Numerical evaluation of internal femur osteosynthesis based on a biomechanical model of the loading in the proximal equine hindlimb.

Femoral fractures are often considered lethal for adult horses because femur osteosynthesis is still a surgical challenge. For equine femur osteosynthesis, primary stability is essential, but the detailed physiological forces occurring in the hindlimb are largely unknown. The objective of this study was to create a numerical testing environment to evaluate equine femur osteosynthesis based on physiological conditions. The study was designed as a finite element analysis (FEA) of the femur using a musculoskeletal model of the loading situation in stance. Relevant forces were determined in the musculoskeletal model via optimization. The treatment of four different fracture types with an intramedullary nail was investigated in FEA with loading conditions derived from the model. The analyzed diaphyseal fracture types were a transverse (TR) fracture, two oblique fractures in different orientations (OB-ML: medial-lateral and OB-AP: anterior-posterior) and a "gap" fracture (GAP) without contact between the fragments. For the native femur, the most relevant areas of increased stress were located distally to the femoral head and proximally to the caudal side of the condyles. For all fracture types, the highest stresses in the implant material were present in the fracture-adjacent screws. Maximum compressive (-348 MPa) and tensile stress (197 MPa) were found for the GAP fracture, but material strength was not exceeded. The mathematical model was able to predict a load distribution in the femur of the standing horse and was used to assess the performance of internal fixation devices via FEA. The analyzed intramedullary nail and screws showed sufficient stability for all fracture types.

Comparison between intramedullary nail and conventional plate for displaced intra-articular calcaneal fractures: A meta-analysis.

OBJECTIVES: This study aimed to compare the efficacy and safety of the intramedullary nail and conventional plate for the treatment of displaced intra-articular calcaneal fractures from clinical comparative trials. MATERIALS AND METHODS: A comprehensive search of English databases was carried out in the Springer, PubMed, ScienceDirect, Web of Science, and Cochrane Library databases until September 2023. Studies on calcaneal fractures treated by an intramedullary nail or a plate were considered for inclusion. Endpoints included duration of operation, length of hospital stay, the Visual Analog Scale (VAS) score, postoperative functional score, radiological parameters, and complications. The mean difference (MD) and risk difference (RD) as the combined variables, as well as the 95% confidence intervals, (CIs) were calculated. RESULTS: Five retrospective controlled studies covering 473 feet at the one-year follow-up met the inclusion criteria. The meta-analysis demonstrated that there were significant differences in the duration of operation (MD: -10.81; 95% CI: -16.32, -5.31; p=0.0001), length of hospital stay (MD: -3.65; 95% CI: -4.35, -2.95; p<0.00001). No significant differences were found regarding postoperative American Orthopaedic Foot and Ankle Society (AOFAS) Ankle-Hindfoot Scale (MD: 0.36; 95% CI: -3.89, 4.61; p=0.87), VAS (MD: 1.95; 95% CI: -0.30, 4.21; p=0.09), or postoperative Böhler angle (MD: 0.94; 95% CI: -0.04, 1.92; p=0.06) between the two groups. The incidence of total complications (RD: -0.31; 95% CI: -0.46, -0.17; p<0.0001) and wound-healing complications (RD: -0.16; 95% CI: -0.30, -0.03; p=0.02) were lower in the intramedullary nail group. There were no significant differences in the incidences of revision surgery, implant removal, superficial wound infection, deep infection, and nonunion. CONCLUSION: Compared to conventional plates, the intramedullary nail showed a shorter duration of operation, reduced length of hospital stay, and fewer postoperative total complications and wound-healing complications in treating displaced intra-articular calcaneal fractures.

Finite element analysis of the stability of retrograde intramedullary nail and plate-screw combinations for periprosthetic femoral fractures following total knee replacement.

OBJECTIVE: Periprosthetic fractures following total knee replacement are rare but challenging. The goal of the treatment is to achieve the most stable fixation that allows early mobilization. Therefore, the aim of this study was to evaluate the biomechanical results of the use of different fixation systems in the treatment of distal femur periprosthetic fractures with finite element analysis. MATERIALS AND METHODS: A total knee prosthesis was implanted in Sawbone femur models. A transverse fracture line was created in the supracondylar region and was fixed in four different groups. In group 1, fracture line fixation was fixed using retrograde intramedullary nailing. In group 2, fixation was applied using a lateral anatomic distal femoral. In group 3, in addition to the fixation made in group 1, a lateral anatomic distal femoral plate was used. In group 4, in addition to the fixation made in group 2, a 3.5 mm Limited Contact Dynamic Compression Plate (LC-DCP) was applied medially. Computed Tomography (CT) scans were taken of the created models and were converted to three-dimensional models. Axial and rotational loading forces were applied to all the created models. RESULTS: The least deformation with axial loading was observed in the double plate group. Group 3 was determined to be more advantageous against rotational forces. The greatest movement in the fracture line was found in group 2. The application of the medial plate was determined to reduce the tension on the lateral plate and increase stability in the fracture line. CONCLUSIONS: Combining a lateral anatomic plate with intramedullary nailing or a medial plate was seen to be biomechanically more advantageous than using a lateral plate or intramedullary nailing alone in the treatment of distal femoral periprosthetic fractures.

