A. Poignard

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.

Revisiting high tibial osteotomy: fifty years of experience with the opening-wedge technique.

Since the first description by Debeyre of medial opening-wedge high tibial osteotomy proximal to the tibial tuberosity in 1951 and with the publication of our results in the English-language literature in 19871, our orthopaedic department has performed this osteotomy in 3756 patients over a period of more than fifty years. Although the opening-wedge osteotomy is not new, the advantages of the opening-wedge as compared with a closing-wedge technique have been discussed only recently, particularly in the English-language literature2-9. The aim of the present report is to describe (1) the key steps in the surgical technique, (2) the determination of the size of the wedge, (3) the improvements in the technique during the past twenty years, (4) the specific problem of posterior slope and patella baja, and (5) the technique of concomitant total knee arthroplasty and opening-wedge tibial osteotomy to avoid the need for soft-tissue release in knees with severe varus deformity. ### Source of Funding No funds were received in support of this study. ### Initial Exposure A longitudinal incision is made from the medial border of the patellar tendon distally along the medial aspect of the tibia for 10 cm. The insertions of the sartorius, gracilis, and semitendinosus muscles are divided, and the tendons are separated from bone as described previously1. The pes anserinus is incised longitudinally, 0.5 cm medial to its attachment to the tibia; if only moderate valgus is required, the incision can be incomplete. The distal portion of the superficial medial collateral ligament is exposed and is separated from bone proximally as far as the level of the osteotomy, which should be started at least 3.5 cm distal to the medial joint line and directed laterally and proximally toward the tip of the fibula. The posterior compartment is opened at the level of the osteotomy …

Variation of the impact duration during the in vitro insertion of acetabular cup implants

The acetabular cup (AC) is an implant impacted into a bone cavity and used for hip prosthesis surgery. Initial stability of the AC is an important factor for long term surgical success. The aim of this study is to determine the variations of the impact duration during AC implant insertion. Twenty-two bone samples taken from bovine femurs were prepared ex vivo for the insertion of an acetabular cup implant, following the surgical procedure used in the clinic. For each bone sample, ten impacts were applied using reproducible mass falls (3.5 kg) in order to insert the AC implant. Each impact duration was recorded using a wide bandwidth force sensor. For all bone samples, the impact duration was shown to first decrease as a function of the impact number, then reaching a stationary value equal in average to 4.2±0.7 ms after an average number of 4.1±1.7 impacts. The impact duration may be related to variations of the bone-implant interface contact rigidity because of an increase the amount of bone tissue in contact with the AC implant. Measurements of impact duration have a good potentiality for clinical application to assist the surgeon during the insertion of the AC implant, providing valuable information on the bone-implant interface contact properties.

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.

Autologous bone marrow stromal cells are promising candidates for cell therapy approaches to treat bone degeneration in sickle cell disease

Osteonecrosis of the femoral head is a frequent complication in adult patients with sickle cell disease (SCD). To delay hip arthroplasty, core decompression combined with concentrated total bone marrow (BM) treatment is currently performed in the early stages of the osteonecrosis. Cell therapy efficacy depends on the quantity of implanted BM stromal cells. For this reason, expanded bone marrow stromal cells (BMSCs, also known as bone marrow derived mesenchymal stem cells) can be used to improve osteonecrosis treatment in SCD patients. In this study, we quantitatively and qualitatively evaluated the function of BMSCs isolated from a large number of SCD patients with osteonecrosis (SCD-ON) compared with control groups (patients with osteonecrosis not related to SCD (ON) and normal donors (N)). BM total nuclear cells and colony-forming efficiency values (CFE) were significantly higher in SCD-ON patients than in age and sex-matched controls. The BMSCs from SCD-ON patients were similar to BMSCs from the control groups in terms of their phenotypic and functional properties. SCD-ON patients have a higher frequency of BMSCs that retain their bone regeneration potential. Our findings suggest that BMSCs isolated from SCD-ON patients can be used clinically in cell therapy approaches. This work provides important preclinical data that is necessary for the clinical application of expanded BMSCs in advanced therapies and medical products.

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 operators 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.

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.