Patients With Lateral and Anterolateral Cam Morphology Have Greater Deformities Versus Typical Anterolateral Deformity Alone but No Differences in Postoperative Outcomes: A Propensity-Matched Analysis at Minimum 5-Year Follow-Up

Jordan H Larson; Reagan S Chapman; Sachin Allahabadi; Daniel J Kaplan; Kyleen Jan; Omair Kazi; Onur Hapa; Shane J Nho

doi:10.1016/j.arthro.2024.03.020

Patients With Lateral and Anterolateral Cam Morphology Have Greater Deformities Versus Typical Anterolateral Deformity Alone but No Differences in Postoperative Outcomes: A Propensity-Matched Analysis at Minimum 5-Year Follow-Up

Arthroscopy. 2024 Mar 21:S0749-8063(24)00242-1. doi: 10.1016/j.arthro.2024.03.020. Online ahead of print.

Authors

Jordan H Larson¹, Reagan S Chapman¹, Sachin Allahabadi², Daniel J Kaplan³, Kyleen Jan¹, Omair Kazi⁴, Onur Hapa⁵, Shane J Nho¹

Affiliations

¹ Section of Young Adult Hip Surgery, Division of Sports Medicine, Department of Orthopedic Surgery, Rush Medical College of Rush University, Rush University Medical Center, Chicago, Illinois, U.S.A.
² Department of Orthopedic Surgery, Houston Methodist, Houston, Texas, U.S.A.
³ Department of Orthopedic Surgery, New York University Langone Orthopedic Hospital, New York, New York, U.S.A.
⁴ Section of Young Adult Hip Surgery, Division of Sports Medicine, Department of Orthopedic Surgery, Rush Medical College of Rush University, Rush University Medical Center, Chicago, Illinois, U.S.A.. Electronic address: nho.research@rushortho.com.
⁵ Department of Orthopedics and Traumatology, Dokuz Eylül University; Balçova, Izmir, Turkey.

PMID: 38521208
DOI: 10.1016/j.arthro.2024.03.020

Abstract

Purpose: To compare pre- and postoperative findings between patients undergoing hip arthroscopy for femoroacetabular impingement syndrome with lateral impingement versus those without lateral impingement METHODS: Patients who underwent primary hip arthroscopy for femoroacetabular impingement syndrome between 2012 and 2017 with minimum 5-year follow-up were included. Alpha angle (AA) was measured on preoperative anteroposterior (AP) and 90° Dunn radiographs. Patients with AA >60° on Dunn view but not AP view (no lateral impingement) were propensity matched by sex, age, and body mass index in a 1:3 ratio to patients with AA >60° on both views (lateral impingement). Demographic characteristics, radiographic and intraoperative findings, reoperation rates, and patient-reported outcomes (PROs) were compared between groups. Categorical variables were compared using the Fisher exact testing and continuous variable using 2-tailed Student t tests.

Results: Sixty patients with lateral impingement (65.0% female, age: 35.3 ± 13.0 years) were matched to 180 patients without lateral impingement (65.0% female, age: 34.7 ± 12.5 years, P ≥ .279). Patients with lateral impingement had larger preoperative AAs on both Dunn (71.0° ± 8.8° vs 67.6° ± 6.1°, P = .001) and AP radiographs (79.0° ± 12.1° vs 48.2° ± 6.5°, P < .001). However, there were no differences in postoperative AAs on either view (Dunn: 39.0° ± 6.1° vs 40.5° ± 5.3°, AP: 45.8° ± 9.0° vs 44.9° ± 7.0°, P ≥ .074). Labral tears began more superiorly in patients with lateral impingement (12:00 ± 0:49 vs 12:17 ± 0:41, P = .030), and they demonstrated greater rates of acetabular and femoral cartilage damage (P = .030 for both); however, there were no differences in PROs or reoperation rates between the groups at 5-year follow-up.

Conclusions: Although cam deformities located laterally and anterolaterally are larger than those located anterolaterally alone, both can be resected adequately, resulting in similar postoperative radiographic measurements, PROs, and survivorship.

Level of evidence: Level III, retrospective cohort study.