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Biomedical subjects

M F Dillingham

Publications and source records attributed to M F Dillingham.

18 recordsLinked to original sources
PubMed2001

Dynamic MR imaging and stress testing in glenohumeral instability: comparison with normal shoulders and clinical/surgical findings.

Our objectives were to test the hypotheses that: 1) during shoulder motion, glenohumeral alignment differs between asymptomatic shoulders and those with symptomatic instability; 2) during magnetic resonance (MR)-monitored physical exam or stress testing, glenohumeral alignment differs between asymptomatic shoulders and those with instability; and 3) glenohumeral translation during MR stress testing correlates with findings of shoulder instability by clinical exam and exam under anesthesia (EUA). Using an open-configuration 0.5 T MR imaging (MRI) system, we studied symptomatic shoulders in 11 subjects and compared them to their contralateral asymptomatic shoulders. Each shoulder was studied during abduction/adduction and internal/external rotation to determine the humeral head position on the glenoid. An examiner also performed the MR stress test on each shoulder by applying manual force on the humeral head during imaging. All shoulders were assigned an instability grade from the MR stress test, and this grade was correlated with: 1) clinical exam grade assigned during preoperative assessment by an orthopedic surgeon and 2) intraoperative instability grade by EUA immediately preceding arthroscopy. With dynamic abduction and internal/external rotation, the humeral head remained centered on the glenoid in 9 of 11 shoulders, but in two subjects there were dramatic demonstrations of subluxation. With stress testing, a trend toward more joint laxity was demonstrated in symptomatic than in asymptomatic joints (P = 0.11). MR grading of instability correlated directly with clinical grading in six cases and underestimated the degree of instability relative to clinical exam in the other cases. MR instability grading systematically underestimated instability compared with EUA in 7 of the 10 cases that underwent surgical repair. We concluded that dynamic MR evaluation of glenohumeral alignment did not demonstrate abnormalities in symptomatic shoulders in 8 of 10 patients, whereas 2 patients showed dramatic findings of subluxation. Manual stress testing during dynamic MR examination showed a strong correlation with clinical instability grading. Dynamic shoulder MR examination during stress testing could, with further validation, become a useful adjunct to shoulder instability evaluations. J. Magn. Reson. Imaging 2001;13:748-756.

Adolescent↗
PubMed2000

MR imaging of cyclops lesions.

OBJECTIVE: Localized anterior fibrosis (cyclops lesion) is a known cause of extension loss of the knee after anterior cruciate ligament (ACL) reconstruction. We describe MR imaging as a noninvasive diagnostic tool to examine cyclops lesions. SUBJECTS AND METHODS: Thirty-three MR studies of 31 patients with residual persistent extension loss after ACL reconstruction using patellar tendon autograft were reviewed and compared with results of second arthroscopy. We used MR imaging to describe the ACL graft signal intensity and course, tibial and femoral tunnel placement. quantitative measurements of notch size and shape, and the presence or absence of cyclops lesions. When a cyclops lesion was revealed on MR imaging, the signal-intensity characteristics, location, and size were documented. Preoperative MR imaging findings were then correlated with findings at arthroscopy. RESULTS: The sensitivity, specificity, and accuracy of revealing a cyclops lesion on MR imaging were 85.0%, 84.6%, and 84.8%, respectively. We found no statistically significant differences in the size of intercondylar notches for patients with and patients without cyclops lesions. CONCLUSION: MR imaging was sensitive, specific, and accurate in revealing cyclops lesions in a subgroup of patients with extension loss after ACL reconstruction.

Adolescent↗
PubMed1999

Arthroscopic treatment of shoulder instability: current concepts and techniques.

The incidence of glenohumeral joint instability is estimated to effect between 2 and 8% of the population. It represents at least one third of all shoulder related emergency room visits. When one considers the spectrum of shoulder instability, including transient subluxation, the true incidence of glenohumeral instability is probably grossly under-reported. Although any age group can be affected, shoulder instability is primarily a disease of the young. The occurrence of instability is inversely proportional to the age of the patient and the time of original injury. A patient who dislocates for the first time as a teen can expect a redislocation rate approaching 90% in his or her lifetime. Therefore, many authors recommend early surgical treatment to repair the lesion.

Journal Article↗
PubMed1996

Treatment of inflammatory arthritis by synovial ablation: a comparison of the holmium: YAG laser, electrocautery, and mechanical ablation in a rabbit model.

