Long-term Outcome of the Dutch Common Channel Trial (DUCATI): Preservation of Superior Weight Loss Results Without Significant Malnutrition Side Effects.

PURPOSE: The optimal bowel limb lengths for laparoscopic Roux-en-Y gastric bypass (LRYGB) to maximize weight loss while minimizing nutritional deficiencies in severe obesity treatment remain a topic of debate. The multi-center Dutch Common Channel Trial (DUCATI) aims to compare the outcomes of a very long Roux Limb Roux-en-Y gastric bypass (VLRL-LRYGB) with a standard Roux-en-Y gastric bypass (S-LRYGB). METHODS: A total of 444 patients were randomly assigned in a 1:1, double-blind manner to undergo either VLRL-RYGB or S-LRYGB. Five-year follow-up data were assessed, concentrating on weight loss, obesity-related medical conditions, complications, re-operations, and malnutrition. RESULTS: Both groups had comparable total alimentary lengths (RL + CC). The VLRL-LRYGB group demonstrated significantly greater %TWL (32.2% vs. 28.6%, p = 0.002) and %EWL (81.2% vs. 70.3%, p = 0.002) at 5 years. Eight (3.6%) patients in the VLRL-LRYGB group versus 2 (0.9%) in the S-LRYGB group (p = 0.055) needed modification surgery for malabsorption. Suboptimal clinical response rate was significantly higher (22.0% vs. 8.3%) in S-LRYGB group. No significant differences for nutrient deficiencies in favor of the S-LRYGB group were found. CONCLUSION: A 100-cm common channel with a relatively long Roux limb provides superior, sustainable weight loss over 5 years, without significantly increased rate of malabsorption-related re-operations. These results suggest that a longer Roux limb can still ensure adequate micronutrient uptake in the total alimentary tract. These findings should be considered in discussions regarding the optimal Roux-en-Y limb length for severe obesity treatment.

Survival and functional outcomes after hemiarthroplasty in children with proximal tibial osteosarcoma.

BACKGROUND: Treatment options for correcting limb-length discrepancy after limb-salvage reconstruction for proximal tibial osteosarcoma in children have several limitations. Therefore, we aimed to evaluate the feasibility, complications, prognosis, and clinical outcomes of reconstruction using hemiarthroplasty after tumor resection in pediatric patients with proximal tibial osteosarcoma. METHODS: We conducted a comprehensive retrospective analysis of the data of pediatric patients with osteosarcoma of the proximal tibia who underwent surgery between December 2008 and November 2018 at our center. We enrolled 49 consecutive patients who underwent hemiarthroplasty. The cruciate ligaments of all patients were reconstructed using special spacers, and the medial and lateral collateral ligaments of the knee and joint capsule were reconstructed using a mesh. Postoperatively, if the unequal length of both lower limbs exceeded 4 cm or knee instability occurred, a second-stage surgery was performed for limb lengthening and replacing the distal femoral prosthesis. We analyzed the oncological prognosis, complications of hemiarthroplasty, postoperative stability, and postoperative function. RESULTS: The follow-up period ranged between 11 and 159 months, with a median of 84 (62, 129) months. The overall 5-year survival rate was 83.2%. Thirty-nine patients survived at the end of the follow-up period with 34 prostheses (87.2%). The overall prosthesis survival rate was 87.4% after 5 years, indicating the long-term benefits of the procedure. Limb length was measured in 28 adult patients. The average limb-length discrepancy was 33 ± 15 mm with a median of 33 mm (21, 47); the femur and tibia caused a discrepancy of 8.5 ± 9.9 mm and 24.8 ± 15.5 mm, respectively. The patients had 30-135° of knee motion, with a mean of 82 ± 24°. The femoral tibial angle was greater on the affected side than on the healthy side, with a mean difference of 4.5°±3.6°. The Musculoskeletal Tumor Society (MSTS) score was 25 ± 3. Five patients underwent second-stage distal femoral prosthesis replacement, with mean MSTS scores of 24 ± 2 and 28 ± 1 before and after second-stage surgery, respectively. CONCLUSIONS: Hemiarthroplasty in children reduces limb-length discrepancy in adulthood by rebuilding cruciate ligaments, lateral collateral ligaments, and the joint capsule, thereby improving knee stability.

Can limb length discrepancies be corrected with the Masquelet technique? A technical trick.

