Ankle osteonecrosis in fifty-one children and adolescent's leukemia survivors: a prospective randomized study on percutaneous mesenchymal stem cells treatment.

PURPOSE: Corticoid treatment associated with haematologic treatments can lead to ankle osteonecrosis in children's survivors of acute leukemia (ALL). Based on the efficiency of mesenchymal stem cells (MSCs) in hip osteonecrosis, we performed an evaluation of this treatment in 51 children and adolescents who had symptomatic ankle osteonecrosis after therapy for haematologic cancer. MATERIAL AND METHODS: The 51 patients had a total of 79 osteonecrosis sites on MRI, with 29 talus sites, 18 metaphyseal tibia sites, 12 epiphyseal tibia sites, eight calcaneus sites, six fibula sites, four navicular sites, and two cuboid sites. In this prospective randomized trial, 37 ankles were addressed for cell therapy, 37 others for core decompression alone, and 20 were considered as a control group without treatment. We analyzed the outcome of this treatment osteonecrosis, the number and characteristics of bone marrow mesenchymal cells (MSCs) that could be transplanted, and the risks of tumorigenesis in these patients with haematologic cancers. The patients were operated on over a period of ten years from 2000 to 2010 and were monitored through December 31, 2019. RESULTS: Despite a normal systemic blood cells count, MSCs in the iliac crest (counted as CFU-F) were in low number (1021 MSCs/mL; range 314-3015) and were of host origin after even allogeneic bone marrow transplantation. Better clinical outcomes (pain, foot and ankle deformity) and osteonecrosis repair on MRI with absence of collapse were obtained in ankles that received cell therapy as compared with those with core decompression alone or those without initial surgery. No tumour was found on MRI at the sites of injection and this study found no increased risk of recurrence or of new cancer in this population after an average follow-up of 15 years. CONCLUSIONS: These results suggest that autologous MSCs can improve the quality of life of leukemia survivors with ankle osteonecrosis.

Subchondral bone or intra-articular injection of bone marrow concentrate mesenchymal stem cells in bilateral knee osteoarthritis: what better postpone knee arthroplasty at fifteen years? A randomized study.

PURPOSE: There is an increasing number of reports on the treatment of knee osteoarthritis (OA) using mesenchymal stem cells (MSCs). However, it is not known what would better drive osteoarthritis stabilization to postpone total knee arthroplasty (TKA): targeting the synovial fluid by injection or targeting on the subchondral bone with MSCs implantation. METHODS: A prospective randomized controlled clinical trial was carried out between 2000 and 2005 in 120 knees of 60 patients with painful bilateral knee osteoarthritis with a similar osteoarthritis grade. During the same anaesthesia, a bone marrow concentrate of 40 mL containing an average 5727 MSCs/mL (range 2740 to 7540) was divided in two equal parts: after randomization, one part (20 mL) was delivered to the subchondral bone of femur and tibia of one knee (subchondral group) and the other part was injected in the joint for the contralateral knee (intra-articular group). MSCs were counted as CFU-F (colony fibroblastic unit forming). Clinical outcomes of the patient (Knee Society score) were obtained along with radiological imaging outcomes (including MRIs) at two year follow-up. Subsequent revision surgeries were identified until the most recent follow-up (average of 15 years, range 13 to 18 years). RESULTS: At two year follow-up, clinical and imaging (MRI) improvement was higher on the side that received cells in the subchondral bone. At the most recent follow-up (15 years), among the 60 knees treated with subchondral cell therapy, the yearly arthroplasty incidence was 1.3% per knee-year; for the 60 knees with intra-articular cell therapy, the yearly arthroplasty incidence was higher (p = 0.01) with an incidence of 4.6% per knee-year. For the side with subchondral cell therapy, 12 (20%) of 60 knees underwent TKA, while 42 (70%) of 60 knees underwent TKA on the side with intra-articular cell therapy. Among the 18 patients who had no subsequent surgery on both sides, all preferred the knee with subchondral cell therapy. CONCLUSIONS: Implantation of MSCs in the subchondral bone of an osteoarthritic knee is more effective to postpone TKA than injection of the same intra-articular dose in the contralateral knee with the same grade of osteoarthritis.

Hip osteonecrosis and pregnancy in healthy women.