Unravelling variations: an examination of entry point selection in proximal femoral cephalomedullary nailing.

BACKGROUND: The exact positioning of the cephalomedullary (CM) nail entry point for managing femoral fractures remains debatable, with significant implications for fracture reduction and postoperative complications. This study aimed to explore the variability in the selection of the entry point among trauma surgeons, hypothesizing potential differences and their association with surgeon experience. METHODS: In this prospective multicenter study, 16 participants, ranging from residents to senior specialists, partook in a simulation wherein they determined the optimal entry point for the implantation of a proximal femoral nail antirotation (PFN-A; DePuy Synthes) in various femora. The inter- and intra-observer variability was calculated, along with comprehensive descriptive statistical analysis, to assess the variability in entry point selection and the impact of surgeon experience. RESULTS: In this study, the mean distance from the selected entry points to the calculated mean entry point was 3.98 mm, with a smaller distance observed among surgeons with more than 500 implantations (ANOVA, p = 0.050). Intra-surgeon variability for identical femora averaged at 5.14 mm, showing no significant differences across various levels of surgical experience or training. Notably, 13.6% of selected entry points would not allow a proper intramedullary positioning of the implant, thereby rendering anatomical repositioning unfeasible. Among these impossible entry points, a significant skew towards anterior placement was observed (70.6% of the impossible entry points), with a smaller fraction being overly lateral (27.5%) or medial (13.7%). On a patient level, the impossibility rate varied widely from 0 to 35% among the different femora examined, with a significantly higher rate seen in younger patients (mean age 55.02 versus 60.32; t-test for independent samples, p = 0.04). CONCLUSIONS: Significant variations exist in surgeons' selection of entry points for proximal femoral nailing, underscoring the task's complexity. Experience does not prevent the choice of unfeasible entry points, emphasizing the inadequacy of a universal approach and pointing towards the necessity for a patient-specific strategy for improved outcomes. TRIAL REGISTRATION NUMBER: DRKS00032465.

Percutaneous intramedullary screw or rush pin fixation of unstable ankle fractures in patients with fragile soft tissue - retrospective study of 80 cases.

INTRODUCTION: The standard surgical procedure for unstable ankle fractures is fixation of the lateral malleolus with a plate and screws. This method has a high risk of complications, especially among patients with fragile skin conditions. The aim of this study was to estimate the re-operation rates and identify complications in patients with an unstable ankle fracture, surgically treated with an intramedullary screw or rush pin. MATERIALS AND METHODS: We identified all patients who were surgically treated with either a 3.5-mm screw or rush pin at Aarhus University Hospital, Denmark, from 2012 to 2018. Major complications were re-operations within three months. We included 80 patients, of which 55 (69%) were treated with a 3.5-mm intramedullary screw and 25 (31%) with a rush pin. The majority of the study population was female (59) and the mean age was 75 (range 24 to 100) years. Of the 80 patients included, 41 patients had more than 2 comorbidities. RESULTS: Three patients underwent re-operation within three months due to either fracture displacement or hardware cutout. Radiographs obtained after six weeks showed that nine patients had loss of reduction. Additionally, four patients had superficial wound infections and six patients had delayed wound healing. CONCLUSIONS: Intramedullary fixation of distal fibula fractures with either a screw or rush pin has low re-operation rates. However, the high proportion of patients with radiological loss of reduction is concerning.

[Comparative study of minimally invasive titanium elastic nail and steel plate on the treatment of fracture of tibiofibular fracture in adults].

