Angle-Adjustable Dynamic Hip Screw Plate for Unstable Trochanteric Fractures in Middle-Aged Patients: Mid-Term Outcomes and Return to Sport.

BACKGROUND: There are conflicting results in the literature regarding the superiority of proximal femoral nails over dynamic hip screw (DHS) plates. The primary aim of this study is to evaluate mid-term post-injury patient-reported outcome measures (PROMs) and return to sport (RTS) in middle-aged patients treated with the DHS plate for unstable trochanteric fractures. METHODS: Fifty-seven middle-aged patients (35-64 years) treated for proximal femoral fractures of type 31-A2 and 31-A3 according to the AO/OTA classification with the DMS Dynamic Martin Screw (KLS Martin Group, Jacksonville, FL, USA) between January 2017 and December 2019 were enrolled. RESULTS: Forty-nine patients were included in this retrospective study, and the average age was 54.1 years (SD 8.4). The average follow-up duration at final follow-up was 60.5 months (SD 8.6). Post-operative complications included only one case of aseptic loosening of the implant, with a complication rate of 2%. There were no infections, peri-implant fractures, or other complications reported. Two out of the forty-nine patients (4.1%) required treatment with a total hip arthroplasty due to post-traumatic arthritis. The Harris Hip Score at final follow-up was 77.1 (SD 20.1), and the Western Ontario and McMaster Universities Osteoarthritis Index was 21.6 (SD 13.7). The overall rate of RTS was 57.7%. CONCLUSIONS: Treatment with DHS for unstable trochanteric fractures is a safe option in middle-aged patients, ensuring a good functional recovery.

Finite-Element Analysis of a Novel Cephalomedullary Nail for Restricted Sliding to Reduce Risk of Implant Failure in Unstable Intertrochanteric Fractures.

OBJECTIVE: How to restrict sliding of cephalomedullary nail and rigid reconstruct medial support for unstable intertrochanteric fractures remains a challenge. This study aims to explore the feasibility of a novel cephalomedullary nail for restriction sliding and reconstruction of medial femoral support to prevent failure in unstable trochanteric fractures through finite element analysis. METHODS: The DICOM files of a unilateral femur spiral computed tomography (CT) scans from a elderly female were converted into STL files, and the most common clinical trochanteric fracture model with the absence of medial support, AO/OTA 31-A2.3 was simulated by removing the posterior medial femur. The model of a novel medial sustain nail (MSN-II) and a widely used nail (proximal femoral nail anti-rotation PFNA-II) were modeled according to the manufacturer-provided engineering drawing. Different loads were applied to the femoral head to simulate the postoperative weight bearing gait. The sliding distance of helical blade in femoral neck, maximum stress of femur and nail, displacement of proximal fragment were analyzed to revealing the mechanical stability of unstable trochanteric fracture stabilized by different implant. RESULTS: The sliding distance of helical blade in the femoral neck, the maximum stress on the femur and nail, the displacement of proximal fragment in MSN-II under 2100N axial load were 0.65 mm, 689 MPa, 1271 MPa, 16.84 mm respectively, while that were 1.43 mm, 720.8 MPa, 1444 MPa, 18.18 mm, respectively in PFNA-II. The difference between the two groups was statistically significant (P < 0.05) and the stress was mainly distributed in medial distal side of nail but helical blade and the proximal aperture for the nail in MSN-II. Compared to PFNA-II, MSN-II demonstrates biomechanical merit against femur medialization, cut-out and coax varus. CONCLUSION: The sliding distance of helical blade in femoral neck, the maximum stress on the femur and nail, and the displacement of proximal fragment of MSN-II were less than those of PFNA-II in the treatment of unstable intertrochanteric fractures. Therefore MSN-II has better stability than PFNA-II and it may have the potential to avoid femur medialization and cut out. It might be an option in unstable trochanteric fracture because of its superiority in restricted sliding and medial support reconstruction.

Primary hemiarthroplasty after unstable trochanteric fracture in elderly patients: mortality, readmission and reoperation.

