Aim

To describe the management of PJI due to S. aureus in CRIOAcs in 2019 and to particularly focus on the evaluation of the efficacy of DAIR regarding control of infection and risk factors for failure up to 12 months.

Aim

Cutibacterium acnes, a skin commensal, is responsible for 5–10% of prosthetic joint infections (PJI). All current microbiological definitions of PJI require two or more identical commensal isolates to be recovered from the same procedure to diagnose PJI and rule out contamination. Unlike coagulase negative staphylococci, C.acnes shows a highly stereotypical susceptibility profile making impossible to phenotypically assess the clonal relationship of isolates. In order to determine the clonal relationship of multiple C.acnes isolates recovered from arthroplasty revisions, we analyzed by multi-locus sequence typing (MLST) C.acnes isolates grown from orthopedic device-related infections (ODRI) in a reference center for bone and joint infection.

Aim

Our hospital is a referral center for Bone and Joint Infection (BJI) with a 15-bed orthopedic unit. Patients benefit from a multidisciplinary team management (surgeons, anesthetists, infectious disease physicians, microbiologists, dietician etc.). Computerized drug prescriptions are performed by anesthetists, surgical residents, surgeons and infectious disease physicians. Since 2015, a pharmacist has been included in ward rounds and in weekly multidisciplinary consultative meetings, where antibiotic treatment strategies are decided for hospitalized patients. This work aimed to assess the impact of a pharmacist in this unit to limit prescription errors.

Osteoporosis following ovariectomy has been suggested to modulate bone response to polyethylene wear debris. In this work, we evaluate the influence of estrogen deficiency on experimental particle-induced osteolysis. Polyethylene (PE) particles were implanted onto the calvaria of wild-type (WT), sham-ovariectomized (OVX), OVX mice and OVX mice supplemented with estrogen (OVX+E2) (12 mice per group). Sham-implanted mice served as internal controls. After 14 days, seven skulls per group were analyzed with a high-resolution micro-computed tomography (CT) and by histomorphometry, and for tartrate-specific alkaline phosphatase. Five calvariae per group were cultured for the assay of IL-1, IL-6, TNF- and RANKL secretion using quantitative ELISA. The expression of RANKL and OPG mRNA were evaluated using real-time PCR. As assessed by CT and by histomorphometry, PE particles induced an extensive bone resorption and an intense inflammatory reaction in WT, sham-OVX and OVX+E2 mice. In OVX mice group, these features appeared considerably attenuated. In WT, sham-OVX and OVX+E2 mice, PE particles induced an increase in serum IL-6, in TNF-and RANKL local concentrations, and resulted in a two-fold increase in RANKL/OPG mRNA ratio. Conversely, these parameters remained unchanged in OVX mice after PE implantation. The combination of two well-known bone resorptive mechanisms ultimately attenuated osteolytic response, suggesting a protective effect of estrogen deficiency on particle-induced osteolysis. This paradoxical phenomenon was associated with a downregulation of pro-resorptive cytokines. It is hypothesized that excessive inflammatory response was controlled, illustrated by the absence of increase of serum IL-6 in OVX mice after PE implantation.

Purpose of the study: Oestrogen depletion leads to osteoclastic hyperactivity and subsequent postmenopausal osteoporosis. Little is known about interactions with bone absorption induced by wear particles from joint bearings. The purpose of this study was to evaluate bone response to polyethylene (PE) particles in a mouse model of oestrogen deficiency.

Material and methods: Particles of PE were implanted in the calvaria of seven non-ovariectomised mice and in seven ovariectomised mice (OVX). Fourteen mice were operated on without implantation of the particles (7 non-OVX and 7 OVX, control groups). The mice were sacrificed at two weeks. The crania were studied under a microscanner and histologically without decalcification.

Results: The microscanner showed that particles of PE induced a significant decrease in bone thickness in non-OVX mice (p=0.04), while the thickness remained unchanged in OVX mice who had received the particles (p=0.40). After implantation of the PE particles, the number of osteoclasts per mm of bone perimeter was 2.84±1.6 in the non-OVX mice and 1.74±1.3 in OVX mice (p=0.004). Compared with controls, the mean loss of bone was 12±10% in the non-OVX mice versus 4.7±0.9%in the OVX mice (p=0.004).

