Purpose: According to the Finnish registry, the ABG1 stem has a 94% survival (90–98) at seven years. A multi-centric study in Torino found 99% survival at five years. These studies have however reported worrisome radiographic images showing absorption of the calcar in 27% of the cases. We studied the clinical and radiological outcome of 102 ABG1 stems inserted between September 1990 and December 1996.

Material: This prospective study included 91 consecutive patients (102 hips): 75 men and 27 women, mean age at surgery 63.1 years (range 34–81). The posterior approach was used for treatment of degenerative joint disease (82%) or osteonecrosis (11%). A size 5 or 6 stem was inserted in 60% of the cases. A metal-backed cup with a polyethylene insert was used in 45%, a zircona cup in 55%. The head diameter was 28 mm in 91% of the cases. At review, five patients had died, ten were lost to follow-up, eight responded to a phone interview, and x-rays were obtained for 79. Mean follow-up was 90.6 months (median 86.4 months).

Methods: The Postel Merle d’Aubigné (PMA) and Harris (HHS) scores were recorded for all patients. Position and quality of bone fixation were analysed. Stem migration was calculated on the different x-rays by calculating the distance between the centre of the head and the summit of the greater trochanter. Lucent lines (Gruen), osteolysis and the ARA score were noted. The SOFCOT 1997 radio-clinical classification was used. Actuarial survival curves were plotted taking stem revision as the endpoint. Quantitative data were compared with the chi-square test.

Results: The PMA pain score improved from 2.9 to 5.7 and the overall PMA score from 11.2 to 15.7. The HHS at last follow-up was 83.6 points. The stem was perfectly aligned in 81 cases, showed varus deviation in 26 and valgus deviation in four. A change from the initial alignment was noted in three cases and stem impaction in two. Six stem revisions were required for malposition (n=1), fracture during operation (n=3), or pain (n=2). Finally, there were no radiographic anomalies for 53 hips (class A), radiographic anomalies without clinical expression for 17 (class B), pain without detectable radiographic anomaly for six (class C), and poor clinical results with radiographic anomalies for four (class D). The ARA score was 5 or 6 in 51 cases. The 15-year actuarial survival rate was 88.9±4%.

Discussion: The form of the ABG1 implant allows an excellent alignment in only 80% of the cases. The metaphyseal anchor is achieved by bone remodelling of the calcar (23 atrophies including 10 severe cases)—to be differentiated from osteolysis (8 cases)—and an excessively transparent femur in the proximal 1A, B and 7 (12 cases). Transmission of force to the diaphyseal zone remains abnormal (30 thickenings with four overall thickenings) and two severe cases of diaphyseal necrosis.

Conclusion: The changes in the design of the ABG2 which has an under-dimensioned stem should improve shaft remodelling. The form of the implant and the favourable effect of hydroxyapatite coating responsible for bone remodelling in zone 1 and 7 (Gruen) should be given particular attention in the upcoming years.

Purpose: Removing cement for revision total hip arthroplasty is always a challenge. The OSCAR device (Orthosonics Ltd UK) provides an elegant solution. We conducted a prospective study of ultrasound ablation using this device in 19 patients undergoing revision total hip arthroplasty to assess feasibility.

Material and methods: Between March 1999 and January 2001, 17 patients, ten women and seven men underwent revision of their femoral component for aseptic loosening (14 cases) or infection (five cases). The Vives criteria as modified by SOFCOT were six grade 1, six grade 2, five grade 3 and two grade 4. The femoral stem removed had a standard length in 17 cases and measured 250 mm in one. The cement obturated the femur in one case with a proximal misinsertion. On the average, the terminal plug went 40 mm beyond the tip of the stem. Trochanterotomy was used ten times and anterior approach in nine. Two ultrasound probes were used: scraper probes that removed cement from the walls and a perforating probe when needed to remove the terminal plug. We recorded the time needed to remove all the cement, the ease or difficulty of the process, the presence of misinserted cement, need for other methods (new window, femorotomy), duration of the hospital stay, and delay to weight-bearing with crutches. The quality of the cementing and presence of cement overflow were determined on plain radiographs. All patients were reviewed for this work.

