Effects of lower limb length discrepancy on spinopelvic compensation following total hip arthroplasty in patients with developmental dysplasia of the hip.

BACKGROUND: Limited research has examined the impact of lower limb length discrepancy (LLLD) alteration on spinopelvic compensation in individuals with developmental dysplasia of the hip (DDH). This study aimed to investigate the effects of LLLD on spinopelvic compensation following total hip arthroplasty (THA) and elucidate the complex biomechanical adaptations in the spinopelvic structures. METHODS: A retrospective review of DDH patients undergoing THA from January 2014 to December 2021 categorized individuals with Crowe type I and II into the low dislocation group (LDG, n = 94) and those with Crowe type III and IV into the high dislocation group (HDG, n = 43). Demographic data, as well as preoperative, postoperative, and last follow-up imaging data, including lower limb length (LLL), sacral obliquity (SO), iliac obliquity (IO), hip obliquity (HO), Cobb angle, apical vertebral translation (AVT), and coronal decompensation (CD), were collected for analysis. RESULTS: Patients in the LDG had a significantly higher surgical age and shorter disease duration (P<0.05). In LDG, patients exhibited substantial postoperative reductions in LLLD, SO, IO, and HO (P<0.05), while Cobb Angle, AVT, and CD showed no statistically significant changes (P>0.05). The variation in LLLD correlated significantly with the variations in SO, IO, and HO (P<0.05). Postoperative outcomes in the HDG demonstrated marked decreases in LLLD, SO, IO, HO, and CD (P<0.05), with no significant change in Cobb angle and AVT (P>0.05). The variation in LLLD correlated significantly with the variations in SO, IO, HO, and CD (P<0.05). CONCLUSIONS: THA effectively reduces LLLD in patients with DDH, and the variation in LLLD correlates meaningfully with the recovery of spinopelvic compensatory mechanisms.

Leg length discrepancies (LLD): An etiology to be considered in its proper measure. A critical and historical review.

INTRODUCTION: Studies of leg-length discrepancies (LLD) have been the subject of debate for almost 200 years. A large number of studies have emerged, most frequently using assessment criteria based on painful symptoms or joint damage. DEVELOPMENT: While many authors argue for a threshold of 10-20 mm to establish a link between pain and LLD, most publications based on radiography show lesion stigmata on lumbar, hip and knee joints as early as 6 mm. This would be linked to comorbidities. DISCUSSION: Some studies argue forcefully that leg-length correction below 20 mm is of no benefit. The authors of the present article, on the other hand, evoke the notion of lesion risks in the absence of correction, even for small deviations in the presence of certain associated factors and according to their importance. CONCLUSION: The authors argue for the need to define in the future a lesion significance score that would not be correlated to painful symptomatology, but rather to the presence of co-morbidities such as age, anatomical variability, sports practice and/or patients' professional activities. Other parameters, such as mobility, should also be taken into consideration, while gender, height and weight do not appear to be significantly related.

Mathematical explanations for knee osteotomies: "Dear engineer, how would you explain it in a simple way?"

INTRODUCTION: Knee osteotomies are effective procedures to treat different deformities and to redistribute the load at the joint level, reducing the risk of wear and, consequently, the need for invasive procedures. Particularly, knee osteotomies are effective in treating early arthritis related to knee deformities in young and active patients with high functional demands, with excellent long-term results. Precise mathematical calculations are imperative during the preoperative phase to achieve tailored and accurate corrections for each patient and avoid complications, but sometimes those formulas are challenging to comprehend and apply. METHODS: Four specific questions regarding controversial topics (planning methods, patellar height, tibial slope, and limb length variation) were formulated. An electronic search was performed on PubMed and Cochrane Library to find articles containing detailed mathematical or trigonometrical explanations. A team of orthopedic surgeons and an engineer summarized the available Literature and mathematical rules, with a final clear mathematical explanation given by the engineer. Wherever the explanation was not available in Literature, it was postulated by the same engineer. RESULTS: After the exclusion process, five studies were analyzed. For three questions, no studies were found that provided mathematical analyses or explanations. Through independent calculations, it was demonstrated why Dugdale's method underestimates the correction angle compared to Miniaci's method, and it was shown that the variation in patellar height after osteotomy can be predicted using simple formulas. The five included studies examine postoperative variations in limb length and tibial slope, providing formulas applicable in preoperative planning. New formulas were independently computed, using the planned correction angle and preoperatively obtained measurements to predict the studied variations. CONCLUSIONS: There is a strict connection among surgery, planning, and mathematics formulas in knee osteotomies. The aim of this study was to analyze the current literature and provide mathematical and trigonometric explanations to important controversial topics in knee osteotomies. Simple and easy applicable formulas are provided to enhance the accuracy and outcomes of this surgical procedure.

