An OI diagnosis can be confirmed through DNA or collagen testing, but in many cases the occurrence of bone fractures with little trauma and the presence of other clinical features such as blue sclera are sufficient for a diagnosis. A skin biopsy can be performed to determine the structure and quantity of type I collagen. DNA testing can confirm the diagnosis, however, it cannot exclude it because not all mutations causing OI are known and/or tested for. OI type II is often diagnosed by ultrasound during pregnancy, where already multiple fractures and other characteristic features may be present. Relative to control, OI cortical bone shows increased porosity, canal diameter, and connectivity in micro-computed tomography.

An important differential diagnosis of OI is child abuse, as both may present with multiple fractures in various stages of healing. Differentiating them can be difficult, especially when no other characteristic features of OI are present. Other differential diagnoses include rickets, osteomalacia, and other rare skeletal syndromes.

Diagnosis of Bruck syndrome must distinguish the association of contractures and skeletal fragility. Ultrasound is used for prenatal diagnosis. The diagnosis of a neonate bears resemblance to arthrogryposis multiplex congenital, and later in childhood to osteogenesis imperfecta.

Osteochondromas are often asymptomatic and may not cause any kind of discomfort. They are often found accidentally when an X-ray is done for an unrelated reason.

- X-rays are the first tests performed that characterize a lesion. They show a clear picture of dense structures of bones, and will also indicate bone growth pertaining to osteochondroma.

- Computed Tomography (CT) scan can identify the bony lesion in great details and show the presence of calcification. These tests also provide great details, especially in soft tissues with the aide of cross-sectional images.

- Magnetic Resonance Imaging (MRI) is the most accurate method for detecting bone masses in symptomatic cases to depict precise morphology of a tumor. It is used to verify if the palpable mass is continuous with the cortex of the affected bone and to differentiate an osteochondroma from other lesions on the surface of the bone. MRI can also be used to look for cartilage on the surface of tumor and can depict any vascular complications caused by the tumor. An MRI can identify tumors of the spinal column and is often used to diagnose low grade osteosarcoma.

- Ultrasound is done if aneurysms or pseudoaneurysms and venous or arterial thrombosis is suspected. Ultrasound is an accurate method for examining the cartilaginous cap of the osteochondroma. It is also a way of pinpointing bursitis. However, it cannot be used to predict if the growth of tumor is inward in regards to the cap.

- Angiography is used to detect vascular lesions caused by osteochondroma due to ossified cartilaginous cap. It is also used to characterize malignant transformation lesions through neovascularity.

- Clinical testing such as sequence analysis can be done of the entire coding regions of both "EXT1" and "EXT2" to detect mutations.

- A biopsy of the tissue sample of the tumor can also be taken to check for cancer.

Tests for osteochondroma can also identify diseases such as secondary peripheral chondrosarcoma and Multiple osteochondromatosis. In large, secondary chondrosarcoma arises at the site of osteochondroma due to increased thickness of the cartilage cap indicating potential malignant transformation. The symptoms of multiple osteochondromatosis are similar to solitary osteochondroma, but they are often more severe. Painless bumps can arise at the site of tumor and pain and other discomforts can also take place if pressure is put on the soft tissues, nerves, or blood vessels. Dysplasia Epiphysealis Hemimelica (DEH) or Trevor's disease and metachondromatosis (MC) are considered differential diagnosis of both solitary and hereditary osteochondromas. DEH is described as a type of over growth at one or more epiphyses. Similar to osteochondroma, DEH is diagnosed prior to 15 years of age and the growth of lesions end at puberty, when the growth plates close. Metachondromatosis is a rare disorder that exhibit symptoms of both multiple osteochondromas and enchondromas in children and is also inherited in autosomal dominant mode.

