Mechanical stability of the femoral fixation for single- and double-bundle ACL reconstruction in an in vitro experimental model

Anterior cruciate ligament ACL reconstruction using the double-bundle (DB) technique is gaining popularity. A possible weak link in the DB technique could be that two tendon grafts of smaller diameters are used. The purpose of this study was to test different femoral fixation methods and graft diameters representing single-bundle (SB) and DB ACL reconstructions and compare their biomechanical properties. We hypothesized that SB 6-mm graft constructs had inferior biomechanical properties than SB 9-mm grafts or DB 2 × 6-mm grafts. Furthermore, we hypothesized that interference (IF) screw fixation would demonstrate less elongation and a higher stiffness than Endobutton (Smith & Nephew®, Inc., Andover, Massachusetts, USA) fixation (EBF). We performed an in vitro study using porcine knees and extensor tendons. The mechanical test consisted of a cyclic test followed by a load-to-failure test. We found that 6-mm graft constructs had an ultimate failure load that was up to 40% less than both the 9-mm and 2 × 6-mm graft constructs, despite the fixation method (P-values ≥ 0.004). Comparing fixation methods, EBF was superior to IF concerning maximum load to failure (P < 0.001); IF resulted in a higher stiffness of the femur/graft complex than the EBF (P < 0.001) but no significant difference in elongation between fixation methods. Since the two graft strands are subjected to different loads in different knee flexion angles, the reduced strength of the individual graft strands in DB ACL reconstruction could be a concern.

The combination of radiostereometric analysis and the telos stress device results in poor precision for knee laxity measurements after anterior cruciate ligament reconstruction

PURPOSE

Several devices for measuring knee laxity following anterior cruciate ligament ACL reconstruction exist, but the precision of the methods has never been optimal. Therefore, a new standardized protocol (NSP) was made, aiming at ensuring a reliable positioning of the Telos Stress Device (TSD) which theoretically could result in precise knee laxity measurements when using radiostereometric analysis (RSA) in combination with TSD.

METHOD

The TSD was applied to the knee of 30 healthy persons, using both the NSP and the official company instructions. The position of the stress arms of the TSD was marked following each measurement. The reliability of each protocol was calculated as the difference in length between the first and second markings. The NSP for the TSD was then used in a clinical study. Thirty-five patients underwent ACL reconstruction. Double measurements of knee laxity by RSA were performed at a 3-month follow-up.

RESULTS

Using the NSP for TSD positioning, the prediction interval at the marking sites ranged from ±0.4 to ±1.1 mm. Following the company instructions, the prediction interval ranged from ±0.8 to ±3.9 mm depending on marking site. Thus, the precision of positioning the stress arms of the TSD was improved at all marking sites using the NSP compared with the original company protocol. The double measurements of the knee laxity in the clinical study resulted in a mean difference of 0.0 mm and a prediction interval of ±5.2 mm.

CONCLUSION

Even though the NSP improved the positioning of the TSD on patients' extremities, the combination of NSP-TSD and RSA was not able to provide acceptable knee laxity measurements in a clinical setting compared with published precision data for other devices on the market. Therefore, the Telos Stress Device is not recommendable for use in knee laxity measurements following ACL reconstruction.

Serial dilation versus extraction drilling in anterior cruciate ligament reconstruction: a biomechanical study

The hamstring tendon graft has become increasingly popular in anterior cruciate ligament reconstruction because of low donor-site morbidity. However, the tibial fixation is considered difficult, mainly because of low tibial mineral bone density. Therefore, we tested whether preparation of the tibial tunnel with compaction by serial dilation provided a stronger anchorage of the graft-fixation-device complex than does traditional extraction drilling of the tibial tunnel. In 20 bovine tibiae, the bone tunnels were created with either extraction drilling (group 1) or compaction by serial dilation (group 2). Twenty bovine digital extensor tendons were fixated in the bone tunnel with an Intrafix tibial fastener. The graft-fixation-device complexes were mounted in a hydraulic test machine. The fixation strength was evaluated after cyclic loading. The difference between the serial dilation group and the extraction drilling group ranged from a mean slippage of 0 mm at 70-220 N, to a mean slippage of 0.1 mm at 70-520 N. We found no significant difference in slippage of the graft-fixation-device complex after 1,600 cycles. This study failed to show a significant difference between compaction by serial dilation and extraction drilling of the tibia bone tunnel in anterior cruciate ligament reconstruction.

