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Biomedical subjects

C M Robinson

Publications and source records attributed to C M Robinson.

At least 55 records · Page 3Linked to original sources

Tibial fractures with bone loss treated by primary reamed intramedullary nailing.

We reviewed the results of the treatment of 30 tibial fractures with minor to severe bone loss in 29 patients by early soft-tissue and bony debridement followed by primary locked intramedullary nailing. Subsequent definitive closure was obtained within the first 48 hours usually with a soft-tissue flap, and followed by bone-grafting procedures which were delayed for six to eight weeks after the primary surgery. The time to fracture union and the eventual functional outcome were related to the severity and extent of bone loss. Twenty-nine fractures were soundly united at a mean of 53.4 weeks, with delayed amputation in only one patient. Poor functional outcome and the occurrence of complications were usually due to a departure from the standard protocol for primary management. We conclude that the protocol produces satisfactory results in the management of these difficult fractures, and that intramedullary nailing offers considerable practical advantages over other methods of primary bone stabilisation.

Activities of Daily Living↗

Hip fractures in adults younger than 50 years of age. Epidemiology and results.

A review of the records of 3147 patients with hip fractures admitted to the authors' institution during a 5-year period revealed that 95 (3%) patients were aged 50 years or less at the time of fracture. Of patients between the ages of 20 and 40 years, hip fracture most commonly occurred in men after high-energy injuries. These injuries commonly occurred in the subtrochanteric and basicervical regions, or as a vertical transcervical fracture. In contrast, most patients between 40 and 50 years of age were medically frail and sustained osteoporotic-type fractures during simple falls. A treatment protocol of early reduction followed by internal fixation was evaluated in 75 nonpathologic fractures. At a mean of 25 months, fracture union with a good or satisfactory functional outcome was found in 57 (76%) patients, and 5 (7%) patients died of unrelated medical problems. Complications of primary treatment developed in 16 (21%) patients, but only 13 (17%) revision procedures were required. A satisfactory functional outcome was found in 10 patients who had uncomplicated revision surgery, but there were poor functional results in the 3 who required tertiary surgery. Despite the previously reported poor results of treatment of hip fracture in young adults, these results demonstrate that satisfactory results can be achieved with early, accurate fracture reduction followed by rigid internal fixation.

Adult↗

Transcardiac echocardiography during invasive intramedullary procedures.

We performed transoesophageal echocardiography in 111 operations (110 patients) which included medullary reaming for fresh fractures of the femur and tibia, pathological lesions of the femur, and hemiarthroplasty of the hip. Embolic events of varying intensity were seen in 97 procedures and measured pulmonary responses correlated with the severity of embolic phenomena. Twenty-four out of the 25 severe embolic responses occurred while reaming pathological lesions or during cemented hemiarthroplasty of the hip and, overall, pathological lesions produced the most severe responses. Paradoxical embolisation occurred in four patients, all with pathological lesions of the femur (21%); two died. In 12 patients large coagulative masses became trapped in the heart. Extensive pulmonary thromboembolism with reamed bone and immature clot was found at post-mortem in two patients; there was severe systemic embolisation of fat and marrow in one who had a patent foramen ovale and widespread mild systemic fat embolisation in the other without associated foraminal defect. Sequential analysis of blood from the right atrium in five patients showed considerable activation of clotting cascades during reaming.

Aged↗

Medullary lavage reduces embolic phenomena and cardiopulmonary changes during cemented hemiarthroplasty.

We randomised 24 patients before they had a cemented hemiarthroplasty for hip fracture to receive either thorough or minimal saline lavage of the femoral canal. We then determined the effect in each group on the thromboembolic and cardiopulmonary responses to the pressurised insertion of cement, using transoesophageal echocardiography to show the echogenic embolic response. We found a statistically significant reduction in both the duration of the response and the number of large emboli in patients who had had thorough lavage as compared with the control group with minimal lavage. There was also less disturbance of pulmonary function, as assessed by the change in end-tidal CO2 levels and oxygen saturation, in patients who had thorough lavage. Three patients had a significant fall in blood pressure during cement insertion; all had only minimal lavage. We consider that thorough lavage should be an essential part of the preparation of the proximal femur before cement insertion.

Aged↗

Intracapsular hip fractures. Results of management adopting a treatment protocol.

