Introdução: A discrepância no comprimento dos membros inferiores (DCMI) está associada a alterações biomecânicas na marcha e a uma grande variedade de desordens ortopédicas, que incluem uma possível sobrecarga do tendão tibial posterior. Neste sentido, hipotetizamos que há associação entre a presença de DCMI e disfunção do TTP. Objetivo: O presente estudo foi realizado para comparar a frequência e a magnitude de DCMI em um grupo com e outro sem disfunção do tendão tibial posterior (DTTP), bem como para relacionar características clínicas com a presença da doença. Modelo do estudo: Estudo caso-controle. Método: O estudo envolveu 118 pacientes com diagnóstico de DTTP atendidos entre janeiro de 2009 e setembro de 2012 e 118 voluntários controles pareados por gênero e raça. Através de escanometria radiográfica ou tomográfica, a frequência da DCMI, assim como a média da DCMI absoluta e a média da DCMI relativa foram comparadas entre os dois grupos. Resultados: A prevalência da DCMI e as médias da DCMI absoluta e da DCMI relativa foram significativamente maiores no grupo de casos (94,9%, 5,64 mm e 7,36% respectivamente) do que no grupo controle (79,7%, 3,28 mm e 4,18% respectivamente) (p<0.001). Conclusões: Os resultados deste estudo demonstram haver uma relação entre a DCMI e a presença de DTTP. Devido a importantes alterações biomecânicas geradas pela DCMI, esta é possivelmente um fator predisponente para o desenvolvimento da DTTP. / Background: Leg length discrepancy (LLD) is associated with a variety of orthopedic disorders and biomechanical gait changes that involve possible overload of the posterior tibial tendon (PTT). In view of the biomechanical disturbances induced by LLD, an association may exist between LLD and PTT dysfunction (PTTD). Purpose: To compare the frequency and magnitude of LLD between subjects with and without PTTD and ascertain whether associations exist between clinical features and presence of dysfunction. Study design: Casecontrol study. Methods: A total of 118 patients with a diagnosis of PTTD were seen between January 2009 and September 2012 and compared to 118 sex- and race-matched volunteers. The frequency of LLD, the mean absolute LLD and the mean relative LLD were measured by conventional (radiographic) or CT scanography and compared between cases and controls. Results: The prevalence of LLD and mean absolute and relative LLD values were significantly greater in the case group (94.9%, 5.64 mm and 7.36% respectively) than in the control group (79.7%, 3.28 mm and 4.18% respectively) (p<0.001). Conclusion: The findings of this study demonstrate a relationship between LLD and PTTD. In light of the major biomechanical changes it induces, LLD may be a predisposing factor for development of PTTD.

Introdução: A discrepância no comprimento dos membros inferiores (DCMI) está associada a alterações biomecânicas na marcha e a uma grande variedade de desordens ortopédicas, que incluem uma possível sobrecarga do tendão tibial posterior. Neste sentido, hipotetizamos que há associação entre a presença de DCMI e disfunção do TTP. Objetivo: O presente estudo foi realizado para comparar a frequência e a magnitude de DCMI em um grupo com e outro sem disfunção do tendão tibial posterior (DTTP), bem como para relacionar características clínicas com a presença da doença. Modelo do estudo: Estudo caso-controle. Método: O estudo envolveu 118 pacientes com diagnóstico de DTTP atendidos entre janeiro de 2009 e setembro de 2012 e 118 voluntários controles pareados por gênero e raça. Através de escanometria radiográfica ou tomográfica, a frequência da DCMI, assim como a média da DCMI absoluta e a média da DCMI relativa foram comparadas entre os dois grupos. Resultados: A prevalência da DCMI e as médias da DCMI absoluta e da DCMI relativa foram significativamente maiores no grupo de casos (94,9%, 5,64 mm e 7,36% respectivamente) do que no grupo controle (79,7%, 3,28 mm e 4,18% respectivamente) (p<0.001). Conclusões: Os resultados deste estudo demonstram haver uma relação entre a DCMI e a presença de DTTP. Devido a importantes alterações biomecânicas geradas pela DCMI, esta é