Long-term functional implications of the iatrogenic rotational malalignment of healed diaphyseal femur fractures following intramedullary nailing

Management of rotational malalignment following operative treatment of fractures of the lower extremities. A scoping review

BACKGROUND

Rotational malalignment after operative fracture treatment of the lower extremity may be associated with increased pain and functional impairment. Despite its clinical relevance, there are no uniform management guidelines. The aim of this scoping review is to provide an overview of all available evidence to diagnose and treat rotational deformities of the lower extremity following operative fracture treatment.

METHODS

This scoping review was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. A literature search was carried out on 22 August 2023 by two independent reviewers in the Pubmed (MEDLINE), Embase, Web of Science, and Cochrane library databases. The search strategy was developed with the assistance of a biomedical information specialist. The main search terms were tibial and femoral malrotations. Disagreements were resolved through discussion with a third reviewer.

RESULTS

After screening and quality assessment of 3929 unique identified records, 50 articles were included for qualitative synthesis. Most studies were retrospective case reports or case series. Thirty studies focused on the femur, 11 on the tibia and nine included both femur and tibia. Most of the included studies presented cases where malrotation was associated with other limb deformities. Only 18 studies focused solely on the treatment of malrotation of the lower extremities after operative fracture treatment. Regarding diagnosis, bilateral CT-scans were used in 34 studies. Regarding treatment, external fixation was used in two studies, internal fixation (either intramedullary nail or plate) in 45 studies, and in three studies the authors used both. Overall, revision surgery resulted in good clinical outcomes with low complication rates.

CONCLUSION

This scoping review reveals that rotational malalignment following operative treatment of lower extremity fractures remains an important complication. Although it occurs frequently and is associated with severe disability for the patient, standardized guidelines regarding the terminology, diagnosis, indications for intervention and treatment are lacking. CT-scan is the most used diagnostic modality in daily clinical practice. Revision surgery, using diverse operative techniques, demonstrated positive results, significantly alleviating patient complaints with few complications. Nevertheless, an international consensus regarding the optimal management pathway is needed, and future prospective clinical studies seem therefore necessary.

Incidence of Rotational Malalignment after Intertrochanteric Fracture Intramedullary Nailing: A CT-Based Prospective Study

Background and Objectives: Rotational malformation after intramedullary nailing of intertrochanteric fractures is a relatively common, possibly severe, and difficult-to-detect complication, since intraoperative radiographic imaging allows for the assessment of the quality of reduction in the frontal and sagittal planes, but not in the transverse plane. The purpose of this study is to evaluate the rotational malalignment after intramedullary nailing of intertrochanteric fractures and to investigate a possible connection with specific patients' or fractures' characteristics. Materials and Methods: 74 patients treated with intramedullary nailing due to an intertrochanteric fracture underwent a postoperative CT of the pelvis-hips and knees. The value of the anteversion was measured both in the operated-on (angle 1) and in the healthy hip (angle 2) based on the technique described by Jeanmart et al. and the difference in anteversion (D angle = angle 1 minus angle 2) was calculated. A positive D angle indicated the presence of excessive internal overcorrection of the distal fragment during fracture reduction, while a negative D angle indicated the presence of excessive external overcorrection. The absolute value of the D angle represents the postoperative difference in anteversion between the two hips. The patients were divided into three groups according to this value: group A, with D < 5° (physiological difference); group B, with 5° < D < 15° (acceptable rotational alignment); and group C, with D ≥ 15° (rotational deformity). Results: Group A constitutes 56.8%, group B 12.2%, and group C 31.1% of the study population. Overall, 79.7% of the patients presented a positive angle D, while, for group C, the percentage was even higher at 91.3%. According to the AO/OTA classification system, 37.8% of the cases were stable fractures, 47.3% were unstable fractures, and 14.9% were reverse oblique fractures. Based on our analysis, the type of fracture has a serious impact on the rotational alignment, since the statistical significance of the mean angle D for the three types of fracture is reliable (p = 0.029). Stable fractures present the lowest anteversion difference values, while reverse oblique fractures present the highest difference. Conclusions: Our study reveals that the percentage of rotational malalignment after the intramedullary nailing of intertrochanteric fractures remains high (31.1%), despite the proper use of radiographic imaging during the intraoperative fracture reduction. In most cases (91.3%), this malalignment appears to be a matter of internal overcorrection. A clear correlation between hip's rotational deformity and patients' functional outcome has yet to be proven, and constitutes our objective in the near future.

