Measuring Lower Extremity Rotational Alignment: A Review of Methods and Case Studies of Clinical Applications

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.

Progress in Computer-Assisted Navigation for Total Knee Arthroplasty in Treating Knee Osteoarthritis with Extra-Articular Deformity

Total knee arthroplasty (TKA) is a well-established treatment for end-stage knee osteoarthritis. However, in patients with concomitant extra-articular deformities, conventional TKA techniques may lead to unsatisfactory outcomes and higher complication rates. This review summarizes the application of navigated TKA for treating knee osteoarthritis with extra-articular deformities. The principles and potential benefits of computer navigation systems, including improved component alignment, soft tissue balancing, and restoration of mechanical axis, are discussed. Research studies demonstrate that navigated TKA can effectively correct deformities, relieve pain, and improve postoperative joint function and quality of life compared with conventional methods. The advantages of navigated TKA in terms of surgical precision, lower complication rates, and superior functional recovery are highlighted. Despite challenges like the learning curve and costs, navigated TKA is an increasingly indispensable tool for achieving satisfactory outcomes in TKA for knee osteoarthritis patients with extra-articular deformities.

Individual Bilateral Difference of Femur, Tibia, and Leg Rotation: A Clinical Study of 141 Healthy Japanese Individuals Using Computed Tomography

Background The malrotation of a femur and tibial fracture after surgery has been described in many articles. However, these studies have not considered individual bilateral differences (IBDs). The IBD of femur and tibial rotation has been identified via computed tomography (CT) in recent American studies. The IBD in rotation should be considered during femur and tibial surgery. However, IBDs in femur and tibial rotation remain unknown in the Japanese population. This study aimed to evaluate the rotation of the femur, knee, tibia, and leg, sex differences, and IBD in rotation among Japanese individuals with healthy bones by using CT analysis. Materials and methods In total,141 patients who underwent CT angiography or venography were included (70 men, 71 women; mean age, 44.7 years). The bilateral axial femur, knee, tibia, and leg rotation alignment were independently measured. The distribution, sex, and IBD were analyzed. The IBD in rotation had two statistical factors: absolute bilateral difference (ABD) and relative bilateral difference (RBD). Results The mean ABD of femur rotation was 6.5°, and the distribution of ABD of femur rotation ≤15° was 95%. The mean ABD of tibia rotation was 5.1°, and the distribution of ABD of tibia rotation ≤10° was 89%. The RBD of femur rotation was not significantly different between the right and left sides. The RBD of tibia rotation showed a higher mean external rotation of 3.3° on the right side (<0.001). The Pearson correlation coefficients of the femur, knee, tibia, and leg rotation between the right and left sides were high (r= 0.702-0.81; all, p<0.001). All elements of rotation showed significant differences between men and women, whereas the ABD and RBD of all elements showed no significant difference. Conclusion The distributions of ABD in femur and tibia rotation supported the previous definition of an acceptable rotation difference between the normal and fractured femur and tibia of ≤15°and ≤10°, respectively. The possibility of higher external rotation on the right side needs to be taken into account during tibial surgery.

Clinical validation of the 'C-arm rotational view (CARV)': study protocol of a prospective randomised controlled trial

INTRODUCTION

Rotational malalignment occurs in up to 30% of cases after intramedullary nailing of tibial shaft fractures. The aim of this study is to assess the clinical feasibility of a newly introduced standardised intraoperative fluoroscopy protocol coined 'C-arm rotational view (CARV)' in order to reduce the risk of rotational malalignment during intramedullary nailing of tibial shaft fractures. The CARV includes predefined fluoroscopy landmark views of the uninjured side to obtain correct alignment of the injured side with use of the rotation of the C-arm.

METHODS AND ANALYSIS

This randomised controlled trial will be conducted in a level 1 trauma centre. Adult patients with an open or closed tibial fracture, eligible for intramedullary nailing, will be enrolled in the study. The interventional group will undergo intramedullary nailing guided by the CARV protocol to obtain accurate alignment. The control group is treated according to current clinical practice, in which alignment control of the tibia is based on clinical estimation of the treating surgeon. The primary endpoint is defined as the degree of rotation measured on low-dose postoperative CT scans.

ETHICS AND DISSEMINATION

The study protocol will be performed in line with local ethical guidelines and the Declaration of Helsinki. The results of this trial will be disseminated in a peer-reviewed manuscript. Future patients are likely to benefit from this trial as it aims to provide a clinically feasible and easy-to-use standardised fluoroscopy protocol to reduce the risk for rotational malalignment during intramedullary nailing of tibial shaft fractures.

TRIAL REGISTRATION NUMBER

NCT05459038.

