Residual Limb Length Research Articles

Shape Analysis of Prosthetic Socket Rectification Procedure for Transtibial Amputees

Achieving a comfortable socket residual limb interface is crucial for effective prosthetic rehabilitation, depending on the precise characterisation and fluctuations in the shape and volume of residual limbs. Clinicians rely on subjective and iterative methods for shaping sockets, often involving a trial-and-error approach. This study introduces a framework for measuring, analysing, and comparing residual limb shape and volume using scanned data to facilitate more informed clinical decision-making. Surface scans of 44 transtibial residual limb casts of various sizes and lengths were examined. All scans were spatially aligned to a mid-patella and subjected to analysis using a shape analysis toolbox. Geometric measurements were extracted, with particular attention to significant rectified regions during the cast rectification process. Following PTB guidelines, our analysis revealed substantial alterations, primarily in the mid-patella region, followed by the patellar tendon area. Notably, there was a significant volume change of 6.02% in the region spanning from mid-patella to 25% of the cast length. Beyond this point, linear cast modifications were observed for most amputees up to 60% of the cast length, followed by individual-specific deviations beyond this region. Regardless of residual limb size and length, the modifications applied to positive casts suggested categorising patients into five major groups. This study employs the AmpScan shape analysis tool, to comprehend the cast rectification process used for capturing and assessing the extent of rectification on patients’ residual limb casts. The clinical implications of our research are threefold: (a) the comparison data can serve as training resources for junior prosthetists; (b) this will aid prosthetists in identifying specific regions for rectification and assessing socket fit; (c) it will help in determining optimal timing for prosthetic fitting or replacement.

Subtrochanteric Shortening Osteotomy Provides Superior Function to Trochanter Slide Osteotomy in THA for Patients With Unilateral Crowe Type IV Dysplasia at a Minimum of 3 Years.

Performing THA in patients with high-riding developmental dysplasia of the hip (DDH) is associated with serious complications and technical challenges. Various methods of shortening osteotomy are available to facilitate femoral head reduction during THA in patients with high-riding hips; subtrochanteric shortening osteotomy and trochanteric slide osteotomy plus proximal shortening are the most common techniques. However, which approach is superior remains a topic of controversy. (1) Is there any difference in clinical outcomes (defined as the Harris Hip Score [HHS] and residual limb length discrepancy) at a minimum of 3 years between subtrochanteric shortening osteotomy and trochanteric slide osteotomy in patients with Crowe Type IV DDH who underwent THA? (2) Is there any difference in the risk or type of complications between the two approaches? We performed a retrospective, comparative study of two groups (subtrochanteric shortening osteotomy versus trochanteric slide osteotomy) matched for sex and preoperative HHS at a minimum of 3 years of follow-up. Between 2010 and 2018, we performed 67 THAs in patients with unilateral Crowe Type IV DDH. During that time, we generally used a trochanteric slide osteotomy for THA in all patients with Crowe Type IV hips and performed subtrochanteric shortening osteotomy when a conical stem was not available. A total of 42% (28) had THA with subtrochanteric shortening osteotomy, and 58% (39) had THA with trochanteric slide osteotomy. Of those, 89% (25) and 74% (29), respectively, were accounted for with complete datasets for possible matching at a minimum of 3 years of follow-up. Patients were matched for gender and preoperative HSS (within 10 points), leaving 22 patients in each group (79% of the subtrochanteric shortening osteotomy group and 56% of the trochanteric slide osteotomy group) for evaluation and analysis. Age (42 versus 46 years), gender (female: 73% versus 73%), preoperative HSS (40 versus 40), and preoperative leg length discrepancy (5.9 versus 5.3 cm) were comparable between the two groups (p > 0.05). The trochanteric slide osteotomy group exclusively received Cone Wagner (Zimmer) implants (100%), while Corail (DePuy Synthes) implants (77%) were the most commonly used in the subtrochanteric shortening osteotomy group. HHS at a minimum of 3 years as well as the presence or absence of a limp and Trendelenburg sign, functional leg length discrepancy, nonunion, nerve palsy, and other surgical complications were recorded and compared between the groups based on data drawn from a longitudinally maintained institutional database. At a mean follow-up of 73 months, improvement in HHS was greater in the subtrochanteric shortening osteotomy group than in the trochanteric slide osteotomy group (48 ± 4 points versus 36 ± 11 points, mean difference 12 points [95% CI 7 to 17 points]; p < 0.001). Although the preoperative leg length discrepancy was similar between the groups, there was a greater postoperative improvement in the subtrochanteric shortening osteotomy group (44 ± 8 mm and 38 ± 8 mm in the subtrochanteric shortening osteotomy and trochanteric slide osteotomy groups, respectively; p = 0.02). The risk of nonunion was higher with a trochanteric slide osteotomy than with a subtrochanteric shortening osteotomy (23% [5 of 22] versus 0% [0 of 22]; p = 0.048). Other complications, including intraoperative periprosthetic fractures, nerve palsy, heterotopic ossification, revision surgery, and dislocation, did not differ between the groups. In patients with Crowe Type IV hips undergoing THA, surgeons might consider subtrochanteric shortening osteotomy rather than trochanteric slide osteotomy to minimize the risk of nonunion and achieve superior hip function. Better correction of leg length discrepancy may also be possible with subtrochanteric shortening osteotomy. The long-term survivorship of hips after these two techniques, as well as the influence of the specific anatomy of the proximal femur on the choice of technique, remain to be explored in future studies. Level III, therapeutic study.