PURPOSE: Osteonecrosis has been reported to be associated with pregnancy in the absence of other known risk factors for the disease. Few population-based data exist to support an association since the association is rare. We investigated the association of the femoral head and pregnancy to define if pregnancy was a risk factor and to define the risk period. METHODS: Using a case-crossover method design among 652 patients who were healthy (without any known cause of osteonecrosis) during or after pregnancy, we defined the periods of risk based on the timing of reported osteonecrosis and pregnancy. We compared each patient's likelihood of osteonecrosis during a ten years period including five years antepartum, pregnancy and five years postpartum with nine month intervals for the ten year and three month intervals for the two years after gestation. RESULTS: For the 436 women who had only one child and one hip osteonecrosis, the incidence of osteonecrosis was 71.8% during pregnancy and the postpartum period, compared with 28.2% during the equivalent antepartum period for this population. Nine months after delivery, the risk of osteonecrosis declined progressively over time, from an odds ratio of 14.5 (95% confidence interval, 8.2-18.3) in last trimester of pregnancy. After the 27th month following onset of pregnancy, the relative risk was no more significantly different from the baseline risk observed in the antepartum period of women who had osteonecrosis before gestation. For women with several children, a subsequent pregnancy was not associated with osteonecrosis. CONCLUSIONS: A risk of hip osteonecrosis is present during the end of pregnancy and after delivery, and appears to decrease quickly.

Higher prevalence of periprosthetic fractures with ceramic on polyethylene hip bearing compared with ceramic on ceramic on the contralateral side: a forty year experience with hip osteonecrosis.

PURPOSE: It is unclear whether late THA periprosthetic femoral fractures are related to a mechanical mechanism that decreases strength of the femur (for example, loosening) or to a biological problem as osteolysis. It is also unknown if ceramic on ceramic bearing couples decrease the risk of late periprosthetic fractures as a result of the absence of wear and osteolysis. MATERIAL AND METHODS: We therefore asked whether the cumulative long-term fractures were different according to the couple of friction ceramic on ceramic or ceramic on polyethylene in 327 patients (654 hips) with bilateral THA (one ceramic-ceramic, and the contralateral ceramic-polyethylene) who had THA with cemented stems performed between from 1978 to 2000 for osteonecrosis. RESULTS: There were two intra-operative fractures (0.3%). The median follow-up was 22 years (range, 15-40 years), and at the most recent follow-up, the cumulative number of late (after 7 years of follow-up) post-operative fractures was 32 (5% of 654 hips). Fractures were unilateral, which means for the 327 patients, a 10% rate of fractures. Periprosthetic fractures increased in number with follow-up: seven fractures (1% of 654 hips) occurred within ten years of THA implantation, 20 (3%) within 20 years, 26 (4%) within 30 years, and 32 (5%) within 40 years. The risk of fracture was influenced (p < 0.001) by the bearing surfaces at the time of prosthetic implantation, low (0.3%) for ceramic on ceramic (1/32 fractures; 1/327 hips), high (10%) for ceramic on PE (31/32 fractures; 31/327 hips). CONCLUSION: In summary, when the contralateral hip of the same patient is the control, after 40 years of follow-up, post-operative fractures occur 30 times more often on the side with PE cup than on the side with ceramic/ceramic bearing.

Subchondral stem cell therapy versus contralateral total knee arthroplasty for osteoarthritis following secondary osteonecrosis of the knee.

PURPOSE: Total knee arthroplasty (TKA) implanted in patients with secondary osteonecrosis (ON) related to corticosteroids have relatively poor outcome (20% revision rate) at a mean follow-up of only eight years. With the hypothesis that subchondral bone marrow injection might improve knees in these patients, we evaluated 30 patients who had bilateral knee osteoarthritis with severe joint space narrowing and received TKA in one knee and subchondral bone marrow concentrate injection in the contralateral knee. MATERIAL AND METHODS: A prospective randomized controlled clinical trial was carried out in 60 knees of 30 patients (mean age 28 years, 18-41) who presented bilateral osteoarthritis secondary to knee ON related to corticosteroids in relation with different severe medical conditions. During the same anesthesia, one knee received TKA; for the other knee, a bone marrow graft containing an average of 6500 MSCs/mL (counted as CFU-F, range 3420 to 9830) was delivered to the subchondral bone of the femur and tibia. The length of anesthesia related to each procedure (bone marrow aspiration and subchondral injection of concentrated bone marrow versus total knee arthroplasty) was measured. Peri-operative outcomes, morbidity, complications, and safety of the two procedures were compared. Subsequent admissions for revision surgery were identified. At the most recent follow-up (average of 12 years, range 8 to 16 years), clinical outcomes of the patient (Knee Society score) were obtained along with radiological imaging outcomes (MRIs for knees with subchondral bone marrow injection). RESULTS: Anesthesia related to the TKA side was longer than for the cell therapy group. Medical and surgical complications were more frequent after TKA. A higher number of thrombophlebitis was observed on the side with TKA (15%) versus none on the side with cell therapy (0%). At the most recent follow-up (average of 12 years, range 8 to 16 years), six (out of 30) TKA knees needed subsequent surgery versus only one with cell therapy. The Knee Score had improved and remained similar in the TKA and cell therapy groups (respectively 80.3 points ± 11 versus 78.3 ± 23); 21 patients preferred the knee with cell therapy and 9 preferred the knee with TKA. Knees with cell therapy had improvement on cartilage and bone marrow lesions observed at the site of bone marrow subchondral injection. CONCLUSIONS: Subchondral autologous bone marrow concentrate was an effective procedure for treating young patients with knee osteoarthritis following secondary ON of the knee related to corticosteroids with a lower complication rate and a quicker recovery as compared with TKA.

