Outcomes of Surgical Management of Supracondylar Periprosthetic Femur Fractures

Retrograde intramedullary nail fixation with oblique fixed angle screws versus locking plates in periprosthetic supracondylar fractures after total knee arthroplasty

PURPOSE

Common surgical procedures in the treatment of periprosthetic distal femur fractures (PPFF) include osteosynthesis with fixed angle locking plates (LP) and retrograde intramedullary nails (RIN). This study aimed to compare LPs to RINs with oblique fixed angle screws in terms of complications, radiographic results and functional outcome.

METHODS

63 PPFF in 59 patients who underwent treatment in between 2009 and 2020 were included and retrospectively reviewed. The anatomic lateral and posterior distal femoral angle (aLDFA and aPDFA) were measured on post-surgery radiographs. The Fracture Mobility Score (FMS) pre- and post-surgery, information about perceived instability in the operated leg and the level of pain were obtained via a questionnaire and previous follow-up (FU) examinations in 30 patients (32 fractures).

RESULTS

The collective (median age: 78 years) included 22 fractures treated with a RIN and 41 fractures fixed with a LP. There was no difference in the occurrence of complications (median FU: 21.5 months) however the rate of implant failures requiring an implant replacement was higher in fractures treated with a LP (p = 0.043). The aPDFA was greater in fractures treated with a RIN (p = 0.04). The functional outcome was comparable between both groups (median FU: 24.5 months) with a lower outcome in the post-surgery FMS (p =  < 0.001).

CONCLUSION

Fractures treated with RIN resulted in an increased recurvation of the femur however the rate of complications and the functional outcome were comparable between the groups. The need for implant replacements following complications was higher in the LP group.

Early Complications of a Novel Retrograde Intramedullary Femoral Nail in the Treatment of Femur Fractures

OBJECTIVES

To determine the early implant failure rate of a novel retrograde intramedullary femoral nail.

METHODS

DESIGN

Retrospective cohort study.

SETTING

Academic level 1 trauma center.

PATIENTS SELECTION CRITERIA

Patients aged 18 years and older with an acute OTA/AO 32-A, 32-B, 32-C, and 33-A fractures or periprosthetic distal femur fracture from April 2018 to April 2022 were included in the study. The 2 interventions compared were the Synthes Expert retrograde/antegrade femoral nail (or control implant) versus the next-generation retrograde femoral nail (RFN)-advanced retrograde femoral nail (RFNA or experimental implant) (Synthes, West Chester, PA).

OUTCOME MEASURES AND COMPARISONS

Early implant-related complications between the experimental and control implants were assessed including locking screw back out, screw breakage, intramedullary nail failure, need for secondary surgery, and loss of fracture reduction.

RESULTS

Three hundred fourteen patients were identified with a mean age of 31.0 years, and 62.4% of the patients being male. Open fractures occurred in 32.5% of patients with 3.8% of injuries being distal femur periprosthetic fractures. Fifty-six patients were in the experimental group and 258 patients in the control group. Mean follow-up was 46.8 weeks for the control cohort and 21.0 weeks for the experimental cohort. Distal interlocking screw back out occurred in 23.2% (13 of 56) of the experimental group patients and 1.9% (5 of 258) of the control group patients ( P < 0.0001). Initial diagnosis of interlocking screw back out occurred at an average of 3.2 weeks postoperatively (range, 2-12 weeks). Fifty-four percent of patients who sustained screw back out underwent a secondary operation to remove the symptomatic screws (12.5% of all patients treated with the experimental implant required an unplanned secondary operation due to screw back out). A logistic regression model was used to predict screw back out and found the experimental implant group was 4.3 times as likely to experience distal locking screw back out compared with the control group ( P = 0.01).

CONCLUSIONS

The retrograde femoral nail-advanced implant was associated with a significantly higher rate of screw back out with a substantial number of unplanned secondary surgeries compared with the previous generation of this implant.

LEVEL OF EVIDENCE

Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Periprosthetic Distal Femoral Fractures Around a Total Knee Arthroplasty: a Meta-analysis Comparing Locking compression Plating and Retrograde Intramedullary Nailing

Purpose

The number of total knee replacements (TKRs) performed per year has been increasing annually and it is estimated that by 2030 demand would reach 3.48 million procedures per year in the United States Of America. The prevalence of periprosthetic fractures (PPFs) around TKRs has followed this trend with incidences ranging from 0.3% to 3.5%. Distal femoral PPFs are associated with significant morbidity and mortality. When there is sufficient bone stock in the distal femur and a fracture pattern conducive to fixation, locking compression plating (LCP) and retrograde intramedullary nailing (RIMN) are commonly used fixation strategies. Conversely, in situations with loosening and deficient bone stock, a salvage procedure such as a distal femoral replacement is recognized as an alternative. This meta-analysis investigates the rates of non-union, re-operation, infection, and mortality for LCPs and RIMNs when performed for distal femoral PPFs fractures around TKRs.

Method

A search was conducted to identify articles relevant to the management of distal femoral PPFs around TKRs in adherence to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) checklist. Articles meeting the inclusion criteria were then assessed for methodological quality using the methodological items for non-randomised studies (MINORS) criteria. Articles were reviewed, and data were compiled into tables for analysis.