The relationship between residual limb length and running ability in male amputee football players with lofstrand crutches

The relationship between residual limb length and running ability in male amputee football players with lofstrand crutches

Comparison of prosthetic mobility and balance in transfemoral amputees with bone-anchored prosthesis vs. socket prosthesis.

The literature comparing bone-anchored prosthesis (BAP) with socket prosthesis (SP) consistently reports improvement in physical health and quality of life using primarily patient-reported outcome measures (PROMs). To determine the differences in mobility and balance using performance-based outcome measures and PROMs in people with transfemoral amputations (TFAs) fitted with BAP vs. SP. Causal comparative. Two groups of people with TFAs were recruited: one using a BAP (N = 11; mean age ± standard deviation, 44 ± 14.9 years; mean residual limb length as a percentage of the intact femur, 68% ± 15.9) and another group using a SP (N = 11; mean age ± standard deviation, 49.6 ± 16.0 years; mean residual limb length as a percentage of the intact femur, 81% ± 13.9), and completed the 10-meter walk test, component timed-up-and-go, Prosthetic Limb Users Survey of Mobility™ 12-item, and Activities-specific Balance Confidence Scale. There were no statistically significant differences between the BAP and SP groups in temporal spatial gait parameters and prosthetic mobility as measured by the 10-meter walk test and component timed-up-and-go, yet large effect sizes were found for several variables. In addition, Activities-specific Balance Confidence Scale and Prosthetic Limb Users Survey of Mobility™ scores were not statistically different between the BAP and SP groups, yet a large effect sizes were found for both variables. This study found that people with TFA who use a BAP can demonstrate similar temporal spatial gait parameters and prosthetic mobility, as well as self-perceived balance confidence and prosthetic mobility as SP users. Therefore, suggesting that the osseointegration reconstruction surgical procedure provides an alternative option for a specific population with TFA who cannot wear nor have limitations with a SP. Future research with a larger sample and other performance-based outcome measures and PROMs of prosthetic mobility and balance would further determine the differences between the prosthetic options.

Validation of body composition assessment for unilateral amputees via BIA by comparison with DXA

Amputees suffer from metabolic diseases. Thus, for a healthy life, management through body composition (BC) tests is useful. We aimed to validate between the bioimpedance analysis (BIAInBody_S10) and dual-energy X-ray absorptiometry (DXALunar Prodigy) method for evaluating BC in amputees. 78 male (n = 66) and female (n = 12) unilateral amputees, with either trans femoral amputation (TFA) or trans tibial amputation (TTA), were recruited.Correlation, agreement, and differences between fat free mass (FFM) and percentage fat mass (PFM), computed with the two methods, were tested using methods such as Pearson’s and Spearman’s correlation, Lin's concordance correlation coefficient (CCC), Bland–Altman plot, bivariate linear regression, and %Diff = 100*(BIA-DXA)/DXA. In all groups, the FFM_BIA value was significantly overestimated compared to FFM_DXA; by contrast, the PFM_BIA value was significantly underestimated with respect to PFM_DXA. Additionally, differences between the results from the two methods were significantly higher for TFA than for TTA. In addition, a lower agreement between the two methods was observed in the TFA compared to the TTA group based on the correlation estimated through Lin's CCC. Moreover, body composition assessment with BIA needs to be carefully interpreted in amputees with some length of residual limb, especially regarding the TFA group.

