The Psoas Impingement is a known complication after a Hüft total endoprosthesis (Hüft-TEP). This problem arises from a mechanical irritation of the tendon of the Musculus iliopsoas (Hüftbeuger), which often leads to an Entzündungsreaktion. A decisive factor for this can be a reduced Anteversion of the cup implant, which restricts the range of motion of the Hüftbeugemuskels einschränkt.

What is anteversion?

The Anteversion describes the inclination of the hip joint socket forward. It is crucial to ensure the mobility and stability of the artificial hip joint and avoid conflicts with surrounding structures. If the anteversion is too low, the front edge of the socket can irritate the iliopsoas tendon, especially during movements such as lifting the leg. A suboptimal position of the implant thus increases the likelihood of a psoas impingement.

Causes of Psoas Impingement after Hip Replacement

Psoas impingement typically occurs due to:

• Mispositioning of the cup: Especially a reduced anteversion or a not deep enough position of the cup increases the mechanical friction.
• Overhang of the cup rim: An overhang irritates the tendon.
• Muscle atrophy or weakness: A weakened iliopsoas often leads to a dysfunctional load that overstrains the tendon.
• Presence of foreign body reactions: Tissue reactions to the implant material can additionally promote pain.

Classic symptoms of psoas impingement

Patients with psoas impingement suffer from the following symptoms:

• Groin pain: These occur especially when lifting the leg (flexion) and when sitting down. The pain can become chronic and intensify the longer the irritation persists.
• Strength limitations: Patients frequently report a feeling of weakness in the hip flexor muscle, which makes everyday movements difficult, as climbing stairs or lifting the leg.
• Snapping sounds: Occasionally patients feel or hear a snap when the tendon slides over the cup rim.
• Daily life limitations: The pain can significantly affect quality of life by limiting sporting activities or longer walking distances.

Diagnosis of Psoas Impingement

The following methods are used for a reliable diagnosis:

• Clinical examination: The doctor checks typical symptoms such as groin pain during passive hip flexion and rotation.
• Diagnostic infiltration: The tendon is injected with local Betäubungsmittel. If the symptoms disappear temporarily, a psoas impingement is likely.
• Imaging methods: Röntgen and CT can show misalignments of the cup implant or mechanical conflicts.
• Ultrasound examination: May show an Entzündung or swelling of the tendon.
• MRI: Particularly helpful for visualizing soft tissues and entzündlichen processes.

Treatment Options for Psoas Impingement after Hip Replacement

There are various approaches to treating psoas impingement:

Conservative Therapy:

• Physiotherapy: Special Übungen for Kräftigung and mobilization of the iliopsoas können relieve the symptoms. A professional guidance is essential to unload the muscle and avoid faulty movements.
• Medication treatment: Anti-inflammatory medications (e.g., NSAIDs) help reduce swelling and pain.
• Injections: Corticosteroid injections into the iliopsoas tendon can provide short-term pain relief.

Surgical Therapy:

• Acetabular component revision: If the hip cup is suboptimally positioned, surgical reposition may be needed to correct anteversion.
• Tendon release: In severe cases, the iliopsoas tendon is surgically lengthened or decompressed. This procedure should be carefully considered, as it can cause functional limitations.

Prevention of Psoas Impingement

• Optimal implant positioning: A precise planning of the cup and stem position can avoid complications. The correct anteversion angle is particularly relevant here.
• Protection and rehabilitation: After a hip TEP, a gradual increase in load is crucial to avoid overloads and tendon irritation.
• Regular follow-up examinations: Through follow-up examinations, an early Psoas impingement can be detected and treated promptly.

Conclusion

Psoas impingement is a frequently underestimated but serious complication after a hip total endoprosthesis. Early diagnosis and an individually tailored therapy are essential to reduce pain and functional limitations. Thanks to modern surgical methods and improved implant technologies, many problems can already be prevented in advance. The Endoprotheticum Mainz is specialized in optimal care and follow-up of patients with hip prostheses and offers comprehensive counseling and therapy options.