Implants of pure titanium for internal fixation of the peripheral skeleton.

In a multicentre study, a clinical evaluation of the new titanium implants of the sizes 2.7, 2.0 and 1.5 mm was done. In seven centres, 133 patients were operated on and the personal, subjective opinions of the surgeons were recorded. In the opinion of these surgeons experienced in using steel implants, the outcome of the internal fixations was the same for titanium as for steel implants. Three metal-related complications occurred in the smallest size screw type (1.5 mm), namely, one screw broke and two bent. In the cases in which the implant had been removed, good tissue contact with the implant could be seen. Only in one case was there discolouring of the soft tissue due to titanium. It is recommended that surgeons who are used to handling stainless steel screws should be aware of the slightly different behaviour of titanium screws.

[Arthroscopy of smaller joints: hand, elbow and ankle arthroscopy]. / Arthroskopie kleiner Gelenke: Hand- bzw. Ellbogen- und Sprunggelenkarthroskopie.

These joints are accessible, though technically demanding, by arthroscope. Above all, the evaluation of the lesions is not simple. Arthroscopy always represents the last diagnostical alternative. The extraction of loose fragments, the debridement, the shaving and the treatment of infections are excellent indications. Postoperative rehabilitation is favoured and shortened with the arthroscopic approach. Elbow arthroscopy did not greatly, develop during the last years. Posttraumatic situations, corpora libera and cartilage lesions represent the main indications. The arthroscopies of the ankle and the wrist, however, are increasing. Carpal instability and discus problems of the wrist are quite interesting. Lately, endoscopic carpal-tunnel decompression has been propagated, but is still in its experimental phase. At the ankle, osteochondrosis dissecans, flake fracture and fibrosed plica [discovered through arthroscopy, mostly in athletes] are suitable for arthroscopic removal or reconstruction. Interfering osteophytes at the anterior border of the tibia can also be removed arthroscopically. Percutaneous internal fixation and fusion of the ankle joint need first to be evaluated in a long-term follow-up. Arthroscopic debridement and rinsing against infections are quite successful for all the joints. The arthroscopy of a small joint is technically quite demanding; therefore, it should be practised only by a few specialized centres.

[Arthroscopy of the wrist joint]. / Die Handgelenkarthroskopie.

Our experiences with 100 wrist arthroscopies demonstrate the significance of this technique. In all these cases it was possible to clarify whether one or more pathologies were present or whether the joint was intact. The arthroscope makes it possible to discern the quality and extent of lesion far better than with imaging procedures. Arthroscopy for operations on the wrist seems very promising, but we need much more experience before we can appreciate its full potential and value.

Femoral expansion in total hip arthroplasty.

With increasing age, the femoral medullary canal expands and cortical thickness decreases. Examination of the radiographs of 22 hips that had undergone total hip arthroplasty revealed that at a mean interval of 11.5 years the medullary canal had expanded at an average rate of +0.328 mm/year (P less than .0001). There was a concomitant mean cortical atrophy of -0.155 mm/year (P = .0006). These rates of expansion are similar to those observed in natural aging. The presence of a femoral prosthesis is associated with temporal changes in femoral geometry similar in magnitude to those occurring in the natural femur. Because of the fundamental changes in load transmission caused by the presence of a femoral prosthesis, these geometric changes may be in part secondary to the bone's adaptation to altered load transmission, as well as to natural aging phenomena. Recognition of the pattern of natural femoral expansion suggests certain strategies for design criteria that seek to maximize fit.