The impact of transfemoral socket adduction on pelvic and trunk stabilization during level walking - A biomechanical study.

It is common practice to align transfemoral prosthetic sockets in adduction, due to the physiologic, adducted femoral alignment in unimpaired legs. An adducted femoral and socket alignment helps tightening hip abductors to stabilize the pelvis and reduce pelvic and trunk related compensatory movements. How do different socket adduction conditions (SAC) of transfemoral sockets affect pelvic and trunk stabilization during level ground walking in the frontal plane? Seven persons with transfemoral amputation with medium residual limb length participated in this study. The prosthetic alignment in the sagittal plane was performed according to established recommendations. SAC varied (0°, 3°, 6°, 9°). Kinematic and kinetic parameters were recorded in a gait laboratory with a 12-camera optoelectronic system and two piezoelectric force plates embedded in a 12-m walkway. The measurements were performed during level ground walking with self-selected comfortable gait speed. In the frontal plane, nearly all investigated kinematic and kinetic parameters showed a strong correlation with the SAC. The pelvis was raised on the contralateral side throughout the gait cycle with increasing SAC. During the prosthetic side stance phase, the mean shoulder obliquity and mean lateral trunk lean to the prosthetic side tended to be reduced with increased SAC. Prosthetic side hip abduction moment decreased with increasing SAC. The results confirm that transfemoral SAC contributes to pelvic stabilization and reduced compensatory movements of the pelvis and trunk. Transfemoral SAC of 6 ± 1° for bench alignment seems adequate for amputees with medium residual limb length. However, the optimum value for the individual patient may differ slightly.

Simultaneous multisegmental and multifocal corrections of complex lower limb deformities with a hexapod external fixator

IntroductionExternal fixators are a part of the therapeutic arsenal used in the correction of complex pediatric lower limb deformities. These long iterative procedures, which are commonly performed over several months, strongly impact the lives of these children and their families. To reduce these drawbacks, we perform, whenever possible, a simultaneous multisegmental and/or multifocal correction of these deformities. HypothesisSimultaneous multilevel correction of complex pediatric deformities using external fixators does not result in more complications than sequential corrections. Materials and methodsSixteen patients were treated with this hexapod external fixator correction procedure. The mean age was 13.9 years. The corrections involved 12 femurs and 20 tibias, representing 53 osteotomies on 23 limbs. The quality of the correction was assessed by measuring the mechanical axis deviation (MAD), residual limb length discrepancy (RLLD) and a new, specifically defined, criterion called the “angular healing index” (AHI). Complications were assessed according to Lascombes’ classification. ResultsThe mean MAD went from 30 to 13.5 mm (P<.05) and the mean RLLD from 33.2 to 6.9 mm (P<.05). The mean AHI was 74.1 days/cm (16.7 to 319). The overall complication rate was 13/23 operated limbs or 56.5% (4.3% grade 1, 43.3% grade 2, 9.3% grade 3, and no grade 4). DiscussionOne-stage multilevel corrections of complex pediatric lower limb deformities represent a difficult technical challenge, and any reduction in treatment time must not adversely impact the quality of the results. The rate and severity of complications compared to monofocal/segmental procedures were no higher than that reported in the literature. This study demonstrated the feasibility of multisegmental and multifocal corrections, which reduced the total treatment duration compared to successive corrections, without adversely affecting the result or increasing the complication rate. Level of evidenceIV; retrospective study.

Understanding Implications of Residual Limb Length, Strength, and Range-of-Motion Impairments of Veterans With Upper Limb Amputation.

The aim of the study was to describe and quantify the relationship between limb impairment variables to key functional outcomes. This was an observational study of 107 participants with unilateral above/at-elbow or below-elbow/wrist amputation. Demographics, prosthesis characteristics, residual limb length, and prevalence of passive range-of-motion restrictions, and strength impairments were described. Correlations between impairment variables were estimated. Linear regressions examined associations between impairment variables and activity performance, health-related quality of life, disability, and prosthesis satisfaction. Prevalence of short/very short below- and above-elbow residua was 25.7% and 12.5%, respectively. Shorter below-elbow/wrist residual limb length was correlated with elbow flexion weakness (r = 0.30) and prevalence of passive range of motion (r = 0.25). Shoulder prevalence of passive range-of-motion restrictions were correlated with shoulder (r = 0.27-0.51) and elbow weakness (r = 0.25-0.46). In regressions, activity performance was worse for those with shoulder flexion prevalence of passive range-of-motion restrictions (B = -5.0, P = 0.03) and better for those with flexion restrictions (B = 3.3, P = 0.04) compared with normal prevalence of passive range of motion. Prosthetic satisfaction was lower for those with limited elbow prevalence of passive range of motion. Short below-elbow residual limb length was correlated with impairment of elbow flexion strength and prevalence of passive range of motion. Prevalence of passive range-of-motion restrictions were most prevalent at the shoulder and were strongly correlated with weakness in the same planes of motion. Few significant associations were found between impairment variables and outcomes.

