Bicortical screw fixation provides superior biomechanical stability but devastating failure modes in periprosthetic femur fracture care using locking plates

[Concept for the treatment of periprosthetic proximal femoral fractures]

Due to demographic changes and increased survival rates of total hip arthroplasties, the incidence of periprosthetic proximal femoral fractures is increasing. The current treatment concept requires accurate preoperative planning. Besides patient-related risk factors, fracture type, prosthesis stability, and bone quality influence whether osteosynthesis or a revision arthroplasty is required.

Comparison of five methods for locked-plate fixation of complex diaphyseal fractures

BACKGROUND

Peri-prosthetic fractures (PPFs) are steadily rising in number due to population ageing and increased performance of joint replacement procedures. Although PPFs without implant loosening are usually managed by internal fixation, no consensus exists regarding the optimal construct. The primary objective of this study was to compare five constructs, and the secondary objective was to compare sub-groups of mono-cortical screw constructs, with the goal of identifying the method most appropriate for diaphyseal fracture fixation when prosthetic material is present within the intra-medullary canal.

HYPOTHESIS

The primary hypothesis was that fixation using bi-cortical screws, i.e., the current reference standard, was superior over other fixation methods. The secondary hypothesis was that adding double cerclage to mono-cortical screw fixation provided the greatest mechanical strength.

MATERIALS AND METHODS

Synthetic osteoporotic bone was used to compare five methods for locking-screw fixation of a femoral diaphyseal plate. One method involved bi-cortical screws and four methods mono-cortical screws, with no cerclage wire, a single cerclage wire on either side positioned near or at a distance from the fracture, and two cerclage wires on both sides of the fracture. A complex fracture was simulated by creating a 2-cm diaphyseal gap. Load-to-failure was determined by applying compression loading along the anatomical axis of the femur.

RESULTS

Bi-cortical screw fixation provided greater mechanical strength than did three of the four mono-cortical screw constructs. The exception was the mono-cortical-screw and double-cerclage construct, for which no significant difference was found compared to bi-cortical screw fixation. Thus, mono-cortical screw fixation with double cerclage may be the best alternative when presence of an implant in the intra-medullary canal precludes bi-cortical screw fixation.

CONCLUSION

The findings from this study have clear implications for clinical practice. The study hypotheses were partly confirmed. The absence of a significant difference between the reference-standard bi-cortical screw fixation method and mono-cortical screw fixation with double cerclage, combined with the results regarding the secondary objective, suggest that mono-cortical screws plus double cerclage deserve preference in patients with an intra-medullary implant. Clinical studies are needed to assess the results of this bench study.

LEVEL OF EVIDENCE

IV, bench 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.

"Stress taper" fixation increases torsional failure strength in a cadaveric femur model

BACKGROUND

To potentially limit peri-implant fractures our institution commonly implements a "stress-taper" fixation construct in which the screw lengths towards the proximal end of a construct are incrementally decreased, in order to avoid a focal stress-riser when loaded. To assess this construct, we asked: 1) Does the stress taper strategy increase torsional strength than the bicortical locking construct when biomechanically tested in a cadaveric femur model? 2) Does it fail in a less comminuted fracture pattern?

METHODS

Seven matched pairs of cadaveric femora were randomly assigned to one of two distal femur fixation groups: plating with stress taper strategy or bicortical fixation. Specimens were first cyclically loaded, then axially rotated to failure under 800 N of compression. Peak torque at failure, degrees of rotation at failure, and energy to failure were calculated and compared using paired t-tests. Fractures were categorized with the assistance of fluoroscopy according to the Orthopedic Trauma Association classification, 32.

FINDINGS

There was significantly greater peak torque (110.6 ± 49.7 Nm vs. 80.6 ± 35.2 Nm), rotation at failure (23.8 ± 5.3° vs 18.9 ± 4.5°) and energy to failure (25.3 ± 15.7 J vs. 14.1 ± 8.3 J) in the stress-taper group as compared to the bicortical group (p = 0.0424), (p = 0.0213) and (p = 0.0460), respectively. 6/7 fractures in the stress-taper group were classified 32 A1 with 1/7 classified A2. 5/7 fractures in the bicortical group were classified B1 and 2/7 classified A2.

