Perspective

Study links history of back pain to poorer results after hip arthroscopy for FAI

Although a comparison of patients with and without a history of low back pain showed significant improvements in both groups more than 1 year following hip arthroscopy for femoroacetabular impingement, researchers from Chicago discovered lower absolute clinical scores in the back pain group.

“This study shows that back pain prior to hip arthroscopy for femoroacetabular impingement actually predicts inferior results,” Benjamin G. Domb, MD, said regarding the study, which was presented at the American Academy of Orthopaedic Surgeons 2012 Annual Meeting.

Study cohorts

 a patient who underwent spinal fusion and has a cam lesion on both hips
This AP radiograph shows a patient who underwent spinal fusion and has a cam lesion on both hips.

Image: Boster I

Domb and his colleagues Itamar Botser, MD, Ronald Paik, MD, and Rima Nasser, MD, studied 114 patients — 89 cases without back pain and 25 cases with a history of back pain — who had at least 1-year follow-up after undergoing arthroscopic surgery for femoroacetabular impingement (FAI). The researchers noted the history, severity and duration of back pain in each case. They excluded from the study patients with a high Tonnis grade, a history of revision or previous hip conditions, such as developmental dysplasia of the hip, avascular necrosis and Legg-Calve-Perthes Disease.

Outcome measures for the study included the Non-arthritic Hip Score (NAHS), modified Harris Hip Score (mHHS), Visual Analog Scale (VAS) and patient satisfaction measured on a 10-point scale.

A comparison of the groups revealed no significant differences in age, gender, follow-up time or how many months patients showed back pain symptoms prior to surgery, Botser said. Labral tear size, Tonnis grade and the number of anchors used were also similar between groups. In addition radiographic findings preoperatively and postoperatively showed no significant differences between groups, according to the study abstract.

The investigators found that patients with a history of back pain had less pain and lower NAHS and mHHS results than those without back pain, but these differences were not statistically significant.

Absolute differences

At 15-month follow-up both groups improved significantly for all outcome measures and there was no difference in the relative improvement between the groups. However, investigators found that absolute mHHS and NAHS outcomes were significantly lower in the back pain group than those without back pain. They also discovered that patients without a history of back pain were significantly more satisfied with the surgery.

“FAI patients with a history of back pain improved significantly after the surgery,” Domb said. “However, their clinical results and satisfaction are inferior to patients without back pain. We believe that both the patient and the surgeon’s expectations should be adjusted accordingly.” – by Jeff Craven

Reference:
  • Botser I, Nasser R, Domb B. Back pain prior to hip arthroscopy for femoroacetabular impingement predicts inferior results. Paper # 662. Presented at the American Academy of Orthopaedic Surgeons 2012 Annual Meeting. Feb. 7-11. San Francisco.
For more information:
  • Benjamin G. Domb, MD, can be reached at Hinsdale Orthopaedics Associates, 1010 Executive Ct., Suite 250, Westmont, IL; 630-455-7130; email: dombsteam@gmail.com.
  • Disclosure: Domb and colleagues have no relevant financial disclosures.

Although a comparison of patients with and without a history of low back pain showed significant improvements in both groups more than 1 year following hip arthroscopy for femoroacetabular impingement, researchers from Chicago discovered lower absolute clinical scores in the back pain group.

“This study shows that back pain prior to hip arthroscopy for femoroacetabular impingement actually predicts inferior results,” Benjamin G. Domb, MD, said regarding the study, which was presented at the American Academy of Orthopaedic Surgeons 2012 Annual Meeting.

Study cohorts

 a patient who underwent spinal fusion and has a cam lesion on both hips
This AP radiograph shows a patient who underwent spinal fusion and has a cam lesion on both hips.

Image: Boster I

Domb and his colleagues Itamar Botser, MD, Ronald Paik, MD, and Rima Nasser, MD, studied 114 patients — 89 cases without back pain and 25 cases with a history of back pain — who had at least 1-year follow-up after undergoing arthroscopic surgery for femoroacetabular impingement (FAI). The researchers noted the history, severity and duration of back pain in each case. They excluded from the study patients with a high Tonnis grade, a history of revision or previous hip conditions, such as developmental dysplasia of the hip, avascular necrosis and Legg-Calve-Perthes Disease.