A novel in vivo porcine model of intervertebral disc degeneration induced by cryoinjury.

PURPOSE: Degenerative disc disease involves sequential events that lead to the loss of cells, a decrease in disc matrix production, disc dehydration, and alteration of its biomechanical properties. The aim of this study was to determine whether cryoinjury of the nucleus pulposus performed through endplate perforation contributes to disc degeneration and to compare this technique with standard methods. METHOD: Under general anesthesia, the lumbar discs of six pigs were exposed and randomly submitted to needle puncture of the annulus fibrosus (NeP), isolated endplate injury (EP), or cryoinjury using a 2.5-J Thompson cryoprobe applied through a single endplate perforation (EP+cryo). The remaining discs served as controls. Animals were sacrificed at two months and the harvested lumbar spines were submitted to CT scan and MRI investigations. Histologic analysis was performed to assess the degree of disc degeneration. RESULTS: CT scan showed that decrease in average disc height was more important after cryoinjury (49.3%) than after endplate perforation (16.9%) (P < 0.0001) or needle puncture (19.4%) (P < 0.0001). On MRI, the dehydration ratio was significantly more important after EP+cryo (60%) than after NP (40%) or EP (30%) (P < 0.0001). After cryoinjury, the histologic score developed for this study was significantly higher than after needle puncture or endplate perforation (P < 0.0001). CONCLUSIONS: Imaging and histological analysis showed that disc cryoinjury applied through endplate perforation was superior to the classical NeP and EP models to induce experimental disc degeneration. This model appears suitable for testing safety and efficacy of novel treatments of intervertebral disc degeneration.

Stem cell therapy in early post-traumatic talus osteonecrosis.

PURPOSE: Avascular necrosis of the talus is one of the most notable complications associated with talar neck fractures with frequent evolution of the osteonecrosis into a difficult arthrodesis. We tested whether the injection of bone marrow mesenchymal stem cells (MSCs) could improve the repair process of the osteonecrosis. MATERIAL AND METHODS: Forty-five early (without collapse) post-traumatic talus osteonecroses (group 1; study group) were treated between 1995 and 2012 with percutaneous injection of progenitor cells (autologous bone marrow concentrate from the iliac crest). The number of MSCs transplanted in each ankle of group 1 was 124 × 103 cells (range 101 × 103 to 164 × 103 cells). The evolution of these osteonecroses treated with autologous bone marrow implantation was compared with the evolution of a control group of 34 talar osteonecroses without collapse and treated with only core decompression (group 2; control group) between 1985 and 1995. The outcome was determined by progression in radiographic stages to collapse, by the need of arthrodesis, and by the time to successfully achieve fusion for patients who needed arthrodesis. RESULTS: For the 45 ankles with autologous concentrate bone marrow grafting, collapse frequency was lower (27%, 12 among 45 versus 71%, 24 among 34; odds ratio 0.1515, 95% CI 0.0563-0.4079; P = 0.0002) and follow-up showed longer duration of survival before collapse or arthrodesis, compared to 34 ankles of the control patients with core decompression alone. Furthermore, the time to successfully achieve fusion after arthrodesis was significantly shorter in patients treated with bone marrow progenitors as compared with the other ankles, which had core decompression alone. CONCLUSION: In our study the early conservative surgical treatment with autologous bone marrow grafting improved the natural course of the disease as compared with core decompression alone.

Comparison of fixed-bearing and mobile-bearing total knee arthroplasty after high tibial osteotomy.

PURPOSE: There is no information comparing the results of fixed-bearing total knee replacement and mobile-bearing total knee replacement in the same patients previously treated by high tibial osteotomy. The purpose was therefore to compare fixed-bearing and mobile-bearing total knee replacements in patients treated with previous high tibial osteotomy. METHODS: We compared the results of 57 patients with osteoarthritis who had received a fixed-bearing prosthesis after high tibial osteotomy with the results of 41 matched patients who had received a rotating platform after high tibial osteotomy. The match was made for length of follow-up period. The mean follow-up was 17 years (range, 15-20 years). The patients were assessed clinically and radiographically. RESULTS: The pre-operative knee scores had no statistically significant differences between the two groups. So was the case with the intra-operative releases, blood loss, thromboembolic complications and infection rates in either group. There was significant improvement in both groups of knees, and no significant difference was observed between the groups (i.e., fixed-bearing and mobile-bearing knees) for the mean Knee Society knee clinical score (95 and 92 points, respectively), or the Knee Society knee functional score (82 and 83 points, respectively) at the latest follow-up. However, the mean post-operative knee motion was higher for the fixed-bearing group (117° versus 110°). In the fixed-bearing group, one knee was revised because of periprosthetic fracture. In the rotating platform mobile-bearing group, one knee was revised because of aseptic loosening of the tibial component. The Kaplan-Meier survivorship for revision at ten years of follow-up was 95.2% for the fixed bearing prosthesis and 91.1% for the rotating platform mobile-bearing prosthesis. CONCLUSIONS: Although we did manage to detect significant differences mainly in clinical and radiographic results between the two groups, we found no superiority or inferiority of the mobile-bearing total knee prosthesis over the fixed-bearing total knee prosthesis for patients previously operated by high tibial osteotomy.