Ultrasonography as a tool for diagnosis, guidance of local steroid injection and, together with pressure algometry, monitoring of the treatment of athletes with chronic jumper's knee and Achilles tendinitis: a randomized, double‐blind, placebo‐controlled study

BACKGROUND

The diagnosis of Achilles and patella tendinitis has until recently been based on clinical examination, and treatment with local steroid injection has been given blindly. This is the first randomized, double blind, placebo-controlled study of local steroid injection in athletes with chronic tendinitis, which used ultrasonography to increase diagnostic accuracy, to guide the correct placement of local steroid and, conjunctively with pressure algometry, to objectify and monitor the results of treatment.

METHOD

Forty-eight athletes each with severe symptomatic tendinitis of a patellar (24) or Achilles tendon (24) for more than 6 months, whose conditions were confirmed ultrasonographically, and who all failed conservative treatment (rehabilitation) were included in this double-blind, placebo-controlled study and treated with three ultrasonographically guided peritendinous injections of steroid or placebo.

RESULTS

The conditions of only one-third of the referred athletes with clinically suspected tendinitis were confirmed by ultrasonographic examination. The ultrasonographically guided peritendinous injection of steroid had a significant effect in reducing pain and thickening of tendons.

CONCLUSION

Ultrasonography should be used in the future to assure precise diagnosis and to guide the peritendinous injection of steroid in chronic Achilles and patella tendinitis. Ultrasonography and pressure algometry are recommended as objective methods for monitoring the effect of treatment. Ultrasonographically guided injection of long-acting steroid can normalize the ultrasonographic pathological lesions in the Achilles and patellar tendons, and has a dramatic clinical effect but when combined with aggressive rehabilitation with running after a few days, many will have relapse of symptoms within 6 months.

The reliability of balance tests performed on the kinesthetic ability trainer (KAT 2000)

The Kinesthetic Ability Trainer (KAT 2000) is a balance platform designed for training and functional testing of the neuromuscular control system. Forty healthy and sports-active persons were tested and 1 month later retested to investigate the reliability of the KAT 2000 testing "one-leg static balance" and "two-leg dynamic balance". A significant improvement at retesting on the same day was seen in both tests; furthermore the dynamic test result improved significantly with retesting 1 month later. The data obtained made it possible to calculate the 95% confidence limits for an unchanged test result for a single person and a group of persons. The results show a clear learning effect when the persons are retested, especially in the dynamic test. The KAT 2000 can be used as a tool for testing groups of persons both in short- and long-term studies, but it cannot be used for testing single persons due to the great variance in the test results. Further investigations involving injured persons are needed to determine the range of improvement after intervention.

"Little league elbow"--acute traction apophysitis in an adolescent badminton player

A case of an acute traction apophysitis, "little league elbow", in an adolescent badminton player is presented. After a period of intense badminton activity, the patient developed typical signs of inflammation related to his elbow. X-ray showed soft tissue calcifications and ultrasound showed intra-articular swelling and a possible apophysitis related to the elbow. After a period of immobilization followed by low activity he could return to normal sports activity.

[Waiting lists--how valid are the official numbers? Evaluation of a waiting list at a department of orthopedic surgery]

With increasing waiting lists for admission to hospital, the aim of this study was to investigate the reliability of an orthopaedic waiting list. Questionnaires were sent to every patient listed as waiting for more than three months. The questionnaire addressed the current symptoms and the current need for surgical treatment. In case of no reply, a further evaluation was done before eventual removal from the waiting list. Of 809 questionnaires mailed, replies were received from 409. A total of 376 were removed from the list, including 111 due to registration errors in the central data base. This study has shown how the indication for operation changes during the waiting period but also that information from data bases can be most unreliable. We find the reasons so general, that we recommend a corresponding evaluation of other waiting lists. Altogether, today's waiting list is faulty and thus provides a wrong basis for management.

Prevention of injuries in long-distance runners

The possibility of reducing the incidence of injuries in long-distance runners was investigated in 41 recreational long-distance runners. They were divided into two matched groups according to age, sex, weight, height, experience, training and incidence of injury during the previous year. The runners in the study group were clinically investigated before the season started, and individual training programmes were drawn up. The other group served as controls. The runners receiving prevention and training programmes improved in training technique and had increased training mileage, race participation and racing mileage. In 1 year a total of 50 injuries were recorded, 29 in the study group and 21 in the controls. The injury incidence per 1000 hours of competition was significantly lower in the study group with a preventive training regimen than in the controls (30.7 versus 62.5).

[Finger tip injuries. A comparative study of silver sulfadiazine and fucidin gauze]

Eighty-eight superficial finger-tip lesions were randomized after thorough cleaning to either silver sulphadiazine treatment of Fucidin fusidic acid gauze. In the silver sulphadiazine group the wounds were covered with a non-sterile PVC gloce and redressed at least every third day; in the other group Fucidin gauze was applied and a tubigauze dressing was left in situ for ten days, after which a new dressing was applied. All patients were treated until healed and followed for at least six months after injury. Patients in the silver sulphadiazine group required shorter time for healing and shorter sick leave. The treatment is recommended because of the easy procedure and the good results.

