Search

Problem: The anatomically shaped pcl (ESKA) total hip replacement has a porous coating of the proximal stem and the cup to allow for bony ingrowth. The tip of the stem is polished., Method: We report the results of 96 THR 6.2 years (5.25-6.7) after implantation., Results: There were no revisions during this period. One stem showed radiographic loosening at follow-up. There was stress-shielding in 9.4% in contrast to the concept of proximal fixation. Thigh-pain was found in 9.4%. One patient demonstrated disabling thigh-pain despite radiologic bony ingrowth. By drilling the femur distal to the tip of the stem a remarkable relief was achieved., Conclusion: Despite numerous cases of stress-shielding (9.4%), bony ingrowth occurs in 97%. The tcl-THR performs sufficiently after 6 years of implantation.

Background: Anorectal symptoms after haemorrhoidectomy are common and treatment is often empirical. Because of this, an audit was carried out of the value of anal endosonography in patients with anorectal symptoms after haemorrhoidectomy., Methods: Between May 1993 and February 1997, 16 patients (ten men and six women of median age 56 (range 35-77) years) were investigated by anal endosonography for anorectal symptoms after haemorrhoidectomy which involved anorectal incontinence (n = 10), anal pain (n = 4) and obstructive defaecation (n = 2). The findings were compared with those in a matched group of asymptomatic patients after haemorroidectomy., Results: Anal endosonography demonstrated an abnormality in 12 symptomatic patients. Of the ten patients with anorectal incontinence, endosonography showed an internal anal sphincter defect (n = 5), a combined sphincter defect (n = 2) and an isolated external anal sphincter defect (n = 1). Normal appearances were seen in all asymptomatic patients. The endosonographic abnormalities of the four patients with anal pain included internal anal sphincter defect (n = 1), extrinsic mass (n = 1), and intersphincteric abscess (n = 1). One of the two patients with obstructive defaecation had an isolated external anal sphincter defect on endosonography., Conclusion: These results show a high yield of endosonographic abnormalities in patients who experience symptoms after haemorrhoidectomy. In particular, occult sphincter injury as a cause of incontinence in these patients can frequently be demonstrated.

We tested the effectiveness of bilateral continuous paravascular femoral nerve blocks in a patient following bilateral femoral shaft surgery in whom other analgesic regimens were considered contraindicated or of limited effectiveness. Bilateral continuous femoral paravascular nerve blocks were performed using a previously described technique. General anesthesia was subsequently used to facilitate surgery, which was a bilateral osteosynthesis using dynamic hip screws for osteolytic metastases of the proximal extremities of both femurs. A continuous infusion of lidocaine, morphine, and clonidine was established in both femoral catheters preoperatively and used postoperatively as the principle source of analgesia. Radiographic contrast was used to document the position of both catheters and to document the spread of injectate. Visual analog scale (VAS) pain scores were recorded in the recovery room and at 4, 16, 24, 48, and 72 hours postoperatively. Plasma lidocaine levels were determined by gas chromatography at 4, 16, and 48 hours postoperatively. Sensory assessment in the distribution of the femoral, lateral cutaneous, and obturator nerves was performed to confirm the presence of sensory blockade. We successfully provided analgesia with bilateral continuous femoral paravascular nerve blocks. Pain scores at rest were consistently rated good to excellent (VAS < 20 mm). Evidence of sensory conduction block was present throughout the infusion. Plasma concentrations of lidocaine were consistently below toxic levels (1.35 to 1.65 micrograms/ml). Radiographic contrast studies failed to demonstrate movement of contrast to the level of the lumbar plexus. Bilateral continuous femoral paravascular nerve blocks can be used to provide effective and safe analgesia in patients requiring aggressive analgesia in whom other techniques may be contraindicated.