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.

Malrotation of Long Bones

Rotational malreduction is a common yet underreported postoperative complication following intramedullary nailing of long bone fractures. In most situations, this can be prevented at the time of initial surgery with meticulous preoperative planning, careful use of intraoperative fluoroscopy, and awareness of risk factors for malrotation. However, rotational alignment remains difficult to assess by clinical examination so a high index of suspicion is always necessary. Here, the authors review the literature on this complication and report on 3 such cases of femoral and the tibial malrotation, methods for calculating femoral version and tibial torsion, and techniques for correcting these deformities.

Intraoperative torsion control using the cortical step sign and diameter difference in tibial mid-shaft fractures

AIM

Intramedullar nailing of tibial mid-shaft fractures is a common surgical treatment. Fracture reduction, however, remains challenging and maltorsion is a common discrepancy which aggravates functional impairment of gait and stability. The use of radiographic tools such as the cortical step sign (CSS) and the diameter difference sign (DDS) could improve fracture reduction. Therefore, the validity of the CSS and DDS was analyzed to facilitate detection of maltorsion in tibial mid-shaft fractures.

METHODS

Tibial mid-shaft fractures were induced in human cadaveric tibiae according to the AO classification type A3. Torsional discrepancies from 0° to 30° in-/external direction were enforced after intramedullary nailing. Fluoroscopic-guided fracture reduction was assessed in two planes via analysis of the medical cortical thickness (MCT), lateral cortical thickness (LCT), tibial diameter (TD), anterior cortical thickness (ACT), posterior cortical thickness (PCT) and the transverse diameter (TD) of the proximal and distal fracture fragment.

RESULTS

The TD, LCT and ACT have shown a highly significant correlation to predict tibial maltorsion. While a model combining ACT, LCT, PCT and TD lateral was most suitable model to identify tibial maltorsion, a torsional discrepancy of 15°was most reliably detected with use of the TD and ACT.

CONCLUSION

The present study has shown, that maltorsion can be reliably assessed by the CSS and DDS during fluoroscopy. Thus, torsional discrepancies in tibial mid-shaft fractures can be most reliably assessed in the lateral plane by analysis of the LCT and TD.

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.

Femoral malrotation from diaphyseal fractures results in changes in patellofemoral alignment and higher patellofemoral stress from a finite element model study

BACKGROUND

Malrotation of the femur is a frequent complication in the management of a diaphyseal fracture. It is often responsible for pain and adverse functional results. Among these complications, contact stress effects on the patellofemoral joint are recognized as predictive factors of impaired results. The purpose of this study was to analyze the effect of malrotation on stress distribution on the patellofemoral joint, using radiological measurement and three-dimensional finite element models.

METHODS

Functional analysis of the patellofemoral joint was evaluated in eight knee pairs from patients with unilateral femoral fractures and subsequent femoral malrotation. A computed tomography-based protocol allowed patellofemoral joint analysis. A finite element model of the healthy (contralateral) knee was then created from 3D reconstruction at 30° flexion. In a finite element model, incremental rotational malalignment was simulated to observe changes in stress distribution on the patellar surface.

RESULTS

Femoral malrotation was associated with anomalies of patellofemoral joint rotational alignment. Internal rotation resulted in increased stress on the lateral side of the patella, and external rotation increased inferior medial side stress.

CONCLUSIONS

Rotational disorders of the distal femur resulted in increased stress on the patellofemoral joint and alignment changes. Malrotation in internal and external rotation might cause patellofemoral pain syndrome from rotations <10°. Care should be taken especially for internal malrotation in the management of femoral shaft fracture.

Reproducibility of low-dose stereography measurements of femoral torsion after IM nailing of femoral shaft fractures and in intact femurs

INTRODUCTION

Rotational malunion is a complication of intramedullary (IM) nailing for femur fractures. Symptoms can appear with 15° or more of axial deformity. None of the currently available measurement methods have a satisfactory reliability/irradiation ratio. The purpose of this study was to study the reproducibility of measuring femoral torsion with an EOS(®) low-dose stereography (LDX) system.

HYPOTHESIS

LDX is a reproducible method for measuring post-traumatic femoral torsion.