Exact diagnosis remains widely built on precise history taking, with the characteristic clinical and radiographic skeletal features. Genetic diagnosis is based on DNA sequencing. Because plasma COMP levels are significantly reduced in patients with COMP mutations, such as pseudoachondroplasia, measuring plasma COMP levels has become a reliable means of diagnosing this and pathopysiologically similar disorders.

A combination of medical tests are used to diagnosis kniest dysplasia. These tests can include:

- Computer Tomography Scan(CT scan) - This test uses multiple images taken at different angles to produce a cross-sectional image of the body.

- Magnetic Resonance Imaging (MRI) - This technique proves detailed images of the body by using magnetic fields and radio waves.

- EOS Imaging - EOS imaging provides information on how musculoskeletal system interacts with the joints. The 3D image is scanned while the patient is standing and allows the physician to view the natural, weight-bearing posture.

- X-rays - X-ray images will allow the physician to have a closer look on whether or not the bones are growing abnormally.

The images taken will help to identify any bone anomalies. Two key features to look for in a patient with kniest dysplasia is the presence of dumb-bell shaped femur bones and coronal clefts in the vertebrae. Other features to look for include:

- Platyspondyly (flat vertebral bodies)

- Kyphoscoliosis (abnormal rounding of the back and lateral curvature of the spine)

- Abnormal growth of epiphyses, metaphyses, and diaphysis

- Short tubular bones

- Narrowed joint spaces

Genetic Testing - A genetic sample may be taken in order to closely look at the patient's DNA. Finding an error in the COL2A1 gene will help identify the condition as a type II chondroldysplasia.

A diagnosis can be made by an evaluation of medical history and clinical observation. The Beighton criteria are widely used to assess the degree of joint hypermobility. DNA and biochemical studies can help identify affected individuals. Diagnostic tests include collagen gene mutation testing, collagen typing via skin biopsy, echocardiogram, and lysyl hydroxylase or oxidase activity. However, these tests are not able to confirm all cases, especially in instances of an unmapped mutation, so clinical evaluation by a geneticist remains essential. If there are multiple affected individuals in a family, it may be possible to perform prenatal diagnosis using a DNA information technique known as a linkage study. There is poor knowledge about EDS among practitioners.

More than 1 in 2 people with OI also have dentinogenesis imperfecta (DI) - a congenital disorder of formation of dentine. Dental treatment may pose as a challenge as a result of the various deformities, skeletal and dental, due to OI. Children with OI should go for a dental check-up as soon as their teeth erupt, this may minimize tooth structure loss as a result of abnormal dentine, and they should be monitored regularly to preserve their teeth and oral health.

Accurate assessment of plain radiographic findings remains an important contributor to diagnosis of pseudoachondroplasia. It is noteworthy that vertebral radiographic abnormalities tend to resolve over time. Epiphyseal abnormalities tend to run a progressive course. Patients usually suffer early-onset arthritis of hips and knees. Many unique skeletal radiographic abnormalities of patients with pseudoachondroplasia have been reported in the literature.

- Together with rhizomelic limb shortening, the presence of epiphyseal-metaphyseal changes of the long bones is a distinctive radiologic feature of pseudoachondroplasia.

- Hypoplastic capital femoral epiphyses, broad short femoral necks, coxa vara, horizontality of acetabular roof and delayed eruption of secondary ossification center of os pubis and greater trochanter.

- Dysplastic/hypoplastic epiphyses especially of shoulders and around the knees.

- Metaphyseal broadening, irregularity and metaphyseal line of ossification. These abnormalities that are typically encountered in proximal humerus and around the knees are collectively known as “rachitic-like changes”.

- Radiographic lesions of the appendicular skeleton are typically bilateral and symmetric.

- Oval shaped vertebrae with anterior beak originating and platyspondyly demonstrated on lateral radiographs of the spine.

- Normal widening of the interpedicular distances caudally demonstrated on anteroposterior radiographs of the dorsolumbar region. This is an important differentiating feature between pseudoachondroplasia and achondroplasia.

- Odontoid hypoplasia may occur resulting in cervical instability.

