Radiological assessment of the safe zone for medial minimally invasive plate osteosynthesis in the distal femur with computed tomography angiography

Is augmented femoral lateral plating with helically shaped medial plates biomechanically advantageous over straight medial plates?

Dual plating of comminuted distal femoral fractures allows for early patient mobilization. An additional helically shaped medial plate avoids the medial vital structures of the thigh. The aim of this study is to investigate the biomechanical competence of an augmented lateral locking compression plate distal femur (LCP-DF) using an additional straight versus a helically shaped medial LCP of the same length. Ten pairs of human cadaveric femora were instrumented with a lateral anatomical 15-hole LCP-DF. Following, they were pairwise instrumented with either an additional medial straight 14-hole LCP (group 1) or a 90°-helical shape LCP (group 2). All specimens were biomechanically tested under quasi-static and progressively increasing combined cyclic axial and torsional loading until failure. Initial interfragmentary axial displacement and flexion under static compression were significantly smaller in group 1 (0.11 ± 0.12 mm and 0.21 ± 0.10°) versus group 2 (0.31 ± 0.14 mm and 0.68 ± 0.16°), p ≤ 0.007. Initial varus deformation under static compression remained not significantly different between group 1 (0.57 ± 0.23°) and group 2 (0.75 ± 0.34°), p = 0.085. Flexion movements during dynamic loading were significantly bigger in group 2 (2.51 ± 0.54°) versus group 1 (1.63 ± 1.28°), p = 0.015; however, no significant differences were observed in terms of varus, internal rotation, and axial and shear displacements between the groups, p ≥ 0.204. Cycles to failure and load at failure were higher in group 2 (25,172 ± 6376 and 3017 ± 638 N) compared to group 1 (22,277 ± 4576 and 2728 ± 458 N) with no significant differences between them, p = 0.195. From a biomechanical perspective, helical double plating may be considered a useful alternative to straight double plating, demonstrating ameliorated damping capacities during flexion deformation and safer application as the medial neurovascular structures of the thigh are avoided.

Navigation of femoral and popliteal artery around the knee with CT angiography: implications for surgical interventions

PURPOSE

Uncertainty about the exact position of the femoral and popliteal arteries in the medial thigh and posterior knee might increase vascular complications in surgical procedures. This study aimed to document femoral and popliteal arteries in the medial thigh and around the knee to assist surgeons in developing safer surgical approaches.

METHODS

The study included 120 patients-180 lower limbs-who underwent CT angiography (CTA) of the lower extremity. The distance from the femoral artery to the anterior border, midsagittal axis, and posterior border of the femur and the popliteal artery to the medial, lateral, and midpoint posterior cortex of the proximal tibia was measured in two- and three-dimensional CTA images.

RESULTS

The femoral artery was found to be on average 236.93 ± 29.61 mm, 195.34 ± 26.12 mm, and 146.28 ± 33.18 mm away from the adductor tubercle at the anterior, midsagittal axis, and posterior borders of the femur, correspondingly. The popliteal artery was to be located on average 5.40 ± 2.50 mm posterior to the midpoint of the plateau tibia at the joint line.

CONCLUSION

Considering the mentioned femoral/popliteal artery distances to the femur and proximal tibia would direct surgeons to the safe zones for more accurate surgical approaches in the medial thigh and around the knee when performing osteotomies, knee arthroplasty, arthroscopy, and trauma surgeries, to reduce possible vascular damages.

LEVEL OF EVIDENCE

IV.

The double-plate fixation technique prevents varus collapse in AO type C3 supra-intercondylar fracture of the distal femur

INTRODUCTION

Varus collapse followed by osteosynthesis for distal femoral fractures with conventional implants has been well documented but is seldom mentioned in fractures managed with locking plates. The purpose of this study was to assess the incidence of varus collapse after treating complex supra-intercondylar fractures of the distal femur (AO type C3) using a Single Plate (SP) or Double Plate (DP) fixation technique.

MATERIALS AND METHODS

We retrospectively reviewed 357 patients with distal femoral fractures who were treated at our hospital between 2006 and 2017. After excluding cases of infection, malignancy, periprosthetic fracture, revision surgery, pediatric fracture, and extra-articular fracture, 54 patients were included in the study. All demographic data and radiological and clinical outcomes were reviewed and analyzed.

RESULTS

There were 54 patients enrolled into this study with age from 15 to 85 years old (mean 41.6, SD = 19.9), and 32 of them were open fractures (59%). The patients were further divided into either an SP (n = 15) or a DP group (n = 39). Demographics, including age, sex, injury severity score, and open fracture type, were all compatible between the two groups. The overall nonunion rate was 25.9% (n = 14; 6 from the SP and 8 from the DP group; p = 0.175). The varus collapse rate was 9.3% (n = 5; 4 from the SP and 1 from the DP group (p = 0.018).

CONCLUSIONS

The varus collapse rate after osteosynthesis with a single lateral locking plate could be as high as 26.7% in AO type C3 fractures of the distal femur, which would be decreased to 2.6% by adding a medial buttress plate. Surgeons should consider DP fixation to avoid varus collapse in severely comminuted complete intra-articular fractures of the distal femur.

Technique, Indications and Limitations of a Minimally Invasive Approach to Treat Distal Radius Fractures and Malunions

The minimally invasive flexor carpi radialis approach can be used for volar locking plate fixation of distal radius fractures. It offers the advantage of preserving ligamentotaxis, which facilitates the reduction and the small size of the scar improves the esthetic result of the procedure. It is indicated for extra-articular fractures of the distal radius. In the case of an intra-articular fracture, an arthroscopy may be associated. In the case of a proximal diaphyseal extension of the fracture, a second proximal approach can be added in order to use a longer plate. Relative contraindications are comminuted articular fractures in elderly osteoporotic patients. Functional and radiological results are comparable to those obtained with the extented flexor carpi radialis approach. A conversion of the procedure for a larger incision is always possible in the case of a difficult reduction.

Medial and lateral dual plating of native distal femur fractures: a systematic literature review

Introduction

Lateral locked plating (LLP) development has improved outcomes for distal femur fractures. However, there is still a modest rate of nonunion in fractures treated with LLP alone, with higher nonunion risk in high-energy fractures, intra-articular involvement, poor bone quality, severe comminution, or bone loss. Several recent studies have demonstrated both the safety and the biomechanical advantage of dual medial and lateral plating (DP). The purpose of this study was to evaluate the clinical outcomes of DP for native distal femoral fractures by performing a systematic review of the literature.