Results

10 articles met the inclusion criteria, reporting on 528 PPFs. The overall incidence of complications was: non-union 9.4%, re-operation 12.9%, infection 2.4%, and mortality 5.5%. This meta-analysis found no significant differences between RIMN and LCP in rates of non-union (9.2% vs 9.6%) re-operation (15.1% vs 11.3%), infection (2.1% vs 2.6%), and mortality (6.0% vs 5.2%), respectively.

Conclusion

This meta-analysis demonstrated no significant difference in rates of non-union, re-operation, infection, and mortality between RIMN and LCP and both remain valid surgical treatment options.

Optimal surgical treatment for periprosthetic distal femoral fractures after total knee arthroplasty: a Bayesian-based network analysis

BACKGROUND

The surgical methods for periprosthetic distal femoral fractures (PDFFs) after total knee arthroplasty included locking compression plate (LCP), retrograde intramedullary nailing (RIMN), and distal femoral replacement (DFR). However, the optimal treatment remains controversial. We performed a network meta-analysis (NMA) to provide the optimal surgical method for PDFFs.

MATERIALS AND METHODS

Electronic databases, including Embase, Web of Science, Cochrane Library, and PubMed, were searched for studies that compared LCP, RIMN, and DFR for PDFFs. The quality of the included studies was assessed according to the Newcastle-Ottawa scale. Pairwise meta-analysis was performed by Review Manager version 5.4. The NMA was conducted in Aggregate Data Drug Information System software version 1.16.5. We calculated odds ratios (ORs) and 95% confidence intervals (CIs) for postoperative complications and reoperations.

RESULTS

A total of 19 studies and 1198 patients were included, of whom 733 for LCP, 282 for RIMN, and 183 for DFR. Pairwise meta-analysis comparing LCP to RIMN and LCP to DFR showed no significant difference in complications and reoperations except that RIMN had a higher risk of malunion comparing to LCP (OR 3.05; 95% CI 1.46-6.34; P = 0.003). No statistically significant effects were found in the NMA of overall complications, infection, and reoperation. However, results of rank probabilities showed that DFR ranked best in overall complications and reoperation, RIMN ranked best in infection but worst in reoperation, and LCP ranked worst in infection and middle in reoperation.

DISCUSSION

We found similar complication rate and reoperation rate between LCP, RIMN, and DFR. The results of rank probabilities favored DFR, and further studies with high-level evidence are expected to verify the optimal surgical method for PDFFs.

LEVEL OF EVIDENCE

Level II; network meta-analysis.

Modified fixation for periprosthetic supracondylar femur fractures: Two case reports and review of the literature

BACKGROUND

Periprosthetic supracondylar femoral fractures (PSFs) present a challenge in terms of optimizing fixation in patients with poor bone quality. Surgical treatment and peri-operative management of PSFs in the elderly remain a burden for orthopedic surgeons. Among different treatment options, locking plate (LP) and retrograde intramedullary nail (RIMN) have shown favorable results. However, reduced mobility and protected weight-bearing are often present in the postoperative older population. With a purpose of allowing for early weight-bearing, a modified nail plate combination (NPC) was redesigned for PSF management.

CASE SUMMARY

In our cases, two elderly osteoporotic female underwent total knee arthroplasty (TKA), and then suffered from low energy trauma onto their knees after falling to the floor. Plain radiographs or computed tomography scans demonstrated oblique or transverse PSFs, both of which occurred at the distal femur above TKA. The modified NPC technique was performed for treatment of PSFs. The patient was made foot flat weight bearing in 1 wk. At 6-mo follow-up, the union was ultimately achieved using modified NPC with satisfactory implant outcomes.

CONCLUSION

Neither LP nor RIMN alone may provide adequate support to allow for union in circumstances where the patient has severely osteopenic bone. Therefore, developing a modified implant offer an alternative choice for treating PSFs. These two cases revealed that this technique is a viable option for the geriatric osteoporotic PSFs, offering safe, early weight bearing and favorable clinical outcomes.

Outcomes of dual plating for unstable distal femoral fractures: a subgroup comparison between periprosthetic and non-periprosthetic fractures

PURPOSE

This study aimed to evaluate the outcomes of dual plating for unstable distal femoral fractures via a subgroup analysis between periprosthetic and non-periprosthetic fractures.

METHODS

This retrospective cohort study analyzed the outcomes of dual plating for unstable distal femoral fractures among 49 consecutive patients (43 women and 6 men) enrolled from July 2008 to August 2020. The patients were divided into periprosthetic (group P, n = 29) and non-periprosthetic (group N, n = 20) groups. The radiographic outcomes included the mechanical lateral distal femoral angle (mLDFA) and union rate based on the computed tomography findings. The clinical parameters included the knee range of motion and knee society score (KSS).

RESULTS

The mean patient age was 71.1 years, and the average follow-up period was 37 months (range, 12-138 months). Union was achieved in 47 patients (96%). The average final mLDFA was 90.5° in group P and 88.3° in group N. The average final knee range of motion was 130° in group P and 107° in group N. The average final KSS was 73.8 in group P and 87.1 in group N.

CONCLUSION

Dual plating for distal femoral fractures yielded an excellent union rate and limb alignment with a low complication rate.

