The painful total hip arthroplasty is a serious problem in orthopaedics that is difficult to diagnose. In most cases, pain in a patient with a total hip arthroplasty is caused by loosening of one of the two components, that is, of the femoral stem or of the acetabular implant. In most such cases the diagnosis can be made by imaging, such as plain radiographs, computed tomography, magnetic resonance imaging or a bone scan. In some cases, however, the pain may be caused by other, less common causes, one of which is impingement against the iliopsoas tendon.
The iliopsoas tendon is the termination of a fairly large and powerful flexor of the hip. The anatomy of the muscle is such that it essentially runs directly in front of the hip joint. The muscle therefore comes into close contact with the joint.
In recent years there has been an ever-increasing tendency to use large-sized implants in total hip arthroplasty. The reason is that the use of a large-diameter head, fitted to an acetabular implant of corresponding size, is associated with significantly lower rates of dislocation. The use of implants of such dimensions has therefore been increasing steadily in recent years. However, because of the large diameter of the components, they are more likely to come into greater contact with the anterior structures of the hip joint, the most important of which is the iliopsoas tendon.
In general, it is difficult to prove that pain after total hip arthroplasty is caused by impingement against the iliopsoas tendon. The diagnosis rests mainly on clinical findings, but also on supplementary imaging investigations. In such cases iliopsoas tenotomy has been proposed in order to remove the cause of the pain. This treatment is carried out in many centres worldwide in comparable cases, without any systematic recording of the results. Only a few studies have assessed the results of open or endoscopic-arthroscopic iliopsoas tenotomy.
In a recent study published in the journal “Orthopaedic Traumatology and Surgical Research”, an attempt was made to confirm the hypothesis that endoscopic-arthroscopic iliopsoas tenotomy can provide rapid relief from pain and has low complication rates.
This prospective multicentre study included 63 cases of endoscopic or arthroscopic tenotomy for impingement between the acetabular implant and the iliopsoas tendon, carried out in eight different hospitals. The mean follow-up was eight months, with a minimum period of six months and no patients lost to follow-up. At follow-up, the Oxford hip score, the patient’s subjective satisfaction, anterior pain and iliopsoas strength were assessed. All complications and previous operations were also recorded. 44% of the patients followed a rehabilitation protocol.
At the final assessment, 92% of patients reported relief of their symptoms. The Oxford score, muscle strength and pain on hip flexion showed significant improvement. The complication rate was 3.2%, with complete resolution of all cases, however. The mean hospital stay was 0.8 nights. In two cases arthroscopy revealed metallosis, giving the indication for revision and exchange of the acetabular implant. The only predictive factor was the prominence of the acetabular implant on the oblique radiograph. Rehabilitation significantly improved muscle strength.
The authors of the study concluded that endoscopic or arthroscopic tenotomy for impingement between the acetabular implant and the iliopsoas tendon after total hip arthroplasty gives significant relief from anterior pain in more than 92% of cases. The low complication rate makes this treatment option the treatment of choice in cases where conservative treatment has failed. Arthroscopy can also redefine the diagnosis in cases with pathology of the prosthetic joint. The projection of the acetabular implant on the preoperative oblique view is the most important predictive criterion and can guide treatment.
Source: Guicherd W, Bonin N, T Gicquel, Gedouin JE, Flecher X, M Wettstein, Thaunat M, Prevost N, Ollier E, May O; French-speaking Arthroscopy Society. Endoscopic or arthroscopic iliopsoas tenotomy for iliopsoas impingement followingtotal hip replacement. A prospective multicenter 64-case series. Orthop Traumatol Surg Res. 2017.