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Biomedical subjects

P Jokl

Publications and source records attributed to P Jokl.

At least 19 recordsLinked to original sources
PubMed2004

Master's performance in the New York City Marathon 1983-1999.

BACKGROUND: Physical activity in older people is believed to slow down the natural aging process through its effects on disuse atrophy. OBJECTIVES: To show that elite master (age above 50) male and female athletes, as a group, have improved their running times over the last two decades at a greater rate than their younger counterparts. METHODS: Running time, age, and sex of all 415,000 runners in the New York City Marathon from 1983 to 1999 were examined using linear regression analysis. RESULTS: The number of master participants increased at a greater rate than their younger counterparts (p<0.05). Running times for the top 50 male and female finishers over the past two decades showed significantly greater improvement in the master groups than in the younger age groups (p<0.001). CONCLUSIONS: Participation in the New York City Marathon is increasing at a higher rate in the master groups than in other age groups. Male and female masters continued to improve running times at a greater rate than the younger athletes, whose performance levels have plateaued. This is the largest study to compare master athletic performance with younger counterparts and men with women.

Adolescent↗
PubMed1999

Endometriosis of the pelvis presenting as hip pain. A case report.

Endometriosis is a disorder resulting from the presence of actively growing and functioning endometrial tissue in aberrant sites outside the uterus. Ectopic implantation of the endometrium can be located throughout the pelvic cavity. Depending on the location of the endometriosis, it can mimic common musculoskeletal problems, especially in young women who are menstruating. A young woman presented to an orthopaedic specialist with bilateral hip pain for the last several years. Magnetic resonance imaging subsequently was performed on both hips and showed evidence of bilateral intrapelvic endometriosis adjacent to both acetabula. The patient was seen by her gynecologist, who prescribed cyclic hormonal suppressive therapy. On followup visit to the orthopaedist, the patient's symptoms had resolved completely.

Adult↗
PubMed1996

Maximal contraction lessens impact response in a muscle contusion model.

The effect of muscle contraction on a contusion injury model was studied in the gastrocnemius muscle of anesthetized rats. Both limbs of 18 rats received a contusion injury with a blunt non-penetrating impact. One hind limb was relaxed during impact and the other was electrically stimulated to tetanic contraction. The impact was produced using a drop-mass technique (mass = 171 g, height = 101 cm, spherical radius of impactor tip = 6.4 mm). The impact response was determined by sampling (10 kHz) the transmitted impact force and the displacement of the impactor. In a subgroup of nine rats, the severity of the contusion injury was measured by recording contractile tension in twitch and tetanus within two hours of injury. We found that the peak impact force was significantly less (p < 0.01), while the peak impact displacement was significantly greater (p < 0.01) in the contracted limb. Correspondingly, the impact stiffness of the contracted limb was significantly less (p < 0.01) than the impact stiffness in the relaxed limb. Both impacts produced significant injuries relative to an uninjured control group. The tetanic tension (31 +/- 4 N) generated by the muscles that were contracted during impact was significantly (p < 0.03) greater than that generated by the muscles that were relaxed during impact (27 +/- 4 N). The findings from this specific model indicate that the impact response of the limbs with relaxed muscle was dominated by the underlying bone, while maximally contracted muscle decreased the influence of the bone and lessened the impact response. Maximally contracted muscle was not more susceptible to injury and may act as protective mechanism against some impacts.

Animals↗
PubMed1996

Regional anesthesia in knee arthroscopy: a new technique involving femoral and sciatic nerve blocks in knee arthroscopy.

We describe a new anesthetic technique of femoral and sciatic nerve blocks in knee arthroscopy. The sciatic nerve block is administered through a posterior approach, and the block of the femoral and lateral femoral cutaneous nerves in a single anterior approach. This type of regional anesthesia is safe and effective, providing excellent intraoperative and postoperative analgesia as well as minimizing postoperative complications.

Adult↗
PubMed1994

MR diagnosis of tears of anterior cruciate ligament of the knee: importance of ancillary findings.

