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Biomedical subjects

B F Morrey

Publications and source records attributed to B F Morrey.

At least 109 records · Page 6Linked to original sources
PubMed1995

Use of distraction arthroplasty in unstable fracture dislocations of the elbow.

Patients with persistent instability after experiencing posterior dislocation of the ulnohumeral joint associated with large unstable fractures of the coronoid process of the ulna can be challenging to manage. To date, no reports have documented an effective treatment program for this injury. Joint stiffness or persistent instability results in most cases. Seven patients are discussed who were treated with a joint distraction device. Six (86%) of the 7 patients had successful outcomes at a minimum followup of 2 years. The mean arc of flexion before surgery was 33 degrees; after surgery, the arc increased to 88 degrees. The joint distraction device provides immobilization of periarticular fractures and simultaneously allows for joint movement, which results in a stable and mobile joint. Without this device, a 20% satisfactory result for this injury was reported; this percentage improved to 86% by rendering the joint stable with adequate motion.

Adult↗
PubMed1995

Morphology of the torn rotator cuff.

The morphological characteristics of shoulders with torn rotator cuffs were determined using 41 embalmed specimens. The following parameters were measured in the supraspinatus (SSP), infraspinatus (ISP) and subscapularis (SSC) muscles: the length, thickness and width of the extramuscular tendon; the length of the intramuscular tendon; the length and width of a tear, if present, muscle fibre length; and muscle volume. The cross-sectional area (CSA) of the tendon was measured on the photographic image of slices of the tendon using an image analysis system, and the CSA of the muscle was calculated by dividing the muscle volume by muscle fibre length. The rotator cuff was intact in 11 shoulders. A partial-thickness tear of the cuff was present in 12 shoulders, a full-thickness tear of the SSP in 11 shoulders, and a full-thickness tear of more than 2 tendons in 7. Overall incidence of full-thickness tears of the rotator cuff was 44%, and that of partial-thickness tears 29%. With increase of tear size, the functional tendon length (extramuscular tendon length plus tear length) increased by a statistically significant amount in the SSP, ISP and SSC, whereas muscle fibre length decreased in SSP and ISP. It is concluded that the increased functional tendon length and decreased muscle fibre length are the main morphological changes that make the rotator cuff a physiologically abnormal unit. Surgical repair of the torn cuff would be expected to improve these anatomical changes and restore the kinetics of the glenohumeral joint.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1995

Semiconstrained elbow replacement for distal humeral nonunion.

We have reviewed 36 of 39 consecutive patients with an average age of 68 years who had semiconstrained elbow replacement for distal humeral nonunion at an average follow-up of 50.4 months (24 to 127). Of these, 31 (86%) had satisfactory results, three (8%) had fair, and two (6%) had poor results; 32 patients (88%) had moderate or severe pain before and 91% had no or only mild discomfort after the procedure. Motion had improved from a mean arc of 29 degrees to 103 degrees before operation to 16 degrees to 127 degrees after surgery. All five flail extremities were stable at last assessment. There were seven complications (18%): two patients had deep infection, two had particulate synovitis, two had ulnar neuropathy and one had worn polyethylene bushes. Five of these seven, excluding the two with transient nueropathy, required reoperation (13%). Joint replacement arthroplasty can be a safe and reliable treatment for this difficult clinical condition, seen most commonly in elderly patients. This is a significant advance, since repeated osteosynthesis has been shown to be ineffective in most patients.

Activities of Daily Living↗
PubMed1994

Malrotation of the humeral component of the capitellocondylar total elbow replacement is not the sole cause of dislocation.

Malrotation of the humeral component of the capitellocondylar total elbow replacement is thought but not proved to be one of the major causes of postoperative dislocation. The purpose of this study was to quantitate the effect of malrotation of the humeral component on the kinematics and laxity of the capitellocondylar total elbow prosthesis. Eleven fresh previously frozen elbows were used. With the humeral component in optimal position, external rotation, or internal rotation, movements of the elbow with neutral, valgus, and varus loading were monitored with an electromagnetic tracking device. When the humeral component was positioned in external rotation, the ulna was more valgus and supinated than when the component was in optimal position, and when the component was in internal rotation the ulna was more valgus in extension and more supinated in flexion. Malrotation in external rotation decreased valgus-varus laxity, and malrotation in internal rotation increased rotational laxity. Only one elbow became dislocated, despite constant severe maltracking between the components in all of the specimens. We concluded that although malrotation of the humeral component influences the laxity and causes maltracking, it is not the primary cause of postoperative dislocation. The contribution of other factors should be investigated.

Aged↗
PubMed1994

Motion and laxity of the capitellocondylar total elbow prosthesis.

