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Greater Trochanteric Pain Syndrome: An Intraoperative Endoscopic Classification System with Pearls to Surgical Techniques and Rehabilitation Protocols

Over the past decade, understanding of disorders compromising greater trochanteric pain syndrome (GTPS) has increased dramatically. Nonsurgical treatment options include physical rehabilitation and activity modification, anti-inflammatory as well as biologic injections into the peritrochanteric compartment, and administration of oral analgesics. Multiple open and endoscopic treatment options exist when nonsurgical management is unsuccessful in patients with refractory lateral-sided hip pain, with or without weakness. No true consensus exists within the literature regarding operative techniques of GTPS or postoperative rehabilitation protocols. We present an endoscopic classification system of GTPS with 5 distinct types, which seems to correlate well with preoperative diagnoses and postoperative rehabilitation protocols. The classification system is intuitive, and the corresponding surgical techniques are reproducible for surgeons treating peritrochanteric pathology. Level of Evidence: I (hip); II (extra-articular, impingement).

H istorically, patients with lateral-sided hip pain have been diagnosed with trochanteric bursitis and treated with physical therapy, nonsteroidal antiinflammatory drugs, and corticosteroid injections. [1][2][3][4][5][6] Advancements in magnetic resonance imaging (MRI) as well as experience with hip arthroscopy have led to an improved understanding of peritrochanteric pain etiology and its management. [7][8][9][10][11][12] Greater trochanteric pain syndrome (GTPS) has expanded to include disorders of the peritrochanteric space encompassing trochanteric bursitis, gluteus medius and minimus tendinopathy or tears, and external coxa saltans (i.e. snapping hip). 1,4 Affecting 10% to 25% of the general population, 4 and frequently reported with pain and tenderness in the low back, buttocks, or lateral thigh, GTPS is often a difficult entity to diagnose for musculoskeletal clinicians practicing without an index of suspicion for peritrochanteric pathology. 13 Delay in diagnosis has been shown to lead to significant delays in management for this patient population. 14 Furthermore, once the diagnosis is made, there is a paucity of literature and lack of consensus detailing criteria for intraoperative management or postoperative rehabilitation protocols that may predict optimal patient-reported outcomes.
The purpose of this article is to provide an overview of anatomy, discuss relevant diagnostic workups, introduce an intraoperative GTPS endoscopic classification system with 5 distinct types, and describe detailed surgical techniques for each type. Additionally, we provide postoperative rehabilitation protocols that correspond to surgical management.

Anatomy
The anatomy of the peritrochanteric space has been well described in multiple previous reports. 1,13,15 The largest of the 3 main bursae, the subgluteus maximus, also known as the trochanteric bursa, is depicted in Figure 1. 9 The peritrochanteric space contains insertional footprints of the gluteus medius and gluteus minimus on the superoposterior and anterior greater trochanteric facets, respectively.

Diagnostic Workup
A thorough history and physical examination is necessary to diagnose GTPS. Clinical examination includes inspection of the peritrochanteric musculature, looking for signs of atrophy or neuromuscular weakness. Palpation for tenderness and measures of abductor strength should be performed routinely. Single-legged stance and Trendelenburg gait assess gait patterns and the flexion, abduction, and external rotation (FABER) and Ober tests look for signs of discomfort. 9,16,17 Preoperative physical examination variables should include greater trochanter (GT) tenderness (none, 1þ, 2þ), Trendelenburg gait (yes/ no), and abductor strength (scale 0 to 5).
The most common imaging modalities used in the evaluation for GTPS are plain radiography, ultrasonography, and MRI, with MRI as the primary means of evaluating a patient for GTPS. 1,8,12 Surgical Technique The surgical technique for steps 1 to 11 are shown in Video 1.

