The Variation of the Pelvis in Unilateral Crowe Type IV Developmental Dysplasia of the Hip.

OBJECTIVE: To investigate variation of the pelvis in unilateral Crowe type IV developmental dysplasia of the hip (DDH) and analyze the reliability of pelvic landmarks. METHODS: We retrospectively received preoperative anteroposterior pelvic radiographs for 89 adult patients with unilateral Crowe type IV DDH at our institution between September 2008 and May 2019. Forty-eight patients without a false acetabulum was type IVA and 41 with a false acetabulum was type IVB. The heights of the ilium, acetabulum, and ischium areas in affected and unaffected sides were measured. The ratios of the three areas in entire pelvis are calculated. The discrepancies of bilateral iliac crest, inferior sacroiliac articulation, teardrop, and ischial tuberosity on the bisector of the pelvis were also measured. RESULTS: The mean heights of the ilium, acetabulum, ischium areas in the affected side were 74.4, 88.6, and 37.0 mm, respectively, in type IVA group and 77.7, 83.5, and 37.8 mm, respectively, in type IVB group. The heights in the unaffected side were 82.1, 84.6, and 43.8 mm, respectively, in type IVA group and 84.6, 82.0, and 44.0 mm, respectively, in type IVB group. The ratios of the ilium, acetabulum, ischium areas in affected side of Crowe type IVA group were 0.37, 0.44, and 0.19, respectively, and the ratios in unaffected side were 0.39, 0.40, and 0.21, respectively. The ratios in affected side of Crowe type IVB group were 0.39, 0.42, and 0.19, respectively, and the ratios in unaffected side were 0.40, 0.39, and 0.21, respectively. The discrepancies of bilateral iliac crest, inferior sacroiliac articulation, teardrop, and ischial tuberosity on the line of the bisector of the pelvis in Crowe type IVA group were 5.6, 5.2, 2.0, and 7.1 mm, respectively. Those in Crowe type IVB group were 8.1, 3.5, 3.5, and 4.9 mm, respectively. CONCLUSIONS: Pelvic asymmetry was a common occurrence in unilateral Crowe type IV DDH in adults. Furthermore, it should be reliable to use teardrop as pelvic landmark to balance leg length discrepancy in preoperative planning.

Inertial measurement units for the detection of the effects of simulated leg length inequalities.

BACKGROUND: Leg length inequalities (LLI) are a common condition that can be associated with detrimental effects like low back pain and osteoarthritis. Inertial measurement units (IMUs) offer the chance to analyze daily activities outside a laboratory. Analyzing the kinematic effects of (simulated) LLI on the musculoskeletal apparatus using IMUs will show their potentiality to improve the comprehension of LLI. METHODS: Twenty healthy participants with simulated LLI of 0-4 cm were analyzed while walking with an inertial sensor system (MyoMotion). Statistical evaluation of the peak anatomical angles of the spine and legs were performed using repeated measurement (RM) ANOVA or their non-parametric test versions (Friedman test). RESULTS: Lumbar lateral flexion and pelvic obliquity increased during the stance phase of the elongated leg and decreased during its swing phase. The longer limb was functionally shortened by higher hip and knee flexion, higher hip adduction, dorsiflexion, and lower ankle adduction. Finally, the shorter leg was lengthened by higher hip and knee extension, hip abduction, ankle plantarflexion, and decreased hip adduction. CONCLUSION: We found differing compensation strategies between the different joints, movement planes, gait phases, and amounts of inequality. Overall the shorter leg is lengthened and the longer leg is shortened during walking, to retain the upright posture of the trunk. IMUs were helpful and precise in the detection of anatomical joint angles and for the analysis of the effects of LLI.

Pelvic Sagittal Torsion Caused by Induced Leg Length Discrepancy: Geometrical Illusion May Influence Measures Based on Superior-iliac Spines Positions.