BACKGROUND: Most unstable trochanteric fractures are treated with internal fixation and often with high complication rates. Hemiarthroplasty might be an alternative method in difficult condition, especially in unstable comminuted fracture in fragile bone. However, few have investigated the long-term outcomes after hemiarthroplasty for unstable trochanteric fracture. We conducted a population-based retrospective cohort study of trochanteric fracture after primary hemiarthroplasty using competing risk analysis on their long-term outcomes, including mortality, readmission and reoperation. METHODS: We studied a total of 2798 patients over 60 years old, with a mean age of 79 years, of which 68% are females and 67.23% have at least one comorbidity. They underwent a hemiarthroplasty for unstable trochanteric fracture during the period between January 1, 2000 and December 31, 2010 and were follow-up until the end of 2012, or death. Survival analysis and Cox model were used to characterize mortality. Competing risk analysis and Fine and Gray model were used to estimate the cumulative incidences of the first readmission and the first reoperation. RESULTS: The follow-up mortality rate for 1-year was 17.94%; 2-year, 29.76%; 5-year, 56.8%; and 10-year, 83.38%. The cumulative incidence of the first readmission was 16.4% for 1-year and 22.44% for 3-year. The cumulative incidence of the first reoperation was 13.87% for 1-year, 18.11% for 2-year, 25.79% for 5-year, and 38.24% for 10-year. Male gender, older age, higher Charlson Comorbidity Index (CCI) and lower insured amount were all risk factors for the overall mortality. Older age and higher CCI were risk factors for the first readmission. Older age was a protective factor for reoperation, which is likely due to the competing death. CONCLUSIONS: The mortality and revision rates after hemiarthroplasty for unstable trochanteric fracture are acceptable as a salvage procedure for this fragile sub-population.

Augmentation of intramedullary nailing in unstable intertrochanteric fractures using cerclage wire and lag screws: a comparative study.

BACKGROUND: Unstable intertrochanteric fractures present a challenge to orthopaedic surgeons, with varied geometry of the fractures and a wide choice of implants and techniques. The patients are usually osteoporotic, with multiple co-morbidities and poor tolerance for complications and re-operations. Lateral wall reconstruction and stability of the trochanteric fragments are considered important in providing a better outcome of these difficult injuries. We present a technique of lateral wall and trochanteric reconstruction using Cerclage wires and lag screws in the greater trochanter in addition to intramedullary nailing, and the radiological and functional outcome of this technique of augmentation. MATERIALS AND METHODS: This prospective study includes 154 patients from 2010 to 2015 presenting to the institute with an unstable intertrochanteric fracture. They were sequentially operated with intramedullary nailing (IMN) and augmentation with cerclage wire and/or Anteroposterior screw in greater trochanter, and 77 patients with IMN only. Operating time and need for blood transfusion post-surgery were documented. Patients were followed up for minimum of 12 months and radiological union time, complications and functional outcome using Harris Hip Score were noted at 1 year. Statistical analysis was performed to compare the results in both groups RESULTS: The mean union was 3.6 months in group A and 4.1 months in group B, with no statistically significant difference. The operating time needed for augmentation was 10 minutes more than IMN only. Blood transfusion was not required in any case. The incidence of complications like screw cut out, back out and non-union was lower in augmented group, and good functional outcome was greater in the augmented group which was statistically significant. The reoperation rate was lower in augmented group. CONCLUSIONS: This new technique of augmentation of fixation of intramedullary nail in unstable trochanteric fractures using cerclage wires and lag screws for lateral wall reconstruction is useful in reducing complications of the procedure and provides good radiological and functional outcome. It requires little additional operating time with minimal blood loss and soft tissue injury.

Comparison of the Treatment Results between Reduction with Percutaneous Wiring and Reduction without Percutaneous Wiring in Reverse Oblique Trochanteric Fractures (AO Classification 31-A3.3)

PURPOSE: The aim of this study was to investigate the utility of percutaneous wiring in the reduction of reverse oblique trochanteric fractures (AO classification 31-A3.3) by analyzing the treatment results with or without the use of percutaneous wiring. MATERIALS AND METHODS: Thirty-five cases from January 2008 to August 2014 that could be followed-up for at least one year were selected among patients with unstable trochanteric fractures who underwent either internal fixation or open reduction. Seventeen patients underwent surgery with percutaneous wire fixation but another 18 patients underwent surgery without it. All patients received a closed reduction and internal fixation with an intramedullary nail. The factors evaluated were as follows: the length of operation, loss of blood, length of in-hospital stay, lower limb function scale, return to preinjury daily life, change in femur neck shaft angle, postoperative gap of the fracture site, time taken for bone attachment, quality of post-operative reduction, and complications. RESULTS: No significant difference in the mean operative time, loss of blood, length of in hospital stay, lower limb function scale, return to pre-injury daily life, change in femur neck shaft angle, postoperative gap of the fracture site, and quality of postoperative reduction was observed between the two groups. A significant difference was noted in the time taken for bone attachment (p=0.032). Bone attachment took 13.3 weeks (9–17 weeks) on average when fixed with percutaneous wiring and no patient was found to have any complications. When treated without percutaneous wiring, however, bone attachment took 17.8 weeks (12.5–28.0 weeks) on average and three cases resulted in delayed union. CONCLUSION: Percutaneous wiring is a recommended treatment option for patients with an unstable trochanteric fracture.

