Influence of the preoperative L5S1 disc state on lateral L2 to L5 fusion's outcomes at an average follow-up of 3,5 years (minimum 2 years).

INTRODUCTION: The impact of pre-existing degeneration of a disc underlying a lumbar arthrodesis via lateral approach on long-term clinical outcome has, to our knowledge, not been studied. When performing arthrodesis between L2 and L5, its extension to L5S1 is challenging because it imposes a different surgical approach. Therefore, surgeon's temptation is to not include L5S1 in the fusion even in case of discopathy. Our objective was to study the influence of the preoperative L5S1 status on the clinical outcome of lumbar lateral interbody fusion (LLIF) using a pre-psoatic approach between L2 and L5 with a minimum follow-up of 2 years. MATERIAL AND METHODS: Patients who underwent LLIF from L2 to L5 between 2015 and 2020 were included in our study. We studied VAS, ODI, and global clinical outcome before surgery and at last follow-up. The L5-S1 disc was radiologically studied in preoperative imaging. Patients were included in two groups (A "with" and B :without" L5-S1 disc degeneration) to compare the clinical outcomes at last follow-up. Our primary objective was to evaluate the rate of L5-S1 disc revision surgery at last follow-up. RESULTS: 102 patients were included. 2 required L5-S1 disc surgery following overlying arthrodesis. Our results showed a significant improvement in the patients' clinical outcomes at the last follow-up (p < 0.0001). We did not find any significant difference on clinical criteria between groups A & B. CONCLUSION: A preop L5S1 disc degeneration does not seem to impact the final clinical outcomes after lumbar lateral interbody fusion at a minimal two years F.U. It should not be systematically involved in an overlying fusion.

Incidence and impact of implant subsidence after stand-alone lateral lumbar interbody fusion.

BACKGROUND: Few data are available on the occurrence after stand-alone lateral lumbar interbody fusion (LLIF) of implant subsidence, whose definition and incidence vary across studies. The primary objective of this work was to determine the incidence of subsidence 1 year postoperatively, using an original measurement method, whose validity was first assessed. The secondary objective was to assess the clinical impact of subsidence. HYPOTHESIS: Implant subsidence after stand-alone LLIF is a common complication that can adversely affect clinical outcomes. MATERIAL AND METHODS: Of 69 included patients who underwent stand-alone LLIF, 67 (97%) were re-evaluated at least 1 year later. Furthermore, 63 (91%) patients had two available computed tomography (CT) scans for assessing subsidence, one performed immediately after surgery and the other 1 year later. Reproducibility of the original measurement method was assessed in a preliminary study. Subsidence was defined as at least 4mm loss of fused space height. RESULTS: The incidence of subsidence was 32% (20 patients). Subsidence was global in 7 (11%) patients and partial in 13 (21%) patients. Mean loss of height was 5.5±1.5mm. Subsidence predominated anteriorly in 50% of cases. The lordotic curvature of the fused segment was altered in 50% of patients, by a mean of 8°±3°. Fusion was achieved in 67/69 (97%) patients. The Oswestry score and visual analogue scale scores for low-back and nerve-root pain were significantly improved after 1 year in the overall population and in the groups with and without subsidence. DISCUSSION: Reproducibility of our measurement method was found to be excellent. Subsidence was common but without significant clinical effects after 1 year. Nevertheless, subsidence can be associated with pain and can result in loss of lumbar lordosis, which is a potential risk factor for degenerative disease of the adjacent segments. A score for predicting the risk of subsidence will now be developed by our group as a tool for improving patient selection to stand-alone LLIF. LEVEL OF EVIDENCE: IV, retrospective cohort study.

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.

Particularities of anterior fusion in L4-L5 isthmic spondylolisthesis.

