Biomedical subjects

R S Richards

Publications and source records attributed to R S Richards.

At least 19 recordsLinked to original sources

PubMed2001

Ilizarov hybrid external fixation for fractures of the distal radius: Part I. Feasibility of transfixion wire placement.

The advantages of Ilizarov external fixation, allowing early motion of adjacent joints during fixation of periarticular fractures, have not yet been applied to distal radius fractures. A magnetic resonance imaging study of 10 normal volunteers evaluated the safety of passing percutaneous transfixion pins across the distal radius in 3 forearm positions. Even in the optimal forearm position, the safe zones between the transfixion pin, vessel, nerve, or tendon was small, suggesting that open placement would be required. A cadaver study in 8 specimens demonstrated that the pins could be placed with an open technique using an aiming device and that the pins could be placed without limiting forearm rotation. The proximity of vital structures to transfixion pins dictates open placement to safely apply Ilizarov fixation to distal radius fractures.

Adult↗

PubMed2001

The effect of flexor tendon repair bulk on tendon gliding during simulated active motion: an in vitro comparison of two-strand and six-strand techniques.

The gliding function of 2-strand (Tajima) and 6-strand (Savage) techniques of flexor tendon repair were compared in an in vitro biomechanical model. Stainless steel beads were inserted directly into the metacarpals, phalanges, and flexor digitorum profundus tendons of 22 human cadaver specimens. The FDP tendons were loaded from 5 to 25 N using a pneumatic actuator. The angular rotation and tendon excursion of the cadaver specimens were measured radiographically. The gliding function of the repairs was compared with core suture only, core suture plus epitenon repair, and sheath repair. There was no significant difference in angular rotation or linear excursion between the 2-strand and 6-strand techniques of flexor tendon repair. The addition of the epitendinous suture to the core suture improved the angular rotation and linear excursion for the 2-strand technique. Although the 6-strand repair tended to increase the repair site bulk more than the conventional 2-strand technique, the gliding function of the repair techniques was equivalent.

Aged↗

PubMed2001

Assessment of complications of distal radius fractures and development of a complication checklist.

The purposes of this study were to determine the overall incidence of distal radius fracture (DRF) complications, determine the incidence and types of DRF complications in a consecutive cohort of 250 patients with DRFs, describe DRF complications reported by patients compared with those reported by physicians, and formulate a DRF complication checklist to improve recording of DRF complications. We found that the overall complication rates vary widely (6% to 80%). Physician-reported complication data were collected for 236 patients, and a physician-reported complication rate of 27% was determined. A patient-reported complication rate of 21% was found for 207 patients whose patient-reported data were collected. We also noted that patients and physicians assess DRF complications differently: patients are more focused on symptoms than diagnoses. A DRF complication checklist was developed to improve prospective data collection. The checklist includes a classification for all DRF complications and allows for assessment of severity of each complication.

Adult↗

PubMed2001

Validity of pulp-to-palm distance as a measure of finger flexion.

This study investigated the validity of pulp-to-palm distance measures as clinical indicators of finger flexion capacity. Pulp-to-palm distance and goniometry of the metacarpophalangeal, proximal interphalangeal and distal interphalangeal joints were measured by a single tester in 50 patients with abnormal digital flexion using a computerized hand assessment system. The correlation between pulp-to-palm distance measurements and total finger flexion measures obtained by goniometry, was moderate (r=-0.46 and -0.51). This indicates that the measures are not interchangeable. The relationship between an upper extremity disability score (DASH) and restricted motion was stronger for the goniometric measurements (r=0.45, P<0.01) than for the pulp-to-palm distance measurements (r<0.30, P>0.01). Both types of range of motion measurements were able to discriminate between minimal and substantial upper extremity disability. Further methodological evaluation is required to support the use of pulp-to-palm distance measures as an outcome indicator.

Adult↗

PubMed2000

Responsiveness of the short form-36, disability of the arm, shoulder, and hand questionnaire, patient-rated wrist evaluation, and physical impairment measurements in evaluating recovery after a distal radius fracture.

