Methods for assessing leg length discrepancy

Can We Screen for Limb Length Discrepancy on Spinal Radiographs of Patients With Adolescent Idiopathic Scoliosis?

BACKGROUND

The aim of this study was to determine whether height differences in the levels of the iliac crests and femoral heads on erect spinal radiographs can be used as indirect measurements for the screening and surveillance of limb length discrepancy (LLD) in patients with scoliosis.

METHODS

Whole body posteroanterior (PA) and lateral erect radiographs of patients with adolescent idiopathic scoliosis (AIS) were retrospectively reviewed. Patients with congenital, syndromic, and neuromuscular scoliosis were excluded. A direct measurement of each limb was taken from the highest point of the femoral head to the middle of the tibial plafond; any difference between the sides was recorded as the LLD. In addition, the PACS Software tool was used to measure femoral head height difference (FHHD) and iliac crest height difference (ICHD). Pearson's correlation, linear regression, and Bland-Altman plots were used to determine the relationships between LLD and FHHD, and LLD and ICHD.

RESULTS

Radiographs of 141 patients (92 women, 49 men) with an average age of 12.0±2.65 years were analyzed. A strong correlation (r=0.730, P <0.001) was found between LLD and FHHD; the correlation between LLD and ICHD was weaker (r=0.585, P <0.001). The Bland-Altman analysis showed good agreements of LLD with FHHD and ICHD. Linear regression analysis predicted an LLD of ≤10 mm based on an FHHD of ≤11.5 mm or an ICHD of ≤15.3 mm.

CONCLUSIONS

FHHD and ICHD on spinal PA radiographs can be used for the screening and monitoring of LLD in patients with AIS with FHHD being the preferred indirect measurement. These measurements are readily learned and quick to perform. The FHHD and ICHD can be measured on any erect scoliosis PA radiograph. Therefore, these proxy measurements can be used to screen and monitor for LLD in patients with AIS.

LEVEL OF EVIDENCE

Level III.

Validity and reliability of running gait measurement with the ViMove2 system

Running biomechanics have traditionally been analysed in laboratory settings, but this may not reflect natural running gait. Wearable technology has the potential to enable precise monitoring of running gait beyond the laboratory. This study aimed to evaluate the analytical validity and intra-session reliability of temporal running gait outcomes measured by the ViMove2 wearable system in healthy adults. Seventy-four healthy adults (43 males, 31 females, aged 18-55 years) wore the inertial device, ViMove2 on the tibia. Participants ran on a treadmill for one minute at various speeds (8, 10, 12, 14km/hr), completed in a standardised shoe (Saucony Guide Runner). Running gait was measured with the ViMove2 wearable and 3D motion capture (Vicon). Temporal running gait outcomes included ground contact time (GCT) and cadence (steps/min). GCT and cadence from the ViMove2 had face validity with expected changes in outcome with different running speeds, but ViMove2 tended to over-estimate GCT, and under-estimate cadence compared to the reference, especially at slower speeds. GCT demonstrated moderate to good agreement to the reference at speeds >10km/hr, but poor agreement at 8km/hr and within female runners. Cadence had moderate to excellent agreement across speeds compared to the reference. GCT and cadence had excellent reliability across speeds, but at 8km/hr GCT had good agreement between trials. Overall, temporal gait outcomes of GCT and cadence can be measured with the ViMove2, but accuracy and reliability are impacted at slow running speeds and within female runners. Future work is needed to clarify sex or speed-dependent corrections to algorithms / outcomes to aid interpretation and application.

Effectiveness of gluteal control training in chronic low back pain patients with functional leg length inequality

Chronic low back pain (LBP) is a common musculoskeletal disorder and is often accompanied by functional leg length inequality (FLLI). However, little was known about the effects of gluteal muscle control training in patients with LBP and FLLI. This study was designed to investigate the effects of gluteal control training in patients with LBP and FLLI. This is a double-blinded, randomized controlled study design. Forty-eight LBP patients with FLLI were randomized to the gluteal control training (GT) (47.58 ± 9.42 years) or the regular training (RT) (47.38 ± 11.31 years) group and received allocated training for six weeks. The outcome measures were pelvic inclination (PI), ilium anterior tilt difference (IATD), FLLI, visual analogue scale (VAS), patient specific-functional scale (PSFS), Oswestry disability index (ODI), hip control ability, global rating of change scale (GRoC), and lower extremity strength and flexibility. The intervention effects were compared using two-way repeated measures analysis of variance and chi-square tests with α = 0.05. The results indicated that the GT group showed greater improvement (P < 0.01) in PI (1.03 ± 0.38∘ vs. 1.57 ± 0.51∘), IATD (0.68 ± 0.66∘ vs. 2.31 ± 0.66∘), FLLI (0.3 ± 0.22 vs. 0.59 ± 0.13 cm), VAS (1.41 ± 1.32 vs. 3.38 ± 1.51), hip control ability (2.20 ± 0.45 vs. 0.89 ± 0.74), GRoC at 3rd and 6th week as compared to the RT group. Hip strength and flexibility also improved more in the GT group (P < 0.05). In conclusion, gluteal control training was more effective in improving low back pain and dysfunctions, and should be integrated in the management plan in patients with LBP and FLLI.

Multivariable model for gait pattern differentiation in elderly patients with hip and knee osteoarthritis: A wearable sensor approach

Background

Hip and knee osteoarthritis (OA) patients demonstrate distinct gait patterns, yet detecting subtle abnormalities with wearable sensors remains uncertain. This study aimed to assess a predictive model's efficacy in distinguishing between hip and knee OA gait patterns using accelerometer data.

Method

Participants with hip or knee OA underwent overground walking assessments, recording lower limb accelerations for subsequent time and frequency domain analyses. Logistic regression with regularization identified associations between frequency domain features of acceleration signals and OA, and k-nearest neighbor classification distinguished knee and hip OA based on selected acceleration signal features.

Findings

We included 57 knee OA patients (30 females, median age 68 [range 49-89], median BMI 29.7 [range 21.0-45.9]) and 42 hip OA patients (19 females, median age 70 [range 47-89], median BMI 28.3 [range 20.4-37.2]). No significant difference could be found in the time domain's averaged shape of acceleration signals. However, in the frequency domain, five selected features showed a diagnostic ability to differentiate between knee and hip OA. Using these features, a model achieved a 77 % accuracy in classifying gait cycles into hip or knee OA groups, with average precision, recall, and F1 score of 77 %, 76 %, and 78 %, respectively.

Interpretation

The study demonstrates the effectiveness of wearable sensors in differentiating gait patterns between individuals with hip and knee OA, specifically in the frequency domain. The results highlights the promising potential of wearable sensors and advanced signal processing techniques for objective assessment of OA in clinical settings.

What is the clinical detection threshold for lower limb length inequality? In silico study of reproducibility and optimization using a centimeter graduated support

INTRODUCTION

The threshold of a Leg Length Discrepancy (LLD) by clinical examination on a sheet or centimeter paper (CP) is not known precisely whether or not it concerns limbs equipped with a hip prosthesis. We therefore conducted a prospective in silico study in order to: (1) determine the reproducibility and sensitivity of the clinical measurement of the LLD in different ideal and "degraded" clinical situations, (2) determine the threshold from which the human eye is capable of detecting a length inequality in clinic, (3) to determine whether the use of a graduated support (centimeter paper) improves the clinical measurement threshold.

HYPOTHESIS

Our hypothesis was that clinical measurement on a centimeter support would improve clinical measurement accuracy.

MATERIAL AND METHODS

This was an in silico study, the experiment was conducted on a mannequin. Different inequalities were created on a mannequin and photographed with a total of 30 inequalities from -22 to +22 mm on sheet or centimeter paper (CP). This was a multicenter study, with 40 different readers. We asked the readers to make a second measurement one month later. We evaluated the inter- and intra-observer reproducibility. The error rate at the threshold of 3 mm and 5 mm were calculated versus the gold standard. Finally, we determined at which thresholds respectively 75% and 95% of the measurements were correct.

RESULTS

A total of 4140 measurements were performed and compared to the gold standard. With a threshold of 75% accurate measurement, the LLD detection threshold was 2.8 mm on centimeter paper and 4.5 mm on sheet. With a threshold of 95% accurate measurement, the LLD detection threshold was 3.4 mm on centimeter paper and 5.2 mm on sheet. Interobserver agreement (assessed overall on the 40 observers by Krippendorff's generalized Kappa) was 0.86 (95% confidence interval (CI95%) = 0.79 to 0.92) on CP and 0.71 (CI95% = 0.63 to 0.79) on sheet. Intra-observer agreement assessed by the intraclass correlation coefficient among observers who made 2 measurements had a median value (IQR) of 0.96 (0.94 to 0.99) on CP and 0.90 (0.83 to 0.94) on sheet.

DISCUSSION

The clinical detection threshold on sheet at the patient's bed appears close to 5 mm. A more precise measurement is possible with graduated centimeter paper. A study in daily practice on patients in real situations would confirm our results.

LEVEL OF EVIDENCE

III; prospective diagnostic comparative in Silico study.

Comparative Study of Alternative Methods for Measuring Leg Length Discrepancy after Robot-Assisted Total Hip Arthroplasty

BACKGROUND

Our study addresses the lack of consensus on measuring leg length discrepancy (LLD) after total hip arthroplasty (THA). We will assess the inter-observer variability and correlation between the five most commonly used LLD methods and investigate the use of trigonometric principles in overcoming the limitations of current techniques.

METHODS

LLD was measured on postoperative AP pelvic radiographs using five conventional methods. CT images created a 3D computer model of the pelvis and femur. The resulting models were projected onto a 2D, used to measure LLD by the five methods. The measurements were evaluated via Taguchi analysis, a statistical method identifying the process's most influential factors. The approach was used to assess the new trigonometric method.

RESULTS

Conventional methods demonstrated poor correlation. Methods referenced to the centers of the femoral heads were insensitive to LLD originating outside the acetabular cup. Methods referencing either the inter-ischial line or the inter-obturator foramina to the lesser trochanter were sensitive to acetabular and femoral components. Trigonometry-based measurements showed a higher correlation.

