Treatment outcome of the Masquelet technique in 195 infected bone defects-A single-center, retrospective case series.

BACKGROUND: The Masquelet technique is a surgical procedure for the reconstruction of bone defects. During the first step, an osteosynthetically stabilized defect is filled with a cement spacer. The spacer induces a foreign body membrane, called a Masquelet membrane. In a follow-up procedure, the spacer is replaced by a bone graft, which ossifies in the subsequent phase. MATERIAL AND METHODS: A total of 171 patients with 195 septic bone defects on the extremities that had been treated with the Masquelet procedure at the BG Klinikum in Hamburg, Germany, from 2011 to 2021 were retrospectively analysed, comparing patients who reached full weight and load bearing on the affected extremity to those who failed to do so. Defect size and configuration, microbiological results and treatment methods as well as comorbidities and epidemiologic data were analysed for factors influencing the treatment outcome. RESULTS: In all, 113[66%] of the patients were male, and 58[34%] were female, with an age distribution of 52 +/-16 years. Out of 171 patients, 24 patients had two defects. The number of patients that reached full weight bearing was 152[89%], the follow-up period was 2 +/-1 years (median +/- SD). Full weight bearing capability was negatively by the defect size as defects >62 mm tended to be less likely to reach full weight bearing than smaller defects. A secondary stabilization with an internal stabilization was applied in 58[34%] of all patients and positively influenced the attainment of full weight and load bearing. DISCUSSION: With 171 patients and 195 septic bone defects treated at a single centre with the Masquelet Technique, this study represents a comparably large cohort. Demographics, defect characteristics and treatment outcomes did not differ from those of other cohorts described in the literature. Defects larger than 62 mm showed lower chances to reach full weight bearing and can be defined as "critical defect size" for the Masquelet technique based on our data.

[Therapeutic strategies for joint infections]. / Therapiestrategie bei Gelenkinfektionen.

Joint infections represent a severe complication that results in irreversible joint destruction when left untreated or treated inadequately. The reasons for joint infections include endogenous hematological and exogenous factors. In the patient cohort described here, the empyema was almost exclusively acquired through iatrogenic measures (e.g. arthroscopic operations, punctures and intra-articular infections) or as a result of fractures close to the joint and penetrating injuries. Acute joint empyema is an orthopedic emergency, which must be immediately surgically treated because irreversible cartilage damage can rapidly occur due to the pathophysiological process. Acute joint empyema must be treated arthroscopically. Chronic empyema must be assumed when the clinical symptoms last for more than 7 days. Chronic empyema should be treated by arthrotomy, synovectomy and removal of extraneous material including cruciate ligament replacement material.

[Classification of haematogenous and post-traumatic osteomyelitis]. / Klassifikation der Osteomyelitis und Osteitis.

A classification of osteomyelitis must reflect the complexity of the disease and, moreover, provide conclusions for the treatment. The classification is based on the following eight parameters: source of infection (OM [osteomyelitis]/OT [post-traumatic OM]), anatomic region, stability of affected bone (continuity of bone), foreign material (internal fixation, prosthesis), range of infection (involved structures), activity of infection (acute, chronic, quiescent), causative microbes (unspecific and specific bacteria, fungi) and comorbidity (immunosuppressive diseases, general and local). In the long version of the classification, which was designed for scientific studies, the parameters are named by capital letters and specified by Arabic numbers, e.g., an acute, haematogenous osteomyelitis of a femur in an adolescent with diabetes mellitus, caused by Staphylococcus aureus, multi-sensible is coded as: OM2 Lo33 S1a M1 In1d Aa1 Ba2a K2a. The letters and numbers can be found in clearly arranged tables or calculated by a freely available grouper on the internet (www.osteomyelitis.exquit.net). An equally composed compact version of the classification for clinical use includes all eight parameters, but without further specification. The above-mentioned example in the compact version is: OM 3 S a Ba2 K2. The short version of the classification uses only the first six parameters and excludes causative microbes and comorbidity. The above mentioned example in the short version is: OM 3 S a. The long version of the classification describes an osteomyelitis in every detail. The complexity of the patient's disease is clearly reproducible and can be used for scientific comparisons. The for clinical use suggested compact and short versions of the classification include all important characteristics of an osteomyelitis, can be composed quickly and distinctly with the help of tables and provide conclusions for the individual treatment. The freely available grouper (www.osteomyelitis.exquit.net) creates all three versions of the classification in one step.

