Three main points in diagnosing thumb hypoplasia are: width of the first web space, instability of the involved joints and function of the thumb. Thorough physical examination together with anatomic verification at operation reveals all the anomalies. An X-ray of the hand and thumb in two directions is always mandatory. When the pediatrician thinks the condition is associated with some kind of syndrome other tests will be done. More subtle manifestations of types I and II may not be recognized, especially when more obvious manifestations of longitudinal radial deficiency in the opposite extremity are present. Therefore, a careful examination of both hands is important.

When it comes to treatment it is important to differentiate a thumb that needs stability, more web width and function, or a thumb that needs to be replaced by the index finger. Severe thumb hypoplasia is best treated by pollicization of the index finger. Less severe thumb hypoplasia can be reconstructed by first web space release, ligament reconstruction and muscle or tendon transfer.

It has been recommended that pollicization is performed before 12 months, but a long-term study of pollicizations performed between the age of 9 months and 16 years showed no differences in function related to age at operation.

It is important to know that every reconstruction of the thumb never gives a normal thumb, because there is always a decline of function. When a child has a good index finger, wrist and fore-arm the maximum strength of the thumb will be 50% after surgery in comparison with a normal thumb. The less developed the index finger, wrist and fore-arm is, the less strength the reconstructed thumb will have after surgery.

Diagnosis is suspected clinically and family history, neuroimaging and genetic study helps to confirm Behr Syndrome.

Treatment of manifestations: special hair care products to help manage dry and sparse hair; wigs; artificial nails; emollients to relieve palmoplantar hyperkeratosis.

While the clinical picture may point towards the diagnosis of the Roussy–Lévy syndrome, the condition can only be confirmed with absolute certainty by carrying out genetic testing in order to identify the underlying mutations.

Diagnosis of a trigger thumb is solely made by these clinical observations and further classified into four stages:

Not much research has been done on the epidemiology of congenital trigger thumbs. There are a few reports on the incidence in their respective studies. The most recent data comes from a Japanese study by Kukichi and Ogino where they found an incidence 3.3 trigger thumbs per 1,000 live births in 1 year old children.

Diffuse, symmetric white matter abnormalities were demonstrated by magnetic resonance imaging (MRI) suggesting that Behr syndrome may represent a disorder of white matter associated with an unknown biochemical abnormality.

The complete or partial absence of the pectoralis muscle is the malformation that defines Poland Syndrome. It can be treated by inserting a custom implant designed by CAD (computer aided design). A 3D reconstruction of the patient's chest is performed from a medical scanner to design a virtual implant perfectly adapted to the anatomy of each one. The implant is made of medical silicone unbreakable rubber. This treatment is purely cosmetic and does not make up for the patient's imbalanced upper body strength.

The Poland syndrome malformations being morphological, correction by custom implant is a first-line treatment. This technique allows a wide variety of patients to be treated with good outcomes. Poland Syndrome can be associated with bones, subcutaneous and mammary atrophy: if the first, as for pectus excavatum, is successfully corrected by a custom implant, the others can require surgical intervention such as lipofilling or silicone breast implant, in a second operation.

There are a few different classifications conceived to categorize the spectrum of variety of congenital clasped thumb. In literature X classifications have been described for clasped thumb. The two most relevant of the existing classifications, to our opinion, are the classifications of McCarrol and Tjuyuguchi et al.

The most global format is the classification of McCarrol, which divides the congenital clasped thumbs into two groups. Group I includes the supple clasped thumb, when the thumb is only passively correctable. While complex clasped thumbs, thumbs which cannot be moved neither passively or actively, belong to group II.

Tjuyuguchi et al. designed a classification existing of three groups:

- Group I: The supple clasped thumb, where the thumb is passively abductable and extendable against the resistance of thumb flexors, without other digital anomalies.

- Group II: The clasped thumb with hand contractures, where the thumb is not passively extendable and abductable, with or without other digital anomalies.

- Group III: The clasped thumb which is associated with arthrogryposis.

Usually, a common form of treatment for the condition is a type of hand cream which moisturises the hard skin. However, currently the condition is incurable.

