Weight-bearing recommendations after operative fracture treatment—fact or fiction? Gait results with and feasibility of a dynamic, continuous pedobarography insole

Material Properties and Engineering Performance of Bone Fracture Plates Made from Plant Fiber Reinforced Composites: A Review

Bone fracture plates are usually made from titanium alloy or stainless steel, which are much stiffer than bone. However, overly stiff plates can restrict axial interfragmentary motion at the fracture leading to delayed callus formation and healing, as well as causing bone "stress shielding" under the plate leading to bone atrophy, bone resorption, and plate loosening. Consequently, there have been many prior efforts to develop nonmetallic bone fracture plates with customized material properties using synthetic fibers (e.g., aramid, carbon, glass) in polymer resin. Even so, plant fibers (e.g., flax, roselle, sisal) offer additional advantages over synthetic fibers, such as availability, biodegradability, less toxicity during processing, lower financial cost, and recyclability. As such, there is an emerging interest in using plant fibers alone, or combined with synthetic fibers, to reinforce polymers for various applications. Thus, this is the first review article on the material properties and engineering performance of innovative bone fracture plates made from composite materials reinforced by plant fibers alone or supplemented using synthetic fibers. This article presents material-level fiber properties (e.g., elastic modulus, ultimate strength), material-level plate properties (e.g., fatigue strength, impact toughness), and bone-plate engineering performance (e.g., overall stiffness, plate stress), as well as discussing general findings, study quality, and future work. This article may help engineers and surgeons to design, fabricate, analyze, and utilize novel bone fracture plates.

Biomechanical testing of a computationally optimized far cortical locking plate versus traditional implants for distal femur fracture repair

BACKGROUND

This study experimentally validated a computationally optimized screw number and screw distribution far cortical locking distal femur fracture plate and compared the results to traditional implants.

METHODS

24 artificial femurs were osteotomized with a 10 mm fracture gap 60 mm proximal to the intercondylar notch. Three fixation constructs were used. (i) Standard locking plates secured with three far cortical locking screws inserted according to a previously optimized distribution in the femur shaft (n = 8). (ii) Standard locking plates secured with four standard locking screws inserted in alternating plate holes in the femur shaft (n = 8). (iii) Retrograde intramedullary nail secured proximally with one anterior-posterior screw and distally with two oblique screws (n = 8). Axial hip forces (700 and 2800 N) were applied while measuring axial interfragmentary motion, shear interfragmentary motion, and overall stiffness.

FINDINGS

Experimental far cortical locking plate results compared well to published computational findings. Far cortical locking femurs contained the highest axial motion within the potential ideal range of 0.2-1 mm and a sheer-to-axial motion ratio < 1.6 at toe-touch weight-bearing (700 N). At full weight-bearing (2800 N), Standard locking-plated femurs had the only axial motion within 0.2-1 mm but had an excess shear-to-axial motion ratio. Nail-implanted femurs underperformed at both forces.

INTERPRETATION

For toe-touch weight-bearing, the far cortical locking construct provided optimal biomechanics to allow moderate motion, which has been suggested to encourage early callus formation. Conversely, at full weight-bearing, the standard locking construct offered the biomechanical advantage on fracture motion.

Partial weight-bearing following ankle fracture: what's the actual load in early recovery?

PURPOSE

This study investigates the learning efficacy for partial weight load before discharge as well as the impact of biofeedback during the learning process.

METHODS

We monitored weight-bearing in 57 patients who had surgery for ankle fractures. Continuous measurements without and with biofeedback were performed in the early postoperative stage in order to, first, assess how well these patients could apply what they have learned before being discharged, and second, to examine the influence of biofeedback.

RESULTS

Using conventional teaching methods, only about one-third of patients (36.8% on the ground and 29.2% on the stairs) were able to maintain a satisfactory load. One-fourth of the patients did not place any weight on their leg, which was shown to be due to excessive pain at the time of the measurement (p < 0.05). A further one-fourth loaded inadequately low, while the remainder loaded excessively. Patients benefited significantly from the activation of audio-visual biofeedback in real time. As a result, loads in a target zone between 15 and 30 kg could be significantly increased (p < 0.05).

CONCLUSION

We conclude that the majority of ankle fracture patients were unable to learn partial weight bearing in the early postoperative stage using traditional techniques. Additionally, each patient's ability to carry out a given loading varied. Using an audio-visual real-time biofeedback modality led to significantly improved performance. These findings support the proposed utility of audiovisual feedback in early rehabilitation. With the use of outpatient real-time biofeedback systems, therapists will be able to respond specifically to the needs of each individual patient.

TRIAL REGISTRATION

Trial registration: DRKS00031136, Registered 01.02.2023 - Retrospectively registered, https://www.drks.de/DRKS00031136.

Characteristic Changes of the Stance-Phase Plantar Pressure Curve When Walking Uphill and Downhill: Cross-Sectional Study

BACKGROUND

Monitoring of gait patterns by insoles is popular to study behavior and activity in the daily life of people and throughout the rehabilitation process of patients. Live data analyses may improve personalized prevention and treatment regimens, as well as rehabilitation. The M-shaped plantar pressure curve during the stance phase is mainly defined by the loading and unloading slope, 2 maxima, 1 minimum, as well as the force during defined periods. When monitoring gait continuously, walking uphill or downhill could affect this curve in characteristic ways.

OBJECTIVE

For walking on a slope, typical changes in the stance phase curve measured by insoles were hypothesized.

METHODS

In total, 40 healthy participants of both sexes were fitted with individually calibrated insoles with 16 pressure sensors each and a recording frequency of 100 Hz. Participants walked on a treadmill at 4 km/h for 1 minute in each of the following slopes: -20%, -15%, -10%, -5%, 0%, 5%, 10%, 15%, and 20%. Raw data were exported for analyses. A custom-developed data platform was used for data processing and parameter calculation, including step detection, data transformation, and normalization for time by natural cubic spline interpolation and force (proportion of body weight). To identify the time-axis positions of the desired maxima and minimum among the available extremum candidates in each step, a Gaussian filter was applied (σ=3, kernel size 7). Inconclusive extremum candidates were further processed by screening for time plausibility, maximum or minimum pool filtering, and monotony. Several parameters that describe the curve trajectory were computed for each step. The normal distribution of data was tested by the Kolmogorov-Smirnov and Shapiro-Wilk tests.

RESULTS

Data were normally distributed. An analysis of variance with the gait parameters as dependent and slope as independent variables revealed significant changes related to the slope for the following parameters of the stance phase curve: the mean force during loading and unloading, the 2 maxima and the minimum, as well as the loading and unloading slope (all P<.001). A simultaneous increase in the loading slope, the first maximum and the mean loading force combined with a decrease in the mean unloading force, the second maximum, and the unloading slope is characteristic for downhill walking. The opposite represents uphill walking. The minimum had its peak at horizontal walking and values dropped when walking uphill and downhill alike. It is therefore not a suitable parameter to distinguish between uphill and downhill walking.

CONCLUSIONS

While patient-related factors, such as anthropometrics, injury, or disease shape the stance phase curve on a longer-term scale, walking on slopes leads to temporary and characteristic short-term changes in the curve trajectory.

Long-term continuous instrumented insole-based gait analyses in daily life have advantages over longitudinal gait analyses in the lab to monitor healing of tibial fractures

Introduction: Monitoring changes in gait during rehabilitation allows early detection of complications. Laboratory-based gait analyses proved valuable for longitudinal monitoring of lower leg fracture healing. However, continuous gait data recorded in the daily life may be superior due to a higher temporal resolution and differences in behavior. In this study, ground reaction force-based gait data of instrumented insoles from longitudinal intermittent laboratory assessments were compared to monitoring in daily life. Methods: Straight walking data of patients were collected during clinical visits and in between those visits the instrumented insoles recorded all stepping activities of the patients during daily life. Results: Out of 16 patients, due to technical and compliance issues, only six delivered sufficient datasets of about 12 weeks. Stance duration was longer (p = 0.004) and gait was more asymmetric during daily life (asymmetry of maximal force p < 0.001, loading slope p = 0.001, unloading slope p < 0.001, stance duration p < 0.001). Discussion: The differences between the laboratory assessments and the daily-life monitoring could be caused by a different and more diverse behavior during daily life. The daily life gait parameters significantly improved over time with union. One of the patients developed an infected non-union and showed worsening of force-related gait parameters, which was earlier detectable in the continuous daily life gait data compared to the lab data. Therefore, continuous gait monitoring in the daily life has potential to detect healing problems early on. Continuous monitoring with instrumented insoles has advantages once technical and compliance problems are solved.

The Fundamentals and Applications of Wearable Sensor Devices in Sports Medicine: A Scoping Review

PURPOSE

To (1) characterize the various forms of wearable sensor devices (WSDs) and (2) review the peer-reviewed literature of applied wearable technology within sports medicine.

METHODS

A systematic search of PubMed and EMBASE databases, from inception through 2023, was conducted to identify eligible studies using WSDs within sports medicine. Data extraction was performed of study demographics and sensor specifications. Included studies were categorized by application: athletic training, rehabilitation, and research.

