Aims

The purpose of this study was to evaluate the infection-free outcome of patients underwent revision of total joint arthroplasty (TJA) for presumed aseptic causes, with positive intra-operative cultures.

Aim

Diagnosis of periprosthetic joint infection (PJI) is challenging given the limitations of available diagnostic tests. Recently, several studies have shown a role of the long pentraxin PTX3 as a biomarker in inflammatory diseases and infections. This single-center prospective diagnostic study evaluated the diagnostic ability of synovial fluid and serum PTX3 for the infection of total hip arthroplasty (THA) and total knee arthroplasty (TKA).

Aim

Diagnosis of periprosthetic joint infection (PJI) is still challenging due to limitations of available diagnostic tests. Many efforts are ongoing to find out novel methods for PJI diagnosis. Recently, several studies have shown a role of the long pentraxin PTX3 as a biomarker in inflammatory diseases and infections. This pilot diagnostic study evaluated the diagnostic ability of synovial fluid and serum PTX3 for the infection of total hip arthroplasty (THA) and total knee arthroplasty (TKA).

Almost any kind of bacteria can be involved in prosthetic joint infections (PJI).

In 2014 we collected data on 3 patients presenting with hip or knee pain and radiological signs of prosthetic joint mobilization without any other clinical or biochemical suspect of infection.

Interestingly, in all cases we isolated bacteria very rarely involved in human infections: Cupriavidus pauculus, Ralstonia paucula and Neisseria flavescens. Both Cupriavidus pauculus and Ralstonia paucula are Gram negative environmental bacteria which can contaminate water (tap, pool and mineral) and have been isolated from a variety of human clinical sources including blood, wounds, sputum, urine, eye, throat and peritoneal fluid, as non pathogenic flora. In such two patients we were able to cure the infection with quinolones (both strains were sensible). Neisseria species are Gram-negative bacteria included among the proteobacteria. Neisseria flavescens is often found in the upper respiratory tract and oropharynx of humans, rarely associated with infectious process (necrotizing pneumonia and empyema). In this last patient we successfully used piperacillin-tazobactam i.v. during hospitalization and shifted to amoxicillin-clavulanate per os at discharge.

In conclusion, any bacteria can induce PJI: in some cases pre-operative blood tests are normal and therefore useless. We need new tests to overcome this diagnostic problem (such as alpha-defensin) and we must check on rare bacteria prolonging incubation to a more extended period of time (as in Propionebacterium acnes or Mycobacterium spp) and/or sending samples to specialized laboratories.

We thank all the medical and nurse staff of Prosthetic Joint Replacement Unit of Orthopaedic Center, Humanitas Research Hospital

Introduction: Angular and torsional deviations of femur are usually combined with Congenital Dislocation of the Hip (CDH) and increase the complications of hip arthroplasty. The aim of this study is to evaluate surgical and reconstructive options for the treatment of CDH.

Material and Methods: In this retrospective study, we evaluated the results and complications of 55 primary cementless total hip arthroplasties, all of whom had Crowe type-IV developmental dysplasia of the hip. The arthroplasty was performed in combination with a subtrochanteric shortening osteotomy and with placement of the acetabular component at the level of the anatomic hip center. The patients were evaluated at a mean of 8,1 years postoperatively.

Results: From 1984, more than 2000 cases of arthroplasty have been performed in dysplastic hip, 565 cases had a previous femoral osteotomy; 128 cases needed correction of femoral side deformity; 64 had a greater trochanteric osteotomy. In 9 cases rotational abnormality and shortening were controlled with plate and distal femur osteotomy. 55 cases were treated by a shortening subtrochanteric osteotomy. Only non-cemented stems were used. 4 failures occurred for the incorrect fixation of the metaphysis. The fixation can be obtained only by prosthetic press-fit, but it is preferable to use metal wires. There was no sciatic injury; indeed shortening osteotomy provides an easy control of deformity and lengthening, with a maximum of 4 cm. One case was reviewed for heterotopic calcification (grade 4). One infection of the soft tissue was medically cured. There were two revisions for polyethylene failure at 8 and 12 years postoperative.

