Aims. The aim of this study was to establish consensus statements on the diagnosis, nonoperative management, and indications, if any, for medial patellofemoral complex (MPFC) repair in patients with patellar instability, using the modified Delphi approach. Methods. A total of 60 surgeons from 11 countries were invited to develop consensus statements based on their expertise in this area. They were assigned to one of seven working groups defined by subtopics of interest within patellar instability. Consensus was defined as achieving between 80% and 89% agreement, strong consensus was defined as between 90% and 99% agreement, and 100% agreement was considered to be unanimous. Results. Of 27 questions and statements on patellar instability, three achieved unanimous consensus, 14 achieved strong consensus, five achieved consensus, and five did not achieve consensus. Conclusion. The statements that reached unanimous consensus were that an assessment of physeal status is critical for paediatric patients with patellar instability. There was also unanimous consensus on early mobilization and resistance training following nonoperative management once there is no apprehension. The statements that did not achieve consensus were on the importance of immobilization of the knee, the use of orthobiologics in nonoperative management, the indications for MPFC repair, and whether a vastus medialis oblique advancement should be performed. Cite this article: Bone Joint J 2023;105-B(12):1259–1264

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: A relationship between vastus medialis oblique (VMO) strength and anterior pain and disability has been suggested. A biomechanical protocol was used to access the deficiency of the quadriceps muscles in patients with anterior knee pain. Methods and Results: A biomechanical evaluation was conducted on 54 patients with anterior knee pain (34 females and 20 males). All patient x-rays were normal through interpretation by a blinded radiologist. A Kistler force plate, a VICON motion analysis system and surface electromyography were used to quantify biomechanical function during isometric, walking and squatting exercises. For 42 of the 54 (78%) subjects, during isometric and walking exercises we observed that activation of the VMO, rectus femoris (RF) and vastus lateralis (VL) muscles of the symptomatic leg was not significantly different from those of the asymptomatic leg (p< 0.01). However, for 31 patients (57%) during the eccentric phase of the squat exercises, the symptomatic leg presented with high activation of VL compared to VMO and RF (p< 0.01). During the concentric phase, 45 patients (83%) presented with higher activation of the VL compared to the VMO. Conclusion: VMO activity during squatting for the symptomatic patient with anterior knee pain leg differs fundamentally during walking and isometric exercise compared to squatting tasks. Moreover, the relative contribution of the VL compared to the VMO during the eccentric phase of the squat exercises was different to those recorded during the concentric phase. Therefore, we suggest that maximal isometric and or isokinetic exercises are not sufficient to access the quadriceps function in relation to anterior knee pain. A thorough biomechanical assessment, including functional testing to reproduce the patient’s pain and locate the nature of the symptoms is suggested

Background: Recently, less invasive techniques for total knee arthroplasty (TKA) were introduced and the early results suggest a more rapid return of flexion and functional activities, while requiring fewer analgesics after surgery. Despite these findings, there is concern over the possibility of a steep learning curve and the potential risks of implant misalignment or poor fixation that may compromise long-term results. The purpose of this study was to analyze the potential learning curve effect on clinical and radiographic Results: Methods: This retrospective review compares the first 30 (Group 1) to the latest 30 cases (Group 2) in one surgeon’s consecutive series of 152 mini-incision mid-vastus TKA. Pre- and postoperative Knee Society Scores were compared, implant alignment was measured, and flexion was evaluated during hospital stay, at 6 weeks and 3 months after surgery. Complications and operative data were collected. Results: Flexion was significantly higher in group 2 during hospitalization and at all clinical follow-up evaluations. At last follow-up mean flexion was 111° ± 8 (95–125) in group 1 and 121° ± 11 (90–140) in group 2 (p= 0.001). The mean length of skin incision was 11.7 cm ± 1.5 (8–15) with a mean incision length of the vastus medialis oblique muscle of 3.2 cm ± 1.0 (1–5). A steady improvement of knee and function scores was found in the entire series which were significantly greater in group 2. There were no complications and the radiographic evaluation found no implant or limb misalignment, or signs of early loosening. Conclusion: The introduction of a mini-incision technique is an evolutionary process. The clinical and functional results show continued improvement after more than 100 cases. There was no classical learning curve effect and no increased complication rate in the earlier series. Thus far, the benefits of the mini-incision mid-vastus approach outweigh the new technique related difficulties and possible new risks. There are no signs of compromise that will affect the long-term results of mini-incision TKA

Aims

The Oswestry-Bristol Classification (OBC) is an MRI-specific assessment tool to grade trochlear dysplasia. The aim of this study is to validate clinically the OBC by demonstrating its use in selecting treatments that are safe and effective.