Until more molecular and clinical studies are performed there will be no way to prevent the disease. Treatments are directed towards alleviating the symptoms. To treat the disease it is crucial to diagnose it properly. Orthopedic therapy and fracture management are necessary to reduce the severity of symptoms. Bisphosphonate drugs are also an effective treatment.

Osteogenesis imperfecta is a rare condition in which bones break easily. There are multiple genetic mutations in different genes for collagen that may result in this condition. It can be treated with some drugs to promote bone growth, by surgically implanting metal rods in long bones to strengthen them, and through physical therapy and medical devices to improve mobility.

Osteochondromas are benign lesions and do not affect life expectancy. Complete excision of osteochondroma is curative and the reoccurrences take place when the removal of tumor is incomplete. Multiple reoccurrences in a well-excised lesion indicate that it may be malignant. The risk of malignant transformation takes place in 1–5% of individuals. If any symptoms of cancerous tumor takes place, then the patient should be evaluated by a bone specialist. No treatment is necessary for Solitary osteochondromas that are asymptomatic. Treatments for solitary osteochondroma are careful observation over time and taking regular x-rays to monitor any changes in the tumor. If the lesion is causing pain with activity, nerve or vessel impingement, or if the bone growth has fully matured and the presence of a large cartilage cap is prominent, then it is advised that the tumor be surgically removed.

Osteochondromas have a low rate of malignancy (<1%) and resection of the tumor is suggested if symptoms such as pain, limitation of movement, or impingement on nerves or vessels occur. Resection of the tumor also takes place when the tumor increases in size and progresses towards malignancy. During surgical resection, the entire lesion along with the cartilaginous cap should be removed to minimize any chances of reoccurrences. Surgical treatment becomes the sole treatment of choice if common complications such as fractures, symptoms of peripheral nerves such as paresthesia, paraplegia, peroneal neuropathy, and upper limb neuropathy take place. A prophylactic resection is suggested if the lesion lies next to a vessel.

Depending on the size and location of the tumor, the time it takes to return to normal daily activities varies between individuals. Limitation on some activities is advised if pain or discomfort persists after surgical excision.

Many features of gerodermia osteodysplastica (GO) and another autosomal recessive form of cutis laxa, wrinkly skin syndrome (WSS, ""), are similar to such an extent that both disorders were believed to be variable phenotypes of a single disorder.

Several delineating factors, however, suggest that gerodermia osteodysplastica and wrinkly skin syndrome are distinct entities, but share the same clinic spectrum.

While the prevailing feature of wrinkly, loose skin is more localized with GO, it is usually systemic, yet eases in severity with age during the course of WSS. Also, as the fontanelles ("soft spots") are usually normal on the heads of infants with GO, they are often enlarged in WSS infants.

While WSS is associated with mutations of genes on chromosomes 2, 5, 7, 11 and 14; GO has been linked to mutations in the protein GORAB. A serum sialotransferrin type 2 pattern, also observed with WSS, is not present in GO patients.

But perhaps the most notable feature, differentiating GO from WSS and similar cutis laxa disorders, is the age-specific metaphyseal peg sometimes found in GO-affected long bone, near the knee. Not appearing until around age 4–5, then disappearing by physeal closure, this oddity of bone is thought to represent a specific genetic marker unique to GO and its effects on bone development.

Because kniest dysplasia can affect various body systems, treatments can vary between non-surgical and surgical treatment. Patients will be monitored over time, and treatments will be provided based on the complications that arise.

"Osteosclerosis", an elevation in bone density, is normally detected on an X-ray as an area of whiteness, and is where the bone density has significantly increased. Localized osteosclerosis can be caused by injuries that compress the bone, by osteoarthritis, and osteoma.

One of the biggest risks factors faced by the affected foals is susceptibility to secondary infection. Within three to eight days after birth, the foal may die from infection or is euthanized for welfare reasons.

