Biomedical subjects

X Roussignol

Publications and source records attributed to X Roussignol.

4 recordsLinked to original sources

PubMed2003

[Tripolar arthroplasty for recurrent total hip prosthesis dislocation].

PURPOSE OF THE STUDY: The purpose of this study was to assess the results of revision surgery for recurrent total hip prosthesis dislocation using a tripolar prosthesis composed of a conventional stem with a mobile head of an intermediary prosthesis measuring more than 40 mm and a modified cup. This technique was used in two centers in Rouen France and Los Angeles USA. MATERIAL AND METHODS: Twenty-one hips in 21 patients were operated on. The mobile heads measured 40 to 47 mm. Mean patient age was 70 years (range 29-92). The indication for the tripolar prosthesis was reserved for extremely unstable hips in patients with major risk factors for recurrent dislocation. These 21 patients had experienced 95 dislocations. The acetabular cup was custom-made for the large-diameter heads. A cemented polyethylene cup was used in 14 cases and a press-fit metal-backed around a polyethylene insert in 7. The polyethylene thickness varied from 6.5 to 16 mm for the cemented cups and 4 to 5 mm for the press-fit cups. Fourteen femoral stems were left in place as were two press-fit cups where only the inserts were changed. Mean follow-up was 5.4 years (range 3-11.8). RESULTS: There has been no recurrent dislocation for 20 hips. One patient experienced a dislocation one week after surgery which required a second revision procedure to reposition the acetabular implant. Final outcome was good at 7.6 years for this hip. One patient who had not had any recurrent dislocation died 4 years after the revision surgery due to a cause unrelated to the prosthesis. Two patients were lost to follow-up at 3.7 and 6 years, both were pain free and had no radiological anomalies. Infection occurred in one patient undergoing chemotherapy for a myeloma; the head and neck had to be resected. For the 20 other patients, functional outcome, assessed with the UCLA score, showed improvement in pain (5.8 preoperatively, 9.2 at last follow-up), walking (4.8 and 8 respectively), function (4 and 6 respectively), and daily activities (3.3 and 5.2 respectively). A revision procedure was necessary for one patient during the 4(th) year because of a fracture of the polyethylene insert on a metal-back cup; the insert alone was changed. Excepting the patient with infection, there were no cases of certain or probable loosening during the follow-up. DISCUSSION: The tripolar prosthesis with a mobile cup and a large-diameter head appears to be a reliable solution for these severely unstable hips. The procedure can often be limited to the acetabular component, reducing morbidity. The thickness of the polyethylene cup is a limitation which may affect long-term survival. Search for a highly wear-resistant couple continues.

Adult↗

PubMed2003

[Anterior radial nerve transposition in humerus midshaft fractures: anatomic and clinical study].

PURPOSE OF THE STUDY: Plate fixation of midshaft humerus fractures raises the risk of radial nerve injury. Anterior transposition of the radial nerve has been proposed as a possible solution but few reports have been published. The purpose of the present study was to validate the effect of transposition on the transposed radial nerve and its branches. MATERIAL AND METHODS: We conducted an anatomic study on 10 cadavers. The length of the radial nerve between 2 anatomic landmarks was determined before and after transposition and plate fixation. A clinical evaluation was performed four years after surgery in 6 patients with midshaft humerus fractures treated with plate fixation after radial nerve transposition. RESULTS: The anatomic study demonstrated a mean gain of 11 mm in the length of the radial nerve with no problem for the transposed nerve or its branches. Clinically, osteosynthesis was facilitated and tension on the nerve was reduced. DISCUSSION: These 2 complementary studies demonstrated the releasing effect of transposition on the radial nerve and the facilitated osteosynthesis reported by others. The benefit of transposition is particularly important when bone fixation is particularly difficult to achieve without risk of injuring the radial nerve. Transposition does however require an extensive dissection, and the patient must be informed. CONCLUSION: The ideal indication for anterior transposition of the radial nerve is an oblique fracture of the mid-third to lower-third of the humeral shaft with radial palsy at onset. A certain degree of comminution facilitates the technique. Indications for this technique could however be widened to include cases of difficult osteosynthesis where the option to transpose the radial nerve is always a peroperative decision.

Adult↗

PubMed2001

[Osteoid osteoma after an old femoral shaft fracture].

An osteoid osteoma was discovered at the site of fusion of a mid-third femoral shaft fracture in an 18-year-old girl. This unusual localization was revealed by persistent pain after ablation of the material after fracture healing. Postoperatively, a discharge from the skin wound that persisted for a few days, raised the differential diagnosis between low-grade bone infection and an osteoid osteoma suggested by the patient's age and the clinical presentation. Computed tomography and leukocyte-labeled bone scintigraphy provided the diagnosis of osteoid osteoma that was confirmed at pathology examination after resection. Isotopic mapping of this very small intraosseous lesion that exhibited strong isotope uptake was particularly contributive.

Adolescent↗

PubMed2000

[Experimental study of the primary stability of locked centro-medullary nailing of the humeral diaphysis].

PURPOSE OF THE STUDY: A clinical trial on the treatment of humeral shaft nonunions with locked nailing evidenced 5 failures among 13 cases. The circumstances leading to the nonunion, the patient's condition, and the nailing method were not found to have a predominant effect explaining this outcome. Inversely, clinical data suggested that abnormal mobility of the nonunion appeared to result from play in the assembly. To check this hypothesis, we measured primary stability in three nailing models using cadaver bones. MATERIALS AND METHODS: Three nailing models, Seidel (S), Russel-Taylor (RT) and ACE were tested, each on 5 cadaver specimens. A 1 cm segmental resection was made in the mid third of the humerus to simulate an unstable nonunion. The nailing was performed in accordance with the instructions furnished by the manufacturers. The nailed specimens were placed in a testing device which alternatively applied a rotation force around the longitudinal axis (+/- 0.5 Nm), an axial compression-traction force (+/- 20 N) and a transverse shear force applied at the level of the osteotomy (+/- 20 N). RESULTS: This study demonstrated an instability of the three nails when submitted to a rotation force or a shear force: 14 to 28 degrees and 1.6 to 3.4 mm respectively for the RT nail; 8 to 20 degrees and 1 to 3 mm for the S nail; 5 to 15 degrees and 1.7 to 3.2 mm for the ACE nail. The ACE nail appeared to be more stable when submitted to compression-traction force; the S nail accepted a 0.05 to 0.65 mm play which reached 9.7 mm for the RT nail. This instability appeared to result from play in the locking systems. DISCUSSION: These findings would demonstrate that these nailing systems cannot, in themselves, provide satisfactory primary stability. The experimentally evidenced instability would contribute, probably in association with locally unfavorable physiological or biological conditions, to the failure rate observed when nailing is used alone. CONCLUSION: The locking system for tested nails would have to be modified to eliminate play in the assembly before continuing their use for the treatment nonunion of the humeral shaft.

Aged↗