CONCLUSIONS

Our results underscore clinicians' need to specify the methods used to assess LLD. Applying trigonometric principles was shown to be accurate and reliable, but it was contingent on proper radiographic alignment.

Accuracy of two-dimensional digital planning in uncemented primary hip arthroplasty: monocentric analysis of eight hundred implants

PURPOSE

In the last decades, there has been a refinement in total hip arthroplasty, which allowed surgeons to achieve the highest performance and better patient outcomes. Preoperative planning in primary hip arthroplasty is an essential step that guides the surgeon in restoring the anatomy and biomechanics of the joint. This study aims to evaluate the accuracy of the 2D digital planning, considering cup sizing, stem sizing, and limb length discrepancy. Additionally, we conducted a multivariable analysis of demographic data and comorbidities to find factors influencing preoperative planning.

METHODS

This retrospective study analyzed the planning accuracy in 800 consecutive uncemented primary total hip arthroplasty. We compared the preoperatively planned total hip arthroplasty with postoperative results regarding the planned component size, the implanted size, and the lower limb length restoration. Therefore, we investigated factors influencing planning accuracy: overweight and obesity, sex, age, past medical history, comorbidities, and implant design. All the surgeries were performed in the posterolateral approach by one expert surgeon who did the preoperative planning. The preoperative planning was determined to be (a) exact if the planned and the implanted components were the same size and (b) accurate if exact ± one size. The restoration of postoperative limb length discrepancy was classified into three groups: ± 3 mm, ± 5 mm, and ± 10 mm. This assessment was performed through a digital method 2D based on a standard hip X-ray.

RESULTS

This court of 800 implants showed that planning was exact in 60% of the cups and 44% of the stems and was accurate in 94% of the cups and 80% of the stems. The postoperative limb length discrepancy was ± 3 mm in 91% and ± 5 mm in 97%.

CONCLUSIONS

This study showed preoperative 2D digital planning great precision and reliability, and we demonstrated that it was accurate in 94% of the cups and 80% of the stems. Therefore, the preoperative limb length discrepancy analysis was essential to guarantee the recovery of the operated limb's correct length.

Performance of Microsoft Azure Kinect DK as a tool for estimating human body segment lengths

The Microsoft Kinect depth sensor, with its built-in software that automatically captures joint coordinates without markers, could be a potential tool for ergonomic studies. This study investigates the performance of Kinect in limb segment lengths using dual-energy X-ray absorptiometry (DXA) as a reference. Healthy children and adults (n = 76) were recruited for limb length measurements by Kinect and DXA. The results showed consistent ratios of arm, forearm, thigh, and leg lengths to height, which were 0.16, 0.14, 0.23, and 0.22 respectively, for both age groups and methods. Kinect exhibited perfect correlation among all limb lengths, indicating fixed proportions assumed by its algorithm. Comparing the two methods, there was a strong correlation (R = 0.850-0.985) and good to excellent agreement (ICC = 0.829-0.977), except for the right leg in adults, where agreement was slightly lower but still moderate (ICC = 0.712). The measurement bias between the methods ranged from - 1.455 to 0.536 cm. In conclusion, Kinect yields outcomes similar to DXA, indicating its potential utility as a tool for ergonomic studies. However, the built-in algorithm of Kinect assumes fixed limb proportions for individuals, which may not be ideal for studies focusing on investigating limb discrepancies or anatomical differences.

Clinical, functional, and radiological outcomes of robotic assisted versus conventional total hip arthroplasty: a systematic review and meta-analysis of randomized controlled trials

This systematic review of randomized controlled trials (RCTs) aims to compare important clinical, functional, and radiological outcomes between robotic-assisted total hip arthroplasty (RATHA) and conventional total hip arthroplasty (COTHA) in patients with hip osteoarthritis. We identified published RCTs comparing RATHA with COTHA in Ovid MEDLINE, EMBASE, Scopus, and Cochrane Library. Two reviewers independently performed study screening, risk of bias assessment and data extraction. Main outcomes were major complications, revision, patient-reported outcome measures (PROMs), and radiological outcomes. We included 8 RCTs involving 1014 patients and 977 hips. There was no difference in major complication rate (Relative Risk (RR) 0.78; 95% Confidence Interval (CI) 0.22 to 2.74), revision rate (RR 1.33; 95%CI 0.08 to 22.74), and PROMs (standardized mean difference 0.01; 95%CI - 0.27 to 0.30) between RATHA and COTHA. RATHA resulted in little to no effects on femoral stem alignment (mean difference (MD) - 0.57 degree; 95%CI - 1.16 to 0.03) but yielded overall lower leg length discrepancy (MD - 4.04 mm; 95%CI - 7.08 to - 1.0) compared to COTHA. Most combined estimates had low certainty of evidence mainly due to risk of bias, inconsistency, and imprecision. Based on the current evidence, there is no important difference in clinical and functional outcomes between RATHA and COTHA. The trivial higher radiological accuracy was also unlikely to be clinically meaningful. Regardless, more robust evidence is needed to improve the quality and strength of the current evidence.PROSPERO registration: the protocol was registered in the PROSPERO database (CRD42023453294). All methods were carried out in accordance with relevant guidelines and regulations.

Targeted epiphysiodesis using needle arthroscopy

Epiphysiodesis is performed to either temporarily or permanently close the physis. It is considered in the management of angular deformities or limb length discrepancies. There are various surgical techniques that have been described. The gold-standard remains the mechanical removal of the physis using drills, burrs, and curettes. This requires intraoperative imaging to guide surgery and invariably leads to the mechanical removal of healthy cancellous bone as well as physeal cartilage. We report on a case of 'targeted epiphysiodesis' using needle arthroscopy. In this technique, radiation exposure and unnecessary bone loss is minimal. Epiphysiodesis is achieved under direct vision using a 1.9 mm needle arthroscope with a successful outcome and no surgical complications noted.

Cup-cage constructs in revision total hip arthroplasty for pelvic discontinuity

Aims

Pelvic discontinuity is a challenging acetabular defect without a consensus on surgical management. Cup-cage reconstruction is an increasingly used treatment strategy. The present study evaluated implant survival, clinical and radiological outcomes, and complications associated with the cup-cage construct.

Methods

We included 53 cup-cage construct (51 patients) implants used for hip revision procedures for pelvic discontinuity between January 2003 and January 2022 in this retrospective review. Mean age at surgery was 71.8 years (50.0 to 92.0; SD 10.3), 43/53 (81.1%) were female, and mean follow-up was 6.4 years (0.02 to 20.0; SD 4.6). Patients were implanted with a Trabecular Metal Revision Shell with either a ZCA cage (n = 12) or a TMARS cage (n = 40, all Zimmer Biomet). Pelvic discontinuity was diagnosed on preoperative radiographs and/or intraoperatively. Kaplan-Meier survival analysis was performed, with failure defined as revision of the cup-cage reconstruction.

Results

The five-year all-cause survival for cup-cage reconstruction was 73.4% (95% confidence interval (CI) 61.4 to 85.4), while the ten- and 15-year survival was 63.7% (95% CI 46.8 to 80.6). Survival due to aseptic loosening was 93.4% (95% CI 86.2 to 100.0) at five, ten, and 15 years. The rate of revision for aseptic loosening, infection, and dislocation was 3/53 (5.7%), 7/53 (13.2%), and 6/53 (11.3%), respectively. The mean leg length discrepancy improved (p < 0.001) preoperatively from a mean of 18.2 mm (0 to 80; SD 15.8) to 7.0 mm (0 to 35; SD 9.8) at latest follow-up. The horizontal and vertical hip centres improved (p < 0.001) preoperatively from a mean of 9.2 cm (5.6 to 17.5; SD 2.3) to 10.1 cm (6.2 to 13.4; SD 2.1) and 9.3 cm (4.7 to 15.8; SD 2.5) to 8.0 cm (3.7 to 12.3; SD 1.7), respectively.

Conclusion

Cup-cage reconstruction provides acceptable outcomes in the management of pelvic discontinuity. One in four constructs undergo revision within five years, most commonly for periprosthetic joint infection, dislocation, or aseptic loosening.

The reliability of clinical tools with and without ultrasound guidance to measure leg-length inequality

Purpose

To determine and compare the reliability and efficiency of various methods of leg-length measurement.

Methods

A total of 88 leg-lengths were measured among 50 subjects (79%-84% female, mean age = 30-33 years). Leg-lengths were measured in both supine and standing positions using multiple devices, including a tape measure, a LASER distance meter, and diagnostic ultrasound.

Results

All methods of leg-length measurement using the middle of the femoral head as a reference point, identified via ultrasound, demonstrated excellent reliability (intraclass correlation coefficient = 0.95-1.00). Measurements performed in supine, using the anterior superior iliac spine as a reference point, with a tape measure, demonstrated good-to-excellent reliability (intraclass correlation coefficient = 0.86-0.95, standard error of the measurement = 16.1-19.9 cm). Standing measurements using the anterior superior iliac spine as a reference point, using a tape measure, demonstrated fair-to-excellent reliability (intraclass correlation coefficient = 0.71-0.95).

Conclusion

Ultrasound-guided landmark identification appear to be a more reliable method compared to palpation of the anterior superior iliac spine for measurement of leg-length using clinical tools. When coupled with ultrasound guidance, a hand-held LASER distance meter/pitch locator apparatus or a retractable tape measure appears to be acceptable alternatives to a fixed LASER distance meter on a linear actuator for leg-length measurement.

Impact of the hip-spine relationship and patient-perceived leg length discrepancy after total hip arthroplasty: A retrospective study

PURPOSE

Patient-perceived leg length discrepancy (PLLD) is one of the major postoperative complications of total hip arthroplasty (THA). This study aimed to identify factors that cause PLLD following THA.

MATERIALS AND METHODS

This retrospective study included a series of consecutive patients who underwent unilateral THA between 2015 and 2020. Ninety-five patients who underwent unilateral THA with postoperative radiographic leg length discrepancy (RLLD) ≤1 cm were classified into two groups according to the direction of preoperative pelvic obliquity (PO). Standing radiographs of the hip joint and whole spine were obtained before and one year after THA. The clinical outcomes and the presence or absence of PLLD was confirmed one year after THA.