After cruciate ligament reconstruction using an autogenous central bone-patellar tendon-bone graft persistent complaints are described in the literature. There is the difficulty to distinguish the morbidity associated with the graft harvest and the morbidity caused by the injury and the reconstruction procedure. In order to clarify the morbidity resulting from the graft harvest alone, we evaluated those patients who had transplantat harvest from the opposite knee. Between 1990 and 1995 a central bone-tendon-bone graft has been taken from the contralateral uninjured knee in 37 patients, in 22 cases for anterior and in 15 cases for posterior cruciate ligament reconstruction. 27 patients were clinically (IKDC Score), isokinetically and radiologically followed up in an average of 25.3 months after the operation (range: 9-73 months). 21 patients were classified into IKDC group A. Except of one patient with an extension deficit of 5 degrees all others showed normal range of motion. Only 5 of 27 patients expressed minimal knee pain during vigorous activities. Three of them reported about weather sensitivity in addition. These 6 patients were ranked in group B. No patient was classified into IKDC group C or D. The isokinetic examination showed a normal level of quadriceps strength. At final followup, the technique of Blackburne and Peel was used to assess patellar height. There was no radiographic evidence of patella contracture or baja. According to our results taking the autogenous CBTB graft used for cruciate ligament reconstruction leads to no serious morbidity.

We investigated 15 patients with painful hip arthroplasties using intra-articular injection of bupivicaine. Fourteen had pain relief and 13 of them were subsequently found to have loosening of one or both components. The relief of pain after total hip arthroplasty by intra-articular injection of bupivicaine indicates that a satisfactory result is probable after revision surgery with refixation of the components.

A case of reflex sympathetic dystrophy (RSD) after total hip replacement (THR) is reported. It is a very unusual cause of pain after any arthroplasty procedure. Three-phase bone imaging diagnosed the condition and sympathetic blockade was used for confirming and treating the condition. The role of the bone scan in differentiating RSD from other causes of pain after THR is highlighted.

Objective: To determine the incidence and natural history of knee pain following tibial nailing., Design: A retrospective analysis of patients treated by tibial nailing evaluating a consecutive series of patients with isolated tibial shaft fractures., Setting: A level one trauma center in Vancouver, British Columbia., Patients: A group of 107 consecutive patients with 110 tibial fractures treated by interlocking tibial nailing., Intervention: Patients were contacted and interviewed by the authors. Clinical records and radiographs were analysed., Main Outcome Measurements: Incidence of knee pain; time of onset; relationship of nail position on radiographs to knee pain; relationship to knee pain to site of nail insertion; response to nail removal., Results: At a mean follow-up period of thirty-two months (12-58 months), sixty-one (57%) patients (63 of 110 knees) had developed anterior knee pain. There was no correlation between nail protrusion and knee pain. Insertion of the nail through the patella tendon was associated with a higher incidence of knee pain compared to the paratendon site of nail insertion (77% and 50% respectively). Of patients with knee pain, 80% (49/61) required nail removal. At a mean duration of 16 months following nail removal, pain was completely relieved in 22 patients and partially relieved in 17. In the remaining 10 patients, there was no improvement., Conclusions: Based on this data, we would recommend a parapatellar tendon incision for nail insertion, and nail removal for those patients with a painful knee. The causes of knee pain after tibial nailing are multi-factorial and require further study.

In 118 patients with intra- and extraarticular distal femoral fractures we used open reduction and internal fixation with a dynamic condylar screw. We recorded general implant related complications in a very low percentage of patients. In evaluation of the long-term results in eighty one patients after follow-up of more than five years we found occasional pain in eighteen patients and frequent pain in two patients. 70% of the patients presented with free range of motion in knee joint. Only five patients had a clinically important malunion of greater than five degrees. We found malrotation of greater than ten degrees in four patients. 90% of patients were found to have a stable knee joint. The functional result according to Neer was excellent in more then 50 percent and satisfying in 40 percent of the patients. Only in 5 patients the result was determined as unsatisfying or as a failure. No arthrotic changes were found in the femoro-patellar and femoro-tibial joint in about 75 percent of the cases. Grade 2 changes were found in 15 percent in the femoro-patellar joint and in 18 percent in the femoro-tibial joint. Grade 3 arthrotic changes were seen even in less than 10 percent in both parts of the knee joint.

Arthrography of hip arthroplasties is a safe, easy-to-perform procedure. It is mainly indicated when infection of the arthroplasty is suspected: the contrast agent fills bone defects that may be present between normal bone and the prosthesis and reaspiration of injected fluids may lead to bacteriological diagnosis. Another indication for arthrography of hip arthroplasties is unexplained painful hip prosthesis.

