[Use of an new modular revision arthroplasty system for the knee reconstruction]. / Einsatz eines neuen modularen revisionsendoprothetischen Systems zur Kniegelenksrekonstruktion.

OBJECTIVE: Reconstruction of stable knee joint kinematics using modular axis-guided revision implants after failed knee arthroplasty surgery. INDICATIONS: Revision implant for bone defects (type Anderson Orthopaedic Research Institute [AORI] III) in case of revision arthroplasty. Primary implant in case of mediolateral instability (>grade I) or multidirectional instability. CONTRAINDICATIONS: Persistent or current joint infection, general infection (e.g. pneumonia), missing metaphysis femoral and/or tibial, insufficient extensor apparatus. SURGICAL TECHNIQUE: Standard approach extending the previously used skin incision. Arthrotomy, synovectomy and collection of multiple samples for microbiological and histopathological analyses. Preparation of the femur with reamers of increasing diameter. Subsequently, a reference stem is anchored and after referencing the correct rotation and joint line height; the femoral osteotomy is performed after fixation of the 5­in­1 cutting block. Following the femoral osteotomy, the box of the femoral prosthesis is prepared. In addition, the tibia is prepared using an intramedullary reference system. Level of constraint and additional tibial augmentation is chosen according to the amount of defect bone and according to ligament stability. POSTOPERATIVE MANAGEMENT: Full load bearing; standard wound control and sterile dressings; limitation of active/passive range of motion only in case of weakened extensor apparatus. RESULTS: Between 03/2011 and 05/2018, a total of 48 patients underwent revision arthroplasty using the described system. The mean follow-up was 24 months (range 21-35 months). In 30 of the 48 cases, a rotating hinge variant was implanted, while in 18 cases a semiconstrained variant was implanted. Indications to revision arthroplasty: infection (n = 22), aseptic loosening (n = 11), instability (n = 11), periprosthetic fracture (n = 3) and PMMA allergy (n = 1). In 11 cases, revision had to be performed due to persistent infection (n = 6) and aseptic loosening (n = 5): 9 cases could be successful treated by a two-step revision procedure, while in 2 cases it was necessary to perform an arthrodesis. The 2­year implant survival rate was 77%.

Load transfer and periprosthetic fractures after total hip arthoplasty: Comparison of periprosthetic fractures of femora implanted with cementless distal-load or proximal-load femoral components and measurement of the femoral strain at the time of implantation.

BACKGROUND: Little is known about the causes and mechanisms underlying periprosthetic fractures around femoral components particularly in relation to the stem design. In an in vitro study 20 pairs of fresh cadaveric femora were loaded to fracture axially and transversally. FINDINGS: When proximal femoral strain was measured at the time of impaction of cementless stems the load transfer was determined by the underlying anatomy rather than by the shape of the stem, so that the so-called "load transfer" properties - proximal or distal - ascribed to stem designs are a myth. The axial-load and the transverse-load model were then exposed to loads to failure (fracture) and showed a biphasic pattern throughout independent of the impact direction. In the second phase, the fracture phase proper, the bone behaved like a brittle solid. Failure occurred very rapidly within less than 5 milliseconds. The forces to failure were between 2 and 11 kN. Most of the fractures (82.5%) occurred above the stem tip. INTERPRETATION: Note that the study was confined to early preosteointegration fractures. Neither the stem design nor the impact direction, i.e. on the knee or on the side of the hip, was related to the fracture morphology.

[Periprosthetic Femoral Fractures: Classification and Therapy]. / Proximale periprothetische Femurfrakturen: Klassifikation und Therapie.

Periprosthetic femoral fractures can be categorized into proximal fractures around a hip stem or distally around a knee arthroplasty. This paper focuses on the proximal periprosthetic fractures. It is important to classify the fracture at diagnosis and to perform accurate planning of the surgery. Basically it is necessary to decide if the implant is fixed or loose, in the latter case a revision surgery including the change of the endoprosthesis is neccessary. If the implant is fixed an open reduction and internal fixation can be done. All implants have to be available on site because in the course of the intervention the plan could change. Due to rising numbers of primary arthroplasties and more elderly patients an increase of periprosthetic fractures can be expected. The treatment of periprosthetic fractures is an economic and surgical challenge. It is important to provide competence for these cases concerning both operative techniques and interdisciplinary treatment.

