Lateral fixation: an alternative surgical approach in the prevention of complete atypical femoral fractures

Incomplete Atypical Femoral Fracture With Severe Bowing Treated by Intramedullary Nail and Corrective Osteotomy

We present the case of an 82-year-old female who had difficulty walking due to right thigh pain caused by incomplete atypical femoral fracture (AFF). The femoral bowing was so severe that intramedullary nail insertion was impossible, so we performed a corrective osteotomy of the femur and inserted the intramedullary nail. Postoperatively, the femoral pain disappeared, and bone fusion was achieved at one year and two months postoperatively. In cases of incomplete AFF with very severe femoral bowing, internal fixation with an intramedullary nail combined with corrective osteotomy of the femur is useful.

Incomplete Diaphyseal Atypical Femoral Fracture due to Increased Anterolateral Bowing: Treatment with Corrective Osteotomy and Intramedullary Nailing with Augmented Plate Fixation

BACKGROUND

Increased anterolateral bowing of the femur is associated with atypical femoral fractures among older patients (including both those receiving and those not receiving treatment with bisphosphonates) as well as a greater likelihood of occurring in the diaphyseal versus the subtrochanteric region. Prophylactic intramedullary (IM) nailing is recommended for the treatment of incomplete atypical femoral fractures, which are radiographically evident. However, this bowing deformity is considered to be a major obstacle to IM nailing as it may be associated with postoperative complications. Corrective osteotomy combined with IM nailing straightens the exaggerated curvature of the femur. We hypothesized that this technique may lead to the safe and rapid healing of incomplete diaphyseal atypical femoral fractures, thereby reducing lateral tensile stress.

METHODS

From October 2015 through March 2020, 17 female patients (20 femora) with a mean age of 76.1 years (range, 68 to 86 years) underwent a surgical procedure for the treatment of an incomplete diaphyseal atypical femoral fracture associated with anterolateral bowing. The surgical technique consisted of minimally invasive osteotomy and reconstruction with use of IM nailing, with or without an augmentation plate. Preoperative and postoperative radiographic findings (lateral and anterior bowing angles, anterolateral bowing grade, and lateral distal femoral angle [LDFA]) were compared. Primary union, time to union, and complications were evaluated as the outcomes.

RESULTS

Primary bone union was achieved in 19 of the 20 femora at a mean of 24.9 weeks (range, 20 to 40 weeks). There were 2 instances of delayed union, which healed at 36 and 40 weeks. The lateral bowing angle, anterior bowing angle, and LDFA significantly improved postoperatively (from 12.0° to 3.3°, from 17.3° to 11.5°, and from 93.5° to 88.8°, respectively) (p < 0.001). There was 1 instance of nonunion, which healed after plate augmentation without a bone graft.

CONCLUSIONS

Given the pathophysiology of elevated lateral tensile stress, corrective osteotomy and IM nailing may be an acceptable solution for the treatment of incomplete diaphyseal atypical femoral fractures associated with increased anterolateral bowing.

LEVEL OF EVIDENCE

Therapeutic Level III . See Instructions for Authors for a complete description of levels of evidence.

Plate osteosynthesis for atypical femoral fractures in patients with severely bowed femurs: comparing short versus long segment fixation - a case series

BACKGROUND

Intramedullary nail fixation is currently the modality of choice in surgical treatment for atypical femoral fractures (AFF). Its uses are limited, however, in severely bowed femurs, narrow medullary canals, or in the presence of thick endosteal callus at the apex of the femoral curve. In these cases, extramedullary plate osteosynthesis is preferred. The consideration when adopting plate osteosynthesis is whether a short or long segment fixation is superior. We hypothesize that a long segment fixation has the potential advantage of protecting the entire length of the femur from future fractures in the adynamic bone. In this series, we present two cases from our institution, with the aims of discussing the benefits and limitations of short versus long segment plate fixation in AFF.

CASE SUMMARY

We report two uncommon cases of bisphosphonate-related AFF in two Asian patients with severe femoral curvature, who were treated with extramedullary plate osteosynthesis at our institution. One patient underwent fixation with a short segment plate osteosynthesis, and the other received a long plate osteosynthesis spanning the proximal to distal femur in an attempt to protect the bone from future fractures. Both patients showed a favourable and uncomplicated course post-surgery, with early return to ambulation and radiographic bone union at follow up.