Arthroscopic Retrograde Intramedullary Nailing of Periprosthetic Fractures After Total Knee Arthroplasty—Technique, Safety, and Outcomes

Background

Periprosthetic fractures after total knee arthroplasty are notoriously challenging entities to manage. The 2 major fixation techniques utilized include locking compression plates and retrograde intramedullary nailing. The challenges in obtaining correct entry points in the presence of the superimposing femoral component in retrograde intramedullary nailing often warrants a full knee joint arthrotomy. Thus, the purpose of this first series is to describe the arthroscopy-assisted retrograde intramedullary nailing (ARIN) technique and evaluate clinical results and potential risks and benefits.

Methods

This was a retrospective review of prospectively collected data obtained from 16 patients treated with the ARIN technique. Data obtained included operative time, size of incision, and intraoperative complications. In the postoperative course, patients were assessed for time to union, functional outcomes using the Knee Society Score, and the presence of complications.

Results

Nine male and 7 female patients were included with a mean age of 70.8 years. The patients were followed up for a minimum of 24 months. The mean operative time was 86.5 minutes. Union was achieved in all fractures with an average union time of 15.9 weeks. The mean Knee Society Score obtained at 2 years postoperatively was 84.6. No major complications were documented during the follow-up period. None of the cases required conversion to the conventional open technique.

Conclusions

The ARIN technique has demonstrated results comparable with those from previous resources. Although results from this series suggest that the utilized technique is safe and offers a less invasive approach, direct clinical comparisons in larger scale trials are required.

A comparison of distal femoral replacement versus fixation in treating periprosthetic supracondylar femur fractures: a systematic review and meta-analysis

BACKGROUND

The treatment of periprosthetic femur fractures around a total knee replacement remains a technical challenge for the orthopedic surgeon. Management options include non-operative treatment, plate fixation, intramedullary nailing and distal femur replacement (DFR), with few studies comparing fixation with DFR. This is an up-to-date meta-analysis in the literature to directly compare clinical outcomes between fixation and distal femoral replacement in the treatment of supracondylar periprosthetic femur fractures.

METHODS

A stratified literature search of the Medline, EMBASE and Cochrane databases was performed. All studies in English language were searched from inception to July 2022. The search was performed with the following MeSH terms: Periprosthetic fracture AND ORIF OR Internal Fixation AND Distal Femur Replacement. The search was conducted using a predesigned search strategy where all eligible literature was critically appraised for methodological quality using the Cochrane collaboration tool. We included Level I, II and III studies comparing fixation with DFR in the treatment of periprosthetic supracondylar femur fractures. Data from eligible studies were extracted by two authors (NP and AR) and a table created which included author, year, sample size, mean age, measured parameters, follow-up period, fracture classification, length of stay (days), mortality rate, revision rate and complication rate.

RESULTS

The extracted data were pooled for meta-analysis using RevMan® v5.3.5 software (Nordic Cochrane Centre, Copenhagen, Denmark) and forest plots constructed. A p value < 0.05 was considered statistically significant and confidence intervals (CI) set to 95%. A total of six studies were included in the meta-analysis (n = 406). 153 patients underwent distal femur replacement and 253 patients underwent fixation with a mean follow-up time of 71.4 months. The results of this analysis suggest no statistically significant difference in measured outcomes.

CONCLUSION

The results of this meta-analysis suggest no proven statistically significant difference between DFR and fixation in terms of length of hospital stay, mortality rate, revision rate and complication rate for the treatment of periprosthetic supracondylar femur fractures. Further prospective randomized research may help to define the specific indications for each treatment option which must include fracture configuration. Early functional outcome and cost-effectiveness have yet to be evaluated in the available literature.

Does distance from joint line influence complications after distal femur fractures in native and periprosthetic knees?

BACKGROUND

Distal femur fractures are projected to increase in incidence secondary to an aging population and growing utilization of total knee arthroplasty. Surgical management is the standard of care, but optimal treatment for far distal fractures is still unclear. Our study investigates if there are distal femur fractures too distal to be treated with lateral locked plating in periprosthetic fractures.

METHODS

One hundred and ten consecutive patients treated with locked plating for distal femur fractures around a total knee replacement were identified using CPT codes. Fractures were classified by length of the distal fracture segment and Su classification. Complications studied were nonunion, malunion, infection, further fracture related surgery, readmission within 90 days, and mortality within 1 year of surgery. Sixty six fractures met inclusion criteria of 180 days of follow-up or sustaining a complication prior to180 days.

RESULTS

The size of the distal fracture segment and Su classification did not correlate with increased complication rate in periprosthetic distal femur fractures.

CONCLUSIONS

There was no difference between complications following lateral locked plating of distal femur fractures based on the size of the distal fracture segment in periprosthetic fractures. Lateral locked plating is an effective treatment modality for these fractures regardless of how distal the fracture extends.

Results of Low Distal Femur Periprosthetic Fractures

OBJECTIVES

To compare retrograde intramedullary nail (RIMN) and open reduction internal fixation (ORIF) in very distal periprosthetic distal femur fractures (PDFFs) to determine whether RIMN is an acceptable option for these fractures that are often considered too distal for IMN due to limited bone stock.

DESIGN

Retrospective comparative series.

SETTING

Level 1 trauma center.

PATIENTS

Patients were treated with fracture fixation for a very distal PDFF, defined as the fracture extending to the anterior flange of the implant or distal. Fifty-six patients met inclusion criteria, with 8 excluded for less than 12 months of follow-up.

INTERVENTION

The intervention involved fracture fixation with RIMN or ORIF.

