Femoral torsion after interlocked nailing of unstable femoral fractures

Accuracy of the Lesser Trochanter Profile as a Marker of Femoral Rotation: Computed Tomography-Based Study of 1,722 Femora

BACKGROUND

The lesser trochanter (LT) profile is an often-used marker for proximal femoral rotation, particularly during the operative fixation of femoral fractures. Previous studies have come to conflicting conclusions about its reliability for this purpose.

METHODS

The SOMA (Stryker Orthopaedic Modeling and Analytics) database (Stryker) was used to identify 1,722 computed tomographic (CT) scans of whole femora. Each femur was taken through an 80° rotational arc in 2.5° increments, and the LT profile was constructed for each position. These 56,826 LT profile measurements were then correlated with the femoral rotation.

RESULTS

Across the arc of motion studied, the LT correlated weakly with proximal femoral rotation (R 2 = 0.32). There was a 35° arc, between 10° and 45° relative external rotation of the proximal femur, within which the LT profile only changed by 1 mm. The mean overall femoral anteversion was 21.2°, and women tended to have more femoral anteversion (23.9°) than men (19.2°). On average, men had a 1.6-mm more prominent LT than women. Side-to-side differences in femoral anteversion as well as LT position and size were not significant or were clinically unimportant.

CONCLUSIONS

A large-scale, CT-based study shows that the LT profile is a less reliable marker of proximal femoral rotation than previously thought. This is true particularly if there is relative external rotation of the proximal femur, where the proximal femur can undergo up to 35° of rotation before 1 mm of change in the LT profile occurs. Care must be taken to check other markers of rotation such as by clinical examination during fixation of femoral fractures and not rely solely on the LT profile.

CLINICAL RELEVANCE

In the largest study of its kind, this CT-based study of 56,826 LT profile measurements found that when the proximal femur is externally rotated, the LT profile becomes an unreliable marker of rotation, which can lead to excessive internal rotation of the distal fracture fragment. The LT profile should be used with caution, and confirmation of rotation by other means is recommended.

Evaluation of Intraoperative Fluoroscopic Techniques to Estimate Femoral Rotation: A Cadaveric Study

OBJECTIVES

To compare three fluoroscopic methods for determining femoral rotation.

METHODS

Native femoral version was measured by computed tomography in 20 intact femurs from 10 cadaveric specimens. Two Steinmann pins were placed into each left femur above and below a planned transverse osteotomy which was completed through the diaphysis. Four surgeons utilized the true lateral (TL), neck-horizontal angle (NH), and lesser trochanter profile (LTP) techniques to correct the injured femur's rotation using the intact right femur as reference, yielding 120 measurements. Accuracy was assessed by comparing the angle subtended by the two Steinmann pins before and after manipulation and comparing against version measurements of the right femur.

RESULTS

Absolute mean rotational error in the fractured femur compared to its uninjured state was 6.0° (95% CI, 4.6-7.5), 6.6° (95% CI, 5.0-8.2), and 8.5° (95% CI, 6.5-10.6) for the TL, NH, and LTP techniques, respectively, without significant difference between techniques ( p = 0.100). Compared to the right femur, absolute mean rotational error was 6.6° (95% CI, 1.0-12.2), 6.4° (95% CI, 0.1-12.6), and 8.9° (95% CI, 0.8-17.0) for the TL, NH, and LTP techniques, respectively, without significant difference ( p = 0.180). Significantly more femurs were malrotated by >15° using the LTP method compared to the TL and NH methods (20.0% vs 2.5% and 5.0%, p = 0.030). Absolute mean error in estimating femoral rotation of the intact femur using the TL and NH methods compared to CT was 6.6° (95% confidence interval [CI], 5.1-8.2) and 4.4° (95% CI, 3.4-5.4), respectively, with significant difference between the two methods ( p = 0.020).

CONCLUSIONS

The true lateral (TL), neck-horizontal angle (NH), and the lesser trochanter profile (LTP) techniques performed similarly in correcting rotation of the fractured femur, but significantly more femurs were malrotated by >15° using the LTP technique. This supports preferential use of the TL or NH methods for determining femoral version intraoperatively.

Intraoperative fluoroscopic protocol to avoid rotational malalignment after nailing of tibia shaft fractures: introduction of the 'C-Arm Rotational View (CARV)'

PURPOSE

Rotational malalignment (≥ 10°) is a frequent pitfall of intramedullary-nailing of tibial shaft fractures. This study aimed to develop an intraoperative fluoroscopy protocol, coined 'C-Arm Rotational View (CARV)', to significantly reduce the risk for rotational malalignment and to test its clinical feasibility.

METHODS

A cadaver and clinical feasibility study was conducted to develop the CARV-technique, that included a standardized intraoperative fluoroscopy sequence of predefined landmarks on the uninjured and injured leg in which the rotation of the C-arm was used to verify for rotational alignment. A mid-shaft tibia fracture was simulated in a cadaver and an unlocked intramedullary-nail was inserted. Random degrees of rotational malalignment were applied using a hand-held goniometer via reference wires at the fracture site. Ten surgeons, blinded for the applied rotation, performed rotational corrections according to (1) current clinical practice after single-leg and dual-leg draping, and (2) according to the CARV-protocol. The primary outcome measure was the accuracy of the corrections relative to neutral tibial alignment. The CARV-protocol was tested in a small clinical cohort.

RESULTS

In total, 180 rotational corrections were performed by 10 surgeons. Correction according to clinical practice using single-leg and dual-leg draping resulted in a median difference of, respectively, 10.0° (IQR 5.0°) and 10.0° (IQR 5.0°) relative to neutral alignment. Single-leg and dual-leg draping resulted in malalignment (≥10°) in, respectively, 67% and 58% of the corrections. Standardized correction using the CARV resulted in a median difference of 5.0° (IQR 5.0°) relative to neutral alignment, with only 12% categorized as malalignment (≥10°). The incidence of rotational malalignment after application of the CARV decreased from 67% and 58% to 12% (p =  <0.001). Both consultants and residents successfully applied the CARV-protocol. Finally, three clinical patients with a tibial shaft fracture were treated according to the CARV-protocol, resulting all in acceptable alignment (<10°) based on postoperative CT-measurements.

CONCLUSION

This study introduces an easy-to-use and clinically feasible standardized intraoperative fluoroscopy protocol coined 'C-arm rotational view (CARV)' to minimize the risk for rotational malalignment following intramedullary-nailing of tibial shaft fractures.

Letter to the editor regarding "Important tips and numbers on using the cortical step and diameter difference sign in assessing femoral rotation - Should we abandon the technique?"

We have read the paper "Important tips and numbers on using the cortical step and diameter difference sign in assessing femoral rotation - Should we abandon the technique?" [1] with great interest. Restoring femoral rotation during intramedullary nailing can pose challenges to many experienced surgeons. Femur rotational side-to-side asymmetry which is greater than 10 ° will cause functional deficit. We propose a surgical technique which allows surgeons to evaluate and reduce the malrotated femur intraoperatively. This technique also improves the ergonomics of the surgery and can be used simultaneously with other femoral rotation evaluation techniques. LEVEL OF EVIDENCE: V.

Clinical versus radiological method for adjusting rotational alignment during femoral shaft fractures intramedullary nailing and the malrotation impact on the functional outcomes: early results from a prospective cohort study

OBJECTIVES

The primary objective of the current study is to assess which is better for obtaining the proper femoral rotation during IMN of femoral fractures, the radiological or clinical method. The secondary objectives were to document malrotation's incidence and its effect on the hip and knee functional outcomes.

METHODS

Thirty-three patients with unilateral femoral shaft fractures were treated using intramedullary nails (IMN) on a usual radiolucent operative table. Intraoperative rotation adjustment was performed using a radiological method (relying on the contralateral lesser trochanter profile) in 16 patients (group A), while in 17 patients, a clinical method was used (group B). Postoperative assessment of malrotation was performed using a CT scan, and 15 degrees was the cutoff value where below is an acceptable rotation (group I) and above is true malrotation (group II). Functional assessment was performed using the Harris hip score (HHS), the Tegner Lysholm Knee Scoring Scale (TLKSS), and the Neer score.

