The Treatment of Periprosthetic Distal Femoral Fractures After Total Knee Replacement: A Critical Analysis Review

Outcomes of operatively managed periprosthetic distal femur fractures compared to fractures in patients with native knees

Introduction

With the increasing incidence of total knee arthroplasty (TKA), there is an expected rise in rate of periprosthetic fractures in the coming years. It is unclear how the outcomes of patients with distal femur fractures (DFF) and a total knee arthroplasty compare to patients of the same age group with native knees (NK).

Materials and methods

A retrospective review was completed for distal femur fractures treated with surgical fixation from January 2019-March 2021. We excluded patients <50 years old, non-ambulatory patients, revision surgeries, and patients with less than 90 days of follow-up. A chart review was performed to collect age, gender, BMI, smoking status, American Society of Anesthesiology (ASA) classification, fracture type, fixation method, time to full weight bearing, and complications. Comparisons between the TKA vs native knee groups were performed using t-test, chi-square, and Fisher's exact test where appropriate.

Results

138 patients were included in our study with a mean age of 74 years. 69 DFF ipsilateral to a TKA were included in the study group and 71 DFF were included in the native knee group. Age, sex, BMI, smoking status, and ASA class were similar between the groups. All patients with periprosthetic femur fractures had 33A AO/OTA fracture classification. Patients with native knees were more likely to receive dual implant fixation, 15.5% compared to 4.3% (p = 0.02). Full weight bearing was achieved at 8.5 vs 8.6 weeks between the NK and TKA groups (p = 0.64). The complication rate was 16.9% in the NK group vs. 7.2% in the TKA group (p = 0.21).

Conclusion

Patients with periprosthetic femur fractures have similar time to weight bearing and complications rate with patients with distal femur fracture in native knees. We found a higher utilization rate of dual implant fixation in the native knee group.

Minimally invasive surgery of femoral periprosthetic fractures increases the rate of consolidation and decreases time to bone healing without a higher rate of complications

BACKGROUND

Knee periprosthetic femoral fractures (KPPFF) are becoming more frequent due to the increasing number of arthroplasties and the aging population, for whom maintaining autonomy and function remains a challenge. The use of locking plates has improved functional results and promoted the development of "minimally invasive" surgical (MIS) approaches. Despite the availability of literature comparing between different types of osteosynthesis for KPPFF, there is a paucity of information available on the complications of osteosynthesis using locking plates, depending on the approach. We therefore carried out a retrospective multicenter study (nine centers: Dijon, Grenoble, Lille, Marseille, Nice, Paris, Saint-Étienne, Strasbourg, Colmar) as part of a Symposium of the French Society of Orthopedic Surgery and Traumatology (SOFCOT). Following osteosynthesis of KPPFF by locking plates carried out by a standard approach or by a minimally invasive approach (MIS), the objectives were: (1) to compare the complications, (2) to evaluate whether the radiological and clinical results (rate and time of consolidation, resumption of weight bearing, lack of reduction, postoperative autonomy) were comparable in the two groups.

HYPOTHESIS

The hypothesis was that performing an MIS approach in these indications does not confer more complications than a standard approach, and rather, the MIS approach offers better functional and radiological results.

MATERIAL AND METHOD

Five hundred and seventy-three patients presented with KPPFF over the periods studied (retrospective series from January 2012 to December 2016, then prospective series from January to December 2019). After applying the inclusion criteria (KPPFF by locking plate) and exclusion criteria (tumor context, infectious, intraoperative fractures, fractures on loose prostheses, other osteosynthesis methods, treatment by prosthetic revision, patients under the age of 18, follow-up less than 1-year, incomplete files), a global series of 306 patients was retained. Two groups were created according to the approach performed: a standard approach group (S, n=228) and a minimally invasive approach group (MIS, n=78). The demographic data of the population were recorded, as was the criteria for autonomy (Parker score, place of living). Postoperative complications were sought (infection, mechanical complication, surgical revision). Finally, the radiological and clinical results were evaluated (rate of, and time to consolidation, resumption of weight bearing, lack of reduction, postoperative autonomy).

RESULTS

The comparison of the two subgroups, S and MIS, found complication rates are comparable in the two groups in terms of infections [S group: n=18 (7.9%), MIS group: n=2 (2.6%)], mechanical complications [S: n=23 (10.1%), MIS: n=2 (2.6%)], and surgical revision [S: n=33 (14.5%), MIS: n=7 (8.9%)], and a lack of difference in postoperative autonomy [Parker; S group: 4.7±2.4 (0-9) vs. MIS group: 5±2, 7 (0-9)]. On the other hand, the time to return to weight bearing was shorter in the MIS group [4.3±3.5weeks (0-12) versus 10.1±10.1weeks (0-110), p<0.001]. The rate of nonunion was lower in the MIS group [n=1 vs. n=20, i.e. 1.7% vs. 11.1% (p=0.031)] and the time to consolidation was shorter [7.5±4.3weeks (6-30) versus 15.2±9.4weeks (5-78) (p<0.001)].

