Proposal for the classification of peri-implant femoral fractures: Retrospective cohort study

Risk factors for one-year mortality in 440 femoral peri-implant fractures: insights from the PIPPAS prospective, multicentre, observational study

Aims

The Peri-Implant and PeriProsthetic Survival AnalysiS (PIPPAS) study aimed to investigate the risk factors for one-year mortality of femoral peri-implant fractures (FPIFs).

Methods

This prospective, multicentre, observational study involved 440 FPIF patients with a minimum one-year follow-up. Data on demographics, clinical features, fracture characteristics, management, and mortality rates were collected and analyzed using both univariate and multivariate analyses. FPIF patients were elderly (median age 87 years (IQR 81 to 92)), mostly female (82.5%, n = 363), and frail: median clinical frailty scale 6 (IQR 4 to 7), median Pfeiffer 4 (1 to 7), median age-adjusted Charlson Comorbidity Index (CCI) 6 (IQR 5 to 7), and 58.9% (n = 250) were American Society of Anesthesiologists grade III.

Results

Overall, 90.5% (n = 398) of the patients were treated surgically, 57.0% (n = 227) retained the implant, and 88.7% (n = 353) managed with fixation. Mortality rates were 8.2% (n = 3.6) in-hospital, 11.4% (n = 50) at 30 days, 21.1% (n = 93) at six months, and 21.6% (n = 95) at 12 months. Medical complications, mainly delirium, were common in the acute setting (52.7%, n = 215). The nonunion rate was 4.1% (n = 18). Mortality risk factors in the univariate analysis were age, living at a nursing home, no walking outdoors, frailty variables, fractures in the distal epiphysis, fractures around a proximal nail, discharge to a healthcare facility, and no osteoporotic treatment at discharge. Protective factors against mortality in the univariate analysis were surgical treatment by an experienced surgeon, management without an arthroplasty, allowing full weightbearing, mobilization in the first 48 hours postoperatively, and geriatric involvement. Risk factors for mortality in the multivariate analysis were cognitive impairment (Pfeiffer's questionnaire) (hazard ratio (HR) 1.14 (95% CI 1.05 to 1.23), p = 0.002), age-adjusted CCI (HR 1.18 (95% CI 1.07 to 1.30), p = 0.001), and antiaggregant or anticoagulant medication at admission (HR 2.00 (95% CI 1.19 to 3.38), p = 0.009). Haemoglobin level at admission was protective against mortality (HR 0.85 (95% CI 0.74 to 0.97), p = 0.018).

Conclusion

Mortality in FPIFs occurs mainly within the first six months of follow-up. Early co-management and clinical optimization, particularly targeting frail older patients, is crucial in reducing mortality following these fractures.

Clinical and Functional Outcomes of Peri-Implant Fractures Associated with Short Proximal Femur Nails: Prevention Strategies and Key Insights

Background: Hip fractures are prevalent among the elderly and impose a significant burden on healthcare systems due to the associated high morbidity and costs. The increasing use of intramedullary nails for hip fracture fixation has inadvertently introduced risks; these implants can alter bone elasticity and create stress concentrations, leading to peri-implant fractures. The aim of this study is to investigate the outcomes of peri-implant hip fractures, evaluate the potential causes of such fractures, determine the type of treatment provided, assess the outcomes of said treatments, and establish possible improvement strategies. Methods: We conducted a retrospective observational study on 33 patients with peri-implant hip fractures (PIFs) who underwent surgical management at Río Hortega University Hospital from 2010 to 2022. The collected data included demographics, initial fracture characteristics, the peri-implant fracture classification, implant details, surgical outcomes, functional scores, and complications. Functional capacity was evaluated using the Parker Mobility Score (PMS). Results: The cohort (91% female, mean age 87.6 years) included 34 peri-implant fractures. The mean time from the initial fracture to the PIF was 47.2 months (nine patients developed PIFs within 2 months). Most fractures (76%) were managed with implant removal and the insertion of a long intramedullary nail, with cement augmentation in 31% of cases. The mean surgical time was 102 min, and the average hospital stay was 9.6 days. Postoperative complications occurred in 27%, with a perioperative mortality rate of 9%. Functional capacity showed a significant decline, with an average PMS loss of 4.16 points. Mortality at one year post-PIF was 36%, rising to 83% at five years. Radiographic consolidation was observed in 72% of cases at an average of 6.04 months, though 24% of patients died before consolidation. Statistically significant correlations were found for PMS pre-index fracture (PMS1: r = 0.354, p < 0.05), pre-PIF (PMS2: r = 0.647, p < 0.001), and post-PIF (PMS3: r = 0.604, p < 0.001). Conclusions: Peri-implant hip fractures present complex challenges due to their surgical difficulty and impact on patient mobility and survival. Successful management requires individualized treatment based on fracture type, implant positioning, and patient factors. These findings underscore the need for preventive measures, particularly in implant choice and techniques like overlapping and interlocking constructs, to minimize the secondary fracture risk.