Results: It took less than 60 min to remove the cement in 14 cases and from 60 to 90 min for four cases; the cement could not be totally removed in one case. There was one fracture (grade 4 during a third revision operation). The end plug was removed under good conditions in 14 cases. The femoral stem could be recemented in nine cases using a longer stem in five. Cementing was satisfactory in 12 cases. Deferred surgery was required for the five cases with infection; in two cases the cement persisted at the second operation requiring a new ablation process. There were no cases of misinsertion. Mean hospital stay was 10.1 days and weight-bearing was authorised on the third day for patients without infection. At a mean follow-up of 8.5 months, there have been no cases of revision, fracture or stem migration.

Discussion: The rate of total hip arthroplasty revision is an estimated 10%. The risk of an incident during cement ablation is an estimated 18% to 28%. Advantages of the ultrasound technique include: shorter operative time, simple material, less danger for weak bone as noted in our patients, absence of the need for complementary fixation, shorter hospital stay, and lower cost. Histology studies have demonstrated the absence of deleterious effects of ultrasound ablation explaining the good quality of recementing (12 cases).

Conclusion: Ultrasound ablation of femoral cement is effective for aseptic revision. In case of infection, the presence of persistent cement might be related to recurrent infection.

Purpose: Loosening and wear of the polyethylene insert remains an important problem after ten years. The Harris-Galante 1 (HGP1) press fit titanium backed cup appears to provide an interesting alternative. We studied the clinical and radiological outcome of 191 total hip arthroplasties performed between June 1985 and June 1990.

Material and methods: This prospective continuous series included 174 patients (191 hips), 76 women and 98 men, mean age 62.1 years (19–83). The posterior approach was used in all cases for treatment of degenerative hip disease (80%) or osteonecrosis (14.6%). The polyethylene-metal cup was used with a 28mm head in 90.7% of the cases. The press-fit cup was fixed with three screws. At review, 39 patients had died (45 hips), 25 were contacted for a phone interview, and two were lost to follow-up; 119 patients were re-examined and had a standard radiography series at last follow-up. Mean follow-up was 11.9 years (10–15). The Postel Merle d’Aubigné (PMA) score and the Harris hip score (HHS) were used to assess outcome. Quality of bone fixation and cup migration were studied as were lucent lines classed according to De Lee. Wear was calculated using the Livermore method and osteolysis using the Mulroy method. Actuarial survival curves were plotted using reoperation as the end-point if the polyethylene insert was changed or revision if the cup was changed for any reason. Qualitative data were compared using chi square test.

Results: There was one death on day three and three dislocations including two requiring reoperation for an insert overhang. The PMA pain score improved from 2.58 to 5.5 and the overall PMA score from 10.5 to 16.2. the HHS improved from 53.5 to 87.2 points. A lucent line measuring < 1 mm was found in 12 cases; one was complete, nine were in a single zone. Osteolysis was found in 28 cases and was qualified as severe in four. Mean polyethylene wear was 0.1 mm (volume 65.5 mm³). There was no case with cup migration or cup tilt and none of the cups had to be changed. Five polyethylene inserts were changed due to wear at a mean 145 months. The actuarial survival curve taking into account the seven insert changes showed a mean 15-year survival of 96.7±3%.

Discussion: The Harris-Galante press-fit cup has exhibited good behaviour at a mean 11.9 years follow-up. Mean annual wear was = 0.1 mm in 42 patients; it was > 0.2 mm in 18 patients including five who required reoperation to change the insert at 145 months. Osteolysis was noted in 28 cases, an important problem.

Conclusion: With only two patients lost to follow-up at ten years, this prospective review demonstrates well that the press-fit cup is well tolerated which has suffered from comparison with cemented cups. Five worn inserts had to be changed, requiring a simple operation. There were four cases of severe osteolysis.