Outcome measures for the study included the Non-arthritic Hip Score (NAHS), modified Harris Hip Score (mHHS), Visual Analog Scale (VAS) and patient satisfaction measured on a 10-point scale.

A comparison of the groups revealed no significant differences in age, gender, follow-up time or how many months patients showed back pain symptoms prior to surgery, Botser said. Labral tear size, Tonnis grade and the number of anchors used were also similar between groups. In addition radiographic findings preoperatively and postoperatively showed no significant differences between groups, according to the study abstract.

The investigators found that patients with a history of back pain had less pain and lower NAHS and mHHS results than those without back pain, but these differences were not statistically significant.

Absolute differences

At 15-month follow-up both groups improved significantly for all outcome measures and there was no difference in the relative improvement between the groups. However, investigators found that absolute mHHS and NAHS outcomes were significantly lower in the back pain group than those without back pain. They also discovered that patients without a history of back pain were significantly more satisfied with the surgery.

“FAI patients with a history of back pain improved significantly after the surgery,” Domb said. “However, their clinical results and satisfaction are inferior to patients without back pain. We believe that both the patient and the surgeon’s expectations should be adjusted accordingly.” – by Jeff Craven

Reference:
  • Botser I, Nasser R, Domb B. Back pain prior to hip arthroscopy for femoroacetabular impingement predicts inferior results. Paper # 662. Presented at the American Academy of Orthopaedic Surgeons 2012 Annual Meeting. Feb. 7-11. San Francisco.
For more information:
  • Benjamin G. Domb, MD, can be reached at Hinsdale Orthopaedics Associates, 1010 Executive Ct., Suite 250, Westmont, IL; 630-455-7130; email: dombsteam@gmail.com.
  • Disclosure: Domb and colleagues have no relevant financial disclosures.

    Perspective

    This paper provides important information on patients that will undergo hip arthroscopy. Unfortunately, we do not have very much information on who will do better with hip arthroscopy and the long-term outcomes of this procedure. It is common to see patients with back pain that radiates to the hip with objective MRI finding to support the back symptoms. It is difficult to decide whether to operate the hip or back and in my experience these patients are difficult to please. As this paper suggests, these patients should be informed and consented properly before proceeding to hip arthroscopy. I commend these authors for bringing some light on this matter.

    • A. Mazhar Tokgozoglu, MD
    • Orthopaedics Today Europe Editorial Board member Professor of Orthopaedics and Traumatology Hacettepe University Faculty of Medicine Ankara, Turkey

    Disclosures: Tokgozoglu has no relevant financial disclosures.

    Perspective
    Dean K. Matsuda, MD

    Dean K. Matsuda, MD

    Albeit a single study with limited follow-up, my take is that the findings are valuable, supporting what one might expect: if a given patient has symptomatic femoroacetabular impingement (FAI) and lumbar pain, and if the patient expects symptoms from both conditions to improve or resolve with hip surgery (open or arthroscopic) alone, that patient may have improvement of the former but not the latter. This could lead to relative disappointment as reflected in lower surgical satisfaction. I would add, though, that constrained hip motion from FAI, which is thought by some to contribute to detrimental transfer stresses (theoretically contributing, at least, in part to conditions such as athletic pubalgia, sacroilitis and even ACL tears), may also play some etiologic role in low back pain. If so, it would be interesting to see if select patients with such pain actually improve with FAI surgery.

    Intra-articular hip pathology is thought to typically generate deep anterior and trochanteric pain, but not posterior pain. Although I inform my patients who have a component of buttock or posterior pain that this may not improve with hip surgery, I have been surprised that a few patients claim postoperative relief. Perhaps posterior hip pain may, on occasion, be directly referred from the hip and/or derive secondary benefit by improving hip motion thereby decreasing lumbar transfer stress. An injection challenge into the symptomatic hip may help clarify which component of pain might improve with FAI surgery, aiding preoperative patient counseling, and expectation-setting. Finally, any patient with a history of sciatica should be advised that hip distraction may aggravate this condition.

    • Dean K. Matsuda, MD
    • Orthopedics Today Editorial Board member Los Angeles

    Disclosures: Matsuda has no relevant financial disclosures.

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