HED2 is suspected after infancy on the basis of physical features in most affected individuals. GJB6 is the only gene known to be associated with HED2. Targeted mutation analysis for the four most common GJB6 mutations is available on a clinical basis and detects mutations in approximately 100% of affected individuals. Sequence analysis is also available on a clinical basis for those in whom none of the four known mutations is identified.

Medical diagnosis of CGL can be made after observing the physical symptoms of the disease: lipoatrophy (loss of fat tissues) affecting the trunk, limbs, and face; hepatomegaly; acromegaly; insulin resistance; and high serum levels of triglycerides. Genetic testing can also confirm the disease, as mutations in the AGPAT2 gene is indicative of CGL1, a mutation in the BSCL2 gene is indicative of CGL2, and mutations in the CAV1 and PTRF genes are indicative of CGL3 and CGL4 respectively. Physical diagnosis of CGL is easier, as CGL patients are recognizable from birth, due to their extreme muscular appearance, which is caused by the absence of subcutaneous fat.

CGL3 patients have serum creatine kinase concentrations much higher than normal (2.5 to 10 times the normal limit). This can be used to diagnose type 3 patients and differentiate them from CGL 1 and 2 without mapping their genes. Additionally, CGL3 patients have low muscle tone when compared with other CGL patients.

The surgery takes place under general anaesthesia and lasts less than 1 hour. The surgeon prepares the locus to the size of the implant after performing a 8-cm axillary incision and inserts the implant beneath the skin. The closure is made in 2 planes.

The implant will replace the pectoralis major muscle, thus enabling the thorax to be symmetrical and, in women, the breast as well. If necessary, especially in the case of women, a second operation will complement the result by the implantation of a breast implant and / or lipofilling.

Lipomodelling is progressively used in the correction of breast and chest wall deformities. In Poland syndrome, this technique appears to be a major advance that will probably revolutionize the treatment of severe cases. This is mainly due to its ability to achieve previously unachievable quality of reconstruction with minimal scaring.

No surgical outcomes studies exist for evaluating the function of the thumbs after an on-top plasty reconstruction.

Few clinical outcome studies exist regarding the treatment of central polydactyly. Tada and colleagues note that satisfactory surgical correction of central polydactyly is difficult to achieve and that outcomes are generally poor. In Tada’s study, 12 patients were reviewed. All patients required secondary surgical procedures to address flexion contractures and angular deviation at the IP joint level.

However, several primary factors contribute to the complexity of central polydactyly reconstruction. Hypoplastic joints and soft tissues that predispose the reconstructed finger to joint contracture, and angular deformities as well as complex tendon anomalies, are often difficult to address. Therefore, treatment is wholly dependent on the anatomic components present, the degree of syndactyly, and the function of the duplicated finger.

Electrophysiologic testing is an essential part of the evaluation of Anterior interosseous nerve syndromes. Nerve conduction studies may be normal or show pronator quadratus latency.⁠⁠

Electromyography (EMG) is generally most useful and will reveal abnormalities in the flexor pollicis longus, flexor digitorum profundus I and II and pronator quadratus muscles.⁠⁠

The role or MRI and ultrasound imaging in the diagnosis of Kiloh-Nevin syndrome is unclear.⁠

If asked to make the "OK" sign, patients will make a triangle sign instead.

This 'Pinch-Test' exposes the weakness of the Flexor pollicis longus muscle and the flexor digitorum profundus I leading to weakness of the flexion of the distal phalanges of the thumb and index finger. This results in impairment of the pincer movement and the patient will have difficulty picking up a small item, such as a coin, from a flat surface.

Treatment of congenital clasped thumb includes two types of therapy: conservative and surgical.

Tissue biopsy is the gold standard. Macroscopically this reveals pale muscle tissue. Microscopically infarcted patches of myocytes. Necrotic muscle fibers are swollen and eosinophilic and lack striations and nuclei. Small-vessel walls are thickened and hyalinized, with luminal narrowing or complete occlusion. Biopsy cultures for bacteria, fungi, acid-fast bacilli and stains are negative in simple myonecrosis.

