Biomedical subjects

F A Matsen

Publications and source records attributed to F A Matsen.

At least 19 recordsLinked to original sources

PubMed2001

Observations on retrieved polyethylene glenoid components.

It is recognized that retrieved polyethylene hip and knee components may undergo substantial changes from their preimplantation form. Little information is available, however, regarding retrieved polyethylene glenoid components. We report on 39 glenoid components removed at an average of 2.5 years after implantation. Of components for which clinical data were available, the commonest reason for the revision arthroplasty was loosening of the glenoid component; many components also showed glenohumeral instability. The articular surface contours of most of the components were altered. Of components, 28 had obvious erosion of the rim, 27 had surface irregularities, 11 were fractured, and 9 had central wear. These observations in retrieved glenoid components point to the potential of polyethylene for deformation in vivo, especially when the mechanics of the arthroplasty are compromised.

Equipment Failure Analysis↗

PubMed2001

Outcome of nonoperative management of full-thickness rotator cuff tears.

The study documented the functional outcome in a consecutive series of 46 patients from an individual practice meeting the inclusion criteria of (1) a full-thickness rotator cuff tear seen by ultrasonography, arthrogram, or magnetic resonance imaging, (2) absence of a Workers' Compensation claim or previous surgery, (3) followup of at least 1 year, and (4) election of nonoperative management by the patient. Twenty-six of the tears involved only the supraspinatus, two involved the supraspinatus and infraspinatus, and two involved the supraspinatus, infraspinatus, and subscapularis (16 reports did not specify the size of the tear). Treatment consisted only of patient education and a home program of gentle stretching and strengthening. Patients completed the Simple Shoulder Test at the initial visit and sequentially at 6-month intervals thereafter. At an average followup of 2.5+/-1.6 years, 27 (59%) patients experienced improvement with nonoperative treatment, 14 (30%) patients experienced worsening, and five (11%) patients remained unchanged. The average number of Simple Shoulder Test functions the patients could perform initially was 5.6+/-3.2. At the latest followup, the average number of Simple Shoulder Test functions the patients could perform improved to 7.0 +/-3.8. The ability to sleep on the affected side and the ability to place the hand behind the head were significantly improved.

Aged↗

PubMed2001

Improvement in comfort and function after cuff repair without acromioplasty.

The repair of full thickness rotator cuff tears traditionally has included acromioplasty and coracoacromial ligament section. Acromioplasty can be complicated by deltoid detachment, compromise of the deltoid lever arm, anterosuperior instability, and adhesions of the rotator cuff tendons under the bleeding cancellous bone of the osteotomized acromion. This report concerns the improvement in shoulder function at a minimum of 2 years after 27 full thickness rotator cuff repairs were done without deltoid detachment, acromioplasty, or section of the coracoacromial ligament. The mean number of Simple Shoulder Test functions that the patients could do increased from six of 12 before surgery to 10 of 12 at an average followup of 4 years after surgery. Eight of 12 individual Simple Shoulder Test functions were significantly improved after the procedure. There also was a significant improvement in the Short Form-36 comfort, physical role function, and mental health scores. When done without acromioplasty, cuff repair avoids the possibility of deltoid detachment, altered deltoid mechanics, anterosuperior instability, and tendon scarring to the cancellous undersurface of the acromion.

Female↗

PubMed2000

Challenges in evaluating patients lost to follow-up in clinical studies of rotator cuff tears.

