Hip Joint Capsular Anatomy, Mechanics, and Surgical Management

Abstract

ä Hip joint capsular ligaments (iliofemoral, ischiofemoral, and pubofemoral) play a predominant role in functional mobility and joint stability. ä The zona orbicularis resists joint distraction (during neutral positions), and its aperture mechanism stabilizes the hip from adverse edge-loading (during extreme hip flexion-extension). ä To preserve joint function and stability, it is important to minimize capsulotomy size and avoid disrupting the zona orbicularis, preserve the femoral head size and neck length, and only repair when or as necessary without altering capsular tensions. ä It is not fully understood what the role of capsular tightness is in patients who have cam femoroacetabular impingement and if partial capsular release could be beneficial and/or therapeutic. ä During arthroplasty surgery, a femoral head implant that is nearly equivalent to the native head size with an optimal neck-length offset can optimize capsular tension and decrease dislocation risk where an intact posterior hip capsule plays a critical role in maintaining hip stability. Characteristics Anatomy Human ligaments consist of predominantly type-I collagen (85%) and combinations of type III, V, VI, XI, and XIV (15%) 21,22. Within the hip joint, higher ratios of type-III collagen in the ligamentous capsule are associated with hip instability 23,24 , whereas elevated levels in the cartilage are associated with Disclosure: The authors indicated grant support from the Engineering and Physical Sciences Research Council (EPSRC) (EP/K027549/1 and EP/ N006267/1) and the Wellcome Trust (088844/Z/09/Z), during the conduct of the study. On the Disclosure of Potential Conflicts of Interest forms, which are provided with the online version of the article, one or more of the authors checked "yes" to indicate that the author had a relevant financial relationship in the biomedical arena outside the submitted work (http://links.lww.com/JBJS/F511).

Arthroscopic Triple Reconstruction in the Hip Joint: Restoration of Soft-Tissue Stabilizers in Revision Surgery for Gross Instability

“…Gross instability in a non-dysplastic hip is either post-traumatic or, more often, iatrogenic from prior arthroscopy 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 with disruption of the soft-tissue stabilizers. 1 , 2 , 3 While commenting on iatrogenic instability, Byrd 11 identified 6 contributing factors. The patient may have all of these factors, placing him or her at increased risk of complex hip instability.…”

“…The primary stabilizers of the hip joint are the capsuloligamentous structures, whereas the labrum and the LT act as secondary stabilizers. 1 , 2 , 3 The hip joint labrum has proprioceptive and nociceptive functions and aids in load distribution. The aim of the different hip labral restoration techniques—repair, augmentation, or reconstruction 34 , 35 , 36 —is to help maintain intra-articular fluid pressurization.…”

“…Gross hip instability in an active adult with previous normal hip anatomy is usually due to disruption of the primary and secondary stabilizers of the hip joint. 1 , 2 , 3 Although such a disruption can result from a high-grade injury, it can be iatrogenic after previous hip arthroscopy. 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 The patient usually presents with a painful limp and recurrent subluxation of the affected hip that may result in frequent falls.…”

Arthroscopic Treatment of Hip Dislocation After Previous Hip Arthroscopy: Capsular Reconstruction With Labral Augmentation

“… 5 Magnetic resonance arthrogram effectively shows soft-tissue pathology in patients postoperative hip arthroscopy and can be used to identify capsular defects ( Fig 1 ). 6 , 7 …”

“…5 Magnetic resonance arthrogram effectively shows soft-tissue pathology in patients postoperative hip arthroscopy and can be used to identify capsular defects (Fig 1). 6,7 The labrum also plays an essential role in the normal function of the hip. It stabilizes the hip joint, increases the depth of the acetabulum, creates a suction seal that aids with synovial fluid lubrication, and preserves the articular cartilage of the hip.…”