Matrix-induced autologous chondrocyte implantation (MACI) in the knee: clinical outcomes and challenges.

PURPOSE: Matrix-induced autologous chondrocyte implantation (MACI) has demonstrated effectiveness in treating isolated cartilage defects of the knee but medium- and long-term evidence and information on the management of postoperative complications or partially successful cases are sparse. This study hypothesised that MACI is effective for up to 5 years and that patients with posttreatment problems may go on to obtain clinical benefit from other interventions. METHODS: A follow-on, prospective case series of patients recruited into a previous controlled, randomised, prospective study or newly enroled. Patients were followed up 6, 12, 24 and 60 months after surgery. Outcome measures were Tegner (activity levels) and Lysholm (pain, stability, gait, clinical symptoms) scores. Zone-specific subgroups were analysed 6, 12 and 24 months postoperatively. RESULTS: Sixty-five patients were treated with MACI. Median Tegner score improved from II to IV at 12 months; an improvement maintained to 60 months. Mean Lysholm score improved from 28.5 to 76.6 points (±19.8) at 24 months, settling back to 75.5 points after 5 years (p > 0.0001). No significant differences were identified in the zone-specific analysis. Posttreatment issues (N = 12/18.5 %) were resolved with microfracture, debridement, OATS or bone grafting. CONCLUSIONS: MACI is safe and effective in the majority of patients. Patients in whom treatment is only partially successful can go on to obtain clinical benefit from other cartilage repair options. This study adds to the clinical evidence on the MACI procedure, offers insight into likely treatment outcomes, and highlights MACI's usefulness as part of an armamentarium of surgical approaches to the treatment of isolated knee defects. LEVEL OF EVIDENCE: Prospective case control study with no control group, Level III.

Influences of fit and fill following hip arthroplasty using a cementless short-stem prosthesis.

INTRODUCTION: The purpose of this study consisted in examining the effects of fit and fill ratio of the Metha prosthesis (BBraun, Aesculap, Tuttlingen, Germany) on radiological and clinical outcomes at a follow-up of 1 year. METHODS: 40 patients were included. Fit and fill ratio measurements, radiological and clinical examinations were performed preoperatively and postoperatively. Correlations were established between fit and fill ratio, and potential factors like sex, age, body mass index, Harris Hip Score and changes of radiological signs. RESULTS: The whole cohort (100%) had a tight fit and fill ratio (>0.8) at the proximal level and at each follow-up. "Champagne-flute" configuration provoked high distal tight-fit and fill ratio. Poor distal fit and fill ratio compared to the proximal and the mid-stem level was measurable at each follow-up (p < 0.05). Correlations between fit and fill ratio and preoperative femur configurations were detectable. CONCLUSIONS: Implanting the Metha prosthesis induces tight fit and fill ratio at the proximal and coated sections. Preoperative femur configuration should be considered to achieve best fit and fill situation and therefore excellent primary stability. In most cases "normal" and "stove-pipe" configurations provide good proximal fit and fill. Since "champagne-flute" configuration induces undesirable tight distal fit and fill ratio the size of the Metha (®) stem should be adequately increased to achieve a more proximal load transmission.

The role of the peroneal tendons in passive stabilisation of the ankle joint: an in vitro study.

PURPOSE: Peroneal tendons are known as active stabilizer in acute ankle sprain while an intact ankle mortise and intact lateral ligaments are required for passive stability of the ankle joint. The goal of this study is to determine the peroneal tendons as passive stabilizer in case of lateral ligament instability. METHODS: Twelve (12) human lower leg cadaver specimens underwent a torsion simulation in the testing system, 858 Mini Bionix(®) (MTS(®) Systems Corporation, Eden Prairie, MN, USA) and a specially designed mounting platform for the specimens. The preset torsion between tibia and calcaneus was primarily set at 30° of internal rotation during plantar flexion and hindfoot inversion. The resisting torque around mechanical tibial axis was recorded which ensures stability in ankle sprain trauma. The first series of measurements were performed on healthy specimens and the following after transecting structures in following order: ATFL (anterior talofibular ligament) in combination with CFL (calcaneofibular ligament), followed by peroneus longus tendon and finally peroneus brevis tendon. RESULTS: The combined lateral ATFL and CFL instability shows a decrease of the resisting torque which ensures stability in ankle sprain trauma. Only a transection of PLT with existing lateral dual-ligament instability results in a significant decrease in torque (p < 0.0001). CONCLUSION: The PLT has a substantial effect on passive stability at a present lateral ligament lesion in ankle sprain trauma. A deficiency in viscoelastic properties of the peroneus longus tendon must be considered in diagnostic and treatment for ankle instability.

Fatigue fracture of a short stem hip replacement: a failure analysis with electron microscopy and review of the literature.

