Purpose of the study: The rate of intra and postoperative complications is generally high after surgery for neurogenic paraosteoarthropathy, also termed hetero-topic ossification.

Material and methods: We present a series of 60 cases of osteoma involving the hip joint, analyzing complications in comparison with data in the literature.

Results and discussion: Vascular complications (n=7): one required suture of the common femoral artery, three ligature of the deep femoral artery, two ligature of the deep femoral vein and one ligature of the collateral branches of the deep femoral vessels. Mean intraoperative blood loss was 1300 cc. None of the vascular complications gave rise to death or amputation. Early septic complications (n=4): three occurred after simple resection of the ossification and cured after surgical revision and antibiotics with no major impact on joint motion; one occurred after a procedure for resection of the ossification plus total hip arthroplasty and led to ankylosis of the hip joint but cured after surgical revision and prolonged antibiotic therapy. Sepsis was favored by a long hemorrhagic surgical procedure in patients at risk. Neurological complications (n=0): such complications are greatly feared but rare. Posterior ossifications expose the sciatic nerve to injury but generally displacement the nerve rather than enclosing it in the osteoma. Fracture complications (n=1): the outcome was favorable, both in terms of bone healing and joint motion. A classical complication mentioned in the literature and synonym to recurrent ossification or invalidating residual stiffness. Most are favored by ankylosis, osteoporosis, immobilization and a particularly dynamic surgeon. Recurrences (n=6): all were posttraumatic with a delay from accident to surgery ≥ 18 months.

Conclusion: Complications are related to the localization of the osteoma (relations with nerves and vessels), associated osteopathy, and the complete or partial joint stiffness. Preoperative imaging (x-rays and computed tomography with contrast injection) should localize the osteoma, keeping in mind that certain localizations create preferential conditions for certain risks. An analysis of the topography of the paraosteoarthropathy should enable the surgeon to choose the most appropriate approach. Intraoperatively, risk assessment can usefully anticipate complications which always compromise functional outcome.

Purpose: Polyethylene wear in total hip arthroplasty remains the most limiting factor for implant survival. Several predictive factors are well identified, but the position of the articulating pieces remains to be studied in detail. We searched for a correlation between polyethylene wear and the position of the femoral and acetabular pieces, particularly the femoral offset.

Material and methods: Sixty-six patients underwent total hip arthroplasty for osteoarthritis or osteonecrosis. The patients were reviewed at 10.8 years (four bilateral prostheses). The preoperative, immediate postoperative (1 month) and last follow-up (10 years) AP pelvis views were digitalized. A dedicated software traced the different axes for measurement. Wear at ten years, femoral offset, cup eccentration or medialisation, ascent or descent, and cup inclination were measured.

Results: Mean polyethylene wear was 1.23 mm at ten years with linear curve of 0.11 mm/yr. Preoperative femoral offset was restored in 71.4% of the cases. Univariate regression analysis revealed that only femoral offset was correlated with less wear at ten years. Polyethylene wear at ten years fell from 1.26 mm for preoperative offset restitution less than 98% to 1.13 mm for restitution greater than 102%.

Discussion: Image processing allowed greater accuracy in the measurement of polyethylene wear. The rate of wear reported in the literature ranges from 0.1 to .015 mm/yr. Restitution of femoral offset guarantees less wear due to the reduction in the resultant force applied on the articulation as well as stress on the implants. Furthermore hip stability is improved. Several factors are involved in production of wear debris and correct restitution of the centre of rotation is only one of the elements which reduce wear.

Conclusion: Wear was not excessive in this series. Among the position parameters, only femoral offset had an influence, having a beneficial effect on polyethylene wear. This emphasises the importance of having a wide variety of implants available in order to respond to the different anatomic presentations of the femur.

Purpose: There has only been one reported series of 30 cases of greater trochanter fracture during total hip arthroplasty and 26 of these were postoperative discoveries. We evaluated the frequency of this event and its postoperative consequences.

