Double plating in Vancouver type B1 periprosthetic proximal femur fractures: A biomechanical study

Biomechanics of PHILOS plates in Vancouver B1 periprosthetic femoral fracture

Objective: To investigate the clinical efficacy of PHILOS plates in the treatment of Vancouver B1 periprosthetic femoral fracture (PFF) and to validate its biomechanical reliability via finite element analysis and mechanical testing on the Synbone femoral models. Methods: Ten males and eight females with Vancouver B1 PFF who underwent PHILOS plate fixation between September 2017 and January 2022 were selected. The average age was 72.61 ± 8.19 years, with a range of 57-86 years old. X-ray films were taken to assess the fracture healing situation around the femoral prosthesis as well as the position of the PHILOS plates and femoral prosthesis. Two different plates (the PHILOS plate and the Cable GTR plate) were used for fixation, and the differences in biomechanical stability of the two fixation methods were compared using finite element analysis and mechanical testing on the Synbone femoral models to validate the biomechanical dependability of the PHILOS plate. Results: All 18 cases were followed for at least 1 year, as a result. The average period of follow-up was 17 months, ranging from 12 to 36 months. At the most recent follow-up, Harris scores for the hip joints of patients ranged from 82 to 89, with an average score of 86. The X-rays revealed that all fractures surrounding the femoral prosthesis had healed and that there was no looseness in the femoral prosthesis. None of the PHILOS license plates had expired. All patients were able to perform full-load walking, and pain and claudication in affected limbs were significantly reduced. Finite element analysis and mechanical testing of the Synbone femoral model revealed that the fixation effect of the PHILOS group was superior to that of the Cable group; consequently, PHILOS plates can be used to effectively fix fractures around the proximal femoral prosthesis. Conclusion: PHILOS plates are initially used in the treatment of Vancouver B1 PFF, which may be a good choice due to their simpler operation, lower medical costs, and satisfactory clinical efficacy.

Surgical outcomes of dual-plate fixation for periprosthetic femur fractures around a stable hip arthroplasty stem

INTRODUCTION

The incidence of periprosthetic femur fractures is increasing. Multiple treatment methods exist to treat fractures surrounding stable hip arthroplasty implants including locking plate fixation, cable fixation, allograft augmentation, and revision arthroplasty. No consensus regarding optimal treatment has been reached, and significant complications remain. Recently, biomechanical studies have demonstrated the benefits of orthogonal dual-plate fixation, but little clinical data exist. The purpose of the current study was to investigate the clinical and radiographic outcomes of dual-plated periprosthetic femur fractures around stable hip stems.

MATERIALS AND METHODS

Patients with periprosthetic femur fractures following hip arthroplasty with a stable femoral stem treated with dual-plate fixation were identified through chart review at a single institution. Fracture classification, fixation characteristics, radiographic outcomes, clinical outcomes and complications including re-operation were recorded.

RESULTS

Over a 12-year period, 31 patients (mean age 77 years at surgery, range 48-94) underwent dual plating by three traumatologists for implant-stable periprosthetic femur fractures surrounding a hip arthroplasty stem. There were 27 Vancouver B1-type and 9 inter-prosthetic fractures. Average follow-up was 2 years. Of the 26 patients with minimum 6-month follow-up, 24 (92%) united after index surgery (mean time to union 6.0 months, range 1.5-14.0). Mean time to full weight-bearing post-operatively was 2.6 months (range 1.5-4.0 months). Two patients required secondary surgery to address nonunion.

CONCLUSIONS

Dual-plating achieved high union rates with an acceptable complication profile for the treatment of periprosthetic femur fractures surrounding a stable hip arthroplasty stem. Our preferred fixation construct involves a lateral plate spanning the entire femur secured with non-locking bicortical screws supplemented with an anteriorly based reconstruction plate. Additional prospective research is required to confirm the results of this study.

