Purpose: The purpose of this work was to validate the most reliable technique for obtaining ligament isometry of the knee in flexion.

Material and methods: This prospective series of non-cemented non-posterior stabilised Interax knee prostheses (Howmedica) implanted by the same surgeon included 57 genu varum knees with degenerative disease. Mean preoperative femorotibial varus was 8.23°. Landmarks used intraoperatively included the posterior condylar line (PCL), the biepicondylar line (BECL) and the Whiteside line (WL). Ligament balance was measured with the Derby tensor.

Results: The first part of the assessment concerned ligament balance in extension. Mean initial medial retraction, measured with the tensor, was 3.6°. Release of the concavity was performed in 62% of the knees with mean residual retraction of 1°. The second time was to evaluate balance at 90°. Using the anatomic landmarks, the PCL was parallel to the BECL in 22% of the knees and perpendicular to the WL in 26%. There was a weak angulation in 28% and 30% of the knees and in 50% and 44% respectively. There was thus a strong correlation intra-operatively between these two landmarks and the initial radiographic varus. Evaluation with the tensor showed mean 2.96° medial retraction. The correlation between the anatomic measures and the tensor ligament measures was very significant. When the BECL was parallel to the PCL, medial retraction with the tensor was 1.12°. The angulation was small, 2.25°. When the angle was wide, the mean measure was 4.4°. We found the same results with the WL. External rotation of the anteroposterior femoral cut was then guided by these different measures. It was 2.6° on average (0–6°). Residual medial retraction, measured with the tensor, was thus significantly improved, only 0.4° on average (−2 to +2).

Discussion: After ligament rebalancing in extension, there persisted frequently an imbalance in flexion (62%). This was independent of the preoperative varus. It was corrected by external rotation of the femoral implant, the value assess approximately from the landmarks. It was measured in our hands reliably with the Derby ligament tensor.

Purpose: Osteolysis is one of the important issues during the life of noncemented total hip arthroplasty (THA). The purpose of this study was to evaluate a series of 228 THA using an ABG-1 implant to determine the incidence of osteolysis and contributive factors.

Material and methods: This series of 228 THA using noncemented ABG-1 anatomic implants coated with hydroxyapatite was implanted in 210 patients, 116 women and 112 men, mean age 62.2 years. The indication was primary osteoarthritis (53.6%), primary necrosis (21.5%), posttraumatic osteoarthritis (11.8%), rheumatoid disease (8.3%) and hip dysplasia (4.8%). The bearings were, 200 zirconium-polyethylene (87.7%), 28 metal-polyethylene (12.3%). At mean 88.6 months follow-up, a minimum 60 months postoperatively, we reviewed 163 patients (37 patients died without revision, 28 (12.3%) were lost to follow-up, and 17 had undergone a revision procedure). We analyzed osteolysis on the digitalized radiograms using the Delee-Charnley classification to which we added a fourth retroacetabular zone. Polyethylene wear was measured with the Imagika(r) software using the method described by Martell.

Results: The 17 cup revisions (8.5%) were required for instability (4 pt), loosening (4 pt), osteolysis (4 pt), infection (3 pt), and limping (1 pt). Overall implant survival was 92.1%. Implant survival, considering loosening and osteolysis as failure, was 96.1%. Mean wear at last follow-up was 1.26 mm, for an annual average of 0.17 mm (0.04 – 0.69 mm/yr). Acetabular osteolysis was observed in 41.6% of cases, mainly in the Delee-Charnley zone 1, but was also found in all the other zones. The average surface area was an estimated 223 mm2. Possible factors favoring osteolysis were: aetiology, age, gender, activity level, body mass index, Charnley ABC classification, presence of preoperative acetabular defects, cup size, polyethylene insert thickness, position of the insert rim, cup inclination, complementary fixation, bearing type, polyethylene offset and wear. There was a statistically significant relationship between osteolysis and: the Charnley classification (p=0.012), presence of preoperative acetabular defects (p=0.0034), cup inclination angle (p=0.035), cup size (p=0.042), polyethylene thickness (p< 0.01), use of complementary fixation (p=0.048), and polyethylene wear (p=0.0011). Paradoxically, we did not find any relationship with gender, age, body mass index, and the other factors.