PURPOSE: L4-L5 isthmic spondylolisthesis may be associated with lumbosacral transitional vertebrae (LSTV) and altered venous vascular anatomy. The objectives of this study were to describe the anatomical characteristics of L4-L5 ISPL and the intraoperative difficulties encountered during the approach for anterior lumbar interbody fusion (ALIF). METHODS: This is a retrospective review of 20 ALIFs for L4-L5 ISPL. The anatomy of the common iliac veins confluence and the position of L4-L5 with respect to the projection of the iliac crest were analysed on CT-scan. Intraoperative difficulties were noted. RESULTS: A LSTV was present in 60% of cases, associated with abnormally distal positioning of L4-L5 below the projection of the iliac crest. The common iliac veins confluence was abnormally proximal compared to L4-L5. No complication was noted, even if the approach was unusually difficult in 11 cases. DISCUSSION: Anterior lumbotomies are difficult because the left common iliac vein courses transversely across the left anterolateral aspect of the L4-L5 disc and L5 vertebral body, increasing the risk of vascular injury. Those difficulties have led us to abandon lumbotomies to treat L4-L5 ISPL to favour a pure anterior approach (midline) or an exclusive posterior approach. LEVEL OF EVIDENCE: IV (retrospective study).

Degenerative lumbar spondylolisthesis: cohort of 670 patients, and proposal of a new classification.

Degenerative spondylolisthesis is common in adults. No consensus is available about the analysis or surgical treatment of degenerative spondylolisthesis. In 2013, the French Society for Spine Surgery (Societe francaise de chirurgie du rachis) held a round table discussion to develop a classification system and assess the outcomes of the main surgical treatments. A multicentre study was conducted in nine centres located throughout France and Luxembourg. We established a database on a prospective cohort of 260 patients included between July 2011 and July 2012 and a retrospective cohort of 410 patients included in personal databases between 2009 and 2013. For patients in the prospective cohort clinical assessments were performed before and after surgery using the self-administered functional impact questionnaire AQS, SF12, and Oswestry Disability Index (ODI). Type of treatment and complications were recorded. Antero-posterior and lateral full-length radiographs were used to measure lumbar lordosis (LL), segmental lordosis (SL), pelvic incidence (PI), pelvic tilt (PT), sagittal vertical axis (SVA), and percentage of vertebral slippage. Mean follow-up was 10 months. We started a randomised clinical trial comparing posterior fusion of degenerative spondylolisthesis with versus without an inter-body cage. 60 patients were included, 30 underwent 180° fusion and 30 underwent 360° fusion using an inter-body cage implanted via a transforaminal approach. We evaluated the quality of neural decompression achieved by minimally invasive fusion technique. In a subgroup of 24 patients computed tomography (CT) was performed before and after the procedure and then compared. Mean age was 67 years and 73% of degenerative spondylolisthesis were located at L4-L5 level. The many surgical procedures performed in the prospective cohort were posterior fusion (39%), posterior fusion combined with inter-body fusion (36%), dynamic stabilization (15%), anterior lumbar fusion (8%), and postero-lateral fusion without exogenous material (2%). Peri-operative complications of any severity occurred in 17% of patients. The AQS, ODI and SF12 scores were improved significantly at follow-up. We found no differences in clinical improvements across surgical procedure types. Circumferential fusion (360°) was associated with greater relief of nerve root pain and better lordosis recovery after 1 year compared to postero-lateral fusion (180°). Post-operative CT images showed effective decompression of nervous structures after minimally invasive fusion. Longer follow-up of our patients is needed to assess the stability of the results of the various surgical procedures. Based on a radiological analysis, the authors propose a new classification with five types of degenerative spondylolisthesis: type 1, SL>5° and LL>PI-10°; type 2, SL<5° and LL>PI-10°; type 3, LL25°; and type 5, sagittal imbalance with SVA>4 cm. PROOF LEVEL: IV Observational cohort study. Retrospective review of prospectively collected outcome data.

Outcomes of anterior lumbar interbody fusion in low-grade isthmic spondylolisthesis in adults: a continuous series of 65 cases with an average follow-up of 6.6 years.

