Computer-navigated revision total knee arthroplasty for failed unicompartmental knee arthroplasty.

The most frequent technical difficulty encountered at unicompartmental knee arthroplasty (UKA) revision to total knee arthroplasty (TKA) is filling in all bone defects. These bone defects can render difficult components positioning, mechanical axis restitution, and ligament balance assessment, which are the three most important parameters for successful TKA. We describe a computer-assisted technique which makes it possible to control these three parameters before removal of the implants that have caused the bone defects. Our study is based on a series of 20 cases, with a minimum follow-up of 2 years. The anatomical and clinical results were very satisfying and comparable to results of primary TKA. We recommend this computer-navigated technique, which is as simple as a primary TKA procedure.

[Total hip arthroplasty in patients with chronic renal failure transplant or dialysis]. / Arthroplastie totale de hanche chez l'insuffisant rénal chronique greffé ou dialysé.

PURPOSE OF THE STUDY: Total hip arthroplasty (THA) is generally proposed for renal transplant patients with invalidating hip disease. For patients on chronic dialysis, the few published series report a higher rate of complications. These patients are considered more vulnerable. We report the results of a retrospective mid-term analysis of 28 renal failure patients (37 hips) with THA comparing renal transplant recipients with chronic dialysis patients. MATERIAL AND METHODS: THA was performed on 37 hips in 28 patients with renal failure between January 1993 and 2004. Treatment for the renal disease was transplantation or chronic dialysis. Mean patient age at the time of the arthroplasty was 56 years. Nine patients had bilateral THA. At review, four patients had died and none were lost to follow-up. Mean time between transplantation and hip arthroplasty was 9.9 years. Among the fourteen dialysis patients (21 hips), five had had a renal transplant. Mean time from onset of dialysis to arthroplasty was 12.3 years. At mean postoperative follow-up of six years (range 24 months to 12 years), 24 patients were living. Thirty-five hips had no surgical history. Aseptic osteonecrosis was the dominant etiology (75% of operative indications in the graft group and 52% in the dialysis group). The preoperative Postel-Merle-d'Aubigné score was 7.6 in the dialysis group and 10.3 in the graft group. Most of the cups were not cemented (n=31, 84%), as were most of the stems (n=29, 78%). All survivors were reviewed. The PMA score was determined. RESULTS: Early postoperative complications in the dialysis patients were: deep vein thrombosis (n=3), pulmonary embolism (n=4), operative site hematoma (n=2) and immediate septic complication with prompt revision and preservation of the implants (n=1). For the graft group, complications were: early dislocation (n=2), lung disease (n=3). Four patients, all in the dialysis group, died. At review, the mean PMA score was 14.2 in the dialysis patients and 15.7 in the graft patients. There were no radiological signs of loosening, nor of polyethylene wear, and no ectopic ossifications could be identified. There were no late infections. DISCUSSION: In renal transplant recipients, total hip arthroplasty is a reliable treatment for hip disease, providing good mid-term results and a morbidity close to that observed in the general population. Conversely, dialysis patients have a greater perioperative morbidity. Use of non-cemented implants is not associated with a higher rate of loosening than with cemented implants. It can be recalled that this type of surgery must be performed within the framework of careful pluridisciplinary patient management.

[Total hip arthroplasty after hip arthrodesis performed for septic arthritis]. / Désarthrodèse-prothèse de hanche pour séquelle d'arthrite septique: apropos d'une série de 17 cas à 6 ans de recul.