BACKGROUND AND OBJECTIVE: Although the majority of patients with immune-mediated inflammatory arthritis are managed conservatively, some patients may require synovectomy if they have persistent pain secondary to chronic unresponsive swelling of a joint. In this study, three methods of synovial ablation using laser energy, electrocautery, and mechanical debridement were compared in an in vivo chronic synovitis rabbit model. STUDY DESIGN/MATERIALS, AND METHODS: In the first phase of this study, the optimal laser energy/pulse frequency combination for synovial ablation in this model was determined. In the study's second phase, 48 mature rabbits were then divided into four equal groups: laser synovectomy, electrocautery synovectomy, mechanical synovectomy, and control. Chronic synovitis was induced in both stifles of all treatment groups and in the right stifle of the control rabbits. Synovectomy was performed on one stifle of each rabbit; the contralateral stifle served as a sham-operated control. Six rabbits per group were euthanized 2 weeks and 3 months after surgery, respectively. RESULTS: There were no differences among groups in synovial fluid parameters, except at 2 weeks, when the electrocautery group had significantly more white blood cells than the laser and mechanical debridement groups. Histologic examination revealed that mechanical debridement resulted in significantly more synovial hemorrhage, capillary dilatation, plasma cell infiltration, lymphocyte infiltration, joint capsular defects, and poorer synovial ablation than ablation achieved with either laser energy or electrocautery. CONCLUSION: Laser energy and electrocautery achieved similar results when used for ablative purposes, although electrocautery did not achieve the same degree of synovial ablation as laser energy.

Analysis of Variance↗
PubMed1995

Patellar tendon graft harvesting using horizontal incisions for anterior cruciate ligament reconstruction.

Autograft endoscopic anterior cruciate ligament (ACL) reconstruction traditionally has been performed via standard arthroscopy portals and a single longitudinal anterior incision. This vertical incision is used for harvesting the central third of the patellar tendon with patellar and tibial bone blocks. From 1992 to 1995, more than 400 cases have been done with a new technique of graft procurement. This new method employs two transverse incisions that are more cosmetic and are less likely to become a source of pain or flexion limitation.

Anterior Cruciate Ligament↗
PubMed1995

Lateral retinacular release. The holmium:YAG laser versus electrocautery.

A retrospective study was conducted in which several parameters of postoperative recovery were compared between 2 groups of patients: 25 patients who had lateral retinacular release surgery in which the holmium:yttrium-aluminum-garnet (Ho:YAG) laser was used, and a control group of 17 patients who had the same surgery in which electrocautery was used. Postoperative recovery times of patients treated with the Ho:YAG laser were significantly decreased as compared with the recovery rates of patients in the control group. Morbidity also was reduced in the group for whom the laser was used. The results of this study indicate that the 2.1-micron-wave-length, pulsed Ho:YAG laser can be used safely and effectively to perform lateral retinacular release surgery.

Adult↗
PubMed1995

Osteitis pubis in collegiate football players.

Osteitis pubis in athletes is an inflammatory condition of the pubic symphysis and surrounding muscular insertions. It is of uncertain etiology, however, and is seen particularly in those sports requiring sprinting and sudden changes of direction. There is a paucity of literature of this condition occurring in players of American football. This report presents two such cases and details proposed etiology and a specific management protocol.

Adult↗
PubMed1993

Holmium laser surgery.

This relatively new form of laser energy, with its powerful and precise ability to ablate the dense tissues of the musculoskeletal system as well as its transmissibility in fiberoptic cables and a fluid medium, makes this an ideal tool for use in orthopedic surgery. Its importance as a new orthopedic modality may well lie in its unique ability to gain access to small articular compartments while providing superior homeostatic control, thereby decreasing postoperative morbidity. While not yet in widespread use, its popularity is rapidly spreading and research into a variety of new applications is growing steadily.

Arthroscopy↗
PubMed1991

Normal cervical spine morphometry and cervical spinal stenosis in asymptomatic professional football players. Plain film radiography, multiplanar computed tomography, and magnetic resonance imaging.