Results of total knee arthroplasty are uniformly good. There is, however, a certain subset of patients who, despite an excellent radiographic result, do not do well. From 1992 through 1994, 20 patients were referred for pain and disability after total knee arthroplasty with normal appearing office radiographs. Fluoroscopic radiographs were obtained after other causes of disability were excluded. In 14 of the 20 patients, the diagnosis of aseptic loosening was made with fluoroscopically guided radiographs. Each patient thought to have a loose component at fluoroscopy did, in fact, have a loose component at revision. Each patient improved after revision with an average increase in the Hospital for Special Surgery score of 26 points. Fluoroscopically guided radiographs can be helpful in evaluating the patient with a painful total knee arthroplasty and normal appearing office radiographs.

Evaluation of a painful total knee replacement has been limited to physical examination, aspiration, plain radiographs, and radionuclide studies. Visualization of the polyethylene tibial-bearing component without surgery has not been possible. Polyethylene wear is a well-recognized cause of total knee replacement failure. We have developed an ultrasound method to evaluate polyethylene insert shape and thickness with the ability to clearly demonstrate structural loss of plastic. Before clinical trials, a total knee replacement was cemented into a fresh cadaver knee. Ultrasound imaging of the polyethylene insert was performed in the longitudinal plane using a 10 MHz linear transducer. A characteristic bone/metal/polyethylene interface enabled recognition of the insert material from which its dimension was estimated. The entire perimeter of the liner, the metal tray, and the bone-metal interface was visualized. Five consecutive measurements at each location were performed on each of the 8-, 10-, and 12-mm polyethylene liners with the ultrasonographer blind to the insert thickness. Once removed, measurements were made directly on the liners adjacent to the marked points with an electronic caliper. Coefficient of variation (r2) ranged from 1.6% to 8.3% for the ultrasound measurements, and 0.26% to 1.5% for the caliper measurements. A plot of ultrasound versus caliper measurements allowed calculation of a linear equation, with r2 = 0.98, demonstrating high correlation between the two measurements. Our ultrasound measurements are accurate to 0.5 mm with a 95% confidence interval. Ultrasound is an accurate way to measure the dimensions of the polyethylene liner in total knee replacement arthroplasty. Early experiences with ultrasound evaluation prior to revision have been very encouraging for the evaluation of polyethylene wear, defects, and of prosthetic loosening.

We studied 70 patients after uncemented hip replacement with the Lord prosthesis which has a relatively long, completely macrotextured stem. The mean follow up was for 9.5 years. We compared radiographs at one year after operation, at 5 years and at the last follow up. Twenty-five patients (36%) had deep or circumferential pain in the thigh. Of the 44 who were most active at 5 years those with thigh pain had less proximal cortical loss than those without (p < 0.05), most cortical bone formation distally and most often had incomplete radiolucent lines at the mid-stem level, perhaps indicating more elastic displacement of the bone relative to the prosthesis. The presence of radiolucent lines correlated with the increase in cortical width at 5 years (p < 0.01). Cortical remodelling continued after 5 years at all levels except at the tip (p < 0.01). The relative elastic displacement at the interface could cause pain and may contribute to the pattern of bone remodelling in the femur after uncemented hip replacement.

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.

Persisting postoperative thigh pain is a common problem in cementless total hip prostheses occurring in a rate of about 15-20% of the patients. The reason for that phenomenon has not become clear so far. In a clinical, radiological and scintigraphic study 70 patients with 81 PCA cementless total hips were randomized in groups with (n = 34) and without significant thigh pain (n = 36). All patients underwent clinical examination including a standardized questionnaire, x-ray and 3-phase bone scintigraphy. Quantitative assessment of Tc-99m-MDP uptake was made. In the group of patients with persisting thigh pain the scintigraphic analysis showed an significantly increased uptake at the tip and the medial and lateral femur. These findings could not be correlated with clinical loosening of the prosthesis. Slight or moderate uptake in the area of the greater and lesser trochanter as well as the tip was a common finding in PCA prosthesis in all patients. In the radiological analysis no difference between both groups was evident. The study showed that patients with thigh pain after cementless PCA total hip prosthesis have specific regions of significantly increased uptake in scintigraphic examination (tip, medial and lateral femur), which cannot be correllated with clinically or radiologically signs of loosening. The morphologic reasons for the thigh pain remain unclear.

SPECT greatly enhances the utility of radionuclide bone scanning and is superior to planar techniques in many instances. Its unique ability to localize sites of increased metabolic activity to specific anatomic sites is a significant advance in clinical science, with meaningful applications to daily patient care.