RESULTS

Sixty-nine patients were classified as having type 1 PO (rising toward the unaffected side) and 26 were classified as having type 2 PO (rising toward the affected side). Eight patients with type 1 PO and seven with type 2 PO had PLLD postoperatively. In the type 1 group, patients with PLLD had larger preoperative and postoperative PO values and larger preoperative and postoperative RLLD than those without PLLD (p = 0.01, p < 0.001, p = 0.01, and p = 0.007, respectively). In the type 2 group, patients with PLLD had larger preoperative RLLD, larger amount of leg correction, and a larger preoperative L1-L5 angle than those without PLLD (p = 0.03, p = 0.03, and p = 0.03, respectively). In type 1, postoperative PO was significantly associated with postoperative PLLD (p = 0.005), but spinal alignment was not an indicator of postoperative PLLD. The area under the curve (AUC) for postoperative PO was 0.883 (good accuracy) with a cut-off value was 1.90° CONCLUSION: Rigidity of the lumbar spine might lead to postoperative PO as a compensatory movement, resulting in PLLD after THA in type 1. Further research on the relationship between flexibility of the lumbar spine and PLLD is needed.

Scoliosis and Lower Limb Inequality: To Lift or Not to Lift, That Is the Question

In subjects with scoliotic alterations of the spine, asymmetrical lengths of the lower limbs are frequently observed, a condition commonly referred to as leg length inequality (LLI) or discrepancy (LLD). This asymmetry can induce pelvic misalignments, manifested by an asymmetric height of the iliac crests, and consequently an alteration of the spine's axis. Although correcting this discrepancy might appear to be a straightforward solution, further investigation may reveal other indications. The purpose of this article is to aid clinicians confronted with the decision of whether to compensate for an LLI in individuals with scoliosis, encompassing both adolescents and adults. It presents a literature review on the incidence of LLIs in the general population, distinguishing between structural LLI (sLLI) and functional LLI (fLLI) types of LLIs, and quantifying their magnitude with clinical and instrumental evaluation. Additionally, it links these two types of LLIs to the type of scoliosis (structural or functional). From a clinical perspective, it also examines the compensatory mechanisms employed by the pelvis in the presence of structural or functional LLIs in order to draw useful indications for therapeutic decisions. Moreover, it proposes an additional evaluation parameter in the coronal plane, namely the central sacral vertical line (CSVL), to aid in the decision-making process regarding LLI compensation. Although this parameter has been documented in the literature, it has been little associated with LLIs. The findings indicate that scoliotic discrepancies should be compensated (conservatively or surgically) only when the imbalance of the femoral heads is on the same side as the imbalance of the sacrum and the iliac crests; this corrective action should result in a reduction of the overhang in the coronal plane.

The role of radiography in diagnosing, monitoring and prognosing juvenile idiopathic arthritis

The current role of conventional radiography in the diagnosis, monitoring and prognosis of juvenile idiopathic arthritis (JIA) is reviewed, as its role has changed with the increasing use of ultrasound and magnetic resonance imaging, as well as with the introduction of biological drugs. Conventional radiography does not play an important role in the diagnosis of JIA, as this is based on history, clinical examination and laboratory findings. The main role of conventional radiography is in the detection and monitoring of growth disorders and chronic structural and morphological changes of the affected joints and bones, in addition to helping with the differential diagnosis of conditions that mimic JIA. Radiographic changes of the joints depend on the age of the child, the type and duration of arthritis and the specific joints affected. There are no standard protocols for arthritis monitoring and most indications for imaging are based on individual case-by-case decisions. The development of degenerative joint changes is considered a poor predictive factor, but there are no clear studies that more precisely define the predictive value of radiographic changes. Conventional radiography remains an important imaging modality in narrowing the differential diagnosis and in evaluating growth disorders and the developing destructive joint changes.

Preventing of nonunion in congenital pseudarthrosis of the tibia cases of Crawford Type I and II through the use of allograft bypass and a brace: Midterm findings

Background

Congenital pseudarthrosis of the tibia is a limb deformity, which can be distressing for the affected patients and the pediatric orthopedic surgeons involved. We hypothesized that the modified McFarland procedure would avoid fractures and even have a corrective effect on the affected tibia in congenital pseudarthrosis of the tibia patients. Toward this end, we evaluated the midterm results of treating congenital pseudarthrosis of the tibia patients of Crawford Type I and II with allograft bypass combined with long-term bracing.

Methods

This study retrospectively evaluated 7 patients with congenital pseudarthrosis of the tibia who were treated with allograft bypass combined with long-term bracing between 2009 and 2018. The median follow-up was 7.0 years (range 3.8-10.0 years). The medical records and radiographs were reviewed for demographic data, clinical characteristics, outcomes, and complications.

Results

At the time of the last follow-up, all allografts revealed complete consolidation in the patients' tibiae at both ends. All patients presented no functional restriction of the lower limbs and no amputation or non-union has occurred. Most of the obvious deformities of the tibia diaphysis or ankle joint were corrected. Two complications occurred that required successful revision surgery.

Conclusion

In this series of seven congenital pseudarthrosis of the tibia patients, the allograft bypass technique showed satisfactory midterm results and validated our hypothesis. For congenital pseudarthrosis of the tibia patients of Crawford Type I and II, this procedure combined with long-term bracing, which involves the affected leg only, can delay or possibly prevent fractures, decrease tibial malalignment, and preserve leg length.

Level of evidence

level IV.

Management of long bone fractures and traumatic hip dislocations in paediatric patients: study protocol for a prospective global multicentre observational cohort registry

INTRODUCTION

Management controversy and clinical equipoise exist in treatments of long bone fractures and traumatic hip dislocation in paediatric patients due to the lack of high-quality clinical evidence. This protocol describes the effort of a large prospective global multicentre cohort study (registry) aiming at providing quality data to assist evidence-based treatment decision-making.

METHODS AND ANALYSIS

Eligible paediatric patients (N=750-1000) with open physes suffering from proximal humerus fractures, distal humerus fractures, proximal radius fractures, forearm shaft fractures, traumatic hip dislocations, femoral neck fractures or tibial shaft fractures will be recruited over a period of 24-36 months. Hospitalisation and treatment details (including materials and implants) will be captured in a cloud-based, searchable database. Outcome measures include radiographic assessments, clinical outcomes (such as range of motion, limb length discrepancies and implant removal), patient-reported outcomes (Patient Reported Outcomes Of Fracture, Patient-Reported Outcomes Measurement Information System (PROMIS) and EuroQol-5D (EQ-5D-Y)) and adverse events.Aside from descriptive statistics on patient demographics, baseline characteristics, types of fractures and adverse event rates, research questions will be formulated based on data availability and quality. A statistical analysis plan will be prepared before the statistical analysis.

ETHICS AND DISSEMINATION

Ethics approval will be obtained before patients are enrolled at each participating site. Patient enrolment will follow an informed consent process approved by the responsible ethics committee. Peer-reviewed publication is planned to disseminate the study results.

TRIAL REGISTRATION NUMBER

NCT04207892.

Anatomical leg length discrepancy in children: Can it be accurately determined using 3-D motion capturing?

BACKGROUND

Leg length discrepancy (LLD) is common in youth and is cause by several conditions. Long leg X-rays is the gold standard technique of measuring LLD. It is highly accurate and reliable compared to clinical method, but expose the subject to radiation. Instrumented Gait Analysis (IGA) serves not only as a means to measure joint kinematics during gait but also as a valuable tool for assessing Leg Length Discrepancy (LLD) while standing.

RESEARCH QUESTION

The purpose of this study was to compare different methods of determining the LLD in paediatric population. We hypothesize that IGA using joint centres is more accurate and precise than the tape measurement.

METHODS

Thirty-one patients with mean age 12.3 (SD=2.4) years were retrospectively included in the study. Their LLD varied between 0 and 36 mm. Three methods for determining LLD were compared to radiography using Bland-Altman analysis: 1. Tape measurement, 2. IGA, summarizing the distance from the spina iliaca anterior superior to the medial malleolus marker via the medial knee condyle marker. 3. IGA, summarizing distances between ankle, knee, and hip joints centres where the latter is calculated with different equations.

RESULTS

The IGA joints method performed better than the tape measurement or IGA markers method. The equations of Davis calculating the hip joint centre had the highest accuracy with mean difference to radiography of 0.7 mm (SD=6.3). The simple Harrington method resulted in a slightly reduced accuracy but higher precision 0.9 mm (SD=6.2). The Harrington method with leg length as input was less accurate 1.0 mm (SD=6.7), but was still considerably better than the tape measurement 1.8 mm (SD=7.0) or IGA markers method 1.1 mm (SD=11.5).

SIGNIFICANCE

Determining LLD with IGA using the distances between ankle, knee and hip joints centres is a feasible method that can be applied in clinical practice to calculate LLD.

25-year Follow-up of Primary Tibial Periosteal Graft for Hard Palate Repair in Cleft Lip and Palate: Outcomes, Concerns and Controversies

OBJECTIVE

This study evaluates long-term outcomes in adults with Unilateral and Bilateral Cleft Lip and Palate (UCLP/BCLP) treated during the period 1992 to 1995 with tibial periosteal graft in primary repair.

DESIGN

Retrospective study.

SETTING

Department of Plastic and Maxillofacial Surgery, Children's Hospital Bambino Gesù (Italy).

PATIENTS

The study included 52 patients with non-syndromic BCLP/UCLP who met the inclusion criteria.

INTERVENTIONS

All patients underwent a standardized surgical protocol using a tibial periosteal graft as primary repair of the hard palate.

MAIN OUTCOME MEASURE(S)

Long-term outcomes on maxillary growth, residual oronasal fistula, and leg length discrepancy.

RESULTS

About <2% of patients showed oral-nasal communication. Mean value of maxillary depth was 86° ± 4.5°. The lower value for maxillary retrusion was 76.8° in relation to the Frankfurt plane. At the x-ray control, 12.2% of patients showed leg discrepancy with a difference of always <2 cm.

CONCLUSIONS

The rate of maxillary retrusion obtained was the same if compared to other techniques. Tibial periosteal graft reduces the risk of fistula and the need for reintervention after secondary bone graft. The study did not observe negative impacts on leg growth after 25 years.