Single-stage treatment of infected tibial non-unions and osteomyelitis with bone marrow granulocytes precursors protecting bone graft.

PURPOSE: Infected non-unions present a clinical challenge, especially with risk of recurrent infection. Bone marrow contains granulocyte precursors identified in vitro as colony forming units-granulocyte macrophage (CFU-GM) have a prophylactic action against infection. We therefore tested the hypothesis that bone marrow concentrated granulocytes precursors added to a standard bone graft could decrease the risk of recurrence of infection when single-stage treatment of infected tibial non-unions is performed with bone graft. METHODS: During a single-stage procedure 40 patients with infected tibial non-union received a spongious bone graft supercharged with granulocytes precursors after debridement (study group). A control group (40 patients) was treated in a single stage with local debridement and standard bone graft obtained from the iliac crest. The antibiotic therapy protocol was the same (60 days) in the two groups. CFU-GM progenitors were harvested from bone marrow aspirated on the opposite iliac crest of the site where the cancellous bone was obtained. Union (radiographs and CT scan), a recurrence of clinical infection, and need for subsequent surgery were evaluated. RESULTS: Thirty-eight (95%) patients who received graft supercharged with granulocytes precursors achieved successful union without recurrence of infection during the seven-year follow-up versus 28 (70%) control patients; for the control group the mean graft resorption volume was 40%, while no bone graft resorption was found for the study group. CONCLUSION: Supercharging the cancellous bone graft with bone marrow granulocytes precursors protect the site of infected non-union from recurrence of infection and bone resorption of the graft.

Stem cell therapy in bilateral osteonecrosis: computer-assisted surgery versus conventional fluoroscopic technique on the contralateral side.

PURPOSE: Surgical management of osteonecrosis with core decompression with stem cell therapy is a new procedure. The technique is performed with fluoroscopic guidance. This study attempts to determine if computer-navigated technique can improve the procedure. METHODS: Thirty consecutive patients with bilateral symptomatic osteonecrosis without collapse were included in this study during the year 2011. A prospective, randomized, and controlled study was conducted on 60 hips (bilateral osteonecrosis) using conventional fluoroscopy technique on one side and computer-based navigation on the contralateral side. Bone marrow aspirated from the two iliac crests was mixed before concentration. Each side received the same volume of concentrated bone marrow and the same number of cells 110,000 ± 27,000 cells (counted as CFU-F). RESULTS: Computer navigation achieved better parallelism to the ideal position of the trocar, with better trocar placement as regards to tip-to-subchondral distance and ideal centre position within the osteonecrosis for injection of stem cells. Using computer navigation took fewer attempts to position the trocar, used less fluoroscopy time, and decreased the radiation exposure as compared with surgery performed with conventional fluoroscopy. At the most recent follow-up (6 years), increasing the precision with computer navigation resulted in less collapse (7 versus 1) and better volume of repair (13.4 versus 8.2 cm3) for hips treated with the computer-assisted technique. CONCLUSIONS: The findings of this study suggest that computer navigation may be safely used in a basic procedure for injection of stem cells.

Cell therapy versus simultaneous contralateral decompression in symptomatic corticosteroid osteonecrosis: a thirty year follow-up prospective randomized study of one hundred and twenty five adult patients.