Impact of Level of Pediatric Amputation on Selection of Prosthetic Component Options

ABSTRACT Introduction Amputation is one of the oldest surgeries known to the human race. The principles of amputation in children are different than in adults. Common indications for amputation include congenital, traumatic, infection, malignancy, vascular, and other pathology. Improper prosthetic fitting or inability to use the most modern available prosthesis can lead to dissatisfaction and compromised high-level function. The aim of this study was to assess residual limbs for compatibility to fit the most modern prosthetic components. Methods This study is a retrospective review of medical records of patients who underwent amputation between the pelvis and midfoot before 18 years of age. Age, sex, etiology, and level of amputation were recorded. A senior certified prosthetist graded the limbs based on limitations the residual limb imposed on options for the highest functioning modern prosthetic components. Results Sixty-one patients were identified (35 male, 26 female) with a mean age at assessment of 17.35 years (range, 1.86–35.35 years). Congenital causes and tumors were the most common etiology. Amputations around the ankle were most common (25), followed by transtibial (20). There were 59% grade 1 limbs with no restrictions to component options, 28% grade 2 with moderate restrictions, and 13% grade 3 or severely limited component options due to the residual limb. Most grade 1 residual limbs were transtibial or proximal. Amputations distal to transtibial were of all grades. Conclusions The choices for optimal high-level prosthetic components are much less limited for transtibial amputation than more distal amputations leading to potentially less high-level prosthetic function. Managing the residual limb length and prosthetic fitting ability is an important element in pediatric amputations if the goal is to fit mature young adults with the highest functioning level prosthetic components.

Posteromedial tibial deformity: Radiological evolution and treatment of the discrepancy

IntroductionPostero-medial deformity (DMPT), unlike other congenital forms that affect the tibia, presents a good evolution spontaneously correcting the important misalignments that present at birth based on the classic orthopaedic laws of Wolff and Hueter-Volkmann, leaving slight residual angulations and variable limb length discrepancy. Material and methodsAuthors carry out a retrospective review of cases diagnosed with DPMT, the evolution of the tibial angulation and the discrepancy in the length of fourteen patients (11 males and 3 females) followed and treated between the years 2003 and 2018. Seven of these were treated by callus distraction. We have considered: PA and lateral of the tibia and stand-up entire limbs X-ray during age growth, along with the clinical records of the patients. ResultsThe medial diaphyseal radiological deformity of the newborn or neonatal period was 34° and the final 10°. The posterior deformity evolved from 46° to a final angulation of 11°. The physeal angulation in the initial AP projection was 34° and the end view was 8° and in the lateral projection from 44 to 6°. The mechanical axis of the limb was correcting towards a neutral axis in relation to the aforementioned physeal and diaphyseal correction in all cases except two. In five of the cases, although the mechanical axis was normal-aligned, at the tibial level it ran eccentrically and externally to the tibial cortex. The length relationship between the short tibia and the healthy tibia maintains a constant proportion throughout the growth of 89%, that is, the inhibition of growth is 11%. We observe that 80% of the discrepancy is found in the tibia and that the remaining 20% was exposed from the height of the tarsus. Two patients presented a traumatic and accidental diaphyseal fracture of the tibia. The difference in the length of the tibia was compensated to seven patients by callus distraction of 5.4cm using the callotasis method with a Healing Index of 34.5days/cm. ConclusionsDPMT improves substantially during the first years of life. Joint alignment of the knee and ankle is achieved before the correction of diaphyseal deformity. The tibia length discrepancy increases with the growth of the child since there is an 11% growth inhibition that will cause a skeletal maturity discrepancy between 4–7cm. Callus distraction before skeletal maturity is the method chosen to compensate this discrepancy.

