Internal fixation and revision arthroplasty for interprosthetic femoral fractures: a case series of fifty patients

Interimplant femoral fracture: analysis of risk factors

Interimplant fractures present a significant challenge for orthopedic surgeons. Despite a noticeable rise in these cases in recent years, our understanding of this specific fracture type remains limited. This study aims to analyze and identify the primary risk factors associated with interimplant femoral fractures. We conducted a retrospective analysis involving 20 patients with interimplant femoral fracture (case group) and 18 patients who had both proximal and distal femoral implants but did not experience interimplant fractures (control group). Our analysis focused on demographic factors (age, sex, BMI) and radiographic parameters (implant types, gap between implants, cortical thickness, femoral canal area) to identify potential risk factors. In the case group, all patients were females, whereas in the control group, 16 patients were female and 2 were males. The mean age in the case group was 88 [Formula: see text] 9 years and in the control group was 87 [Formula: see text] 12 years. None of the demographic differences reached statistical significance. The mean cortical thickness in the case group was 6 [Formula: see text] 2.25 mm, whereas in the control group, it was 9 [Formula: see text] 1.75 mm (p-value < 0.001). The median gap between the proximal and distal tips of the implants measured 194 [Formula: see text] 126 mm in the case group and 66 [Formula: see text] 78 mm in the control group (p-value < 0.001). Additionally, the mean femoral canal area was 284 [Formula: see text] 102 mm2 in the case group and 227 [Formula: see text] 26 mm2 in the control group (p-value < 0.010). Our data indicate that a small cortical thickness, a wide femoral canal area, and having a hip arthroplasty despite a gap between the implants exceeding 110 mm are factors that elevate the risk of interimplant femoral fracture. Notably, osteoporosis therapy emerges as a protective factor against these fractures.

[Treatment aspects of interprosthetic femur fractures-retrospective analysis of 70 patients]

BACKGROUND

Interprosthetic femur fractures (IFF) are rare injuries, whose surgical treatment is basically with osteosynthesis or revision arthroplasty. Various therapy algorithms have been proposed based on very small study collectives. Factors influencing the outcome are not known.

OBJECTIVES

The aim of the retrospective monocentric study is to derive a treatment algorithm based on a large number of cases and to identify factors influencing the outcome.

MATERIALS AND METHODS

Between 2006 and 2020, 70 IFF were identified. The surgical treatment comprised 38 osteosyntheses, 30 revision arthroplasties and 2 amputations. With classification and time to surgery, 69 perioperative variables were recorded. General and operative complications, as well as mortality, were determined in the follow-up period of 1 year.

RESULTS

ASA and Charlson score correlated with 1‑year-mortality. In addition, preoperatively increased CRP levels, reduced hemoglobin and the CHA2DS2-VASc score were identified as factors influencing mortality. Surgery within 24 h showed a trend towards fewer general complications. Transferred patients indicated an increased mortality. Based on classification according to Pires et al. or Füchtmeier et al. no clear treatment decision could be made. Relevant criteria for the surgical treatment were fracture localization, implant stability, bone vitality, anchoring possibility of the revision stem, as well as general condition of the patient.

CONCLUSIONS

The identified factors influencing the outcome correspond to those of patients with hip fractures. IFF should be treated timely. A treatment path was developed on the basis of the largest patient group to date.

A systematic review of the surgical outcomes of interprosthetic femur fractures

Background

Interprosthetic femur fractures (IFFs) are rare, but the treatment is challenging. Currently, there are many treatment methods used in practice, but an updated systematic review of comparison of common different surgical outcomes has not been thoroughly inspected.

Methods

A systematic review of retrospective studies was conducted. The resource databases of PubMed, Cochrane, and Embase were searched using a combination of the keywords involving IFFs and surgical outcomes from inception through June 2021. Data collected included patient demographics, intraoperative data, and postoperative outcomes. Outcomes were measured based on healing time, revision rate, complication rate, and functional scores.

Results

Forty studies were included for review with a total of 508 patients. Average reported age of patients was 78.7 years old and 403 (79.3%) were females. Overall union rate was 74.0% with 376 of 508 patients achieving fracture union after primary treatment of IFF. Only 271 patients had reported healing times of fractures with a mean of 5.15 months. The plate, prosthetic revision, nail/rod, and external fixator groups had mean healing times of 4.69, 8.73, 6.5, and 5.1 months, respectively. Revision rates were highest in the femur replacement treatment group with 9 (32.1%) patients needing at least one reoperation surgery for any reason. Overall, hardware failure and non-unions were the most reported complications in treatment of IFFs. Postoperative functional outcome scores were available for 242 patients. Harris Hip Scores for the plate, revision, replacement, nail/rod, and plate + revision groups were 76.84, 77.14, 69.9, 77, and 78.4, respectively.