PURPOSE: Symptomatic osteonecrosis related to corticosteroids has a high risk of progression to collapse in absence of treatment. The purposes of this study were to evaluate the results of autologous bone marrow grafting of the symptomatic hip in adult patients with osteonecrosis and to compare the results with core decompression alone in the contralateral symptomatic hip. MATERIALS AND METHODS: A total of 125 consecutive patients (78 males and 47 females) with bilateral osteonecrosis (ON) and who had both hips symptomatic and at the same stage on each side (stage I or II) were included in this study from 1988 to 1998. The volume of osteonecrosis was measured with MRI in both hips; the smaller size ON was treated with core decompression, and the contralateral hip with the larger ON was treated with percutaneous mesenchymal cell (MSC) injection obtained from bone marrow concentration. The average total number of MSCs (counted as number of colony forming units-fibroblast) injected in each hip was 90,000 ± 25,000 cells (range 45,000 to 180,000 cells). RESULTS: At the most recent FU (average 25 years after the first surgery, range 20 to 30 years), among the 250 hips included in the study, 35 hips (28%) had collapsed at the most recent follow-up after bone marrow grafting, and 90 (72%) after core decompression (CD). Ninety-five hips (76%) in the CD group underwent total hip replacement and 30 hips (24%) in the bone marrow graft group (p < 0.0001). Hips undergoing only CD were approximately three times more likely to undergo a primary THA (odds ratio: 10.0278; 95% CI: 5.6117 to 17.9190; p < 0.0001) as compared with hips undergoing an initial bone marrow grafting. For the 90 hips treated with bone marrow injection and without collapse, the mean volume of repair evaluated by MRI at the most recent follow-up was 16.4 cm3 (range 12 to 21 cm3) corresponding to a decrease of the pre-operative average volume from 22.4 cm3 (range 35-15 cm3) to 6 cm3 (range 12-0 cm3); as percentage of the volume of the femoral head, the decrease moved from 44.8 to 12%. CONCLUSION: Core decompression with bone marrow injection improved the outcome of the disease as compared with core decompression alone in the same patient.

History of concentrated or expanded mesenchymal stem cells for hip osteonecrosis: is there a target number for osteonecrosis repair?

PURPOSE: Despite multiple possible treatments, the risk of collapse remains the main problem of osteonecrosis. Heart failure (HF). In an effort to address the reverse this issue, curative strategies with regenerative medicine are increasingly being considered. The aim of this technology is to halt or reverse progression of the disease to collapse. MATERIAL AND METHODS: The pioneering report by Hernigou published in 2002 was the first pilot study suggesting that injection of bone marrow stem cells was a safe approach able to improve osteonecrosis in patients with early stages. Since then, an impressive number of studies and trials employing unselected BM-derived cells (1000 the last 2 years) showed that delivery of those cells to the site of osteonecrosis during core decompression was somehow able to ameliorate the patient with osteonecrosis. In order to translate the promise of this cell therapy into better clinical benefit, many questions need to be addressed. In this review, we therefore analyzed current clinical experience of the literature and our experience of 4000 cases to address these questions and particularly the number of cells that should be injected. RESULTS: After almost 20 years of clinical research in this field, we are still far from having drawn conclusions on the number of cells we should inject in regenerating hip osteonecrosis. Findings are difficult to interpret due to heterogeneity of causes of osteonecrosis, as well as differences in the cells count, sample quality, and stages of osteonecrosis. The authors address specific issues, as cell quality, cell numbers, volume of osteonecrosis, concentration of cells, and ex vivo expansion. Bone marrow mesenchymal stem cells are supposed to be "functionally competent," but are collected from the bon, marrow of patients with diseases and risk factors of osteonecrosis. The recipient organ (bone osteonecrosis) is a tissue where several alterations have already occurred. These questions are addressed in this review. CONCLUSION: In this review, we analyzed current clinical experience regarding cell therapy and address issues that should be a guide for future cell-based therapeutic application in osteonecrosis.

Knee and hip intra-articular adipose tissues (IAATs) compared with autologous subcutaneous adipose tissue: a specific phenotype for a central player in osteoarthritis.

OBJECTIVES: Compared with subcutaneous adipose tissue (SCAT), infrapatellar fat pad (IFP), the main knee intra-articular adipose tissue (IAAT), has an inflammatory phenotype in patients with osteoarthritis (OA). We phenotyped suprapatellar fat pad (SPFP) and hip acetabular fat pad (AFP), two other IAATs, to determinate the unique signature of IAATs compared with SCAT. METHODS: IFP, SPFP, AFP and autologous SCAT were obtained from patients with OA during total knee (n=38) or hip replacement (n=5). Fibrosis and adipocyte area were analysed by histology and vascularisation, leucocyte and mast cell infiltration were analysed by immunohistochemistry for von Willebrand factor, leucocytes and tryptase, respectively. Secretion of interleukin (IL)-6, IL-8 and prostaglandin E2 (PGE2) was assessed by ELISA. The mRNA expression of adipocyte-associated genes (ATGL, LPL, PPAR-γ, FABP4 and CD36) and developmental genes (SFRP2, HoxC9 and EN1) was determined. The inflammatory response of isolated fibroblast-like synoviocytes (FLS) to autologous IFP and SPFP conditioned media was examined. RESULTS: Fibrosis, vascularisation and leucocyte and mast cell infiltration were greater in IAATs than SCAT, and levels of IL-6, IL-8 and PGE2 were greater in all IAATs than SCAT. IFP and SPFP induced a similar inflammatory response to FLS. Adipocyte area was smaller in IAATs than SCAT. Adipocyte-associated and developmental genes showed a similar gene expression pattern in all IAATs, different from SCAT. CONCLUSIONS: IFP but also SPFP and AFP (gathered under the term 'IAAT') may play a deleterious role in OA by affecting joint homeostasis because of their inflammatory phenotype and their close interaction with synovium in the same functional unit.