Intraoperative Measurement of Tibial Rotation With Lateral Axis Views Using C-arm for Tibial Fractures

Malrotation of tibial fractures after intramedullary nailing remains an unsolved problem. The incidence of malrotation >10° on computer tomography (CT) measurements has been high in cases of tibial shaft fractures. We aimed to assess the accuracy of a novel method for the measurement of tibial rotation using lateral axis views of the C-arm, to prevent postoperative malrotation. Consecutive patients with fresh tibial fractures treated by intramedullary nailing between January 2021 and December 2022 were included prospectively. Baseline tibial external rotation (TER) was measured preoperatively on the non-injured normal side with CT. After proximal or distal screw fixation, the C-arm TER was measured based on lateral axis views (tibial posterior condylar axis and bimalleolar axis views). The C-arm TER was compared with the normal-side CT TER; when the difference was ≤5°, the procedure progressed, and screw fixation was carried out. The fractured-side CT TER was measured one week post-operatively. Twenty patients (13 males and seven females) were included. The mean age was 52.4 years. The Orthopaedic Trauma Association (OTA) classification was 42A in five patients, 42B in twelve patients, and 42C in three patients. The mean difference between C-arm TER and fractured-side CT TER was 2.3°±1.7°, with Pearson correlation coefficient r=0.968. The mean difference between normal-side CT TER and fractured-side CT TER was 4.8°±2.8°, and there was no incidence of malrotation >10°. The C-arm method was highly accurate in estimating CT measurements and preventing tibial malrotation.

Feasibility of mitigating out-toeing gait using compression tights with inward-directing taping lines

Out-toeing gait may cause alterations in lower limb biomechanics that could lead to an increased risk of overuse injuries. Surgery and physical therapy are conventional methods for mitigating such gait, but they are costly and time-consuming. Wearable devices like braces and orthoses are used as affordable alternatives, but they apply non-negligible stress on the skin. Haptic feedback-delivering shoes were also recently developed, but they require actuators and power sources. The purpose of our study is to develop compression tights with inward directing taping lines that apply compression to lower limb muscles and segments to facilitate inward rotation of the foot, overcoming the drawbacks of previous methods. These compression tights were manufactured to fit the average height, leg length, hip girth, and waist girth of South Korean females in their twenties. The efficacy of these compression tights was evaluated by comparing walking kinematics and user satisfaction of 12 female dancers with an out-toeing gait under three conditions: wearing tights with taping lines, tights without taping lines, and basic bicycle shorts. The foot rotation angles and joint kinematics were recorded using a pressure-pad treadmill and motion capture system, respectively. Multiple pairwise comparisons revealed that the compression tights with inward-directing lines significantly reduced foot rotation angles (up to an average of 20.1%) compared with the bicycle shorts (p = 0.002 and 0.001 for dominant and non-dominant foot, respectively) or the compression tights without taping lines (p = 0.005 and p = 0.001 for dominant and non-dominant foot, respectively). Statistical parametric mapping revealed significant main effects of the tight type on joint kinematics. Also, t-tests revealed that the participants reported significantly higher ratings of perceived functionality and usability on the compression tights with inward-directing taping lines. In conclusion, we developed a comfortable and practical apparel-type wearable and demonstrated its short-term efficacy in mitigating out-toeing gait.

Slow-motion smartphone video improves interobserver reliability of gait assessment in ambulatory cerebral palsy

Purpose

Structured visual gait assessment is essential for the evaluation of pediatric patients with neuromuscular conditions. The purpose of this study was to evaluate the benefit of slow-motion video recorded on a standard smartphone to augment visual gait assessment.

Methods

Coronal and sagittal plane videos of the gait of five pediatric subjects were recorded on a smartphone, including four subjects with ambulatory cerebral palsy and one subject without gait pathology. Twenty-one video scorers were recruited and randomized to evaluate slow-motion or normal-speed videos utilizing the Edinburgh Visual Gait Score. The slow-motion group (N = 11) evaluated the videos at one-eighth speed, and the normal-speed group (N = 10) evaluated the same videos at normal speed. Interrater reliabilities were determined by calculating intraclass correlation coefficients for each group as a whole, for each Edinburgh Visual Gait Score item, and after stratification by evaluator experience level.

Results

The slow-motion group exhibited an intraclass correlation coefficient of 0.65 (95% confidence interval: 0.58-0.73), whereas the normal-speed group exhibited an intraclass correlation coefficient of 0.57 (95% confidence interval: 0.49-0.65). For less-experienced scorers, intraclass correlation coefficients of 0.62 (95% confidence interval: 0.53-0.71) and 0.50 (95% confidence interval: 0.40-0.59) were calculated for slow motion and normal speed, respectively. For more-experienced scorers, intraclass correlation coefficients of 0.69 (95% confidence interval: 0.61-0.76) and 0.67 (95% confidence interval: 0.58-0.75) were calculated for slow motion and normal speed, respectively.

