MRI picked up abductor tendon tears after lateral-approach hip replacement

Design

Retrospective diagnostic accuracy study with surgical reference standard

Population

36 patients with total hip replacement (lateral approach) having revision for suspected abductor tear

Primary outcome

MRI detection of gluteus medius and minimus tendon tears

Effect

Sensitivity 0.86–1.00, specificity 0.90–1.00 across two readers

This retrospective study included 36 patients who had revision surgery for suspected gluteus medius or minimus tendon tears after total hip replacement through a lateral approach, all with a preoperative MRI. Two readers graded the tendons, and operative findings were the reference.

Both readers detected tears with sensitivity of about 0.86 to 1.00 and specificity of about 0.90 to 1.00. A visible tendon defect and fluid around the greater trochanter were strongly associated with surgically confirmed tears, as was more fatty atrophy of the muscle.

The cohort was small and highly selected: everyone had surgery, which inflates apparent accuracy because clinically equivocal patients who were not operated on are missing. Metal artefact reduction sequences are essential, and image quality depends on the implant.

Still, for a patient with lateral hip pain and a limp after a lateral-approach replacement, MRI with metal artefact reduction is a reasonable test to plan revision, looking specifically for a defect and peritrochanteric fluid.

• Consider MRI with metal artefact reduction for suspected abductor tears after hip replacement.
• Look for a tendon defect and peritrochanteric fluid; both were strongly linked to tears.
• Grade fatty atrophy of gluteus medius and minimus in the report.
• Interpret accuracy cautiously; all patients in this study went to surgery.

Why it matters

Abductor failure is a common cause of pain after lateral-approach hip replacement, and imaging decides who goes back to theatre.

Don't overread it

A small, surgically selected cohort; accuracy in unselected patients will be lower.

The statistics, in plain English

Sensitivity is the share of real tears found and specificity the share of intact tendons correctly called intact. With 36 patients, all of whom had surgery, these figures are likely to be higher than in everyday practice. The very large odds ratios reflect small numbers rather than precise estimates.

Read the rest in the app

You have read your two free briefings this month. The app carries all 27 specialties, every morning, free — and this finding is waiting in it.

Get Daily Doctor — free

Scan to keep reading on your phone. No account needed to start.