The motion and laxity of the capitellocondylar unconstrained total elbow prosthesis were assessed, with use of an electromagnetic tracking device and stimulated muscle-loading, after implantation in seventeen cadaveric elbows. The axis of motion of the elbows with the capitellocondylar implants averaged 2.1 +/- 2.3 degrees more varus angulation than that of the intact elbows. This difference may be attributed to the design of the implant, as the 5-degree-valgus humeral component used in this study has a smaller valgus inclination than the articular surface of the distal aspect of the humerus. Although the maximum valgus-varus laxity of the capitellocondylar elbow prostheses was, on the average, 4.3 +/- 2.4 degrees greater than normal (with simulated muscle-loading), the data must be interpreted in light of the fact that this in vitro study did not allow for soft-tissue healing. The prosthetic components tracked well, and there were no dislocations or malarticulations provided that appropriate soft-tissue tensioning and positioning of the components had been achieved at the time of implantation. Sectioning of either the medial or the lateral collateral ligament resulted in gross instability of the joint after capitellocondylar arthroplasty. The ulnar attachment of the medial collateral ligament was found to be vulnerable to injury during the positioning of the ulnar component of this implant.

Aged↗
PubMed1994

Treatment of nonunion of olecranon fractures.

We report the results in 24 consecutive patients treated from 1976 to 1991 for nonunion of olecranon fractures. Their mean age was 42 years, and the mean interval from fracture to treatment for nonunion was 19 months. Management was by rehabilitation and activity as tolerated for three, continued immobilisation for one, and operative treatment for 20. Operations included excision of the olecranon fragment (1), osteosynthesis (16), and joint replacement (3). Four patients also had distraction arthroplasty. At a mean follow-up of 18 months no patient had severe residual elbow pain but three had moderate and six had mild symptoms. The mean arc of motion was 98 degrees representing an average improvement of 11 degrees. Twelve patients had an excellent result, four good, six fair, and two a poor result. Union had been achieved in 15 of the 16 patients treated by osteosynthesis.

Adolescent↗
PubMed1994

Dynamic anterior stabilisers of the shoulder with the arm in abduction.

The stabilising effects on the glenohumeral joint of each of the rotator-cuff muscles and of the biceps were studied with the arm in abduction and external rotation in 13 cadaver shoulders. The muscles were loaded one at a time with forces proportional to their cross-sectional areas. We recorded the positions of the humeral head before and after the application to the humerus of an anterior force of 1.5 kg. When the capsule was intact, the anterior displacement with the subscapularis loaded was significantly larger than with the other muscles loaded (p = 0.0009). With the capsule vented, the displacement with the biceps loaded was significantly smaller than that with the subscapularis loaded (p = 0.0052). After creating an imitation Bankart lesion, the displacement with the biceps loaded was significantly less than with any of the rotator-cuff muscles loaded (p = 0.0132). We conclude that in the intact shoulder, the subscapularis is the least important anterior stabiliser, and that the biceps becomes more important than the rotator-cuff muscles as stability from the capsuloligamentous structure decreases. Strengthening of the biceps as well as the rotator-cuff muscles should be part of the rehabilitation programme for anterior shoulder instability.

Adult↗
PubMed1994

Inflammatory arthritis after failure of silicone rubber replacement of the radial head.

The management of radial head fractures complicated by ligamentous disruption remains a matter of controversy. The use of a silicone radial head implant to provide temporary stability is thought to help to protect the ligaments during healing. The reported complications of long-term implantation of a silicone replacement include fracture, dislocation, synovitis, lymphadenitis and subchondral resorption. We now report one case in which an inflammatory process resulted in generalised cartilage degeneration. This has not previously been noted.

Arthritis↗
PubMed1993

Orthopedics.

Explore the source record for details and available documents.

Arthroplasty↗
PubMed1993

Hand position affects elbow joint load during push-up exercise.

Electromagnetic motion sensors and a piezoelectric force plate were used to record simultaneously upper-extremity motion and forces in nine healthy male subjects during push-ups in six different hand positions. The intersegmental loading pattern on the elbow joint during a push-up exercise was investigated. The importance of hand position on these loads was examined. Peak forces exerted on the elbow joint along the forearm axis averaged 45% of the body weight for the 'normal' hand position and were significantly decreased if hands were positioned either 'apart' or 'superior' from 'normal'. The peak torque in the 'normal' position tended to produce elbow flexion and was 2305.9 N cm, or 56% of the maximal isometric extensor torque, which was significantly different from hands 'apart' and hand 'together' at 29 and 71% of the maximal isometric torque, respectively. The maximum torque about the forearm axis tended to produce forearm pronation with a mean value of 315.4 N cm (35% of the maximal isometric supinator torque). The maximum valgus torque at the elbow opposed by the medial ligamentous structure was 1241 N cm and was significantly increased if the hand was positioned superiorly. The valgus torque increased by 42% for the one-handed push-up under simulated fall condition. The results of this analysis give an insight into the biomechanics of a normal elbow and to its load-carrying capacity. The data may be extrapolated to the design of rehabilitation programs and possibly to the mechanisms of forearm injury during a fall.

Adult↗
PubMed1993

Relationship of hemoglobin level and duration of hospitalization after total hip arthroplasty: implications for the transfusion target.