Discussion: The anatomic abnormalities associated with CDH and previous femoral osteotomy increase the complexity of hip arthroplasty. We had best results with the femoral shortening subtrochanteric osteotomy where a rapid consolidation was obtained. Moreover, the functional result was better for the management of the insertion of the muscle tendons in particular the mediogluteus and also for the relatively correct positioning in favour of the reciprocal relationship of the pelvic-trochanter. The detachment of the greater trochanter associated with a metaphyseal proximal shortening, remains an effective technique for the treatment of malformations that are difficult to treat, but there is a high risk of pseudarthrosis of greater trochanter.

Conclusion: Femoral shortening subtrochanteric osteotomy preserves the proximal femoral anatomy, avoids the problems associated with reattachment of the greater trochanter, and facilitating a cementless femoral reconstruction in relatively young patients.

Introduction: Acetabular bone defects are critical and frustrating issue; indeed is possible to obtain good reconstruction with conventional Methods: (i.e. bulk graft, cage and cement) but good results are limited to short and mid term. Aim of this paper is to present reconstructive method based on filling the defect with an augment made of tantalum (augmentation technique).

Methods: We analized 42 cases from February 2005 to March 2009 with an average age of 63 years old with acetabular defect, scored 3A or more (4 patients had pelvic disjunction) according Paprosky classification.

The average age was very low, with 12 cases under 60 years (28,57%) and 21 under 70 (50%). 18 patients were re-revision (at time of surgery were at third or fourth surgical procedure) representing 54,2% of cases. Complete clinical, radiographic evaluation and survivorship analysis for the entire study cohort was performed from an average follow up of 26 months (min 6–max 55 months).

Results and Discussion: Preliminar results are encouraging: in only two case we had poor results with step pain and prescribed partial load and walking with two crutches, slight radiographic sign of migration where present at the last follow-up. These patients were previously submitted to many surgical procedures with significant bone loss, soft tissue damages and both with history of previous infection, classified as pelvic disjunction. One of these reported a ischiatic palsy.

In the remaining cases we obtained good functional recover, no failures at two years average of follow-up. 40 patients didn’t show hip or groin pain during stance position or walking, no bone resorption or implant mobilization were seen at radiographic follow-up. The HHS increases from 23,04 pre op to 85,15 post op. In no case were found clinical, radiographic, or biochemical signs of infection.

According with literature the rationale of augmentation technique with trabecular metal should give long lasting favourable results for its excellent bone ingrowth and mechanical properties.

Our results almost match the results of other authors. These brilliant results, partially due to osteoconductive proprieties of tantalum (despite we require time to confirmate), are certainly obtained thank to the optimal centre of rotation reconstruction, always close the physiological one.

The experience that we gathered using uncemented stems for revisions with diaphyseal anchorage gave us satisfactory outcomes both for survival curve

(94% of cases – 15 yrs follow-up) and for clinical results in the aseptic mobilisations.

Thus, we extended this technique in the re-implant of septic prostheses.

We treated 43 cases of septic hip prostheses from 2003 to 2006. The treatment of choice has been the two-stage revision with the implant of temporary spacer, utilising the one-stage treatment just in few cases selected from needle-aspiration positive culture. The technique foresees the utilisation of Wagner uncemented revision stems in 98% of cases and 2% using a first implant prosthesis. Accompaniment antibiotic protocol has been protracted for 3 – 6 months till the negativity of the inflammation index.

Average follow-up of 26 months shows good clinical and radiographical results with percentage of a new revision of the two-stage in 2.32% (1 case).

The uncemented components are confirmed to be the best presidia for the implant stability retrieval in the immediate and long-term either, the two-stage strategy appears sure enough for the re-infections control especially associated with an adequate antibiotic treatment. Therefore, the choice strategy proposed by us favours the uncemented implants in combination with the two-stage.

Background: This report presents the long term (over 20 years) experience with the use of a grit-blasted, press-fit femoral prosthesis.

Methods: The first 300 consecutive primary THA procedures using a collarless, three-dimensional tapered, straight, titanium alloy stem with a grit-blasted surface (performed in 299 patients) were evaluated up to twentytwo years. A cementless all-polyethylene socket in 80 percent of the cases, were used. Radiographic evaluation, performed by an independent observer using a zonal analysis method, included assessment of component migration, Engh’s implant-bone femoral fixation score, implant-bone demarcations, and periprosthetic osteolysis. The average duration of long-term radiographic follow-up was 12.6 years (range; 10 to 16 years).

