Cell therapy for post-traumatic hip osteonecrosis in young patients.

PURPOSE: To investigate the effects of mesenchymal stem cells injections for treatment of post-traumatic osteonecrosis of the femoral head. METHODS: A total of 46 patients were eligible and enrolled in the study. Twenty-three patients were treated with cell therapy and 23 patients with hip arthroplasty (control group). During a minimum follow-up duration of 10years, radiographs were used to evaluate the radiological results, and the Harris Hip Score (HHS) and visual analog scale were chosen to assess the clinical results. RESULTS: For the cell therapy group, the product obtained by bone marrow aspiration in the iliac crest before concentration had a mean value of 2480 MSCs/mL (range 730 to 3800). The concentration product was containing average 9300 MSCs/mL (range 3930 to 19,800). At the most recent follow-up (average 15years after the first surgery, range 10 to 20years), among the 23 hips treated with cell therapy (concentrate bone marrow), 6 hips (26%) had collapsed and had required total hip arthroplasty (THA) without revision. Among the 23 hips treated with a primary THA, 7 (30.4%) had required one revision (second THA) at a mean follow-up of 6years (range 1 to 12years); two of these 7 hips had a re-revision; principal causes of revision were recurrent dislocations (3 cases) aseptic loosening (3 revisions) and infection (1 revision). As consequence, we observed significant (P<0.01) better survival time before revision for the cell therapy group. Better results with cell therapy were obtained for treatment at early stages before collapse. CONCLUSION: The present study has demonstrated encouraging effects of cell therapy in early post-traumatic hip osteonecrosis and provides another choice for treatment in early stages I to II.

Cell therapy for posttraumatic shoulder osteonecrosis.

PURPOSE: This study compared the clinical and radiological results of bone marrow mesenchymal stem cell implantation with traditional simple core decompression (CD) using a matched pair case-control design for osteonecrosis of the humeral head (ONHH) after fracture of the proximal humerus. PATIENTS: We retrospectively reviewed 64 patients who had surgery for ONHH. Thirty patients had been treated with cell therapy between 2010 and October 2015, with 18 patients at pre-collapse stage (8 stages-I, 10 stages-II), and 12 patients at post-collapse stages (7 stages-III and 5 stages-IV). Using a matched pair case-control design, these 30 study patients were compared to 34 other patients who were treated with simple core decompression (CD) without cells (control group). METHODS: The cell therapy group was treated with percutaneous mesenchymal cell (MSCs) injection obtained from bone marrow (BM) concentration. During a mean follow-up duration of 7years (5 to 10years), radiographs performed each year were used to evaluate the radiological results; the Constant score and visual analogue scale were chosen to assess the clinical results. We assessed stage progression, collapse and arthroplasty conversion rate. Survivor rate analysis was performed using these parameters as the primary endpoints. RESULTS: Among the 30 shoulders included in the cell therapy group, three (10%) humeral heads had collapsed at the most recent follow-up, versus 25 (74%) in 34 shoulders after simple core decompression (P<0.0001). As consequence, we observed statistically significant difference (P=0.0001) in the humeral head survival (absence of arthroplasty conversion) rate at the end time point between the cell therapy group (93% survival) and simple core decompression (26% survival). Better results were obtained for early stages (stages I and II) osteonecrosis without collapse at baseline. CONCLUSION: Core decompression with cell therapy was a safe and effective procedure for treatment in the pre-collapse stages of posttraumatic shoulder osteonecrosis and improved the outcome of the disease as compared with simple core decompression without cells.

Return to sports and quality of life after high tibial osteotomy in patients under 60 years of age.