RESULTS

In total, 43 studies met criteria for inclusion in this review. Forms of WSDs include pedometers, accelerometers, encoders (consisting of magnetometers and gyroscopes), force sensors, global positioning system trackers, and inertial measurement units. Outcome metrics include step counts; gait, limb motion, and angular positioning; foot and skin pressure; change of direction and inclination, including analysis of both body parts and athletes on a field; displacement and velocity of body segments and joints; heart rate; plethysmography; sport-specific kinematics; range of motion, symmetry, and alignment; head impact; sleep; throwing biomechanics; and kinetic and spatiotemporal running metrics. WSDs are used in athletic training to assess sport-specific biomechanics and workload with a goal of injury prevention and training optimization, as well as for rehabilitation monitoring and research such as for risk predicting and aiding diagnosis.

CONCLUSIONS

WSDs enable real-time monitoring of human performance across a variety of implementations and settings, allowing collection of metrics otherwise not achievable. WSDs are powerful tools with multiple applications within athletic training, patient rehabilitation, and orthopaedic and sports medicine research.

CLINICAL RELEVANCE

Wearable technology may represent the missing link to quantitatively addressing return to play and previous performance. WSDs are commercially available and portable adjuncts that allow clinicians, trainers, and individual athletes to monitor biomechanical parameters, workload, and recovery status to better contextualize personalized training, injury risk, and rehabilitation.

Does Far Cortical Locking Improve Fracture Healing in Distal Femur Fractures: A Randomised, Controlled, Prospective Multicentre Study

(1) Background: Bone healing is influenced by various mechanical factors, such as stability, interfragmentary motion, strain rate, and direction of loading. Far cortical locking (FCL) is a novel screw design that promotes bone healing through controlled fracture motion. (2) Methods: This study compared the outcome of distal femur fractures treated with FCL or SL (standard locking) screws and an NCB plate in a randomised controlled prospective multicentre trial. The radiographic union scale (RUST) and healing time was used to quantify bone healing on follow-up imaging. (3) Results: The study included 21 patients with distal femur fractures, 7 treated with SL and 14 treated with FCL screws. The mean working length for patients with SL screws was 6.1, whereas for FCL screws, it was 3.9. The mean RUST score at 6 months post fracture was 8.0 for patients with SL plates and 7.3 for patients with FCL plates (p value > 0.05). The mean healing time was 6.5 months for patients with SL plates and 9.9 months for patients with FCL plates (p value < 0.05). (4) Conclusions: Fractures fixed with SL plates had longer working lengths and faster healing times when compared to FCL constructs, suggesting that an adequate working length is important for fracture healing regardless of screw choice.

Assessing lower extremity loading during activities of daily living using continuous-scale physical functional performance 10 and wireless sensor insoles: a comparative study between younger and older adults

PURPOSE

This study aims to investigate the lower extremity loading during activities of daily living (ADLs) using the Continuous Scale of Physical Functional Performance (CS-PFP 10) test and wireless sensor insoles in healthy volunteers.

METHODS

In this study, 42 participants were recruited, consisting of 21 healthy older adults (mean age 69.6 ± 4.6 years) and 21 younger healthy adults (mean age 23.6 ± 1.8 years). The performance of the subjects during ADLs was assessed using the CS-PFP 10 test, which comprised 10 tasks. The lower extremity loading was measured using wireless sensor insoles (OpenGo, Moticon, Munich, Germany) during the CS-PFP 10 test, which enabled the measurement of ground reaction forces, including the mean and maximum total forces during the stance phase, expressed in units of body weight (BW).

RESULTS

The total CS-PFP 10 score was significantly lower in older participants compared to the younger group (mean total score of 57.1 ± 9.0 compared to 78.2 ± 5.4, respectively). No significant differences in the mean total forces were found between older and young participants. The highest maximum total forces were observed during the tasks 'endurance walk' (young: 1.97 ± 0.34 BW, old: 1.70 ± 0.43 BW) and 'climbing stairs' (young: 1.65 ± 0.36 BW, old: 1.52 ± 0.28 BW). Only in the endurance walk, older participants showed a significantly higher maximum total force (p < 0.001).

CONCLUSION

The use of wireless sensor insoles in a laboratory setting can effectively measure the load on the lower extremities during ADLs. These findings could offer valuable insights for developing tailored recommendations for patients with partial weight-bearing restrictions.

Weight-bearing Restrictions after Distal Femur Fractures - Review of Current Literature

The incidence of distal femur fractures increases in the geriatric patient. The primary treatment goal in these fractures is early mobilisation to prevent secondary injuries associated with immobility. In light of the increasing spectrum of therapeutic options for postoperative fracture treatment, including double plating, nail-plate combination and distal femur replacement as postoperative treatments, weight-bearing recommendations are becoming increasingly important. The aim of this study was thus to analyse the weight-bearing recommendations and associated therapy results within the literature of the past 9 years and compare the recommendations to our own approach.

Temporary Partial Weight-Bearing Restriction in Elderly Patients Treated With a Plate Fixation After a Distal Femur Fracture had a Negative Long-Term Impact on Gait Recovery

Background

Restricted weight-bearing is still used after lower extremity fracture surgery in elderly patients. The long-term effect on gait recovery in elderly patients with distal femur fractures (DFF) and their ability to comply with the restrictive weight-bearing regime is unknown. This study aimed to investigate the effect of restricted postoperative weight-bearing on gait recovery (actual weight-bearing and cadence) during a 1-year follow-up.

Methods

This study evaluated secondary outcomes from a randomized controlled trial (32 patients ≥65 years, with a traumatic DFF). Internal fixation was achieved using an anatomical lateral plate. Patients were allocated to either immediate full weight-bearing (FWB) or partial weight-bearing (PWB) (30% of body weight) for 8 weeks. Pressure-sensitive sensors (F-scan™ system, Tekscan, Massachusetts, USA) were used to measure weight-bearing and cadence postoperatively and at 8-, 16-, and 52-week follow-ups. Twenty-six patients with at least 1 measurement were included.

Results

There was a statistically significant difference in actual weight-bearing between the PWB and FWB groups postoperatively of 32.3% (95% confidence interval CI, -50.0; -13.0, P < .001) and at the 8-week follow-up of 36.8% (95% CI -61.0; -18.0, P = .01), but not at later follow-ups. The PWB group presented a consistently lower cadence compared to the FWB group, which was statistically significant at the 16-week follow-up with 9.0 steps/min (95% CI -16.2; -1.1, P = .047) and 52-week follow-up with 9.3 steps/min (95% CI -18.0; -3.9, P = .009).

Conclusions

Restricting postoperative weight-bearing in elderly patients with a DFF had a significant effect on postoperative weight-bearing. The effect lingered with a delayed return to FWB and persistent significantly lower cadence in the PWB group. These findings suggest that even temporary weight-bearing restrictions most likely have negative long-term effects on gait function at 1 year and, therefore, cannot be recommended.

Factors Associated With Long-Term Quadriceps Muscle Function After Surgical Fixation of Lower Extremity Fractures

OBJECTIVE

The long-term performance of the quadriceps femoris muscle and physical function following surgical repair of a lower extremity fracture remains largely undefined. The purpose of this study was to investigate between-limb differences in quadriceps performance 12 months after surgical fixation of a lower extremity fracture. It was hypothesized that the injured limb would be significantly weaker, have a lower rate of torque development (RTD), and that there would be a reduced step-down performance compared to the uninjured limb 12 months after surgery. Additionally, this study sought to identify demographic, surgical, and psychological factors associated with poor quadriceps function 12 months after surgery.

METHODS

Quadriceps performance was measured bilaterally in 95 participants (49 female), aged 42 (SD = 14.5) years, 12 months after surgical fixation of a lower extremity fracture. Isometric quadriceps strength and RTD were quantified using isometric dynamometry, and a timed step-down test was used to evaluate quadriceps performance. Independent predictor variables from the time of surgery were extracted from participants' medical records. Kinesiophobia was screened at the time of testing. Wilcoxon signed-rank tests and linear regression analyses were used to assess between-limb differences in quadriceps performance and to determine factors associated with quadriceps performance 12 months after surgery.

RESULTS

Significant between-limb differences in each measure of quadriceps performance were identified (peak torque involved: 1.37 [0.71] Nm × kg-1; uninvolved: 1.87 [0.74] Nm × kg-1; RTD involved: 4.16 [2.75] Nm × kg-1 × s-1; uninvolved: 6.10 [3.02] Nm × kg-1 × × -1; and single-leg step-downs involved: 12.6 [5.0]; uninvolved: 21.7 [14.8]). Female biological sex, external fixation, and kinesiophobia at 12 months were associated with reduced after-surgery quadriceps performance outcomes.

CONCLUSION

Quadriceps performance is impaired 12 months after surgical repair of a lower extremity fracture, particularly in female participants, in cases requiring external fixation, and in those with higher kinesiophobia 12 months after surgery.

IMPACT

Because long-term quadriceps weakness negatively impacts functional mobility, targeted strengthening should be emphasized after surgical repair of lower extremity fracture.