Discussion: This analysis demonstrated the determining causes of osteolysis: time, polyethylene thickness, polyethylene wear, the Zicronium-polyethylene bearing. Wear was probably not only the consequence of the Zicronium-polyethylene bearing but was also related to the quality of the polyethylene, and the instability of the insert. Diffuse osteolysis is favored by orifices in the first-generation cups which have been eliminated in the ABG-2 cups.

Purpose: The purpose of this work was to evaluate the mid-term behaviour of 228 ABG-1 femoral stems implanted without cement in patients with at least five years follow-up.

Material and methods: The series included 228 ABG-1 (cup and femur) non-cemented hydroxyapatite-coated anatomic total hip prostheses implanted in 210 patients. Mean age was 62.2 years, 116 women, 112 men. Indications were: primary degenerative disease (53.6%), primary necrosis (21.5%), posttraumatic osteoarthritis (11.8%), rheumatoid disease (8.3%) and dysplasia (4.8%). A zincronium-polyethylene bearing was used for 200 hips (87.7%) and metal-polyethylene for 28. We retained for analysis 163 patients with mean 88.6 months follow-up [37 died without revision, 28 lost to follow-up (12.3%), 17 surgical revision]. The Postel Merle d’Aubigné (PMA) and Harris Hip Score (HHS) were noted. Radiographically, the AGORA Engh-Massin and ARA femur scores were determined; osteolysis was evaluated with the Gruen classification.

Results: The seventeen femoral revisions were related to aseptic loosening (n=4), fracture of the femur (n=4), sepsis (n=3), instability (n=3), pain (n=2), and limping (n=1). Overall survival was 92.5% at 88.6 months, relative survival (loosening) was 98.2%. At last follow-up, the PMA score was 17.3 and 92.7% of the patients had an excellent or good outcome (PMA > 14). The mean HHS was 96.4. Ninety-six percent of the patients were pain free. Radiologically, 112 stems were evaluated at last follow-up. The Engh-Massin classification showed that 102 stems presented certain bone ingrowth (85.2%), 15 suspected (12.3%), and two showed fibrous encapsulation with one case of implant instability. The ARA femur score was good or excellent in 70.5%, fair in 13.1%, poor in 16.4%. Hypertrophic cortical reaction was noted in Gruen zones 2–3 or 5–6 in 27.9% and was not correlated with pain. These reactions were however associated in more than half of the cases with a position anomaly in the frontal plan or an oversized stem. There was on incomplete pedestal and no extensive proximal stress shielding. Femoral osteolysis was very limited (mean surface area 145 mm2) in zones 1 and 7 in 21.3% of the cases. There were no cases of distal osteolysis.

Discussion: These data confirm the very good mid-term behaviour of the anatomic stems coated with hydroxyapatite. This metaphyseal coating acts like a barrier preventing diffusion of wear particles along the shaft. Stem migration was minimal, to the order of one millimetre, and did not continue beyond the first year. Over time, a constant trabecular metaphyseal endocortical bone reaction was observed, reflecting stress transmission to the proximal portion of the hydroxyapatite-coated femoral implant.

Purpose: We report the results at more than five years of a consecutive series of total knee arthroplasties (TKAs) implanted without cement and with preservation of the posterior cruciate ligament (PCL).

Material and methods: This series included 98 patients who underwent 109 primary TKAs between 1994 and 1998. Mean patient age was 67.7 years. The press-fit Interax prosthesis has a macroporous hydroxyapatite coating since 1996. The patella was resurfaced in 92% of the cases with a cemented polyethylene button. Ligament balance and joint space were controlled by progressive release of the ligaments with a tensor derby. Clinical assessment was based on the KSS. Radiological assessment included the femorotibial axis, the position of the implants, and the bone-implant interfaces.