Prospective mid-term results of a consecutive series of a short stem.

A large number of short stem prostheses for hip -arthroplasty have been introduced in the past years. Although there is a large increase of publications about short stems, there is still little data available about survival and revision rates. We report prospectively on the outcome of 84 consecutive NANOS® short stem prostheses in 81 patients. We have included 37 female patients and 44 male patients with an average age of 61.6 ±â€ˆ9.2 years. The main diagnoses were osteoarthritis in 67 patients, dysplastic osteoarthritis in 8 patients and avascular necrosis of the femoral head in 6 patients. Along with demographic data and co-morbidities, the Harris Hip Score was recorded preoperatively and at follow-up. The Harris Hip Score increased from 36.6 ±â€ˆ14.5 preoperatively to 94.5 ±â€ˆ8.8 at the final follow-up. During the main follow-up time (27.7 months ±â€ˆ5.7) none of the 84 stems were revised, intraoperatively three fissure fractures occurred.

The Charcot foot: pathophysiology, diagnosis and classification.

Neuropathic changes in the foot are common with a prevalence of approximately 1%. The diagnosis of neuropathic arthropathy is often delayed in diabetic patients with harmful consequences including amputation. The appropriate diagnosis and treatment can avoid an extensive programme of treatment with significant morbidity for the patient, high costs and delayed surgery. The pathogenesis of a Charcot foot involves repetitive micro-trauma in a foot with impaired sensation and neurovascular changes caused by pathological innervation of the blood vessels. In most cases, changes are due to a combination of both pathophysiological factors. The Charcot foot is triggered by a combination of mechanical, vascular and biological factors which can lead to late diagnosis and incorrect treatment and eventually to destruction of the foot. This review aims to raise awareness of the diagnosis of the Charcot foot (diabetic neuropathic osteoarthropathy and the differential diagnosis, erysipelas, peripheral arterial occlusive disease) and describe the ways in which the diagnosis may be made. The clinical diagnostic pathways based on different classifications are presented. Cite this article: Bone Joint J 2016;98-B:1155-9.

Osteochondritis dissecans of the medial femoral condyle : New cell-free scaffold as a treatment option.

There is no gold standard in treating osteochondral lesions, which is why the treatment remains very challenging. Osteochondral defects can occur in any joint, but the most common locations are the knee and the ankle. Trauma, repeated microtrauma, avascular necrosis and osteochondritis dissecans (a special type of avascular necrosis) are blamed for the cartilage damage and the damage of adjacent subchondral bone. The self-healing ability of the cartilage is unfortunately very poor; thus, it is necessary to develop new methods of cartilage repair. Unfortunately, few data and long-term survival rates for these new scaffolds are available. We report a case of osteochondritis dissecans treated with a new cell-free scaffold MaioRegen® (Fin-Ceramica Faenza Spa, Faenza, Italy).

First clinical study of a novel complete metal-free ceramic total knee replacement system.

BACKGROUND: The aim of the study was to evaluate the safety and efficacy of a novel metal-free ceramic total knee replacement system. METHODS: Thirty-eight primary total knee arthroplasties (TKAs) were performed on 34 patients using the metal-free BPK-S ceramic total knee replacement system with both the femoral and tibial components of an alumina/zirconia ceramic composite. The clinical outcome was evaluated pre- and postoperatively at 3 (n = 32 TKA) and 12 months (n = 32 TKA) using the Knee Society Score (KSS), the Oxford Knee Score and the EQ-5D. Safety analysis was performed by radiological examination and assessment of adverse events. RESULTS: Postoperatively, the KSS, Oxford Knee Score and EQ-5D improved significantly at 3 and 12 months (p < 0.001). Non-progressive partial radiolucent lines were observed in six cases, but there was no osteolysis and no implant loosening. Induction or exacerbation of allergies did not occur during the follow-up. CONCLUSIONS: The metal-free BPK-S ceramic total knee replacement system proved to be a safe and clinically efficient alternative to metal implants in this short-term follow-up study.

