This article is about the evaluation of possible differences in biomechanical or histomorphological properties of bone healing between saw osteotomy and random fracturing after 6 months. A standardized, 308 oblique monocortical saw osteotomy of sheep tibia was carried out, followed by manual fracture completion of the opposed cortical bone. Fixation was performed by bridge plating (4.5 mm, LCDCP, broad). X-rays were taken immediately after surgery and at the end of the study. Polychrome fluorescent staining was performed according to a standardized protocol in the 2nd, 4th 6th, 10th, 14th, 18th, 22th and 26th week. Ten sheep were comprehensively evaluated. Data for stiffness and histomorphology are reported. The average bending stiffness of the operated bone was higher (1.7 (SD 0.3) with plate (MP) vs. 1.5 without plate) than for the intact bone (1.4 (SD 0.2), though no significant differences in bending stiffness were observed (P > 0.05). Fluorescence staining revealed small numbers of blood vessels and less fragment resorption and remodeling in the osteotomy gap. Bone healing after saw osteotomy shows a very close resemblance to 'normal' fracture healing. However, vascular density, fragment resorption, fragment remodeling, and callus remodeling are reduced at the osteotomy. There have been extensive studies of the biology of fracture healing in the sheep tibia. 1-7 Diaphyseal saw osteotomy of long bones, although a common surgical procedure in the forearm, femur, tibia, and metatarsal, [8][9][10][11] is not always free from complications. Nonunion or refracturing following implant removal is a seldom, but well-known complication. 12,13 Experimental studies have shown that vascular perfusion of the cortical bone can be disturbed during osteotomy and plate osteosynthesis as a result of a variety of factors. 14 Iatrogenicinduced, circumscribed heat necrosis of the bone or microscopic sequestrum formation at the level of the osteotomy can trigger infections and interfere with normal bone healing. 15 Several methods of osteotomy have already been evaluated with an animal model. [16][17][18][19] However, these studies always assumed that bone healing is identical to that occuring after common fracturing over a specified period of time.To our knowledge, there have been no studies evaluating differences between partial osteotomy and a neighboring partial fracture. The present study was therefore designed to test the hypothesis of whether differences in bone healing between saw osteotomy and random fracturing, in terms of tissue necrosis, vascularization, and remodeling, are apparent under long-term observation. The aim of the study was to determine histomorphological and biomechanical properties of the partially osteotomied sheep tibia after a period of 6 months. The osteotomy of the same bone, at the same level as the manual fracture, should provide an answer to the question of whether bone healing is the same over the same time course. MATERIALS AND METHODS Integrated Fracture and Osteotomy ModelEleven mat...

The treatment of comminuted fractures of the radial head with concomitant injuries of the ulnar complex by resection of the radial head usually does not provide satisfactory long-term results. Other than joint instability in the elbow and a limited range of motion, radius proximalisation in the sense of ulnocarpal impingement, osteoarthritis and pain in the elbow have been described. Between 1995 and 1997, 11 radial head prostheses were implanted in ten patients who had sustained a comminuted fracture of the radial head with concomitant injury to the ulnar complex. A follow-up survey was conducted with the patients on average 5 years after the injury. Eight patients with nine implants participated in the follow-up, one patient had died and another refused to participate but declared that he did not suffer from any impairment. According to the Morrey score, two of the results were found to be very good, five to be good, one to be fair and one to be poor. Despite the severe injuries sustained by the elbow, neither joint instability in the elbow nor proximalisation of the radius, cubitus valgus, ulnar nerve syndrome, nor loosening of the prosthesis were found in any of the patients. In the event of comminuted fractures of the radial head which are impossible to reconstruct by osteosynthesis and which occur with concomitant ulnar ligamentous or osseous injury, the implantation of a prosthesis is preferred over the resection of the head of the radius.