Peri-implant femoral fractures in elderly: Morbidity, mortality, treatment options and good practices

PURPOSE

Femur fractures are among the most common fractures treated surgically, representing a significant challenge for the orthopedic surgeon. Peri-implant femoral fractures (PIFFs) represent a rare complication of the surgical treatment. It is necessary to pay attention during osteosynthesis, evaluating not only the fracture site but the entire femoral skeletal structure, the characteristics of the fracture, the health comorbidities, and the risk of malunion and pseudarthrosis. There are few studies on the incidence, treatment, and outcomes of PIFFs near osteosynthesis. This study aimed to investigate PIFF after osteosynthesis of femoral fractures and evaluate the mortality after surgery and the morbidity associated with these types of fractures.

METHODS

A retrospective cohort study was carried out at the IRCCS Galeazzi Orthopedic Institute, Milan, Italy, between January, 2017 and December, 2022. Inclusion criteria were the presence of a femur fracture around an intramedullary nail to treat a previous fracture, follow-up ≥ 12 months, and patient age ≥ 65 years. Exclusion criterion was intraoperative periprosthetic fractures. The data were expressed as frequency and percentage. Continuous variables were expressed as mean ± standard deviation or median and range.

RESULTS

Overall, 25 patients were enrolled (88.0% female) and the mean age was 84.5 years (range of 70 - 92 years). There were 20 patients having type B PIFF and 5 having type C. In 22 patients, multiple comorbidities were found with an average Charlson comorbidity score of 5.5 and the mean time to peri-implant fracture was 38 months. After surgery, 1 patient (4.0%) presented renal failure, 1 (4.0%) needed removal surgery for their loosening, and 2 (8.0%) presented surgical site infection. Nine patients (36.0%) died within 1 year with a mortality rate of 20. 0% at 30 days, 8.0% at 3 months, and 8.0% at 12 months.

CONCLUSIONS

PIFFs in elderly patients are associated with high short-term mortality and morbidity, so careful planning for primary fracture surgery and patient awareness to ensure prolonged compliance and a healthy lifestyle are essential for prevention.

Periprosthetic and peri-implant femoral fractures and timeliness to surgery: A retrospective matched cohort study

Purpose

Periprosthetic (PPFF) and peri-implant femoral fractures (PIFFs) are troublesome complications of prosthetic and implant surgery, the prior being described to have a greater delay to surgery when compared with standard hip fractures. The implications of PPFF delay being disputed in the current literature and those of PIFF have not been investigated. The aim of this study was to determine whether the time from radiological examination to surgery differs between hip fractures and PPFF/PIFF, and the possible consequences of delay and group affiliation on morbidity, mortality, and readmissions.

Methods

One hundred and thirty-six participants were admitted to Danderyd hospital during 2020, cases exposed to PPFF or PIFF (n = 35) and hip fracture controls (n = 101) matched at 1:3 with respect to age and sex. Timestamps from radiology, surgery, and death were retrieved from the Swedish fracture registry, data on adverse events (AEs), and readmissions were collected through retrospective medical record review for 90-days postsurgery.

Results

Linear regression showed that time to surgery differed in case and control cohorts by a mean of 24.8 h, p < 0.001, and AEs were significantly more common in cases, p = 0.046. Unadjusted binary logistic regression indicated a possible relationship between time to surgery increasing the rate of AEs by 1.3% per hour of delay, 95% confidence interval [CI]: (1-1.03).

Conclusion

This study reveals a significant delay in surgery for PPFFs and PIFFs compared with standard hip fractures, leading to higher adverse event rates. While mortality and readmissions did not differ significantly, the delay underscores the need for timely intervention in these complex cases. Further research is needed to address these challenges and improve patient outcomes.

Level of Evidence

III.

Therapy aspects of peri-implant femoral fractures-a retrospective analysis of 64 patients

PURPOSE

The incidence of peri-implant femoral fractures (PIFF) is increasing. Information regarding outcomes, timing of surgery, risk factors, and a clinically applicable treatment algorithm are lacking. The aim of this study was to identify outcome-related risk factors and to derive a treatment algorithm.