The frequency of this disorder is unknown, but it is very rare. Only a few families with the condition have been reported.

Spondyloperipheral dysplasia is an autosomal dominant disorder of bone growth. The condition is characterized by flattened bones of the spine (platyspondyly) and unusually short fingers and toes (brachydactyly). Some affected individuals also have other skeletal abnormalities, short stature, nearsightedness (myopia), hearing loss, and mental retardation. Spondyloperipheral dysplasia is a subtype of collagenopathy, types II and XI.

Biopsies of the skin may be performed to identify the cleavage that takes place at the dermal-epidermal junction. Another test that can aid in a diagnosis of JEB is the positive Nikolsky’s sign. By applying pressure to the skin, transverse movements can indicate slipping between the dermal and epidermal layers. An easier and more definitive test is through polymerase chain reaction (PCR). This method allows mane and tail samples to be genetically tested for the mutated genes that cause the condition. Hair samples must be pulled, not cut, with roots attached. The test can detect both JEB1 and JEB2. Testing costs around $35.00 US per sample.

There are several disorders that share some characteristics with Ehlers–Danlos syndrome. For example, in cutis laxa the skin is loose, hanging, and wrinkled. In EDS, the skin can be pulled away from the body but is elastic and returns to normal when let go. In Marfan syndrome, the joints are very mobile and similar cardiovascular complications occur. People with EDS tend to have a "Marfanoid" appearance (e.g., tall, skinny, long arms and legs, "spidery" fingers). However, physical appearance and features in several types of Ehlers–Danlos syndrome also have characteristics including short stature, large eyes, and the appearance of a small mouth and chin, due to a small palate. The palate can have a high arch, causing dental crowding. Blood vessels can sometimes be easily seen through translucent skin, especially on the chest. The genetic connective tissue disorder, Loeys-Dietz Syndrome, also has symptoms that overlap with EDS.

In the past, Menkes disease, a copper metabolism disorder, was thought to be a form of Ehlers–Danlos syndrome. It is not uncommon for patients to be misdiagnosed with fibromyalgia, bleeding disorders or other disorders that can mimic EDS symptoms before a correct diagnosis is made. Because of these similar disorders and complications that can arise from an un-monitored case of EDS, a correct diagnosis is very important. Pseudoxanthoma elasticum (PXE) is worth consideration in diagnosing a patient.

Chondromyxoid fibromas can share characteristics with chondroblastomas with regards to histologic and radiographic findings. However they more commonly originate from the metaphysis, lack calcification and have a different histologic organization pattern. Other differential diagnoses for chondroblastoma consist of giant cell tumors, bone cysts, eosinophilic granulomas, clear cell chondrosarcomas, and enchondromas (this list is not exhaustive).

OFC may be diagnosed using a variety of techniques. Muscles in patients afflicted with OFC can either appear unaffected or "bulked up." If muscular symptoms appear upon the onset of hyperparathyroidism, they are generally sluggish contraction and relaxation of the muscles. Deviation of the trachea (a condition in which the trachea shifts from its position at the midline of the neck), in conjunction with other known symptoms of OFC can point to a diagnosis of parathyroid carcinoma.

Blood tests on patients with OFC generally show high levels of calcium (normal levels are considered to range between 8.5 and 10.2 mg/dL, parathyroid hormone (levels generally above 250 pg/mL, as opposed to the "normal" upper-range value of 65 pg/mL), and alkaline phosphatase(normal range is 20 to 140 IU/L).

X-rays may also be used to diagnose the disease. Usually, these X-rays will show extremely thin bones, which are often bowed or fractured. However, such symptoms are also associated with other bone diseases, such as osteopenia or osteoporosis. Generally, the first bones to show symptoms via X-ray are the fingers. Furthermore, brown tumors, especially when manifested on facial bones, can be misdiagnosed as cancerous. Radiographs distinctly show bone resorption and X-rays of the skull may depict an image often described as "ground glass" or "salt and pepper". Dental X-rays may also be abnormal.

