Analysis of the morphology of the distal femur, and by extension of the femoral components in total knee arthroplasty (TKA), has largely been related to the aspect ratio, which represents the width of the femur. Little is known about variations in trapezoidicity (i.e. whether the femur is more rectangular or more trapezoidal). This study aimed to quantify additional morphological characteristics of the distal femur and identify anatomical features associated with higher risks of over- or under-sizing of components in TKA.

We analysed the shape of 114 arthritic knees at the time of primary TKA using the pre- operative CT scans. The aspect ratio and trapezoidicity ratio were quantified, and the post- operative prosthetic overhang was calculated. We compared the morphological characteristics with those of 12 TKA models.

There was significant variation in both the aspect ratio and trapezoidicity ratio between individuals. Femoral trapezoidicity was mostly due to an inward curve of the medial cortex. Overhang was correlated with the aspect ratio (with a greater chance of overhang in narrow femurs), trapezoidicity ratio (with a greater chance in trapezoidal femurs), and the tibio- femoral angle (with a greater chance in valgus knees).

This study shows that rectangular/trapezoidal variability of the distal femur cannot be ignored. Most of the femoral components which were tested appeared to be excessively rectangular when compared with the bony contours of the distal femur. These findings suggest that the design of TKA should be more concerned with matching the trapezoidal/ rectangular shape of the native femur.

Purpose of the study: The pertinence of locking for major femoral revision remains a controversial issue. We conducted a retrospective multicentric study to assess the benefit and potential clinical and radiographic complications after using a long locked stem entirely coated with hydroxyapatite.

Material and methods: Our series included 77 patients (42 women, 35 men), mean age 71 years (range 34–90) reviewed at minimum one year. A modular implant was used; the long curved stem allowed total integration. Screws guaranteed distal locking. There were 71 revision THA on trochanteric-shaft fractures, three shaft nonunions, 34 aseptic loosenings, 9 septic loosening, 21 fractures on prosthesis, 6 implant failures and one instability. Seventy percent of patients had stage 3 and 4 bone lesions. Mean follow-up was 60 months.

Results: At last follow-up, 90% of patients were satisfied or very satisfied. The mean Harris function score improved from 32 to 83 and the PMA from 7 to 15. Sixty-four patients were pain free and 22% had pain solely under stress. There were 15 bone complications: dislocation (n=3), early infection (n=3 including 2 recurrences), implant failure (n=2), secondary femur fracture (n=5). Stem survival was 94% at nine years. Radiographically, total stem stability was noted in 73 patients (95%); instability was noted in four cases of fracture. Undeniable metaphyseal improvement was noted in 20% of cases, more modest improvement in 32%; the situation was considered unchanged in 31%. Locking was successful in all cases; cortical bone in contact with the locking screw was unchanged in 59 cases, slightly thickened in 16, including one case with a context of septic recurrence. The locking was dismantled in two cases (one empirically and one for pain), but the stem remained stable.

Discussion: Major damage to the femur can compromise stabilisation of the proximal or diaphyseal implants. Distal locking contributes to the initial mechanical stability, indispensable for secondary osteointegration of the implant. However, with total hydroxyapatite coating, rapid fixation in healthy zones is also crucial. Reconstruction of metaphyseal bone is not easy to quantify, but the absence of bone absorption is noteworthy.

Purpose of the study: The correct position of the femoral and tibial tunnes for anterior cruciate ligament (ACL) reconstruction is a determining factor for favorable outcome. We used a novel computer-assisted system which enables intraoperative localization of the tunnel centers on the lateral view of the knee before drilling. This technique uses fluoroscopy combined with a passive system for computer-assisted image acquisition and processing to provide the surgeon with the desired positions. We report the anatomic and clinical results observed in a prospective series comparing this technique with the classical technique of independent blind tunnels.

Material and methods: Thirty-seven patients underwent computer-assisted surgery and 36 classical surgery without computer assistance performed by a senior surgeon. Mean patient age was 27 years in both groups. The patients were reviewed at mean 2.2 years (range 1–4.5 years). Data recorded included the KT-1000 laxity, radiographic drawer and the IKDC score (1999).