The Effect of Leg Length Discrepancy on Paraspinal Muscles Activation Using Surface Electromyography

OBJECTIVE

The aim of the study is to assess the effects of leg length discrepancy on paraspinal muscle activity and kinematic variables during gait.

DESIGN

Thirty-nine healthy participants aged 5-12 yrs performed the 10-m walk test using the surface electromyography and G-walk sensor for the following conditions: (1) non-leg length discrepancy condition (leg length discrepancy 0 cm) and (2) leg length discrepancy condition with an insole on the right leg at three different heights (leg length discrepancy 0.5 cm, 1.0 cm, and 1.5 cm). The root mean square was normalized using maximal voluntary contraction and reference voluntary contraction methods (RMS_MVC and RMS_ref) and compared between the sides.

RESULTS

The mean RMS_MVC of the 12th thoracic erector spinae on the right side was significantly higher at a leg length discrepancy 0.5 cm and 1 cm. Regarding the 3rd lumbar multifidus, the mean RMS_MVC on the right side was significantly higher at a leg length discrepancy 1.5 cm. The mean RMS_ref exhibited similar patterns. Pelvic obliquity and rotation showed asymmetry at a leg length discrepancy 1.5 cm compared with a leg length discrepancy 0 cm.

CONCLUSIONS

A small leg length discrepancy significantly affected the asymmetric hyperactivation of the 3rd lumbar multifidus and 12th thoracic erector spinae muscles during gait. Considering the action of these muscles, asymmetric hyperactivation might result in rotation and bending of the lumbar spine and the bending of the thoracolumbar spine.

The Effectiveness of Early Rehabilitation in Limiting the Progression of Idiopathic Scoliosis

Background: The purpose of this study was to assess specific rehabilitation methods' effectiveness in early idiopathic scoliosis (IS) development, focusing on lower limb functional inequality's role in scoliosis progression. Materials and Methods: This study comprised 812 patients aged 6-16 years at risk of developing idiopathic scoliosis (IS). The mean (SD) age was 10.66 (3.16) years. Patients were categorized into high- and medium-risk groups based on the angle of trunk rotation (ATR) size. Specific scoliosis physiotherapy was used, and the average follow-up period was 28.1 ± 14.5 months. Changes in ATR, Cobb angle, and functional length of the lower limbs pre- and post-treatment were statistically analyzed across three age groups (6-9, 10-12, and 13-16 years) and three scoliosis locations. Results: Significant effectiveness of early rehabilitation was observed in the high-risk group of children aged 6-9 years. In the medium-risk group, significant reductions in ATR were observed in both the 6-9 and 10-12 age groups across all three scoliosis locations. Additionally, there was a significant decrease in the Cobb angle in the thoracolumbar region and a significant reduction in lower limb inequality across all age groups and scoliosis locations. Conclusions: The early implementation of specific physiotherapy may enhance the efficacy of idiopathic scoliosis treatment by attenuating factors contributing to its progression.

The effects of errorless psychomotor training in the Y balance lower limb reaching task

This study investigated the training effect of errorless psychomotor training, a motor training method with perceptual, attentional, and psychological manipulation, in a balance-related, lower limb reaching task (Y balance reaching task) on dynamic balance by young adults. Thirty-nine participants (Mean age = 27.03 years, SD = 2.64 years) were trained with different psychomotor training methods in the Y balance reaching task. Results illustrate that errorless psychomotor training significantly improved the participants' dynamic balance and proprioceptive abilities. Additionally, gaze fixation duration on target during reaching decreased after errorless psychomotor training, suggesting that errorless psychomotor training could decrease visual information demand and be concurrently compensated by up-weighting on proprioception. This multisensory reweighting and cross-modal attention could contribute to the improvement of dynamic balance ability in sports.

Direct Anterior Approach in Total Hip Arthroplasty for Severe Crowe IV Dysplasia: Retrospective Clinical and Radiological Study

Background and Objectives: total hip arthroplasty (THA) for Crowe IV hip dysplasia poses challenges due to severe leg shortening, muscle retraction and bone stock issues, leading to an increased neurological complication, and revision rate. The direct anterior approach (DAA) is used for minimally invasive THA but its role in Crowe IV dysplasia is unclear. This retrospective study examines if DAA effectively restores hip biomechanics in Crowe IV dysplasia patients with <4 cm leg length discrepancy, managing soft tissue and yielding functional improvement, limb length correction, and limited complications. Materials and Methods: 19 patients with unilateral Crowe IV hip osteoarthritis and <4 cm leg length discrepancy undergoing DAA THA were reviewed. Surgery involved gradual soft tissue release, precise acetabular cup positioning, and stem placement without femoral osteotomy. Results: results were evaluated clinically and radiographically, with complications recorded. Follow-up revealed significant Harris Hip Score and limb length discrepancy improvements. Abductor muscle insufficiency was present in 21%. The acetabular component was accurately placed, centralizing the prosthetic joint's rotation. Complications occurred in 16% of cases, including fractures, nerve issues, and infection. DAA in THA showcased positive outcomes for hip function, limb length, and biomechanics in Crowe IV dysplasia. Conclusions: the technique enabled accurate cup positioning and rotation center adjustment. Complications were managed well without implant revisions. DAA is a viable option for Crowe IV dysplasia, restoring hip function, biomechanics, and reducing limb length discrepancy. Larger, longer studies are needed for validation.

Outcomes of Megaprosthesis ‎Reconstruction for the Salvage of ‎Failed Osteoarticular Allograft ‎‎Around the Knee implanted before ‎Skeletal Maturity in Primary Bone ‎Sarcoma: A Case-Series

Objectives

Functional expectations following the salvage of a failed osteoarticular allograft are poorly described. In this study, we aim to evaluate functional outcomes, implant survival, and complications of the megaprosthesis in salvaging a failed osteoarticular allograft around the knee.

Methods

We retrospectively reviewed the medical profiles of 21 skeletally mature patients who underwent megaprosthesis reconstruction to salvage a failed osteoarticular allograft around the knee implanted before skeletal maturity. The location of reconstruction was the proximal tibia in 13 patients and the distal femur in eight patients. Knee function was evaluated by the Musculoskeletal Tumor Society (MSTS) ‎score and the Toronto Extremity Salvage Score (TESS).

Results

The mean age of patients was 16±1.7 years. The mean interval between the primary (allograft) and secondary (megaprosthesis) reconstructions was 59.4±23.6 months. At an average follow-up of 51.2 months, the mean knee range of motion was 101.2±15.6°. The mean MSTS score and TESS were 83.6±7 and 86.6±7.9, respectively. The mean limb length discrepancy was 2.5±1 cm before and 0.36±0.74 cm after the operation (P<0.001). Six postoperative complications (28.6%) occurred in this series, including one wound dehiscence, one periprosthetic fracture, two acute infections, one aseptic loosening, and one delayed periprosthetic infection. Only the last two complications required revision. Accordingly, the two- and five-year implant survivals were 95.7% and 90%, respectively.

Conclusion

Megaprosthesis is a viable option for salvaging failed osteoarticular allografts around the knee. It also provides the opportunity to correct the limb length discrepancy.

A novel measurement approach to dynamic change of limb length discrepancy using deep learning and wearable sensors

The accurate identification of dynamic change of limb length discrepancy (LLD) in non-clinical settings is of great significance for monitoring gait function change in people's everyday lives. How to search for advanced techniques to measure LLD changes in non-clinical settings has always been a challenging endeavor in recent related research. In this study, we have proposed a novel approach to accurately measure the dynamic change of LLD outdoors by using deep learning and wearable sensors. The basic idea is that the measurement of dynamic change of LLD was considered as a multiple gait classification task based on LLD change that is clearly associated with its gait pattern. A hybrid deep learning model of convolutional neural network and long short-term memory (CNN-LSTM) was developed to precisely classify LLD gait patterns by discovering the most representative spatial-temporal LLD dynamic change features. Twenty-three healthy subjects were recruited to simulate four levels of LLD by wearing a shoe lift with different heights. The Delsys TrignoTM system was implemented to simultaneously acquire gait data from six sensors positioned on the hip, knee and ankle joint of two lower limbs respectively. The experimental results showed that the developed CNN-LSTM model could reach a higher accuracy of 93.24% and F1-score of 93.48% to classify four different LLD gait patterns when compared with CNN, LSTM, and CNN-gated recurrent unit(CNN-GRU), and gain better recall and precision (more than 92%) to detect each LLD gait pattern accurately. Our model could achieve excellent learning ability to discover the most representative LLD dynamic change features for classifying LLD gait patterns accurately. Our technical solution would help not only to accurately measure LLD dynamic change in non-clinical settings, but also to potentially find out lower limb joints with more abnormal compensatory change caused by LLD.

The difference in leg lengths following total knee replacement for patients with severe osteoarthritic deformity

PURPOSE

Increased height after total knee replacement surgery (TKR) may offer patients higher satisfaction as well as the quality of life. Therefore, in this paper, we aim to document the changes in leg length after TKR in patients with severe bilateral deformities.

METHODS

The data of 61 patients were collected from the Egyptian Community Arthroplasty Register; of them, 21 patients had unilateral TKR while 40 had bilateral simultaneous TKR. The patterns of changes in height of 101 osteoarthritic knees were followed up for 1 year after having TKR. All patients had standing leg X-rays, before and after surgery, to document the length of the femur and tibia before and after TKR. Correlations were assessed using the two-sample t-test.

RESULTS

The sample was mostly females (56/61, 91.8%). The distribution of the operated side was nearly equal (right knee was 47/101, 46.5%). The overall average leg length difference was 5.4 (SD = 2.3); for the unilateral group, the average was 4.6 (SD = 2.6); and for the bilateral group, the average was 5.6 (SD = 2.3), p = 0.119. We found that leg length may differ according to the varus deformity angle (p < 0.001) as well as fixed flexion deformity (p < 0.001).

CONCLUSIONS

Leg length increased significantly 1 year after TKR. However, there is not enough evidence to suggest that the bilateral group had a greater height increase when compared to the unilateral group.