We evaluated the responsiveness of patient questionnaires and physical testing in the assessment of recovery after distal radius fracture. Patients (n = 59) were assessed at their baseline clinic visit and again 3 and 6 months after injury. At each visit patients completed a short form-36, Disability of the Arm, Shoulder, and Hand questionnaire, and patient-rated wrist evaluation (PRWE). At 3 and 6 months grip strength, range of motion, and dexterity were analyzed. Standardized response means (SRM) and effects sizes were calculated to indicate responsiveness. The PRWE was the most responsive. Both the PRWE (SRM = 2.27) and the Disability of the Arm, Shoulder, and Hand (SRM = 2.01) questionnaire were more responsive than the short form-36 (SRM = 0.92). The physical component summary score of the short form-36 was similar to that of the physical component subscales. Questionnaires were highly responsive during the 0- to 3-month time period when physical testing could not be performed. Of the physical tests, grip strength was most responsive, followed by range of motion. Responsive patient-rating scales and physical performance evaluations can assist with outcome evaluation of patients with distal radius fracture.

Adolescent↗

PubMed2000

Pneumomediastinum after injection injury to the hand.

Pneumomediastinum as a consequence of injection injury to the hand has not been previously reported. We present a 22-year-old male who developed pneumomediastinum when a high pressure hose injected air into his hand. The anatomic continuity between peripheral ulnar neurovascular bundle and the hilar vessels provided the route for air entering the hypothenar eminence to penetrate the mediastinum. After ruling out life-threatening causes of pneumomediastinum such as esophageal perforation, his management included observation and serial radiographs. By one week there was complete resolution of the mediastinal air. This report demonstrates that pneumomediastinum may be associated with air injection injury of the hand, and that expectant management is appropriate.

Adult↗

PubMed2000

Free radicals in chronic fatigue syndrome: cause or effect?

We have demonstrated that certain morphological and biochemical changes occur in chronic fatigue syndrome (CFS) and in rheumatoid arthritis (RA). These changes in RA can be explained by the well-established inappropriate increase in free radical generation. The similar changes in CFS suggest a similar explanation and a possible role for free radicals in the aetiology of this condition.

2,3-Diphosphoglycerate↗

PubMed2000

Blood parameters indicative of oxidative stress are associated with symptom expression in chronic fatigue syndrome.

Full blood counts, ESR, CRP, haematinics and markers for oxidative stress were measured for 33 patients diagnosed with chronic fatigue syndrome (CFS) and 27 age and sex matched controls. All participants also completed symptom questionnaires. CFS patients had increases in malondialdehyde (P <0.006), methaemoglobin (P <0.02), mean erythrocyte volume (P <0.02) and 2,3-diphosphoglycerate (P <0.04) compared with controls. Multiple regression analysis found methaemoglobin to be the principal component that differentiated between CFS patients and control subjects. Methaemoglobin was found to be the major component associated with variation in symptom expression in CFS patients (R(2) = 0.99, P <0.00001), which included fatigue, musculoskeletal symptoms, pain and sleep disturbance. Variation in levels of malondialdehyde and 2,3-diphosphoglycerate were associated with variations in cognitive symptoms and sleep disturbance (R(2) = 0.99, P <0.00001). These data suggest that oxidative stress due to excess free radical formation is a contributor to the pathology of CFS and was associated with symptom presentation.

2,3-Diphosphoglycerate↗

PubMed1998

The role of erythrocytes in the inactivation of free radicals.

We propose that, in addition to its function of gas exchange, the erythron provides a mechanism for the inactivation of reactive oxygen and oxide radicals in vivo. In carrying out this function, individual erythrocytes undergo changes in biochemical and structural properties, which are reflected by shape and functional alterations. The changes indicate damage to the labile components of the red cell and demonstrate the expendable nature of the individual red cell. We propose that a superoxide anion channel allows the transport of superoxide and other free radicals into the red cell, where they are deactivated by the erythrocyte antioxidant system which effectively prevents extensive oxidative damage to tissues.

Erythrocytes↗

PubMed1998

Measurement of the scaphoid humpback deformity using longitudinal computed tomography: intra- and interobserver variability using various measurement techniques.