Patient and Room Setup
1. Preoperative preparation begins with general anesthesia, with the patient positioned supine on an arthroscopic traction table with a well-padded perineal post. The following surgical instruments should be available during this case: 70 arthroscope, three 8.25 Â 9-mm twist-in cannulas (Arthrex, Naples, FL), epinephrine (1 mg/3 L bag of fluid), 30 bird beak suture passer (Arthrex), and suture retriever (Arthrex). 2. The leg is placed in 15 to 30 of abduction to relax the iliotibial (IT) band and allow for working space in the peritrochanteric compartment. 3. Intraoperative fluoroscopy is used with the C-arm entering the surgical field from the contralateral side. The image is centered over the GT (Fig 2). Diagnostic Endoscopy of the Peritrochanteric Space 5. Initial access to the peritrochanteric space is done through the DALA portal under fluoroscopic guidance with the image intensifier centered over the GT. 6. A 5.0-mm hip access cannula (Arthrex) is brought into the peritrochanteric space between the interval of the sartorius and tensor fascia lata. 7. Visualization of the shiny white vastus lateralis fascia confirms appropriate scope position. 8. The AL portal is created (or accessed), and a shaver is introduced anterior to the IT band. 9. Thorough trochanteric bursectomy is completed in every case to a) relieve symptomatic trochanteric bursitis and b) allow for visualization of the abductor complex. 10. With a probe, diagnostic endoscopy assesses the abductor complex, including superficial tendon tears and undersurface delamination, gluteus maximus tendon insertion, and undersurface of the IT band. 11. If injury to the abductor complex is identified, the surgeon should reference the presented GTPS endoscopic classification system (

GTPS Classification System
An underlying theme of our GTPS classification system is use of endoscopic diagnosis to guide management. Although multiple previous studies have shown good correlation with preoperative imaging and intraoperative findings in refractory GTPS, little consensus exists as to what to do with these findings. 9,18,19 As such, proper surgical indications and management are of utmost importance to optimize postoperative patient outcomes. In this section and in Table 1, we present the classification types, and respective subtypes, in increasing level of severity. Intraoperative findings ranging from isolated trochanteric bursitis to fullthickness abductor tendon tears with severe retraction will be discussed with corresponding preoperative

Diagnosis: GTPS Type 1
Endoscopically, GTPS type I consists of isolated trochanteric bursitis without evidence of abductor injury. Clinically, preoperative physical examination consists of tenderness to palpation over the peritrochanteric space. MRI findings are consistent with trochanteric bursitis. Recommended surgical management consists of endoscopic trochanteric bursectomy.

Surgical Technique: Endoscopic Bursectomy
The 70 arthroscope is inserted into the peritrochanteric space through the DALA portal. Aiming just inferior to the vastus ridge under fluoroscopic visualization allows the surgeon to avoid iatrogenic damage to the gluteus medius insertion (Fig 3A). An arthroscopic shaver is then introduced through the AL portal, and trochanteric bursectomy with debridement is performed. The entire peritrochanteric space is examined, including the gluteus medius and maximus insertions, for signs of tearing or injury. A probe must be used to confirm tendon stability and to rule out undersurface tendon delamination injuries ( Fig 3B).

Rehabilitation Protocol
20-lb flat-foot weightbearing restriction for 2 weeks Hip brace (Donjoy X-Act ROM Hip Brace; DJO Global, Vista, CA) to be worn for 2 weeks Rehabilitation to begin the day after surgery.

Diagnosis: GTPS Type II
GTPS type II consists of trochanteric bursitis and surface fraying of the gluteus medius or gluteus minimus tendons, respectively. Clinically, preoperative physical examination is consistent with tenderness to palpation over the peritrochanteric space with maintained abductor strength. MRI findings typically show insertional tendinosis of the gluteus medius or gluteus minimus tendons in addition to subgluteal inflammation. Recommended surgical management consists of endoscopic trochanteric bursectomy with trochanteric micropuncture. 1,4,8 Surgical Technique: Endoscopic Trochanteric Micropuncture A 70 arthroscope is used to view the peritrochanteric space through the DALA portal, and a 45 microfracture awl is introduced through the 8.25-mm cannula within the PL portal ( Fig 4A). The limb can be rotated internally and externally to provide better access to the trochanteric region. To stimulate healing, a microfracture awl is used to create multiple holes within the lateral facet of the GT through the diseased gluteus medius tendon ( Fig 4B). The awl is driven to a depth of 3 to 5 mm with a light mallet.

