**2.2 Tendon pain (iliopsoas tendonitis)**

Tendon inflammation around the implant is one of the typical causes of pain after THR. Amongst these, iliopsoas tendonitis secondary to hip replacement has a prevalence of up to 4.3% according to several authors (Ala Eddine et al., 2001; Bricteaux et al., 2000; Dora et al., 2007). Various factors can be responsible for iliopsoas inflammation, but particular attention should be drawn to changes in the course of the tendon due to the resection of the femoral head in hip replacement surgery. This modifies the course of the tendon bringing it closer to the medial edge of the prosthetic acetabulum and femoral neck, increasing the probability of impingement (O'Sullivan et al., 2007).

Arthroscopy after Total Hip Replacement Surgery 83

techniques (Bricteaux et al., 2000; Della Valle et al., 2001; Heaton & Dorr, 2002; Taher & Power, 2003) and, more recently, using arthroscopic techniques (Cuéllar et al., 2009; McCarthy et al., 2009). Iliopsoas tendon lengthening has also been proposed (Trousdale et

A frequent cause of pain following hip replacement surgery, commonly associated with Trendelenburg gait pattern. This is more common when a transgluteal approach has been used (Horwitz et al., 1993; Masonis & Bourne, 2002; Nolan et al., 1975; Obrant et al., 1989; Svensson et al., 1990). The pathological findings are very similar to those found in rotator cuff tendons in the shoulder, as has been previously described (Bunker et al., 1997; Kagan, 1999). These include bursitis, tendonitis and other tendon injuries, as well as muscle

The diagnosis of these conditions can be reached using modified MRI techniques to minimise the artefacts generated by the implants and performing the imaging using frequency-encoding gradient parallel to the long axis of the prosthesis (Pfirrmann et al.,

 In most patients with hip implants some fluid accumulates around the trochanter. Pfirrmann Pfirrmann et al., 2005) reports in his paper that he found a volume than greater than 4 mls of fluid in those patients with pain and a limp. The same paper reports statistics concerning other complications in the trochanteric region related to hip replacement surgery: defects in the gluteus minimus and gluteus medius tendons were found in 56% and 62% symptomatic patients, respectively, compared to in just 8% and 16% of asymptomatic

MRI allows assessing muscle atrophy and fatty degeneration. As in the shoulder, these signs are a poor prognostic factor. These findings are associated with a Trendelenburg gait and are almost exclusively seen in patients with painful hips (Pfirrmann et al., 2005). Another cause of this gait pattern is a lesion in the superior gluteal nerve, which may result from hip surgery, in particular, when the lateral approach is used. (Ramesh et al., 1996). The approaches that entail greater trochanter osteotomy may cause pain due to non union, failure to remove loose bone fragments or breakage of the wires used in the procedure. Treatment in such cases often requires surgical intervention, although it is possible to

The treatment of greater trochanter pain syndrome and trochanteric bursitis can also be achieved using bursoscopy (Weber & Berry, 2007). High-grade tears of gluteal tendons may need to be repaired by open surgery (Weber & Berry, 2007), but can also be addressed using

This is a common cause of pain following hip surgery (Beck, 2009; Krueger et al., 2007). Any adhesions within the joint capsule or around the femoral neck tend to cause impingement, producing pain and limiting mobility (Krueger et al., 2007). Indeed, such adhesions have been described as a potential cause of pain in relation to hip prostheses. (Bajwa & Villar, 2011; Cuéllar et al., 2009; McCarthy et al., 2009). We reported the presence of structured fibrous bands occupying the medial recess (Fig-2 A,B) (Cuéllar et al., 2009). We also found fibrous structures located between the acetabulum and the prosthetic neck and in wider

al., 1995). In some cases, the acetabular component needs to be revised.

patients; while poor gait was associated with tears larger than 2.5 cm.

remove loose bone fragments and wires using bursoscopy. (Cuéllar et al., 2009).

**2.3 Trochanteritis - Gluteal muscle tears** 

2005; Twair et al., 2003; White et al., 2000).

**2.4 Intra-articular adhesions: Arthrofibrosis** 

areas across the new joint (Fig-3 A,B).

atrophy.

arthroscopy.

Fig. 1. Assessment of prosthetic component loosening under A) direct visualisation and B) fluoroscopic control.

