment was performed in 2 cases found after operation. One patient was out of bed early after operation, 7 patients were in bed for 1 month, and 1 patient deteriorated to A3 type after operation and was in bed for 3 months. All the 9 patients were followed up 6-12 months, with an average of 8 months. Fracture healing was achieved in 8 patients. One patient with vacant interlocking screw had a secondary spiral fracture of the femoral shaft 3 months later, and was refixed with a long cephalomedullary nail and circlage wiring. Conclusion Distal interlocking screw off target is rare, but when it occurs, it leaves a large cortical hole in the osteoporotic femoral shaft, reducing bone strength; the use of precision instruments and attention to technical details can reduce this adverse phenomenon.
ObjectiveTo explore the biomechanical stability of the medial column reconstructed with the exo-cortical placement of humeral calcar screw by three-dimensional finite element analysis. MethodsA 70-year-old female volunteer was selected for CT scan of the proximal humerus, and a wedge osteotomy was performed 5 mm medially inferior to the humeral head to form a three-dimensional finite element model of a 5 mm defect in the medial cortex. Then, the proximal humeral locking plate (PHILOS) was placed. According to distribution of 2 calcar screws, the study were divided into 3 groups: group A, in which 2 calcar screws were inserted into the lower quadrant of the humeral head in the normal direction for supporting the humeral head; group B, in which 1 calcar screw was inserted outside the cortex below the humeral head, and the other was inserted into the humeral head in the normal direction; group C, in which 2 calcar screws were inserted outside the cortex below the humeral head. The models were loaded with axial, shear, and rotational loadings, and the biomechanical stability of the 3 groups was compared by evaluating the peak von mises stress (PVMS) of the proximal humerus and the internal fixator, proximal humeral displacement, neck-shaft angle changes, and the rotational stability of the proximal humerus. Seven cases of proximal humeral fractures with comminuted medial cortex were retrospectively analyzed between January 2017 and December 2020. Locking proximal humeral plate surgery was performed, and one (5 cases) or two (2 cases) calcar screws were inserted into the inferior cortex of the humeral head during the operation, and the effectiveness was observed. Results Under axial and shear force, the PVMS of the proximal humerus in group B and group C was greater than that in group A, the PVMS of the internal fixator in group B and group C was less than that in group A, while the PVMS of the proximal humerus and internal fixator between group B and group C were similar. The displacement of the proximal humerus and the neck-shaft angle change among the 3 groups were similar under axial and shear force, respectively. Under the rotational torque, compared with group A, the rotation angle of humerus in group B and group C increased slightly, and the rotation stability decreased slightly. All the 7 patients were followed up 6-12 months. All the fractures healed, and the healing time was 8-14 weeks, with an average of 10.9 weeks; the neck-shaft angle changes (the difference between the last follow-up and the immediate postoperative neck-shaft angle) was (1.30±0.42)°, and the Constant score of shoulder joint function was 87.4±4.2; there was no complication such as humeral head varus collapse and screw penetrating the articular surface. ConclusionFor proximal humeral fractures with comminuted medial cortex, exo-cortical placement of 1 or 2 humeral calcar screw of the locking plate outside the inferior cortex of the humeral head can also effectively reconstruct medial column stability, providing an alternative approach for clinical practice.