CONCLUSION

We expect to see an increase in the number of patients with AFF and bowed femurs, especially with the increased usage of bisphosphonates given an ageing Asian population. Surgical treatment with short and long plate osteosynthesis are options with their own advantages and limitations. With the advent of new anatomical plate options, long segment fixation has become more accessible and may be considered in this patient group as it has the potential advantage of protecting the adynamic femur from future fractures. Further studies should be targeted to determine which method of treatment is superior in this particular group of patients.

Surveillance of atypical femoral fractures in a nationwide fracture register

Background and purpose - To continuously assess the incidence of atypical femoral fractures (AFFs) in the population is important, to allow the evaluation of the risks and benefits associated with osteoporosis treatment. Therefore, we investigated the possibility to use the Swedish Fracture Register (SFR) as a surveillance tool for AFFs in the population and to explore means of improvement. Patients and methods - All AFF registrations in the SFR from January 1, 2015 to December 31, 2018 were enrolled in the study. For these patients, radiographs were obtained and combined with radiographs from 176 patients with normal femoral fractures, to form the study cohort. All images were reviewed and classified into AFFs or normal femur fractures by 2 experts in the field (gold-standard classification) and 1 orthopedic resident educated on the specific radiographic features of AFF (educated-user classification). Furthermore, we estimated the incidence rate of AFFs in the population captured by the register through comparison with a previous cohort and calculated the positive predictive value (PPV) and, where possible, the inter-observer agreement (Cohen's kappa) between the different classifications. Results - Of the 178 available patients with AFF in the SFR, 104 patients were classified as AFF using the goldstandard classification, and 89 using the educated-user classification. The PPV increased from 0.58 in the SFR classification to 0.93 in the educated-user classification. The interobserver agreement between the gold-standard classification and the educated-user classification was 0.81. Interpretation - With a positive predictive value of 0.58 the Swedish Fracture Register outperforms radiology reports and reports to the Swedish Medical Products Agency on adverse drug reactions as a diagnostic tool to identify atypical femoral fractures.

A Novel Surgical Method for Treating Symptomatic Incomplete Atypical Femoral Fracture using Percutaneous Elastic Intramedullary Nailing

Purpose:

To introduce the principles and procedure of percutaneous elastic intramedullary nailing (PEIN) as a treatment for symptomatic incomplete atypical femoral fracture (SIAFF).

Methods:

From October 2014 to April 2019, 6 cases of SIAFF were treated with PEIN. Two pre-bent 4-mm stainless-steel nails were used to apply compressive force to the fracture site. The antegrade method was used for proximal fractures and the retrograde method for middle and distal femoral fractures. The femoral bowing angle in the coronal and sagittal planes, and the time required for callus formation and union, were evaluated on plain radiographs in both planes. Thigh pain, tenderness, and complications were also assessed.

Results:

The mean operating time was 65.00 ± 22.64 min. No case progressed to complete atypical fracture. In one case, fracture occurred around the point of nail entry after the patient fell from a chair on postoperative day 7. The incomplete fracture lines were united in 5 cases, after excluding one case with a complication. The time taken to confirm endocortical callus formation, fracture line disappearance, and clinical union was 2.11 ± 0.53, 6.45 ± 4.10, and 6.45 ± 3.65 months, respectively.

Conclusions:

PEIN is a quick, simple but effective treatment for SIAFF that considers the fracture mechanism and is applicable to cases with severe femoral bowing.

Level of evidence:

Level IV, case series.

Precontoured Plate Fixation for Incomplete Atypical Diaphyseal Fracture of Femur using Three-Dimensional Printing Rapid Prototyping: Two Cases Reports

Background

Reconstruction intramedullary nail spanning the whole length of the femur has been the gold standard treatment for complete atypical diaphyseal fractures of the femur (ADF). However, in cases of incomplete ADF combined with severe bowing, this approach might have complications and lead to iatrogenic complete fracture. We report two cases of incomplete ADF with severe bowing using a precontoured plate (PCP) after rapid prototyping (RP) of the deformed femurs with three‐dimensional printing (3DP) technology.

