Surgeons share strategies for preserving the hip joint

Preserving the hip joint to delay arthroplasty has become more common, and several surgical procedures have demonstrated pain relief and improved function. On Wednesday, a panel of surgeons shared their perspectives and expertise on hip joint preservation.

It starts with the diagnosis
Successful treatment depends on an accurate diagnosis, but little consensus exists on how to conduct an examination, said Bryan T. Kelly, MD, of the Hospital for Special Surgery. Noting that the origin of hip pain can be difficult to identify, he said the clinician must first distinguish between intra- and extra-articular pain (Table 1).

Table 1: Disorders of the hip

Intra-articular disorders

labral tears

chondral injury

ligamentum teres tears

femoroacetabular impingement


loose bodies


Extra-articular disorders

capsular problems

snapping hip

lateral hip pain

pubic pain


nerve avulsion injuries

nerve compression

The history should note the mechanism and duration of pain; aggravating activities; clicking, catching, and locking; previous surgery; and physical therapy. Passive range of motion in the standard hip categories should be checked.

“Internal rotation at 90 degrees of flexion tells us a lot—not only about the mechanics of the joint but also about its functional capacity,” Dr. Kelly said. “Most activities, whether for athletics or activities of daily living, require a certain degree of rotation. Without that, the joint will sustain a direct impaction injury or some kind of secondary compensatory problem will develop.”

The impingement is used to identify areas of contact or motion-induced conflict between the anterior aspect of the hip and the socket; this occurs with flexion, adduction, and internal rotation. But impingement also occurs in other sites, and straight flexion is probably the second most common provocative position for pain. Pain with flexion and external rotation does not mean the patient does not have impingement, Dr. Kelly said.

The exam should also test for trochanteric pain, instability, and posterior impingement, as well as for strength, palpation pain, and the peritrochanteric space.

The comprehensive examination looks at five points for the five body positions of standing, sitting, supine, lateral, and prone. For example, the standing examination incorporates general status, gait, spine, pelvis, and the Trendelenburg test; the supine examination includes passive range of motion, strength, provocative pain, pubalgia, and special tests. Diagnostic measures are taken as appropriate.

“The location and quality of the pain should correspond to the mechanical diagnosis and primary and secondary injury patterns,” Dr. Kelly said. “If they do, then correcting the mechanical problems and primary and secondary injuries should lead to a good outcome.”

FAI tips
Michael Leunig, MD, reviewed the primary considerations in surgical dislocation to treat femoroacetabular impingement (FAI) and strategies to avoid or manage complications.

Surgical dislocation, which was introduced around 1990, enables the performance of safe intracapsular procedures within the hip and the identification of FAI. Although less invasive approaches such as arthroscopy have partially replaced dislocation, this open procedure remains useful for addressing complex deformities, Dr. Leunig said.

He identified the following absolute indications for surgical dislocation:

  • global overcoverage
  • severe retroversion
  • posterolateral cam FAI (which cannot be reached by an anterior approach)
  • a combined intra- and extra-articular impingement (because an intracapsular procedure is not sufficient)
  • the need for intra-articular procedures.

Relative indications that may be managed with less invasive techniques include anterior-superior cam deformities, laxity, and mild osteoarthritis. Contraindications include inability to identify an anatomic deformity, nonmechanical disease, and high-grade osteoarthritis.

During surgery, “respecting the medial femoral circumflex artery (MFCA) is key to a safe dislocation procedure,” said Dr. Leunig, because this artery is the primary source of vascularity to the femoral head. He noted that the obturator externus muscle protects the MFCA from overstretching, “so as long as this muscle is intact, problems with perfusion will not occur.”

Dr. Leunig provided some strategies for dealing with surgical problems and complications (Table 2).