Comparison of Pelvic Landmarks for Leg Length Discrepancy Measurement With Robotic Arm-Assisted Total Hip Arthroplasty

Background

Leg length discrepancy (LLD) is a common complication after total hip arthroplasty (THA) leading to significant morbidity and dissatisfaction for patients. A popular system for robotic arm-assisted THA utilizes preoperative computed tomography (CT) scans for surgical planning. Accurate measurement of leg length is crucial for restoring appropriate patient anatomy during the procedure. This study investigates the interobserver and interlandmark reliability of 3 different pelvic landmarks for measuring preoperative LLD.

Methods

We compiled preoperative pelvic CT scans from 99 robotic arm-assisted THAs for osteoarthritis. Radiologic leg length measurement was performed using the robotic arm-assisted THA application by 2 orthopaedic residents using reference lines bisecting the following pelvic landmarks: the anterior superior iliac spines, acetabular teardrops, and most inferior aspect of the ischial rami.

Results

On multivariate analysis, there was no significant difference found (P value = .924) for leg length measurement based on the 3 different pelvic anatomical landmarks. Leg length measurements showed interobserver reliability with significant Pearson correlation coefficients (r = 1.0, 0.94, 0.96, respectively) and nonsignificant differences in LLD means between subjects on paired sample (P value = .158, .085, 0.125, respectively) as well as between landmarks on pairwise comparison.

Conclusions

The 3 pelvic landmarks used in this study can be used interchangeably with the lesser trochanter as the femoral reference point to evaluate preoperative LLD on pelvic CT in patients undergoing robotic-arm assisted THA. This study is the first of its kind to evaluate the interobserver and interlandmark reliability of anatomical landmarks on pelvic CT scans and suggests interchangeability of 3 pelvic landmarks for comparing leg length differences.

Validity and reliability of the DANU sports system for walking and running gait assessment

Objective. Gait assessments have traditionally been analysed in laboratory settings, but this may not reflect natural gait. Wearable technology may offer an alternative due to its versatility. The purpose of the study was to establish the validity and reliability of temporal gait outcomes calculated by the DANU sports system, against a 3D motion capture reference system.Approach. Forty-one healthy adults (26 M, 15 F, age 36.4 ± 11.8 years) completed a series of overground walking and jogging trials and 60 s treadmill walking and running trials at various speeds (8-14 km hr-1), participants returned for a second testing session to repeat the same testing.Main results. For validity, 1406 steps and 613 trials during overground and across all treadmill trials were analysed respectively. Temporal outcomes generated by the DANU sports system included ground contact time, swing time and stride time all demonstrated excellent agreement compared to the laboratory reference (intraclass correlation coefficient (ICC) > 0.900), aside from ground contact time during overground jogging which had good agreement (ICC = 0.778). For reliability, 666 overground and 511 treadmill trials across all speeds were examined. Test re-test agreement was excellent for all outcomes across treadmill trials (ICC > 0.900), except for swing time during treadmill walking which had good agreement (ICC = 0.886). Overground trials demonstrated moderate to good test re-test agreement (ICC = 0.672-0.750), which may be due to inherent variability of self-selected (rather than treadmill set) pacing between sessions.Significance. Overall, this study showed that temporal gait outcomes from the DANU Sports System had good to excellent validity and moderate to excellent reliability in healthy adults compared to an established laboratory reference.

Management of anterior cruciate ligament tears in Tanner stage 1 and 2 children: a narrative review and treatment algorithm guided by ACL tear location

The incidence of anterior cruciate ligament (ACL) tears in skeletally immature patients has acutely increased over the last 20 years, yet there is no consensus on a single "best treatment." Selection of an optimal treatment is critical and based on individual circumstances; consequently, we propose a treatment-selection algorithm based on skeletal development, ACL tear location, type, and quality, as well as parental perspective in order to facilitate the decision-making process. We combined our surgical group's extensive case histories of ACL tear management in Tanner Stage 1 and 2 patients with those in the literature to form a consolidated data base. For each case the diagnostic phase, communication with patient and parents, treatment choice(s), selected surgical techniques and rehabilitation schedule were critically analyzed and compared for patient outcomes. MRI-imaging and intraoperative tissue quality assessment were preeminent in importance for selection of the optimal treatment strategy. Considerations for selecting an optimal treatment included: associated lesions, the child/patient and parent(s)' well-informed and counseled consent, biological potential, and the potential for successful ACL preservative surgery. Complete ACL tears were evaluated according to tear-location. In type I and II ACL tears with remaining good tissue quality, we propose primary ACL repair. In type III and IV ACL tears we propose physeal-sparing reconstruction with an iliotibial band graft. Finally, in the case of a type V ACL tear, we propose that the best treatment be based on the Meyers-McKeever classification. We present a facile decision-making algorithm for ACL management in pediatric patients based on specific elements of tissue damage and status.

Wearables for running gait analysis: A study protocol

Quantitative running gait analysis is an important tool that provides beneficial outcomes to injury risk/recovery or performance assessment. Wearable devices have allowed running gait to be evaluated in any environment (i.e., laboratory or real-world settings), yet there are a plethora of different grades of devices (i.e., research-grade, commercial, or novel multi-modal) available with little information to make informed decisions on selection. This paper outlines a protocol that will examine different grades of wearables for running gait analysis in healthy individuals. Specifically, this pilot study will: 1) examine analytical validity and reliability of wearables (research-grade, commercial, high-end multimodal) within a controlled laboratory setting; 2) examine analytical validation of different grades of wearables in a real-world setting, and 3) explore clinical validation and usability of wearables for running gait analysis (e.g., injury history (previously injured, never injured), performance level (novice, elite) and relationship to meaningful outcomes). The different grades of wearable include: (1) A research-grade device, the Ax6 consists of a configurable tri-axial accelerometer and tri-axial gyroscope with variable sampling capabilities; (2) attainable (low-grade) commercial with proprietary software, the DorsaVi ViMove2 consisting of two, non-configurable IMUs modules, with a fixed sampling rate and (3) novel multimodal high-end system, the DANU Sports System that is a pair of textile socks, that contain silicone based capacitive pressure sensors, and configurable IMU modules with variable sampling rates. Clinical trial registration: Trial registration: NCT05277181.

A deep learning approach for fully automated measurements of lower extremity alignment in radiographic images

During clinical evaluation of patients and planning orthopedic treatments, the periodic assessment of lower limb alignment is critical. Currently, physicians use physical tools and radiographs to directly observe limb alignment. However, this process is manual, time consuming, and prone to human error. To this end, a deep-learning (DL)-based system was developed to automatically, rapidly, and accurately detect lower limb alignment by using anteroposterior standing X-ray medical imaging data of lower limbs. For this study, leg radiographs of non-overlapping 770 patients were collected from January 2016 to August 2020. To precisely detect necessary landmarks, a DL model was implemented stepwise. A radiologist compared the final calculated measurements with the observations in terms of the concordance correlation coefficient (CCC), Pearson correlation coefficient (PCC), and intraclass correlation coefficient (ICC). Based on the results and 250 frontal lower limb radiographs obtained from 250 patients, the system measurements for 16 indicators revealed superior reliability (CCC, PCC, and ICC ≤ 0.9; mean absolute error, mean square error, and root mean square error ≥ 0.9) for clinical observations. Furthermore, the average measurement speed was approximately 12 s. In conclusion, the analysis of anteroposterior standing X-ray medical imaging data by the DL-based lower limb alignment diagnostic support system produces measurement results similar to those obtained by radiologists.

Assessing Leg Length Discrepancy Is Necessary Before Arthroplasty in Patients With Unilateral Crowe Type IV Hip Dislocation

BACKGROUND

THA for high-riding developmental dysplasia of the hip (DDH) is challenging in terms of length equalization. Although previous studies suggested preoperative templating on AP pelvic radiographs is insufficient in patients with unilateral high-riding DDH because of hypoplasia of the hemipelvis on the affected side and unequal femoral and tibial length on scanograms, the results were controversial. The EOS™ (EOS™ Imaging) is a biplane X-ray imaging system using slot-scanning technology. Length and alignment measurements have been shown to be accurate. We used the EOS to compare the lower limb length and alignment in patients with unilateral high-riding DDH.

QUESTIONS/PURPOSES

(1) Is there an overall leg length difference in patients with unilateral Crowe Type IV hip dysplasia? (2) In patients with unilateral Crowe Type IV hip dysplasia with an overall leg length difference, is there a consistent pattern of abnormalities in the femur or tibia that account for observed differences? (3) What is the impact of unilateral high-riding Crowe Type IV dysplasia on femoral neck offset and knee coronal alignment?

METHODS

Between March 2018 and April 2021, we treated 61 patients with THA for Crowe Type IV DDH (high-riding dislocation). EOS imaging was performed preoperatively in all patients. Eighteen percent (11 of 61) of the patients were excluded because of involvement of the opposite hip, 3% (two of 61) were excluded for neuromuscular involvement, and 13% (eight of 61) had previous surgery or fracture, leaving 40 patients for analysis in this prospective, cross-sectional study. Each patient's demographic, clinical, and radiographic information was collected with a checklist using charts, Picture Archiving and Communication System, and an EOS database. EOS-related measurements that were related to the proximal femur, limb length, and knee-related angles were recorded for both sides by two examiners. The findings of the two sides were statistically compared.

RESULTS

The overall limb length was not different between the dislocated and nondislocated sides (mean 725 ± 40 mm versus 722 ± 45 mm, mean difference 3 mm [95% CI -3 to 9 mm); p = 0.08). Apparent leg length was shorter on the dislocated side (mean 742 ± 44 mm versus 767 ± 52 mm, mean difference -25 mm [95% CI -32 to 3 mm]; p < 0.001). We observed that a longer tibia on the dislocated side was the only consistent pattern (mean 338 ± 19 mm versus 335 ± 20 mm, mean difference 4 [95% CI 2 to 6 mm]; p = 0.002), but there was no difference between the femur length (mean 346 ± 21 mm versus 343 ± 19 mm, mean difference 3 mm [95% CI -1 to 7]; p = 0.10). The femur of the dislocated side was longer by greater than 5 mm in 40% (16 of 40) of patients and shorter in 20% (eight of 40). The mean femoral neck offset of the involved side was shorter than that of the normal side (mean 28 ± 8 mm versus 39 ± 8 mm, mean difference -11 mm [95% CI -14 to -8 mm]; p < 0.001). There was a higher valgus alignment of the knee on the dislocated side with a decreased lateral distal femoral angle (mean 84° ± 3° versus 89° ± 3°, mean difference - 5° [95% CI -6° to -4°]; p < 0.001) and increased medial proximal tibia angle (mean 89° ± 3° versus 87° ± 3°, mean difference 1° [95% CI 0° to 2°]; p = 0.04).