What is the underlying mechanism for the failure mode observed in the proximal femoral locking compression plate? A biomechanical study.

PURPOSE: Recently, several cases of clinical failure have been reported for the Proximal Femoral Locking Compression Plate (PF-LCP). The current study was designed to explore biomechanically the underlying mechanism and to determine whether the observed failure was due to technical error on insertion or to implant design. METHODS: A foam block model simulating an unstable intertrochanteric fracture was created for 3 study groups with 6 specimens each. Group C was correctly instrumented according to the manufacturer's guidelines. In Group P and Group A, the first or second proximal screw was placed with a posterior or anterior off-axis orientation by 2° measured in the transversal plane, respectively. Each construct was cyclically tested until failure using a test setup and protocol simulating complex axial and torsional loading. Radiographs were taken prior to and after the tests. Force, number of cycles to failure and failure mode were compared. RESULTS: A screw deviation of 2° from the nominal axis led to significantly earlier construct failure in Group P and Group A in comparison to Group C. The failure mode was characterised by loosening of the off-axis screw due to disengagement with the plate, resulting in loss of construct stiffness and varus collapse of the fracture. CONCLUSIONS: In our biomechanical test setup, the clinical failure modes observed with the PF-LCP were reproducible. A screw deviation of 2° from the nominal axis consistently led to the failure. This highlights how crucial is the accurate placement of locking screws in the proximal femur.

A biomechanical evaluation of proximal femoral nail antirotation with respect to helical blade position in femoral head: A cadaveric study.

OBJECTIVE: Despite new developments in the management of osteoporotic fractures, complications like screw cutout are still found in the fixation of proximal femur fractures even with biomechanically proven better implants like proximal femoral nail antirotation (PFNA). The purpose of this cadaveric study was to investigate the biomechanical stability of this device in relation to two common positions (center-center and inferior-center) of the helical blade in the femoral head in unstable trochanteric fractures. MATERIALS AND METHODS: Eight pairs of human cadaveric femurs were used; in one group [center-center (C-C) group], the helical blade of PFNA was fixed randomly in central position both in anteroposterior and lateral view, whereas in the other group it was fixed in inferior one-third position in anteroposterior and in central position in lateral view [inferior-center (I-C) group]. Unstable intertrochanteric fracture was created and each specimen was loaded cyclically till load to failure RESULTS: Angular and rotational displacements were significantly higher within the C-C group compared to the I-C group in both unloaded and loaded condition. Loading to failure was higher in the I-C group compared to the C-C group. No statistical significance was found for this parameter. Correlations between tip apex distance, cyclic loading which lead to femoral head displacement, and ultimate load to failure showed a significant positive relationship. CONCLUSION: The I-C group was superior to the C-C group and provided better biomechanical stability for angular and rotational displacement. This study would be a stimulus for further experimental studies with larger number specimens and complex loading protocols at multicentres.

Treatment of Unstable Trochanteric Fracture Using Sliding Hip Screw with Wiring of Lesser Trochanter / 대한정형외과학회잡지

PURPOSE: To evaluate the effect of the sliding hip screw with wiring of lesser trochanter for the treatment of unstable trochanteric fractures. MATERIALS AND METHODS: we analysed retrospectively 39 cases between 1995 and 1999. All cases were followed up for more than 1 year. Using modified Watson-Jonson approach, we performed reduction of the fracture as anatomically possible extent. RESULTS: Bony union was obtained in average 6 months. Nonunion with metal failure occurred in one case. The average sliding of lag screw was 11mm. The average change of neck-shaft angle (NSA) was 1.8degrees respectively. Satisfactory NSA was achieved in 33 cases except 2 cases of varus and 4 cases of valgus both exceeding 10degrees. CONCLUSION: The sliding hip screw with wiring of lesser trochanter is a useful option for unstable trochanteric fractures because of its initial stability as buttress effect on posteromedial cortex to allow early ambulation.