Knee Joint Bone Defects: Reconstruction With Bone Transport and Arthrodesis

BackgroundThe increasing in primary total knee arthroplasty has led to an increase in infectious complications, revision surgery, and bone loss. Knee joint bone defects (KJBD) may be managed using bone transport and arthrodesis with Ilizarov or bone transport over nail (BTON) techniques. The aim of this study is to compare both techniques in the reconstruction of KJBDs. MethodsThis was a retrospective cohort study of 29 patients with extensive KJBD. All patients underwent reconstruction of the KJBD using bone transport (either Ilizarov or BTON techniques). The primary outcome variables for comparison between the two groups included time in frame (days), external fixation index (EFI, days/cm), residual limb length discrepancy (cm), and complications (Caton classification). ResultsGender and age profiles were comparable. Mean time spent in frame for bone transport was 566 days (σ = 236, 95% CI 429-702) for the Ilizarov cohort and 191 days (σ = 162, 95% CI 101-280) for BTON (P < .0001). EFI for the period of bone transport was 75.1 d/cm (σ = 41.5, 95% CI 51.1- 99.1) for the Ilizarov cohort and 24.7 d/cm (σ = 24.0, 95% CI 11.4-38) for BTON (P = .0004). Union, limb length discrepancy and complication rates were comparable between both groups. ConclusionFor the management of KJBD after failed total knee arthroplasty, BTON is preferred due to significantly less time spent in frame, lower EFI, and higher rates of normal mechanical alignment. The Ilizarov method may be useful when there is a contraindication to BTON.

Deformidad posteromedial de la tibia: evolución radiológica y tratamiento de la discrepancia

IntroductionPostero-medial deformity (DMPT), unlike other congenital forms that affect the tibia, presents a good evolution spontaneously correcting the important misalignments that present at birth based on the classic orthopedic laws of Wolff and Hueter-Volkmann, leaving slight residual angulations and variable limb length discrepancy. Material and methodsAuthors carry out a retrospective review of cases diagnosed with DPMT, the evolution of the tibial angulation and the discrepancy in the length of fourteen patients (11 males and 3 females) followed and treated between the years 2003 and 2018. Seven of these were treated by callus distraction. We have considered: PA and lateral of the tibia and stand-up entire limbs x-ray during age growth, along with the clinical records of the patients. ResultsThe medial diaphyseal radiological deformity of the newborn or neonatal period was 34° and the final 10°. The posterior deformity evolved from 46° to a final angulation of 11°. The physeal angulation in the initial AP projection was 34° and the end view was 8° and in the lateral projection from 44 to 6°. The mechanical axis of the limb was correcting towards a neutral axis in relation to the aforementioned physeal and diaphyseal correction in all cases except two. In five of the cases, although the mechanical axis was normal-aligned, at the tibial level it ran eccentrically and externally to the tibial cortex. The length relationship between the short tibia and the healthy tibia maintains a constant proportion throughout the growth of 89%, that is, the inhibition of growth is 11%. We observe that 80% of the discrepancy is found in the tibia and that the remaining 20% ??was exposed from the height of the tarsus. Two patients presented a traumatic and accidental diaphyseal fracture of the tibia. The difference in the length of the tibia was compensated to seven patients by callus distraction of 5.4cm using the callotasis method with a Healing Index of 34.5 days/cm. ConclusionsDPMT improves substantially during the first years of life. Joint alignment of the knee and ankle is achieved before the correction of diaphyseal deformity. The tibia length discrepancy increases with the growth of the child since there is an 11% growth inhibition that will cause a skeletal maturity discrepancy between 4-7cm. Callus distraction before skeletal maturity is the method chosen to compensate this discrepancy.

The influence of hip muscle strength on gait in individuals with a unilateral transfemoral amputation.

