Correcting rotational deformity following femoral nailing

Femoral-tibial contact stresses on fixed rotational femur models

Objectives

This study aims to quantitatively evaluate the femoral-tibial contact pressure on the knee under certain malrotaional degrees.

Methods

Femoral-tibial contact pressure was carried out on 14 fixed rotational knee models under 200/400/600 N vertical load using ultra-low-pressure sensitive film technology, rotation angles including neutral position (0°, anatomically reduced), 5°, 10°, and 15° internally and externally. Data were collected and analyzed with SPSS software.

Results

There are significant statistical differences between the medial contact pressure among rotational deformities (including neutral position) (P < 0.01), the increase in the degree of fixed internal malrotation of the femur resulted in a linear increase in the medial femoral-tibial contact pressures (P < 0.05) under 200/400/600 N vertical load, while increase in the degree of fixed external malrotation resulted in a linear decrease (P < 0.05). Except the 200 N compression, we can't find significant differences in lateral contact pressures (P > 0.05). In the comparison of medial to lateral contact pressures, no statistically significant differences were found in neutral and 5° internal rotation under 200/400 N, neutral, 5° internal rotation, and 15° external rotation under 600 N. In contrast, medial contact pressures were higher than lateral at other angles (P < 0.05).

Conclusion

Obvious contact pressure changes were observed in rotatory femur. Doctors should detect rotational deformity as much as possible during operation and perform anatomical reduction. For patients with residual rotational deformities, indication of osteotomy should not be too broad.

Use of Lesser Trochanter Profile as a Rotational Alignment Guide in Intramedullary Nailing for Femoral Shaft Fracture

BACKGROUND

Malrotation after nailing of femoral shaft fractures occurs in about 25% of cases. It can cause substantial functional problems. The lesser trochanter (LT) profile has been used to assess rotational alignment. However, the extent to which the LT profile is symmetrical between limbs, whether the LT profile varies as a function of age or sex, and the efficacy of the LT profile technique remain unknown. The purpose of this study was to determine if there was a significant side-to-side length difference in the LT profile (LTD) according to age and sex.

METHODS

We attempted to determine the amount of medial prominence of the lesser trochanter relative to the medial cortex of the femoral shaft (the LT profile) using 3-dimensional computed tomography (3D-CT) images of normal femora obtained bilaterally (366 subjects) in anatomic positions. We also compared the left and right sides to determine the amount of natural asymmetry by age and sex. In addition, we compared the side-to-side difference in the LT version with the LTD to determine whether the LTD represented the difference in femoral rotation.

RESULTS

The LTD was <4 mm (meaning an LT version difference of <10°) in 83% of the subjects, but was ≥4 mm (an LT version difference of ≥10°) in 17%. Subset analysis demonstrated that the differences were greatest in women >70 years of age. The largest LTD (both sexes) was observed in individuals over 70 years of age (2.62 ± 1.37 mm, compared with <55 years: 1.55 ± 1.36 mm and 55 to 70 years: 2.27 ± 1.70 mm). There was no significant difference between sexes in the under-70 age groups. However, the LTD was significantly greater in women over 70 years than in men over 70 years (3.10 ± 1.42 versus 2.41 ± 1.30 mm).

CONCLUSIONS

Since the LTD demonstrated side-to-side symmetry within 4 mm, or 10° of rotation, in 83% of all subjects, we consider the LT profile to be useful as a guide to assess rotational reduction clinically. However, surgeons should recognize that, in 17% of cases, using this technique could result in malrotation of ≥10°. The rate of malrotation may be even higher in women over 70, for whom supplemental techniques to ensure correct rotation may be appropriate.

Assessment of the quality of life in patients with varying degrees of equalization of lower limb length discrepancy treated with Ilizarov method

BACKGROUND

Inequalities in leg length result in functional disorders, as they impair the biomechanics of the musculoskeletal system, significantly reducing the quality of life (QoL). This study used the WHOQoL-BREF questionnaire in patients with varying degrees of lower leg shortness who had undergone treatment by the Ilizarov method, compared to a healthy control group.

METHODS

Fifty-eight patients treated with the Ilizarov method for discrepancies in lower limb length were grouped by degree of limb equalization (group 1, 37 treated individuals with limb length discrepancy < 1 cm; group 2, 21 individuals with discrepancy ≥ 1 cm but not more than 4 cm). The control group 3 contained 61 healthy individuals. Patient quality of life (QoL) was assessed using a shortened version of the WHOQoL-BREF questionnaire, at least 24 months after the end of Ilizarov therapy.

RESULTS

Control subjects obtained higher scores in all domains than subjects in both treatment groups, as well as significantly higher self-assessed QoL, and health, in the physical, psychological, social, and general lifestyle domains, as compared to those with inequalities ≥ 1 cm. Furthermore, patients with inequalities ≥ 1 cm had higher odds ratios of low self-assessment (3.28 times; p = 0.043), low self-assessment of health (4. 09 times; p = 0.047), and low physical and psychological domains (respectively 6.23 times; p = 0.005 and 8.46 times, p = 0.049) compared with patients with inequality < 1 cm. The shortened version of the WHOQoL questionnaire was used.

