Outcomes After Surgical Excision of Knee Osteochondromas

Abstract

Source: Wu M, Zheng ET, Anderson ME, et al Surgical treatment of solitary periarticular osteochondromas about the knee in pediatric and adolescent patients: complications and functional outcomes. J Bone Joint Surg Am. 2021;103(14):1276-1283; doi:10.2106/JBJS.20.00998Investigators from multiple institutions conducted a cohort study to assess outcomes in children after surgical excision of solitary knee osteochondromas (SKO). Patients ≤19 years old who underwent surgery for histology-confirmed SKO at the study hospital from 2003–2016 were included. Demographics and clinical features, such as SKO chief presenting symptom, type (sessile or pedunculated), and site (distal femur, proximal tibia, or proximal fibula), were abstracted from the medical record.The primary outcomes were major surgical complications and post-surgical functional outcomes. Major complications were obtained from the medical record and defined as Clavien-Dindo Grade III complications, such as recurrence-required surgical excision, deep wound infection, intraoperative vascular injury, and persistent pain. Post-surgical functional outcomes were assessed by administering 2 validated functional outcome measures (Pediatric International Knee Documentation Committee measure, or Pedi-IKDC, and Hospital for Special Surgery Pediatric Functional Activity Brief Scale, or Pedi-FABS) among those who could be reached by letter and/or telephone post-surgery. The Pedi-IKDC is scored from 0-100, and the Pedi-FABS is scored 0-30, with higher scores on each measure suggesting better functional ability. Investigators used multivariate regression to assess the association between demographic and clinical features with outcomes after adjusting for potential confounders.There were 264 patients included in analysis, 43% of whom provided post-surgical functional outcome data at a mean duration of follow-up of 5.8 years. Overall, most patients were male (58%), were athletes (81.4%), and had a chief presenting symptom of pain (90%). Most SKOs were pedunculated (65%) and were located in the distal femur (59%).There were 6 patients (2%) who had major complications, including 3 with recurrence requiring surgical excision. The mean Pedi-IKDC and Pedi-FABS scores were 97 and 16.7, respectively. The odds of a major complication were significantly lower in older children, pedunculated lesions, and lesions in the proximal tibia.The investigators conclude that surgical excision of SKOs was associated with infrequent major complications and good functional outcomes.Dr Hennrikus has disclosed no financial relationship relevant to this commentary. This commentary does not contain a discussion of an unapproved/investigative use of a commercial product/device.A solitary osteochondroma is the most common benign bone tumor in children and adolescents.1 The tumor stems from a developmental disorder in the growth plate resulting in a metaphyseal bony projection with a cartilaginous cap. The tumor can be pedunculated or sessile.2 In approximately 15 % of cases, multiple tumors occur due to the autosomal dominant disorder, multiple hereditary exostoses.3As the child grows, the osteochondroma also grows. The osteochondroma can cause symptoms due to irritation of adjacent tendons, nerves, or arteries.4 In children and adolescents, surgical excision is indicated if symptoms such as pain, swelling, or snapping are present. In rare cases, if the osteochondroma has not been excised in childhood, malignant transformation as an adult can occur.5The current study is the largest consecutive series of patients from 1 institution investigating the peri-operative complications and functional outcomes following surgical excision of solitary knee osteochondromas in pediatric and adolescent patients. A total of 264 cases were reviewed over a 14-year study period. All had radiographic diagnosis and histologic confirmation of the diagnosis by a pathologist. Sixty-five percent of tumors were pedunculated, and 35% were sessile. Fifty-nine percent were located at the distal femur, and 41% were at the proximal tibia or fibula. Sixty-nine percent were located on the medial knee, and 31 % were lateral. Ninety-six percent of patients returned to sports at an average of 2.5 months. Patient-reported outcome scores were excellent. Only 6 patients had a complication requiring re-operation, including 3 who had a recurrence of the tumor due to inadequate excision.The authors concluded that regardless of the orthopaedic surgeon’s fellowship training (oncologist, sports medicine, or pediatrics) or the location of the osteochondroma, surgical excision of the benign tumor resulted in excellent outcomes with minimal complications.Surgical excision of solitary osteochondromas about the knee in children and adolescents is safe and effective. As these benign tumors commonly present in adolescent athletes, pediatricians need to keep osteochondromas in the differential diagnosis of causes of knee pain.