A. Relationship between muscle tone and deformity A large amount of literature has demonstrated that increased muscle tone can lead to restricted myostatin synthesis through the production of neural adhesion factors, which eventually leads to muscle mass deficiency, muscle atrophy, and then tendon contracture, while increased muscle tone can also lead to restricted muscle and bone growth, mismatch of musculoskeletal growth rate, mismatch of active and antagonist muscle growth rate can also lead to the appearance of deformities. Thus there is a clear causal relationship between muscle tone and deformity, i.e. increased muscle tone is the cause and deformity is the effect, and the deformity can continue to develop. It follows that tendon lengthening by surgery alone results in recurrence. However, experienced orthopedic surgeons will perform tendon lengthening and release surgery to a greater extent, thereby reducing recurrence. However, the tendon is a tendinous continuation of the muscle, and the inevitable result of excessive tendon lengthening is a weakening of the muscle strength. The Lewis experience: In 2006, Lewis Children’s Hospital published a study of a large sample (note that it was a large sample, which is not easy in a country with such strict ethics as the United States) of patients with spastic cerebral palsy who underwent SPR early (2-5 years), late, and no SPR, and concluded that the incidence of spastic cerebral palsy in the early (2-5 years), late, and no SPR groups eventually underwent orthopedic surgery. It was concluded that the incidence of eventual orthopedic surgery after SPR surgery at an early age (2-5 years) was significantly lower than in the later SPR surgery group and the no SPR surgery group, and also the extent of orthopedic surgery was significantly lower than in the latter two groups. They concluded that early intervention with SPR surgery blocked the basis for deformity and reduced the need for future orthopedic surgery, while also reducing myasthenia gravis. The recommended appropriate time frame for surgery is 2-5 years of age. It is also important to mention here that many publications mention that a possible distal complication of SPR surgery is scoliosis deformity, but in the Lewis study, none of the children operated early developed scoliosis deformity in the distal period (>7.5 years). The reason was that the increased muscle tone led to gait abnormalities and lower limb deformities that required abnormal spinal posture to compensate. After early hypotonia, these causes were removed, hence the above results. In contrast, in some patients with scoliosis deformity reported in the past literature, most had spinal instability, small joint slippage or even anterior spinal deformity long before surgery. In these patients, we also consider preoperatively whether to perform internal spinal fixation to increase spinal stability in the early postoperative period. Iowa Conclusion: A systematic review of 113 orthopaedic surgeons concluded that the most commonly used lengthening procedures for clubfoot are the “Z” lengthening and the HOKE procedure, with a few using the gastrocnemius fascial zone (zone 1) cut lengthening (strayer procedure, etc.). The reason for the high support of the “Z” lengthening and the Hoke procedure is that most people believe that there is less muscle weakness in the gastrocnemius than in zone 1, which has been confirmed in the literature by kinetic analysis. This is because the only force in the body that produces a forward gait is derived from the triceps calf muscle. The Iowa conclusion is that more than 50% of tendon lengthening procedures are followed by a significant reduction in muscle strength and some patients experience excessive lengthening, culminating in varying degrees of recurrence in more than 70% of patients. Therefore, it is very important to choose tendon lengthening surgery carefully, choose a reasonable treatment plan, sequence, and figure out the cause and effect relationship for patients with cerebral palsy. As a physician, standing on a multidisciplinary and multidisciplinary level and making scientific decisions about the treatment plan for each patient is also a basic skill that must be possessed.