Periprosthetic fractures of the distal femur after total knee arthroplasty : Plate versus nail fixation

Management of periprosthetic femoral fractures following total knee arthroplasties using locking plates or intramedullary nailing. Comparative study of 567 cases

INTRODUCTION

Proximal femur fractures in elderly patients pose a common problem that requires surgical management. The main objective of this study was to compare the results of treatment by locked plate (LP) and by anterograde (AIN) or retrograde (RIN) intramedullary nailing. The secondary objective was to analyze the complications related to each group. The hypothesis of this study was that the radiological and clinical results of each group were comparable.

MATERIALS AND METHODS

The data of 438 patients from 8 centers were studied retrospectively with 365 LP and 69 cases of intramedullary nailing (49 AIN and 20 RIN). The groups were comparable in terms of mean age (75±2years), mean preoperative Parker score (5.3±0.5) and mean KOOS score (74±2). Most patients lived at home before their fracture [n=375 (86%)]. At follow-up, the joint range of motion, the KOOS and Parker scores, living premises, the time required to regain full weight-bearing, the time required for consolidation as well as the reduction alignment: frontal, sagittal, horizontal.

RESULTS

The average follow-up was: 79±2weeks (65 to 82). The functional and radiological results were comparable, although nailing allowed a faster return to weight-bearing (1±2weeks for nailing versus 7±2weeks for LP, p=0.048) and a better postoperative Parker score (5.5±0.5 for nailing versus 4.7±0.2 for LP, p=0.045). Rotational malalignment in femoral nailing was often in the direction of internal rotation, compared to the LP (p=0.045). Complications were comparable with the exception of mortality, which was more frequent for LP [22.5% in the LP group versus 13% in the nailing group (p=0.045)]. Complications were categorized as: mechanical complications 6.8% of LP, 5.7% of nailing (p>0.05), infections [11% of LP, 5.8% of nailing (p>0.05)], surgical revisions [2% of LP, 10% of nailing (p>0.05)].

DISCUSSION AND CONCLUSION

The hypothesis was refuted. These results show that nailing conferred a faster recovery of weight-bearing, a better Parker score, and is associated with a lower mortality rate. The morbidity rate is comparable between the two techniques. Indeed, when the indication for osteosynthesis by LP or by nailing is made, and both choices are technically justifiable, it would be prudent to favor the technique, which carries the least risk, which in this case is nailing. This conclusion must, however, be taken in to consideration with regard to the reduced number of nailing. A larger series of nailing, particularly retrograde, would be necessary to be able to confirm this last difference between the 2 groups.

LEVEL OF EVIDENCE

IV; comparative retrospective study.

Posterior Cruciate Ligament Injury After Retrograde Nailing of Periprosthetic Distal Femur Fractures: A Report of 2 Cases

CASE

A 51-year-old man and 64-year-old woman with bilateral cruciate-retaining total knee arthroplasties (CR-TKAs) who sustained unilateral periprosthetic distal femur fractures above their CR-TKA and experienced knee instability secondary to an iatrogenic posterior-cruciate-ligament (posterior cruciate ligament [PCL]) injury from retrograde intramedullary nailing. Both patients recovered knee stability after undergoing revision surgery.

CONCLUSION

Many CR-TKA designs have sufficient medial-lateral intercondylar distance to place a retrograde nail, femoral components with a relatively posterior transition from the trochlear groove to the intercondylar box will necessitate a nail starting point closer to the PCL origin. This may contribute to iatrogenic postoperative knee instability for patients with CR-TKA designs.

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.

Retrograde Intramedullary Nailing Versus Locked Plating for Extreme Distal Periprosthetic Femur Fractures: A Multicenter Retrospective Cohort Study

OBJECTIVES

To compare clinical and radiographic outcomes after retrograde intramedullary nailing (rIMN) versus locked plating (LP) of "extreme distal" periprosthetic femur fractures, defined as those that contact or extend distal to the anterior flange.

METHODS

DESIGN

Retrospective review.

SETTING

Eight academic level I trauma centers.