Influence of Weight Bearing on Postoperative Complications after Surgical Treatment of the Lower Extremity

PURPOSE

In order to prevent implant failure and secondary fracture dislocation, it is often recommended that patients perform partial weight-bearing after surgery of the lower extremity. Previous examinations showed that patients are often not able to follow these instructions. In this study, patients who had undergone surgery of the lower extremity were studied in order to analyze whether incorrect loading influenced the number and severity of complications.

METHODS

Fifty-one patients were equipped with electronic shoe insoles, which measure loading and other parameters. The measurement period was 24 to 102 hours. Median duration of follow-up was 490 days. The primary outcome parameter was postoperative complications leading to revision surgery. Statistical analysis was performed using the chi-square and Fisher exact tests with significance set at a p < 0.05.

RESULTS

Seven out of fifty-one patients had postoperative complications. Four wound complications, one implant failure, chronic instability after fracture of the tibia, and one implant loosening of a hip prosthesis were recorded. In total, 26 of 39 patients were not able to follow the postoperative instructions. Five of the twenty-six patients with difficulties in partial weight-bearing suffered a postoperative complication. In comparison, only 2 of the other 25 patients were affected. There was no statistically significant correlation between high weight-bearing and occurrence of complications (p = 0.29).

CONCLUSION

Most of the patients were unable to follow the surgeon's instructions for partial weight-bearing. Excessive loading did not seem to influence the number and severity of postoperative complications, especially regarding implant failure. Therefore, we should continue with measurements and reevaluate the "partial weight-bearing doctrine".

Continuous real-time biofeedback in orthosis improves partial weight bearing on stairs

INTRODUCTION

Climbing up and down stairs with crutches is a particular challenge. The current study evaluates a commercially available insole orthosis device for weighing an affected limb and for biofeedback training of gait. This study was done on healthy, asymptomatic individuals before applying to the intended postoperative patient. The outcomes should demonstrate whether a continuous real-time biofeedback (BF) system is more effective on stairs than the current protocol involving a bathroom scale.

MATERIALS AND METHODS

59 healthy test subjects received both crutches and an orthosis and learned to apply a 3-point gait with a partial load of 20 kg using a bathroom scale. Thereafter, the participants were asked to complete an up-and-down course, first without (control group) and then with (test group) an audio-visual real-time biofeedback (BF). Compliance was evaluated using an insole pressure measurement system.

RESULTS

Using the conventional therapy technique, 36.6% of the steps up and 39.1% of the steps down in the control group were loaded with < 20 kg. By activating continuous biofeedback, steps with < 20 kg could be increased significantly to 61.1% upstairs (p < 0.001) and 66.1% downstairs (p < 0.001). All subgroups profited from the BF system, independent of age, gender, side relieved, dominant or non-dominant side.

CONCLUSIONS

Traditional training without biofeedback led to poor performance for partial weight bearing on stairs, even among young and healthy individuals. However, continuous real-time biofeedback clearly improved compliance, indicating its potential to enhance training and support future research in patient populations.

Commercially available pressure sensors for sport and health applications: A comparative review

Pressure measurement systems have numerous applications in healthcare and sport. The purpose of this review is to: (a) describe the brief history of the development of pressure sensors for clinical and sport applications, (b) discuss the design requirements for pressure measurement systems for different applications, (c) critique the suitability, reliability, and validity of commercial pressure measurement systems, and (d) suggest future directions for the development of pressure measurements systems in this area. Commercial pressure measurement systems generally use capacitive or resistive sensors, and typically capacitive sensors have been reported to be more valid and reliable than resistive sensors for prolonged use. It is important to acknowledge, however, that the selection of sensors is contingent upon the specific application requirements. Recent improvements in sensor and wireless technology and computational power have resulted in systems that have higher sensor density and sampling frequency with improved usability - thinner, lighter platforms, some of which are wireless, and reduced the obtrusiveness of in-shoe systems due to wireless data transmission and smaller data-logger and control units. Future developments of pressure sensors should focus on the design of systems that can measure or accurately predict shear stresses in conjunction with pressure, as it is thought the combination of both contributes to the development of pressure ulcers and diabetic plantar ulcers. The focus for the development of in-shoe pressure measurement systems is to minimise any potential interference to the patient or athlete, and to reduce power consumption of the wireless systems to improve the battery life, so these systems can be used to monitor daily activity. A potential solution to reduce the obtrusiveness of in-shoe systems include thin flexible pressure sensors which can be incorporated into socks. Although some experimental systems are available further work is needed to improve their validity and reliability.

A Wearable Biofeedback Device for Monitoring Tibial Load During Partial Weight-Bearing Walking

Patients with tibial fractures are usually advised to follow a partial weight-bearing gait rehabilitation program after surgery to promote bone healing and lower limb functional recovery. Currently, the biofeedback devices used for gait rehabilitation training in fracture patients use ground reaction force (GRF) as the indicator of tibial load. However, an increasing body of research has shown that monitoring GRF alone cannot objectively reflect the load on the lower limb bones during human movement. In this study, a novel biofeedback system was developed utilizing inertial measurement units and custom instrumented insoles. Based on the data collected from experiments, a hybrid approach combining a physics-based model and neural network architectures was used to predict tibial force. Compared to the traditional physics-based algorithm, the physical guided neural networks method showed better predictive performance. The study also found that regardless of the type of weight-bearing walking, the peak tibial force was significantly higher than the peak tibial GRF, and the time at which the peak tibial compression force occurs may not be consistent with the time at which the peak vertical GRF occurs. This further supports the idea that during gait rehabilitation training for patients with tibial fractures, monitoring and providing feedback on the actual tibial force rather than just the GRF is necessary. The developed device is a non-invasive and reliable portable device that can provide audio feedback, providing a viable solution for gait rehabilitation training outside laboratory and helping to optimize patients' rehabilitation treatment strategies.

Recommendations for physiotherapy and physical activity for children with Legg-Calvé-Perthes disease: a survey of pediatric orthopedic surgeons and physiotherapists in Sweden

BACKGROUND AND PURPOSE

Physiotherapy, restrictions of physical activity, and weightbearing are part of the treatment of children with Legg-Calvé-Perthes disease (LCPD). Prescription practices are widely discussed and vary between pediatric orthopedic surgeons (POSs) and physiotherapists (PTs). The purpose of this study was to identify recommendations for treatment methods in clinical practice to find some consensus and elaborate guidelines.

PATIENTS AND METHODS

A web-based questionnaire including 3 cases of LCPD (initial, fragmentation, and reossification stages) was answered by 25 POSs and 19 PTs. They were asked to describe their preferred recommendations for physiotherapy, including stretching, strengthening, weightbearing, and physical activities in relation to, e.g., range of motion (ROM) pain, sex, and disease stage.

RESULTS

ROM was considered to be important when recommending physiotherapy; PTs also recognized pain and disease stage. Sex was reported as a factor with low importance. Stretching exercises were recommended for all disease stages. Recommendations for strengthening exercises varied for the initial and fragmentation stages. None of the participants recommended total non-weightbearing. Most restricted trampolining, running, ball sports, and gymnastics in the first 2 stages of the disease and allowed swimming, short walks, cycling, and horse riding without restrictions for all stages.

CONCLUSION

We found high agreement on recommending stretching exercises for all disease stages, but controversies regarding recommendations for strengthening exercises in the initial and fragmentation stages. No non-weightbearing treatment for the affected hip was recommended by any participants at any stage of the disease. There was no clear consensus regarding the appropriate timeline for resuming full activities.

Biomechanical design optimization of distal femur locked plates: A review

Clinical findings, manufacturer instructions, and surgeon's preferences often dictate the implantation of distal femur locked plates (DFLPs), but healing problems and implant failures still persist. Also, most biomechanical researchers compare a particular DFLP configuration to implants like plates and nails. However, this begs the question: Is this specific DFLP configuration biomechanically optimal to encourage early callus formation, reduce bone and implant failure, and minimize bone "stress shielding"? Consequently, it is crucial to optimize, or characterize, the biomechanical performance (stiffness, strength, fracture micro-motion, bone stress, plate stress) of DFLPs influenced by plate variables (geometry, position, material) and screw variables (distribution, size, number, angle, material). Thus, this article reviews 20 years of biomechanical design optimization studies on DFLPs. As such, Google Scholar and PubMed websites were searched for articles in English published since 2000 using the terms "distal femur plates" or "supracondylar femur plates" plus "biomechanics/biomechanical" and "locked/locking," followed by searching article reference lists. Key numerical outcomes and common trends were identified, such as: (a) plate cross-sectional area moment of inertia can be enlarged to lower plate stress at the fracture; (b) plate material has a larger influence on plate stress than plate thickness, buttress screws, and inserts for empty plate holes; (c) screw distribution has a major influence on fracture micro-motion, etc. Recommendations for future work and clinical implications are then provided, such as: (a) simultaneously optimizing fracture micro-motion for early healing, reducing bone and implant stresses to prevent re-injury, lowering "stress shielding" to avoid bone resorption, and ensuring adequate fatigue life; (b) examining alternate non-metallic materials for plates and screws; (c) assessing the influence of condylar screw number, distribution, and angulation, etc. This information can benefit biomedical engineers in designing or evaluating DFLPs, as well as orthopedic surgeons in choosing the best DFLPs for their patients.