BACKGROUND: Long-term follow-up studies are necessary to critically evaluate the outcome of a treatment intervention for a specific disorder. However, patients may cease participating in a long-term study and become lost to follow-up; thus, their current condition is unknown. The underlying characteristics that predispose a patient to become lost to follow-up are difficult to identify and control. Patients who are lost to follow-up may be contacted by telephone; however, the effect of administering a functional assessment questionnaire by telephone compared with that of mailing a questionnaire is unknown. The purpose of this study was to compare patients who continued to respond to requests for follow-up with those who did not. A second purpose was to compare responses obtained by mail with those obtained by telephone interview. METHODS: Two hundred and twenty-four patients with a rotator cuff tear were enrolled in an ongoing study of shoulder function and general health. Self-assessment questionnaires were mailed to every patient at six-month intervals. Sixty-seven patients (30 percent) regularly responded to mailings (identified as responders in this study), fifty-five patients (25 percent) responded occasionally (these patients were not included in the analysis), and 102 patients (46 percent) ceased to respond and became lost to follow-up (identified as nonresponders in this study). This investigation was performed to determine: (1) the characteristics of nonresponders compared with those of responders, (2) the functional status of nonresponders as assessed with a questionnaire over the telephone, and (3) the effect of administering a self-assessment functional questionnaire by telephone compared with that of sending the same questionnaire by mail. RESULTS: Nonresponders tended to have lower initial scores for the mental health summary (p = 0.03) and for social function (p = 0.01), were less likely to have had surgery (p = 0.009), and were less likely to consume alcohol (p = 0.03). At the last known time when they completed the mailed questionnaire, nonresponders reported significantly worse shoulder function than responders (p = 0.0001). However, on telephone questioning the mean number of shoulder functions that the nonresponders indicated that they could perform was greater than the mean number documented on their last mailed questionnaire (p < 0.0001). In a random subgroup of responders, the mean number of functions that the patients indicated that they could perform when interviewed by telephone was significantly greater than the number indicated on their most recent mailed questionnaire (p < 0.01). The results obtained by telephone from this random subgroup of responders were similar to those obtained by telephone from the nonresponders. CONCLUSIONS: There are differences between patients who continue to participate in a study and those who become lost to follow-up. Functional assessment questionnaires administered by telephone yield different results than the same questionnaires sent by mail. These considerations are relevant to the design, implementation, and interpretation of clinical studies in which functional questionnaires are used.

Female↗

PubMed2000

Correlations with patients' perspectives of the result of lower-extremity amputation.

BACKGROUND: Patients' perceptions of the result of lower-extremity amputation vary widely, yet the factors associated with this variability are not well understood. Our objective was to identify important correlations with the perceived result that may help to indicate the factors that deserve particular emphasis in the management of patients who have had an amputation. METHODS: In this retrospective study, 148 patients who had had a major lower-extremity amputation completed a standardized questionnaire designed to assess the demographic characteristics, comorbidities, amputation characteristics, prosthetic function, and social function at a mean of seven years after surgery. We correlated each of these variables with four result metrics: general satisfaction, quality of life, freedom from frustration, and walking distance. RESULTS: The four result metrics were significantly and strongly correlated with (1) the comfort of the residual limb; (2) the condition of the contralateral limb; (3) the comfort, function, and appearance of the prosthesis; (4) social factors; and (5) the ability to exercise recreationally (p < 0.0001). Interestingly, the level and laterality of the amputation were not significantly correlated with the patients' perceived result. CONCLUSIONS: The perceived result of amputation is not associated with the amount of the limb that was amputated but rather with factors that may be optimized by surgical, prosthetic, and social management.

Amputation, Surgical↗

PubMed1999

Reexpression of type IIA procollagen by adult articular chondrocytes in osteoarthritic cartilage.

OBJECTIVE: To test for the reexpression of the chondroprogenitor splice variant of the gene COL2A1, type IIA procollagen (containing a cysteine-rich NH2 propeptide), in adult articular chondrocytes in osteoarthritic (OA) joint disease. METHODS: In situ hybridization and immunohistochemical localization were performed on normal and OA articular cartilage specimens. The presence of type IIA procollagen messenger RNA (mRNA) expression was confirmed by Northern blot analysis. RESULTS: In normal articular cartilage, no expression of mRNA or presence of type IIA procollagen was found. In OA articular cartilage, focally intense staining for type IIA protein was detected. Consistent with this, chondrocytes, particularly in the middle zones of articular cartilage, expressed type IIA procollagen mRNA. OA repair cartilage typically showed a broad zone of cells expressing type IIA mRNA and protein. CONCLUSION: Type IIA procollagen is reexpressed by adult articular chondrocytes in OA cartilage degeneration, indicating the potential reversion of the cells to a chondroprogenitor cellular phenotype. The absence of type IIA mRNA and protein in normal adult articular cartilage and its onset in the diseased state suggests type IIA procollagen as a marker of OA.

Adult↗

PubMed1999

The lateral impaction of the shoulder.

