bluuebunny/crossref_metadata_2025_split huggingface dataset:
Intracellular biogenesis of collagen fibrils in ‘activated fibroblasts’ of tendo Achillis
Authors: Santander R. González , Arriba M. A. Plasencia , Cuadrado G. Martinez , Alonso A. Lopez , Martinez M. González-Santander , Alonso F. J. Martinez , Monteagudo M. , Lobo M. V. Toledo 
Published: February 2018

We have studied the formation of collagen fibrils in ‘activated fibroblasts’ of tendo Achillis of rabbits. The tendon was in the process of regeneration after experimental partial tenotomy. Samples were taken from the peri-incisional region and analysed by transmission electron microscopy. Ultrastructural examination showed the presence of a ‘fine dense granular substance’ inside the rough endoplasmic reticulum and procollagen filaments. These come together to form collagen fibrils in the dilated vacuoles of the rough endoplasmic reticulum. The possible intra- and extracellular origin of collagen fibrils is suggested. Within the cell biosynthesis of collagen fibrils take place with the formation of collagen substance which gives rise to procollagen filaments. These make contact in parallel apposition to produce striated ‘spindle-shaped bodies’ which elongate by the longitudinal attachment of more procollagen filaments and form intracellular nascent collagen fibrils.
Nitric oxide in fracture repair
Authors: Corbett S. A. , Hukkanen M. , Batten J. , McCarthy I. D. , Polak J. M. , Hughes S. P. F. 
Published: February 2018

Our aim was to investigate whether nitric oxide synthase (NOS) isoforms, responsible for the generation of NO, are expressed during the healing of fractures. To localise the sites of expression compared with those in normal bone we made standardised, stabilised, unilateral tibial fractures in male Wistar rats. Immunostaining was used to determine the precise tissue localisation of the different NOS isoforms. Western blotting was used to assess expression of NOS isoform protein and L-citrulline assays for studies on NOS activity. Control tissue was obtained from both the contralateral uninjured limb and limbs of normal rats. Immunohistochemistry showed increased expression of endothelial NOS (eNOS) to be strongest in the cortical blood vessels and in osteocytes in the early phase of fracture repair. Western blot and image analysis confirmed this initial increase. Significantly elevated calcium-dependent NOS activity was observed at day 1 after fracture. Inducible NOS (iNOS) was localised principally in endosteal osteoblasts and was also seen in chondroblasts especially in the second week of fracture healing. Western blotting showed a reduction in iNOS during the early healing period. Significantly reduced calcium-independent NOS activity was also seen. No neuronal NOS was seen in either fracture or normal tissue. Increased eNOS in bone blood vessels is likely to mediate the increased blood flow recognised during fracture healing. eNOS expression in osteocytes may occur in response to changes in either mechanical or local fluid shear stress. The finding that eNOS is increased and iNOS reduced in early healing of fractures may be important in their successful repair.
Human bone allografts can induce T cells with high affinity for donor antigens
Authors: Deijkers R. L. M. , Bouma G. J. , van der Meer-Prins E. M. W. , Huysmans P. E. , Taminiau A. H. M. , Claas F. H. J. 
Published: February 2018

We analysed the cellular immune response in ten transplantations of different massive bone allografts, of which five had a poor clinical outcome. Cytotoxic T lymphocytes (CTL) and T helper lymphocytes (TH) against mismatched donor antigens were found in all patients. More importantly, CTL with a high affinity for donor antigens were found in five cases. High-affinity CTL need no CD8 molecule to stabilise the antigen binding and are strongly associated with rejection of heart and corneal transplants. Even after removal of most of the bone-marrow cells, we found high-affinity CTL and high TH frequencies. This T-cell response could be detected over a period of years. We conclude that frozen bone allografts can induce high-affinity donor-specific CTL. The present assay allows qualification and quantification of the levels of CTL and TH in the blood. This approach may be helpful in studying the effect of the immune response on the outcome of the graft.
Polyethylene wear, osteolysis and acetabular loosening with an HA-coated hip prosthesis
Authors: Røkkum M. , Brandt M. , Bye K. , Hetland K. R. , Waage S. , Reigstad A 
Published: February 2018