Computer-Based Mechanobiological Fracture Healing Model Predicts Non-Union of Surgically Treated Diaphyseal Femur Fractures

As non-unions are still common, a predictive assessment of healing complications could enable immediate intervention before negative impacts for the patient occur. The aim of this pilot study was to predict consolidation with the help of a numerical simulation model. A total of 32 simulations of patients with closed diaphyseal femoral shaft fractures treated by intramedullary nailing (PFNA long, FRN, LFN, and DePuy Synthes) were performed by creating 3D volume models based on biplanar postoperative radiographs. An established fracture healing model, which describes the changes in tissue distribution at the fracture site, was used to predict the individual healing process based on the surgical treatment performed and full weight bearing. The assumed consolidation as well as the bridging dates were retrospectively correlated with the clinical and radiological healing processes. The simulation correctly predicted 23 uncomplicated healing fractures. Three patients showed healing potential according to the simulation, but clinically turned out to be non-unions. Four out of six non-unions were correctly detected as non-unions by the simulation, and two simulations were wrongfully diagnosed as non-unions. Further adjustments of the simulation algorithm for human fracture healing and a larger cohort are necessary. However, these first results show a promising approach towards an individualized prognosis of fracture healing based on biomechanical factors.

Early postoperative step count and walking time have greater impact on lower limb fracture outcomes than load-bearing metrics

INTRODUCTION

Weight-bearing protocols for rehabilitation of lower extremity fractures are the gold standard despite not being data-driven. Additionally, current protocols are focused on the amount of weight placed on the limb, negating other patient rehabilitation behaviors that may contribute to outcomes. Wearable sensors can provide insight into multiple aspects of patient behavior through longitudinal monitoring. This study aimed to understand the relationship between patient behavior and rehabilitation outcomes using wearable sensors to identify the metrics of patient rehabilitation behavior that have a positive effect on 1-year rehabilitation outcomes.

METHODS

Prospective observational study on 42 closed ankle and tibial fracture patients. Rehabilitation behavior was monitored continuously between 2 and 6 weeks post-operative using a gait monitoring insole. Metrics describing patient rehabilitation behavior, including step count, walking time, cadence, and body weight per step, were compared between patient groups of excellent and average rehabilitation outcomes, as defined by the 1-year Patient Reported Outcome Measure Physical Function t-score (PROMIS PF). A Fuzzy Inference System (FIS) was used to rank metrics based on their impact on patient outcomes. Additionally, correlation coefficients were calculated between patient characteristics and principal components of the behavior metrics.

RESULTS

Twenty-two patients had complete insole data sets, and 17 of which had 1-year PROMIS PF scores (33.7 ± 14.5 years of age, 13 female, 9 in Excellent group, 8 in Average group). Step count had the highest impact ranking (0.817), while body weight per step had a low impact ranking (0.309). No significant correlation coefficients were found between patient or injury characteristics and behavior principal components. General patient rehabilitation behavior was described through cadence (mean of 71.0 steps/min) and step count (logarithmic distribution with only ten days exceeding 5,000 steps/day).

CONCLUSION

Step count and walking time had a greater impact on 1-year outcomes than body weight per step or cadence. The results suggest that increased activity may improve 1-year outcomes for patients with lower extremity fractures. The use of more accessible devices, such as smart watches with step counters combined with patient reported outcome measures may provide more valuable insights into patient rehabilitation behaviors and their effect on rehabilitation outcomes.

"Bring Your Own Device"-A New Approach to Wearable Outcome Assessment in Trauma

Background and Objectives: Outcome data from wearable devices are increasingly used in both research and clinics. Traditionally, a dedicated device is chosen for a given study or clinical application to collect outcome data as soon as the patient is included in a study or undergoes a procedure. The current study introduces a new measurement strategy, whereby patients' own devices are utilized, allowing for both a pre-injury baseline measure and ability to show achievable results. Materials and Methods: Patients with a pre-existing musculoskeletal injury of the upper and lower extremity were included in this exploratory, proof-of-concept study. They were followed up for a minimum of 6 weeks after injury, and their wearable outcome data (from a smartphone and/or a body-worn sensor) were continuously acquired during this period. A descriptive analysis of the screening characteristics and the observed and achievable outcome patterns was performed. Results: A total of 432 patients was continuously screened for the study, and their screening was analyzed. The highest success rate for successful inclusion was in younger patients. Forty-eight patients were included in the analysis. The most prevalent outcome was step count. Three distinctive activity data patterns were observed: patients recovering, patients with slow or no recovery, and patients needing additional measures to determine treatment outcomes. Conclusions: Measuring outcomes in trauma patients with the Bring Your Own Device (BYOD) strategy is feasible. With this approach, patients were able to provide continuous activity data without any dedicated equipment given to them. The measurement technique is especially suited to particular patient groups. Our study's screening log and inclusion characteristics can help inform future studies wishing to employ the BYOD design.

Gait Analysis to Monitor Fracture Healing of the Lower Leg

Fracture healing is typically monitored by infrequent radiographs. Radiographs come at the cost of radiation exposure and reflect fracture healing with a time lag due to delayed fracture mineralization following increases in stiffness. Since union problems frequently occur after fractures, better and timelier methods to monitor the healing process are required. In this review, we provide an overview of the changes in gait parameters following lower leg fractures to investigate whether gait analysis can be used to monitor fracture healing. Studies assessing gait after lower leg fractures that were treated either surgically or conservatively were included. Spatiotemporal gait parameters, kinematics, kinetics, and pedography showed improvements in the gait pattern throughout the healing process of lower leg fractures. Especially gait speed and asymmetry measures have a high potential to monitor fracture healing. Pedographic measurements showed differences in gait between patients with and without union. No literature was available for other gait measures, but it is expected that further parameters reflect progress in bone healing. In conclusion, gait analysis seems to be a valuable tool for monitoring the healing process and predicting the occurrence of non-union of lower leg fractures.

DOES THE APPLICATION OF CONVERSION FRACTURE-TREATMENT METHOD AND THE TECHNOLOGY OF TELEMEDICAL MOVEMENT MONITORING AFFECT THE LONG-TERM RESULTS OF THE TREATMENT OF VICTIMS WITH MULTIPLE GUNSHOT LONG BONES FRACTURES?

OBJECTIVE

The aim: To improve the results of treatment of patients with multiple gunshot fractures of long bones by developing the technology of fixation method conversion with combined autoplasty and postoperative telemedical control (loading +ROM (range of motion).

PATIENTS AND METHODS

Materials and methods: Two comparison groups were formed: the main (84 patients) and the control (62 patients). For the patients of this group all elements of the restorative treatment system were used (DCO, extrafocal osteosynthesis (including hinged), ultrasonic cavitation, NPWT, biochemical indicators of blood, conversion technology with usage of regenerative technologies, rehabilitation program) and telemedical control with applications (ROM+weight bearing). The control group (62 patients) - patients who received almost the same treatment, but only autoplasty with cancellous bone was included for bone plastics an telemedical counseling were not used.

RESULTS

Results: 1 year after the final method of fixation, it was established that the relative indicators were also lower in the patients of the main group, and a statistically significant difference was found in the indicator of the frequency of contracture formation, which may indicate the timely establishment of low dynamics in increasing the amplitude of movements and appropriate response (redress, arthrolysis, tenolysis).

CONCLUSION

Conclusions: Implementation of telemedicine and combined plastic surgery of bone defects in the restorative treatment system reduce the frequency of major complications that affect the objective result, affect better physical and mental health indicators during the observation period of 12 months.

Comparison of Percutaneous Screw Fixation to Open Reduction and Internal Fixation in Acetabular Fractures: A Matched Pair Study Regarding the Short-Term Rate of Conversion to Total Hip Arthroplasty and Functional Outcomes

Closed reduction and percutaneous internal fixation (CRPIF) for acetabular fractures was introduced as a less invasive alternative to open reduction and internal fixation (ORIF) for moderately displaced fractures. Currently, comparisons of ORIF and CRPIF outcomes are rare. Twenty-three patients treated with CRPIF were matched with patients treated with ORIF based on sex, age, and fracture classification. Surgery-dependent and -independent factors of the in-hospital stay, the conversion rate to total hip arthroplasty (THA), and quality of life were assessed. The ORIF group had a higher preoperative fracture step (p = 0.04) and gull wing sign (p = 0.003) compared with the CRPIF group. Postoperatively, the gap and step size were not significantly different between the groups (p > 0.05). CRPIF required less time (p < 0.0001) and transfusions (p = 0.009) and showed fewer complications (p = 0.0287). Four patients were converted to THA (CRPIF, n = 1; ORIF, n = 3; p = 0.155) because of posttraumatic osteoarthritis. Functional outcomes and pain were similar in both groups (p > 0.05). The present study revealed less blood loss and a lesser extent of reduction in patients treated with CRPIF than in those treated with ORIF. The rates of conversion to THA and functional outcomes did not differ between CRPIF and ORIF. CRPIF appeared to be a valuable treatment option for selected patients.