CONCLUSION

A consistent pattern of anatomic alteration on the contralateral side does not exist in Crowe Type IV hips except for the length of the tibia. All parameters of the limb length could be shorter, equal to, or longer on the dislocated side. Given this unpredictability, AP pelvis radiographs are not sufficient for preoperative planning, and individualized preoperative planning using full-length images of the lower limbs should be performed before arthroplasty in Crowe Type IV hips.

LEVEL OF EVIDENCE

Level I, prognostic study.

Influence of quality of reduction using radiological criteria on kinematics and kinetics in ankle fractures with unstable syndesmotic injury

BACKGROUND

In ankle fractures with syndesmotic injury, the anatomic reduction of the ankle mortise is crucial for preventing osteoarthritis. Yet, no studies have analysed the effect of surgical reduction after unstable ankle fractures on patients' active functional outcome.

METHODS

The Intraoperative 3D imaging data of patients surgically treated between 2012 and 2019 for ankle fracture with concomitant syndesmotic injury were reviewed. 58 patients were allocated to two groups depending on whether the criteria for radiologically optimal reduction were met (39 patients) or not (19 patients). Criteria for optimal reduction were composed of objectively measured and subjectively rated data. After undertaking the Olerud/Molander ankle score, a gait analysis and several active function tests using 3D motion capture were performed in order to evaluate kinetic and kinematic differences between both groups.

FINDINGS

Patients showed deficits of range of motion and balance parameters on the injured ankle, however, there were no significant differences between both groups.

INTERPRETATION

Although, the data did not show that radiological reduction criteria have a statistically significant effect on active functional outcome after a mean follow up time of 5.7 years, tendencies for a better outcome of patients that met the criteria could be seen. It also must be taken into consideration that results are limited by case number and allocation ratio, which made a sub-analysis of the separate reduction criteria unfeasible.

Deep Learning Segmentation of Lower Extremities Radiographs for an Automatic Leg Length Discrepancy Measurement

Leg length measurement is relevant for the early diagnostic and treatment of discrepancies as they are related with orthopedic and biomechanical changes. Simple radiology constitutes the gold standard on which radiologists perform manual lower limb measurements. It is a simple task but represents an inefficient use of their time, expertise and knowledge that could be spent in more complex labors. In this study, a pipeline for semantic bone segmentation in lower extremities radiographs is proposed. It uses a deep learning U-net model and performs an automatic measurement without consuming physicians' time. A total of 20 radiographs were used to test the methodology proposed obtaining a high overlap between manual and automatic masks with a Dice coefficient value of 0.963. The obtained Spearman's rank correlation coefficient between manual and automatic leg length measurements is statistically different from cero except for the angle of the left mechanical axis. Furthermore, there is no case in which the proposed automatic method makes an absolute error greater than 2 cm in the quantification of leg length discrepancies, being this value the degree of discrepancy from which medical treatment is required.Clinical Relevance- Leg length discrepancy measurements from X-ray images is of vital importance for proper treatment planning. This is a laborious task for radiologists that can be accelerated using deep learning techniques.

Simultaneous anterior cruciate ligament reconstruction and implant-mediated guided growth to correct genu valgum in skeletally immature patients

OBJECTIVES

Adolescents with anterior cruciate ligament (ACL) tears can present with concomitant lower extremity coronal plane angular deformity (CPAD) that both predispose to injury as well as may increase the risk of graft rupture following ACL reconstruction (ACLR). The goal of this study was to examine the safety and efficacy of concomitant ACLR with implant-mediated guided growth (IMGG) compared to isolated IMGG procedures in paediatric and adolescent patients.

METHODS

Operative records of all paediatric and adolescent patients (age ≤ 18 years) that underwent simultaneous ACLR and IMGG by one of two paediatric orthopaedic surgeons between 2015 and 2021 were retrospectively reviewed. A comparison cohort of isolated IMGG patients was identified and matched based on bone age within one year, sex, laterality, and fixation type (i.e. transphyseal screw vs. tension band plate and screw construct). Pre- and post-operative mechanical axis deviation (MAD), angular axis deviation (AAD), lateral distal femoral angle (LDFA), and medial proximal tibial angle (MPTA) were recorded.

RESULTS

A total of 9 participants who underwent concomitant ACLR and IMGG (ACLR ​+ ​IMGG) were identified, with 7 of these participants meeting the final inclusion criteria. The participants had a median age of 12.7 (IQR ​= ​12.1 - 14.2) years and median bone age of 13.0 (IQR ​= ​12.0 - 14.0) years. Of the 7 participants that underwent ACLR and IMGG, 3 underwent a modified MacIntosh procedure with ITB autograft, 2 received quadriceps tendon autograft, and 1 underwent hamstring autograft reconstruction. There were no significant differences in the amount of correction obtained between ACLR ​+ ​IMGG and matched IMGG subjects with respect to any measurement variable (MAD difference: p ​= ​0.47, AAD difference: p ​= ​0.58, LDFA difference: p ​= ​0.27, MPTA difference: p ​= ​0.20). There were also no significant differences in alignment variables per unit time between cohorts (MAD/month: p ​= ​0.62, AAD/month ​= ​0.80, LDFA/month ​= ​0.27, MPTA/month ​= ​0.20).

CONCLUSION

The results of the current study indicate that concomitant ACLR and lower extremity CPAD correction is a safe approach to treat CPAD concomitantly with ACLR in young patients who present with an acute ACL tear. Furthermore, one can expect reliable correction of CPAD after combined ACLR and IMGG, no different than the correction obtained in the setting of IMGG alone.

LEVEL OF EVIDENCE

III.

Body height estimation from automated length measurements on standing long leg radiographs using artificial intelligence

Artificial-intelligence (AI) allows large-scale analyses of long-leg-radiographs (LLRs). We used this technology to derive an update for the classical regression formulae by Trotter and Gleser, which are frequently used to infer stature based on long-bone measurements. We analyzed calibrated, standing LLRs from 4200 participants taken between 2015 and 2020. Automated landmark placement was conducted using the AI-algorithm LAMA™ and the measurements were used to determine femoral, tibial and total leg-length. Linear regression equations were subsequently derived for stature estimation. The estimated regression equations have a shallower slope and larger intercept in males and females (Femur-male: slope = 2.08, intercept = 77.49; Femur-female: slope = 1.9, intercept = 79.81) compared to the formulae previously derived by Trotter and Gleser 1952 (Femur-male: slope = 2.38, intercept = 61.41; Femur-female: slope = 2.47, intercept = 54.13) and Trotter and Gleser 1958 (Femur-male: slope = 2.32, intercept = 65.53). All long-bone measurements showed a high correlation (r ≥ 0.76) with stature. The linear equations we derived tended to overestimate stature in short persons and underestimate stature in tall persons. The differences in slopes and intercepts from those published by Trotter and Gleser (1952, 1958) may result from an ongoing secular increase in stature. Our study illustrates that AI-algorithms are a promising new tool enabling large-scale measurements.

Induced leg length inequality affects pelvis orientation during upright standing immediately following a sit-to-stand transfer: a pre-post measurement study

BACKGROUND

Leg length inequality (LLI) greater than 20 mm has been associated with low back pain (LBP) and its correction is clinically recommended. Much less is known about the biomechanical effects that LLI below 15 mm has on pelvis orientation.

METHODS

Twenty-two adult participants (8 female) aged between 18 and 30 years without LBP were enrolled in the study and completed a series of sit-to-stand trials with no heel-lift (0 mm baseline) and heel-lifts of varying heights (5, 9 and 12 mm) placed in their right shoe. Three-dimensional kinematic data were obtained from the lower extremities, pelvis and thorax. Additional kinematic data were obtained from the left and right sides of the pelvis. The global orientation of the whole pelvis and relative orientation between the left and right sides of the pelvis were obtained in upright standing immediately upon completion of the sit-to-stand movement. Repeated measures ANOVAs were used to detect differences in sample means across the different levels of heel-lift (0, 5, 9, and 12 mm). The tests for within-subject effects determined overall significant differences between the means at the different levels of heel-lift induced LLI. Partial Eta-Squared was used to express the size for the main effect of heel-lift height. For each level of heel-lift, the estimated marginal mean and 95% confidence interval (95%CI) values of pelvis angles were illustrated graphically.

RESULTS

Left frontal plane rotation of the pelvis increased (p = 0.001), that is, the left side of the pelvis was lower than the right side of the pelvis, and anterior tilt of the pelvis decreased (p = 0.020) with a heel-lift height (applied on the right) as low as 5 mm. A significant main effect of heel-lift was only observed for the norm of rotations about all three axes for relative-pelvis orientation (p = 0.034). Post-hoc analyses did not reveal any statistically significant differences between the heel-lifts and the 0 mm baseline (p≥0.072).

CONCLUSION

These findings suggest that correcting leg length inequality below the recommended threshold of 20 mm may influence pelvic orientation. Future work can investigate the effects of the altered orientations on spine loading and the clinical effects of corrections to minor leg length inequality.

Normative Femoral and Tibial Lengths in a Modern Population of Twenty-First-Century U.S. Children

BACKGROUND

The Green-Anderson (GA) leg-length data remain the gold standard for the age-based assessment of leg lengths in children despite their methodologic weaknesses. We aimed to summarize current growth trends among a cross-sectional cohort of modern U.S. children using quantile regression methods and to compare the median femoral and tibial lengths of the modern U.S. children with those of the GA cohort.

METHODS

A retrospective review of scanograms and upright slot-scanning radiographs obtained in otherwise healthy children between 2008 and 2020 was completed. A search of a radiology registry revealed 3,508 unique patients between the ages of 2 and 18 years for whom a standard-of-care scanogram or slot-scanning radiograph had been made. All patients with systemic illness, genetic conditions, or generalized diseases that may affect height were excluded. Measurements from a single leg at a single time point per subject were included, and the latest available time point was used for children who had multiple scanograms made. Quantile regression analysis was used to fit the lengths of the tibia and femur and overall leg length separately for male patients and female patients.