[Definition of the Diagnosis Osteomyelitis-Osteomyelitis Diagnosis Score (ODS)]. / Zur Definition der Diagnose Osteomyelitis - Osteomyelitis-Diagnose-Score (ODS).

AIM: The disease "osteomyelitis" is characterised by different symptoms and parameters. Decisive roles in the development of the disease are played by the causative bacteria, the route of infection and the individual defense mechanisms of the host. The diagnosis is based on different symptoms and findings from the clinical history, clinical symptoms, laboratory results, diagnostic imaging, microbiological and histopathological analyses. While different osteomyelitis classifications have been published, there is to the best of our knowledge no score that gives information how sure the diagnosis "osteomyelitis" is in general. METHOD: For any scientific study of a disease a valid definition is essential. We have developed a special osteomyelitis diagnosis score for the reliable classification of clinical, laboratory and technical findings. The score is based on five diagnostic procedures: 1) clinical history and risk factors, 2) clinical examination and laboratory results, 3) diagnostic imaging (ultrasound, radiology, CT, MRI, nuclear medicine and hybrid methods), 4) microbiology, and 5) histopathology. RESULTS: Each diagnostic procedure is related to many individual findings, which are weighted by a score system, in order to achieve a relevant value for each assessment. If the sum of the five diagnostic criteria is 18 or more points, the diagnosis of osteomyelitis can be viewed as "safe" (diagnosis class A). Between 8-17 points the diagnosis is "probable" (diagnosis class B). Less than 8 points means that the diagnosis is "possible, but unlikely" (class C diagnosis). Since each parameter can score six points at a maximum, a reliable diagnosis can only be achieved if at least 3 parameters are scored with 6 points. CONCLUSION: The osteomyelitis diagnosis score should help to avoid the false description of a clinical presentation as "osteomyelitis". A safe diagnosis is essential for the aetiology, treatment and outcome studies of osteomyelitis.

[Medium-term results of surgical treatment for osteitis of the clavicle]. / Mittelfristige Ergebnisse der operativen Behandlung bei Claviculaosteitis.

AIM: Osteitis of the clavicle is rare and not well described in the international literature. We describe a concept of surgical treatment with medium-term observations. METHOD: A total of 22 patients (12 women, 10 men; BMI Ø 24.6 kg/m(2), age Ø 48 years) with osteitis of the clavicle were included in the series. The treatment regime consisted of a surgical approach. Data collection was prospective. Data gathered preoperatively and at follow-up included clinical examination, laboratory findings, radiographs and the Constant scoring system. The mean follow-up period was 13.3 (3-53) months. RESULTS: The described surgical concept was able to permanently eliminate infection in all cases studied. Surgical revisions were required in six patients. The average Constant score showed a significant increase from 66 to 84 at follow-up. Patients also showed good functional results after total resection of the clavicle. CONCLUSION: The reported treatment regime provides reliable results in terms of eliminating infection with good clinical results. Neighboring joints were frequently also involved in the infection and needed to be surgically addressed.

[Principles of OSG arthrodesis in cases of joint infection]. / Prinzipien der OSG-Arthrodese bei Gelenkinfekt.

A chronic empyema of the ankle joint often develops after an open fracture or surgery. In the case of the destruction of the joint due to an infection, an arthrodesis should be performed. Normally we use an external fixator with two bone-nails placed into the calcaneus and two into the tibia. The arthrodesis is distracted and Septopal is permanently implemented. At 4-6 weeks after surgery the Septopal is removed, with distraction being reduced and a cancellous bone-graft taken from the dorsal iliac crest is performed to fill the bony defect. After bone healing, the external fixator is removed and the patient mobilized in a brace. Initially, weight-bearing is limited to 10 kg but is increased gradually to full weight. The brace is used for 6-9 months; later the patient is mobilized in orthopaedic shoes. In difficult cases, also in combination with a malposition which has to be corrected or a lengthening of the lower limb, we use the Ilizarov fixator. From 1993 to 2003 we performed arthrodeses of the ankle joint due to infectious destruction in 107 cases. In 82.2%, the empyema was caused by a fracture of the ankle joint and the following treatment. In 58% of the patients, we saw associated diseases such as obesity, alcohol abuse, diabetes and malposition of the foot. In 55% we found Staphylococcus aureus. In 86%, we used the external AO-fixator, in 14% the Ilizarov fixator. The patient retained the fixator for an average of 128 days. In our study, 92.1% of the 101 patients who had completed therapy showed a good stability an average of 4.5 years after the arthrodesis. In 5% we found partial stability, while three patients had to be amputated. In 57 patients (56.4), an arthrosis of the tarsal bones was found, and 38 patients (54.3%) of the 70 patients who at the time of the arthrodesis were still working could return to work.