17 patients had radiographic demonstration of injury to the clavicle, scapula and ribs from an impact delivered to the lateral shoulder. The study included 13 males and 4 females whose ages ranged from 18 to 83 years (average 45 years). Most injuries were sustained in falls or motor vehicle accidents. Analysis of these cases suggests a biomechanical hypothesis concerning the transmission of the impact forces within the shoulder girdle. According to this hypothesis, the impaction force applied to the lateral shoulder is transmitted from outside inward following two paths. The anterior and superior path passes through the acromio-clavicular joint, the clavicle, the costo-clavicular joint and the sterno-clavicular joint. The posterior and inferior path is transmitted within the gleno-humeral joint, the scapula and the scapulo-thoracic joint. Major impacting force is required to disrupt the anterior and posterior arches of the shoulder girdle. When both of these supporting structures are damaged, the patient is at risk for more serious injuries, including disruption of the thorax, shoulder joint, brachial plexus and neck.

Accidental Falls↗

PubMed1999

Monitoring for compartmental syndrome using near-infrared spectroscopy: a noninvasive, continuous, transcutaneous monitoring technique.

BACKGROUND: The diagnosis of compartmental syndrome (CS) may be delayed because current monitoring techniques are invasive and intermittent and the compartment pressure (CP) that predicts ischemia is variable. Fiber-optic devices using near-infrared (NIR) wavelength reflection can determine the redox state of light-absorbing molecules and have been used to monitor venous hemoglobin saturation to detect ischemia during low-flow states. The purpose of this study was to determine if NIR spectroscopy can provide continuous, transcutaneous, noninvasive monitoring for muscle ischemia in an animal model of CS. METHODS: Nine swine were anesthetized and a 20-mm NIR probe was placed over the anterolateral compartment of the hind leg to provide continuous determination of muscle oxyhemoglobin level. Needles were inserted into the compartment to measure CP. A nerve stimulator was placed over the peroneal nerve to induce dorsiflexion twitch. Albumin was infused into the muscle to incrementally increase CP until there was complete loss of dorsiflexion, then after 20 minutes fasciotomy was performed. RESULTS: All animals lost dorsiflexion at CP of 43+/-14 mm Hg. There was a significant inverse correlation between CP and oxyhemoglobin level (r = -0.78; p < 0.001) and a correlation between oxyhemoglobin and perfusion pressure (mean arterial pressure minus CP) (r = 0.66; p < 0.001). Redox state was a more consistent predictor of twitch loss than perfusion pressure. CONCLUSION: Muscle oxyhemoglobin level measured by NIR spectroscopy strongly reflected CP, perfusion pressure, and loss of dorsiflexion twitch. Currently available portable NIR devices may provide the benefit of continuous, noninvasive monitoring for CS. Further studies to determine the role of this technology in the detection of compartmental syndrome are warranted.

Animals↗

PubMed1998

Total shoulder arthroplasty versus hemiarthroplasty. Current trends.

Currently, a debate exists regarding the indications for hemiarthroplasty and total shoulder arthroplasty. A number of factors are important in making this decision. The article discusses some of the variables related to choosing the appropriate procedure for every patient. The authors also discuss their approach to various arthritic conditions of the shoulder, the rationale behind their approach, and their results. Future work will be necessary before more definitive recommendations can be made, and they may well be different for each individual surgeon.

Arthritis↗

PubMed1998

The correlation of comorbidity with function of the shoulder and health status of patients who have glenohumeral degenerative joint disease.

We studied the effect of comorbidities on function of the shoulder and health status in a group of eighty-five consecutive patients who had glenohumeral degenerative joint disease of sufficient severity to meet one surgeon's criteria for the performance of shoulder arthroplasty. A questionnaire was used to identify the comorbidities, such as other diseases, social factors, or a work-related injury, for each patient. The number of functions on the Simple Shoulder Test that the patient could perform had a significant negative correlation with the number of comorbidities (r = -0.32, intercept = 4.6 per cent, slope = -0.6, and p = 0.0031). Each parameter on the Short Form-36 (except for physical role function) had a significant negative correlation with the number of comorbidities (p < 0.05). This negative relationship was strongest for general health perception (r = -0.42) and vitality (r = -0.35). We concluded that the number of comorbidities has a quantitative effect on function of the shoulder. In the evaluation of the functional status of patients and the effectiveness of treatment, the effects of comorbidity must be controlled. The results of the present study demonstrate that the scores on the Short Form-36 are quantitatively related to the number of comorbidities. The six parameters that are unrelated to function of the shoulder (physical function, social function, emotional role function, mental health, vitality, and general health perception) may provide a practical way to integrate the effects of all potential comorbidities on individual patients. Future clinical research will be strengthened by efforts to measure the impact of comorbidities and by strategies to control for their effects.