PATIENT SELECTION CRITERIA

Adult patients with periprosthetic distal femur fractures at or distal to the anterior flange (OTA/AO 33B-C[VB1]) treated with rIMN or LP.

OUTCOME MEASURES AND COMPARISONS

The primary outcome was reoperation to promote healing or to treat infection (reoperation for elective removal of symptomatic hardware was excluded from this analysis). Secondary outcomes included nonunion, delayed union, fixation failure, infection, overall reoperation rate, distal femoral alignment, and ambulatory status at final follow-up. Outcomes were compared between patients treated with rIMN or LP.

RESULTS

Seventy-one patients treated with rIMN and 224 patients treated with LP were included. The rIMN group had fewer points of fixation in the distal segment (rIMN: 3.5 ± 1.1 vs. LP: 6.0 ± 1.1, P < 0.001) and more patients who were allowed to weight-bear as tolerated immediately postoperatively (rIMN: 45%; LP: 9%, P < 0.01). Reoperation to promote union and/or treat infection was 8% in the rIMN group and 16% in the LP group ( P = 0.122). There were no significant differences in nonunion ( P > 0.999), delayed union ( P = 0.079), fixation failure ( P > 0.999), infection ( P = 0.084), or overall reoperation rate ( P > 0.999). Significantly more patients in the rIMN group were ambulatory without assistive devices at final follow-up (rIMN: 35%, LP: 18%, P = 0.008).

CONCLUSIONS

rIMN of extreme distal periprosthetic femur fractures has similar complication rates compared with LP, with a possible advantage of earlier return to weight-bearing. Surgeons can consider this treatment strategy in all fractures with stable implants and amenable prosthesis geometry, even extreme distal fractures.

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.

Periprosthetic distal femur fractures around total knee replacements: A comprehensive review

With a growing number of patients undergoing total knee replacements globally, coupled with an elderly population, the incidence of periprosthetic fractures around total knee replacements is increasing. As such, this is a highly topical subject that is gaining increasing interest within the orthopaedic community. This review provides a narrative synthesis of the most contemporary literature regarding distal femoral periprosthetic fractures. We review the related epidemiology, initial patient evaluation, the evolution and relevance of the classification systems and treatment options, particularly related to endoprosthetics and hybrid fixation constructs. The latest orthopaedic evidence related to this topic has been included.

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.

Periprosthetic distal femur fractures treated by retrograde intramedullary nails with a 10-degree distal bend achieve significantly better post-operative radiographic alignment when compared to conventional retrograde nails

INTRODUCTION

Periprosthetic distal femur fractures (PPDFFs) are a common complication after total knee arthroplasty (TKA). In the setting of well-fixed TKA components, treatment options include retrograde intramedullary nailing (rIMN) or lateral locked plating. Treatment with rIMN has historically been associated with potential for extension deformity when using conventional nails. We hypothesized that the PPDFFs treated with an intramedullary nail with a specifically designed 10-degree distal bend for periprosthetic fractures would result in improved post-operative sagittal alignment compared to conventional intramedullary nails.

MATERIALS AND METHODS

The study was conducted at a level-1 trauma center over a 12-year period (2010 - 2022). Patients over the age of 18 who sustained a PPDFF treated with rIMN were identified. The primary outcomes of the study were post-operative coronal and sagittal alignment determined by reviewing post-operative radiographs.

RESULTS

A total of 50 patients were included. Twenty-three patients were treated with a rIMN with a 10° distal bend. Twenty-seven patients were treated with a rIMN with distal bend of 5° The mean aPDFA for the 10° distal bend group was 81.7° compared to 92.8° in the 5° distal bend group (p<0.001). There were 3/23 (13%) significant sagittal plane deformities the 10° distal bend group compared to 11/27 (41%) in the 5° distal bend group (p = 0.03). There was one patient with a post-operative extension deformity in the 10° distal bend group compared to 11 patients in the 5° distal bend group (p = 0.02).