Methods

Studies reporting clinical outcomes for DP of native distal femur fractures were identified and systematically reviewed. Publications without full-text manuscripts, those solely involving periprosthetic fractures, or fractures other than distal femur fractures were excluded. Fracture type, mean follow-up, open versus closed fracture, number of bone grafting procedures, nonunion, reoperation rates, and complication data were collected. Methodologic study quality was assessed using the Coleman methodology score.

Results

The initial electronic review and reverse inclusion protocol identified 1484 publications. After removal of duplicates and abstract review to exclude studies that did not discuss clinical treatment of femur fractures with dual plating, 101 potential manuscripts were identified and manually reviewed. After final review, 12 studies were included in this study. There were 199 fractures with average follow-up time of 13.72 months. Unplanned reoperations and nonunion occurred in 19 (8.5%) and 9 (4.5%) cases, respectively. The most frequently reported complications were superficial infection (n = 6, 3%) and deep infection (n = 5, 2.5%) postoperatively. Other complications included delayed union (n = 6, 3%) not requiring additional surgical treatment and knee stiffness in four patients (2%) necessitating manipulation under anesthesia or lysis of adhesions. The average Coleman score was 50.5 (range 13.5-72), suggesting that included studies were of moderate-to-poor quality.

Conclusions

Clinical research interest in DP of distal femoral fractures has markedly increased in the past few decades. The current data suggest that DP of native distal femoral fractures is associated with favorable nonunion and reoperation rates compared with previously published rates associated with LLP alone. In the current review, DP of distal femoral fractures was associated with acceptable rates of complications and generally good functional outcomes. More high-quality, directly comparable research is necessary to validate the conclusions of this review.

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.

Biomechanical and anatomical considerations for dual plating of distal femur fractures: a systematic literature review

INTRODUCTION

Distal femur fractures are challenging injuries historically associated with high rates of nonunion and varus collapse with operative management. As a result, clinical and research interest in dual plating (DP) of distal femur fractures has seen a dramatic increase in recent years. The purpose of this study was to systematically review the literature regarding vascular anatomy and biomechanics of distal femur fractures treated with DP constructs.

MATERIALS AND METHODS

A systematic literature review of two medical databases (PubMed & Scopus) was performed to identify peer-reviewed studies on the anatomy and biomechanics regarding DP of distal femur fractures. A total of 1,001 papers were evaluated and 14 papers met inclusion criteria (6 anatomy and 8 biomechanics). Methodological quality scores were used to assess quality and potential bias in the included studies.

RESULTS

In the biomechanical studies, DP constructs demonstrated greater axial and rotational stiffness, as well as less displacement and fewer incidences of failure compared to all other constructs. Vascular studies showed that the femoral artery crosses the mid-shaft femur approximately 16.0-18.8 cm proximal to the adductor tubercle and it is located on average 16.6-31.1 mm from the femoral shaft at this location, suggesting that medial plate application can be achieved safely in the distal femur. The methodological quality of the included studies was good for biomechanical studies (Traa score 79.1; range 53-92.5) and excellent for anatomical studies (QUACs score 81.9; range 69.0-88.5).

CONCLUSIONS

Existing biomechanics literature suggests that DP constructs are mechanically stronger than other constructs commonly used in the treatment of distal femur fractures. Furthermore, medial distal femoral anatomy allows for safe application of DP constructs, even in a minimally invasive fashion. Dual plating should be considered for patients with distal femur fractures that have risk factors for instability, varus collapse, or nonunion.

Safe and dangerous zones for the superficial femoral artery in femoral surgery

The proximity of the superficial femoral artery (SFA) to the femur exposes the SFA to risks that have serious complications. Although surgeons have used the lateral or medial approach to lessen these risks, they have not been eliminated. Therefore, this study aimed to identify dangerous and safe zones in terms of the SFA that can be used during femoral surgical procedures, using anatomical reference points. Computed tomography angiography (CTA) of 50 patients aged between 16 and 60 years obtained from the local institution's database was examined. Radiological and clinical measurements were performed to determine the position of the SFA relative to the femur. The mean age of the patients included in this study was 38.08 ± 9.44 (16-60) years. The average ratio of the distance between the proximal and distal borders of the dangerous zone and the lateral joint spaces (LJS) to the distance between the greater trochanter (GT) and LJS was 0.5722 ± 0.053, respectively. The average ratio of the distance between the end of the dangerous zone and LJS to the distance between the GT and LJS was 0.4108 ± 0.05026. This study found that 40% and 60% of the clinically measured distance between the GT and LJS can be used to determine safe and dangerous zones during femoral surgery. Additionally, the half distance between the anterior superior iliac spine (ASIS) and medial joint space (MJS) and one-fourth of the distance between the ASIS and LJS can be used to determine safe and dangerous zones in patients whose GT are not easily palpated.

Surgical outcomes of retrograde nailing enhanced with minimally invasive cerclage cable fixation for infra-isthmal femoral fracture

BACKGROUND

Infra-isthmal femoral fracture has been known as one of the risk factors for femoral nonunion. Retrograde intramedullary nailing can provide reliable stability of the distal fragment in infra-isthmal femoral fracture, but adequate reduction is required to achieve a successful outcome. This study aimed to evaluate the surgical outcomes of retrograde nailing enhanced with minimally invasive cerclage cable fixation for infra-isthmal femoral fracture.

METHODS

Between March 2013 and July 2017, 15 patients with infra-isthmal fractures treated with retrograde nailing and minimally invasive cerclage cable fixation were included in this study. Cerclage cable was applied for reduction aid (reduction cable) or prevention of further displacement in non-displaced extension of the distal spiral fracture (prevention cable). Number and function of cerclage cables, operation time, additional surgery, and complications were assessed. Further displacement of the wedge after nailing, coronal and sagittal alignment, displacement of the main fragment, and time from injury to union were evaluated as radiologic outcomes.

RESULTS

Of the 15 patients in this study, 14 were treated with reduction cables. Average postoperative coronal and sagittal angulation was 1.7° (1° varus to 4° valgus) and 1.6° (2° flexion to 11° extension). Mean displacement between the main fragments was 3.5 mm (range 0-22 mm). Four of the 14 cases used additional prevention cables combined with reduction cable. Only one case was treated solely with a prevention cable. A total of five prevention cables were maintained without further displacement. All patients achieved bone union, and the average time to union was 22.7 weeks (range 9-44 weeks). There were no complications as a result of surgery, such as infection or major neurovascular injury.