Cobb-1 versus cobb-to-cobb anterior fusion for adolescent idiopathic scoliosis Lenke 5C curves: a radiological comparative study.

PURPOSE: Anterior fusion is a well-established procedure for the treatment of Lenke 5C adolescent idiopathic scoliosis (AIS). This retrospective study aimed to assess preoperative and postoperative radiographic differences between the conventional anterior fusion and anterior short fusions (ASF) in Lenke 5C AIS. METHODS: Radiographic data of 42 consecutive cases of Lenke 5C AIS, which were surgically treated through anterior segmental fusion, were analyzed retrospectively. Patients have been divided into two groups: C group (n = 19) treated by the conventional fusion from the proximal end vertebra to the distal end vertebra of the main curve and C-1 group (n = 23) treated by ASF, sparing the lowest end vertebra of the main curve. Cobb angles of main curve, apical vertebra tilt, C7 coronal tilt, lowest instrumented vertebra angle (LIV angle), LIV adjacent level disc angulation (LIVDA), and the first uninstrumented vertebra angle (FUV angle) were measured on anteroposterior radiographs of the entire spine. LIVDA, FUV wedging, and rotation were measured on stretch films. C7 sagittal tilt, lumbar lordosis, thoracic kyphosis, and proximal kyphosis junction were measured on lateral radiographs of the entire spine. Repeated-measures analysis of variance and fisher test were used for the statistical analysis. RESULTS: The preoperative main curve was 39.9 ± 9.1° in the C group vs. (versus) 42.8 ± 11.8° in the C-1 group. At a mean follow-up of 26.2 months (range 10.5-66.3 months), postoperative main curve improved of 75.8 ± 21.2 % (10.4 ± 9.2°, p < 0.001) in the C group and of 52.7 ± 18.7 % (20.1 ± 8.1°, p < 0.001) in the C-1 group. All parameters improved except the LIVDA, which was slightly impaired, especially in the C-1 group with 5.6 ± 4.2° vs. 4.4 ± 2.2° in the C group. On stretch films, FUV rotation was the only parameter to differ; it was graded at 1 ± 0.7 in the C-1 group vs. 0.6 ± 0.5 in the C group (p = 0.04). No disk obliquity just under the future instrumentation and equivalent FUV wedging were found in any of the two groups. CONCLUSIONS: The conventional anterior fusion and ASF give equivalent correction in Lenke 5C AIS, but ASF seems to induce adding-on of the disk below the LIV. FUV rotation on stretch films does not seem to be a predictive factor of postoperative radiological outcome.

Ex Vivo Evaluation of Cementless Acetabular Cup Stability Using Impact Analyses with a Hammer Instrumented with Strain Sensors.

The acetabular cup (AC) implant stability is determinant for the success of cementless hip arthroplasty. A method based on the analysis of the impact force applied during the press-fit insertion of the AC implant using a hammer instrumented with a force sensor was developed to assess the AC implant stability. The aim of the present study was to investigate the performance of a method using a hammer equipped with strain sensors to retrieve the AC implant stability. Different AC implants were inserted in five bovine samples with different stability conditions leading to 57 configurations. The AC implant was impacted 16 times by the two hammers consecutively. For each impact; an indicator IS (respectively IF) determined by analyzing the time variation of the signal corresponding to the averaged strain (respectively force) obtained with the stress (respectively strain) hammer was calculated. The pull-out force F was measured for each configuration. F was significantly correlated with IS (R² = 0.79) and IF (R² = 0.80). The present method has the advantage of not modifying the shape of the hammer that can be sterilized easily. This study opens new paths towards the development of a decision support system to assess the AC implant stability.

Outcome of knee revisions for osteoarthritis and inflammatory arthritis with postero-stabilized arthroplasties: a mean ten-year follow-up with 90 knee revisions.

PURPOSE: Patients with rheumatoid arthritis (RA) and osteoarthritis (OA) may require revision total knee replacement. Few studies have compared post-operative complications, results and risk of re-revision in RA and OA patients. MATERIAL AND METHODS: Forty-five RA patients who had undergone revision TKA from 1998 to 2010 were selected and matched with 45 OA patients who had revision during the same period. Results of the use of a revision postero-stabilized implant in osteoarthritis were compared to results of its use in inflammatory arthritis. With a mean follow-up of ten years (range, 5-17 years) we determined differences in comorbidities, risk for peri-operative adverse events, functional and radiological results, and risk of subsequent re-revision, between patients suffering from OA versus RA. RESULTS: There were higher comorbidities, post-operative (<30 days) adverse events, and mortality at average ten years FU in RA than in OA patients. The mean overall changes in function scores were greater for the RA revision group when compared with the OA revision group. Taking steroids (Cox's regression, p = 0.001), and methotrexate or TNFα blockers (Cox's regression, p = 0.02) were not significant factors for radiolucent lines in RA and for loosening. At average ten years followup, patients with RA undergoing revision TKAs were not more likely to have a re-revision (4 among 45 patients; 9 %) than patients with OA undergoing revision in our department (7 patients; 15 %). CONCLUSIONS: Similar results for the knee were observed in these two forms of arthritis in spite of the fact that the initial local joint status and general health status are worse in inflammatory rheumatoid arthritis than in "degenerative" osteoarthritis. However, complications were more frequent with RA.

