Olof Lundin

Comparison of open and arthroscopic stabilization for recurrent shoulder dislocation in patients with a Bankart lesion.

We performed a prospective study of 117 patients (119 shoulders) with symptomatic, recurrent anterior post-traumatic shoulder instability to compare open versus arthroscopic reconstruction. Arthroscopic reconstructions (N = 66) were performed using bioabsorbable tacks (Suretac fixators), whereas open reconstructions (N = 53) were performed with suture anchors. All of the patients had a Bankart lesion. Independent observers examined 108 of the 119 shoulders (91%) at a median follow-up period of 28 months (range, 24 to 63) for the arthroscopic group and 36 months (range, 24 to 63) for the open group. The recurrence rate, including both dislocations and subluxations, was 9 of 60 (15%) in the arthroscopic group, compared with 5 of 48 (10%) in the open group. At follow-up, the Rowe score was 93 points (range, 39 to 100) and the Constant score was 91 points (range, 56 to 100) in the arthroscopic group, compared with 89 points (range, 53 to 100 and 57 to 100 for the Rowe and Constant scores, respectively) for both scores in the open group. The only significant difference was in external rotation in abduction, which was 90° (range, 50° to 135°) in the arthroscopic group and 80° (range, 25° to 115°) in the open group. Both methods produced stable and well-functioning shoulders in the majority of patients.

Partial rupture of the patellar ligament Results after operative treatment

Partial rupture of the patellar ligament, also known as jumpers knee, is defined as a repetitive overload lesion at the bone-ligament junction at the lower patellar pole. It is found mainly in athletes and is caused either by microruptures or partial macroruptures of the proximal part of the ligament. The abnormal anatomical lesion is focal degeneration, microruptures and macroruptures, and devitalized tissue at the insertion of the patellar ligament. Proliferation and neovascularization are often found, as well as degeneration and incomplete tissue healing. Surgical treatment is indicated only if a pro longed and well-supervised conservative treatment pro gram fails. We operated on 78 patients with jumpers knee, by carefully removing the abnormal tissue from the ligament. At follow-up examination, 71 of 78 pa tients had excellent or good functional results and complete resumption of sports activities. Objective measurements of thigh muscle strength using a Cybex II dynamometer correlated with the functional results at a low angular velocity.

Closing patellar tendon defects after anterior cruciate ligament reconstruction: absence of any benefit

Abstract The most common graft in anterior cruciate ligament (ACL) surgery involves using the central one-third of the patellar tendon. Knowledge concerning the postoperative disability after harvesting the patellar tendon is, however, limited. The aim of this study was to evaluate the impact patellar tendon suture and bone grafting of the patellar bone defect might have in terms of functional outcome and patellofemoral pain after harvesting the bone-tendon-bone graft, compared with leaving the harvested site non-sutured and non-grafted. Sixty patients, scheduled for arthroscopically assisted ACL reconstruction, were randomly allocated to two groups. In group I, suture of the patellar tendon and bone grafting of the patellar defect were performed. In group II, the tendon gap and the patellar defect were left open. Preoperatively, there was no significant difference between the groups when comparing objective knee stability, as measured with a KT-1000 laxity meter, Lysholm score, Tegner activity level, IKDC score, or patellofemoral pain score. Both groups had a significantly improved Lysholm score at the 2-year follow-up, without any difference between them. Tegners activity level was significantly lower at follow-up, compared with the pre-injury level in both groups. The patellofemoral pain score improved significantly after the reconstruction, without any difference between the groups. Ultrasonography did not reveal any difference between the groups in terms of healing of the tendon gap. This study revealed no differences in donor site morbidity, functional outcome, patellofemoral pain score or knee joint stability between the two treatment groups. The conclusion is that suture of the patellar tendon and bone grafting of the patellar defect do not improve the functional results or reduce donor site morbidity after arthroscopically assisted ACL.

Exposure of the porcine spine to mechanical compression: differences in injury pattern between adolescents and adults.

Abstract Recent studies of the spine in adolescents who have sustained trauma have shown injuries to the growth zone, whereas injuries to the vertebral body have been described in other studies of only adults. There are also reports on different clinical signs and radiological findings in adolescents with lumbar disc herniation when compared to adults. In order to find an explanation for these differences between adolescents and adults, this experimental study was performed. Six cadaveric lumbar motion segments (vertebral body-disc-vertebral body) obtained from three young male pigs and six lumbar motion segments obtained from three mature male pigs were tested in axial compression to failure. All units were examined with plain radiography and magnetic resonance imaging before and after compression. After the compression, histological samples were taken from the injury site. In the adolescents, a fracture was consistently found in the endplate through the posterior part of the growth zone, displacing the anulus fibrosus with a bony fragment at the point of insertion to the vertebra. This type of injury could not be detected in any of the adults; instead, there was a fracture of the vertebra in four cases, and in two cases, a rupture of the anulus fibrosus without a bony fragment was seen. This study showed that, when compressed to failure, the weakest part of the lumbar spine of the adolescent pig differs from that of the mature pig in the same way that studies on human spinal units have shown.