The results of the treatment of 166 patients with intracapsular fractures of the femoral neck during a 30-month period are reviewed. A protocol was adopted whereby patients younger than 65 years of age, together with those with undisplaced fractures, were treated with internal fixation, whereas patients older than 85 years of age were treated with primary hemiarthroplasty. The remaining 120 patients, aged 65-85 years, with displaced fractures were carefully evaluated preoperatively using a scoring system of their physiologic status. The more ambulant and independent patients who were medically fit and mentally alert, with good proximal femoral bone stock, who achieved a physiologic status score (PSS) of 20 or more from a maximum of 26, were managed by reduction and internal fixation of their fractures. Those patients with a PSS below 20 were treated with replacement arthroplasty. At a mean of 21 months postfracture, the mortality was 14%, although, among survivors, there was a low incidence of fracture-related complications, with only 5% of the total group requiring reoperation for infection, internal fixation failure, or prosthetic dislocation. The functional outcome was satisfactory in both treatment groups, although the mean scores for regained mobility and final placement more closely approximated the prefracture scores in the patients undergoing internal fixation. The authors conclude that preoperative assessment of the PSS is a useful guide in determining the appropriate treatment for these fractures, and that internal fixation in the 42% of patients aged 65-85 years with a high PSS appears to be well justified.

Activities of Daily Living↗

The two-part proximal humeral fracture: a review of operative treatment using two techniques.

A review of 45 patients who have undergone surgery for two-part fractures of the proximal humerus (Neer Group III) is reported using two operative techniques, AO plating and intramedullary Rush pins. Good functional results were obtained using the former technique in seven out of eight of the patients under the age of 50 years who mainly sustained their original injury as a result of high-energy motor vehicle accidents. However, in the more common low-energy, osteoporotic fracture in the elderly population, results were unsatisfactory in 12 out of 14 cases where AO plating was used, usually as a result of fixation failure. The Rush pin technique produced more reliable results in this age group, with satisfactory functional scores being obtained in 16 out of 23 patients. It is suggested that the Rush pin technique is preferable to plate fixation in the more common osteoporotic insufficiency fracture in the elderly.

Adult↗

Nonsteroidal antiinflammatory drugs, perioperative blood loss, and transfusion requirements in elective hip arthroplasty.

A study of 160 elective total hip arthroplasties revealed that those patients receiving nonsteroidal antiinflammatory drugs (NSAIDs) in the preoperative period had a significantly increased perioperative blood loss and transfusion requirement when compared with a control group receiving other forms of analgesia for their osteoarthritis. The results suggest that NSAIDs are implicated in increasing the operative blood loss in these patients. The range of increased blood loss varied from 1.57 to 2.08 times the blood loss in the control group, and this effect was seen when the operation was carried out under spinal as well as when under general anesthesia.

Aged↗

Changing prevalence of osteomalacia in hip fractures in southeast Scotland over a 20-year period.

In a randomized study of 81 patients with fresh hip fractures who underwent bone biopsy at the time of surgery there was no histologically detectable osteomalacia. This represented a fall in prevalence since a similar study 20 years previously had shown a 12 per cent incidence in the same population. The implications for routine histological screening and measurement of serum bone biochemistry in patients with hip fractures is discussed. The majority of patients in the study group had histologically detectable osteoporosis suggesting that this was an important factor in the aetiology of femoral neck fractures.

Aged↗

Locked nailing of humeral shaft fractures. Experience in Edinburgh over a two-year period.

We report the results of locked Seidel nailing for 30 fractures of the humerus. There were frequent technical difficulties at operation especially with the locking mechanisms. Protrusion of the nail above the greater tuberosity occurred in 12 cases, usually due to inadequate locking, and resulted in shoulder pain and poor function. Poor shoulder function was also seen in five patients with no nail protrusion, presumably because of local rotator cuff damage during insertion. Our results suggest that considerable modifications are required to the nail, and possibly to its site of insertion, before its use can be advocated.

Adult↗

Assay of immune cytolysis of lymphocytes and tumour cells by automatic determination of cell volume distribution.

Immune cytolysis (lysis) of cells due to the action of antibody in the presence of complement is usually substantiated by the uptake of vital dye by the cells, or by the escape of radiolabel from the cells. Immune cytolysis has now been assayed by determination of cell volume distribution with a Coulter multi-channel particle size analyser used in conjunction with a Coulter counter. For Ehrlich ascites and sarcoma-180 cells, volume degradation corresponding to vital staining was obtained only if trypsin (final concentration 625 microgram/ml) was added immediately after the usual 1 h incubation period for cells, antibody and complement. For L1210 leukaemia cells, trypsin was added at 0 degrees just 1 min before Coulter evaluation, to avoid potentiation of antibody-mediated cell lysis by trypsin. Immune cytolysis of mouse thymic, splenic and lymph node lymphocytes required addition of pronase (final concentration 625 microgram/ml) at 0 degrees for further disruption of antibody-damaged cells, prior to determination of cell volume distribution in the Coulter equipment. Scanning electron micrographs of L1210 cells undergoing immune cytolysis illustrated the changes in cell volume recorded by the Coulter apparatus. This new method for determination of immune cytolysis provides detailed information about the volume distribution of target cells, which permits detection of subtle changes and gives insight into the process of cytolysis. It is not intended to displace other procedures in routine use, except that complete automation of the present method is possible in future.

