Biomedical subjects
Publications and source records attributed to P J Fowler.
It is very likely that Royal Navy doctors will be called upon more and more in the future to work on similar overseas exercises. I found the experience immensely challenging and educational and would have no hesitation in volunteering for further deployments or recommending other RN doctors to do the same.
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The purpose of this paper was to determine the extent to which the technique used in ACL reconstruction and fixation influences graft placement. This is a Comparative Radiographic cohort study. Precise graft placement is one of the most crucial components of a successful anterior cruciate ligament (ACL) reconstruction. Two commonly used techniques of ACL reconstruction are arthroscopic bone-patellar tendon-bone (B-PT-B) autograft with interference screw fixation and semi-tendinosus and gracilis (ST + G) tendon autograft with endobutton femoral and multiple staple belt buckle tibial fixation. Using radiographic measurements of bone tunnel position following ACL reconstruction this study quantified the extent to which these techniques influenced graft placement. Femoral and tibial tunnel position in ACL reconstruction was determined using the post-operative radiographs of 40 male patients who had undergone ACL reconstruction (20 B-PT-B and 20 ST + G). The primary outcome measure was location of bone tunnel position following ACL reconstruction. Measurements were based on the guidelines of Amis et al. Femoral tunnel position of B-PT-B grafts was an average of 9.36% more anterior in the sagittal plane than with ST + G grafts. The mean position of B-PT-B grafts was at 31.11% (SD = 5.45%). The mean position of the ST + G grafts was 21.76% (SD = 6.62%). This difference between the two was found to be significant (p < .001). As demonstrated by this study, placement and orientation may vary to accommodate technique and fixation. Clinical outcomes measured were similar in both groups.
The high incidence of injuries that occur later during a session of sports or recreational activities suggests that fatigue may contribute to altered neuromuscular control of the lower limb and an individual's subsequent altered ability to dynamically stabilize the knee joint. One possible mechanism is a fatigue-mediated alteration in proprioception. This paper reviews experimental evidence of fatigue-induced changes in knee joint position sense and movement sense, or kinesthesia. We will discuss the possible physiological mechanisms behind these changes, including the role of joint and muscle receptors in proprioception and neuromuscular control of the knee, and the role of fatigue in changes in afferent output from muscle and joint receptors. We will then explore the implications that alteration in proprioception may have for dynamic stabilization of the knee joint.
PURPOSE: To report our experience with the use of the (Eclipse) elastomeric pump for ambulatory Patient Controlled Regional Analgesia (PCRA) METHOD: After a pilot study using this device in patients admitted to the hospital, seven patients received PCRA at home using the elastomeric pump. Patients with a variety of continuous regional anesthetic blocks were sent home with written and verbal instructions regarding the use of this device, boluses, side effects of local anesthetics and removal of block catheters. Patients were contacted daily to collect data with regards to the efficacy of the block, problems associated with the use of this device and their satisfaction with the method of analgesia. RESULTS: During the pilot study there were two catheter disconnections requiring rescue analgesics. Two patients had the entire contents of the bulb delivered over several minutes. Among the seven patients receiving PCRA at home, one patient had to be admitted to the hospital. One patient had block catheter slip out during transit. The volume delivered could not be measured. Patients found it difficult to know if the drug had been delivered. Three patients noted that the pumps were empty earlier than expected. One patient found it difficult to change the bulb. No patient had difficulty with catheter removal or with bolusing. CONCLUSIONS: PCRA offers excellent postoperative analgesia at home. Elastomeric pumps facilitate PCRA but are imprecise with drug delivery and may not be safe for epidural infusions. The safety of this device for peripheral nerve blocks should be evaluated further.