The decisive early phase of bone regeneration

Bone has a remarkable endogenous regenerative capacity that enables scarless healing and restoration of its prior mechanical function, even under challenging conditions such as advanced age and metabolic or immunological degenerative diseases. However - despite much progress - a high number of bone injuries still heal with unsatisfactory outcomes. The mechanisms leading to impaired healing are heterogeneous, and involve exuberant and non-resolving immune reactions or overstrained mechanical conditions that affect the delicate regulation of the early initiation of scar-free healing. Every healing process begins phylogenetically with an inflammatory reaction, but its spatial and temporal intensity must be tightly controlled. Dysregulation of this inflammatory cascade directly affects the subsequent healing phases and hinders the healing progression. This Review discusses the complex processes underlying bone regeneration, focusing on the early healing phase and its highly dynamic environment, where vibrant changes in cellular and tissue composition alter the mechanical environment and thus affect the signalling pathways that orchestrate the healing process. Essential to scar-free healing is the interplay of various dynamic cascades that control timely resolution of local inflammation and tissue self-organization, while also providing sufficient local stability to initiate endogenous restoration. Various immunotherapy and mechanobiology-based therapy options are under investigation for promoting bone regeneration.

Simulation-based prediction of bone healing and treatment recommendations for lower leg fractures: Effects of motion, weight-bearing and fibular mechanics

Despite recent experimental and clinical progress in the treatment of tibial and fibular fractures, in clinical practice rates of delayed bone healing and non-union remain high. The aim of this study was to simulate and compare different mechanical conditions after lower leg fractures to assess the effects of postoperative motion, weight-bearing restrictions and fibular mechanics on the strain distribution and the clinical course. Based on the computed tomography (CT) data set of a real clinical case with a distal diaphyseal tibial fracture, a proximal and a distal fibular fracture, finite element simulations were run. Early postoperative motion data, recorded via an inertial measuring unit system and pressure insoles were recorded and processed to study strain. The simulations were used to compute interfragmentary strain and the von Mises stress distribution of the intramedullary nail for different treatments of the fibula, as well as several walking velocities (1.0 km/h; 1.5 km/h; 2.0 km/h) and levels of weight-bearing restriction. The simulation of the real treatment was compared to the clinical course. The results show that a high postoperative walking speed was associated with higher loads in the fracture zone. In addition, a larger number of areas in the fracture gap with forces that exceeded beneficial mechanical properties longer was observed. Moreover, the simulations showed that surgical treatment of the distal fibular fracture had an impact on the healing course, whereas the proximal fibular fracture barely mattered. Weight-bearing restrictions were beneficial in reducing excessive mechanical conditions, while it is known that it is difficult for patients to adhere to partial weight-bearing recommendations. In conclusion, it is likely that motion, weight bearing and fibular mechanics influence the biomechanical milieu in the fracture gap. Simulations may improve decisions on the choice and location of surgical implants, as well as give recommendations for loading in the postoperative course of the individual patient.

Effects of age, body height, body weight, body mass index and handgrip strength on the trajectory of the plantar pressure stance-phase curve of the gait cycle

The analysis of gait patterns and plantar pressure distributions via insoles is increasingly used to monitor patients and treatment progress, such as recovery after surgeries. Despite the popularity of pedography, also known as baropodography, characteristic effects of anthropometric and other individual parameters on the trajectory of the stance phase curve of the gait cycle have not been previously reported. We hypothesized characteristic changes of age, body height, body weight, body mass index and handgrip strength on the plantar pressure curve trajectory during gait in healthy participants. Thirty-seven healthy women and men with an average age of 43.65 ± 17.59 years were fitted with Moticon OpenGO insoles equipped with 16 pressure sensors each. Data were recorded at a frequency of 100 Hz during walking at 4 km/h on a level treadmill for 1 minute. Data were processed via a custom-made step detection algorithm. The loading and unloading slopes as well as force extrema-based parameters were computed and characteristic correlations with the targeted parameters were identified via multiple linear regression analysis. Age showed a negative correlation with the mean loading slope. Body height correlated with Fmean_load and the loading slope. Body weight and the body mass index correlated with all analyzed parameters, except the loading slope. In addition, handgrip strength correlated with changes in the second half of the stance phase and did not affect the first half, which is likely due to stronger kick-off. However, only up to 46% of the variability can be explained by age, body weight, height, body mass index and hand grip strength. Thus, further factors must affect the trajectory of the gait cycle curve that were not considered in the present analysis. In conclusion, all analyzed measures affect the trajectory of the stance phase curve. When analyzing insole data, it might be useful to correct for the factors that were identified by using the regression coefficients presented in this paper.

Characteristics and Effectiveness of Postoperative Rehabilitation Strategies in Ankle Fractures: A Systematic Review

OBJECTIVES

To explore the characteristics and to report on the effectiveness of postoperative rehabilitation strategies for people with an ankle fracture.

DATA SOURCES

PubMed, Cochrane Library, EMBASE, Web of Science, and CINAHL were searched to identify studies published from January 2010 to November 2021.

STUDY SELECTION

Studies that described or evaluated postoperative rehabilitation strategies for surgically repaired ankle fractures were included.

DATA EXTRACTION

Data on postoperative rehabilitation were extracted in accordance with the Template for Intervention Description and Replication guide. Quality was assessed using the National Heart, Lung, and Blood Institute's Study Quality Assessment Tools.

DATA SYNTHESIS

Meta-analysis was planned to look at the effectiveness of postoperative rehabilitation strategies. Forty studies described postoperative rehabilitation strategies without evaluating effectiveness, whereas 15 studies focused on evaluating effectiveness. Because of the large variety in postoperative strategies and outcomes, narrative synthesis was deemed most suitable to answer our aims. Characteristics of postoperative rehabilitation strategies varied widely and were poorly described in a way that could not be replicated. Most of the studies (48%) used a late weight-bearing approach, although definitions and details around weight-bearing were unclear.

CONCLUSIONS

Late weight-bearing has been the most common postoperative approach reported in the past 10 years. The variety of definitions around weight-bearing and the lack of details of rehabilitation regimens limit replication and affect current clinical practice. The authors propose to adopt consistent definitions and terminology around postoperative practices such as weight-bearing to improve evidence for effectiveness and ultimately patient outcomes.

LEVEL OF EVIDENCE

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

Concepts and clinical aspects of active implants for the treatment of bone fractures

Nonunion is a complication of long bone fractures that leads to disability, morbidity and high costs. Early detection is difficult and treatment through external stimulation and revision surgery is often a lengthy process. Therefore, alternative diagnostic and therapeutic options are currently being explored, including the use of external and internal sensors. Apart from monitoring fracture stiffness and displacement directly at the fracture site, it would be desirable if an implant could also vary its stiffness and apply an intervention to promote healing, if needed. This could be achieved either by a predetermined protocol, by remote control, or even by processing data and triggering the intervention itself (self-regulated 'intelligent' or 'smart' implant). So-called active or smart materials like shape memory alloys (SMA) have opened up opportunities to build active implants. For example, implants could stimulate fracture healing by active shortening and lengthening via SMA actuator wires; by emitting pulses, waves, or electromagnetic fields. However, it remains undefined which modes of application, forces, frequencies, force directions, time durations and periods, or other stimuli such implants should ideally deliver for the best result. The present paper reviews the literature on active implants and interventions for nonunion, discusses possible mechanisms of active implants and points out where further research and development are needed to build an active implant that applies the most ideal intervention. STATEMENT OF SIGNIFICANCE: Early detection of delays during fracture healing and timely intervention are difficult due to limitations of the current diagnostic strategies. New diagnostic options are under evaluation, including the use of external and internal sensors. In addition, it would be desirable if an implant could actively facilitate healing ('Intelligent' or 'smart' implant). Implants could stimulate fracture healing via active shortening and lengthening; by emitting pulses, waves, or electromagnetic fields. No such implants exist to date, but new composite materials and alloys have opened up opportunities to build such active implants, and several groups across the globe are currently working on their development. The present paper is the first review on this topic to date.

Wearable technology in orthopedic trauma surgery - An AO trauma survey and review of current and future applications

The use of wearable sensors to track activity is increasing. Therefore, a survey among AO Trauma members was conducted to provide an overview of their current utilization and determine future needs and directions. A cross sectional expert opinion survey was administered to members of AO Trauma. Respondents were surveyed concerning their experience, subspeciality, current use characteristics, as well as future needs concerning wearable technology. Three hundred and thirty-three survey sets were available for analysis (Response Rate 16.2%). 20.7% of respondents already use wearable technology as part of their clinical treatment. The most prevalent technology was accelerometry combined with smartphones (75.4%) to measure general patient activity. To facilitate the use of wearable technology in the future, the most pressing issues were cost, patient compliance and validity of results. Wearable activity monitors are currently being used in trauma surgery. Surgeons employing these technologies mostly measure simple activity or activity associated parameters. Cost was the greatest perceived barrier to implementation. Further research, especially concerning the interpretation of the outcome values obtained, is required to facilitate wearable activity monitoring as an objective patient outcome measurement tool.