CONCLUSIONS

The minimally invasive cerclage cable technique could be a useful and safe enhancement in retrograde nailing for infra-isthmal femoral fracture in order to prevent further displacement and to reduce the main fracture.

New Classification for Periprosthetic Distal Femoral Fractures Based on Locked-Plate Fixation Following Total Knee Arthroplasty: A Multicenter Study

BACKGROUND

This study aimed to establish a new classification using locked-plate fixation for periprosthetic distal femoral fracture (PDFF) following total knee arthroplasty (TKA) and to determine when dual locked-plate fixation is necessary through defining this classification.

METHODS

One-hundred fifteen consecutive PDFFs that underwent operative treatment were reviewed from 2011 to 2019 with minimum 1-year follow-up. Most PDFFs were fixed with single or dual locked-plate fixations using the minimally invasive plate osteosynthesis technique. Based on preoperative radiographs, PDFFs were classified according to the level of main fracture line relative to the anterior flange of femoral component: type I and II, main fracture line located proximal and distal to the anterior flange; and type III, component instability regardless of fracture line requiring revisional TKA. Furthermore, type II fractures were subclassified based on the direction of fracture beak as follows: type II_L, lateral-beak; type II_M, medial-beak. The incidence, treatment methods, and complications were analyzed according to the classification.

RESULTS

Incidences of type I, II_L, II_M, and III were 64.4%, 8.7%, 24.3%, and 2.6%, respectively. Meanwhile, most PDFFs in type I and II were treated with lateral single locked-plate fixations, except for type II_M, which was treated with either single or dual locked-plate fixations. Overall complications were significantly higher in type II (28.9%) than in type I (10.8%, P = .019). In type II_M, bone union-related complications were significantly higher in single locked-plate fixation (50.0%) than in dual locked-plate fixation (5.6%; P = .013).

CONCLUSION

The new classification provides practical and obvious strategies for the treatment of PDFF following TKA using locked-plate fixation. For type II_M fracture, dual plate fixation is necessary to prevent fixation failure or nonunion.

The missing piece of the trauma armoury-medial femoral condyle plate

Fixation of distal femoral fractures is often challenging due to the fracture configuration and associated poor bone quality. Dual plating (lateral and medial) has become an acceptable option to provide improved stability versus a single plate fixation. Though there are several commercially available anatomically designed plates for the lateral femoral condyle, there is no anatomic plate available in UK specifically for medial fixation of distal femur fractures. Our aim is to determine the best suited pre-contoured plate for stabilising the medial femoral condyle (MFC). Right sided femur sawbones were used to determine how well 18 different pre-contoured anatomical plates (Depuy Synthes, Leeds, UK) fit the medial femoral condyle. Some of these had variable angle (VA) option. Lift off, fit and notch penetration were assessed and recorded independently by 4 orthopaedic trauma surgeons. The number and distribution of screws in the MFC that each plate allowed was also determined. To do this the MFC was divided into quadrants: Proximal anterior (PA), distal anterior (DA), proximal posterior (PP) and distal posterior (DP). The ipsilateral anterolateral proximal tibial (VA and 4.5 mm non-VA), PHILOS, posteromedial proximal tibial and ipsilateral lateral extra-articular distal humeral plate offered good sagittal fit, less than 2 mm lift off at the condyles and no diaphyseal lift off. Plate positioning in the PA quadrant offered the best fit. The ipsilateral anterolateral proximal tibial plates (VA) and PHILOS allowed at least 4 screws to be placed in the PA and 2 in the PP quadrant with no notch penetration. The Tomofix provided good fit, but all 4 screws were in PA quadrant, with distal screws causing notch penetration. The non-VA and PHILOS plates did not offer the VA advantage. The ipsilateral anterolateral proximal tibial VA plates provided the best anatomical fit for the MFC with the greatest number of screws in the condylar quadrants with the option of variable angle screw placement.

Dual-Plating in Distal Femur Fracture: A Systematic Review and Limited Meta-analysis

INTRODUCTION

Although lateral locking plate has shown promising results in distal femur fracture, there are high rates of varus collapse and implant failure in comminuted metaphyseal and articular fractures. This systematic review evaluates the functional outcomes and complications of dual plating in the distal femur fracture.

MATERIALS AND METHODS

Manual and electronic search of databases (PubMed, Medline Embase and Cochrane Central Register of Controlled Trials) was performed to retrieve studies on dual plate fixation in the distal femur fracture. Of the retrieved 925 articles, 12 were included after screening.

RESULTS

There were one randomized-controlled, four prospective and seven retrospective studies. A total of 287 patients with 292 knees were evaluated (dual plating 213, single plating 76, lost to follow-up 3). The nonunion and delayed union rates following dual plate fixations were up to 12.5% and 33.3%, respectively. The mean healing time ranged from 11 weeks to 18 months. Good to excellent outcome was observed in 55-75% patients. There was no difference between the single plate and dual plate fixation with regards to the functional outcomes (VAS score, Neer Score and Kolmert's standard) and complications. Pooled analysis of the studies revealed a longer surgical duration (MD - 16.84, 95% CI - 25.34, - 8.35, p = 0.0001) and faster healing (MD 5.43, 95% CI 2.60, 8.26, p = 0.0002) in the double plate fixation group, but there was no difference in nonunion rate (9.2% vs. 0%, OR 4.95, p = 0.13) and blood loss (MD - 9.86, 95% CI - 44.97, 25.26, p = 0.58).

CONCLUSION

Dual plating leads to a satisfactory union in the comminuted metaphyseal and articular fractures of the distal femur. There is no difference between the single plate and dual plate with regards to nonunion rate, blood loss, functional outcomes and complications. However, dual fixation leads to faster fracture healing at the cost of a longer surgical duration.

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.

Surgical Tips and Tricks for Distal Femur Plating

Distal femur fractures are challenging fractures to treat, with nonunion rates as high as 22%. Precontoured locking plates have mitigated some earlier causes of failure, while introducing new challenges. The recognition of troublesome injury patterns and appropriate preoperative planning can avoid common pitfalls. Adjunctive techniques, including the use of a radiolucent triangle, an external fixator, unicortical plates, and crossing K-wires, can assist with fracture reduction and maintenance. It is important to understand the common pitfalls involved with distal femur plating and to consider a wide array of techniques to combat these challenges.