MAIN OUTCOME MEASUREMENTS

The primary outcome was unplanned return to surgery. Secondary outcomes included fracture union, radiographic alignment, visual analog score, and Patient-Reported Outcome Measurement Information System (PROMIS) Physical Function (PF) and Pain Interference.

RESULTS

The mean follow-up period was 27 months. Twelve patients were treated with ORIF and 36 with RIMN. Twenty-one fractures were at the flange, and 27 extended distal to the flange. There were no differences between fixation methods for reoperation, deep infection, nonunion, malunion, visual analog score pain score, and PROMIS Pain Interference score. The mean PROMIS PF score was higher in the RIMN group compared with that in the ORIF group. There were 5 reoperations in the RIMN group (14%) and 3 in the ORIF group (25%).

CONCLUSIONS

This is the largest series, to the best of our knowledge, of a subset of very distal PDFFs. The results suggest that RIMN may be an acceptable treatment option for these very difficult fractures.

LEVEL OF EVIDENCE

Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Comparable Outcomes Between Native and Periprosthetic Fractures of the Distal Femur

Despite the rising prevalence of arthroplasty and aging population, limited data exist regarding differences in periprosthetic fracture clinical outcomes compared with native counterparts. This study compares differences in hospital treatment, morbidity, and mortality associated with periprosthetic distal femur fractures at an urban level 1 trauma center. We retrospectively reviewed all adult AO/OTA type 33 fractures (526) that presented to our institution between 2009 and 2018. In total, 54 native and 54 periprosthetic fractures were matched by age and gender. We recorded demographics, operative measures, length of stay (LOS), discharge disposition, and mortality. We used McNemar's and paired t-tests for analysis where appropriate (p < 0.05) (IBM SPSS Statistics for Windows, Version 26.0. Armonk, NY; IBM Corp.). The average age at injury was 74 years ± 12 (native) compared with 73 years ± 12 (periprosthetic). After 1:1 matching, the groups had similar body mass index (31.01 vs. 32.98, p = 0.966 for native and periprosthetic, respectively) and mechanisms of injury with 38 native and 44 periprosthetic (p = 0.198) fractures from low-energy falls. Both groups had 51/54 fractures managed with open reduction internal fixation with a locking plate. The remaining were managed via amputation or intramedullary nail fixation. Mean operative time (144 minutes (±64) vs. 132 minutes (±62), p = 0.96) and estimated blood loss (319 mL (±362) vs. 289 mL (±231), p = 0.44) were comparable between the native and periprosthetic groups, respectively. LOS: 9 days ± 7 (native) versus 7 days ± 5 (periprosthetic, p = 0.31); discharge disposition (to skilled nursing facility/rehab): n = 47 (native) versus n = 43 (periprosthetic, p = 0.61); and mortality: n = 6 (native) versus n = 8 (periprosthetic, p = 0.55). No significant differences were observed. We found no statistical differences in morbidity and mortality in periprosthetic distal femur fractures treated over 10 years at a level 1 trauma center. Native and periprosthetic AO/OTA type 33 distal femur fractures are serious injuries with similar outcomes at a level 1 trauma center.

Nail diameter significantly impacts stability in combined plate-nail constructs used for fixation of supracondylar distal femur fractures

Objectives:

Plate-nail (PN) combinations have been described for fixation of supracondylar distal femur fractures. Small diameter retrograde intramedullary nails (rIMN) are commonly used. The purpose of this study was to investigate the effect of nail diameter on construct stability. We hypothesized that a larger diameter rIMN would not significantly change the stiffness of the PN construct when tested in torsional or axial loading.

Methods:

Twelve synthetic osteoporotic femurs were used to compare nail diameters in an extraarticular supracondylar distal femur fracture model (Orthopaedic Trauma Association/Arbeitsgemeinschaft für Osteosynthesefragen type 33-A3). Constructs were fixed with a 12-hole 4.5 mm pre-contoured lateral distal femoral locking plate combined with either a 9 mm (n = 6) or an 11 mm (n = 6) retrograde intramedullary nail (rIMN). Specimens were cyclically loaded in torsion and axial compression. The primary outcome was construct stiffness, calculated using the average slope of the force-displacement curves.

Results:

The 11 mm PN construct was approximately 1.6 times stiffer than the 9 mm PN construct averaged across all torsional loads (2.39 +/− 0.41 Nm/deg vs 1.44 +/− 0.17 Nm/deg) and approximately 1.3 times stiffer than the 9 mm PN construct averaged across all axial loads (506.84 +/− 44.50 N/mm vs 376.77 +/− 37.65 N/mm). There were no construct failures.

Conclusions:

In this biomechanical model, nail diameter had a significant effect on both torsional and axial stiffness in PN constructs. While the use of smaller diameter rIMNs has been proposed to allow for easier placement of implants, the effect on overall construct stiffness should be considered in the context of the patient, their fracture and desired postoperative weight bearing recommendations.

Level of Evidence: N/A

Current Reconstruction Options in Periprosthetic Fractures Around the Knee

BACKGROUND

Periprosthetic fractures are a rare complication after total knee arthroplasty (TKA). However, the incidence of these fractures is growing after the increasing number of TKAs performed every year and the progressive aging of the population. In addition, the surgical treatment and peri-operative management of these complications are demanding, representing a challenge for the orthopedic surgeon.

SIGNIFICANCE

A thorough understanding of these fractures and a correct classification are necessary in order to select the most suitable surgical treatment. The aim of this review was to analyze the epidemiology, classification, diagnosis, surgical treatment, and outcomes of periprosthetic knee fractures in order to give an exhaustive overview.