Risk Factor Analysis for Growth Arrest in Paediatric Physeal Fractures-A Prospective Study.

Background: Fractures through the physis account for 18-30% of all paediatric fractures, leading to growth arrest in up to 5.5% of cases. We have limited knowledge to predict which physeal fractures result in growth arrest and subsequent deformity or limb length discrepancy. The purpose of this study is to identify factors associated with physeal growth arrest to improve patient outcomes. Methods: This prospective cohort study was designed to develop a clinical prediction model for growth arrest after physeal injury. Patients ≤ 18 years old presenting within four weeks of injury were enrolled if they had open physes and sustained a physeal fracture of the humerus, radius, ulna, femur, tibia or fibula. Patients with prior history of same-site fracture or a condition known to alter bone growth or healing were excluded. Demographic data, potential prognostic indicators, and radiographic data were collected at baseline, during healing, and at one- and two-years post-injury. Results: A total of 332 patients had at least six months of follow-up or a diagnosis of growth arrest within six months of injury. In a comparison analysis, patients who developed growth arrest were more likely to be older (12.8 years vs. 9.4 years) and injured on the right side (53.0% vs. 45.7%). Initial displacement and angulation rates were higher in the growth arrest group (59.0% vs. 47.8% and 47.0% vs. 38.8%, respectively), but the amount of angulation was similar (27.0° vs. 28.4°). Rates of growth arrest were highest in distal femoral fractures (86%). Conclusions: The incidence of growth arrest in this patient population appears higher than the past literature reports at 30.1%. However, there may be variances in diagnostic criteria for growth arrest, and the true incidence may be lower. A number of patients were approaching skeletal maturity, and any growth arrest is likely to have less clinical significance in these cases. Further prospective long-term follow-up is required to determine risk factors, incidence, and true clinical impact of growth arrest when it does occur.

Technical Considerations in One Anastomosis Gastric Bypass-the Israeli Society of Metabolic and Bariatric Surgery Experience.

BACKGROUND: One anastomosis gastric bypass (OAGB) is gaining popularity worldwide due to its safety and effectiveness. OAGB is the most commonly performed metabolic bariatric surgery (MBS) in Israel. Israel is the only country where OAGB is the most prevalent MBS. Our aim is to address OAGB technical aspects using a national survey completed by members of the Israeli Society of Metabolic and Bariatric Surgery (ISMBS). MATERIALS AND METHODS: An online-survey composed of a 17-item-based questionnaire was sent to ISMBS members. All responses were collected and analyzed. RESULTS: A total of 47/64 (73.4%) ISMBS members participated in the survey. Most surgeons (74.5%) had > 10 years of MBS experience, and most (61.7%) performed > 100 MBS/year. The majority (78.7%) perform OAGB as their most common procedure. Most surgeons fashion a 10-15-cm pouch and use a 36-Fr bougie, (57.4% and 38.3%). Regarding bowel length measurement, 70% use visual estimation and 10.6% routinely measure total small bowel length (TSBL). The most common reasons for creating a longer biliopancreatic limb (BPL) were high body mass index (BMI) and revisional surgery (83.3% and 66%, respectively). In a primary procedure of a patient with a BMI = 40, most (76.6%) would create a 150-200-cm BPL. In patients with a BMI > 50 or revisional cases, most (70.2% and 68.0%) would create a 175-225-cm BPL. CONCLUSION: OAGB is the most prevalent MBS performed in Israel. This survey showed common preferences and variations among ISMBS members. Further studies are needed in order to standardize and build a consensus on OAGB technique.

A Novel Approach for Correcting Limb Length Discrepancy in Total Hip Arthroplasty.