Results: At last examination only five hips were lost to follow-up and 84 patients were deceased. The femoral revision rate was 7 percent (two hips for aseptic loosening, five hips for septic loosening, and twelve hips with osseointegrated stems for severe progressive femoral osteolysis) and the acetabular revision rate was 28% (revised for either socket migration or progressive peri-acetabular osteolysis or both). Survivorship, based on any revision (femoral or acetabular) was 89% at ten years and 65% at twenty years; survivorship of the femoral component was 95% at ten years and 89% at twenty years. The incidence of femoral periprosthetic osteolysis, was 47%, with 5% of distal endosteal osteolysis. Radiographic femoral implant-bone fixation was stable, bone-ongrowth in 97%; stable, fibrous-fixation in 1%.

Conclusions: The grit-blasted, press-fit, collarless, tapered femoral component continued to perform well clinically and radiographically up to twenty years of follow-up despite the challenging environment of peri-prosthetic osteolysis associated with the acetabular component design. This implant is still in use virtually without design modifications. This study demonstrates the durability of the results of the grit-blasted femoral component and indicates that such an implant offers a viable alternative for fixation without bone cement.

Introduction: T.H.A. revisions are constantly increasing: and it’s known that bone defects – expecially if severe like in rirevision cases – are the main problem to manage during the revision surgery. Since 1988, we have chosen to bypass the bone defects by using an “elastic” non-invading tapered stem (SL Wagner); morsel bone graft is rarely necessary, we never use a massive one. According to our philosophy in revisioning, stability should be obtained by a diaphysary anchorage as proximal as possible.

Methods: Our research concerns 150 cases of SL revision stems implanted from December ’88 to December ’91. The average age is 67 years old, complete clinical evaluation and survivorship analysis for the entire study cohort was performed from 8 to 12 years follow-up, radiographic analysis in 81 cases with 101 months avg. follow-up (min. 60 – max. 143).

Results and Discussion: 4 cases required rirevision; 20 patients deceased; 12 were lost to follow-up; 96 examinated.

Clinical evaluations show an average score of 78 (acc. to HHS); 82,3 percent of patients are pain free, while slight pain still persists in a 13,7 percent pain in a 3,9 percent.

The radiographic analysis has put into evidence only 1 case of mobilization, and suffering bone in 4 percent of cases; by contrast, 79,5 percent show astonishing endosteal bone formation.

Background. Total hip replacement (THR) has become the ideal treatment for any disorder causing joint destruction. Surgery-related infections are reported only in 1–2 % of THR, but antibiotic prophylaxis is necessary because infections are associated with significant morbidity and occasionally death. 1st and 2nd –generation cephalosporin or, in hospital with methicillin-R Staphylococcus spp (MRSA, MRSE) high prevalence, vancomycin, are the most frequently drug emplojed. The most frequent side effects of antibiotic prophylaxis are allergic reaction and pseudomembranous enterocolitis.

The objective of the present study was to assess the efficacy and tolerability of antibiotic prophylaxis for THR at S. Corona Hospital Pietra Ligure SV (Italy).

In our hospital the majority of prostethic device infections are due to MRSA, but recently we have described increment of infection due to Pseudomonas spp and other gram-. For this reason we used association of vancomycin plus pefloxacin in primary prophylaxis.

Methods. Retrospective analysis of 1118 THR performed in the period 2003–2004, receiving surgical prophylaxis with a single dose of the association vancomycin 1000 mg plus pefloxacin 400 mg. Data collection regarded patients’ age at surgery and reasons for THR. The presence of a surgery-related infection was investigated by means of a phone interview about the function of the hip device (presence of pain, deambulation impairment, fever). Patients with pain or other problems were submitted to physical exam, laboratory tests, plain radiograph and if necessary to exclude of infection, radioisotopic scans.

Results. We report the preliminary data on 218 THR in 211 patients (81 M, 122 F, median age 67.49 aa, range 29–91). THR was performed for: osteoarthrites in 168 cases, trauma in 26, osteonecrosis in 9, displasia in 4 cases, previous osteotomy in 4. 167/211 patients were submitted to a phone interview and 44 to a clinical examination.

Conclusions. In our center, the association of vancomycin-pefloxacin resulted effective and well tolerated as single dose prophylaxis for THR.

Introduction: The anatomic abnormalities associated with the dysplastic hip increase the complexity of hip arthroplasty, in addition previous femural osteotomy can deformate proximal femur.

Despite the fact that uncemented cup and stems are specifically designed for dysplasia to recover the true acetabular region in Crowe IV and sometimes Crowe III additional surgical procedure are required.