INTRODUCTION: Since knee osteoarthritis is unicompartmental in most cases, a knee osteotomy is the most logical solution to limit degeneration of the arthritic compartment, thereby delaying knee arthroplasty. Younger patients have high functional demands. The purpose of this study was to evaluate the return to sports and quality of life after high tibial osteotomy (HTO) in athletic patients less than 60 years of age. The hypothesis was that patients can return to sports within 1 year of HTO. MATERIALS AND METHODS: A single-centre, retrospective study was performed of 30 patients under 60 years of age with medial tibiofemoral osteoarthritis and no history of surgery or trauma who underwent HTO between January 2014 and August 2015. The primary endpoint was the return to sport at 1 year based on the Tegner score. Secondary endpoints were the subjective IKDC score, Lysholm score and SF-36. RESULTS: The mean follow-up was 1.3 years [1-1.5] and no patients were lost to follow-up. All the patients had returned to sports at 1 year: 73.3% at their pre-surgery level (before the pain started) and 23.3% at a higher level. Their quality of life was significantly improved according to the SF-36 questionnaire: 65.3% pre-operatively compared with 72.5% postoperatively (P=0.01). The preoperative and 1-year postoperative scores were comparable for the Tegner (P=0.167), IKDC (P=0.093) and Lysholm (P=0.061). CONCLUSION: HTO allows patients to resume their sports activities within 1 year of surgery and significantly improves their quality of life. LEVEL OF EVIDENCE: Level IV - Retrospective cohort study.

Beta-tricalcium phosphate for orthopedic reconstructions as an alternative to autogenous bone graft.

Autogenous bone graft (autograft) remains the gold standard in the treatment of many orthopedic problems. However, graft harvest can lead to perioperative morbidity and increased cost. We tested the hypothesis that an osteoconductive matrix, beta-tricalcium phosphate (ß-TCP), would be a safe and effective alternative to autograft alone. Beta-tricalcium phosphate (ß-TCP) is considered as one of the most promising biomaterials for bone reconstruction. This study analyzes the outcomes of patients who received ß-TCP as bone substitutes in orthopedic surgery. METHODS: A total of 50 patients were enrolled in a controlled, non-inferiority clinical trial to compare the safety and efficacy of ß-TCP (25 patients) with those of autograft (25 patients) in indications requiring usually autograft. These 50 patients were categorized according to the etiology and morphology of the 54 bone defects resulting from elective surgical procedures, such as 34 open-wedge high tibial osteotomies, and 20 osteonecrosis treatments with core decompression. Radiographic (healing process with or without integration of ß-TCP), clinical (no other surgical procedure), functional outcomes and safety (with or without complications) were assessed through fifty-two weeks postoperatively. RESULTS: With regard to the primary endpoint (radiographic evolution), the fusion rate of the 34 open-wedge osteotomies was 100% (17 among 17) for patients in the group with ß-TCP compared with 94% (16 among 17) for patients in the autograft group. For the 20 cavitary defects (osteonecrosis), the radiographic union rates, as determined by the presence of osseous bridging, were 100% for patients in the group with ß-TCP and 100% for those in the autograft group. Clinically at one year, all quality-of-life and functional outcome data supported non-inferiority of ß-TCP compared with autograft, and patients in the ß-TCP group were found to have less pain and an improved safety profile. CONCLUSIONS: Treatment with ß-TCP resulted in comparable fusion rates, less pain and fewer side effects as compared with treatment with autograft. This study established clinical parameters where the ß-TCP alone can successfully support the osteogenic process.

Failure of high tibial varus osteotomy for lateral tibio-femoral osteoarthritis with<10° of valgus: Outcomes in 19 patients.

BACKGROUND: Osteotomy is a rational approach to slowing knee osteoarthritis progression by modifying loads, thereby avoiding joint replacement in younger individuals. Varus femoral osteotomy is recommended only in patients with more than 10° of valgus. The objective here was to assess outcomes of tibial varus osteotomy in patients with lateral compartment tibio-femoral osteoarthritis and less than 10° of valgus. The hypothesis was that high tibial varus osteotomy produces satisfactory and long-lasting improvements. MATERIAL AND METHODS: A single-centre retrospective study was conducted in 19 consecutive patients managed by high tibial varus osteotomy between January 2005 and May 2012. Mean age was 54.5years. The clinical IKS knee and function scores and radiological parameters were determined pre-operatively then after 6 and 12months and at last follow-up. The primary outcome measure was the global IKS score. Failure was defined as a global IKS score <140 or total knee arthroplasty (TKA). Secondary outcome measures were a post-operative hip-knee-ankle (HKA) angle between 180° and 183° and less than 10° of joint line obliquity. The hypothesis was that high tibial varus osteotomy produced satisfactory and long-lasting improvements in lateral compartment tibio-femoral osteoarthritis. RESULTS: After the mean follow-up of 4.3years (range, 2-9years), 10/19 patients had a global IKS score <140. Among them, 7 underwent TKA after a mean of 5.0±2.7years. Varus tibial osteotomy was followed by significant improvements in the IKS knee and function scores from baseline to last follow-up (P<0.05). A global IKS<140 predicted TKA. Mean HKA angle values were 186.3±2.9° pre-operatively and 181.3°± 3.9°at last follow-up (P<0.05); the HKA angle was within the 180°-183° range in 8 (42.1%) patients. Mean post-operative joint line obliquity was 7.8±3.0°. An HKA angle outside the 180-183° range and joint line obliquity >10° were associated with poor outcomes. DISCUSSION: High tibial varus osteotomy produces unsatisfactory medium-term outcomes, with an overall failure rate of 52%. At present, high tibial varus osteotomy has no role in the management of lateral compartment tibio-femoral osteoarthritis with <10° of valgus. LEVEL OF EVIDENCE: IV, retrospective cohort study.