A main cause of pain is related to the acetabular component being in the wrong position (retroversion and lateralisation) or being too large. Non-cemented hip prostheses tend to have a larger diameter than cemented polyethylene implants, and thus, are more often associated with tendonitis due to iliopsoas impingement (Ala Eddine et al., 2001; Bajwa & Villar, 2011; Bricteaux et al., 2000; Dora et al., 2007; O'Sullivan et al., 2007). Tendonitis may be also caused by extrusion of the cement or by the screw used being too large in relation to the course of the iliopsoas tendon (Jasani et al., 2002; O'Sullivan et al., 2007).

There are other causes which are less common and more difficult to demonstrate such as: impingement on the femoral neck due to the presence of residual anteromedial osteophytes; the shape of certain types of prostheses, which increases the risk of impingement in the transition area between the femoral head and the femoral neck; and increased femoral offset (O'Sullivan et al., 2007).

In a small percentage of cases it is not possible to identify the precise cause of the tendonitis. This may be due to anatomical factors as pointed out by Noble, whose study showed that the proximal femur is flatter in women than in men, a subtle difference that might favour impingement. This theory is supported by the sex ratio of 3:1 (Noble et al., 1995).

Tendonitis should be suspected in the presence of referred pain in the groin during activities requiring active flexion of the hip, especially climbing stairs and getting in and out of cars. In the physical examination, pain will be reproduced on performing movements that stretch the iliopsoas (hyperextension, external rotation) or resisted flexion, as well as internal rotation.

With regards to treatment options, the conservative approach is always considered first, injecting corticosteroids around the tendon under ultrasound guidance (Adler et al., 2005; Ala Eddine et al., 2001; Bricteaux et al., 2000; Dora et al., 2007; O'Sullivan et al., 2007; Wank et al., 2004). However, the degree of clinical improvement varies greatly and this procedure is often unsuccessful (Adler et al., 2005; Ala Eddine et al., 2001; Bricteaux et al., 2000; Cuéllar et al., 2009; Jasani et al., 2002; McCarthy et al., 2009; O'Sullivan et al., 2007). Other therapeutic options include iliopsoas tenotomy by conventional surgical techniques

Fig. 1. Assessment of prosthetic component loosening under A) direct visualisation and B)

A main cause of pain is related to the acetabular component being in the wrong position (retroversion and lateralisation) or being too large. Non-cemented hip prostheses tend to have a larger diameter than cemented polyethylene implants, and thus, are more often associated with tendonitis due to iliopsoas impingement (Ala Eddine et al., 2001; Bajwa & Villar, 2011; Bricteaux et al., 2000; Dora et al., 2007; O'Sullivan et al., 2007). Tendonitis may be also caused by extrusion of the cement or by the screw used being too large in relation to

There are other causes which are less common and more difficult to demonstrate such as: impingement on the femoral neck due to the presence of residual anteromedial osteophytes; the shape of certain types of prostheses, which increases the risk of impingement in the transition area between the femoral head and the femoral neck; and increased femoral offset

In a small percentage of cases it is not possible to identify the precise cause of the tendonitis. This may be due to anatomical factors as pointed out by Noble, whose study showed that the proximal femur is flatter in women than in men, a subtle difference that might favour

Tendonitis should be suspected in the presence of referred pain in the groin during activities requiring active flexion of the hip, especially climbing stairs and getting in and out of cars. In the physical examination, pain will be reproduced on performing movements that stretch the iliopsoas (hyperextension, external rotation) or resisted flexion, as well as internal

With regards to treatment options, the conservative approach is always considered first, injecting corticosteroids around the tendon under ultrasound guidance (Adler et al., 2005; Ala Eddine et al., 2001; Bricteaux et al., 2000; Dora et al., 2007; O'Sullivan et al., 2007; Wank et al., 2004). However, the degree of clinical improvement varies greatly and this procedure is often unsuccessful (Adler et al., 2005; Ala Eddine et al., 2001; Bricteaux et al., 2000; Cuéllar et al., 2009; Jasani et al., 2002; McCarthy et al., 2009; O'Sullivan et al., 2007). Other therapeutic options include iliopsoas tenotomy by conventional surgical techniques

the course of the iliopsoas tendon (Jasani et al., 2002; O'Sullivan et al., 2007).

impingement. This theory is supported by the sex ratio of 3:1 (Noble et al., 1995).

fluoroscopic control.

**A B**

(O'Sullivan et al., 2007).

rotation.

techniques (Bricteaux et al., 2000; Della Valle et al., 2001; Heaton & Dorr, 2002; Taher & Power, 2003) and, more recently, using arthroscopic techniques (Cuéllar et al., 2009; McCarthy et al., 2009). Iliopsoas tendon lengthening has also been proposed (Trousdale et al., 1995). In some cases, the acetabular component needs to be revised.