METHODS

Sixty-four PIFFs treated between 01.01.2006 and 31.12.2020 in a level I trauma centre were evaluated retrospectively for fracture pattern, surgical technique, risk factors, complications, and 1-year mortality. The study was approved by the ethics committee (No. 21-2714-104).

RESULTS

One-year mortality was 24.1%. Surgical complications occurred in 4.7%, and general complications in 15.6% of the patients. General complications, low haemoglobin level at admission, elevated CHA2DS2-VASc, and Charlson score resulted in increased 1-year mortality. Time to surgery > 24 h did not increase complication or mortality rates. The three predominant fracture patterns were fractures close or distal to cephalomedullary nails, close or proximal to distal lateral plates, and close or distal to sliding hip screws. Recommendations for surgical treatment were derived: Osteosynthesis should enable as much weight-bearing as possible; the initial implant should only be removed, if this is essential for the new osteosynthesis; lateral locking plates should span the whole femur; antegrade nails should have a cephalomedullary component to avoid consecutive femoral neck fractures; implants should overlap to reduce the risk of consecutive inter-implant fractures.

CONCLUSION

Risk factors for 1-year mortality in patients with PIFFs were identified. A treatment algorithm and general principles for surgery of PIFFs were developed.

Is nail-plate docking worth the effort? A biomechanical analysis of docking a plate and a nail in peri-implant femur fractures

Purpose

The ideal treatment of peri-implant femur fractures (PIFFs) remains unclear due to the thin clinical and biomechanical evidence concerning the most suitable form of osteosynthesis. The purpose of the present study was thus to determine the biomechanical stability that results from combining a cephalomedullary nail and a plate for proximal PIFFs, especially when the nail-plate docking technique is applied.

Methods

Twenty four PIFFs were simulated in both 12 foam and 12 composite specimens and were stabilized via a combination of a cephalomedullary nail and a plate. The control group (n = 6) had a nail and a plate without a connection, while the intervention group (n = 6) had a screw that connected the plate with the interlocking screw hole of the nail, thereby creating a nail-plate docking system. The specimens were evaluated under axial and torsional loading using a material-testing machine and a 3D metrology system.

Results

The data regarding stiffness, failure load, and failure displacement showed significantly higher stability for specimens without nail-plate docking. For docked specimens, a non-significant trend toward a higher resistance to torque was observed. Both techniques displayed no significant difference in fracture gap displacement or total displacement.

Conclusion

The present study suggests that nail-plate docking of a cephalomedullary nail, and a plate significantly decreases the stiffness and stability of osteosynthesis under axial loading. However, there seems to be a tendency toward higher resistance to torque. Therefore, surgeons should consider this technique if higher torsional stability is necessary, and they should decide against it, if axial stability is preferred.

Surgical treatment of peri-implant femoral fractures - case report and literature review

Introduction. Peri-implant femoral fractures (PIFF) are defined as fractures of the femur with the presence of previously implanted non-prosthetic osteosynthetic material. A review of available literature revealed that there are several proposed classifications and sets of guidelines for surgical treatment of PIFF. Case outline. A 49-year-old patient was injured from a fall on the same level, the day before admission to the hospital. The anamnesis at admission showed that six months earlier, he had sustained a pertrochanteric fracture of the left femur, which had been treated surgically with a short cephalomedullary nail. Two years prior to hospital admission, the patient had sustained a tibial plateau fracture of the same leg, which was treated non-surgically with above the knee cast immobilization. After the fracture had healed, paresis of the peroneal nerve was diagnosed, while subsequent follow-up revealed secondary post-traumatic arthrosis of the knee joint. Reduction and fixation of the fracture was performed on a surgical extension table, with the use of fluoroscopy. Previously implanted osteosynthetic material was removed, a short cephalomedullary nail, and fixation of the fracture was carried out with a long cephalomedullary nail. Six months after the operation, the patient can ambulate independently, without assistance. He reports no pain in the left groin and upper leg but reports pain and limitation of movement in the left knee joint. Conclusion. By reviewing the available literature, we found that the patient was cared for in our hospital in keeping with all current recommendations for surgical treatment of this type of fracture.