Medial minimally invasive helical plate osteosynthesis of the distal femur - a new technique

INTRODUCTION

The goal of this study was to evaluate distal femoral minimally invasive plate osteosynthesis (MIPO) from a distal medial approach by use of a pre-bent helical implant.

MATERIAL & METHODS

A total of 18 lower extremities was evaluated. A 29.6 cm steel plate was constructed and pre-bent on bone specimens with a torsion of 55.7° A 5 cm incision was performed from the tip of the medial epicondyle alongside its centre in a proximal direction. The medial border of the vastus medialis was retracted anteriorly. The level of the proximal skin incision was determined using the length of the pre-bent plates. The proximal incision was performed at a length of 4 cm at the described height at a line between the lateral epicondyle and the tip of the greater trochanter. A raspatory was advanced beneath the vastus medialis in a proximal direction to create an extraperiosteal tunnel for plate insertion. The plate was fixed to the bone at its proximal and distal portion via screws. Following dissection, the distance between the nearest perforator to the proximal plate end was evaluated. The vertical distances between the medial border of the plate and the femoral artery and femoral nerve were measured at the level of the proximal plate end and at the level of the proximal margin of the vastoadductor membrane.

RESULTS

The most proximal perforating artery was located at a mean distance of 20.15 mm starting from the proximal plate margin. The mean interval between the medial border of the plate at the level of its proximal tip and the femoral artery was 51.9 mm. The average distance between the femoral nerve and the medial border of the proximal part of the plate was 42.3 mm. Regarding the interval between the medial border of the plate and the femoral artery, this was at a mean of 40.5 mm at the level of the proximal margin of the vastoadductor membrane. During dissection, none of the specimens showed any lesions of the adjacent anatomical characteristics.

CONCLUSION

Our results indicate MIPO of the distal femur from a medial approach as a safe technique.

Minimally invasive plate osteosynthesis with dual plating for periprosthetic distal femoral fractures following total knee arthroplasty

Introduction

Adequate treatment for periprosthetic distal femur fractures is challenging because of various reasons, including severe osteoporosis and distal fragments that are too small or too distal. We have introduced a new surgical technique for dual plating of periprosthetic distal femur fractures following total knee arthroplasty (TKA) and determined the clinical and radiological outcomes of minimally invasive plate osteosynthesis (MIPO) with a dual locking compression plate (LCP).

Materials and methods

Between January 2010 and July 2019, 18 patients [mean age, 74.8 (68–89) years; average follow-up period, 14.8 (12–43) months] underwent MIPO with distal femoral LCP laterally and proximal humeral internal locking system (PHILOS) medially for periprosthetic distal femoral fractures following TKA. The minimum follow-up was 1 year. The clinical and radiological outcomes were assessed using the modified WOMAC scores, knee range of motion, time to callus formation, time to union, and complications of malunion, nonunion, and shortening.

Results

The average time to union was 18.4 weeks (range, 10–51 weeks) and to callus formation was 7.8 weeks (range, 2–14 weeks). At the 1-year follow-up, the average JLETS was 37.6 (range, 24–53), average knee ROM was 110.3° (range, 80–135°), and average varus-valgus angles of the distal femur were 3.2° (range, −2.9–10.5°). No nonunion, broken plates, or implant failure occurred. Malunion occurred in three patients.

Conclusion

MIPO with dual LCP is a reliable method for stabilizing periprosthetic distal femoral fractures following TKA, with satisfactory bone union rates and low complication rates.

Excellent outcomes after double-locked plating in very low periprosthetic distal femoral fractures

INTRODUCTION

Very low periprosthetic distal femur fractures (PPDFFs) are rare injuries and often have a relatively high failure rate after single lateral locked plating. The double plating technique yields good outcomes in osteoporotic fractures of the distal femur. To date, there is limited information on double-locked plate fixation of very low PPDFFs. This study aimed to evaluate the outcomes and complications of surgically treated very low PPDFFs using double-locked plate fixation.

MATERIALS AND METHODS

Between January 2013 and December 2018, sixty-one consecutive patients with PPDFFs have been conducted. Only Su type III PPDFFs with double-locked plate fixation through a lateral minimally invasive approach and a medial subvastus approach to the distal femur were analyzed. Patients were encouraged to perform straight leg raising exercises and active knee motion on the second postoperative day. Assisted weight bearing from the early postoperative days was supported, and full weight-bearing was allowed after healing the fracture site. All patients were evaluated according to the time to union, limb alignment, range of knee motion, Knee Society Score, and presence of complications.

RESULTS

Twenty one patients (17 females and 4 males, mean age 76 years, range 56-90) were included in the study. There were 10 of 33-A1, 6 of 33-A2 and 5 of 33 A3 fractures, according to the AO classification. Of 21 patients, 20 achieved union at an average of 14 weeks postoperatively. Postoperative limb alignment was satisfactory in all cases, with an average mechanical distal lateral femur angle of 89° and average mechanical posterior distal femur angle of 86°. All patients recovered the knee joint motion similar to that of the contralateral side, and daily life pre-injury. The average knee and function scores were 94 and 89, respectively. There were one case of non-union and three cases of superficial wound infection, which resolved after intravenous antibiotic therapy.

CONCLUSIONS

Double locked plating showed excellent radiographic and functional outcomes with few complications in patients with very low PPDFFs. Based on these promising results, we propose the consideration of double-locked plate fixation in the treatment of very low PPDFFs.

Minimally invasive anterior plate osteosynthesis of the distal radius: A 710 case-series

INTRODUCTION

Since the 2000s, internal fixation of distal radius fracture by volar locking plate on an extended flexor carpi radialis (FCR) approach has become the gold standard.

OBJECTIVE

The present study aimed to assess medium-term results of minimally invasive plate osteosynthesis (MIPO) in distal radius fracture.

MATERIAL AND METHODS

The series comprised of 710 cases (512 female; mean age, 58 years). The 15mm approach was on the lateral edge of the FCR. The plate was slipped under the pronator quadratus. Closure used intradermal running suture without drain or orthosis.