Table 2: Strategies for surgical problems and complications



Insufficient exposure

Enlarge the incision and follow correct retractor placement steps

Heterotopic ossification

Atraumatic execution and use of correct instruments

Suspected surgical muscle damage

Two weeks of antibiotic prophylaxis

Trochanteric irritation from screws

Tell the patient before surgery that screws might be removed 4 to 6 months after surgery

Trochanteric nonunion

Refix or avoid with a step and ridge cut osteotomy


Avoid by using spherical templates for the femoral head


Follow the patient closely; if symptomatic, advise patient about acetabular redirection

About 6 percent of patients will have adhesions. To avoid them, Dr. Leunig recommended starting continuous passive motion shortly after surgery, no later than the day after. Arthroscopy may be necessary if decreased range of motion is present.

PAO pointers
Periacetabular osteotomy (PAO) can be used to manage acetabular dysplasia, but the procedure is relatively complex, with the potential for major complications and treatment failures, which have been the source of some criticism.

John C. Clohisy, MD, said that PAO has gone through a “learning curve experience.” In a 2009 review of 600 PAO cases, the major complication rate varied from 6 to 36 percent. A more recent analysis, however, found a complication rate of 3 percent, and all the complications were treated and resolved without long-term disability or morbidity. “From the learning curve perspective, the PAO is quite safe,” Dr. Clohisy said.

Indications for PAO include a healthy, well-conditioned patient younger than 40 years, with symptomatic acetabular dysplasia, a congruent joint that has “healthy” articular cartilage without major joint degeneration, and good hip range of motion.

Potential negative predictive factors include body mass index greater than 30, age older than 40, certain comorbidities, previous reconstructive surgery, suboptimal congruity, articular cartilage or labral disease, and severe or chronic symptoms or poor hip function.

Surgeon training is an important factor. “I think it is very helpful to have a surgeon mentor or a co-surgeon when you first perform PAO,” Dr. Clohisy said. Cadaver work is also instructive, as is an adequate case volume and familiarity with the potential technical problems of the operation.

Postoperative pain management is multimodal, with epidural administration the first night. Prophylactic antibiotics are used for 24 hours, and Dr. Clohisy uses a wound drain for 1 to 2 days. Toe-touch weight bearing begins on day. Continuous passive motion seems to be effective for pain and stiffness. Flexion beyond 90 degrees is not permitted. Aspirin and pneumatic stockings at day one serve for deep vein thrombosis prophylaxis. Full weight bearing begins at 1 month, with progression, and the target for full activity in young patients is 4 months.

Also participating in the symposium was Young-Jo Kim, MD, PhD, who detailed common pitfalls in hip imaging. Most problems occur with mild or mixed structural deformities, he said. Poor radiographic technique can lead to false positive findings, and joint damage is often underestimated on plain radiographs.

Standard radiographic views should include an AP pelvic radiograph, a false profile of the acetabulum (which is most sensitive in detecting acetabular dysplasia), and a 45-degree Dunn lateral view of the proximal femur (which is most sensitive in detecting a cam lesion). Magnetic resonance imaging and computed tomography are helpful in detecting subtle cam deformities.

Christopher M. Larson, MD, provided an overview of how to avoid or treat complications in arthroscopic procedures. Complications include iatrogenic labral and chondral injury, neuropraxis, and acetabular and femoral over- and underresections.

He advised avoiding resection of more than 30 percent of the neck width, and recommended dynamic assessment with fluoroscopy. Underresections tend to occur superiorly with the patient in the supine position, and anteriorly and antero-inferiorly with the patient in the lateral position. In resection of the anterior and anteroinferior neck, he recommended working with the hip in flexion, and with the antero-superior, he recommended extension.

“Attention to detail and careful technique can limit the potential for intraoperative and postoperative complications,” he said.

Disclosure information: Dr. Kelly—Pivot Medical, A-2 Surgical; Dr. Leunig—Smith & Nephew, Pivot Medical; Dr. Clohisy—Biomet, Wright Medical Technology, Zimmer; Dr. Kim—Siemens Health Care, Johnson & Johnson, Procter & Gamble; Dr. Larson—Smith & Nephew, A2 Surgical.

Prepared by Terry Stanton, senior science writer for AAOS Now.