INTRODUCTION: This study aimed to evaluate the accuracy of the suture technique, along with the utilization of a spirit-level device which is an instrument designed to indicate whether a surface is horizontal or vertical, in comparison to the conventional supraacetabular pin method and caliper measurement for correcting leg length discrepancy (LLD) during total hip arthroplasty (THA). Materials and methods: Consecutive patients who underwent unilateral primary THA between January 2021 and March 2023 were included in the study. The exclusion criteria were severe flexion and adduction contracture that could affect the accuracy of measurements, a history of lower extremity surgery, the presence of lower extremity deformity, and the absence of postoperative full-length radiographs. Patients were allocated into two groups based on the technique employed for correcting LLD during THA. Group 1 (n=62) consisted of patients evaluated using the suture technique with a spirit-level device, while group 2 (n=75) comprised patients who underwent the supraacetabular pin method with caliper measurement. The distance between the inter-teardrop line and the tip of the lesser trochanter was measured for both hips to assess LLD. RESULTS: The mean preoperative LLD was similar between groups, which was 11.6 ± 9.1 mm in group 1 and 9.5 ± 9.8 mm in group 2 (p=0.191). Postoperatively, group 1 had a significantly lower LLD compared to group 2 (p<0.001). CONCLUSION: According to the results obtained from this study, the use of a suture technique in conjunction with a spirit-level device to achieve a consistent leg position is an effective method for correcting LLD during THA.

Impact of hindlimb length variation on jumping dynamics in the Longshanks mouse.

Distantly related mammals (e.g. jerboa, tarsiers, kangaroos) have convergently evolved elongated hindlimbs relative to body size. Limb elongation is hypothesized to make these species more effective jumpers by increasing their kinetic energy output (through greater forces or acceleration distances), thereby increasing take-off velocity and jump distance. This hypothesis, however, has rarely been tested at the population level, where natural selection operates. We examined the relationship between limb length, muscular traits and dynamics using Longshanks mice, which were selectively bred over 22 generations for longer tibiae. Longshanks mice have approximately 15% longer tibiae and 10% longer femora compared with random-bred Control mice from the same genetic background. We collected in vivo measures of locomotor kinematics and force production, in combination with behavioral data and muscle morphology, to examine how changes in bone and muscle structure observed in Longshanks mice affect their hindlimb dynamics during jumping and clambering. Longshanks mice achieved higher mean and maximum lunge-jump heights than Control mice. When jumping to a standardized height (14 cm), Longshanks mice had lower maximum ground reaction forces, prolonged contact times and greater impulses, without significant differences in average force, power or whole-body velocity. While Longshanks mice have longer plantarflexor muscle bodies and tendons than Control mice, there were no consistent differences in muscular cross-sectional area or overall muscle volume; improved lunge-jumping performance in Longshanks mice is not accomplished by simply possessing larger muscles. Independent of other morphological or behavioral changes, our results point to the benefit of longer hindlimbs for performing dynamic locomotion.

Metabolic outcomes in obese mice undergoing one-anastomosis gastric bypass (OAGB) with a long or a short biliopancreatic limb.

One-anastomosis gastric bypass (OAGB) has gained importance as a simple, safe, and effective operation to treat morbid obesity. We previously found that Roux-en-Y gastric bypass surgery with a long compared with a short biliopancreatic limb (BPL) leads to improved weight loss and glucose tolerance in obese mice. However, it is not known whether a long BPL in OAGB surgery also results in beneficial metabolic outcomes. Five-week-old male C57BL/6J mice fed a high-fat diet (HFD) for 8 weeks underwent OAGB surgery with defined BPL lengths (5.5 cm distally of the duodenojejunal junction for short and 9.5 cm for long BPL), or sham surgery combined with caloric restriction. Weight loss, glucose tolerance, obesity-related comorbidities, endocrine effects, gut microbiota, and bile acids were assessed. Total weight loss was independent of the length of the BPL after OAGB surgery. However, a long BPL was associated with lower glucose-stimulated insulin on day 14, and an improved glucose tolerance on day 35 after surgery. Moreover, a long BPL resulted in reduced total cholesterol, while there were no differences in the resolution of metabolic dysfunction-associated steatotic liver disease (MASLD) and adipose tissue inflammation. Tendencies of an attenuated hypothalamic-pituitary-adrenal (HPA) axis and aldosterone were present in the long BPL group. With both the short and long BPL, we found an increase in primary conjugated bile acids (pronounced in long BPL) along with a loss in bacterial Desulfovibrionaceae and Erysipelotrichaceae and simultaneous increase in Akkermansiaceae, Sutterellaceae, and Enterobacteriaceae. In summary, OAGB surgery with a long compared with a short BPL led to similar weight loss, but improved glucose metabolism, lipid, and endocrine outcomes in obese mice, potentially mediated through changes in gut microbiota and related bile acids. Tailoring the BPL length in humans might help to optimize metabolic outcomes after bariatric surgery.NEW & NOTEWORTHY Weight loss following OAGB surgery in obese mice was not influenced by BPL length, but a longer BPL was associated with improved metabolic outcomes, including glucose and lipid homeostasis. These changes could be mediated by bile acids upon altered gut microbiota. Further validation of these findings is required through a randomized human study.