Fracture patterns of the adolescent porcine spine: An experimental loading study in bending-compression

Study Design. To expose functional spinal units from adolescent porcine to mechanical flexion-compression and extension-compression to failure. The biomechanical, radiologic, magnetic resonance imaging, and histologic characteristics are described. Objectives. The aim of the present study was to investigate the fracture pattern of functional spinal units from adolescent porcine lumbar spines in in vitro compression loading and bending. Summary of Background Data. In several studies, it has been shown that the adolescent spine, especially the vertebral growth zones, is vulnerable to trauma. A high frequency of abnormalities affecting the spine has been found among athletes participating in sports with high demands on the back. The etiology of these abnormalities is still a controversial issue. Methods. Sixteen functional spinal units obtained from eight adolescent male pigs were used. Eight functional spinal units were exposed to flexion-compression and eight functional spinal units to extension-compression loading to failure. They were examined with plain radiography and magnetic resonance imaging before and after the loading. The functional spinal units were finally examined macroscopically and histologically. Results. Fractures/separations were seen in the growth zone anteriorly and more frequently, posteriorly in functional spinal units exposed to flexion-compression. In the extension-compression group, such injuries occurred only anteriorly. Only large fractures could be seen on plain radiographs and on magnetic resonance imaging. Macroscopically, a fracture/separation could be seen in 15 cases and histologically in all 16 cases. The median angle at failure for the flexion group was 17° (range, 12–19) and for the extension group 17° (range, 13–19°). The median ultimate compression load in the flexion-compression group was 1894 N (range, 1607–3138 N) and in the extension-compression group 1801 N (range, 1158–2368 N). Conclusions. The weakest part of the growing porcine lumbar spine, when compressed into flexion- or extension-compression, was the growth zone. The injury was more extensive in extension loading than during flexion loading. Growth zone injuries of the adolescent spine may go undetected on plain radiographs and magnetic resonance imaging.

Postoperative analgesic effects of an external cooling system and intra-articular bupivacaine/morphine after arthroscopic cruciate ligament surgery

The aim of this study was to evaluate the analgesic effect of an external cooling system with or without the combined effect of intra-articularly administered bupivacaine/morphine after arthroscopic anterior cruciate ligament (ACL) reconstruction. Fifty patients with isolated ACL insufficiency operated on under general anaesthesia were randomized to three different postoperative treatment groups. Group I was treated with the cooling system during the first 24 h after surgery and an intraarticular injection of 20 ml of physiological saline given at the completion of surgery; in group II, the cooling system was combined with an intra-articular injection of 20 ml bupivacaine 3.75 mg/ml and 1 mg of morphine at the end of the operation; while group III (placebo group) received an intra-articular injection of 20 ml of physiological saline at the completion of surgery. Pain was assessed using a visual analogue scale (VAS) at 1, 2, 4, 6, 24 and 48 h postoperatively. Supplementary analgesic requirements were registered. In group I 80% (16/20) and in group II 90% (18/20) of the patients were satisfied with the postoperative pain control regimen (NS). This was significantly better than in group III, where 30% (3/10) were satisfied. The pain scores were significantly lower in the two treatment groups compared with the placebo group during the entire postoperative period. The pain score was significantly lower in group II than in group I at 24 and 48 h after surgery. The supplementary analgesic requirements were also lower in the two treatment groups compared with the placebo group. No complications due to the use of the cooling system or the intra-articular injections of bupivacaine/morphine were observed. The external cooling system used in this study provides an effective method of obtaining pain relief after arthroscopic surgery. The combination with an intra-articular injection of morphine and bupivacaine results in a slightly greater analgesic effect than the cooling system alone.

Intramuscular Pressure in the Leg and Thigh Related to Tensile Strap Force During Knee Brace Wear An Experimental Study in Man

The effects of a functional knee brace on intramuscular pressure in the leg and thigh were measured in eight subjects with a mean age of 32 years. Pressures in the tibialis anterior and rectus femoris muscles were recorded without a knee brace and with a brace applied with strap tensile force of 25 N, 50 N, and a force preferred by the subject. External compression caused by the brace significantly increased intramuscular pressures at rest and muscle relaxation pressure during exercise in the leg and thigh muscles. Pressure in the tibialis anterior muscle increased 3 to 10 times, to mean values between 17.5 and 41 mm Hg, depending on the tensile force of the straps used at brace application. Corresponding mean pressure values in the rectus femoris muscle were between 17.5 and 32.5 mm Hg. Mean pressures in the standing subject varied between 37 and 62 mm Hg. Our study showed that intramuscular pressure at rest and muscle relaxation pressure during exercise in the tibialis anterior and the rectus femoris muscles increased significantly in the braced limb. Local blood perfusion pressure in the supine subject decreased significantly, by 16% to 42%, in the compressed muscles.

Effects of a Functional Knee Brace on Leg Muscle Function

The effects of a functional knee brace on local intra muscular pressures and on calculated blood perfusion pressure in the tibialis anterior muscle of the legs of six volunteers were determined. Torque generation during dorsiflexion of the ankle joint was measured with a Ki netic Computerized ergometer, and the time to elicit muscle fatigue during exercise was recorded. For each experimental subject studies compared right with left unbraced legs, then right braced with left unbraced legs, and finally right unbraced with left braced legs. In the braced leg, intramuscular pressure at rest and muscle relaxation pressure during exercise were significantly higher, and the time to elicit muscle fatigue was 35% shorter. The calculated local blood perfusion pressure was lower because of the increased muscle relaxation pressure. We conclude that the increased muscle re laxation pressure during exercise caused by a knee brace is a possible explanation for the premature development of muscle fatigue in the braced leg.