ABSTRACT
BACKGROUND: Guided growth is commonly used to treat frontal plane alignment deformities in skeletally immature individuals. Treatment aims are to correct the biomechanical loading of the knee and to avoid more invasive surgery that would be required after skeletal maturity. There is little published evidence of pain perception or functional limitations in this population. In addition, the intervention has the potential to worsen pain and function with hardware implantation, and symptoms may not fully resolve after removal. Understanding of pain and function limitations in this population is important to guide the clinical expectations. METHODS: Individuals with idiopathic knee genu valgum who underwent hemiepiphysiodesis with tension plate constructs were identified through a medical records database search. Patient-reported outcomes measurement information system Physical Function/Mobility and Pain Interference domain scores were assessed before hemiepiphysiodesis, immediately before hardware removal, and after hardware removal. Radiographs were also assessed at these times to record the zones and angles of deformity and correction. RESULTS: Twenty-eight subjects (53 operative limbs) contributed to the analysis. Mobility and pain interference as measured by the patient-reported outcomes measurement information system were below typical values in a small percentage of the population studied, only 3.6% scored in the moderate and none in the severe categories for both domains. Valgus by radiographic zone was corrected in all patients without significant rebound at follow-up. Compared with preoperative levels, mobility scores improved before hardware removal. Pain Interference scores improved both before hardware removal and at the final follow-up. CONCLUSIONS: Frontal plane knee deformities in the idiopathic population do not cause pain or limit mobility in most subjects. This is critical information, emphasizing that surgical decisions may be made based on the deformity alone, presence of symptoms, and possible future morbidity secondary to valgus deformity. If surgery is postponed because an individual is asymptomatic, the window for correction with guided growth may be lost. Individuals undergoing hemiepiphysiodesis can expect that their pain and function will not be worse during the time that hardware is in place and that surgery is likely to improve any pain they may be experiencing. LEVEL OF EVIDENCE: Level III; retrospective comparative study.