RESULTS

Reduction and internal fixation with locking plates or intramedullary nails represents the preferred option in case of a stable prosthetic implant. Conversely, in case of loose tibial and/or femoral component, implant revision is mandatory. Conservative treatment is rarely indicated.

CONCLUSION

A deep understanding of the characteristics and patterns of periprosthetic knee fractures, and the determination of the stability of the prosthetic implant are necessary in order to establish the correct treatment.

Review of patient-reported outcomes in periprosthetic distal femur fractures after total knee arthroplasty: a plate or intramedullary nail?

Purpose

This study reviewed the literature regarding the patient-reported treatment outcomes of using either open reduction and internal fixation (ORIF) with a plate and screw system or intramedullary nail (IMN) fixation for periprosthetic distal femur fractures around a total knee arthroplasty.

Methods

A total of 13 studies published in the last 20 years met the inclusion criteria. The studies included 347 patients who were allocated to ORIF (n = 249) and IMN (n = 98) groups according to the implants used. The primary outcome measures were the Knee Society Score or the Western Ontario and McMaster Universities osteoarthritis index. The secondary outcome measures included knee range of motion and the rates of complications, including non-union, malunion, infection, revision total knee arthroplasty, and reoperation. Statistical significance was set at P < 0.05.

Results

The mean Knee Society Scores of ORIF and IMN groups were 83 and 84, respectively; the mean postoperative range of motion of the knee were 99° and 100°, respectively (P < 0.05); the non-union rates were 9.4 and 3.8%, respectively (P > 0.05); the malunion rates were 1.8 and 7.5%, respectively (P < 0.05); surgical site infection rates were 2 and 1.3%, respectively (P > 0.05); the reoperation rates were 9.6 and 5.1%, respectively (P > 0.05); and revision rates of total knee arthroplasty were 2 and 1%, respectively (P > 0.05).

Conclusion

Based on the patient-reported outcome assessments, both ORIF with a plate and screw system and IMN fixation are well-accepted techniques for periprosthetic distal femur fractures around a TKA, and they produce similar functional outcomes.

Locked compression plating versus retrograde intramedullary nailing in the treatment of periprosthetic supracondylar knee fractures: a systematic review and meta-analysis

BACKGROUND

Periprosthetic fractures of the distal femur above a total knee arthroplasty (TKA) have traditionally been managed by locking compression plating (LCP). This technique is technically demanding and is associated with high rates of non-union and revision. More recently, retrograde intramedullary nailing (RIMN) has been proposed as an acceptable alternative. This meta-analysis aims to evaluate clinical outcomes in patients with periprosthetic supracondylar femoral fractures who were treated with LCP and RIMN.

METHODS

An up-to-date literature search was carried out using the pre-defined search strategy. All studies that met the inclusion criteria were assessed for methodological quality with the Cochrane's collaboration tool. Operative time, functional score, time-to-union, non-union rates and revision rates were all considered.

CONCLUSION

Ten studies with a total of 531 periprosthetic fractures were included. This meta-analysis has suggested that there is no significant difference in any of the outcome measures assessed. Further, more extensive literature is required on the subject to draw more robust conclusions.

Biomechanical evaluation of the docking nail concept in periprosthetic fracture fixation around a stemmed total knee arthroplasty

Intramedullary femoral nails provide an ideal mechanical axis for periprosthetic fracture fixation. Slotted nails allow a connection to a total knee arthroplasty (TKA) stem. This study aims to compare implant and construct stiffness, interfragmentary movement and cycles to failure between an antegrade slotted femoral nail construct docked to a TKA stem and a distal femoral locking plate in a human periprosthetic femoral fracture model. In eight pairs of fresh-frozen human femora with stalked TKA, a 10 mm transverse osteotomy gap was set simulating a Rorabeck type II, Su type I fracture. The femora were pairwise instrumented with either an antegrade slotted nail coupled to the prosthesis stem, or a locking plate. Cyclic testing with a progressively increasing physiologic loading profile was performed at 2 Hz until catastrophic construct failure. Relative movement at the osteotomy site was monitored by means of optical motion tracking. In addition, four-point bending implant stiffness, torsional implant stiffness and frictional fit of the stem-nail connection were investigated via separate non-destructive tests. Intramedullary nails exhibited significantly higher four-point bending and significantly lower torsional implant stiffness than plates, P < 0.01. Increasing difference between nail and stem diameters decreased frictional fit at the stem-nail junction. Nail constructs provided significantly higher initial axial bending stiffness and cycles to failure (200 ± 83 N/mm; 16'871 ± 5'227) compared to plate constructs (93 ± 35 N/mm; 7'562 ± 1'064), P = 0.01. Relative axial translation at osteotomy level after 2'500 cycles was significantly smaller for nail fixation (0.14 ± 0.11 mm) compared with plate fixation (0.99 ± 0.20 mm), P < 0.01. From a biomechanical perspective, the docking nail concept offers higher initial and secondary stability under dynamic axial loading versus plating in TKA periprosthetic fracture fixation.

Proximal Femur Peri-Implant Fracture After Lateral Femur Locking Plate: A Report of 2 Cases

CASE

This case report discusses 2 cases of proximal femur peri-implant fractures after the use of lateral locking plates for distal femur periprosthetic fractures.