Cellular therapies for the treatment of non-union: the past, present and future.

Non-union fracture is a pathological condition having some impairment of the cellular part of the repair: a reduction of MSC and of the osteoblastic activation. Non union is therefore a good indication for cell-based therapies using stem cells. We described the rational of this treatment and described the technique of autologous bone marrow concentrate implantation that was until now used. With the development of stem cell research and regenerative medicine, we believed that therapy based on cytotherapy has great potential. In this review, clinical applications of cytotherapy are summarized and analyzed. Current problems and future challenges are discussed.

Posterior tibial slope changes after opening- and closing-wedge high tibial osteotomy: a comparative prospective multicenter study.

INTRODUCTION: Valgus high tibial osteotomy is considered to be an effective treatment for unicompartmental medial osteoarthritis. It is generally admitted that tibial slope increases after open-wedge high tibial osteotomy and decreases after closing-wedge high tibial osteotomy. However, the effects on posterior tibial slope of closing- or opening-wedge osteotomies remain controversial. HYPOTHESIS: We analyzed the modifications of tibial slope after opening- and closing-wedge high tibial osteotomies and compared the results of these two procedures. We hypothesized that there was no difference in postoperative tibial slope between opening and closing-wedge osteotomies. PATIENTS AND METHODS: This prospective consecutive nonrandomized multicenter study was conducted between January 2008 and March 2009 and included 321 patients: 205 men and 116 women. A total of 224 patients underwent an opening-wedge high tibial osteotomy and 97 a closing-wedge osteotomy. The mean age was 52 years ± 9 and the mean body mass index was 28kg/m(2) ± 5. The main etiology was primary arthritis. Posterior tibial slope was measured preoperatively and at the last follow-up on a lateral radiograph in relation to the posterior tibial cortex. RESULTS: In the opening-wedge group, a definite 0.6° increase in tibial slope (P=0.016) was observed. In the closing-wedge group, a definite 0.7° decrease in tibial slope (P=0.02) was found. Fourteen percent of the opening-wedge osteotomies increased tibial slope by 5° or more versus only 2% of the closed-wedge osteotomies (P<0.001). Twelve percent of the closing-wedge high tibial osteotomies led to a decrease of 5° or more of the tibial slope versus 7% of the opening-wedge osteotomies (P<0.02). DISCUSSION AND CONCLUSION: These results confirm what is generally reported in the literature, i.e., an increase in tibial slope in opening-wedge high tibial osteotomy and a decrease in the slope in closing-wedge osteotomies. These tibial slope changes appear to be very limited in this series, less than 1° on average. However, there was a bias since the open-wedge technique was preferred in cases with substantial varus deformity. We emphasize the importance of surgical technique to avoid alteration of the tibial slope, particularly in opening-wedge high tibial osteotomy for which we recommend a release of posterior soft tissue and a complete osteotomy of the posterior cortex of the tibia. LEVEL OF EVIDENCE: III. Prospective consecutive nonrandomized multicenter study.

Non-simultaneous bilateral hip fracture: epidemiologic study of 241 hip fractures.