OBJECTIVE: To compare the clinical outcomes of using elastic intramedullary nail and plate to fix fibular fracture. METHODS: The 60 patients with tibiofibular fractures admitted from January 2015 to December 2022 were divided into two groups:intramedullary nail group and plate group, 30 cases each, intramedullary nail group was treated with elastic intramedullary nail fixation group, plate group was treated with steel plate and screw fixation group. Intramedullary nail group, there were 18 males and 12 females, aged from 22 to 75 years old with an average of (39.4±9.8) years old, including 24 cases of traffic accidents injury, 6 cases of falling injury, 23 cases of closed fractures, 7 cases of open fractures. Steel plate group, there were 15 males and 15 females, aged from 24 to 78 years old with an average of (38.6±10.2) years old. The 22 cases were injured by traffic accident, 8 cases were injured by falling. The 24 cases were closed fractures and 6 cases were open fractures. The operation time, intraoperative bleeding, American Orthopedic Foot and Ankle Society (AOFAS) ankle and hind foot scores, clinical healing time of fibula and the incidence of wound complications were compared between the two groups. RESULTS: The patients in both groups were followed up for 6 to 21 months, with an average of (14.0±2.8) months. Compared with plate group, intramedullary nail group had shorter operative time, less bleeding, shorter clinical healing time of fibula, and lower infection rate of incision, and the difference was statistically significant (P<0.05). There were 2 cases of delayed healing in intramedullary nail group, 1 case of nonunion in plate group, and 2 cases of delayed healing in plate group, and there was no statistically significant difference between the two groups (P>0.05). In the last follow-up, according to the AOFAS scoring standard, the ankle function in intramedullary nail group was excellent in 17 cases, good in 12 cases, fair in 1 case, with an average of (88.33±4.57) points, while in plate group, excellent in 16 cases, good in 10 cases, fair in 4 cases, with an average of (87.00±4.14) points;There was no statistical difference between the two groups (P>0.05). CONCLUSION: Elastic intramedullary nail has the advantages of short operation time, less intraoperative bleeding, short fracture healing time and less incision complications in the treatment of fibular fracture, which is worthy of clinical application.

Treatment of presumed aseptic non-union of the humeral shaft by osteosynthesis combining intramedullary nailing and screw plate.

In 2020, the most common treatment for presumed aseptic non-union of the humeral shaft seems to be decortication, often associated with bone autografting, and stabilized by a screw plate. We propose to evaluate an original technique of rigid osteosynthesis combining intramedullary nailing and screw plate. Between January 2004 and January 2020, 45 patients underwent treatment of presumed aseptic non-union of the humeral shaft by osteosynthesis combining intramedullary nailing and a screw plate. The minimum radio-clinical follow-up was one year postoperatively. The series included 19 men and 26 women with a mean age of 53 years (range 19-84 years). Bone consolidation was achieved in 43 patients, a rate of 95.5%. Comparing patients who achieved bone consolidation with the two failed consolidations did not reveal any statistically significant factor. Interobserver agreement was almost perfect (k=0.93) for the use of the RUST for humeral shaft fractures treated with intramedullary nailing and screw plate. In our study, the treatment of presumed aseptic non- union of the humeral shaft with an osteosynthesis combining intramedullary nailing and screw plate gives, with 95.5% of bone consolidation, results equal to or even superior to the different treatments currently described in the literature.

Evaluation of the mechanical behaviour of the expandable wedge locked nail fixation in retrograde use: A finite element study.

INTRODUCTION: In literature, there have been many studies conducted to research the alternatives of standard interlocking intramedullary nailing. The expandable wedge locked nail fixation, which is thought as a new alternative to the standard interlocking nailing, has been presented in previous numerical studies. The antegrade usage of the wedge locked nail fixation has provided promising results. From this point, the aim of the study is to evaluate mechanical behavior of its retrograde usage on femur models. Additionally, another aim of the study is to investigate the effect of fracture level on mechanical properties of the fixation. MATERIALS AND METHODS: The mechanical behaviors of the wedge locked nail and standard interlocking nail fixations were compared by finite element methods. Sawbones femurs having osteotomies at five different levels to simulate different fractures were fixed with wedge locked nail or interlocking nail by using retrograde approach. With respect to the fracture level, two different nail lengths were used. Axial compression load was applied to fixations. The mechanical behaviors of the fixations were evaluated with respect to stiffness of the fixations and stresses occurred on both implants and bones. RESULTS: Any of the wedge locked nail fixation did not slip at canal. The stress and stiffness results were mostly close with each other for both nail types. The maximum stresses at locking elements or bones contacting these elements increased with decreased distance between the fracture and relevant locking elements. DISCUSSION: The wedge locked nail fixation showed comparable results to the standard interlocking nail fixation with respect to the stiffness and stress. Under axial loading, wedge locked nail provided a secured fixation without any slippage and preserved its position inside the medullary canal. It may be thought as a safe alternative to the standard interlocking nail fixation for retrograde usage. Additionally, according to stress results, it is advised to the surgeons to avoid a close locking to the fracture line.