Purpose of the study is to analize surgical procedure and then reconstruction options on severe hip dysplasia.

Materials and methods: From 1984 till today 2308 cases of arthroplasty were performed in dysplastic hip, 565 cases have a previous femoral osteotomy; out of these 2308 cases 128 cases need treatment for corrections of femural side deformity.

64 cases were subjected to a greater trochanteric osteotomy. In 12 cases proximal femural shortening was associated. In 9 cases rotational abnormality and shortening were controlled with a distal femur osteotomy.

55 cases were treated by a shortening subtrochanteric osteotomy that allows corrections of any deformity. Only uncemented stems were used and in the majority of cases a specific device for displastic hip (Wagner Conus produced by Zimmer).

Discussion: Long-term results in these patients are steadily inferior to that in the general population (70% survival at 15 yrs). On femural side early failures are the reflection of learning curve and are due to insufficient fixation of the osteotomy.

Despite this, the more promising outcomes are concerning shortening subtrochanteric osteotomy with uncemented stem but only early and mid-term data are available.

Introduction In our experimental design we evaluated the osteogenic potential of h-bone marrow (hBM), h-mesenchymal stem cells (hMSC), bone morphogenetic protein (BMP-7) and the combination hMSC plus BMP-7. The aim of the study was to define the capacity to elicit bone formation of expanded hMSC alone and associated with BMP-7

Material and methods A rat femoral segmental defect model was used in this study. 12 male athymic rats were used. The institutional Animal Ethics Committee approved the study. Athymic rats test graft groups consisted of: G1-autoclaved bone and h-BM; G2-bone and h-MSC; G3-bone with BMP-7; G4-bone and h-MSC with BMP-7. h-BM aspirates were harvested from iliac crests of patients undergoing to THA. A plate has been fixed on the femurs with four cerclage wires before a femoral gap of 6mm has been realized in the diaphysis. Gap was filled with different graft. Defect was evaluated at 2, 4, 8, 12 weeks after implantation with radiographs. Evaluation of bone graft has been done using a Cook classification. Histological study with toluidine blue and safranine O at 12 weeks has been performed in each group.

Results At 8–12 weeks after surgery G1 shown non visible new bone formation, G2 minimal new disorganized bone and G3 disorganized new bone bridging graft to host at both ends. The G4 group show significant new bone and graft remodelling. Histological analysis confirmed the rx results.

Conclusion The association hMSC plus BMP-7 determines a significant activation of the osteogenic activity at 8 weeks that may have a remarkable impact on the future orthopedic surgery strategies.

It has been shown that mesenchymal stem cells (MSCs) and BMP are involved in bone formation. The aim of the study was to evaluate the osteogenic potential of human bone marrow (hBM), human expanded MSC (hexp-MSC), BMP-7, and hexp-MSC plus BMP-7, to treat a rat femoral segmental defect.

Sprague-Dawley (SD) and athymic rats (Nu) were used. SD rats where used in order to define surgical technique. Nu rats groups consisted of: G1-autoclaved bone and human bone marrow (hMNC); G2-bone and hexp-MSC; G3-bone with BMP-7 only; and G4-bone and hexp-MSC with BMP-7. A plate was attached to the femoral diaphysis with two cerclage wires. Then a 6-mm femoral gap was made and filled with a different graft. At regular intervals, the femoral defect was evaluated with radiographs, using a modified six-grade Cook classification.

At 8 weeks G1 showed non-visible new bone formation; G2 minimal new disorganised bone; G3 disorganised new bone bridging the graft to host at both ends; and G4 significant new bone and graft remodelling. Histological analysis confirmed these results.

Our results showed that although the osteogenic activity may be improved by hMSC (G2) as well as by BMP-7 (G3), the association hexp-MSC plus BMP-7(G4) produced graft osteointegration at 8 weeks after surgery. This may have a remarkable impact on future orthopaedics surgery strategies.

Human mesenchymal stem cells (hMSC), residing in the bone marrow, can be purified, expanded in cell culture and under appropriate stimuli may differentiate along the osteogenic, chondrogenic and adipogenic lineages. The aim of this study was to investigate the expansion capability and differentiation potential of MSCs obtained from femur, pelvis and acetabular cancellous bone of aged patients in order to establish whether these cells, isolated and expanded in vitro, can be used in a new approach in orthopaedic revision surgery.