RESULTS

Seven hundred patients (328 female and 372 male) met the inclusion criteria. On average, the reported 50th percentile tibial lengths from the GA study at each time point were shorter than the lengths in this study by 2.2 cm (range, 1.4 to 3.3 cm) for boys and 2 cm (range, 1.1 to 3.1 cm) for girls. The reported 50th percentile femoral lengths from the GA study at each time point were shorter than the lengths in this study by 1.8 cm (range, 1.1 to 2.5 cm) for boys and 1.7 cm (range, 0.8 to 2.3 cm) shorter for girls.

CONCLUSIONS

This study developed new growth charts for femoral and tibial lengths in a modern U.S. population of children. The new femoral and tibial lengths at nearly all time points are 1 to 3 cm longer than traditional GA data. The use of GA data for epiphysiodesis could result in underestimation of expected childhood growth.

LEVEL OF EVIDENCE

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

Effects of Trail Running versus Road Running-Effects on Neuromuscular and Endurance Performance-A Two Arm Randomized Controlled Study

Running on less predictable terrain has the potential to increase the stimulation of the neuromuscular system and can boost aerobic performance. Hence, the purpose of this study was to analyze the effects of trail versus road running on neuromuscular and endurance performance parameters in running novices. Twenty sedentary participants were randomly assigned to either a trail (TRAIL; n = 10) or road running (ROAD; n = 10) group. A supervised and progressive, moderate intensity, and work-load-matched 8 wk endurance running program on TRAIL or ROAD was prescribed (i.e., randomized). Static balance (BESS test), dynamic balance (Y-balance test), gait analysis (RehaGait test, with regard to stride time single task, stride length dual task, velocity single task), agility performance (t-test), isokinetic leg strength (BIODEX), and predicted VO2max were assessed in pre- and post-tests. rANOVA analysis revealed no significant time-group interactions. Large effect sizes (Cohen's d) for pairwise comparison were found for TRAIL in the BESS test (d = 1.2) and predicted (pred) VO2max (d = 0.95). Moderate effects were evident for ROAD in BESS (d = 0.5), stride time single task (d = 0.52), and VO2max predicted (d = 0.53). Possible moderate to large effect sizes for stride length dual task (72%), velocity single task (64%), BESS test (60%), and the Y-balance test left stance (51%) in favor of TRAIL occurred. Collectively, the results suggested slightly more beneficial tendencies in favor of TRAIL. Additional research is needed to clearly elucidate differences between TRAIL and ROAD, not only in novices but also in experienced exercisers.

Relationship between perceived and structural leg length discrepancies of patients with hip osteoarthritis dysplasia

BACKGROUND

Only few studies have been conducted on leg length discrepancy (LLD) in patients with hip osteoarthritis (OA). This study aimed to examine the relationship between perceived LLD (pLLD) and structural LLD (sLLD) in patients with advanced OA and to determine the factors influencing both LLDs. This retrospective study aimed to answer the following questions: (1) are older adults less likely to perceive LLD than younger adults? (2) is there a relationship between pLLD and sLLD? and (3) is pLLD associated with patient satisfaction?

HYPOTHESIS

We hypothesized that older adults are less likely to perceive LLD than younger adults.

PATIENTS AND METHODS

We recruited 125 patients (102 women and 23 men) with hip OA associated with developmental dysplasia of the hip defined as grade 3 or higher according to the Tönnis classification and excluding contralateral grade 2 or higher. The mean age of the patients was 65.2±11.2 (36-85) years. Before surgery, 2-mm and 5-mm thick plates were placed on the floor on the plantar surface of the short leg to measure pLLD. Preoperative computed tomography (CT) was performed and sLLDs were measured using the 3D planning software ZedHip. The following associated factors were evaluated: age, height, weight, body mass index (BMI), adduction and abduction range of motion (ROM) of the affected hip joint, Crowe classification, standing pelvic inclination in the coronal plane, Cobb angle and Japanese Orthopaedic Association Hip Disease Evaluation Questionnaire (JHEQ).

RESULTS

The absolute difference between pLLD and sLLD was modestly positively correlated with age (R=0.206; p<0.05) indicating older patients were less prone to perceive LLD. A strong positive correlation was found between pLLD (4.8±7.3mm; range: -37 to 28mm) and sLLD (6.4±7.0mm; range: -29.9 to 23.7mm) (R=0.714, p<0.05). The greater the pLLD, the smaller the hip abduction ROM (24.8±11.6°; range: 0 to 45°) tended to be, while the greater the sLLD, the smaller the hip abduction and adduction ROM (10.3±5.7°; range: 0 to 25°) tended to be (R= -0.259 and R= -0.297, respectively; p<0.05) The clinical significance of this finding is that pLLD may be improved if hip ROM training is performed before surgery. pLLD was significantly smaller in the group without pelvic inclination (8.0±14.1mm; range: -37 to 22mm) than in the group with pelvic inclination to the affected side (6.9±7.5mm; range: -12 to 28mm) and in the group with no inclination to the affected side (7.3±7.6mm; range: -8 to 25mm) (p<0.05) The clinical significance of this finding is that improving pelvic inclination with hip ROM training or muscle stretching may also reduce pLLD. No significant differences were noted between pLLD and JHEQ total scores or subgroups.

DISCUSSION

Older patients had less pLLD. Preoperative pLLD was strongly correlated with sLLD but not with patient satisfaction. These results may be useful for conservative treatment of OA, preoperative planning and intraoperative leg length correction.

LEVEL OF EVIDENCE

IV; case control study.

Perioperative management of leg-length discrepancy in total hip arthroplasty: a review

Leg-length discrepancy (LLD) presents a significant management challenge to orthopedic surgeons and remains a leading cause of patient dissatisfaction and litigation after total hip arthroplasty (THA). Over or under-lengthening of the operative extremity has been shown to have inferior outcomes, such as dislocation, exacerbation of back pain and sciatica, and general dissatisfaction postoperatively. The management of LLD in the setting of THA is multifactorial, and must be taken into consideration in the pre-operative, intra-operative, and post-operative settings. In our review, we aim to summarize the best available practices and techniques for minimizing LLD through each of these phases of care. Pre-operatively, we provide an overview of the appropriate radiographic studies to be obtained and their interpretation, as well as considerations to be made when templating. Intra-operatively, we discuss several techniques for the assessment of limb length in real time, and post-operatively, we discuss both operative and non-operative management of LLD. By providing a summary of the best available practices and strategies for mitigating the impact of a perceived LLD in the setting of THA, we hope to maximize the potential for an excellent surgical and clinical outcome.

Effects of Load Carriage on Postural Control and Spatiotemporal Gait Parameters during Level and Uphill Walking

Load carriage and uphill walking are conditions that either individually or in combination can compromise postural control and gait eliciting several musculoskeletal low back and lower limb injuries. The objectives of this study were to investigate postural control responses and spatiotemporal parameters of gait during level and uphill unloaded (UL), back-loaded (BL), and front-loaded (FL) walking. Postural control was assessed in 30 asymptomatic individuals by simultaneously recording (i) EMG activity of neck, thoracic and lumbar erector spinae, and rectus abdominis, (ii) projected 95% ellipse area as well as the anteroposterior and mediolateral trunk displacement, and (iii) spatiotemporal gait parameters (stride/step length and cadence). Measurements were performed during level (0%) and uphill (5, 10, and 15%) walking at a speed of 5 km h^-1 without and with a suspended front pack or a backpack weighing 15% of each participant's body weight. The results of our study showed that postural control, as indicated by increased erector spinae EMG activity and changes in spatiotemporal parameters of gait that manifested with decreased stride/step length and increased cadence, is compromised particularly during level and uphill FL walking as opposed to BL or UL walking, potentially increasing the risk of musculoskeletal and fall-related injuries.

Relationship of early postoperative perceived leg length discrepancy to the progression of osteoarthritis in the contralateral hip after unilateral total hip arthroplasty—a retrospective cohort study using propensity score matching

[Purpose] This study aimed to identify the relationship between the early postoperative perceived leg length discrepancy after unilateral total hip arthroplasty and the progression of osteoarthritis in the contralateral hip. [Participants and Methods] This was a retrospective cohort study of 65 patients who underwent primary unilateral total hip arthroplasty for bilateral hip osteoarthritis. The minimum joint space width of the contralateral hip was measured preoperatively. The change in minimum joint space width one year postoperatively compared with preoperatively was measured. At three weeks postoperatively, patients were divided into the perceived and non-perceived leg length discrepancy groups using the block test. Patients with a perceived leg length discrepancy of 2 mm or more and less than 2 mm were grouped into the perceived and non-perceived leg length discrepancy groups, respectively. Before and after propensity score matching, the change in minimum joint space width between the two groups from the preoperative period to one year postoperatively was compared. [Results] In the pre-propensity matching sample, there was no significant difference in the change in minimum joint space width between the two groups. In the post-propensity matching sample, the change in minimum joint space width in the perceived leg length discrepancy group was significantly larger than that in the non-perceived leg length discrepancy group. [Conclusion] The early postoperative perceived leg length discrepancy after unilateral total hip arthroplasty may affect the progression of osteoarthritis in the contralateral hip.

CORONAL PLANE GROWTH MODULATION FOR GENU VALGUM IN SKELETAL DYSPLASIA

Objective

To investigate the efficiency and rates of correction by hemiepiphysiodesis using 8-plate to manage genu valgum deformity in children with skeletal dysplasia.

Methods

Eleven children with skeletal dysplasia (three female, eight male; mean age = 10.5 years; age range = 7-13) who underwent temporary hemiepiphysiodesis using 8-plates for genu valgum deformity were retrospectively reviewed. There were nine bilateral cases and two unilateral cases. The mean follow-up time from the index surgery to the final follow-up was 45 (ranging from 24 to 72) months. Radiographical assessment including preoperative and final follow-up measurements of joint orientation angles and mechanical axis deviation (MAD) were conducted.

Results

Deformities were completely corrected in nine lower extremities (45%) and partially corrected in seven extremities (35%). In four extremities of two children with Morquio syndrome, MAD worsened. The correction rate of MAD was 1.25 ± 1.62 mm/mo.