Adult↗

PubMed1998

The humeroscapular motion interface.

Motion between the humerus and scapula commonly is described as glenohumeral motion. However, humeroscapular motion occurs at two distinct sites. In addition to the motion at the diarthrodial glenohumeral joint, movement occurs between the proximal humerus and related structures and the surrounding sleeve of structures, including the acromion, deltoid, coracoid, coracoacromial ligament, and the muscles attached to the coracoid. This site of nonarticular shoulder motion is defined as the humeroscapular motion interface. Nonarticular humeroscapular motion can be documented and measured using standard magnetic resonance imaging techniques. The maximum average interfacial motion using axial images was 29.1 mm, which occurred at the level of the maximum diameter of the humeral head. Interfacial motion varied depending on the site measured. If pathologic conditions such as adhesions secondary to trauma or surgery interfere with or obliterate this space at sites of significant sliding motion, overall shoulder motion will be limited. Successful treatment of shoulder stiffness related to humeroscapular restraints is likely to require restoration of the normal sliding motion at the humeroscapular motion interface, in addition to resolving restraints affecting the glenohumeral joint motion.

Adult↗

PubMed1997

A comparison of patients with late-stage rheumatoid arthritis and osteoarthritis of the shoulder using self-assessed shoulder function and health status.

OBJECTIVE: To compare the function and health status of individuals with advanced rheumatoid arthritis (RA) and osteoarthritis (OA) of the shoulder using standardized patient self-assessment tools. METHODS: A group of patients with late-stage arthritic involvement of the shoulder was evaluated at the time of initial presentation using 2 questionnaires, one focusing on shoulder function and other on overall health status. RESULTS: There was substantial variability in the shoulder function and health status within each diagnostic group; however, both groups demonstrated significant deficits in their Simple Shoulder Test responses and in many of their Health Status Questionnaire-Short Form 36 scores. While the patients with RA tended to have somewhat greater impairment of shoulder function, many of the differences were not statistically significant. By contrast, most health status parameters were significantly more impaired in the patients with RA. CONCLUSIONS: Among patients with late-stage shoulder arthritis, the overall health status of those with RA is significantly worse than those with OA. Differences in health status may be important in selecting the optimal management for individual patients with late-stage shoulder arthritis. Self-assessment questionnaires are effective in characterizing these differences.

Activities of Daily Living↗

PubMed1997

Arthroscopic management of refractory shoulder stiffness.

Glenohumeral stiffness is a major cause of shoulder disability and pain. Conventional management strategies often fail to yield consistent or prompt return of comfort and function. Over the past 5 years, we have employed a prospective approach to the evaluation and management of glenohumeral stiffness using arthroscopic release of capsular contractures for the most refractory. This report concerns the first 30 patients who failed at least 6 months (28 month mean) of nonoperative management for unilateral refractory shoulder stiffness and who were managed by arthroscopic capsular release. Fourteen patients were diabetic. Follow-up averaged 33 months (range 12 to 56 months). Each patients' motion and strength was documented according to the American Shoulder and Elbow Surgeons standard examination. Functional outcome measures were patient-assessed using the Simple Shoulder test before and after surgery. Before surgery, active range-of-motion of the affected shoulder average 41% of the opposite asymptomatic side. The day after surgery, motion had improved dramatically to a mean of 78%. An additional 15% of motion was gained after discharge from the hospital. The final motion averaged 93% of the opposite side. All Simple Shoulder Test (SST) parameters and six of nine SF-36 health status scores were improved significantly. Only 6% of patients were able to sleep comfortably on their side and 35% could place 1 lb. on a shelf at shoulder height before surgery. After surgery, 73% were able to sleep comfortably on the affected side and 83% were able to place 1 lb. on a shelf at shoulder height. There were no differences among all outcome measures between diabetic or nondiabetic patients. Three patients developed recurrent refractory stiffness. The only complication was a single axillary neuropraxia which resolved spontaneously. No patient developed instability. Arthroscopic capsular release can be a safe and effective tool in the management of refractory shoulder stiffness.