OBJECTIVE: To investigate whether a common measure of sagittal pelvic torsion based on the superior iliac spines behave similarly to predictions of a rigid (non-torsioned) plane, when leg length discrepancies (LLD) are induced. METHOD: Twenty-four young asymptomatic participants were subjected to pelvic posture measurements that use the anterior-superior iliac spines (ASISs) and posterior-superior iliac spines (PSISs) as references, while standing on level ground and with a one-, two- and three-centimeter lifts under the left foot. A special caliper with digital inclinometers was used. The following angles were measured: angles of the right and left PSIS-to-ASIS lines; right-left relative angle (RLRA), as the angle between the right and left PSIS-to-ASIS lines, which is a traditional lateral-view measure intended to detect sagittal torsions; angle of the inter-ASISs line; angle of the inter-PSISs line; anterior-posterior relative angle (APRA), as the angle between the inter-ASISs and inter-PSISs lines. According to trigonometric predictions based on the geometry given by the lines linking the superior iliac spines (i.e. a trapezoid plane), a pure lateral tilt of the pelvis, without interinnominate sagittal motion, would change RLRA in a specific direction and would not change APRA. RESULTS: Repeated-measures ANOVAs revealed that RLRA (p<0.001) and right and left PSIS-to-ASIS angles (p≤0.001) changed, and APRA did not change (p=0.33), as predicted. CONCLUSIONS: At least part of the sagittal torsion detected by measures that assume the PSIS-to-ASIS angles as the sagittal angles of the innominates is due to pelvic geometry and not to the occurrence of actual torsion, when LLDs are induced.

Femoral lengthening might impair physical function and lead to structural changes in adjacent joints: 10 patients with 27 to 34 years' follow-up.

Background and purpose - Literature describing long-term functional outcome and osteoarthritis (OA) in adjacent joints after femoral lengthening is rare. We evaluated physical function and the presence of radiographic OA in adjacent joints in 10 patients ≥ 27 years after femoral lengthening.Patients and methods - We conducted a cross-sectional study of 10 patients treated by unilateral femoral lengthening. Follow-up was between 27 and 34 years. Physical function was evaluated by the 30-second sit-to-stand (30sSTS) and a stair test and was compared with reference values. 4 single-legged hop tests were used to assess difference in physical function between the lengthened and contralateral limb. Radiographic OA was evaluated by joint space width (JSW) and Kellgren and Lawrence (KL) classification.Results - The patients scored worse compared with reference values on the 30sSTS and stair test, and worse on the lengthened limb on the single- and triple-hop test. Radiographic OA was found in the hip or knee in the lengthened limb in 3 of 10 patients based on JSW and 4 of 10 based on KL. No radiographic OA was found in unlengthened limbs.Interpretation - Our results showed impaired physical function both in general and of the lengthened limb. Additionally, we found a possible association between femoral lengthening and radiographic OA in adjacent joints in the long term. However, the sample size of the current study is small.

Inter-limb difference of mechanical work in limb length discrepancy.

BACKGROUND: Limb length discrepancy (LLD) is common and is associated with musculoskeletal disorders. Selection of adaptation strategies, the side more susceptible to complications, and the relationships between LLD magnitude and musculoskeletal complications are unclear. To elucidate these ambiguities, studies on gait parameters in LLD have been conducted. However, studies on inter-limb difference of mechanical work in LLD are rare. RESEARCH QUESTION: To investigate whether inter-limb differences in mechanical work in LLD and the relationship between LLD magnitude and mechanical work performed by each lower limb are significant. METHODS: Thirty-seven participants with LLD and without neuromuscular disorders disturbing normal gait were included. Three-dimensional motion analysis was conducted to obtain data on mechanical work, including joint work and the individual limb method (ILM) work. Mechanical work performed by the longer and shorter limbs was compared using paired t-test. Relationships between LLD and mechanical work were investigated using correlation and multiple regression analyses in both limbs. Eighteen participants had LLD > 20 mm, large group (LG), and 19 had LLD < 20 mm, small group (SG). Data exploration was conducted for the effect of LLD severity (LG vs. SG) on mechanical work. RESULTS: LLD showed significant inter-limb difference of mechanical work and negative correlations with positive and negative ILM work performed by the shorter limb. The shorter limb in SG performed significantly larger positive ILM work than the longer limb, whereas the longer limb in LG performed significantly larger negative ILM work than the shorter limb. SIGNIFICANCE: LLD showed inter-limb difference of ILM work and different adaptation strategies between LG and SG. These differences attribute to the decrease in ILM work performed by the shorter limb with the increase in LLD. Mechanical work including ILM work should be included in future studies to prevent complications and development of treatment methods for LLD.