CONCLUSION

The use of locking plate technology for fixation of distal femur periprosthetic fractures is a common treatment modality. Although much has been reported regarding healing and complication rates of distal femoral periprosthetic fractures, little has been reported about peri-implant fractures subsequent to treatment using locking plates. We propose the importance of developing a method of fixation to protect the entire femur in osteoporotic patients sustaining distal femur periprosthetic fractures at the index surgery to avoid this complication.

Distal femur nonunion treated with retrograde intramedullary nailing and RIA: a case report

The current treatment of distal femur fractures includes locking plating and retrograde intramedullary nailing. These fractures are difficult to manage also for experienced surgeons, with results not always satisfactory. Reported nonunion rates now range from 0 to 34%. Factors associated with nonunion include comorbidities, such as obesity and diabetes, as well as the presence of open fractures, medial bone defects and comminuted fractures. This case report summarizes all of these assumptions and it concerns a 58 years old patient who underwent to 6 surgical procedures before to arrive to bone healing. (www.actabiomedica.it)

Effectiveness of circular external fixator in periprosthetic fractures around the knee

Background

The incidence of periprosthetic fractures after total joint arthroplasty (TJA) is rising due to an increasing number of TJAs performed annually and the growing elderly population. In many elderly patients with periprosthetic fractures, the bone strength is lowered due to the deterioration of bone quality and a decrease in bone quantity; rigid fixation of the fracture is difficult. It is a challenging operation for orthopedic surgeons. The usefulness of circular external fixation for periprosthetic fractures has been reported in several case studies. The aim of this study was to investigate the rate of union and complications associated with circular external fixation in periprosthetic fractures around the knee.

Methods

We included 19 patients with periprosthetic femur and tibial fractures who underwent osteosynthesis using a circular external fixator and had at least 2 years of follow-up. All patients had comorbidities and high risks associated with anesthesia. Tourniquets were not used in any of the patients. There were no cases in which the skin incision was placed, and the closed reduction technique was used in all cases.

Results

A 100% union rate was achieved with no serious complications. All fractures healed after a mean time of 14.3 ± 5.2 weeks (range, 8–38 weeks). The walking ability was the same level as before the injury in 13 cases.

Discussion

There are many comorbidities associated with periprosthetic fractures in elderly patients. Double-plate or revision surgery were largely invasive and had high risks associated with anesthesia. Circular external fixation is a feasible and effective treatment option because it provides stable fixation, prompt postoperative mobilization, and has no major complications, especially in elderly patients who are treated for periprosthetic fractures.

Conclusion

Circular external fixation is a safe and reliable method for periprosthetic fractures around the knee in elderly patients.

Level of evidence

Level IV, retrospective case series.

Periprosthetic Fractures of the Distal Femur: Is Open Reduction and Internal Fixation or Distal Femoral Replacement Superior?

BACKGROUND

The purpose of this study is to compare open reduction and internal fixation (ORIF) to distal femoral replacement (DFR) for treatment of displaced periprosthetic distal femur fractures.

METHODS

We identified 72 patients with minimum 2-year follow-up following a displaced periprosthetic distal femur fracture: 50 were treated with ORIF and 22 with DFR. Outcomes were assessed with multivariate regression analysis and include Knee Society Scores (KSS), infection rates, revision incidence, and mortality.

RESULTS

Patients treated with DFR had a higher Charlson comorbidity index (5.2 vs 3.8; P = .006). The mean postoperative KSS were similar between groups, but the Knee Society Functional Scores were higher in the ORIF group (P = .01). Six ORIF patients (12%) and 3 DFR patients (14%) underwent a revision surgery (P = .1). In the ORIF group, 3 revisions were associated with periprosthetic infection, and 3 revisions occurred for aseptic nonunion. In the DFR group, 1 infection was treated with irrigation and debridement, and 2 cases of patellar maltracking resulted in 1 liner exchange with soft tissue release and 1 femoral revision for malrotation. More patients in the ORIF group required repeat revisions, with twice as many total revisions (P < .001). Six ORIF patients and 7 DFR patients died within 2 years (P = .26).

CONCLUSION

The Knee Society Functional Score favored ORIF, but the total incidence of revision was higher in the ORIF cohort. Given the high mortality and the substantial risk of reoperation in both groups, additional studies are needed regarding the prevention of and optimal treatment for patients with periprosthetic distal femur fractures.

Equivalent union rates between intramedullary nail and locked plate fixation for distal femur periprosthetic fractures - a systematic review

BACKGROUND

The incidence of periprosthetic fracture following total knee arthroplasty continues to rise as the number of knee arthroplasty procedures increases. Management of periprosthetic fractures can be complex, with locked compression plating (LCP) and intramedullary nailing (IMN) being the most commonly used treatment options. We performed a systematic review to report and compare the clinical and radiographic outcomes of patients treated with intramedullary nail fixation versus plate fixation for periprosthetic fractures of the distal femur.

METHODS

Several databases were screened. Studies evaluating intramedullary nail fixation or locked plate fixation for distal femur periprosthetic fractures were included. Primary and secondary variables as mentioned below, when included, were analyzed and compared.

