COMPARISON OF EFFECTS OF DIFFERENT NAIL TIP POSITIONS ON ANTERIOR KNEE PAIN AFTER INTRAMEDULLARY INTERLOCKING NAILING FOR TIBIAL SHAFT FRACTURES

Objective: To determine the frequency of anterior knee pain after intramedullary interlocking nailing in tibial shaft fractures and to compare the intensity of anterior knee pain between positive and negative anterior cortex nail groups.Study Design: Quasi-experimental study. Place and Duration of Study: Department of Orthopaedic Surgery, Combined Military Hospital Rawalpindi, from Oct 2018 to Apr 2019. Methodology: 100 cases of tibial shaft fracture were divided into two groups according to anterior cortex nail distance. Patients 18-40 years of age of both genders, closed fractures, Gustilo Andersen I open tibial diaphyseal fractures and nail tip more than 5mm from tibial tuberosity were included. Patients with osteoarthritis, pathological fractures, renal disease, open fracture GA-II & GA-III and knee instability were excluded from the study. Both groups with positive and negative anterior cortex nail distance were compared for pain using the chi-square test. Results: Frequency of anterior knee pain after intramedullary interlocking nailing in tibial shaft fractures was found in 24% of patients. 8 (16%) out of 50 patients in the group with nail tip deep to anterior cortex had anterior knee pain while 16 (32%) out of 50 patients in the group with nail tip protruding from anterior cortex suffered anterior knee pain (p-value = 0.061). Conclusion: Intramedullary interlocking nailing in tibial shaft fractures with nail tip deep to anterior cortex showed less pain as compared to nail tip protruding from anterior cortex although it was not statistically significant.

Preoperative muscle thickness influences muscle activation after arthroscopic knee surgery

Purpose The aim of this study was to compare the correlation between preoperative quadriceps femoris muscle thickness and postoperative neuromuscular activation and quadriceps femoris strength in patients with and without patellofemoral pain after arthroscopic partial meniscectomy. Methods A series of 120 patients were prospectively analysed in a longitudinal cohort study of patients scheduled for arthroscopic partial meniscectomy. The patellofemoral pain group included patients who developed anterior knee pain after surgery while the control group included those who had not done so. Patients with preoperative patellofemoral pain, previous knee surgeries as well as those on whom additional surgical procedures had been performed were excluded. Of the 120 initially included in the study, 90 patients were analysed after the exclusions. Results There is a direct correlation between preoperative quadriceps femoris muscle thickness and the neuromuscular activity values and the strength of the muscle at 6 weeks after surgery. These results were seen exclusively in the group of patients who do not develop patellofemoral pain (0.543, p = 0.008). The group of patients who developed anterior knee pain in the postoperative period did not show this correlation (n.s.). Conclusion In patients without patellofemoral pain after meniscectomy, the greater the preoperative thickness of the quadriceps femoris, the more postoperative neuromuscular activation and strength they had. This correlation did not occur in those patients who develop patellofemoral pain after meniscal surgery. Level of evidence II.

Risk Factors for the Occurrence and Protraction of Anterior Knee Pain in Children and Adolescents: a Prospective Cohort Study of 3 Years

Background: Anterior knee pain (AKP) is a common limitation to children’s participation in social and physical activities. Therefore, to prevent the occurrence and protraction of AKP, it is crucial to identify risk factors. The purpose of this study was to clarify the factors associated with the occurrence and protraction of AKP in children and adolescents. Method: A three-year prospective cohort study was conducted with children and adolescents aged 8–14 in Japan. We recorded the occurrence of AKP, heel buttock distance, straight leg raising angle (SLRA), dorsiflexion angle of the ankle joint, and the Hospital for Special Surgery Pediatric Functional Activity Brief Scale (HSS Pedi-FABS). Logistic regression analysis was performed to calculate the odds ratio (OR) for each predicted risk factor for the occurrence and protraction of AKP among subjects without AKP at baseline. Results: We recruited 1,254 children and adolescents for the present study, and 1,133 children and adolescents who did not have AKP at baseline were included in the analysis. Six to nine percent of the subjects developed AKP annually. A high HSS Pedi-FABS score significantly predicted AKP occurrence (in 2017, OR 1.07, 95% CI 1.02−1.12, p = 0.003; in 2018, OR 1.05, 95% CI 1.01−1.10, p = 0.025). Of the participants, 32.9% developed chronic AKP during the follow-up period. When 8-year-old was used as a reference age, 13-year-old subjects (right side, OR 2.37, 95% CI, 1.00−5.61, p = 0.05) and 14-year-old subjects (right side, OR 2.57, 95% CI, 1.00−6.60, p = 0.049; left side, OR 6.32; 95% CI 1.33−30.00, p = 0.020) were at a significantly higher risk of AKP protraction. Conclusions: This study showed that a greater physical activity level was a risk factor for the onset of anterior knee pain in childhood. In addition, one-third of the children and adolescents developed chronic knee pain, and elderly adolescents were at a higher risk of protraction.

The Influence of Mathematical Definitions on Patellar Kinematics Representations

A correlation between patellar kinematics and anterior knee pain is widely accepted. However, there is no consensus on how they are connected or what profile of patellar kinematics would minimize anterior knee pain. Nevertheless, answering this question by merging existing studies is further complicated by the variety of ways to describe patellar kinematics. Therefore, this study describes the most frequently used conventions for defining patellar kinematics, focusing on the rotations. The similarities and differences between the Cardan sequences and angles calculated by projecting axes are analyzed. Additionally, a tool is provided to enable the conversion of kinematic data between definitions in different studies. The choice of convention has a considerable impact on the absolute values and the clinical characteristics of the patello-femoral angles. In fact, the angles that result from using different mathematical conventions to describe a given patello-femoral rotation from our analyses differ up to a Root Mean Squared Error of 111.49° for patellar flexion, 55.72° for patellar spin and 35.39° for patellar tilt. To compare clinical kinematic patello-femoral results, every dataset must follow the same convention. Furthermore, researchers should be aware of the used convention’s implications to ensure reproducibility when interpreting and comparing such data.

Fat Chance for Hidden Lesions: Pictorial Review of Hoffa's Fat Pad Lesions

Hoffa's fat pad (HFP) is the most commonly afflicted among all the knee fat pads. Anterior knee pain is common in various pathologies of HFP, as it is richly innervated. A potpourri of the intrinsic and extrinsic pathologies and the tumors and tumor-like conditions affect HFP, and MRI remains the fundamental modality to assess them and provide a specific diagnosis.