Predictor index of functional limb length discrepancy.

INTRODUCTION: Limb length discrepancy (LLD) of lower extremities is underdiagnosed due to compensatory mechanisms during locomotion. The natural course of compensation leads to biomechanical alteration in human musculoskeletal system leading to adverse effects. General consensus accepts LLD more than 2 cm as significant to cause biomechanical alteration. No studies were conducted correlating height and lower extremities true length (TL) to signify LLD. Examining significant LLD in relation to height and TL using dynamic gait analysis with primary focus on kinematics and secondary focus on kinetics would provide an objective evaluation method. METHODOLOGY: Forty participants with no evidence of LLD were recruited. Height and TL were measured. Reflective markers were attached at specific points in lower extremity and subjects walked in gait lab at a self-selected normal walking pace with artificial LLDs of 0, 1, 2, 3, and 4 cm simulated using shoe raise. Accommodation period of 30 min was given. Infrared cameras were used to capture the motion. Primary kinematic (knee flexion and pelvic obliquity (PO)) and secondary kinetic (ground reaction force (GRF)) were measured at right heel strike and left heel strike. Functional adaptation was analyzed and the postulated predictor indices (PIs) were used as a screening tool using height, LLD, and TL to notify significance. RESULTS: There was a significant knee flexion component seen in height category of less than 170 cm. There was significant difference between LLD 3 cm and 4 cm. No significant changes were seen in PO and GRF. PIs of LLD/height and LLD/TL were analyzed using receiver operating characteristic curve. LLD/height as a PI with value of 1.75 was determined with specificity of 80% and sensitivity of 76%. CONCLUSION: A height of less than 170 cm has significant changes in relation to LLD. PI using LLD/height appears to be a promising tool to identify patients at risk.

Temporary hemiepiphysiodesis for correcting idiopathic and pathologic deformities of the knee: A retrospective analysis of 355 cases.

BACKGROUND: Hemiepiphysiodesis is a well-established treatment option in cases of pathologic deformities and leg discrepancies during evolution. The aim of this study was to evaluate the postoperative angular measurement, correction correlated with age at operation time, and postoperative complication rate. MATERIAL AND METHODS: A total of 355 patients were treated with 887 8-plates between April 2007 and January 2013. Their mean age was 12.18 years (range four to 16 years), and the mean time to axis correction was 17.32 months (range two to 62 months). We analysed the entire population and also performed subgroup analyses for idiopathic, pathologic, varus, valgus and leg length discrepancy. RESULTS: The mean durations (time from (hemi-) epiphysiodesis to implant removal) in the idiopathic and pathologic groups were 13.24 and 21.3 months, respectively. The time to implant removal was 18.39 months for idiopathic varus deformities and 11.07 months for idiopathic valgus deformities. For the pathologic deformity group it was 24.9 and 20 months in the varus and valgus subgroups, respectively. CONCLUSIONS: Hemiepiphysiodesis is a well-established treatment option to correct angular deformities. The rate of correction was slower and less successful in pathologic deformities and for leg length discrepancies. This suggests that earlier intervention is appropriate for these patients. A higher body mass index (BMI) was observed for valgus deformity, but no correlation was present between BMI and durability.

Standing in Schroth trained position significantly changes Cobb angle and leg length discrepancy: a pilot study.

