Biomedical subjects
Publications and source records attributed to R M Atkins.
In a series of 126 consecutive pilon fractures, we have described anatomically explicable fragments. Fracture lines describing these fragments have revealed ten types of pilon fracture which belong to two families, sagittal and coronal. The type of fracture is dictated by the energy of injury, the direction of the force of injury and the age of the patient.
The phenomenon colloquially known as a fiber fuse occurs when an optical fiber carrying high power is damaged or in some way abused. Beginning at the damage site a brilliant, highly visible plasmalike disturbance propagates back toward the optical source at speeds ranging from 0.3 to approximately 3 m/s, leaving in its wake a trail of bubbles and voids. We suggest that the bubble tracks in fused fibers are the result of a classic Rayleigh instability that is due to capillary effects in the molten silica that surrounds the vaporized fiber core. We report measurements of the bubble distribution and the collapse time that are consistent with this contention.
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A total of 57 patients, aged between 23 and 86 years, with complex regional pain syndrome (CRPS) type 1 nine weeks after an isolated closed fracture of the distal radius, was randomised to receive either serial intravenous regional blockade (IVRB) with 15 mg of guanethidine in 30 ml of 0.5% prilocaine or serial IVRB with 30 ml of normal saline at weekly intervals until the tenderness in their fingers had resolved or they had received a maximum of four IVRBs. The analgesic efficacy was assessed at 24 hours, 48 hours and one week after each procedure by the dolorimetry ratio and verbal pain scores, and at intervals up to six months after the fracture. There was no significant difference in the number of IVRBs administered or in finger tenderness, stiffness or grip strength between the two groups. The guanethidine group experienced more pain in the affected hand (p = 0.025) and at six months had more vasomotor instability (p < 0.0001) compared with the control group. IVRB using guanethidine offers no significant analgesic advantage over a normal saline placebo block in the treatment of early CRPS type 1 of the hand after fracture of the distal radius. It does not improve the outcome of this condition and may delay the resolution of vasomotor instability when compared with the placebo.
We describe 24 fractures of the tuberosity of the calcaneus in 22 patients. Three were similar to the type of avulsion fracture which has been well-defined but the remainder represent a group which has been unrecognised previously. Using CT and operative findings we have defined the different patterns of fracture of the calcaneal tuberosity. Ten fractures extended into the subtalar joint, but did not fit the pattern of the common intra-articular fracture as described classically. We have defined a new pattern which consists of a fracture of the medial calcaneal process with a further fracture which separates the upper part of the tuberosity in the semicoronal plane. Non-operative treatment of displaced fractures resulted in a mis-shapen heel and a poor functional outcome. Open reduction and internal fixation with either a plate or compression screw did not give satisfactory fixation. We prefer to use an oblique lateral tension-band wire. This technique gave excellent fixation and we recommend it for the treatment of displaced fractures of the tuberosity of the calcaneus.
The ipsilateral and contralateral fibulae have been used as a vascularised bone graft for loss of tibial bone usually by methods which have involved specialised microvascular techniques to preserve or re-establish the blood supply. We have developed a method of tibialisation of the fibula using the Ilizarov fixator system, ipsilateral vascularised fibular transport (IVFT), and have used it in five patients with massive loss of tibial bone after treatment of an open fracture, infected nonunion or chronic osteomyelitis. All had successful transport, proximal and distal union, and hypertrophy of the graft without fracture. One developed a squamous-cell carcinoma which ultimately required amputation of the limb. The advantage of IVFT is that the fibular segment retains its vascularity without the need for microvascular dissection or anastomoses. Superiosteal formation of new bone occurs if the tibial periosteal bed is retained. Other procedures such as corticotomy and lengthening can be carried out concurrently.
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We present a series of three patients with segmental, high energy open tibial fractures with bone loss (2-7 cm), where we have used distraction through a fracture site to replace lost bone. The open fracture was treated by debridement and shortening to eliminate the bone and soft tissue defect. Limb length was restored by distraction instituted through the closed segmental fracture. The length of regenerate formed at the fracture site ranged from 10 to 30 mm. In each case, bone formation at the distracted fracture site was satisfactory and times for regenerate consolidation were similar to those seen in standard corticotomies. These findings suggest that new bone will form in distraction reliably from high-energy fracture sites.
End caps on intramedullary nails are intended to facilitate removal and to allow length adjustment of the nail in situ. A case is reported in which the end cap made nail removal technically more difficult.
We describe a technique for the use of modified Ilizarov olive wires to stabilize bone fragments or segments or to act as a "motor" to move individual bone fragments. This technique was used in twelve patients with severe articular or comminuted open fractures referred to the unit for reconstruction with the Ilizarov frame. Six patients had comminuted plafond fractures of the tibia, and three had tibial plateau fractures. In these cases the articular fragments were reduced and stabilized until union. The modified pushing olive wire is a valuable adjunct to the Ilizarov frame.