OBJECTIVE: To identify the approaches to management of anterior cruciate ligament (ACL) injury by Canadian orthopedic surgeons. METHODS: A questionnaire was mailed to 234 physicians randomly chosen from the Canadian Orthopaedic Association directory to obtain the following information: 1) how orthopaedic surgeons diagnose acute hemarthroses; 2) how patients in any of three common ACL injury scenarios would be managed; 3) what variations exist in surgical technique; and 4) how patient variables such as age, gender, and alignment influence the decision-making process. RESULTS: The return rate was 72%, and 56% of respondents were from academic centers. Patients such as those described in the protocol are routinely managed by 80% of the respondents. The diagnosis of acute hemarthrosis is predominantly made by means of clinical examination and radiographs. Magnetic resonance imaging (MRI) is used occasionally by 43% and routinely by 6% of those who responded; arthroscopy is used routinely by 24%. For the competitive athlete with a complete ACL tear, 64% would recommend reconstruction and 33% would recommend bracing and rehabilitation. For reconstruction, 59% would use bone-patellar tendon-bone (B-PT-B) autograft and 32% would use hamstring tendon autograft; 40% would incorporate the ACL stump during reconstruction. Of the respondents, 77% would advocate ACL reconstruction for competitive athletes with chronic ACL injury. Of these, 63% would use B-PT-B autograft and 27% would use hamstring tendons. If bracing and rehabilitation failed, 98% would recommend ACL reconstruction. In ACL reconstruction, synthetic augmentation would be used by 12% in chronic cases and by 16% in acute cases. In making the decision to perform ACL reconstruction, 53% consider limb alignment to be important and 67% consider moderate patellofemoral pain to be important. Seventy-one percent are influenced by patellofemoral pain when choosing a surgical technique, with a trend toward semitendinosis autograft rather than B-PT-B autograft reconstruction. For the 8-year-old child with an acute ACL injury, 63% of the respondents would recommend rehabilitation and bracing. For the 14-year-old, 45% would recommend rehabilitation and bracing and 37% would recommend ACL reconstruction after physeal closure. CONCLUSION: The results of the survey indicate that, with respect to some of the issues, there is a wide variation in management of acute and chronic ACL injuries among Canadian orthopedic surgeons. Future research and randomized, controlled clinical trials should be directed toward these areas.
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Anterior cruciate ligament injury in the skeletally immature is becoming increasingly recognized and reported. History taking and physical examination based on the principles of ACL injuries in adults, with adjuncts such as arthroscopy and MRI, are effective in diagnosing ACL injury in the young patient. Evaluation of the young patient's true level of skeletal immaturity by comparison with family growth history, examination for signs of sexual maturity, and radiographic evaluation is critical. The risk of physeal damage with surgical treatment is related to the immaturity of the distal femoral and proximal tibial physes. The functional results of nonsurgical treatment of ACL injury, either as an attempt at definitive treatment or as a temporizing plan until skeletal maturity occurs, are poor and the risks of reinjury and further meniscal and cartilage damage are significant. Surgical treatment for primary repair or extra-articular reconstruction alone has not proven to be efficacious. In the adolescent patient who is approaching skeletal maturity, risk of physeal injury is low and intra-articular reconstruction can be performed as in the adult patient. Results with respect to decreased laxity and return to athletic activities mirror those described in adults. In patients with significant growth remaining, however, surgical treatment carries much higher risks of physeal damage and subsequent deformity. Yet, as noted above, intra-articular reconstruction in truly skeletally immature patients using a soft-tissue graft through a transphyseal tibial tunnel of moderate or small diameter and the over-the-top position on the femur has not been shown to cause early physeal closure, limb-length discrepancy, or angular deformity. In humans, the maximum diameter of graft tunnel that will not cause physeal closure has not been determined Animal studies have shown that the tibial physis can be very sensitive to drilling. Therefore it is wise to use moderate tunnel diameters. Bone-patellar tendon-bone grafts have been used with success in patients closer to skeletal maturity. Their use has not been reported in the very skeletally immature knee and cannot be recommended because of the presumed high risk of physeal closure with a bone plug traversing the physis. It is hoped that improved understanding of the ACL injury in the skeletally immature patient will provide treatment options that will restore enduring knee function and prevent early arthrosis.
The purpose of this study was to evaluate the outcome of transphyseal ligament reconstruction in skeletally immature children with midsubstance anterior cruciate ligament (ACL) disruption. Five consecutive patients (mean age, 12.9 years; range, 8 to 14 years) with radiographically documented "wide" open growth plates and a minimum of 5 cm of expected remaining growth, underwent intra-articular reconstruction of the ACL. Operative treatment included three ACL reconstructions using hamstring tendons and two with quadriceps patellar tendon. All involved a centrally placed 6-mm or smaller tibial drill hole through an open physis and graft placement in an over-the-top position on the femur. At an average follow-up of 7.4 years (range, 4.5 to 9.9 years), no patient had a positive anterior drawer, Lachman, or pivot shift test. On KT-1000 arthrometer testing, all patients had 3 mm or less of increased anterior-posterior displacement (mean +/- SD = 1.0 +/- 1.6 mm). Magnetic resonance imaging showed that four tibial physes had fused in a symmetric fashion and one was still open. Orthoroentgenograms showed that no patient had a significant leg length discrepancy (-0.8 mm +/- 3.4 mm). The mean increase in height postoperatively was 17.7 cm (range, 7.6 to 31.0 cm). Overall, using the International Knee Documentation Committee (IKDC) evaluation form, there were four patients with grade A and one with grade C. The one patient with a poor IKDC grade had sustained a subsequent patellar dislocation with osteochondral fracture. In conclusion, ACL reconstruction using small drill holes placed through open tibial physes does not seem to adversely affect outcome or future growth.