We have followed up for a period of seven to nine years 100 consecutive arthroplasties of the hip in which an entirely HA-coated implant had been used. The clinical results were excellent and bony incorporation was extensive in all components. No stem became loose or subsided but five cups were revised because of loosening after 3.8 to 5.5 years, having functioned painlessly and shown radiological ingrowth. Revision procedures because of excessive polyethylene wear have been performed on 18 hips and are planned for six more. Two eroded metal backings with worn-through polyethylene were exchanged; six hips showed metallosis without polyethylene wear-through. There were two cases of granulomatous cysts in the groin and 66 hips had osteolysis located periarticularly, in the greater trochanter or in the acetabulum.
Screw versus suture fixation of Mitchell’s osteotomy
Authors: Calder J. D. F. , Hollingdale J. P. , Pearse M. F. 
Published: February 2018

We studied prospectively 30 patients who had a Mitchell’s osteotomy secured by either a suture followed by immobilisation in a plaster boot for six weeks, or by a cortical screw with early mobilisation. The mean time for return to social activities after fixation by a screw was 2.9 weeks and to work 4.9 weeks, which was significantly earlier than those who had stabilisation by a suture (5.7 and 8.7 weeks, respectively; p < 0.001). Use of a screw also produced a higher degree of patient satisfaction at six weeks, and an earlier return to wearing normal footwear. The improvement in forefoot scores was significantly greater after fixation by a screw at six weeks (p = 0.036) and three months (p = 0.024). At one year, two screws had been removed because of pain at the site of the screw head. Internal fixation of Mitchell’s osteotomy by a screw allows the safe early mobilisation of patients and reduces the time required for convalescence.
Does arthritis progress in the retained compartments after ‘Oxford’ medial unicompartmental arthroplasty?
Authors: Weale A. E. , Murray D. W. , Crawford R. , Psychoyios V. , Bonomo A. , Howell G. , O’Connor J. , Goodfellow J. W. 
Published: February 2018

We determined the outcome of 56 ‘Oxford’ unicompartmental replacements performed for anteromedial osteoarthritis of the knee between 1982 and 1987. Of these, 24 were in patients who had died without revision, one was lost to follow-up and two had been revised. Of the remaining 29 knees, 26 were examined clinically and radiologically, two were only examined clinically and one patient was contacted by telephone. The mean age of the patients was 80.3 years. At a mean follow-up of 11.4 years (10 to 14) the measurements of the knee score, range of movement and degree of deformity were not significantly different from those made one to two years after operation, except that the range of flexion had improved. Comparison of fluoroscopically-controlled radiographs at a similar interval of time showed no change in the appearance of the lateral compartments. The retained articular cartilage continued to function for ten or more years which suggests that anteromedial osteoarthritis may be considered as a focal disorder of the knee. This justifies continued efforts to develop methods of treatment which preserve intact joint structures.
The length of the patellar tendon after unicompartmental and total knee replacement
Authors: Weale A. E. , Murray D. W. , Newman J. H. , Ackroyd C. E. 
Published: February 2018

Patella infera may occur after reconstruction of the anterior cruciate ligament (ACL), high tibial osteotomy and total knee replacement (TKR). Restriction of movement of the knee and pain may result. Our aim was to compare the incidence and to assess the effects of patella infera after TKR and unicompartmental knee replacement (UKR). We reviewed radiographs of the knees of 84 patients who had had either TKR or UKR as part of a randomised, controlled trial. The length of the patellar tendon was measured on serial radiographs taken before, at eight months and at five years after operation. There was no significant change in the length of the patellar tendon after UKR, but a significant reduction was observed after TKR. Five years after the operation, the shortening of the tendon had increased to a mean of 3.5 mm. Of the knees with TKR reviewed at five years, 34% developed patella infera, defined as 10% or more of shortening, compared with 5% of those with UKR. Shortening was greatest in those knees which had required a lateral release; in this subgroup the mean shortening was 7.2 mm. Shortening correlated with restriction of movement and pain in the knee. Our study has shown that patella infera develops in most patients after TKR with lateral release, and in approximately 25% of patients after TKR without this additional procedure. Patella infera rarely occurs after UKR. It is associated with restriction of movement and pain in the knee. It may be an effect of the more extensive exposure required to perform TKR and may, in part, explain the better clinical results of UKR.
The placement of lumbar pedicle screws using computerised stereotactic guidance
Authors: Girardi F. P. , Cammisa F. P. , Sandhu H. S. , Alvarez L. 
Published: February 2018