Conclusion

Each treatment method should be carefully considered by the surgeon depending on the patient. Locking plate was the most common method for the treatment of the patients with IFFs. Half of them combined with cerclage wires/cables. Around two thirds' patients could achieve union with the fastest mean healing time around 4.69 months. Other less common methods included prosthetic revision, femur replacement, nail/rod, external fixator, etc. A small number of patients treated with Ilizarov external fixator, and it has proven to be a viable option with few complications and high union rates.

Direct medical costs of interprosthetic femoral fracture treatment: A cohort analysis

INTRODUCTION

Periprosthetic femoral fractures (PPFs) represent a challenging clinical problem with a fast-rising incidence. Interprosthetic fractures (IPFs) represent one of its most difficult variants. There is a paucity of data regarding the financial burden of PPFs, and none for IPFs. This study aims to estimate the direct medical cost of the surgical treatment of IPFs in NHS, and analyse the factors influencing this when using different methods of surgical treatment.

METHODS

A cohort of patients with IPFs treated in a single academic unit over a period of 8-years with different surgical methods was studied. In-hospital details, as well as outpatient follow-up data, were gathered relevant to their clinical and radiological outcome until discharge. Local and national NHS data were acquired from the financial department, as well as industry-related resources. The economic analysis was structured as a cost identification analysis (CIA) of the overall cohort, but also as a comparative best-case scenario (uncomplicated course till discharge) comparison between the 3 main different management strategies (a) revision arthroplasty (RTHA), b) plate fixation (ORIF), c) combination of implants (COMBO).

RESULTS

Data from 28 patients (22 females) with IPFs were analysed with a median age of 78.4 years. The overall direct medical cost of treating this cohort of patients was £468,330, with a median of £15.625 (range £10,128 to 33,060). Comparing the three different surgical modalities, the median cost in groups a, b, and c was £20,793 (range £12,110 to £24,116), £12,979 (range £10,128 to £20,555), and £22,316 (range £10,938 to £23,081) respectively. In all groups, the 2/3 of the identified costs were relevant to the inpatient stay. Transfusions were the highest (3 units of cRBC on average) to the patients that received a revision THA vs the other two groups (p=0.022). There was statistically significant higher mean overall cost between the RTHA and the ORIF groups (£19,453 vs. £14,201, p=0.0242), but not when compared with the COMBO cases (£19,453 vs. £18,788, p=0.86).

CONCLUSION

The first cost identification study and "best case scenario" comparative analysis for IPFs demonstrated a significant overall direct medical cost, when managing these complex fractures with variable contemporary techniques. Evidence based reimbursement strategies should be developed to allow the sustainability of the clinical service we offer in this challenging patient population.

Interprosthetic femoral fractures managed with modern distal femoral locking plates: 10 years' experience at a UK major trauma centre

INTRODUCTION

Interprosthetic femoral fractures (IFF) are rare but increasing with an ageing population. Operative management is challenging and there is currently a paucity of outcome data in literature. The purpose of this study was to evaluate outcomes of IFFs managed with modern distal femoral locking plates, in a larger sample size than previously published.

METHOD

This retrospective study reviewed 49 closed IFFs in 48 patients at a major trauma center from 2009 to 2019 occurring between previous total hip arthroplasty (n=38), hemi hip arthroplasty (n=3), dynamic hip screw (n=6) or cephalomedullary nail (n=2) and total knee arthroplasty. They were managed with Minimally Invasive Plate Osteosynthesis (MIPO) employing modern biological fixation techniques and stabilised with VA-LCP Condylar (Synthes; n=28) or Peri-Loc (S&N; n=21) plate. Clinical and radiographic outcomes were measured.

RESULTS

The majority of fractures were in female patients (80%), who were elderly (average 83 years), and comorbid (55% ASA grade 3 or 4). Most fractures were Pires type IIA and OTA/AO type 33A. Average plate spanning femur was 16 holes, with average working length of 6 holes. 86% had unrestricted weight bearing immediately post operatively. 31 fractures reached radiological (n=25) or clinical (n=6) union. 13 patients died with 2 lost to follow up. There were 3 non-unions, with implant failure occurring before 4 months in all 3. We present a union rate of 91% (n=31/34).

CONCLUSION

IFFs are occurring with increasing frequency in a frail elderly population. In patients with IFFs, MIPO and biological fixation techniques using modern distal femoral locking plates can achieve high rate of union when combined with immediate unrestricted weight bearing postoperatively.