RESULTS

At a mean 7 months' follow-up, mean scar length was 17mm (range, 10-40mm), pain 1.13/10 (0-8), Quick-DASH 13.28 (0-86.36), and patient-rated wrist evaluation (PRWE) 11.48 (0-91). Compared to contralateral values, mean flexion was 87.23%, extension 88.52%, pronation 96.17%, supination 93.41%, and grip strength 79.68%. Hardware was removed in 45.92% of cases. There were 16 cases of secondary displacement, with 4 revision procedures, one of sepsis at 6 months, 10 of complex regional pain syndrome, and 14 of median nerve paresthesia, with 4 carpal tunnel release procedures.

DISCUSSION

The minimally invasive FCR approach can be used for volar plate fixation of distal radial fracture. It has the advantage of conserving ligamentotaxis, facilitating reduction and improving scar esthetics. The incision can be extended if need be.

LEVEL OF EVIDENCE

III; single-centre retrospective study.

Anthropometric Factors on Safe Distances between Popliteal Vessels to the Femur for Cerclage Wiring of the Distal Femoral Fracture: A Magnetic Resonance Imaging Study

Background and Objectives: The proximity of the popliteal vessels in the distal femur may increase the risk of iatrogenic vascular injury during cerclage wiring. In this study, the closest location and distance of the popliteal vessels to the femur was examined using magnetic resonance imaging (MRI). The associations between anthropometric factors and the distance that would guide the placement of wires safely during surgery were also identified. Materials and Methods: We reviewed adult knee magnetic resonance images and recorded: (1) the relation and the shortest horizontal distance (d-H) from the femoral cortex to the popliteal vessels in axial images and (2) the vertical distance (d-V) from the adductor tubercle to the axial level of the d-H values in coronal images. The effects of anthropometric factors (sex, age, body height, body weight, body mass index, thigh circumference, femoral length and femoral width) on these distances were analysed. Results: Analysis of 206 knee magnetic resonance images revealed that the closet locations of popliteal vessels were at the posteromedial aspect of the femur. The d-H and d-V were 7.38 ± 3.22 mm and 57.01 ± 11.14 mm, respectively, and were both shorter in women than in men (p < 0.001). Multivariate analysis identified thigh circumference and femoral length as the most influential factors for the d-H and d-V, respectively (p < 0.001). Linear regression demonstrated a strong positive linear correlation between the thigh circumference and the d-H and between the femoral length and the d-V (Pearson’s r = 0.891 and 0.806, respectively (p < 0.001)). Conclusions: The closet location and distance of the popliteal vessels to the femur provide useful information for wire placement during distal femoral fracture surgery while minimising the risk of vascular injury. Given that patients with a smaller thigh circumference and a shorter femoral length are more likely to have a smaller d-H and a shorter d-V, respectively, cautious measures should be taken in such cases.

The effects of dual plating on the vascularity of the distal femur

AIMS

Dual plating of distal femoral fractures with medial and lateral implants has been performed to improve construct mechanics and alignment, in cases where isolated lateral plating would be insufficient. This may potentially compromise vascularity, paradoxically impairing healing. This study investigates effects of single versus dual plating on distal femoral vascularity.

METHODS

A total of eight cadaveric lower limb pairs were arbitrarily assigned to either 1) isolated lateral plating, or 2) lateral and medial plating of the distal femur, with four specimens per group. Contralateral limbs served as matched controls. Pre- and post-contrast MRI was performed to quantify signal intensity enhancement in the distal femur. Further evaluation of intraosseous vascularity was done with barium sulphate infusion with CT scan imaging. Specimens were then injected with latex medium and dissection was completed to assess extraosseous vasculature.

RESULTS

Quantitative MRI revealed a mean reduction of 21.2% (SD 1.3%) of arterial contribution in the lateral plating group and 25.4% (SD 3.2%) in the dual plating group (p = 0.051); representing a mean decrease in arterial contribution of 4.2%. The only significant difference found between both experimental groups was regionally, at the lateral aspect of the distal femur with a mean drop in arterial contribution in the lateral plating group of 18.9% (SD 2.6%) versus 24.0% (SD 3.2%) in the dual plating group (p = 0.048), representing a mean decrease in arterial contribution of 5.1%. Gross dissection revealed complete destruction of periosteal vessels underneath either medial or lateral plates in both groups. The network of genicular branches contributing to the posterior and distal femoral condyles was preserved in all specimens. A medial vascular pedicle was found dividing from the superficial femoral artery at a mean 12.7 cm (SD 1.7) proximal to the medial epicondyle and was undisrupted in the dual plating group.

CONCLUSION

Lateral locking-plate application resulted in mean 21.2% reduction in distal femur vascularity. Addition of medial plates did not further markedly decrease vascularity. As such, the majority of the vascular insult occurred with lateral plating alone. Supplemental medially based fixation did not lead to marked devascularization of the distal femur, and should therefore be considered in the setting of comminution and poor bone stock in distal femoral fractures. Further clinical research is required to confirm the results of this study. Cite this article: Bone Joint J 2020;102-B(4):530-538.

Neurovascular Bundle Entrapment and Through Knee Amputation After Cerclage Cabling of Distal Femoral Peri-implant Fracture: A Case Report

CASE

We report the case of an 82-year-old woman with diabetes, arteriosclerosis, chronic heart failure, and hypertension treated with an anatomical locking plate and multiple cables for a spiral-wedged periprosthetic fracture of the distal femur which was complicated by direct occlusion of the femoral artery and crush of the sciatic nerve, resulting in leg necrosis and, ultimately, through-knee disarticulation despite early recognition and arterial repair.

CONCLUSIONS

Neurovascular injury is a potential complication of cerclage cables placement around the femoral shaft during complex fracture fixation. Devastating complications cannot always be corrected despite early vascular intervention.

A case series of mortality and morbidity in distal femoral periprosthetic fractures

Periprosthetic distal femoral fractures are occurring in increasing numbers. There is limited research into outcomes and mortality. This study aimed to assess the 1 year mortality and complications requiring further surgery in the two years following a presentation with a periprosthetic distal femoral fracture. A retrospective case series of periprosthetic distal femoral fractures at a single trauma centre was undertaken. All patients were included who presented with a distal femur periprosthetic fracture between 1st January and 2008 and 31st March 2015. 60 patients with 49 females and 11 males. Mean age was 80.7. Median time to surgery was 63 h 42 (70%) underwent open reduction internal fixation, 13 (21.7%) underwent revision arthroplasty and 5 (8.3%) underwent non-operative treatment. Median length of stay was 14 days. There were 12 (20%) complications requiring further surgery within 2 years. There were 2 (3.3%) deaths in 30 days and 8 (13.3%) within 1 year following fracture. Periprosthetic distal femoral fractures are becoming a common orthopaedic presentation. They occur in a complex group of patients and have high rates of mortality and complications.

