The femoroacetabular conflict is a recognized cause of hip pain in young patients. It is associated with rim tears. Two types of conflict have been described: impingement due to retroversion of the acetabulum and «cam effect» associated with insufficient head/neck offset. A recent subject of debate has been isolated treatment of the rim tear without treating the often unrecognized bone anomaly. The purpose of this study was to assess short-term outcome after surgical remodeling of the head/neck junction for the treatment of femoroacetabular conflicts.

Material and methods: There were 37 hips (18 men and 16 women) with chronic pain for more than three months. Mean patient age was 41 years (range 24–52). Preoperative 3D CT and MRI with gadolinium arthrography were available for all patients. Surgical remodeling of the head/neck junction via digastric trochanterotomy with surgical dislocation was performed. Preoperatively, the mean Notzli alpha angle was 65.6° (range 42–95°). Among the 34 patients, only four practiced sports requiring large range hip motion. MRI revealed a rim lesion in all patients. The following tests were performed: UCLA hip test, WOMAC (Western Ontario McMaster Osteoarthritis) index, and SF-12.

Results: Mean follow-up was 2.5 years (range 2–4); pre- and postoperative scores were: WOMAC 59.2 and 81.0 (p< 0.001), UCLA scores 4.2 and 7.9 for pain, 7.3 and 9.0 for gait, 6.2 and 8.5 for function, 4.3 and 6.9 for activity (p< 0.05). The physical component of the SF-12 improved from 37.4 to 44.2 (p< 0.006) and the mental component from 46.0 to 51.6 (p< 0.03). None of the hips required revision to modify the joint configuration. Two complications were noted: one rupture of the greater trochanter and one heterotopic ossification requiring resection. Osteonecrosis was not observed. The trochanter implants were removed in nine patients because of pain.

Discussion: The femoroacetabular conflict results from insufficient concavity of the anterolateral head/neck junction associated with a rim tear. Correction of the bony anomaly provided significant short-term functional improvement both for the hip and for the patient’s general health. Correction of the offset by surgical dislocation of the hip is effective and safe treatment of the femoroacetabular conflict with preservation of the rim.

Thirty-seven hips in thirty-four patients, mean age forty-one, underwent surgical dislocation of the hip with chondro-osteoplasty for the treatment of femoroacetabular impingement. At a mean follow-up of 2.1 years (2.0–4.0), the pre & post-operative outcome scores were for the: WOMAC 59.2 to 81.0 (p< 0.001), UCLA Hip Scores for pain 4.2 to 7.6;walking 7.3 to 8.6;function 6.2 to 8.1;activity level 4.3 to 6.9 (p< 0.05); and SF-12 physical 37.4 to 48.0 (p< 0.003) & mental 46.0 to 51.6 (p< 0.01). No hips have undergone further reconstructive surgery. Complications: one failure of fixation of the trochanteric osteotomy and one excision of bilateral ectopic ossification. No cases of osteonecrosis.

The purpose of our study was to evaluate the early clinical results and quality of life outcome after chondro-osteoplasty of the femoral head/neck junction for the treatment of femoroacetabular impingement.

An offset correction by surgical dislocation of the hip joint is a safe and an effective procedure in the treatment of femoroacetabular impingement commonly associated with labral tears.

Femoro acetabular impingement is a due to an absence of concavity at the anterolateral head neck junction associated with labral pathology. At short-term followup correction of the bony abnormality has improved functional outcome both from a disease-specific and health-related standpoint.

Thirty-seven hips (eighteen males; sixteen females) with persistent hip pain mean age forty-one (twenty-four to fifty-two) underwent 3-Dimensional CT of the pelvis and MR Arthrography prior to undergoing surgical dislocation with chondro-osteoplasty of the femoral head/neck junction. Preoperatively, the mean alpha angle of Notzli was 65.6(range, 42.0–95). At a mean follow-up of 2.1 years (2.0–4.0), the pre & post-operative outcome scores were for the: WOMAC 59.2 to 81.0 (p< 0.001), UCLA Hip Scores for pain 4.2 to 7.6;walking 7.3 to 8.6;function 6.2 to 8.1;activity level 4.3 to 6.9 (p< 0.05); and SF-12 physical 37.4 to 48.0 (p< 0.003) & mental 46.0 to 51.6 (p< 0.01). No hips have undergone further reconstructive surgery. Complications: one failure of fixation of the trochanteric osteotomy and one excision of bilateral ectopic ossification. No cases of osteonecrosis. Nine hips had removal of painful internal fixation.

Because the femoral head/neck junction is preserved in hip resurfacing, patients may be at greater risk of impingement, leading to abnormal wear patterns and pain. We assessed femoral head/neck offset in 63 hips undergoing metal-on-metal hip resurfacing and in 56 hips presenting with non-arthritic pain secondary to femoroacetabular impingement. Most hips undergoing resurfacing (57%; 36) had an offset ratio ≤ 0.15 pre-operatively and required greater correction of offset at operation than the rest of the group. In the non-arthritic hips the mean offset ratio was 0.137 (0.04 to 0.23), with the offset ratio correlating negatively to an increasing α angle. An offset ratio ≤ 0.15 had a 9.5-fold increased relative risk of having an α angle ≥ 50.5°. Most hips undergoing resurfacing have an abnormal femoral head/neck offset, which is best assessed in the sagittal plane.