Masquelet technique is a well-established procedure for reconstruction of bone defects secondary to such causes as infections, non-unions, tumors or open fractures with bone loss. The management of limb length discrepancies following bone defects has been well established using bone transport and remains the preferred choice amongst reconstruction surgeons. One of the criticisms of the Masquelet technique has been its limitation to address limb length discrepancies. We describe a technique for the correction of limb length discrepancies using the Masquelet technique.

The need for state-of-the-art orthopedic surgical technology in low- to middle income countries : The case of distraction epiphyseolysis for limb lengthening in children with fibular hemimelia in Uzbekistan.

INTRODUCTION: Amongst low- to middle income countries (LMIC), outdated and poorly documented orthopedic interventions may pose patients at risk for complications, serious adverse events (SAE) and unsatisfactory results, contradicting the World Health Organization's (WHO) Safe Surgery mandates. Use cases of conditions managed inadequately in LMIC environments are necessary to increase awareness of stakeholders and overcome deficiencies in collaboration with high-income countries (HIC). MATERIALS AND METHODS: Methodological and clinical experts from the BG Kliniken and the Charité, Berlin, Germany, were invited to investigate established processes for musculoskeletal disorders and injuries in Tashkent, Uzbekistan. Congenital lower leg discrepancy due to fibular hemimelia was recognized as an illustrative example to prove the effectiveness of local treatment guidelines, still relying on distraction epiphyseolysis (chondrodiatasis) via an Ilizarov frame. Routine data from hospital records, images and outpatient follow-up examinations were compared to estimates from a review of studies of limb-lengthening by other techniques. RESULTS: Data from 16 of 49 immature patients (10 males, 6 females, mean age at surgery, 4.2 ± 2.3 years) undergoing chondrodiatasis between 2017 and 2021 showed a mean limb elongation of 2.4 (95% confidence interval [CI], 1.9 to 2.9) cm after a median follow-up of 29 (range, 24 to 36) months. While no complications or SAE were noted, findings are compatible with a risk of 21% under an upper 97.5% confidence limit for null events. No reproducible classification of hemimelia, surgical or general complications, assessment of functional outcomes or health-related quality of life were available. The pooled average length gain from 21 studies on different other interventions with osteotomy enrolling 458 limbs was 5.1 (95% CI, 5.0 to 5.3) cm. CONCLUSIONS OF THE USE CASE: Limb lengthening for hereditary fibular hemimelia in Uzbekistan revealed rather obsolete surgical algorithms, inadequate documentation, and unreliable outcome assessment. Resource limitations notwithstanding, knowledge transfer, implementation of current procedures and hardware, and international collaboration is vital to improve quality of care in this scenario and for the benefit of LMIC in general.

The length of the biliopancreatic limb in one anastomosis gastric bypass.

Introduction: The one-anastomosis gastric bypass (OAGB), first published by Dr Rutledge in 1997 is now a well-established procedure in the bariatric-metabolic armamentarium. This procedure based on a (single) loop gastro-jejunal anastomosis (the biliopancreatic limb or BPL) with a long narrow gastric pouch combines restriction with hypo-absorption. The biliopancreatic limb and in particular its length is held responsible for the degree of the hypo-absorptive effect but the most appropriate or "optimal" length of the BPL remains debatable. Methods: The following text is based on a comprehensive and meticulous selection of the most recent literature in Cochrane, Pubmed and Google Scholar using the search terms "biliopancreatic limb", "biliopancreatic limb in one anastomosis gastric bypass" in an attempt to define not only the most common used biliopancreatic limb length but also to find out If there is an "ideal" limb length not only to optimize the outcomes of the OAGB in terms of weight loss and resolution of obesity-related diseases but also to reduce the potential side-effects in particular nutritional deficiencies. Results: Until today there is no consensus about the "standard" or "ideal" length of the biliopancreatic limb in OAGB, a fixed length of 200 cm is still the most common used procedure although many reports and studies are in favour of shorter limb lengths adjusted to the BMI or the total small bowel length. Conclusion: The "ideal" or "optimal" biliopancreatic limb length in OAGB still needs to be defined. There are different options and all of them have their credits, the question remains if a consensus can be reached regarding the best strategy to obtain the best outcome.

Does the length of bypassed bowel during distal gastric bypass affect weight loss?