Conclusions

Visual gait assessment is enhanced by the use of slow-motion smartphone video, a tool widely available throughout the world with no marginal cost.

Level of evidence

level I, randomized study.

Measurement of Lag-Screw Anteversion With an iPhone During Trochanteric Fracture Surgery

Introduction  A useful way to easily evaluate femoral rotation during surgery for trochanteric fractures is not known. Hence, this pilot study aimed to develop an intraoperative indicator to evaluate anteversion in femoral trochanteric fractures. Material and methods Prospectively, from June 2021 to January 2022, all patients with femoral trochanteric fractures (Orthopaedic Trauma Association classification: 31A1-3) treated using a cephalo-medullary nail with a lag-screw neck-shaft angle of 125° were included in this study. During surgery, lag-screw anteversion (LS-AV) was measured using the goniometer application in an iPhone with the fractured femur table-top-plane level with the traction table floor. Accuracy was analyzed by comparing axial-projected lag-screw anteversion (AxP-LS-AV) and three-dimensional computed tomography lag-screw anteversion (3DCT-LS-AV) measurements after surgery. Results Fifty patients (14 males and 36 females) were included in the study. The mean age was 87 (range; 69-98) years; the Orthopaedic Trauma Association classifications were A1 (28 patients), A2 (18 patients), and A3 (4 patients). The mean LS-AV was 10.7° ± 6.9°, the mean AxP-LS-AV was 12.8° ± 8.3°, and the mean 3DCT-LS-AV was 13.1° ± 8.6°. The median difference between AxP-LS-AV and 3DCT-LS-AV was 3.0° (range: 0°-12°), and 40 (80%) patients had differences of ≤5° (Bland-Altman plot: inside of limit of agreement = 86%, paired t-test p = 0.7, Pearson correlation coefficient r = 0.817, p <0.001). Conclusion Femur malrotation is defined as a deformity of >15° relative to the normal contralateral limb. Intraoperative LS-AV iPhone measurement on table-top-plane standard had sufficient accuracy as an indicator of anteversion in femoral trochanteric fractures.

Femoral matched tibia component rotation has little effect on the tibial torsion after total knee arthroplasty

PURPOSE

Tibiofemoral synchronization technique matches the rotational alignment of the tibial component to the femoral component during the total knee arthroplasty (TKA). The rotational axis of the proximal tibia can be changed by this technique, which affects tibial torsion postoperatively. The purpose of this study was to investigate whether the tibiofemoral synchronization technique affect the tibial torsion, and the lower limb rotation after primary TKA. It was hypothesised that the tibial torsion would change after primary TKA.

METHODS

Ninety-three posterior stabilised TKAs from 89 patients were included from January 2017 to December 2018. Mechanical hip-knee-ankle axis (mHKA), in plain radiographs, femoral anteversion, tibial torsion, femoral neck-malleolar angle (FNMA), and rotational alignment of the femoral and the tibial components in pre- and postoperative CT scans were measured by two blinded observers. The primary outcome was a postoperative change in femoral anteversion, tibial torsion and FNMA. Clinical outcomes were evaluated using the American Knee Society Knee Score (AKSKS)/Function Score (AKSFS), and Oxford Knee Score (OKS) preoperatively and at 1 year after TKA. Patients' perception of changes in the foot progression angle after TKA was investigated. Statistical significance was set at p < 0.05.

RESULTS

The mean rotational mismatch between the femoral and the tibial component was 0.6 ± 3.2°. There was a significant decrease in femoral anteversion (9.5 ± 6.7° vs. 5.2 ± 6.6°, p < 0.001), and a significant increase in the FNMA (17.6 ± 9.7° vs. 21.8 ± 10.5°, p = 0.005) after TKA, while no significant change in tibia torsion was observed (25.4 ± 8.8° vs. 24.9 ± 9.3°, p = 0.739). AKSS (37.8 ± 15.1 vs. 92.8 ± 8.8, p < 0.001), AKSFS (53.9 ± 18.1 vs. 89.9 ± 5.3, p < 0.001), and OKS (18.0 ± 7.3 vs. 39.9 ± 4.8, p < 0.001) were significantly improved at 1 year after TKA. Ten knees (11%) had changes in tibial torsion greater than ± 10° postoperatively. Four of five patients who had changes in FNMA greater than 15° perceived the external rotation of the foot progression angle after TKA. All four patients had an increase in tibial torsion larger than 10°.

CONCLUSION

Our study shows that the tibiofemoral synchronization technique less likely affects the tibial torsion after primary TKA.

Putting it all Together: Evaluating Patellar Instability Risk Factors and Revisiting the "Menu"

Management of the patient with multiple risk factors for recurrent patellar instability is complex. Surgeons must possess familiarity with the anatomic risk factors that are associated with first time and recurrent instability events and weigh them in the patient's individualized surgical "menu" options for surgical patellar stabilization. Addressing individual risk factors, pairing imaging findings with physical examination, and thoughts on prioritizing risk factors to determine which should be prioritized for surgical correction are discussed.