INTRODUCTION: Surgical treatment of isthmic spondylolisthesis continues to be controversial. The fusion procedure can either be instrumented using a posterior and/or anterior approach or non-instrumented. The role of associated decompression, reduction of the slippage, disc height restoration and lordosis restoration has not definitely been established. The goal of this study was to evaluate the efficacy of anterior approach for interbody fusion (ALIF) without any reduction maneuver. MATERIALS AND METHODS: Sixty-five patients with isthmic spondylolisthesis were operated on, using an ALIF. The average patient age was 40 years. The preoperative maximum walking time was 20 minutes. Ten patients had radiculopathy. The average preoperative Beaujon Hospital disability index was 9/20. Standard static and dynamic X-rays were evaluated in all patients; a CT scan was performed in 33 patients 1 year after the surgery. The olisthetic vertebra had slipped by an average of 12 mm. Thirty-five of the spondylolisthesis cases had abnormal vertebral motion. RESULTS: At an average follow-up of 6.6 years, lumbar pain and radicular pain had been reduced by 4.6 and 5 points on the visual analogue scale, respectively. Twenty-seven patients could walk for an unlimited amount of time. Three patients still had radiculopathy. The Beaujon Hospital disability index had improved by an average of 7.3 points. The fusion rate was 91%. The slippage had decreased by 30%, despite no specific reduction maneuvers at the time of surgery. The disc height had increased by 177%. On the sagittal plane, lordosis had improved by 5°, without any changes in the pelvic parameters. CONCLUSION: In situ ALIF provides results that are comparable to those obtained with other techniques. This study confirms the essential role of fusion in achieving good functional results, given that hypermobility of the olisthetic level contributes to the symptoms generation. LEVEL OF EVIDENCE: Level IV. Retrospective study.

Periacetabular cement extrusion in the course of total hip replacement: incidence and consequences. An analysis from 269 consecutive cemented total hips.

INTRODUCTION: Periacetabular cement extrusion during total hip arthroplasty is a frequent adverse event. This study sought to determine the contributing factors and any functional consequences of this type of extrusion, which has been insufficiently studied in the literature. HYPOTHESIS: We hypothesized that the occurrence of periacetabular cement extrusion could be the cause of an alteration in the functional result and/or intrapelvic complications. PATIENTS AND METHODS: We retrospectively analyzed a series of 269 total hip prostheses consecutively implanted through a posterolateral approach using a second-generation technique with high-viscosity cement over a period of 1 year (186 standard cemented cups [69%] and 83 retentive cemented cups [31%]). The series comprised 110 males and 159 females aged a mean 69.3±16.8 years (range, 35-96 years). The indication for arthroplasty was primary osteoarthritis in 135 cases (50.4%), necrosis of the femoral head in 56 cases (20.8%), fracture of the femoral neck in 71 cases (26.5%), and seven cases of inflammatory arthritis. We radiographically assessed the frequency of periacetabular cement extrusion and then sought to determine the contributing factors as well as any eventual functional consequences based on the Modified Harris Hip Score, the existence of hip pain, and signs of pelvic dysfunction. RESULTS: Periacetabular cement extrusion was found in 68 patients (25%) and was more frequent in women. No other contributing factor was identified, notably the indication for arthroplasty, the operator's experience level, or the type of cemented cup. Extrusion was not accompanied by a change in the Harris function score nor an increased frequency of urinary or pelvic disorders. DISCUSSION: Periacetabular cement extrusion is frequent but its consequences are rare (mechanical, vascular, neurological, urological, or visceral). Preventing their occurrence with well-adapted technique is warranted (avoidance of perforating anchoring holes, control of cement penetration). Given the rarity of the consequences, ablation of any extrusion diagnosed intraoperatively should be cautiously pondered upon to prevent any potential iatrogenic incident for a doubtful gain. In cases of local pain persistence, the usual causes of hip pain should be ruled out before attributing the source of functional discomfort to extrusion and envisioning its removal.

Treatment of infected hip arthroplasty.