Course of the Femoral Artery in the Mid- and Distal Thigh and Implications for Medial Approaches to the Distal Femur: A CT Angiography Study

INTRODUCTION

Unfamiliarity with the location of the femoral artery in the medial thigh has tempered surgeons' enthusiasm for medial approaches to the distal femur. The purpose of this study was to define the relationship of the femoral artery to the mid- and distal femur to assist in safely approaching the femur for fracture care.

METHODS

Fifteen patients undergoing CT with angiography (CTA) of the lower extremity (CTA) were evaluated. From three-dimensional CTA images, the distance of the artery at the anterior border, midsagittal line, and posterior border of the femur from the distal femur at both the adductor tubercle and medial femoral condyle was measured.

RESULTS

The average distances of the adductor tubercle to the femoral artery were 23.2 cm (±3.3), 18.8 cm (±3.4), and 14.3 cm (±4.1) at the level of the anterior border, midsagittal line, and posterior border of the femur, respectively. The descending genicular artery (DGA) originated 10.8 cm (±1.3) proximal to the adductor tubercle.

DISCUSSION

A wide safe zone exists in the medial distal femur. The artery crosses the midsagittal axis of the medial femur an average of 18.8 cm proximal to the adductor tubercle.

Biomechanical assessment of single LISS versus double-plate osteosynthesis in the AO type 33-C2 fractures: A finite element analysis

OBJECTIVES

In the present study, we assessed the biomechanical advantage between the single LISS and double-plate used in AO type 33-C2 fractures with the method of finite element analysis, which will help surgeons choose the optimal therapy to the unstable distal femoral fracture.

METHODS

The AO type 33-C2 fractures and the models of LISS plate and medial plate was constructed in 3-matic software and UG-NX software respectively. We then assembled the single plate and the double-plate to the fracture model separately to form the fixation models. After meshing the models' elements, we used the Abaqus software to perform the finite element analysis. Values of peak Von Mises Stress (VMS) on the plate, maximum deformation of the models and the distance changes of the fracture gap were used to capture the mechanical factors in this study.

RESULTS

Our results indicated that the single LISS underwent 1.2 times higher amount of stress than the double-plate (316.0 MPa VS 281.6 MPa). And the medial plate dispersed some stresses (the maximum stress is 47.4 MPa). Single-plate generated 3 times greater bending angle than double-plate (0.6° VS 0.2°). The bending angles of the single and double-fixation-fracture models are 0.9° and 0.3° respectively. The maximum distance changes of the fracture gap in the single-plate model was 2 times higher than that of double-plate model (2.6 mm VS 1.3 mm). In the torsional load analysis, peak VMS of the single and double model was 1.0 MPa and 0.8 MPa respectively. And the bending angle was 0.8° in the single model and 0.4° in the double model.

CONCLUSIONS

The double-plate is more effective scenario using in the distal femoral fractures, particular in unstable fractures with joint involvement.

Is augmented LISS plating biomechanically advantageous over conventional LISS plating in unstable osteoporotic distal femoral fractures?

Treatment of complex osteoporotic distal femur fractures with the Less Invasive Stabilization System (LISS) has been associated with high complication rates. The aim of this study was to investigate the biomechanical competence of two different techniques of augmented versus conventional LISS plating. Unstable distal femoral fracture AO/OTA 33-A3 was created via osteotomies in artificial femora simulating osteoporotic bone. Three study groups, consisting of 10 specimens each, were created for fixation with either LISS plate, LISS plate with additional polylactide intramedullary graft, or LISS plate plus medial locking plate (double plating). All specimens were non-destructively tested under axial (20-150 N) and torsional (0-4 Nm) quasi-static loading. Each bone-implant construct was tested with two different working length (WL) configurations (long and short) of the LISS plate. Relative movements between the most medial superior and inferior osteotomy aspects were investigated via three-dimensional motion tracking analysis. Double plating revealed significantly smaller longitudinal and shear displacement than the other two techniques (p ≤ 0.001). In addition, LISS plus graft fixation was with significantly less longitudinal displacement in comparison to conventional LISS plating (p < 0.001). Long WL resulted in significantly higher longitudinal and shear displacement compared to short WL for LISS and LISS plus graft (p ≤ 0.032), but not for double plating (p > 0.999). In conclusion, intramedullary grafting resulted in significantly increased fracture stability under axial loading in comparison to conventional LISS plating. Although it was not efficient enough to provide comparable stability to double plating, intramedullary grafting may be considered as a useful biological alternative to the latter in a surgeon's armamentarium. © 2018 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:2604-2611, 2018.

Safe zones and a technical guide for cerclage wiring of the femur: a computed topographic angiogram (CTA) study

INTRODUCTION

Cerclage wiring for reduction of complex femoral shaft fractures can create iatrogenic vascular injury.

OBJECTIVE

To describe the anatomical relation of blood vessels to the femur and develop a technical guide for safe passage of cerclage wire.

MATERIALS AND METHODS

CT lower-limb angiographs (CTA) of 80 patients were reviewed and analysed to identify the superficial femoral artery (SFA) and the deep femoral artery (DFA) as well as the relation of those arteries to the femoral cortex. The total length of the femur was measured and divided into eight equal segments (seven levels). At each level, the medial half of the femur was divided into eight sectors labelled A through H and the position of the SFA and DFA was recorded. The shortest distance between the femoral cortex and the SFA and DFA at each level was measured. The data was analysed using STATA version 10.0.

RESULTS

The average total femoral length from the tip of greater trochanter to lateral joint line was 402.98 ± 26.16 cm. The average distances from the SFA to the femur (d1) for levels 1 through 7 were 37.20 ± 5.0, 32.09 ± 4.74, 27.13 ± 4.19, 27.71 ± 5.46, 23.71 ± 4.40, 13.63 ± 3.59 and 10.08 ± 3.09 mm, respectively. The average distances between the DFA and the femur (d2) for levels 1 through 3 were 26.70 ± 4.13, 14.76 ± 3.27 and 9.58 ± 3.79 mm, respectively. The position of the SFA is located in sectors B through E at levels 1-3 and in sectors E through H at levels 4-7 and the position of the DFA located in sectors B through F at levels 1-3.