Results: Mean time from ACL tear to reconstruction was 30 months in both groups. Computer assistance increased operative time 9.3 minutes (range 4–13). The IKDC score was 67.9% A, 29.7% B, and 2.7% C in computer-assistance surgery patients and 60% A, 37.1% B and 2.9% B for classical surgery patients. The mean IKDC function score was 89.7/100 for the computer-assisted patients and 89.5/100 for the others. Mean manual maximal laxity (KT-1000) was 7 mm before surgery and less than 2 mm at last follow-up. Differential laxity was less than 2 mm in all patients who underwent computer-assisted surgery and in 97.7% of the others. The mean differential laxity for the medial compartment as measured on the postoperative stress films was 2.4 mm (range 0–12 mm) for computer-assisted surgery patients and 3 mm (range 0–10 mm) for the others. In the computer-assised surgery patients, the femoral tunnels were centered on a smaller area. There was not significant difference in the IKDC score, the KT-1000 findings and the stress x-rays between the two techniques.

Conclusion: The results of these two techniques in this report are similar to data reported in the literature. Computer-assistance enables more accurate and reproducible tunnel positioning with no significant clinical impact.

Purpose: Failed anterior cruciate ligament reconstruction as defined by recurrent pathologic laxity, is increasingly commonplace. We reviewed 77 patients who had undergone unsuccesful anterior cruciate ligament surgery to correct persisting instability, and who underwent revision surgery.

Material and Methods: During the first operative treatment, were used synthetic ligament in 18 cases, autograft in 54 cases, extra-articular plasty in 4 cases, allograft in 1 case and primary repair in 1 case. For revision, we used autograft in all cases according to differents anatomicals factors: 41 patellar tendons, 15 quadriceps tendons and 17 hamstring tendons. 46 patients had meniscectomy during one of the two surgeries ; 19 patients had cartilage lesions (grade 3 or 4).

For clinical evaluation, we used the IKDC score (1999), and laxity measurement with the KT-1000 arthrometer and stress X-rays.

The mean follow-up was 24 months.

Results The mean IKDC subjective score was 71,5 and 75% of knee were considered as normal or nearly normal. The surgery was successfull in objectively improving the stability in most of patients with a KT-1000 differential maxi-manual of 2 1,7 mm.

We found no statistical difference between the three groups of graft used for revision. The results are a trend toward less good results, when patients had a meniscec-tomy. Subjectively the result were worse in cases of cartilage lesion. In fact, no patient who had grade IV lesion returned to there previous level activity (pre-operative level activity). The worse results are in the group of failed synthetic ligaments.

Conclusion ACL revision surgery leads to poorer results than primary surgery.

There was no clinical difference for the revision, whether we used autograft of patellar tendon, quadriceps tendon or hamstring tendon with an adapted fixation device.

On the other hand, meniscal or cartilage lesion or the use of synthetic grafts are factors of poor clinical outcome.

Purpose: Several techniques have been described for the treatment of unstable fractures of the upper humerus. None appear to be appropriate for subtuberosity fractures, associated or not with a fracture of the trochiter or impacted valgus cephalotuberosity fractures, allowing a stable fixation with anatomic reduction while preserving blood supply to the bone fragments. For the last year, we have studied prospectively a percutaneous minimally invasive technique for this type of fracture. Our preliminary results are analysed here.

Material and methods: We used this technique for 12 patients aged 30 to 87 years with five displaced subtuberosity fractures, six subtuberosity fractures with a trochiter fracture and one impacted valgus cephalotuberosity fracture. Excepting the cephalotuberosity fracture, the joint fragment of the head was reduced by external manipulation under image amplifier guidance. Fixation was achieved with two 25/10 threaded pins inserted percutaneously in retrograde fashio from the anterolateral cortical to the humeral shaft. For eight cases, a third pin was inserted percutaneously from the trochiter to the medial cortical of the humerus. When percutaneous reduction of the trochiter was impossible (three cases) and for the cephalotuberosity fracture, we used a minimal transdeltoid lateral incision to reduce the trochiter and achieve reduction.

Results: Reduction was very satisfactory in all cases. There was one superficial infection that required pin withdrawal at three weeks leading to the only secondary displacement that was minimal and tolerable. We removed the pins after a mean two months. There were no nonunions. Seven patients have a follow-up greater than six months and exhibited a Constant score of 87% (71% to 100%).

Discussion: This techniques has provided very satisfactory results for rapid and stable fixation of the cephalic fragment without loss of blood supply and with a material easy to remove.

Conclusion: These early results are very encouraging and incite us to pursue this technique and analyse long-term results.