INTERPRETATION

'Stress taper fixation' in distal femurs may be protective against peri-implant fractures compared to traditional bicortical fixation. The 'stress taper' concept can increase torsional failure strength in an in vitro model.

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.

The effect of surgeon-controlled variables on construct stiffness in lateral locked plating of distal femoral fractures

Background

Nonunion following treatment of supracondylar femur fractures with lateral locked plates (LLP) has been reported to be as high as 21 %. Implant related and surgeon-controlled variables have been postulated to contribute to nonunion by modulating fracture-fixation construct stiffness. The purpose of this study is to evaluate the effect of surgeon-controlled factors on stiffness when treating supracondylar femur fractures with LLPs:

Does plate length affect construct stiffness given the same plate material, fracture working length and type of screws?

Does screw type (bicortical locking versus bicortical nonlocking or unicortical locking) and number of screws affect construct stiffness given the same material, fracture working length, and plate length?

Does fracture working length affect construct stiffness given the same plate material, length and type of screws?

Does plate material (titanium versus stainless steel) affect construct stiffness given the same fracture working length, plate length, type and number of screws?

Methods

Mechanical study of simulated supracondylar femur fractures treated with LLPs of varying lengths, screw types, fractureworking lenghts, and plate/screw material. Overall construct stiffness was evaluated using an Instron hydraulic testing apparatus.

Results

Stiffness was 15 % higher comparing 13-hole to the 5-hole plates (995 N/mm849N vs. /mm, p = 0.003). The use of bicortical nonlocking screws decreased overall construct stiffness by 18 % compared to bicortical locking screws (808 N/mm vs. 995 N/mm, p = 0.0001). The type of screw (unicortical locking vs. bicortical locking) and the number of screws in the diaphysis (3 vs. 10) did not appear to significantly influence construct stiffness (p = 0.76, p = 0.24). Similarly, fracture working length (5.4 cm vs. 9.4 cm, p = 0.24), and implant type (titanium vs. stainless steel, p = 0.12) did also not appear to effect stiffness.

Discussion

Using shorter plates and using bicortical nonlocking screws (vs. bicortical locking screws) reduced overall construct stiffness. Using more screws, using unicortical locking screws, increasing fracture working length and varying plate material (titanium vs. stainless steel) does not appear to significantly alter construct stiffness. Surgeons can adjust plate length and screw types to affect overall fracture-fixation construct stiffness; however, the optimal stiffness to promote healing remains unknown.

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.

Treatment of distal femur fractures with VA-LCP condylar plate: A single trauma centre experience

INTRODUCTION

Given the recent criticisms in the literature regarding Synthes Variable Angle Locking Compression Condylar Plate (VA-LCP), the purpose of this study was to evaluate functional outcome, fracture healing, and complications of distal femoral intra-articular fractures using this device.

METHODS

Patients with distal femoral fractures treated with 4.5 mm VA-LCP Curved Condylar Plate were included in this retrospective study. Follow-ups were at 4 weeks, 3 months, 6 months and 1 year. For the clinical and functional assessment of the knee, WOMAC, Koos Knee Survey, the Knee Score Society and the SF-12 questionnaire were used. Radiographically we assessed the fracture healing and the angles of the operated limb compared to the healthy contralateral limb. Complications have also been described.

RESULTS

Forty-two patients with distal femoral fractures were included in the study. The mean follow-up was 8 months. Most cases (57%) reported a type 33-A fracture. Radiological healing was achieved in 33 cases; the mean time required to heal was 13 weeks. Three patients had an early postoperative complication and four cases had a late complication. Five cases required additional surgical procedures. Most patients (47.2%) achieved a complete flexion of 130° or more. WOMAC mean value 27.4%, KSS mean value 77.6 for the clinical part and 60 for the functional part, KOOS mean score 60.1, SF-12 mean score 46.1 for MCS and 35.5 for PCS.

DISCUSSION

The results of this retrospective study suggest that VA-LCP Curved Condylar Plates have a good functional outcome and fracture healing similar to other standard distal femoral locking plates. VA technology allows greater versatility in fractures internal fixation regardless of the plate design. Fixation devices or Prosthesis implants previously placed may be avoided, as in periprosthetic fractures. Moreover, we have not recorded any early mechanical damage.