The clinical outcomes of a consecutive series of deep total joint infections treated with a prosthesis retaining protocol were reviewed. The treatment of deep periprosthetic joint infections is challenging. In recent years, two-stage exchange arthroplasty has emerged as the gold standard for successful elimination of infection. With success rates averaging 82% to 96%, this treatment method has both the highest and most consistent rate of infection eradication. Another alternative in the treatment of the deep periprosthetic infection is the single-stage exchange arthroplasty. Successful eradication of infection after single-stage exchange arthroplasty has been reported to average from 60% to 83% after total hip infections. While both the single and two-stage exchange arthroplasty are viable treatment options, they are associated with negative factors such as they are time consuming, expensive, and may entail a 6- to 12-week period with a minimally functioning extremity after prosthesis removal. This paper reports the general principles of management, the treatment of acute infection occurring in the postoperative period or later, and the treatment of chronic infection by exchange arthroplasty or resection arthroplasty.

Anterior dislocation of a total hip replacement. Radiographic and CT-scan assessment. Behavior following conservative management.

BACKGROUND: Hip dislocation is one of the most frequent complications of total hip replacement. The direction of dislocation matters. Most dislocations are posterior; anterior dislocation remains rare and its treatment is controversial. STUDY OBJECTIVES: To clinically and radiologically evaluate the outcomes of the conservative (orthopaedic without revision surgery) treatment of anterior hip dislocations after total hip replacement by immobilisation of the hip in 45 degrees flexion, 10 to 20 degrees abduction and neutral rotation (deck chair position). MATERIALS AND METHODS: Between 1997 and 2007, 19 patients (11 women, 7 men), aged between 36 and 89 years old (average age 64.6 years), operated on for hip osteoarthritis using a posterolateral approach, presented with anterior dislocation of their cemented total hip arthroplasty. Instability during extension associated with external rotation was noted at surgery in eight cases. Ten dislocations occurred in the immediate postoperative period (within 48 hours) and nine within an average postoperative delay of 39 days (6-82). After reduction of the dislocation by closed manipulation, the patients were treated by immobilisation in the deck chair position for an average of 2 weeks (10-21 days). Radiological and functional assessment (based on the Merle d'Aubigné score [PMA]) was performed on average at 4 years after surgery. The inclination of the cup in the frontal plane and any lengthening of the operated extremity were measured on an AP pelvic plain film with the patient in the standing position. Cup and femoral stem anteversion were calculated by CT-scan in 16 cases. RESULTS: At the last follow-up, four patients had had recurrent anterior dislocations (one patient had had two dislocations). They were again treated with immobilisation in the deck chair position for two weeks without further recurrence. None of the patients underwent revision surgery on the temporarily unstable operated hip. Thirteen patients had no pain and eleven had an unlimited walking perimeter. The final average PMA score was 16 (12-18). The patients who presented with one or two recurrences had a PMA of 18 in the final follow-up. Six patients presented with at least 5 mm of shortening (average: 10 mm, maximum 25 mm) with one case of 10 mm of lengthening. The average cup inclination angle in frontal plane views was 48 degrees (40-57 degrees). It was more than 50 degrees in seven cases. The average cup anteversion in CT-scan was 30 degrees (14-60 degrees). The average femoral anteversion in CT-scan was 24 degrees (3-52 degrees). A total of 12 implants (eight cups and four femoral stems) had at least 25 degrees excessive anteversion on CT-scan assessment. DISCUSSION, CONCLUSION: Anterior dislocation after total hip replacement is associated with approximately 10 degrees of excessive femoral and acetabular anteversion respectively. Nevertheless, correction of these architectural anomalies is not necessary because immobilisation in the deck chair position for 2 weeks effectively prevents recurrence and results in satisfactory medium-term functional results.

[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.

Retrieved Unicompartmental Implants with Full PE Tibial Components: The Effects of Knee Alignment and Polyethylene Thickness on Creep and Wear.