Allografts supercharged with bone-marrow-derived mesenchymal stem cells possess equivalent osteogenic capacity to that of autograft: a study with long-term follow-ups of human biopsies.

PURPOSE: Bone-marrow-derived mesenchymal stem cells (BM-MSCs) have been proposed to enhance bone formation in allografts. However, it is not known whether a combination of MSCs, contained in bone marrow concentrate (BMC) and structural allograft could be better than an allograft without MSCs and equivalent to a femoral head autograft in terms of histologic bone formation and long-term cellularity in the graft. After ten years of follow-up, three types of grafts: those initially loaded with BM-MSCs; dead, irradiated allografts; autografts. MATERIALS AND METHODS: Twenty patients received acetabular grafting during hip surgery and subsequently underwent femoral hip revision eight to 13 years later (average 10 years). Revision surgery was for reasons other than graft failure. These 20 patients had received eight allografts initially loaded with BM-MSCs: six dead irradiated allografts and six autografts. The number of MSCs present in the three types of graft were evaluated at the time of initial surgery and at revision. New bone formation associated in the acetabular graft was assessed by histology and calculated as a percentage of total available bony area. RESULTS: At the most recent follow-ups (average 10 years), concentration of MSCs in allografts previously loaded with BM-MSCs was higher than that found in autografts. There were low or no MSCs found in uncharged allografts. New-bone-formation analysis showed that allografts loaded with BM-MSCs produced more new bone (35 %; range 20-50 %) compared with either uncharged allografts (9 %; range 2-15 %) or autografts (24 %; range 12-32 %). CONCLUSIONS: Our observations with allografts charged with BM-MSCs provides evidence in support of a long-term benefit of supercharging bone allografts with autologous BM-MSCs.

Dual-mobility arthroplasty failure: a rationale review of causes and technical considerations for revision.

PURPOSE: Dual-mobility arthroplasty is an alternative to conventional total hip arthroplasty (THA) in appropriately selected, active adults with degenerative, necrotic or post-traumatic hip disease or with revision hip arthroplasty. Numerous papers have been published with results of dual-mobility arthroplasty, but there have been no comprehensive literature reviews that summarise the most recent findings and help the orthopaedic surgeon facing different scenarios in which revision of one or both components of a dual-mobility arthroplasty is indicated. METHODS: We performed a PubMed search for papers published on dual-mobility arthroplasty that provided data on revision and add our experience in order to describe different revision scenarios. We collected data on revision for any reason, for aseptic loosening, for infection, or for dislocation. For each complication, we summarise causes and diagnosis of this complication and describe the direction of possible therapeutic options. RESULTS: The dual-mobility arthroplasty offers the benefit of increased stability without compromising clinical outcomes and implant longevity. However, as with conventional arthroplasties, complications are also reported, with the most frequent being cup loosening, dislocation, accelerated wear and infection. Dual-mobility implants also have some specific complications secondary to their specific design, with the presence of a third joint. For example, intraprosthetic dislocation due to retentive failure of the polyethylene (PE) liner on the femoral head is a complication observed exclusively with this type of implant and involves articulation failure between the femoral head and the PE liner. Mechanical conflict with the iliopsoas tendon has also been reported, probably due to femoral head size, cup design, and/or a dysplastic hip. This systematic review of the literature identified several options for treating each complication, and in particular, options regarding conserving or not of one the two articulating devices. CONCLUSIONS: These findings can inform discussions relating to risks and benefits of different therapeutic options when performing revision of a dual-mobility arthroplasty.

Dual-mobility implants prevent hip dislocation following hip revision in obese patients.

PURPOSE: Revision total hip arthroplasty (THA) is associated with increased rates of dislocation in obese patients. It is not known whether dual-mobility implants decrease dislocation in these patients with obesity. METHODS: We retrospectively reviewed two groups of revision THAs to compare the dislocation rate between 32 obese patients (BMI >30 kg/m2) with standard cups, and 35 obese patients (BMI >30 kg/m2) with dual-mobility cups. All patients received the same implants except for diameter head (32-mm head with standard cups and 28-mm head with dual mobility) and had the same cemented stem that was not changed at revision. The patients were followed at routine intervals and were specifically queried about dislocation. The two groups were similar in terms of age, gender, causes of revision and follow-up since the primary arthroplasty. RESULTS: With standard liners, more hips in obese patients dislocated than did hips in obese patients who received dual-mobility implants. The number of dislocations in standard hips was at one year follow-up 15.6 % (5 of 32) compared with 0 % in dual-mobility hips and was at five year follow-up 21.8 % (7 of 32) compared with 2.8 % (1 of 35). After a mean follow-up of seven years no cases of loosening were found. Five patients in the obese group with a standard liner underwent re-revision surgery, the additional re-operations being necessary to treat recurrent postoperative dislocation. CONCLUSIONS: Obese patients should be counselled about the important risk of dislocation that occurs with standard liners after revision THA. Dual-mobility liners in these patients with hip revision is an efficient technique to prevent post-operative hip dislocation.