Computer-assisted frameless stereotactic image guidance allows precise preoperative planning and intraoperative localisation of the image. It has been developed and tested in the laboratory. We evaluated the efficacy, clinical results and complications of placement of a pedicle screw in the lumbar spine using this technique. A total of 62 patients (28 men, 34 women) had lumbar decompression and spinal fusion with segmental pedicle screws. Postoperative CT scans were taken of 35 patients to investigate the placement of 330 screws. None showed penetration of the medial or inferior wall of a pedicle. Registration was carried out 66 times. The number of fiducial points used on each registration averaged 5.8 (4 to 7) The mean registration error was 0.75 mm (0.32 to 1.72). This technique provides a safe and reliable guide for placement of transpedicular screws in the lumbar spine.
Percutaneous repair of the ruptured tendo Achillis
Authors: Webb J. M. , Bannister G. C. 
Published: February 2018

Percutaneous repair of the ruptured tendo Achillis has a low rate of failure and negligible complications with the wound, but the sural nerve may be damaged. We describe a new technique which minimises the risk of injury to this nerve. The repair is carried out using three midline stab incisions over the posterior aspect of the tendon. A No. 1 nylon suture on a 90 mm cutting needle approximates the tendon with two box stitches. The procedure can be carried out under local anaesthesia. We reviewed 27 patients who had a percutaneous repair at a median interval of 35 months after the injury. They returned to work at four weeks and to sport at 16. One developed a minor wound infection and another complex regional pain syndrome type II. There were no injuries to the sural nerve or late reruptures. This technique is simple to undertake and has a low rate of complications.
Characteristics of bone ingrowth and interface mechanics of a new porous tantalum biomaterial
Authors: Bobyn J. D. , Stackpool G. J. , Hacking S. A. , Tanzer M. , Krygier J. J. 
Published: February 2018

We have studied the characteristics of bone ingrowth of a new porous tantalum biomaterial in a simple transcortical canine model using cylindrical implants 5 × 10 mm in size. The material was 75% to 80% porous by volume and had a repeating arrangement of slender interconnecting struts which formed a regular array of dodecahedron-shaped pores. We performed histological studies on two types of material, one with a smaller pore size averaging 430 μm at 4, 16 and 52 weeks and the other with a larger pore size averaging 650 μm at 2, 3, 4, 16 and 52 weeks. Mechanical push-out tests at 4 and 16 weeks were used to assess the shear strength of the bone-implant interface on implants of the smaller pore size. The extent of filling of the pores of the tantalum material with new bone increased from 13% at two weeks to between 42% and 53% at four weeks. By 16 and 52 weeks the average extent of bone ingrowth ranged from 63% to 80%. The tissue response to the small and large pore sizes was similar, with regions of contact between bone and implant increasing with time and with evidence of Haversian remodelling within the pores at later periods. Mechanical tests at four weeks indicated a minimum shear fixation strength of 18.5 MPa, substantially higher than has been obtained with other porous materials with less volumetric porosity. This porous tantalum biomaterial has desirable characteristics for bone ingrowth; further studies are warranted to ascertain its potential for clinical reconstructive orthopaedics.
The intercruciate band of the human knee
Authors: Morgan-Jones R. L. , Cross M. J. 
Published: February 2018

Thirty cruciate ligaments were retrieved from either cadavers or limbs which had been amputated. Each specimen was sectioned and stained to demonstrate the presence of collagen, nerves and vessels. All 30 specimens contained an interconnecting band of collagen fibres between the anterior and posterior cruciate ligaments. Vascular structures were present in all specimens and nerve fibres were identified in 26 (86%). We have called this structure the ‘intercruciate band’. The anterior and posterior cruciate ligaments should no longer be thought of in isolation, but together as a ‘cruciate complex’.
Development of the ball-and-socket ankle as assessed by radiography and arthrography
Authors: Takakura Y. , Tanaka Y. , Kumai T. , Sugimoto K. 
Published: February 2018

