So I'm Anthony Celia from Seton Hall University in New Jersey, going to discuss deep gluteal space. Our disclosures are on the arthroscopy and AOS website. So sources of hip pathology, we think about in, you know, four separate locations, the pubic, more central area, core muscle injuries, typically cause pain in that area. Groin is your intra-articular pathology, lateral side of the hip, greater trochanteric pain syndrome and other pathologies in the lateral compartment. And posterior or buttock pain, we kind of refer to typically as deep gluteal space. So the deep gluteal space is essentially the area deep to and underneath the gluteus maximus, you can see the other borders here, and is defined by buttock pain that radiates down down to really the hamstring after prolonged sitting. The deep gluteal space pathology is associated more commonly in females, those with generalized ligamentous laxity and those with hip dysplasia. And essentially, this kind of extra spinal nerve entrapment may be due to multiple pathologies, typically, hamstring syndrome, piriformis syndrome, ischiofemoral impingement, post fracture abnormalities, and others. And we'll go through a couple cases here to highlight some of the more common deep gluteal space pathology you see in practice. So this case, a 50 year old male cyclist has sitting pain, again, with inability to sit longer than a half hour, tenderness in the sciatic notch and some lower extremity paresthesias. This physical exam maneuver was positive, you can see here, palpation lateral to the ischial tuberosity with forward flexion, internal rotational leg, as described by Dr. Hal Martin as the piriformis stress test, piriformis stretch test. Here you see an EMG report with some abnormality in the tibial division of the sciatic nerve. So our differential, thinking about lateral side and posterior, you know, posterior hip pain, deep gluteal space syndrome, as well as spinal type causes. So although there's a pretty broad differential, this case, due to the physical exam and EMG report, and we'll talk about some diagnostic injections as well, is piriformis syndrome in this patient. So it's really the proximity of the piriformis to the sciatic nerve that essentially causes compression of the nerve and the abnormal nerve pathology, as well as pain in the buttock. The physical therapy treatments are the mainstay of treatment for this, and then we try to avoid surgical management of this as much as possible. And you can see this piriformis stretching, foam rolling, core strengthening, stabilization of the lumbar sacral spine is hopefully the definitive treatment. However, non-surgical management can be expanded into injections, into the piriformis, into the tendon sheath, and you can see it there in the arthrogram localization. But now mostly we typically would do ultrasound guided injections for this. Surgical release is indicated with an extensive, at least six months, in my practice, usually longer, of conservative management of piriformis syndrome diagnosed on a combination of physical exam, history, dynamic testing, ultrasound guided injections with temporary relief of symptoms. And in these severe cases, surgical treatment with release, either open or arthroscopic, can be utilized. Arthroscopic, the advantage is smaller incisions, less dissection, and in my opinion, better visualization, although that may be contradictory to our slide here. But I think, you know, arthroscopically, you can kind of get a wider field of view with less dissection and see the sciatic nerve and associated structures. So our way that we publish in arthroscopy techniques is in the lateral position. You can see here the landmarks. It can also be well done as described by Dr. Hal Martin in the supine position with the internal rotation of the leg. My preference is to approach these now through a posterior approach with the table jackknifed because that way allows me to have access to other structures. Typically, these patients with deep glial space syndrome have multiple pathologies such as hamstring issues as well as the piriformis. So you kind of see the three posterior portals and the two arrows indicate lateral and distal. The posterior lateral, the white arrow, and accessory posterior lateral portal which can be utilized to access the piriformis. So here you see the bursa over the piriformis insertion on the posterior aspect of the trochanter. And as we move distally, you see the sciatic nerve that we would bluntly dissect either with a switching stick or the back of a full radius shaver, avoiding any damage and also proximity with the ablation device. Here we release the tendinous portion of the piriformis off of the fossa and allow that to decrease the stress on the sciatic nerve indirectly. So performing both a direct decompression as well as interact through a piriformis release of the tendinous portion. You can see here of concern especially with your accessory posterior lateral portal that the inferior gluteal artery may be at risk as well as obviously the sciatic nerve which you're going to identify in your surgical fields. There's been some outcome studies on this with with reasonable improvement and modified Harris-Hipps scores and pain scores. However, you know, in my opinion, the, you know, the outcomes are not always perfect with this and they're typically maybe other, you know, spinal causes of pathology and nerve, you know, improvement in nerve function may be slightly variable. So indications are important here. The second case is a 42-year-old female figure skater with hip and buttock pain, worse with skating and longer stride walking, does radiate into the thigh, has a snapping type sensation, has had a previous history of spine surgery. The typical physical exam is normal. She shows us this maneuver does cause the snapping and pain. You can see her radiographs are fairly normal, no labral tear. So again, our differential is pretty wide. This physical exam maneuver with extension in neutral position causes pain and with abduction, it relieves that those symptoms that were reproduced with extension neutral position. So you can see here the narrowing of the issue femoral space on the MRI. And here you can see some articles that more define this and the quadratus narrowing in the space between the lesser and the pelvis. So this is an issue of femoral impingement, which causes pathology to the quadratus femoris and the sciatic nerve. Conservative treatment is to train the athlete to avoid this impingement and kind of improve their pelvic mechanics, core muscle strengthening, stretching, and modifications. Ultrasound guided injections can be helpful in that period where physical therapy is hopefully improving their mechanics. You can see the sciatic nerve here and the quadratus. Injection outcomes, short-term improvement in symptoms shown by multiple studies. However, in refractory cases, surgical management can be considered. So again, this picture shown here from Dr. Martin's work in the supine position, this area can be accessed. Again, my preference for deep glial space is through these five portals where the posterior lateral and posterior lateral accessory portals can be used to localize the lesser trochanter. The medial femoral circumflex shown here is of great importance to avoid. I will typically use image transpire to bluntly dissect directly over the lesser and confirm appropriate position. Here you see the sciatic nerve and quadratus. And in this arthroscopic video here, we are splitting the quadratus directly over the lesser to avoid the vasculature, first perforator, distally, and medial femoral circumflex approximately. So that will allow some protection if you get the appropriate window and localize it under image intensifier. And then essentially can utilize a burr to coplane the lesser as you would in a typical acromioplasty. Important to remove the bony debris and use heterotopic ossification prophylaxis postoperatively with NSAIDs. Here you see our intra-op fluoro and three-month post-op x-ray there showing decompression of the lesser trochanter. Post-operative protocol, as I mentioned, we would use NSAIDs for HO prophylaxis. I don't typically use any bracing, but would avoid resisted hip flexion and isolation of the psoas. Surgical outcomes are, again, variable, but Dr. Martin has shown good results in his series improvement function. So important to realize that there's kind of no way to really decompress it without affecting the psoas footprint to some degree. So important to counsel a patient preoperatively. Hip flexion weakness, they'll certainly notice. I've had typically improvement in that to where patients don't have significant appreciable weakness, although you may notice some on physical exam in the long term. So in conclusion, deep gluteal space syndrome is defined as sciatic nerve dysfunction due to entrapment in this deep gluteal space under the gluteus maximus. Physical exam and diagnostic injections are very helpful to isolate the diagnosis. EMG MRI testing may be normal, but potentially helpful and should be obtained in most cases, certainly in MRI in every case. Ruling out other causes of symptoms is extremely important because most commonly sciatic nerve issues are due to issues with the spine. So having your spine colleagues evaluate these patients thoroughly. Conservative management is the mainstay of treatment with rehabilitation and guided injections, but arthroscopy has been shown to be successful in select cases. Here are some references and thank you for your time.

deep gluteal space pathology

buttock pain

hamstring syndrome

piriformis syndrome

ischiofemoral impingement