PURPOSE OF THE STUDY: Revision total hip arthroplasty (THA) after hip arthrodesis is an uncommon and challenging operation. The task would appear to be even more difficult if the arthrodesis was performed because of septic arthritis due to the theoretical risk of recurrent infection. We report our fifteen-year experience. MATERIAL AND METHODS: This retrospective study concerned 17 procedures performed in 17 patients (11 women, 6 men) between 1988 and 2003 on 5 right and 12 left hips. All of the patients had arthrodesis for sepsis: eight subsequent to tuberculosis and nine subsequent to septic arthritis (Staphylococcus aureus). We examined the impact of the initial arthrodesis (surgical technique, position, leg length) on neighboring joints and indications for de-fusion. Mean age was 53 years (range 32-74) and on average, the patients had a fixed hip for 36 years (range 7-59). Mean follow-up was six years (range 11 months to 15 years). Revision surgery was performed via a posterolateral approach for 12 hips (nine trochanterotomies) and via an anterolateral approach for five hips for implantation of nine cemented implants, six press fit implants, and two hybrid implants (cemented cup and press fit stem). Clinical assessment at last follow-up noted pain, walking capacity and joint motion. Leg length discrepancy was measured and complications were noted. RESULTS: The position of the original arthrodesis was considered satisfactory (flexion 20 degrees , adduction 0-10 degrees , external rotation 0-20 degrees ) for eight hips; leg length discrepancy was 4 cm (2-8 cm). Neighboring joints involved concerned the lumbar spine in 15 patients, the ipsilateral knee in ten patients, the contralateral knee in eight and the contralateral hip in six. The decision to remove the arthrodesis was based on functional needs related to lumbar pain (n=6), the homolateral knee (n=10, limping and leg length discrepancy), or an operation on the ipsilateral knee. After surgery, 14 hips (83%) were free of pain with improvement of the lumbar pain and pain of the homolateral knee. Six patients walked without support but 16 still had a limp. Flexion was 78 degrees . Leg length discrepancy was 2.5 cm on average and seven patients had balanced limbs. The postoperative period was uneventful for 14 of 17 patients (one paresia of the common fibular nerve, one femoral phlebitis, one early infection). Six late complications were noted: nonunion of the greater trochanter (n=2), recurrent ankylosis (n=1) and loosening (n=3). DISCUSSION AND CONCLUSION: An earlier history of infection does not appear to be a contraindication for implantation of a total hip arthroplasty after hip arthrodesis. Despite the long recovery period and the modest gain in joint motion, 80% of patients were satisfied after having had a blocked hip for 36 years on average.

[Aspergillar prosthetic hip infection with false aneurysm of the common femoral artery and cup migration into the pelvis]. / Infection aspergillaire et faux anévrisme mycotique fémoral au cours d'un descellement de prothèse totale de hanche avec migration intra-pelvienne de l'implant acétabulaire.

We report a case of Aspergillus fumigatus infection of a total hip arthroplasty. This rare infection was demonstrated at surgical revision of a loosened prosthesis with migration of the cup into the pelvis associated with a false aneurysm of the femoral artery. A vascular time was required before the orthopedic revision. This case illustrates the importance of the preoperative work-up in the event of cup migration. The double approach was required in our patient to control and repair the vascular structures. The difficult treatment of Aspergillus fumigatus is also discussed.

[Total hip arthroplasty after treatment of acetabular fracture]. / Arthroplastie de hanche pour séquelle de fracture de l'acétabulum.

PURPOSE OF THE STUDY: The aim of this retrospective analysis was to examine complications and technical difficulties observed during implantation of total hip arthroplasty (THA) after treatment of an acetabular fracture. MATERIAL AND METHODS: Forty patients (thirty men and ten women), mean age 50 years, were included in the study. The acetabular fracture had been treated surgically in 23 and orthpedically in 17. Mean time from initial trauma to implantation of the THA was eleven years. Hydroxyapatite-coated cups were inserted without cement in 32 patients. Cemented cups in eight (with two Kerboull cross, one Muller ring, and five simple polyethylene). Five femoral stems were cemented. Preoperative planning was designed to restore the center of the initial hip rotation to avoid excessive cup medialisation. Acetabular defects found intra-operatively were significantly greater in the group of patients treated orthopedically than in those treated surgically (p = 0.02). Autografts were thus used more frequently in the former (65%). RESULTS: One patient presented an intraoperative complication. The postoperative complications included phlebitis (n = 1), infection (n = 1), fibular nerve paralysis (n = 2), dislocation (n = 4), and heterotopic ossification (n = 7). The rate of postoperative complications was significantly higher in the group of patients treated surgically (52.2% versus 17.6%, p < 0.02). At last follow-up, mean 52 months, the mean Postel-Merle-d'Aubigne function score was 16.7. The rate of acetabular revision was 15% with four cemented cups being replaced at more than ten years due to aseptic loosening. Two press-fit cups were replaced early for infection in one patient and disassembly in another. DISCUSSION: Despite the high rate of complications, the mid-term results were good, encouraging us to continue this procedure as the first intention treatment using either a press fit cup with or without an autograft, or a cemented cup with a metal ring (Kerboull or Burch-Schneider).