RESULTS

The patients' mean age was 30.7 ± 9.3 years; 81.8% were males, and the left side was injured in 63.6% of patients. After a mean follow up of 18.2 ± 6.9 months, all fractures were united, and the overall mean amount of rotational difference between the fractured and the contralateral side was 14.7° ± 6.0 (3-29.4), 84.8% were in external rotation. No difference in the mean rotational deformity in group A compared to group B. Measurements were 13.9 ± 6.7 and 15.7 ± 5.5, respectively (p = 0.47). Seventeen (51.5%) patients in group I with a mean deformity of 9.8 ± 3.4 (3-14.7), while group II consisted of 16 (48.5%) patients with a mean deformity of 19.6 ± 3.7 (15.3-29.4). There was no difference in the functional scores between group I and group II; HHS was 89.4 ± 7.4 versus 87.7 ± 8.9 (p = 0.54), TLKSS was 84.6 ± 9.6 versus 80.4 ± 13.9 (p = 0.32), and Neer score was 87.9 ± 9.5 versus 83 ± 12.5 (p = 0.21) for group I and group II, respectively.

CONCLUSION

There was no difference in malrotation incidence after unilateral femoral fractures IMN with either an intraoperative clinical or radiological method for rotational adjustment; furthermore, malrotation did not affect the functional outcomes.

Acute Correction of Femoral Malrotation After Intramedullary Nailing Using an Intraoperative Digital Protractor

OBJECTIVE

 The goal of the study is to diagnose and accurately correct malrotation of femur fractures after intramedullary (IM) nailing.

MATERIALS AND METHODS

An institutional review board (IRB) approved prospective study that was performed at a U.S. level 1 trauma center. After IM nailing of comminuted femur fractures, a computed tomography (CT) scanogram was routinely performed to detect the difference in the postoperative femoral version. Patients with malalignment greater than 15 degrees compared to the contralateral side were informed about the discrepancy and offered to have it acutely corrected. A four-pin technique was used: two Schanz pins were used for measuring angles and two different pins were used to turn and correct the malalignment. The pin in the distal fragment is placed directly under the nail to prevent shortening in comminuted fractures. The nail was unlocked either proximally for retrograde nails or distally for antegrade nails. The Bonesetter Angle application was used as a digital protractor to intraoperatively measure the two reference pins and correct the malrotation. Alternate holes were used for relocking the nail. All patients received a CT scanogram after correction.

RESULTS

 19/128 patients with comminuted femoral fractures over five years with malrotations between 18 and 47 degrees were included in the study with an average malrotation of 24.7 + 8 degrees. All patients were corrected to an average of 4.0 +/- 2.1 degrees difference, as compared to the contralateral side (range 0-8). No patients required further surgeries to correct malrotation.

CONCLUSION

 Comminuted fractures with malrotation >15 degrees after femoral nailing have an incidence of 15% at our institution. This technique provides an efficient and accurate correction method with the use of an intraoperative digital protractor, avoiding the need for revision IM nailing or osteotomies.

Minimally Invasive Derotational Osteotomy of Long Bones: Smartphone Application Used to Improve the Accuracy of Correction

Correction of rotational malalignments caused by fractures is essential as it may cause pain and gait disturbances. This study evaluated the intraoperative use of a smartphone application (SP app) to measure the extent of corrective rotation in patients treated using minimally invasive derotational osteotomy. Intraoperatively, two parallel 5 mm Schanz pins were placed above and below the fractured/injured site, and derotation was performed manually after percutaneous osteotomy. A protractor SP app was used intraoperatively to measure the angle between the two Schanz pins (angle-SP). Intramedullary nailing or minimally invasive plate osteosynthesis was performed after derotation, and computerized tomography (CT) scans were used to assess the angle of correction postoperatively (angle-CT). The accuracy of rotational correction was assessed by comparing angle-SP and angle-CT. The mean preoperative rotational difference observed was 22.1°, while the mean angle-SP and angle-CT were 21.6° and 21.3°, respectively. A significant positive correlation between angle-SP and angle-CT was observed, and 18 out of 19 patients exhibited complete healing within 17.7 weeks (1 patient exhibited nonunion). These findings suggest that using an SP app during minimally invasive derotational osteotomy can result in accurate correction of malrotation of long bones in a reproducible manner. Therefore, SP technology with integrated gyroscope function represents a suitable alternative for determination of the magnitude of rotational correction when performing corrective osteotomy.

Impact of Internal Malrotation of the Femur Followed by Derotational Osteotomy as Demonstrated by 3D Gait Analysis: A Case Report

CASE

An 18-year-old man with 48° of internal malrotation of the femur after nailing underwent derotational osteotomy with gait dynamics and electromyography data collected preoperatively and postoperatively. Hip abduction and internal foot progression angles were significantly deviated from normal preoperatively compared with the contralateral side. At 10 months postoperatively, the hip was abducted and externally rotated throughout the entire gait cycle. His Trendelenburg gait had resolved, and he reported no residual functional concerns. Before corrective osteotomy, walking velocity was significantly slower with shorter stride lengths.

CONCLUSION

Significant internal malrotation of the femur impairs hip abduction and foot progression angles as well as gluteus medius activation during ambulation. Derotational osteotomy considerably corrected these values.

Femoral shaft fractures treated by antegrade locked intramedullary nailing: EOS stereoradiographic imaging evaluation of rotational malalignment having a functional impact

INTRODUCTION

The standard treatment of femoral shaft fractures is intramedullary nailing. One of the most frequent complications is femoral malrotation. Our study sought to: 1) use EOS imaging to determine the amount of rotational malalignment after intramedullary nailing that has an impact on 6-month functional results; 2) determine the incidence of femoral malrotation based on EOS imaging; 3) determine the risk factors for postoperative femoral malrotation that impacts the 6-month functional results. The hypothesis was that EOS imaging can be used to determine the amount of femoral malrotation that has a functional impact in patients treated by percutaneous femoral intramedullary nailing.

MATERIAL AND METHODS

We performed a prospective, single-center study between September 2017 and February 2020. Patients who had suffered a femoral shaft fracture treated with antegrade intramedullary nailing were included in this study. Femoral anteversion was measured at 6 months with an EOS stereoradiographic imaging system. Patients were assessed at 6 months with the WOMAC, Oxford, Harris and MDP functional scores. The SF-12 quality of life score was also determined.

RESULTS

Thirty patients were evaluated at 6 months postoperatively, 15 women (50%) and 15 men (50%) who were 47 years old on average [16; 94]. The average anteversion was 19.9°C [-23°; 75°]. The functional scores (Oxford and Harris) were altered when there was 14° or more difference in femoral torsion between the operated side and the healthy side with a sensitivity of 0.88 and a specificity of 0.77. The risk factors for femoral malrotation were age under 35 years (p=0.01), urgent surgical management (p=0.008), location in middle third of femoral shaft (p=0.05), and short spiral fracture (p=0.02).

CONCLUSION

The use of EOS imaging allowed us to demonstrate that functional hip outcomes are altered at 6 months postoperatively when greater than 14° femoral malrotation is present compared to the contralateral side after femoral intramedullary nailing. The risk factors that contributed to intraoperative rotational malalignment were age less than 35 years, urgent surgical management, mid-shaft femoral fracture and short spiroid fractures.

LEVEL OF EVIDENCE

II.

Intraoperative Comparative Femoral Rotation Imaging: Do not Overlook Parallax

OBJECTIVE

To investigate the degree of error due to parallax during intraoperative rotational imaging involving the distal femur.

METHODS

Twelve, fresh-frozen, lower-extremity cadaveric specimens were studied. The limbs were positioned supine and rotated until the posterior femoral condyles were superimposed using a C-arm. The C-arm was then repositioned to place the femoral condyles at the anterior and posterior margins of the image intensifier. The rotation necessary to resuperimpose the femoral condyles due to parallax was recorded. A second C-arm was then used from the contralateral side to simulate the rotational imaging technique to determine the magnitude and directionality of combined parallax.

RESULTS

All 12 specimens demonstrated parallax, resulting in rotational discrepancies. Compared with central field of view alignment, the mean rotational discrepancy was 5.6 and 5.5 degrees for anterior and posterior positions, respectively. Contralateral imaging resulted in an additive effect with rotational differences of 9.0 and 12.6 degrees for bilateral anterior and posterior positions, respectively.

CONCLUSIONS

Parallax causes rotational discrepancies with fluoroscopic imaging of the distal femur when the posterior femoral condyles are off-center in the imaging field of view. If femoral condyles are not centered when obtaining intraoperative rotational imaging of the uninjured and injured femurs, parallax can result in potentially clinically significant rotational deformity even if the femurs seem perfectly matched at the conclusion of surgery. We recommend perfectly centering of the posterior femoral condyles in the imaging field of view when obtaining lateral images of the distal femur to prevent this potentially overlooked contribution to malrotation.

