Abstract. OBJECTIVES. Valgus high tibial osteotomy (HTO) represents an effective treatment for patients with medial compartment osteoarthritis (OA) in a varus knee. However, the mechanisms which cause this clinical improvement are unclear. Previous studies suggest a wider stance gait can reduce medial compartment loading via reduction in the external knee adduction moment (KAM); a measure implicated in progression of medial compartment OA. This study aimed to measure whether valgus HTO is associated with a postoperative increase in static stance width. METHODS. 32 patients, recruited in the Biomechanics and Bioengineering Centre Versus Arthritis HTO study, underwent valgus (medial opening wedge) HTO. Weightbearing pre- and post- operative radiographs were taken showing both lower limbs. The horizontal distance, measured from a fixed point on the right talus to the corresponding point on the left, was divided by the talus width to give a standardised “stance width” for each radiograph. The difference between pre- and post- operative stance width was compared for each patient using a paired sample t-test. RESULTS. Preoperatively, mean stance was 4.00 talar-widths but postoperatively this increased to 5.41. This mean increase of 1.42 talar-widths was statistically significant (p=0.001) and represents a mean proportional increase in stance width of 35.5% following HTO. Of the 32 patients, 23 showed increased stance width and 9 decreased (range −4.64 to 6.00 talar-widths). CONCLUSIONS. These findings indicate an association of frontal plane surgical realignment at the proximal tibia via a medial opening wedge HTO with an increased stance width on postoperative radiographs. Considering both wider stance gait and HTO have been shown to affect the progression of medial compartment OA, these results may explain one mechanism contributing to the efficacy of HTO surgery. However, the range of changes in stance width suggests significant variability in how patients adapt at a whole-limb and whole-body level following HTO. Declaration of Interest. (b) declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research reported:I declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project

Background. In the adolescent population, operative management of hallux-valgus is controversial. Operations may be less successful than in adults and post-operative recurrence is more common before full skeletal maturity. This study assesses the radiographic, functional and qualitative outcomes of surgical Hallux Valgus correction in adolescents. Methods. Three independent reviewers retrospectively analysed pre and post-operative radiological markers of hallux valgus severity for 44 operations on patients age 13–18. The patient cohort were also asked the Manchester-Oxford foot questionnaire (MOXFQ) to assess functional outcome via telephone interview and patient notes were reviewed for any evidence of complications. Results. There was no evidence of NICE recognised complications from any of the operations performed, however there was persistence or recurrence in 20.8%, requiring a second operation in 10.3%. Radiologically, all operations performed resulted in a reduction in hallux valgus severity. The hallux valgus angle showed a mean reduction of 18.0 degrees (16.3–19.7) and the inter-metatarsal angle by 7.3 degrees (6.55–8.14). 93% of operations resulted in a good MOXFQ outcome score of less than 20 out of a possible 80 negative functional outcome points. This score worsened with age in a statistically significant manner (p=0.03) but had no significant correlation with BMI. Conclusion. Surgical correction of adolescent hallux valgus reduces the radiographic severity, which correlates with good long term outcome. This surgery provides beneficial results to the patient, however there is a high recurrence rate, correlating with younger age and this must be taken into account

Introduction

Accurate assessment of alignment in pre-operative and post-operative knee radiographs is important for planning and evaluating knee replacement surgery. Existing methods predominantly rely on manual measurements using long-leg radiographs, which are time-consuming to perform and are prone to reliability errors. In this study, we propose a machine-learning-based approach to automatically measure anatomical varus/valgus alignment in pre-operative and post-operative standard AP knee radiographs.

