Introduction. A large number of total knee arthroplasty (TKA) patients, particularly in Japan, India and the Middle East, exhibit anatomy with substantial proximal tibial torsion. Alignment of the tibial components with the standard anterior-posterior (A-P) axis of the tibia can result in excessive external rotation of the tibial components with respect to femoral component alignment. This in turn influences patellofemoral (PF) mechanics and forces required by the extensor mechanism. The purpose of the current study was to determine if a rotating-platform (RP) TKA design with an anatomic patellar component reduced compromise to the patellar tendon, quadriceps muscles and PF mechanics when compared to a fixed-bearing (FB) design with a standard dome-shaped patellar component. Methods. A dynamic three-dimensional finite element model of the knee joint was developed and used to simulate a deep knee bend in a patient with excessive external tibial torsion (Figure 1). Detailed description of the model has been previously published [1]. The model included femur, tibia and patellar bones, TKA components, patellar ligament, quadriceps muscles, PF ligaments, and nine primary ligaments spanning the TF joint. The model was virtually implanted with two contemporary TKA designs; a FB design with domed patella, and a RP design with anatomic patella. The FB design was implanted in two different alignment conditions; alignment to the tibial A-P axis, and optimal alignment for bone coverage. Four different loading conditions (varying internal-external (I-E) torque and A-P force) were applied to the model to simulate physiological loads during a deep knee bend. Quadriceps muscle force, patellar tendon force, and PF and TF joint forces were compared between designs. Results. The RP design demonstrated consistently lower medial-lateral (M-L) force at the PF joint than the FB design, with greater differences between designs in later flexion once the patella was engaged in the sulcus groove; root-mean-square (RMS) differences in M-L force averaged 50 N less in the RP design throughout the flexion cycle, and 70 N less after 45° flexion (Figure 2). The FB design aligned for optimal bone coverage demonstrated 15% higher M-L forces than the FB design aligned with the tibial A-P axis. RMS load required by the quadriceps muscle was 60 N lower with the RP design than the FB design throughout the cycle (Figure 2). Discussion. Comparing a RP design with an anatomic patellar component and a FB design with a domed patellar component, the RP design demonstrated lower M-L PF joint and soft-tissue extensor mechanism forces. Differences were more pronounced under conditions of high I-E torque where the RP design accommodated large relative TF rotation. Differences in FB alignment resulted in substantially different PF M-L forces; when the FB component was mal-aligned with respect to the tibial A-P axis (and the line-of-action of the patellar tendon) the resulting M-L PF force was increased. The RP design reduced the demands on the extensor mechanism and loads on the PF joint and facilitated better coverage of the resected tibial bone surface

Introduction and Objective. The geometry of the proximal tibia and distal femur is intimately linked with the biomechanics of the knee and it is to be considered in total knee arthroplasty (TKA) component positioning. The aim of the present study was to evaluate the proximal tibial torsion in relation to the flexion-extension axis of the knee in healthy and pathological cohort affected by knee osteoarthritis (OA). Materials and Methods. We retrospectively analyzed computed tomography scans of OA knee of 59 patients prior to TKA and non-arthritic knee of 39 patients as control. Posterior condylar angle (PCA), femoral tibial torsion (TEAs-PTC and TEAs-PTT), proximal tibial torsion (PTC-PTT and PCAx-PTC) and distance between tibial tuberosity and the trochlear groove (TT-TG) were measured. Results. No differences were found for gender, age, TG-TT and PCAn angles. Statistically significant differences were found for all the other angles considered. Significant relation was found between Tibial Torsion and TEA-PTT angles, between PCAx-PTC and TEA-PTC, between TEA-PTT and TEA-PTC and between PCAx-PTC and TEA-PTT. All measures, except TG-TT and PCAn angles, showed high validity (AUC > 75%) in detecting OA, with TEA-PTT displaying the highest validity with an AUC of 94.38%. Conclusions. This is the first study to find significant differences in terms of proximal tibia geometry and anatomy between non arthritic and OA knees. It is conceivable that such anatomy could be implicated in the development of OA. Based on our data, the TEAs is a valid reference for correct positioning of tibial component in TKA. Indeed, setting the tibial component parallel to TEAs makes the prosthetic knee more similar to the native non-arthritic knee