OBJECTIVE: Detection of tears of the anterior cruciate ligament with MR is usually based on the appearance of the ligament. However, other MR findings may be useful to establish the diagnosis. We assessed the utility of these ancillary MR findings for detecting tears and for differentiating partial from complete tears of the anterior cruciate ligament. MATERIALS AND METHODS: MR images of 68 patients who had arthroscopic correlation were retrospectively reviewed by two radiologists who did not know the arthroscopic findings. The reviewers noted the presence and location of bone bruises (nonlinear low signal in the bone marrow on T1-weighted images), assessed posterior displacement of the posterior horn of the lateral meniscus, and measured the posterior cruciate ligament angle. At arthroscopy, 39 patients had tears of the anterior cruciate ligament (24 complete, 15 partial) and 29 had intact anterior cruciate ligaments. RESULTS: The presence of bone bruising in the posterolateral tibial plateau had sensitivities of 50% and 46%, with corresponding specificities of 97% and 97% for the two reviewers. Posterior displacement of the posterior horn of the lateral meniscus had a sensitivity of 56% for both reviewers, with 100% and 97% specificities. An angle of the posterior cruciate ligament less than 105 degrees had sensitivities of 72% and 74%, with corresponding specificities of 79% and 86%. The prevalence of these findings was similar in patients with partial tears and those with complete tears. CONCLUSION: Ancillary MR imaging findings may be helpful for diagnosing tears of the anterior cruciate ligament when diagnosis based on the MR appearance of the ligament is equivocal. Ancillary findings cannot be used to differentiate patients with partial tears from those with complete tears. The presence of bone bruising in the posterior aspect of the tibial plateau and posterior displacement of the posterior horn of the lateral meniscus are highly specific for a torn anterior cruciate ligament; therefore, the presence of either of these findings should be considered strong evidence of a tear of the anterior cruciate ligament.

Adult↗
PubMed1993

SLAP lesions of the glenoid labrum diagnosed with MR imaging.

Tears of the superior portion of the glenoid labrum in patients without shoulder instability have recently been described. These tears, which include the "anchor" of the biceps tendon to the labrum, have been labeled "SLAP lesions" (superior labrum anterior to posterior). This study was performed to determine the magnetic resonance (MR) findings in patients with SLAP lesions. Retrospective review of the shoulder arthroscopy reports on patients who underwent MR imaging using a 1.5-T unit and subsequent arthroscopy by a single surgeon identified six patients with SLAP lesions (average age 36 years, range 17-65 years). MR images demonstrated atypical morphology indicative of tear in the superior portion of the labrum in four of the six patients, but only one tear had been identified preoperatively. Radiologists interpreting MR images of the shoulder should be aware of the MR findings of SLAP lesions as these tears can be a significant cause of patient disability and are difficult to diagnose clinically.

Adolescent↗
PubMed1993

The results of arthroscopic debridement of glenoid labral tears based on tear location.

A retrospective, average 2-year review of 14 patients with a primary glenoid labral tear treated by arthroscopic debridement was conducted to evaluate the long-term results of labral debridement based on tear location in preoperatively stable shoulders. All patients with concomitant pathology requiring an additional open or arthroscopic procedure were eliminated from this study. Every patient complained of shoulder pain mainly with overhead activities and nine patients (64%) also described "clicking" with shoulder movement. All shoulders were stable to translation in all quadrants during the preoperative examination and examination under anesthesia. The functional results at 6 months' follow-up were 93% excellent or good. However, the results at > 1 year's follow-up (average 2 years) were only 71% excellent or good, with a statistically significant 50% of patients decreased in function. The best results were in the superior and anterior-inferior regions. Three patients with large anterior-superior lesions (60%) developed postoperative instability noted at > 6 months postsurgery, representing a significant difference between groups. One of these patients was able to regain a good functional result with rotator cuff strengthening therapy. Close observation of patients after large anterior-superior labral tear arthroscopic debridement is advised because they are at risk for the delayed onset of instability.

Adolescent↗
PubMed1993

The role of exercise in the treatment of inflammatory arthritis.

A routine of regular exercise is important in patients with inflammatory arthritis. Most patients with stage I and stage II RA are capable of engaging in an exercise program. Benefits include increased cardiovascular and muscle endurance, as well as improved muscle strength (Table 1). This in turn allows patients to function more independently and with an improved quality of life. Exercise programs are designed to restore range of motion, improve strength and endurance, and at the same time provide a social outlet and opportunity for improved self esteem. Exercises should progress slowly during which time patients should be closely monitored for symptoms of increased joint inflammation.

Arthritis, Rheumatoid↗
PubMed1992

Normal and abnormal glenoid labrum: assessment with multiplanar gradient-echo MR imaging.