CONCLUSION

Performing an MIS approach in the management of KPPFF by locking plate osteosynthesis does not cause any more complications than a standard approach. In addition, higher consolidation rates can be obtained in shorter periods of time. This study suggests that it proposing osteosynthesis using the MIS approach as a primary surgery is a reasonable choice when treatment using locking plates is chosen for a KPPFF, subject to technical expertise.

LEVEL OF EVIDENCE

III; observational study.

Revision total knee arthroplasty with periprosthetic distal femoral fracture

Treatment strategies for periprosthetic distal femoral fracture depend on the type of fracture, level with respect to the prosthesis, and prosthesis fixation. The usual treatment is internal fixation by nail or locking plate. This can be more difficult when the fracture is close to the joint, is destabilizing the prosthesis or is associated with reduced bone stock, and implant exchange should be considered, depending on the patient's health status. The aim is to obtain the fastest possible recovery while limiting complications and minimizing surgery time for often frail and elderly patients. The present study details the implant revision technique in periprosthetic distal femoral fracture, which requires experience in traumatology and prosthetic revision and material adapted to the situation. LEVEL OF EVIDENCE: V, expert opinion.

[High revision rates and mortality after treatment of periprosthetic distal femur fractures with a distal femur replacement : An analysis from the EPRD]

BACKGROUND

Periprosthetic distal femoral fractures (PDFF) are challenging injuries, as mostly geriatric patients with serious comorbidities are affected. Revision to a distal femoral replacement (DFR) is often the best option in very distal fractures, poor bone stock and/or loose total knee replacement. Data on outcome after these surgeries is limited.

OBJECTIVES

This study was initiated to analyze the outcome after distal femoral replacement for periprosthetic distal femoral fractures.

MATERIALS AND METHODS

Data of the German Arthroplasty Registry (EPRD) were analyzed. From a total of 43,945 revision knee replacement surgeries in the registry, 629 patients could be identified with a PDFF in which a DFR was used for revision. The mean age was 79.1 years, and 84.1% were female. Revisions and mortality were analyzed and compared with patient groups with a similar procedure (revision total knee arthroplasty) or similar general condition (fracture hip replacement). To make the groups more comparable, matched-pair-analyses were performed that included age, gender, BMI and comorbidities as matching parameters.

RESULTS

Within 1 year after surgery 17.1% of the patients died and 10.4% were revised. Within 4 years 35.5% died and 22.3% were revised. Revision rates were lower in elective knee revisions (1 year 6.0%, 4 years 16.8%). Periprosthetic joint infection (PJI) accounted for 50% of all revisions, resulting a PJI rate of 7.3%. Mortality after DFR was similarly high as after fracture hip arthroplasty.

CONCLUSION

After DFR for PDFF every third patient died, and every fifth patient needed revision within 4 years after surgery, which demonstrates the severity of this injury. Efforts should be undertaken to provide optimal treatment to these high-risk patients to reduce unfavorable outcomes. Surgeries should be well prepared and performed as early as possible in hospitals with adequate experience.

High revision rates and mortality after distal femoral replacement for periprosthetic distal femoral fractures: analysis from the German Arthroplasty Registry (EPRD)

PURPOSE

This study was initiated to analyze the outcome after distal femoral replacement (DFR) for periprosthetic distal femoral fractures (PDFF).

METHODS

Data from the German Arthroplasty Registry (EPRD) were analyzed. A total of 626 patients could be identified with a DFR for PDFF. Mean age was 78.8 years, and 84.2% were female. Revisions and mortality were analyzed and compared with patient groups with a similar procedure (revision total knee arthroplasty) or similar general condition (fracture total hip arthroplasty, hip hemiarthroplasty). Matched-pair-analyses were performed.

RESULTS

Within one year after surgery, 13.2% of the patients had died and further 9.4% were revised. Within four years, 32.7% had died and 19.7% were revised. Revisions were nearly twice as high as in the comparison groups. Periprosthetic infection (PJI) was the most frequent cause for revision, resulting in a PJI rate of 12.8%, which was lower in the comparison groups. Mortality after DFR was as similar high as after fracture hip arthroplasty.

CONCLUSION

PDFF are a serious injury, and the necessary surgical treatment has a high risk of complications. Every third patient after DFR for PDFF had died and every fifth patient needed revision within 4 years after surgery. Efforts should be undertaken to provide optimal treatment to these high-risk patients to reduce unfavorable outcomes.