Background. The importance of total ankle replacement (TAR) implant orientation in the axial plane is poorly understood with major variation in surgical technique of implants on the market. Our aims were to better understand the axial rotational profile of patients undergoing TAR. Methods. In 157 standardised CT Scans of end-stage ankle arthritis patients planning to undergo primary TAR surgery, we measured the relationship between the knee posterior condylar axis, the tibial tuberosity, the transmalleolar axis(TMA) and the tibiotalar angle. The foot position was measured in relation to the TMA with the foot plantigrade. The variation between medial gutter line and the line bisecting both gutters was assessed. Results. The mean external tibial torsion was 34.5±10.3°(11.8–62°). When plantigrade the mean foot position relative to the TMA was 21±10.6°(0.7–38.4°) internally rotated. As external tibial torsion increased, the foot position became more internally rotated relative to the TMA(pearson correlation 0.6;p< 0.0001). As the tibiotalar angle became more valgus, the foot became more externally rotated relative to the TMA(pearson correlation −0.4;p< 0.01). The mean difference between the medial gutter line and a line bisecting both gutters was 4.9±2.8°(1.7°-9.4°). More than 51% of patients had a difference greater than 5°. The mean angle between the medial gutter line and a line perpendicular to the TMA was 7.5°±2.6°(2.8°-13.7°). Conclusion. There is a large variation in rotational profile of patients undergoing TAR, particularly between the medial gutter line and the transmalleolar axis. Surgeon designers and implant manufacturers need to develop consistent methods to guide surgeons towards judging appropriate axial rotation of their implanton an individual basis. We recommend careful clinical assessment and CT scanspre-operatively to enable the correct rotation to be determined

Background. Authors sought to determine the degree of lateral condylar hypoplasia of distal femur was related to degree of valgus malalignment of lower extremity in patients who underwent TKA. Authors also examined the relationships between degree of valgus malalignment and degree of femoral anteversion or tibial torsion. Methods. This retrospective study included 211 patients (422 lower extremities). Alignment of lower extremity was determined using mechanical tibiofemoral angle (mTFA) measured from standing full-limb AP radiography. mTFA was described positive value when it was valgus. Patients were divided into three groups by mTFA; more than 3 degrees of valgus (valgus group, n = 31), between 3 degrees of valgus to 3 degrees of varus (neutral group, n = 78), and more than 3 degrees of varus (varus group, n = 313). Condylar twisting angle (CTA) was used to measure degree of the lateral femoral condylar hypoplasia. CTA was defined as the angle between clinical transepicondylar axis (TEA) and posterior condylar axis (PCA). Femoral anteversion was measured by two methods. One was the angle formed between the line intersecting femoral neck and the PCA (pFeAV). The other was the angle formed between the line intersecting femoral neck and clinical TEA (tFeAV). Tibial torsion was defined as a degree of torsion of distal tibia relative to proximal tibia. It was determined by the angle formed between the line connecting posterior cortices of proximal tibial condyles and the line connecting the most prominent points of lateral and medial malleolus. Positive values represented relative external rotation. Negative values represented relative internal rotation. Results. Greater lateral femoral condylar hypoplasia was related to increased valgus alignment of lower extremity. Correlation coefficient between mTFA and CTA was 0.253 (p < 0.001). Valgus group showed increased CTA, which was 10.2° ± 1.9°. CTA was 7.4° ± 2.5° in neutral group and 6.6° ± 4.8° in varus group. There was significant positive correlation between the degree of valgus alignment and the degree of femoral anteversion (r = 0.145, p = 0.003). pFeAV was 16.7° ± 5.8° in valgus group, 12.1° ± 6.0° in neutral group and 10.9° ± 7.0° in varus group. There was no correlation between degree of valgus alignment and degree of femoral anteversion (r = 0.060, p = 0.218). In terms of tibial torsion, increased valgus malalignment was associated with increased tibial torsion (r = 0.374, p < 0.001). Valgus group showed increased tibial torsion than other groups. Tibial torsion was 32.6° ± 6.2° in valgus group, 26.3° ± 6.9° in neutral group and 22.6° ± 7.2° in varus group. Conclusions. Increased valgus alignment of lower extremity was related to greater lateral femoral condylar hypoplasia. However, increased valgus alignment was not related to degree of femoral anteversion whereas it was related to increased external tibial torsion. Our findings should be considered when determining proper rotational alignment in TKA