Animals↗

Passive immunotherapy for mouse leukemias with antisera of "directed" specificity: synergism with the action of cyclophosphamide.

Antileukemia sera with "directed" specificity are produced by immunization of rabbits with mouse leukemia cells admixed with normal antigen blocking (NAB) serum. Addition of NAB serum to the leukemia cells inhibits production of antibodies to normal cell components and directs specificity toward leukemia cell antigens. The resulting antileukemia serum (ALK-NABS) was not sufficiently potent to produce more than moderate therapy in the standard L1210 leukemia therapy assay. When given together with noncurative doses of cyclophosphamide (CTX), ALK-NABS acts synergistically. It is most effective when given early after injection of the leukemia cells and prior to injection of CTX. Daily repeated injections of a given dose are more effective than a single injection of that dose. Most important, small doses of ALK-NABS produce a significant prolongation of lifespan in conjunction with CTX. Results of therapy for BW-A leukemia with ALK-NABS in conjunction with CTX were negative.

Animals↗

Preparation and therapeutic potential of rabbit antisera with "directed" specificities for mouse leukemias.

Several immunization regimens for preparation of ALK-NABS were compared. One series of eight intravenous injections spaced over 5 weeks gave an ALK-NABS with potency and specificity that could be bettered only slightly by a second series of four injections spaced over 2 weeks, whereas a third series of injections was deleterious. Use of late immune antisplenocyte NABS for such immunizations produced ALK-NABS reagents with the highest in vitro specificity to leukemia cells relative to splenocytes after absorption, whereas early immune antisplenocyte NABS gave ALK-NABS with the highest antileukemia specificity relative to thymocytes. Therapy experiments with leukemias L1210 and BW-A showed increased survival times for isogeneic mice injected intraperitoneally with 10(3) (L1210 only), 10(4), and 10(5) (higher significance for L1210) cells, when ALK-NABS was given intraperitoneally in high dose on 4 or 5 successive days starting 1 day after inoculation of leukemia cells. In additional experiments with 10(5) cells given intraperitoneally, lower doses of ALK-NABS were progressively more effective with L1210 leukemia, producing some survivors without any apparent toxicity from the antiserum. In contrast, a similar experiment with leukemia BW-A was entirely negative. Addition of guinea pig serum to already excessive amounts of antiserum was not helpful.

Animals↗

Enzymatic degradation of tumor cells damaged by antibody plus complement.

Rapid degradation of ascites tumor cells damaged by the action of antibody plus complement was found to be accomplished by all proteolytic enzymes active at physiologic pH that were tested. For three types of murine ascites tumor cells (Ehrlich ascites, sarcoma-180, and L1210 leukemia), this rate of degradation at low trypsin concentrations was proportional to a high power of enzyme concentration. This suggests that the simultaneous action of two or more enzyme molecules at adjacent cell surface sites is necessary. Cell degradation was assayed by determination of cell volume distribution with a Coulter multi-channel particle size analyzer. The present study may offer clues to in vivo mechanisms of cell degradation.

Animals↗

'Sufficient' absorption--a quantitative method to replace 'exhaustive' absorption.

At present, the only guideline for removal of undesired reactivities from an antiserum is that no activity against the cross-reacting (undesired) antigens should remain after exhaustive absorption. Since this guideline sets no upper limit on the amount of undesired antigens required for an exhaustive absorption, waste of possibly precious material and of time in performing multiple sequential absorptions can result. To minimize the quantity of antigen and of experimental work required for an absorption, a quantitative approach is suggested: the antiserum is test-absorbed with various amounts of the undesired antigens, and antibody activity still present against these antigens is then tested. The results can be plotted as a curve by use of Reif's modification of the Von Krogh equation. Thus, the exact amount of undersired antigens sufficient to remove all detectable reactivity against these antigens can be determined. The procedure is termed 'sufficient' rather than 'exhaustive' absorption, to stress that only detectable amounts (rather than every last trace) of undesirable antibodies have been removed. The nomenclat re 'exhaustive absorption' gives no indication that any practical attempt to achieve it can hardly escape having the same limitations as 'sufficient absorption'; it is therefore suggested that the misleading non-quantitative nomenclature 'exhaustive absorption' be eliminated from immunological terminology. 'Sufficient absorption' has been applied to the absorption of undesired (blood group) antibodies from rabbit antisera to CEA.

ABO Blood-Group System↗