A unilateral transfemoral amputation (TFA) has a major impact on function. A leg-length discrepancy is the primary structural change, accompanied by the loss of lower-limb muscle volume and function. Prostheses can help individuals with a TFA to regain function, but such individuals still do not reach the functional level of unimpaired peers and exhibit gait deviations. This study gives insight into the causality between residual limb strength and gait deviations in individuals with a TFA. A convenient sample of 13 male individuals with a TFA (38.0 ± 12.6y; 179.7cm ± 6.5cm; 82.9kg ± 12.4kg) was recruited for this study. One participant with TFA was excluded, as he differed from the rest of the cohort, in residual limb length and the use of walking aids. A cohort of 18 unimpaired subjects served as a reference group (REF; nine females; 44y ± 13y; 174cm ± 9cm; 71kg ± 12kg). All participants underwent a conventional clinical gait analysis using a marker based 3D motion capture system and force platforms. Kinematics and kinetics were determined utilizing standard modelling methods. All subjects underwent a strength test, using a custom-made device to determine isometric moments of the hip joint in abduction, adduction, extension, and flexion. Peak values for maximum isometric moments for each movement direction and selected kinematic and kinetic values were derived from the results. Differences between subjects with TFA and unimpaired were compared using a Mann-Whitney U Test and associations between groups by Spearman's rank correlation. The participants with a TFA showed a significantly lower maximum isometric moment for hip abduction (0.85 vs. 1.41 Nm/kg p < .001), adduction (0.87 vs. 1.37 Nm/kg p = .001) and flexion (0.93 vs. 1.63 Nm/kg p = .010) compared to the reference group. Typically reported gait deviations in people with a TFA were identified, i.e. significant lower cadence and increased step width. We further identified altered coronal plane hip and trunk kinematics, with significantly higher ranges of motion during involved side stance-phase. Gait kinetics of individuals with a TFA showed significantly lower peak values during stance for hip abduction, adduction and extension moments in comparison to the reference group. We identified a moderate negative correlation between maximum isometric moment for hip abduction and trunk obliquity range of motion (ρ = -0.45) for participants with a TFA, which was not significant (p = 0.14). We showed that there are strength deficits in individuals with TFA and, that there are moderate correlations between gait deviations, i.e. lateral trunk lean during involved side stance and isometric hip abductor moment. The relation between maximum moments during gait and the corresponding maximum isometric moment may therefore be helpful to detect strength related compensation mechanisms. However, the moderate, non-significant correlation between lateral trunk lean and isometric hip abductor moment was the only one which corresponded directly to a gait deviation. Thus results must be interpreted with care. This study suggests that gait deviations in individuals with TFA are multifactorial and cannot be exclusively explained by their strength deficits. Future studies should explore the relationship between strength with kinematics and kinetics during gait in this population.

Cortical and medullary morphology of the tibia.

Bone resorption caused by stress shielding and insufficient bone-implant contact continues to be problematic for orthopedic endoprostheses that utilize osseointegration (OI) for skeletal fixation. Morphologic analyses have helped combat this issue by defining anatomic parameters to optimize endoprosthesis loading by maximizing bone-implant contact. These studies have not typically included diaphyseal medullary morphology, as this region is not pertinent to total joint replacement. To the contrary, percutaneous OI endoprostheses for prosthetic limb attachment are placed in the diaphysis of the long bone. This study examined the cortical and medullary morphology of 116 fresh-frozen human cadaveric tibia using computed tomography. Anatomic landmarks were selected and custom MATLAB scripts were used to analyze the cross-sectional cortical and medullary morphology normalized to biomechanical length (BML). BML measured the distance between the tibial plateau and the tibial plafond. Properties such as cortical thickness, medullary diameter, and circularity of the medullary canal were quantified. We tested the influence of sex and laterality on morphology, and examined variations along the length of the bone. Results showed that while both sex and laterality impacted the location of anatomic landmarks, only sex influenced cross-sectional morphology. Overall, morphology significantly affected shape along the length of the bone for all examined properties except medullary circularity. This analysis found that distal to 35% BML, the canal is conducive to a circular implant, with medullary diameter ranging from 13 to 32 mm between 20 and 80% BML. A large size range is necessary for sufficient implant contact in order to accommodate residual limb length after amputation.

Estimated forces and moments experienced by osseointegrated endoprostheses for lower extremity amputees