Dual-mobility or Constrained Liners Are More Effective Than Preoperative Bariatric Surgery in Prevention of THA Dislocation.

BACKGROUND: Obesity is associated with an increased risk of dislocation after total hip arthroplasty (THA). However, in patients with obesity, it is not known whether the risk is only in the early postoperative period or whether it persists several years after surgery, and whether having bariatric surgery before undergoing THA and/or receiving a specific device (such as a dual-mobility or constrained acetabular liner) is more effective in terms of decreasing the risk of dislocation. QUESTION/PURPOSES: (1) What is the cumulative risk of dislocation in patients with obesity after THA in the absence of a dual-mobility or constrained liner, and is this related to component positioning? (2) Does bariatric surgery before undergoing THA decrease dislocation risk in patients with obesity? (3) Are dual-mobility and constrained liners efficient in preventing dislocation in patients with obesity? METHODS: At our university-based practice, all surgeons adhered to the following treatment approaches: Before 2000 no dual-mobility implants or constrained liners were used for primary THAs. Between 2000 and 2008, all patients whose body mass index (BMI) was greater than 30 kg/m(2) received dual-mobility liners (or constrained liners), except when they had previously had bariatric surgery. After 2008, all patients with BMIs over 30 kg/m(2) as well as those patients who were previously treated with bariatric surgery (regardless of BMI at the time of the index THA) received dual-mobility or constrained liners. This case-control study compared the dislocation percentage between 215 hips in nonobese patients (BMI ≤ 30 kg/m(2)), 215 hips in patients with obesity (BMI > 30 kg/m(2)) who received standard cups, 85 hips in patients with bariatric surgery before THA using standard cups (with reduction to a BMI < 30 kg/m(2)), and 155 hips in patients with obesity who received dual-mobility (when younger than 70 years) or constrained liners (when older than 70 years). All patients received the same implants except for different femoral head diameters (32-mm head with standard cups and 28-mm head with dual-mobility or constrained liners). The patients were followed at routine intervals and were specifically queried about dislocation. All the 670 hips had a minimum followup of 5 years with a mean followup of 14 years (range 5-25 years). At the most recent followup, 101 (15%) hips were lost to followup (respectively, 36 of 215, 34 of 215, five of 85, 24 of 155), which is the same ratio as observed among the underlying populations from which the patients were drawn. RESULTS: With standard liners, more hips in patients with BMI > 30 kg/m(2) dislocated than did hips in nonobese (BMI < 30 kg/m(2)) patients. The cumulative number of dislocations (first time without recurrent dislocation) was 6% (13 of 215) at 1-year followup in obese patients compared with 2% (four of 215) in nonobese patients (odds ratio [OR], 3.4; 95% confidence interval [CI] 1.09-10.58; p = 0.03) and was 13% (28 of 215) at 15 years followup compared with 4% (eight of 215) in nonobese patients (OR, 3.9; 95% CI 1.72-8.71; p = 0.001). When bariatric surgery was performed before THA, BMI declined from 42 kg/m(2) to 28 kg/m(2), but with the same standard liners, more hips after bariatric surgery dislocated at 1-year followup than did hips in patients with obesity without preoperative bariatric surgery (13% [11 of 85] compared with 6% [13 of 215]; OR, 0.43; 95% CI 0.18-1.01; p = 0.05). Dual-mobility or constrained implants decreased the risk of dislocation, and fewer hips in patients with obesity with dual-mobility or constrained liners at 7 years followup had dislocated than did hips with standard liners (2% [three of 155] compared with 9% [20 of 215]; OR, 0.19; 95% CI 0.05-0.66; p = 0.01) bringing this number in line with the number observed in nonobese subjects with standard cups. CONCLUSIONS: With standard liners, the risk of dislocation is increased in patients with obesity. Preoperative decrease of BMI (with bariatric surgery) in patients with obesity did not prevent the risk of dislocation with standard liners. Use of dual-mobility or constrained liners in these patients is an effective technique to reduce the risk of postoperative hip dislocation. However, we do not yet know the full risks of loosening of dual-mobility and constrained liners in this obese population. LEVEL OF EVIDENCE: Level III, therapeutic study.