Early resuming of sport like bike, even on the same day as the surgery.Read More
Unilateral discrepancy is a shortening of bone which affects equal limb length. For an upper limb, a small difference in the length of the arm or forearm has no effect on function. However, for lower limbs, if there is a length difference of even 2-3 cm, this will induce a limp and in most cases, will tilt the pelvis to one side, causing a spine curvature or scoliosis. 1 in 1000 people have a unilateral discrepancy of over 6 cm, whilst several thousand present discrepancies between 2 to 6 cm.
Two types of shortening can occur:
Intercalary or isolated, which is where a singular bone is affected. This is usually caused by trauma.
Longitudinal, which involves more than one bone, is caused by a genetic defect or as a result of alterations in growth. Longitudinal bone shortening is primarily linked to patients with congenital shortening, which may result in the following:
• Short femur, or Proximal Femoral Focal Deficiency (PFFD)
• Fibular hemimelia
• Tibial hemimelia
• Foot deformity (such as clubfoot)
Common discrepancy are discrepancies present in the standard population. Up to 1/1000 people present a discrepancy over 6 cm, but several thousants of people present discrepancies from 2 to 6 cm.
Origins may vary, some being congenital (gradually increasing from birth, even if limited to only 2 cm at adulthood), others being mild forms of PFFD, and further ones being after trauma (generally 1 to 4 cm in femurs).
Treatment is more successful with intramedullary nails. The Guichet nail allows patients a full return to sports from the first postoperative day, with the aim to resume sports completely from the 3rd to 4th month of recovery.
Congenital Short Femur – PFFD
Congenital short femur is a longitudinal deficiency of the lower limb. Symptoms may be more visibly obvious to one section of a limb, such as the femur or tibia, but other limb functions can also be affected. The deficiency is usually located at thigh level, with severe cases of discrepancy ranging from 5cm to 35cm difference.
Picture above : Patient with a congenital short femur. On the right, a 6 cm standard modified shoe is used for walking hiding the large deformity.
Bone length differences are generally associated with:
• Abnormal acetabulum (pelvic socket)
• Shortened varus of the femur
• Lower femoral valgus
• Hypoplasia of thigh muscles and tendons
• Congenital deficiency of ligaments
• Fibular hemimelia (wherein the fibula is shorter than normal to the tibia)
• Rounded ankle joint with hypoplasia
• Missing section of the foot (for example, missing the arch and fifth toe)
The aim of treatment is to attain functional joints and restore equal bone length by the end of a patient’s growth period. If the patient does not undergo numerous operations prior to treatment, the success rate is higher, as less procedures will reduce problems on the final results.
For treatment, joint stablisation would be addressed first, with lengthening procedures performed after.
However, in more severe cases, full reconstruction may be required. This can be a stress on patients, therefore it is important for all surgical decisions to be discussed between the surgeon and patient in an effort to prevent multiple operations.
Promising techniques have been developed to treat short stature, yet in some cases, amputation may be option. This depends on:
• Observed deformities (prediction of limb discrepancy)
• Complexity of surgical procedures
• Length of hospitalisation
Good alignment and joint stability are required before any lengthening operation, including corrections for axis malalignments and pseudarthrosis.
A common feature of PFFD is a lack of cruciate ligaments in the knee joints. In order to stabilise the knee for the use of lengthening nails, reconstruction of the ligaments is strongly advised.
When bones are lengthened with Albizzia, the complications are fewer than if external fixators are used.
The Albizzia nail can allow length gains up to 18 cm. Aftercare relies on the patient wearing orthoses or modified shoes up to the end of growth.
The fibula is the long, small bone on the outside of the leg. In cases of fibular hemimelia, the fibula is hypotrophic or absent, which leads to the shortening of the leg and lateral deviation, placing the patient’s weight on the tibia. This defect of the fibula can lead to the decreasing stability or tilting of the ankle, creating a valgus deformity.
Shortened limbs can be associated with various lesions:
• Absence or hypoplasia of the fibula and associated muscles
• Deviation of the ankle into valgus
• Absent lateral arch of the foot
• Congenital deficiency of cruciate ligaments
• Congenital short femur
The condition Tibial hemimelia is a rare but severe congenital disorder. Treatment aims to restore a limb to function correctly, which would not only allow the patient to walk, but also participate in sports activities and drive a car.
However, treatment for Tibial hemimelia is difficult, as all cases need to be recognised early to prevent unnecessary surgical procedures and therapeutic errors.