RESULTS

One prospective comparative study, 9 retrospective comparative studies, and 28 retrospective case series with 1,188 patients were included in this review. No statistically significant differences were found between IMN and LCP when analyzing union rate or time to union. Plating demonstrated a statistically significant decrease in the overall complication rate and reoperation rate when compared with IMN (p<0.003). IMN demonstrated a slightly higher percentage of patients reaching full weight bearing status and a quicker time to full weight bearing (100% and 7.6 weeks) when compared to plating (94% and 15.8 weeks). A higher percentage of patients treated with IMN returned to preinjury activity when compared to those treated with plating (70.8% vs. 61.6%).

CONCLUSIONS

Both intramedullary nail and locked plate fixation offer unique benefits in terms of clinical and radiographic outcomes for treatment of periprosthetic distal femur fractures after total knee arthroplasty. While the standard of care remains controversial, an increase in the recent literature has allowed for better clarification of the significant clinicoradiologic advantages and disadvantages of both popular treatment options.

Usefulness of bilateral plate fixation for periprosthetic distal femur fracture after total knee arthroplasty

•

Author got reliable fixation with double plating in situation, could not get secure stability by unilateral lateral plating.

•

Authors used medial parapatella approach for placing an additional plate on the medial side of distal femur.

•

Parapatella approach for additional plating can check screw length, femoral component stability and rotation, and polyethylene insert wear.

Introduction

Recently, good results of locking compression plate (LCP) have been reported in the case of fixation using plate, but when fractures extend too distal over the proximal border of femoral component, operations are highly challenging.

Presentation of case

Author reports two cases that couldn't get reliable fixation by LCP alone because of poor bone quality with chronic infection and far juxta-fracture of prosthesis. Fractures were fixed to the medial and lateral sides of the distal femur with LCPs and were healed successfully.

Discussion

Indirect healing (endochondral bone formation) using anatomical alignment and bridge plating using LCP is usually used rather than direct healing (intramembranous) through anatomical reduction and rigidly stable fixation for periprosthetic distal femoral fracture. Proper flexible fixation is helpful for indirect bone healing through the callus formation, but too flexible fixation cannot maintain fracture fragments until the callus formation provides sufficient stability. Medial parapatella approach for additional medial side plating have many advantages that it can confirm the screw length which not penetrate intercondylar box or medial cortex, and can check component stability, rotation, wear of the polyethylene insert.

Conclusion

Bilateral plate fixation through additional medial parapatella approach is useful method for obtaining secure fixation to poor bone quality or extremely distal femoral periprosthetic fracture.

Analysis of mortality after surgical treatment of periprosthetic distal femur fractures

INTRODUCTION

The incidence of periprosthetic fractures of the knee is increasing due to the increase in the number of total knee arthroplasties performed, together with population aging. We found few studies that analyze mortality in our setting after surgery. Our objective was to evaluate mortality and survival after surgical treatment of periprosthetic fractures of the distal femur in our environment.

MATERIAL AND METHOD

We conducted a retrospective observational study of a consecutive series of 97 patients surgically treated in our centre for periprosthetic knee fracture between 2007-2015, with a minimum follow-up of 12months. Diverse sociodemographic, clinical and surgical variables were analyzed. A consultation was made to the National Death Index of the Ministry of Health for the analysis of mortality and survival was analyzed using the Kaplan-Meier method.

RESULTS

We reviewed a total of 97 patients with an average age of 75years, of which 86 were women and 11 were men. Of the patients, 50.5% of patients had some comorbidity. The average delay until the intervention was 3.1days. With respect to the treatment, 45 patients were operated by osteosynthesis with plate (49.5%), 40 with intramedullary nail (41.2%) and 9 with revision of the arthroplasty (9.3%). A total of 30 deaths were recorded during the follow-up, with cumulative mortality in the first year, at 3 and at 10 years of 7.2%, 17.5% and 30.9%, respectively, progressively increasing in people over 75years. There was no significant difference in mortality rates with the osteosynthesis method. The main complication was pseudoarthrosis (6.2%).

CONCLUSIONS

Periprosthetic knee fractures are associated with high rates of complications and mortality. The patient's age and the lesion itself are non-modifiable factors that can influence mortality after surgery, while other variables such as the type of intervention or surgical delay did not show differences in mortality rates in our study.

Locking plates versus retrograde intramedullary nails in the treatment of periprosthetic supracondylar knee fractures. A retrospective multicenter comparative study

INTRODUCTION

Biomechanical studies demonstrated the superiority of retrograde supracondylar intramedullary nails (RIN) against locking plates (LP) for the treatment of periprosthetic supracondylar femoral fractures (PSFs); however, clinical results are still conflicting. This study aimed to compare LP and RIN, as well as, cemented and uncemented nails in the treatment of PSFs regarding fracture healing, complications and functional results.

MATERIALS AND METHODS

A retrospective multicenter analysis of 60 PSFs classified as Rorabeck type I or II was performed. Thirty-one cases were treated with LP while in 29 cases RIN were used. Out of the latter, 14 had nailed cementoplasty, while 15 an uncemented nail.

RESULTS

The two groups were comparable concerning gender, ASA score, operated side, follow-up time, fracture type and mechanism of injury. The LP was significantly younger than the RIN group. Forty-six cases had fracture union at an average of six months, 11 were healed between seven and twelve months (delayed unions), and three developed non-unions. There was no significant difference in the median union time between RIN and LP groups (six vs five months, p = 0.707) or cemented and uncemented nailing groups (5.5 vs six months, p = 0.354). The RIN group had fewer delayed unions or non-unions than LP group; however, not reaching significance (4 vs 10, p = 0.190). Complications were fewer but non-significantly different between cemented and uncemented nails (one vs five, p = 0.481). The mean postoperative flexion was comparable between RIN and LP groups (99.1° vs 94.9°, p = 0.547) or cemented and uncemented nails (102° vs 96.3°, p = 0.4). The mean Oxford Knee Score did not differ between LP and RIN groups (30.8 vs 31.3, p = 0.93) as well as between cemented and uncemented nails (31.5 vs 30.6, p = 0.801).

