Purpose of the study: Theoretically, long-term functional and radiographic degradation is predictable after ankle fusion, but sound evidence from consecutive analysis of the same cohort is lacking. The purpose of this study was to evaluate the same cohort of patients who underwent ankle fusion.

Material and Methods: The cohort included 52 ankle fusions which had been analyzed in 1984 at seven years (2–22 years) of follow-up then again in 2000 using the same evaluation criteria. Among the 52 patients, six were lost to follow-up, 20 had died and one had undergone leg amputation. The second analysis thus included 25 patients (18 men and 7 women), mean age 62±12.6 years (40–94) at the 2000 assessment performed 23±4.5 years (19–36 years) after the fusion. Functional outcome was assessed with the 100-point Duquennoy scale. Osteoarthritis of the subtalar and mediotarsal joints were assessed preoperatively and at follow-up using the same scale.

Results: The functional outcome did not deteriorate significantly between 1984 and 2000. The mean score was 65.8±22.6 (19–92) in 1984 and 64.7±18.3 (34–90) in 2000 (p=0.67). Fifteen patients (60%) had a good or very good outcome at seven years, and 14 (56%) at 23 years. Between 1984 and 2000, ten patients improved their score (on average 10.4 points, range 1–21 points), two had an unchanged score and thirteen a lower score (on average 10 points, range −1 to −24). Ten of these thirteen patients developed severe intercurrent conditions explaining the degradation. At last follow-up, sixteen ankles were pain free or nearly pain free. Twelve patients considered their ankle as a forgotten problem and had no regrets concerning the operation. The evolution of the subtalar joint in 16 cases (nine fusions including five at the same time as the ankle fusion and four performed within four years) showed that all developed early osteoarthrtic degradation with aggravation between 1984 and 2000, leading in the majority of cases to severe degenerative disease. This osteoarthritis was painful in less than one-third of the cases (including the four secondary subtalar fusions and the four sub-talar fusions which were painful at mobilization). The mediotarsal joints degradation was later and less severe than for the subtalar joint with a majority of moderate osteoarthritis. Ten ankles exhibited compensatory hypermobility of the forefoot measured at more than 15° without pain.

Discussion: This long-term follow-up with two successive assessments using the same evaluation criteria did not demonstrated late degradation of function expected after ankle fusion. It did show however the presence of radiographic degradation of the subtalar joint but with little clinical expression at a minimal follow-up of 19 years. There was no need for complementary fusion between 4 and 23 years follow-up.

Aims: We studied by means of a magnetic resonance imaging (MRI) protocol, the junction area between supratrochlear (ST) surface and the femoral trochlear groove (FT). The variations of this junction area are they correlated with the patientñs functional signs and with the patellar cartilage injuries?Method: We practised on 87 patients (64 patellar instability, 23 patellar pains) and 25 witnesses, an MRI: DESS and MPR sequences. The trochlear bump was studied in the sagittal plan according to the aspect of the junction area and in measuring itñs height. Results: The junction area was dismembered in 4 types according to its slope with the ST surface: ÒßatÒ, ÒroundÒ, ÒobliqueÒ and ÒsquareÒ. No atÒ typeÒßwas found in cases of FT dysplasia. The ÒobliqueÒ and ÒsquareÒ types were more frequent in cases of important projection of the FT (p< 0.0001). These two types were more frequently associated with the patellar cartilage injuries (p< 0.08). The trochlear projection was maximum (p< 0.0001) in FT dysplasia with spur, with a maximum effect in this case on patellar instability (p< 0.01) and also on patellar pain (p< 0.05). Conclusion: The junction area between the ST surface and the FT groove was dismembered in 4 types. A þrst ßat type without trochlear bump, and 3 types deþning a trochlear Òstep of stairÒ, round, square and oblique in order of growing gravity. The latter two were more common when patellar cartilage injuries existed.

Aims: This study compared in vivo kinematics of a posterior stabilized TKA inserted either with a fixed (FBC) or with a mobile bearing component (MBC). Methods: Ten patients with unilateral previously defined TKA were selected among 150 TKA performed in 2000 by a single surgeon according to the following criteria: primary TKA because of osteoarthritis, controlateral knee free of clinical symptoms, patient < 80, TKA flexion > 90°, knee IKS score > 80/100. Ten TKA (10 patients) were selected differing only by the adjunction of the mobile bearing (5 MBC and 5 FBC). The range of the 3 knee rotations (flexion, axial rotation, varus-valgus) were assessed by means of a 6-degree freedom electromagnetic goniometer during: level walking, rising from a chair, non weight-bearing flexion. Non-parametric tests compared motions between TKA and contro-lateral knee and between MBC and FBC. Results: FBC had a better mobility that MBC in valgus-varus, which was related to a larger frontal laxity. According to the increase in frontal laxity, FBC demonstrated better axial rotations that MBC in non-weight-bearing (NS). However, better ranges of axial rotation were recorded in MBC in weight-bearing (p< 0.05) (MBC axial rotation exceeded by 10° the motions of FBC). In patients with MBC, there was no difference in range of motion between the TKA and the controlateral healthy knee. In the FBC group the range of axial rotation was lower in the TKA by comparing with the controlateral knee (p< 0.05). Conclusion: With a unique prosthetic design our study suggests the role of MBC to reproduce a physiological range of axial rotation in weight-bearing. The MBC better reproduced knee kinematics Shoulder instability