A Retrospective analysis of peri-implant fractures: insights from a large volume clinical Study

PURPOSE

Peri-implant fractures (PIFs) are a concept in evolution for which different diagnostic criteria have been proposed and modified over time. They have not been extensively reported. PIFs are usually located in the distal part of previous osteosynthesis, where fragile bone is in contact with the rigid implant and are a significant complication after orthopaedic surgery, which requires careful management and treatment. This clinical study presents findings from a retrospective analysis of PIF's, providing description of characteristics and outcomes. They provide information about the associated risk factors and description of the effectiveness of various treatments.

MATERIALS AND METHODS

A retrospective analysis was performed in a clinical study involving patients with PIFs. Data from medical records, radiographic images, and surgical reports were collected and analyzed. The study included patients with refracture of pre-existing osteosynthesis admitted to the hospital between 2015 and 2022. Demographic information, fracture characteristics, surgical interventions, and post-operative outcomes were assessed. Each case was followed for a minimum of one year after surgery, and a critical analysis was performed by senior surgeons. Furthermore, the PIFs were classified according to the type of initial implant and the position of the new fracture in relation to the original implant.

RESULTS

Between 2015 and 2022, out of 18,813 fractures treated at a Level 1 traumatology hospital, a total of 85 patients with PIF's were identified. Fracture characteristics varied, including location, fracture pattern, and implant type. Most of the PIFs, 71 cases (83.53%), occurred in the femur. Additionally, there were seven cases (8.24%) involving the humerus, four cases (4.71%) affecting the tibia/fibula, two cases (2.35%) in the radius, and one case (1.18%) involving the clavicle. Surgical management was the primary attitude in treatment. Various techniques were used, including the use of longer and stronger implants to achieve high-quality fixation, facilitating early rehabilitation and return to previous activities. Postoperative complications after surgery for PIFs were observed in 16 cases (18.8%).

CONCLUSIONS

Peri-implant fractures (PIF) are a distinct topic and a challenging condition with a high rate of postoperative complications. Complications after the second surgery may be severe and life threatening in older patients. A classification can be useful to make decisions about the optimal treatment in different anatomic areas and type of implant used for primary osteosynthesis. Currently there are no standardized protocols for management, therefore each case should be carefully discussed and planned before surgery.

A Novel Comprehensive Classification for Non-Prosthetic Peri-Implant Fractures

Non-prosthetic peri-implant fractures (NPPIFs) are often reported mixed with periprosthetic fractures (PPFs), but they are different entities. Due to the increase in the age of the world’s population and to the intensification of surgeries for fractures, nowadays, peri-implant fractures are a very frequent entity in clinical practice, with an increasing trend expected in the future. A clear exclusive classification of NPPIFs is not reported in the literature. The aim of this study is to provide a valid comprehensive classification for all the NPPIFs. X-rays of all the peri-implant cases treated in our unit in a 3-year period were retrospectively collected. Five orthopedic surgeons reviewed 30 X-rays of NPPIFs, providing a code according to the classification proposed. After a 3-month interval, they reviewed the same X-rays. Eighteen femoral, eight humeral, and four forearm peri-implant fractures were collected and showed to the raters. Inter- and intra-observer reliability was calculated using a k-statistic, showing a moderate agreement between observers (κ = 0.73) and a substantial agreement between the observations of the same viewer (κ = 0.82). The literature lacks a comprehensive classification for peri-implant fractures that considers all the bones and all the types of implants. The proposed classification is meant to be an instrument for orthopedic surgeons to categorize these types of fractures and seems to be simple, easy to comprehend, and reproducible. This new classification can provide the orthopedic surgeon a reliable method to clearly catalogue different fractures according to the site and the implants; the physicians can use it, through a code, in clinical practice to describe an NPPIF without the need of images. Further studies may be necessary to confirm the validity and eventually to improve the suggested classification.

Non-prosthetic implant-related femur fractures in post-polio patients

The overall societal impact of poliomyelitis worldwide is decreasing, rendering it almost absent in most developed countries. However, even there, patients are still seen who contracted it in endemic areas or developed polio before vaccinations became widely available. Post-polio syndrome (PPS) causes skeletal and neurological changes that increase affected individuals' likelihood of fractures, including fractures requiring complex surgical treatment. The existence of previous internal fixation creates a particularly difficult challenge. We present here the surgical management of four post-polio patients who suffered non-prosthetic implant-related femoral fractures. Injuries occurred at earlier ages than implant-related fractures in non-polio patients and three of the four fractures occurred around plates, a phenomenon which is usually rare. The treatment of implant-related fractures in patients with post-polio syndrome poses significant technical challenges, often creating problematic functional sequelae for patients and high costs for healthcare systems.