CONCLUSIONS

After at least 24 months of treatment with the Ilizarov method, patients with limb length discrepancy < 1 cm did not differ significantly from healthy individuals in the WHOQoL self-assessment of mental functioning, social, or life satisfaction.

Pedobarographic analysis of body weight distribution on the lower limbs and balance after ankle arthrodesis with Ilizarov fixation and internal fixation

BACKGROUND

A number of various techniques were proposed to stabilized ankle arthrodesis, among them external and internal fixation. Appropriate balance and adequate distribution of lower limb loads determine normal biomechanics of the locomotor system. We hypothesized that various techniques used to stabilize ankle arthrodesis may exert different effects on (1) balance and (2) distribution of lower limb loads.

METHODS

Retrospective analysis included 47 patients who underwent ankle arthrodesis with external stabilization with Ilizarov fixator (group 1, n = 21) or internal stabilization with screws (group 2, n = 26) between 2007 and 2015. Balance and distribution of lower limb loads were determined with a pedobarographic platform.

RESULTS

In group 1, average load of the operated and non-operated limb amounted to 48.8% and 51.2%, respectively, and in group subjected to internal stabilization to 48.4% and 51.6%, respectively. Neither the intragroup nor the intergroup differences in the distribution of lower limb loads were statistically significant. Mean length of the center of gravity (COG) path was 137.9 cm for group 1 and 134 cm for group 2, and mean COG area amounted to 7.41 cm2 and 6.16 cm2, respectively. The latter intergroup difference was statistically significant.

CONCLUSIONS

Balance after ankle arthrodesis with Ilizarov fixation is worse than after the same procedure with internal stabilization. Despite correction of ankle deformity, musculoskeletal biomechanics still remains impaired. While ankle fusion with either Ilizarov or internal fixation provide appropriate distribution of lower limb loads, none of these procedures normalize patients' balance.

Balance and lower limb loads distribution after Ilizarov corticotomy

INTRODUCTION

Normal balance and symmetric distribution of lower limb loads are associated with adequate muscle strength, joint mobility and proprioception. The aim of this study was to analyze the distribution of lower limb loads and balance prior to and after axis correction and lengthening with Ilizarov method.

MATERIALS AND METHODS

The prospective analysis included 20 patients from our clinic, who have been subjected to distraction-corrective lower limb corticotomies with the Ilizarov method in 2014-2015. Balance and distribution of lower limb loads were determined with a pedobarographic platform.

RESULTS

Prior to the surgery, mean loads on affected and non-affected limbs corresponded to42%and58%of body weight, respectively. Mean loads on affected and non-affected limbs during the postoperative examination did not differ significantly. Mean path length of the center of gravity prior to and after the surgery amounted to143.27 cm and 125.11 cm, respectively. Mean area of the center of gravity was 7.81 cm²prior to the surgery and 5.81 cm²after the procedure.

DISCUSSION

Our present study showed that distraction-corrective Ilizarov corticotomy may provide more symmetric distribution of lower limb loads and improvement of balance. This outcome should be considered satisfactory from the perspective of the locomotor system statics. Corticotomies with Ilizarov method provide symmetric distribution of loads between non-affected and operated limb.

Interlocking Intramedullary Nailing Versus Locked Dual-Plating Fixation for Femoral Shaft Fractures in Patients with Multiple Injuries: A Retrospective Comparative Study

PURPOSE

Intramedullary nailing (IMN) is a popular method in the management of femoral shaft fractures (FSFs). However, whether the association of IMN with pulmonary fat emboli can compromise the pulmonary and nervous systems is debatable. The purpose of this study is to compare IMN with the locked dual plating (LDP) method by assessing the clinical outcomes of FSF patients with head or chest injury.

METHOD

A total of 126 FSF patients were included in this study between January 2010 and July 2016 and divided into LDP and IMN groups. Patient demographic characteristics, operative time, blood loss, Harris Hip Score, Lysholm Knee Score, radiological outcomes, and systemic complications were collected and compared between the two treatment groups. Patients were followed up for at least 12 months.

RESULTS

The LDP group performed better than IMN in terms of operative time, estimated blood loss amount, and malunion rate. Differences in function scores, fracture union rate, overall pulmonary complication rate, and in-hospital mortality between the two groups were not significant. Average radiographic union time was significantly longer in the LDP group (36.3 weeks) than in the IMN group (32.5 weeks). One case of fixation failure occurred postoperatively in the LDP group, whereas one case of fracture nonunion took place in the IMN group.

CONCLUSION

Our findings suggest that dual-plating fixation is a promising method for FSFs with multiple injuries. However, the retrospective nature of this study necessitates high-quality trials to be performed to assess the clinical efficiency of dual plating.