possivelmente um fator predisponente para o desenvolvimento da DTTP. / Background: Leg length discrepancy (LLD) is associated with a variety of orthopedic disorders and biomechanical gait changes that involve possible overload of the posterior tibial tendon (PTT). In view of the biomechanical disturbances induced by LLD, an association may exist between LLD and PTT dysfunction (PTTD). Purpose: To compare the frequency and magnitude of LLD between subjects with and without PTTD and ascertain whether associations exist between clinical features and presence of dysfunction. Study design: Casecontrol study. Methods: A total of 118 patients with a diagnosis of PTTD were seen between January 2009 and September 2012 and compared to 118 sex- and race-matched volunteers. The frequency of LLD, the mean absolute LLD and the mean relative LLD were measured by conventional (radiographic) or CT scanography and compared between cases and controls. Results: The prevalence of LLD and mean absolute and relative LLD values were significantly greater in the case group (94.9%, 5.64 mm and 7.36% respectively) than in the control group (79.7%, 3.28 mm and 4.18% respectively) (p<0.001). Conclusion: The findings of this study demonstrate a relationship between LLD and PTTD. In light of the major biomechanical changes it induces, LLD may be a predisposing factor for development of PTTD.

Introdução: A discrepância no comprimento dos membros inferiores (DCMI) está associada a alterações biomecânicas na marcha e a uma grande variedade de desordens ortopédicas, que incluem uma possível sobrecarga do tendão tibial posterior. Neste sentido, hipotetizamos que há associação entre a presença de DCMI e disfunção do TTP. Objetivo: O presente estudo foi realizado para comparar a frequência e a magnitude de DCMI em um grupo com e outro sem disfunção do tendão tibial posterior (DTTP), bem como para relacionar características clínicas com a presença da doença. Modelo do estudo: Estudo caso-controle. Método: O estudo envolveu 118 pacientes com diagnóstico de DTTP atendidos entre janeiro de 2009 e setembro de 2012 e 118 voluntários controles pareados por gênero e raça. Através de escanometria radiográfica ou tomográfica, a frequência da DCMI, assim como a média da DCMI absoluta e a média da DCMI relativa foram comparadas entre os dois grupos. Resultados: A prevalência da DCMI e as médias da DCMI absoluta e da DCMI relativa foram significativamente maiores no grupo de casos (94,9%, 5,64 mm e 7,36% respectivamente) do que no grupo controle (79,7%, 3,28 mm e 4,18% respectivamente) (p<0.001). Conclusões: Os resultados deste estudo demonstram haver uma relação entre a DCMI e a presença de DTTP. Devido a importantes alterações biomecânicas geradas pela DCMI, esta é possivelmente um fator predisponente para o desenvolvimento da DTTP. / Background: Leg length discrepancy (LLD) is associated with a variety of orthopedic disorders and biomechanical gait changes that involve possible overload of the posterior tibial tendon (PTT). In view of the biomechanical disturbances induced by LLD, an association may exist between LLD and PTT dysfunction (PTTD). Purpose: To compare the frequency and magnitude of LLD between subjects with and without PTTD and ascertain whether associations exist between clinical features and presence of dysfunction. Study design: Casecontrol study. Methods: A total of 118 patients with a diagnosis of PTTD were seen between January 2009 and September 2012 and compared to 118 sex- and race-matched volunteers. The frequency of LLD, the mean absolute LLD and the mean relative LLD were measured by conventional (radiographic) or CT scanography and compared between cases and controls. Results: The prevalence of LLD and mean absolute and relative LLD values were significantly greater in the case group (94.9%, 5.64 mm and 7.36% respectively) than in the control group (79.7%, 3.28 mm and 4.18% respectively) (p<0.001). Conclusion: The findings of this study demonstrate a relationship between LLD and PTTD. In light of the major biomechanical changes it induces, LLD may be a predisposing factor for development of PTTD.