BackgroundPercutaneous osseointegrated (OI) docking of prosthetic limbs returns loading directly to the residual bone of individuals with amputations. Lower limb diaphyseal biomechanics have not been studied during the wide range of daily activities performed by individuals with lower extremity amputations; therefore, little is known about the loads experienced at the bone-endoprosthetic interface of a percutaneous OI device. Research questionDoes residual limb length and/or gender influence loading magnitudes in the diaphysis of the femur or tibia during daily activities? MethodsThis observational study used motion capture data from 40 non-amputee volunteers performing nine activities ranging from low to high demand, to virtually simulate residual limbs of amputees. To simulate diaphyseal bone loading in individuals with lower limb amputations, virtual joints were defined during post-processing at 25, 50, and 75 % of residual limb length of both the femur and the tibia, representing six clinically relevant residual limb lengths for OI device placement. Peak axial distractive and compressive forces, torsional moments, and bending moments were calculated for each activity. Comparisons were made between genders and between different levels of the simulated residual limb. ResultsFor simulated above and below knee amputations, short residual limbs showed the highest average bending, torsion, and axial distractive loads, while axial compressive loads were highest for long residual limbs. Absolute maxima for all subjects showed this same trend, except in below knee torsion, where 75 % residual tibia length showed the maximum. The highest demand activities yielding peaks in all directions were cutting with right leg planted, jump, run, and fall. SignificanceOverall, individuals with shorter residual limbs experienced higher diaphyseal forces. This should be taken into consideration during surgical implantation of percutaneous OI devices where residual limb length can potentially be shortened, and during rehabilitation of percutaneous OI patients.

Subtrochanteric femoral shortening for hip centre restoration in complex total hip arthroplasty with functional outcome

Aims Complex total hip arthroplasty (THA) with subtrochanteric shortening osteotomy is necessary in conditions other than developmental dysplasia of the hip (DDH) and septic arthritis sequelae with significant proximal femur migration. Our aim was to evaluate the hip centre restoration with THAs in these hips. Methods In all, 27 THAs in 25 patients requiring THA with femoral shortening between 2012 and 2019 were assessed. Bilateral shortening was required in two patients. Subtrochanteric shortening was required in 14 out of 27 hips (51.9%) with aetiology other than DDH or septic arthritis. Vertical centre of rotation (VCOR), horizontal centre of rotation, offset, and functional outcome was calculated. The mean followup was 24.4 months (5 to 92 months). Results The mean VCOR was 17.43 mm (9.5 to 27 mm) and horizontal centre of rotation (HCOR) was 24.79 mm (17.2 to 37.6 mm). Dislocation at three months following acetabulum reconstruction required femoral shortening for offset correction and hip centre restoration in one hip. Mean horizontal offset was 39.72 (32.7 to 48.2 mm) compared to 42.89 (26.7 to 50.6 mm) on the normal side. Mean Harris Hip Score (HHS) of 22.64 (14 to 35) improved to 79.43 (68 to 92). Mean pre-operative shortening was 3.95 cm (2 to 8 cm). Residual limb length discrepancy was 1.5 cm (0 to 2 cm). Sciatic neuropraxia in two patients recovered by six months, and femoral neuropraxia in one hip recovered by 12 months. Mean Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) was 13.92 (9 to 19). Mean 12-item short form survey (SF-12) physical scores of 50.6 and mental of 60.12 were obtained. Conclusion THA with subtrochanteric shortening is valuable in complex hips with high dislocation. The restoration of the hip centre of rotation and offset is important in these hips. Level of evidence IV Femoral shortening useful in conditions other than DDH and septic sequelae. Restoration of hip centre combined with offset to be planned and ensured.

Subtrochanteric femoral shortening for hip centre restoration in complex total hip arthroplasty with functional outcome.

AimsComplex total hip arthroplasty (THA) with subtrochanteric shortening osteotomy is necessary in conditions other than developmental dysplasia of the hip (DDH) and septic arthritis sequelae with significant proximal femur migration. Our aim was to evaluate the hip centre restoration with THAs in these hips.MethodsIn all, 27 THAs in 25 patients requiring THA with femoral shortening between 2012 and 2019 were assessed. Bilateral shortening was required in two patients. Subtrochanteric shortening was required in 14 out of 27 hips (51.9%) with aetiology other than DDH or septic arthritis. Vertical centre of rotation (VCOR), horizontal centre of rotation, offset, and functional outcome was calculated. The mean followup was 24.4 months (5 to 92 months).ResultsThe mean VCOR was 17.43 mm (9.5 to 27 mm) and horizontal centre of rotation (HCOR) was 24.79 mm (17.2 to 37.6 mm). Dislocation at three months following acetabulum reconstruction required femoral shortening for offset correction and hip centre restoration in one hip. Mean horizontal offset was 39.72 (32.7 to 48.2 mm) compared to 42.89 (26.7 to 50.6 mm) on the normal side. Mean Harris Hip Score (HHS) of 22.64 (14 to 35) improved to 79.43 (68 to 92). Mean pre-operative shortening was 3.95 cm (2 to 8 cm). Residual limb length discrepancy was 1.5 cm (0 to 2 cm). Sciatic neuropraxia in two patients recovered by six months, and femoral neuropraxia in one hip recovered by 12 months. Mean Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) was 13.92 (9 to 19). Mean 12-item short form survey (SF-12) physical scores of 50.6 and mental of 60.12 were obtained.ConclusionTHA with subtrochanteric shortening is valuable in complex hips with high dislocation. The restoration of the hip centre of rotation and offset is important in these hips.Level of evidence IVFemoral shortening useful in conditions other than DDH and septic sequelae.Restoration of hip centre combined with offset to be planned and ensured.