We performed a study to determine the prevalence, severity, and natural history of pain in the thigh in patients who had a total hip replacement with a porous-coated anatomic prosthesis and to determine if there was an association between the radiographic findings and the pain in the thigh. We previously reported the results in these patients two years after the operation. The present study included ninety-four patients (101 total hip replacements) who had been followed for a minimum of five years--six of the original group of patients had died from unrelated causes, two had had a revision, and one had been lost to follow-up. The patients were assessed prospectively with use of the Harris hip score and a visual-analog scale for pain in the thigh. Two of us, who were blinded to the clinical result, reviewed the radiographs retrospectively for the morphology of the proximal aspect of the femur; distal fit; metaphyseal fill; alignment of the stem; shedding of beads; distal cortical hypertrophy; pedestal formation; cancellous condensations at the distal end of the porous ingrowth surface; and the presence, extent, and location of radiolucent lines around the femoral component. At five years, pain in the thigh was found in association with twenty-seven hips (27 per cent). The pain was new in fourteen thighs (14 per cent), unchanged (from that at the two-year follow-up examination) in eight (8 per cent), increased in four (4 per cent), and decreased in one (1 per cent). Pain in the thigh was most strongly associated with a poor Harris hip score and the presence of loose beads.

Current data on the interpretation of nuclear medicine scans following total hip replacement are reviewed along with a new diagnostic test--the dynamic computed tomographic scan. Intraoperative diagnostic tests include frozen section, Gram's stain, and mechanical testing. This information is consolidated with that previously presented into a series of algorithms for evaluating the painful total hip replacement.

Persisting postoperative pain of the thigh is a common problem of cementless hip endoprostheses occurring in about 15-20% of the patients. We performed a comparative study including patients with (n = 40) and without (n = 45) pain of the thigh. 85 cementless porous-coated anatomic (PCA) hip endoprostheses in 74 patients were examined. All patients underwent clinical examination including a standardized questionnaire, x-ray, and 3-phase bone scintigraphy. Slight or moderate 99mTc-MDP uptake in the area of the greater and lesser trochanter as well as at the tip was a common finding in PCA prostheses in patients without pain and was not a sign of loosening of the hip. Radiologically, there was no difference between patients with and without pain. However, persisting pain of the thigh in patients with PCA prosthesis corresponded with an increased uptake at the tip and the medial and lateral femur, not being a sign of loosening even in this group. The special biomechanical conditions of cementless prostheses causing inhomogeneous intraosseous stress distribution are supposed to be the reason for that.

Patients who continue to have or who develop abdominal pain after apparently successful cholecystectomy pose diagnostic difficulties. This study reports 384 such patients, investigated by endoscopic retrograde cholangiopancreatography (ERCP). There were 146 patients with abdominal pain alone with no previous history of common bile duct (CBD) exploration, of whom only 17 (11.6 per cent) had CBD stones on ERCP. Bile duct calculi were present in 76 of 140 patients (54.3 per cent) with abnormal biochemical findings (raised alkaline phosphatase and/or amylase level) and in 34 of 57 (60 per cent) with an abnormality detected on ultrasonography or intravenous cholangiography. A combination of biochemical and radiological abnormalities was present in 37 patients and was associated with CBD stones in 28 (76 per cent). Patients who had undergone CBD exploration represented a special group, of whom the majority (75 per cent) had common duct stones at ERCP even in the absence of biochemical and radiological abnormalities. ERCP is a useful investigation in patients with persistent postcholecystectomy symptoms. Other features in addition to pain or a history of CBD exploration may be relevant to the decision to perform ERCP in the investigation of these patients.

The ideal noninvasive test of sphincter of Oddi dysfunction (SOD) does not exist and the diagnosis of patients with postcholecystectomy pain often relies on invasive procedures. In this paper we describe a scintigraphic test for SOD: the scintigraphic score. This score combines quantitative and visual criteria for interpretation of hepatobiliary scans. Twenty-six consecutive postcholecystectomy patients underwent hepatobiliary imaging, ERCP, and sphincter manometry. Twelve patients had SOD and 14 had normal sphincters determined by clinical findings, ERCP, and manometric studies. All patients with normal sphincter had scores of 0-4, while patients with SOD had values of 5-12 for a perfect sensitivity and specificity of 100%. Hepatobiliary scans scored in this fashion may become the noninvasive test of choice to screen postcholecystectomy patients with suspected SOD.