We studied the development of ball-and-socket deformity of the ankle by arthrography and radiography in 14 ankles of ten patients with congenital longitudinal deficiency of the fibula accompanied by various anomalies. The mean follow-up was for 18 years 10 months. In three ankles in infants less than one year old the lateral and medial sides of the ankle were already slightly round. In another seven ankles the ball-and-socket appearance developed before the age of five years. This was thought to be due to osseous coalition which limits eversion and inversion. In another four ankles in children who were over the age of one year at the initial examination, the deformity was demonstrated by arthrography and radiography at their first examination. Ball-and-socket deformity accompanied by tarsal coalition is an acquired deformity secondary to limitation of movement of the subtalar and midtarsal joints. It has completely developed by about five years of age.
Periprosthetic bone remodelling around a prosthesis for distal femoral tumours
Authors: Lan F. , Wunder J. S. , Griffin A. M. , Davis A. M. , Bell R. S. , White L. M. , Ichise M. , Cole W. 
Published: February 2018

We used dual-energy x-ray absorptiometry (DEXA) to evaluate the extent of periprosthetic bone remodelling around a prosthesis for distal femoral reconstruction, the Kotz modular femoral tibial replacement (KMFTR; Howmedica, Rutherford, New Jersey). A total of 23 patients was entered into the study which had four parts: 1) 17 patients were scanned three times on both the implant and contralateral legs to determine whether the precision of DEXA measurements was adequate to estimate bone loss surrounding the anchorage piece of the KMFTR; 2) in 23 patients the bone mineral density (BMD) in different regions of interest surrounding the diaphyseal anchorage was compared with that of the contralateral femur at the same location to test whether there was consistent evidence of loss of BMD adjacent to the prosthetic stem; 3) in 12 patients sequential studies were performed about one year apart to compare bone loss; and 4) bone loss was compared in ten patients with implants fixed by three screws and in 13 without screws. The mean coefficients of variation (SD/mean) for the 17 sets of repeated scans ranged from 2.9% to 7.8% at different regions of interest in the KMFTR leg and from 1.4% to 2.5% in the contralateral leg. BMD was decreased in the KMFTR leg relative to the contralateral limb and the percentage of BMD loss in general increased as the region of interest moved distally in the femur. Studies done after one year showed no consistent pattern of progressive bone loss between the two measurements. The ten patients with implants fixed by screws were found to have a mean loss of BMD of 42% in the most distal part of the femur, while the 13 without screw fixation had a mean loss of 11%. DEXA was shown to have adequate precision to evaluate loss of BMD around the KMFTR. This was evident relative to the contralateral leg in all patients and generally increased in the most distal part of the femur. In general, it stabilised between two measurements taken one year apart and was greater surrounding implants fixed by cross-locking screws.
Parathyroid hormone (1-34) increases the density of rat cancellous bone in a bone chamber
Authors: Skripitz R. , Andreassen T. T. , Aspenberg P. 
Published: February 2018

Intermittent treatment with parathyroid hormone (PTH) has an anabolic effect on both intact cancellous and cortical bone. Very little is known about the effect of the administration of PTH on the healing of fractures or the incorporation of orthopaedic implants. We have investigated the spontaneous ingrowth of callus and the formation of bone in a titanium chamber implanted at the medioproximal aspect of the tibial metaphysis of the rat. Four groups of ten male rats weighing approximately 350 g were injected with human PTH (1-34) in a dosage of 0, 15, 60 or 240 μg/kg/day, respectively, for 42 days from the day of implantation of the chamber. During the observation period the chamber became only partly filled with callus and bone and no difference in ingrowth distance into the chamber was found between the groups. The cancellous density was increased by 90%, 132% and 173% in the groups given PTH in a dosage of 15, 60 or 240 μg/kg/day, respectively. There was a linear correlation between bone density and the log PTH doses (r2= 0.6). Our findings suggest that treatment with PTH may have a potential for enhancement of the incorporation of orthopaedic implants as well as a beneficial effect on the healing of fractures when it is given in low dosages.
Cemented total hip arthroplasty with autogenous acetabular bone grafting for hips with developmental dysplasia in adults
Authors: Inao S. , Matsuno T. 
Published: February 2018