The intra- and interobserver variability of 3 techniques for measuring the humpback deformity of 37 scaphoids using longitudinal computed tomography was assessed. The 3 measuring techniques were the lateral intrascaphoid angle, the dorsal cortical angle, and the height-to-length ratio. The intraobserver reliability of the intrascaphoid angle was poor; the dorsal cortical angle was moderate to excellent, and the height-to-length ratio was excellent. The interobserver reliability of the intrascaphoid angle was poor to moderate, the dorsal cortical angle was moderate to excellent, and the height-to-length ratio was moderate to excellent. For all 3 observers, the intra- and interobserver reliability was the best for the height-to-length ratio and worst for the intrascaphoid angle. The height-to-length ratio is the most reproducible method of assessing the humpback deformity. Clinical correlation is required to establish whether the height-to-length ratio will be of value in predicting the outcome of fractures of the scaphoid.

Carpal Bones↗

PubMed1998

Load relaxation and forces with activity in Hoffman external fixators: a clinical study in patients with Colles' fractures.

A small-frame Hoffman external fixation bar instrumented with strain gauges to quantify bending and torsional forces was applied to 4 patients with a displaced metaphyseal fracture of the distal radius. Measurements were taken during surgery as well as at 1, 3, and 6 weeks after surgery during activities of daily living and hand therapy mobilization. Radiographs also were taken before and after reduction and at each subsequent visit. Force decay occurred after reduction of the fracture, averaging only 26% of the initial distraction forces by 5 minutes. These forces plateaued and did not significantly change over the subsequent 40-minute observation period. There was no correlation between carpal height index and the forces measured in the external fixator. Significant changes in external fixator forces were measured during activities of daily living and hand therapy mobilization, but these returned to baseline after the activities were performed. The most provocative activities studied were twisting a doorknob and lifting heavy objects. These activities should be performed with caution by patients with unstable distal radial fractures.

Activities of Daily Living↗

PubMed1998

Erythrocyte antioxidant systems protect cultured endothelial cells against oxidant damage.

A study was undertaken to assess the ability of the erythrocyte to protect other tissues against oxidative damage. Radiolabelled (51Cr) human umbilical vein endothelial cells (HUVEC) were incubated with erythrocytes and neutrophils activated with phorbol myristate acetate (PMA). Damage to the endothelial cells was indicated by release of radioactivity into the suspending medium. We found that the co-incubation of HUVEC with an increasing range of erythrocyte concentrations resulted in a dose-dependent reduction in the release of radioactivity. When the ability of superoxide to cross the erythrocyte membrane or the glutathione systems was inhibited, the extent of endothelial cell damage increased. Inhibition of the catalase system did not affect results. It was concluded that the erythrocytes afforded some protection against oxidative damage to the endothelial cells by taking up and deactivating the superoxide ions. This protection depends upon intact erythrocyte antioxidant systems. These data support the hypothesis that erythrocytes can provide antioxidant protection to other tissues in vivo.

4-Acetamido-4'-isothiocyanatostilbene-2,2'-disulfo↗

PubMed1998

Transmetacarpal intramedullary K-wire fixation of proximal phalangeal fractures.

The management of unstable phalangeal fractures has been associated with significant morbidity. Percutaneous transmetacarpal intramedullary Kirschner wire fixation of proximal phalangeal fractures has been described as a useful technique. We present a retrospective review of 35 digits in 24 patients with unstable fractures of the proximal phalanx treated using this technique between 1985 and 1995. Outcome measures, including radiological adequacy of reduction, total active range of motion, development of joint contracture, grip strength, and digital grip strength, were assessed. Good or excellent results were obtained in 76% of fractures (19 of 25) that were treated and followed. Thirty-two percent of digits (8 of 25) treated developed a proximal interphalangeal joint flexion contracture. Flexion contracture averaged 18.1 deg at the involved joints. Seven secondary procedures were required in 6 patients. Major complications noted during the study included loss of reduction with rotational deformity in four digits, and one nonunion. The use of skeletal traction devices was associated with three of the major complications observed. These devices should not be used concurrently on or adjacent to any digit treated by intramedullary pinning. We conclude that transmetacarpal axial Kirschner wire fixation is a technically simple method of treating unstable proximal phalangeal fractures, and good or excellent results can be obtained in the majority of appropriately selected patients.

