When Is Surgery Needed for Multiple Osteochondromas?

When deciding whether to remove the bumps (osteochondromas) caused by Multiple Osteochondromas (MO), the general rule is to leave them alone unless they are causing specific problems. Because every surgery carries risks—such as infection, scarring, or damage to nearby tissues—doctors rely on a “watch and wait” approach for bumps that do not hurt and do not interfere with your child’s movement or growth ^[1][2]. The goal of MO treatment is not to remove every bump, but to maintain a pain-free, active life with good joint function.

However, surgery becomes the best medical choice when a bump begins to actively harm your child’s quality of life, bone development, or overall health.

The “Watch and Wait” Approach

For the vast majority of patients, asymptomatic bumps (bumps that cause no pain or functional issues) are simply monitored over time ^[1]. Your child’s care team, ideally guided by a pediatric orthopedic surgeon or an orthopedic oncologist, will typically recommend regular check-ups and X-rays to track the size of the bumps and how they might be affecting bone growth ^[3]. To track bumps at home without increasing your own anxiety, avoid checking them every day. Instead, it can be helpful to take a photo of the bump from the same angle every few months, or simply rely on how the bump feels to your child during normal daily activities. In most cases, children with MO can participate in normal activities and sports unless a specific bump is causing pain.

It is completely natural for parents to feel anxious seeing new bumps appear and wanting them removed immediately. But removing a bump simply because it is there exposes a child to unnecessary surgical risks. Furthermore, if a bump is removed before a child has finished growing (typically in their late teens), surgeons must be incredibly careful not to damage the physis (the growth plate of the bone). Damaging the growth plate during an early surgery can actually cause new bone deformities, such as knock-knees (genu valgum) ^[4][5].

Strict Reasons for Surgery

Doctors will strongly recommend surgical removal if an osteochondroma meets one or more of the following strict criteria:

1. Pain and Restricted Movement

Surgery is often indicated when a bump rubs against surrounding muscles or tendons, causing severe pain, mechanical impingement, or a restricted range of motion ^[6][7]. Sometimes, the friction from a bump can cause a fluid-filled sac called a bursa to form over it. If this bursa becomes inflamed and painful (bursitis) and does not respond to conservative treatments, surgery may be necessary to remove both the bursa and the underlying bump ^[8][9].

2. Nerve or Blood Vessel Compression

Because osteochondromas grow outward from the bone, they can sometimes press into nearby nerves or blood vessels ^[10].

• Nerve compression: If a bump presses on a nerve, your child might experience numbness, tingling (“pins and needles”), or muscle weakness ^[11][12]. Removing the bump relieves the pressure and usually results in a full neurological recovery ^[11].
• Blood vessel compression: Less commonly, a bump can rub against a blood vessel, restricting blood flow or creating a pseudoaneurysm (a ballooning of the blood vessel wall). This most often happens behind the knee (the popliteal artery) and requires surgical removal of the bump along with vascular repair ^[13][14].

3. Correcting Pediatric Deformities

As a child grows, osteochondromas can interfere with normal bone development. This is especially common in the forearms and the legs ^[15]. If a bump is causing the bones to bow, creating a difference in limb length, or leading to angular deformities (like the wrist turning inward or knock-knees), surgeons will operate to remove the bump and correct the bone alignment ^[15][16]. For example, surgery in the forearm might involve removing the bump and lengthening the shorter bone to restore function ^[16][17].

4. Suspected Malignancy

While the overall risk is very low, there is a small chance that a benign (non-cancerous) osteochondroma can change into a malignant (cancerous) tumor called a chondrosarcoma ^[18][19]. This is rare in children and more commonly seen in adulthood ^[20]. However, you should contact your doctor immediately if you notice:

• A sudden, rapid increase in the size of a bump ^[20].
• New-onset pain in a bump that used to be painless ^[20][21].

If imaging (like an MRI) shows a thickened “cartilage cap” on the bump, doctors will surgically remove the entire bump to investigate and prevent cancer ^[21][22]. (Note: Cartilage caps are naturally thicker in growing children than in adults. If an MRI report mentions a “thick cap,” do not panic—your orthopedic specialist will interpret this in the context of your child’s age.) When surgery is performed, it is crucial that the surgeon removes the entire cartilage cap to minimize the risk of the bump growing back ^[7][23].

Making the Decision

Choosing to have surgery is always a balance of risks and benefits. If a bump is not causing any of the problems listed above, the best medical choice is almost always to leave it alone. Keep a consistent eye on your child’s bumps, maintain your regular orthopedic appointments, and encourage your child to communicate openly about any new pain, tingling, or changes in how they move.