Discussion: The volume of osteolysis induced by PE particles was smaller in OVX mice compared with non-OVX mice.

Conclusion: These results suggest that a deficit in oestrogens has a protective effect against bone adsorption induced by PE particles.

Effectiveness of total hip arthroplasty (THA) for acute fracture of the femoral neck is still debated. The purpose of this retrospective controlled study was to compare the results of THA done for fracture of the femoral neck with a similar group of matched THAs done for osteoarthritis (OA).

From 1993 to 2000, 25 patients (25 hips) had THA for displaced femoral neck fracture. There were 18 women and 7 men, with a mean age of 73+/− 8.5 years (range, 55 to 93 years). The control group was composed of 25 patients (27 hips) who had THA for primary OA. Patients were matched for age, sex, medical comorbidity, surgical approach, prosthesis, and surgeon. Cemented implants with a Me-PE couple were used in the great majority. All patients had radiographic assessment. Functional results were rated according to the grading system of Merle d’Aubigné.

One patient (one hip) was lost to follow-up in each group. The mean follow-up was 6 years (range, 3.5 to 10 years). No revision was performed in this series. Complications included one postoperative dislocation in both groups. At the last follow up evaluation, 21 hips and 23 hips were classified excellent or very good in the “fracture” group and in the control group respectively. No progressive radiolucent line and no osteolysis were recorded. Mean annual PE wear was 0.096 +/− 0.094 (range, 0 to 0.26 mm) in the studied group compared with 0.125+/− 0.095 (range, 0 to 0.24 mm) in the control (p=0.30).

THA for acute femoral neck fracture and THA for OA provided comparable mid to long term results in elderly patients.

Purpose: Total hip arthroplasty after failure of femoral osteotomy raises high risk of complications. Outcome has been controversial. The purpose of this retrospective analysis was to evaluate the difficulties and results.

Material and methods: Between March 1974 and January 1995, 68 patients (82 hips), 51 women and 17 men, mean age 59±11.5 years (32–84) underwent surgery. Initial indications were mainly acetabular and/or femoral dysplasia (n=47 hips) or congenital dislocation (n=21 hips). Mean time between osteotomy and arthroplasty was 13.8±8.4 years (10 months-45 years). We used cemented titanium femoral stems (Ceraver Ostal) with an alumina (n=66) or polyethylene (n=16) cup. An alumina-alumina bearing was used in 67 hips (81%). Functional outcome was assessed with the Postel-Merle-d’Aubligné score. Radiological analysis searched for lucent lines and signs of wear. The actuarial survival was determined.

Results: One patient (1 hip) was lost to follow-up. Thirteen patients (14 hips) died of intercurrent causes. Six hips required revision for aseptic loosening (isolated cup loosening in five and bipolar loosening in one) at 8.5 years on average (4.5–12). There were 22 intraoperative complications (27%) including 18 fractures or femoral stem misalignments and four cases of damage to the acetabular fundus. Other complications included one postoperative dislocation, two sciatic nerve palsies with partial recovery, and one non-union of the greater trochanter. There were no infections. At maximum follow-up (11.8±4.7 years, ragne 5.4–20), the mean functional score was 16.5 (15–18) versus 9.9 (6–14) preoperatively (p< 0.05). There were no femoral lucent lines. A complete lucent line around the cup was observed in eleven hips including six with a massive cemented alumina cup. Considering revision for aseptic loosening as failure, cumulative survival at 12 years was 82% (95%IC 67–96%) for the cup and 98% (92–99.7%) for the femoral stem.

Discussion: These results confirm the high risk of intraoperative complications of total hip arthroplasty performed for failure of femoral osteotomy. Architectural changes expose these patients to technical problems. The survival of the implants appears to be relatively unaffected by the prior procedure but the functional results are slightly less satisfactory then for primary arthroplasties.

