The aim is to investigate if there is a relation between patellar height and knee flexion angle. For this purpose we retrospectively evaluated the radiographs of 500 knees presented for a variety of reasons.

We measure knee flexion angle using a computer-generated goniometer. Patellar height was determined using computer generated measurement for the selected ratios, namely, the Insall–Salvati (I/S), Caton–Deschamps (C/D) and Blackburne–Peel (B/P) indices and Modified I/S Ratio.

A search of an NHS hospital database was made to identify the knee x rays for patients who were below the age of forty. A senior knee surgeon (DC) supervised three trainee trauma and orthopaedics doctors (HA, JM, ES) working on this research. Measurements were made on the Insall–Salvati (I/S), Caton–Deschamps (C/D) and Blackburne–Peel (B/P) indices and Modified I/S Ratio. The team leader then categorised the experimental measurement of patients’ knee flexion angle into three groups. This categorisation was according to the extent of knee flexion. The angles were specifically, 10.1 to 20, 20.1 to 30, and 30.1 to 40 degrees of knee flexion.

Out of the five-hundred at the start of the investigation, four hundred and eighteen patients were excluded because they had had either an operation on the knee or traumatic fracture that was treated conservatively.

Assessment of coronal knee laxity via manual stress testing is commonly performed during joint examination. While it is generally accepted that the knee should be flexed slightly to assess its collateral restraints, the importance of the exact degree of flexion at time of testing has not been documented. The aim of this study therefore was to assess the effect of differing degrees of knee flexion on the magnitude of coronal deflection observed during collateral stress testing.

Using non-invasive infrared technology, the real-time coronal and sagittal mechanical femorotibial (MFT) angles of three asymptomatic volunteers were measured. A single examiner, blinded to the real-time display of coronal but not sagittal alignment, held the knee in maximum extension and performed manual varus and valgus stress manoeuvres to a perceived end-point. This sequence was repeated at 5° increments up to 30° of flexion. This provided unstressed, varus and valgus coronal alignment measurements as well as overall envelope of laxity (valgus angle – varus angle) which were subsequently regressed against knee flexion.

Regression analysis indicated that all regression coefficients were significantly different to zero (p < 0.001). With increasing knee flexion, valgus MFT angles became more valgus and varus MFT angles became more. The overall laxity of the knee in the coronal plane increased approximately fourfold with 30° of knee flexion.

The results demonstrated that small changes in knee flexion could result in significant changes in coronal knee laxity, an observation which has important clinical relevance and applications. For example the assessment of medial collateral ligament (MCL) injuries can be based on the perceived amount of joint opening with no reference made to knee flexion at time of assessment. Therefore, close attention should be paid to the flexion angle of the knee during stress testing in order to achieve a reliable and reproducible assessment.

Movement dysfunction resulting in a knee valgus position during weight bearing activity is associated with increased risk of Anterior Cruciate Ligament injury and Patellofemoral Pain Syndrome especially in young active females. In clinical practice determining the critical knee flexion angle (CKFA) during a single leg squat (SLS) test is used to assess this dysfunction, yet its reliability is unknown. This study aimed to determine rater agreement in determining the presence of knee valgus movement (yes/no) during a SLS test in recreational females (n = 16, age 24.3 ±7.9 yrs, height 165.7±4.8m, mass 62.5±6.4kg) and the intra and inter-rater reliability of measuring CKFA using SiliconCoach™. Three experienced physiotherapists viewed 48 randomised SLS test videos. One physiotherapist repeated the viewing for test-retest analysis. Test-retest agreement for rating SLS test was acceptable (weighted kappa (k) = 0.667). Inter-rater agreement was moderate to substantial (weighted k = 0.284–0.613). Intra-rater reliability of CKFA was acceptable for all three raters (ICC>0.6). Inter-rater absolute reliability was below 5% of the mean CKFA (SEM 4.26 degrees). As previous research reports intra-rater agreement is better than inter-rater agreement when assessing movement dysfunction during functional activity via visual rating. Intra-rater within session and between session reliability for measuring the CKFA using SiliconCoach™ was acceptable and better than inter-rater reliability. Further research is needed to assess the concurrent and construct validity of the protocols used in this study. It is recommended that qualitative research be performed to identify factors that affect physiotherapist's rating of functional activities.