Primary medullary nailing of femoral fractures is burdened by the risk of central and pulmonary complications in patients with polytrauma, especially in conjunction with craniocerebral or thoracic trauma. This also applies to unreamed medullary nailing. Primary treatment with external fixation necessitates secondary surgery with an altered procedure, the timing of which is not predictable. Plate osteosynthesis with anatomical repositioning of the fragments and rigid fixation is a technically demanding procedure, but can lead to fragment necrosis due to fragment denudation. In a prospective study conducted from 1 September 1994 to 30 June 1996 on 17 polytraumatized patients (average ISS:30 points), simple femoral stem fractures (A-1 to B-3 of the AO-classification) were stabilized by elastic plate osteosynthesis using biological technique. While cautiously preserving the periosteal and muscle connections to the bone, a plate is inserted as a bridge without any interfragmentary compression. At least two to four holes are left free in the center of the plate. This allows micro-movements in the fracture gap without the risk of material fatigue. All of the fractures were immediately stabilized on the day of the accident. In four patients with severe craniocerebral trauma or manifest shock, the procedure was changed to plate osteosynthesis after application of primary external fixation. Secondary injuries (joint and pelvic fractures or craniocerebral trauma) delayed early loading in 12 cases. Four patients were mobilized postoperatively under partial loading. A fixation callus was radiologically detectable on average 6 weeks after surgery. This often allowed additional loading, depending on the secondary injuries. Full loading was possible after 14 weeks. Complications included one case of surgery-related malpositioning, one soft-tissue infection, one case of plate detachment after a fall and one case of periosseous calcification. There were no cases of bone infections or pseudoarthroses. Elastic plate osteosynthesis is thus a conservative osteosynthesis procedure with a low complication rate in polytraumatized patients, even in those with simple femoral fractures.

This study investigated to what extent quality of life four years or more after the fracture is determined by initial staging (Gustilo subclassification, time from injury to arrival at hospital), by the therapeutic course (length of hospital stay, number of operations), by complications (amputation, infection) and by demographic factors (gender, age). A total of 197 patients after type III open tibial shaft fractures (type IIIA 70, type IIIB 85, type IIIC 42) from nine centers volunteered to participate in this study. During patients' follow-up appointments (mean duration of follow-up 50 months), therapeutic course, pre-surgical staging and demographic data were recorded by the surgeon. Patients were asked to rate quality of life on the Nottingham Health Profile and on a visual analogue scale. Multiple regression analysis (stepwise) identified two predictors for reducing overall quality of life (F-test: P = 0.007): number of operations (adjusted beta: -0.21) and age (adjusted beta: -0.17). Other factors showed no significant relationship with overall quality of life or with subscales of the Nottingham Health Profile. These findings indicate a dilemma between two therapeutic goals: good functional outcome, which often requires repeated operations, and quality of life, which suffers under prolonged surgical treatment.

No current studies regarding saw injuries have been published in German literature for quite some time. Despite awareness measures and safety instructions, saw accidents along with crush injuries are the most common causes of severe hand injuries. Approximately 12,000 circular saw injuries occur in Germany each year. Since professional providers have increased prices due to the rising energy costs and a wide range of different home appliance saws are available, increasing use has been made of portable circular saws in the do-it-yourself market sector. At our hospital, we evaluated the data of 51 male patients with saw injuries. The present study investigated factors that may contribute to accidents involving saws. 80 % of the accidents occurred at home, usually on weekends or after work. 51 % of the accidents happened while patients cut firewood. In 84 % of the cases, an electric table saw was used. The majority of severe hand injuries were sustained with lower priced saws. Injuries occurred most frequently between 11 a. m. and 2 p. m., primarily with injuries to bones, tendons, blood vessels and nerves. Replantable amputations or partial amputations occured rarely. In 37 % of the patients, anatomical reconstruction using osteosynthesis and/or microsurgical techniques was performed successfully. Saw injuries to the hand are sustained almost exclusively by men. Serious injuries from low-priced table saws and due to the lack of protective covering are predominant. Preventive measures and mandatory training could reduce the number of saw injuries in the years to come. The results obtained by us largely confirm the data from previous publications.