Purpose: The aim of this study was to evaluate quality-of-life (QoL) in patients undergoing bilateral hip arthroplasty implanted during the same operation.

Material and methods: Sixty-one patients (28 women and 33 men) underwent surgery between November 1989 and February 2002. Average age was 42±14 years (13–76). Indications were primary osteoarthritis (n=24), secondary osteoarthritis (n=31), aseptic osteonecrosis (n=25) and rheumatoid disease (n=6). The implants (Ceraver Osteal) were cemented (50 stems, 11 cups) or coated with hydroxyapatite (72 stems, 11 cups). An alumina-alumina bearing was used in all cases. The Postel-Merle-d’Aubigné score was noted to assess function. QoL was measured prospectively in 27 patients using the SF-36 and the WOMAC, preoperatively and every three months.

Results: None of the patients were lost to follow-up. Complications included two intraoperative femoral fractures treated by cerclage, one early dislocation, three thromboemoblic events (including one case of pulmonary embolism). Unipolar revision was required for one hip due to aseptic acetabular loosening at 6.5 years. Surgical cleansing was performed in one other hip for infection. Intraoperative blood loss was 1529±451 ml (540–2550). Mean hospital stay was 13±2.5 days (8–22). At mean follow-up of 49±33 months (12–162), the mean function score was 17.8±0.5 (16–18) versus 10±2.7 (3–14) preoperatively (p< 0.05). Clinical outcome was good or excellent in 98% of the hips. There were no radiological signs of wear. A complete lucent line developed around one cup. The quality of life scores improved significantly (p< 0.01) as soon as three months postoperatively for the items ‘social activity’, ‘physical activity’ and ‘pain’, particularly in men p< 0.05).

Discussion: Bilateral hip arthroplasty during the same operative time is not advocated by all authors. It is a difficult surgical situation requiring rigor and skill. The drawbacks include longer operative time, greater blood loss, and in some patients, higher morbidity. This approach however enables treating bilateral disease in one operation, particularly in younger subjects. Use of an alumina-alumina bearing and non-cemented implants is particularly indicated. The results of this series validate the efficacy of this technique which allows rapid improvement in the patients’ quality-of-life.

Purpose: Classical instrument sets for implantation of total knee arthroplasty (TKA) can be perfected. Computer-assisted implantation appears to offer improved technical quality. The purpose of this study was to compare a matched series of TKA implanted with the conventional method and with a computer-assisted navigation system.

Material and methods: Seventy-eight prostheses implanted with a computer-assisted system based on 3D CT-scan reconstruction of the lower limb were matched with 78 prostheses implanted by a highly-trained operator. The knees were matched for gender, aetiology, surgical approach, and axial deviation. There were no significant differences between the groups for these variables. An intramedullary aiming device was used for knees undergoing the conventional procedure. Navitrack(r) was used for the computer-assisted implantations. The same prosthetic system (Wallaby) was used for both series. An independent operator assessed the double-foot stance gonometries. The femorotibial axis was measured as was the individual position of the tibial and femoral pieces.

Results: Axis was within 3° varus and 3° valgus for 92% of the knees operated on with the navigation system. This same range was found for 59% of the conventional procedures. The difference was significant (p< 0.0001). Analysis of the individual femoral and tibial components did not demonstrate any significant difference.

Discussion: Results of TKA are dependent in part on operative technique. The objective is generally achieved with the computer-assisted technique but is not with the conventional technique. Navigation could be useful to achieve successfully short-term objectives. Its contribution to mid-term outcome remains to be demonstrated.