Femoral periprosthetic fracture treatment using the Ortho-Bridge System: a biomechanical study

BACKGROUND

We undertook a comparative biomechanical study of type B1 fractures around femoral prostheses following cemented hip arthroplasty using the Ortho-Bridge System (OBS) and a locking compression plate/locking attachment plate structure (LCP + LAP). We aimed to investigate the biomechanical characteristics and advantages of the OBS compared with LCP + LAP when treating this fracture type.

METHODS

An OBS fixation model was designed based on OBS and LCP + LAP fixation characteristics. The LCP + LAP combination (Group A) and three different OBS combinations (Groups B, C, and D) were used to fix a B1 fracture model with a femoral periprosthetic fracture. Axial compression and torsion experiments were then performed using simple and comminuted fracture models. The axial compression failure experiment was carried out, and the model stiffness during axial compression, torsion angle in torsion test, and vertical load in the final failure test were collected.

RESULTS

When simulating simple oblique fractures, no significant difference was found among the four groups in terms of stiffness in the axial compression experiment (P = 0.257). The torsion angle of the LCP + LAP system was significantly higher compared with the OBS system (P < 0.05). When simulating a comminuted fracture, the experimental data for axial compression showed that the rigidity measurements of the three combinations of the OBS system were higher compared with the LCP + LAP system (P = 0.000) and that the torsion angles of three combinations of the OBS system were smaller compared with the LCP + LAP system (P < 0.05). In the axial compression failure test, the fixed failure mode of the LCP + LAP system was the destruction of the contact cortex at the fracture site, whereas the failure modes in the three OBS combinations involved fracture around the screws above the osteotomy and destruction of the contact cortex at the fracture site.

CONCLUSIONS

The findings revealed that the OBS produced superior biomechanical outcomes compared with LCP + LAP, especially for the bridging two-rod dual cortex. According to the performance observed after model axial compression destruction, the OBS was fixed and provided greater stress dispersion, which might make it more suitable for facilitating early functional movement and avoiding the failure of internal fixation.

Use of the Locking Attachment Plate for Internal Fixation of Periprosthetic Femur Fractures

Introduction

The locking attachment plate (LAP) can be added to a locking compression plate (LCP) to allow the fixation of locking screws bicortically around a femoral implant. We aimed to examine surgical and fracture characteristics associated with healing for periprosthetic femur fractures (PPFFx) treated with constructs employing LAP fixation. We hypothesize that the addition of an LAP provides stable peri-implant fixation.

Materials &Methods

We retrospectively reviewed a consecutive series of 28 PPFFx surgically treated with LCP-LAP constructs by 4 surgeons from 2015-2020. Fractures were classified and grouped using the Vancouver Classification System and included 12 B1, 2 B2, 11 C fractures, and 3 fractures around other stemmed implants. Primary outcome measures included hardware failure such as screw pullout, broken screws, and plate fracture. Clinical complications including infection, non-union, malunion, and reoperation were recorded.

Results

No LAP failures, screw pullout, or broken screws were observed. Two fractured plates (7.1%) occurred in patients with Vancouver C fracture types. Overall complication rate was 17.9% and included 3 non-unions, 1 deep infection, and 1 implant loosening with painful hardware, each requiring reoperation. Differences were observed between unions and nonunions for total number of screws (12.4 vs 14.7, P = .005) and number of locking screws used (8.04 vs 11.3, P = .03).

Conclusion

The LAP provides adequate fixation and low failure rates where fixation is required around a well-fixed stem. When failures occur, it is from plate breakage and not due to failure of fixation at the area of plate-stem overlap.

The race for the classification of proximal periprosthetic femoral fractures : Vancouver vs Unified Classification System (UCS) - a systematic review

Background

Periprosthetic femoral fractures (PFFs) represent a major cause for surgical revision after hip arthroplasty with detrimental consequences for patients. The Vancouver classification has been traditionally used since its introduction in 1995. The Unified Classification System (UCS) was described in 2014, to widen the spectrum by aiming for a more comprehensive approach. The UCS also aimed to replace the Vancouver classification by expanding the idea of the Vancouver classification to the whole musculoskeletal apparatus. After introduction of the UCS, the question was raised, whether the UCS found its place in the field of analysing PFFs. Therefore, this systematic review was performed to investigate, the use of the UCS compared to the established Vancouver classification.