We carried out primary cemented total hip arthroplasty (THA) on 25 hips in 21 patients with developmental dysplasia of the hip, using autogenous acetabular bone grafts. The socket was placed at the level of the true acetabulum and bone from the femoral neck was used as graft. Five hips were excluded, leaving 20 which were followed up for a mean of 12.9 years (10 to 18). The mean modified Merle d’Aubigné and Postel functional scores were 5.6 for pain, 4.3 for mobility and 4.2 for range of movement. Radiological examination showed aseptic loosening in three sockets but not in the stems. The bone grafts had united and showed no evidence of late failure.
Hydroxyapatite coated with hepatocyte growth factor (HGF) stimulates human osteoblasts in vitro
Authors: Zambonin G. , Camerino C. , Greco G. , Patella V. , Moretti B. , Grano M. 
Published: February 2018

We have studied in vitro the effect of a hydroxyapatite (HA) tricalcium phosphate material coated with hepatocyte growth factor (HA-HGF) on cell growth, collagen synthesis and secretion of metalloproteinases (MMPs) by human osteoblasts. Cell proliferation was stimulated when osteoblasts were incubated with untreated HA and was further increased after exposure to HA-HGF. The uptake of [3H]-proline was increased after treatment with HA. When osteoblasts were exposed to HA-HGF, collagen synthesis was increased with respect to HA. The secretion of MMPs in control cells was undetectable, but in HA and HA-HGF cells MMP 2 and MMP 9 were clearly synthesised. Our results suggest that HA can promote osteoblast activity and that HGF can further increase its bioactivity.
Toe-walking in children younger than six years with cerebral palsy
Authors: Cottalorda J. , Gautheron V. , Metton G. , Charmet E. , Chavrier Y. 
Published: February 2018

Our aim in this retrospective study was to analyse the value of serial corrective casts in the management of toe-walking in children aged less than six years with cerebral palsy. A total of 20 children (10 hemiplegic and 10 diplegic) had elongation of the triceps surae by serial casting at a mean age of four years and one month. The mean passive dorsiflexion of the foot with the knee in extension was 3° (−10 to +5) and 12° (0 to +15) with the knee in flexion. After removal of the cast passive dorsiflexion was 20° (+10 to +30) with the knee in extension, and 28° (+10 to +35) with the knee in flexion. At a mean follow-up of 3.08 years (2.08 to 4.92), passive dorsiflexion was 9° (−10 to +20) with the knee in extension and 18° (0 to +30) with the knee in flexion. Serial corrective casts are useful for the treatment of equinus in young children as the procedure is simple and the results are at least equal to those of other non-operative techniques. It is a safe alternative to surgical procedures especially in young children. If the equinus recurs operation can be undertaken on a tendon which is not scarred.
Instability of the hip in neonates
Authors: Danielsson L. G. 
Published: February 2018

In a prospective study conducted between 1990 and 1997, 24 101 newborn infants were examined for neonatal instability of the hip and classified by the ethnic origin of their parents. In 63% their mother and father were of Swedish extraction and in 24% they were born in a foreign country. Those of foreign extraction were split into ethnic and geographical subgroups. Although the incidence of treated (dislocatable-unstable) hips was greater in Swedes (7.6‰), than in other geographical groups (5.8‰) it was not significantly different (p = 0.065). A total of 12.7‰ were referred from the neonatal ward to the orthopaedic clinic with suspected dislocatable or unstable hips; 6.8‰ were treated (5.4‰ dislocatable, 1.4‰ unstable), but 5.9‰ were not treated since their ultrasound examination was normal. Two hips were diagnosed late and one case of mild avascular necrosis was found. Examination by dynamic ultrasound decreased the number of treated cases by 5.9‰ but was not an absolute guarantee of diagnosis.
In vivo strain measurements to evaluate the strengthening potential of exercises on the tibial bone
Authors: Milgrom C. , Finestone A. , Simkin A. , Ekenman I. , Mendelson S. , Millgram M. , Nyska M. , Larsson E. , Burr D. 
Published: February 2018

Mechanical loading during physical activity produces strains within bones. It is thought that these forces provide the stimulus for the adaptation of bone. Tibial strains and rates of strain were measured in vivo in six subjects during running, stationary bicycling, leg presses and stepping and were compared with those of walking, an activity which has been found to have only a minimal effect on bone mass. Running had a statistically significant higher principal tension, compression and shear strain and strain rates than walking. Stationary bicycling had significantly lower tension and shear strains than walking. If bone strains and/or strain rates higher than walking are needed for tibial bone strengthening, then running is an effective strengthening exercise for tibial bone.