Femoral neck fractures after internal fixation of trochanteric fractures with implants in situ in adults: A systematic review

Hip fractures following intramedullary nailing fixation for femoral fractures

INTRODUCTION

Proximal peri-implant femoral fractures occur following intramedullary nailing (IMN) fixation for trochanteric, femoral shaft, and distal femoral fractures. However, analyses of secondary hip fractures (SHFs) using large clinical samples are lacking. Therefore, we aimed to report the incidence and clinical outcomes of SHF after nailing fixation (IMN or cephalomedullary nailing [CMN]) for overall femoral fractures. In addition, we focused on IMN for femoral shaft fractures and investigated the risk factors for SHF.

METHODS

This multicenter, retrospective, cohort study included 2,293 patients aged > 60 years who underwent nailing fixation for femoral fractures. The primary outcome was the incidence of SHF. In the assessment of clinical outcomes, we evaluated reoperation and the regaining of walking ability following SHF management. In addition, we conducted multivariable logistic regression analyses to examine the association between risk factors and SHF.

RESULTS

Seventeen (0.7%) patients had SHFs, including 12 femoral neck fractures and 5 trochanteric fractures. Antegrade IMN was the most common type of nailing fixation. Multivariable analysis demonstrated that the absence of femoral head fixation was significantly associated with the incidence of SHF following IMN for femoral shaft fractures (odds ratio, 17.0; 95% confidence interval, 1.9-2265.7; p=0.006). In the assessment of clinical outcomes, there were two reoperations (16.7%) in the secondary femoral neck fracture group. Patients with secondary trochanteric fractures tended to have a lower probability of regaining walking ability than those with secondary femoral neck fractures (20% vs. 50%).

CONCLUSIONS

In this multicenter study, the incidence of SHF after nail fixation for femoral fractures was 0.7%. The absence of femoral head fixation was significantly associated with SHF, and the clinical outcomes were poor. Therefore, femoral head fixation at the initial IMN fixation for femoral fractures may be a fixation option for surgeons to consider as an SHF prevention measure.

Research Update on Stress Riser Fractures

Stress fractures are fatigue-induced fractures which are caused by repetitive force, often from overuse. They are well-established and frequently encountered in the field of orthopedics. Stress fractures occur in the bone because of low-bone strength and high chronic mechanical stress placed on the bone. Stress riser fractures are also stress fractures that occur because of the presence of cortical defects (holes), changes in stiffness, sharp corners, and cracks (fracture lines). Periprosthetic or peri-implant fractures are good examples of stress riser fractures that occur in regions where stress forces are higher than those in the surrounding material. Most stress riser fractures are related to technical errors (iatrogenic causes) and are difficult to manage. It is possible and more effective to prevent the creation of stress riser fractures through better surgical techniques. The proper terminology for stress fractures, stress riser fractures, periprosthetic fractures, peri-implant fractures, interprosthetic fractures, and interimplant fractures is discussed. This review of the current state of knowledge, diagnosis, treatment, and prevention of stress riser fractures is based on clinical evidence and recent literature.

Complications of implant removal after healed hip fractures

INTRODUCTION

Osteosynthesis of pertrochanteric fractures is one of the most frequently performed procedures in orthopaedic trauma care. Auto-dynamization during fracture healing can lead to lateralization of the screw or blade. This can cause debilitating complaints, which sometimes necessitate the removal of the screw or blade. After removal of the implant, we observed spontaneous femoral neck fractures in five patients. This article presents an evaluation of these cases with reference to literature.

MATERIALS AND METHODS

Five cases of spontaneous femoral neck fracture (SFNF) after cephalomedullary nail removal are described. A literature search was performed on the incidence of chronic pain and gait impairment associated with auto-dynamization, and on risk factors for dynamization and complications after implant removal. Based on these findings recommendations are made for the prevention of SFNF.

RESULTS

Over a 2-year period, we observed five cases of SFNF after cephalomedullary nail removal. In literature, reduced mobility, gait impairment and chronic pain are associated with screw or blade dynamization. Pertrochanteric fractures with AO-type 2 classification were associated with more dynamization and screw lateralization and henceforth more trochanteric pain and gait disturbances. SFNF after cephalomedullary nail removal occurs with an incidence of at least 15%, affecting mostly elderly patients. This severe complication mostly occurs within 3 weeks after implant removal. Risk factors associated with SFNF are pre-existing systemic osteoporosis, stress-shielding, pre-loading of the implant and nail removal of the cephalomedullary implant.

CONCLUSION

The clinical indications for implant removal in healed pertrochanteric fractures are not well established and should be restricted to specific cases. After removal of these implants without replacement partial weight-bearing should be advised strictly. Based on our findings it is recommended to replace the cephalomedullary nail with a shorter one, ideally combined with implant augmentation.

Biomechanics of Osteoporotic Fracture Fixation

PURPOSE OF REVIEW

Fractures of osteoporotic bone in elderly individuals need special attention. This manuscript reviews the current strategies to provide sufficient fracture fixation stability with a particular focus on fractures that frequently occur in elderly individuals with osteoporosis and require full load-bearing capacity, i.e., pelvis, hip, ankle, and peri-implant fractures.

RECENT FINDINGS

Elderly individuals benefit immensely from immediate mobilization after fracture and thus require stable fracture fixation that allows immediate post-operative weight-bearing. However, osteoporotic bone has decreased holding capacity for metallic implants and is thus associated with a considerable fracture fixation failure rate both short term and long term. Modern implant technologies with dedicated modifications provide sufficient mechanical stability to allow immediate weight-bearing for elderly individuals. Depending on fracture location and fracture severity, various options are available to reinforce or augment standard fracture fixation systems. Correct application of the basic principles of fracture fixation and the use of modern implant technologies enables mechanically stable fracture fixation that allows early weight-bearing and results in timely fracture healing even in patients with osteoporosis.