ObjectiveTo review the advancement made in the understanding of valgus impacted proximal humeral fracture (PHF). MethodsThe domestic and foreign literature about the valgus impacted PHF was extensively reviewed and the definition, classification, pathological features, and treatment of valgus impacted PHFs were summarized. Results PHF with a neck shaft angle ≥160° is recognized as a valgus impacted PHF characterized by the preservation of the medial epiphyseal region of the humeral head, which contributes to maintenance of the medial periosteum’s integrity after fracture and reduces the occurrence of avascular necrosis. Therefore, the valgus impacted PHF has a better prognosis when compared to other complex PHFs. The Neer classification designates it as a three- or four-part fracture, while the AO/Association for the Study of Internal Fixation (AO/ASIF) categorizes it as type C (C1.1). In the management of the valgus impacted PHF, the selection between conservative and surgical approaches is contingent upon the patient’s age and the extent of fracture displacement. While conservative treatment offers the advantage of being non-invasive, it is accompanied by limitations such as the inability to achieve anatomical reduction and the potential for multiple complications. Surgical treatment includes open reduction combined with steel wire or locking plate and/or non-absorbable suture, transosseous suture technology, and shoulder replacement. Surgeons must adopt personalized treatment strategies for each patient with a valgus impacted PHF. Minimally invasive surgery helps to preserve blood supply to the humeral head, mitigate the likelihood of avascular necrosis, and reduce postoperative complications of bone and soft tissue. For elderly patients with severe comminuted and displaced fractures, osteoporosis, and unsuitable internal fixation, shoulder joint replacement is the best treatment option. ConclusionCurrently, there has been some advancement in the classification, vascular supply, and management of valgus impacted PHF. Nevertheless, further research is imperative to assess the clinical safety, biomechanical stability, and indication of minimally invasive technology.
ObjectiveTo investigate the position of the anterior fracture line in AO/Orthopaedic Trauma Association (AO/OTA) type A2 unstable intertrochanteric fractures and its impact on the incidence of anterior cortical reduction loss after cephalomedullary nail fixation. MethodsA clinical data of 95 patients with intertrochanteric fractures who met the selection criteria between April 2020 and February 2023 was retrospectively analyzed. All patients were treated with cephalomedullary nail fixation, and the intra- and post-operative imaging data were complete. Among them, there were 37 males and 58 females. The age ranged from 61 to 97 years, with an average of 79.6 years. The time from injury to operation ranged from 7 hours to 11 days, with an average of 2.8 days. According to the 2018-AO/OTA classification standard, there were 39 cases of type 31-A2.2 and 56 cases of type 31-A2.3. Intraoperative fluoroscopy was used to record the number of patients with satisfactory fracture alignment. The preoperative CT data were imported into Mimics17.0 software to simulate the fracture reduction and measure the distance between the anterior fracture line and the intertrochanteric line bony ridge. The fractures were classified as transcapsular fractures, extra-capsular fractures, and intra-capsular fractures according to the distance. CT three-dimensional reconstruction was performed within 2 weeks after operation to observe the number of patients with anterior cortical reduction loss. The postoperative anterior cortical reduction loss incidence in patients with satisfactory fracture alignment, and the relationship between postoperative anterior cortical reduction loss and the position of the anterior fracture line were observed. Results There were 52 cases (54.7%) of transcapsular fractures, 24 cases (25.3%) of extra-capsular fractures, and 19 cases (20.0%) of intra-capsular fractures. Among them, 41 of the 52 transcapsular fractures had satisfactory fracture alignment, and 4 (9.8%) of them experienced anterior cortical reduction loss after operation; 19 of the 24 extra-capsular fractures had satisfactory fracture alignment, and no anterior cortical reduction loss occurred; 16 of the 19 intra-capsular fractures had satisfactory fracture alignment, and 7 (43.8%) of them experienced anterior cortical reduction loss after operation. There was a significant difference in the incidence of anterior cortical reduction loss between groups (χ2=8.538, P=0.003). All patients were followed up 3-26 months (mean, 9 months). Among them, 91 cases had fracture healing, and 4 cases had nonunion.Conclusion In AO/OTA type A2 unstable intertrochanteric fractures, where the anterior fracture line is located within the joint capsule, there is a high risk of anterior cortical reduction loss after operation.