Diagnosis of cervical spinal stenosis or instability rests on the objective findings depicted on static and dynamic radiographs. Before abnormal spinal morphometry can be determined, it is first necessary to establish normal values for the specific patient population being evaluated. Several studies have attempted to establish norms for plain film measurements of the cervical spine in children and adults, but few have applied consistent methods for generating precise measurements. The first part of this study established normal values for cervical spinal morphometry and segmental spinal motion in the elite athlete. The second part of this study determined the most accurate screening method for detecting cervical spinal stenosis. Three sagittal diameters of the cervical spinal canal were compared to determine which represented the smallest midline diameter on static and dynamic radiographs. The Torg ratio was also evaluated as a method to detect significant cervical spinal stenosis and was shown to have a high sensitivity but poor positive predictive value. The study clarified why the ratio yields a large number of false positive cases. From the results of this study, an algorithm has been developed for the evaluation of stenosis of the cervical spine in athletes.

Adult↗
PubMed1988

The pseudoradicular syndrome. Lower extremity peripheral nerve entrapment masquerading as lumbar radiculopathy.

Of approximately 4,000 patients with complaints of lower extremity pain who were referred to our center for evaluation of suspected lumbar radiculopathy, 36 were found to have peripheral nerve entrapments as the sole cause of their leg pain. Nine patients had femoral nerve entrapments just proximal to the inguinal ligament. Seven patients had saphenous nerve entrapments about the knee. Twenty patients had peroneal nerve entrapments at or above the popliteal space. Nine patients had tibial nerve entrapments in the popliteal space. The diagnosis was established on the basis of electrophysiologic studies coupled with the results of selective spinal and peripheral nerve blocks. Seven patients with saphenous nerve lesions, 12 patients with peroneal nerve lesions, nine patients with tibial nerve lesions, and four patients with femoral nerve lesions, for a total of 32 (71%) cases underwent surgical exploration and external neurolysis. Forty-four percent of the cases had a positive nerve root tension sign, and 44% (20/45) had spinal range of motion abnormalities. Back pain complaints were noted in 49% (22/45) of the cases. The pseudoradicular syndrome should be considered in cases of undiagnosed persistent leg pain. Peripheral nerve lesions should be ruled out prior to considering lumbar spine surgery.

Adult↗
PubMed1982

The white blood cell scan in orthopedics.

A new nuclear scanning technique was found more specific for bone, joint, and soft tissue infections than any previously described scanning technique. The leukocyte scan, whereby a patient's own cells are labeled with a radioactive tagging agent (111In oxine), can distinguish an active infectious process from other pain-inducing conditions. Ninety-seven 111In labeled autologous leukocyte scans were performed in 88 patients. The findings in 17 of 40 patients scanned for possible acute osteomyelitis, six of nine for suspected septic arthritis, and six for possible soft tissue infections, were positive. Subsequent clinical courses verified the infectious nature of these processes in all patients. Patients who had chronic osteomyelitis (14), bony metastases (four patients), heterotopic ossification (three), and degenerative arthritis (two) demonstrated negative findings. Of the seven patients scanned for acute long-bone fractures, one demonstrated positive findings. Nine scans demonstrated positive findings without determined causes. The leukocyte scan is a useful addition to the diagnostic tools of the orthopedic surgeon.

Adult↗
PubMed1979

Successful use of dantrolene sodium in human malignant hyperthermia syndrome: a case report.

We present a case of malignant hyperthermia in which successful management included the intravenous use of dantrolene sodium. A subsequent operation under spinal anaesthesia with oral dantrolene prophylaxis did not lead to development of malignant hyperthermia. Since this syndrome is rare during regional anaesthesia, the role of prophylactic oral dantrolene in preventing the redevelopment of malignant hyperthermia in our patient is open to question.

Adult↗
PubMedDate not supplied

Bursoscopy of the trochanteric bursa.

We report two cases in a single patient with severe, refractory trochanteric bursitis, treated successfully with bursoscopy and bursectomy. The symptoms, clinical findings, surgical technique, and short-term results are described.

Adult↗
PubMedDate not supplied

Turf-toe: an analysis of metatarsophalangeal joint sprains in professional football players.

Metatarsophalangeal joint injuries of the great toe (turf-toe) are receiving increasing attention in the literature because of the prevalence of synthetic surfaces and lighter, more flexible shoes. Eighty active professional football players were evaluated. The mechanism of injury was hyperextension in 85% of the players. Eighty-three percent reported their initial injury on artificial turf (P less than 0.05). Other factors significantly related to the incidence of turf-toe included player age (P less than 0.01), number of years in professional football (P less than 0.01), and range of ankle dorsiflexion (P less than 0.05). Turf-toe injury resulted in significantly decreased range of motion of the first metatarsophalangeal joint (P less than 0.01).