Introduction. Snapping hip syndrome is a common condition affecting 10% of the population. It is due to the advance of the iliotibial band (ITB) over the greater trochanter during lower limb movements and often associated with hip overuse, such as in athletic activities. Management is commonly conservative with physiotherapy or can be surgical to release the ITB. Here we carry out a systematic review into published surgical management and present a case report on an overlooked cause of paediatric snapping hip syndrome. Materials & Methods. A systematic review looking at published surgical management of snapping hip was performed according to PRISMA guidelines. PubMed, MEDLINE, EMBASE, CINAHL and the Cochrane Library databases were searched for “((Snapping hip OR Iliotibial band syndrome OR ITB syndrome) AND (Management OR treatment))”. Adult and paediatric published studies were included as few results were found on paediatric snapping hip alone. Results. 1548 studies were screened by 2 independent reviewers. 8 studies were included with a total of 134 cases, with an age range of 14–71 years. Surgical management ranged from arthroscopic, open or ultrasound guided release of the ITB, as well as gluteal muscle releases. Common outcome measures showed statistically significant improvement pre- and post-operatively in visual analogue pain score (VAPS) and the Harris Hip Score (HHS). VAPS improved from an average of 6.77 to 0.3 (t-test p value <0.0001) and the HHS improved from an average of 62.6 to 89.4 (t-test p value <0.0001). Conclusions. Although good surgical outcomes have been reported, no study has reported on the effect of rotational profile of the lower limbs and snapping hip syndrome. We present the case of a 13-year-old female with snapping hip syndrome and trochanteric pain. Ultrasound confirmed external snapping hip with normal soft tissue morphology and radiographs confirmed no structural abnormalities. Following extensive physiotherapy and little improvement, she presented again aged 17 with concurrent anterior knee pain, patella mal-tracking and an asymmetrical out-toeing gait. CT rotational profile showed 2° of femoral neck retroversion and excessive external tibial torsion of 52°. Consequently, during her gait cycle, in order to correct her increased foot progression angle, the hip has to internally rotate approximately 35–40°, putting the greater trochanter in an anterolateral position in stance phase. This causes the ITB to snap over her abnormally positioned greater trochanter. Therefore, to correct rotational limb alignment, a proximal tibial de-rotation osteotomy was performed with 25° internal rotation correction. Post-operatively the patient recovered well, HHS score improved from 52.5 to 93.75 and her snapping hip has resolved. This study highlights the importance of relevant assessment and investigation of lower limb rotational profile when exploring causes of external snapping hip, especially where ultrasound and radiographs show no significant pathology

Purpose: Mal-tracking or dislocation of the patella is often the result of abnormal anatomy. Understanding the anatomy will clarify the treatment options available. The common anatomical causes of dislocation range from the valgus knee to patella alta and external tibial torsion. External tibial torsion results in symptoms ranging from patello-femoral pain to subluzation or dislocation. Many patients become symptomatic after an injury and recognition of the anatomical pathology helps in the treatment decision. Method: A retrospective study was carried out on 232 rotational high tibial osteotomies in 221 patients operated on between 1990–2004. The pre-operative degree of external tibial torsion and ‘Q’ angle was noted. The extent of any patello-femoral pathology was documented, as well as the degree of correction. Assessment was carried out using the HSS score and the Lysholm score. Notation was made of prior surgery, including arthroscopy, patella tendon tarnsfer and patellectomy. Results: Of the 232 cases, 80% showed good to excellent results with resolution of patello-femoral pain and instability. Ten percent had residual pain but no instability and 20 cases proceeded to total knee replacement. The best results were seen in cases of pain and instability with minimal patello-femoral arthritis. Some cases with end-stage patello-femoral arthritis were improved with the improvement in quadriceps function via reduction in the ‘Q’ angle. Conclusion: Rotational osteotomy of the proximal tibia for symptomatic patella instability secondary to significant external tibial torsion results in good to excellent results in 80% of cases