ObjectiveTo measure the rotation angle of the head-neck fragment of intertrochanteric fracture after cephalomedullary nail fixation by three-dimensional CT imaging, and to explore its clinical significance.MethodsThe clinical data of 68 patients with unstable intertrochanteric fracture of AO/Orthopaedic Trauma Association (AO-OTA) type 31-A2 treated with cephalomedullary nail fixation and with complete intraoperative fluoroscopy and postoperative three-dimensional CT imaging data between July 2016 and October 2018 were retrospectively analyzed. Among them, there were 21 males and 47 females, aged 68-93 years, with an average age of 81.8 years. There were 31 cases of AO/OTA type 31-A2.2 and 37 cases of 31-A2.3. Fracture reduction quality was evaluated according to Baumgaertner et al. and Chang et al. criteria. The anteromedial cortical contact or not of each patient was observed by three-dimensional CT imaging on T3DView software after operation. The rotation of head-neck fragments were divided into three types: non-rotation, flexion rotation, and hyperextension rotation. The rotation angles of each type were measured and the relationship between the rotation type of the head-neck fragments and the contact of the anteromedial cortex was analyzed.ResultsThe reduction and fixation of the small trochanter were not performed in 68 patients. According to Baumgaertner et al. criteria, the quality of fracture reduction was excellent in 15 cases (22.1%), acceptable in 50 cases (73.5%), and poor in 3 cases (4.4%). According to Chang et al. criteria, 31 cases were excellent (45.6%), 33 cases were acceptable (48.5%), and 4 cases were poor (5.9%). Thirty-nine cases (57.4%) received anteromedial cortical support and 29 cases (42.6%) did not receive cortical support. Three-dimensional CT imaging showed non-rotation in 12 cases (17.6%), flexion rotation in 39 cases (57.4%), and hyperextension rotation in 17 cases (25.0%). There were 7 cases (58.3%), 30 cases (76.9%), and 2 cases (11.8%) of cortical support in non-rotation group, flexion rotation group, and hyperextension rotation group, respectively. The rotation angles were (1.05±0.61), (13.96±6.17), (8.21±3.88)°, respectively. There were significant differences between groups (P<0.05).ConclusionIn the unstable intertrochanteric fracture after cephalomedullary nail fixation, the rotation of head-neck fragment exists in most patients, and the types of flexion rotation and non-rotation can easily obtain cortical support reduction.
ObjectiveTo evaluate the effectiveness of proximal femoral nail anti-rotation (PFNA) in treatment of high plane intertrochanteric femur fractures.MethodsA retrospective analysis was performed on 33 patients who underwent closed reduction and PFNA fixation for high plane intertrochanteric femur fracture between January 2016 and June 2019. There were 12 males and 21 females with an average age of 75.1 years (mean, 47-89 years). The fractures were caused by falling from height in 21 cases, by traffic accident in 7 cases, and by other injuries in 5 cases. Fractures were classified as type A in 14 cases and type B in 19 cases according to self-defined fracture classification criteria; and as type 31-A1.2 in 14 cases and as type 31-A2.2 in 19 cases according to AO/Orthopedic Trauma Association (AO/OTA) classification criteria. The time from injury to operation was 2-5 days (mean, 2.7 days). The operation time, intraoperative blood loss, hospital stay, fracture reduction quality, fracture healing time, internal fixation failure, and Parker-Palmer score were recorded.ResultsThe operation time was 40-75 minutes (mean, 55 minutes). The intraoperative blood loss was 50-150 mL (mean, 64 mL). The hospital stay was 5-15 days (mean, 8.7 days). All incisions healed by first intention. Twenty-eight patients were followed up 12-18 months with an average of 13.6 months. The fracture reduction quality was rated as excellent in 9 cases (32.1%), good in 17 cases (60.7%), and poor in 2 cases (7.1%) by Chang’s criteria. Parker-Palmer score was 6-9 (mean, 7.9) at last follow-up.ConclusionHigh plane intertrochanteric femur fracture is a special type of intertrochanteric fracture, which can be diagnosed by imaging examination. PFNA fixation can achieve satisfactory results and prevent the occurrence of internal fixation failure effectively.