#### **2.3 Trochanteritis - Gluteal muscle tears**

A frequent cause of pain following hip replacement surgery, commonly associated with Trendelenburg gait pattern. This is more common when a transgluteal approach has been used (Horwitz et al., 1993; Masonis & Bourne, 2002; Nolan et al., 1975; Obrant et al., 1989; Svensson et al., 1990). The pathological findings are very similar to those found in rotator cuff tendons in the shoulder, as has been previously described (Bunker et al., 1997; Kagan, 1999). These include bursitis, tendonitis and other tendon injuries, as well as muscle atrophy.

The diagnosis of these conditions can be reached using modified MRI techniques to minimise the artefacts generated by the implants and performing the imaging using frequency-encoding gradient parallel to the long axis of the prosthesis (Pfirrmann et al., 2005; Twair et al., 2003; White et al., 2000).

 In most patients with hip implants some fluid accumulates around the trochanter. Pfirrmann Pfirrmann et al., 2005) reports in his paper that he found a volume than greater than 4 mls of fluid in those patients with pain and a limp. The same paper reports statistics concerning other complications in the trochanteric region related to hip replacement surgery: defects in the gluteus minimus and gluteus medius tendons were found in 56% and 62% symptomatic patients, respectively, compared to in just 8% and 16% of asymptomatic patients; while poor gait was associated with tears larger than 2.5 cm.

MRI allows assessing muscle atrophy and fatty degeneration. As in the shoulder, these signs are a poor prognostic factor. These findings are associated with a Trendelenburg gait and are almost exclusively seen in patients with painful hips (Pfirrmann et al., 2005). Another cause of this gait pattern is a lesion in the superior gluteal nerve, which may result from hip surgery, in particular, when the lateral approach is used. (Ramesh et al., 1996). The approaches that entail greater trochanter osteotomy may cause pain due to non union, failure to remove loose bone fragments or breakage of the wires used in the procedure. Treatment in such cases often requires surgical intervention, although it is possible to remove loose bone fragments and wires using bursoscopy. (Cuéllar et al., 2009).

The treatment of greater trochanter pain syndrome and trochanteric bursitis can also be achieved using bursoscopy (Weber & Berry, 2007). High-grade tears of gluteal tendons may need to be repaired by open surgery (Weber & Berry, 2007), but can also be addressed using arthroscopy.

#### **2.4 Intra-articular adhesions: Arthrofibrosis**

This is a common cause of pain following hip surgery (Beck, 2009; Krueger et al., 2007). Any adhesions within the joint capsule or around the femoral neck tend to cause impingement, producing pain and limiting mobility (Krueger et al., 2007). Indeed, such adhesions have been described as a potential cause of pain in relation to hip prostheses. (Bajwa & Villar, 2011; Cuéllar et al., 2009; McCarthy et al., 2009). We reported the presence of structured fibrous bands occupying the medial recess (Fig-2 A,B) (Cuéllar et al., 2009). We also found fibrous structures located between the acetabulum and the prosthetic neck and in wider areas across the new joint (Fig-3 A,B).

Arthroscopy after Total Hip Replacement Surgery 85

The principles of impingement in the prosthetic hip are similar to those described by Ganz for the normal hip (Ganz et al., 2003). A cam type impingement is found in implants with small femoral heads that are poorly differentiated from the femoral neck, Pincer type impingement is caused in those hips where there's been inadequate and insufficient removal of osteophytes. Finally, mixed cam-pincer impingement is caused by a combination of having a small femoral head, a ratio between head and neck of less than 2.0, over sizing of the acetabular component, and a polyethylene liner having sharp rather than rounded edges

Certain anatomical conditions may increase the risk of prosthetic impingement. It has been reported that very flexible patients have a greater risk of impingement at the extremes of the range of motion (Beaulé et al., 2002; Geller et al., 2006). There is a difference in tilt of the pelvis when the patient is supine on the operating table, and when they are active in movement. This difference tends to lead to an overly horizontal positioning of the acetabular component, which makes impingement more likely (Malik et al., 2007; McCollum