Purpose: The aim of this research was to characterize the correlation of magnetic resonance image (MRI) measurements of femoral anteversion and tibial torsion with transverse plane kinematics from the gait analysis of ten healthy and nine cerebral palsy (CP) children. Methods: The bone morphologies of nine spastic diplegic CP and ten healthy children were obtained by analysis of 3D MRIs. Location of anatomical landmarks along the femur and tibia were detected using medical imaging software. Each point was then defined with respect to bone-embedded femoral and tibial Cartesian coordinates, allowing 3D reorientation of the bone independent of the patient position within the scanner. Femoral anteversion was defined as the angle between the femoral neck and the transcondylar plane. Tibial torsion was defined as the angle between the transcondylar axis of the proximal tibia and the bi-malleolar axis. Three-dimensional motion of the lower limbs was measured using gait analysis. Transverse plane kinematics, including hip rotation and foot progression angles were recorded. Results: A moderate correlation was found between femoral anteversion, and maximum and average hip rotation in CP children (0.64 and 0.65). A high correlation was also seen between tibial torsion and maximum and average values of hip rotation for CP children (0.71 and 0.74). In healthy children, the only correlation observed was between femoral anteversion and average foot progression in stance (0.75). Discussion: In healthy children, femoral anteversion appears to influence foot progression angle, implying that this can lead to an internally rotated gait. In CP children, the correlation between femoral anteversion and hip rotation is only moderate. The interaction between different joints is more complex and the rotation of joints is determined by multiple factors. This study showed that tibial torsion also plays a role in determining hip rotation during gait

Introduction. Torsional malalignment syndrome (TMS) is a unique combination of rotational deformities in the lower limb, often leading to severe patellofemoral joint pain and disability. Surgical management of this condition usually consists of two osteotomies in each affected limb, with simultaneous correction of both femoral anteversion and external tibial torsion. However, we believe that a single supratubercular osteotomy followed by tibial derotation with the Taylor Spatial Frame (TSF) can be used to provide a significant improvement in both appearance and function. Materials and Methods. This is a retrospective case analysis in which we will be reviewing 16 osteotomies performed by one surgeon between 2006 and 2017. The study includes 11 patients with a mean age of 16.7 ± 0.8 years. Pre and post-operatively, patients were fully evaluated through history and physical examination, and CT rotational profiling. Statistical analyses were performed in order to determine whether or not any observed clinical or cosmetic improvements were statistically significant. Results. The results show significant improvements in scores reported on post-operative functional assessment, with mean Oxford Knee Score (OKS) increasing by 18.3 and mean Kujala Anterior Knee Pain Scale (AKPS) also increasing by 31.4. In addition to this, post-operative clinical assessment showed a reduced thigh-foot angle (TFA) in all cases, by a mean value of 31.9o. The angle of the transmalleolar axis (TMA) was successfully reduced in 14/16 cases, by a mean value of 8.6o. Statistical analysis showed all of these results to be statistically significant where p<0.05. Conclusions. The results show that supratubercular osteotomy, followed by gradual correction with TSF, can be used to provide a significant improvement in both appearance and function for patients suffering from TMS

Torsional changes in the lower limbs represent a serious clinical problem. The evaluation of the physiological development of the relationship between femur and tibia in the axial plane is necessary for final assessment. The authors observed 940 patients aged from 4 to 15 years to identify the most important modifications of torsion of the lower limbs during paediatric age. Clinical examination includes assessment in the standing and supine position and observation of the gait features so that the physiological-pathological borderline can be defined, along with peculiar aspects of single and combined deformities, in order to identify indications for osteotomy. The types of torsion are classified as: (1) isolated augmentation of femoral anteversion; (2) isolated reduction of femoral anteversion; (3) isolated medial tibial torsion; (4) isolated lateral tibial torsion; and (5) combined torsion (femoral anteversion combined with lateral tibial torsion). The anatomy and the natural progression of femoral and tibial torsion can be assessed by clinical methods. Radiographic methods such as axial CT views are indicated in cases in which clinical examination does not provide clear information and, in particular, if qualitative and quantitative diagnosis is required in order to establish the therapeutic protocol. The authors conclude by suggesting that the physiological development of torsion should be followed up to skeletal maturity in order to make a general evaluation and to decide on treatment

Purpose: Mal-tracking or dislocation of the patella is often the result of abnormal anatomy. Understanding the abnormal anatomy will clarify the treatment options available. The common anatomical causes of dislocation range from the valgus knee with an elevated ‘Q’ angle to patella alta with a hypo-plastic trochlea, to external tibial torsion, resulting in an excessive ‘Q’ angle. External tibial torsion results in symptoms ranging from patello-femoral pain to subluxation or dislocation. Many patients are asymptomatic prior to an injury. The decision to correct the underlying anatomical abnormality is often a difficult one. Methods: A retrospective study of 232 rotational HTO’s in 221 patients operated on between 1990 and 2003 was conducted. The pre-operative degree of external tibial torsion and ‘Q’ angle was noted as well as the degree of rotation. The extent, if any patello-femoral pathology, was noted. Assessment was carried out using the HSS scoring system and Lysholm score.|Notation was made of prior surgery to the knee ranging from arthroscopy to patella tendon transfer to patellectomy. Results: Of the 232 cases 80% were good to excellent with resolution of patello-femoral pain and instability. 10% had residual pain but no instability and 20 cases had to proceed to total knee replacement.|The best results were seen in cases with pain and instability but minimal patello-femoral pathology. Even cases with end-stage patello-femoral osteoarthritis were improved by maximizing the function of the extensor mechanism. Conclusions: Rotational osteotomy of the proximal tibia for symptoms of patello-femoral instability secondary to significant external tibia torsion provided much better results than isolated patella tendon transfer

