Michel Henri Fessy

Survival of cementless dual mobility socket with a mean 17 years follow-up

PURPOSE OF THE STUDY As part of the 2006 symposium of the French Hip and Knee Society devoted to the dual mobility socket, we report a retrospective multicentric series of 438 first-intention total hip prostheses with a dual mobility socket at a mean 17 years follow-up. The purpose of our report was to ascertain the 15-year survival of this socket and analyze failures. MATERIAL AND METHODS The series included 438 primary replacements. This was a homogeneous multicentric series. The cementless sockets were 80 Novae-1 titanium Serf cups and 358 Novae-1 stainless steel Serf cups. All stems were inserted without cement: 185 Pf((R)) stainless steel screwed Serf stems, 228 PRO titanium screwed Serf stems, and 25 Corail stems. The mobile polyethylene insert was retaining. All of the heads were 22.2-mm chromium-cobalt heads. Degenerative hip disease was the main etiology and mean follow-up was 17 years (range, 12-20). Mean age at implantation was 54.8 years (range, 23-87). The actuarial method with a 95% confidence interval was used to determine the 15-year cup survival rate. RESULTS At the last follow-up, none of the patients had presented an episode of early or late instability. Analysis of the socket at last follow-up showed 13 aseptic loosenings, 23 intraprosthetic dislocations, and seven replacements of the polyethylene insert for wear. The overall 15-year prosthesis survival rate was 89.2+/-8.7%. The overall 15-year socket survival rate was 96.3+/-3.7%. DISCUSSION The fact that, at last follow-up, none of the implants had shown instability confirms the long-term stability of the dual mobility socket. The results in terms of 15-year survival confirm earlier reports. The main cause of failure was cup fixation, which is the weak point of this technique with the initial Novae cup design, which did not have hydroxyapatite coating. The second leading cause was intraprosthetic dislocation, which can be divided into three main categories. The first is intraprosthetic dislocation in a context of pure wear with normal function of the dual mobility socket; the retaining feature of the insert loses its efficacy due to wear. The second category is intraprosthetic dislocation in a context of cup loosening with a third-body effect and increased retention wear, in which case we consider that cup loosening is the primary event leading to rapid secondary wear and subsequent intraprosthetic dislocation. The third category is intraprosthetic dislocation caused by a blockage in a context of fibrosis or impingement involving severe heterotopic ossifications. We had only two femoral failures related to aseptic loosening, most certainly related to use of noncemented implants, which limits the extension of granulomas to the polyethylene. Studying the three series from Saint-Etienne more specifically, where three different configurations were used, it would appear that the titanium cup has a better survival rate and that the titanium used for the thinner necks may be an unfavorable factor for intraprosthetic dislocation.

Étude d'une série de 438 cupules non cimentées à double mobilité

PURPOSE OF THE STUDY Within the framework of the 2007 symposium of the French Hip and Knee Society devoted to the dual mobility socket, we report a retrospective multicentric series of 438 first-intention total hip prostheses with a dual mobile socket at 17 years mean follow-up. The purpose of our report was to ascertain the 15-year survival and analyze failures. MATERIAL AND METHODS The series included 438 first-intention prostheses. This was a homogeneous multicentric series. Sockets were: 80 Novae-1 titanium Serf cups and 358 Novae-1 stainless steel Serf cups. All stems were inserted without cement: 185 Pf) stainless steel screwed Serf stems, 228 PRO titanium screwed Serf stems, 25 Corail stems. The mobile polyethylene insert was retaining. All of the heads were 22.2mm chromium-cobalt heads. Degenerative hip disease was the main etiology and mean follow-up was 17.18 years (range: 12-20). Mean age at implantation was 54.8 years (range: 23-87). The actuarial method with 95% interval of confidence was used to determine the 15-year cup survival. RESULTS At last follow-up, none of the patients had presented an episode of early or late instability. Analysis of the socket at last follow-up showed: 13 aseptic loosenings, 23 intraprosthetic dislocations, and seven replacements of the polyethylene insert for wear. The overall 15-year prosthesis survival was 89.2+/-8.7%. The overall 15-year socket survival was 96.3+/-3.7%. DISCUSSION The fact that at last follow-up none of the implants had exhibited instability confirms the long-term stability of the dual mobility socket. The results in terms of 15-year survival confirm earlier reports. The main cause of failure was cup fixation, which is the weak point of this technique with the initial Novae cup, which did not have hydroxyapatite coating. The second leading cause was intraprosthetic dislocation, which can be divided into three main categories. The first is intraprosthetic dislocation in a context of pure wear with normal function of the dual mobility; the retaining feature of the insert looses its efficacy due to wear. The second category is intraprosthetic dislocation in a context of cup loosening with a third-body effect and increased retention wear, in which case we consider that the cup loosening is the primary event leading to secondary rapid wear and subsequent intraprosthetic dislocation. The third category is intraprosthetic dislocation cause by a cam effect in a context of fibrosis or impingement involving a large calcification. We have had only two femoral failures by aseptic loosening, most certainly related to use of noncemented implants, which limits the extension of granulomas to the polyethylene. Studying more specifically the three series from Saint-Etienne where three different configurations were used, it would appear that the titanium cup has a better survival and that the titanium used for the thinner necks would be an unfavorable factor for intraprosthetic dislocation.

