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Biomedical subjects

J L Pozo

Publications and source records attributed to J L Pozo.

At least 19 recordsLinked to original sources

Rate of blood loss over 48 hours following total knee replacement.

The purpose of this study was to determine the rate of blood loss after total knee arthroplasty and assess the efficacy of drains using autologous blood transfusion. A prospective study was undertaken of 100 consecutive patients undergoing routine total knee arthroplasty. The diagnosis was osteoarthritis in 85% of patients and rheumatoid arthritis in 12% of cases. The rate of blood loss was recorded hourly for the first 12 h, 4 hourly for the subsequent 12 h and 6 hourly for the following 24 h. Autologous blood was reinfused within 12 h of surgery according to the protocol. Eighty-four percent of the total blood drained, was collected in the first 12 h and 94% in the first 24 h. 69% of the total blood which was drained was reinfused. The mean preoperative haemoglobin was 13.18 gm/dl and 10.23 gm/dl on the 5th day. A mean volume of 70-80 ml of homologous blood was reinfused in addition to the autologous transfusion in 11 of the 100 cases. There were no cases of deep or superficial sepsis, nor any identifiable complications related to the autologous blood transfusion. This study suggests it is safe to remove the postoperative joint drain after the 12-h period.

Arthritis, Rheumatoid↗

Haemangiomas around the knee mimicking medial meniscal tears. Report of two cases and review of the literature.

There are few reports in the English literature of extra-articular lesions simulating intra-articular pathology of the knee. Two cases of histologically confirmed haemangiomas related to the distal femur, presenting with knee pain suggestive of medial meniscal damage, are reported. A 27-year-old woman presented with persistent anteromedial right knee pain despite having undergone two arthroscopies for medial meniscal damage. An MRI showed a soft tissue mass on the medial side of the distal femoral metaphysis. The symptoms resolved only after open resection of the lesion. Histology showed a periosteal haemangioma. The second patient, a 24-year-old woman, complained of posteromedial left knee pain for 3 months. Although a medial meniscal tear was suspected, an MRI showed a soft tissue mass close to the bone of the distal femoral diaphysis. The symptoms resolved after open resection of the lesion. Histology showed a soft tissue haemangioma. Both patients were asymptomatic with normal MRI scans 6 to 12 months postoperatively. Although meniscal tears can present in young patients without a history of trauma, an MRI is extremely useful in diagnosing other lesions causing similar symptoms. Haemangiomas around the knee are rare, in particular periosteal haemangiomas of the distal femur as no report has been found in the English literature.

Adult↗

The causes and mechanisms of meniscal injuries in the sporting and non-sporting environment in an unselected population.

The aim of this study was to establish the aetiology and circumstances of meniscal injuries in the general adult population. We studied a group of patients who underwent arthroscopy under the care of the same surgeon between 1991 and 1998 (1236 patients). The study group included 392 patients, aged 18 to 60 years, with no previous knee injury, surgery or arthritis, with normal X-rays and meniscal injuries proven at arthroscopy. No professional athletes were included in the study group. The patients with Sports injuries (mean age 33 years) accounted for 32.4% of cases. The patients with Non-sporting injuries (mean age 41 years) accounted for 38.8% of tears. 71.9% of these happened in activities of daily living (and half of this group sustained their tear by squatting or ascent from this position). Patients without identifiable injury (mean age 43 years) represented 28.8% of cases. Male:Female ratio was 4:1. Medial tears accounted for two thirds of cases. This type of study, not undertaken since the advent of MRI or arthroscopy, shows that in the general population, two thirds of meniscal tears occurred in the absence of sporting activities, frequently within the ambit of every day activities and in the absence of the classic injury mechanism. Ascent from a squat is a common mechanism of injury not widely described or emphasised.

Adolescent↗

Association between anatomopathologic graft disorders during reperfusion and vena cava sIL-2r in orthotopic liver transplantation.