Creep and true wear of polyethylene are difficult to evaluate on radiographs of knee arthroplasties and for this reason the true rate of polyethylene wear in vivo after unicompartmental arthroplasty is not well known. This study evaluated the creep and true wear in fifty-five medial retrieved unicompartmental implants that had a flat articular surface at the time of implantation.All the full polyethylene tibial components had the same design and were retrieved from eleven to 224 months (mean 152 months) after their implantation. The postoperative varus deformity had been measured on weight-bearing radiographs of the whole limb (hip-knee-ankle angle). The retrieved implants were placed in a coordinate measuring machine and the coordinates of a grid of points were obtained. Using this system, a three dimensional scaled image of the implant could be created and was used to calculate the total penetration of the femoral condyle due to true wear and creep.Total linear penetration rates ranged from 0.18 to 2.6 millimeters per year (mean 0.25 millimeters per year). Linear penetration rates due to true wear ranged from 0.08 to 1.4 millimeters per year (mean 0.13 millimeter per year), and penetration due to creep ranged from 0.07 to 1.9 millimeters per year (mean 0.12 millimeters per year).The linear and volumetric penetration rates of the femoral condyle due to true wear were negatively correlated with the duration of implantation. The linear penetration rate due to creep was higher in the first two years after the implantation compared to the subsequent years. Using multiple linear regression analyses to remove the confounding effects of age, weight, gender and thickness of the implant, we found that an increase of the postoperative varus deformity was due to an increase of creep (p = 0.03) but not with an increase of true wear (p = 0.25). Thinner implants were due to an increase of creep (p = 0.02) but not with an increase of true wear (p = 0.34). Increase in age was in relation with decrease of wear (p = 0.02) and increase of weight with increase in creep (p = 0.03).Plastic deformation had a high influence on the penetration rate of the femoral condyle in full polyethylene implants. There is a risk of an increased penetration and a decrease of the remaining thickness of the tibial plateau when the implant is too thin, the knee mal-aligned and the patient heavy - each of these factors increasing the creep deformation. In conclusion, our study suggests that surgeons using the Lotus Mk I unicompartmental knee replacement for medial tibiofemoral arthritis should beware of the overweight patient (>90kg) with a tibial implant of less than 9 mm. There is a risk of increased penetration and decreased thickness of the tibial implant when it is too thin, the knee malaligned, and the patient heavy. All these factors increase creep deformation.

[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.

Percutaneous autologous bone-marrow grafting for nonunions. Surgical technique.

BACKGROUND: Bone marrow aspirated from the iliac crest contains progenitor cells that can be used to obtain bone-healing of nonunions. However, there is little available information regarding the number and concentration of these cells that are necessary to obtain bone repair. The purpose of this study was to evaluate the number and concentration of progenitor cells that were transplanted for the treatment of nonunion, the callus volume obtained after the transplantation, and the clinical healing rate. METHODS: Marrow was aspirated from both anterior iliac crests, concentrated on a cell separator, and then injected into sixty noninfected atrophic nonunions of the tibia. Each nonunion received a relatively constant volume of 20 cm(3) of concentrated bone marrow. The number of progenitor cells that was transplanted was estimated by counting the fibroblast colony-forming units. The volume of mineralized bone formation was determined by comparing preoperative computerized tomography scans with scans performed four months following the injection. RESULTS: The aspirates contained an average (and standard deviation) of 612 +/- 134 progenitors/cm(3) (range, 12 to 1224 progenitors/cm(3)) before concentration and an average of 2579 +/- 1121 progenitors/cm(3) (range, 60 to 6120 progenitors/cm(3)) after concentration. An average total of 51 x 10(3) fibroblast colony-forming units was injected into each nonunion. Bone union was obtained in fifty-three patients, and the bone marrow that had been injected into the nonunions of those patients contained >1500 progenitors/cm(3) and an average total of 54,962 +/- 17,431 progenitors. The concentration (634 +/- 187 progenitors/cm(3)) and the total number (19,324 +/- 6843) of progenitors injected into the nonunion sites of the seven patients in whom bone union was not obtained were both significantly lower (p = 0.001 and p < 0.01, respectively) than those in the patients who obtained bone union. The volume of the mineralized callus measured at four months on the computerized tomography scans of the patients who had union ranged from 0.8 to 5.3 cm(3) (mean, 3.1 cm(3)). There was a positive correlation between the volume of mineralized callus at four months and the number (p = 0.04) and concentration (p = 0.01) of fibroblast colony-forming units in the graft. There was a negative correlation between the time needed to obtain union and the concentration of fibroblast colony-forming units in the graft (p = 0.04). CONCLUSIONS: Percutaneous autologous bone-marrow grafting is an effective and safe method for the treatment of an atrophic tibial diaphyseal nonunion. However, its efficacy appears to be related to the number of progenitors in the graft, and the number of progenitors available in bone marrow aspirated from the iliac crest appears to be less than optimal in the absence of concentration.