This study reviews our 13-years experience with Haas’s multiple-longitudinal osteotomy technique for correction of tibial deformities in children. In this procedure multiple longitudinal bi-cortical osteotomies are made parallel in the proximal tibia. The deformity is corrected by applying moderate force in the desired plane. Fixation is achieved with either a long cast or with “pins-in-plaster”. Sixty osteotomies were performed in 37 children. Thirty-five cases had internal tibial torsion (ITT), 11 had external tibial torsion (ETT) and 14 had a Tibia Vara deformity. Twenty-one cases had Spastic Cerebral Palsy and 15 cases were associated with Clubfeet. One boy had bilateral tibia vara associated with SMED (Spondylo-meta-epiphyseal dysplasia). Twenty-two (36/7%) of the deformities had no underlying musculoskeletal conditions. Thigh-foot angles were corrected by a mean of 24. °. for ITT and −28° for ETT. Mean correction for tibia vara was 20°. Average anesthesia time for unilateral cases was 47 minutes. No neurologic or infectious complications, postoperative fractures or physeal damage occurred. There was one case of delayed union and 1 case of postoperative antecurvatum deformity. All 7 cases of postoperative recurrent deformities were associated with CP or SMED. This technique is a simple, safe and efficient method for correcting tibial torsional and varus deformities for both healthy children and those with underlying conditions. It allows accurate alignment of different deformities with an uniform osteotomy technique, which preserves bone continuity and provides inherent stability, thus avoiding the use of internal fixation

Fifty-five patients were assessed with a minimum of five- year follow up. Patients in this study underwent initial conservative treatment consisting of twelve months of physio. Those patients who continued to have recurrent instability underwent surgery. Only patients without rotational abnormalities of the femur were included. Tibial rotational was assessed geriometrically, with the degree of external rotation corrected to 20 – 23°. Those patients with associated patella alta underwent a distal transfer of the patella tendon also. Assessment included range of motion, thigh girth, quads strength, effusion and a modified Lystrom knee score assessed function and pre and post-op radiographic assessment. The purpose of this paper is to report on the results of rotational osteotomy of the proximal tibia to treat patella instability. At a mean follow-up of seven years (range 5 – 8.2) 76% of knees treated for congenital dislocation of the patella with external tibial torsion, achieved good to excellent results. External tibial torsion associated with an increased “Q” angle is an important factor in recurrent dislocation of the patella. It is surgically correctable with a rotational osteotomy of the proximal tibia above the patella tendon insertion. This technique “normalizes” the extensor mechanics and produces better results than patella tendon transfer. Ninety percent of the patients were female with an average age of thirty (range fourteen to forty-five years). Prior unsuccessful surgical procedures included lateral release (sixteen) Maquet procedure (ten) Hauser (sixteen) medialization of the patella tendon (ten) semitendinosis tenodesis and patellectomy (two). Pre-operative external tibial torsion averaged 45° (range 40° – 65°) with an average rotational correction of 25°. The average pre-op “Q” angle was 27° and post-op 14°. Outcome assessment of the fifty-five knees showed twenty-six excellent, sixteen good and thirteen poor. Overall 76% were good to excellent. Outcome assessment was performed using a modified Lysholm score and the Tegner activity scale. The average pre-op score was forty and post-op seventy. Patients with less painful symptoms pre-op had significantly better outcomes. Knees that had undergone multiple unsuccessful surgical procedures had poorer outcomes

