Kienböck disease and negative ulnar variance.

We compared the degree of ulnar variance, measured on standardized radiographs of the wrist, in forty-four patients who had Kienböck disease with that in ninety-nine control subjects who had been selected from a general clinic population and had radiographs of the wrist. The purpose of our study was to determine if there is a true relationship between negative ulnar variance and the development of Kienböck disease. Gender was not found to influence the degree of ulnar variance, but an association was found between age and negative ulnar variance in both the control subjects and the patients who had Kienböck disease. The findings of the present study confirmed an association between negative ulnar variance and the development of Kienböck disease even after correction for the influence of age on the measurement of ulnar variance.

Timing of critical thrombosis after replantation surgery of the digits.

The time at which critical thrombosis occurred was assessed in a group of 63 patients (76 digits) following replantation surgery. The influence of smoking and mechanism of injury were examined with respect to the risk of thrombosis. The highest risk of critical thrombosis after replantation occurred in the first 3 days after surgery, although some risk remained up to 2 weeks. The higher risk of late failure in smokers may represent the effects of a return to smoking after discharge. Mechanism of injury did not appear to affect the timing of critical thrombosis. This report should help surgeons plan the timing of discharge against the known ongoing risk of replantation failure. Strong advice against resumption of smoking seems to be appropriate.

Slipped capital femoral epiphysis. Incidence and clinical assessment of physeal instability.

In an unselected series of 55 cases of slipped capital femoral epiphysis (SCFE) we observed an incidence of 25% of epiphyseal reduction, mostly unintentional. Reduction indicated physeal instability and was associated with an effusion, detected by sonography on admission, and inability to bear weight. The true prevalence of instability may be higher since an effusion was noted in 33 cases (60%) on the initial sonographic assessment. Serial radiographs showed reduction in 12 (22%), with an average change of 15.1 degrees in the head-neck angle. Serial sonography showed reduction in 7 out of 20 cases (35%), with an average change of 3.7 mm in displacement. In two cases reduction was seen on sonography but not on radiography. Of the hips which showed subsequent reduction, 12 had had a bone scan on admission; three showed initial epiphyseal avascularity but only one progressed to symptomatic avascular necrosis. All stable hips had normal epiphyseal vascularity on the initial bone scan. This indicates the importance of injury from the initial displacement in causing avascular necrosis, rather than effusion, vascular compromise or iatrogenic injury from gentle repositioning. Physeal instability in SCFE is common and should be assessed clinically on admission. It is indicated by joint effusion or inability to bear weight. A slip is very unlikely to be unstable in a child able to bear weight and with no sonographic effusion.

The role of autologous blood transfusion in joint replacement surgery.

The efficacy of predeposited autologous blood transfusion (PABT) with and without intra/postoperative blood salvage to reduce or eliminate the need for homologous blood transfusion (HBT) in primary total hip or knee replacement surgery was investigated by retrospective and prospective studies. Depending on the type of surgery, one to three units of PABT eliminated the need for HBT in 50 to 78% of patients, but, intra/postoperative blood salvage alone reduced the need only in 11 to 29%. In contrast, blood salvage, when combined with three units of PABT, eliminated the need for HBT in all patients undergoing primary joint replacement surgery. A cost comparison analysis showed that blood salvage was more expensive than PABT, and therefore it should be limited to patients who had predeposited fewer than three units of autologous blood.

Ultrasonic features of acute osteomyelitis in children.

The ultrasonic findings in 38 children with osteomyelitis of the limb bones were analysed in four time-related groups based on the interval between the onset of symptoms and the ultrasonic examination. Deep soft-tissue swelling was the earliest sign of acute osteomyelitis; in the next stage there was periosteal elevation and a thin layer of subperiosteal fluid, and in some cases this progressed to form a subperiosteal abscess. The later stages were characterised by cortical erosion, which was commonly present in those who had had symptoms for more than a week. Concurrent septic arthritis was revealed in 11 patients, most frequently in association with osteomyelitis of the proximal femur or the distal humerus. Four weeks after clinical cure, ultrasonic examination showed no abnormalities. Ultrasonography is therefore a useful additional method for the diagnosis and assessment of osteomyelitis and its complications.

Ultrasonic signs of pelvic osteomyelitis in children.