Peri-implant fracture: a rare complication after intramedullary fixation of trochanteric femoral fracture

INTRODUCTION

Trochanteric femoral fractures are among the most common operatively treated fractures. Intramedullary fixation has become the treatment of choice in many centers around the world. Nevertheless, the knowledge of rare complications of these fractures is limited. In this study, the incidence and treatment strategies for peri-implant fractures (PIF) were assessed.

MATERIALS AND METHODS

A single-center retrospective cohort study was done on 987 consecutive operatively treated trochanteric fractures. PFNA cephalomedullary nail was used as a fixation method. All patients were followed up from patient records for peri-implant fractures. Plain radiographs as well as different salvage methods were analyzed and compared.

RESULTS

The total rate of peri-implant fractures was 1.4% (n = 14). The rate of PIF for patients treated with short (200 mm) nails, intermediate-length (240 mm) nails, and long nails was 2.7% (n = 2), 1.5% (n = 11), and 0.7% (n = 1), respectively (ns, p > 0.05 for difference). Treatment of choice for PIF was either ORIF with locking plate (57%, n = 8) or exchange nailing (43%, n = 6). None of the PIF patients needed additional surgeries for non-union, malunion, or delayed union.

CONCLUSIONS

A PIF is a rare complication of intramedullary fixation of trochanteric fractures. It can be treated with either locking plates or exchange nailing with sufficient results. There are no grounds for favoring long nails to avoid PIFs.

Fractures after cephalomedullary nailing of the femur : Systematization of surgical fixation based on the analysis of a single-center retrospective cohort

PURPOSES

Femoral implant related fractures (IRF) are a growing pathology in an increasingly elderly and frail population. A series of IRF after cephalomedullary nail (CMN) fixation of a femoral fracture is analyzed and an algorithm described to guide the management of such fractures.

METHODS

All eligible patients operated on for IRF fixation after CMN were reviewed regarding their demographics, comorbidities, injury pattern, and treatment. Primary outcomes were mortality and local complications. Secondary outcomes were time to consolidation, time to weight-bearing initiation, length of hospitalization, and discharge destination.

RESULTS

The incidence of IRF requiring fixation was 1.3% after 3401 CMN implantation procedures. Elderly women with comorbidities and plate fixation predominated. One-year mortality was 18.6%, being higher for patients presenting with infection and those unable to walk at the end of follow-up. Local complications occurred in 25.6%. Median time to weight-bearing was 9.1 weeks, but longer for patients with plate fixation or complications. Patients presenting with an infection and those discharged to nursing facilities had more comorbidity.

CONCLUSIONS

Following an algorithm presented here, patients were treated either with nail exchange or lateral locking plate fixation, permitting straightforward evaluations and acceptable results in a very high-risk population.

Interimplant femoral fractures

The number of hip or knee arthroplasties, and internal fixations of the proximal and distal femur, is increasing in proportion to the growing and ageing population, whose life expectancy is lengthening. Thus, fractures of the femur between proximal and distal implants, although rare, are becoming more frequent. Women over the age of 70, with fragile bones and whose ends of the two implants are close to each other ("kissing implants") are particularly vulnerable to them. Reliable and reproducible fracture classifications exist when it comes to 2 prostheses, but they are less well established in the presence of one, or even two, non-prosthetic implants. Their treatment is difficult and must consider the possibility of fracture consolidation while ensuring or restoring the stability and role of the implants. Whether it is the main element of treatment or a complement to prosthesis revision, locked plating forms the basis of the treatment but it must be rigorous, considering that failures are mainly the result of technical errors. Other more invasive treatments (total femoral arthroplasty, cortical sleeves) are offered more rarely if consolidation appears compromised.

A pilot agreement study of a new classification system for Peri-implant femoral fractures

BACKGROUND

Peri-implant fractures occur in association with an implant, used to treat a previous injury that is still attached to the bone. We recently published a proposal for a classification system for peri-implant femoral fractures [Videla-Cés, Injury,2019].

AIM

To assess the agreement of our classification system for peri-implant femoral fractures among a group of future users of said classification system.

METHODS

A prospective, multicentre, international agreement pilot study was conducted among a group of independent traumatologists/orthopaedic surgeons (evaluators): senior (a minimum of 10 years' experience) and junior (in fourth or fifth training year). A set of 30 radiographs of peri-implant femoral fractures were selected (stratified into 3 levels of difficulty: low, medium and high). Each evaluator interpreted the radiographs on 2 different occasions separated by a period of one month and in a different order each time. The level of difficulty was masked from the evaluators and they had one week to classify the radiographs each time. Logistic regression and Cohen's kappa coefficient (κ) and its 95% confidence interval (95%CI) were used to assess the accuracy and agreement, both intra- and inter-evaluator. Between senior and junior surgeons was performed an exploratory analysis.