no / Leg length discrepancy (LLD) refers to the medical a condition where legs are of different lengths. This condition might affect gait and posture, and may lead to various orthopedic disorders that can have serious repercussions on the individual, be it physiological, psychological, social, economic, or ergonomic. In order to ameliorate the rehabilitation of individuals with LLD, it is imperative to understand the biomechanics of LLD in these individuals. Hence, the current study’s objective is to characterize the plantar pressures of individuals with Leg Length Discrepancy in comparison to those of asymptomatic individuals. This pilot study employs a pedar-x in-shoe pedobarograph system to gather the history of dynamic plantar pressures in one adult male individual with LLD and a representative adult normal volunteer with no diagnosed neurological or musculoskeletal disorders. The obtained results reveal quantifiable differences in the study metrics between the two individuals during walking. These results provide a proof-of-concept for this study, and may serve as diagnostic tools to better rehabilitate individuals with LLD and, thus, provide them with a better quality of life. Future work is to incorporate an extended study of 10 normal individuals versus 10 individuals with LLD, and includes both males and females, as well as both adults and adolescents.

Greater trochanteric pain (GTP) is a regional pain syndrome characterized by lateral hip pain and tenderness. Its incidence after total hip arthroplasty (THA) is variable. Bursal inflammation, degenerative changes of the attachment of the gluteal muscles, direct operative trauma and biomechanical disturbance of the operated hip have been discussed as being related to GTP. The diagnosis is purely clinical because radiological and laboratory investigations show no definite pathology. Although most treatment modalities are conservative, some patients may develop refractory complaints leading to surgical intervention. In study I we studied the incidence of GTP in 172 consecutive patients who underwent THA during 2002 at Sundsvall Hospital. Patients with GTP (n=21, incidence 12%) were matched with controls from the same cohort. The THA outcome was assessed using the Western Ontario and McMaster Universities Arthrosis (WOMAC) Index. Trochanteric tenderness was studied using an electronic pressure algometer. We found an association between the occurrence of GTP and postoperative uncorrected lengthening of the operated limb of ≥ one centimetre. The WOMAC index revealed a reduction of the clinical outcome in the GTP group. In Study II we tested the value of using an algometer in the diagnosis of GTP after THA. We measured the pressure-pain threshold (PPT) over the greater trochanter and ilio-tibial band in 18 patients and 18 matched controls. Both groups were evaluated using the visual analogue scale (VAS). We found the algometer to have a good predictive validity and reproducibility. However, there was large inter-individual variability across subjects. The PPT ratio of 0.8 (affected vs. unaffected side) can be used as a cutoff ratio to establish GTP. There was no correlation between PPT measurements and VAS. Because of a low positive predictive value and large inter-individual variability, the pressure algometer has a limited value as a screening tool. In study III we proposed a new surgical treatment for refractory GTP after THA consisting of distal lengthening of the ilio-tibial band (ITB) by Z-plasty under local anaesthesia. This method was used in 12 women between March 2004 and June 2006. The patients were followed up by phone interview 3-4 months postoperatively and by an EQ-5D questionnaire and clinical examination including evaluation with the algometer at 1-3 years postoperatively. We found that the patients‘ quality of life was markedly improved following the operation (EQ-5D = 0.26 preoperatively vs. 0.67 postoperatively; p &lt;0.005). There were no postoperative complications. In study IV we evaluated the accuracy of a commonly used clinical method of LLD measurement (anterior superior iliac spine-medial malleolus) by comparing it to a reliable radiological method (tear drop-lesser trochanter) in 139 patients before and after THA. We found the correlation between the clinical and radiological methods to be weak preoperatively (r=0.21, ICC= 0.33) while the correlation was moderate postoperatively (r= 0.45, ICC=0.62). It is therefore recommended that the radiological method be used to measure leg length discrepancy in patients who undergo THA.