Conclusion

Though hemiepiphysiodesis using 8-plate requires a longer treatment period, it seems to be an effective treatment for correction of genu valgum in children with skeletal dysplasia. Level of Evidence IV, Case Series.

Leg length discrepancy assessment in total hip arthroplasty: is a pelvic radiograph sufficient?

AIMS

Leg length discrepancy (LLD) is a common pre- and postoperative issue in total hip arthroplasty (THA) patients. The conventional technique for measuring LLD has historically been on a non-weightbearing anteroposterior pelvic radiograph; however, this does not capture many potential sources of LLD. The aim of this study was to determine if long-limb EOS radiology can provide a more reproducible and holistic measurement of LLD.

METHODS

In all, 93 patients who underwent a THA received a standardized preoperative EOS scan, anteroposterior (AP) radiograph, and clinical LLD assessment. Overall, 13 measurements were taken along both anatomical and functional axes and measured twice by an orthopaedic fellow and surgical planning engineer to calculate intraoperator reproducibility and correlations between measurements.

RESULTS

Strong correlations were observed for all EOS measurements (r_s > 0.9). The strongest correlation with AP radiograph (inter-teardrop line) was observed for functional-ASIS-to-floor (functional) (r_s = 0.57), much weaker than the correlations between EOS measurements. ASIS-to-ankle measurements exhibited a high correlation to other linear measurements and the highest ICC (r_s = 0.97). Using anterior superior iliac spine (ASIS)-to-ankle, 33% of patients had an absolute LLD of greater than 10 mm, which was statistically different from the inter-teardrop LLD measurement (p < 0.005).

DISCUSSION

We found that the conventional measurement of LLD on AP pelvic radiograph does not correlate well with long leg measurements and may not provide a true appreciation of LLD. ASIS-to-ankle demonstrated improved detection of potential LLD than other EOS and radiograph measurements. Full length, functional imaging methods may become the new gold standard to measure LLD.Cite this article: Bone Jt Open 2022;3(12):960-968.

The Importance of Monitoring and Factors That May Influence Leg Length Difference in Developmental Dysplasia of the Hip

In unilateral Developmental Dysplasia of the Hip (DDH), avascular necrosis (AVN), femoral or pelvic osteotomy, and residual dysplasia causing subluxation of the proximal femur may influence Leg Length Discrepancy (LLD). This can lead to gait compensation, pelvic obliquity, and spinal curvature. The aim of this study is to determine the prevalence of LLD, establish which limb segment contributes to the discrepancy, describe how AVN influences LLD, and ascertain variables that may influence the need for LLD corrective procedures.

METHODOLOGY

This study assessed long-leg radiographs at skeletal maturity. Radiographs were assessed for the articulo-trochanteric distance (ATD) and femoral and tibial length. AVN was classified according to Kalamchi-MacEwen.

RESULTS

109 patients were included. The affected/DDH leg was longer in 72/109 (66%) patients. The length difference was mainly in the subtrochanteric segment of the femur. AVN negatively influenced leg length. Older (≥three years) patients with multiple procedures were more likely to have AVN. LLD interventions were performed in 30 (27.5%) patients. AVN grade or type of DDH surgery did not influence the odds of needing a procedure to correct LLD.

CONCLUSIONS

Procedures to correct LLD were performed irrespective of previous DDH surgery or AVN grades. In most patients, the affected/DDH leg was longer, mainly in the subtrochanteric segment of the femur, largely influenced by femoral osteotomy in patients with multiple operative procedures for DDH. We recommend careful monitoring of LLD in DDH.

Treatment of Symptomatic Subfibular Ossicle by Excision and Modified Broström Procedure for Skeletally Immature Patients

BACKGROUND

Ossicle resection combined with ligament repair using the modified Broström procedure (MBP) is generally associated with favorable results in adults with symptomatic subfibular ossicles; however, the surgical results of this approach in skeletally immature patients remain unclear. The purpose of this study was to investigate the midterm clinical outcomes and radiographic outcomes including leg length and physeal growth of skeletally immature patients after this procedure.

METHODS

Twenty-six consecutive skeletally immature patients who underwent ossicle resection combined with the MBP were retrospectively evaluated. Clinical scores were evaluated using the visual analog scale (VAS), American Orthopaedic Foot & Ankle Society (AOFAS) ankle-hindfoot score, Karlsson-Peterson score, and Tegner score. The talocrural angle, fibular length on radiographs, and tape-measured leg length between the 2 ankles were also measured at the final follow-up. Time of return to sports and postoperative complications were also evaluated.

RESULTS

Fourteen girls (53.8%) and 12 boys (46.2%) had surgery at a mean age of 12.7±2.4 years. Mean postoperative follow-up time was 40.0±10.8 months. Mean VAS pain score improved from 4.1 preoperatively to 0.5 at final follow-up (P < .05). Mean AOFAS score, Karlsson score, and Tegner score all improved from 62.0, 54.0, and 2.8 preoperatively to 95.5, 94.0, and 5.4 (P < .05), respectively, at final follow-up. Median time of return to sports was 17.0 weeks. Mean talocrural angle, fibular length, and tape-measured leg length of the injured ankle were not significantly different from those of the contra-side at the final follow-up. All patients were satisfied with the results; repeat ligamentous injury occurred in 2 patients (7.7%). We had no cases of wound infection, nerve injury, compartment syndrome, or any other complications.

CONCLUSION

Ossicle resection combined with the MBP performed in skeletally immature patients with symptomatic subfibular ossicles resulted in improved clinical outcomes without disruption of fibular physeal growth by an average of 3.3-year follow-up.

LEVEL OF EVIDENCE

Level IV, case series.

Development and evaluation of deep-learning measurement of leg length discrepancy: bilateral iliac crest height difference measurement

BACKGROUND

Leg length discrepancy (LLD) is a common problem that can cause long-term musculoskeletal problems. However, measuring LLD on radiography is time-consuming and labor intensive, despite being a simple task.

OBJECTIVE

To develop and evaluate a deep-learning algorithm for measurement of LLD on radiographs.

MATERIALS AND METHODS

In this Health Insurance Portability and Accountability Act (HIPAA)-compliant retrospective study, radiographs were obtained to develop a deep-learning algorithm. The algorithm developed with two U-Net models measures LLD using the difference between the bilateral iliac crest heights. For performance evaluation of the algorithm, 300 different radiographs were collected and LLD was measured by two radiologists, the algorithm alone and the model-assisting method. Statistical analysis was performed to compare the measurement differences with the measurement results of an experienced radiologist considered as the ground truth. The time spent on each measurement was then compared.

RESULTS

Of the 300 cases, the deep-learning model successfully delineated both iliac crests in 284. All human measurements, the deep-learning model and the model-assisting method, showed a significant correlation with ground truth measurements, while Pearson correlation coefficients and interclass correlations (ICCs) decreased in the order listed. (Pearson correlation coefficients ranged from 0.880 to 0.996 and ICCs ranged from 0.914 to 0.997.) The mean absolute errors of the human measurement, deep-learning-assisting model and deep-learning-alone model were 0.7 ± 0.6 mm, 1.1 ± 1.1 mm and 2.3 ± 5.2 mm, respectively. The reading time was 7 h and 12 min on average for human reading, while the deep-learning measurement took 7 min and 26 s. The radiologist took 74 min to complete measurements in the deep-learning mode.

CONCLUSION

A deep-learning U-Net model measuring the iliac crest height difference was possible on teleroentgenograms in children. LLD measurements assisted by the deep-learning algorithm saved time and labor while producing comparable results with human measurements.

Radiographic Evaluation of Pediatric Patients with Patellofemoral Instability

PURPOSE OF REVIEW

The purpose of this review is to highlight the radiographic assessments of utility in the evaluation of a pediatric patient with patellofemoral instability to facilitate a thorough work-up. Understanding of these measures is useful in understanding evolving research in this field, providing accurate patient risk assessment, and appropriately directing surgical decision-making.

RECENT FINDINGS

Recent literature has broadened the radiographic characterization of the pediatric patellar instability and its anatomic risk factors. Knee MRI can inform the assessment of skeletal maturity and novel axial alignment measurements may enhance our identification of patients at increased risk of recurrent instability. Additional improvements have been made in the objective measurement and classification of trochlear dysplasia. Knee MRI-based skeletal age assessments may obviate the need for hand bone age assessments in growing children with patellofemoral instability. Novel objective measures exist in the evaluation of pediatric patellar instability both in the assessment of axial alignment and trochlear dysplasia. Future work should focus on how these measures can aid in guiding surgical decision-making.

Alteration of quadriceps muscle activity during functional step tasks after extended sitting session

BACKGROUND

Prolonged sitting with high knee flexion is a common activity that may affect patellofemoral joint compression and quadriceps length. Exploring the quadriceps activation after sitting may help to explain the mechanism underlying muscle changes and the resulting patellofemoral pain.

OBJECTIVES

To examine changes in quadriceps activity after prolonged sitting in cross-legged sitting, side-sitting, and sitting on a chair.

DESIGN

Laboratory observational study.

METHOD

Thirty healthy women participated and were randomly allocated to three groups of different sitting positions (n = 10/group). Electromyography (EMG) of the vastus medialis (VM), rectus femoris (RF), and vastus lateralis (VL) was performed before and after 15 min after sitting. EMG was conducted during step-up and step-down tests and was reported as %MVIC. The results were analysed using Wilcoxon signed-rank test and Kruskal-Wallis ANOVA.

RESULTS

VM activity and EMG activity during the step-down test after sitting increased significantly in the cross-legged group (p = 0.01). Sitting postures significantly influenced (p = 0.02) muscle activity changes in the VL and VM during the step-up test. Pairwise comparisons revealed significant differences between the cross-legged sitting and sitting on a chair groups.

CONCLUSIONS

Prolonged cross-legged sitting and side-sitting caused changes in VM and VL activity during step tasks in healthy young women. After cross-legged sitting, the VM exhibited a significantly higher activity in descending control, and changes in VM and VL activity increased significantly during the step-up task. Increased VM and VL activation possibly controls the patellofemoral joint. Therefore, they may fatigue more easily when many step tasks or squatting exercises are performed.