The short term clinical consequences of prosthetic impingement include pain, reduced mobility, instability, subluxation and frank dislocation (Barrack et al., 2001; Barrack, 2003; Brien et al., 1993; Brown & Callaghan, 2008; Cobb et al., 1996; Hedlundh & Carlsson, 1996; Malik et al., 2007; McCollum & Gray, 1990; Padgett et al., 2006). In the longer term, excessive friction between the prosthetic components results in the release of metallic particles and wear of metallic edges which may lead to metallosis and osteolysis. These make early

It is not always easy to identify impingement on the basis of patient medical history, clinical examination or radiographic studies, given that it is a dynamic process. Patients with pain and subluxation require CT scans to identify the presence of osteophytes and the relative position and orientation of the components. (Cuéllar et al., 2009; Cuéllar et al., 2010; Pierchon et al, 1994). As we have indicated in previous studies (Cuéllar et al., 2009, 2010), the best way to demonstrate the existence of instability is by Examination Under Anesthesia

Hip resurfacing implants, having larger femoral heads, offer a greater degree of mobility and stability but the ideal ratio between femoral head and neck is hard to achieve and, therefore, they involve a higher risk of impingement with associated instability (Fig-4 B). (Bajwa & Villar, 2011; Cuéllar et al., 2009; Cuéllar et al., 2010; Khanduja & Villar, 2008).

Lumbar spine and radicular pain should be ruled out because of the well known association between degenerative changes in the spine and hip joint. Pain in the gluteal area extending beyond the popliteal region also suggests that it has its origin in the lumbar spine (Bozic & Rubash, 2004; White, 1998). Patients with lumbar spine disorders may experience worsening of radicular pain after hip replacement surgery due to increase in mobility and physical

Pain that begins when a patient starts walking is commonly associated with loosening, and iliopsoas tendonitis, but it can also be derived from lumbar spine disorders (Bozic &

**2.5 Femoro-acetabular impingement - Subluxation-Prosthesis dislocation** 

(Malik et al., 2007).

& Gray, 1990).

loosening of the implant more likely.

(EUA) with X ray control (Fig- 4 A,B A,B).

**2.6 Pain of unknown origin - Other causes of pain** 

activity (Bozic & Rubash, 2004; Bohl & Steffee, 1979).

Rubash, 2004; Bohl & Steffee, 1979)

In around 1% of the cases the cause of pain remains unknown.

The symptoms are similar to those of iliopsoas tendonitis. Patients refer pain in the groin radiating down the inner thigh during activities involving flexion of the hip, such as climbing stairs, but also going down stairs and up or downhill, getting in and out of cars, and turning over in bed . (Beck, 2009; Krueger et al., 2007). There are usually no signs of iliopsoas tendonitis with ultrasound-guided injections, and the response to nerve block tends to be non conclusive or negative.

A definitive diagnosis can be obtained by arthroscopy. Treatment consists of debridement and removal of the adhesions, by the same arthroscopic portal (Cuéllar et al., 2009; Krueger et al., 2007; McCarthy et al., 2009).

Fig. 2. Structured fibrous bands in the medial compartment: A) medial and B) infero-medial view (righ hip)

Fig. 3. Fibrosis: A) between the acetabulum and the prosthetic neck; and B) widespread arthrofibrosis

The symptoms are similar to those of iliopsoas tendonitis. Patients refer pain in the groin radiating down the inner thigh during activities involving flexion of the hip, such as climbing stairs, but also going down stairs and up or downhill, getting in and out of cars, and turning over in bed . (Beck, 2009; Krueger et al., 2007). There are usually no signs of iliopsoas tendonitis with ultrasound-guided injections, and the response to nerve block

A definitive diagnosis can be obtained by arthroscopy. Treatment consists of debridement and removal of the adhesions, by the same arthroscopic portal (Cuéllar et al., 2009; Krueger

Fig. 2. Structured fibrous bands in the medial compartment: A) medial and B) infero-medial

Fig. 3. Fibrosis: A) between the acetabulum and the prosthetic neck; and B) widespread

tends to be non conclusive or negative.

**A B**

**A B**

et al., 2007; McCarthy et al., 2009).

view (righ hip)

arthrofibrosis

### **2.5 Femoro-acetabular impingement - Subluxation-Prosthesis dislocation**

The principles of impingement in the prosthetic hip are similar to those described by Ganz for the normal hip (Ganz et al., 2003). A cam type impingement is found in implants with small femoral heads that are poorly differentiated from the femoral neck, Pincer type impingement is caused in those hips where there's been inadequate and insufficient removal of osteophytes. Finally, mixed cam-pincer impingement is caused by a combination of having a small femoral head, a ratio between head and neck of less than 2.0, over sizing of the acetabular component, and a polyethylene liner having sharp rather than rounded edges (Malik et al., 2007).