CT analysis of femoral malrotation after intramedullary nailing of trochanteric fractures

PURPOSE

Functional results after internal fixation of trochanteric femoral fractures may be negatively affected by healing in a non-physiological position. The aim of this study was to evaluate the occurrence and severity of femoral malrotation after nailing of trochanteric fractures.

MATERIALS AND METHODS

The authors conducted a prospective study focused on a CT analysis of malrotation after intramedullary nailing of trochanteric fractures (AO 31A1-3) in 101 patients. We recorded the type of fracture, method of anesthesia, scheduled surgery vs. acute surgery, and the surgeon's experience as possible risk factors for limb malrotation after trochanteric fracture surgeries.

RESULTS

The average extent of malrotation was 9° of internal rotation ranging from 29° of external to 48°of internal rotation. In 35% of patients, we observed a rotation greater than 15°, and in 15 patients (15%), the rotation was greater than 25°. The risk of significant internal malrotation was significantly higher than external malrotation (37 vs. 4 patients). None of the factors observed proved to be statistically significant. The effect of general anesthesia and the type of intertrochanteric fracture came closest to having a significant effect on rotational error.

CONCLUSION

Improper reduction of a trochanteric fracture is a common problem that can lead to femur malrotation. In our study, a rotational error greater than 15° occurred in 35% of the patients, but none of the monitored factors represented a statistically significant risk for this complication.

Flouroscopic Control of Tibial Torsion After Intramedullary Nailing: A Technical Trick

After intramedullary nailing of tibia shaft fractures, torsional malalignment greater than 10 degrees occur in up to 41% of operated legs. The reason is the difficult clinical assessment of rotation intraoperatively, the large variation in absolute torsion of the tibia, and the absence of established reliable methods to fluoroscopically evaluate tibial rotation and compare with the contralateral side. We present here a fast and low-tech intraoperative method on how to achieve identical tibial torsion of the operated and noninjured side. The method can be used for tibia shaft and metaphyseal fractures and only requires a normal C-arm fluoroscope with 2 monitors. First, a true lateral image of the knee on the noninjured side with the femoral condyles aligned is obtained. Second, with the leg and the C-arm rotation and tilt fixed, the fluoroscope is moved parallel to the patient axis and a lateral ankle image is obtained and saved. The fibula position relative to the tibia at the level of the Volkmann tubercle on the lateral view defines the torsion of the tibia. The sequence described above is repeated on the operated side after implantation of the nail before proximal locking. On the operated side, the fibula position relative to the tibia should be identical to the noninjured side before proximal locking takes place. Otherwise, a rotational malalignment is present and must be corrected. The comparison between operated and noninjured side is easy on a fluoroscope with 2 monitors. The complete examination takes a few minutes and has minor additional radiation exposure. We performed the intraoperative torsion control in 10 patients and performed a postoperative low-dose Computer Tomography-control of the torsion of both legs and found the rotational deformity to be less than 10 degrees in all patients.

Analysis of Computed Tomography-Based Technique for Measuring Femoral Anteversion: Implications for Measuring Rotation After Femoral Intramedullary Nail Insertion

OBJECTIVES

To assess the reliability of the current computed tomography (CT)-based technique for determining femoral anteversion and quantify the prevalence and magnitude of side-to-side differences.

DESIGN

Cross-sectional cohort study.

SETTING

Academic trauma center.

PATIENTS

We reviewed CT scans from 120 patients with bilateral full-length axial cuts of both femurs. Two hundred forty femurs with no fractures or other identifying features in their femora were included. Ten unique data sets were created to measure anteversion of the left and right sides.

MAIN OUTCOME MEASUREMENTS

Intraobserver and interobserver reliability were calculated using intraclass correlation coefficients (ICCs) and pooled absolute differences. The mean absolute difference between the sides was determined using a fixed-effects model.

RESULTS

Interobserver reliability was high (ICC: 0.85, 95% confidence interval [CI]: 0.83-0.88). The pooled mean absolute magnitude of variation between reviewers was small at 1.6 degrees (95% CI: 1.4-1.8 degrees) per scan. The intraobserver reproducibility was high (ICC: 0.91, 95% CI: 0.88-0.93) with a mean error of 2.7 degrees (95% CI: 2.2-3.1 degrees) per repeat viewing of the same scan by the same person. The magnitude of side-to-side variation was 2.0 degrees (95% CI: 1.5-2.6 degrees). Twenty-one subjects (18%, 95% CI: 12%-25%) had a mean side-to-side calculated femoral anteversion difference of ≥10 degrees, whereas 6 (5%, 95% CI: 2-10) subjects had a calculated mean side-to-side difference of ≥15 degrees.

CONCLUSIONS

CT based femoral anteversion measurement techniques demonstrate good precision. Only 1 in 20 patients had side-to-side differences of 15 degrees or more.

Femoral Derotation Osteotomy Improves Hip and Spine Function in Patients With Increased or Decreased Femoral Torsion

PURPOSE

To evaluate the outcomes of proximal femoral derotation osteotomy (PFDO) on the hip and spine function of patients with abnormal femoral torsion.

METHODS

This retrospective study included patients who underwent PFDO to treat increased or decreased femoral torsion between July 2014 and February 2019. The exclusion criteria were: previous fracture, fixation of slipped capital femoral epiphysis or osteotomy in the ipsilateral femur; PFDO associated to varus or valgus osteotomy; Tönnis grade 2 or 3 osteoarthritis; and PFDO performed to treat knee abnormalities. Hip function was assessed through the modified Harris Hip Score (mHHS). A subgroup of consecutive patients with low back pain before the PFDO and operated after 2017 had the spine function assessed through the Oswestry disability index (ODI).

RESULTS

A total of 37 hips (34 patients) were studied: 15 hips with increased femoral torsion and 22 with decreased femoral torsion. Eight patients were male and 26 were female. The average age at PFDO was 33 years (range, 15-54 years). At a mean follow-up of 24 months (range, 12-65 months), the mean mHHS improved from 58.1 ± 14.3 before PFDO to 82 ± 15.6 at the most recent follow-up (P < .001). Improvement in the mHHS above the minimum clinically important difference (MCID) was observed in 33 hips (89%). In the subgroup of 14 consecutive patients with ODI available, the ODI improved from a mean of 45% ± 16% before the PFDO to 22% ± 17% at the most recent follow-up (P = .001). Nine (64.3%) of the 14 patients presented improvement in the ODI above the MCID. Revision procedure with a larger intramedullary nail was necessary in 2 hips to treat nonunion.

CONCLUSION

Proximal femoral derotation osteotomy improves the hip and spine function in patients with increased or decreased femoral torsion and nonarthritic hips.

LEVEL OF EVIDENCE

Level IV, therapeutic case series.

Rotational malalignment in femoral nailing: prevention, diagnosis and surgical correction

Background and aim of the work:

to review and discuss the literature about rotational malalignment during and after femoral nailing.

Methods:

analysis of the literature on prevention and evaluation of rotation during femoral nailing, clinical and subjective consequences of malrotation and techniques used to correct the deformity, both in the acute and chronic phase.

Results:

malrotation is very common after femoral nailing. The exact definition of a malrotated femur is controversial, but it is widely agreed that a rotational malalignment <10° is considered normal while >30° is a deformity which requires correction. The complaints of the patients with a malrotated femur can be various and can involve the hip, the knee or below the knee. The ability to compensate for the deformity while standing and walking may decrease the symptoms. Surgical correction is feasible with many techniques and devices: the procedure involving derotation, changing the locking screws and maintaining the nail is safe, reproducible and relatively easy.

Conclusions:

prevention of malrotation during femoral nailing is the cornerstone of successful operation outcomes. If rotational malalignment is suspected, prompt diagnosis and adequate surgical treatment are mandatory to overcome this common complication. (www.actabiomedica.it)

Quantitative Lesser Trochanter Profile Versus Cortical Step Sign in Assessing Femoral Malrotation After Femoral Nailing

We describe the novel quantitative lesser trochanter profile (QLTP) technique to determine the magnitude and direction of femoral malrotation and to compare its performance with the cortical step sign technique. For this assessment, 9 orthopaedic surgeons estimated the magnitude and direction of femoral malrotation with each technique in 198 anteroposterior view images of the proximal cadaveric femur and osteotomy sites. Based on the results, the main benefit of the QLTP technique over the cortical step sign technique is the ability to determine the direction of femoral malrotation. The QLTP technique was also more accurate in measuring malrotation and had less error. However, the QLTP technique requires additional imaging, and the mean difference in error between the 2 techniques might not be clinically meaningful.