Comparative Outcomes of Elastic Stable Intramedullary Nailing vs. Plate Fixation in Pediatric Femoral Shaft Fractures. A Prospective Study.

BACKGROUND: Pediatric femoral fractures are common in emergency rooms, with treatment options varying by age. This study compares elastic stable intramedullary nailing (ESIN) and plate fixation for diaphyseal femoral fractures in children aged 5-10. MATERIAL AND METHODS: Conducted at Al-Kindi Teaching Hospital, Baghdad, from December 2017 to December 2019, this prospective study included 32 children with closed transverse diaphyseal femoral fractures. Patients were divided into two groups: 16 treated with ESIN (Group 1) and 16 with plate fixation (Group 2). Criteria excluded comminuted, open, or pathological fractures. RESULTS: Group 1 had a mean age of 7.1 years and weight of 23.7 kg; Group 2 had a mean age of 7.8 years and weight of 30.9 kg. ESIN resulted in shorter operative times (58.4 minutes), earlier weight-bearing, and quicker fracture union (8.8 weeks) compared to plate fixation (76.3 minutes, 11.9 weeks). Blood loss was significantly less in Group 1 (32.8 ml) versus Group 2 (205.0 ml). No significant differences in wound healing or leg length discrepancies were observed. CONCLUSIONS: 1. Our study indicates a preference for Elastic Stable Intramedullary Nailing (ESIN) over plate fixation for pediatric femoral shaft fractures in children aged 5-10 years. 2. ESIN is associated with shorter operative times and faster commencement of weight-bearing, critical in pediatric recovery. 3. While ESIN is generally preferable, plate fixation may be better suited in certain clinical scenarios, emphasizing the importance of personalized treatment. 4. Based on our findings, ESIN is recommended for treating transverse diaphyseal femur fractures in the specified pediatric age group. 5. Recommends further studies, including randomized controlled trials, for a more comprehensive understanding of these treatments' long-term outcomes.

Is Elastic Stable Intramedullary Nailing a Viable Treatment Option for Diaphyseal Fractures of the Humerus in Adults? A 29-case Series Prospective Study.

BACKGROUND: Humerus shaft fractures are common in orthopaedic practice. The emphasis in treatment has shifted from prolonged immobilisation to early mobilisation and internal fixation when needed for a quicker return to normal function. Internal fixation methods include plate osteosynthesis and intramedullary nailing. This study specifically evaluated the effectiveness of flexible intramedullary nails in treating diaphyseal humeral fractures. MATERIAL AND METHODS: Between April 2007 and January 2010, Alexandria University Hospital treated 29 patients (21 males, 8 females) with diaphyseal humeral fractures. Treatment involved closed reduction and percutaneous fixation using two flexible nails. Patients, aged 17 to 65 with a mean age of 32, were included if they did not have pathological fractures, were above 16 years old, and were medically suitable. Causes included pedestrian vehicle accidents (17 cases) and falls or sports-related activities (12 cases). Surgical intervention occurred 1 to 8 days after the injury. RESULTS: Between April 2007 and January 2010, Alexandria University Hospital treated 29 patients (21 males, 8 females) for diaphyseal humeral fractures using closed reduction and percutaneous fixation with two flexible nails. Patients, aged 17 to 65, were monitored for an average of 18 months. Radiographic assessments showed complete union in nineteen fractures within 13 to 21 weeks. One patient experienced non-union but was successfully treated with bone grafting and plating. There were no significant intraoperative complications. Notably, four patients with preoperative radial nerve injuries recovered within 6 to 8 weeks. Evaluation using the Stewart and Hundley Scoring technique showed excellent outcomes for 60% of patients, good outcomes for 30%, fair outcomes for 5%, and poor outcomes for 5%. CONCLUSIONS: 1.The Elastic Stable Intramedullary Nailing (ESIN) technique shows promise in the treatment of humeral shaft fractures. 2. However, the success of treatment may depend on various factors, including patient age, fracture characteristics, and the presence of complications such as open fractures and radial nerve palsy. 3. Careful consideration of these factors is necessary when selecting a treatment approach for humeral shaft fractures.

Comparative study of retrograde intramedullary nailing versus locking extramedullary plating in complete articular fractures with metaphyseal comminution of the distal femur.