MATERIAL AND METHODS

The intra- and inter-observer reproducibility was studied in 45 patients who had a femoral fracture treated by IM nailing. Both the injured and contralateral healthy femurs were modelled. Bland-Altman plots were used to analyze the measurements made by three different observers (two orthopedic surgeons and one radiologist). For a given comparison, the interval between the upper limit of agreement (ULA) and lower limit of agreement (LLA) had to be within [-5°; 5°] for the examination to qualify as reproducible. Measurements were made by three observers (A, B, C) on the injured and healthy femur.

RESULTS

With the fractured femurs (n=39), the intra-observer [LLA; ULA] interval was [-16.295; 12.977]; it was [-18.475; 16.744] for the A-B pairing, [-13.316; 13.532] for the B-C pairing and [-17.839; 19.355] for the A-C pairing. With the healthy femurs (n=37), the intra-observer [LLA; ULA] interval was [-7.909; 7.88]; it was [-11.924; 11.639] for the A-B pairing, [-12.654; 11.93] for the B-C pairing and [-11; 12.009] for the A-C pairing.

DISCUSSION

The [LLA; ULA] intervals were greater than the [-5; +5] interval in all cases. LDX reproducibility is not sufficient for measuring femoral torsion after fracture or in healthy femurs. Observer experience, cohort size and the perfectible image quality are likely sources of bias. Conversely, the use of Bland-Altman plots and the multidisciplinary training of observers are major strengths of this study. Reproducibility will likely improve as the software is developed further and the image acquisition improves.

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.

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.

Decreased muscle strength is associated with impaired long-term functional outcome after intramedullary nailing of femoral shaft fracture

PURPOSE

To examine the long-term outcome after intramedullary nailing of femoral diaphysial fractures measured as disease-specific patient reported function, walking ability, muscle strength, pain and quality of life (QOL).

METHODS

Cross-sectional study. Retrospective review and follow-up with clinical examination of 48 patients treated with intramedullary nailing after femoral shaft fracture between 2007 and 2010. The patients underwent a clinical examination and assessment of walking ability, maximal muscle strength during knee flexion and extension and hip abduction. Hip disability and Osteoarthritis Outcome Score (HOOS) and questionnaire evaluating QOL (Eq5D-5L) were completed by patients.

RESULTS

Fourty-eight patients agreed to participate. Mean time for follow-up was 4.7 years. The mean HOOS scores were 84.9 (Pain), 86.6 (ADL), 85.0 (Symptoms), 72.6 (QOL), and 69.1 (Sport). The mean muscle strength of knee flexion with the injured leg (226.0 N) was significantly lower then knee flexion with the non-injured leg (259.5 N, P < 0.0001). Likewise for knee extension (335.2 vs 406.4 N, P < 0.001) and hip abduction (129.2 vs 156.0 N, P < 0.001). Significant association between HOOS and an increase in the difference in muscle strength were observed as well as between worse HOOS outcome and increasing body mass index.

CONCLUSION

This study showed that decreased muscle strength for knee flexion, knee extension and hip abduction was associated with worse long-term functional outcome measured with a disease-specific questionnaire (HOOS) after intramedullary nailing of femoral shaft fracture.

Does electromagnetic-manual guided distal locking influence rotational alignment in antegrade femoral nailing?

PURPOSE

The aim of this study was to determine whether distal locking using an electromagnetic-manual guided distal locking decreases the malrotation rate in femur fractures treated with intramedullary nailing.

METHODS

A total of 113 adult patients having unilateral femoral shaft fractures treated using IM nails were evaluated regarding demographic features, injury mechanism, fracture type, interval between trauma and nailing, operation time and number of image intensifier shots during the operation at least one year after nailing. Patients were divided into two groups according to distal locking technique. All patients had also undergone clinical examination for lower extremity alignment and range of motion and filled out the SF-36 questionnaire and undergone ultrasound measurement of femoral anteversion angles to reveal any rotational femoral malalignment.

RESULTS

Group 1 consisted of 47 patients (41.6 %) with electromagnetic-manual targeting guided distal locking and group 2 consisted of 66 patients (58.4 %) with free-hand distal locking. Both groups were statistically similar regarding demographic features, injury mechanism, fracture type, interval between trauma and nailing, clinical examination and SF-36 results. Operation time and number of image intensifier shots were significantly less in group 1. No statistically significant difference was found between the femoral anteversion angles of injured and uninjured sides of the patients in both groups.

CONCLUSIONS

Although there is no significant effect on malrotation, previously known advantages lead us to state that electromagnetic-manual guided distal interlocking is an advantageous treatment option in femoral shaft fractures.