Use of Wearable Technology to Measure Activity in Orthopaedic Trauma Patients: A Systematic Review

BACKGROUND

Patient-Reported Outcome Measures (PROMs) are widely used for measurement of functional outcomes after orthopaedic trauma. However, PROMs rely on patient collaboration and suffer from various types of bias. Wearable Activity Monitors (WAMs) are increasingly used to objectify functional assessment. The objectives of this systematic review were to identify and characterise the WAMs technology and metrics currently used for orthopaedic trauma research.

METHODS

PubMed and Embase biomedical literature search engines were queried. Eligibility criteria included: Human clinical studies published in the English language between 2010 and 2019 involving fracture management and WAMs. Variables collected from each article included: Technology used, vendor/product, WAM body location, metrics measured, measurement time period, year of publication, study geographic location, phase of treatment studied, fractures studied, number of patients studied, sex and age of the study subjects, and study level of evidence. Six investigators reviewed the resulting papers. Descriptive statistics of variables of interest were used to analyse the data.

RESULTS

One hundred and thirty-six papers were available for analysis, showing an increasing trend of publications per year. Accelerometry followed by plantar pressure insoles were the most commonly employed technologies. The most common location for WAM placement was insoles, followed by the waist. The most commonly studied fracture type was hip fractures followed by fragility fractures in general, ankle, "lower extremity", and tibial fractures. The rehabilitation phase following surgery was the most commonly studied period. Sleep duration, activity time or step counts were the most commonly reported WAM metrics. A preferred, clinically validated WAM metric was not identified.

CONCLUSIONS

WAMs have an increasing presence in the orthopaedic trauma literature. The optimal implementation of this technology and its use to understand patients' pre-injury and post-injury functions is currently insufficiently explored and represents an area that will benefit from future study.

SYSTEMATIC REVIEW REGISTRATION NUMBER

PROSPERO ID:210344.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s43465-022-00629-0.

Validity and Reliability of the Insole3 Instrumented Shoe Insole for Ground Reaction Force Measurement during Walking and Running

Pressure-detecting insoles such as the Insole3 have potential as a portable alternative for assessing vertical ground reaction force (vGRF) outside of specialized laboratories. This study evaluated whether the Insole3 is a valid and reliable alternative to force plates for measuring vGRF. Eleven healthy participants walked overground at slow and moderately paced speeds and ran at a moderate pace while collecting vGRF simultaneously from a force plate (3000 Hz) and Insole3 (100 Hz). Intraclass correlation coefficients (ICC) demonstrated excellent vGRF agreement between systems during both walking speeds for Peak 1, Peak 2, the valley between peaks, and the vGRF impulse (ICC > 0.941). There was excellent agreement during running for the single vGRF peak (ICC = 0.942) and impulse (ICC = 0.940). The insoles slightly underestimated vGRF peaks (−3.7% to 0.9% bias) and valleys (−2.2% to −1.8% bias), and slightly overestimated impulses (4.2% to 5.6% bias). Reliability between visits for all three activities was excellent (ICC > 0.970). The Insole3 is a valid and reliable alternative to traditional force plates for assessing vGRF during walking and running in healthy adults. The excellent ICC values during slow walking suggests that the Insole3 may be particularly suitable for older adults in clinical and home settings.

Effects of assistive insole feedback training on immediate and multi-day partial weight bearing retention during walking: A pilot study

BACKGROUND

Adherence to partial weight bearing (PWB) plays a crucial role in early rehabilitation and motor control. Dynamic biofeedback insole systems provide a supportive function on immediate PWB adherence, while important long-term retention effects and potential advantages to a conventional static training remain unknown.

RESEARCH QUESTION

Is acoustic insole feedback training effective for the retention of prescribed PWB adherence and is there any advantage relative to static training using a conventional bathroom scale? Methods Twenty-four volunteers were randomized into two groups receiving biofeedback training (N = 12) via a mobile insole system (Loadsol®) or conventional training using a bathroom scale (N = 12). After initial PWB training (20 kg) of one randomized leg, the immediate and one-week retention effects were analysed using mean and maximum load (N) and overload rate (%). Statistical analysis was performed using a two-way repeated measures ANOVA with post-hoc pairwise comparisons (p < 0.05).

RESULTS

A significantly (p < 0.001) improved immediate and long-term PWB adherence was found for the insole feedback group during walking. A significant (p < 0.001) reduction of the overload rate by 86% was found for the insole feedback group when compared to the conventional training group after one week. Significant (p < 0.01) reductions by 51% and 46% was also found for the mean and maximum load in the insole feedback group when compared to the conventional training group.

SIGNIFICANCE

The use of insole feedback systems can serve as a viable tool to become familiar with PWB and to provide optimal retention of specified loads. Therefore, such systems serve as an advantageous training intervention to maintain a prescribed PWB during locomotion.

Weight-bearing in Trauma Surgery (WiTS) Study: A national survey of UK Trauma & Orthopaedic multidisciplinary health professionals

INTRODUCTION

Weight-bearing (WB) status following a fracture or surgical fixation is an important determinant of the mechanical environment for healing. In order for healthcare professionals to communicate and understand the extent of bearing weight through a limb, clear terminology must be used. There is widespread variation in the usage and definitions of WB terminology in the literature and clinical practice. This study sought to define the understanding and extent of variation across the United Kingdom.

METHODS

A nationwide online survey of UK-based Trauma & Orthopaedic (T&O) multidisciplinary healthcare professionals was conducted. Participants answered seven questions assessing their usage and understanding of various WB terminology.

RESULTS

A total of 707 responses were received: 48% by doctors, 32% by physiotherapists, 13% by occupational therapists and 7% from other healthcare professionals. In terms of understanding of WB terminology with respect to percentage body weight (BW), 89% of respondents interpret 'full WB' as 100% BW, 97% interpret 'non WB' as 0% BW, 80% interpret 'partial WB' as 50% BW, and 89% interpret 'touch/toe-touch WB' as 10% or 20% BW. There were statistically significant differences between the responses of doctors and therapists for these four terms, with doctors tending to give higher %BW values. 'Protected WB' and 'WB as tolerated' had less consensus and more variability in responses. The majority (68%) of respondents do not usually quantify terminology such as 'partial WB' with a value, and 94% agreed that standardisation of WB terminology would improve communication amongst professionals.

CONCLUSION

This study provides evidence of the substantial variation in the understanding of WB terminology amongst healthcare professionals, which likely results in ambiguous rehabilitation advice. Existing literature has shown that patients struggle to comply with terms such as 'partial weight-bearing'. We recommend consensus within the T&O multidisciplinary community to standardise and define common weight-bearing terminology.

Identification of hip fracture patients at risk for postoperative mobilisation complications via handgrip strength assessment

INTRODUCTION

Treatment of older adult hip fracture patients can be challenging and requires early postoperative mobilisation to prevent complications. Simple clinical tools to predict mobilisation/weight-bearing difficulties after hip fracture surgery are scarcely available and analysis of handgrip strength could be a feasible approach. In the present study, we hypothesised that patients with reduced handgrip strength show incapability to follow postoperative weight-bearing instructions.

MATERIALS AND METHODS

Eighty-four patients aged ≥ 65 years with a proximal femur fracture (trochanteric, n = 45 or femoral neck, n = 39), who were admitted to a certified orthogeriatric center, were consecutively enrolled in a prospective study design. Five days after surgery (intramedullary nailing or arthroplasty), a standardised assessment of handgrip strength and a gait analysis (via insole forcesensors) was performed.

RESULTS

Handgrip strength showed positive correlation with average peak force during gait on the affected limb (0.259), postoperative Parker Mobility Score (0.287) and Barthel Index (0.306). Only slight positive correlation was observed with gait speed (0.157). These results were congruent with multivariate regression analysis.

CONCLUSION

Assessment of handgrip strength is a simple and reliable tool for early prediction of postoperative mobilisation complications like the inability to follow weight-bearing instructions in older hip fracture patients. Follow-up studies should evaluate if these findings also match with other fracture types and result in personalised adjustment of current aftercare patterns. In addition, efforts should be made to combine objectively collected data as handgrip strength or gait speed in a prediction model for long-term outcome of orthogeriatric patients.

Analysis of partial weight bearing after surgical treatment in patients with injuries of the lower extremity

INTRODUCTION

After surgical treatment of injuries of the lower extremity, partial weight bearing is often suggested until soft tissue consolidation. It is doubtful, if this recommendation can be implemented, even in the case that a patient is performing partial weight bearing with a physical therapist. Consequently the question remains, if patients are able to implement partial weight bearing after surgery and which factors favor incompliance.

MATERIALS AND METHODS

49 patients, who underwent surgical treatment after injuries of the lower extremity, were equipped with electronic shoe insoles on both sides. Different weight bearing instructions were given depending on the type of injury and surgery (full weight bearing vs. 20 kg weight bearing vs. non-weight bearing). Besides loading, other factors like age, gender, weight and physical activity were evaluated. Statistical analysis was performed using Chi-square and Fisher's exact test with significance set at a p value < 0.05.