Years of potential life lost after hip fracture among postmenopausal women

From January 1987 and onwards all cases of hip fracture in Arhus County, Denmark, were registered in a prospective multicenter investigation. Until December 1990, 2273 postmenopausal women (greater than 50 years) with first hip fractures were registered. Of these 643 sustained a hip fracture in 1988. Life tables were constructed for different age groups; the excess mortality (in comparison with the reference population) for each age group ranged from 10 to 20 percent. The years of potential life lost (YPLL) (life expectancy method) were calculated for the 1988 cohort and compared with the YPLL due to other selected conditions calculated from official vital statistics. The YPLL rates (per 1000 persons) were as follows: hip fracture 9.2, ischemic heart disease 73, cerebrovascular disease 29, breast cancer 20 and cancer of the uterus 6.7. We propose that hip fracture mortality data should be continuously registered and evaluated using the YPLL method to detect changes caused by the expected increase in the number of hip fractures.

Badminton injuries

In a one year period, from 1 January 1986 to 31 December 1986, 4303 patients with sports injuries were treated at Aarhus Amtssygehus and Aarhus Kommunehospital. The mean age was 21.6 years (range 7-72 years) and 2830 were men. Two hundred and seventeen badminton injuries occurred in 208 patients (136 men) with a mean age of 29.6 years (range 7-57 years), constituting 4.1 percent of all sport injuries in Aarhus. Joints and ligaments were injured in 58.5 percent of the patients, most frequently located in the lower limb and significantly more often among patients younger than 30 years of age. Muscle injury occurred in 19.8 percent of the patients. This type of injury was significantly more frequent among patients older than 30 years of age. Most injuries were minor. However, 6.8 percent of the patients were hospitalized and 30.9 percent received additional treatment by a physician. As the risk of injury varies with age, attempts to plan training individually and to institute prophylactic measures should be made.

Skiing injuries: a study from a Danish community

A Danish investigation of skiing injuries is presented from the casualty wards of two hospitals. The material consisted of 119 skiing injuries. Fifty-three per cent of the patients were women. Eighty-three injuries occurred abroad, mainly in Austria and Norway. Injury rate was not related to sex. The highest injury rate was found in the age group 20 to 29 years old. The most frequent injuries were sprains (knee 43, finger 14), fractures (39) and contusions (19). Injuries requiring hospitalization were common. None of these resulted in permanent major disability.

Antibiotic prophylaxis in lower-extremity amputations due to ischemia. A prospective, randomized trial of cephalothin versus methicillin

The efficiency of prophylactic antibiotic therapy in amputation surgery was studied in a prospective, randomized trial of a first-generation cephalosporin (cephalothin) compared with a narrow-spectrum beta-lactam stable penicillin (methicillin). Eighty-eight patients received cephalothin 2 g X 4 on the day of operation, while 86 patients received methicillin 1 g X 4. The patients were followed up for 21 days. Infected wounds occurred in 14.8% of the patients in the cephalothin group, compared with 14% in the methicillin group. The frequency of deep infections was 10.2% versus 4.7% (P = 0.1611). The reamputation frequency was 18.2% in the cephalothin group compared with 12.8% in the methicillin group; the frequency of below-knee reamputation was 18.4% versus 7.7% (P = 0.1469). No clostridial infections were found. The study did not demonstrate any significant difference between cephalothin and methicillin in the prophylaxis for lower-extremity amputations, although the latter drug tended to be the best choice.

Exercise-induced knee joint laxity in distance runners

The objectives of this study were to evaluate the effect of exercise on knee joint laxity. If exercise induced laxity is physiological, incorporation of this quality into a ligament replacement material would be indicated. Twenty recreational long distance runners average age 41 (range 24 to 50 yr) were tested before and immediately after 30 minutes of running. Using a computerized goniometer type instrument (Acufex KSS), knee flexion, axial tibial rotation and anterior-posterior tibial displacement were simultaneously recorded, while the runners underwent tests of static as well as dynamic knee joint laxity. At 30 degrees of knee flexion, a maximum increase of 16 per cent in mean total anterior-posterior laxity post-exercise was found. At the examination 30 minutes post-exercise, laxity at 30 degrees of knee flexion was still increased. However, laxity at 90 degrees of knee flexion had decreased to pre-exercise levels or below. Anterior tibial displacement, recorded during eccentric quadriceps activity (0 to 90 degrees of knee flexion) with weights attached to the foot, showed a maximum of 18 per cent increase in total anterior-posterior laxity post-exercise. It is suggested that the laxity increase is caused in part by a true ligamentous laxity increase, and in part by a decreased resting tone of the fatigued muscles.