INTRODUCTION: Fractures of the distal femur with metaphyseal comminution and complete intra-articular involvement (AO/OTA classifications 33C2 and 33C3) present challenges for reduction and fixation. However, an optimal fixation method remains unknown. This study aimed to compare the clinical and radiographic outcomes of locking extramedullary plating (LEP) and retrograde intramedullary nailing (RIN) for complete distal femoral intra-articular fractures with metaphyseal comminution. MATERIALS AND METHODS: Between January 2016 and May 2022, 80 patients (45 men and 35 women; average age, 56.7 years) diagnosed with AO/OTA 33C2 and 33C3 were treated with either LEP or RIN and followed up for at least one year. Post-operative evaluations included radiographic assessments of bone union rate, timing, and alignment. Clinically, the knee joint range of motion (ROM), lower extremity functional scale (LEFS), and Kellgren and Lawrence (KL) grade were analyzed. The complications were also compared. RESULTS: 36 underwent LEP and 44 underwent RIN. Bone union was observed in 69.4% and 63.6% of the patients in the LEP and RIN groups, respectively (p = 0.64). The average union time was 6.9 months for the LEP group and 6.6 months for the RIN group (p = 0.51). A tendency toward varus deformity was observed in the RIN group, although the difference was not statistically significant. No significant differences were observed in knee ROM, LEFS, or KL grade. Complications included non-union (33.8%; RIN, 11; LEP, 16), varus deformity (5%; RIN, 4; LEP, 0), infection (1.3%; RIN, 0; LEP, 1), heterotrophic ossification (1.3%; RIN, 0; LEP, 1), and wound dehiscence (2.5%; RIN, 2; LEP, 0). CONCLUSIONS: The surgical fixation methods, RIN and LEP, for complete distal femoral intra-articular fractures with metaphyseal comminution showed similar clinical and radiological outcomes. However, regardless of the type of fixation device used, there was a reduced rate of bone union owing to high energy and a less favorable prognosis.

Laterally Protruded Cephalomedullary Nail Lag Screws are a Source of Consistent Thigh Pain After Pertrochanteric Fracture.

OBJECTIVES: To assess the correlation between the amount of proximal screw lateralization and clinical symptoms in patients treated with a cephalomedullary nail (CMN) after a pertrochanteric fracture. DESIGN: Retrospective study. SETTING: Level 1 trauma center. PATIENT SELECTION CRITERIA: Patients operated for a pertrochanteric fracture (OTA/AO A1, A2, A3) between 2019 and 2022 and treated with a CMN were included. OUTCOME MEASURES AND COMPARISONS: Three measurements were evaluated: D1 distance between the most laterally prominent point of the lag screw and the line tangent to the greater trochanter, D2 distance between the lateral femoral cortex and the most laterally prominent point of the lag screw, and D3 distance between the point where the lag screw emerges at the lateral edge of the femur shaft and the skin's surface. Clinical scores and information regarding lateral thigh pain were obtained, and a correlation analysis was performed. RESULTS: Mean age of the study cohort (n = 134) was 77.9 ± 12.3 years. Patients with categorical protrusion (considered present in cases where the distance between the lateral tip of the lag screw and the lateral border of the greater trochanter was ≥0.2 mm) had significantly higher rates of lateral thigh pain ( P = 0.007) and discomfort while lying on the side ( P = 0.032) compared with those without protrusion. Correlation analyses showed a positive correlation between measurements D1 and D2 and lateral thigh pain (r = 0.324 and r = 0.334, respectively, P < 0.001) and a negative correlation between D3 and lateral thigh pain (r = -0.286, P = 0.001). Regression analysis showed that higher D1 and D2 distances and shorter D3 distances are risk factors for lateral thigh pain ( P = 0.001, 0.001, and 0.002, respectively). CONCLUSIONS: Increasing lateral protrusion of the lag screw leads to significantly greater clinical complaints and lateral hip pain in patients treated with a CMN. Patients with lower distance between the lateral femoral wall and the skin are at higher risk of lateral pain. LEVEL OF EVIDENCE: Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Early Complications of a Novel Retrograde Intramedullary Femoral Nail in the Treatment of Femur Fractures.

