Kohler’s disease is a rare, temporary bone condition primarily affecting the feet of young children. It is classified as an osteochondrosis, a disorder affecting bone growth centers. The condition involves a disturbance in the blood supply to a specific midfoot bone, leading to temporary damage and subsequent repair. Although it causes pain and limping, Kohler’s disease is benign and self-limiting, resolving completely on its own over time.
Underlying Mechanism and Affected Population
The condition involves the navicular bone, one of the seven tarsal bones located on the inner arch of the foot. Kohler’s disease is caused by temporary avascular necrosis, the death of bone tissue due to an interruption of its blood supply. This lack of blood flow causes the bone to temporarily soften, collapse, and flatten. While the exact cause of this vascular disruption is unknown, it is thought to be related to mechanical compression during a specific developmental period.
The navicular bone is the last tarsal bone to begin hardening (ossifying), making it vulnerable to strain in active children. This disorder typically affects children between the ages of two and ten, peaking between four and seven years old. Boys are affected more often than girls, sometimes up to five times as frequently. While the disease usually affects only one foot, both feet may be involved in about 25% of cases.
Recognizing the Signs
Parents or caregivers often first notice a child developing a painful limp, which may be intermittent or continuous. The pain is typically felt in the medial arch or the inner side of the midfoot. This discomfort can be progressive, often leading to difficulty putting weight on the affected foot or an unwillingness to participate in normal activities.
The child may adopt a characteristic antalgic gait, walking on the outer edge of the foot to relieve pressure on the painful navicular bone. Swelling and tenderness are common, localized directly over the navicular bone in the arch of the foot. The onset of symptoms is often gradual, and the pain typically worsens after physical activity.
Diagnostic Procedures and Treatment Approach
The diagnosis of Kohler’s disease begins with a physical examination, noting tenderness over the navicular bone and observing the child’s limp. The primary tool for confirming the condition is a plain X-ray of the foot. The X-ray will reveal characteristic changes in the navicular bone, including flattening, fragmentation, and increased density (sclerosis). Advanced imaging like Magnetic Resonance Imaging (MRI) is rarely needed unless symptoms are atypical or another condition is suspected.
Treatment for Kohler’s disease is consistently conservative, focusing on relieving symptoms and reducing stress on the affected bone. The primary approach involves rest and activity modification to avoid high-impact activities. Non-steroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen, are often used for pain management.
For more symptomatic cases, temporary immobilization is standard practice to reduce pressure and allow the bone to heal. This is typically done with a short-leg walking cast or boot, worn for approximately four to eight weeks. This period of casting can significantly shorten the duration of symptoms. After the cast is removed, orthotic devices or arch supports may be used to provide continued support as the child transitions back to regular activities.
Long-Term Outlook
The prognosis for children diagnosed with Kohler’s disease is excellent because the condition is self-limiting. The bone naturally re-establishes its blood supply and heals, with symptoms typically resolving within a few months to two years. Clinical symptoms are often relieved much sooner, sometimes within three months of starting conservative management. The navicular bone eventually regains its normal shape and structure, and there are no long-term complications or permanent foot deformities associated with the condition.