Mid-term outcomes of arthroscopic-assisted Core decompression of Precollapse osteonecrosis of femoral head-minimum of 5 year follow-up

Abstract

Background: Osteonecrosis of the femoral head (ONFH) is a progressive disease that leads to collapse and the development of secondary arthritis. The preferred management of ONFH remains controversial. Arthroscopic-assisted management of ONFH is a new and evolving approach for hip preservation. We hypothesis that arthroscopy is able to improve ONFH outcomes by achieving accurate and minimally invasive decompression while successfully addressing concomitant intraarticular pathologies resulting in reliable mid-term outcomes.

Methods: This was a retrospective cohort analysis. All patients had atraumatic ONFH with a precollapse lesion and a minimum follow-up of 5 years.

Results: A total cohort of 11 hips (8 patients) was identified. The mean patient follow-up was 7 years ±1.48 years (range, 64-118 months). The Ficat-Alret classification found on preoperative imaging was Stage I-3 (27.2%), IIa-4 (36.4%), and IIb-4 (36.4%) hips. Four (36.4%) hips experienced mechanical issues, including locking, catching, and buckling. The most common concomitant pathology addressed at the time of arthroscopy, was labral repair/debridement-8 (73%), followed by microfracture-7 (64%). At final follow-up, 6 hips (54.5%) had not converted to THA. Upon further stratification, Stage I-100%, Stage IIa-75%, for a combined 87%, had not converted to THA, in contrast, 100% of hips categorized as Stage IIb had converted to THA. Ficat-Alret staging, especially Stage IIb, was significantly associated with conversion to THA. (p-value = 0.015) There were 0% major or minor complications.

Conclusions: To our knowledge, this is the longest reported follow-up of arthroscopic-assisted management of ONFH. Arthroscopic-assisted management is a promising surgical approach that provides safe, accurate, and minimally invasive decompression, resulting in reliable results with an acceptable conversion rate to THA.

Level of evidence: Level IV, Case Series.

Keywords: Core decompression; Femoral head preservation; Femoral head preserving; Hip arthroscopy; Mechanical symptoms; Mid-term follow-up; Mid-term outcomes; ONFH; Osteonecrosis; Osteonecrosis of the femoral head.

Fig. 1

a Preoperative plain AP X-ray of left hip demonstrating a Stage IIa osteonecrotic lesion. b MRI T1-weighted coronal image of left hip shows a geographic pattern of the necrotic area

Fig. 2

a Fluoroscopy AP of left hip demonstrating the positioning of the guide wire in the femoral head directed towards the necrotic area, while monitoring the femoral head cartilage by arthroscope to avoid articular cartilage penetration. b Fluoroscopy Lateral of left hip showing the positioning of the guide wire

Fig. 3

Plain AP pelvis X-ray at 5 years follow-up of a patient with a Stage IIa lesion of the left hip that shows preserved joint space without lesion progression

Fig. 4

Intraoperative arthroscopic image demonstrating flattening of femoral head. Arthroscopy functions diagnostically, by allowing for the precise assessment of the articular surfaces of both the femoral head and the acetabulum for accurate staging and evaluation

Fig. 5

Intraoperative arthroscopic image demonstrating treatment of chondral wear with microfracture of the acetabulum. Arthroscopy functions therapeutically for the entire hip joint, by treatment of concomitant intra-articular pathology, including: loose bodies, pincer lesions, cam lesions, synovitis, labral tears, and chondral defects