Purpose: Use of a mobile tibial plateau for total knee arthroplasty (TKA) is designed to reduce wear and improve prosthetic kinetics. The purposes of this study were: 1) to compare the kinetics of a posterior stabilised TKA implanted with a fixed plateau (FP) or a mobile plateau (MP) and, 2) to determine whether the mobile plateau improves axial rotation.

Material and methods: Ten patients with a unilateral TKA (HLS) with a fixed or mobile plateau were selected for this study according to the following criteria: arthroplasty for degenerative knee disease, healthy contralateral knee, age < 80 years, pain-free prosthesis, IKS > 80/100, flexion > 90°, follow-up > 1 year. There were five patients with a fixed plateau and five patients with the same prosthesis except with a mobile plateau. Knee movement (flexion-extension, axial rotation, valgus-varus) were measured with an electromagnetic goniometer on the implanted and healthy sides. Four movements were recorded: walking, standing up sitting down, flexion-extension without loading. Amplitudes were compared with non-parameteric statistical tests between the healthy side and the implanted side and between the two types of implants

Results: The FP knees were more mobile in valgus-varus due to greater residual frontal laxity than the MP knees. This extra laxity generated excessive axial rotation on the FP during non-loaded movements. Conversely, when loaded, axial rotation of the MP knees was 10° greater (mean, p < 0.05) than for the FP knees, giving better stability in the frontal plane. This study did not demonstrate any difference in flexion between FP and MP. Patients with an MP prosthesis did not have significantly different amplitudes of the three movements for the healthy versus implanted knee. For the patients with a FP prosthesis, axial rotation and frontal plane movement was lower in the implanted knee than in the healthy knee (p< à.05).

Discussion: This study devoted to the design of a single prosthesis demonstrated the usefulness of the mobile plateau for axial rotation during loaded movement. The kinetics of MP prostheses is similar to that of the healthy knee. Better axial rotation with MP prostheses during loaded movements suggests the persistence of the plateau mobility which should be confirmed with a cinematographic study.

Purpose: The aims of this work were to assess very long-term outcome and to assess functional course of talocrural arthrodesis as well as to determine the clinical and radiological impact on adjacent joints.

Material and method: Fifty-two talocrural arthrodeses performed in 52 patients between 1963 and 1981 served as the reference population for this study. Clinical and radiological assessment of this series of patients was conducted in 1983, then again in 1999. Twenty-five talocrural arthrodeses in 25 patients were reviewed at a mean 23 years (19 to 36 years) (six patients were lost to follow-up, 20 had died, one had had leg amputation. The arthrodesis had been performed for advanced degenerative joint disease or to correct for post-traumatic deformity, or in two cases, for neurological varus equinus. Functional outcome was evaluated on the Duquennoy and Stahl score (100 points) that was also used for the intermediary assessment. Radiographic assessment included the position of the arthrodesis, the status of the adjacent joints (subtalar and mediotarsal), and residual motion of the forefoot.

Results: At 23 years follow-up, 13 patients (52%) had good (five patients) or very good (eight patients) function and 12 (48%) had fair function, according to the 100 point scale. There were no patients with poor function. Patients without intercurrent conditions (neurological or heart disease, obesity) had good or very good function in 80% of the cases. Patients were very satisfied in 48% of the cases, having “forgotten” their ankle. At the seven-year follow-up analysis, 15 patients (60%) had a very good (ten patients) or good (five patients) result, seven had a fair result, and three had a poor result. Comparing the 7-year and 23-year assessments did not disclose any significant degradation of the result (p = 0.07). Intercurrent conditions explained the two functional degradations, but there were also three functional improvements over the same period. Talocrural arthrodesis induced stiffness in the subtalar joint in all cases, associated with severe osteoarthritis with little clinical expression. There was a slow degradation of the mediotarsal joint but hypermobility useful for good function was maintained in 45% of the cases (mean 24°). Fair results were related to development of subtalar osteoarthritis, malposition of the arthrodesis in the frontal plane (rear foot varus) and presence of intercurrent conditions (cardiovascular, neurological disease).

Conclusion: Talocrural arthrodesis is a safe and reliable procedure for the treatment of destroyed joints. This palliative surgery can restore satisfactory function which persists in the long term.