Periprosthetic humeral fractures are rare but their numbers tend to increase because of the development of shoulder prostheses. We analysed our cases to see if some therapeutic guidelines can be provided.

Material and Methods: Our retrospective monocentric study included 12 patients (11 women, 1 man), with an average age of 76 (49 to 93). 9 were osteoporotic. All fell from their height except a polytrauma. They were operated from 1994 to 2007. 9 fractures were at the tip of the stem. 2 proximal, 1 distal, 10 prostheses were monopolar for previous proximal humeral fractures, 7 were cemented.

Results: Internal fixation was used in 8 cases with difficulties to find a suitable device in the first ones and LCP plates in the last ones. 4 cases had a prosthetic revision (with a humerotomy in one case): 2 monopolar long stems, 2 inverted prostheses (one with a long stem). Several complications were observed: 1 death (polytrauma), 3 radial palsies (which recovered), 1 sepsis (cured), 1 sympathetic dystrophy. The fractures healed at an average of 68 days (60 to 77).

Discussion: These fractures are little mentioned in the literature (15 references), often as case reports; the largest serie comprises 19 cases. The classifications, up to now, are descriptive not orientating the indication. Using a system derived from the SOFCOT 2005 symposium on periprosthetic fractures of the proximal femur seems efficient. A letter for the fracture site (A:metaphyseal, B: at the stem, C: distal) and a figure for the implant fixation (1: fixed, 2:loose, 3: with osteolysis) describe the situation. When reviewing retrospectively our cases we found that types A and C are generally not loose and that this classification gives a good guideline. For internal fixation, previous devices were poorly adapted. Now, LCP plates with locked screws and cables are preferred. In prosthetic revision, the choice between an anatomical or a reversed prothesis depends on the rotator cuff, the glenoid bone stock, and the patient general condition. A long stem is preferable (acting as a ‘nail’).

Conclusion: Regarding periprosthetic fractures, the proximal humerus can be considered as rather similar to the proximal femur. But the glenoid and the cuff may change the type of implant for revision.

Aims: This prospective study investigated the possibilities of substitute osteointegration in an unfavourable environment. Methods: 26 patients aged 57 to 92 years (average 80) have been followed up from 6 to 24 months with serial AP and lateral X-rays. The acetabular damages were: 2 SOFCOT grade I, 9 grade II, and 15 grade III.Granules ofTriosite¨ þlled the cavitary defects mixed with and covered by cancellous bone. One pack was used 13 times; two,6 times; three, 6 times; and four, once. An HA coated hemispherical cementless cup was pressþtted, stable without screws 8 times. Results: In other cases the acetabular cup remained stable without any lucency. Disappearance of the granules was observed only 4 times. In 14 cases osteo-integration seemed in progress, but the granular shape was still discernable. In 8 cases, even at 2 years follow-up, the granules were well visible (those were cases of grade III defects). Conclusion: In acetabular revision of a total hip replacement, the size of the defect may need a large amount of cancellous autograft. Bone substitutes seem an elegant means of sparing the patientñs bone. The rstþpapers on this topic seemed rather enthusiastic, but our experience is more contrasted. It seems that the speed of resorption of this bone substitute be volume-dependant: the bigger the defect, the slower the osteo-integration. May be growth factors should be added to speed up the process.