INTRODUCTION: Hip fractures are an important public health problem given their growing incidence as well as their functional and vital repercussions. With longer survival, patients with a contralateral fracture are increasingly numerous. The objective of this study was to investigate the bilateralization of hip fractures in terms of anatomic location and time to the second fracture. HYPOTHESIS: Contralateral fractures are of the same anatomical type as the primary fractures. PATIENTS AND METHODS: This was a retrospective epidemiological study on all patients managed for hip fractures between January 2007 and May 2008. Each case of bilateralization was studied. RESULTS: We included 241 patients in the study. The mean age at occurrence of the primary fracture was 83.3 years (range, 60-99 years). The distribution showed 45.6% true femoral neck fractures and 54.4% trochanteric fractures. Twenty-six of the 241 patients had already suffered from a hip fracture (10.8%). This fracture was the same type as the recent fracture in 80.8% of the cases. The mean time between the two fractures was 5.6 years (range, 1-277 months). DISCUSSION: The contralateral fractures were the same anatomical type as the primary fracture in eight out of ten patients and the symmetry remains intact in 64-83% depending on the series. The fracture occurred on average within 5 years of the first hip fracture. In cases of asymmetry, the second fracture was more often a trochanteric fracture. The causes explaining this symmetry are several and are poorly known. The risk factors are numerous and their prevention is essential (acting on the patient's environment to prevent falls, rehabilitation to reestablish autonomy after the first fracture, and preventive treatment of osteoporosis), although these notions are often ignored by surgeons. LEVEL OF EVIDENCE: IV, retrospective study.

[Cell therapy in bone-healing disorders]. / Zelltherapie bei Knochenheilungsstörungen.

In addition to stabilizing osteosynthesis and autologous bone transplantation, so-called orthobiologics are playing an increasing role in the treatment of bone-healing disorders. Besides the application of different growth factors, new data in the literature suggest that cell therapeutic agents promote local bone regeneration. Due to ethical and biological considerations, clinical application of progenitor cells for the musculoskeletal system is limited to autologous postpartum stem cells. Here in particular, cell therapy with autologous progenitor cells in one surgical session has delivered first promising results. Based on a review of the literature and on our own experience with 75 patients, this article reviews the rationale and characteristics of the clinical application of cell therapy for the treatment of bony substance defects. Most clinical trials report successful bone regeneration after the application of mixed cell populations from bone marrow.

Elbow osteonecrosis in sickle cells anemia: a study of six cases.

A series of six elbows with aseptic osteonecrotic lesions is reported in a population of sickle cell anemic patients. Pain and range of motion limitation were the most commonly observed symptoms during the course of the disease. Three of these elbows had to undergo a surgical procedure (core decompression or loose body excision).

Steroid-induced osteonecrosis: the number of lesions is related to the dosage.

Severe acute respiratory syndrome (SARS) is a newly described infectious disease caused by the SARS coronavirus which attacks the immune system and pulmonary epithelium. It is treated with regular high doses of corticosteroids. Our aim was to determine the relationship between the dosage of steroids and the number and distribution of osteonecrotic lesions in patients treated with steroids during the SARS epidemic in Beijing, China in 2003. We identified 114 patients for inclusion in the study. Of these, 43 with osteonecrosis received a significantly higher cumulative and peak methylprednisolone-equivalent dose than 71 patients with no osteonecrosis identified by MRI. We confirmed that the number of osteonecrotic lesions was directly related to the dosage of steroids and that a very high dose, a peak dose of more than 200 mg or a cumulative methylprednisolone-equivalent dose of more than 4000 mg, is a significant risk factor for multifocal osteonecrosis with both epiphyseal and diaphyseal lesions. Patients with diaphyseal osteonecrosis received a significantly higher cumulative methylprednisolone-equivalent dose than those with epiphyseal osteonecrosis. Multifocal osteonecrosis should be suspected if a patient is diagnosed with osteonecrosis in the shaft of a long bone.

[Metal/alumine metallosis on tibial osteotomy. A case report]. / Métallose par contact métal/alumine sur une ostéotomie tibiale de valgisation. A propos d'un cas.

Metallosis is mainly described in the hip joint at the time of wear or inappropriate use. Cases have also been reported in patients with a knee prosthesis, but never after tibial osteotomy. We report a rare case of metallosis resulting from metal-alumina contact after open wedge tibial osteotomy. The patient complained of pain, which was relieved after removal of the plate nine months after the first operation. Intraoperative inspection revealed metallosis at the synthesis site and local plate wear at zone of contact with the ceramic filler. Removal of the plate and cleaning of the metallosis zone led to full relief of the pain at one and a half months.