CONCLUSIONS

Osteosynthesis with Synthes 4.5 mm VA-LCP Curved Condylar Plate demonstrated to have no early mechanical failure rate with good clinical and radiological results.

[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.

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.

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.

Biomechanical Evaluation of Osteoporotic Proximal Periprosthetic Femur Fractures With Proximal Bicortical Fixation and Allograft Struts

OBJECTIVES

To evaluate the strength of proximal bicortical fixation using a novel osteoporotic synthetic bone model of Vancouver B1 periprosthetic proximal periprosthetic femur fractures (PFFs) and to assess the influence of strut allograft augmentation with regard to allowing early assisted weight bearing. The secondary aim was to evaluate whether the strut position, either medial or anterior, influenced the strength of the construct.

METHODS

Thirty synthetic osteoporotic femurs were implanted with cemented stems. A segmental defect made distal to the stem simulated a fracture and was repaired with a stainless steel locking compression plate and 2 stainless steel proximal locking attachment plates. Specimens were then divided into 3 groups: no-strut, medial strut, and anterior strut. Cadaveric femoral struts were wired to the specimens. Cyclic axial compression simulated assisted weight bearing and was followed by loading to failure.

RESULTS

Medial struts required higher failure load than no-strut (P = 0.008) and more energy to failure than anterior (P = 0.018) or no-strut (P < 0.001). The higher load to failure, however, would not be advantageous in clinical practice because estimates for assisted weight bearing after fractures in average-weight patients are well below these failure loads. Furthermore, all specimens tolerated cyclical loading. All failures occurred distal to the plate originating at the last screw hole.

CONCLUSIONS

Failure loads for all groups were above what would be expected for low-demand activities of assisted weight bearing. Therefore, proximal bicortical fixation should allow for early, assisted weight bearing without allograft strut augmentation even with lower density bone.

Outcomes of distal femur fractures treated with the Synthes 4.5 mm VA-LCP Curved Condylar Plate

PURPOSE

Given the recent controversy in the literature and the alarming reports of early mechanical failure associated with the use of the Synthes 4.5 mm VA-LCP Curved Condylar Plate in acute distal femur fractures, the goal of our study was to examine the outcomes and mechanical failure rates of this implant in a larger patient population.

METHODS

Patients 18 years of age and older who underwent plate fixation of their acute distal femoral fracture using the Synthes 4.5 mm VA-LCP Curved Condylar Plate were included in this retrospective study. The study data was collected through a retrospective chart review and review of the existing radiographic studies. Primary outcome measure was mechanical hardware failure while secondary outcome measures included nonunion, malunion, and medical and surgical complications.

RESULTS

A total of 74 patients (77 fractures) were included in this study. The fractures were classified according to the OTA/AO classification as 33-A2 (n = 6), 33-A3 (n = 19), 33-C1 (n = 5), 33-C2 (n = 25), and 33-C3 (n = 22). Thirty-two out of 77 fractures presented as open fractures (41.6%). A mechanical failure was observed in 7 patients (9.1%). Twenty additional patients needed a re-operation of the surgical site including two nonunion repairs, one malunion repair, 15 staged treatments of traumatic segmental bone defects, and two soft tissue debridements.

CONCLUSIONS

In our experience, the Synthes 4.5 mm VA-LCP Curved Condylar Plate is a safe and effective implant with a relatively low mechanical failure rate.

Nail and Locking Plate for Periprosthetic Fractures

The incidence of periprosthetic fractures have been increasing, and in patients with osteopenic bone, high body mass index, or a combination both, they are difficult to treat and pose a high risk for malunion. Previous studies have compared the use of locking plates and intramedullary nails, and have found that each has its own strengthens and drawbacks, but neither is superior in terms of treating periprosthetic fractures. Here, we present the technique and series of patients treated with a combination of a retrograde intramedullary nail and flare-to-flare lateral locking plate without the use of allograft or autograft supplementation.

