Pre-sliding of the femoral neck system to prevent postoperative shortening of femoral neck fractures.

Objective: The purpose of this study is to evaluate the effect of pre-sliding of the femoral neck system (FNS) in the prevention of postoperative femoral neck shortening in femoral neck fractures. Method: This study was designed to retrospectively analyze data from 109 patients with femoral neck fractures who were admitted to a Level I trauma center between April 2020 and June 2022. Of these patients, 90 were followed up for more than 12 months. The study included 52 males and 38 females, with 35 cases of Garden I and II fractures and 55 cases of Garden III and IV fractures. The Harris Hip Score at 12 months postoperatively were recorded. The patients were divided into two groups based on their surgical records and postoperative radiography: the Pre-sliding group and the No-pre-sliding group. The purpose of this study is to analyze the role of pre-sliding in preventing femoral neck shortening, fracture healing time, degree of postoperative shortening, complications, and Harris Hip Score, and to make a comparison between the two groups. Results: All 90 patients were followed up for over one year after surgery. A statistically significant difference was observed in the preoperative Garden classification (P < 0.05). At 1 year after the operation, the shortening distance was 6.5 ± 6.4 mm in the No-pre-sliding group and 3.9 ± 3.4 mm in the Pre-sliding group. The Harris Hip Score were 88.7 (79.8, 93.5) in the No-pre-sliding group and 94.8 (87.7, 96.9) in the Pre-sliding group, with a statistically significant difference between the two groups (P < 0.05). Shortening was concentrated at 3 months postoperatively and reached a stable state within 6 months, with less persistent shortening occurring after 6 months. There was no statistically significant difference in the preoperative baseline data. Conclusion: Pre-sliding of the FNS prevents postoperative shortening of the femoral neck and improves hip function as measured by the Harris Hip Score.

[Treatment analysis of complex Schatzker type â £ tibial plateau fractures].

OBJECTIVE: To explore treatment strategy for complex Schatzker Ⅳ tibial plateau fracture. METHODS: Forty-one patients with complex Schatzker type Ⅳ tibial plateau fractures were treated from January 2016 to January 2021, including 28 males and 13 females, aged from 19 to 65 years old with an average of (35.3±19.8) years old. Individualized treatment plan was developed according to preoperative imaging characteristics, medial surgical approach was mainly combined with other auxiliary incisions. Posteromedial inverted L approach was used in 18 patients, posteromedial approach and anterolateral extended approach in 19 patients, and posteromedial approach with anterolateral and lateral condylar osteotomy in 4 patients. Articular surface and facture healing were observed, range of knee joint motion was measured at 12 months after opertaion, and function of knee joint was evaluated by Lysholm scoring system. RESULTS: Forty-one patients were followed up for 12 to 26 months with an average of (13.3±6.8) months. Twenty-nine patients and 10 patients were obtained complete fracture healing at 6 and 12 months after operation respectively, and fracture healing time was 4 to 13 months with an average of (5.0±3.7) months. Two patients occurred posterior medial internal fixation failure and varus deformity of knee joint, and the fracture healed and varus deformity was corrected after the second operation. Range of knee joint motion was (118±29) °, and Lysholm score was(83.0±16.0) points. CONCLUSION: Individualized treatment should be reasonably selected for complex Schatzker Ⅳ tibial plateau fractures, the characteristics of lateral plateau fractures are an important reference for selecting surgical approaches, the effective fixation of posteromedial bone blocks should be pay full attention, and the overall treatment results are satisfied.

An aggressive course of pyoderma gangrenosum mimicking bacterial osteomyelitis after open reduction and internal fixation of a distal radius fracture with a titanium plate.

Pyoderma gangrenosum (PG) is a rare condition characterized by the development of aseptic, non-healing skin ulcers. Any skin trauma, such as a surgical incision, can trigger an outbreak of lesions. Our case and literature review show that a physician should consider PG in every event of a non-healing, aseptic wound after surgery. The treatment of PG requires collaboration within a multidisciplinary team and immunosuppressive therapy is the first line of treatment, while surgical interventions should be avoided in the active stage of PG.

Biomechanical study on parallel cannulated compression screw combined with medial buttress plate fixation and F-type cannulated compression screw fixation in Pauwels III femoral neck fracture：A finite element analysis. / å¹³è¡Œç©ºå¿ƒåŠ åŽ‹èžºé’‰è”åˆå† ä¾§æ”¯æ’‘é’¢æ¿ä¸ŽFåž‹ç©ºå¿ƒåŠ åŽ‹èžºé’‰å›ºå®šPauwels IIIåž‹è‚¡éª¨é¢ˆéª¨æŠ˜ç”Ÿç‰©åŠ›å­¦ç‰¹æ€§çš„æœ‰é™å ƒåˆ†æž.