Rotational Deformity-When and How to Address Femoral Anteversion and Tibial Torsion

Rotational deformity is a less common cause of patellar instability than trochlear dysplasia and patella alta. In some cases, rotational deformity is the primary bony factor producing the instability and should be corrected surgically. More research is needed on what are normal values for femoral version and tibial torsion, as well as when the axial plane alignment needs to be corrected. Many tools can be used to evaluate the axial plane and surgeons should be familiar with each of them. Understanding the advantages and disadvantages of each site for osteotomy will help the surgeon choose the most appropriate osteotomy.

Intraoperative Fluoroscopy for Correcting Rotational Malalignment After Fixation of Tibial Shaft Fracture: A Case Report

CASE

A 29-year-old man previously treated with closed reduction and intramedullary nail (IMN) fixation for a right tibial shaft fracture presented with complaint of the foot pointing outward compared with uninjured side. He was diagnosed with tibial malrotation, and a novel intraoperative imaging technique was used for correction.

CONCLUSION

Literature suggests that the prevalence of tibial malrotation after IMN fixation is greater than previously thought. This case highlights the need for a simple and reliable intraoperative approach to guide and confirm correction of tibial malrotation after IMN fixation, and it demonstrates a technique that can be implemented with immediate results.

Large Individual Bilateral Differences in Tibial Torsion Impact Accurate Contralateral Templating and the Evaluation of Rotational Malalignment

OBJECTIVE

To determine individual bilateral differences (IBDs) in tibial torsion in a diverse population.

METHODS

Computed tomography scans of uninjured bilateral tibiae were used to determine tibial torsion and IBDs in torsion using 4 measurement methods. Age, sex, and self-identified race/ethnicity were also recorded for each subject. Mean tibial torsion and IBDs in torsion were compared in the overall cohort and when stratified by sex and race/ethnicity. Simple and multiple linear regression models were used to correlate demographic variables with tibial torsion and IBDs in torsion.

RESULTS

One hundred ninety-five patients were evaluated. The mean tibial torsion was 27.5 ± 8.3 degrees (range -3 to 47.5 degrees). The mean IBD in torsion was 5.3 ± 4.0 degrees (range 0-23.5 degrees, P < 0.001). 12.3% of patients had IBDs in torsion of ≥10 degrees. In the regression analysis, patients who identified as White had greater average torsion by 4.4 degrees compared with Hispanic/Latinx patients (P = 0.001), whereas age and sex were not significantly associated with absolute torsion. Demographics were not associated with significant differences in IBDs in torsion.

CONCLUSIONS

Tibial torsion varies considerably and individual side-to-side differences are common. Race/ethnicity was associated with differences in the magnitude of tibial torsion, but no factors were associated with bilateral differences in torsion. The results of this study may be clinically significant in the context of using the uninjured contralateral limb to help establish rotational alignment during medullary nail stabilization of diaphyseal tibia fractures. In addition, these findings should be considered in the evaluation of tibia rotational malalignment.

LEVEL OF EVIDENCE

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

Tibial Torsion and Patellofemoral Pain and Instability in the Adult Population: Current Concept Review

PURPOSE OF REVIEW

Tibial torsion is a recognized cause of patellofemoral pain and instability in the paediatric population; however, it is commonly overlooked in the adult population. The aim of this review article is to summarize the current best evidence on tibial torsion for the adult orthopaedic surgeon.

RECENT FINDINGS

The true incidence of tibial torsion in the adult population is unknown, with significant geographical variations making assessment very difficult. CT currently remains the gold standard for quantitatively assessing the level of tibial torsion and allows assessment of any associated femoral and knee joint rotational anomalies. Surgical correction should only be considered after completion of a course of physiotherapy aimed at addressing the associated proximal and gluteal weakness. Tibial torsion greater than 30° is used as the main indicator for tibial de-rotation osteotomy by the majority of authors. In patients with associated abnormal femoral rotation, current evidence would suggest that a single-level correction of the tibia (if considered to be a dominant deformity) is sufficient in the majority of cases. Proximal de-rotational osteotomy has been more commonly reported in the adult population and confers the advantage of allowing simultaneous correction of patella alta or excessive tubercle lateralization. Previous surgery prior to de-rotational osteotomy is common; however, in patients with persistent symptoms surgical correction still provides significant benefit. Tibial torsion persists into adulthood and can play a significant role in patellofemoral pathology. A high index of suspicion is required in order to identify torsion clinically. Surgical correction is effective for both pain and instability, but results are inferior in patients with very high pain levels pre-surgery and multiple previous surgeries.