The study evaluates the effect of 20 mg cisapride twice daily on symptoms and biliary drainage in patients with the postcholecystectomy syndrome. Nineteen patients, all female, went through a randomized, double-blind, placebo-controlled, crossover trial with two 4-week treatment periods separated by a 2-week washout period. Symptoms were registered on diary cards. Biliary drainage was studied with dynamic cholescintigraphy. The down slope of the time-activity curve (T1/2 and elimination index) was used as a measure of the biliary drainage. More symptoms were registered during cisapride therapy than with placebo. This unfavourable effect of cisapride was statistically significant in a subgroup of patients with postcholecystectomy complaints identical to the biliary pain they experienced during injection of contrast at the endoscopic retrograde cholangiopancreatographic examination. Cisapride statistically significantly hastened biliary drainage. The median T1/2 values were 24 and 28 min after cisapride and placebo, respectively (p less than 0.01). In conclusion, cisapride promoted biliary drainage in patients with the postcholecystectomy syndrome but had an unfavourable symptomatic effect in those with bile duct-triggered postcholecystectomy complaints.

The occurrence of pain following a technically satisfactory cemented total hip arthroplasty is of concern for both the orthopedic surgeon and the patient. In order that the source of the pain be accurately located, a scientific approach is required. We present an algorithm for the evaluation of pain following an apparently satisfactory hip arthroplasty which, if followed, results in the correct diagnosis.

The surgical implantation of a Silastic wedge into the lateral subtalar joint (subtalar arthrosis) is designed to restrict the osseous malalignment associated with a flexible or neurogenic flatfoot deformity. We used CT to examine patients who had persistent pain after a subtalar arthrosis and retrospectively reviewed our experience with CT scans of 13 subtalar implants (seven patients) during a 3.5-year period. The CT scans of four asymptomatic subtalar implants showed each implant in the expected position and orientation, and the findings were considered normal. Conversely, the findings on CT scans of all nine painful implants (seven patients) were interpreted as abnormal. The scans showed oblique orientation of four implants (44%), loosening of three implants (33%), extruded methyl methacrylate in the subtalar joint in two implants (22%), and abnormal calcaneal recession in two implants (22%). Five of the nine painful implants were revised with improvement or resolution of symptoms. Our experience suggests that CT scanning of the subtalar joint can show the position and orientation of a subtalar implant and identify causes of persistent pain after a subtalar arthrosis.

The authors propose a simple routine survey to be performed in the case of a painful total hip prosthesis which is generally able to define the diagnosis and the prognosis. X-ray films are more valuable by their repetition than by their simple analysis. Certain minor signs can help predict or detect loosening of the prosthesis or other complications, but in the great majority of cases, radiology alone is not sufficient to make the diagnosis, as the films are only able to show clear spaces around the prosthesis, without being able to definitely confirm the aetiopathogenic significance of this sign. In these cases, when the decision has not been taken to re-operate, more sophisticated investigations are required (scintigraphy, dynamic tests, arthrography), although they must be used with caution as very often the clinical findings will have the last word.

The radiopharmaceuticals gallium-67 and indium-111 labelled leucocytes have been compared in 15 patients with a painful joint prosthesis in an attempt to identify those patients with periprosthetic infection. Gallium-67 images were abnormal in five out of six patients with periprosthetic infection and normal in seven out of nine without evidence of infection. Indium-111 leucocyte images were abnormal in three out of six patients with infection and normal in all nine patients without infection. Indium-111 labelled leucocyte imaging is technically more difficult to perform than gallium-67 imaging. This, combined with the higher sensitivity of gallium-67 imaging for infection around a prosthetic joint, leads us to conclude that gallium-67 imaging is superior to indium-111 leucocyte imaging in identifying infection as a cause of a painful prosthetic joint.

Two cases exemplify that three point uptake on radionuclide bone scans within the first postsurgical year of press-fit cementless joint prostheses appear to be a normal physiomechanical finding.

59 patients with implanted one- or two-sided hip prostheses (n = 74) have been investigated by two different scanning techniques to detect both possible loosening of the prostheses and a possible infection as the cause of the loosening. Of the investigated prostheses 47 were loose; in 45 cases this was evidenced by the bone scan using Tc-99m-DPD, thus showing a sensitivity of 95%. Specificity was 89%. In 21 cases (45%) of loose prostheses an infection could be clinically proven. With the aid of In-111 labeled leukocyte scans, 17 of 21 cases were correctly diagnosed as infected, showing a sensitivity of 91%, while the specificity was 94%. In view of the 93% accuracy, bone scanning can be regarded as the method of choice in detecting loosening of prostheses. The 91% accuracy in proving or ruling out infection by means of the leukocyte scan is high enough to assert correct findings in most cases. The main disadvantage of this method is the very demanding technique for marking of white blood cells.