INTRODUCTION: Weight recurrence (WR) affects > 20% of patients following Roux-en-Y gastric bypass (RYGB). Shortening of the common channel (CC) after RYGB (distal bypass) has been proposed for additional weight loss in patients with WR, but results vary, and concerns for vitamin deficiencies/malnutrition exist. Our aim was to determine whether the percentage of bowel bypassed after distal bypass is associated with the amount of postoperative weight loss. METHODS: Patients undergoing distal bypass between 2018 and 2022 were reviewed. Small bowel limb lengths before and after distal bypass were measured, and the percentage of bypassed bowel was calculated (= bypassed biliopancreatic limb/total small bowel length). Patients were dichotomized into two groups based on the percentage bypassed bowel (≤ 50% vs. > 50%). Weight loss (measured as excess BMI loss; EBIL%), comorbidities resolution, complications, and nutritional deficiencies were reviewed. RESULTS: Thirty female patients underwent distal bypass during the study period. After distal bypass, the Roux was lengthened to 150 cm (75-175 cm) from 75 cm (20-200 cm), and the CC shortened to 150 cm (100-310 cm) from 510 cm (250-1000 cm). These changes resulted in an increase in the size of the bypassed biliopancreatic limb from 40 cm (15-90 cm) to 330 cm (180-765 cm) and a total alimentary limb (TALL; Roux + CC) shortening from 590 cm (400-1075 cm) to 300 cm (250-400 cm). The group with > 50% bowel bypassed had higher EBIL%. Overall EBIL% was 36.9 ± 14.7%, 53.3 ± 25.6%, and 62.1 ± 36.9% at 0.5, 1, and 2 years, respectively. There were minimal vitamin deficiencies. Diabetes resolved in 100% (n = 3/3), HTN in 67% (n = 10/15), and GERD in 73% (n = 11/15). Complication rate was 23%. No reintervention for malnutrition or vitamin deficiencies was required. CONCLUSIONS: Distal bypass effectively leads to considerable weight loss and comorbidity improvement in patients with WR after RYGB, but the amount of weight loss depends on the percentage of bypassed bowel. An exact threshold of bypassed bowel that optimizes weight loss outcomes and simultaneously minimizes the nutritional complications needs to be determined. Meanwhile, close monitoring for vitamin deficiencies is recommended.

Sacroiliac pain after total hip arthroplasty: a combined analysis of clinical data and three-dimensional imaging in standing and sitting positions.

PURPOSE: Patients frequently complain of low back pain and sacroiliac joint pain (SIP) following total hip arthroplasty (THA). We hypothesized that patients with SIP would display different pelvic incidence (PI) values between standing and relaxed sitting positions, indicative of increased motion in the sacroiliac joints. METHODS: In this retrospective case-control study, 94 patients who underwent unilateral THA and experienced SIP were compared with 94 control patients without SIP. SIP was confirmed through clinical tests and investigated using biplanar imaging in both standing and sitting positions. The key parameters analyzed included PI, sacral slope (SS), lumbar lordosis (LL), and limb length discrepancy (LLD). RESULTS: Patients without SIP showed a mean difference in PI of -1.5° (-8°-5°) between standing-to-sitting positions, whereas those with SIP showed a difference of -3.3° (-12°-0°)(P < 0.0001), indicating more motion in the sacroiliac joint during daily activities in the latter group. Patients with SIP showed smaller change in LL between standing-to-sitting positions (mean:6.3°; range:-8°-27°) compared with those without SIP (mean:9.5°; range:-12°-28°)(P = 0.006). No significant differences were noted in functional leg length between patients with (mean:7 mm; range:0-12 mm) and without SIP (mean:7 mm; range:0-11 mm)(P = 0.973). CONCLUSIONS: This study revealed significant sacroiliac joint motion in patients with SIP post-THA, as indicated by PI changes, increased posterior pelvic tilt, and reduced change in the LL. Contrary to common belief, SIP did not correlate with LLD.

Do Cementless Stems Match Any Hip? A Description of Anthropometric Measurements of the Proximal Femur in Colombia.