LEVEL OF EVIDENCE

III.

REGISTRATION OF CLINICAL TRIALS

As this is a registry-derived study of data of the German Arthroplasty Registry (EPRD), no registration was performed.

Biomechanical analysis of different fixation methods for Rorabeck II supracondylar femoral fractures after total knee arthroplasty

BACKGROUND

Locking plate (LP) and retrograde intramedullary nailing (RIMN) are widely used to fix Rorabeck II supracondylar femoral fractures after total knee arthroplasty (TKA). The biomechanical properties of the implant used for treatment influence its longevity. Therefore, we aimed to evaluate the biomechanical stability of different fixations using finite element analysis.

METHODS

Seven finite element models (FEMs) were established, including LP groups (short LP, long LP, and double LP), RIMN groups (short RIMN and long RIMN), and mixed groups (long LP with short RIMN and long LP with long RIMN). The stress of the implants around the fracture area was calculated to evaluate the biomechanical stability under loads.

RESULTS

Stress was mainly distributed around the fracture area in all models. The stress-shielding phenomenon was most evident in the short LP. The trend in maximum equivalent stress values of implants around the fracture area for the seven internal fixations was: short LP (324.63 MPa) > short RIMN (306.37 MPa) > long LP (275.06 MPa) > long RIMN (262.74 MPa) > double LP (203.19 MPa) > long LP with short RIMN (124.42 MPa) > long LP with long RIMN (112.41 MPa). We found that the double LP can better disperse the stress than a single LP, and a long LP with long RIMN can prevent stress concentration and make the stress distribution more uniform.

CONCLUSION

From the perspective of biomechanics, long LP with long RIMN can stabilize fractures and avoid stress concentration in Rorabeck II supracondylar femoral fractures after TKA.

Impact of patient and prosthesis characteristics on common reasons for total knee replacement revision: a registry study of 36,626 revision cases from Australia, Sweden, and USA

BACKGROUND AND PURPOSE

Total knee replacement (TKR) studies usually analyze all-cause revision when considering relationships with patient and prosthesis factors. We studied how these factors impact different revision diagnoses.

PATIENTS AND METHODS

We used data from 2003 to 2019 of TKR for osteoarthritis from the arthroplasty registries of Sweden, Australia, and Kaiser Permanente, USA to study patient and prosthesis characteristics for specific revision diagnoses. There were 1,072,924 primary TKR included and 36,626 were revised. Factors studied included age, sex, prosthesis constraint, fixation method, bearing mobility, polyethylene type, and patellar component use. Revision diagnoses were arthrofibrosis, fracture, infection, instability, loosening, pain, patellar reasons, and wear. Odds ratios (ORs) for revision were estimated and summary effects were calculated using a meta-analytic approach.

RESULTS

We found between-registry consistency in 15 factor/reason analyses. Risk factors for revision for arthrofibrosis were age < 65 years (OR 2.0; 95% CI 1.4-2.7) and mobile bearing designs (MB) (OR 1.7; CI 1.1-2.5), for fracture were female sex (OR 3.2; CI 2.2-4.8), age ≥ 65 years (OR 2.8; CI 1.9-4) and posterior stabilized prostheses (PS) (OR 2.1; CI 1.3-3.5), for infection were male sex (OR 1.9; CI 1.7-2.0) and PS (OR 1.5; CI 1.2-1.8), for instability were age < 65 years (OR 1.5; CI 1.3-1.8) and MB (OR 1.5; CI 1.1-2.2), for loosening were PS (OR 1.5; CI 1.4-1.6), MB (OR 2.2; CI 1.6-3.0) and use of ultra-high molecular weight polyethylene (OR 2.3; CI 1.8-2.9), for patellar reasons were not resurfacing the patella (OR 13.6; CI 2.1-87.2) and MB (OR 2.0; CI 1.2-3.3) and for wear was cementless fixation (OR 4.9; CI 4.3-5.5).

INTERPRETATION

Patients could be counselled regarding specific age and sex risks. Use of minimally stabilized, fixed bearing, cemented prostheses, and patellar components is encouraged to minimize revision risk.

Periprosthetic knee fractures in an elderly population: open reduction and internal fixation vs distal femur megaprostheses

The incidence of periprosthetic fractures of distal femur (PPDFFx) after primary total knee arthroplasties is described around 0.3% and 2.5% and it is increasing as the number of patients with total knee arthroplasty continues to arise. surgical options treatments for PPDFFx include fixation in the form of eather Open reduction and internal fixation (ORIF), or retrograde intramedullary nailing (RIMN), or conventional (non locked) plating, or locked plating such as the Less Invasive Stabilization System (LISS), or dynamic condylar screws. In recent years, however, the use of megaprostheses has been increasing.