Methods

Medline was searched for reports published between 1 January 2016 and 31 November 2020, without language restriction. Included were original articles, irrespective of the level of evidence and case reports reporting on a PFF and using either the Vancouver or the UCS to classify the fractures. Excluded were reviews and systematic reviews.

Results

One hundred forty-six studies were included in the analysis. UCS has not been used in a single registry study, giving a pooled cohort size of 3299 patients, compared to 59,178 patients in studies using the Vancouver classification. Since 2016, one study using UCS was published in a top journal, compared to 37 studies using the Vancouver classification (p=0.29). During the study period, the number of yearly publications remained stagnant (p=0.899).

Conclusions

Despite valuable improvement and expansion of the latter UCS, to date, the Vancouver system clearly leads the field of classifying PFFs in the sense of the common use.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12891-022-05240-w.

LOQTEQ® VA Periprosthetic Plate-A New Concept for Bicortical Screw Fixation in Periprosthetic Fractures: A Technical Note

Internal fixation using angle stable plates is the treatment standard in periprosthetic fractures around stable implants. To provide instant postoperative full weight-bearing, bicortical screw fixation is advisable but often surgically demanding. This work presents the first clinical results of the LOQTEQ^® VA Periprosthetic Plate (aap Implantate AG, Berlin, Germany), a new plate system to simplify screw placement around implants. This plate system uses insertable hinges that allow for variable angle screw anchorage. Data of 26 patients with a mean age of 80 years and a mean follow-up of 13.9 months were retrospectively collected. Patients were clinically and radiologically examined. Bony union was achieved in 14 out of 15 patients with no signs of non-union or implant loosening. One patient, however, presented with implant failure. Clinical scores demonstrated acceptable results. Since the hinge plates are easy to apply, the first results are promising.

A New System for Periprosthetic Fracture Stabilization-A Biomechanical Comparison

In recent years, an increase in periprosthetic femur fractures has become apparent due to the increased number of hip replacements. In the case of Vancouver type B1 fractures, locking plate systems offer safe procedures. This study compared the distal lateral femur plate (LOQTEQ^®, aap Implantate AG) with a standard L.I.S.S. LCP^® (DePuy Synthes) regarding their biomechanical properties in fixation of periprosthetic femur fractures after hip arthroplasty. We hypothesized that the new LOQTEQ system has superior stability and durability in comparison. Eighteen artificial left femurs were randomized in two groups (Group A: LOQTEQ^®; Group B: L.I.S.S. LCP^®) and tested until failure. Failure was defined as 10° varus deformity and catastrophic implant failure (loosening, breakage, progressive bending). Axial stiffness, loads of failure, cycles of failure, modes of failure were recorded. The axial stiffness in Group A with 73.4 N/mm (SD +/− 3.0) was significantly higher (p = 0.001) than in Group B (40.7 N/mm (SD +/− 2.8)). Group A resists more cycles than Group B until 10° varus deformity. Catastrophic failure mode was plate breakage in Group A and bending in Group B. In conclusion, LOQTEQ^® provides higher primary stability and tends to have higher durability.

[Medicine for people with disabilities : Special features of trauma surgical care of extremity injuries in people with severe mental and physical disabilities]

Die von Bodelschwinghschen Stiftungen Bethel blicken auf eine über 150-jährige Tradition in der Behandlung von Menschen mit Behinderungen. Das traumatologische Patient*innenkollektiv ist dabei regelmäßig durch schwerste geistige und körperliche Entwicklungsstörungen und (Mehrfach‑)Behinderungen, mit und ohne Verhaltensstörungen, und internistische Begleiterkrankungen charakterisiert. Diese besondere Kombination erfordert ärztlich wie pflegerisch eine Therapie und Indikationsstellung, welche in allen Behandlungsschritten spezifisch abgewogen und angepasst werden muss. Behandlungsrichtlinien oder Empfehlungen zu diesem Patientenkollektiv existieren in der Literatur nicht. Des Weiteren kann die Behandlung von Frakturen bei Menschen mit Behinderungen nicht immer nach etablierten Konzepten erfolgen. Aufgrund einer hohen postoperativen Komplikationsrate kommt der konservativen Therapie eine entscheidende Rolle zu. Die Entscheidung zur operativen Therapie muss interdisziplinär und individuell unter Berücksichtigung sämtlicher Faktoren getroffen werden. Spezielles Augenmerk muss dabei auf das zu wählende Verfahren (Stabilität, funktionelle Bedürfnisse) gerichtet werden.