STUDY DESIGN: Retrospective. OBJECTIVE: The aim of this study is to evaluate if standing in a Schroth trained position influences the radiographic assessment of Cobb angle and other radiographic parameters compared to a normal standing position. Schroth method has been associated with improved Cobb angle. This study aims to evaluate if standing in the Schroth trained position influences radiographic assessment of Cobb angle compared to a normal standing position. METHODS: This is a retrospective review of patients with adolescent idiopathic scoliosis (AIS) who were participating in Schroth therapy at the time of radiographs. Ten pairs of radiographs were included in this study. Each pair consisted of two micro-dose biplanar PA thoracolumbar spine radiographs obtained on the same day, one with the patient standing in the Schroth trained position and one in their normal standing position. Each pair of radiographs was independently evaluated by three attending pediatric spine surgeons for Cobb angle, coronal balance, shoulder balance, and leg length discrepancy, for a total of 30 paired readings (3 readings for each of the 10 pairs of radiographs). RESULTS: Major Cobb angle was a mean of 6° less (p = 0.02) and the compensatory curve was 5° less (p = 0.03) in the Schroth trained position compared to their normal standing position. Neither coronal balance (p = 0.40) nor shoulder balance (p = 0.16) was significantly different. Mean leg length discrepancy was 6.8 mm greater in the Schroth trained versus normal position (p < 0.001). CONCLUSION: Standing in a Schroth trained position for a PA spine radiograph was associated with a mean change in major Cobb angle of 6° compared to a normal standing position. If bracing was recommended for curves > 25° and surgery for curves > 45°, different treatment recommendations would have been made in 33% (10/30) of attendings' readings for the Schroth versus normally paired radiographs taken on the same day on the same patient. Studies evaluating the effect of Schroth therapy on Cobb angle must report if patients are standing in a normal or Schroth trained position during radiographs for conclusions to be valid, or differences may be due to a temporary, voluntary change in posture. LEVEL OF EVIDENCE: III.

Effect of femoral offset and limb length discrepancy on hip joint muscle strength and gait trajectory after total hip arthroplasty.

BACKGROUD: Femoral offset (FO) and limb length discrepancy (LLD) are important perioperative considerations when performing THA. Decreased FO prevents improvement of gait and muscle recovery and residual LLD has a prominent influence on patient satisfaction with THA, while few studies have investigated the relationship between FO and/or LLD and gait disturbances. We investigated the association between these two factors and hip muscle strength and the results of 3-D gait analysis after THA. METHODS: We evaluated 92 patients (including 20 patients who underwent gait analysis) in whom total hip arthroplasty was performed for unilateral evere osteoarthritis of the hip joint. FO and LLD were measured on a standard anteroposterior radiograph of the pelvis. Hip muscle strength was evaluated by isometric hip flexion (in the manner of straight leg raising test: SLR) and hip abduction strength. To evaluate 3-D walking trajectory, we used a portable gait analyzer. RESULTS: Reduction of global FO by > 5 mm after THA compared to the contralateral hip was associated with hip abductor muscle weakness. On the other hand, LLD ≤ 20 mm had no influence on hip abductor muscle strength and SLR strength. In gait analysis, SLR strength showed a significant difference between the sagittal plane symmetrical and asymmetrical groups. CONCLUSION: Postoperative global FO > 5 mm less than that of the contralateral hip was associated with hip abductor muscle weakness. And, from the results of 3-D gait analysis, SLR weakness may increase gait asymmetry in the sagittal plane.

Sagittal plane deformity after temporary epiphysiodesis of the distal femur for correcting limb length discrepancy.