Prosthetic model, but not stiffness or height, affects maximum running velocity in athletes with unilateral transtibial amputations

The running-specific prosthetic (RSP) configuration used by athletes with transtibial amputations (TTAs) likely affects performance. Athletes with unilateral TTAs are prescribed C- or J-shaped RSPs with a manufacturer-recommended stiffness category based on body mass and activity level, and height based on unaffected leg and residual limb length. We determined how 15 different RSP model, stiffness, and height configurations affect maximum running velocity (vmax) and the underlying biomechanics. Ten athletes with unilateral TTAs ran at 3 m/s to vmax on a force-measuring treadmill. vmax was 3.8–10.7% faster when athletes used J-shaped versus C-shaped RSP models (p < 0.05), but was not affected by stiffness category, actual stiffness (kN/m), or height (p = 0.72, p = 0.37, and p = 0.11, respectively). vmax differences were explained by vertical ground reaction forces (vGRFs), stride kinematics, leg stiffness, and symmetry. While controlling for velocity, use of J-shaped versus C-shaped RSPs resulted in greater stance average vGRFs, slower step frequencies, and longer step lengths (p < 0.05). Stance average vGRFs were less asymmetric using J-shaped versus C-shaped RSPs (p < 0.05). Contact time and leg stiffness were more asymmetric using the RSP model that elicited the fastest vmax (p < 0.05). Thus, RSP geometry (J-shape versus C-shape), but not stiffness or height, affects vmax in athletes with unilateral TTAs.

Knee Arthrodesis Using Ilizarov Method with Autogenous Bone Graft Application in a Second-Stage Surgery: A Case Report of a Morbidly Obese and Diabetic Patient with a Septic Failure of Total Knee Arthroplasty

Currently, the main indication for knee arthrodesis is septic failure of a total knee arthroplasty (TKA). Circular external fixation has shown good results, and it is a good option to treat these cases. We present a case of a morbidly obese female, 55 years old, with a chronic septic failure of TKA, submitted to a knee arthrodesis using the Ilizarov technique. In a second-stage surgery, the remaining bone defect was filled with autogenous iliac crest graft. A radiographic and clinical fusion was verified 3 and 5 months, respectively, after the primary surgery. Twelve months later, she is very satisfied with the surgery results, presenting a Visual Analog Scale score 1 and a stable and pain-free lower limb. The residual limb length discrepancy was 3 cm, and she walks with a shoe lift without external support. Our case emphasizes the importance of autogenous bone graft application in a second-stage surgery to a successful and fast knee arthrodesis using the Ilizarov method in patients with chronic septic failure of TKA and severe comorbidities.

External fixation-assisted reduction for the treatment of neglected hip dislocations with limb length discrepancy: a retrospective study of 13 cases

BackgroundThe purpose of this study was to evaluate a new method for treating neglected hip dislocation with limb length discrepancy by using external fixation-assisted pre-reduction.MethodsThirteen patients admitted between January 2010 to February 2018 with a mean duration from injury to surgery of 5.0 ± 2.1 months and an average preoperative leg-length discrepancy of 7.7 ± 2.3 cm were enrolled in this study. The dislocation and associated acetabular fracture type, clinical outcomes and residual limb length discrepancy were evaluated.ResultsAll patients had posterior dislocations, and nine patients presented with acetabular fractures and were followed-up for at least 12 months. The average traction duration of external fixators was 28.8 ± 8.0 days and all patients received second-stage open reduction and internal fixation. Six patients showed residual limb length discrepancy within 2 cm. Patients showed significant improvement in hip function and pain relief. Complications including avascular femoral head necrosis and osteoarthritis occurred in three patients.ConclusionEffective correction of limb length discrepancy and improved function were observed in patients with neglected hip dislocations and limb equality using traction by external fixation combined with second-stage open reduction. Further follow-up is required to determine long-term outcomes.