Four years after primary implantation of an ESKA Cut short-stemmed prosthesis, a 61-year-old patient suffered fracture of the implant. The combination of missing proximal support of the prosthesis as well as enormous strain on the distal third of the stem can be considered as main reason for the fatigue failure. The special design of the modular implant with a small diameter and a spongy metal surface can be regarded as a contributing factor. This unique case demonstrates a possible failure mechanism of short- and ultra short-stemmed prostheses.

Matrix-induced autologous chondrocyte implantation versus microfracture in the treatment of cartilage defects of the knee: a 2-year randomised study.

Cartilage defects occur in approximately 12% of the population and can result in significant function impairment and reduction in quality of life. Evidence for the variety of surgical treatments available is inconclusive. This study aimed to compare the clinical outcomes of patients with symptomatic cartilage defects treated with matrix-induced autologous chondrocyte implantation (MACI or microfracture (MF). Included patients were >or= 18 and

[Treatment of osteochondral defects of the knee with autologous bone graft and chondrocyte transplantation: an overview together with our results]. / Dizde osteokondral lezyonlarin otolog kemik grefti ve kondrosit implantasyonu ile tedavisi: Genel bakis ve sonuçlarimiz.

OBJECTIVES: Iliac bone grafting and matrix-guided autologous chondrocyte implantation (MACI) can be combined to treat large osteochondral defects of the knee. In this prospective study, we evaluated clinical and magnetic resonance imaging (MRI) findings after one and two years of this treatment method. METHODS: The study included 12 patients who completed a follow-up period of two years. Preoperative arthroscopic and MRI studies revealed grade 3 or 4 osteochondritis dissecans in all the cases. In the first operation, a deep debridement of the sclerotic subchondral bone was performed, followed by press-fit filling of the defect with cancellous bone. In the second operation, a double-layer MACI was fixed within the defect with fibrin glue. The clinical outcomes were evaluated using clinical scores. RESULTS: The clinical outcomes before and 24 months after surgery were as follows: the mean Meyers score increased from 10.2 to 18, Lysholm-Gillquist score increased from 56.6 to 100, and Tegner-Lysholm score increased from 1.8 to 4. These scores did not show notable changes after 12 months. On MRI images, subchondral edema within the bone graft disappeared until the sixth month. Within a year, MRI signal intensity of the cartilage repair tissue well approximated to that of the healthy surrounding cartilage. The thickness of the cartilage repair tissue increased from 1 mm to 1.8 mm within 6 to 12 months. CONCLUSION: Matrix-guided autologous chondrocyte implantation combined with bone grafting may be successfully used in remodeling the joint surface, without causing donor site morbidity within the knee joint. In addition, subchondral pathologic alterations may be effectively treated. Magnetic resonance imaging is a reliable technique to evaluate the repair process.

Gluteal silicone injections and total hip arthroplasty: a case report.

INTRODUCTION: Silicone injection is a common procedure in cosmetic surgery. Granuloma formation and migration are the most commonly observed complications. CASE PRESENTATION: We report an unusual case of avascular necrosis of the hip in a 41-year-old woman from Thailand presenting with hip pain. Subcutaneous nodules were observed in the clinical examination. A pelvic X-ray revealed necrosis of the right femoral head and histological analysis of the punctuated nodules showed a reaction of foreign body granulomas. During surgical treatment with a hip replacement solitary silicone cysts were removed. CONCLUSIONS: This case report emphasizes that orthopedic surgeons treating patients with necrosis of the hip joint in combination with palpable granulomas in the gluteal region have to be aware of silicone augmentation and its potential complications before planning a hip replacement.

Evaluation of implant position and knee alignment after patient-specific unicompartmental knee arthroplasty.

Implant positioning and knee alignment are two primary goals of successful unicompartmental knee arthroplasty. This prospective study outlines the radiographic results following 32 patient-specific unicompartmental medial resurfacing knee arthroplasties. By means of standardized pre- and postoperative radiographs of the knee in strictly AP and lateral view, AP weight bearing long leg images as well as preoperative CT-based planning drawings an analysis of implant positioning and leg axis correction was performed.The mean preoperative coronal femoro-tibial angle was corrected from 7° to 1° (p<0.001). The preoperative medial proximal tibial angle of 87° was corrected to 89° (p<0.001). The preoperative tibial slope of 5° could be maintained. The extent of the dorsal femoral cut was equivalent to the desired value of 5mm given by the CT-based planning guide. The mean accuracy of the tibial component fit was 0mm in antero-posterior and +1mm in medio-lateral projection. Patient-specific fixed bearing unicompartmental knee arthroplasty can restore leg axis reliably, obtain a medial proximal tibial angle of 90°, avoid an implant mal-positioning and ensure maximal tibial coverage.

The anterolateral minimally invasive approach for total hip arthroplasty: technique, pitfalls, and way out.

Different approaches for the hip have been developed for minimally invasive surgery in total hip arthroplasty. The goal of minimally invasive surgery is to reduce invasiveness to skin, muscles, and bone and improve recovery time after total hip arthroplasty. This article describes the technique of a minimally invasive approach to the hip from the anterolateral direction step by step and includes preoperative settings and pitfalls.