BACKGROUND: Outcome of the temporary epiphysiodesis procedure for limb length discrepancy (LLD) is commonly evaluated in the coronal plane. The purpose of this study was to investigate implant position and complications of the distal femur and patella in the sagittal plane after the temporary epiphysiodesis. METHODS: We retrospectively reviewed 27 patients with LLD who underwent temporary epiphysiodesis of the distal femur using staples (11 patients) or eight-plates (16 patients) between 2007 and 2015. The mean age was 9.7 years (range, 6.3-13.8) at the time of epiphysiodesis. The implants were removed after a mean period of 2.6 years (range, 0.8-4.8) from the epiphysiodesis. Correction amount of LLD was measured on anteroposterior long leg standing radiographs. Implant position, extension deformity of the distal femur (>5° from epiphysiodesis to removal of implant) and patella baja (the epiphyseal line midpoint method < 1.0) were evaluated using lateral knee radiographs. RESULTS: The average correction amount of LLD was 17.4 mm (range, 2-34). The average implant position was 43.1% (range, 35-55) from the anterior edge of the distal femoral epiphysis. At removal surgery, 16 patients (59%) had extension deformity of the distal femur and 14 patients (52%) showed patella baja. There were significant correlations between implant position and extension deformity (r = -0.51, p < 0.01) and as well as between correction amount of LLD and patella baja (r = -0.64, p < 0.01). CONCLUSION: After temporary epiphysiodesis for the treatment of LLD, extension deformity of the distal femur and patella baja occurred frequently. Anterior placement of the implants is associated with extension deformity of the distal femur. The implant should be placed in the center of distal femoral physis, not the center of femoral shaft. Excessive correction of LLD should be avoided due to a risk of patella baja.

Femoral Neck Fractures in Children: Issues, Challenges, and Solutions.

Femoral neck fractures in children are rare injuries resulting from high-energy trauma. Different methods of treatment, lack of standard management protocols, and the high risk of complications make this injury one of the biggest challenges that an orthopaedic surgeon can face. This review focuses on the general aspects of the pediatric femoral neck fracture management as well as its complications and possible solutions.

Repeated intramedullary stabilization following failed telescopic nail lengthening - An appropriate treatment strategy.

Externally magnetic-controlled intramedullary telescopic nails for bone lengthening have recently gained popularity due to many advantages when compared to more traditional lengthening methods. Patients requiring lengthening often present with a clinical history of previous multiple surgeries increasing the risk for complications of further procedures. However, studies regarding the treatment of complications following implantation of these devices remain scarce in literature. Therefore, we report our experience with revision surgery after lengthening with a telescopic intramedullary lengthening nail. In 6 out of 20 cases (30%) of lower limb lengthening for leg length discrepancy revision surgery was necessary. Two revisions were necessary due to nail breakage while the other 4 cases required a secondary procedure for non-union. In all cases, revision surgery included standard intramedullary locking nailing with additional autologous bone grafting. The median interval between index and revision surgery was 11.5 months (range 2-15 months). Satisfying clinical results, the intended extend of lengthening and bony consolidation was observed in all 6 patients. We conclude that revision surgery using an intramedullary locking nail with autologous bone grafting after failed telescopic nail-based lengthening represents an useful salvage procedure in these cases.

Acute shortening versus bone transport for the treatment of infected femur non-unions with bone defects.

BACKGROUND: The bone transport technique has been a well-known method in the treatment of osteomyelitis of the long bones with large segmental bone defects. However, one of the major drawbacks with this traditional technique is the long-lasting consolidation period, which may entail infectious and non-infectious complications. To overcome this drawback, several techniques were developed, one of which is acute shortening and re-lengthening. The aims of this study were: 1) to present our experience with a new modified technique of acute shortening and re-lengthening using a monolateral external fixator combined with a retrograde intramedullary nail, and 2) to compare its results with the classic Ilizarov bone transport method in the management of infected non-unions of the distal femur with bone loss. METHODS: This retrospective study compared these two techniques. 17 patients were treated using our modified technique of acute shortening and re-lengthening (Group A); 15 patients were treated using segmental bone transport (Group B). The average follow-up was 66 months (range: 24-180) in Group A and 70 months (range: 24-240) in Group B. The mean bone loss was 5.5 cm (range: 3-10) in Group A and 5.9 cm (range: 3-10) in Group B. The primary outcome of the present study was to compare the external fixator time (EFT) and external fixation index (EFI) between the two groups. The bone and functional status were also assessed. RESULTS: The mean EFI was lower in Group A (mean: 31.8 days/cm; range: 24-50) than in Group B (mean 48.7 days/cm; range: 40-100) (p = 0.02). The mean EFT was shorter in Group A (mean: 120 days; range: 100-150) than in Group B (mean: 290 days; range: 100-400) (p = 0.0003). With respect to the bone and functional results, no difference was observed. CONCLUSIONS: Although both techniques could be employed safely in the treatment of infected non-union of the distal femur with size defects ranging between 3 cm and 10 cm, our modified technique of acute shortening and re-lengthening may confer greater patient satisfaction because of shorter EFI.