The Ilizarov frame uses tensioned fine wires to support bone fragments. The objective of this study was to determine whether these wires deformed plastically under functional load bearing and to determine the significance of such deformation on the long-term performance of frames used for treating lower limb conditions. The mechanical characteristics of the wires were determined by means of destructive tensile tests and used in the construction of a series of finite element models replicating typical frame configurations. Each model was then subjected to a single load cycle representing a single step and the residual displacement (i.e. plastic deformation) was determined. In each case a residual displacement of between 0.26 and 0.42 mm was observed giving a corresponding reduction in wire tension of between 8.3 and 32.8 per cent. These reductions in wire tension reduce the frame's overall stiffness and so compromise its ability to inhibit high-amplitude axial and shear motions at the fracture site which are deleterious to the healing outcome.
We have recently described an extended lateral approach to the hindfoot for the operative treatment of displaced intra-articular fractures of the calcaneum. It has the advantage of avoiding damage to the sural nerve and preserving blood supply to allow prompt healing. We dissected 15 formalin-preserved cadavers, taking photographs to show the structures of the posterolateral aspect of the hindfoot and ankle. We describe a superficial and a deep triangle: the deep triangle contains a constant posterior peroneal artery which supplies the skin of the posterolateral heel. An approach designed to expose the sural nerve will divide this important artery and cause ischaemia of the posterior skin. The extended lateral approach elevates the sural nerve in a thick flap and preserves the blood supply of the skin. We have reviewed 150 consecutive patients after the use of this approach to study the indications for operation, the quality of wound healing, any damage to the sural nerve and other complications. We recommend the careful use of this approach. Our understanding of its anatomical basis has allowed us to widen the indications for its use.
One hundred patients who had sustained a Colles' fracture were observed for features of algodystrophy at 1, 5, 9 and 12 weeks following injury. The diagnosis of algodystrophy was possible as soon as 1 week after fracture. Early diagnosis has important clinical implications: the aetiological factors may become apparent and different treatment modalities be identified; furthermore, early treatment can be started, limiting the morbidity of the condition. It is proposed that patients with features of algodystrophy require physiotherapy after a Colles' fracture. Those without features may not.
In 1989, A. G. Apley recommended cautious surveillance of malignant tumors that developed in association with orthopaedic implants. This retrospective review of the Bristol Bone Tumour Register between 1980 and 1992 reports on 240 malignant soft tissue sarcomas. Eighteen developed in the thigh region of patients more than 50 years old, and 4 of these developed in the soft tissues around a hip arthroplasty.
Levels of bone remodeling agents were measured in conditioned media from cultures of periprosthetic pseudosynovial membranes and related to the radiographic features of the failed joint implants. Radiographs of both cemented hip (n = 28) and cemented knee (n = 11) implants were examined and the pattern of radiolucency was classified as erosive linear, or mixed. Similar levels of interleukin-1-beta (IL-1 beta), interleukin-6, tumor necrosis factor alpha (TNF-alpha), transforming growth factor beta-1, and prostaglandin E2 (PGE2) were found in pseudosynovial membrane conditioned media from all 3 groups of hips and the knee group (all linear). Significant correlations were evident only between PGE2 and TNF-alpha levels in the linear hip group and PGE2 and IL-1 beta levels in the knee group. A close correlation was found between IL-1 beta and TNF-alpha in both linear and erosive hips. It is suggested that coregulation of these bone remodeling agents differs with the radiographic appearance of the failed joint implants. As all the implants were cemented and the results contrast with those of others obtained with pseudosynovial membrane conditioned media from cementless implants, it is considered that cement critically influences the process of implant failure.
In 19 patients who underwent revision arthroplasty for aseptic loosening of total joint arthroplasty, specimens were taken at the time of operation to include the bone-membrane interface. In 16 (84%) of the specimens, sufficient visualization of the interface was possible to allow histologic interpretation. In 13 of these cases, there was prominent evidence of classic bone remodeling with osteoclast-mediated resorption and active new bone formation. These results suggest that the osteolysis in aseptic loosening is mediated through osteoclastic bone resorption and that the bone found in such areas is extremely active. The findings help to explain the efficacy of impacted morselized bone-graft in the treatment of bone lysis in aseptic loosening.
Six existing clinical scoring systems for assessing outcome after calcaneal fracture are reviewed. All were applied to a diverse group of 75 patients who had sustained this injury. Stepwise multiple regression analysis was used to identify the most relevant variables within these systems. Based on this, a simplified and rational outcome scoring system was devised. This system was then tested on a further group of 41 patients and shown to comply well with the characteristics required of an objective outcome score.
We describe our early experiences using the new AO plate for open reduction and internal fixation of displaced intra-articular fractures of the calcaneum. An overview of our operative technique based on 22 cases is given. The relative merits of the new plate are discussed and we conclude that the plate is a useful device for dealing with this complex injury.