Multiple Osteoarticular Exostoses (MHE) – Comprehensive Treatment
Growth under control, effective treatment of multiple osteochondral lesions without compromise. Monitoring of changes, surgical removal of lesions, and correction of knee alignment deformities.
What are multiple osteochondral growths?
Multiple osteochondral exostoses (MHE—multiple hereditary exostoses), also known as multiple osteochondromas, is a rare disease in which benign cartilaginous tumors that also produce bone tissue appear on long bones—most commonly in the femur and tibia. MHE occurs in approximately 1 in 50,000 people, more commonly in males, and the exostoses typically develop during the first 10 years of life and continue to grow until puberty.
Reasons
MHE is an autosomal dominant disorder; a single copy of the mutated gene is sufficient to cause the condition. Most often, the gene is inherited from the parents, although spontaneous mutations also occur. The disorder is associated with mutations in the EXT1 and EXT2 genes (and, according to the literature, also EXT3)—tumor suppressor genes responsible for the proper development and maintenance of bone and cartilage tissue.
Symptoms
Painless lumps near the joints, usually first noticed by parents
Discomfort or pain during physical activity, including nighttime pain that interferes with sleep
Numbness, tingling, and sensory disturbances resulting from pressure on the nerves
Changes in blood flow due to vascular compression
shortening and osteoarticular deformities that limit range of motion
Limb length discrepancy (in 10–50% of patients, the discrepancy is 2 cm or more)
Bowlegs or knock-knees, forearm deformities
Diagnostics
MHE is diagnosed based on a clinical examination, radiological imaging (X-rays, and in the case of larger, rapidly growing lesions, magnetic resonance imaging to assess the cartilaginous “cap” of the exostosis), and, if necessary, histopathological evaluation of a tumor biopsy specimen.
When should you see a specialist?
when a child develops painless lumps near the joints, which are noticeable during a physical examination or through everyday observation
when pain occurs during physical activity or when nighttime pain disrupts sleep
when there is numbness, tingling, or other sensory disturbances in the limbs
when there is a visible difference in leg length or a deformity of the knee axes (knock-knees/bowlegs)
When a growth begins to grow rapidly or is accompanied by increasing pain—in such a situation, a consultation and possible surgery should take place immediately due to the small but real risk of malignancy (approximately 1–2% of cases)
The global standard in the treatment of multiple osteochondral lesions
Paley European Institute Support
Our team specializes in the treatment of rare skeletal disorders in children and adults, combining advanced diagnostic imaging with a personalized surgical and rehabilitation treatment strategy.
Stages of Treatment
From the initial consultation and monitoring of changes over time (regular X-ray follow-ups), through qualification for surgery in cases of pain, rapid growth of bone spurs, or risk of malignancy, to the correction of limb axial deformities and length equalization.
Comprehensive Care
Treatment includes not only the removal of bone spurs, but also the correction of deformities, limb lengthening, and comprehensive postoperative physical therapy—all under the care of a single team of specialists.
How do we treat multiple osteochondral lesions?
Treatment for MHE is tailored to each individual and may include observation, conservative management of symptoms, or surgical intervention.
Diagnostics and Planning
A clinical and radiological study evaluating the number, location, and size of growths
Assessment of limb alignment and length, and the risk of neurological complications
Planning a treatment strategy tailored to the patient's age and stage of growth
Post-operative care
Surgical removal of growths that compress nerves or blood vessels or restrict movement
Femoral osteotomy or removal of osteophytes from the femoral neck in cases of hip lesions
A recovery period lasting approximately 2–3 weeks, during which one should avoid straining the area that underwent surgery
Limb lengthening
Hemiepiphysiodesis—partial, controlled closure of the growth plate to correct the alignment of the knee
In cases of severe axial malalignment and in adults—bone lengthening and angle correction using an external fixator
Rehabilitation and Long-Term Care
Physical therapy to support a return to full fitness after surgery
Regular imaging examinations to monitor for any new changes
Supporting patients and their families in their daily lives with the disease
What challenges do patients with MHE face?
Limited mobility —growths can change the range of possible movements from one day to the next; activities such as walking, running, bending, carrying, or grasping may become difficult.
Manual difficulties – patients with hand and arm involvement may have trouble tying their shoes, writing for long periods, throwing, or swimming certain strokes.
Foot deformities – People with lower-limb involvement often have deformed feet with toes of varying lengths, which causes pain and gait abnormalities.
Fatigue – Limited mobility and pain can lead to getting tired more quickly and the need for longer periods of rest.
Bony Exostoses in the Femur
The femur is affected by osteochondral lesions twice as often as the tibia, making it one of the most important areas to monitor in patients with MHE.
Appearance and location —growths can appear in the area of both the knee and hip joints, including the femoral neck.
Axial deformities —involvement of the femur is often associated with the development of genu varum or genu valgum and limb length discrepancy.
Conservative treatment —regular radiological monitoring of lesions that do not cause symptoms.
Surgical treatment —depending on the location and severity of the lesions, femoral osteotomy, removal of femoral neck exostoses, or hemiepiphysiodesis to correct the knee axis may be performed.
Limb lengthening —in cases of significant leg length discrepancy, external devices are used to enable controlled and precise bone lengthening.
You should entrust your health and that of your children to professionals who know exactly how to manage rare diseases. Please contact us to schedule a consultation.
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Your most frequently asked questions
In Other Words: What You Should Know Before Deciding on Treatment.
MHE (multiple hereditary exostoses) is a rare, hereditary disorder in which numerous benign tumors composed of cartilage and bone tissue develop on the long bones—most commonly on the femur and tibia. On average, each patient has between 15 and 18 exostoses.
Yes. MHE is inherited in an autosomal dominant pattern—a single copy of the mutated gene (most commonly EXT1 or EXT2) is sufficient for the disease to manifest. The gene is usually inherited from one of the parents, although spontaneous mutations also occur.
The disease is very rare—it affects about 1 in 50,000 people, most often men.
The most common initial sign is painless, firm lumps around the joints, which can be felt in the child’s hands or legs. These may be accompanied by pain during physical activity or at night, numbness and tingling, limited joint mobility, as well as a visible difference in limb length or knee misalignment.
In a very small percentage of cases (about 1–2%), the tumor may become malignant and develop into a chondrosarcoma. That is why regular radiological follow-up and orthopedic consultations are so important—they allow for the early detection of concerning changes.
The diagnosis is based on clinical and radiological (X-ray) examination and, if necessary, magnetic resonance imaging (MRI), which allows for the evaluation of the cartilaginous “cap” of the exostoses that is not visible on an X-ray. In certain cases, a histopathological evaluation of a tumor biopsy specimen is necessary.
No. Most growths are asymptomatic and require only regular follow-up over time. Surgery is considered when the growth causes pain, puts pressure on nerves or blood vessels, limits mobility, leads to limb deformity, or grows at an unusually rapid rate.