Assessing Femoral Rotation: A Survey Comparison of Techniques

OBJECTIVES

To compare 3 common techniques for assessing femoral malrotation through a response analysis.

METHODS

Ten intact human cadaveric pelvis-to-knee specimens were used to create a fracture model. A mobile C-arm x-ray system was used to capture images of an intact control femur and a contralateral test femur on each specimen. A midshaft femoral osteotomy was created on the test femur and it was then internally and externally rotated in 5-degree intervals up to 20 degrees. Images were obtained and stored at each increment of malrotation. Eight surveys of 20-paired images each were generated and presented for surgeon review. Accuracy of predicting femoral malrotation using the true lateral technique (TLT), neck horizontal angle (NHA) method, and lesser trochanter profile (LTP) was measured.

RESULTS

Eighty-five surgeons completed a survey with 80 surgeons (94%) acknowledging the use of a described fluoroscopic method for assisting with rotational alignment. Surgeons correctly accepted a fracture rotated less than 20 degrees and rejected a fracture rotated 20 degrees or more 63% of the time. The ability to correctly identify 20 degrees of malrotation varied per technique used to assess rotation. With the LTP and NHA method, 67% of surgeons responded correctly. Surgeons performed significantly worse when using the TLT with only 53% providing correct responses (P < 0.0001).

CONCLUSIONS

Surgeons using described fluoroscopic methods to identify acceptable rotation in femoral shaft fractures are correct 63% of the time. The LTP and NHA techniques are equally reliable and more effective than the TLT at detecting clinically significant femoral malrotation.

Can Views of the Proximal Femur Be Reliably Used to Predict Malrotation After Femoral Nail Insertion? A Cadaver Validation Study

INTRODUCTION

We investigated the relationship between the size of the lesser trochanter visualized on an AP view of the hip and femoral rotation after femoral shaft fracture fixation. We hypothesized that the amount of the lesser trochanter visualized can accurately detect differences in femoral shaft rotation.

METHODS

Sequential fluoroscopic images of 19 matched pairs of cadaver femora were obtained of the proximal femur at 10° increments of internal and external rotation. The relationship between the percentage of the lesser trochanter and the angle of femoral rotation was assessed by regression analysis.

RESULTS

Rotation of the proximal femur follows a relatively linear relationship centered around the neutral rotation position. A 10% change in the lesser trochanter size corresponds to approximately 7° of femoral rotation.

CONCLUSION

The relationship between the size of the lesser trochanter visualized and the degree of femoral rotation after femoral shaft fracture fixation is approximately linear and sensitive to relatively small changes in rotation, making it potentially useful for assessing malrotation after femoral shaft fracture fixation.

Avoiding malalignment in proximal femur fractures treated with newer generation cephalomedullary nails: Some technical tips

Three techniques to avoid malalignment in proximal femoral fractures managed with cephalomedullary nails, have been described. Issues related to rotational mismatch at fracture site, central placement of lag screw in femoral head neck fragment and limb rotation restoration have been addressed. We believe these simple techniques can help in minimizing malreduction in proximal femur fractures and result in favourable outcomes.

[Evolution and principles of intramedullary locked nailing]

Key factors for successful osteosynthetic fracture stabilization are anatomical fracture reduction, restoration of axis and torsion alignment as well as tissue-preserving operative techniques. In long bone fractures, the use of intramedullary long bridging nailing offers ideal conditions for bone healing, as axial and rotational stability is provided by canal-filling nails and locking screws. In addition, the tissue in the fracture region is protected as the intramedullary nail insertion is distant from the fracture. The indication spectrum for modern intramedullary locked nailing includes diaphyseal fractures of long bones, metaphyseal fractures and reconstructions, as well as treatment of nonunion, osteotomy and arthrodesis of the lower extremities. Continuous improvements in nail design and instrumentation as well as the introduction of anatomical reconstruction nails will optimize the spectrum and effectiveness of intramedullary osteosynthesis even further.

Intraoperative ultrasound-guided reduction of femoral shaft fractures using intramedullary nailing: a technical note

OBJECTIVES

Intramedullary (IM) nailing is the preferred method for treatment of femoral shaft fractures. However, for the surgical staff and the patients, exposure to large dose of X-rays is inevitable during the procedure. In this paper, a new technique based on ultrasound is proposed to guide the reduction of femoral fractures, reducing radiation exposure.

METHODS AND RESULTS

By means of particular continuous transverse and multiplanar longitudinal scanning, the deformity pattern information of the fracture could be efficiently acquired. Adequate reduction could be achieved under the real-time guidance of intraoperative ultrasound.

CONCLUSIONS

Intraoperative ultrasound can guide the reduction of femoral shaft fracture using IM nailing, and reduce the radiation exposure of medical staff and patients.

Radiographic cortical thickness parameters as predictors of rotational alignment in proximal femur fractures: A cadaveric study

Radiographic assessment tools such as the cortical step sign (CSS) or the diameter difference sign (DDS) aim to identify clinically relevant rotational malalignment after long bone fracture fixation. We aimed to analyze the effect of rotational malalignment on CSS and DDS parameters in a subtrochanteric fracture model and to construct a prognostic model to identify clinically relevant rotational malalignment. A subtrochanteric transverse osteotomy was set in human femora. Rotation was set stepwise from 0° to 30° in internal and external rotation. Images were obtained using a C-arm and transferred for measuring the medial cortical thickness (MCT), lateral cortical thickness (LCT), femoral diameter (FD) in AP and the anterior cortical thickness (ACT) as well as the posterior cortical thickness (PCT) and the FD of the proximal and the distal main fragment. There were significant differences between the various levels of rotation for each of the absolute values of the evaluated variables. MCT, PCT and FD (AP & lat.) were the most affected parameters. In internal rotation, the MCT, PCT and the FD were the most affected variables. The parameters with the highest correlation with femoral rotation were ACT, PCT and FD. A model combining ACT, LCT, PCT and FD AP was most suitable model in identifying rotational malalignment. The best prediction of clinically relevant rotational malalignment was obtained with the FD and the PCT. The CSS and the DDS are promising tools for detecting rotational deformities of the proximal femur and should be used intra- and postoperatively. © 2018 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res.

Use of Inherent Anteversion of an Intramedullary Nail to Avoid Malrotation in Comminuted Femur Fractures: A Prospective Case- Control Study

OBJECTIVES

To (1) evaluate using the inherent anteversion of a second or third generation femoral nail to set the version of the femur during locked intramedullary nailing of comminuted femoral shaft fractures (Espinosa Technique [ET]) and compare it with our traditional method (traditional group [TG]) and (2) assess the variation of anteversion because of the inherent play in the nail itself.

DESIGN

A prospective IRB-approved study.

SETTING

Academic US Level 1 Trauma Center.

PATIENTS

Fifty-two consecutive patients with comminuted femur fractures all completed the study.

INTERVENTION

The first 27 patients had the anteversion determined using the patellar shadow and lesser trochanter (TG), and the next 25 patients were treated by ET.

MAIN OUTCOME MEASURE

Computed tomography scanogram for femoral anteversion and length in the normal versus operated femur.

RESULTS

A >15 degree difference from native to operated legs was found in 8/27 TG (29%, 95% CI 15.3%-54.2%), with a mean difference of 11.6 ± 10.2 degrees (95% CI 8.8-16.17) verses 1/25 in the ET group (2.5%, 95% CI 0%-15.3%), with a mean difference of 4.8 ± 6.2 degrees (95% CI 1.38-8.9) (P = 0.0068). There was a 5 degree variability in our ability to center the proximal locking screw in the femoral head and 5 degrees variation in distal locking.

CONCLUSIONS

The inherent anteversion of a second generation nail can be used to minimize malrotation of the femur after comminuted fractures during locked intramedullary nailing in patients with normal anteversion and is superior to our present fluoroscopic technique.

LEVEL OF EVIDENCE

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

Incidence of deep infection, union and malunion for open diaphyseal femoral shaft fractures treated with IM nailing: A systematic review

BACKGROUND

and purpose: We have undertaken a systematic review to evaluate the clinical results of intramedullary nailing (IMN) for open diaphyseal femoral fractures on the rates of union, delayed union, malunion, superficial and deep infection and bone grafting.