[Intramedullary pinning of diaphyseal fractures of both forearm bones in adults: 46 cases]. / Embrochage centromédullaire des fractures diaphysaires des deux os de l'avant-bras chez l'adulte.

PURPOSE OF THE STUDY: The goal when treating shaft fractures of the forearm bones is to obtain good bone healing with good preservation of upper limb function. We report a retrospective (1995-2004) consecutive series of patients aged 32 years on average (range 16 to 92 years) who presented 46 shaft fractures of both forearm bones. MATERIAL AND METHODS: Using Hackethal's classification by sixths, the fracture involved the 3rd and 4th sixth in 39 cases (84.7%) for the radius and 33 (71.7%) for the ulna. Seventeen (37%) patients were trauma victims with multiple injuries. Fourteen fractures (30.4%) were open and all fractures were treated: 11 stage I (23.9%), two stage II (4.3%) and one stage III (2.3%). Intramedullary pinning was used in all cases for the radius and the ulna. In 27 patients (58.6%) pinning was achieved without open access to the focus. Pin diameter was 2.5mm for 38 cases (82.6%). Self-controlled rehabilitation exercises were started immediately without complementary immobilization. Outcome was assessed in 41 patients with a mean follow-up of 18 months (range three months to seven years). RESULTS: Functional outcome, according to Tscherne and Oestern, was very good or good in 31 cases (75.5%). For 35 cases (85.4%) bone healing was achieved at mean 3.5 months for the radius and four months for the ulna. Retarded healing was noted in four cases (9.7%) for the ulna. For the 41 patients reviewed, 11 (26.8%) presented axial misalignment of one of the forearm bones with an angle strictly greater than 10 degrees for three. There were six patients with nonunion (14.6%), of both bones in two and one in four. Radioulnar synostosis was observed in four cases (9.7%). No infections or recurrent fractures were noted. DISCUSSION: The localization of the fracture line affected the outcome. Among the four cases with a fracture in the 5th sixth of the radius, two developed misalignment with an angle strictly greater than 10 degrees and one presented a secondary displacement which required revision on day 15 for plate-screw fixation of the radius. This might be due to the spreading corticals of the distal radius where pin stabilization would be less effective than for fractures in the 3rd or 4th sixths where the corticals run parallel. Outcome was less satisfactory when the fracture focus was opened. Four of the six nonunions and three of the four synostoses occurred among the 19 patients who had open pinning. This might be due to loss of the fracture hematoma. Analysis of the type of fixation has shown that our best results were obtained when we used a single 2.5 mm elastic pin. For the cases where we used a smaller pin (2 mm), we had three major misaligments, one nonunion involving both bones and one recurrent dislocation of the radial head. There were no infections or recurrent fractures in this series where the pin was removed in 27 patients (65.6%) at mean one year. CONCLUSION: Intramedullary pinning is an attractive alternative for the treatment of shaft fractures involving both forearm bones in adults. Best results are obtained if the fracture (situated outside the 5th sixth) can be stabilized without opening the focus with a single 2.5 mm pin. This method combines the advantages of closed osteosynthesis, that is, a simple nontraumatic procedure decreasing the risk of suppuration, and early return of function, limiting postoperative immobilization. It enables early sturdy bone healing with a low risk of recurrent fracture.

[Screw fracture after sliding hip screw fixation of an intertrochanteric fracture]. / Fracture de la vis cervicale d'une vis-plaque à glissement. A propos d'un cas à 1, 5 an de recul.

Although no cases have been reported to date, fracture of a sliding hip screw on a screw-plate fixation is a real entity since material watch registries have revealed two non-published cases. We report an illustrative case. A 67-year-old man was hospitalized for a right intertrochanteric fracture. The patient was treated with a sliding hip screw plate fixation (short cannon, 105 mm screw). On the eighth postoperative day, fracture impaction was present with complete loss of impaction reserve associated with secondary discrete divergence in the cannon-screw alignment. Weight-bearing was postponed until the 45th postoperative day. At three months, bone healing had not been achieved. A clear image was also visible at the plate end of the cannon. The patient complained of persistent pain but there were no signs of infection. At the fifth month, the patient fell from the standing position and standard x-rays visualized the nonunion of the intertrochanteric fracture plus a infratrochanteric diaphyseal fracture line in addition to a fracture of the sliding hip screw. The plate screws were intact. The patient underwent revision osteosynthesis with a Medoff plate. Fracture of a sliding hip screw is a rare event. In the present case, the mechanism involved an insufficient impaction reserve and use of a short cannon. Treatment requires extraction of the distal fragment of the screw and a new cemented osteosynthesis.