[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.

Percutaneous autologous bone-marrow grafting for nonunions. Influence of the number and concentration of progenitor cells.

BACKGROUND: Bone marrow aspirated from the iliac crest contains progenitor cells that can be used to obtain bone-healing of nonunions. However, there is little available information regarding the number and concentration of these cells that are necessary to obtain bone repair. The purpose of this study was to evaluate the number and concentration of progenitor cells that were transplanted for the treatment of nonunion, the callus volume obtained after the transplantation, and the clinical healing rate. METHODS: Marrow was aspirated from both anterior iliac crests, concentrated on a cell separator, and then injected into sixty noninfected atrophic nonunions of the tibia. Each nonunion received a relatively constant volume of 20 cm(3) of concentrated bone marrow. The number of progenitor cells that was transplanted was estimated by counting the fibroblast colony-forming units. The volume of mineralized bone formation was determined by comparing preoperative computerized tomography scans with scans performed four months following the injection. RESULTS: The aspirates contained an average (and standard deviation) of 612 +/- 134 progenitors/cm(3) (range, 12 to 1224 progenitors/cm(3)) before concentration and an average of 2579 +/- 1121 progenitors/cm(3) (range, 60 to 6120 progenitors/cm(3)) after concentration. An average total of 51 x 10(3) fibroblast colony-forming units was injected into each nonunion. Bone union was obtained in fifty-three patients, and the bone marrow that had been injected into the nonunions of those patients contained >1500 progenitors/cm(3) and an average total of 54,962 +/- 17,431 progenitors. The concentration (634 +/- 187 progenitors/cm(3)) and the total number (19,324 +/- 6843) of progenitors injected into the nonunion sites of the seven patients in whom bone union was not obtained were both significantly lower (p = 0.001 and p < 0.01, respectively) than those in the patients who obtained bone union. The volume of the mineralized callus measured at four months on the computerized tomography scans of the patients who had union ranged from 0.8 to 5.3 cm(3) (mean, 3.1 cm(3)). There was a positive correlation between the volume of mineralized callus at four months and the number (p = 0.04) and concentration (p = 0.01) of fibroblast colony-forming units in the graft. There was a negative correlation between the time needed to obtain union and the concentration of fibroblast colony-forming units in the graft (p = 0.04). CONCLUSIONS: Percutaneous autologous bone-marrow grafting is an effective and safe method for the treatment of an atrophic tibial diaphyseal nonunion. However, its efficacy appears to be related to the number of progenitors in the graft, and the number of progenitors available in bone marrow aspirated from the iliac crest appears to be less than optimal in the absence of concentration.

[Osteolysis in revision total knee arthroplasty: a comparative study of osteolysis with and without metallosis]. / Ostéolyse dans les reprises de prothèses totales de genou.