Background: Leg length discrepancy following hip arthroplasty causes dissatisfaction to the patient; thus, preoperative planning and implant selection is critical. The purpose of this study was to measure the articular-trochanteric distance (ATD) and femoral neck length (FNL) in our population and compare them to those of 3 of the most used uncemented stems. Methods: In this cross-sectional study, 401 hip radiographs of healthy adults were collected between January and July 2022. The vertical ATD and FNL were measured. A linear regression model was used to identify the relationship between these measurements and age, sex, and height. A logistic regression model was used to assess the matching of native hips with the neck length of the stem. Results: Mean age was 60 years, and 74.56% were women. In 94.3% of hips, the ATD was negative, 3.73% neutral, and 2% positive. In our population, 0.25% of FNL were shorter than POLARSTEM (Smith & Nephew, UK), 10.72% shorter than MetaFix stem (Corin, UK), and 11.97% shorter than Corail stem (DePuy Synthes, USA). In the logistic regression analysis, matching for the POLARSTEM was associated with age but not with sex or height. Conversely, for MetaFix and Corail, stem matching was associated with sex and height. Conclusions: Anthropometric hip measurements vary among individuals, and variables such as age, sex, and height must be considered during preoperative planning and implant selection to avoid leg length discrepancy. Additional studies, including different implants, are required to guide surgeons in selecting a femoral stem that best matches the patient's native hip.

A novel non-invasive electromagnetic extendable intercalary endoprosthesis: a proof-of-concept study.

Introduction: Femur and tibia are the most commonly affected sites for primary malignant bone tumors in children. The wide resection of the tumor frequently requires the physis to be resected. The normal growth of the unaffected limb will result in a significant limb length discrepancy at skeletal maturity. To compensate for this resulting LLD, different generations of extendible endoprostheses have been developed. Non-invasive extendable prostheses eliminate the need for surgical procedures and general anesthesia, enabling gradual and painless lengthening. Currently available non-invasive extendable prostheses focus on joint reconstruction, and no case series analysis of intercalary non-invasive extendable prosthesis has been reported. Therefore, we have designed a novel non-invasive electromagnetic extendable intercalary endoprosthesis. Methods: In vitro mechanical experiments and in vivo animal experiments were conducted. Results: In vitro experiments have confirmed that the prosthetics can extend at a constant rate, increasing by 4.4 mm every 10 min. The average maximum extension force during prosthetic elongation can reach 1306N. In animal in vivo experiments, the extension process is smooth and non-invasive, and the sheep is in a comfortable state. Discussion: The in vitro and in vivo animal studies provide evidence to support the extension reliability, laying the foundation for future large-scale validation experiments.

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.

The Impact of Longer Biliopancreatic Limb Length on Weight Loss and Comorbidity Improvement at 5 Years After Primary Roux-en-Y Gastric Bypass Surgery: A Population-Based Matched Cohort Study.

INTRODUCTION: Different limb lengths are used in Roux-en-Y gastric bypass (RYGB) surgery, as there is no consensus which limb length strategy has the best outcomes. The biliopancreatic limb (BPL) is thought to play an important role in achieving weight loss and associated comorbidity resolution. The objective of this study was to assess the impact of a longer BPL on weight loss and comorbidity improvement at 5 years after primary RYGB. METHODS: All patients aged ≥ 18 years undergoing primary RYGB between 2014-2017 with registered follow-up 5 years after surgery were included. Long BPL was defined as BPL ≥ 100 cm and short BPL as BPL < 100 cm. The primary outcome was achieving at least 25% total weight loss (TWL) at 5 years. Secondary outcomes included absolute %TWL and improvement of comorbidities. A propensity score matched logistic and linear regression was used to estimate the difference in outcomes between patients with long and short BPL. RESULTS: At 5 years, long BPL had higher odds to achieve ≥ 25% TWL (odds ratio (OR) 1.19, 95% confidence interval (CI) [1.01 - 1.41]) and was associated with 1.26% higher absolute TWL (ß = 1.26, 95% CI [0.53 - 1.99]). Furthermore, long BPL was more likely to result in improved diabetes mellitus (OR = 2.17, 95% CI [1.31 - 3.60]) and hypertension (OR = 1.45, 95% CI [1.06 - 1.99]). CONCLUSION: Patients undergoing RYGB with longer BPL achieved higher weight loss and were more likely to achieve improvement of comorbidities at 5 years.

Evaluation of the effect of vascularized fibula graft harvesting on coronal plane alignment and functional outcomes of the lower limb.