METHODS

We searched the electronic databases of EMBASE, MEDLINE, from their inception until December 1st, 2017 with no language restrictions. The reference lists of all included articles and relevant reviews were also examined for potentially eligible studies. Hand search using electronic database of recent major orthopaedic journals was also carried. Two reviewers working independently extracted study characteristics and data to estimate the diagnostic odds ratio and 95% confidence interval for each result.

RESULTS

Seventeen studies were eligible. Pooled estimate of effect size for union rate was 97% (95% CI: 94-99%). Deep infection rate was 6% (95% CI: 3-9.3%) and more prominent in Gustilo type III injuries; superficial infection was 5.6% (95% CI: 3-9.3%). Delayed union rate 3% (95% CI: 1-5.6%) while, malunion rate was 8.4% (95% CI: 5.7-11.6%). The need for bone grafting ranged from 0 to 9%.

CONCLUSIONS

IMN remains the treatment of choice for open femoral diaphyseal fractures with very good union rates. Gustilo grade III injuries demonstrate a distinct higher deep infection rate and strict adherence to established surgical debridement and fixation protocols is advocated. The need for bone grafting can be as high as 9% and patients should be made aware of the possibility of requiring this additional procedure.

Femoral malalignment after gamma nail insertion in the lateral decubitus position

Introduction: Insertion of gamma nail with the patient in lateral decubitus position have the advantages of easier access to the entry point, easier fracture reduction and easier implant positioning. Our study described the incidence of femoral angular and rotational deformity following gamma nail insertion in lateral decubitus position.

Methods: In a prospective clinical case series, 31 patients (26 males and 5 females; the average age of 42.6 years) with 31 proximal femoral shaft fractures that were treated with gamma IMN were included in our study. Postoperatively, computerized tomography scans of the pelvis and both knees (injured and uninjured sides) were examined to measure anteversion angles on both sides. A scout film of the pelvis and upper both femurs was taken to compare the neck shaft angles on both sides.

Results: No angular malalignment was detected in our series; the mean angular malalignment angle was 1.6 ± 1.5°. There was a high incidence of true rotational malalignment of ≥10° in 16 out of 31 patients (51.6%); most of them were external rotational malalignment. Younger age group (≤40 years) had significantly more incidence of rotational malalignment (≥10°) than older age group (>40 years) (P-value 0.019).

Discussion: Gamma nail fixation in lateral decubitus position without the fracture table gives an accurate and easier access to the entry point, good implant positioning with no or minimal angular malalignment (varus −valgus) but poses high incidence of true rotational malalignment. Great care and awareness of rotation should be exercised during fixing proximal femoral fractures in lateral decubitus position.

Malalignment in plate osteosynthesis

The aim for this review is to present general considerations in relation to malalignment after osteosynthesis with plate fixation and its consequences after fractures in adults in each of the following anatomical locations: humerus, forearm, femur, tibia. Recommendations for accepted malalignment in humerus diaphyseal fracture is varus <20 degrees, valgus <15 degrees, sagittal deformity <5 degrees and rotation <30 degrees. Recommendations when treating fractures of the forearm is anatomical reduction. Varus of ulna leads to loss of pronation. Valgus of ulna leads to loss of both pronation and supination. Recommendations for acceptable malalignment in femoral fractures is rotational deformity <15 degrees, increasing varus deformity in intertrochanteric fractures increases load on implant. Cortical-step-sign, profile of lesser trochanter, evaluation of ipsilateral neck anteversion are intraoperative methods to avoid rotational malalignment. Recommendations for accepted malalignment in the tibia is shortening <10mm, varus/valgus <5 degrees, sagittal deformity <10 degrees. Fixation of fibula leads to less rotational and valgus malalignment, but not enough to affect union rate of tibia, complications rate or functional score at 12 months. To avoid malalignment in plating, pre-contoured anatomical plates are available from most manufactures. Being aware that most such plates fit a 50-percentile Caucasian population is important in pre-surgical planning. Evaluation of the contralateral bone and the characteristics of the plate may help in planning additional bending of pre-shaped plates and bending tools should always be available when applying a plate, even a so-called anatomical one.

Is the Lesser Trochanter Profile a Reliable Means of Restoring Anatomic Rotation After Femur Fracture Fixation?

BACKGROUND

Restoring normal femoral rotation is an important consideration when managing femur fractures. Femoral malrotation after fixation is common and several preventive techniques have been described. Use of the lesser trochanter profile is a simple method to prevent malrotation, because the profile changes with femoral rotation, but the accuracy of this method is unclear.

QUESTIONS/PURPOSES

The purposes of this study were (1) to report the rotational profiles of uninjured femora in an adult population; and (2) to determine if the lesser trochanter profile was associated with variability in femoral rotation.

METHODS

One hundred fifty-five consecutive patients (72% female and 28% male) with a mean age of 32 years (range, 12-56 years) with a CT scanogram were retrospectively evaluated. Patients were included if CT scanograms had adequate cuts of the proximal and distal femur. Patients were excluded if they had prior hip/femur surgery or anatomic abnormalities of the proximal femur. CT scanogram measurements of femoral rotation were compared with the lesser trochanter profile (distance from the tip of the lesser trochanter to the medial cortex of the femur) measured on weightbearing AP radiographs. These measurements were made by a single fellowship-trained orthopaedic surgeon and repeated for intraobserver reliability testing. Presence of rotational differences based on sex and laterality was assessed and correlation of the difference in lesser trochanter profile to the difference in femoral rotation was determined using a coefficient of determination (r).

RESULTS

The mean femoral rotation was 10.9° (SD ± 8.8°) of anteversion. Mean right femoral rotation was 11.0° (SD ± 8.9°) and mean left femoral rotation was 10.7° (SD ± 8.7°) with a mean difference of 0.3° (95% confidence interval [CI], -1.7° to 2.3°; p = 0.76). Males had a mean rotation of 9.4°(SD ± 7.7°) and females had a mean rotation of 11.5° (SD ± 9.1°) with a mean difference of 2.1° (95% CI, -0.1° to 4.3°; p = 0.06). Mean lesser trochanter profile was 6.6 mm (SD ± 4.0 mm). Mean right lesser trochanter profile was 6.6 mm (SD ± 3.9 mm) and mean left lesser trochanter profile was 6.5 mm (SD ± 4.0 mm) with a mean difference of 0.1 mm (-0.8 mm to 1.0 mm, p = 0.86). The lesser trochanter profile varied between the sexes; males had a mean of 8.3 mm (SD ± 3.4), and females had a mean of 5.9 mm (SD ± 4.0). The mean difference between sexes was 2.5 mm (1.5-3.4 mm; p < 0.001). The magnitude of the lesser trochanter profile measurement and degree of femoral rotation were positively correlated such that increasing measures of the lesser trochanter profile were associated with increasing amounts of femoral anteversion. The lesser trochanter profile was associated with femoral version in a linear regression model (r = 0.64; p < 0.001). Thus, 64% of the difference in femoral rotation can be explained by the difference in the lesser trochanter profile. Intraobserver reliability for both the femoral version and lesser trochanter profile was noted to be excellent with intraclass correlation coefficients of 0.94 and 0.95, respectively.

CONCLUSIONS

This study helps define the normal femoral rotation profile among adults without femoral injury or bone deformity and demonstrated no rotational differences between sexes. The lesser trochanter profile was found to be positively associated with femoral rotation. Increasing and decreasing lesser trochanter profile measurements are associated with increasing and decreasing amounts of femoral rotation, respectively.

CLINICAL RELEVANCE

The lesser trochanter profile can determine the position of the femur in both anteversion and retroversion, supporting its use as a method to restore preinjury femoral rotation after fracture fixation. Although some variability in the rotation between sides may exist, matching the lesser trochanter profile between injured and uninjured femora can help reestablish native rotation.

Comparison of fluoroscopic techniques for assessment of femoral rotational alignment

Objectives:

Anatomic rotational reduction of diaphyseal femur fractures is essential in restoring limb mechanics. Errors in reproducing anteroposterior (AP) or lateral knee reference radiographs of the contralateral limb could result in inaccuracies during rotational reduction. The objective of this study was to examine whether fluoroscopic rotational variation can be observed with the same degree of precision with AP and lateral distal femur projections.

