It's not arthritis! Resolution of the illusion of joint space narrowing with acetabuloplasty and labral reconstruction for the calcified labrum.

Labral calcification may be part of the natural history of untreated femoroacetabular impingement syndrome (FAIS) in certain patients, making it a potential target for intervention with the goal of preserving the hip joint. The purpose of this study was to investigate if calcified labra create the appearance of lateral joint space narrowing and report minimum 2-year patient-reported outcome measures (PROMs) after treating patients with arthroscopic acetabuloplasty and labral reconstruction. Prospectively collected data on patients who underwent primary hip arthroscopy for FAIS and labral tearing from February 2015 to April 2021 were reviewed. Patients treated with primary labral reconstruction for an intraoperatively confirmed diagnosis of labral calcification were included. A sub-analysis was performed for patients with a minimum of 2-year follow-up. Preoperative and postoperative PROMs for the modified Harris hip score, nonarthritic hip score, the International Hip Outcome Tool-12 and visual analog scale for pain were recorded. Forty-six hips (46 patients) were included, with 19 hips in the sub-analysis. There was a significant increase in apparent lateral joint space width (JSW) measured on supine anteroposterior (AP) pelvis radiographs with no significant changes in medial and central JSW and significant decreases in the lateral and anterior center-edge angles and alpha angle. Patients experienced significant increases in PROMs and high rates of achieving psychometric thresholds. Patients presenting with FAIS and calcified labra may have apparent lateral joint space narrowing on pre-operative supine AP pelvis radiographs. These patients have low rates of full-thickness femoral head and acetabular cartilage pathology, this apparent narrowing can be corrected and excellent outcomes and survivorship can be achieved, with primary labral reconstruction.