Introduction and Aims: External tibial torsion associated with an increased ‘Q’ angle is an important factor in recurrent patella instability. It is surgically correctable with a rotational osteotomy of the proximal tibia above the patella tendon insertion. This technique ‘normalises’ the extensor mechanics and produces better results than patella tendon transfer. Method: Fifty-five patients were assessed with a minimum of five-year follow-up. Patients in this study underwent initial conservative treatment consisting of l2 months of physio. Those patients who continued to have recurrent instability underwent surgery. Only patients without rotational abnormalities of the femur were included. Tibial rotation was assessed geriometrically, with the degree of external rotational corrected to 20–23 degrees. Those patients with associated patella alta, underwent a distal transfer of the patella tendon also. Assessment included range of motion, thigh girth, quads strength, effusion and a modified Lystrom knee score assessed function and pre- and post-op radiographic assessment. Results: Ninety percent of the patients were female with an average of 30 (range 14–45). Prior unsuccessful surgical procedures included lateral release (l6) Maquet procedure (l0), Hauser procedure (l6) medialisation of patella tendon (l0), semitendinosis tenodesis and patellectomy (two). Post-operative follow-up average five to 8.2 years. Pre-operative external tibial torsion averaged 45 degrees (range 40–65 degrees) with an average rotational correction of 25 degrees. The average pre-op ‘Q’ angle was 27 degrees and post-op 14 degrees. Average pre-op functional score has 40 and post-op 70 degrees. Outcome assessment of the 55 knees showed 26 excellent, 16 good and 13 poor. Overall 76% of the knee were good – excellent. Of the 16 patients with associated anterior knee pain, 13 obtained good-excellent results. Patients with less painful symptoms pre-op, had significantly better outcomes. Knees that had undergone multiple unsuccessful surgical procedures, had significantly poorer outcomes. Uniplanar patella tendon transfer in these cases generally results in continued anterior knee pain. Conclusions: Derotational osteotomy re-aligned the extensor mechanism in cases of recurrent dislocation of the patella secondary to external tibial torsion. All patients had some improvement with the surgery, but the patients with poor outcomes continued to have anterior knee pain

Introduction. Patellofemoral pain and instability can be quantified by using the tibial tuberosity to trochlea groove (TT-TG) distance with more than or equal to 20mm considered pathological requiring surgical correction. Aim of this study is to determine if knee joint rotation angle is predictive of a pathological TT-TG. Methods. One hundred limbs were imaged from the pelvis to the foot using Computer Tomography (CT) scans in 50 patients with patellofemoral pain and instability. The TT-TG distance, femoral version, tibial torsion and knee joint rotation angle ((KJRA) were measured. Limbs were separated into pathological and non-pathological TT-TG. Significant differences in the measured angles between the pathological and non-pathological groups were estimated using the t test. The inter- and intraobserver variability of the measurement was performed. Logistic regression analysis was used to find the best combination of rotational angle predictors for a pathological TT-TG. Results. The intraclass correlation coefficients for inter- and intraobserver variability of the measured parameters was higher than 0.94 for all measurements. A statistically significant difference (P=0.024) was found between the KJRA between the pathological (mean=10.6, SD=7.79 degrees) and the non-pathological group (mean=6.99, SD=5.06 degrees). Logistic regression analysis showed that both femoral version (P=0.03, OR = 0.95) and KJRA (P=0.004, OR=1.15) were, in combination, significant predictors of an abnormal TT-TG. Tibial torsion was not a significant predictor. Conclusion. The KJRA can be used as an alternative measurement when the TT-TG distance cannot be measured as in cases of severe trochlea dysplasia and may act as a surrogate for pathological TT-TG

Although optimal alignment is essential for improved function and implant longevity after TKA, we have less bony landmarks of tibia relative to femur. Trans-malleolar axis (TMA) is a reference line of distal tibia in the axial plane, which externally rotated relative to a ML axis of proximal tibia. We originally defined another reference axis associated with the orientation of tibial plafond, and then measured tibial torsion in the 3D-coordinate system. Three-dimensional CAD models of 20 tibiae were reconstructed based on pre-operative CT data from OA patients (16 females and 4 males, 73.8 ± 6.9 years old). TMA was a line connecting each apex of medial and lateral malleolus. The plafond axis (PLA) that we originally defined in this study was a line connecting each midpoint of medial and lateral margin of talocrural facet. In terms of interobserver correlation coefficiency and mean errors of the designated points to define those axes, TMA was found out to be 0.982, 3.14 ± 0.47 mm (medial), and 0.988, 4.88 ± 0.59 mm (lateral). Those of PLA were 0.997, 1.97 ± 0.53 mm (medial), and 0.995, 2.02 ± 0.44 mm (lateral). The tibial torsion was 16.3 ± 6.3°with reference to TMA, and 10.2 ± 8.4°to PLA. Based on these results, as for the rotational reference axis in the axial plain of distal tibia, we consider the plafond axis to be another reliable and reproducible axis, which is expected to be applicable in preoperative planning in TKA to reduce outliers of coronal alignment

