Nuno Craveiro Lopes M.D. 

Head of Orthopedic and Traumatologic Department
Coordinator of Pediatric Orthopedics  and Limb Reconstructive Surgery Unit
Garcia de Orta Hospital, Almada - Portugal

Any comment, suggestion or contact can be done to: nuno.lopes@netvisao.pt

 

CLINICAL CASE

Cumulative Overtraining Crush Injury of Femoral Head (2001)

 

11yo girl doing high performance gymnastics in USA. On a fall over the left foot have done a forced medial rotation of the left hip she felt pain on the buttock and began a  limp with pain and tightness in the left groin.  Her gymnastics performance degraded markedly and she quit the sport to allow the injuries to heal. With no significant improvement over a 4 week period, MRI & bone scan were ordered which revealed a necrotic lesion on the left femur ball.  The condition was diagnosed as Perthes disease.

 

 

I am convicted that this is not a Perthes disease. Rather, there are many signs to suggest that the condition is a possible gymnastics related injury that provoked the lesion.  

In fact, in this case there appears to have been a traumatic event that provoked the lesion which is not compatible with Perthes.  For example, the MRI pattern is atypical of Perthes.  The patient presents a voluminous joint effusion (Fig.5B) and an image of anterior impaction of the femoral head (Fig.2 and 4) with a thin layer of sub-chondral necrosis under the compacted zone (Fig.1 and 2). On Perthes the necrosed zone generally includes a deep thickness of the epiphysis. By the other hand, it don't seen to have articular cartilage thickening, which is an early sign of Perthes (Fig.5A). Finally on the MRI one can see a rupture of the lateral rotator muscles, including gemelli, obturators and quadratus, with abundant extra-articular effusion, which never happens on Perthes disease and shows the severity of the injury 1ncident (Fig.3).
As we interpret the lesion, it is not Perthes nor traumatic AVN; it is a crush injury of the head with sub-chondral fracture and necrosis of the underlying bone tissue caused by crushed trabecular bone and resulting loss of blood supply in the impacted area.
 The probable mechanism can be explained by an immature bone structure subjected to intense training. Although not fully confirmed because the young athlete continued to train with no massive traumatic event to highlight a specific event, it is reasonable to assume that the injury may have come from complex gymnastics maneuver, producing high kinetic velocity. For example, the young gymnast was capable of doing a maneuver that few athletes perform, called a “triple full” which requires a triple rotation in the roll axis and a single rotation in the pitch axis, rotating the body counterclockwise and possibly landing unbalanced on the left foot. It is suggested that a poorly executed maneuver could cause excessive rotational inertia, inducing medial rotation of the limb, first stretching the lateral rotator muscles to its limit, then doing an impact fracture of the anterior head on the anterior wall of the acetabulum, and finally, instead of a total dislocation, muscular/tendinous rupture to the rotator muscles. 

 

Fig.1

Fig. 2

Fig. 3

Fig. 4

Fig. 5

What we propose to do is to introduce a wire guide directed to the center of the necrotic area and thru it make a tunnel just into the sub-chondral bone of the epiphysis with a trephine, procedure that we call Trans-physeal Neck-Head Tunneling (TNHT) and have a experience in about 120 cases of  Perthes disease, on its initial stages. As on the previous cases we expect that TNHT will speed up the evolution of the disease and provide material to make a histological diagnosis. Later, if hinge abduction hip or other head at risk signs develops, appropriated surgical procedures can be applied earlier and in a better vascular environment.

Above: Evolution without TNHT

Bellow. Evolution with TNHT 

Introducing the guide wire.

Trans-physeal neck-head tunneling

 

This surgical procedure was quick (15 minutes) and low traumatic. The patient stayed in bed two days with limbs in flexion-abduction position, then begun walking with crutches and a flexion-abduction brace with no weight bearing on the affected limb. At one month physical therapy was started, namely strengthening and mobilization exercises in the swimming pool, with no weight bearing or weight lifting.

Here are the 4 week MRI control 


Before TNHT

One month follow up after TNHTt

 

Bone material from the patient's epiphysis by TNHD was sent for histological examination and the result clearly shown no signs of Perthes but simple necrosis as seen on a AVN after acute trauma. Histology shows normal bone at the base of the epiphysis with some inflammatory reaction and at the sub-chondral crushed area, simple necrosis, without reparative process on the way.

 

Epiphysis near the growth plate

Epiphysis near sub-chondral

 

So, it is possible that this is a new clinical entity, that we can call "Cumulative Overtraining Crush Injury of Femoral Head", related to high impact sports, such as high performance gymnastics, where momentary loads, torques and efforts on the hip are greater than in other sports. Such excessive loads in a girls at puberty, when hormonal factors, associated to cumulative micro-trauma by overtraining or overuse, can be involved in a process that can diminish bone and joint mechanical resistance and can possible lead to a femoral head crush injury like we suspect in this case. 

 

We will appreciate the report of any other case of Perthes or AVN like lesion, where high impact sports is in environmental history. Please send comments to me at nuno.lopes@netvisao.pt .

 

Meanwhile we have already had report of other 6 such cases on pre puberty or puberty athlete girls from USA, Canada, France and Russia.