OBJECTIVES: Pauwels III fracture is a kind of femoral neck fractures, in which the angle of the fracture line in the coronal plane and the upper edge of the acetabulum is more than 50°. Internal fixation for the treatment of femoral neck fractures is largely performed by cannulated compression screw (CCS), dynamic hip screw, or locking plate. This study aims to compare the biomechanical properties of parallel CCS combined with medial buttress plate fixation and F-type CCS fixation in the treatment of Pauwels III femoral neck fracture by finite element modeling and to determinate the most suitable procedure for such fractures. METHODS: A 52-year-old male volunteer, 176 cm in height and 72 kg in weight, with no history of hip joint, was selected. X-ray and CT examination confirmed that the morphology and bone condition of the right hip of the volunteer were normal. A simulation model of Pauwels III femoral neck fracture was established from the collected CT data of the right proximal femur of the volunteer by the finite element method. Four internal fixations were developed to treat the finite element model: Three CCSs in an inverted triangular parallel configuration combined with medial buttress plate model served as Group A, 2 CCSs in a vertical parallel configuration combined with medial buttress plate model served as Group B, 2 CCSs in a horizontal parallel configuration combined with medial buttress model served as Group C, and the "F" shaped CCS model served as Group D. The distribution of stress, the peak stress, the distribution and maximum of displacement of internal fixations and fracture ends in different models were evaluated. RESULTS: For Groups A, B, C, and D, the peak stresses on the internal fixation were 362.74, 586.84, 558.25, and 208.66 mPa, respectively, all of which occurred near the fractures and the stress distribution in Group D was the most uniform. The maximum displacements of internal fixations in Groups A, B, C, and D were 0.39, 0.45, 0.44, and 0.41 mm, respectively; the peak stresses on the fracture ends were 70.62, 98.48, 55.84, and 65.39 mPa, respectively, all of which were concentrated on the base of femoral neck and lateral cortex of the femoral shaft, and the stresses of Groups C and D were more evenly distributed than those of Groups A and B. The maximum displacements of fracture ends in Groups A, B, C, and D were 0.44, 0.52, 0.50, and 0.44 mm, respectively. CONCLUSIONS: The biomechanical stability of F-type CCS fixation is similar to that of 3 CCSs in an inverted triangular parallel configuration combined with medial buttress plate, with a better dispersion of stress. F-type CCS fixation may be a well option for the treatment of femoral neck fracture of Pauwels III.

Open Reduction and Internal Fixation by Volar Locking Plates and the "Poking Reduction" Technique in Distal Radius Fractures with Displaced Dorsal Ulnar Fragments: A Retrospective Study.

OBJECTIVE: To investigate the clinical and radiological outcomes of distal radius fractures (DRFs) with displaced dorsal ulnar fragments treated with volar locking plate (VLP) and the "poking reduction" technique. METHODS: Between January 2014 and January 2019, 78 unilateral DRFs with displaced dorsal ulnar fragment (AO type C3) treated with VLP were conducted. According to the reduction technique of the dorsal ulnar fragment, the patients were divided into the conventional reduction (CRG) group (33 patients, 14 males and 19 females, mean age 57.2 ± 12.1 years old) and the "poking reduction" (PRG) group (45 patients, 11 males and 34 females, mean age 60.1 ± 12.4 years old). According to the AO classification, there were 21 cases of C3.1 and 12 of C3.2 in the CPG group, 27 cases of C3.1 and 18 of C3.2 in the PRG group. Clinical and radiographic data were extracted from the electronic medical record system. These data were reviewed for clinical outcomes (range of motion, grip strength), radiological outcomes (volar tilt, radial inclination, radial height, step of articular surface), and postoperative complications. The final functional recovery was evaluated by the disabilities of the arm, shoulder, and hand (DASH) score. RESULTS: The mean duration of follow-up was 27 months (range from 12 to 56). The average operation time and intraoperative blood loss did not significantly differ between groups (p > 0.05). Postoperative CT examination showed that the step of articular surface in CPG group (0.8 ± 0.3 mm) was larger than that in PRG group (0.5 ± 0.2 mm) (p < 0.001). The DASH score did not significantly differ between groups (26.1 ± 4.6 in CRG and 24.7 ± 4.0 in PRG, p > 0.05) at 3 months postoperatively. At 6 months and 12 months postoperatively, the DASH score was better in PRG group (11.8 ± 2.5 and 10.4 ± 2.0) than in CRG group (13.6 ± 2.7 and 12.2 ± 2.5) (p = 0.004, p = 0.001, respectively). At 12 months postoperatively, wrist range of motion did not significantly differ between groups (p > 0.05). There was no significant difference in radiological parameters between the two groups (p > 0.05). The incidence of complications was higher in the CRG group (7/33) than in the PRG group (2/45) (p = 0.009). CONCLUSION: The "poking reduction" technique is a wise option for reduction of dorsal ulnar fragment in DRFs. This innovative technique could restore smoothness of the radiocarpal joint effectively, and the dorsal ulnar fragment could be fixed effectively combined with the volar plate.