The ultrasonic findings were reviewed in 13 children in whom pelvic osteomyelitis was diagnosed by a positive 99mtechnetium methylene diphosphonate (MDP) bone scan in conjunction with clinical and laboratory features of osteomyelitis. All patients presented with pain in the region of the hip joint. In six patients the ultrasound study was confined to the hip joint, and all six had normal findings. In seven patients the ultrasound study was extended to include the pelvis. Deep soft tissue swelling was demonstrated in six of these, including a periosseous abscess in one case. Ultrasonography was negative in one patient with a 5-week history, whose pelvic osteomyelitis was resolving at the time of the ultrasound study. Oedema of the obturator internus and externus muscles was observed in osteomyelitis affecting the pubis and ischium, and of the iliacus and/or the gluteus medius muscle in osteomyelitis of the ilium. In children presenting with hip pain who have a normal hip ultrasound study, extension of the ultrasound examination to include these four pelvic muscles may help to identify and document the progression of acute pelvic osteomyelitis.

Arthroscopic removal of acrylic cement from unreduced hip prosthesis.

A case is reported in which entrapped polymethylmethacrylate following traumatic dislocation of a total hip replacement prevented complete reduction. A combined arthroscopic and fluoroscopic technique was used to remove the entrapped polymethylmethacrylate. Manipulation of the total hip prosthesis was done after removal of polymethylmethacrylate to minimize mechanical abrasion. This technique allows direct visual assessment of the articulating surfaces as well as the mechanical stability of the prosthesis. The morbidity related to the procedure is minimal and a short rehabilitation period is the major advantage.

Percutaneous Kirschner wire stabilisation following closed reduction of Colles' fractures.

32 consecutive unstable Colles' fractures were treated by closed reduction and percutaneous Kirschner wire stabilisation through the radial styloid, followed by a below-elbow cast. Radiological assessment was made at five stages of treatment: at the time of the fracture, immediately after operation, after two weeks, after six weeks and a final review at an average period of 15.9 months. Functional assessment was made at the final review. Only three fractures developed secondary displacement, which was due to the wrong placement of the Kirschner wire. There were no complications.

Quality of blood prepared for autotransfusion in primary cemented total hip replacement.

We have measured levels of contaminants (products of cell lysis and other substances) in blood salvaged from patients undergoing primary cemented total hip replacement. Washing of this blood removed an average of 91.4% of the free haemoglobin mass, reduced white cell lysozyme concentrations by 86% and almost totally eliminated fats and particulate matter. Osmotic fragility was significantly improved by washing although not to control levels.

Effects of irrigation fluid on human menisci: an experimental comparison of water, normal saline, and glycine.

A technique has been developed to demonstrate the macroscopic morphology of collagen fiber arrangement in human menisci. It was observed that 0.9% normal saline solution removed the ground substance of the meniscus, leaving intact collagen bundles. This suggests that meniscal damage may occur as a direct result of using normal saline for irrigation during knee arthroscopy. Experiments were conducted using demineralized water and 1.5% glycine for comparison. The disruption of collagen fiber binding in the meniscus by normal saline is time and temperature dependent. Glycine solution causes fibroblast lysis and a lesser degree of collagen alteration. Demineralized water can cause edema in the fibroblast but no notable change in collagen fibers. None of the irrigation solutions tested has proved to be completely safe. Demineralized water is not the ideal solution but is preferable to normal saline or glycine solution, especially when it can be used in conjunction with electrosurgery.

Detection of articular defects using magnetic resonance imaging: an experimental study.

This study evaluates magnetic resonance imaging (MRI) in the detection of surgically created articular defects in bovine knees. A total of 26 articular defects was created in 2 fresh cadaveric cows' knees. The defects created include chondromalacic grade 2 defects, chondral and osteochondral defects from 3 to 15 mm in diameter. The knee joints were repaired in a normal saline bath to exclude air in the joint prior to MR scanning. T1 weighted spin echo (SE) images and 3D gradient echo (FISP 40 degrees 3D) images were obtained. The T1 weighted SE imaging technique detected 15 defects (57.7%) compared with FISP 3D imaging technique detection of 17 defects (65.4%). The two techniques combined enable 21 of 26 defects (80.8%) to be detected. The imaging techniques used in this study were not able to detect chondromalacic defects less than 10 mm in diameter, nor chondral defects less than 5 mm in diameter. However, small osteochondral defects of 3 mm in diameter are detectable provided the depth of the defect is not less than 10 mm. The FISP 3D imaging technique alone is more sensitive in detecting chondral defects. Both imaging techniques have similarly high sensitivities in detecting osteochondral defects. The imaging time for combined T1 weighted SE and FISP 3D sequence is short (16.5 mm) and this combined technique may be useful for MR scanning of knee joints suspected to have articular defects.