Results: Seven (6.4%) of the patients were lost to follow-up. Fifteen (13.4%) died or were demented and two (1.8%) developed late infection and were not included in the primary analysis. Thus, 85 patients (77.9%) were retained for analysis at a mean 5.2 years follow-up. The KSS improved from 33.4 preoperatively to 79.4 at last follow-up. The KSS function score improved from 55.1 to 82.4. Knee flexion was 124.5° preoperatively and 113.1° at last follow-up. Anteroposterior laxity greater than 5 mm was observed in 4.8% at last follow-up. Radiologically, the mechanical femorotibial axis changed from 184.4° to 180.6°. Alpha 95.6°, geta 89.1°, omega 4.77°, gamma 3.8°, sigma 89.4°. Patellar height was 0.84 preoperatively and 0.65 at last follow-up. Lucent lines were observed 3.5 times less frequently with hydroxyapatite coated implants. Patellar loosening and femorotibial loosening were observed in one patient each. Revision procedures were necessary for three prostheses for bipolar loosening, painful stiff knee, and anteroposterior instability. Non-infectious survival rate was 94.1% at 5.2 years.

Discussion: These mid-term clinical results are comparable with those reported in the literature for cemented or non-cemented implants with or without preservation of the posterior cruciate ligament. Longer follow-up is however necessary to assess the anteroposterior stability. The radiographic measurements provide a good demonstration of the operative precision and proper ligament balance. Hydroxyapatite coating improves bony fixation of the implants and provides a fixation comparable with cemented implants.

Conclusion: This series confirms the mid-term reliability of the non-cemented Interax THA with preservation of the posterior cruciate ligament.

Purpose: Fractures involving both the shaft of the femur and the proximal portion of the femur are uncommon. In a meta-analysis of cases reported between 1951 and 1985, Alho recorded 659 cases where a wide range of management strategies were used. We report here a homogeneous series of 17 patients treated with ascending locked anterograde nailing.

Material: This series of 17 patients were young (mean age 36 years). These eleven men and six women were all victims of high-energy trauma; 12 had multiple fractures. The shaft fracture involved the middle third in 15 patients, the lower third in two; the shaft fracture was open in six cases. The proximal fracture was transcervical in nine patients (7 B21, 1 B22, 1 B23) and trochanteric in six (A A32, 1 A31, 2 A12, 2 A33).

Methods: The fracture was reduced under fluorescent guidance on the orthopaedic table in the supine position followed by anterograde nailing with ascending proximal locking in the axis of the neck using a Russel and Taylor reconstruction nail. The osteosynthesis was performed on day 0 in eleven patients, during the first week in three and later in three.

Results: Results are reported for 17 patients. There was one early superficial suppuration which healed favourable after local care. Two shaft fractures exhibited nonunion and were revised to decorticalise the graft. The cervical fracture exhibited early displacement in one patient who underwent revision on day 15; bone healing did not ensue and a total hip arthroplasty was implanted at ten months. All the other fractures healed within three to five months after the first-intention treatment. The long-term follow-up has revealed one case of cephalic necrosis at five years which has required a total hip arthroplasty.

Discussion: These double fractures involving the proximal femur and the shaft of the femur account for 1 to 5% of the femur fractures reported in the literature. They are observed in young victims of high-energy trauma, often associated with other multiple injuries. Diagnosis is not always easy to establish since there may be little or no displacement of the proximal fracture, which may be recognised secondarily after standard nailing (2 out of 17 cases).

The trochanteric fractures are generally easier to diagnose and reduce, and usually heal well. The shaft fractures are more often displaced and readily comminutive, sometimes open, having absorbed the greater part of the trauma energy. These fractures heal like ordinary shaft fractures. Neck fractures are often seen in the lower portion with a vertical fracture line, with or without displacement.

Using a single centromedullary nail for the osteosynthesis of both fractures is an attractive solution. The proximal fracture must however be carefully reduced with percutaneous pins before attempting nail insertion. The postoperative period is generally uneventful. Problems may be encountered if the cervical fracture cannot be perfectly reduced, in which case two separate fixations would be preferable.