A retrospective study of magnetic resonance (MR) imaging of the glenoid labrum performed with multiplanar gradient-echo (MPGR) sequences was done to ascertain the different appearances of the normal labrum and the findings in patients with tears. MPGR images were obtained with a 1.5-T magnet in 37 shoulders of 16 healthy subjects and 19 patients with subsequent surgical evaluation. Increased intralabral signal intensity was seen in 12 of 26 normal shoulders (46%), and atypical morphology was seen in six shoulders (23%). Atypical morphology was present in eight of nine patients with labral tears. Deformity (n = 2 [22%]) and clefts (n = 2 [22%]) were seen in patients with tears. Deformity (n = 3 [12%]) and clefts (n = 1 [4%]) were occasionally seen in healthy subjects. Absence of the labrum and separation of the labrum from the glenoid cavity was present only in patients with tears; therefore, the labrum should be presumed torn in the presence of these findings. Increased intralabral signal intensity on MPGR images did not help predict labral integrity; morphologic findings were more predictive of labral tear.

Adolescent↗
PubMed1992

Can MR imaging effectively replace diagnostic arthroscopy?

A study was performed to determine whether magnetic resonance (MR) imaging is cost-effective and reduces the need for diagnostic arthroscopy of the knee. During a 9-month period, 103 consecutive patients with knee injury that justified diagnostic arthroscopy underwent MR imaging. The MR images were interpreted by means of consensus of three radiologists and reviewed with the referring sports medicine orthopedists. After the examination, 44 patients (42.7%) underwent immediate arthroscopy. The 59 other patients (57.3%) did not undergo arthroscopy; follow-up was performed in 55 of these 59 patients (93%) at a mean of 22 months. The outcome was successful in 49 of 55 patients (89%); 40 patients had normal function and no limitation in activity, six patients with chronic injury of the anterior cruciate ligament underwent reconstruction, and three patients underwent arthroscopy with negative findings. Without the use of MR imaging, all patients in this study would have undergone diagnostic arthroscopy. Because of the diagnoses based on MR images, 53 patients (51.4%) avoided a potentially unnecessary diagnostic arthroscopy, and, as a result, the net savings was $103,700 in the 103 patients.

Adolescent↗
PubMed1992

Chondromalacia patellae: diagnosis with MR imaging.

Most previous studies of MR imaging for detection of chondromalacia have used T1-weighted images. We correlated findings on axial MR images of the knee with arthroscopic findings to determine MR findings of chondromalacia patellae on T2-weighted and proton density-weighted images. The study population included 52 patients who had MR examination of the knee with a 1.5-T unit and subsequent arthroscopy, which documented chondromalacia patellae in 29 patients and normal cartilage in 23. The patellar cartilage was assessed retrospectively for MR signal and contour characteristics. MR diagnosis based on the criteria of focal signal or focal contour abnormality on either the T2-weighted or proton density-weighted images yielded the highest correlation with the arthroscopic diagnosis of chondromalacia. When these criteria were used, patients with chondromalacia were detected with 86% sensitivity, 74% specificity, and 81% accuracy. MR diagnosis based on T2-weighted images alone was more sensitive and accurate than was diagnosis based on proton density-weighted images alone. In conclusion, most patients with chondromalacia patellae have focal signal or focal contour defects in the patellar cartilage on T2-weighted MR images. These findings are absent in most patients with arthroscopically normal cartilage.

Adolescent↗
PubMed1992

Achilles tendon overuse injuries.

Overuse injuries of the Achilles tendon are common in patients engaging in recreational athletics. Achilles tendon overuse injuries exist as a spectrum of diseases ranging from inflammation of the paratendinous tissue (paratenonitis), to structural degeneration of the tendon (tendinosis), and finally tendon rupture. Factors known to predispose patients to Achilles tendinitis include inadequate stretching, training errors, mechanical malalignment of the lower extremities, rigid training surfaces, and occasionally systemic disease. Treatment of the patient with paratenonitis and tendinosis is initially conservative, emphasizing passive stretching, concentric and eccentric strengthening, correction of training errors, and restoration of normal limb alignment. Patients resistant to this protocol often exhibit a more advanced degree of tendon change. A high percentage of these patients can benefit from surgical debridement of the involved tendon, and they can anticipate successful return to recreational athletics. Steroid injections should not be routinely used in patients with Achilles tendinitis. Rupture of the Achilles tendon following intratendinous injection has been reported.

Achilles Tendon↗
PubMed1991

Magnetic resonance imaging of the surgically repaired meniscus: six-month follow-up.