Aim. To determine differences in knee valgus angles produced during a single leg squat and hip muscle strength between healthy subjects and patients with patellofemoral pain (PFP). To determine correlations between variables of hip muscle strength, knee valgus angle and pain. Study design: Observational study of 20 (8 male 12 female) healthy (H) subjects, matched for age height and weight with 20 (8 male 12 female) PFP patients (mean symptom duration 46.75 weeks). All subjects fulfilled specific inclusion and exclusion criteria. Appropriate Ethical approval was obtained. Measures for both groups were Knee valgus angle during a single leg squat using 2D motion capture and SiliconCoach software for measurement of knee valgus angles, hip abduction, internal and external rotation muscle strength using hand held dynamometry, visual analogue scale for pain. Strength was reported as a percentage of body weight. All measures were taken on the affected leg for PFP subjects and matched for the equivalent leg in healthy group. SiliconCoach was determined to be reliable for intra-rater reliability of knee valgus angle (ICC.996). Results. There were no significant differences in age, height and weight (p=.59,.51,.26 respectively). Significant differences existed in hip abduction strength p=.001(PFP 19.93(9.2), H 32.22(8.26)), Hip internal rotation p=0.001 (PFP 12.94(4.35), H 19.53(6.36)), Hip external rotation p=0.001(PFP 10.00(3.07), H 16.26 (4.62)), Knee Valgus Angles p=0.001(PFP 5.31(2.59), H 2.29 (2.35)). No correlations existed between any of the variables including pain. This preliminary study shows that patients with PFP have larger knee valgus angles when doing a single leg squat and significantly weaker hip muscle strength when compared to healthy subjects. The reason for larger knee angles during single leg squat could be hypothesised as being due to weak hip abductor muscles not sufficiently controlling the alignment of the femur. However no correlations were found for these measures, nor were they found for any of the other variables including pain level. In summary the results indicate that hip musculature strengthening of the rotators and abductors and measures to reduce knee valgus angle should be included in the rehabilitation programme of patients with PFP. Further research with larger numbers of subjects should be developed to investigate this subject

Introduction

The management of adolescent hallux valgus (AHV) remains controversial, with reservations about both conservative and surgical treatments. Non-operative management has a limited role in preventing progression. Surgical correction of AHV has, amongst other concerns, been associated with a high prevalence of recurrence of deformity after surgery. We conducted a systematic review to assess clinical and radiological outcomes following surgery for AHV.

Background

Plate fixation is one of several options available to surgeons for the management of pediatric femur fractures. Recent literature reports distal femoral valgus can be a complication following lateral plate fixation of femur fractures. We report on a case of extreme distal femoral valgus deformity and a lateral dislocation of the patella four years after having plate fixation of a left distal femoral fracture.

Objectives

Our objective was to perform a systematic review of the literature and conduct a meta- analysis to investigate the effect of initial varus or valgus displacement of proximal humerus on the outcomes of patients with proximal humerus fractures treated with open reduction and internal fixation.

Background

Patient reported outcomes/experience measures have been a fundamental part of the NHS since 2009. Osteotomy procedures for hallux valgus produce varied outcomes due to their subjective nature. We used PROMS2.0, a semi-automated web-based system, which allows collection and analysis of outcome data, to assess what the patient reported outcome/experience measures for scarf+/− akin osteotomy for hallux valgus are at UHSM.

Though there are many techniques utilised in the correction of hallux valgus (HV), no single approach has been reported to be ideal for all patients to date. A great deal of controversy remains concerning the type of osteotomy, method of fixation, and inclusion of soft tissue procedures. Herein, we compared the outcomes of two different operative techniques, the minimally-invasive modified percutaneous technique and the distal chevron osteotomy, used to treat mild to moderate hallux valgus. This study was conducted in line with the CONSORT 2010 guidelines. 41 patients (58 feet) with mild to moderate hallux valgus were randomly assigned by computer to two different groups. The first group containing 24 patients (33 feet) was treated by the modified percutaneous technique, whereas the second group included 17 patients (25 feet) treated by distal chevron osteotomy. In the modified percutaneous group, after a mean follow up of 43 months, the mean correction of hallux valgus angle (HVA) was 26.69° (P=0.00001), the mean correction of intermetatarsal angle (IMA) was 9.45° (P=0.00001), and the mean improvement of AOFAS score was 47.94 points (P=0.00001). In the chevron osteotomy group, after a mean follow up of 44 months, the mean correction of hallux valgus angle was 26.72° (P=0.00001), the mean correction of intermetatarsal angle was 9° (P=0.00001), and the mean improvement of AOFAS score was 44.76 points (P=0.00001). In our study, the modified percutaneous technique proved to be equally effective as the distal chevron osteotomy, but with fewer complications and a higher rate of patient satisfaction.

Background

Functional outcomes of conservatively managed, valgus impacted proximal humeral fractures are poor. Operative fixation can improve results but can be technically challenging. We prospectively assessed outcomes following fixation of valgus unstable proximal humeral fractures with a novel hybrid fixed angle blade plate, at a minimum of 12 months follow up.

Patellofemoral pain syndrome (PFPS) is a common knee disorder in active individuals. Movement dysfunction of valgus positioning at the knee during weight-bearing is frequently seen in PFPS. A single-leg squat (SLS) is a test commonly used in physiotherapy to assess for movement dysfunction. Kinesio-Tape (KT) is gaining in popularity in treating PFPS and claims to alter muscle recruitment and motor control, however evidence is weak. Objective: To evaluate the effect of KT applied to the quadriceps on muscle activity with electromyography (EMG) of the rectus femoris, vastus lateralis and vastus medialis oblique and motor control via the frontal plane projection angle (FPPA) using 2-dimensional video analysis.