Periprosthetic hip fractures: an update into their management and clinical outcomes

The Vancouver classification is still a useful tool of communication and stratification of periprosthetic fractures, but besides the three parameters it considers, clinicians should also assess additional factors.

Combined advanced trauma and arthroplasty skills must be available in departments managing these complex injuries.

Preoperative confirmation of the THA (total hip arthroplasty) stability is sometimes challenging. The most reliable method remains intraoperative assessment during surgical exploration of the hip joint.

Certain B1 fractures will benefit from revision surgery, whilst some B2 fractures can be effectively managed with osteosynthesis, especially in frail patients.

Less invasive osteosynthesis, balanced plate–bone constructs, composite implant solutions, together with an appropriate reduction of the limb axis, rotation and length are critical for a successful fixation and uneventful fracture healing.

Cite this article: EFORT Open Rev 2021;6:75-92. DOI: 10.1302/2058-5241.6.200050

Periprosthetic fracture fixation in Vancouver B1 femoral shaft fractures: A biomechanical study comparing two plate systems

Introduction

Periprosthetic fractures of the femur are an increasing problem in today's trauma and orthopaedic surgery. Owing to the hip stem, implant anchorage is very difficult in the proximal femur. This study compares two plate systems regarding their biomechanical properties and the handling in periprosthetic fracture fixation of the proximal femur.

Materials and methods

Using eight pairs of fresh, frozen human proximal femora the Locking Compression Plate/Locking Attachment Plate construct (LCP/LAP) (group I, DePuy Synthes) was compared to the new LOQTEQ® periprosthetic distal lateral femur plate (group II, AAP Implantate AG). After implantation of press fit femoral hip stems a Vancouver B1 fracture model was used. Biomechanical testing was performed by cyclic axial loading with a constant increment of 0.1 N/cycle starting from 750 N axial loading. Every 250 cycles an a.p. x-ray was done to evaluate failure.

Results

The Group II showed significant higher axial stiffness (+42%) compared with Group I. In addition, Group II withstood significantly more load-cycles until failure (20%). The mode of catastrophic failure was plate breakage in Group II, whereas, in Group I, all plates showed an early bending followed by plate breakage.

Discussion and conclusion

Both plate systems enable screw placement around hip stems. The hinge plate showed superior biomechanical results compared with the locking compression plate/locking attachment plate construct. Furthermore, the hinge plate offers variable hinges and variable angel locking making bicortical screw placement around hip stems more comfortable and safe.

The translational potential of this article

The results of this study can be directly transferred to patient care. With the innovative hinge plate, the surgeon has a biomechanically superior implant, which also offers improved options for screw placement compared to a standard locking plate.

[Periprosthetic fractures: basics, classification and treatment principles]

Periprosthetic fractures (PPFx) are becoming an increasingly important topic in orthopedics and trauma surgery due to the rising number of endoprosthetic joint replacements. The recently published unified classification system (UCS) has replaced numerous historical classification systems and can be applied to all PPFx regardless of the bone or joint involved. The treatment of PPFx requires individual therapeutic concepts taking patient-dependent and patient-independent factors into consideration. The conservative treatment of PPFx is only justified in exceptional situations. In contrast, the choice between operative treatment and deciding between osteosynthesis or revision arthroplasty is particularly based on the assessment of the implant stability. In order to achieve fracture consolidation and also a good functional outcome, knowledge of the basic biomechanical principles of operative (osteosynthesis or endoprosthesis) treatment of periprosthetic fractures is necessary.