Certain anatomical conditions may increase the risk of prosthetic impingement. It has been reported that very flexible patients have a greater risk of impingement at the extremes of the range of motion (Beaulé et al., 2002; Geller et al., 2006). There is a difference in tilt of the pelvis when the patient is supine on the operating table, and when they are active in movement. This difference tends to lead to an overly horizontal positioning of the acetabular component, which makes impingement more likely (Malik et al., 2007; McCollum & Gray, 1990).

The short term clinical consequences of prosthetic impingement include pain, reduced mobility, instability, subluxation and frank dislocation (Barrack et al., 2001; Barrack, 2003; Brien et al., 1993; Brown & Callaghan, 2008; Cobb et al., 1996; Hedlundh & Carlsson, 1996; Malik et al., 2007; McCollum & Gray, 1990; Padgett et al., 2006). In the longer term, excessive friction between the prosthetic components results in the release of metallic particles and wear of metallic edges which may lead to metallosis and osteolysis. These make early loosening of the implant more likely.

It is not always easy to identify impingement on the basis of patient medical history, clinical examination or radiographic studies, given that it is a dynamic process. Patients with pain and subluxation require CT scans to identify the presence of osteophytes and the relative position and orientation of the components. (Cuéllar et al., 2009; Cuéllar et al., 2010; Pierchon et al, 1994). As we have indicated in previous studies (Cuéllar et al., 2009, 2010), the best way to demonstrate the existence of instability is by Examination Under Anesthesia (EUA) with X ray control (Fig- 4 A,B A,B).

Hip resurfacing implants, having larger femoral heads, offer a greater degree of mobility and stability but the ideal ratio between femoral head and neck is hard to achieve and, therefore, they involve a higher risk of impingement with associated instability (Fig-4 B). (Bajwa & Villar, 2011; Cuéllar et al., 2009; Cuéllar et al., 2010; Khanduja & Villar, 2008).

#### **2.6 Pain of unknown origin - Other causes of pain**

In around 1% of the cases the cause of pain remains unknown.

Lumbar spine and radicular pain should be ruled out because of the well known association between degenerative changes in the spine and hip joint. Pain in the gluteal area extending beyond the popliteal region also suggests that it has its origin in the lumbar spine (Bozic & Rubash, 2004; White, 1998). Patients with lumbar spine disorders may experience worsening of radicular pain after hip replacement surgery due to increase in mobility and physical activity (Bozic & Rubash, 2004; Bohl & Steffee, 1979).

Pain that begins when a patient starts walking is commonly associated with loosening, and iliopsoas tendonitis, but it can also be derived from lumbar spine disorders (Bozic & Rubash, 2004; Bohl & Steffee, 1979)

Arthroscopy after Total Hip Replacement Surgery 87

In all cases, we complete a diagnostic protocol including a full clinical history, blood tests (FBC, ESR, CRP); imaging tests (X-rays, CT and MRI scans); scintigraphy (Tc, Ga, In labeled leukocytes); and ultrasound-guided psoas injections. In some cases scintigraphy and CT

We perform arthroscopic surgery before indicating revision total hip replacement surgery in

The anaesthetist selects the most appropriate anaesthetic technique in each case: spinal

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

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

To gain access, progressive larger dilatators are slid into position through a nitinol

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

Fig. 5. Introduction of a "nitinol" guide wire under fluoroscopic control (A) Progresive

The indications for psoas tenotomy are tendonitis or painful internal snapping hip syndrome that have not improved with conservative treatment, in particular with

scans are repeated after a period of at least 3 months to rule out implant loosening.

all cases of persistent pain where the cause of this has not been clearly identified.

Patients fulfil an informed consent form.

The procedure lasts between 60 and 90 minutes.

assess instability and the presence of "snapping". Joint distraction is required only in a few cases.

larger dilators are slide into position (B).

**3.2 Specific surgical procedures** 

**3.2.1 Psoas tenotomy** 

anaesthesia, general anaesthesia or a combination of both.

guidewire previously inserted under fluoroscopic control (Fig. 5 A, B).

**3.1 Surgical procedure** 

may be additionally used

condition itself.

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

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

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, 1992).

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

A detailed history should provide us information and enable a more accurate diagnosis (Bozic & Rubash, 2004).