UNLABELLED: Graft ischemia-reperfusion injury during orthotopic liver transplantation (OLT) is associated with anatomic and pathologic disorders in the graft, which may cause initial dysfunction. The object of this paper was to evaluate sIL-2r as an indicator of liver damage during graft reperfusion. MATERIAL AND METHODS: Blood samples were drawn from 20 consecutive patients who required OLT secondary to chronic end-stage insufficiency various sites (portal vein, vena cava, pulmonary artery) and during different surgical phases. Following centrifugation and storage at -70 degrees C, sIL-2r was quantitated by chemiluminescence (Immulite, EURO/DPC). In addition biopsies were graded from 0 to III according to the anatomic and pathologic findings. Base excess and ammonia were measured to evaluate the function of the new liver. STATISTICAL ANALYSES: Parameter associations were explored using Spearman's Rho and Kendall's Tau-b methods. RESULTS: There was a correlation between the degree of graft preservation and sIL-2R both during vena cava reperfusion (r=.0591, P=.05) and for the initial 2 hours after reperfusion (r=0.61, P=.062). CONCLUSION: sIL-2r levels drawn from the vena cava after graft reperfusion are associated with its degree of injury.

Drug Therapy, Combination↗

No smoke without fire--simple recommendations to avoid arthroscopic burns.

Despite anecdotal stories, the potential of the arthroscope tip or the light cable end to cause thermal burns to the surgical drapes and to patients has not been investigated in orthopaedic surgery. This study shows that the arthroscopic tip registering a temperature of 41.9 degrees C, is unlikely to cause skin burns but causes singeing of drapes without combustion. The light cable end registers a temperature of 101 degrees C with the potential for causing skin burns. It has been demonstrated to cause combustion of disposable arthroscopic drapes within seconds at a distance of 0.5 cm. It is recommended that the light source should be switched on only after the light cable has been connected to the arthroscope. The light cable end must not rest on the drapes once the light source has been switched on, as thermal burns will occur within seconds. A retractable shield of 2.5 cm fitted to the light cable end may virtually avoid the potential for combustion.

Arthroscopy↗

Addition of morphine to intra-articular bupivacaine does not improve analgesia after day-case arthroscopy.

We conducted a randomized, double-blind, controlled study in patients undergoing day-case knee arthroscopy to evaluate the analgesic effect, for 36 h after operation, of the addition of either 2 mg or 5 mg of morphine to intra-articular bupivacaine. Patients in group BM5 (n = 20) received 0.25% bupivacaine 40 ml with morphine 5 mg; patients in group BM2 (n = 20) received 0.25% bupivacaine 40 ml with morphine 2 mg and patients in group B0 (n = 18) received 0.25% bupivacaine 40 ml only. The drugs were given by intra-articular injection by the surgeon at the end of the operation and the tourniquet released 10 min later. Preoperative and postoperative pain was assessed over the ensuing 36 h, at rest and with movement, using a 100-mm visual analogue scale. There were no significant differences in pain scores, consumption of additional analgesia, or time to first request for analgesia between any of the groups. We conclude that, after day-case knee arthroscopy, no additional analgesic effect was afforded by the addition of morphine to intra-articular bupivacaine.

Adolescent↗

What is a reasonable orthopaedic surgical workload? An analysis of elective and trauma workloads using two different complexity scoring systems.