[Patellofemoral instability in trisomy 21: MPFL-Reconstruction as a single procedure]. / Patellainstabilität bei Patienten mit Trisomie 21: Alleinige MPFL-Rekonstruktion als neue Indikation.

BACKGROUND: Patellar instability is a common orthopaedic condition which is often seen in younger individuals. Biomechanical studies have shown that the medial patellofemoral ligament (MPFL) is the most important soft tissue that restrains lateral subluxation of the patella in the beginning of flexion of the knee joint. METHODS: MPFL reconstruction is an effective procedure to treat recurrent patellar dislocation. Double-bundle and single-bundle procedures have been described. If double-bundle reconstruction is not possible, there are good postoperative outcomes with single-bundle procedure as well. DISCUSSION: This is the first report of MPFL reconstruction as a single procedure to treat patellar instability in patients with down syndrome.

[Loosening of a Calcaneo-Stop Screw after Trampolining]. / Schraubenlockerung nach Calcaneusstoppschraube bei Trampolinspringen.

Flexible flatfoot is a common malalignment in the paediatric population. Arthroereisis with a calcaneo-stop screw is an effective surgical procedure for treating juvenile flexible flatfoot after conservative measures have been fully exploited. In the present report, we describe the case of a loosening of a calcaneo-stop screw in a 12-year-old youth after excessive trampolining.

[Symptomatic os trigonum with irritation of the flexor hallucis longus tendon - arthroscopic management via a dorsal approach]. / Symptomatisches Os trigonum mit Irritation des M. flexor hallucis longus - Arthroskopische Sanierung über dorsale Zugänge.

Therapy-resistant pain in the region of the medial mallelous in the presence of an os trigonum is suggestive for irritation of the flexor hallucis longus tendon. Two patients were treated by arthroscopy in the prone position via a dorsal approach; the os trigonum was removed and the tendon released. Under the conditions of blunt dissection, dorsal arthroscopy of the os trigonum is a safe and expedient operation in our toolbox. After two weeks of partial load-bearing with 2 crutches, pain-free full load-bearing is already possible and after 3 weeks the patients can return to work.

[Complex reconstruction with internal locking plate fixation for Charcot arthropathy]. / Komplexe Rekonstruktionen mit winkelstabiler interner Plattenfixation bei Charcot-Arthropathie.

BACKGROUND: Osteosynthesis and reposition of the Charcot foot is challenging with respect to choice of a proper implant. There is currently no international consensus regarding the optimal implant. OBJECTIVES: Locking plates seem to be an innovative and stable method for reconstruction. The aim of this work is to analyze bone fusion, complications, pseudoarthrosis, and patient satisfaction. METHODS: This paper presents a retrospective analysis of 63 consecutive Charcot feet treated between 2004 and 2014. The mean follow-up time was 2.4 years. RESULTS: All Charcot feet treated between 2004 and 2014 were Sanders type II or III. A bony fusion was achieved in 50 % of the cases, 26 % had a functional pseudoarthrosis with intact implants and pain-free mobility, and 22 % showed no healing with broken implants. Conclusion Internal fixation with locking plates is superior to screw fixation only with regard to biomechanics. We prefer internal fixation plates to external fixation because of stability even in the case of pseudoathrosis and because of the learning curve.

[Pathophysiology and etiology of the Charcot foot]. / Pathophysiologie und Ätiologie des Charcot-Fußes.