[Biomechanical analysis of Magic screw fixation for acetabular posterior column fracture].

This study aims to analyze the biomechanical stability of Magic screw in the treatment of acetabular posterior column fractures by finite element analysis. A three-dimensional finite element model of the pelvis was established based on the computed tomography (CT) and magnetic resonance imaging (MRI) data of a volunteer and its effectiveness was verified. Then, the posterior column fracture model of the acetabulum was generated. The biomechanical stability of the four internal fixation models was compared. The 500 N force was applied to the upper surface of the sacrum to simulate human gravity. The maximum implant stresses of retrograde screw fixation, single-plate fixation, double-plate fixation and Magic screw fixation model in standing and sitting position were as follows: 114.10, 113.40 MPa; 58.93, 55.72 MPa; 58.76, 47.47 MPa; and 24.36, 27.50 MPa, respectively. The maximum stresses at the fracture end were as follows: 72.71, 70.51 MPa; 48.18, 22.80 MPa; 52.38, 27.14 MPa; and 34.05, 30.78 MPa, respectively. The fracture end displacement of the retrograde tension screw fixation model was the largest in both states, and the Magic screw had the smallest displacement variation in the standing state, but it was significantly higher than the two plate fixations in the sitting state. Magic screw can satisfy the biomechanical stability of posterior column fracture. Compared with traditional fixations, Magic screw has the advantages of more uniform stress distribution and less stress, and should be recommended.

The Regularity of Stress Shielding in Internal Fixation Characterized by Hydromechanics.

Stress shielding is an important factor in the internal fixation of a fracture. To explore the regularity of stress shielding in internal fixation, a simplified model of a comminuted femoral shaft fracture bridged by a locking plate was established and finite element analysis was performed to analyze the load distribution between the plate and femur from the proximal end of the femur to the fracture line and investigate the stress shielding degree of the plate on the bone. The stress, deformation, and axial compressive force distribution of four internal fixation schemes under compression were obtained, and the stress shielding degrees on each section was calculated. To compare the regularity of stress shielding and flow distribution, the relationship between the compressive force increment and stress shielding degree was established. The normalized curves of compressive force increment with the plate section position were compared with the flow distribution in a Z-type manifold, a parallel pipe system similar to an internal fixation system in structure and working characteristics. For quantitative comparison, the similarity between normalized curves of the compressive force increment and simulated flow distribution was calculated. The regularity of load distribution along the section position of the plate was similar to the flow distribution in the Z-type manifold. Therefore, the flow distribution pattern of the Z-type manifold can be used to characterize the regularity of load distribution in internal fixation. This study provided a new method to characterize the stress shielding degree of a locking plate on bone.

Total Knee Arthroplasty in Patients with Retention of Prior Hardware Material: What is the Outcome?

BACKGROUND: There is an information gap in literature regarding postoperative outcome of total knee arthroplasty (TKA) in patients with hardware in-situ from the previous knee surgery. The present study aims to evaluate impact of retained hardware on short-term outcome of TKA patients. METHODS: Perioperative radiographs of patients who had undergone TKA between 2007 and 2012 were reviewed and patients in whom partial or complete retention of hardware was evident after TKA were included. These patients were matched in 1 to 2 ratio based on age (+/- 2 years), gender, surgeon and year of surgery to a group of patients that underwent primary TKA without hardware in the affected knee. The average follow up of these patients was 43.45 (range 12-155.2) months. Complication rates were compared between the two groups using statistical tests that took into account the matched data structure. RESULTS: We included a total of 55 cases and 110 controls. The incidence of complications was higher, although not all statistically significant, in the case group. Only mechanical complications were significantly different in the cases group (5.5% versus 0%, P=0.01). Time to event analysis using the mixed-effects Cox model didn't show a statistically significant difference between two groups for various outcomes. CONCLUSION: Presence of retained hardware around the knee may predispose the patient to a higher rate of complications particularly mechanical complications of the implant after TKA. Further studies are required to investigate impact of retained hardware around the knee in patients undergoing TKA.Level of evidence: III.