Physical Therapy Interventions: A Case Report of Building Strength, Confidence, and Mobility in a Seven-Year-Old With Congenital Femoral Deficiency With Coxa Vara.

Congenital femoral deficiency (CFD) and congenital coxa vara (CCV) are rare conditions characterized by abnormal development of the femur and hip joint, respectively. This case report documents the rehabilitation journey of a seven-year-old child diagnosed with CFD and CCV, highlighting the efficacy of physical therapy interventions in enhancing strength, balance, normal gait patterns, confidence, and mobility. Through a comprehensive physiotherapy regimen tailored to the specific needs of the patient, significant improvements in muscle strength, joint stability, and functional mobility were observed over the course of treatment. Moreover, the implementation of targeted exercises and adaptive strategies not only facilitated physical gains but also contributed to bolstering the child's confidence and overall quality of life. This case underscores the pivotal role of physiotherapy in addressing the complex challenges associated with congenital orthopedic anomalies, ultimately fostering independence and well-being in pediatric patients.

The Relationship Between Height and Income With Potential Application to Treatment of Limb Length Discrepancy.

Purpose When treating limb length discrepancy (LLD), decisions regarding lengthening versus contralateral shortening require careful consideration of deformity and patient factors. Using the National Longitudinal Survey of Youth 1979 (NLSY79) database, and income as a quantitative representation of overall socioeconomic benefit, we sought to determine the height at which incremental gains in height have the greatest value. Methods Using the NLSY79 database, we collected demographic data, height, yearly income from wages, college education (full- or part-time), and receipt of government financial aid. Multiple-linear regression and graphical analysis were performed. Results The study population included 9,652 individuals, 4,775 (49.5%) males and 4,877 (50.5%) females. Mean heights were 70.0±3.0 inches and 64.3±2.6 inches for males and females, respectively. Multiple-linear regression analysis (adjusted-r²=0.33) demonstrated height had a standardized-ß=0.097 (p<0.001), even when accounting for confounding factors. Using graphical analysis, we estimated cut-offs of 74 inches for males and 69 inches for females, beyond which income decreased with incremental height. Conclusions Using income as a quantitative representation of socioeconomic value, our analysis found income increased with incremental height in individuals with predicted heights up to 74 inches for males and 69 inches for females. Shortening procedures might receive more consideration at predicted heights greater than these cut-offs, while lengthening might be more strongly considered at the lower ranges of height. Additionally, our multiple-linear regression analysis confirms the correlation between height and income, when factoring in other predictors of income.

Characteristics of terminal hemimelia: What is the difference between terminal hemimelia and classic fibular hemimelia?