Introduction: It has been proposed that rotational gait abnormalities in the normal child are usually reflections of the anatomic deformity. A decreased acetabular and femoral anteversion have been recognized as a predisposing factor for osteoarthritis of the hip and the McKibbin instability index was introduced to quantify this relationship. Additionally, an increased femoral anteversion has been associated with osteoarthritis of the knee. However, it is well known that compensatory factors influence the dynamic rotational profile during gait. We compared rotational computed tomography data with gait analysis to evaluate their correlation and to elucidate the influence of compensatory mechanisms. Materials and Methods: In a prospective study conducted between 2001 and 2005 patients presenting with rotational malalignment were sent for 3D gait analysis. Main exclusion criterion was any kind of neurological affection. Patients in whom surgery was considered were referred to rotational computed tomography. The rotational alignment of the pelvis, hip and knee at different times during the gait cycle as evaluated in the 3D gait analysis was compared to the angular values derived from the rotational computed tomography for the femur and tibia and statistically analyzed and correlated. Results: There were 12 female and 16 male patients with a mean age of 16 (± 9.7) years at the time of gait analysis. After a first evaluation of data 8 limb segments were excluded to increase the quality of data. The mean anteversion of the femur was 29 degrees (2 degrees of retrotorsion to 56 degrees of anteversion) and the mean tibial torsion was 31 degrees (1 to 66 degrees of external torsion). The calculation of the Pearson correlation showed that an increase of femoral anteversion resulted in an increase of pelvic range of motion. An increase of femoral anteversion resulted in an increase of the internal rotation of the hip. Highly significant correlations were found between the rotational–CT values for the tibia and the all parameters describing rotation of the knee. The determination coefficient was high for tibial torsion versus knee rotation (R2 = 0.64), but showed a low value for femoral anteversion versus hip rotation (R2 = 0.2). Conclusion: The rotation of the hip as found in the gait analysis showed only weak correlation with rotational CT data. This is not surprising as the hips segment offers many possibilities for compensation. The torsion of the tibia was found to correlate very strongly with the gait analysis. The McKibbin index seems questionable as a prognostic factor for the individual patient in the light of a multitude of dynamic compensatory influences. Effort should be made to integrate the static instability index with dynamic gait analysis data

Introduction: The standard treatment of adolescent Blount’s disease includes proximal tibial valgus osteotomy and osteotomy of the fibula. Some believe that the fibula should also be fixed to prevent migration and subluxation. We performed correction of deformities in eight patients (10 tibiae) with adolescent Blount’s disease using the Taylor Spatial Frame (TSF). In all patients, the origin (virtual hinge) was placed at the level of the proximal tibial fibular joint. The purpose of this study was to review treatment outcome of proximal tibial osteotomy without osteotomy of the fibula in patients with adolescent Blount disease. Methods: Eight patients (10 tibiae) were treated by proximal tibial osteotomies and gradual correction by TSF without fibular osteotomy over a period of three years. All patients were males with a mean age of 14.6 years (range, 14–17 years). All patients had severe proximal tibial varus, four had significant proximal tibial procurvatum, and six had internal tibial torsion. The fibula was not fixed in five patients, and fixed distally in three. Results: Frames were removed at an average of 12.8 weeks (range, 12–15 weeks). The mean preoperative proximal tibial varus was 16.2. o. (range, 12–19. o. ), corrected to normal values in all patients. The mean preoperative MPTA was 71.4. o. (range, 67–77. o. ) and corrected to a mean MPTA 87.1. o. (range, 85–89. o. ). In four patients (5 tibiae) with proximal tibial procurvatum, the PPTA was corrected to normal range. Mean correction of internal tibial torsion was 10. o. (range, 5–15. o. ), performed in six patients (8 tibias). Pre-operative MAD was 55.8 mm medial to center of the knee (range, 44–77 mm), corrected to a mean MAD of 4.9 mm medial to center of the knee (range, 2–11 mm). Complications included superficial pin tract infections in seven patients. No complications related to the fibula were observed during/after correction. Conclusion: Based on our initial experience, we believe that most patients with adolescent Blount disease could have successful and predictable correction of tibial deformities without a need for osteotomy and fixation of the fibula

