Prof. Dr. med. Dr. h.c. G. Ulrich Exner

FMH Orthopädische Chirurgie

und Traumatologie


Proximal femoral focal deficiency (PFFD).

The PFFD is among the greatest challenges in paediatric orthopaedics as this includes hip malformations, shortening and angular deficiencies of the femur as well as deficiencies of the knee with frequently lacking anterior cruciate ligament.

The child presented here had no stable contact between the femoral head and the femur (pseudarthrosis in the femoral neck/trochanteric region).

With  a series of staged surgical interventions – which need be planned at birth – a stable connection between the hip and the femur, lateron improvement of the acetabular coverage and lengthening of the femur at the end of growth the patient has a stable leg, participates actively in all sports (downhill ski, snow boarding).

The lengthening of the leg included principles developed by us to protect the knee from dislocation, which is a known complication and considered by some as a contraindication for lengthening.

Stability of the skeleton and joints ist he prerequisite for our posture and mobility.

Smaller defects (e.g. caused by degenerative joint diseases, arthritis) can be reconstructed fairly is by joint replacement (e.g. endoprosthesis of hip and knee).

Large defects associated with connatal malformations, endoprosthetic failure or infection are a challenge in orthopaedics.

The goal of our research and clinical work are focused on biologic reconstructions as only these can last for a life.

Different techniques and procedures are available. One such approach, which was extensively deloped by Ilizarov, is to use the plasticity of the grwoing callus as shown in the following patient.

Connatal Pseudarthrosis of the Tibia

When this child started to walk the deformity of the leg was realized by the grandmother. It was not recognised by the consulted surgeon that this was a typical rare malformation with impending pseudarthrosis which should not be touched. It was thought that this was a neoplasia and an open biopsy was performed. Consequently the tibia fractures which was treated by osteosynthesis  The further problems can easily be  seen.

The maldeveloped bone segment was then resected and filled by a segmental transportation.

At the end of growth the lower leg of the patient is fully biologically reconstructed.

Initially trained as a paediatrician Professor Exner has a genuine interest in the well being of children. His specialty in paediatric orthopaedics is the functional improvement of children with malformations.

Hip dysplasia and hip dislocation

As a paediatric orthopaedist Professor Exner traditionally has a great interest in Developmental Dysplasia/Dislocation of the hip. He conducted over 20 years ago the first newborn screening study based on the principles of Professor Reinhard GRAF. This study has become the basis to introduce ultrasound screening fort he detection of hip dysplasia in babies in Switzerland.

Hip dysplasia is not really a malformation, but a maturation problem. All structures are present but ossification to stabilise the acetabular cartilage is delayed. The insufficient bony support of the articular cartilage allows its deformation (‚dysplasia’) and the femoral head to leave the dysplastic acetabulum (‚dislocation’).

With early diagnosis and simple means to keep the femoral head in the acetabulum  until bony maturation is sufficient in nearly 100% of the patients normalisation can be achieved. While in missed untreated cases even with repeated maior surgery rarely a normal hip will develop.

Schematic presentation of the mechanism of hip dislocation with the leg extended in the hip. With flexion and abduction the femoral head is will centered and releaves the acetabular edge from pressure to allow bone to form.

In this case the child is treated with a PAVLIK harness which allows every motion except extension of the legs.