We analyzed the relationship of hemoglobin level and duration of hospitalization of patients who underwent primary cemented total hip arthroplasty for degenerative joint disease at our institution. Retrospectively, we reviewed the medical records of 332 patients treated during a 16-month period (May 6, 1989, to Aug. 20, 1990). The following variables were analyzed: number of postoperative days to dismissal from the hospital, level of hemoglobin preoperatively and at dismissal, decrease in hemoglobin level from preoperatively to time of dismissal, patient age, surgeon, and blood products transfused. No correlation was found between level of hemoglobin at dismissal, preoperative hemoglobin level, or decrease in hemoglobin concentration from preoperatively to time of dismissal and number of days to dismissal from the hospital. Advanced age was associated with a longer hospital stay. A slight but statistically significant difference was noted in duration of hospitalization among patients operated on by different surgeons. Patients who received both autologous and homologous blood required more transfusion (3.8 units) and had a longer hospital stay (10.7 days) than did patients who received autologous blood only (2.4 units and 9.5 days) or homologous blood only (2.6 units and 10.2 days). We conclude that variation in hemoglobin levels among patients in our study was unrelated to duration of hospitalization. This finding suggests that transfusion of autologous or homologous blood to achieve a higher hemoglobin level (higher transfusion target) solely for shortening hospital stay is unwarranted.

Age Factors↗
PubMed1993

Intraarticular pressure of the shoulder.

Nine fresh frozen cadaveric shoulders were used to examine the changes in intraarticular pressure (IAP) of the shoulder joint and the position of the humeral head under various loads to determine the relationship between these parameters. All the soft tissues superficial to the rotator cuff were removed. The position of the humerus relative to the scapula was monitored using an electromagnetic tracking system before and after venting the capsule with 0, 0.5, and 1.0 kg of load applied to the humerus inferiorly in addition to the weight of the arm. Simultaneously, the IAP was monitored using a pressure transducer before venting the capsule. Venting had a significant effect on the position of the humeral head: the positions of the head after venting were significantly lowered in all loading conditions. The average IAP was -76 cm H2O without load, and the value decreased in a linear fashion with increased load; the correlations were significant in four of six shoulders without dislocation. The correlations were less significant between the pressure and the position, and there were no significant correlations between the load and the position. IAP, which is determined primarily by the load applied, is important to stabilize the shoulder inferiorly. Because IAP is intimately related to the external load and the response is specific to individuals, examination of IAP response to external load may be helpful in characterizing various instabilities of the shoulder.

Cadaver↗
PubMed1993

The natural history of the silent hip in bilateral atraumatic osteonecrosis.

The natural history of presymptomatic ischemic necrosis of the femoral head was studied in the contralateral hip of 15 patients undergoing total hip arthroplasty for avascular necrosis between 1979 and 1984. These 15 hips were retrieved from among 416 patients undergoing total arthroplasty during this time period. Presymptomatic avascular necrosis was defined according to three strict criteria that allowed the hips to be studied from an index entry point (no evidence of avascular necrosis). Follow-up examinations of each of these 15 hips from this entry point revealed that all hips eventually collapsed at a mean of 23 months after index entry point (range, 3-66 months). These data indicate that the "silent hip" is at significant risk of developing avascular necrosis and, if it becomes involved, it progresses to collapse in a high percentage of patients in a relatively short time. There was no correlation between underlying etiology and the time to collapse.

Adult↗
PubMed1993

In vitro stability of an unconstrained total elbow prosthesis. Influence of axial loading and joint flexion angle.

Total elbow arthroplasty is often used to replace elbow joints that have been severely damaged by arthritis or trauma. A great disparity of designs exists, however, in currently available elbow prostheses. This study evaluated the intrinsic stability of one popular resurfacing implant, the Capitellocondylar (Johnson and Johnson Orthopaedics, Inc., New Brunswick, NJ) total elbow. The in vitro response of this unconstrained prosthesis to valgus-varus and supination-pronation loading was investigated using a materials testing machine. The influence of compressive loading and flexion angle on the intrinsic stability of the prosthesis was studied. The Capitellocondylar prosthesis was found to have little intrinsic constraint, relying on external forces for component stabilization. Dislocations were common at 111 N of compressive loading, while larger loads progressively stabilized the prosthesis. Joint flexion angle had little influence on the intrinsic constraint of the implant except to increase varus stability at lower flexion angles. The Capitellocondylar total elbow prosthesis, as designed by F. C. Ewald, behaves as an unconstrained implant. Adequate soft tissue supports, which are properly balanced to provide controlled loading, are essential to prevent instability of this arthroplasty.

Biomechanical Phenomena↗
PubMed1993

Fate of ultrahigh molecular weight polyethylene (UHMW-PE) wear debris in patients with hip implants.

The process of ultrahigh molecular weight polyethylene (UHMW-PE) breakdown, started at the articular surface of the cup, continues in small fragments after generation. An assiduous interaction between the UHMW-PE particles and the host cells leads to oxidative changes of the UHMW-PE and to size reduction of the particles simultaneous with transporting them toward, and finally by, lymphatic or blood vessels. The particles are mobilized by means of enzymatic, extracellular matrix-degrading activity of cells that have phagocytosed them or adhered to them. Together, these characteristics indicate an attempt by the natural cellular immunity system to eliminate the implant wear debris. Macrophages are the main effector cells acting as scavengers; however, excessive amount of the wear debris evokes phagocytic activity of cells other than macrophages as well.

Alloys↗