BACKGROUND: Despite extensive research, the pathophysiology of Charcot foot is still not fully understood. In the case of late diagnosis and insufficient therapy, severe deformity may occur. OBJECTIVES: Different theories on the pathophysiology of the Charcot foot are presented and discussed. MATERIALS AND METHODS: This article presents different theories on the pathophysiology of the Charcot foot and presents studies on the cellular, immunological, and bone metabolism level. RESULTS: One theory is based on repetitive microtraumas in the sensoric deficient foot which lead to development of Charcot foot. Another theory is based on pathologic neurovascular innervation leading to morphologic changes. Probably both mechanisms are responsible in combination as etiological factors inducing neuropathy CONCLUSION: A combination of mechanical, vascular, and biologic factors induce the neuropathic foot and result in severe deformity if diagnosis is too late.

[Visualization of local cortical defects in Charcot foot using microcomputed tomography]. / Visualisierung lokaler kortikaler Defekte im Charcot-Fuß mittels Mikrocomputertomographie.

BACKGROUND: In the pathogenesis of diabetic neuropathic osteoarthropathy (Charcot's foot) fractures cause chronic destruction of soft tissue and bone structure. To improve an early diagnosis of Charcot foot, modern diagnostic imaging is mainly based on magnetic resonance imaging (MRI), for example in relation to the detection of cortical bone fractures. OBJECTIVES: In this study we investigated the cortical microstructure in cases of Charcot foot with respect to fractures and porosity in order to visualize local cortical defects. This may substantiate recent efforts in a reclassification based on MRI. MATERIAL AND METHODS: Using microcomputed tomography (microCT) we investigated bone parameters, such as cortical thickness and porosity in order to quantify the local metatarsal microstructure in cases of Charcot foot. RESULTS: All bone samples showed a high degree of cortical porosity including pores that perforated the cortical bone. The data suggest that areas with reduced cortical thickness coincide with large cortical pores that may serve as initial points for fractures. Whether the detected microfractures are physiological or artefacts of preparation could not be determined. CONCLUSION: By means of microCT we were able to visualize and quantify the extent of cortical porosity for the first time in high resolution. The data suggest that both cortical fractures and cortical porosity play an important role in the pathogenesis in cases of Charcot foot.

[Diagnostic for Charcot foot]. / Diagnostik des Charcot-Fußes.

BACKGROUND: Early recognition of Charcot foot can save a long period of suffering for the patient, high doctor and hospital costs and ultimately amputation. OBJECTIVES: This article aims to raise awareness of the diagnostics of Charcot foot also known as diabetic neuropathic osteoarthropathy (DNOAP) and the possible differential diagnostic options (e.g. diabetic foot, erysipelas and peripheral arterial occlusive disease). MATERIAL AND METHODS: Clinical diagnostic pathways and classifications are presented and the resulting treatment options are discussed. RESULTS: In recent years new technologies for wound treatment and interventional radiological optimization of vessels have been developed. Many promising surgical options are available for stabilizing and reconstructimg a plantigrade foot. CONCLUSION: Treatment of Charcot foot should be based on a structured diagnosis and classification. In addition to conservative treatment new surgical options are also available.

[Full contact plaster cast for conservative treatment of Charcot foot]. / Konservative Behandlung des Charcot-Fußes mittels Vollkontaktgips.

BACKGROUND: The gold standard for treatment of early stages of Charcot foot are immobilization with a full contact plaster cast, whereby different periods and loading concepts are described in the literature. OBJECTIVES: The etiology, disease course and preparation for an early conservative therapy are described and a key point is a full contact plaster cast. METHODS: An overview of the etiology, pathogenesis and indications for correct evaluation of the wound situation is given. The correct technique for the total cast is described and illustrated step by step with pictures. RESULTS: If treatment of Charcot foot is initiated in the early stages prevention or healing of ulcers can be achieved; therefore, the correct indications and technique are necessary and the cast should be changed periodically which is a key point of the healing process. Healing results in a reduction of redness, temperature and swelling which should be measured and documented. CONCLUSIONS: Treatment of Charcot foot by full contact cast and immobilization should be initiated as soon as possible.