Prosthesis-Engaging Retrograde Femoral Nail with Locking Plate for the Treatment of a Vancouver B1 Periprosthetic Femur Fracture Nonunion: A Case Report

CASE

Here, we describe a case of a Vancouver B1 periprosthetic femur fracture which initially went on to nonunion after open reduction and internal fixation. Union was ultimately achieved with a construct consisting of a prosthesis-engaging retrograde femoral nail and a locking compression plate.

CONCLUSIONS

This case provides evidence that a construct consisting of a prosthesis-engaging retrograde femoral nail and a locking compression plate is an option for increasing fracture site stability in Vancouver B1 periprosthetic fractures and may be useful for patients with poor bone quality or a previously established nonunion.

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.

Lower reoperation rate with locking plates compared with conventional plates in Vancouver type C periprosthetic femoral fractures: A register study of 639 cases in Sweden

AIM

To investigate demographics and outcomes of Vancouver type C periprosthetic femoral fractures (PPFF) treated with open reduction and internal fixation.

METHODS

Patient data were obtained from medical charts of cases reported to the Swedish Hip Arthroplasty Register and/or from the National Patient Register. Vancouver type C fractures undergoing surgery between 2001 and 2011, in patients who had received their primary THR between 1979 and 2011, were included. Any further reoperation performed between 2001 and 2013 and related to the PPFF constituted the primary outcome.

RESULTS

A total of 632 patients with 639 Vancouver type C fractures were identified. The majority of the patients were women (84%) and they had a fracture distal to a cemented stem (95%). The mean age at the time of fracture was 72 years. Treatment was performed with a locking plate (363 cases), a conventional plate (184 cases), an intramedullary nail (62 cases), or with double plating (30 cases). The overall reoperation rate was 17%, and mortality within one year of the operation was 16%. Locking plates had a significantly lower reoperation rate than conventional plates (p<0.001) and intramedullary nailing (p = 0.005). Interprosthetic femoral fractures did not have a statistically different outcome compared with non-IPFFs.

CONCLUSIONS

The lowest reoperation rate was observed using locking plates in Vancouver type C fractures when compared with conventional plates or intramedullary nailing. The presence of an ipsilateral knee prosthesis did not influence the outcome of the surgical treatment.

Additional fixation of medial plate over the unstable lateral locked plating of distal femur fractures: A biomechanical study

INTRODUCTION

Lateral locked plating is a standard treatment option for distal femur fractures. However, the unstable conditions after lateral locked plating are increasing. The objective of this study was to investigate the biomechanical strength of additional medial plate fixation over the unstable lateral locked plating of distal femur fractures.

MATERIALS AND METHODS

A distal femur fracture model (AO/OTA 33-A3) was created with osteotomies in the composite femur. Three study groups consisting of 6 specimens each were created for single-side lateral locked plating with 6 distal locking screws (LP-6), single-side lateral locked plating with 4 distal locking screws (LP-4), and additional medial locked plating on LP-4 construct (DP-4). A compressive axial load (10 mm/min) was applied in the failure test. Mode of failure, load to failure, and ultimate displacement were documented.

RESULTS

All single-side lateral locked plating (LP-4 and LP-6) showed plate bending at the fracture gap, while none of the DP-4 showed plate bending at the fracture gap. Load to failure of DP-4 (mean 5522 N) was 17.1% greater than that of LP-6 (mean 4713.3 N, p < 0.05) and 29.2% greater than that of LP-4 (mean 4273.2 N, p < 0.05). Ultimate displacement of DP-4 (mean 5.6 mm) was significantly lower than that of LP-6 (mean 8.8 mm, p < 0.05) and LP-4 (mean 9.1 mm, p < 0.05).

CONCLUSIONS

Additional fixation of medial plate significantly increased the fracture stability in distal femur fractures fixed with the lateral locked plating. Especially in the clinical situations where sufficient stability cannot be provided at the distal segment, the medial plate may be considered as a useful biomechanical solution to obtain adequate stability for fracture healing.