A convenience sample of healthy females were recruited and performed 5 single-leg squats with and without KT. EMG of the quadriceps was recorded and dynamic valgus assessed via the FPPA using Dartfish video analysis software. Eccentric and concentric EMG data was recorded and the FPPA measured in single-leg stance and the depth of the squat. Institutional ethical approval was obtained for the study.

16 active females were assessed (mean age 28.94 +6.58 years). Wilcoxon signed-rank tests found no significant change in eccentric or concentric EMG of the quadriceps (%MVC) with KT compared to without (p values 0.35–0.86). Paired-sample t-tests found no significant difference in FPPA between conditions in single-leg stance (p=1.00) or the depth of the squat (p=0.871).

KT did not affect EMG activity of the quadriceps or the FPPA in a SLS when applied to the quadriceps of healthy females, questioning proposed effects of KT on normal muscle tissue. Further research is required into the efficacy of using KT in physiotherapy.

Purpose. Addressing posterior tibial plateau fractures is increasingly recognized as an important prognostic factor for functional outcome. The treatment of posterior tibial plateau fractures is rather demanding and the implants are still standard, off-the-shelf implants. This emphasizes the need for a more thorough morphological study of the posterior tibial plateau, in order to treat these posterior fractures more adequately. We aimed to demonstrate anatomical variations of the tibia in order to develop better implants. Method. After approval of the ethical committee 22 historically available CT scans of intact left tibia”s were segmented using Mimics (Materialise, Belgium). In order to perform principal component analysis, corresponding meshes are necessary. Mesh correspondence was achieved by deforming one selected source tibia to every other target tibia, through non rigid registration. The non-rigid registration algorithm was based on the algorithm described by Amberg et al (ref). After performing the non-rigid registration, principal component analysis was performed in Matlab (Mathworks, USA). Results. The first 3 components account for 98,1% of the anatomical shape variation of the tibia. The first principal component accounts for 95,4, the second accounts for 1,6% and the third component accounts for the remaining 1,1% of variation. In the first principal component the most marked variation was the length and the shaft width. Shorter tibia”s have a steeper and more angled posterior medial and lateral plateau as where longer tibia”s have a more rounded posterior tibia plateau. On the distal end, the tip of the medial malleolus is more prominent in shorter tibia”s than in longer tibia”s. The orientation of the tibiofibular joint is directed more posteriorly in larger tibias where it is orientated more laterally in smaller tibia”s. The slope of the medial and lateral tibia plateau is not related to the length or width of the plateau. The second principal component shows a relationship between a valgus shaped tibia shaft and its relation to a relatively smaller medial plateau”s compared with straight tibia”s of the same length. Valgus shaped, small tibia shafts have more posteriorly tilted lateral plateau”s compared with straight, broad shafted tibias. The third principal component shows that an angular shaped posterior tibia plateau is related to a more increased anterior bowing. The increase in the posterior tilt is mostly marked in the medial tibia plateau. Conclusion. The majority of tibia shape variations is directly related to the length of the shaft. The clinically known varus and valgus deformations represent only a small percentage of the total variation. Nevertheless, their variation within the second component is large and has a direct relation to the morphology of the tibia plateau. This data coud furthermore be used to improve implant design