Creatine kinase may be normal or increased probably depending upon the stage of the condition when sampling is undertaken. ESR is elevated. Planar X-ray reveals soft tissue swelling and may potentially show gas within necrotic muscle, Bone scan may show non specific uptake later in the course. CT shows muscle oedema with preserved tissue planes (non-contrast enhancing). MRI is the exam of choice and shows increased signal on T2 weighted images within areas of muscle oedema. Contrast enhancement is helpful but must be weighed against the risk of Nephrogenic Systemic Fibrosis as many diabetics have underlying renal insufficiency. Arteriography reveals large and medium vessel arteriosclerosis occasionally with dye within the area of tissue infarction . Electromyography shows non specific focal changes.

The Kocher–Debré–Semelaigne syndrome is hypothyroidism in infancy or childhood characterised by lower extremity or generalized muscular hypertrophy, myxoedema, short stature and cretinism. The absence of painful spasms and pseudomyotonia differentiates this syndrome from its adult form, which is Hoffmann syndrome.

The syndrome is named after Emil Theodor Kocher, Robert Debré and Georges Semelaigne.

Also known as Debre–Semelaigne syndrome or cretinism-muscular hypertrophy, hypothyroid myopathy, hypothyroidism-large muscle syndrome, hypothyreotic muscular hypertrophy in children, infantile myxoedema-muscular hypertrophy, myopathy-myxoedema syndrome, myxoedema-muscular hypertrophy syndrome, myxoedema-myotonic dystrophy syndrome.

Kocher-Debre-Semelaigne syndrome gives infant a Hercules appearance.

Surgical decompression can give excellent results if the clinical picture and the EMG suggest a compression neuropathy.

In brachial plexus neuritis, conservative management may be more appropriate.

Spontaneous recovery has been reported, but is said to be delayed and incomplete.

There is a role for physiotherapy and this should be directed specifically towards the pattern of pain and symptoms. Soft tissue massage, stretches and exercises to directly mobilise the nerve tissue may be used.⁠

There is no pharmacological treatment for Roussy–Lévy syndrome.

Treatment options focus on palliative care and corrective therapy. Patients tend to benefit greatly from physical therapy (especially water therapy as it does not place excessive pressure on the muscles), while moderate activity is often recommended to maintain movement, flexibility, muscle strength and endurance.

Patients with foot deformities may benefit from corrective surgery, which, however, is usually a last resort. Most such surgeries include straightening and pinning the toes, lowering the arch, and sometimes, fusing the ankle joint to provide stability. Recovering from these surgeries is oftentimes long and difficult. Proper foot care including custom-made shoes and leg braces may minimize discomfort and increase function.

While no medicines are reported to treat the disorder, patients are advised to avoid certain medications as they may aggravate the symptoms.

Metformin is the main drug used for treatment, as it is normally used for patients with hyperglycemia. Metformin reduces appetite and improves symptoms of hepatic steatosis and polycystic ovary syndrome. Leptin can also be used to reverse insulin resistance and hepatic steatosis, to cause reduced food intake, and decrease blood glucose levels.

Binder's Syndrome/Binder Syndrome (Maxillo-Nasal Dysplasia) is a developmental disorder primarily affecting the anterior part of the maxilla and nasal complex (nose and jaw). It is a rare disorder and the causes are unclear.

The characteristics of the syndrome are typically visible. The syndrome involves hypoplasia of variable severity of cartilaginous nasal septum and premaxilla. It includes complete total absence of the anterior nasal spine. There are also associated anomalies of muscle insertions of the upper lip and the nasal floor and of the cervical spine. Affected individuals typically have an unusually flat, underdeveloped midface (midfacial hypoplasia), with an abnormally short nose and flat nasal bridge. They have an underdeveloped upper jaw, relatively protruding lower jaw with anterior mandibular vertical excess and a Class III skeletal and dental (reverse overjet) profile. They have a small frontal sinus and global facial imbalance.

Treatment is encouraged as early as possible with posteroanterior traction on the maxilla and, at about age 8, reinsertion of the nasolabial muscles onto the anterior border of the cartilaginous system. Many who have a severe case of the disorder undergo plastic surgery or orthodontic treatment for cosmetic reasons.

Recent research has found that Dandy–Walker syndrome often occurs in patients with PHACES syndrome.