Pedobarographic analysis of body weight distribution on the lower limbs and balance after Ilizarov corticotomies

BACKGROUND

Symmetrical distribution of the load of the lower limbs and balance are among the determinants of proper biomechanics of the musculoskeletal system. So far, it has not been elucidated whether the correction of the axis and the equalization of the length of the lower limbs allow for achieving proper balance and load distribution. The aim of the present study was to compare load distribution and balance of patients who underwent Ilizarov method corticotomies with healthy controls.

METHODS

The clinical studies evaluated 57 patients, who underwent corticotomy with the Ilizarov method. The control group consisted of 59 healthy volunteers. The evaluation assessed the distribution of the load of the lower limbs and balance using pedobarographic platform.

FINDINGS

In the study group operated limb bore 48.02% of the load on average, while the healthy limb 51.98%. These differences were not statistically significant. The average percentage of load in limbs in treated and control groups did not differ significantly. In the study group, the average length of path of the center of gravity was 145.47cm. In the control group, the average length of path of the center of gravity was 112.69cm. In the study group, the average area of the center of gravity was 7.54cm(2), while in the control group it was 5.19cm(2).

INTERPRETATION

Ilizarov method corticotomy allows for the obtainment value of the load distribution of the lower limbs in the study group not significantly different from those in a control group, but does not ensure the achievement of completely normal balance.

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.

Computerized navigation for length and rotation control in femoral fractures: a preliminary clinical study

OBJECTIVE

Operative treatment of femoral fractures yields a predictably high union rate, but residual malrotation and leg length discrepancy remain a clinically significant problem. The aim of this study was to determine the safety and efficacy of using computerized navigation in controlling the length and rotation in femoral fracture surgery.

DESIGN

Prospective consecutive case series of 16 skeletally mature patients with femoral fractures undergoing surgical fixation; 14 were fixed with intramedullary nails and 2 with plates.

SETTING

An Academic Level I trauma center.

INTERVENTION

Computerized navigation was used to determine the length and rotation of the operated extremity as compared with the intact healthy contralateral side.

MAIN OUTCOME MEASURE

All patients underwent postoperative computed tomography scanogram for determining the length and rotation.

RESULTS

All fractures healed. Mean rotational difference between the treated and nontreated sides was 3.45 degrees (range, 0-7.7 degrees). Mean length difference between the 2 extremities as calculated by the computed tomography scan was 5.83 mm (range, 0-13 mm). Additional operative time required for computerized navigation was measured in 2 of the cases and totaled ∼30-35 min/case.

CONCLUSION

Computerized navigation was accurate and precise at restoring femoral length and rotation during femoral fracture fixation when the intact contralateral femur was used for reference. Further, large-scale randomized studies are required. Additionally, improvements aimed at decreasing operative time and improving user interface of these systems are recommended.

LEVEL OF EVIDENCE

Therapeutic level IV. See instructions for authors for a complete description of the levels of evidence.

Impact of specialty and level of training on CT measurement of femoral version: an interobserver agreement analysis

BACKGROUND

To determine the interobserver agreement on femoral version measurements between an orthopedic attending, orthopedic senior and junior residents, and an attending radiologist.

MATERIALS AND METHODS

Postoperative computed tomography (CT) scanograms of 267 patients who underwent femoral intramedullary (IM) nailing with corresponding radiology attending reads for femoral version were collected and de-identified. Femoral version measurements performed by a trauma fellowship-trained attending orthopedic surgeon (ORTHO), a senior orthopedic resident (PGY4), a junior orthopedic resident (PGY1), and a musculoskeletal fellowship-trained attending radiologist (RADS) were compared via Pearson's interclass correlation coefficient to assess interobserver level of agreement.

RESULTS

Version measurements provided by the two attending physicians exhibited the highest level of agreement (r = 0.661, p < 0.01). The orthopedic attending and the senior resident had the next highest level of agreement (r = 0.543, p < 0.01). The first-year orthopedic resident had the weakest agreement across the board: with the orthopedic attending, the radiology attending, and the senior resident.

CONCLUSION

Regardless of specialty, experience and higher levels of training produce stronger agreement when measuring femoral version. Residents in training, especially those who are junior, produce weak agreement when compared to their senior colleagues.

LEVEL OF EVIDENCE

Level III, diagnostic study.

Femoral malrotation following intramedullary nail fixation

Intramedullary nailing of femoral shaft fracture can result in inadvertent malalignment. Malrotation is the most common cause of deformity, but it is underrecognized, in part because of the difficulty in accurately assessing rotation as well as the variation that exists in normal anatomy. The consequences of femoral malrotation are not completely understood. However, initial biomechanical studies suggest that it causes a substantial change in load bearing in the affected extremity. Clinical examination, fluoroscopy, and ultrasonography are useful in measuring femoral rotational alignment intraoperatively and postoperatively. CT is useful in the identification of the degree of malrotation and in surgical planning.