Cysts may be lined by osteoclasts and sometimes blood pigments, which lend to the notion of "brown tumors." Such cysts can be identified with nuclear imaging combined with specific tracers, such as sestamibi. Identification of muscular degeneration or lack of reflex can occur through clinical testing of deep tendon reflexes, or via photomotogram (an achilles tendon reflex test).

Fine needle aspiration (FNA) can be used to biopsy bone lesions, once found on an X-ray or other scan. Such tests can be vital in diagnosis and can also prevent unnecessary treatment and invasive surgery. Conversely, FNA biopsy of tumors of the parathyroid gland is not recommended for diagnosing parathyroid carcinoma and may in fact be harmful, as the needle can puncture the tumor, leading to dissemination and the possible spread of cancerous cells.

The brown tumors commonly associated with OFC display many of the same characteristics of osteoclasts. These cells are characteristically benign, feature a dense, granular cytoplasm, and a nucleus that tends to be ovular in shape, enclosing comparatively fine chromatin. Nucleoli also tend to be smaller than average.

Genetic changes are related to the following types of collagenopathy, types II and XI.

The system for classifying collagenopathies is changing as researchers learn more about the genetic causes of these disorders.The clinical features of the type II and XI collagenopathies vary among the disorders, but there is considerable overlap. Common signs and symptoms include problems with bone development that can result in short stature, enlarged joints, spinal curvature, and arthritis at a young age. For some people, bone changes can be seen only on X-ray images. Problems with vision and hearing, as well as a cleft palate with a small lower jaw, are common. Some individuals with these disorders have distinctive facial features such as protruding eyes and a flat nasal bridge.

PD diagnosis is based primarily on the presence and position of ulcers on the skin, as well as identifying particular protein markers in urine. To confirm the diagnosis, a blood test is required to measure prolidase activity.

Chondroid differentiation is a common feature of chondroblastoma. A typical histological appearance consists of a combination of oval mononuclear and multi-nucleated osteoclast-type giant cells. However this is not a prerequisite for diagnosis, as cells with epithelioid characteristics have been observed in lesions of the skull and facial bones. A "chicken-wire" appearance is characteristic of chondroblastoma cells and is the result of dystrophic calcification that may surround individual cells. Although, calcification may not be present and is not a prerequisite for diagnosis. Mitotic figures can be observed in chondroblastoma tissue but are not considered atypical in nature, and therefore, should not be viewed as a sign of a more serious pathology. There is no correlation between mitotic activity and location of the lesion. Furthermore, the presence of atypical cells is rare and is not associated with malignant chondroblastoma. There are no discernible histological differences observed when comparing the aggressive form of chondroblastoma that can cause recurrence or metastases with its less aggressive, benign, counterpart.

Spondyloperipheral dysplasia is one of a spectrum of skeletal disorders caused by mutations in the "COL2A1" gene, located on chromosome 12q13.11-q13.2. The protein made by this gene forms type II collagen, a molecule found mostly in cartilage and in the clear gel that fills the vitreous humour (the eyeball). Type II collagen is essential for the normal development of bones and other connective tissues (the tissues that form the body's supportive framework).

Mutations in the "COL2A1" gene interfere with the assembly of type II collagen molecules. The protein made by the altered "COL2A1" gene cannot be used to make type II collagen, resulting in a reduced amount of this type of collagen in the body. Instead of forming collagen molecules, the abnormal protein builds up in cartilage cells (chondrocytes). These changes disrupt the normal development of bones, leading to the signs and symptoms of spondyloperipheral dysplasia.

The disorder is believed to be inherited in an autosomal dominant manner. This indicates that the defective gene responsible for the disorder is located on an autosome (chromosome 12 is an autosome), and only one copy of the defective gene is sufficient to cause the disorder, when inherited from a parent who has the disorder.