PURPOSE OF THE STUDY: Metallic debris from metallosis can compensate for the radiolucency resulting from bony destruction and compromise preoperative diagnosis of osteolysis. We compared the radiological findings in two groups of patients: those with pure osteolysis resulting from polyethylene debris and those with osteolysis associated with metallosis. MATERIAL AND METHODS: This study compared ten total knee arthroplasties free of metallosis at revision (pathology examination revealed only polyethylene debris) with ten total knee arthroplasties with pathologically confirmed metallosis of the synovium and periprosthetic bony tissue. Revisions were performed for loosening or a femoropatellar problem. At revision, the localization and the degree of tibial and/or femoral osteolysis were noted. Preoperative x-rays were analyzed to search for femoral, tibial or patellar osteolysis and were compared with operative findings. On the AP and lateral views, ten osteolysis zones were defined for each knee (four tibia, five femur, and one patella). RESULTS: Ten knees had osteolysis associated with polyethylene debris alone. Tibial osteolysis was found intraoperatively in 16 of the 40 theoretically possible localizations and was recognized on the preoperative x-rays in all 16. Femoral osteolysis was found intraoperatively in 18 of the 50 theoretically possible localizations was only recognized in 6 of the 18. For the ten knees with metallosis, tibial osteolysis was found intraoperatively in 22 of the theoretically possible localizations and was recognized on preoperative x-rays in 10 of the 22. Femoral osteolysis was found intraoperatively in 32 of the 50 theoretically possible localizations but was only recognized preoperatively in 5 of the 32. Comparisons between the two groups showed that femoral osteolysis was significantly more difficult to identify preoperatively than tibial osteolysis irrespective of the type of osteolysis (with or without metallosis). Furthermore, in patients with metallosis, it was significantly more difficult to recognize osteolysis preoperatively in both the tibial and femoral localizations. DISCUSSION: Metallosis can mask the diagnosis of femoral osteolysis and makes it very difficult to recognize tibial osteolysis. Arguments in favor of osteolysis (abnormal skin pigmentation, radio-opaque effusion, abnormal color and density of the joint fluid) are discussed. When the diagnosis of metallosis is established preoperatively, the chances of finding osteolysis intraoperatively are much higher than suggested by the preoperative x-rays.

Fate of very small asymptomatic stage-I osteonecrotic lesions of the hip.

BACKGROUND: The prognosis for a patient with osteonecrosis of the hip is generally considered to be worse if a large volume of the femoral head is involved, the patient is symptomatic, and the stage of the lesion is advanced. In 1990, we began a prospective study to detect collapse in asymptomatic hips with a very small stage-I osteonecrotic lesion in the femoral head. We hypothesized that such patients would have a favorable prognosis. These hips were followed for a minimum of ten years after the diagnosis. METHODS: A small asymptomatic stage-I osteonecrotic lesion (not seen on plain radiographs) was diagnosed with magnetic resonance imaging in forty patients (forty hips) contralateral to a hip with symptomatic osteonecrosis. The criterion for inclusion in the study was a lesion with a volume of <5 cm(3) involving <10% of the volume of the femoral head. Plain radiographs were made annually in six different projections for all patients. At the most recent follow-up evaluation (average, eleven years), patients with a symptomatic hip but without evidence of collapse on plain radiographs underwent a computerized tomography scan. RESULTS: Thirty-five (88%) of the forty hips became symptomatic, and twenty-nine (73%) demonstrated collapse. The mean interval between the diagnosis and the first symptoms was eighty months. Symptoms always preceded collapse by at least six months. The mean interval between the diagnosis and the collapse was ninety-two months (range, seventy-two to 140 months). The diagnosis of collapse could be made on only one or two of the six radiographic views obtained for each patient at each evaluation. The diagnosis of collapse for two patients was made only on a computerized tomography scan at the most recent follow-up evaluation. At the time of final follow-up, the twenty-nine hips with collapse had symptoms of intractable pain and required surgery. CONCLUSIONS: This study confirms that the diagnosis of collapse is difficult in hips with a very small stage-I osteonecrotic lesion. Multiple radiographic views and computerized tomography scans may be required to demonstrate small areas of collapse. Clinical and radiographic signs of progression of the disease in asymptomatic hips with a very small asymptomatic lesion progress more slowly than do those signs in hips with a large symptomatic stage-II lesion. Because hips with a small area of osteonecrosis do collapse in a large percentage of patients, such patients should be followed carefully over a long period of time. LEVEL OF EVIDENCE: Prognostic study, Level I-1 (prospective study). See Instructions to Authors for a complete description of levels of evidence.