Femoral neck fracture (FNF) is a great challenge for today´s health care and is associated with high mortality and morbidity in the elderly.  In the short term several studies in the literature have demonstrated improved hip function, quality of life and fewer re-operations in elderly patients treated with total hip arthroplasty (THA) instead of internal fixation (IF). There are few reports on the long-term outcome comparing IF and THA. The vast majority of orthopaedic departments in Sweden use the direct lateral (DL) or posteriolateral (PL) approaches for hip arthroplasty. The PL approach has been linked to an increased risk of dislocation of the prosthesis and a higher rate of revision surgery in comparison to the DL approach. There are few reports focusing on radiological risk factors for prosthetic dislocation and patient reported hip function comparing the two surgical approaches for hip arthroplasty in FNF. The randomized controlled trial (RCT) is the gold standard for evaluating medical or surgical interventions. An RCT of high quality has to be internally and externally valid. Internal validity refers to a correct study design to avoid bias skewing the results. External validity (EV) refers to whether the results will be clinically relevant to a definable group of patients and can be extrapolated to the general health care situation. There are only a few reports in the orthopaedic literature focusing on the EV of published studies and none in the field of hip fractures. Study I: This is a RCT of 100 patients with a displaced FNF comparing THA and IF. Follow-up evaluations were performed at three months and 1, 2, 4, 11 and 17 years. It was found that the Harris hip score (HHS) was higher and the rate of reoperations lower for patients treated with THA. Study II: This is a prospective cohort study of 185 hips, comparing the DL and the PL approaches in patients treated with a hemiarthroplasty (HA) for a displaced FNF. Follow-up was after 1 year. There was no difference in patient reported outcome between the groups measured with the HHS and WOMAC index. The PL approach resulted in a higher re-operation rate while the DL approach in a higher incidence of limping. Study III: This is a retrospective cohort study of 373 patients with a cemented bipolar HA using a PL approach for a FNF with a follow-up ranging from 6 months to 7 years. Radiographs and all surgical records were reviewed regarding femoral offset (FO), leg length discrepancy (LLD) and Wiberg angle. Patients with recurrent dislocations had a decreased postoperative FO, LLD and shallower acetabulum on the operated side compared with their controls. Study IV: This is a prospective cohort study of 840 hips comparing patients included in a RCT with those that did not give their informed consent (NC) or did not fulfill the criteria for participating in the trial (MS). Patients in the NC and MS groups had an increased mortality rate in comparison to those included in the study. We did not find any differences in hip function between these groups. The main conclusions of this thesis are: Healthy and lucid elderly patients with good hip function preoperatively, should be treated with THA for a displaced FNF. The DL approach is favourable in treating displaced FNF with HA due to its decreased risk of reoperation but with an identical hip function outcome as the PL approach. Care should be taken to restore the LLD and FO otherwise this may increase the risk of recurrent dislocation of a HA. Our findings suggest that trial participants had a lower mortality rate than non-participants but the functional outcome of non-participants appeared to be satisfactory. This is important to take into consideration when extrapolating study results to a health care system. / Lårbenshalsfrakturer (FNF) är en utmaning för dagens sjukvård och förknippad med hög mortalitet i den äldre befolkningen. FNF orsakas främst av lågenergitrauma efter fall i samma plan hos patienter med benskörhet. Total höftledsprotes (THA) har visat sig ge en bättre höftfunktion, livskvalitet med färre omoperationer hos äldre patienter än sluten reposition samt fixering med skruvar (IF) under de första två-fyra åren efter operation. Få studier har publicerats med