The ligamentum teres is a strong structure of the hip joint. Even today, however, its precise biomechanical role has not been clarified. There are many studies which emphasise the substantial contribution of the ligamentum teres to the stability of the joint. There is also the counter-argument, however, that the ligament has little functional action and is simply an anatomical remnant.
Nevertheless, a partial or complete tear of the ligamentum teres is a not uncommon finding at hip arthroscopy in patients with femoroacetabular impingement of the cam or pincer type and an accompanying tear of the labrum of the acetabulum. In these cases the gold standard for treatment is debridement, while a newly reported technique is reconstruction of the ligament with a tendon graft.
A new study has provided fresh information on the contribution of the ligamentum teres to the hip joint. This study set out to compare the patient-reported outcomes of patients with femoroacetabular impingement, a tear of the acetabular labrum and a complete tear of the ligamentum teres against a control group with an intact ligamentum teres, and also to report the relative risk of the need for total hip arthroplasty in these patients.
Data were collected retrospectively between February 2008 and April 2015. Data were used from patients who had a complete tear of the ligamentum teres, tears of the acetabular labrum and femoroacetabular impingement, and who were assessed for at least two years with the hip outcome scores Modified Harris Hip Score, Non Arthritic Hip score, Hip Outcome Score –Sport specific Subscale, International Hip Outcome tool-12 and Visual Analog Scale. The patients excluded from the study were those with hip osteoarthritis of a grade greater than 1 on the Tonnis classification, previous pathological conditions of the hip and previous surgical procedures.
In all, 18 patients with a minimum follow-up of two years were studied, and each patient case was matched with three control patients, creating a ratio of 18 to 54 patients. The hip outcome scores showed significant improvement in the group with a complete tear of the ligamentum teres, with the exception of the Hip Outcome Score –Sport specific Subscale. In the group with an intact ligamentum teres all the outcome scores improved without exception. It was also observed that the group of patients with a complete tear of the ligamentum teres was three times more likely to require a total hip arthroplasty in the future than the control group.
The authors concluded that after hip arthroscopy the patients with femoroacetabular impingement and a complete tear of the ligamentum teres reported significant improvement in the hip outcome scores. However, the patients with a complete tear of the ligamentum teres were three times more likely to need an eventual total hip arthroplasty in the future. Patients with a complete tear of the ligamentum teres should be considered a group at risk for total hip arthroplasty.
Source: Arthroscopy, January 2019
