Posture may improve after femoral extension osteotomy for hip flexion contractures

Investigators using the posteriorly-based closing wedge osteotomy technique found that sacrofemoral angles improve by up to 33° in many instances.

PRAGUE — A team from the Medical University of South Carolina, in Charleston, U.S.A., found that performing a proximal femoral extension osteotomy was effective in cases of hip flexion contracture in pediatric patients due to spastic cerebral palsy, arthrogryposis and other conditions.

Yuehuei H. An, BMed, MMed, presented the clinical results of the retrospective study of eight patients with a mean age 14 years who had hip flexion contractures with lumbar lordosis averaging more than 46º and discussed a new surgical technique for treating this condition during the SICOT XXV Triennial World Congress 2011.

An noted that all of the cases were carried out by Richard Gross, MD.

Blade plate stabilization

“All patients were doing well at an average 14 months follow-up with improved standing posture and gait,” An said. The mean follow-up ranged from 3 months to 40 months, according to the abstract.

Two patients in series were diagnosed with spastic cerebral palsy and arthrogryposis, and one patient each was diagnosed with metaphyseal dysplasia, neuromuscular scoliosis, sequelae of a septic hip and dysraphism.

For the posteriorly-based closing wedge osteotomy done at the intertrochanteric level in these cases, surgeons made a lateral incision and a straight osteotome and a blade plate fixed with screws to stabilize the osteotomy were typically used.

“The postoperative care was patients getting [physical therapy] PT the next day and weightbearing as tolerated with the aid of a walker or crutches,” An said.

Sacrofemoral angle identified

An and colleagues evaluated several factors postoperatively, including correction of the sacrofemoral angle radiographically, which is normally 45° to 65°, assessment of the patients’ gait and standing posture, and identification of complications.

For most osteotomies, the chisel is placed perpendicular to the long axis of the femur. For this one it is angled from anterior distal to posterior proximal. The angle between the chisel placement and a line perpendicular to the long axis of the femur will dictate the amount of extension achieved when the instrumentation is placed. Image: Gross R

At the patients’ last follow-up examination at 14 months, investigators found that the improvement in sacrofemoral angles — the radiographic angle between the upper surface of the sacrum and the shaft of the femur — averaged about 33°, An noted.

Despite these good results, he cited the few cases in the series and the lack of family/patient functional outcome scoring among the study’s limitations.

During the paper’s discussion, Gross noted that he uses the Tönnis test to check the sacrofemoral angle while the patient is under anesthesia. He has successfully corrected hips with up to 60º contracture using this method. – by Susan M. Rapp

Reference:

• An Y, Gross R. Proximal femur extension osteotomy for treatment of flexion contracture of the hip. Paper #29304. Presented at the SICOT XXV Triennial World Congress 2011. Sept. 6-9. Prague.

• Yuehuei H. An, BMed, MMed, can be reached at North Short LIF – Southside Hospital, 301 E. Main St., Bay Shore, NY 11706, USA; +1-631-968-3777; email: yan@hshs.edu.
• Disclosure: An has no relevant financial disclosures.

The hip flexion deformity is a condition that interferes greatly in the function of the patient. In a nonambulator patient, the sitting position becomes abnormal creating points of hyper-pressure; and in an ambulatory patient it increases the lumbar lordosis and the gait becomes less effective with more energy cost.

The indication for surgical treatment is individualized as in almost all neuromuscular conditions.

The group of patients presented in this study varies in the etiology of the clinical condition and could have an effect in the results, but it is a not common deformity to surgically treat.

Before the surgical indication, there is the need to check if the excessive lumbar lordosis is still flexible otherwise approaching the hip only could not be as effective.

The surgical treatment starts with soft tissue release over the hip joint but rarely has the power to correct deformities greater than 30°.

The surgical technique presented is probably the only way to correct the deformity because of the age of the patients and the severity of it. The osteotomy shown is very effective with low complications. The only point that should be taken is that the follow-up period was not long enough; time until the skeletal maturity is needed to assess the final outcome of these patients.

— Patricia Fucs, MD, PhD
Session moderator
Immediate past Treasurer, SICOT
Disclosure: Fucs has no relevant financial disclosures.