**3.1 Surgical procedure**

86 Modern Arthroscopy

Pain radiating into the upper thigh is associated with loosening of the femoral component, while referred pain in the middle of the thigh is related to the tip of the femoral stem, pressuring the femur. This so called "tip effect" is caused by micro movements of the femoral stem pressuring its surrounding cortical bone bone (Bourne et al., 1994; Bullow et

Fig. 4. EUA showing instability of: A) THR and B) in a resurfacing implant

**A B**

On the other hand, pain in the inguinal or gluteal areas is associated with acetabular loosening, osteolysis and iliopsoas tendonitis. Other less common causes of inguinal pain are: inguinal hernia (Gaunt et al., 1992), inguinal lymphadenopathy, and psoas abscesses, as well as a range of gynaecological and genitourinary disorders (Smith & Rorabeck, 1999). Continuous pain at rest or at night may also be due to a lumbar spine condition, but in such cases malignancy or sepsis should be ruled out (Bozic & Rubash, 2004; Evans & Cuckler,

Other factors that may trigger pain are trauma and systemic processes (Bozic & Rubash, 2004). A recent fall may have caused a fracture of the components (in particular, femoral heads and acetabular cups made of alumina) or loosening. The presence of pain after a systemic process, such as dental or gastrointestinal diagnostic or surgical procedures, should make us suspect arthritis (Robbins et al., 2002). Factors that increase the risk of prosthetic infection include

A detailed history should provide us information and enable a more accurate diagnosis

Patients are referred to our Arthroscopy Unit due to persistence of pain, lack of a clear diagnosis, failure of conservative treatment (physiotherapy, NSAIDs, and psoas ultrasound

obesity, diabetes, rheumatoid arthritis and immunosuppression (Canner et al., 1984).

al., 1996; Robbins et al., 2002).

1992).

(Bozic & Rubash, 2004).

**3. Method of treatment** 

guided injections) or instability.

The procedure lasts between 60 and 90 minutes.

The anaesthetist selects the most appropriate anaesthetic technique in each case: spinal anaesthesia, general anaesthesia or a combination of both.

The patient lies supine on a traction table, as this facilitates fluoroscopic control of the procedure. In all cases, the procedure is preceded by examination under anaesthesia to assess instability and the presence of "snapping".

Joint distraction is required only in a few cases.

We favour the anterolateral and the anterior arthroscopic portals. Depending on therequirements in each case, the posterior peritrochanteric or another distal anterior portal may be additionally used

To gain access, progressive larger dilatators are slid into position through a nitinol guidewire previously inserted under fluoroscopic control (Fig. 5 A, B).

We routinely follow a three steps protocol 1) collection of samples for culture 2) assessment of the degree of loosening of the components; and 3) assessment and treatment of the condition itself.

Fig. 5. Introduction of a "nitinol" guide wire under fluoroscopic control (A) Progresive larger dilators are slide into position (B).
