The efficacy of thermal shrinkage in treating recurrent patellar dislocations remains controversial, primarily due to the qualitative assessment of its effectiveness. To address this issue, a quantitative study was conducted to evaluate the effectiveness of medial parapatellar capsule shrinkage in reducing inflammation. Data on lateral displacement were collected from nine cadaveric knees, comparing shrinkage before and after open surgery or medial shrinkage. A physician applied medial pressure on the patella to simulate clinical examination while measuring force and displacement. Additionally, 10 healthy subjects were tasked with laterally moving the patella under medial force to assess the feasibility of the technique. Four types of data (normal knees, knees subjected to thermal shrinkage, knees subjected to open surgery, and knees from cadavers) were compared based on applied force, resulting displacement, and force-displacement ratio. Results indicated that cadaveric knee displacements and applied forces were significantly higher than those of normal subjects after thermal modification. However, no significant differences were observed before and after thermal modification. Open surgery led to significant reductions in displacement but increased applied forces. Despite thermal shrinkage, no immediate differences were observed in shrunk parapatellar capsules. Immediate improvement in stiffness was observed in the knee capsule post-open surgery on the stiff side