[Mechanoreceptors in the distal aspects of the m. vastus medialis?]. / Mechanorezeptoren in den distalen Anteilen des M. vastus medialis?

Five cadavers were fixed in Jores' solution and alcohol. The distal parts of the medial vastus muscle and the medial parts of the patella ligament and of the capsule of the knee joint were prepared and histologically examined. Previous examinations had shown mechanoreceptors in the knee joint ligaments; the present study was designed to find whether mechanoreceptors could be identified in the anatomical structures mentioned, in which case an arthrotomy by the Payr access would interrupt the muscle reflexes. Only some mechanoreceptors in the medioventral parts of the knee joint capsule close to the tendon of the great muscle could be identified. Thus, when the Payr access is used there is no interruption of the sensibility transmitted by proprioceptors.

Functional construction of the sacroiliac ligamentous apparatus.

The sacroiliac ligamentous apparatus was examined as a part of a biomechanical pelvis-lower extremities system. The ligamentous apparatus of two pelves was freed, and the findings concerning the ligaments and their direction were drawn by a modular constructed, three-dimensional calculator model of the pelvic region. The ligamentous apparatus of the sacroiliac joint belongs to a functional system. Its task is to minimize every movement in this amphiarthrosis. The ligamentous apparatus shows an adaptation to strong or long-time-acting stresses. The junction between the os sacrum, pelvis and the ligamentous apparatus of the sacroiliac joint can be described as self-tightening. Local stresses are also reduced by the ligaments. A loosening in this system, which has to fix the os sacrum to the pelvic girdle, leads to a static insufficiency. The consequence is pain due to an irritation of the lumbosacral trunk. The exact description of the structure allows a representation according to the laws of similarity mechanics. With such a representation one can build up a computer-aided biomechanical model of the pelvis-lower extremities region. Examples for such a model are biomechanical finite-element models. By observing the laws of similarity mechanics (an exact description of geometric, physical and functional conditions) an efficient biomechanical model can be constructed that also takes into consideration the complex functional circumstances, in contrast to previous models. In order to construct such a model, one has to feed the findings of the examination into a data bank, which has to be demanded.

Functional construction of the superficial and deep fascia system of the lower limb in man.

The muscular system, the connective tissue and the bones are the components of a biomechanical pelvis-lower extremity model. The occasional electrical events in the muscles were not taken into account, as they can only be measured by physiological methods. In this publication, the connective tissue of the lower extremities is examined. The connective tissue system of the thigh and leg was prepared; after removal of the muscles the so-called 'hollow' lower extremity could be studied. A topographical documentation followed, and the structure and directions of the fibers were observed with polarized light. The connective tissue systems of the lower extremities and bones form a biomechanical, effective and functional system, the bone-fascia-tendon system. The components of the connective tissue in such a system are the fascia lata, the crural fascia, the iliotibial tract, the femoral and crural intermuscular septa, and the membrana interossea. The iliotibial tract is not the sole part of this system having a tension band effect, other components--above all the lateral femoral intermuscular septum--also reduce the forces acting on the bones. Therefore, the tensile strength of the iliotibial tract has to be considered lower as supposed. The iliotibial tract is not a part of the fascia lata; it is an independent, vertically tightened tendon of the 'pelvic deltoid muscle' (gluteus maximus, tensor fasciae latae). The iliotibial tract passes over the greater trochanter like on a roller bearing. It is not attached directly to the greater trochanter and to the lateral femoral condyle, so that previous models have to be modified. The iliotibial tract glides in a fascia bag which is composed of oblique and horizontal fibers of the broad fascia. The iliotibial tract, as tendon of the pelvic deltoid muscle, continues in a lateral location into the leg where it is fixed to the lateral malleolus. The present report provides a new description of the structure of the connective tissue system of the lower extremities. The model reported complies with the laws of similarity mechanics by describing exactly the geometric, physical and functional conditions. This representation could facilitate the construction of a computer-aided, efficient, biomechanical model of the pelvis-lower extremity region considering also the complex functional circumstances, in contrast to previous models. In order to construct such a model, the data obtained by the examination of the connective tissue of the lower extremities have to be given into a data bank, which, however, has to be built up.