In this preliminary study we enrolled 33 patients undergoing hip arthroplasty in order to investigate CFU-F frequency, expansion ability and differentiation potential of hMSC derived from three different anatomical sites: femural, pelvic and acetabular cancellous bone (ACB).

CFU-F frequency (CFU-F/10 ⁶ MNC) was 63 for pelvis (range 7–122), 90 for bone (39–132) and 47.5 for femur (7–124).CFU-F frequency was higher in ACB than in either pelvis (p=0.04) or femur (p=0.001). The patients were divided into three age groups: G1 ≤50 years (n=6), G2 50 −65 years (n=11), and G3 ≥65 years (n=16); however, CFU-F frequency did not show any statistically significant difference, although the frequency was lower at higher age.

We expanded in cell culture MSC of 16 patients from the three considered sites until the fourth passage. At the first passage there was a higher MSC recovery in ACB (median 12%) than in pelvis (median 8%; p< 0.004) and femur (median 3.8%; p< 0.0004). MSC recovery from pelvis was higher than in femur (p< 0.04). At the second and third passage MSC expansion was found to be significantly higher in ACB than in pelvis alone (median 3.1 vs 1.6, p< 0.01; 1.8 vs 1.2, p< 0.005, respectively), while at the fourth passage it became higher than in pelvis and femur (median 2.6 vs 1.4, p< 0.03; 2.6 vs 1.6, p< 0.0, respectively). At each culture passage, cells showed MSC features as supported by flow cytometry and by the multilineage differentiation potential.

hMSCs seem to have higher frequency in close association with bone; moreover, they show an increased expansion ability in vitro which is still mantained in elderly patients. As these progenitors can differentiate in bone, they seem to be the best choice for the effective repair of bone defects in revision surgery.

Unstable knee caused by an axial deformity mainly occurs in serious valgus cases, which is the result of a femoral external hypoplastic condylus defect and often seen in association with marked debris of the tibial plate and bone –loss. Tibial rotation related to the deficit causes lateral patellar subluxation, and soft tissue retraction fixes the deformity while the preconditions for an anteromedial ligamentous laxity are being created. On replacement the deformities develop because of bone-stock defects as well as ligamentous defects, which are often secondary to debris and/or to primary component misrotations.

In primary surgery the approach is medial for varus and lateral for valgus, in order to help the release. We use the GAP technique to implant semibonded prostheses. In revisions the previous approach is always followed. From 2000 to 2003 52 LCCK Zimmer were implanted. Tuberosity detachment was required in 20 cases.

The increase in TKS was significant.: from 40 to 180. The radiographic alignment supported by taproots centrage is excellent, and there are no signs of radiographical mobilisation in any of the cases.

There were two cases of intolerance, with decubitus of a screw utilised for the tibial tuberosity synthesis. A flexion-extension defect had to be repaired afterwards by surgery and two cases of endostal reaction to the tibial taproot were observed.

Despite the difficulty of treated cases, results appear promising; the combination between prosthesis type and GAP technique confers high stability to the system.

Aims: The purpose of this study is to review eight to eleven year results of a consecutive series of primary hybrid total hip arthroplasties. Methods: 193 patients (197 hips) received a cemented, polished, collarless, femoral component (Ra=1) in association with an uncemented acetabular component (166 grit-blasted titanium ßexible, 17 Ti mesh, and 14 Standard porous cups). Results: Mean age at surgery was 69.5 years (51–90). Most frequent diagnosis was osteoarthritis. Average follow-up was 9.2 years (8.5 to 11.2). 21 patients (23 hips) were lost to follow-up. 24 patients (25 hips) died prior to eight-years and none had undergone revision. Two femoral components, the only two with Grade D cement mantles, were revised for aseptic loosening at 23 and 111mos. One Ti mesh socket was revised for catastrophic poly wear at 113m and one ßexible cup for dislocation at 111m. The remaining 146 stems and cups were available for minimum 8year clinical review. 62 underwent complete radiographic review. Conclusions: Post-op Harris score was 89.3 (68–100). Pain relief was good or excellent in 95% of patients. X-rays revealed 1–2mm of femoral subsidence in 6 hips. Two cases of proximal (zones 7 and 1) femoral osteolysis were identiþed. A cemented polished femoral component and an uncemented acetabulum provide excellent clinical and radiographic results at average 9y follow up. Continued success appears likely in the absence of osteolysis or cement bone demarcation.