A 1-year prospective study of all surgical activity was undertaken by the Orthopaedic Unit using two weighting systems for operative complexity: the Intermediate Equivalent (IE) and the Operative Complexity Score (OCS). The objectives were to define the difference between caseload and workload, and to formulate a reasonable workload for an operating session and a reasonable annual workload for a consultant team. In both elective and trauma surgery the BUPA complex, major+ and major operations represented 50 per cent of the caseload but accounted for approximately 68 per cent of the workload. The BUPA minor and intermediate procedures representing the remaining 50 per cent of the caseload accounted for only 32 per cent of the workload. The number of hours required to undertake all the complex, major+ and major operations was approximately twice that required for the number of minor and intermediate procedures. Despite the marked variation in case mix, the workload achieved by the six teams in the same number of sessions was remarkably similar. On the basis of two consultant and one registrar elective lists per week, a total of 705 IEs (1795 OCS units) could be undertaken by each team in 1 year. An average of 458 IEs (1086 OCS units) of trauma surgery were undertaken by each team. Caseload is a poor performance indicator of surgical activity. This study supports the concept of 3.5-4.0 IEs as reasonable workload for an orthopaedic elective operating session, and 900 IEs (2200 OCS units) as a reasonable annual workload for an orthopaedic team.

England↗

The timing of amputation for lower limb trauma.

We reviewed 35 patients who had an amputation following the failure of treatment for severe lower limb trauma. Seven of the amputations were for ischaemia, within one month of injury; 13 were between one month and one year for infection complicating loss of wound cover in un-united fractures; and 15 were later than one year after injury, mainly for infected non-union. The latter group of patients had had an average of 12 operations and 50 months of treatment, including eight months in hospital. We used a new limb injury score based on damage to the individual tissue elements; this indicated that, even in the absence of neurovascular injury, the presence of severe damage to skin, bone and muscle, with wound contamination, particularly in the lower tibia, had a poor prognosis. We therefore recommend, to avoid multiple operations, with prolonged hospitalisation and suffering, that these patients should have early independent review by orthopaedic and plastic surgeons with the aim of establishing an accurate prognosis for the salvage of a useful limb.

Adolescent↗

Coronal fractures of the lateral femoral condyle.

We reviewed seven patients with coronal fractures of the lateral femoral condyle and studied the mechanism of injury and the radiological features. The influence of soft tissue attachments on the displacement and the blood supply were investigated by clinical and cadaveric studies. All three fractures which were initially undisplaced lost position early during conservative management. Internal fixation gave good results at review, and is recommended to avoid the risk of malunion and possible secondary osteoarthritis.

Adolescent↗

Unacceptable variation in the core diameters of some AO type cancellous screws.

This study assesses the variability in core diameter of a series of cancellous screws and its effect on torque strength. Analysis of a series of 107 cancellous screws revealed a wide variation of the core diameters in our sample. Tests to evaluate the effect of this variation showed that torsional strength is directly proportional to the cube of the radius of the core; a 30% reduction in radius resulting in a 70% loss in torsional strength. Conclusions drawn from this experimental data indicate that variability in core dimensions below the recommended specifications is unacceptable in clinical practice.

Adolescent↗

The Colonna-Hey Groves arthroplasty in the late treatment of congenital dislocation of the hip. A long-term review.

Forty-four patients who had undergone 50 capsular arthroplasties for congenital dislocation of the hip were reviewed after a mean follow-up of 20 years. Their average age at operation was 5.9 years; 31 of the operations were undertaken because of late presentation, the remainder because of the failure of previous surgery. In all, 70% of the hips showed good function despite a reduced range of movement, but patients with bilateral arthroplasties fared poorly. Excellent containment within the acetabulum was found in 80%, but the femoral head was always abnormally high though not unduly lateral or medial. This configuration had remained unchanged during follow-up. The accuracy of reduction along the mediolateral axis was the only variable found to influence the outcome significantly. Functional deterioration, associated with pain, was noted to be more common after 20 years than before, and was associated with radiographic evidence of joint degeneration.

Child↗

Craniocervical instability treated by contoured loop fixation.

Rigid posterior fixation of the skull to the third, fourth and fifth cervical vertebrae was achieved in three patients who, as a result of operation, had gross instability of the craniocervical junction. An anatomically contoured steel loop was secured to the occiput via small burr holes and to the vertebrae by sublaminar wiring. This technique has the advantage over bone grafting, either alone or with cement, in that it affords rigid stabilisation, allows early mobilisation and may contribute to eventual bony fusion.