Periprosthetic osteolysis after AES total ankle replacement: Conventional radiography versus CT-scan

BACKGROUND The aim of this study was to compare conventional X-rays and CT-scan in detecting peri-prosthetic osteolytic lesions, a major concern after total ankle replacement (TAR). METHODS We prospectively assessed 50 patients (mean age 56 years), consecutively operated on by the same senior surgeon, between 2003 and 2006 and with a mean follow-up period of 4 years (range, 2-6.2). The component used was AES total ankle replacement. The etiologies for total ankle arthroplasty were: posttraumatic in 50%, osteoarthritis secondary to instability in 36%. Plain radiographs were analyzed by 4 independent observers, using a 10-zone protocol (location) and 5 size categories. RESULTS At 4-year follow-up, all patients had been CT-scan assessed with the same protocol by 2 independent observers. Plain radiographs showed dramatic progression of severe periprosthetic lyses (>10mm): from 14% to 36% of interface cysts for the tibial component respectively at 2 and 4-year follow-up and from 4% to 30% for the talar implant. The talar component was more accurately assessed by CT-scan (mean frontal and sagittal talar lesion: from 270 mm2 to 288 mm2 for CT-scan versus 133 mm2 to 174 mm2 for X-rays). For tibial cysts, axial views showed larger lesions (313 mm2 than frontal (194 mm2) or sagittal (213.5 mm2) views. At 4-year follow-up, 24% of patients had revision with curetage or arthrodesis, and at 7 years follow-up 38% were revised. CONCLUSION These results are similar to recent AES series, justifying withdrawal of this device. CT-scan was more accurate than X-rays for detecting and quantifying periprosthetic osteolysis. We recommend a yearly radiological control and CT-scan in case of lesion on X-rays.

Do we medialise the hip centre of rotation in total hip arthroplasty? Influence of acetabular offset and surgical technique

Acetabular offset (AO) is the distance between the centre of the femoral head and the true floor of the acetabulum. We quantified the AO in normal hips and compared the displacement of the centre of rotation of the hip (CRH) after conventional and anatomical cup implantation during THA. 100 CT-scans of normal hips were analysed before and after simulating implantation of the acetabular component. Mean AO was 30.8 mm ± 3.The medial shift of the CRH was 1.6 mm ± 1.2 with the anatomical and 4.8 mm ± 1.9 with the conventional technique (p<0.0001). Medialisation was greater than 5 mm in 44% of the cases when the conventional technique was used, but occurred in no case when using the anatomical technique. Differences between men and women were significant: 5.6 mm ± 1.6 and 3.5 mm ± 1.7 with the conventional technique; 2.0 mm ± 1.1 and 0.9 mm ± 0.9 with the anatomical technique (p<0.0001 for both measurements). The concept of hip offset cannot be limited to that of the femoral offset. AO widely varies and cannot be neglected. In patients with significant AO, surgeons should pay close attention to the preparation of the acetabulum. This should be done conservatively so that the acetabular cup can be placed anatomically in order to restore the native hip biomechanics.

Management of Periprosthetic Cystic Changes After Total Ankle Replacement

Total ankle replacement (TAR) was developed in the 1970s as an alternative to arthrodesis in selected patients. It is a challenging procedure in the treatment of osteoarthritis. However, some previous studies have shown a high percentage of rapidly progressing osteolysis associated with TAR. The cause of these cysts remains unclear. Diagnosis requires rigorous assessment and regular follow-up. Depending on the cystic changes, different therapeutic options are available including cyst curettage–bone grafting, revision arthroplasty, or arthrodesis.

Comparison of screw versus locked plate fixation for Scarf osteotomy treatment of hallux valgus

INTRODUCTION The Scarf osteotomy is a commonly used surgical procedure for treating hallux valgus in Europe. Screw fixation is standard practice, although some surgeons now go without internal fixation. Plate fixation is still being studied. The aim of this study was to compare the radiological outcomes of these fixation methods, which has not been performed up to now. HYPOTHESIS Relative to screw fixation, plate fixation of a Scarf osteotomy of the first metatarsal (M1) prevents secondary impaction, without increasing the complication rate or recurrence rate. MATERIALS AND METHODS A retrospective study was performed of two internal fixation methods for Scarf osteotomy (screw vs. plate), by analyzing the secondary impaction of the first metatarsal, recurrence of the hallux valgus (angle M1P1>20) on X-rays, incidence of complications and potential discomfort related to the hardware. The osteotomy procedure was the same in both groups: 50patients were included consecutively in each fixation group between February 2014 and November 2015. RESULTS The mean follow-up was 13.0±2.7months in the screw group and 12.3±1.1 months in the plate group. There were no severe complications, although four cases of delayed wound healing occurred (3in plate group, 1in screw group). In the screw group, there was one case of secondary impaction, two cases of recurrence (4%) and one case of discomfort. In the plate group, there were no cases of impaction, three recurrences (6%) and five cases of discomfort, leading to plate removal in three of these cases. DISCUSSION There was no significant difference between groups in the M1 secondary impaction rate or recurrence rate: screw fixation did not lead to a higher recurrence rate. Systematic fixation with a locked plate for Scarf osteotomy had no advantages over screw fixation in our study. LEVEL OF EVIDENCE II, Comparative study with continuous cohorts.