Good clinical outcomes of Total Knee Arthroplasty (TKA) demand the ability to plan a surgery precisely and measure the outcome accurately. In comparison with plain radiograph, CT-based 3D planning offers several advantages. More specifically, CT has the benefits of avoiding errors resulting from magnification and inaccurate patient positioning. Additional benefits include the assessment in the axial plane and the replacement of 2D projections with 3D data. The concern on 3D CT-based planning, however, lies in the increase of radiation dosage to the patients. An alternative is to reconstruct a patient-specific 3D model of the complete lower extremity from 2D X-ray radiographs. This study presents a clinical validation of a novel technology called “3XPlan” which allows for 3D prosthesis planning using 2D X-ray radiographs. After a local institution review board (IRB) approval, 3XPlan was evaluated on 24 patients TKA. Pre-operatively, all the patients underwent a CT scan according to a standard protocol. Image acquisition consisted of three separate short spiral axial scans: 1) ipsilateral hip, 2) affected knee and 3) ipsilateral ankle. All the CT images were segmented to extract 3D surface models of both femur and tibia, which were regarded as the ground truth. Additionally, 2 X-ray images were acquired for each affected leg and were used in 3XPlan to derive patient-specific models of the leg. For 3D models derived from both modalities (CT vs. X-ray), five most relevant anatomical parameters for planning TKA were measured and compared with each other. Except for tibial torsion, the average differences for all other anatomical parameters are smaller than or close to 3 degrees

Introduction. The aim of the present study was to evaluate the discrepancies of rotational profiles of whole limb between operated and non-operated limb following unilateral total knee arthroplasty. Materials and Methods. We conducted an analysis the CT data from 32 patients undergoing primary unilateral total knee arthroplasty using measured resection technique, which femoral component was always implanted with external rotation to posterocondylar axis from July 2009 to April 2013. Using these CT scan, rotational profiles of total limb such as femoral torsion angle (femoral neck anteversion angle; FTA), tibial torsion angle (TTA), knee joint rotation angle (KJRA) and total limb rotation (TLR) were measured. Results. There were significant discrepancies of FTA and KJRA between operated and non-operated limb following unilateral total knee arthroplasty. The mean difference of operated and non-operated side for FTA and KJRA were −6.51 ± 11.88º (p=0.0041) and −6.83 ± 5.04º (p < 0.001) respectively. However, there were no significant discrepancies of TLR, TTA. TTA and TLR showed strong correlation (r= 0.7309). Conclusion. FTA showed significant side to side discrepancy, TTA and TLR showed no significant discrepancy between operated- and non-operated limbs in patients undergone unilateral TKA. These results are due to the compensation effect of KJRA. However, excessive external rotation of femoral component beyond the compensation effect of prosthetic knee joint can lead to total limb rotational discrepancy in patient undergoing unilateral total knee arthroplasty

Background. A careful consideration of change of the rotational profiles of total limb after unilateral total knee arthroplasty is necessary. The aim of the present study was to evaluate the discrepancies of rotational profiles of total limb between operated and non-operated limb following unilateral total knee arthroplasty. Methods. We conducted a retrospective analysis the CT data from 32 patients undergoing primary unilateral total knee arthroplasty using measured resection technique, which femur implant was applied at an external rotation of 3° relative to the posterior condylar axis from July 2009 to April 2013 in our hospital. Using these CT studies, rotational profiles of total limb such as femoral torsion angle (femoral neck anteversion angle; FTA), tibial torsion angle (TTA), neck-malleolar angle (NMA), knee joint rotation angle (rotational mismatch; KJRA) and total limb rotation (TLR) were measured. Results. There were significant discrepancies of FTA and KJRA between operated and non-operated limb following unilateral total knee arthroplasty. The mean difference of operated and non-operated side for FTA and KJRA were −6.5 ± 11.9° (p=0.004) and −6.8 ± 5.0° (p < 0.001) respectively. However, there were no significant discrepancies of TLR, TTA and NMA. Conclusion. With comparison with non-operated side, although FTA is significantly decreased in operated limb than non-operated limb following total knee arthroplasty, there were no significant discrepancies of NMA and TLR, because of the compensatory effect of KJRA. However, excessive external rotation of femur implant can affect adversely on rotational profiles of total limb. Further long term studies will be required to evaluate the change of the rotational profiles following unilateral total knee arthroplasty