Rehabilitation Protocol
20-lb flat-foot weightbearing restriction for 2 weeks Hip brace to be worn for 2 weeks Rehabilitation to begin the day after surgery.

Diagnosis: GTPS Type IIIA
GTPS type IIIA consists of a partial-thickness (<25%) tear of the gluteus medius or gluteus minimus undersurface attachments to the lateral facet, indicated by Viewing with a 70 arthroscope through the DALA portal, the gluteus medius insertion is probed and confirmed to be partially destabilized on its undersurface from its attachment to the lateral facet. A trochanteric micropuncture is completed before anchor placement, as previously described. 20 This sequence of surgical steps helps prevent poor anchor fixation. Next, a metal punch is introduced into the trochanteric facet, followed by placement of at least 1 pair of PEEK 3.0-mm Knotless SutureTak anchors (Arthrex). Care is taken to internally rotate the extremity while placing the posterior anchor and to maintain a neutral limb when placing the anterior anchor. The repair suture from each anchor is shuttled through the adjacent anchor looped shuttle stitch (A to B and B to A), to create a horizontal mattress suture staple configuration ( Fig 5B). This technique allows for excellent compression of the tendon over the lateral facet ( Fig 5C).

Rehabilitation Protocol
20-lb flat-foot weightbearing restriction for 2 weeks Hip brace to be worn for 2 weeks Rehabilitation to begin the day after surgery.

Diagnosis: GTPS Type IIIB
GTPS type IIIB consists of a partial-thickness (>25%) tear of the gluteus medius or gluteus minimus lateral facet insertion sites, confirmed by direct visualization of injured tendon and destabilization of footprint when probed. Clinically, preoperative physical examination is consistent with moderate abductor weakness. MRI findings are consistent with high-grade partial-thickness tearing of the gluteus medius or gluteus minimus tendinous footprints with associated subgluteal bursal inflammation. Recommended surgical management consists of diseased gluteus medius or minimus tendon debridement followed by tendon repair using the endoscopic transtendinous technique. 22 Surgical Technique: Endoscopic Gluteus Medius Repair, Transtendinous Technique Viewing with a 70 arthroscope through the DALA portal, after completing a trochanteric bursectomy and diseased tendinous debridement, a thorough diagnostic endoscopic examination of the peritrochanteric space is done. All structures are evaluated and probed, including the gluteus maximus, vastus lateralis, IT band, and torn gluteus medius. A beaver blade is inserted through a cannula within the AL portal, and a longitudinal split is made within the midsubstance of the gluteus medius tendon, along the lateral facet adjacent to the injured undersurface tissue (Fig 6A,B). The arthroscope is then inserted through this split within the gluteus medius bursal space, and undersurface tear of the diseased, pathologic tendon is viewed in its entirety. Torn fibers identified on the deep side of the gluteus medius tendon are debrided with a shaver positioned within this AL portal, exposing the lateral facet of the GT. The lateral facet is then decorticated with an arthroscopic burr to create a bleeding bed of bone for healing. Via the accessory PL portal, a doubleloaded 5.5-mm PEEK Corkscrew anchor (Arthrex) is placed through the tendon split in the distal part of the lateral facet footprint (Fig 6C). Next, a Birdbeak grasper (Arthrex) is used to pass 1 limb of each suture through the anterior and posterior tendon leaflets (Fig 6D). Both sets of sutures are then tied using an arthroscopic knot pusher. This technique results in debridement of nonviable tissue, side-to-side repair of the longitudinal tendon split, and firm approximation of the tendon to the footprint along the lateral facet (Fig 6E).

Rehabilitation Protocol
20-lb flat-foot weightbearing restriction for 6 weeks Hip brace to be worn for 6 weeks Rehabilitation to begin at 6 weeks postoperatively.