RESULTS

25 of the 40 patients, who had to perform non- or partial weight bearing, were not able to follow postoperative instructions (compliance rate 37.5%). The average loading of the whole collective was 32.6 kg (4.8-109.2 kg). The specification of loading had no statistically significant influence on real loading (p-value 0.39). Elderly patients were less able to follow instructions than younger patients (36 vs 30.2 kg). Physically active compared to non-active patients overloaded their injured extremity (37.8 vs 28.7 kg). Patients with a high body mass index (BMI) encountered more difficulties to perform partial weight bearing than lightweight patients (36.9 vs 25.1 kg).

CONCLUSIONS

Most patients were not able to follow loading limitation, even a few days after surgery and even if the patients were trained by a physiotherapist. Excessive weight bearing-related complications should be evaluated.

Individualized Determination of the Mechanical Fracture Environment After Tibial Exchange Nailing-A Simulation-Based Feasibility Study

Non-union rate after tibial fractures remains high. Apart from largely uncontrollable biologic, injury, and patient-specific factors, the mechanical fracture environment is a key determinant of healing. Our aim was to establish a patient-specific simulation workflow to determine the mechanical fracture environment and allow for an estimation of its healing potential. In a referred patient with failed nail-osteosynthesis after tibial-shaft fracture exchange nailing was performed. Post-operative CT-scans were used to construct a three-dimensional model of the treatment situation in an image processing and computer-aided design system. Resulting forces, computed in a simulation-driven workflow based on patient monitoring and motion capturing were used to simulate the mechanical fracture environment before and after exchange nailing. Implant stresses for the initial and revision situation, as well as interfragmentary movement, resulting hydrostatic, and octahedral shear strain were calculated and compared to the clinical course. The simulation model was able to adequately predict hardware stresses in the initial situation where mechanical implant failure occurred. Furthermore, hydrostatic and octahedral shear strain of the revision situation were calculated to be within published healing boundaries—accordingly the fracture healed uneventfully. Our workflow is able to determine the mechanical environment of a fracture fixation, calculate implant stresses, interfragmentary movement, and the resulting strain. Critical mechanical boundary conditions for fracture healing can be determined in relation to individual loading parameters. Based on this individualized treatment recommendations during the early post-operative phase in lower leg fractures are possible in order to prevent implant failure and non-union development.

Pedobarography in Physiotherapy: A Narrative Review on Current Knowledge

Pedobarography is a modern technology enabling the assessment of the locomotor system based on the plantar pressure distribution. The technic is useful in the rehabilitation of various types of dysfunction of body movement. This chapter aims to describe the application of pedobarography in clinical therapy. The qualitative analysis is based on a review of articles in English, French, German, Polish, Portuguese, Spanish, Turkish, and Chinese in Medline/PubMed, Cochrane Library, Embase, and PEDro databases. The search covered the articles on clinical trials, randomized controlled trials, meta-analyses, and reviews published over 1984-2020. The literature shows that pedobarography is a safe non-invasive method that is useful for the examination of foot biomechanics with a reference to the entire musculoskeletal system. A pedobarographic examination enables insight into a motion disorder, its plausible relation to a systemic pathology, and monitoring the course of treatment and rehabilitation.

Biomechanics of periprosthetic femur fractures and early weightbearing

PURPOSE

The incidence of periprosthetic fractures is expected to rise increase by 4.6% every 10 years between 2015 and 2060. There are few large series examining optimal fixation constructs or the influence of early ambulation on outcome. The purpose of this narrative review is to investigate the published biomechanical considerations for periprosthetic fracture fixation, with specific consideration of early postoperative weightbearing.

METHODS

A literature review was performed to identify fracture incidences, etiology, and current trends in weightbearing after fixation. Benefits of early weightbearing, current constructs, and biomechanics are reviewed.

RESULTS

The limited data available support medical benefits and increased union rates with early mobilization. Optimal fixation constructs are not agreed upon, but mechanical studies suggest that dual implant constructs can support physiologic weightbearing loads.

CONCLUSION

Further clinical trials are required to investigate fracture union and hardware complications in dual implant construct.

Biomechanical optimization of the far cortical locking technique for early healing of distal femur fractures

This finite element study optimized far cortical locking (FCL) technology for early callus formation in distal femur fracture fixation with a 9-hole plate using FCL screws proximal to, and standard locking screws distal to, the fracture. Analyses were done for 120 possible FCL screw configurations by varying FCL screw distribution and number. A hip joint force of 700 N (i.e. 100% x body weight) was used, which corresponds to a typical 140 N "toe-touch" foot-to-ground force (i.e. 20% x body weight) suggested to patients immediately after surgery. Increased FCL screw distribution (i.e. shorter plate working length) caused a decrease at the medial side and an increase at the lateral side of the axial interfragmentary motion (AIM), mildly affected shaft and condylar cortex Von Mises max stress (σ_MAX), increased plate σ_MAX, and decreased shaft FCL screw and condylar locking screw σ_MAX. Increased FCL screw number decreased AIM and σ_MAX on the shaft cortex, condylar cortex, plate, and FCL screws, but not condylar screws. The optimal FCL screw configuration had 3 FCL screws in plate holes #1, 5, and 6 (proximal to distal) for optimal AIM of 0.2 - 1 mm and reduce shear fracture motion, thereby encouraging early callus formation.

Biomechanical design using in-vitro finite element modeling of distal femur fracture plates made from semi-rigid materials versus traditional metals for post-operative toe-touch weight-bearing

This proof-of-concept study designs distal femur fracture plates from semi-rigid materials vs. traditional metals for toe-touch weight-bearing recommended to patients immediately after surgery. The two-fold goal was to (a) reduce stress shielding (SS) by increasing cortical bone stress thereby reducing the risk of bone absorption and plate loosening, and (b) reduce delayed healing (DH) via early callus formation by optimizing axial interfragmentary motion (AIM). Finite element analysis was used to design semi-rigid plates whose elastic moduli E ensured plates permitted AIM of 0.2 - 1 mm for early callus formation. A low hip joint force of 700 N (i.e. 100% x body weight) was applied, which corresponds to a typical 140 N toe-touch foot-to-ground force (i.e. 20% x body weight) recommended to patients after surgery. Analysis was done using 2 screw materials (steel or titanium) and types (locked or non-locked). Steel and titanium plates were also analyzed. Semi-rigid plates (vs. metal plates) had lower overall femur/plate construct stiffnesses of 508 - 1482 N/mm, higher cortical bone stresses under the plate by 2.02x - 3.27x thereby reducing SS, and lower E values of 414 - 2302 MPa to permit AIM of 0.2 - 1 mm thereby reducing DH.

Impact of anti-gravity treadmill rehabilitation therapy on the clinical outcomes after fixation of lower limb fractures: A randomized clinical trial

OBJECTIVE

To compare the effects of anti-gravity treadmill rehabilitation with those of standard rehabilitation on surgically treated ankle and tibial plateau fractures.

DESIGN

Open-label prospective randomized multicenter study.

SETTING

Three level 1 trauma centers.

SUBJECTS

Patients with tibial plateau or ankle fractures who underwent postoperative partial weight-bearing were randomized into the intervention (anti-gravity treadmill use) or control (standard rehabilitation protocol) groups.

MAIN MEASURES

The primary endpoint was the change in the Foot and Ankle Outcome Score for ankle fractures and total Knee injury and Osteoarthritis Outcome Score for tibial plateau fractures (0-100 points) from baseline (T1) to six weeks after operation (T4) in both groups. Leg circumference of both legs was measured to assess thigh muscle atrophy in the operated leg.

RESULTS

Thirty-seven patients constituted the intervention and 36 the control group, respectively; 14 patients dropped out during the follow-up period. Among the 59 remaining patients (mean age 42 [range, 19-65] years), no difference was noted in the Foot and Ankle Outcome Score (54.2 ± 16.1 vs. 56.0 ± 16.6) or Knee injury and Osteoarthritis Outcome Score (52.8 ± 18.3 vs 47.6 ± 17.7) between the intervention and control groups 6 weeks after operation. The change in the leg circumference from T1 to T4 was greater by 4.6 cm in the intervention group (95% confidence interval: 1.2-8.0, P = 0.005). No adverse event associated with anti-gravity treadmill rehabilitation was observed.

CONCLUSION

No significant difference was noted in patient-reported outcomes between the two groups. Significant differences in muscular atrophy of the thigh were observed six weeks after operation.

Finding NEEMO: towards organizing smart digital solutions in orthopaedic trauma surgery

There are many digital solutions which assist the orthopaedic trauma surgeon. This already broad field is rapidly expanding, making a complete overview of the existing solutions difficult.The AO Foundation has established a task force to address the need for an overview of digital solutions in the field of orthopaedic trauma surgery.Areas of new technology which will help the surgeon gain a greater understanding of these possible solutions are reviewed.We propose a categorization of the current needs in orthopaedic trauma surgery matched with available or potential digital solutions, and provide a narrative overview of this broad topic, including the needs, solutions and basic rules to ensure adequate use in orthopaedic trauma surgery. We seek to make this field more accessible, allowing for technological solutions to be clearly matched to trauma surgeons' needs. Cite this article: EFORT Open Rev 2020;5:408-420. DOI: 10.1302/2058-5241.5.200021.