Methods:

AP and lateral radiographs were obtained from intact knees of 7 cadaveric specimens using fluoroscopy. The lateral condylar width and coronal femoral width from the AP images and the posterior condylar offset and sagittal femoral width from the lateral images were measured by 3 reviewers. Interclass correlation coefficients (ICCs) among the 3 reviewers were calculated. The mean data from all reviewers were plotted against angle of rotation, and the slope (M) and regression of the line were then determined.

Results:

ICCs were 0.997 (lateral) and 0.994 (AP), demonstrating excellent interobserver agreement. The mean (±SD) M value for lateral images was 0.016 ± 0.001 and for AP images was 0.009 ± 0.001 (P < .0001). The higher lateral M value represents a more appreciable difference in size of the measured segment for the same rotational change.

Conclusions:

The observed rotational change was 1.76 times greater on lateral images compared to AP images; thus, the lateral images may be more precise as a reference for rotation. The routine use of lateral knee radiographs to guide intraoperative rotational alignment of the femur may therefore be justified.

Minimizing Leg Length Discrepancy After Intramedullary Nailing of Comminuted Femoral Shaft Fractures: A Quality Improvement Initiative Using the Scout Computed Tomography Scanogram

OBJECTIVES

To prevent leg length discrepancy (LLD) after locked femoral nailing in patients with comminuted femoral shaft fractures.

DESIGN

Prospective consecutive case series aimed at quality improvement.

SETTING

Level 1 Trauma Center PATIENTS:: Ninety-eight consecutive patients with a comminuted femoral shaft fracture underwent statically locked intramedullary nailing, with a focused attempt at minimizing LLD during surgery.

INTERVENTION

A computed tomography scanogram of both legs was performed on postoperative day 1 to assess for residual LLD. Patients were offered the option to have LLD >1.5 cm corrected before discharge.

MAIN OUTCOME MEASURE

LLD >1.5 cm.

RESULTS

Twenty-one patients (21.4%) were found to have an LLD >1.5 cm. An LLD >1.5 cm occurred in 10/55 (18%) antegrade nail patients and 11/43 (26%) retrograde nail patients (P = 0.27). No difference was noted based on the mechanism of injury, surgeon training and OTA/AO type B versus C injury. Ninety of 98 patients left with <1.5 cm LLD, 13/21 had a correction all to ≤0.6 cm, and 8 decided to accept the LLD and declined early correction.

CONCLUSIONS

No patient left the hospital with an LLD >1.5 cm after locked intramedullary nailing for a comminuted femoral shaft fracture without being informed and the option of early correction. We recommend using a full-length computed tomography scanogram after IM nailing of comminuted femur fractures to prevent iatrogenic LLD.

LEVEL OF EVIDENCE

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

Complications and risk management in the use of the reaming-irrigator-aspirator (RIA) system: RIA is a safe and reliable method in harvesting autologous bone graft

BACKGROUND

Autologous bone grafting (ABG) remains the gold standard for augmentation of bone defects. The RIA system has become more prevalent, but evidence regarding risk management and complications remain scarce. This study presents the risk management and complications associated with RIA in the largest single-center case series to date.

METHODS

All records, operative notes, lab data and radiographs of patients receiving a RIA procedure at Heidelberg´s University Hospital between 01/01/2010 and 31/12/2016 were reviewed. Multivariate logistic regression models adjusting for clinically relevant covariates were used to examine the respective relevance regarding the presence and absence of prolonged postoperative pain (PPP).

RESULTS

A total of 341 RIA procedures on 306 patients were performed at our level-1 trauma center. The femur was the main donor site (98.53%; N = 336) whereas only in 1.47% (N = 5) the tibia was utilized. A total of 11 patients showed a relevant loss of hemoglobin requiring blood transfusion. A total of 22 patients suffered from PPP directly associated with the RIA procedure resulting in prevalence of 6.45%. The 6 major complications in our study were of diverse origin and all intraoperative complications took place in the early phase of the RIA procedure in our center (2010-2013). Our data revealed influence of sex (p = 0.0459) and age (p = 0.0596) on the criterion PPP. The favored model including sex and age resulted in an AUC of 66.2% (CI: 55.5%-76.9%).

CONCLUSION

Perioperative blood loss remains a prevalent complication during RIA reaming. In addition, PPP occurs with a prevalence of 6.45%. This study showed a complication rate of 1.76%, emphasizing RIA´s overall safety and furthermore highlighting the need for vigilance in its application and prior extensive hands-on training of surgeons. Level of Evidence: II.

Is Contralateral Templating Reliable for Establishing Rotational Alignment During Intramedullary Stabilization of Femoral Shaft Fractures? A Study of Individual Bilateral Differences in Femoral Version

OBJECTIVES

To determine native individual bilateral differences (IBDs) in femoral version in a diverse population.

METHODS

Computed tomography scans with complete imaging of uninjured bilateral femora were used to determine femoral version and IBDs in version. Age, sex, and ethnicity of each subject were also collected. Femoral version and IBDs in version were correlated with demographic variables using univariate and multivariate regression models.

RESULTS

One hundred sixty-four subjects were included in the study. The average femoral version was 9.4 degrees (±9.4 degrees). The mean IBD in femoral version was 5.4 degrees (±4.4 degrees, P < 0.001). A total of 17.7% of subjects had a difference in version ≥10 degrees, and 4.3% had a difference in version ≥15 degrees. A femur with anteversion ≥20 degrees or retroversion was associated with a greater mean difference in version from the contralateral side compared with those with midrange anteversion.

CONCLUSIONS

Bilateral differences in femoral version are common and can result in a difference from native anatomy that may be clinically significant if only the contralateral limb is used to establish rotational alignment during intramedullary stabilization of diaphyseal femur fractures. This is also an important consideration when considering malrotation of femur fractures because most studies define malrotation as a greater than 10-15-degree difference compared with the contralateral side.

LEVEL OF EVIDENCE

Prognostic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Decortication and osteotomy for the correction of multiplanar deformity in the treatment of malunion in adult diaphyseal femoral deformity: a case series and technique description

AIM

To review patients that have undergone correction of a symptomatic femoral malunion using osteotomy combined with decortication.

METHODS

A retrospective review of all patients who have undergone decortication and multiplanar osteotomy, looking at the pre-operative deformity, correction achieved, time to union and complications.

RESULTS

Seven patients underwent correction under the senior author from 2003 to 2012. Average age was 46 years (range 32-60 years). All had femoral shortening deformity (average 2.7 cm, range 2-4 cm). Each also had at least one other plane of deformity with rotation being the next most commonly encountered in 5 out of the 7 (average 33°, range 0°-45°). Two had tri-planar deformity with the five having bi-planar deformity. Average time to union was 16.3 months (range 7-39 months) with an average of 1.5 operations (range 1-3 operations) to union. One patient has a non-union after five corrective operations.

CONCLUSION

Correction of multiplanar deformity of the femur is challenging. Osteotomy with decortication provides a technique to achieve significant femoral multiplanar deformity correction in a single operation. This publication provides technical description of the operative technique, guidance and results.

Evaluation of malrotation following intramedullary nailing in a femoral shaft fracture model: Can a 3D c-arm improve accuracy?

INTRODUCTION

Difficulty determining anatomic rotation following intramedullary (IM) nailing of the femur continues to be problematic for surgeons. Clinical exam and fluoroscopic imaging of the hip and knee have been used to estimate femoral version, but are inaccurate. We hypothesize that 3D c-arm imaging can be used to accurately measure femoral version following IM nailing of femur fractures to prevent rotational malreduction.

METHODS

A midshaft osteotomy was created in a femur Sawbone to simulate a transverse diaphyseal fracture. An intramedullary (IM) nail was inserted into the Sawbone femur without locking screws or cephalomedullary fixation. A goniometer was used to simulate four femoral version situations after IM nailing: 20° retroversion, 0° version, 15° anteversion, and 30° anteversion. In each simulated position, 3D c-arm imaging and, for comparison purposes, perfect lateral radiographs of the knee and hip were performed. The femoral version of each simulated 3D and fluoroscopic case was measured and the results were tabulated.

RESULTS

The measured version from the 3D c-arm images was 22.25° retroversion, 0.66° anteversion, 19.53° anteversion, and 25.15° anteversion for the simulated cases of 20° retroversion, 0° version, 15° anteversion, and 30° anteversion, respectively. The lateral fluoroscopic views were measured to be 9.66° retroversion, 12.12° anteversion, 20.91° anteversion, and 18.77° anteversion for the simulated cases, respectively.