Diagnosis: GTPS Type IV
GTPS type IV consists of a full-thickness gluteus medius tear without significant retraction. Clinically, preoperative physical examination is consistent with moderate abductor weakness and often positive Trendelenburg testing, either weakness with single leg stance or gait pattern. MRI findings are consistent with a full-thickness gluteus medius tear pattern, possible tendon retraction, and moderate subgluteal bursal inflammation. Recommended surgical management consists of endoscopic versus open gluteus medius repair with double-row configuration. 23 Surgical Technique: Endoscopic Gluteus Medius Repair, Full-Thickness Technique The sequence of repair for full-thickness tendon tears is similar to partial-thickness repairs; however, a double-row suture anchor configuration is used. After entry in the peritrochanteric space, a 70 arthroscope is placed within the DALA portal for visualization (Fig 7A,B). After a thorough bursectomy is completed, a probe is inserted through the AL portal to palpate the gluteus medius tendon footprint. When a full-thickness tear is confirmed and deemed amenable to endoscopic repair, diseased tendon is debrided, and the lateral facet is decorticated using an arthroscopic burr to create a bleeding bed of bone in preparation for suture anchor placement. The tendon repair is then performed with a double-row construct. Two versus 3 double-loaded SwiveLock suture anchors (Arthrex) are placed within the lateral facet proximally via access through the AL and PL portals, respectively. Of note, during placement of anterior anchors, single-or double-row technique, the foot should maintain in neutral rotation. When placing posteriorly based anchors, the lower extremity can be rotated internally, thereby providing better access to the trochanteric footprint ( Fig 7C). Additionally, this position aids in directing the implant target away from the sciatic nerve, which lies posterior to the GT. Suture pairs are then passed in a horizontal mattress configuration through the debrided end of tendon using a Birdbeak passer (Arthrex) as seen in Figure 7D. Next, 4 versus 6 corresponding knots are tied with an arthroscopic knot pusher. A single limb of each proximal row suture anchor knot is then passed into 2 versus 3 additional knotless SwiveLock (Arthrex) suture anchors within the distal row. This completes a crisscross, suture-bridge configuration that provides added compression of the tendon against bone (Fig 7E,F).
Of note, when the tendinous injury is not amenable to endoscopic repair, the open double-row repair technique is used, as seen in Figure 8. A standard posterolateral approach to the left hip is performed with the patient in the lateral decubitus position. An incision is carried through the subcutaneous tissues to identify the fascia lata, which is incised in line with the GT distally and curved posteriorly. Blunt dissection of gluteus maximus fibers is completed. A trochanteric bursectomy is performed with electrocautery, removing inflamed tissue and providing excellent exposure of the gluteus medius tendon. Scar tissue from around the tendon stump is debrided sharply, and the healthyappearing tendon is defined. The area of the GT is decorticated with a handheld burr to create a bleeding bed of bone for tendon healing (Fig 8A). As previously described, a double-row suture bridge construct is created, first by placing double-versus triple-loaded corkscrew (Arthrex) suture anchors within the proximal aspect of the greater trochanteric footprint (Fig 8B). Next, corresponding suture limbs are passed through the tendon in horizontal mattress configuration and tied to complete fixation ( Fig 8C). Next, a single limb from each proximal row knot is loaded distally into 2 versus 3 additional knotless SwiveLock anchors (Arthrex), completing double-row fixation (Fig 8D). Excellent repair construct is created in this fashion and reinforced with #1 Vicryl sutures through the tendon repair.

Rehabilitation Protocol
20-lb flat-foot weightbearing restriction for 8 weeks Hip brace to be worn for 8 weeks Rehabilitation to begin at 6 weeks postoperatively.

