Military study has important lessons for managing pan-labral tears
Successful treatment of circumferential labral tears depends on a comprehensive physical exam, the right imaging, and a pre-established surgical and repair strategy, according to Matthew T. Provencher, MD, LCDR, MC, USN.
Dr. Provencher and his colleagues identified these key factors through a prospective study conducted at The United States Air Force Academy, Colorado Springs, Colo., and the Naval Medical Center San Diego.
His co-author, John M. Tokish, MD, USAF, MC, coordinated the study at the Air Force Academy.
Because pan-labral tears are difficult to diagnose, a thorough history and physical examination that closely focus on the shoulder instability and the patient’s particular symptoms are essential.
“Suspect a pan-labral tear if the patient has multiple dislocations, with a prolonged history of instability symptoms, and repeated instances of instability events that occur with little or no provocation,” advised Dr. Provencher.
“Most patients in the study group (41 shoulders) with pan-labral tears had an initial anterior instability event,” he said. “In fact, many could remember their first episode of instability.”
Patients can have moderate shoulder instability or pain for several years after that first event. But those with circumferential tears will eventually become more symptomatic—experiencing multiple shoulder dislocations and associated pain.
All the patients in the study group had at least 10 instability events. Most also had a Hill-Sachs injury and a small amount of interior glenoid bone loss.
Surgeons need to ask specific questions when conducting the patient history. “These questions aren’t necessarily intuitive for the patient. But they enable you to uncover important information,” he noted.
For example, Dr. Provencher recommends asking the following questions:
- How many times has the shoulder come out of the joint?
- Is it becoming easier to experience instability of the shoulder? Does the shoulder come out with minimal provocative exercise or with the arm at 45 degrees of abduction with a little bit of external rotation?
According to Dr. Provencher, the patient’s symptoms can help distinguish a pan-labral tear from capsular stretch or glenoid bone loss.
A high percentage of patients in the study group had a positive apprehension sign and a positive push-pull test for posterior laxity and pain. They also had positive findings of pain and weakness during an active compression test.
But the most crucial element in diagnosing these tears was the magnetic resonance imaging (MRI) arthrography.
“The results of our study showed that an MRI without intra-articular contrast was not effective at detecting these tears or predicting these injuries. Without critical information from the MRI arthrogram, the surgeons were surprised at the extensive damage they found during surgery,” he said.
In addition, an MRI arthrogram read by a musculoskeletal radiologist was statistically more accurate (92 percent) than one read by a radiologist without that specialized training (13 percent.)
Tactics for successful surgical repair
“When you go into the operating room, you should already know what your operative approach and plan are going to be,” said Dr. Provencher.
The surgeons in his study performed arthroscopic capsulolabral repair with suture anchor fixation, using an average of 7 anchors.
“We repaired the labrum—at times taking a small amount of the capsule (Fig. 1). But if we encountered excessive looseness in the back or other posterior findings, we would repair more of the capsule to decrease the excessive exposure associated with the multiple instability events,” he said.
Procedures were performed with the patient in a lateral decubitus position. “This was a very easy and reliable method to obtain access to all areas of the glenohumeral joint, especially inferiorly and posteriorly. We were able to place the anchors where they were needed (Fig. 2),” he explained.
All the surgeons used one posterior and two anterior portals as well as a posterolateral placement of anchors percutaneously for posterior and inferior joint access.
Pre- and postoperative outcomes were measured with validated outcome instruments. “Mean outcome scores demonstrated improvement in all categories,” Dr. Provencher reported (Table 1).
Although the repairs failed in approximately 15 percent of the study group, and some patients required revision surgery, all patients—including contact athletes—returned to their pre-injury level of sport and to active duty.
The power of two
Dr. Provencher is a strong proponent of multicenter studies. “When more than one center is involved, the power of the study increases,” he said. To obtain sufficient numbers for this prospective study, for example, he turned to his colleague, Dr. Tokish, at the Air Force Academy, “Because the outcomes from The Air Force Academy were very similar to those at the Naval Medical Center in San Diego, we had external validity for the patient care being provided at our center,” said Dr. Provencher.
“Circumferential lesions of the glenoid labrum: The Society of Military Orthopaedic Surgeons Research Collaborative experience” won the 2009 Best Poster Award for the sports medicine and arthroscopy category at the AAOS Annual Meeting, as well as the first place award (staff level) at the 24th Annual Navy-wide Academic Research Competition.
Dr. Provencher’s co-authors include Colleen M. McBratney, MD, USAF, MC; Daniel J. Solomon, MD, CDR, MC, USN; Christopher B. Dewing, MD, LCDR, MC, USN; and Lance E. Leclere, MD, LT, MC, USN.
The authors reported the following disclosures: Dr. Tokish—Arthrex, Inc.; Drs. Provencher, McBratney, Solomon, and LeClere did not have any disclosures to report.
View the 2009 AAOS e-poster presentation. (PowerPoint)
Annie Hayashi is the senior science writer for AAOS Now. She can be reached at firstname.lastname@example.org