[Desmoplastic fibroma or bone desmoid tumor: two cases]. / Le fibrome desmoplastique ou fibrome desmoïde osseux: à propos de 2 nouveaux cas d'une tumeur osseuse rare.

Desmoplastic fibroma or desmoid bone tumor is a rare tumor described for the first time by Jaffe in 1958. It accounts for 0.1 to 0.3% of all benign bone tumors. To date, about 150 cases involving the locomotor system have been reported. Histology is required for certain diagnosis of desmoplastic fibroma. The tumor is composed of sparse fibroblasts in a rich background of collagen fibers, a histological presentation exactly the same as soft tissue desmoid fibroma. We report two new cases of desmoplastic fibroma of the locomotor system. The observations illustrate the radiological diagnosis. MRI was used to search for local extension in bone or soft tissues. Biopsy is necessary to confirm the diagnosis. The histological presentation may be difficult to recognized and distinguish from low grade fibrosarcoma. After treatment, the rate of local recurrence is high in the event of partial resection. Surgery is the optimal treatment, with tumor resection as wide as possible depending on the localization.

[Surgical treatment of acetabular fractures: outcome in a series of 60 consecutive cases]. / Traitement chirurgical des fractures de l'acétabulum: résultats d'une série continue de 60 cas.

PURPOSE OF THE STUDY: The aim of this study was to analyze clinical and radiographic results after surgical treatment of acetabular fractures. MATERIAL AND METHODS: We reviewed 60 consecutive fractures of the acetabulum with loss of joint congruency at mean 5-years follow-up after treatment. There were 49 men and 11 women, mean age 41 years. According to the R.O. grading, the fractures were: 22 class A (33.3%) including 17 type A1, 23 class B (38%) including 10 type B1a2, 14 class C (23.3%) and 1 unclassifiable. Eight of the patients had associated pelvic injury, 40 had hip dislocations and 9 had sciatic nerve injury. Ten femoral head fractures were discovered during the surgical procedure. Three surgical approaches were used: 1) Kocher Langenbeck approach (28 cases), 2) Mears and Rubash triradiate approach (8 cases), 3) extended iliofemoral approach (22 cases), 4) other approaches (2 cases). Anteroposterior and 45 degrees oblique view of the pelvis were obtained for all patients following admission. Computerized tomography scans were performed in all cases. Fracture displacement and congruency of the femoral head with the roof were documented according to the SOFCOT radiographic criteria. The quality of reduction was assessed using the Matta criteria and the Duquennoy and Senegas criteria. Clinical outcome was assessed at follow-up using the Postel-Merle-d'Aubigné score. RESULTS: Anatomic reduction was achieved in 62% of the cases (1 mm or less displacement on all views) and congruency of the femoral head with the roof was excellent in 73% of the cases. Clinical outcome was satisfactory in 80% (excellent or good). Operative complications included significant ectopic bone in 21, and in 2 others sciatic nerve palsy that had resolved at 1 year follow-up. Three patients developed avascular necrosis of the femoral head. DISCUSSION: Clinical outcome depends on the quality of the reduction. Class C and class B fractures with roof injury should thus be treated by large surgical exposure. The triradiate approach increases the incidence of ectopic bone. The higher incidence of ectopic bone in patients treated by osteotomy of the trochanter compared with patients without osteotomy of the trochanter was significant (p<0.05). Avascular necrosis of the femoral head was associated with delayed reduction (66% of the cases). CONCLUSION: Our good clinical results are encouraging; we are pursuing the use of surgical treatment for displaced acetabular fractures. Clinical outcome depends on the use of the appropriate surgical approach.