Leg Length Discrepancy: The Natural History (And What Do We Really Know).

BACKGROUND: The long-term effects of small limb length discrepancies have been poorly documented in the literature. References to low back pain, hip pathology, knee pathology, and foot problems abound in the popular literature. Health care providers frequently recommend the use of lifts for structural and functional limb length discrepancies, yet the natural history of limb length inequality as well as the effectiveness of treatments that may be recommended are obscure. The purpose of this paper is to document and evaluate the literature associated with small limb length discrepancies. METHODS: A search of the English literature was carried out using PubMed to identify papers dealing with the effects of limb length discrepancies. Papers reporting only expert opinion or case reports were excluded. RESULTS: Papers dealing with the natural history of limb length discrepancy as well as studies in which gait analysis was performed in patients with limb length discrepancy were identified. Only 10% of the population has exactly equal lower limb lengths. Approximately 90% of the population has a limb length discrepancy <1.0 cm. Hip and knee pathology is present in an increased number of patients with limb length discrepancies over 5 mm. Hip pathology is more often present in the long leg, knee pathology has been reported in various studies to be more common in either the long or short leg. Low back problems seem to be more common on the short side in patients with limb length discrepancies. A number of different compensatory mechanisms for limb length discrepancy have been identified during gait analysis. CONCLUSIONS: There seems to be a consensus that limb length discrepancies >2.0 cm are frequently a problem. There is some evidence that limb length discrepancies as little as 5 mm can lead to long-term pathology.

The effect of leg length inequality on joint contact forces of lower limbs during walking.

PURPOSE: The aim of this study was to examine the joint contact forces (JCF) between each limb as the LLD magnitude increases during walking activity. METHODS: Eighteen male healthy subjects volunteered to participate in the experiment. Walking gait analysis was conducted with eight different levels of insole to simulate the LLD, starting from 0 cm until 4.0 cm with 0.5 cm increment. Qualisys Track Manager System and C-motion Visual 3D biomechanical tools were used to analyse the results. Four joints (ankle, knee, hip, and pelvis) of lower limb of two legs were investigated. The increment of insoles was placed on the right leg to represent the long leg. RESULTS: The results suggest that the mean contact forces for all joints in the short leg were increased as the increment level increased. On the contrary, the mean contact forces in the long leg decreased when the LLD level increased. Among these four joints, JCF in hip shows a positive increment based on the ASI value. Means that hip shows the most affected joint as the LLD level increase. CONCLUSIONS: The result obtained in this study might help clinicians treat patients with a structural LLD for treatment plan including surgical intervention.

Do component position and muscle strength affect the cup-head translation during gait after total hip arthroplasty?

INTRODUCTION: This study examined whether the component position or muscle strength affects the cup-head translation under in vivo weight-bearing conditions after total hip arthroplasty (THA). We hypothesized that there was a correlation between the hip offset or abductor strength and cup-head translation during gait. MATERIALS AND METHODS: We prospectively evaluated 31 patients undergoing unilateral cementless primary THA. The cup height, cup/stem offset, and limb length discrepancy were measured on anterior-posterior bilateral hip radiographic images. The isometric muscle strength of the lower limbs was quantified using a handheld dynamometer. Continuous radiographic images were recorded during gait, and cup-head translation was analysed using a computer-assisted method. RESULTS: The average cup height, cup/stem offset, and limb length discrepancy were - 3.8 ± 5.1 mm, 1.2 ± 5.2 mm/- 0.7 ± 7.7 mm, and - 2.1 ± 5.2 mm, respectively. The average hip abductor/flexor and knee extensor strength were 86% ± 18%/85% ± 17% and 88% ± 17% of the contralateral healthy hip, respectively. The average cup-head translation during swing phase of gait was - 0.003 ± 0.31 mm. Multiple regression analyses found no significant independent predictors of cup-head translation (p > 0.05). CONCLUSIONS: The component position or muscle strength did not significantly influence cup-head translation during gait after well-positioned primary THA.