Material and methods: Among our series of 1171 total hip arthroplasties performed between 1985 and 2000, 38 patients (3.2%) with greater trochanter fracture were identified (mean age 63 years). Osteosynthesis was performed in all cases. Thirty-one fractures were observed during primary arthroplasty and seven during revision procedures.

Results: Eighteen patients had a favouring condition: corti-costeroid therapy,alcoholism,osteoporosis,diabetes,Paget, ablation of trochanteric material, periprosthetic osteolysis. The anterolateral approach was used in 22 and the posterolateral approach in 16. The fracture occurred along the access route in four (material removal or prefracture situtation), at removal of a previously implanted stem in two, and during implantation in 32. Twelve different stems were involved but a screwed stem was involved in 18 cases, i.e. 10% of all implanted screwed stems, while this complication only occurred in 1.2% of other implanted stems. Immediate weight bearing was authorised in 27 patients and deferred three weeks to three months in eleven. There were two deaths, so follow-up data was available for 36 hips: we observed anatomic bone healing in 22, deformed calluses in five and nonunion in nine, including two cases with infection (three revision procedures were required). Pain persisted at two months for eleven hips and limping persisted for ten (eight nonunions).

Discussion: Prostheses with a large metaphyseal component were involved in the majority of the fractures. The surgical approach was not incriminated. When well stabilised, trochanter fractures healed well. Nonunion, often announced by persistent pain, is an important risk in patients with osteoporosis and a poorly stabilised fracture. Although all cases of nonunion were observed in patients with deferred weight bearing, this criterion is simply the expression of the surgeon’s apprehension in case of less than satisfactory fixation.

Conclusion: Because of the deficient bone stock, which explains the higher rate of nonunion, fracture of the greater trochanter cannot be considered in the same light as a planned osteotomy. Prevention requires choosing a less cumbersome metaphyseal component in patients with favouring conditions. Osteosynthesis must be performed with particular care in order to obtain rapid healing and good functional outcome.

The initial treatment of the congenital clubfoot is still a debated subject among different schools. We report our current experience with Ponseti method.

Materials and Methods: From April 1999 to May 2001 we have consecutively treated with this method 80 idiopathic clubfeet of 57 children put under treatment at neo-natal period. Progressive correction of the deformity has been obtained with 7 toe-to-groin plaster casts changed weekly. When complete derotation of the hind-foot and forefoot has been reached, subcutaneus tenotomy of the tendon Achilles has been performed. At the end of this first period, the feet have been adapted in Denis Browne splint, worn full time for four months and thereafter just at night. The feet have been evaluated clinically (score of Dimeglio and Bensahel), radiologically and some with MRI.

Results: Whole correction of the deformity at the end of treatment with plaster casts, has been achieved for 71 times. When the plaster casts are removed, the talocalcaneal divergence, on antero-posterior and lateral views and the tibial-calcaneal angle (x-ray in maximum dorsal flexion ), were respectively, as an average of 20; 30,7; 21,9 degrees. At an average of 20 months follow up, 54 feet of 80 had a score of 0 or 1 of 20, and 14 had a score of 2; on radiological aspect the talo-calcaneal divergence in antero-posterior and lateral views and the tibial-calcaneal angle were respectively as an average of 29; 24,5; 14 degrees. At this evaluation the percentage of relapses of the deformity was 20% (17 cases). All the relapses have been treated again in plaster casts with 40% of success. So far, only four medial release operations have been necessary. Six feet benefited by the transfer of the tibialis anterior tendon to the third cuneiform and slight medial release.

Discussion and Conclusion: The Ponseti’s method presents several advantages: high quality reduction of the clubfoot with the restoration of a “sub-normal” anatomy, low cost and small displeasing worry for the parents, with this method the functional re-education does not seem to improve the quality of results. The prevention of the relapse goes by good compliance to the splint.