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W M Harper

Publications and source records attributed to W M Harper.

At least 37 records · Page 2Linked to original sources
PubMed1998

Cement as a risk factor for deep-vein thrombosis. Comparison of cemented TKR, uncemented TKR and cemented THR.

A total of 110 total knee replacements (TKRs) was randomised to receive either a cemented or an uncemented prosthesis. Postoperative venography at five to seven days was used to compare the prevalence, site and size of deep-vein thrombosis (DVT). We also compared the findings with those of postoperative venography in a group of patients with cemented total hip replacements (THRs). The total prevalence of DVT was significantly greater after uncemented (81%) than after cemented TKR (55%). Both knee groups had a significantly higher prevalence of DVT than in cemented hip replacements (32%). We found no difference in the proportion with proximal DVT in the three groups (14%, 15% and 16%). The median length of the thrombi was significantly greater after cemented (26.5 cm) than after uncemented TKR (11 cm) or after cemented THR (7 cm). This difference was mainly due to greater lengths of distal rather than proximal thrombi. We conclude that the use of cement may affect the formation of DVT after joint replacement, but does not appear to lead to an increased incidence.

Arthroplasty, Replacement, Hip↗
PubMed1998

Randomised, prospective study comparing cemented and cementless total knee replacement: results of press-fit condylar total knee replacement at five years.

Early implants for total knee replacement were fixed to bone with cement. No firm scientific reason has been given for the introduction of cementless knee replacement and the long-term survivorship of such implants has not shown any advantage over cemented forms. In a randomised, prospective study we have compared cemented and uncemented total knee replacement and report the results of 139 prostheses at five years. Outcome was assessed both clinically by independent examination using the Nottingham knee score and radiologically using the Knee Society scoring system. Independent statistical analysis of the data showed no significant difference between cemented and cementless fixation for pain, mobility or movement. There was no difference in the radiological alignment at five years, but there was a notable disparity in the radiolucent line score. With cemented fixation there was a significantly greater number of radiolucent lines on anteroposterior radiographs of the tibia and lateral radiographs of the femur. At five years, our clinical results would not support the use of the more expensive cementless fixation whereas the radiological results are of unknown significance. Longer follow-up will determine any changes in the results and conclusions.

Adult↗
PubMed1998

Current practice in primary total hip replacement: results from the National Hip Replacement Outcome Project.

As part of the National Study of Primary Hip Replacement Outcome, 402 consultant orthopaedic surgeons from three regions were contacted by postal questionnaire which covered all aspects of total hip replacement (THR). There was a 70% response rate of which 71 did not perform hip surgery, a further 33 refused to take part, leaving 181 valid responses. Preoperative assessment clinics were used by 89% of surgeons, but anaesthetists and rehabilitation services were rarely involved at this stage. Of respondents, 99% used routine thromboprophylaxis, with 79% using a combination of mechanical and chemical methods. Of surgeons, 84% routinely used stockings, whereas 95.5% used chemical prophylaxis, 63% employed low molecular weight heparins. Theatre facilities were shared with other surgical specialties by 6% of surgeons and 18% regularly used body exhaust suits for THR. Antibiotic loaded cement was used by 69% of surgeons, the majority (65%) used a single brand of normal viscosity cement with 9% using reduced viscosity formulations. Modern cementing techniques were commonly used at least in part, 87% used a cement gun and 94% a cement restrictor for femoral cementing. On the acetabulum, 47% pressurised the cement. In all, 36 different femoral stems and 35 acetabular cups were in routine use, but the majority of surgeons (55%) used Charnley type prostheses. Of the surgeons, 57% performed only cemented THR, while 3% exclusively used uncemented THR. Of consultants, 21% followed up their patients to 5 years, the majority discharge patients within the first year. Of concern is a large proportion of surgeons using low molecular weight heparins despite a lack of evidence with regard to reducing fatal pulmonary embolism, and also the small number of surgeons using prostheses of unproven value. Third generation cementing techniques have yet to be fully adopted. The introduction of a national hip register could help to resolve some of these issues.

Arthroplasty, Replacement, Hip↗
PubMed1997

An audit of knee radiographs performed for general practitioners.