DISCUSSION

PSFs with good bone stock can be treated equally with LP or RIN. Nails demonstrated advantages concerning the fracture healing potential. Orthopaedic surgeons need to be trained in both treatment options to manage PSFs. Cemented nails may increase stability and healing capacity in elderly osteoporotic patients; however, further studies are needed.

Setting Yourself Up for Success: Retrograde Intramedullary Nailing in Periprosthetic Fractures About Total Knee Arthroplasty

Treatment of periprosthetic fractures above total knee arthroplasty remains challenging because of assessment of implant stability and the short segment of often osteoporotic bone available for distal fixation. Fractures with significant medial comminution should undergo retrograde intramedullary nailing or dual-implant fixation, as isolated lateral locked plating is not indicated. There are a multitude of objective and subjective factors incorporated into the decision to proceed with retrograde nailing including assessment of the patient's functional status, fracture morphology, implant stability, and compatibility of the prosthesis with retrograde nailing. Here, we review the steps to success in using retrograde intramedullary nailing in the treatment of specific periprosthetic fractures about total knee arthroplasty.

Osteosynthesis Technique for Periprosthetic Femoral Fractures: A Case of Interprosthetic Fracture Between a Total Knee Arthroplasty and a Dynamic Hip Screw

Periprosthetic fractures remain a challenging component of every trauma practice. Total joints have become common in very elderly patients, creating a variety of implanted stress risers that make subsequent fractures unique challenges to address. This creates the need to build a construct that will allow for early weight bearing while trying to reduce the potential for further fractures in the same bone. A minimally invasive submuscular approach with long periprosthetic locking plates can be used for a periprosthetic femoral fracture.

Comparison of outcomes and analysis of risk factors for non-union in locked plating of closed periprosthetic and non-periprosthetic distal femoral fractures in a retrospective cohort study

BACKGROUND

The primary aim was to compare the outcomes of locked plating of closed distal femur periprosthetic and non-periprosthetic fractures by testing the hypothesis that outcomes would be worse in the periprosthetic group. The secondary aim of this study was to identify risk factors for non-union.

METHODS

A single-center study over an 8-year period utilizing a retrospective cohort design was performed. Sixty-eight patients with periprosthetic fractures and 57 patients with non-periprosthetic fractures met inclusion criteria for the study. There was a significant difference between groups in mean age (80.1 years periprosthetic vs. 70.9 years non-periprosthetic (p < 0.001)). Statistical analysis between groups was used to assess the outcomes of time to union, incidence of non-union, post-operative functionality, incidence of complications, progression to revision surgery, and mortality. A secondary multivariable analysis was used to assess risk factors for non-union and factors positively associated with union.

RESULTS

There were no significant differences in outcomes between groups. Union rates were 83.8% (57/68) in the periprosthetic group and 78.9% (45/57) in the non-periprosthetic group (p = 0.648). Comminution was identified as a significant risk factor for non-union (p = 0.005). Use of a submuscular technique had a significant positive association with union (p = 0.006).

CONCLUSIONS

Outcomes of surgical treatment for periprosthetic and non-periprosthetic distal femur fractures are similar. There is a significant risk of non-union in locked plating of both groups.

Periprosthetic knee fractures. A review of epidemiology, risk factors, diagnosis, management and outcome

BACKGROUND AND AIM OF THE WORK

Periprosthetic knee fractures incidence is gradually raising due to aging of population and increasing of total knee arthroplasties. Management of this complication represents a challenge for the orthopaedic surgeon. Aim of the present study is to critically review the recent literature about epidemiology, risk factors, diagnosis, management and outcome of periprosthetic knee fractures.

METHODS

A systematic search of Embase, Medline and Pubmed was performed by two reviewers who selected the eligible papers favoring studies published in the last ten years. Epidemiology, risk factors, diagnostic features, clinical management and outcome of different techniques were all reviewed.

RESULTS

52 studies including reviews, meta-analysis, clinical and biomechanical studies were selected.

CONCLUSIONS

Correct clinical management requires adequate diagnosis and evaluation of risk factors. Conservative treatment is rarely indicated. Locking plate fixation, intramedullary nailing and revision arthroplasty are all valuable treatment methods. Surgical technique should be chosen considering age and functional demand, comorbidities, fracture morphology and location, bone quality and stability of the implant. Given the correct indication all surgical treatment can lead to satisfactory clinical and radiographic results despite a relevant complication rate.

Periprosthetic fractures: epidemiology and current treatment

Periprosthetic fractures are becoming increasingly frequent due to aging population and growing number of total joint replacements involving joints different from hip and knee, such as shoulder and elbow. The treatment of these fractures still represents one of the major challenges for the orthopedic surgeon. Despite all efforts to understand and treat these patients, high rate of failure and mortality are still reported. In this review, the epidemiology of periprosthetic fractures, risk factors and results of surgical treatment are disclosed. Moreover, we propose a treatment algorithm based on the findings of the New Unified Classification System.