CONCLUSION

Cerclage wiring should be started from the posterior intermuscular septum at the linea aspera. The safe area is the proximal half (midshaft) of the femur where the SFA and DFA lie at a safe distance from the femur. Between the midshaft and the distal 1/4, insertion of the passer must be done meticulously with the tip kept close to posteromedial cortex. Below the distal 1/4, the tip of the passer should be kept close to the posterior cortex to avoid injury to the SFA and the sciatic nerve.

Long Volar Plating for Metadiaphyseal Fractures of Distal Radius: Study Comparing Minimally Invasive Plate Osteosynthesis versus Conventional Approach

Background  Minimally invasive plate osteosynthesis (MIPO) has been used in wrist surgery for several years. The purpose of this retrospective study was to compare clinical and radiologic outcomes of MIPO technique with those of a conventional approach in the treatment of metadiaphyseal distal radius fracture by long volar plating. Materials and Methods  Our series consisted of 32 fractures in 31 patients, mean age 63.9 years, including 16 men and 15 women. MIPO technique was used in 15 wrists (group 1) and conventional approach (> 60 mm of skin incision) in 17 wrists (group 2). In group 1, a long volar plate was inserted under pronator quadratus through a 15- to 30-mm distal incision then fixed to the epiphysis of the distal radius. Then, through a 15- to 30-mm proximal incision, the plate was fixed to the diaphysis of the radius, thus reducing the fracture. Results  In group 1, mean distal incision size was 23.5 and 16.9 mm for proximal one. Mean total scar size (sum of both distal and proximal incisions) was 40.0 mm in group 1 and 84.1 mm in group 2. Mean tourniquet time was 58.4 minutes in group 1 and 68.9 minutes in group 2. At latest follow-up, no significant difference was noted in both the groups concerning pain, quick-DASH score, grip strength, ROM, and radiologic data. One extensor pollicis longus rupture treated by tendon transfer was done in group 1. Conclusion  The MIPO technique for metadiaphyseal fractures of the distal radius by long volar plating has cosmetic and economic advantages compared with the conventional approach. Conversion to conventional approach is possible at any time in case of technical difficulties. Level of Evidence  III.

Relationship Between Femur and Femoral Arteries for Identifying Risk Factors for Vascular Injury

Background

This study aimed to identify risk factors for vascular injury in proximal femoral fracture through identifying frequency and distances between femur and femoral arteries with computed tomography angiography and 3-dimensional reconstruction.

Material/Methods

In a series of 400 participants, based on measurement results regarding the distribution of femoral arteries in the medial femur, the femoral portion covering that part was divided into levels A–E. The center region, margin region, and risky area in the medial femur were defined. The frequency of femoral arteries and interested shortest distance between the outer femur and superficial, deep, and perforating femoral arteries (SFAs, DFAs, and PFAs) in the center region, margin region, and risky area at each level were recorded.

Results

There were 173 males and 227 females (average age: 63.61±19.18 years) in this study. The starting point and end point for femoral arteries in the medial femur were from 22.55±4.23% to 54.56±8.39% of the whole femur. The femoral arteries in the medial femur mainly were distributed at levels B (88.2%), C (65.9%), and D (40.6%). The femoral arteries in center regions in the risky area, most of which were DFAs and PFAs, were mainly concentrated at levels B (26.93%) and C (11.81%).

Conclusions

The mid-shaft level was the most risky level, and the DFAs and PFAs were easier to injure than the SFAs when performing internal fixation of proximal femoral fracture. We recommended that great attention be paid to drill and screw insertion around the mid-shaft level for prevention of iatrogenic vascular injury.

Medial Knee Approach: An Anatomical Study of Minimally Invasive Plate Osteosynthesis in Medial Femoral Condylar Fracture

OBJECTIVES

To determine the location of distal medial neurovascular structures, identifying a medial "safe zone" for minimally invasive plate osteosynthesis to treat displaced femoral condylar fractures.

METHODS

Eleven uninjured lower-half torsos were dissected on the bilateral medial lower thigh. A longitudinal incision was made at the midsagittal plane of the medial thigh starting 1 cm proximal to the knee joint and extending to the proximal one-third of the femur. Superficial and deep neurovascular structures were dissected. Distances to the medial vastus and adductor compartment were measured.

RESULTS

Mean distances were 160 ± 31.4 mm from the adductor tubercle to Hunter canal; 94 ± 18.3 mm from adductor tubercle to adductor hiatus; 31.8 ± 9.21 mm from Hunter canal to the femoral shaft; and 31.7 ± 7.78 mm from adductor hiatus to femoral shaft. All specimens had a descending genicular artery (DGA) with a mean distance to the adductor tubercle of 98.4 ± 16.0 mm. The muscular branch of the DGA crossed the femoral shaft at approximately 50 mm from the adductor tubercle; the osteoarticular branch ran along the adductor magnus tendon. The nerve to the vastus medialis was at the posterior border of the vastus medialis, entering at a mean 143 ± 63.0 mm from the adductor tubercle.

CONCLUSIONS

Minor neurovascular branches of the DGA may be vulnerable during medial femoral condyle plating. Careful blunt dissection, proper instrumentation, and plate length within 160 mm allow distal medial femur fixation without additional proximal dissection.

The floating knee: a review on ipsilateral femoral and tibial fractures

In 1975, Blake and McBryde established the concept of 'floating knee' to describe ipsilateral fractures of the femur and tibia.1 This combination is much more than a bone lesion; the mechanism is usually a high-energy trauma in a patient with multiple injuries and a myriad of other lesions.After initial evaluation patients should be categorised, and only stable patients should undergo immediate reduction and internal fixation with the rest receiving external fixation.Definitive internal fixation of both bones yields the best results in almost all series.Nailing of both bones is the optimal fixation when both fractures (femoral and tibial) are extra-articular.Plates are the 'standard of care' in cases with articular fractures.A combination of implants are required by 40% of floating knees.Associated ligamentous and meniscal lesions are common, but may be irrelevant in the case of an intra-articular fracture which gives the worst prognosis for this type of lesion. Cite this article: Muñoz Vives K, Bel J-C, Capel Agundez A, Chana Rodríguez F, Palomo Traver J, Schultz-Larsen M, Tosounidis, T. The floating knee. EFORT Open Rev 2016;1:375-382. DOI: 10.1302/2058-5241.1.000042.