Fifteen patients with painful total hip prostheses were referred for nuclear medicine and roentgenographic arthrography studies to exclude loosening of the acetabular and/or the femoral component. A new radioisotopic technique suitable for the evaluation of both components was developed using dual-isotope single-photon tomography with 99mtechnetium methylene diphosphonate bone imaging and indium-111 diethylenetriaminepentacetic acid arthrography. Thirteen of the 15 subjects were subsequently treated with additional surgery. The surgical findings were compared with the nuclear medicine and roentgenographic results. The overall diagnostic accuracy of both arthrographic procedures was approximately 80%, but the roentgenographic arthrogram was more sensitive and the radionuclide arthrogram was more specific.

Intravenously enhanced computed tomography (CT) was used in patients in whom the differential diagnosis between recurrent herniated disc and postoperative scar was considered. Enhanced CT images demonstrated postoperative herniated discs more accurately than clinical criteria, myelography, or plain or postmetrizamide CT. The scar tissue shows contrast enhancement, but recurrent disc herniation does not. Therefore, contrast-enhanced CT is considered to be a valuable aid in distinguishing between recurrent disc herniation and hypertropic scar formation.

The authors analysed CT-scan with intravenous contrast infusion in 18 patients with recurrent pain after lumbar discectomy. CT showed in these patients the cause of recurrency with 100% accuracy, confirmed by reoperation. Contrast enhancement permitted differentiation of postoperative cicatrix from other causes of lumbar spinal canal stenosis. The authors point out that decision about reoperation should be based upon computed tomography examination.

A retrospective investigation was undertaken to assess the value of bone scintigraphy with 99mtechnetium methylene-diphosphonate in patients referred with hip pain after total hip replacement. The material comprized 68 patients with a total of 68 prostheses. This review revealed that 10/25 of the patients with pathological scintigrams and 6/28 of the patients with normal scintigrams were submitted to replacement of the prostheses. In the way in which it was carried out and interpreted in this department, scintigraphy was of limited value in selection of the patients who required replacement of the prostheses.

The value of endoscopic retrograde cholangiopancreatography (ERCP) in a surgical unit was established by analysing 200 consecutive studies. The selective success rate was 80%. The groups of indications were jaundice (27%), postcholecystectomy pain (22%), recurrent acute pancreatitis (19%), complicated attack of acute pancreatitis (14%), and other (18%). A normal ERC was found and operation thus avoided in 26% of cases with persistent jaundice. In patients with postcholecystectomy pain pathological findings were found in 50% and half of them were operated upon. In pancreatitis demonstration of the pancreatic ducts and grading of the disease facilitated selection of the treatment and enabled preoperative planning of the surgical procedure. The pancreas was resected in 13 of 59 cases with diagnostic ERP. In pancreatic carcinoma ERCP led directly to diagnosis, but only two (ampullary carcinomas) out of ten were operable. The overall complication rate was 4%, including one case of fatal haemorrhagic pancreatitis.

The evaluation of chronic pain after hip arthroplasty has always been a difficult problem and recently scintigraphy has been recommended as a suitable method of examination for this purpose. On the basis of radiographic and laboratory studies, scintigraphy, allergy tests, cultures and histological examinations, in 16 patients with chronic pain in the hip after arthroplasty, it is concluded that radiography and scintigraphy together give valuable information about the cause of pain, especially if the prosthesis is infected. Fenestration of the femoral cortex may verify the diagnosis before replacement of the prosthesis.

Technetium 99Tcm pyrophosphate bone scans were done on 35 patients who complained of persistent hip following total hip replacement. The scans of six patients were normal and the symptoms of these patients either resolved (three) or greatly improved (three) without further treatment. Twenty-nine patients had abnormal scans. Seventeen of these were due to infection or loosening of the prosthesis. Paget's disease of bone, protrusion of the prosthesis and heterotopic ossification also caused scan abnormalities. These causes could not be distinguished from one another on the scan. A radiograph of the hip is essential for interpreting the scan correctly. Scanning of the painful hip prosthesis helps to detect patients in whom serious complications are present or are likely to develop.