Adult↗
PubMedDate not supplied

Biomechanical considerations in patellofemoral joint rehabilitation.

Patellofemoral joint biomechanics during leg press and leg extension exercises were compared in 20 normal subjects (10 men, 10 women) aged 18 to 45 years. Knee moment, patellofemoral joint reaction force, and patellofemoral joint stress were calculated for each subject at four knee flexion angles (0 degree, 30 degrees, 60 degrees, and 90 degrees) during leg press and leg extension exercises. All three parameters (knee moment, patellofemoral joint reaction force, and patellofemoral joint stress) were significantly greater in leg extension exercise than leg press exercise at 0 degree and 30 degrees of knee flexion (P < 0.001). At 60 degrees and 90 degrees of knee flexion, all three parameters were significantly greater in leg press exercise than leg extension exercise (P < 0.001). Patellofemoral joint stresses for leg press and leg extension exercises intersected at 48 degrees of knee flexion. This study demonstrates that patients with patellofemoral joint arthritis may tolerate rehabilitation with leg press exercise better than with leg extension exercise in functional ranges of motion because of lower patellofemoral joint stresses.

Adolescent↗
PubMedDate not supplied

Histologic evaluation of the glenohumeral joint capsule after the laser-assisted capsular shift procedure for glenohumeral instability.

Glenohumeral joint capsule obtained from 42 patients who had undergone an arthroscopic laser-assisted capsular shift procedure was evaluated histologically. A total of 53 samples from the anterior inferior glenohumeral ligament of the joint capsule were collected before and at various times after the procedure (range, 0 to 38 months). Despite glenohumeral instability, joint capsule of the patients before the procedure showed no significant histologic lesions. Laser treatment significantly altered the histologic properties of the tissue as evidenced by hyalinization of collagen and necrotic cells (time 0). Tissues sampled during the short-term period (3 to 6 months) after the procedure demonstrated fibrous connective tissue with reactive cells and vasculature. Collagen and cell morphology returned to normal in the middle- to long-term period (7 to 38 months) after the procedure, while the number of fibroblasts remained elevated. Joint capsule collected from the shoulders of six patients who experienced stiffness after the procedure showed persistent synovial, cellular, and vascular reaction even after 1 year postoperatively, the cause of which is unclear. This study revealed histologic evidence of robust tissue healing and maturation after thermal treatment by the laser-assisted capsular shift procedure, although mechanical and biochemical characterization of the tissue was not evaluated. Correlation with clinical follow-up must be performed to further clarify the advantages and disadvantages of this procedure.

Adult↗
PubMedDate not supplied

Postoperative epidural injection of saline can shorten postanesthesia care unit time for knee arthroscopy patients.

BACKGROUND AND OBJECTIVES: The goal of this prospective, double-blind study was to ascertain if the postanesthesia care unit (PACU) stay of outpatients receiving epidural anesthesia for knee arthroscopy is decreased by injection of epidural saline at the end of the case. METHODS: Twenty healthy patients undergoing knee arthroscopy received lumbar epidural anesthesia with 2% lidocaine. At the end of surgery, in a double-blind design, group 1 patients (intervention group) received 20 mL 0.9% saline injected into the epidural catheter. Patients in group 2 (control group) had 1 mL 0.9% saline injected into the epidural catheter. In the PACU, the epidural catheter was removed, and motor block was assessed at 15-minute intervals according to the Bromage scale. Standard discharge criteria for our ambulatory surgery center were followed. RESULTS: Patients who received 20 mL epidural 0.9% saline remained in phase I (intensive nursing) 83 +/- 8 minutes compared with control patients who stayed 110 +/- 8 minutes (P < .01). Nonmedical issues related to the unavailability of the patients transportation or waiting for medications to be issued from the pharmacy delayed discharge from phase II (non-nursing) in 70% of group 1 patients and 60% of group 2 patients. Time to actual hospital dismissal for group I was 119 +/- 14 minutes, compared with 159 +/- 13 minutes (P < .05) for group 2. CONCLUSION: Patients receiving epidural anesthesia for knee arthroscopy had a shorter PACU stay if they received an injection of saline into the epidural space at the end of surgery.

Adult↗