The appearance and rate of healing of sutured meniscal repairs in 17 patients were evaluated using magnetic resonance scans. While prior studies in animals and humans (1-4) suggest that complete healing can occur as early as 6 wk postoperatively, we found that at 7 wk 15/15 patients demonstrated meniscal defects at the site of repair. At 6 mo, 11/11 patients showed persistent signal abnormalities. Two patients scanned at 11-12 mo also had defects at the site of repair. Therefore, complete meniscal healing appears not to occur as early as previously believed. This may affect decisions regarding the type of suture material used, the surgical treatment of associated injuries and the postoperative rehabilitation regimen. As defects may be present for relatively long periods of time following meniscal repair, caution must be exercised when attempting to diagnose new or recurrent tears in these patients.

Adolescent↗
PubMed1991

Follow-up of grade 2 meniscal abnormalities in the stable knee.

A prospective study of grade 2 meniscal abnormalities in patients with intact anterior cruciate ligaments was done to ascertain whether such lesions progress to complete tears. A follow-up magnetic resonance (MR) image was obtained in 22 patients in whom the initial MR image showed a grade 2 lesion in one or both menisci that had been proved at arthroscopy not to be torn. On the initial images, 27 menisci contained a grade 2 lesion. At follow-up, six of the 27 lesions appeared to have decreased in size (two had completely disappeared). Eighteen lesions appeared unchanged; only three had increased in size. The mean interval between the acquisition of initial and follow-up images was 27.3 months (range, 11-41 months). The two patients whose lesion disappeared were among the youngest patients evaluated. The three patients whose abnormality increased were slightly older and more active than average. The results suggest that in most patients grade 2 lesions are stable at up to 3 years follow-up.

Adolescent↗
PubMed1990

The clinical significance of stage 2 meniscal abnormalities on magnetic resonance knee images.

The Stage 2 meniscal abnormality was subdivided into Stage 2A--linear abnormal signal not contacting an articular surface, Stage 2B--abnormal signal in contact with the articular surface on a single image, Stage 2C--extensive wedge-shaped signal abnormality not in contact with an articular surface. Arthroscopy showed tears in 2A 3%, 2B 0%, 2C 50%. Complete tears should only be diagnosed if contact is seen on more than one image. Many Stage 2C menisci may have tears.

Adult↗
PubMed1990

Osteochondritis dissecans of the knee: a historical review of etiology and treatment.

Osteochondritis dissecans (OCD) is a common entity in both the juvenile and adult populations, with an incidence of 3 to 6/10,000 in adults. Much of the early literature grouped juvenile and adult osteochondritis dissecans, osteochondral fracture, and accessory ossification into the same category. Conclusions were then drawn on the combined group. Nonetheless, this is a diverse group. This review discusses only OCD. There have been multiple etiological theories of OCD, ranging from trauma to ischemia to accessory centers of ossification and to genetics. It is evident that the true etiology is probably multifactorial. Bone scan, computed tomographic scan, and magnetic resonance imaging advances have enhanced the physician's ability to make the diagnosis of osteochondritis dissecans as well as to stage operative intervention. There is a vast difference between juvenile and adult OCD, as seen in the natural history, prognosis, and treatment options. In general, the juvenile patients have better results overall. The indications for operative intervention for these juvenile patients are a nonhealing attached fragment, fully or partially detached lesions of the articular surface, and loose bodies. Nonoperative treatment in the adult patient has been shown to accelerate degenerative arthritis, which involves all 3 compartments of the knee. Therefore, symptomatic lesions and loose bodies comprise the surgical indications for adult OCD. An understanding of this disease process will help the physician optimize the patient's results.

England↗
PubMed1990

Meniscal abnormalities in the asymptomatic population at MR imaging.

Two hundred eighty meniscal horns in 64 asymptomatic volunteers in the 2nd to 8th decades of life were analyzed for meniscal abnormalities. Grade 1, 2, and 3 changes were present in essentially all decades. There was at least a 25% prevalence of meniscal signal abnormalities as early as the 2nd decade. The prevalence of meniscal abnormalities increased sharply with age. The prevalence of all signal abnormalities correlated with age, grade 2 changes having the highest correlation coefficient (+.88). The correlation coefficient for grades 1 and 3 changes were +.60 and +.71, respectively. The posterior horn of the medial meniscus had a significantly higher (P less than .02) prevalence of abnormalities than did the other meniscal locations. There was no significant correlation between subject weight or sex and meniscal signal. The authors conclude that there is a baseline prevalence of meniscal signal in the asymptomatic population.

Adolescent↗