Successful open reduction and internal fixation for displaced femoral fracture in a patient with osteopetrosis: Case report and lessons learned

RATIONALE

Osteopetrosis is a rare disease that predominantly occurs in descendants of inbreeding families. In the case of fractures happen in patients with osteopetrosis, the choice between operative or conservative treatment is still controversial. Open reduction and internal fixation (ORIF) is a conventional treatment for fractures, and it possesses more applicability than conservative treatment. During this surgical treatment, ensure that bone union in the right way is pivotal to success and simultaneously prevents refracture and displacement after the operation. Herein, we present a case of femoral fracture of a patient with osteopetrosis via open reduction and internal fixation. To illustrate successful factors during the treatment process, we discuss experience combined with literature review following case report.

PATIENT CONCERNS

A 67-year-old man who has diagnosed with osteopetrosis over 20 years ago suffered from pain in the left hip last for more than 1 month and he was incapable of walking recently. Before this incident, he had sustained 4 femoral fractures that treated insufficiently by open reduction surgery.

DIAGNOSIS

Physical, radiological, and biological examinations indicated a femoral subtrochanteric fracture that was overlapping displacement between fracture ends.

INTERVENTIONS AND OUTCOMES

Treated with surgery by open reduction with internal fixation and osteotomy, the fracture united in 12 months, and he returned to walk with full weight bearing, during which no complication occurred.

LESSONS

Open reduction and internal fixation is also suitable for the patient with osteopetrosis, and they have similar union ability to the normal. To guarantee successful treatment, specific strategies of operation and rehabilitation program are necessary.

History of internal fixation with plates (part 2): new developments after World War II; compressing plates and locked plates

The first techniques of operative fracture with plates were developed in the 19th century. In fact, at the beginning these methods consisted of an open reduction of the fracture usually followed by a very unstable fixation. As a consequence, the fracture had to be opened with a real risk of (sometimes lethal) infection, and due to unstable fixation, protection with a cast was often necessary. During the period between World Wars I and II, plates for fracture fixation developed with great variety. It became increasingly recognised that, because a fracture of a long bone normally heals with minimal resorption at the bone ends, this may result in slight shortening and collapse, so a very rigid plate might prevent such collapse. However, as a consequence, delayed healing was observed unless the patient was lucky enough to have the plate break. One way of dealing with this was to use a slotted plate in which the screws could move axially, but the really important advance was recognition of the role of compression. After the first description of compression by Danis with a "coapteur", Bagby and Müller with the AO improved the technique of compression. The classic dynamic compression plates from the 1970s were the key to a very rigid fixation, leading to primary bone healing. Nevertheless, the use of strong plates resulted in delayed union and the osteoporosis, cancellous bone, comminution, and/or pathological bone resulted in some failures due to insufficient stability. Finally, new devices represented by locking plates increased the stability, contributing to the principles of a more biological osteosynthesis while giving enough stability to allow immediate full weight bearing in some patients.

High union rates of locking compression plating with cortical strut allograft for type B1 periprosthetic femoral fractures

PURPOSE

Unified classification system (UCS) type B1 periprosthetic femoral fractures are associated with many complications, and management decisions continue to be controversial. The purpose of this study was to evaluate outcomes of UCS type B1 periprosthetic femoral fractures treated by locking compression plating with strut allograft augmentation.

MATERIALS AND METHODS

We retrospectively reviewed 17 consecutive UCS type B1 periprosthetic femoral fractures treated by open reduction and internal fixation using a lateral locking compression plate supplemented with an anterior cortical strut allograft. There was one man and 16 women with an average age of 74 years (range, 57-92 years). All had a cementless hip arthroplasty, and eight of the arthroplasties were revisions.

RESULTS

The mean duration of follow-up was 28 months (range, 12-74 months). All 17 fractures healed successfully at a mean of 20 weeks (range, 12-30 weeks). The mean post-operative Harris hip score was 86 points (range, 77-95 points). No mechanical complications such as failure of plate or screws and malalignment were noted. According to the graft-remodeling classification of Emerson et al., a partial bridging was observed in nine and a complete bridging in eight. Two patients required a removal of the plate due to irritation of the iliotibial band. No femoral stem loosening or deep infection was observed.

CONCLUSION

Our findings indicate that open reduction and internal fixation of UCS type B1 periprosthetic femoral fractures using a lateral locking compression plate supplemented with anterior cortical strut allograft provides adequate mechanical stability of fracture fixation and enhances the fracture healing.