The Royal College of Radiologists (RCR) has published guidelines concerning indications for imaging investigations. These include plain radiography of the knee, the indications for which are locking or signs of restricted movement. This audit consisted of 1153 knee radiographs in a 9 month period, results of a questionnaire sent to general practitioners (GPs), analysis of radiological reports and returned questionnaires (55% of cases), and subsequent comments from the GPs on receiving these results. Only 50% of cases fall within RCR guidelines, 90% of radiographs were normal or showed degenerative change. In 42% of cases, knee radiographs were requested to confirm previously expected degenerative change, and in 30% patient pressure was a significant factor. Most knee radiographs (87%) result in no significant change in management apart from continuation of symptomatic measures. Application of current guidelines, however, would miss some important diagnoses manifest clinically by persistent pain or effusion, for example loose body or Brodie's abscess. In cases of locking, where a radiograph may miss significant soft tissue abnormality, there was concern that reassurance was often gained by a normal examination. This audit shows that many knee radiographs are unnecessary. The guidelines appear appropriate with the proviso that persistent pain and effusion should be included as indications for investigation. Many GPs report medico-legal considerations as important reasons for unnecessary referrals, although the application of guidelines should be protection against this. The referral rate for knee radiographs before and after the communication of these results has not altered.

Adolescent↗
PubMed1997

Knee tumours--duration and nature of symptoms prior to investigation.

The incidence of most musculoskeletal neoplasms is highest around the knee. Royal College of Radiologists Guidelines for diagnostic imaging state that plain radiographs are not routinely indicated for knee pain without restriction of movement or symptoms of locking. The notes of 19 patients with knee tumours presenting over a 5 year period were analysed. Irrespective of age or the grade of malignancy the majority of patients had symptoms for around 6 months prior to the initial radiograph. Only four patients had symptoms which would have merited radiological investigation under the present Guidelines. Even in these patients the symptoms prior to either pathological fracture or locking would not have come under the Guidelines. There is a case for regarding persistent, unilateral knee pain for longer than 6 weeks as an indication for imaging.

Adolescent↗
PubMed1997

Cement pressurisation during hip replacement.

The newer techniques of cementing aim to improve interlock between cement and bone around a femoral stem by combining high pressure and reduced viscosity. This may produce increased embolisation of fat and marrow leading to hypotension, impaired pulmonary gas exchange and death. For this reason the use of high pressures has been questioned. We compared finger-packing with the use of a cement gun by measuring intramedullary pressures during the cementing of 31 total hip replacements and measuring physiological changes in 19 patients. We also measured pressure in more detail in a laboratory model. In the clinical series the higher pressures were produced by using a gun, but this caused less physiological disturbance than finger-packing. The laboratory studies showed more consistent results with the gun technique, but for both methods of cementing the highest pressures were generated during the insertion of the stem of the prosthesis.

Bone Cements↗
PubMed1997

Screening for deep-venous thrombosis after hip and knee replacement without prophylaxis.

We performed routine venography after operation in a consecutive series of 252 patients with total joint arthroplasties in whom no form of routine chemical or mechanical prophylaxis had been used. The prevalence of deep-vein thrombosis (DVT) was 32% (16% distal, 16% proximal) after total hip replacement and 66% (50% distal, 16% proximal) after total knee replacement (p < 0.001). We did not treat distal DVT. There were only two readmissions within three months of surgery because of thromboembolic disease. There were two deaths within this period, neither of which was due to pulmonary embolism.

Cause of Death↗
PubMed1997

Mortality and fatal pulmonary embolism after primary total hip replacement. Results from a regional hip register.

We calculated the rates for perioperative mortality and fatal pulmonary embolism (PE) after primary total hip replacement in a single UK health region, using a regional arthroplasty register and the tracing service of the Office of National Statistics. During 1990, there were 2111 consecutive primary replacements in 2090 separate procedures. Within 42 days of operation a total of 19 patients had died (0.91%, 95% CI 0.55 to 1.42). Postmortem examination showed that four deaths (0.19%, 95% CI 0.05 to 0.49) were definitely due to PE. The overall perioperative mortality and fatal PE rates are low and in our study did not appear to be altered by the use of chemical thromboprophylaxis (perioperative mortality rate: one-tailed Fisher's exact test, p = 0.39; fatal PE rate: one-tailed Fisher's exact test, p = 0.56). The routine use of chemical thromboprophylaxis for primary THR is still controversial. The issue should be addressed by an appropriate randomised, prospective study using overall mortality and fatal PE rate as the main outcome measures, but the feasibility of such a study is questioned.

Adult↗
PubMed1996

Unipolar or bipolar prosthesis for displaced intracapsular hip fracture in octogenarians: a randomised prospective study.

We performed a randomised prospective trial to compare a cemented unipolar prosthesis (Thompson) with a cemented bipolar prosthesis (Monk) in the treatment of displaced intracapsular fractures of the hip in patients over 80 years of age. Patients with a mental test score of less than 5/13 were excluded but the mortality was still about 30% at one year in both groups. We therefore feel that subjective criteria such as the level of pain and the return to the preinjury state are of paramount importance. Two years after operation there was no statistical difference between the rate of complications in the two groups. After adjusting for confounding factors such as differences in the level of function before injury between the groups, the degree of return to the preinjury state was significantly greater (p = 0.04) when using the unipolar prosthesis, which is one-quarter of the price of the bipolar. We cannot therefore justify the use of an expensive bipolar prosthesis in patients over 80 years of age.