[Running injuries sustained in a marathon race. Registration of the occurrence and types of injuries in the 1986 Arhus Marathon]

A questionnaire investigation was undertaken in connection with the Arhus Marathon Race in 1986, with the object of registering experience, previous running injuries, amount of training, running injuries, treatment and causes. A total of 831 replies were obtained (90%). Of these, there were 731 men and 100 women with an average age of 34.6 (11-77) years, duration og training 5.5 months, training distance 47.5 km/week and tempo 10.8 km/hour. Among these, 193 injuries were registered in 161 runners (19%). Eighty-nine had to stop sports for more than one week and 26 still had injuries which limited participation in sport after eight weeks. The injuries consisted of blisters (25%) and stress injuries (66%) particularly in the knee (37%) and leg (23%). Runners who sustained injuries were found to be significantly younger than non-injured runners, their training distance was less and training tempo lower. The causes of the injuries were mainly overexertion. The significance for the types of shoes for stress injuries was investigated and a tendency to increased risk of overexertion injuries was demonstrated on employing competition shoes and cheap jogging shoes.

Mental function in elderly men after surgery during epidural analgesia

To evaluate whether there is a difference in mental function after general anaesthesia and epidural analgesia, a homogeneous group of 40 elderly men (age between 60 and 80) undergoing transurethral prostatectomy was studied. The study was prospective, randomised and double blind. Patients with all types of complications believed to impair mental function were excluded. Long-term, short-term, verbal and visual memory were tested preoperatively, and 4 days, and 3 weeks postoperatively. In conclusion, we found a significant and equal decline in test performance on the fourth postoperative day. Three weeks postoperatively, however, both groups had returned to or exceeded preoperative levels of performance.

[Acromioclavicular dislocation. Conservative or surgical treatment?]

The anatomy of the acromioclavicular joint is described and the mechanism of trauma causing dislocation of the joint is presented. Acromioclavicular dislocation is subdivided according to Allman's classification and special lesions are described. The therapeutic principles are discussed on the basis of the literature. It is concluded that all grade 1 and grade 2 lesions may be treated symptomatically and conservatively with good results. Where grade 3 lesions are concerned, it is concluded that conservative therapy appears to provide better results than operation. The final functional results are the same and the period of convalescence is briefer with conservative therapy. In addition, complications of conservative therapy are less serious and are easy to treat with good results.

Dihydroergotamine and the thromboprophylactic effect of dextran 70 in emergency hip surgery

In a prospective randomized controlled trial treatment with a combination of dextran 70 and dihydroergotamine (DHE) was compared with the administration of dextran 70 alone as prophylaxis against postoperative thrombo-embolic complications in emergency hip surgery. Forty-five consecutive patients with a fractured hip entered the study. Twenty-one were randomized to prophylactic treatment with dextran 70 (group 1) and twenty-four patients received dextran 70 and DHE (group 2). Both regimens were initiated pre-operatively and the surgical and postoperative procedures were the same in the two groups. On the first and fourth postoperative day, Tc-plasmin scintigraphy of the lower extremities and pulmonary ventilation/perfusion scintigraphy were performed to detect any deep vein thrombosis (DVT) and/or pulmonary emboli. A total of 19 per cent of group 1 patients developed DVT and so did 25 per cent in group 2; this difference was not statistically significant. Of the detected DVT, 60 per cent were subclinical, and 7 per cent of the patients had minor pulmonary emboli, all of which were symptomless. No therapeutic difference could be demonstrated between the two regimens. A recent report claiming that adding DHE to the prophylactic administration of dextran 70 considerably reduces the incidence of postoperative DVT in emergency hip surgery is questioned.

Breakage of a sliding hip screw. A case report

I report a case of breakage of a Richards sliding screw used in treatment of a trochanteric fracture. The mechanism was probably prevention of sliding caused by collision with an extra screw.

Postoperative lymphocytopenia and leucocytosis after epidural and general anaesthesia

Few investigations have demonstrated a positive effect of epidural blockade on the leucocytosis and lymphocytopenia secondary to surgery. Thirty elderly patients undergoing total hip replacement were randomly allocated to two groups: epidural analgesia and general anaesthesia. The leucocyte and lymphocyte counts per- and postoperatively were registered. Significant leucocytosis and lymphocytopenia were found in both groups, but no significant difference was found between the groups.