Purpose: Fibular hemimelia has denoted a spectrum of postaxial longitudinal deficiency with fibular aplasia/hypoplasia; the term "terminal hemimelia" is reserved for patients with postaxial longitudinal deficiency having a normal fibula. We aimed to delineate the characteristics of terminal hemimelia. Methods: In total, 30 patients with postaxial longitudinal deficiency who had a normal or hypoplastic fibula and visited our institution between 1992 and 2022 were reviewed. Patients were divided into terminal hemimelia and classic fibular hemimelia groups, and their demographic characteristics and clinical and radiographic findings were compared. Results: Femoral shortening, knee valgus, and tibial spine hypoplasia were less common in terminal hemimelia (n = 13) than in classic fibular hemimelia (n = 17) (p = 0.03, p < 0.001, and p = 0.003, respectively). None of the patients in the terminal hemimelia group exhibited knee instability, whereas 12% of patients with classic fibular hemimelia did. Ball-and-socket ankle and absence of lateral rays were commonly observed in both groups. However, tarsal coalition was observed less frequently in terminal hemimelia (p = 0.004). All terminal hemimelia patients exhibited a painless plantigrade foot without ankle instability. Despite limb-length discrepancy at maturity averaging 40.4 mm for terminal hemimelia and 67.0 mm for classic fibular hemimelia (p < 0.001), patients with terminal hemimelia, except for one, exhibited > 20 mm of limb-length discrepancy. However, 46% of them underwent limb-length equalization procedures, mostly single-stage tibial lengthening, at a mean age of 11.2 years. Conclusion: Terminal hemimelia may present with a milder phenotype than classic fibular hemimelia. It mainly overlaps with the symptoms of fibular hemimelia below the ankle joint and manifests as limb-length discrepancy. However, a considerable number of patients with terminal hemimelia required limb-length equalization procedures, for example single-stage tibial lengthening. Level of evidence: level IV.

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.

Simple bone cysts of the proximal humerus presented with limb length discrepancy: A case report.

BACKGROUND: Simple bone cysts (SBC) are benign tumor-like bone lesions typically identified in children. While SBC may lead to growth disturbances or growth arrest, such cases are uncommon. The mechanisms behind these observations remain unclear. Additionally, research on the etiology of SBC remains inconclusive, and there has been no consensus on the appropriate timing and methodology for treatment. CASE SUMMARY: Here, we present our experience in the successful surgical management of a 10-year-old girl with SBC, who presented with a pathological fracture complicated by malunion of the displaced fracture, varus deformity, and limb length discrepancy. We hypothesized two possible etiologies for the patient's growth arrest and subsequent humerus varus deformity: (1) Direct disruption of the physis by fluid from the cyst itself; and (2) damage to the epiphysis due to repetitive pathological fractures associated with SBC. In addressing this case, surgical intervention was undertaken to correct the proximal humerus varus deformity. This approach offered the advantages of simultaneously correcting angular abnormalities, achieving mild limb lengthening, providing definitive SBC treatment, and reducing the overall treatment duration. CONCLUSION: As per current literature, acute correction of acute angular deformity in proximal humeral SBC is not well comprehended. However, in this specific case, acute correction was considered an optimal solution.

Does Combining Drilling and Curettage to Percutaneous Trans-epiphyseal Screws Improve Correction of Limb Length Discrepancy? A Comparative Study.

Objectives: Physeal drilling and curettage (PDC) and percutaneous epiphysiodesis using transphyseal screws (PETS) are among the most widely used techniques to treat leg-length discrepancy (LLD). This study compared the efficacy and outcomes between PETS alone and PETS combined with PDC (PETS + PDC). Methods: Retrospective study of children who underwent epiphysiodesis of the proximal tibia or distal femur with either PETS or PETS + PDC between 2008 and 2018 at a single institution. Radiographic parameters and complications were reviewed at completion of treatment and most recent follow-up. Results: A total of 23 epiphysiodeses in 15 patients, average age 13.1 years, with either PETS (13 femur/tibias) or PETS + PDC (10 femur/tibias) were included. PETS patients were treated for a longer time (median: 24 months vs 11 months, p = 0.004), however, follow-up time was similar between groups (p = 0.577), on average 2.7 years. In the PETS group, LLD decreased from 2.55 to 0.84 cm at most recent follow-up (p = 0.010), and in the PETS + PDC group from 3.01 to 1.2 cm (p = 0.005), achieving a correction of 1.71 cm for PETS and 1.83 cm for PETS + PDC (p = 0.871). A correction of LLD to ≤ 2 cm was achieved in 8 PETS (89%) and 4 PETS + PDC cases (67%) (p = 0.525). Two PETS patients (22%) and 1 PETS + PDC (17%) patient returned to the OR for further correction due to persistent LLD (p = 1.000). No differences existed in total number of complications, angular deformity or return to physical activity between groups (p ≥ 0.05 for each comparison). Conclusions: This study showed equal efficiency in resolving LLD between the PETS and PETS + PDC procedures with minimal operative complications.Level of Evidence III.

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.

Validity of leg length measurement in the supine and standing position compared with pelvic survey X-ray after total hip arthroplasty.

