Clinical Outcomes for the Treatment of Amorphous Calcification of the Labrum during Hip Arthroscopy with Minimum Two-Year Follow-Up

Background: Calcifications have been documented throughout the human body after repetitive trauma and/or degeneration. Amorphous calcifications (AC) of the hip are uncommon entities, and their etiology and outcomes after treatment remain unclear.

Purpose: This study’s purpose was to evaluate clinical outcomes, satisfaction, demographics, and radiographic findings for patients whose hip arthroscopies involved AC excision accompanied by labral and/or femoroacetabular impingement (FAI) treatment.

Methods: We reviewed 12 patients who underwent primary hip arthroscopy involving surgical excision of AC deposit in the antero-superior labral-capsular recess between October 2008 and July 2013. Demographics, radiographic findings, intra-operative findings, and procedures were reviewed. Minimum follow-up was two years and included visual analog scale (VAS) for pain, patient satisfaction, and the following patient reported outcome (PRO) scores: modified Harris hip score (mHHS), Hip Outcomes Score Sport-Specific Subscale (HOS-SSS) and Non-Arthritic Hip Score (NAHS).

Results: The cohort included 12 females with mean age of 39.9, and mean follow-up time of 39 (24–72) months. Survivorship rate was 92%, with one hip converting to total hip replacement after two years. Significant improvements from pre-operative to two-year post-operative PRO scores were found in NAHS (20.2), HOS-SSS (29.1), and VAS (-3.1). While mHHS improved, it was not found to be statistically significant. Eight of 11 patients (72.7%) had satisfaction≥7. Post-operative radiographic findings showed no subsequent AC in all 12 hips. There were no complications and no revisions were reported. Two of 11 (18.2%) patients had histories of hypothyroidism at the time of surgery, which was found to be significantly different (p=0.03) compared to a large census (4.6%).

Conclusions: The treatment of AC as a part of hip arthroscopy procedures demonstrates significant improvements in PROs and VAS at minimum two-year follow-up post-operatively. Hypothyroidism may be a risk factor for the development of AC, and this relationship should be further investigated.