“When Hannah came to my clinic she had difficulty walking due to severe pain in her right hip, as well as ongoing back and knee problems.
After the initial examination, it was clear that one of Hannah’s legs was significantly shorter than the other. She had been struggling her whole life with developmental hip dysplasia and – with no prior surgery – was finding it increasingly hard to cope.
Hannah needed a total hip replacement. And this was truly going to be The Everest of hip replacement surgery. Since Hannah’s socket was partially formed and also in the wrong place, my team and I would need to determine where to place a replacement – without the usual anatomical landmarks to guide us.”
Hannah was 53 years old and had no history of prior surgery.
On examination, she had restricted and painful movements of her right hip: intact sensation and pulses in her right leg and a leg length discrepancy of 7cm on the right side, which required a 4cm shoe raise to help correct it.
Anteroposterior plain radiograph showed developmental dysplasia of the right acetabulum, with the centre of rotation of the right femoral head 7cm superior compared to the left.
Hannah had right-sided Crowe grade 4 developmental dysplasia of the hip resulting in end-stage osteoarthritis.
This was the cause of her severe leg length discrepancy and pain in the hip and back during walking.
A hip injection would not be appropriate in Hannah’s case and while a shoe raise may help, it is only a partial solution.
Definitive treatment would be a primary total hip replacement to restore the centre of rotation of the joint and provide a mobile, stable hip with more equal leg lengths.
To reduce the risk of excessively stretching the sciatic nerve and soft tissues, our plan was to use a subtrochanteric shortening femoral osteotomy.
Using an S-ROM stem would enable: a) distal fixation (with stem cutting flutes) into the femur, below the osteotomy, and with the required femoral version; b) proximal fixation, above the osteotomy; and c) extensive adjustment of stem diameter, proximal sleeve size, and femoral offsets.
We used a posterior approach to access the right hip joint. The true acetabulum was found and reamed for a press-fitted, small, titanium uncemented socket and two screws and a ceramic liner.
We prepared the femur for an S-ROM, a subtrochanteric osteotomy was done and then the femur re-prepared. By trialling a selection of stems, we were able to select the correct one.
The femoral version was set at the time of stem impaction. We then secured the osteotomy further with bone graft (from the femoral osteotomy) and cerclage wires. A ceramic head was used.
Pre-operative 3D reconstructed CT of the patient’s anatomy. Image courtesy of LEXI Co., Ltd.
3D plan of the acetabular and femoral component’s position and orientation illustrating the planned restoration of the centre of rotation. Image courtesy of LEXI Co., Ltd.
Anteroposterior plain radiograph showing cup in the anatomical hip centre and a well- positioned S-Rom Hip stem with cables to secure the bone graft surrounding the site of the femoral osteotomy done to shorten the femur and prevent stretching of the sciatic nerve.
Four year post-operative video demonstrating Hannah’s improved gait.
Hannah went from only being able to walk short distances in extreme pain to being able to walk pain free without the need for analgesia. The operation completely transformed her life.
“This was an extreme case of developmental dysplasia of the hip. It doesn’t get much more complex for first-time hip replacement surgery.
It’s important in a case with severe leg length discrepancy to remember the soft tissues. Hannah’s muscles and nerves had developed in this position, meaning they were asymmetrical to the contralateral side. Simply bringing down the right hip would therefore not have been an option. The solution is to use a shortening femoral osteotomy.
Developmental dysplasia of the hip is a disease that, if detected early enough, can be preventable via many measures. In the future, due to neonatal screening tests, it will be much less likely that cases such as Hannah’s will be seen.”