INTRODUCTION: The correct adjustment of leg length is a major goal in the implantation of total hip replacements (THRs). Differences in leg length can lead to functional impairment and patient dissatisfaction. By determining leg length at an early stage, before the patient is discharged from hospital, compensatory measures such as the production of special insoles or orthopaedic footwear can be initiated promptly if there is a difference in leg length. Due to shortening of the period of time spent in hospital, the traditional measurement of leg length in a standing position may be increasingly subject to error. A protective posture immediately after surgery or the presence of a twisted pelvis, for example, due to scoliotic spinal misalignments, falsifies the measurement result in the standing position. Here, the measurement of leg length in the supine position may prove to be accurate immediately postoperatively, regardless of potential sources of error, and is to be compared with measurement in the standing position versus radiological measurement on the AP pelvic survey. MATERIAL AND METHODS: The present retrospective study included 190 patients who had undergone primary total hip arthroplasty. The leg length difference (LLD) of the patients was determined pre- and postoperatively both in the supine and standing position and compared with the postoperative radiological pelvic survey image. RESULTS: Postoperatively, it was shown that the mean length measured was 0.35 mm too long in the supine position and 0.68 mm too short in the standing position (p value < 0.001). Determination of the average absolute measurement error produces a deviation of 4.06 mm in the standing and 4.51 mm in the supine position (p value 0.126). CONCLUSIONS: It is shown that the postoperative measurement of LLD in the supine and standing position is equally valid and sufficiently accurate, compared with the gold standard of measurement on a radiograph.

Limb length change after total knee arthroplasty for valgus deformity does not affect the clinical score and is not affected by fixed flexion deformity.

BACKGROUND: The limb length change (LLC) after total knee arthroplasty (TKA) is especially significant in valgus deformity. The higher LLC could cause higher incidences of lower limb length discrepancy (LLD) and low clinical score. However, studies about LLC after TKA for valgus deformity are limited, and there are none on the relationship between LLC and fixed flexion deformity (FFD) in valgus deformity. HYPOTHESIS: (1) The amount of LLC would affect the postoperative LLD, (2) the improvement of fixed flexion deformity (FFD) would affect the amount of LLC, (3) The amount of LLC would affect the improvement in the clinical score after TKA for valgus deformity. PATIENTS AND METHODS: Fifty knees of 50 patients who underwent primary unilateral TKA for valgus-type osteoarthritis between January 2000 and October 2021 were included. A radiological and clinical assessment were performed the day before the operation and at 12 months post-operatively. Full-length standing anteroposterior radiographs were used to measure HKA and LLC. FFD and Hospital for Special Surgery (HSS) score were measured in the outpatient department. RESULTS: The incidence of lengthening was 92.0% and the mean LLC was 18.85mm (SD, 19.60mm). Postoperative LLD over 10mm occurred in 26% and the mean of postoperative LLD was 4.21mm (SD, 7.96mm). The LLC was correlated with postoperative LLD (rs=0.357, p=0.011) and the HKA change (rs=0.375, p=0.007), but not with the FFD improvement (rs=0.164, p=0.255) and HSS improvement (rs=0.076, p=0.613) or postoperative HSS (rs=0.094, p=0.528). CONCLUSION: LLC was affected by HKA improvement but not by FFD improvement after TKA for patients with valgus deformity. Additionally, LLC did not affect the clinical score. LEVEL OF EVIDENCE: III; retrospective cohort study.

The effect of intraoperative fluoroscopy on acetabular component positioning and patient anatomy restoration during posterior or posterolateral approach total hip arthroplasty: a meta-analysis.