Patients with periprosthetic fractures of distal femur after primary total knee arthroplasties treated with ORIF or with the use of Distal femur replacement (DFR) were retrospectively analyzed in this to evaluate differences in intra-operative blood loss, need of blood trasfusion, weight bearing, range of motion, rate of complications, rate of revision surgery and functional outcome according Oxford Knee Score between two groups.

Treatment of Periprosthetic distal femur fracture remains controversial. While ORIF seems to guarantee less percentage of complications and reoperation rate, those treated with megaprosthesis seem to gain better range of motion in a very short post-operative time.

In the future it will be necessary to investigate with greater numbers possible advantages and disadvantages of the various treatments in periprosthetic distal femur fractures.

Management of a Complex Supracondylar Periprosthetic Femur Fracture with Intramedullary Strut Allograft and Bilateral Locking Plates

Supracondylar periprosthetic femoral fractures occurring above total knee replacements have been considered a rare entity. However, they continue to increase in frequency with the increasing number of arthroplasties and the improvement in morbidity and mortality in the concerned patient population. The management of periprosthetic distal femoral fractures is a challenging orthopedic problem. In this brief communication, a case of 49-year-old woman with rheumatoid arthritis who sustained a low distal comminuted periprosthetic femoral fracture is presented. Her fracture was eventually managed with an intramedullary fibular strut allograft and bilateral locking plate placement reaching satisfactory healing and restoration of alignment. The primary aim of this report is to provide insight into this novel technique as a successful alternative to other standard surgical options.

Incorporation of Bone Morphogenetic Protein-2 and Osteoprotegerin in 3D-Printed Ti6Al4V Scaffolds Enhances Osseointegration Under Osteoporotic Conditions

Osteoporosis is an age-related metabolic disease that results in limited bone regeneration capacity and excessive osteoclast activity. After arthroplasty in patients with osteoporosis, poor interface osseointegration resulting from insufficient bone regeneration ability often leads to catastrophic complications such as prosthesis displacement and loosening and periprosthetic fractures. In this study, we prepared a thermosensitive hydrogel loaded with bone morphogenetic protein-2 (BMP-2) to promote osteogenesis and osteoprotegerin (OPG) to inhibit excessive osteoclast activity. To construct three-dimensional (3D)-printed composite scaffolds for implantation, a hydrogel loaded with drugs was injected into porous Ti6Al4V scaffolds. The 3D-printed composite scaffolds showed good biocompatibility and sustained release of BMP-2 and OPG for more than 20 days. In vitro experiments indicated that composite scaffolds promoted osteogenic differentiation and reduced the osteoclastic activation simultaneously. Remarkably, immunofluorescence staining, micro-CT, histological, and biomechanical tests demonstrated that the sustained release of both BMP-2 and OPG from composite scaffolds significantly improved bone ingrowth and osseointegration in osteoporotic defects. In conclusion, this study demonstrated that the BMP-2- and OPG-loaded 3D-printed composite scaffolds can potentially promote osseointegration for osteoporotic patients after joint replacement.

Shaft Fractures in Patients Requiring Primary or Revision Total Knee Arthroplasty Can Be Successfully Treated with Long-Stemmed Implants without Additional Fixation

The aim of this study was to evaluate the bone union, complication rate, clinical and functional outcomes of long-stemmed total knee arthroplasty (TKA) in patients with periprosthetic femoral or tibial shaft fractures and in patients with femoral or tibial shaft fractures with coexisting advanced knee osteoarthritis (OA). This retrospective study comprised 25 patients who underwent surgery due to tibial or femoral shaft fractures: (1) with coexisting severe knee OA or (2) with a periprosthetic fracture requiring implant exchange. In all cases, fracture stabilization was performed intramedullary with the use of long-stemmed implants without the use of additional fixation material (plates, screws, or cerclage). Bone union was achieved in 22/25 patients (88%). One patient required revision with additional plate stabilization due to non-union, and asymptomatic partial bone union was observed in two cases. The group with periprosthetic fractures demonstrated good clinical (mean 73.1 ± 13.3) and moderate functional (mean 59.2 ± 18.8) outcomes in the Knee Society Scoring system (KSS). In the group with shaft fracture and coexisting OA significantly higher clinical (excellent results, mean 84.1 ± 11; p = 0.03) and functional (good results, mean 76.2 ± 20.6; p = 0.04) results were noted. There were no statistically significant differences in terms of range of motion (ROM) or complication rate between these two groups. One-stage TKA with a long-stemmed implant without the use of additional fixation material is an effective method for the treatment of femoral or tibial shaft fractures in patients who require joint replacement. Despite being technically demanding, the approach yields bone union and moderate to excellent clinical and functional outcomes with a relatively low complication rate.