I recently answered a text message from a local sports medicine colleague asking how to treat a 12-year-old soccer player with an acute on chronic, minimally displaced patellar sleeve fracture. This scenario is not uncommon for pediatric sports surgeons. Having been in practice for over 12 years, receiving a phone call or a text message asking questions on managing a surgical condition in an athlete with open growth plates is increasingly common.
Surgical treatment of pediatric sports injuries is growing at an exponential rate. We have seen growing numbers of pediatric anterior cruciate ligament (ACL) tears, patellar dislocations, osteochondral pathology, and sports-related fractures about the knee. All these injuries, when surgically indicated, require some form of surgical modifications to well-established surgical techniques to avoid, or at least minimize, the risk of damage to physis and, thus, promote future growth.
Pediatric ACL Injury
The rising numbers of pediatric ACL reconstructions has been well documented.1 Whether this is due to an increasing incidence or recognition of pediatric ACL injuries is unknown. Other perspectives on the increasing trend in pediatric ACL reconstruction include: (1) a growing awareness that continuing to play with an unstable, ACL-deficient pediatric knee increases the risk of chondral and meniscal injury, and (2) the development and popularization of improved surgical techniques that offer good outcomes with minimal risk of future growth disturbances.
The most common ACL reconstructions in patients with open physis are the extra-articular, extra-physeal (ie Modified McIntosh or Michelli-Kocher technique) utilizing the iliotibial band as a graft soft, an all-epiphyseal ACL reconstruction, or a transphyseal ACL reconstruction. Several have also described hybrid techniques utilizing a combination of the above techniques on the femur and tibia (Figure 1). Surgeons will periodically choose a technique based on the predicated growth remaining. For example, a surgeon might prefer the extra-articular, extra-physeal when there is over three years of expected growth remaining but opt for a transphyseal technique for patients with less than 3 years of growth remaining.
Patellar Dislocation
For recurrent patellar dislocation or a patellar dislocation with an osteochondral fracture, a surgery is typically recommended. The medial patellofemoral ligament (MPFL), or a medial patellofemoral complex, reconstruction has become the workhorse of surgical treatment of patellar instability with overall great outcomes. However, anatomically, the MPFL originates at or near the physis of the distal medial femur.3 A physeal-respecting MPFL reconstruction is an excellent surgical option for pediatric patellofemoral instability, with femoral fixation about 10 mm distal to the physis using Schöttle’s fluoroscopic point to confirm relative isometry (Figure 2). Occasionally, a distal realignment may be needed in conjunction with an MPFL reconstruction. A tibial tubercle osteotomy is not an option for a growing patient with an open proximal tibial physis; however, several periosteal transfer techniques have also been described with good outcomes and low risk to the physis [Masquijo article].
Osteochondral Pathology
Both osteochondritis dissecans (OCD) or osteochondral fractures are unique conditions common to the pediatric athlete. Treating chondral injuries, as in older patients, requires additional consideration when using microfracture, scaffolds, or cell-based treatments for osteochondral-related injuries. Solutions to treat the subchondral bone including drilling, fixation, grafting, and osteochondral transplantation are more commonly utilized when surgery is indicated.
Goals of surgical treatment of OCD, when indicated, include providing biology and stability. Whether a dense sclerotic rim or bone in the progeny fragment, drilling is the most common and effective strategy in breaking down the sclerotic rim, stimulating neovascularization, and ultimately healing the lesion (Figure 3).4 When instability is suspected, either on magnetic resonance imaging or based on arthroscopic assessment, fixation is required in the form of screws (both metal or bioabsorbable), chondral darts, or suture bridge construct.
Sports-Related Fracture About the Knee
Physeal fracture of the distal femur, a patellar sleeve fracture, or a tibial tubercle fracture are all common sports-related fractures that occur in the growing knee. A displaced physeal fracture of the distal femur can present with similar neurovascular concerns as a knee dislocation and has a very high risk of physeal arrest. Patellar sleeve fractures are commonly missed due to no fracture seen on x-ray. Asymmetric patella alta can aid in diagnosis, though ultrasound or other advanced imaging may also be helpful. Displaced tibial tubercle fractures are associated with compartment syndrome and soft tissue necrosis, often requiring urgent reduction and fixation. In young athletes with more than two years of growth remaining, a tibial tubercle fracture may lead to recurvatum if growth arrest occurs at the tibial tubercle.
Conclusion
Proper diagnosis and management of the pediatric knee injuries are essential to ensuring long-term joint health and function. A comprehensive approach that considers growth potential, anatomical differences, and complication risks is key to optimizing outcomes. Advancements in imaging, surgical techniques, and rehabilitation continue to refine treatment strategies, emphasizing the importance of individualized care. By prioritizing early intervention, physeal-sparing techniques, and patient-specific rehabilitation plans, surgeons can help young athletes safely return to activity while minimizing long-term risks.
References
1. Tepolt FA, Feldman L, Kocher MS. Trends in Pediatric ACL Reconstruction From the PHIS Database. J Pediatr Orthop. 2018;38(9):e490-e494.
2. Ellis HB, Jr., Zak TK, Jamnik A, Lind DRG, Dabis J, Losito M, et al. Management of Pediatric Anterior Cruciate Ligament Injuries: A Critical Analysis. JBJS Reviews. 2023;11(8).
3. Shea KG, Styhl AC, Jacobs JC, Jr., Ganley TJ, Milewski MD, Cannamela PC, et al. The Relationship of the Femoral Physis and the Medial Patellofemoral Ligament in Children: A Cadaveric Study. Am J Sports Med. 2016;44(11):2833-2837.
4. Nissen CW, Albright JC, Anderson CN, Busch MT, Carlson C, Carsen S, et al. Descriptive Epidemiology From the Research in Osteochondritis Dissecans of the Knee (ROCK) Prospective Cohort. Am J Sports Med. 2022;50(1):118-127.