Recent studies on fibular osteotomy for varus gonarthrosis and possible subsequent biomechanical changes have attracted increasing attention to the topic. Existing studies have focused mainly on proximal fibular osteotomy with short follow-up periods. The aim of this study was to investigate changes in the alignment of the coronal plane of the ankle and knee joints in patients who underwent vascularized fibula graft harvest (VFGH). The evaluation was based on functional outcomes and radiological measurements.In the comparison between the VFGH side and the contralateral side, no significant differences in the knee inclination (KI) or talar inclination (TI) angle, knee medial clear space (K-MCS) or ankle medial clear space (A-MCS) distance were noted. However, a significant difference in the hip knee (HKA) angle was observed between the operated and nonoperated sides (0.3° ± 1.8° and 1.5° ± 1.9°, respectively [p = 0.019]). Statistically significant differences in both the knee society score (KSS) and the AOFAS scores were found between the ipsilateral donor limb and the contralateral healthy limb. Although the contralateral healthy side had better clinical scores than the VFGH side, the outcomes of the VFGH side were still satisfactory or excellent.

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.

Does the limb lengthening reduce the incidence of hip dislocation in patients with neurological disorders and insufficient muscle tension who undergoing hip arthroplasty?

Background: The soft-tissue tension is closely associated with postoperative hip dislocation in patients undergoing total hip arthroplasty (THA), especially for those patients with neurological disorders and insufficient muscle tension. The aim of this study is to explore the effect of limb lengthening on the incidence of complications following THA in patients with neurological disorders and insufficient muscle tension. Methods: This retrospective analysis examines individuals with neurological disorders, such as ischemic stroke and poliomyelitis, who underwent primary total hip arthroplasty (THA) at our medical center between January 2015 and April 2021. Demographic and baseline characteristics (such as age, gender, muscle strength) were obtained from medical records. The limb length, offset and the positional parameters of both acetabular and femoral component were measured on pre- and postoperative plain radiograph. The primary outcome was the occurrence of hip dislocation. The secondary outcome included the incidence of other complications and the hip function (determined by Harris score). The correlation between the occurrence of hip dislocation and limb lengthening was analyzed. Results: A total of 258 patients were finally analyzed. The hip dislocations were identified in 35 patients (overall incidence = 13.57%). The incidence of early dislocation was lower in patients whose limb-length discrepancy (LLD) was over 20 mm (incidence = 4.1% for LLD >20 mm, 12.2% for LLD 10 mm-20 mm and 17% for LLD <10 mm). The odds ratio (OR) was 0.206 and 95% confidence interval (CI) was 0.058-0.737 (compared between LLD <10 mm and LLD >20 mm). But the no difference was identified regarding on the incidence of late dislocation among patients with different LLD. Moreover, the overall incidence of other complications was elevated in patients with LLD >20 mm (incidence = 17.58% for LLD >20 mm, 11.11% for LLD 10 mm-20 mm and 3.19% for LLD <10 mm; OR = 6.464, 95% CI = 1.768-23.640). And the Harris scores, which reflected the hip function, was gradually decreased with the increasing in LLD. In terms of the relationship between the offset and dislocation rate, it was found that increased offset discrepancy was associated with decreased dislocation incidence (incidence = 4.71% for offset discrepancy >10 mm, 12.5% for offset discrepancy 5 mm-10 mm and 17.20% for offset discrepancy <5 mm; OR = 0.238, 95% CI = 0.076-0.742). Furthermore, increased offset discrepancy also bring a reduction in late dislocation. The incidences of late dislocation were 0%, 2.5% and 10.8% for offset discrepancy >10 mm, offset discrepancy 5 mm-10 mm and 17.20% for offset discrepancy respectively. Different from that of LDD, the incidences of other complications were similar among patients with different offset discrepancy. Besides, no influence of offset discrepancy on the hip function was identified in this study. Conclusion: Unfortunately, although increasing in limb length could partially reduce early dislocation postoperatively, it could not affect the incidence of late dislocation in those patients with neurological disorders and insufficient muscle tension. Moreover, over limb lengthening was associated with other postoperative complications and worse hip function. Instead, additional offset could reduce the probability of postoperative dislocation, without increasing the incidence of other complications. Therefore, femoral stem with lower cervico-diaphyseal angle (higher offset) should be recommended to patients with neurological disorders who were in high risk of postoperative dislocation. Isolated increasing in limb length should be avoided.

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.

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.

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.

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.

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.

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.