OBJECTIVES: To determine the early implant failure rate of a novel retrograde intramedullary femoral nail. DESIGN: Retrospective cohort study. SETTING: Academic level 1 trauma center. PATIENTS SELECTION CRITERIA: Patients aged 18 years and older with an acute OTA/AO 32-A, 32-B, 32-C, and 33-A fractures or periprosthetic distal femur fracture from April 2018 to April 2022 were included in the study. The 2 interventions compared were the Synthes Expert retrograde/antegrade femoral nail (or control implant) versus the next-generation retrograde femoral nail (RFN)-advanced retrograde femoral nail (RFNA or experimental implant) (Synthes, West Chester, PA). OUTCOME MEASURES AND COMPARISONS: Early implant-related complications between the experimental and control implants were assessed including locking screw back out, screw breakage, intramedullary nail failure, need for secondary surgery, and loss of fracture reduction. RESULTS: Three hundred fourteen patients were identified with a mean age of 31.0 years, and 62.4% of the patients being male. Open fractures occurred in 32.5% of patients with 3.8% of injuries being distal femur periprosthetic fractures. Fifty-six patients were in the experimental group and 258 patients in the control group. Mean follow-up was 46.8 weeks for the control cohort and 21.0 weeks for the experimental cohort. Distal interlocking screw back out occurred in 23.2% (13 of 56) of the experimental group patients and 1.9% (5 of 258) of the control group patients ( P < 0.0001). Initial diagnosis of interlocking screw back out occurred at an average of 3.2 weeks postoperatively (range, 2-12 weeks). Fifty-four percent of patients who sustained screw back out underwent a secondary operation to remove the symptomatic screws (12.5% of all patients treated with the experimental implant required an unplanned secondary operation due to screw back out). A logistic regression model was used to predict screw back out and found the experimental implant group was 4.3 times as likely to experience distal locking screw back out compared with the control group ( P = 0.01). CONCLUSIONS: The retrograde femoral nail-advanced implant was associated with a significantly higher rate of screw back out with a substantial number of unplanned secondary surgeries compared with the previous generation of this implant. LEVEL OF EVIDENCE: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Comparison of ESIN and other minimally invasive techniques for anterior pelvic ring injury: a finite element analysis and case-control study.

OBJECT: A novel technique, percutaneous elastic stable intramedullary nail fixation (ESIN), proposed by our team for the treatment of anterior pelvic ring injury. Finite element analysis and retrospective case-control study were used to compare biomechanical properties and clinical outcomes between ESIN and other techniques. METHODS: Four groups of finite element models of pelvic anterior ring injury were simulated, including ESIN (model A), retrograde transpubic screw fixation (RTSF, model B), subcutaneous internal fixator (model C), and external fixator (model D), and a vertical downward load of 500 N was applied to the S1 vertebral endplate. Stress and displacement distributions of intact pelvis, displacement distributions of pubic fracture fragments, and stress distributions of fixation devices were analysed. Then 31 patients with anterior pelvic ring injury (15 in the ESIN group and 16 in the RTSF group) were reviewed. Clinical outcomes were evaluated at the final follow-up. Postoperative complications were also recorded. RESULTS: Under 500N loading, the intact stability of the pelvis was compared as follows: model B (20.58 mm, 121.82 MPa), model A (20.80 mm, 129.97 MPa), model C (22.02 mm, 141.70 MPa), and model D (22.57 mm, 147.06 MPa). The regional stability of superior pubic ramus was compared as follows: model B (9.48 mm), model A (10.16 mm), model C (10.52 mm), and model D (10.76 mm). All 31 patients received follow-up at least 12 months postsurgery (range 12-20 months). Age, sex, injury mechanism, fracture type, time between the injury and operation, American Society of Anesthesiologists score, intraoperative blood loss, hospital stay, follow-up period, time to union, and Majeed scores did not differ significantly between the two groups ( P >0.05). However, the differences in the duration of unilateral surgery, unilateral intraoperative fluoroscopy and one-time success rate were significant ( P <0.05). CONCLUSIONS: With sufficient biomechanical stability and minimally invasive advantage, the percutaneous technique using ESIN can be used to successfully treat anterior pelvic ring injuries. In addition, advantages over RTSF include a shorter duration of surgery, reduced requirement for intraoperative fluoroscopy, and a higher one-time success rate. ESIN therefore constitutes a good alternative to RTSF.

Antibiotic cement-coated rigid locked nails in infected femoral and tibial nonunion. Reoperation rates of commercial versus custom-made nails.

INTRODUCTION: The objective of this study is to assess bone union, infection control, and reoperation rates in a series of patients with infected femoral or tibial nonunion treated with antibiotic-cement-coated rigid nails and to compare the results obtained with custom-made nails versus commercial nails. METHODS: We retrospectively analyzed a series of consecutive patients with infected nonunion of the femur or the tibia treated with antibiotic-cement-coated rigid nails between January 2010 and 2020. We assessed patients' distinctive characteristics, initial injury, type of nail used (custom-made nail with vancomycin or commercial nail with gentamicin), success rate (bone union + infection control), reoperation rate, and failure rate. Comparative analyses were conducted between reoperated and non-reoperated patients regarding the type of nail used. A multivariate regression analysis was performed to assess the risk variables that impacted reoperation rates. RESULTS: We included 54 patients with 22 (40.74%) infected femoral nonunions and 32 (59.25%) tibial nonunions, who were treated with 38 (70.37%) custom-made antibiotic-cement coated nails and 16 (29.62%) commercial nails. Bone union and infection control were achieved in 51 (94.44%) cases. The reoperation rate was 40.74% (n = 22), and the failure rate was 5.55% (n = 3). The use of custom-made nails was associated with a higher risk of reoperation (Odds Ratio 4.71; 95% Confidence Interval 1.10 - 20.17; p = 0.036). CONCLUSION: Antibiotic-cement-coated nails reached a 94.44% success rate. Nails manufactured in the OR coated with vancomycin cement were associated with a higher risk of reoperation than commercial nails loaded with gentamicin cement. LEVEL OF EVIDENCE: III comparative, observational, non-randomized.

