Purpose of the study: Drilling along yields disappointing results for osteonecrosis of the femoral head due to the high failure rate despite prolonged rest and also because of the risk of fracture. To prevent these problems, we have developed a new drilling technique which was evaluated prospectively.

Material and methods: The procedure performed percutaneously uses a lateral cortical orifice measuring 5mm, non-concentrated autologous bone marrow was injected after drilling. Osteoinductive protein (BMP7) was associated in random fashion (groups BMP+ and BMP−). Ficat stage 1 and 2 necrosis was included. Outcome was the rate or revision for prosthesis.

Results: Forty hips (36 patients) were included and assessed at mean four years (range 2–6). The necrosis was related to: alcoholism (n=5), cortisone (n=25), barotraumas (n=2), metabolic disease (n=4), idiopathic condition (n=4). Group BMP- (drilling+bone marrow) included 24 hips and group BMP+ (drilling+bone marrow+BMP7) 16 hips. The groups were comparable regarding necrosis stage (15% stage 3, 65% stage 2, 20% stage 1) and mean Koo index (27 BMP+ vs 34 BMP-; NS). There were no infections and no fractures despite immediate and complete weight-bearing. The revision rate for prosthesis was higher in the BMP- group (67%) than in the BMP+ group (43%) but the difference did not reach significance (p=0.10). The failure rate was not affected by the severity of the necrosis in the BMP+ group: all stage 3 hips were revised in the BMP- group versus none in the BMP+ group. The only variable predictive of revision for prosthesis was the Koo index (p=0.02).

Discussion: Adjunction of BMP did not improve significantly the success rate of drilling with bone marrow adjunction but adding BMP appeared to limit the unfavourable impact of server necrosis observed in the BMP- group. To reach a statistical power of 80%, 40 cases would be needed in each arm. This threshold has not yet been reached. It can be noted however that the proposed method does ensures early weight bearing without the risk of complications. Similarly, since it is a percutaneous procedure, later arthroplasty is not compromised. The principle confounding factor, the richness of the bone marrow, was not assessed, motivating a new randomized trial with measurement of CFU-F.

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.

Purpose: The distal tibiofibular joint is implicated in ankle movement but has been the topic of less work than the talotibial joint. Its mobility within the talo-crural complex has not been described in detail as precisely as its static role. The purpose of this work was to develop a simple noninvasive method for characterising in vivo the mobility of the fibula at the ankle level between is positions in dorsal and plantar flexion.

Material and methods: We used 32 computed tomo-graphic studies of the ankle in 16 healthy volunteers (men and women), one study in each position of ankle flexion. We identified one cross-sectional slice through the syndesmosis in each of the two positions. A medio-lateral reference line was drawn tangent to the posterior cortical of the tibial metaphysis. The displacement of the fibula in relation to the tibia when moving between the two positions of ankle flexion was calculated using a remarkable landmark on the tibia, the anterior rim of the posterior tibial incisure, and the polar co-ordinates of the ends of the anteroposterior axis of the fibula.The repeatability and reproducibility of this method were tested.

Results: Repeatability was satisfactory for translation movements. Reproducibility was fair except for the reference line where it was good. When the ankle moved from dorsal flexion to plantar flexion, the fibula moved medially 1.25 mm (0.03–2.58 mm) (p< 0.0001) without correlation with the amplitude of the ankle flexion. Mean anterioposterior displacement was 0.46 mm (NS) with a wide range from −1.58 to +7.2 mm. It was correlated with lesser amplitude of ankle flexion.

Discussion: This dynamic method confirms published data concerning active mediolateral tibiofibular approach during plantar flexion. The results point out the variability of the anteroposterior movement of the fibula, the influence of the amplitude and the flexion position of the ankle, and the possible antepulsion effect of fibular tendons. The three-dimensional movement of the ankle joint merits further study including its tibio-fibular and talofibular components in view of potential prosthetic repair of the ankle.

Conclusion: Distal tibiofibular mobility is undeniable. We call for more work to achieve a better understanding of the lateral component of the talocrural complex.

We reviewed radiographs and CT scans of 38 total hip arthroplasties which had dislocated (36 posteriorly; 2 anteriorly) and compared the alignment of the prosthetic components with those of 14 uncomplicated arthroplasties. No difference was found between the alignment of the prosthetic components in the two groups. In the seven patients who had reoperations, the cause of dislocation diagnosed by CT was confirmed in only two cases (one retroversion of the cup and one protruding osteophyte). Muscular imbalance rather than malposition of the components was the major factor determining dislocation. CT allows accurate measurement of cup and neck anteversion but contributes little to preoperative planning.