HEMIEPIPHYSIODESIS IN PEDIATRIC ORTHOPAEDICS AS A TREATMENT OF KNEE DEFORMITIES

Аннотация

Hemiepiphysiodesis is a growth modulation technique widely used in pediatric orthopaedics to correct coronal plane deformities of the knee, including genu valgum and genu varum. The procedure involves temporary tethering of one side of the growth plate (physis) to harness the remaining growth potential and gradually realign the limb. Compared to osteotomies, hemiepiphysiodesis is less invasive, associated with fewer complications, and allows for gradual correction with minimal discomfort. This review outlines the anatomical principles, biomechanical rationale, surgical techniques, patient selection criteria, and postoperative follow-up protocols. Additionally, it addresses the limitations and potential complications of the procedure, emphasizing the importance of surgical timing and precise deformity analysis for optimaloutcomes. Keyword: Pediatric orthopaedics, hemiepiphysiodesis, growth modulation, genu valgum, genuvarum, physeal tethering, 8-plate, coronal deformity correction, guided growth surgery. Angular deformities of the knee joint, particularly genu valgum (knock-knee) and genu varum (bow-leg), are among the most common orthopaedic conditions in children. While many cases of physiologic deformity correct spontaneously with growth, persistent or progressive deformities may impair gait, induce pain, and predispose to patellofemoral maltracking, joint instability, and early-onset osteoarthritis. Surgical correction is indicated when thedeformity issymptomatic, progressive, orexceeds physiological norms forage. Historically, corrective osteotomies were the standard of care; however, they are invasive, carry significant morbidity, and often require prolonged rehabilitation. In contrast, hemiepiphysiodesis,a procedure that modulates growth byasymmetrically arresting oneside of the growth plate, offers a less invasive and reversible means of correction. This approach capitalizes on the child’s remaining growth potential and has evolved from early staple fixation to modern tension-band plating systems, such as the 8-plate, which provide more controlled andsafer correction. The growth plate (physis) is a cartilaginous structure responsible for longitudinal bone growth in children. Angular deformities can arise due to asymmetrical growth from either intrinsicphyseal abnormalities or external mechanical stresses. Hemiepiphysiodesis works by inhibiting growth on one side of the physis, allowing the contralateral side to grow freely. Overtime, this results in angular correction toward the mechanical axis. This principle was first established by Phemister and further refined by Blount and Stevens, who introduced guided growth usingflexibleplating systems. The correction rate depends on:  Patientage (younger children correct faster)  Remaininggrowth potential  Location ofdeformity (distal femurvs. proximal tibia)  Etiology ofdeformity (idiopathic, metabolic, post-traumatic) Hemiepiphysiodesis is primarily indicated in skeletally immature patients presenting with coronal plane deformities of the knee, such as genu valgum or genu varum, that are symptomatic, progressive, or exceed normal physiological alignment for age. Early page225 INTERNATIONAL JOURNAL OF ARTIFICIAL INTELLIGENCE ISSN:2692-5206,ImpactFactor:12,23 AmericanAcademicpublishers,volume05,issue05,2025 Journal: https://www.academicpublishers.org/journals/index.php/ijai intervention is particularly valuable in cases with significant deformity likely to result in mechanical axis deviation, which can lead to gait disturbances, patellofemoral instability, pain, and early degenerative joint changes if left untreated. Ideal candidates are typically children with at least 12–18 months of growth remaining, in whom gradual correction through growth modulation is feasible. Underlying etiologies may range from idiopathic deformities to pathological causes such as Blount disease, rickets, skeletal dysplasias, and post-traumatic physeal disturbances. It is critical to differentiate between physiologic variants and pathologic deformities, with the latter often requiring closer monitoring and more aggressivemanagement. The decision to proceed with hemiepiphysiodesis must account for the site of the deformity (distal femur, proximal tibia, or both), the degree and direction of angular deviation, and skeletal maturity. Long-standing anteroposterior standing radiographs of the lower limbs are essential for precise preoperative planning, enabling calculation of the mechanical lateral distal femoral angle (mLDFA) and medial proximal tibial angle (MPTA), which inform the level and side of the intervention. Deformities affecting both the distal femur and proximal tibia may require dual-level hemiepiphysiodesis. Additionally, growth prediction tools such as the Green-Anderson growth remaining chart or the Paley multiplier method assist in determining the optimal timing of intervention to achieve full correction without overcorrection. Once surgical indication is confirmed