Biomechanical Study of Intramedullary Versus Extramedullary Implants for Four Types of Subtrochanteric Femoral Fracture.

OBJECTIVES: To compare the biomechanical performance of proximal femoral nail anti-rotation (PFNA), the "upside-down" less invasive plating system (LISS), and proximal femoral locking plate (PFLP) in fixing different fracture models of subtrochanteric fractures. METHODS: Thirty composite femurs were divided into three equal groups (PFNA, PFLP, and reverse LISS). The implant-femur constructs were tested under axial compression load (0-1400 N) from models I to IV, which represented the Seinsheimer type I subtrochanteric fracture, type IIIa subtrochanteric fracture with the posteromedial fragment reduced; type IIIa subtrochanteric fracture with the posteromedial fragment lost; and type IV subtrochanteric fracture, respectively. Axial stiffness was analyzed for each group. Each group was then divided into two subgroups, one of which underwent torsional and axial compression failure testing, while the other subgroup underwent axial compression fatigue testing. The torsional stiffness, failure load, and cycles to failure were analyzed. RESULTS: PFNA had the highest axial stiffness (F = 761.265, p < 0.0001) and failure load (F = 48.801, p < 0.0001) in model IV. The axial stiffness and failure load of the PFLP were significantly higher than those of the LISS (p < 0.0001, p = 0.001). However, no significant difference in axial stiffness was found between models I to III (model I: F = 2.439, p = 0.106; model II: F = 2.745, p = 0.082; model III: F = 0.852, p = 0.438) or torsional stiffness in model IV (F = 1.784, p = 0.187). In fatigue testing, PFNA did not suffer from construct failure after 90,000 cycles of axial compression. PFLP and LISS were damaged within 14,000 cycles, although LISS withstood more cycles than PFLP (t = 3.328, p = 0.01). CONCLUSION: The axial stiffness of the three implants was similar in models I to III. The biomechanical properties of PFNA were the best of the three implants in terms of axial stiffness, failure load, and fatigue testing cycles in model IV. The axial stiffness and failure load of the PFLP were better than those of the reverse LISS, but PFLP had fewer cycles in the fatigue tests than the reverse LISS.

Intramedullary nail versus sliding hip screw for stable and unstable trochanteric and subtrochanteric fractures : 17,341 patients from the Norwegian Hip Fracture Register.

AIMS: The aim of this study was to investigate if there are differences in outcome between sliding hip screws (SHSs) and intramedullary nails (IMNs) with regard to fracture stability. METHODS: We assessed data from 17,341 patients with trochanteric or subtrochanteric fractures treated with SHS or IMN in the Norwegian Hip Fracture Register from 2013 to 2019. Primary outcome measures were reoperations for stable fractures (AO Foundation/Orthopaedic Trauma Association (AO/OTA) type A1) and unstable fractures (AO/OTA type A2, A3, and subtrochanteric fractures). Secondary outcome measures were reoperations for A2, A3, and subtrochanteric fractures individually, one-year mortality, quality of life (EuroQol five-dimension three-level index score), pain (visual analogue scale (VAS)), and satisfaction (VAS) for stable and unstable fractures. Hazard rate ratios (HRRs) for reoperation were calculated using Cox regression analysis with adjustments for age, sex, and American Society of Anesthesiologists score. RESULTS: Reoperation rate was lower after surgery with IMN for unstable fractures one year (HRR 0.82, 95% confidence interval (CI) 0.70 to 0.97; p = 0.022) and three years postoperatively (HRR 0.86, 95% CI 0.74 to 0.99; p = 0.036), compared with SHS. For individual fracture types, no clinically significant differences were found. Lower one-year mortality was found for IMN compared with SHS for stable fractures (HRR 0.87; 95% CI 0.78 to 0.96; p = 0.007), and unstable fractures (HRR 0.91, 95% CI 0.84 to 0.98; p = 0.014). CONCLUSION: This national register-based study indicates a lower reoperation rate for IMN than SHS for unstable trochanteric and subtrochanteric fractures, but not for stable fractures or individual fracture types. The choice of implant may not be decisive to the outcome of treatment for stable trochanteric fractures in terms of reoperation rate. One-year mortality rate for unstable and stable fractures was lower in patients treated with IMN. Cite this article: Bone Joint J 2022;104-B(2):274-282.