[Diabetic foot syndrome and diabetic neuropathic osteoarthropathy (DNOAP): an update of conservative and surgical therapy methods]. / Diabetisches Fußsyndrom und diabetische neuropathische Osteoarthropathie (DNOAP).

A diabetic foot or Charcot foot diagnosed in time can reduce a lot of problems for the patient, lessen high medical expense, and last but not least prevent an amputation. Good treatment options of the diabetic foot result from new technologies in wound management, angioplastic vessel improvement and optimised orthopaedic aids. Nevertheless it stays a challenging issue for practitioners and medical and health care as well as hospital owners to master this problem which will be even growing in the long run. This article intends to raise the awareness for the diabetic foot and the neuropathic osteoarthropathy, and furthermore illustrate diagnostic steps and offer therapeutic options. After distinguishing the diabetic foot from the Charcot foot a selective therapy for each entity has to be initiated. An interdisciplinary approach of specialists in dermatology, radiology, orthopaedic and internal medicine, plastic surgery and orthopaedic shoemaking is essential for a good therapeutic monitoring in order to avoid the amputation of the lower leg.

[Differences in plantar loading between orthosis with and without lateral wedge in healthy subjects]. / Veränderungen der Fußdruckparameter mit und ohne laterale Schuhranderhöhung bei gesunden Probanden.

BACKGROUND: Insoles and foot orthotics change the distribution of the plantar pressure. No information exists concerning the effects of plantar pressure distribution and lateral wedge orthoses. The purpose of this study was to determine the effect of the lateral wedge on the plantar pressure distribution. METHODS: The GP Mobil Data system was used to evaluate the data mentioned above, using a 6 mm lateral wedge orthotic worn by 50 healthy volunteers (100 feet). Patient age was 18 to 61 years. The first measurement was performed with, the second without a 6 mm lateral wedge. 50 volunteers walked a standardised distance of 10 m and the results with and without the wedge were compared. For evaluation, the foot was divided in 6 different anatomic regions. Statistical analysis was performed with the t2 test using graph pad prism. RESULTS: The preliminary results revealed that the maximum peak pressure and intermediate pressure, contact time and force time integral decreased significantly at the medial middle- and forefoot plus the heel and increased significantly at the lateral middle- and forefoot using the lateral wedge. The maximum peak pressure under the great toe decreased by 22 % using a wedge, under the MTP I joint by 19 %, under the MTP II-III joints by 8 % and under the heel by 7 %. By contrast, maximum peak pressure increased under the area of MTP IV-V (+ 11.3 %) and under the lateral metatarsus (+ 15 %) when wearing a wedge. CONCLUSION: This study reveals the effects of a lateral wedge orthosis on the plantar pressure distribution of the foot. These relationships and the changing pattern may serve as a useful guide for the clinician. A full medical screen of the foot should be undertaken before laterally wedged foot orthotic devices are prescribed.

Radio-lunate arthrodesis in rheumatoid arthritis: outcome and techniques.

BACKGROUND AND PURPOSE: The wrist is one of the most affected joints in rheumatoid arthritis. The purpose of this retrospective study was to assess clinical, functional and radiographic results of radio-lunate arthrodesis. Two different operation and fixation techniques are compared and detailed outcome after this intervention is presented. METHODS: Twenty-seven patients with long-standing rheumatoid arthritis were operated on, either by stabilisation of the arthrodesis with Shapiro staples (n = 14) or by Herbert screw (n = 13) and followed for a mean of 5.4 years. RESULTS: Radio-lunate arthrodesis resulted in high overall and subjective satisfaction concerning function, grip and return to work. Grip strength was 35 kPa for the dominant and 26 kPa for the non-dominant hand. No revision, pseudoarthrosis or hardware failure was observed; only two conservatively treated wound healing problems were reported. The procedure resulted in a mean flexion of 26° and a mean extension of 24°; a clear improvement was also seen in activities of daily life. No difference between both groups was observed for pain, complication rate or functional outcome. INTERPRETATION: Due to high patient satisfaction and functional outcome, radio-lunate wrist arthrodesis can be recommended independent of fixation method.