[Electromyographic examinations of the gluteal and adductor muscles after arthrodesis of the hip (author's transl)]

Ergebnisse und Erfahrungen der Remobilisation von H�ftarthrodesen

INTRODUCTION

With the predictably good outcome of total hip arthroplasty today (THA), hip arthrodesis currently has limited indications. Over the long term, however, most patients develop secondary degenerative arthritis in the spine, contralateral hip, and ipsilateral knee due to overloading. The deteriorating condition of these joints eventually causes the onset of pain, which often requires conversion of a fused hip to a THA. The results and experiences of conversions of a hip arthrodesis into a THA are reported.

INTRODUCTION

Between 1 January 1985 and 31 December 2001 conversion of a previously performed arthrodesis of the hip to THA was carried out in a total of 45 patients; 34 patients could be followed up after the conversion to THA after a mean of 77.5 months (min.: 24, max.: 208). The primary indications for the conversion were low back pain (n=21) and ipsilateral knee pain (n=13).

RESULTS

The mean age at the time of THA was 75.3 years (min.: 32, max.: 74). The mean time interval between the arthrodesis and the conversion to THA was 30.4 years (min.: 5, max.: 66). Of 34 hips, 29 (85%) were either pain free or had minimal pain. Complications included one persisting sciatic nerve palsy, two superficial infections, two periprosthetic fractures, and two heterotopic ossifications IV degrees with one recurrence of ankylosis and one marked reduction of motion. Revision arthroplasty was performed in four hips. Postoperatively 7 patients showed no limping, 11 showed a slight limp, and 17 a pronounced limp. Recurrent dislocations occurred in one patient.

CONCLUSION

We conclude that this operation can lead to satisfactory results even after a long duration of the arthrodesis. There is a high rate of complications after conversion of a hip arthrodesis to a total hip arthroplasty. These issues must be carefully considered and discussed with the patient before any conversion procedure.

Hip and knee replacement after longstanding hip arthrodesis

This study determined whether patients with severe knee disease below a hip arthrodesis can be treated successfully with total knee replacement alone or whether such patients require total hip arthroplasty followed by knee replacement. Eighteen patients who had hip arthrodesis for a mean of 33 years underwent total hip replacement alone, total knee replacement alone, or a combination of both. The Harris hip score improved from a mean of 55.3 to a mean of 86.9 points at 45 months after total hip arthroplasty. The Hospital for Special Surgery knee score improved from a mean of 33 to a mean of 78 points in patients who had total knee replacement after total hip arthroplasty. The Hospital for Special Surgery knee score improved from a mean of 35 to a mean of 44 points in patients having total knee replacement alone below a hip arthrodesis. The followup after total knee replacement averaged 53 months. These data suggest that a knee replacement alone in a patient with a fused hip is unlikely to provide a satisfactory result. Patients with severe knee disease below hip arthrodesis require total hip arthroplasty followed by knee replacement. This applies even when severe osteoarthritis of the knee is the primary complaint.

[Total prosthesis after ankylosis of the hip joint. Report of 22 cases]

Between 1968 and 1987 we carried out a total replacement arthroplasty on 22 hips which were either ankylosed or had previously undergone arthrodesis. The hips were revised because of pain due to pseudoarthrosis or malposition, pain in the other joints such as the lumbar spine, the ipsilateral knee or the contralateral hip, fractures about the hip, or professional disability. Significant functional and subjective improvement was obtained. The revised hips were painfree, stable and had an average range of flexion of 70 degrees. Pain in other joints was improved if their degenerative changes were moderate, but many required further procedures. Revision of a hip arthrodesis to a replacement arthroplasty is a worthwhile procedure in suitable cases.

Selective type II fibre muscular atrophy in patients with osteoarthritis of the hip

The size and the distribution of type I and tye II fibres was determined in the gluteus maximus (21 cases), gluteus medius (56 cases) and tensor faciae latae (27 cases) muscles of patients with osteoarthritis of the hip. The patients were of both sexes, aged between 37 and 64 years (younger group) and between 65 and 78 years (older group). Autopsy material of the two comparable age groups and of a group of "normal" adults (aged 22-44 years) served as controls. It was shown statistically that the diameter of both types of fibres and the relative number of type II fibres diminished with progressing age. In patients with osteoarthritis the degree of the selective atrophy of type II fibres was significantly higher than in the control groups. The atrophy is interpreted as a consequence of diminished muscular activity. No neurogenic lesions were detected either in the muscles of the patients or in those of the control groups.