Activities of Daily Living↗
PubMed1995

Reduction of temperatures generated by the triple reamer within the femoral head.

The triple reamer is a convenient tool for reaming the proximal femur when using a sliding screw and plate device, but unnecessarily high temperatures may be generated within the femoral head while the lateral cortex is being reamed. Nineteen female patients over 60 years old were randomized to either the standard or a modified reaming technique with the triple reamer during internal fixation of proximal femoral fractures. Temperatures generated within the femoral head were measured. Results showed a mean peak temperature of 51.9 degrees C (range 42-66) using the standard method and 46.3 degrees C (range 40-52) using the modified method (P = 0.07). A significant difference (P < 0.05) was found in the duration of temperature elevation above the critical 44 degrees C (17.4s vs 5.7s), it being prolonged in the standard group. Even in this osteoporotic patient group, damaging temperatures which may contribute to the mechanical failure of fixation, are generated within the femoral head. A simple method to avoid this problem is described.

Female↗
PubMed1995

Direct and indirect MRI findings in ganglion cysts of the common peroneal nerve.

MRI findings in three cases of ganglion cyst of the common peroneal nerve are presented. In each case the cyst was imaged as an oval structure in transverse section section adjacent to the fibular neck. The cyst extended in a tubular fashion over several slices with an inferior extension towards the superior tibiofibular joint. Signal intensity was intermediate on T1- and high on T2-weighted images. In addition, increased signal on both T1- and T2-weighted images was noted throughout the peroneal compartment and was associated with clinical and EMG evidence of denervation. This has not been previously described but may be an important indirect sign which, when seen, should prompt a careful search in the region of the fibular neck for an underlying ganglion cyst of the common peroneal nerve.

Adolescent↗
PubMed1995

Isotope bone scans in patients with painful knee replacements: do they alter management?

A retrospective review of the scintigraphic appearances, clinical findings and outcome in 12 patients presenting with painful knee replacements was made. Three patients required revision surgery; symptoms in the remaining nine patients settled without operative management. Three examinations failed to identify prostheses proven to be infected by aspiration and four were falsely positive for infection without supportive clinical evidence. Four examinations demonstrated loosening and in one patient the bone scan was normal but the prostheses was loose at revision surgery. There were no specific features to predict which prostheses required surgical revision and the ability to diagnose or exclude infection was limited. It is concluded that the results of three phase 99Tcm bone scans in symptomatic knee prostheses are of little assistance in guiding clinical management and that a period of conservative management should be considered prior to operative intervention.

Humans↗
PubMed1995

Single-photon-emission computerised tomography compared with planar bone scan to assess femoral head vascularity.

We performed single-photon-emission CT (SPECT) and planar bone scans to assess femoral head vascularity in ten patients with displaced intracapsular hip fracture. The heads were labelled with tetracycline and after excision at hemiarthroplasty were assessed for tetracycline uptake distribution by fluorescence under UV light. The four which had the greatest tetracycline uptake were normal on SPECT and planar imaging. In two cases the planar bone scans were normal although SPECT suggested avascularity thus giving false-negative results. Surgeons should be aware of this; SPECT may prove to be a more accurate method of assessing vascularity of the femoral head in fractures of the femoral neck.

Arthroplasty↗
PubMed1995

A subjective health indicator for follow-up. A randomised trial after treatment of displaced intracapsular hip fractures.

We report a randomised prospective trial of the early results of three types of treatment for displaced intracapsular hip fractures. We used a questionnaire sent to patients at about six months (Nottingham Health Profile, NHP) in addition to clinical assessments. There was a 67.4% usable response to the questionnaire, similar to that in other studies using the NHP. There were more responders from younger patients, those walking independently before injury and those with higher mental test scores on admission. In the younger group (65 to 79 years) we found a trend for better scores in most NHP indices after the use of a bipolar prosthesis rather than a unipolar prosthesis or internal fixation, particularly for social function, pain and physical mobility. Postal assessment using the NHP gave a satisfactory response rate even in the elderly, and can provide an extra assessment to complement or replace hospital follow-up in some circumstances.

Activities of Daily Living↗
PubMed1993

Preoperative skin traction for fractures of the proximal femur. A randomised prospective trial.

We report the results of a randomised trial to determine the effects of skin traction on 252 patients awaiting surgery for fractures of the proximal femur. They were allocated randomly to be nursed free in bed or to receive Hamilton-Russell skin traction. No differences were found between the groups in terms of pain suffered, analgesia required, frequency of pressure sores or ease of operation. The application of skin traction to patients with fractures of the upper femur is time-consuming and we recommend therefore that its routine use should be discontinued.

Adult↗