OBJECTIVE: To investigate the effects of muscular fatigue on knee joint proprioception. DESIGN: Prospective study. SETTING: Exercise physiology laboratory. PARTICIPANTS: Sixteen (eight men and eight women) healthy volunteers ages 19-27 years, with no history of neuromuscular disorders, vestibular disorders, or lower limb injuries (e.g., ligament/meniscus tear). INTERVENTION: Three separate fatigue protocols [ramp test (RT), continuous test (CT), and interval test (IT)] were performed. All tests consisted of lower limb cycling on a computer-driven cycle ergometer (Lode). The RT was used to calculate the maximal aerobic power (VO2max) and determine the work rates for the CT and IT. Work rate for the RT increased 20/25 W/min to maximal exhaustion. The CT consisted of cycling at 80% VO2max until maximal exhaustion. The IT consisted of cycling alternately at 120% VO2max and at 40% VO2max for 30 s each to the point of maximal exhaustion. MAIN OUTCOME MEASURE: In the standing position, subjects were instructed to perform a two-legged squat to specific knee flexion angles. The absolute angular error (AAE) was measured for each test angle using an electrogoniometer (Penny & Giles, Blackwood, Gwent, U.K.) placed laterally across the dominant knee joint. AAE was defined as the absolute difference between test angle and subject perceived angle of knee flexion. RESULTS: A statistically significant increase in AAE after the RT (1.0 +/- 0.66 degree, p < 0.01), CT (0.70 +/- 0.66 degree, p < 0.03), and IT (1.24 +/- 0.79 degrees, p < 0.01) protocols was observed in the male subjects. Female subjects reported a statistically significant increase in AAE after the CT (0.73 +/- 0.73 degree, p < 0.03) and IT (1.1 +/- 0.89 degrees, p < 0.01) protocols and a nonsignificant increase in AAE (0.19 +/- 0.70 degree, p > 0.5) after the RT protocol. CONCLUSION: These findings suggest that exercising to fatigue may produce a change in subjects' reproduction ability of knee joint angles. This may represent a decline in proprioceptive function after heavy exercise bouts. Whether this suggested proprioceptive decline is at the clinical significance level (e.g., significantly altering joint stability and motion) cannot be determined from the present findings.
PURPOSE: To compare the diagnostic efficacy of current-generation middle- and high-field-strength magnetic resonance (MR) imagers in the diagnosis of anterior cruciate ligament (ACL) tears. MATERIALS AND METHODS: In 114 of 230 patients referred for knee imaging, MR imaging at 0.5 and 1.5 T was performed with identical sequences but with a slightly longer total imaging time and bandwidth optimization at 0.5 T. Radiologists were blinded to diagnosis and field strength. Sensitivity, specificity, and accuracy were determined, and ACL tear was confirmed by means of arthroscopy and pathology. RESULTS: There was no difference between the field strengths in accuracy, sensitivity, or specificity for the diagnosis of ACL tears in 86 patients with disrupted ACLs and 28 patients with intact ACLs. Accuracy for all ACL tears was 90% at 0.5 T and 91% at 1.5 T. Similarly, there were no differences in diagnosis of meniscal tears (79 with, 149 without) or posterior cruciate ligament tears (seven with, 107 without). CONCLUSION: Higher field strength does not confer higher accuracy in the diagnosis of ACL tears at MR imaging.
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In the 1970s, J. C. Kennedy reported on the use of synthetic augmentation in combination with hamstring tendons in anterior cruciate ligament reconstruction. This article explores the surgical approach, technique, and rationale for reconstruction of the posterior cruciate ligament-deficient knee using autograft hamstring and the Kennedy ligament augmentation device.
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There is no doubt that the understanding of shoulder mechanics and pathology will continue to evolve. It is not appropriate to consider that all patients, especially young athletes, who have shoulder pain have "impingement." Rather, a careful evaluation will result in the correct diagnosis and the institution of the appropriate treatment. A step-by-step assessment and management scheme is necessary for each health care professional dealing with athletes. If surgery is deemed necessary, the correction of the anatomic abnormality with minimal disruption of normal anatomy will be the key to allowing the athlete to return to his or her chosen sport.