Minimally invasive plate osteosynthesis for midshaft clavicular fractures using superior anatomic plating

BACKGROUND

The minimally invasive plate osteosynthesis procedure has been widely applied for long-bone fixations; however, this technique is not commonly used for clavicular midshaft fractures. In this study, we introduced this technique for midshaft clavicular fractures using superior anatomic locking plates and evaluated its clinical and radiographic outcomes.

MATERIALS AND METHODS

From June 2013 to July 2014, 15 patients with acute midshaft clavicular fractures were treated with the minimally invasive plate osteosynthesis technique using a 3.5-mm clavicular superior anatomic locking plate. Anteroposterior plain X-ray images of the clavicle were taken at 4-week intervals until union was observed. The last clinical follow-up assessments were performed postoperatively at a mean of 16.54 months (range, 10-23 months). In addition, for clinical evaluations, the Constant score and the Disability of the Arm, Shoulder and Hand score were assessed.

RESULTS

The average operative time was 60.2 ± 20.1 minutes (range, 40-80 minutes), with blood loss of 25 ± 5 mL (range, 20-30 mL) during the operation. The mean union time for the patients was 10.1 ± 1.4 weeks (range, 8-12 weeks), and no delayed union or nonunion was observed. There were no major complications, including infections, plate breakages, or neurovascular injuries. No skin irritation was observed, and only 2 patients felt local incision numbness. All patients obtained satisfactory shoulder functions. The mean Constant score was 99 ± 1.8 (range, 95-100), and the mean Disability of the Arm, Shoulder and Hand score was 3.8 ± 2.9 (range, 0-10) at the last control visit.

CONCLUSION

The minimally invasive plate osteosynthesis procedure that was introduced in this study for midshaft clavicular fractures with superior anatomic locking plate is a reproducible procedure and an alternative to conventional operative methods.

What is new in distal femur periprosthetic fracture fixation?

Distal femoral periprosthetic fractures are on the rise. Increased mortality of these injuries is also evident from recent data. Their incidence and risk factors have been extensively reported in the past but new data are being available that merit attention. The increased incidence and the even higher projected incidence should direct the focus of future strategies to the education of surgeons, relevant capacity of hospital and reconfiguration of health care resources. New and potentially modifiable risk factors should be taken into consideration to the informed consent process and new studies should be developed to clarify the causative relationship of the new risk factors such as the peptic ulcer disease and the COPD. The main internal fixation techniques remain the lateral locking plating and the retrograde intramedullary nailing. New techniques in plating are the supplementary medial plate in selected cases and the far cortical locking. Nailing is considered a valid option especially in fractures located well above the anterior flange of the femoral component of the arthroplasty. Results and outcomes from good quality studies are still sparse regarding the comparison between plating and nailing. Interprosthetic fractures constitute an entity that is lately gaining considerable attention. The best method of management of these injuries is still evolving with considerable amount of work being done in the clinical and biomechanical level.

The safety and feasibility of minimally invasive plate osteosynthesis (MIPO) on the medial side of the femur: A cadaveric injection study

INTRODUCTION

Minimally invasive plate osteosynthesis (MIPO) on the medial side of the femur appears to be a dangerous procedure due to possible femoral artery injury.

OBJECTIVE

This study aims to determine the feasibility of applying MIPO of the femur via the medial approach, and to determine the anatomical relationship and structures at risk between the artery and the implant using computed tomography angiography.

MATERIALS AND METHODS

A descriptive study of ten fresh cadavers was done. Two separate incisions were made, creating a submuscular tunnel close to the medial side of the femur. An 11- or 13-hole LCP lateral proximal tibial plate (5.0mm) was inserted through the distal incision into the submuscular tunnel and fixed. A CT angiogram with 3D reconstruction was made to determine the distance from and location of the plate relative to the femoral artery and surgical dissection was done to identify the structures at risk.

RESULTS

No disruptions of superficial or deep femoral arteries were found. The closest distances from the superficial femoral artery and deep femoral artery to the plate were 8.3-27.2mm (average 16.3mm) (99% CI: 12.7-19.9) at the level 3 and 4.5-20.0mm (average 8.6mm) (99% CI: 6.4-10.9) at the level 2 in the proximal part of femur, respectively. The location where the SFA crossed the anterior cortex of the femur in the sagittal plane was 9.7-36.0% of the femoral length (average 20.1%) (99% CI: 15.0-25.3%) and the posterior cortex of the femur was 24.7-55.3% of the femoral length (average 40.8%) (99% CI: 35.0-46.7%). The location where the DFA crossed the anterior cortex of the femur in the sagittal plane was 7.9-25.3% of the femoral length (average 13.4%) (99% CI: 10.6-16.3%) and where it crossed the posterior cortex of the femur was 21.7-39.4% of the femoral length (average 31.2%) (99% CI: 27.1-33.3%).

CONCLUSION

MIPO of the femur via medial approach is a feasible option for treatment of femoral fractures when the lateral approach is contraindicated. The distal 60% of the femoral length is safe for this approach.

Periprosthetic fractures of the distal femur following total knee arthroplasty: even very distal fractures can be successfully treated using internal fixation

PURPOSE

We treat periprosthetic fracture of the distal femur above total knee arthroplasty using single or double plating and the minimally invasive plate osteosynthesis (MIPO) technique. Here, we report the results of using this operative treatment and our analysis of whether very distally extended fractures can also be successfully treated using internal fixation.

METHODS

We retrospectively reviewed 32 periprosthetic distal femoral fractures. Mean patient age was 73 years and mean follow-up period 25 months. There were 11 (34.4 %) Su type I/II and 21 (65.6 %) type III fractures. All Su type I/II fractures were treated by single plating, whereas 14 of 21 (66.7 %) type III fractures were treated using double plating and the MIPO technique. We defined bony union as the primary endpoint of this study based on callus formation across the fracture site at two or more cortices (1 medial and 1 other) on 3D computed tomography (CT).

RESULTS

Bony union was confirmed in 30 cases (93.8 %) after a mean time to union of 3.7 (range, 3-7) months. Two patients showed nonunion (6.2 %), and one demonstrated delayed union (3.1 %), none of whom complied with our rehabilitation protocol. There was one instance of nonunion among both Su types I/II and III fractures; however, this difference was not significant (p = 0.577).

CONCLUSIONS

Periprosthetic fractures of the distal femur can be successfully healed using internal fixation, either the single- or double-plate MIPO technique, even for very distally extended fractures.