Diagnosis: GTPS Type V
GTPS type V consists of thickened inflammatory bursitis and full-thickness gluteus medius tear with significant retraction. Preoperative physical examination is typically consistent with severe abductor weakness and positive Trendelenburg testing, or even inability to ambulate without assistance. MRI findings are often consistent with a retracted, irreparable, fullthickness abductor tear pattern and significant subgluteal inflammation or edema due to increased Surgical Technique: Open Gluteus Maximus and Tensor Fascia Lata Transfer As previously described, a standard posterolateral approach to the hip is performed. At the level of the fascia lata, an incision made in line with the GT distally is curved sharply in the posterior direction, separating the anterior two-thirds of the gluteus maximus, along with its insertion on the fascia lata, and IT band from the posterior one-third. A plane is then developed between the IT band and the gluteus medius. In this manner, the entire IT band and fascia lata are separated from the gluteus medius and preserved for later gluteus maximus transfer. The gluteus medius is then closely inspected and often is found to have severe retraction, up to 4 to 5 cm, with severe atrophy ( Fig  9A). An attempt to repair the gluteus medius can be undertaken as described in the aforementioned open repair technique. To augment difficult repairs, or in cases of irreparable injury because of poor tissue quality and retraction, the gluteus maximus and tensor fascia lata transfer may be used. The anterior third of the gluteus maximus is then separated from the posterior two-thirds, and this triangular flap is transferred to the GT, recreating the abductor mechanism (Fig 9B). This is secured to the GT with 3 double-loaded corkscrew anchors, each of which is used to pass 2 horizontal mattress suture configurations. After knots are tied, a single limb from each knot is passed in a suture bridge fashion and anchored distally to an additional 2 to 3 knotless SwivelLock suture anchors (Arthrex). After completion of the tendon transfer construct, additional No. 1 Vicryl sutures are then used to close the transferred gluteus maximus to the vastus lateralis fascia. Both the lateral femoral circumflex artery and the superior gluteal nerve should be identified and protected throughout this procedure.

Rehabilitation Protocol
20-lb flat-foot weightbearing restriction for 8 weeks Hip brace to be worn for 8 weeks Rehabilitation to begin at 6 weeks postoperatively.

Summary of Guidelines and Precautions after Surgery
Weightbearing/Hip Brace/Rehabilitation A hip brace is used in all patients to facilitate healing and pain relief after a surgical procedure by providing support and restricting range of motion (ROM) of the operative extremity. Type IIIB 2 crutches (or rolling walker) 20-lb flat-foot weightbearing for the first 6 weeks postoperatively

ROM
Type IIIB-V: For first 6 weeks postoperatively, no active hip abduction and IR; no passive hip ER and adduction. See Appendix for full rehabilitation protocol.

Discussion
Surgical management of GTPS has been reserved for patients with symptoms that have been present for a minimum of 6 to 12 months and in whom nonsurgical treatment has been unsuccessful. As such, various open or endoscopic techniques 1,9,27 have been described to treat GTPS depending on the etiology of the pain; however, to our knowledge, there is no consensus on recommended techniques based on intraoperative findings.
Our classification system relies on endoscopic confirmation of the pathological tissue, which may correlate with the preoperative diagnosis. Few studies have focused on the clinical presentation of patients with GTPS. Lindner et al. 11 found that 45 of 45 (100%) patients presenting with greater trochanteric tenderness to palpation or abductor weakness were diagnosed with a gluteus medius tear. In that same study, preoperative MRI findings were misdiagnosed 43% of the time by radiologists, which led the authors to conclude that physician experience with GTPS imaging is critical to accurate diagnosis. Ebert et al. 28 set out to describe the clinical, functional, and biomechanical presentation of patients with symptomatic abductor tears of the hip. Results of that study showed the difficulty in assessing patients with GTPS due to significantly reduced patientreported outcomes, active hip ROM in all planes, and hip abduction strength compared to an age-matched control group with end-stage hip osteoarthritis.
In response to the aforementioned difficulties in diagnosis, and in an attempt to improve the accuracy of surgical indications, Chandrasekaran et al. 29 recently identified clinical features predicting the need for operative intervention in patients with gluteus medius tears. The authors identified reduced power of resisted hip abduction and the presence of gait deviation as factors which significantly increased the likelihood of surgical intervention. 29 The authors specifically noted the need for early diagnosis to avoid problems of tendon retraction and fatty infiltration, which can potentially improve surgical outcomes in an often missed or delayed diagnosis.
It is our hope that this article aids in early diagnosis of an often difficult-to-treat patient population with an evidence-based algorithmic approach, as illustrated in Figure 10. Identification of preoperative diagnostic variables such as greater trochanteric tenderness, abductor weakness, Trendelenburg gait, or pertinent MRI findings can help clinicians diagnose GTPS at early symptom onset (Tables 2 and 3). The endoscopic classification system, with corresponding surgical techniques, presented in this article will help surgeons with intraoperative diagnostic decision making. Additionally, the associated rehabilitation protocols will help aid in streamlining communication between treating providers, patients, and physical therapists.