Aims: The purpose of this retrospective study was to report on the minimum 10-year follow-up results of a consecutive series of cemented low friction total hip arthroplasties performed for avascular necrosis of the femoral head. Methods: One hundred and twenty-two THAs in 96 patients were performed between January 1980 and December 1990. All prostheses were of Charnley- Kerboull design, combining a 22.2-mm femoral head and an all-polyethylene socket. Both components were cemented. The mean age of the series was 50.8 ± 13.3 years (21–85 years). Eighty hips were graded Ficat III and 42 hips were graded Ficat IV. Results: At the minimum 10-year follow-up evaluation, 59 patients (75 hips) were still alive and had not been revised at a mean of 13.9 years (10–21 years), 7 patients (7 hips) had been revised, 20 patients (24 hips) had died from unrelated causes, and 10 patients (16 hips) were lost to follow-up. The mean dñAubignŽ hip score was 17 ± 1 at the latest follow-up. The mean wear rate for unrevised hips was 0.07± 0.06 mm per year. Revision was performed for polyethylene wear associated with periprosthetic osteolysis in 6 hips and for deep sepsis in one. Three hips had recurrent dislocations. The survival rate at 15 years, using revision for any reason as the end-point, was 88.5% (95% conþdence interval, 80.2 to 96.9%). Conclusions: This series indicated that Charnley Kerboull low friction total hip arthroplasty for avascular necrosis could provide satisfactory long-term clinical and radiologic results.

Purpose: Filling bone loss during revision total hip arthroplasty raises many problems related both to the surgical technique and to the type of bone substitute used. The purpose of this study was to report the clinical and radiographic results obtained in a series of femur reconstructions using impacted calcium phosphate ceramics.

Material and methods: The technique used here was derived from the method developed for impacted fragmentary grafts by Ling and Gie. Grains of macroporous biphasic calcium phosphate ceramic (MBCP) were impacted into the femoral shaft to obtain a stable sheath into which the stem could be cemented (Ceraver Osteal). This technique was used from March 1996 to october 2000 in 18 patients (20 hips) undergoing revision for femoral loosening in 11 (including septic loosening in eight), femoral osteolysis (one hip), pain (one hip), and instability (one hip). Mean age ate revision was 66 years (range 30–79). Most of the femoral bone defects were classed grade IV. The grains of MBCP were used alone in 13 cases, in a mixture with allografts in five cases, and in a mixture with autologous bone in two cases.

Results: Mean follow-up was 31 months (range 8–70). None of the patients were lost to follow-up. There were two intraoperative femur shaft fractures which healed without sequela. Two patients required a second revision for loosening (including one septic) 20 and 16 months after the first revision. At last follow-up, the mean PMA score had improved to 16 (12–18) (p< 0.05) and 67% of the patients achieved a good or excellent clinical result. Radiologically, there were 14 cases of good osteointegration of the MBCP grains without implant migration. Mean shortening was 3 mm (3–5) was observed in three cases and a stable incomplete lucent line was observed in one patient with no clinical impact.

Discussion: Calcium phosphate ceramic material can be useful to overcome the problem of major bone loss in RTHA. It provides an attractive alternative to the disadvantages of bone grafting and helps, in theory, improve primary implant stability. The original technique presented here has allowed us to achieve promising short-term results in young patients with an adequate femur.

Purpose: Fracture of alumina implants is a rare cause of total hip arthroplasty (THA) failure. Over the last twenty years, improvement in the design of ceramic implants has helped reduce this risk. We observed five cases of alumina implant fracture over the last year. The purpose of this work was to analyse these recent events and to examine our experience to search for an explanation.

Material and methods: Between 1976 and 2002, eleven patients, five women and six men, mean age 57 years (range 32–87 years) required revision surgery for fracture of an alumina component. The time interval from primary surgery to revision was 36.5 months (range 7 – 106 months). An alumina-alumina couple was involved in nine cases and an alumina-PE couple in two. The primary THA used a press-fit metal backed alumina cup for five hips, a cemented alumina cup for three hips and a massive press-fit alumina cup for one. The alumina head measured 32 mm for ten hips, 22.2 mm for one. The femoral stems were cemented in seven cases, and hydroxyapatite surfaced in four. The acetabular component was involved in four cases and the femoral head in seven.

Results: Identified causes of ceramic implant fracture were: high-power trauma (insert) (n=1), insufficient head diameter (n=1), and defective head match (n=1). For the eight other fractures, involving three insets and five heads, no triggering factor could be identified. The three insert fractures involved two 50-mm cups and one 52-mm cup. Insert design had been changed before these fractures. Mean time from insertion to fracture was 12 months (range 8.5–15 months) in these cases.