CONCLUSION

This study demonstrates the utility of a novel intraoperative method to evaluate femur rotational malreduction following IM nailing. The use of 3D c-arm imaging to measure femoral version offers accuracy and reproducibility.

Intraoperative Correction of Femoral Rotational Deformity Using a Conventional Navigation System and a Smartphone: A Novel Technique

The intraoperatively rotational control of femoral shaft fractures treated with a closed intramedullary interlocking nailing is a challenging problem. A novel surgical technique that includes respective insertions of guidewires into the proximal and distal femur under the guidance of a 2-dimensional fluoroscopy-based navigation system and the measurements of the intersection angle subtended by the proximal and distal guidewires with the smartphone positional software has been designed to provide intraoperatively quantitative parameters of femoral rotation deformation. The comparison of these parameters with preoperative measurement values of the contralateral intact femur on computed tomography images was used to align the proximal and distal femur fragments based on periaxial rotation. The purpose of this study was to evaluate its clinical suitability. Ten adult patients with femoral shaft fractures were attempted to correct intraoperatively femoral rotational deformity using this novel technique. The additional operation time was 20.04 ± 3.27 minutes. The angle of femoral anteversion was 20.85° ± 4.22°, 38.14° ± 19.07°, and 22.77° ± 3.38° in the contralateral intact and preoperatively and postoperatively injured femur, respectively. The mean absolute difference between both limbs was preoperatively 21.55° ± 10.14° with a statistically significant difference ( P = .005) and postoperatively 3.24° ± 1.69° with no statistically significant difference ( P = .092). Our results showed this novel technique could become an effective tool to correct intraoperatively rotational malalignment of femoral fractures.

Trochanteric entry femoral nails yield better femoral version and lower revision rates-A large cohort multivariate regression analysis

INTRODUCTION

Intramedullary nailing (IMN) has become the standard of care for the treatment of most femoral shaft fractures. Different IMN options include trochanteric and piriformis entry as well as retrograde nails, which may result in varying degrees of femoral rotation. The objective of this study was to analyze postoperative femoral version between three types of nails and to delineate any significant differences in femoral version (DFV) and revision rates.

MATERIALS & METHODS

Over a 10-year period, 417 patients underwent IMN of a diaphyseal femur fracture (AO/OTA 32A-C). Of these patients, 316 met inclusion criteria and obtained postoperative computed tomography (CT) scanograms to calculate femoral version and were thus included in the study. In this study, our main outcome measure was the difference in femoral version (DFV) between the uninjured limb and the injured limb. The effect of the following variables on DFV and revision rates were determined via univariate, multivariate, and ordinal regression analyses: gender, age, BMI, ethnicity, mechanism of injury, operative side, open fracture, and table type/position. Statistical significance was set at p<0.05.

RESULTS

A total of 316 patients were included. Piriformis entry nails made up the majority (n=141), followed by retrograde (n=108), then trochanteric entry nails (n=67). Univariate regression analysis revealed that a lower BMI was significantly associated with a lower DFV (p=0.006). Controlling for possible covariables, multivariate analysis yielded a significantly lower DFV for trochanteric entry nails than piriformis or retrograde nails (7.9±6.10 vs. 9.5±7.4 vs. 9.4±7.8°, p<0.05). Using revision as an endpoint, trochanteric entry nails also had a significantly lower revision rate, even when controlling for all other variables (p<0.05).

CONCLUSION

Comparative, objective comparisons between DFV between different nails based on entry point revealed that trochanteric nails had a significantly lower DFV and a lower revision rate, even after regression analysis. However, this is not to state that the other nail types exhibited abnormal DFV. Translation to the clinical impact of a few degrees of DFV is also unknown. Future studies to more in-depth study the intricacies of femoral version may lead to improved technology in addition to potentially improved clinical outcomes.

Reliable Method for Avoiding Malrotation Deformity After Intramedullary Nailing of Comminuted Femur Fractures: Clinical Validation of a Previously Described Technique

OBJECTIVES

To evaluate a previously described technique using the inherent anteversion of intramedullary nail (IMN) to avoid malrotation in comminuted femur fractures and describe the use of magnetic resonance imaging (MRI) as an alternative method for assessing postoperative femoral version.

DESIGN

Prospective consecutive cohort study.

SETTING

Level I trauma center.

PATIENT/PARTICIPANTS

Twenty-five consecutive patients with comminuted femur fractures (Winquist III/IV, OTA/AO 32-B/32-C) treated by a single surgeon with IMN between September 1, 2011, and February 28, 2015.

INTERVENTION

IMN on a fracture table with intraoperative femoral version set by the inherent version of the implant. All patients received a postoperative computed tomography (CT) or MRI to assess femoral version.

MAIN OUTCOME MEASUREMENTS

Mean difference in postoperative femoral anteversion (DFA) between injured limb and uninjured limb as measured by CT or MRI. Mean difference in postoperative femoral version of the injured femur from the inherent version of the implant (12 degrees) was measured with CT or MRI.

RESULTS

The mean postoperative DFA was 9.1 ± 5.6 degrees. Postoperative DFA greater than 15 degrees was found in 2 (8.0%) patients. Mean difference in postoperative version of the injured femur from the inherent 12 degrees of the implant was 7.1 ± 5.4 degrees. Patients tolerated MRI studies well.

CONCLUSIONS

Our previously described technique using the inherent anteversion of an IMN is effective and leads to a very low rate of malrotation, even in highly comminuted fractures. The technique is particularly useful in treating bilateral femur fractures. MRI can be used safely and effectively to assess anteversion after fixation of femur fractures.

LEVEL OF EVIDENCE

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

A Simple Method for Measurement of Femoral Anteversion-Validation and Assessment of Reproducibility

OBJECTIVES

To propose a simple method for measurement of femoral anteversion (AV) with a conventional fluoroscope, to evaluate the interobserver and intraobserver reliability of this method on the basis of human cadaver femurs, and to validate such method on the basis of computed tomography (CT).

METHODS

Fourteen human cadavers with 28 intact femurs were included in the study. Three blinded observers measured femoral AV of the specimen with a fluoroscope. The session was repeated 8 weeks later and CT of the femurs were performed. Mean AV values and the difference between single and mean AV values were calculated. Interobserver/intraobserver reliability of the proposed method was assessed. Correlation between AV values measured with fluoroscope and CT was calculated.

RESULTS

Mean AV was 18.1° when measured with fluoroscope and 19.2° when measured with CT. Mean differences between single AV values were 2.2° with fluoroscope and 2.5° with CT. The mean maximum observer variation per specimen was 8.8°. Interobserver reliability was excellent (intraclass correlation coefficient: 0.853) and intraobserver reliability was good (intraclass correlation coefficient: 0.682). A high correlation was found between AV values measured with fluoroscope and CT (rho = 0.739, P < 0.01).

CONCLUSION

The presented technique allows reliable and simple measurement of femoral AV with a conventional fluoroscope. The mean interobserver variation is comparable to what has been reported for CT. Maximum interobserver variation was <15° in all specimens. A clinical study will be necessary to prove the value of this technique for intraoperative adjustment of femoral AV according to the intact contralateral side.

Rigid Intramedullary Nailing of Femoral Shaft Fractures for Patients Age 12 and Younger: Indications and Technique

Femoral shaft fractures are common injuries in the pediatric and adolescent age groups. Rigid intramedullary nailing is an excellent treatment option for older children and adolescents, particularly for length-unstable fractures and larger patients (>49 kg). Appropriate indications, contraindications, and preoperative assessment are described. The rigid nailing surgical technique is detailed including positioning, operative steps, pearls, and pitfalls. Complications and the reported outcomes of lateral trochanteric entry nailing are reviewed from the published series.

Prevention of inaccurate targeting of proximal screws during reconstruction femoral nailing

PURPOSE

The purpose of this study was to identify the underlying cause by simulating the forces involved in a controlled laboratory setting, and then to illustrate some intraoperative tips on how to detect this malalignment and suggest solutions prevent this intraoperative complication.

METHODS

The Expert Asian Femoral Nail (A2FN) and Proximal Femoral Nail Antirotation (PFNA) reconstruction nail systems were evaluated to compare the characteristics of each nailing system and their reactions to soft tissue tension at the time of proximal reconstruction screw placement. Soft tissue tension was simulated by placing a fulcrum under the distal drill sleeve and exerting a load on the targeting device via the addition of weights. The occurrence and degree of guide malalignment were determined while gradually increasing the weight.

