Purpose of the study: Revision total knee arthroplasty with major destruction of bone and ligament tissue raises the problem of choosing between a complex reconstruction with a semi-constrained prosthesis or a much more simple procedure using a hinged prosthesis which transmits all of the stress to the bone anchors. The choice is basically one of longevity of the bony fixation of these constrained prostheses (and the deterioration of the articulated pieces). The present work reports the long-term outcome observed with constrained hinged prosthesis with a cemented press-fit stem implanted for bone tumors where the stress is even greater than for revisions.

Material and methods: The series included 32 prostheses implanted in young active subjects (mean age 33 years). A hinged, non-rotating Guepar II revision prosthesis was implanted. The part of the implant corresponding to the reconstruction after tumor resection was custom-made but the part implanted in «healthy» bone (for example the tibial piece in a patient with a femoral tumor) was the same as used for revisions prostheses inserted after loosening. On the healthy side, press-fit quadrangular stems were used, generally adapted to the endosteum by reaming. The prosthesis was fixed by simple mechanical adjustment before cementing, using the French paradox system (JBJS 2003). Before 1993, a metal-polyethylene bearing was used and after 1993 a metal-on-metal bearing without inserts.

Results: Among the 32 patients with a malignant tumor, 19 survived, seven with 2–10 years follow-up and 12 with 10–21 years follow-up. For the overall series, there was only one case of osteolysis on a tibial tumor which was revised at 12 years. There was one infection (hematogeneous) at 21 years (antibiotic cement). Prostheses with polyethylene inserts produced laxities or synovitis with 50% requiring synovectomy and insert replacement. There were no cases of synovitis for the metal-on-metal bearings. Two stems (inserted in adolescents) were too thin and had to be changed because of fracture without loosening.

Discussion: Prosthesis survival was 88% at ten years (1 osteolysis, 2 fractures on tumor), even for the constrained prostheses, even for young and active subjects.

Conclusion: The very good longevity of cemented pressfit stems (and the absence of synovitis and osteolysis with metal-on-metal bearings, and the low rate of infection) should be kept in mind as a possible alternative to very complex and possibly less predictable procedures in the presence of certain very severe loosenings with bone and ligament destruction.

We evaluated the long-term fixation of 64 press-fit cemented stems of constrained total knee prostheses in 32 young patients with primary malignant bone tumours. Initial stable fixation, especially in rotation, was achieved by precise fit of the stem into the reamed endosteum, before cementation. Complementary fixation, especially in migration and rotation, was obtained by pressurised antibiotic-loaded cement. The mean age at operation was 33 years (13 to 61). No patient was lost to follow-up; 13 patients died and the 19 survivors were examined at a mean follow-up of 12.5 years (4 to 21). Standard revision press-fit cemented stems were used on the side of the joint which was not involved with tumour (26 tibial and six femoral), on this side there was no loosening or osteolysis and stem survival was 100%. On the reconstruction side, custom-made press-fit stems were used and the survival rate, with any cause for revision as an end point, was 88%, but 97% for loosening or osteolysis. This longevity is similar to that achieved at 20 years with the Charnley-Kerboull primary total hip replacement with press-fit cemented femoral components.

We recommend this type of fixation when extensive reconstruction of the knee is required. It may also be suitable for older patients requiring revision of a total knee replacement or in difficult situations such as severe deformity and complex articular fractures.

Purpose: A consecutive series of 32 metaphyseal locked hydroxyapatite coated stems were reviewed at a maximum 5 years to analyse the effect of the type of distal (diaphyseal) and proximal (metaphyseal) fixation on clinical and radiological outcome (distal shaft fixation: tight or moderate; hydroxyapatite coating: complete or limited to metaphysic; approach: window or endofemoral).

Material and methods: Stems were used to treat femoral osteolysis (35% SOFCOT stage III and IV femoral loosening) with significant acetabular osteolysis (59% segmentary osteolysis and 47% revisions with structural allografts). Nineteen stems were implanted with a femoral window and 13 via endofemoral access. Twenty-six were screw locked. To study the effect of the type of fixation on clinical and radiographic outcome, we studied metaphyseal “regeneration”, and intraoperative diaphyseal anchorage. Anchorage was considered tight when the endosteum and the stem were in contact over at least 40 mm, and the difference in diameter between the stem and the endosteum was 1 mm or less. Anchorage was considered moderate when the height of contact was less than 40 mm and the endosteumstem difference in diameter was greater than 2 mm.

Results: The results were encouraging, with a clinical score (PMA) of 15/18, and stable diaphyseal fixation of the prosthesis in 31 hips (one migration of about 1 cm with secondary blockage in one non-locked stem). There were few complications: no infections, one isolated dislocation, one screw fracture, but three replacements of overly long stems, one trochanteric non-union which was not reoperated. In 22 hips with more than one year follow-up, shaft fixation of the stem was complete (no osteolytic lucent line), and a line of bone densification (particularly in hips with less solid anchorage) was seen in ten hips. There appeared to be bone regeneration around the hydroxy-apatite metaphysis in 50% of the cases. There were no cases of secondary osteolysis. This “regeneration” did not appear to be different after window or endofemoral replacement. It was the same with tight (63% of hips) or moderate anchorage. There was no stress shielding even when the distal stem was coated with hydroxyapatite.

Conclusion: It appears that good results can be obtained at mid-term with this type of prosthesis using a short distal (60 mm) fixation, limiting the diaphyseal escalation and requirement for femoral window.

Purpose: In 1996, we reported the results of 65 coracoid blocks for chronic anterior instability. We found 6% true recurrence and 34% persistent apprhension. In order to improve these results, we modified our operative technique, associating capsuloplasty in the event of hyperlaxity. The purpose of the present work was to assess mid-term results.

Material and methods: Eighty-eight coracoid blocks were performed between 1995 and 2000 by the same operator. In 41 cases, the classical technique was used. In 47 cases we associated capsuloplasty. The indication for surgery was documented recurrent instability in all cases, with radiographic, MRI or endoscopic confirmation of an anteroinferior capusloligament lesion. Capsuloplasty was associated if signs suggested hyperlaxity: self-reducing dislocation, absence of notch, external rotation arm to body (RE1) greater than 80°, presence of a significant groove, laxity of the inferior flap of a T capsulotomy. Mean patient age was 24 years (14–42) and mean follow-up was 40 months (24–60). Clinical results were assessed with the Duplay criteria and three x-rays were obtained (standard AP, Lamy lateral view and glenoid lateral view).

Results: Eighty-five percent of the patients achieved a good or very good result according to the Duplay criteria. Eighty-eight percent of the blocks held without modification and 12% developed osteolysis. There were no cases of degeneration. One patient experienced recurrent dislocaion. The rate of persistent apprehension declined (12%) compared with our earlier experience. This improvement was achieved at the cost of greater loss of RE1 in the group with capsuloplasty (−20° versus −8°), but without impact on sports activity (82£% returned to their sports activities including 72% at the same level without significant difference between the groups with and without capsulotomy).

Discussion: These results demonstrate that capsuloplasty is warranted if there are signs of hyperlaxity. This technique allowed us to improve results concerning recurrence and persistent apprehension at the cost of less mobility but without effect on sports activities. We detail the objective criteria used to define hyperlaxity and describe the usual clinical expression of radiographic, arthroscopic, and arthroscopic findings.