Discussion: To our knowledge, all reported cases of ceramic implant fracture have concerned the prosthetic head. The present series demonstrates a recent development, fracture of acetabular implants. It is hypothesised that these fractures could be explained by an insufficient cup diameter associated with a recent change in the design of the metal-backed flush ceramic insert. These inserts have been modified and now have an “overhang” design associated with a thicker layer of ceramic for the smaller cup diameters. These accidents remain rare but justify careful surveillance, particularly during the first postoperative year.

Purpose: The purpose of this retrospective study was to assess clinical and radiological outcome at ten years follow-up at least in a continuous series of total hip arthroplasties performed in patients with aseptic necrosis of the femoral head.

Material and methods: The series included 122 arthroplasties performed between January 1980 and December 1996 in 96 patients (26 women and 70 men), aged 50.8±13.3 years (range 21–85 years). The underlying cause was essential necrosis in 40.6%, cortocosteroid threapy in 19.8%, chronic alcoholism for 17%, trauma for 12%, and another medical cause for 10%. The Ficat and Arlet classification was grade IV 80 hips, grade III 42 hips. All arthroplasties were performed via the transtrochanteric approach. Cemented Charnley-Kerboull implants were used with a metal-polyethylene couple in all cases. The Merle d’Aubigné score was used to assess functional outcome. Cup wear was measured according to Livermore. Actuarial survival curves were calculated.

Results: Follow-up was greater than ten years for all patients (mean 13±2.6 years, range 10–21 years). At last follow-up 59 patients (75 hips) were living and had not undergone revision and seven patients (seven hips) had undergone revision of the acetabular and/or femoral component. Twenty patients (24 hips) had died and ten patients (16 hips) were lost to follow-up. Revision procedures were performed for periacetabular osteolysis in one hip, infection in one hip, and acetabular loosening in five hips. Three patients experienced luxation or subluxation. The mean preoperative function score was 11 (range 5 – 16) compared with 17 (14–18) at last follow-up (p < 0.05). Clinical outcome was good or excellent in 95% of the patients and fair or poor in 5%. Mean overall cup wear was 0.965 mm (0–5) for non revised hips. Lucent lines were found around eleven acetabular implants and six femoral implants. Cumulative survival, considering revision as failure, was 88.5% at 15 years (95% confidence interval 80.2 – 96.9%).

Discussion and conclusion: The results of this series lead to the conclusion that low-friction total hip arthroplasty is the treatment of choice for advanced stage femoral head necrosis.

Purpose: Revision total knee arthroplasty (RTKA) is particularly difficult and results more variable than primary total knee arthroplasty due to the added problem of bone loss. Massive bone allografts have been proposed to restore bone stock and mechanical conditions as close to the physiological situation as possible. The purpose of this retrospective analysis was to assess clinical and radiological results after knee reconstruction with massive allografts in patients undergoing revision total knee arthroplasty.

Materials and method: This series included 14 patients who underwent a revision procedure between February 1990 and August 1998 for RTKA with segmentary bone loss and bone defects. This group included seven patients with mechanical failure and seven others with septic loosening. Reconstruction was achieved with a massive allograft sealed around a long stem cemented implant. The composite assembly was impacted into the patient’s bony segment. The allografts were used to reconstruct the distal femur in nine cases, the proximal tibia in one, and both in the others. The IKS score and radiographic homogenisation of the host-graft junction were assessment criteria.

Results: Mean follow-up was 50 months (24–110). Mean IKS score was significantly improved from 43 (11–70) pre-operatively to 75 (40–100) at last follow-up (Wilcoxon test, p = 0.002). At last follow-up, the flexion-extension amplitude was 91±10°. Radiographic integration of the allografts was achieved in 14 out of 18 grafts. Three allografts were resorbed leading to fracture with subsequent implant failure and a new revision in two. There were no infections.

Discussion and conclusion: Bone grafts may be a solution to the difficult problem of bone loss during RTKA. Massive grafts combined with long stem implants have given encouraging early and mid-term results. The duration of these results is under evaluation.