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.

Abstract. Objectives. Impingement in total hip replacements (THRs), including bone-on-bone impingement, can lead to complications such as dislocation and loosening. The aim of this study was to investigate how the location of the anterior inferior iliac spine (AIIS) affected the range of motion before impingement. Methods. A cohort of 25 CT scans (50 hips) were assessed and nine hips were selected with a range of AIIS locations relative to the hip joint centre. The selected CT Scans were converted to solid models (ScanIP) and THR components (DePuy Synthes) were virtually implanted (Solidworks). Flexion angles of 100⁰, 110⁰, and 120⁰ were applied to the femur, each followed by internal rotation to the point of impingement. The lateral, superior and anterior extent of the AIIS from the Centre of Rotation (CoR) of the hip was measured and its effect on the range of motion was recorded. Results. There was found to be a significant (p<0.05) inverse relationship between the ROM of the THR and the lateral measure of the AIIS. Of the three measures, the lateral AIIS measure showed the strongest relationship with ROM to impingement (R=0.73) with the anterior and superior measures resulting in R values of 0.41 and 0.56 respectively. For every millimetre lateral the AIIS location, there was typically a loss of 1.2° of range of motion. With increasing lateralisation, the AIIS was positioned more directly over the femur, thereby reducing the ROM in the THR during high flexion positions. No soft tissue was included in the models which would have affected the ROM. Conclusions. The results from this study have shown that the lateral measure of the AIIS could be a predictor for bone-on-bone impingement. To build confidence, wider study of AIIS location variation is needed, as well as analysis under impingement prone activities of daily living. 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

Aims

Animal models have been developed that allow simulation of post-traumatic joint contracture. One such model involves contracture-forming surgery followed by surgical capsular release. This model allows testing of antifibrotic agents, such as rosiglitazone.

One of the most controversial issues in total knee replacement is whether or not to resurface the patella. In order to determine the effects of different designs of femoral component on the conformity of the patellofemoral joint, five different knee prostheses were investigated. These were Low Contact Stress, the Miller-Galante II, the NexGen, the Porous-Coated Anatomic, and the Total Condylar prostheses. Three-dimensional models of the prostheses and a native patella were developed and assessed by computer. The conformity of the curvature of the five different prosthetic femoral components to their corresponding patellar implants and to the native patella at different angles of flexion was assessed by measuring the angles of intersection of tangential lines.

The Total Condylar prosthesis had the lowest conformity with the native patella (mean 8.58°; 0.14° to 29.9°) and with its own patellar component (mean 11.36°; 0.55° to 39.19°). In the other four prostheses, the conformity was better (mean 2.25°; 0.02° to 10.52°) when articulated with the corresponding patellar component. The Porous-Coated Anatomic femoral component showed better conformity (mean 6.51°; 0.07° to 9.89°) than the Miller-Galante II prosthesis (mean 11.20°; 5.80° to 16.72°) when tested with the native patella. Although the Nexgen prosthesis had less conformity with the native patella at a low angle of flexion, this improved at mid (mean 3.57°; 1.40° to 4.56°) or high angles of flexion (mean 4.54°; 0.91° to 9.39°), respectively. The Low Contact Stress femoral component had the best conformity with the native patella (mean 2.39°; 0.04° to 4.56°). There was no significant difference (p > 0.208) between the conformity when tested with the native patella or its own patellar component at any angle of flexion.

The geometry of the anterior flange of a femoral component affects the conformity of the patellofemoral joint when articulating with the native patella. A more anatomical design of femoral component is preferable if the surgeon decides not to resurface the patella at the time of operation.