Date of Award

January 2021

Document Type

Thesis

Degree Name

Medical Doctor (MD)

Department

Medicine

First Advisor

Jonathan N. Grauer

Abstract

Previous studies have suggested inferior results of arthroscopic acetabular labral repair primarily in two groups of patients: (1) patients over forty years old and (2) patients with significant hip osteoarthritis (OA). Harvesting bone marrow aspirate concentrate (BMAC) from the body of the ilium at the time of hip arthroscopy and injecting it into the hip joint at the end of the arthroscopic procedure has been recently described as a technique to address cartilage lesions in the hip and is a technically and biologically feasible option that limits donor site morbidity. Two studies were performed to address the following questions: (1) what is the best treatment for patients older than 40 years old with symptomatic labral tears and limited radiographic OA, and (2) can BMAC improve outcomes of arthroscopic labral repair in patients with concomitant chondral lesions.

A single-surgeon randomized control trial (RCT) was conducted, in which patients over 40 years old with symptomatic labral tears and limited radiographic osteoarthritis (Tönnis grade 0-2) were randomized to arthroscopic surgery (acetabular labral repair) with postoperative physical therapy (SPT) or physical therapy alone (PTA). The primary outcomes were International Hip Outcome Tool (iHOT-33) and modified Harris Hip Score (mHHS) at 12 months after initiation of assigned treatment protocol. Primary analysis was performed on an intention-to-treat (ITT) basis using linear mixed-effect models. In this analysis, patients’ scores were attributed to the treatment to which they were initially randomized, even if they later crossed over to the other treatment arm. Given the limitations of ITT analyses in surgical RCTs with high crossover, a modified as-treated (mAT) analysis, which attributed crossover patients’ scores prior to crossover to PTA and scores after crossover to SPT, was performed.

To assess whether BMAC injection into the hip at the time of arthroscopic acetabular labral repair can improve functional outcomes in patients with labral tears and concomitant hip OA, a second study was performed in which prospectively collected patient-reported outcome measures (PROMs) from patients who underwent BMAC application during arthroscopic labral repair were retrospectively compared to a historical control cohort that did not receive BMAC.

The RCT enrolled 90 patients (mean ± 95% CI age: 49.4 ± 1.2 years), and 81 patients completed 12-month follow-up (42 SPT, 39 PTA). Twenty-eight of 44 PTA patients crossed over to SPT within the study period (63.6%). Intention-to-treat analysis revealed significantly greater 12-month iHOT-33 scores (+12.11; p=0.007) and mHHS scores (+6.99 points; p=0.04) in SPT than PTA. Modified as-treated analysis showed that these differences exceeded the minimal clinically important difference of 10.0 (SPT-PTA iHOT-33= +11.95; p=0.05) and 8.0 points (SPT-PTA mHHS= +9.76; p=0.04), respectively.

Patients treated with BMAC at the time of arthroscopic labral repair (n=62) reported similar postoperative PROMs to those treated without BMAC (n=62). Among patients with Outerbridge grade 2-3 OA, patients treated with BMAC reported significantly greater improvements in iHOT-33 at 12-months (37.0 ± 2.3 vs. 22.8 ± 3.8, p=0.002) and 24-months (40.8 ± 3.8 vs. 22.8 ± 3.9, p=0.010) than those treated without BMAC.

In patients over 40 years old with limited osteoarthritis and symptomatic labral tears, arthroscopic acetabular labral repair leads to better outcomes than physical therapy. Thus, age>40 years should not be considered a contraindication to arthroscopic acetabular labral repair. Additionally, patients with moderate OA undergoing arthroscopic acetabular labral repair may experience superior outcomes with concurrent BMAC application.

Comments

This thesis is restricted to Yale network users only. This thesis is permanently embargoed from public release.

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