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 reduces graft slippage compared to extraction drilling in anterior cruciate ligament reconstruction: a randomized controlled trial using radiostereometric analysis.

PURPOSE: This study tested the hypothesis that serial dilation of the tibial tunnel could provide a stronger anchorage of the graft-fixation-device complex compared to traditional extraction drilling. METHODS: Forty patients (22 men and 18 women) undergoing ACL reconstruction were randomized to either extraction drilling (group ED) or compaction by serial dilation (group SD) of the tibial tunnel. Tantalum beads were placed in the tibia, femur, and in the hamstring graft. Radiostereometric analysis (RSA) was performed postoperatively and again after 6, 12, and 24 weeks. Migration of graft in the bone tunnels as well as knee laxity was assessed using RSA and a TELOS stress device. RESULTS: Six patients (three men and three women) were excluded during follow-up, which resulted in 17 patients in group ED [median age 30 years (range 20-50)] and 17 patients in group SD [median age 32 years (range 20-49)]. The mean migration of the graft in the tibial bone canal after 3 months was 1.3 (SD 0.6) mm in group ED and 0.8 (SD 0.5) mm in group SD (P = 0.02). The overall knee laxity after 3 months was 13.0 (SD 4.0) mm in group ED and 10.9 (SD 3.1) mm in group SD. CONCLUSION: This study found less slippage of the hamstring graft in the tibial bone canal in the serial dilated group compared to the extraction drilling group. The clinical relevance of the difference is unknown. No difference in stress radiographic knee laxity was found between the two groups.

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.

[Acromioclavicular dislocation. Conservative or surgical treatment?]. / Akromioklavikulaer luksation. Konservativ eller operativ behandling.

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.

[Waiting lists--how valid are the official numbers? Evaluation of a waiting list at a department of orthopedic surgery]. / Ventende til indlaeggelse--er de officielle tal reelle? Ventelisteopgørelse på en ortopoedkirurgisk afdeling.

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.

[Running injuries sustained in a marathon race. Registration of the occurrence and types of injuries in the 1986 Arhus Marathon]. / Løbeskader ved motionsmarathon. Registrering af skadehyppighed og skadetyper ved Arhus Marathon 1986.

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.

[Finger tip injuries. A comparative study of silver sulfadiazine and fucidin gauze]. / Pulpalaesioner. En sammenlignende undersøgelse af sølvsulfadiazin og fusidin-gaze.

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.

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.

"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.

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.

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.

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).

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.

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.