New tip-apex distance and calcar-referenced tip-apex distance cut-offs may be the best predictors for cut-out risk after intramedullary fixation of proximal femur fractures.

Cut-out is one of the most common mechanical failures in the internal fixation of trochanteric hip fractures. The tip-apex distance (TAD), and the calcar-referenced tip apex distance (CalTAD) are the radiographic parameters that most predict the risk of cut-out. The optimal CalTAD value has not yet been defined, but the optimal TAD value is reported as 25 mm or less. However, this cut-off is highly specific but poorly sensitive. The aim of this study was to determine highly specific and sensitive TAD and CalTAD values and shed light on the role of other clinical variables. A total of 604 patients were included in this retrospective cross-sectional study. For each patient the following data were recorded: number of cut-out, AO/OTA classification, quality of the reduction, type of nail, cervicodiaphyseal angle, type of distal locking, post-operative weight-bearing, TAD and CalTAD values, and the position of the screw head in the femoral head according to the Cleveland system. The incidence of cut-out across the sample was 3.1%. The median TAD in the cut-out group was 38.72, while in the no cut-out group it was 22.16. The median CalTAD in the cut-out group was 39.34, while in the no cut-out group it was 22.19. The cut-off values for TAD and CalTAD with highest value of sensitivity and specificity for the risk of cut-out were 34.8 and 35.2, respectively. The incidence of cut-out can be reduced by performing careful minimal reduction and ensuring stable fixation by avoiding TAD > 34.8 mm and CalTAD > 35.2 mm.

Comparison of Minimally Invasive Fixation of Mid-Shaft Clavicular Fractures with Threaded Elastic Intramedullary Nail (TEIN) and Elastic Locking Intramedullary Nail (ELIN).

OBJECTIVE: To compare the effectiveness of threaded elastic intramedullary nail and elastic locking intradullary nail (ELIN) for mid-shaft clavicular fractures. METHODS: The clinical data of 47 patients with middle clavicle fracture treated by TEIN and ELIN from August 2017 to March 2019 were analyzed retrospectively. Twenty-three patients received intramedullary fixation treatment with ELIN, nine males and 14 females, AO/OTA fracture classification type 2A (n = 17) and 2B (n = 6). Twenty-four patients received intramedullary fixation treatment with TEIN, including nine males and 15 females, AO/OTA classification: type 2A (n = 18) and 2B (n = 6). All patients were anesthetized with ipsilateral cervical plexus block. After internal fixation was removed, the clinical outcomes were assessed and evaluated. The Constant-Murley score and disabilities of the arm, shoulder and hand questionnaire (DASH) score were compared between the two groups to evaluate the functional status of all patients. The study was done accordingly to the guidelines provided by the ethics committee. RESULTS: All patients in the two groups completed the operation successfully and were followed up. In the ELIN group, the operation time was 20.78 ± 7.71 min, intra-operative blood loss was 13.26 ± 9.72 mL, incision length was 1.60 ± 0.92 cm, internal fixation removal time was 12.86 ± 2.24 weeks, Constant-Murley score was 99.30 ± 1.36 points and DASH score was 1.43 ± 3.00 points. In the TEIN group, the operation time, intra-operative blood loss, incision length, internal fixation removal time, Constant-Murley and DASH scores were 22.83 ± 8.17 min, 22.08 ± 11.22 mL, 2.48 ± 0.84 cm, 15.66 ± 5.58 weeks, 95.79 ± 7.38 point and 6.69 ± 11.55 point respectively. In the ELIN group, four cases developed skin irritation, and the symptoms were relieved after removal of internal fixation. In the TEIN group, one patient's internal fixation broke and had an obvious scar at the incision, but there was no fracture after replacement of internal fixation; withdrawal of TEIN occurred in four patients, the nail did not shift again until the last follow-up; skin irritation and temporary bursitis occurred in six patients, and the symptoms were relieved after internal fixation was removed. No other conditions were found in the patients, and bony healing was achieved in all patients. CONCLUSION: ELIN prevents shortening and malunion of the clavicle, reduces secondary damage to related tissues, and leads to restoration of clavicle length and faster osseous healing.