RESULTS

35 traumatologists/orthopaedic surgeons (17 senior and 18 junior) from 16 tertiary hospitals from 4 countries acted as evaluators. The accuracy, percentage of correct classifications (2 digits and 3 letters), in the first and second evaluation was: 56% (95%CI: 53-59%) and 55% (95%CI: 51-57%), respectively. (insert space) Negligible differences were found between junior and senior evaluators (first evaluation, OR: 1.46, 95%CI: 0.82-2.61, p-value: 0.199; second evaluation, OR: 1.06, 95%CI: 0.56-2.00, p-value: 0.860). (insert space) Both medium and low radiograph difficulty were associated with a lower probability of an incorrect classification compared with those of high difficulty (first evaluation, OR: 7.60, 95%CI: 5.24-11.05, p-value: <0.001; OR: 14.15, 95%CI: 9.12-21.96, p-value: <0.001, respectively; second evaluation, OR: 7.11, 95%CI: 4.88-10.38, p-value: <0.001, OR: 15.28, 95%CI: 9.77-23.89, p-value: <0.001). (insert space) The kappa for intra-observer agreement between the first and second evaluation was: 0.66, 95%CI: 0.63, 0.69. The kappa for inter-observer agreement considering all 30 radiographs was: 0.40, 95%CI: 0.40, 0.41 in the first evaluation and 0.39, 95%CI: 0.39, 0.40 in the second evaluation.

CONCLUSION

The proposed classification for peri-implant femoral fractures may be useful and user-friendly. Future studies are needed to assess the how clinically useful this classification system may be (the third phase in the validation process).

Peri-implant fractures of the upper and lower extremities: a case series of 61 fractures

PURPOSE

To assess outcomes for patients who sustained peri-implant fractures (PIFs).

METHODS

Medical records of patients who sustained a PIF were reviewed for demographic, injury, outcome, and radiographic data. PIFs were classified using a reproducible system and stratified into cohorts based on fracture location. Clinical outcomes were evaluated for each cohort.

RESULTS

Fifty-six patients with 61 PIFs with at least 6 months of follow-up were included. The mean age of the cohort was 60.4 ± 19.5 years. Twenty-two (36.1%) PIFs occurred in males, while 39 (63.9%) occurred in females. Fifty-two (85.2%) PIFs were sustained from a low-energy injury mechanism. PIFs were most often treated with plate/screw constructs (50.8%). Complications included: 6 (9.8%) nonunions, 5 of which were successfully treated to healing, 5 (8.2%) fracture related infections (FRI), and 1 (1.6%) hardware failure. Sixty (98.4%) PIFs ultimately demonstrated radiographic healing.

CONCLUSION

PIFs are usually treated surgically and have a relatively high incidence of complications, with nonunion in femoral PIFs being the greatest. Despite this, the rate of ultimate healing is quite high.

Fractures around Trochanteric Nails: The "Vergilius Classification System"

INTRODUCTION

The fractures that occurred around trochanteric nails (perinail fractures, PNFs) are becoming a huge challenge for the orthopaedic surgeon. Although presenting some specific critical issues (i.e., patients' outcomes and treatment strategies), these fractures are commonly described within peri-implant ones and their treatment was based on periprosthetic fracture recommendations. The knowledge gap about PNFs leads us to convene a research group with the aim to propose a specific classification system to guide the orthopaedic surgeon in the management of these fractures.

MATERIALS AND METHODS

A steering committee, identified by two Italian associations of orthopaedic surgeons, conducted a comprehensive literature review on PNFs to identify the unmet needs about this topic. Subsequently, a panel of experts was involved in a consensus meeting proposing a specific classification system and formulated treatment statements for PNFs. Results and Discussion. The research group considered four PNF main characteristics for the classification proposal: (1) fracture localization, (2) fracture morphology, (3) fracture fragmentation, and (3) healing status of the previous fracture. An alphanumeric code was included to identify each characteristic, allowing to describe up to 54 categories of PNFs, using a 3- to 4-digit code. The proposal of the consensus-based classification reporting the most relevant aspects for PNF treatment might be a useful tool to guide the orthopaedic surgeon in the appropriate management of these fractures.