BACKGROUND: Positioning implant components and restoring patient anatomy during total hip arthroplasty (THA) are essential for joint stability, polyethylene liner wear, and range of motion. Previous studies comparing intraoperative fluoroscopy with no fluoroscopy during the posterior or posterolateral approach have reported conflicting results. This meta-analysis evaluated if intraoperative fluoroscopy improves component positioning and femoral component position compared to no fluoroscopy during posterior or posterolateral approach total hip arthroplasty. METHODS: The Preferred Reporting Items for Systematic Reviews and Meta-Analyses standards were followed when conducting the systematic review. We searched Web of Science, Embase, PubMed, Cochrane Controlled Trials Register, Cochrane Library, Highwire, CBM, CNKI, VIP, and Wanfang database in May 2023 to identify studies involving Intraoperative fluoroscopy versus no fluoroscopy during posterior or posterolateral approach total hip arthroplasty. Finally, we identified 1133 patients (1145 hips) assessed in seven studies. RESULTS: There were no significant differences in terms of acetabular cup inclination angle (ACIA, P = 0.43), ACIA within safe zone rate (P = 0.58), acetabular cup anteversion angle (ACAA, P = 0.46); ACAA within safe zone rate (P = 0.72), Combined safe zone rate (P = 0.28), dislocation rate (P = 0.64) and infection rate (P = 0.94) between two groups. Compared with the no fluoroscopy group, the intraoperative fluoroscopy group had more operation time (P < 0.00001), less femoral component offset difference (FCOD, P = 0.03), and less LLD (P < 0.00001). CONCLUSION: Even though intraoperative fluoroscopy was not related to an improvement in cup location or dislocation incidence. Our findings demonstrate that the restoration of leg lengths and femoral offset can be significantly improved by using intraoperative fluoroscopy to supplement good surgical skills in THA. The advantages of intraoperative fluoroscopy might become more apparent for surgeons with less experience. To ascertain whether intraoperative fluoroscopy for posterior or posterolateral approach total hip arthroplasty will have clinical benefits and improve the survival of prostheses, more well-powered and well-designed long-term follow-up studies were necessary.

A Method of Time Prediction in Epiphysiodesis for Limb Length Discrepancy Based On Multiplier.

Objectives: The most critical step in the calculation of final limb length discrepancy (LLD) is estimating the length of the short limb after skeletal maturity(Sm). Paley's multiplier method is a fast, convenient method for calculating Sm and LLD after skeletal maturity; nonetheless, the calculation of the process of Sm and LLD in acquired type cases is complex in contrast to congenital type in this method. Notwithstanding, the multiplier method uses a variable called "growth inhibition" for the calculation process in acquired type LLD; however, its mathematical proof has not been published yet. The present study aims to find out whether there is an alternative way to estimate the length of Sm and LLD in skeletal maturity without using growth inhibition (GI) and its complex calculation process in acquired type LLD. Methods: We used trigonometric equations to prove the GI concept and conducted proportionality analysis to calculate the length of short limbs and LLD in skeletal maturity without using GI. Results: Based on the results, the following proportionality can estimate the length of the short limb in skeletal maturity. (ΔLm/ΔL = ΔSm/ΔS). Conclusion: The GI concept can be proved trigonometrically; nonetheless, its numerical value is not necessary for estimating the length of the short limb in skeletal maturity. Instead, a simple proportionality analysis serves the purpose of calculation.

Magnetically Driven Intramedullary Limb Lengthening in Patients with Pre-existing Implanted Programmable Devices: A Case Series.

Aim: The aim of the study is to demonstrate the safety and efficacy of the use of magnetically controlled intramedullary nails in patient with programmable implantable devices. Background: Magnetically driven intramedullary limb lengthening devices have revolutionised the field of limb reconstruction. Because the system is powered by strong magnets, there are warnings to avoid the use of the device in patients with implanted programmable devices, such as cardiac pacemakers. Materials and methods: Four patients with three different types of programmable implanted devices presented to two centres for limb lengthening and limb reconstruction. Each patient had a limb length discrepancy and desired correction using an intramedullary lengthening device. After thorough counselling about the potential risks and benefits of the procedure as well as discussions with each patient's medical team, the decision to proceed with surgery was made. Results: All four patients underwent osteoplasty with insertion of a magnetically driven intramedullary lengthening nail. Goal length was achieved with successful consolidation and subsequent nail removal in all patients. There were no malfunctions of the implantable devices during the distraction phase in any of the patients. Conclusion: With proper precautions, intramedullary lengthening can be performed safely and successfully using a magnetically driven nail in patients with previously implanted programmable devices. Clinical significance: This initial experience suggests use of magnetically controlled intramedullary nails in patient with programmable implantable devices can be undertaken safely within constraints of precautions. How to cite this article: Iobst CA, Hatfield DN, Forro SD, et al. Magnetically Driven Intramedullary Limb Lengthening in Patients with Pre-existing Implanted Programmable Devices: A Case Series. Strategies Trauma Limb Reconstr 2023;18(2):111-116.