[Total hip arthroplasty after failure of per- and subtrochanteric fracture fixation in elderly subjects]. / Prothèses totales de hanche après echec de fixation de fractures per et sous-trochantériennes chez les sujets agés.

PURPOSE OF THE STUDY: Most pertrochanteric fractures can be successfully fixed with osteosynthesis. Osteosynthesis fails however is a small number of patients who require re-operation for implantation of a total hip prosthesis. This situation occurs in particular when the material has penetrated the acetabulum and in elderly subjects. Although this type of arthroplasty is routine practice, few series have been reported. We present here outcome and complications of total hip arthroplasty after failure of per- and sub-trochanteric fracture fixation. MATERIAL AND METHODS: Between 1990 and 2000, twenty patients aged 79 years on average (range 62-78 years) underwent revision for total hip arthroplasty after failure of osteosynthesis for fracture of the upper femur. A gliding THS had been used for fixation in 18 patients, a plate in one and a Gamma nail in one. Osteosynthesis failure was related to early disassembly in ten patients, pseudarthrosis in eight and malunion in two. Revision was performed via a posterolateral approach in all cases. A standard total hip prosthesis was used in 16 patients, a longer femoral stem was required in four. Femoral components were cemented in 18 patients and non-cemented in two. The cup was a standard cemented cup in 12, retaining and cemented in eight. RESULTS: Mean operative time and blood loss were greater than in first-intention arthroplasties. All patients had lost their independence prior to the revision procedure. Despite their age, all recovered independence after a stay in rehabilitation. Most still required crutches. Use of a retaining cup enabled avoiding dislocation in all cases. For those who did not have a retaining cup, dislocation was the most frequent complication (3/12). The difficulties observed were: 1) elimination of associated infection before surgery; many of these elderly subjects had altered ESR and CRP values for various reasons; 2) abnormal position of the trochanteric mass because of a rotation defect; 3) malunion of the upper femur in the frontal or sagittal planes; 4) more or less easily achieved positioning of the femoral piece on the calcar; 5) difficult intraoperative identification of limb length due to loss of usual landmarks on the lesser and greater trochanter; 6) removal of fracture screws which sometimes required use of a trephine and bridging the last screw hole with a longer centromedullary stem. The most frequent postoperative orthopedic problems were leg length discrepancy (1-2 cm for eight patients), gluteus medius insufficiency, limping and pain at palpation of the trochanteric area. DISCUSSION: Despite the difficult technique and the potential complications which are more important than for first-intention arthroplasties, this series demonstrates that total hip prosthesis is a reliable solution for treating fixation failures of the upper femur.

[Radiographic diagnosis of dislocated inverted shoulder prosthesis: two cases of unrecognized dislocation]. / Diagnostic radiologique des luxations de prothèse d'épaule inversée: à propos de 2 luxations passées inaperçues.

Dislocation of inverted shoulder prostheses are rarely described in the literature. Diagnosis is relatively difficult as illustrated by two cases reported here which went unrecognized. The problem is the absence of any clear clinical sign of dislocation and the rather difficult interpretation of the radiographic images. We propose a method for analyzing the radiographic images which can be used to confirm the absence of dislocation on the AP view.

[Intra- and postoperative fractures of the femur in total knee arthroplasty: risk factors in 32 cases]. / Facteurs du risque de fracture du fémur distal dans les protheses totales du genou: Etude de 32 fractures per et postopératoires.