Adolescent↗

PubMed1997

Arthroscopic diagnosis of intra-articular soft tissue injuries associated with distal radial fractures.

Arthroscopy was used to assess the soft tissue injuries associated with distal radial fractures in 118 acute intra- and extra-articular fractures. The triangular fibrocartilage complex (TFCC) was torn in 46 of 118 patients--in 35% of intra-articular fractures and in 53% of extra-articular fractures. No correlation between ulnar styloid fractures and TFCC injuries could be found. Scapholunate (SL) ligament injuries with instability were present in 21.5% of intra-articular fractures and in 6.7% of extra-articular fractures. Lunotriquetral (LT) ligament injuries with instability were present in 6.7% of intra-articular fractures. and in 13.3% of extra-articular fractures. Combined SL and LT injuries were present in 5.6% of intra-articular fracture. Preoperative radiographs correlated with TFCC injury. Patients with TFCC tears had greater shortening and dorsal angulation on the preoperative radiographs. Preoperative radiographs had no predictive value for interosseous ligament injury. Ligamentous injuries are commonly associated with both intra-articular and extra-articular distal radial fractures.

Adolescent↗

PubMed1997

Abnormalities of the hook of the hamate in patients with carpal tunnel syndrome.

The hook of the hamate is an important landmark in endoscopic carpal tunnel release. We studied the incidence of abnormalities of the hook of the hamate in patients with carpal tunnel syndrome. One hundred thirty-one consecutive patients presenting with carpal tunnel syndrome underwent carpal tunnel radiography. Abnormalities of the hook of the hamate were present in 6 of 131 patients (4.6%). The hook of the hamate was aplastic in 3 of 131 patients (2.3%). A bipartite hook of the hamate was present in 1 patient (0.8%). A nonunion of an old fracture of the hook of the hamate was found in two patients (1.6%). The previously reported incidence of an aplastic hook of the hamate in the general population is 1 of 1,452 (0.06%). The odds ratio revealed a 34-fold increase in the risk of hamate abnormalities in the carpal tunnel population (p < 0.001). Hook of the hamate abnormalities may be more common than previously reported.

Adolescent↗

PubMed1997

Giant cell tumor of the proximal phalanx: a case report.

We report a 45-year-old man who presented with a 3-month history of pain and swelling in the proximal phalanx of the right fifth finger. After biopsy and pathological examination the lesion was found to be an aggressive (Enneking's stage 3) giant cell tumor of the proximal phalanx. Due to the high rate of recurrence of stage 3 giant cell tumors in the hand after en bloc resection, it was decided to amputate the right little finger through the metacarpo-phalangeal joint. After a 3-year follow-up of the patient there have been no recurrences or metastases.

Amputation, Surgical↗

PubMed1997

Clenched-fist injury complicated by methicillin-resistant Staphylococcus aureus.

Hand infections are a common sequela of clenched-fist injuries. The majority of these infections are due to Staphylococcus and Streptococcus species. Methicillin-resistant Staphylococcus aureus (MRSA) is increasingly being isolated in Canadian health care facilities. In addition, MRSA now needs to be considered in community acquired hand infections that fail to respond to common empiric therapy. A 51-year-old man with MRSA due to a hand injury was treated successfully with vancomycin. The prevalence, mechanism of resistance and treatment of MRSA are briefly reviewed.

Cellulitis↗

PubMed1995

Longitudinal computed tomography of the scaphoid: a new technique.

Computed tomography is increasingly utilized for the evaluation of scaphoid fracture, nonunion, and deformity. We have developed a new technique of positioning patients while performing longitudinal computed tomography of the scaphoid. With the wrist positioned in radial deviation and neutral flexion, greater patient comfort is provided and immobilization of the wrist is not required. A reproducible image can be obtained with attention to the alignment of the scanning plane to the longitudinal axis of the scaphoid on the scout image, and verified with the "target sign". High resolution images, which clearly demonstrate the abnormalities of the scaphoid, can be produced even if the patient has a cast on the wrist or if there is hardware in situ.

Carpal Bones↗