CONCLUSION

Retrograde intramedullary nailing of PPDFF with a 10° distal bend results in significantly better alignment in the sagittal plane when compared to a conventional 5° nail. The use of a 5° nail resulted in an extension deformity significantly more frequently. We therefore recommend the utilization of a rIMN with a 10° distal bend when treating PPDFFs.

SUMMARY

Periprosthetic distal femur fractures are a common complication following total knee arthroplasty. While several studies report on the use of retrograde intramedullary nails in the treatment of periprosthetic distal femur fractures, there are limited reports of the use of a novel retrograde intramedullary nail with a 10° distal bend in the treatment of these injuries. Herein we present a radiographic study comparing coronal and sagittal postoperative alignment following treatment with retrograde intramedullary nails with a 10° distal bend versus conventional retrograde nails with a 5° distal bend.

"Nailable" Does Not Always Mean Reducible in Distal Femur Fractures: Arthroplasty Component and Nail Design Matter

Distal femur fractures above a total knee arthroplasty (TKA) are challenging. These fractures can be fixed with a retrograde intramedullary nail (rIMN), but the design of the femoral component of the TKA influences the starting point for an rIMN. We performed a biomechanical study to evaluate how different TKA components influence the starting point for an rIMN and how that can lead to a deformity in the sagittal plane. We simulated a distal femur fracture with three different arthroplasty components. We used three different implants to simulate fracture reduction and measured the resultant sagittal plane deformity. Low and moderate femoral component ratio (FCR) design components were able to maintain fracture alignment within 5° of anatomic. High FCR component (more posterior starting point) sagittal plane deformities of up to 15° were observed with both the straight and medium Herzog bend nails, which was statistically significant (P<.001). Use of a high Herzog bend nail decreased the deformity by an average of 6°, which was statistically significant (P<.001). There is variability in how the TKA design affects the starting point and thus the sagittal plane alignment after fixation. This study helps quantify the effect of arthroplasty component design on fracture alignment. [Orthopedics. 2023;46(1):35-38.].

Comparison of morbidity-mortality and functional results between implant exchange and internal fixation by plate for periprosthetic femoral fracture in total knee arthroplasty: A 52-case series

INTRODUCTION

Surgical options for periprosthetic femoral fracture in total knee arthroplasty (TKA) are controversial. The present retrospective study compared morbidity, mortality and functional results between implant exchange (group IE) and internal fixation by plate (group IF). The study hypothesis was that implant exchange does not give rise to more complications than plate fixation and that functional results are equivalent.

METHODS

Fifty-two femoral fractures in contact with a TKA implant were studied. The IE and IF groups (n 32 and 20, respectively), were comparable for age, gender and ASA score. Mean age was 80.5 years (range, 53-96 years). Morbidity and mortality were assessed on Clavien score; functional assessment used the KOOS questionnaire.

RESULTS

Mortality was 50% in group IF and 40% in group IE (p=0.4817). One patient was lost to follow-up. Complications were seen in 15 group IF patients (48.4%) versus 5 in group IE (26.3%) (p=0.14760), with infection in 5 (16.1%) and 2 patients (10.5%) respectively (p=0.69475). In both groups, 9 patients (i.e., 28.1% and 40% respectively) showed grade 2 complications (p=1). Revision surgery was performed in 8 grade 3b patients (25%) in the IF group and in 3 (15%) in the IE group (p=1). Mean KOOS score was 40 (range, 20-72) in IF and 65 (range, 50-93) in IE (p=0.0004).

CONCLUSION

Morbidity and mortality were comparable between implant exchange and plate fixation for periprosthetic femoral fracture in TKA. KOOS functional scores were better with implant exchange. Implant exchange may be suited to complex fracture with stable implant.

LEVEL OF EVIDENCE

IV, observational study.

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.

Distal femoral replacement or internal fixation for management of periprosthetic distal femur fractures: A systematic review

BACKGROUND

The number of periprosthetic fractures above a total knee arthroplasty continues to increase. These fractures are associated with a high risk of morbidity and mortality. Techniques for addressing these fractures include open reduction internal fixation (ORIF) and revision arthroplasty, including distal femoral replacement (DFR). The primary aim of this review is to compare mortality and reoperation rates between ORIF and DFR when used to treat periprosthetic distal femur fractures.