Adult↗

PubMed1996

Effect of a chondral-labral defect on glenoid concavity and glenohumeral stability. A cadaveric model.

One of the primary stabilizing mechanisms of the glenohumeral joint is concavity-compression, the maintenance of the humeral head in the concave glenoid fossa by the compressive force generated by the surrounding muscles. This mechanism is active in all glenohumeral positions but it is particularly important in the functional mid-range, in which the capsule and ligaments are slack. The effectiveness of concavity-compression in the stabilization of a joint can be characterized in terms of the ratio between the maximum dislocating force that can be stabilized in a given direction and the load compressing the head into the glenoid (the stability ratio). Glenoid concavity can be described by the lateral humeral displacement during translation across the glenoid. The purpose of the present investigation was to characterize the concavity and stability ratios of normal cadaveric glenoids, to measure the effect of an anteroinferior chondral-labral defect on these parameters, and to measure the effectiveness of a simulated operative reconstruction on the restoration of glenoid concavity and the stability ratio. The chondral-labral defect created in this study reduced the height of the glenoid by approximately 80 per cent and the stability ratio by approximately 65 per cent for translation in the direction of the defect. Reconstruction of the anteroinferior aspect of the glenoid concavity with use of an autogenous biceps-tendon graft restored normal values for these variables.

Aged↗

PubMed1996

Early effectiveness of shoulder arthroplasty for patients who have primary glenohumeral degenerative joint disease.

Twenty-nine consecutive patients who met strict criteria for a diagnosis of primary glenohumeral degenerative joint disease completed standardized questionnaires regarding general health status as well as function of the shoulder before I performed a total glenohumeral arthroplasty. The patients completed the forms again at an average of ten months after the operation. Comparison of the preoperative and postoperative responses to the questions regarding health status demonstrated highly significant improvement in the patients' assessments of over-all bodily pain (p < 0.0001) and physical function (p < 0.0005) as well as significant improvement in role function (p < 0.05) and the anticipated change in general health status (p < 0.05). Concurrently, comparison of the responses to the questions regarding function of the shoulder indicated highly significant improvement in the ability of the patients to sleep on the side, to tuck in the back of a shirt, to place the hand behind the head, to toss overhand (p < 0.0001 for all), and to place one pound (0.5 kilogram) (p < 0.005) or eight pounds (3.6 kilograms) (p < 0.0001) on a shelf at shoulder level. The comparison also revealed significant (p < 0.05) improvement in the ability of the patients to place a coin on a shelf, to carry twenty pounds (9.1 kilograms) at the side, to wash the back of the contralateral shoulder, and to do their usual work.

Activities of Daily Living↗

PubMed1995

A model for the study of wounds in normal elderly adults and patients with peripheral vascular disease or diabetes mellitus.

The purpose of the study was to test the hypothesis that significant delays in cutaneous wound healing could be demonstrated using standard wounds and high quality histological methods in patients with severe peripheral vascular disease (PVD) and/or diabetes mellitus (DM) compared to healthy elderly controls. Additionally, we proposed that standard wounds on the arms of elderly controls would heal more rapidly than comparable wounds on the legs. In order to test these hypotheses we developed and characterized a partial thickness wound model which could be used safely in human subjects. The study population consisted of 25 elderly normal volunteers, 17 patients with PVD, and 24 patients with DM. Standard wounds were created using a Simplate II bleeding-time device. A total of 309 wounds ranging in age from 1 to 25 days were determined to be suitable for analysis. A global index of wound maturity was developed based on selected epidermal and dermal events of repair which could be scored histologically. The superficial component (within 0.1 mm of the epidermis) and deep components of dermal wounds were analyzed separately. Simultaneously created arm and leg wounds were studied in 15 of the elderly controls. Transcutaneous partial pressure of oxygen (TcPO2) measurements were used to estimate the severity of cutaneous ischemia. Data analysis revealed that the most striking differences observed were in dermal events of repair. Control wounds were more mature than dermal wounds from patients with PVD (P < 0.05). A significant reduction in the number of neutrophils and macrophages (P < 0.05) was demonstrated in 7-day-old wounds of patients with PVD compared to controls. Patients with DM showed a similar trend of reduced wound maturity but it did not reach statistical significance. Wounds created in skin with TcPO2 > 20 were more mature than wounds with TcPO2 < or = 20 (P < 0.05) and arm wounds were more mature than leg wounds (P < 0.01). The most significant difference noted in this wound model was that the superficial compartment of dermal wounds was significantly more mature than the deep compartment (P < 0.001). Good agreement was observed between two independent scorers of wound histology and no complications were noted in either patients or controls when using this human wound model. We conclude that the model described allows evaluation of both epidermal and dermal events of repair with relative safety even in patients with PVD and DM.(ABSTRACT TRUNCATED AT 400 WORDS)