PURPOSE OF THE STUDY: We reviewed fractures of the distal femur occurring during or after total knee arthroplasty in order to identify risk factors. MATERIAL AND METHODS: Twelve intraoperative fractures occurred between 1990 and 2000 among 617 total knee arthroplasties performed during this period. The circumstances of these fractures were noted in comparison with other prosthetic implants. Twenty other fractures of the distal femur occurred in 20 patients who had had a total knee arthroplasty during the same time period. Mean patient age at surgery was 72 years (range 69-77). In addition to demographic data, we noted risk factors: bone demineralization related to general condition, rheumatoid arthritis or corticosteroid therapy, trochlear notch prior to the trochlear cut, bone resorption under the femoral implant, repeated knee surgery, abnormal stress on the distal femur due to hip disease, periprosthetic osteolysis without loosening related to polyethylene debris or metallosis, loosening, type of prosthesis, loss of bone stock because of the femoral implant, life of prosthesis. RESULTS: Intraoperative fractures usually occurred in specific circumstances: use of a posterior stabilized prosthesis, probably with insufficient preparation and position of the stabilization element, probably excessive impaction in osteoporotic bone (rheumatoid arthritis), difficult exposure (arthroplasty after prior osteotomy), fracture starting from the separator passing over the posterior aspect of the tibia and reaching the intercondylar notch. Independently of these intercondylar fractures, supracondylar or diaphyseal fractures were essentially observed for revision prostheses using a femoral stem. Postoperative fractures were observed in patients who had prior surgery of the distal femur (revision of femoral osteotomy, fracture of the distal femur, arthrodesis), in patients with significant loss of bone stock (posterior stabilized prosthesis), or poor bone quality (rheumatoid arthritis), and in elderly patients with neurological impairment and frequent falls. The trochlear notch did not appear to be sufficient to be the only cause of fracture but was nevertheless an element frequently associated with other risk factors. DISCUSSION AND CONCLUSION: This study shows that fracture of the distal femur occurs in certain preferential circumstances. Considering these elements, a certain number of preventive measures can be discussed for technical modifications or choice of implants.

[Treatment of fractures of the distal femur on total knee arthroplasty]. / Traitement des fractures du fémur distal sur prothèse totale de genou.

PURPOSE OF THE STUDY: Fractures of the distal femur near a total knee arthroplasty are usually observed in patients aged over 70 years victims of low-energy trauma. The rate of complications is high: in the literature 25-75 %, even when treated by experienced surgeons. The purpose of this study was to detail therapeutic modalities used for the treatment of these fractures with their advantages and disadvantages and to determine the morbidity of complications which do occur. MATERIAL AND METHODS: Twenty distal fracture of the femur were treated between 1990 and 2000 in twenty patients who had a total knee arthroplasty. Mean patient age at surgery was 72 years (range 69-77). The fracture was a short oblique fracture in four, transversal in five, long and spiral in four and comminuted in the others. In four fractures, the preoperative radiographic analysis suggested concomitant loosening. Therapeutic modalities included suspension traction for two, femorotibial external fixation for two. Retrograde nailing was possible in two patients. Fixation with a screw plate or a blade plate was used for nine fractures. The prosthesis was revised systematically if loosening was observed. This was done in three cases with preservation of the tibial piece and in two cases, changing the complete prosthesis, using a long femoral stem in all. RESULTS: Mean follow-up was two to ten years. Immediate weight bearing was possible for four of the five patients for whom only the femoral piece was changed with a long stem. For the others, weight bearing was deferred until fracture healing was obtained after a mean five months (range 4-42). Bone healing required one, or two, revisions in three patients. Three patients died within one year of their fracture of the distal femur. There were no cases of infection or late healing. At last follow-up, the knee and function score regressed after treatment of the fracture. The two scores dropped 20 points compared with the pre-operative score (78 +/- 15 to 56 +/- 19 for the knee score and 72 +/- 16 to 54 +/- 18 for the function score). The knee score fell because of difficulty going up and down stairs and use of crutches. Treatments which stiffened the knee were traction suspension and external fixation. Loss of joint motion was about the same with or without prosthesis revision. The tibiofemoral angle measured before the fractures (postoperative goniometry) then after fracture healing or after changing the femoral prosthesis, showed an alignment of 183 degrees before the fracture and 178 degrees after healing or revision of the femoral piece. Three patients experienced another fracture of the same femur after healing of the initial fracture or after changing the knee prosthesis. DISCUSSION: Fracture of the distal femur on a total knee prosthesis is a serious complications because of the mortality and the difficulty in achieving functional recovery after treatment. Therapeutic difficulties involve the type of skin incision, the position of the screws in relation to the femoral component, the possible need for bone graft, and finally the requirement to change the femoral piece with a centro-medullary stem.