METHODS

A systematic review including MEDLINE, Embase and Cochrane Library databases was completed from inception to April 10, 2021. Studies including a comparator cohort were meta-analyzed.

RESULTS

Fourteen studies were identified for inclusion, of which, five had sufficient homogeneity for inclusion in a meta-analysis. 30-day and 2-year mortality was 4.1% and 14.6% in the DFR group. There was no statistically significant difference between ORIF and DFR (log Odds-Ratio (OR) = -0.14, 95 %CI: -0.77 to 0.50). The reoperation rate in the DFR group was 9.3% versus 14.8% for ORIF, with no difference between groups (log OR = 0.10, 95 %CI: -0.59 to 0.79). There was no difference in rates of deep infection (log OR = 0.22, 95 %CI: -0.83 to 1.28). Direct comparison of functional outcomes was not possible, though did not appear significant.

CONCLUSION

DFR in the setting of periprosthetic distal femur fractures is equivalent to ORIF with respect to mortality and reoperation rate and thus a safe and reliable treatment strategy. DFR may be more reliable in complex fracture patterns where the ability to obtain adequate fixation is difficult.

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.

Risk factors of early periprosthetic femoral fracture after total knee arthroplasty

Background

Periprosthetic femoral fracture (PFF) is a serious complication after total knee arthroplasty (TKA). However, the risk factors of PFF in the early postoperative setting are not well documented. This study determines the risk factors of early PFF after primary TKA.

Methods

This study recruited 24 patients who had early PFF within postoperative 3 months and 96 control patients. Demographic data (age, gender, weight, height, body mass index, Deyo-Charlson comorbidity index, diagnosis, operated side, underlying diseases and history of steroid usage intraoperative outcomes), intraoperative outcomes (operative time, surgical approach, type and brand of the prosthesis), and radiographic outcomes (distal femoral width; DFW, prosthesis-distal femoral width ratio; PDFW ratio, anatomical lateral distal femoral angle; LDFA, the change of LDFA, femoral component flexion angle; FCFA and anterior femoral notching; AFN) were recorded and compared between groups. Details of PFF, including fracture pattern, preoperative deformity, and time to PFF were also documented.

Results

In univariate analysis, the PFF group had significantly older, right side injury, rheumatoid, dyslipidemia, Parkinson patients than the control group (p < 0.05). No cruciate-retaining design was used in PFF group (p = 0.004). Differences between the prosthetic brand used were found in this study (p = 0.049). For radiographic outcomes, PFF group had significantly lower DFW but higher PDFW ratio and postoperative LDFA than the control group (p < 0.05). While the change of LDFA, FCFA and AFN were similar between groups. The fracture patterns were medial condylar (45.8%), lateral condylar (25.0%) and supracondylar fracture (29.2%). The mean overall time to PFF was 37.2 ± 20.6 days (range 8–87 days). Preoperative deformity was significantly different among the three patterns (p < 0.05). When performed multivariate analysis using the logistic regression model, age was only an independent risk factor for early PFF. The cut-off point of age was > = 75 years, with a sensitivity of 75.0% and specificity of 78.1%.

Conclusion

This study determined that age was the independent risk factors for early PFF. However, further well-controlled studies with a larger sample size were needed to address this issue.

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.

Treatment of B1 Distal Periprosthetic Femur Fractures

The burden of periprosthetic distal femoral fractures is projected to increase accordingly with the increase in total knee arthroplasties (TKAs) performed globally in the future. Less invasive plating and intramedullary (IM) nailing techniques still seem to provide similar outcomes based on current literature. Double-plating and combination techniques may prove to be beneficial in the future pending further large-scale studies but currently have not demonstrated superiority over single plating and IM nailing based on current evidence. Distal femoral replacement may provide a useful option for future treatment, provided it is performed by a trained knee arthroplasty surgeon.