RESULTS

When soft tissue tension was simulated on the drill/guide sleeve of the A2FN, the drill sleeve deviated from the proximal screw hole proportionally to the weight applied and the K-wire guide passed outside of the nail at a weight of 7 kg. However, the drill sleeve of the PFNA was aligned exactly to the center of nail axis and the K-wire passed cleanly through the proximal locking hole regardless of weight applied.

CONCLUSIONS

Inaccurate guidance of the screw-targeting device can be caused by soft tissue tension. Thus, the authors recommend that careful attention be placed on minimizing soft tissue tension during proximal screw placement while using the targeting device of the A2FN system.

[Antegrade femoral intramedullary nailing in a lateral position]

BACKGROUND

Intramedullary nailing is the gold standard for the treatment of femoral shaft fractures; however, rotational malalignment remains a common complication. The patient can be positioned on the fracture table in a supine position or alternatively in the lateral decubitus position without any traction.

OBJECTIVE

The aim of this article is to describe an effective method to control intraoperative torsion of the femur.

METHOD

The surgical technique described in this article is the standard procedure for femoral shaft fractures and subtrochanteric fractures in this level 1 trauma center. The patient is positioned in a lateral position on a radiolucent table with free draping of the injured leg. Using the C-arm, reduction can be performed with this technique with precise placing of the nails and torsion can be exactly adjusted and controlled with the aid of the femoral neck axis, the distal locking holes and both parallel femoral condyles.

RESULTS

The described technique represents an effective method for the intraoperative control of femoral torsion. With an acceptable and most probably clinically irrelevant bias, this technique is able to avoid significant rotational malalignment. It does not prolong the operative procedure and does not require additional navigation settings. It has also been shown to be helpful in the treatment of subtrochanteric fractures.

CONCLUSION

The surgical technique of anterograde intramedullary nailing using the lateral decubitus position without any traction device and free draping of the injured leg represents a safe and reliable treatment concept and offers logistical advantages compared to the supine position of the patient on a fracture table. Together with other described methods of intraoperative torsional control of femoral fractures, the radiological technique described in this study is an easily applicable and safe method, which needs to be confirmed in clinical studies.

Does MIPO of fractures of the distal femur result in more rotational malalignment than ORIF? A retrospective study

PURPOSE

Intraoperative control of rotational malalignment poses a big challenge for surgeons when using modern MIPO (minimally invasive plate osteosynthesis) techniques. We hypothesized that distal femoral fractures treated with MIPO technique are more often fixed in malrotation than those treated with open reduction internal fixation (ORIF).

METHODS

In this retrospective study, we identified 20 patients who met the inclusion criteria and agreed to take part in the study. In ten patients MIPO was applied, in the other ten ORIF was used. Mean age was 44.8 (19-71 years). Functional status was assessed using clinical scores (Harris Hip Score, WOMAC Hip, KS Score, WOMAC Knee, Kujala Score). Rotational alignment was assessed with magnetic resonance imaging and compared to the opposite leg.

RESULTS

We discovered a significant difference in the mean rotational difference between the MIPO group (14.3°) and the ORIF group (5.2°). Functionally, patients in the ORIF group outperformed patients in the MIPO group in all clinical scoring systems although no one proved to be statistically significant. MIPO technique was associated with significantly more rotational malalignment compared to ORIF in distal femur fracture fixation. However, implant failure and nonunion was more common in the ORIF group, with a revision rate of 3 versus 1 in the ORIF group. Clinical scoring did not significantly different between both groups.

CONCLUSION

Taking into account the undisputable advantages of minimally invasive surgery, improved teaching of methods to avoid malrotation as well as regular postoperative investigations to detect any malrotation should be advocated.

Torsional malalignment, how much significant in the trochanteric fractures?

OBJECTIVES

The rotational alignment is definitely important in the long bones such as tibias and femurs. We also predict the importance of rotational alignment in the trochanteric fractures. So we measured torsional malalignment in trochanteric fracture and anlaysed their risk factors and their clinical significance.

METHODS

A total of 109 inpatients who had undergone internal fixation following trochanteric fracture and a postoperative pelvic CT scan between 2008 and 2013, with at least one year follow-up, were selected. Factors that affect torsional malalignment, such as age, gender, fracture stability, injured area, operative time, time of surgery after admission, and ASA status, were investigated. Factors that affect the patients' clinical results in malrotation, including ambulation time after surgery, postoperative complication rates, pain assessment of VAS one year postoperatively and Koval score, were also investigated.

RESULTS

Of the 109 subjects, torsional malalignment was observed in 28 (25.7%) subjects with a mean torsional malalignment angle of 20.7° (range: -31.2° to 27.1°). Torsional malalignment risk factors were fracture stability (p=0.021) and operative time (p=0.043). In terms of the time to ambulation after surgery, the postoperative complication rates, and the VAS and Koval scores at one year postoperatively, no statistically significant difference was observed between the torsional malalignment patients and the non-deformity patients.

CONCLUSIONS

In this study, 25.7% of the patients who had undergone internal fixation following trochanteric fracture experienced torsional malalignment. Major factors of the torsional malalignment were an unstable fracture and the consequent delay in the operative time. But the torsional malalignment was deemed to have no effect on clinical results.

Preoperative virtual reduction reduces femoral malrotation in the treatment of bilateral femoral shaft fractures

INTRODUCTION

In bilateral femoral shaft fractures, significant malrotation (>15°) occurs in about 40 % of cases after intramedullary nailing. Most of the methods that provide rotational control during surgery are based on a comparison to the intact femur and, thus, not applicable for bilateral fractures. In this study, we evaluated if preoperative virtual reduction can help improving rotational alignment in patients with bilateral femoral shaft fractures.

MATERIALS AND METHODS

Seven patients with bilateral femoral shaft fractures were initially treated with external fixation of both femurs. After obtaining a CT scan of both legs, the fractures were reduced virtually using the software program VoXim®, and the amount and direction of rotational correction were calculated. Subsequently, the patients were treated by antegrade femoral nailing and rotation was corrected to the preoperatively calculated amount.

RESULTS

After external fixation, the mean rotational difference between both legs was 15.0° ± 10.2°. Four out of seven patients had a significant malrotation over 15°. Following virtual reduction, the mean rotational difference between both legs was 2.1° ± 1.2°. After intramedullary nailing, no case of malrotation occurred and the mean rotational difference was 6.1° ± 2.8°.

CONCLUSIONS

Preoperative virtual reduction allows determining the pretraumatic femoral antetorsion and provided useful information for the definitive treatment of bilateral femoral shaft fractures. We believe that this procedure is worth being implemented in the clinical workflow to avoid malrotation after intramedullary nailing.

Important tips and numbers on using the cortical step and diameter difference sign in assessing femoral rotation--should we abandon the technique?

Rotational malalignment during femoral nailing is common despite having various intraoperative assessment methods. The cortical step sign and diameter difference sign (CSSDDS) is commonly used because of convenience, yet it lack proper scientific scrutiny and is thought to be error prone. Using a software algorithm, cross-sectional dimensions were obtained from CT scans of 22 intact adult femurs at the proximal, mid and distal diaphysis. With multiple simulated scenarios the sensitivity of CSSDDS was comprehensively determined at all possible C-arm positions. At rotation, cortical width changed most significantly around the thick linea aspera and femoral diameter changed most significantly at the sagittal plane. At 15 degrees of rotation and with the linea aspera in view, CSSDDS thresholds of 0.3mm, 0.6mm and 1mm had sensitivities of 98.8%, 93.1% and 73.8%. With the linea aspera masked behind the femur and out of view, the sensitivities significantly deteriorated to 96.4%, 77.1% and 44.1% respectively. CSSDDS is sufficiently sensitive only when strict rules are followed. It is imperative that the operator position the image intensifier in lateral view under proper magnification so that steps of less than 0.6mm around the linea aspera may be appreciated.

Patient positioning on the operative table for more accurate reduction during elastic stable intramedullary nailing of the femur: a technical note

Elastic stable intramedullary nailing is currently considered a clinical practice standard for the treatment of femoral fractures in children in the age-appropriate group. Malreduction, particularly in rotation, due to the closed reduction technique has been reported. We describe a new technique of positioning on a standard operating table that permits better control of rotational alignment during femoral elastic stable intramedullary nailing.