Case presentation

Two patients presented with gradually worsening thigh pain, especially during walking. The patients had been using bisphosphonates for 4 and 10 years, respectively. Radiography showed an incomplete fracture in the lateral cortex of the right femur shaft. The lateral bowing angles measured in the affected femurs were 15° and 14°, and the anterior bowing angles were 20° and 16°, respectively. In bone scans, both patients showed hot uptake in the right mid‐shaft of the femur. Preoperatively, the affected femur of the patient was reconstructed by 3DP RP using CT, and the plate was bent to the shape of the bone model. The ADF was fixed with a PCP using the minimally invasive plate osteosynthesis technique. Both patients were encouraged to start full weight‐bearing and return to their preinjury activity level in daily life immediately after surgery. At 2 years postoperatively, radiography showed healing of the fracture site without recurrence of thigh pain and implant‐related problems.

Conclusion

Although intramedullary nailing is the standard surgical treatment for complete ADF, PCP using 3DP RP could be an effective treatment option for incomplete ADF with severely curved femur.

Intramedullary Nailing: Definitive as well as Prophylactic Fixation Method in a Case of Bilateral Atypical Femoral Fractures - A Case Report

Introduction:

Atypical femoral fractures(AFF) are rare. To get more knowledge, these cases are being reported at an increasing rate in recent literature. Surgical treatment in these fractures is controversial.

Case Report:

A 73-year-old lady, known rheumatoid and osteoporotic with a history of long-term bisphosphonate intake, presented with sudden onset right thigh pain after trivial trauma. We diagnosed a complete atypical femoral fracture, treated with closed intramedullary nailing. 4 months later, she presented with dull aching left thigh pain for 2 weeks. Radiographic features suggested an incomplete atypical femoral fracture, treated with prophylactic insitu intramedullary nailing. At 1 year follow-up, lady was walking well with stick support.

Conclusion:

Our case highlights two important points. Intramedullary nailing is a minimally invasive treatment option for incomplete and complete AFF. We should have a high index of suspicion in diagnosing and recognizing warning signs of incomplete fractures such as prodromal thigh pain and isolated focal lateral cortical thickening, thereby preventing further progression and treatment with prophylactic nailing at an early stage.

A Periprosthetic Femoral Fracture with Characteristics of Atypical Femoral Fracture

Although the definition of atypical femoral fracture (AFF) excludes periprosthetic femoral fracture (PFF), the number of reports about PFF with characteristics of AFF is increasing. We present the case of such a fracture in this report. An 87-year-old woman who underwent bipolar hip arthroplasty for a femoral neck fracture 38 months prior reported left thigh pain with no history of trauma. Radiographs showed a simple transverse fracture at the level of the stem distal end with features of AFF: periosteal thickening of the lateral cortex, a medial spike, and a noncomminuted fracture. She presented other features resembling AFF: history of bisphosphonate use, prodromal symptoms, no associated trauma, and lateral bowing of the contralateral femur. The fracture showed nonunion after the initial osteosynthesis, and a revision surgery of the arthroplasty and osteosynthesis was performed. Nine months after the surgery, bony union was achieved and she regained the ability to walk. It is supposed that the fracture was influenced by a stress force related to implants and lateral bowing concentrating on the fracture site as a mechanical factor in addition to bisphosphonates as a biological factor. It would be important to recognize that AFF could occur at the peri-implant location, and early detection and treatment are essential.

Current Understanding of Epidemiology, Pathophysiology, and Management of Atypical Femur Fractures

PURPOSE OF REVIEW

To summarize reports published since the 2013 American Society of Bone and Mineral Research Task Force Report on atypical femoral fractures (AFF).

RECENT FINDINGS

The absolute incidence of AFFs remains low. AFFs are primarily associated with prolonged bisphosphonate (BP) exposure, but have also been reported in unexposed patients and those receiving denosumab for osteoporosis and metastatic bone disease. Asians may be more susceptible to AFFs. Lateral femoral bowing and varus hip geometry, which increase loading forces on the lateral femoral cortex, may increase AFF risk. Altered bone material properties associated with BP therapy may predispose to AFFs by permitting initiation and increasing propagation of micro-cracks. Relevant genetic mutations have been reported in patients with AFFs. Single X-ray absorptiometry femur scans permit early detection of incomplete and/or asymptomatic AFFs. Orthopedists recommend intramedullary rods for complete AFFs and for incomplete, radiologically advanced AFFs associated with pain and/or marrow edema on MRI. Teriparatide may advance AFF healing but few data support its efficacy. Greater understanding of biological and genetic predisposition to AFF may allow characterization of individual risk prior to initiating osteoporosis therapy and help allay fear in those at low risk for this complication, which remains rare in comparison to the osteoporotic fractures prevented by antiresorptive therapy.