långtidsuppföljning av THA jämfört med IF. Vid behandling av felställd FNF med halv höftledsplastik (HA) eller THA finns olika kirurgiska metoder (snittföring) för implantation av protesen. Majoriteten av ortopedkliniker i Sverige använder direkt lateral (DL) eller posteriolateral (PL) snittföring. PL har kopplats till en ökad risk för luxation av protesen (urledsvridning), vilket i sin tur genererat en högre risk för omoperation jämfört med DL. Få studier har utvärderat höftfunktion med avseende på snittföring. Detsamma gäller vilka radiologiska faktorer som påverkar risken förprotesluxation. Det finns olika typer av studiedesigner för utvärdering av medicinska och kirurgiska behandlingsmetoder. Studiedesignen med högst bevisvärde anses vara den randomiserade kontrollerade studien (RCT). För att en RCT skall hålla hög kvalitet krävs intern och extern validitet. Intern validitet syftar på ett korrekt studieupplägg som mäter det som avses och undviker påverkan av icke önskvärda faktorer. Extern validitet (EV) innebär att erhållna resultat från studien är generaliserbara och kan extrapoleras till andra grupper än den studerade. Det inga rapporter i ortopediska litteraturen med fokus på EV med patienter som drabbats av FNF. Studie I: Prospektiv randomiserad studie av 100 patienter med en felställd FNF jämförs THA med IF med avseende på höftfunktion och reoperationer. Uppföljning gjordes efter tre månader samt 1, 2, 4, 11 och 17 år. HHS som mått på höftfunktion var högre och andelen reoperationer lägre för patienter som behandlades med THA. Studie II: Prospektiv kohortstudie med 183 patienter med felställd FNF behandlade med HA och antingen DL eller PL. Vi fann ingen skillnad i patientrapporterad höftfunktion utvärderat med HHS och WOMAC efter 1 år men en ökad förekomst av hälta vid DL. Studie III: Retrospektiv kohortstudie av 373 patienter opererade med en cementerad bipolär HA och PL. Postoperativa röntgenbilder granskades avseende femoral offset (FO), postoperativ benlägdsskillnad (LLD) samt acetabulär Wibergvinkel och relaterades till återkommande protesluxationer. Detta relaterades till återkommande luxationer. Uppföljningstiden varierade mellan 6 månader och 7 år. Patienter med återkommande luxationer hade en minskad postoperativ global FO, förkortad LLD och grundare acetabulum på den opererade sidan jämfört med kontroller. Studie IV: Prospektiv kohortstudie av 840 patienter med felställd FNF där patienter som ingick i en RCT jämförs med de som inte gav sitt samtycke för deltagande eller ej inkluderats i screeningprocessen. De patienterna som inte gav sitt samtycke hade ökad dödlighet, men ingen skillnad i höftfunktion jämfört med deltagare. Slutsatser • Friska och kognitivt vitala äldre patienter med god höftfunktion innan en felställd lårbenshalsfraktur bör behandlas med total höftledsprotes. • DLsnittföring ger ett lika bra patientrapporterad höftfunktion men en ökad förekomst av hälta jämfört med PL snitt vid behandling med halvprotes på grund av en felställd lårbenshalsfraktur. • Ansträngning bör göras för att återställa benlängdsskillnad samtfemoral offset och därigenom minska risken för återkommande luxation. • Våra resultat tyder på att patienter som deltar i en randomiserad studie har lägre dödlighet än patienter som avböjt att delta samt de som missats i screeningprocessen. Det är viktigt att ta hänsyn till när extrapolerar studieresultat till ett hälso-och sjukvårdssystem. Detta bör vägas in i värderingen av studieresultatens externa validitet.

This master's thesis is focused on determination and analysis of stress and strain in femur with distraction intramedullary nail for treating leg length discrepancy with the method of distraction osteogenesis. Thesis is mainly focused on states after distraction when the callus consolidates. Problem of determining stress and strain is solved by computational modeling using FEM. Detailed description of modeling is included in this thesis, complicated 3D geometry of bone was acquired from segmentation of CT images. Computational model is solve with 4 different types of callus geometry and also material properties of callus are varied. The influence on stress and strain when the middle distal screw is not applied is also analyzed.