Valgus unloader knee braces are a conservative treatment option for medial compartment knee osteoarthritis (OA). These braces are designed to reduce painful, and potentially injurious compressive loading on the damaged medial side of the joint through application of a frontal-plane abduction moment. While some patients experience improvements in pain, function, and joint loading, others see little to no benefit from bracing [1]. Previous biomechanical studies investigating the mechanical effectiveness of bracing have been limited in either their musculoskeletal detail [2] or incorporation of altered external joint moments and forces [3]. The first objective was to model the relative contributions of gait dynamics, muscle forces, and the external brace abduction moment to reducing medial compartment knee loads. The second objective was to determine what factors predict the effectiveness of the valgus unloading brace. Seventeen people with knee OA (8 Female age 54.4 +/− 4.2, BMI 30.00 +/− 4.0 kg/m. 2. , Kellgren-Lawrence range of 1–4 with med. = 3) and 20 healthy age-matched controls participated in this study which was approved by the institutional ethics review board. Subjects walked across a 20m walkway with and without a Donjoy OA Assist knee brace while marker trajectories, ground reaction forces, and lower limb electromyography were recorded. The external moment applied by the brace was estimated by multiplying the brace deformation by is pre-determined brace-stiffness. For each subject, a representative stride was selected for each brace condition. A generic musculokeletal model with two legs, a torso, and 96 muscles was modified to include subject-specific frontal plane alignment and medial and lateral contact locations [4]. Muscle forces, and tibiofemoral contact forces were estimated using static optimization [4]. We defined brace effectiveness as the difference in the peak medial contact force between the braced and the unbraced conditions. A stepwise regression analysis was performed to predict brace effectiveness based on: X-ray frontal plane alignment, medial joint space, KL grade, mass, WOMAC scores, unbraced walking speed, trunk, hip and knee joint angles and moments. The OA Assist brace reduced medial joint loading by approximately 0.1 to 0.2 BW or roughly 10%, during stance. This decrease was primarily due to the external brace abduction moment, and not changes in gait dynamics, or muscle forces. The brace effectiveness could be predicted (R. 2. =0.77) by the KL grade, and the magnitude of the hip adduction moment in early stance (unbraced). The brace was more effective for those that had larger hip adduction moments and for those with more severe OA. The valgus knee brace was found to reduce the medial joint contact force by approximately 10% as estimated using a musculoskeletal model. Bracing resulted in a greater reduction in joint contact force for those who had more severe OA while still maintaining a hip adduction moment similar to that of healthy controls

This study aimed to overcome the subjective nature of routine assessment of knee laxity and develop a repeatable, objective method using a hand-held force application device (FAD). Eighteen clinicians (physiotherapists, consultants, trainees) volunteered to measure the coronal angular deviation of the right knee of a healthy volunteer using a validated non-invasive infrared measuring system. Effort was taken to ensure the knee flexion angle (∼2°) and hand positions were constant during testing. Three varus and valgus stress tests were conducted, in which maximum angular deviation was determined and subsequently averaged, in the following order of conditions: manual stress without the FAD up to a perceived end-point (before); with the FAD to apply a moment of 18 Nm; and again without the FAD (after). A repeated measures ANOVA was used to analyse the results. All three groups of clinicians produced measurements of valgus laxity with consistent mean values and standard deviations (<1°) for each condition. For varus mean values were consistent but standard deviations were larger. Valgus deviations varied significantly between conditions (p < 0.01), with deviations achieved using the FAD greater than both before (p < 0.01) and after (p < 0.05) indicating that the perceived endpoints were less than that achieved at 18 Nm. However varus perceived endpoints were no different to that achieved at 18 Nm, suggesting that clinicians usually apply a greater valgus moment than varus. Furthermore, the non-significant increase in valgus deviation between before and after (p = 0.123) is suggestive of a training trend, especially for trainees. Our standardised knee laxity assessment may have a role in improving the balancing techniques of TKA and the diagnosis of collateral ligament injuries. Also, by quantifying the technique of senior clinicians, and with use of the FAD, the perceptive skills of more junior trainees may be enhanced

This study explored the relationship between the initial stability of the femoral component and penetration of cement into the graft bed following impaction allografting.

Impaction allografting was carried out in human cadaveric femurs. In one group the cement was pressurised conventionally but in the other it was not pressurised. Migration and micromotion of the implant were measured under simulated walking loads. The specimens were then cross-sectioned and penetration of the cement measured.

Around the distal half of the implant we found approximately 70% and 40% of contact of the cement with the endosteum in the pressure and no-pressure groups, respectively. The distal migration/micromotion, and valgus/varus migration were significantly higher in the no-pressure group than in that subjected to pressure. These motion components correlated negatively with the mean area of cement and its contact with the endosteum.

The presence of cement at the endosteum appears to play an important role in the initial stability of the implant following impaction allografting.

The aim of our study was to investigate whether placing of the femoral component of a hip resurfacing in valgus protected against spontaneous fracture of the femoral neck.

We performed a hip resurfacing in 20 pairs of embalmed femora. The femoral component was implanted at the natural neck-shaft angle in the left femur and with a 10° valgus angle on the right. The bone mineral density of each femur was measured and CT was performed. Each femur was evaluated in a materials testing machine using increasing cyclical loads.

In specimens with good bone quality, the 10° valgus placement of the femoral component had a protective effect against fractures of the femoral neck. An adverse effect was detected in osteoporotic specimens.

When resurfacing the hip a valgus position of the femoral component should be achieved in order to prevent fracture of the femoral neck. Patient selection remains absolutely imperative. In borderline cases, measurement of bone mineral density may be indicated.