Adult↗

Transoral decompression and posterior fusion for rheumatoid atlanto-axial subluxation.

Cervical myelopathy is an uncommon but potentially fatal complication of rheumatoid atlanto-axial subluxation. Computerised myelotomography with three-dimensional reconstruction shows that rheumatoid pannus, together with the odontoid peg, contributes significantly to anterior cervico-medullary compression. These findings were the basis for treatment by transoral anterior decompression and posterior occipitocervical fusion, which removes both bony and soft-tissue causes of compression and allows early mobilisation without major external fixation. We report encouraging results from this combined approach in 14 patients who had progressive neurological deterioration.

Adult↗

Surgical treatment of cervical cord compression in rheumatoid arthritis.

Cervical myelopathy is a rare but potentially dangerous complication of rheumatoid arthritis and presents considerable therapeutic problems. A conservative approach carries high mortality and surgical intervention is not without serious risks. Reduction of subluxation and posterior fusion is widely practised but may require prolonged bed rest and continuous skull traction, sometimes for many weeks. When anterior decompression has been attempted prolonged immobilisation and external fixation have created problems. In this series 23 rheumatoid patients with cervical myelopathy were investigated over a four-year period. Seventeen underwent anterior decompression of the cervical cord, of whom 14 had a transoral removal of the odontoid peg and pannus and posterior occipitocervical fusion during the same anaesthetic without mortality or serious postoperative complications; all but one have improved. The authors believe that early mobilisation after a combined cord decompression and internal fixation has reduced the mortality and morbidity. Management of cervical myelopathy in rheumatoid arthritis and indications for operation are discussed.

Adult↗

The behaviour pattern of the scoliosis associated with osteoid osteoma or osteoblastoma of the spine.

The behaviour pattern of the scoliosis associated with osteoid osteoma or osteoblastoma of the spine is described. In patients presenting with symptoms at or around skeletal maturity, the scoliosis is postural. Excision of the lesion ensures complete resolution of the curve. In the growing child, however, an initial postural scoliosis may develop vertebral rotation with structural characteristics. The magnitude of the curve and the associated vertebral rotation is dependent on the time interval between the onset of symptoms and the surgical treatment. Although removal of the lesion usually results in regression of the curve, a prolonged delay in treatment may result in a progressive structural scoliosis. A possible mechanism for the behaviour of the scoliosis is discussed.

Adolescent↗

Osteoid osteoma and benign osteoblastoma of the spine. Clinical presentation and treatment.

The clinical presentation and treatment of 18 cases of osteoid osteoma or osteoblastoma of the spine are described, with an average follow-up of 4.2 years (range three months to 11.5 years). The average delay between the onset of symptoms and definitive diagnosis was 19 months. All patients presented with marked spinal stiffness and a painful scoliosis. The lesion was situated in the pedicle in the 15 patients with involvement of the thoracolumbar spine. A surgical approach allowing direct access to the pedicle without entering the spinal canal or jeopardising spinal stability is described. Surgical treatment afforded immediate relief of pain and an early return of full spinal mobility.

Adolescent↗

Basilar impression in osteogenesis imperfecta. A report of three cases in one family.

Basilar impression is a well-recognised though rare complication of osteogenesis imperfecta. Three patients, all members of the same family, with advanced basilar impression complicating osteogenesis imperfecta tarda, are described. The clinical features in these cases illustrate the natural history of this condition: from asymptomatic ventricular dilatation, through the foramen magnum compression syndrome, to death from brain-stem compression. The radiological criteria on which the diagnosis is based, are defined. Review of the literature reveals only seven previously documented cases, all in patients with mild forms of osteogenesis imperfecta. The unusually low incidence of basilar impression in osteogenesis imperfecta and its apparent restriction to patients with mild forms of the disease is discussed. The examination of close relatives of patients with basilar impression and osteogenesis imperfecta is emphasised in order to anticipate the onset of severe neurological complications.

Adult↗