What Is Osteochondroma?

One of the intriguing, yet frequently misdiagnosed, conditions affecting our skeletal system is osteochondroma, a bone tumour that sometimes appears without any obvious symptoms. Envision a disease that modifies the basic structure of your skeleton. This article’s goal is to provide a clear understanding of osteochondroma and insights into its treatment and impact on everyday life. 

Introduction

Growth plates, or the regions of growing tissue around the ends of long bones, are directly associated with the production of osteochondromas. Cells aid in the development and shape of bones during normal bone growth. An abnormal sticking out of the bones is formed in cases of osteochondroma due to a genetic mutation that affects the cells that produce both bone and cartilage.¹

Osteochondromas are those outgrowths that most often occur in infancy or adolescence and progressively get bigger. Once an individual reaches skeletal maturity, the tumours usually stop growing. While single osteochondromas account for the majority of cases, some people may have several osteochondromas at once, a disease known as Multiple Hereditary Exostoses (MHE).²

Osteochondromas account for 10.1% of all bone tumour diagnoses, and are the most prevalent benign tumours of the bone.³ Osteochondromas can develop in any bone, although they usually appear close to the extremities of long bones, such as the femur, tibia, and humerus.¹ It is to be noted that although osteochondromas are usually benign, their size and location may result in symptoms or consequences. As with any medical issue, the best possible outcomes for osteochondroma patients depend heavily on early discovery and adequate therapy.

How do osteochondromas form?

Osteochondromas are formed due to a number of factors:

• Genetic factors: Osteochondroma formation has been linked to mutations in certain genes, including EXT1 and EXT2. A person only needs to inherit one copy of the mutated gene from either parent to develop MHE because the disorder is inherited in an autosomal dominant manner⁴
• Cellular abnormalities: Cellular irregularities in the growth plate areas are caused by a mutation in the genes linked to osteochondroma. This causes a disruption in the balance between the growth of the bones and the formation of cartilage, resulting in the bony projections seen in this disease
• Environmental factors: Environmental factors may also play a role in the formation of osteochondromas, even if genetics plays a major part. However, particular environmental causes have yet to be fully discovered⁵

Types of osteochondromas

There are two types of osteochondromas: Solitary Osteochondromas and Multiple Hereditary Exostoses (MHE). While most osteochondromas that form are solitary and happen without any cause, some people may have multiple osteochondromas.

Solitary osteochondromas are not inherited and occur more often than MHEs. Rather than being passed down from one’s parents, solitary osteochondromas happen because of random genetic changes that happen during a person's development. Although they can appear in any bone, the ends of the long bones are where solitary osteochondromas usually form and these growths tend to be painless. Despite the fact that solitary osteochondromas are usually benign if they grow on surrounding tissues like blood vessels or nerves, they could cause symptoms such as discomfort, restricted joint movement, nerve compression, and redness around the area.⁵

Multiple osteochondromas are seen throughout the skeleton in MHE. These tumours can affect different bones and people with MHE may develop many tumours on different bones. Due to MHE's autosomal dominant inheritance pattern, a person who has the illness has a 50% risk of passing it on to each of their offspring. When bones are actively developing, which occurs during infancy or adolescence,, osteochondromas in MHE often become visible. As the individual grows, tumour size and quantity of osteochondromas may both increase. Because MHE involves many tumours, it can cause more complications compared to patients who have solitary osteochondroma. Skeletal abnormalities, variations in limb length, and limited range of joint movement are a few examples of these consequences.⁶

Diagnostic procedures

Usually diagnosing osteochondromas starts with medical providers inquiring about the individual’s medical history and symptoms. A physical examination might also be done to identify a bony mass or malformation. 

Bone structures are often observed through X-rays. On X-ray pictures, osteochondromas usually show up as bony protrusions. Osteochondromas can be identified by using X-rays to determine their location and size.⁷ CT scans and 3D reconstructions are also done to offer finer pictures of the bones and are especially helpful in assessing how the osteochondroma interacts with surrounding structures.⁸ Because MRI and ultrasounds are good at displaying soft tissue structures, these are useful for evaluating how osteochondromas affect the blood vessels, muscles, and nerves in the area.^1,7 

In cases when numerous osteochondromas run in the family, genetic testing may be required. Based on the unique features of the osteochondroma and its effects on the patient's health, the data obtained from these diagnostic tests helps medical professionals create a treatment plan that is appropriate.

