Hip arthroscopy classically considers the articular space (central and peripheral compartments). However, the hip region has two more “compartments” that can be treated arthroscopically called “extra-articular compartments”: the trochanteric and gluteal compartments.
Surrounding the hip joint are powerful muscles. Two of the most important are the gluteus medius and the ischio-tibialis. The gluteus medius is the main abductor of the hip abductors and is essential for gait and pelvic balance, and damage to the gluteus medius is the main cause of Trendelenburg lameness. It inserts distally into the greater trochanter (lateral bony protrusion of the hip) in the form of a broad and narrow tendon. The ischiotibials are the muscle group of the posterior thigh (semitendinosus, semimembranosus and biceps femoris). They are bi-articular so they are responsible for hip and knee movements. Their proximal insertion is joint in the ischion (bony protrusion in the gluteal region – part of the hip bone). They are fundamental for hip extension and centering the femoral head in the acetabulum (very important in physical activity and sports).
Arthroscopy has revolutionized the treatment of tendon lesions of both the gluteus medius and the ischiotibia. Unlike the ischiotibials, tendon injuries of the gluteus medius are rarely traumatic or acute. They are mostly degenerative and inflammatory with chronic pain with episodes of aggravation. They occur in the trochanteric region, so they are often generically called “trochanteritis”. The misuse of this term has long led to these lesions being neglected, misdiagnosed and consequently mistreated. MRI is fundamental for the diagnosis and surgical planning of these lesions. It not only confirms the injury, but also assesses the quality of the tendon and the muscle atrophy and dystrophy (decisive factors in the potential recovery from the injury).
Arthroscopy of the trochanteric space allows the repair of ruptures in the tendon of the gluteus medius in a mini-invasive way (see hip arthroscopy). A repair (suture) is made from the tendon to the bone (to reattach the tendon to the bone) using devices called anchor sutures. Technically, small holes are made in the bone (in this case in the greater trochanter) where small “anchors” equipped with suture threads are implanted and passed through the tendon and “tied” against the bone.
The same is done in the gluteal compartment to repair proximal ischiotibial injuries (same technique as described but in this case they are fixed to the ischion). Proximal rupture/avulsion of the ischiotibials is an acute traumatic injury, frequent in sports (football, martial arts and athletics) and causing great disability (due to loss of muscle strength), pain and sometimes complications (neuropathic lesions due to stretching of the sciatic nerve) which compromise physical activity and sporting performance (see tendon ruptures). Timely and appropriate treatment is often decisive for these patients/athletes.
The era of hip arthroscopy has revolutionized not only the treatment of these injuries but also their assessment and diagnosis, as in the past they were underdiagnosed and therefore not treated properly.
For massive ruptures with significant retraction, open technique is necessary to locate the tendon stump, to release unwanted adhesions from the scar process and robustly reinsert the tendons to their bony bed.