Design approaches and challenges for biodegradable bone implants: a review

Introduction: Biodegradable materials have been at the forefront of cutting-edge research and offer a truly viable option in the designing and manufacturing of bone implants in biomedical engineering. Most research regarding these materials has focused on their biological characteristics and mechanical behavior vis-à-vis nonbiodegradable (NB) materials; but the design aspects and parametric configurations of biodegradable bone implant have somehow not received as much attention as they deserved.Area covered: This review aims to develop insight into the parametrically conceptualized design of biodegradable bone implant and takes into due consideration the characteristics of bone-biodegradable implant interface (BBII), design techniques employed for conventionally used bone implants to optimize parameters using standard test methods, traditional design, and finite element analysis approaches for implant and healing behavior, manufacturing techniques, real-time surgical simulations, and so on.Expert opinion: Some successful and conventionally used NB bone implants do not dissolve or degrade with time and require removal through a complicated surgery after fulfilling the intended objectives. These bone implants should be reconceptualized and designed with an appropriate biodegradable material while paying due attention to all factors/parameters involved and striking a balance between these factors with the ultimate objective of fulfilling all desired orthopedic requirements.

Early complications and reoperation rates are similar amongst open reduction internal fixation, intramedullary nail, and distal femoral replacement for periprosthetic distal femur fractures: a systematic review and meta-analysis

BACKGROUND

Our purpose was to perform a systematic review and meta-analysis to evaluate complication and revision rates for periprosthetic distal femur fractures (PPDFF) treated with: (1) ORIF using periarticular locking plates (ORIF), (2) retrograde intramedullary nail (IMN), and (3) distal femoral replacement (DFR).

METHODS

Systematic review of the literature was performed to identify eligible studies (N = 52). Identified treatment groups were: ORIF (N = 1205 cases), IMN (N = 272 cases), and DFR (N = 353 cases). Median follow-up was 30 months (range 6-96 months). Primary outcomes were: (1) major complication rates and (2) reoperation rates over the follow-up period. Secondary outcomes were incidence of deep infection, periprosthetic fracture, mortality over the follow-up period, 1-year mortality, non-union, malunion, delayed union, and hardware failure. Data for primary and secondary outcomes were pooled and unadjusted analysis was performed. Meta-analysis was performed on subset of individual studies comparing at least two of three treatment groups (N = 14 studies). Odds-ratios and their respective standard errors were determined for each treatment group combination. Maximum likelihood random effects meta-analysis was conducted for primary outcomes.

RESULTS

From the systematic review, major complication rates (p = 0.55) and reoperation rates (p = 0.20) were not significantly different between the three treatment groups. DFR group had a higher incidence of deep infection relative to IMN and ORIF groups (p = 0.03). Malunion rates were higher in IMN versus ORIF (p = 0.02). For the meta-analysis, odds of major complications were not significantly different between IMN versus DFR (OR 1.39 [0.23-8.52]), IMN versus ORIF (OR 0.86 [0.48-1.53]), or the ORIF versus DFR (OR 0.91 [0.52-1.59]). Additionally, odds of a reoperation were not significantly different between IMN versus DFR (OR 0.59 [0.08-4.11]), IMN versus ORIF (OR 1.26 [0.66-2.40]), or ORIF versus DFR (OR 0.91 [0.51-1.55]).

CONCLUSIONS

There was no difference in major complications or reoperations between the three treatment groups. Deep infection rates were higher in DFR relative to internal fixation, malunion rates were higher in IMN versus ORIF, and periprosthetic fracture rates were higher in DFR and IMN versus ORIF.