Aged↗

PubMed1995

The effect of articular conformity and the size of the humeral head component on laxity and motion after glenohumeral arthroplasty. A study in cadavera.

We used a cadaveric model to examine the mechanical effects of changes in the conformity of the articular surfaces and the size of the humeral head component in glenohumeral arthroplasty. The experimental system permitted a manual clinical examination of the glenohumeral joint while sensors monitored the humeroscapular position and orientation as well as the forces and torques applied by the examiner. Four preparations were compared: an anatomical humeroscapular preparation and three glenohumeral arthroplasty preparations (one with anatomically sized components and a radius of curvature of the glenoid that was four millimeters larger than that of the humeral head, one with anatomically sized components and a radius of curvature of the glenoid that was equal to that of the humeral head, and one with a non-anatomical, large humeral head component and a radius of curvature of the glenoid that was equal to that of the humeral head). All motions, including flexion, external and internal rotation, and maximum elevation, were diminished with use of the non-anatomical, large humeral head component. Laxity of the joint on drawer and sulcus tests was not affected by the conformity of the articular surfaces but was decreased significantly by implantation of the large humeral head component. The kinematics of the glenohumeral joint were not markedly altered by reduction of the uniformity between the articular surfaces of the prosthetic components. In all preparations, obligate displacement of the humeral head associated with a passive range of motion occurred at smaller angles with the large humeral head component.

Aged↗

PubMed1995

Association of sonographically detected subacromial/subdeltoid bursal effusion and intraarticular fluid with rotator cuff tear.

OBJECTIVE: Although an association between sonographically detected joint fluid and rotator cuff disease has been reported, the significance of sonographically detected subacromial/subdeltoid bursal effusion has not been studied. We examined a group of patients who had shoulder sonography and surgery to determine the association between bursal and joint effusion and surgically proved tears of the rotator cuff. MATERIALS AND METHODS: We retrospectively reviewed the preoperative shoulder sonography reports of 163 patients for the presence of fluid within the subacromial/subdeltoid bursa or glenohumeral joint. Surgical reports were obtained to determine the status of the rotator cuff. The sonographic reports of 232 asymptomatic shoulders were also reviewed to determine the prevalence of fluid within the subacromial/subdeltoid bursa or the glenohumeral joint. RESULTS: Sixty-seven (41%) of the 163 patients had a joint effusion, bursal fluid, or both. Joint effusion alone was seen in 35 patients. Fourteen of these had a normal rotator cuff at surgery, and 21 had a rotator cuff tear (sensitivity, 22%; specificity, 79%; positive predictive value, 60%). Bursal fluid alone was seen in 10 patients, seven of whom had a rotator cuff tear (sensitivity, 7%; specificity, 96%; positive predictive value, 70%). In 22 patients, fluid was seen in both the bursa and the joint; 21 had surgically proved rotator cuff tears (sensitivity, 22%; specificity, 99%; positive predictive value, 95%). Of the 232 asymptomatic shoulders, 16 (6.9%) had isolated joint effusions, eight (3.4%) had isolated bursal effusions, and four (1.7%) had both joint and bursal effusions. CONCLUSION: The sonographic finding of intraarticular fluid alone (without bursal fluid) has both a low sensitivity and a low specificity for the diagnosis of rotator cuff tears. However, the finding of fluid in the subacromial/subdeltoid bursa, especially when combined with a joint effusion, is highly specific and has a high positive predictive value for associated rotator cuff tears. Sonographically detected fluid in both the joint and the bursa is an uncommon finding in asymptomatic shoulders. The sonographic observation of fluid in the subacromial bursa, either isolated or combined with a joint effusion, should prompt a careful evaluation of the supraspinatus tendon for tear.

Acromion↗