Mobilising the patient: With emphasis on innovative technologies

Treatment of trauma patients and fractures has changed dramatically throughout the years. From conservative methods to nowadays various kinds of screws, pins, plates and nails for optimal fixation of fractures. This lead to changes in post-operative management as well, from bedrest to (partial) weight bearing. Some patients however have very limited to no ability to mobilise, such as critical ill patients on the Intensive Care Unit, amputees or spinal cord injured patients. Due to innovations such as hydrotherapy, osseointegrated prosthesis and exoskeletons, even these people can mobilise. Thanks to innovations like these an increasing number of trauma patients are able to fully reintegrate into community life and get back to an active and independent life style.

Factors Affecting Compliance With Weight-Bearing Restriction and the Amount of Weight-Bearing in the Elderly With Femur or Pelvic Fractures

OBJECTIVE

To determine the factors affecting the amount of weight-bearing during gait training in the elderly patients who underwent internal fixation after femur or pelvic fractures and how well they performed the weight-bearing restriction as directed by the physiatrist.

METHODS

In this retrospective chart review study, we measured the amount of weight-bearing on the affected side in 50 patients undergoing internal fixation surgery and rehabilitation after femur or pelvic fracture using a force plate. Patients receiving non-weight-bearing or partial weight-bearing education were considered to perform weight-bearing restriction well when the amount of weight-bearing was <50 lb. Furthermore, regression analysis was performed to determine the effects of postoperative complications, age, cognitive function, and pain on weightbearing restriction.

RESULTS

Variables affecting the amount of weight-bearing were age (r=0.581, p<0.001), weight-bearing education type (r=0.671, p<0.001), manual muscle strength of hip flexion on the non-affected side (r=-0.296, p=0.037), hip abduction (r=-0.326, p=0.021), knee extension (r=-0.374, p=0.007), ankle plantar flexion (r=-0.374, p=0.008), right hand grip strength (r=-0.535, p<0.001), Korean version of Mini-Mental State Examination (r=-0.496, p<0.001), Clinical Dementia Rating (r=0.308, p=0.03), and pain visual analog scale scores (r=0.318, p=0.024). The significant predictor of the amount of weight-bearing among these variables was age (β=0.448, p=0.001). The weight-bearing restriction adherence rate was significantly lower, at 22%, for patients aged ≥65 years as compared to 73% for those <65 years.

CONCLUSION

Age was a major variable affecting the amount of weight-bearing. Compliance with weight-bearing restriction was significantly lower in patients aged ≥65 years than in patients <65 years.

Effect of investigator observation on gait parameters in individuals with stroke

Improvements in gait speed following various training paradigms applied to patients post-stroke does not always lead to changes in walking performance, defined as gains in daily stepping activity. We hypothesized that testing conditions, specifically the presence of an observer, influences patient behaviors and resultant outcomes may overestimate their true walking capacity. This potential Hawthorne effect on spatiotemporal and biomechanical measures of locomotor function in individuals post-stroke has not been assessed previously. Fifteen ambulatory individuals with chronic stroke wore instrumented insoles and performed two separate normal-pace walking assessments, including unobserved conditions during which participants were unattended and unaware of data collection, and observed conditions with an investigator present. Gait analysis was conducted outside of a laboratory setting using instrumented insoles equipped with a 3D accelerometer and pressure sensors which captured the spatiotemporal kinematics, vertical ground reaction forces and foot acceleration. Data were compared using paired comparisons, with subsequent correlation and stepwise regression analyses to explore potential associations between Hawthorne-induced changes in walking strategies, gait speed and locomotor performance (daily stepping). Except for cadence, other measures of spatiotemporal parameters and swing kinematics (acceleration) were not significantly different between observed vs unobserved conditions. However, analyses of ground reaction forces revealed significantly greater paretic limb loading (Δ1^st peak = 1.5 ± 1.6 N/kg Δ2^nd peak = 1.4 ± 1.8 N/kg; p < 0.01) and increases in weight bearing symmetry (11-24%, p < 0.01) during observed vs unobserved conditions. This potential Hawthorne effect was greater in those with slower walking speeds and shorter stride lengths but was not related to daily stepping. The present findings suggest that biomechanical parameters of walking function may be related to the presence of an observer and highlight the need to separately measure locomotor capacity (gait speed) and performance (daily stepping).

Weight-bearing restrictions reduce postoperative mobility in elderly hip fracture patients

BACKGROUND AND PURPOSE

Reduced mobility is a severe threat to the clinical outcomes and survival of elderly hip fracture patients. These patients generally struggle to comply with partial weight bearing, yet postoperative weight-bearing restrictions are still recommended by nearly 25% of surgeons. Therefore, we hypothesized that weight-bearing restrictions in elderly hip fracture patients merely leads to reduced mobility, while transposing full weight to the fractured extremity remains unaffected disregarding the prescribed aftercare.

PATIENTS AND METHODS

41 equally treated patients with pertrochanteric fractures were enrolled consecutively in a maximum care hospital in a pre-post study design (level of evidence 2). A study group of 19 patients was instructed to maintain partial weight bearing (PWB), whereas the control group of 22 patients was instructed to mobilize at full weight bearing (FWB). All patients were asked to participate in a gait analysis using an insole force sensor (loadsol^®, Novel, Munich, Germany) on the fifth postoperative day.

RESULTS

The postoperative Parker Mobility Score in the PWB group compared to the FWB group was significantly reduced (3.21 vs. 4.73, p < 0.001). Accordingly, a significantly lower gait speed in the PWB group of 0.16 m/s vs. 0.28 m/s was seen (p = 0.003). No difference in weight bearing was observed in between the groups (average peak force 350.25 N vs. 353.08 N, p = 0.918), nor any differences in the demographic characteristics, ASA Score, Barthel Index or EQ5D.

INTERPRETATION

Weight-bearing restrictions in elderly hip fracture patients contributed to a loss of mobility, while no significant differences in loading of the affected extremity were observed. Therefore, postoperative weight-bearing restrictions in elderly hip fracture patients should be avoided, to achieve early mobilization at full weight bearing.

Fine Wire Circular Fixation for Displaced Intra-Articular Calcaneal Fractures: A Systematic Review

Intra-articular calcaneal fractures represent an ongoing challenge for the orthopedic community, with the benefits of the previous "gold standard" treatment of open reduction and internal fixation having been called into question in several large randomized controlled trials. Fine wire circular fixation may represent a useful alternative treatment for these injuries, combining minimally invasive application with rigid fixation, which allows the possibility of early weight bearing We performed a systematic review of published studies that used circular fixation for calcaneal fractures and recorded functional outcomes at follow-up. In a total of 11 studies with 255 calcaneal fractures for which there was follow-up, our inclusion criteria were met: 8.2% of fractures were bilateral, 11.9% of fractures were open fractures, and 12.6% of patients had multiple orthopedic injuries. Functional outcomes were assessed with the use of a variety of tools across the different studies, but outcomes compared favorably with those seen with open reduction and internal fixation. Although pin site infections were common (22.6%), serious complications, including deep infection (0.8%), wound infection (1.6%), and complex regional pain syndrome (0.8%), were exceedingly rare. The results suggest that this is a viable alternative treatment for calcaneal fractures, but higher-quality randomized controlled trials are required before the technique can enter mainstream use.

Increased therapy demand and impending loss of previous residence status after proximal femur fractures can be determined by continuous gait analysis - A clinical feasibility study

Proximal femur fractures account for increased healthcare costs whenever patients are unable to return to their previous state of residence. Studies suggest that patients benefit from early weight-bearing, yet compliance to weight-bearing regimes is poorly investigated. Aim of the study was thus to show the clinical feasibility of a new measurement tool able to determine continuous weight-bearing behavior after intramedullary nail osteosynthesis of intertrochanteric femur fractures, assess the influence of weight-bearing on clinical outcome and determine rehabilitation demand based on early postoperative gait performance. In an observational study, gait data of 22 patients with intertrochanteric femur fractures were evaluated. During the inpatient stay patients were continuously monitored with a gait analysis insole. Primary outcome was the amount of weight-bearing reached. Short-term functional outcome, as well as return to the previous state of living were evaluated in relation to weight-bearing and activity during the inpatient stay. With the presented technique continuous gait data of all patients during postoperative mobilization could be obtained. Only 13 patients reached full weight-bearing. The technique was feasible to determine correlations between weight-bearing and outcome, as well as between gait activity and outcome. Significant gait differences between patients able to return to their previous state of living and those who could not were seen. Dynamic insole measurements are feasible to continuously determine the postoperative gait performance. Their postoperative use showed, that the continuous compliance to permissive weight-bearing after intertrochanteric fractures is low. The presented measurement technique has the potential to identify patients at risk for reduced outcome and impending loss of previous residence status. Further studies will have to investigate the effects of technology assisted "patient at risk" identification and adapted therapy on clinical outcome.