Local Efficacy of Corticosteroids as an Adjuvant for Periarticular Cocktail Injection in Simultaneous Bilateral Total Knee Arthroplasty: A Prospective Randomized Double-Blind Controlled Trial

Multimodal cocktail periarticular injections comprising corticosteroids are the most suggested therapy for postoperative discomfort and swelling following total knee arthroplasty (TKA). Nevertheless, previous findings cannot be applied to instances of unilateral total knee arthroplasty on bilateral knees. This randomized, prospective, double-blind, controlled clinical study examines the efficacy as well as safety of periarticular multimodal cocktail injection along or sans corticosteroids in certain situations. The 60 patients (120 knees) that experienced concurrent bilateral total knee arthroplasty were provided periarticular injections along additional betamethasone (7 mg) in the randomized knee, as well as the other knee, where corticosteroid was not administered. Key results were “pain scores at rest as well as in action” on a visual analogue scale of 11 pt. Other results included motion range, swelling of the thigh, Hospital for Special Surgery score (HSS score), and adverse effects were measured between the two sides. No statistically promising variations were found in the visual analogue scale ranking, motion range, girth of the thigh, and HSS score, as well as complications between the two sides. The impact on treatment outcomes was maintained between the knees on postoperative day 3 or at 3 months of follow-up. Multimodal periarticular injection without corticosteroid will alleviate postoperative swelling and pain. More studies are needed for the use of betamethasone as a corticosteroid in periarticular multimodal cocktail injections. This Chinese Clinical Trial Registry is registered with ChiCTR-OPC-17013503, dated 2017-11-23, available from http://www.chictr.org.cn/showproj.aspxproj=23146.

Distal femoral fine wire traction assisted retrograde nailing of the femur

Here we describe the surgical technique for using distal femoral fine wire traction during retrograde femoral nailing and present case examples. This technique allows for hands-free distraction across the fracture site to restore length and alignment, while not interfering with the preparation and insertion of the retrograde femoral nail. Distal femoral fine wire traction is a useful adjunctive technique to restore length and effect an indirect reduction in femur fractures being stabilized with a retrograde nail.

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.

Periprosthetic femoral re-fractures pathogenesis, classification, and surgical implications

Periprosthetic femoral re-fractures (PFRFs) represent an emerging challenge for orthopaedic surgeons, since their incidence is growing in the last years, but very few experiences about their management have been currently published. The present study aims to (1) introduce, for the first time, an etiologic classification for PRFRs and (2) to provide surgical and pharmacological tips for the correct management of these injuries. Periprosthetic femoral re-fractures (PFRFs) could be classified into traumatic-PFRFs (T-PFRFs) and pathological-PFRFs (P-PFRFs). T-PFRFs, i.e. the "true" periprosthetic re-fractures, present as new fracture lines occurring proximally or distally to a previous periprosthetic fracture, that has correctly healed. They are generally unpredictable injuries but, in selected cases, it is possible to predict them by analyzing the construct used in the treatment of the previous periprosthetic fracture. P-PFRFs, on the other hand, define re-fractures occurring on a previous periprosthetic non-union or delayed union: the new fracture line appears in the same district of the old one. According to the etiologic factors influencing the P-PFRFs pathogenesis, it is possible to define re-fractures caused by mechanical failures, biological failures, septic failures and multifactorial failures, i.e., a combination of the previously mentioned concerns. A successful postoperative outcome, following the surgical management of PFRFs, requires the correct identification of all the underlying causes, which should be promptly and appropriately managed.

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

Periprosthetic distal femoral fracture after total knee arthroplasty carries substantial morbidity and mortality regardless of fixation technique. Surgical treatment is favored in most patients compared with conservative therapy because of high rates of nonunion, malunion, and reoperation after casting or bracing. Internal fixation techniques including retrograde intramedullary nailing and locked plating are favored for surgical treatment in most fractures when bone stock in the distal fragment allows for appropriate fixation. In the setting of deficient distal femoral bone stock or femoral component loosening, revision arthroplasty with distal femoral replacement is the favored technique. Further studies with regard to the use of intramedullary nailing, locked plating, and distal femoral replacement are necessary to refine the indications for each technique and to define the use of combinations of these fixation techniques.

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.

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.

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.

Biomechanics-Hot Topics Part I

This study summarizes presentations of a symposium on biomechanically related hot topics of the 2015 Basic Science Focus Forum. Each topic emphasizes a biomechanical challenge common to all 4 of these presentations: an ideal fixation technique should deliver ample stability and sufficient flexibility to prevent fixation failure and to restore normal function.