Treatment options

• Observation & monitoring: When osteochondromas don't cause noticeable functional impairment and are asymptomatic, observation and routine monitoring would be advised by healthcare providers. This approach would be applied where the tumours are stable, tiny, and not pressing on the surrounding tissues. To monitor any changes in the size or structure of the osteochondroma, medical professionals perform imaging examinations and clinical evaluations on a regular basis ⁹
• Surgery: Surgery may be necessary when osteochondromas result in discomfort, restrict joint movement, compress nerves, or present other issues. A popular and successful treatment method is excision, or the surgical removal of the osteochondroma. Orthopaedic doctors will take into account osteochondroma's dimensions, location, and potential effects on surrounding structures. The aim of the surgery is to remove the tumour while protecting the healthy tissue around it. Following surgery, there is only a 2% chance of the osteochondroma forming again but regular follow–up appointments should be made¹
• Rehabilitation: After surgery, rehabilitation is essential to regain mobility, muscular strength, and joint function. Programmes for physical therapy are customised to meet the needs of each patient. In order to track the patient's development, identify any recurring symptoms, and handle any possible consequences, follow-up treatment is important. During follow-up appointments, routine imaging studies (X-rays) may be performed to make sure the afflicted region is healing correctly and that the osteochondroma has been fully removed

Prognosis

For those with osteochondromas, the long-term prognosis is usually favourable, especially with proper care. After surgery, solitary osteochondromas often have a good prognosis with a very low chance of recurrence. A patient's age, the efficiency of their therapy, and the existence of any related problems are some variables that affect their prognosis. Long-term care and monitoring are essential for people with MHE. Even though MHE can be difficult because of the possibility of many tumours, improvements in medical care – such as surgical methods and rehabilitation – help to achieve better results.

Preventive Measures

Since osteochondromas can happen spontaneously and are commonly associated with genetic factors, prevention of their growth is difficult. Nonetheless, there are a few approaches and factors that can assist in reducing the chance of complications or any other issues:

• Genetic counselling: Genetic counselling may be beneficial for those with Multiple Hereditary Exostoses (MHE) or those with a family history of osteochondromas. People can make educated decisions regarding family planning and get important information about the condition's genetic origin through this procedure
• Early identification and surveillance: Imaging tests and routine physical examinations can help identify osteochondromas early on. Keeping an eye on any discovered osteochondromas enables management in the event of difficulties, particularly for those who know they have a genetic predisposition to inheriting osteochondromas
• Avoiding injuries: Although trauma is not usually the cause of osteochondromas, trauma or excessive stress on a bone that already has an osteochondroma may increase the risk of complications, including fractures.¹ It's best to take care not to injure any regions of any known osteochondromas
• Regular follow-ups: Patients with osteochondromas need to have follow-up visits with their healthcare provider on a regular basis. This entails routine imaging tests and clinical assessments to track the development of osteochondromas and evaluate any possible side effects. 

Summary

The most common benign bone tumour, osteochondroma, usually appears as a cartilage-capped bony protrusion towards the ends of long bones. A genetic predisposition plays a role in the formation of Multiple Hereditary Exostoses (MHE), which are characterised by numerous osteochondromas, although they are typically solitary and happen spontaneously. The production of osteochondroma is mostly dependent on genetic mutations, namely in the EXT1 and EXT2 genes. Although rare, genetic factors play a major role in the formation of numerous osteochondromas.

Osteochondromas frequently have mild symptoms, and many of them are asymptomatic. On the other hand, problems might occur if these growths push against neighbouring tissues, resulting in discomfort, limiting joint motion, or rarely, disrupting blood vessels. Additionally, there can be obvious abnormalities.

When it comes to therapy, observing the tumour is frequently appropriate for asymptomatic patients. Surgery, which involves removing the osteochondroma, is required when symptoms or problems arise. For the best possible outcome following surgery, physical therapy and other types of rehabilitation are essential. Due to genetic factors, it is still difficult to prevent osteochondromas from developing in the first place. However, proactive measures like genetic counselling, early detection, and regular monitoring can help manage these benign bone tumours effectively and prevent complications.