Periprosthetic fracture fixation of the femur following total hip arthroplasty: A review of biomechanical testing - Part II

BACKGROUND

Periprosthetic femoral fracture is a severe complication of total hip arthroplasty. A previous review published in 2011 summarised the biomechanical studies regarding periprosthetic femoral fracture and its fixation techniques. Since then, there have been several commercially available fracture plates designed specifically for the treatment of these fractures. However, several clinical studies still report failure of fixation treatments used for these fractures.

METHODS

The current literature on biomechanical models of periprosthetic femoral fracture fixation since 2010 to present is reviewed. The methodologies involved in the experimental and computational studies of periprosthetic femoral fracture fixation are described and compared with particular focus on the recent developments.

FINDINGS

Several issues raised in the previous review paper have been addressed by current studies; such as validating computational results with experimental data. Current experimental studies are more sophisticated in design. Computational studies have been useful in studying fixation methods or conditions (such as bone healing) that are difficult to study in vivo or in vitro. However, a few issues still remain and are highlighted.

INTERPRETATION

The increased use of computational studies in investigating periprosthetic femoral fracture fixation techniques has proven valuable. Existing protocols for testing periprosthetic femoral fracture fixation need to be standardised in order to make more direct and conclusive comparisons between studies. A consensus on the 'optimum' treatment method for periprosthetic femoral fracture fixation needs to be achieved.

Influence of treatment modality on morbidity and mortality in periprosthetic femoral fracture. A comparative study of 71 fractures treated by internal fixation or femoral implant revision

INTRODUCTION

The incidence of periprosthetic femoral fracture is constantly increasing, with high associated morbidity and mortality. Surgical treatment is guided by the Vancouver classification, but the influence of type of treatment on morbidity and mortality has been little analyzed. The theoretical advantage of implant revision over internal fixation is that it should allow earlier weight-bearing, although the impact of this on morbidity and mortality and autonomy has not been demonstrated. We conducted a case-control study, to assess the influence of type of treatment (implant revision or internal fixation) (1) on mobility and autonomy and (2) on morbidity and mortality.

HYPOTHESIS

The study hypothesis was that clinical results and morbidity and mortality do not differ between these two types of treatment.

METHODS

A retrospective study included 70 patients with a total of 71 femoral periprosthetic fractures treated between 2007 and 2014. Two treatment groups, comparable for mean age, gender and ASA and Parker scores, were studied. Mean age was 78±13.5years (range, 23-95years). Thirty-six fractures (50.7%) were treated by implant revision via a posterolateral approach, using a revision stem with (n=11) or without cement (n=25) (REVISION group); immediate postoperative weight-bearing was authorized. Thirty-five fractures (49.3%) were treated by open reduction and internal fixation, using a locking plate (ORIF group); weight-bearing was authorized only in the third month. Mean follow-up was 43±27months (range, 0.75-107months).

RESULTS

Autonomy on Parker score was reduced by 2 points at 1year's follow-up. Mean preoperative scores were 7.32±1.79 (range, 3-9) and 7.43±1.79 (range, 4-9) in the REVISION and ORIF group, respectively, (p=0.8), falling to 5.06±2.6 (range, 0-9) and 4.5±2.01 (range, 0-9) respectively at follow-up (p=0.349). Sixteen patients in the REVISION group versus 13 in the ORIF group had made adaptations in their home or changed place of residence (p=0.2). At last follow-up, 18 patients (28.6%) had died: 12 (37.5%) in the ORIF and 6 (19.3%) in the REVISION group (p<0.05). Survival with death as endpoint at a mean 3.5years was 88±11% in the REVISION group versus 51±11% in the ORIF group (p=0.02). Three implant replacements were performed in each group (p=0.83). Twelve medical or surgical complications occurred in the ORIF group (37.5%) and 11 in the REVISION group (34%) (p=0.9).

CONCLUSION

Implant revision for periprosthetic femoral fracture showed significantly lower overall mortality than internal fixation, without difference in terms of treatment failure or complications requiring revision surgery.

LEVEL OF EVIDENCE

Level III, case-control study.