Clinical efficacy of orthopilot navigation system versus conventional manual of total hip arthroplasty: A systematic review and meta-analysis.

BACKGROUND: To compare the clinical efficacy between Orthopilot navigation system and conventional manual surgery in total hip arthroplasty (THA). METHODS: Electronic databases were searched to identify randomized controlled trials (RCTs) investigating Orthopilot navigation system versus conventional manual in patients undergoing THA. Outcome measurements include anteversion angle, inclination angle, preoperative leg length discrepancy, postoperative leg length discrepancy and femoral offset. Statistical software Stata 12.0 was used for data-analysis. RESULTS: A total of 5 studies were finally included in this meta-analysis. The results showed that the conventional manual group have a less anteversion angle than that in Orthopilot navigation system group (weighted mean difference (WMD) = 4.67, 95% confidence interval (CI) = 3.53, 5.82, P = .000). And pooled analysis showed that the inclination angle in Orthopilot navigation group was less than that in conventional manual group (WMD = -4.19, 95% CI = -8.00, -0.37, P = .031). There was no significant difference between the preoperative leg length discrepancy and postoperative leg length discrepancy (P > .05). Orthopilot navigation system compared with conventional manual procedure was associated with decreased of femoral offset by 2.76 (WMD = -2.76, 95%CI = -3.90, -1.62, P = .000). CONCLUSION: Both Orthopilot navigation system and conventional THA result in significant improvements in patient function with similar overall complication rates and have their own edges in cup position.

Understanding Skeletal Growth and Predicting Limb-Length Inequality in Pediatric Patients.

Limb-length inequality in a child can be a complex condition for patients, parents, and medical providers. Managing these patients and explaining the treatment options to families requires knowledge of the potential risks associated with leaving a discrepancy untreated and a thorough understanding of skeletal growth. The provider must also be familiar with the available growth prediction methods as treatment is influenced by the anticipated discrepancy at skeletal maturity. This article provides an overview to skeletal growth, assessing skeletal maturity and growth prediction to help providers develop an organized and thoughtful approach to treating pediatric patients with limb-length inequalities.

Pressure distribution under the contralateral limb in Charcot arthropathy with different walking speeds.

BACKGROUND: The total contact cast has been recognized as the "gold standard" for treatment of Charcot neuro-osteoarthropathy (CN). However, removable cast walkers (RCWs) became an alternative option especially after resolution of the acute stage. RCWs with an elevated sole construction often induce leg length discrepancy (LLD) that could significantly affects plantar pressure (PP) distribution in diabetic patients with neuropathy. AIM: To study the additional effect of walking speed on PP abnormalities induced by LLD. METHOD: The study included 16 patients with diabetes (59±8.8years; 8 men and 8 women), with unilateral CN offloaded by RCW. In-shoe PP distribution was measured using F-scan (Tekscan Inc.), whilst patients walked at their normal speed (53±4 steps/min), versus short slow steps (24±3/min) under the two walking conditions: (1) neglected LLD, and (2) corrected LLD. RESULTS: The greatest reduction in PP was seen during reduction of walking speed, with corrected LLD, followed by corrected LLD with normal walking speed, followed by neglected LLD with slowing of walking speed. The highest PP was found when the patient remain on their normal walking speed and LLD was neglected. CONCLUSION: The contralateral foot of CN offloaded with RCW, is subjected to high pressure loads beneath the hallux, 1st, 2nd, 3rd, and 5th metatarsal heads. As such, care should be taken not only to avoid minor LLD, but to also advise the patient to practice short slow steps while walking, so that pressure overload on contralateral limb and its possible contribution to the development of bilateral Charcot, could be minimized.