Biases in a randomized comparison of three types of screw fixation in displaced femoral neck fractures.

We studied fixation of displaced femoral neck fractures prospectively in a randomized multicenter study, comparing 2 Olmed screws, 2 Tronzo screws and 3 Ullevaal hip screws. The study population consisted of 482 women and 125 men, of whom 432 women and 100 men were older than 65 years of age. Their median age was 80 (54-97) years. Despite agreement on criteria, the rates of reoperations for pain and failure--salvage (prosthesis replacement) and other reoperations (removal of implant)--differed significantly between the 3 hospitals regardless of type of fixation. In total, the percentages of salvage operations were: Olmed screw 17/175, Tronzo 17/130 and Ullevaal screw 11/302 (n.s.); the percentages of other reoperations were 11, 6 and 13, respectively (n.s.). In the whole series, the 2-year rate of salvage operations was 14%. No differences between the implants were found in patients older than 65 years of age. We conclude that an agreed, common definition of a hard end-point (reoperation) does not ensure comparability of results, because of differences in clinical decision making.

The Hauser operation for patellar dislocation. 3-32-year results in 63 knees.

The Hauser operation for patellar dislocation was performed in 34 women and 20 men, median age 18 (3-55) years; one leg was amputated because of wound infection with chronic septic arthritis. At the time of follow-up, 8 (3-32) years after the operation 57 knees had normal or almost normal patellar stability, but only 26 knees were free from pain. Only 16 knees had both normal patellar stability and were without pain. Patellar arthrosis had developed in 16 knees and femorotibial arthrosis in 23 knees. Eleven patients operated on before the age of 15 years showed varying grades of axial deformity of the proximal tibia.

Sliding of the compression hip screw in femoral neck fractures.

Backing out of the compression screw in the sliding screw-plate hip osteosynthesis was analyzed in a series of 71 hips with medial femoral neck fractures during an observation period of 12-42 months, with a median of 26 months. In addition to the compression screw device, a parallel cranial lag screw was used. A postoperative primary diastasis in the fracture space of 1-5 mm in 11 cases did not predispose to major sliding of the screws or to healing problems. Thirteen of 27 fractures with late screw telescoping of 4 mm or more showed healing disturbances, 11 late segmental collapses, and 2 nonunions, compared with 7 disturbances, 6 late segmental collapses, and 1 nonunion among 39 cases with screw gliding of 3 mm or less. The difference was significant (p less than 0.05, Mann-Whitney). Five early mechanical failures were excluded from this analysis.

Extra-articular stabilization of the knee a.m. Losee.

During 1979-81, 34 patients were operated according to Losee for chronic disabling anterior cruciate insufficiency. Twenty-nine patients were available for follow-up after 2 (1-4) years. At follow-up, 20 patients had a negative Slocum test. Twenty-one patients had a Lysholm knee score greater than 77 points, and were classified as good or excellent, with a significant relation to anterolateral stability.

Primary repair in posterior cruciate ligament injuries.

A retrospective study of 32 consecutive patients with acute injury of the posterior cruciate ligament (PCL) treated by primary repair is presented. Only six patients had isolated injuries of the PCL, five of these as avulsion of a bone fragment from the tibia. The remaining 26 patients sustained combined ligament injuries, including 18 total ACL tears. All ruptured ligaments were repaired. At follow-up after 4 (1-7) years, function in 26 patients was excellent-good and in six fair-poor. Moderate or severe posterior instability was found in seven patients by clinical examination but their function was as good as in those with stable knees. Inferior functional results, however, were more often related to rotatory instability. Primary repair of PCL-injuries, including all associated ligament injuries, is recommended.

Knee function following suture of fresh tear of the anterior cruciate ligament.

A retrospective consecutive series of 60 patients treated with primary suture of knee ligament injuries is presented. All patients had an anterior ligament (ACL) tear. In 54 patients this injury was combined with a medial compartment tear. Four patients had isolated tears of the ACL. At follow-up after 4 years, 11 patients complained of instability, and in eight of these an anterolateral rotatory instability was demonstrated by the Slocum test. In contrast, only five of 49 patients with subjectively stable knees had positive Slocum tests. Thirty of 47 patients with negative Slocum tests had excellent function, compared with four of 13 patients with positive tests.

Effects of a distal venting hole in the femur during total hip replacement.

In 18 patients who underwent total hip replacement, the intramedullary pressure in the femur was measured during the insertion of the femoral prosthesis component. Half the patients had a pressure release hole (diameter 4.5 mm) drilled into the medullary canal at the distal end of the femur, the other half not. In the patients without a venting hole, the intramedullary pressure increased transiently to a median of 390mmHg during the insertion of the femoral stem, while those with a venting hole only showed an increase to 23mmHg. A drop in arterial oxygen tension of 2.2kPa and in thrombocytes of 51 x 10(9)/1 was found in those without a venting hole, while the corresponding values in those with a venting hole were 0.9kPa and 20 x 10(9)/1. Furthermore, a significant correlation was demonstrated between the increase in intramedullary pressure and the drop in oxygen tension and in blood platelets. No significant change in blood pressure was measured during operation in either group.

Patellofemoral disorders treated by operations.

Thirty-six patients with patellofemoral disorders treated with various operative procedures were evaluated after an average follow-up period of 29 (6 to 72) months. Instability of the patella, either recurrent dislocation or subluxation, was present preoperatively in 27 knees (Group A). Twelve patients (Group B) were operated on for chondromalacia, which was not combined with a history of instability. Good results were obtained in 15 cases in Group A and in only three cases in Group B. Simple procedures, lateral release alone and medial duplication alone appeared to be ineffective methods.

Effect of instability of experimental fracture healing.

Bilateral tibial osteotomy with fracturing of the fibula was performed on ten Wistar rats weighing 300--350 g. Intramedullary nailing was performed with 1.4 mm nails after reaming. On the left side solid stainless rods were used, while on the right side the nails had a middle part made of titanium-nickel wire covered with polyvinylchloride (PVC), giving the nail a high degree of flexibility. After 8 weeks, nine of the ten flexible nails showed fracture of the central wire. The continuity was, however, maintained by the PVC tube. The bones with flexible nailing always showed hypertrophic callus while there was only scanty callus on the side with rigid nailing. Strength, deformation at fracture and stiffness were measured in a three-point bending test after removal of the solid nails and the fibulae. The strength of the tibiae was greatest on the side with flexible nailing, as was the deformation at fracture. The mean stiffness was higher in the bones with rigid nails, but the difference here was not statistically discernible.

Anterior interbody fusion of the lumbar spine.

Anterior interbody fusion of the lumbar spine by the extraperitoneal technique was performed in 47 patients with incapacitating low-back pain due to spondylolisthesis (26 patients) or disc degeneration (21 patients). The mean age was 38.2 years. Forty-five patients were re-examined 2--6 years postoperatively. According to the patients' own evaluation at follow-up, 53 per cent were free or almost free of back pain, 29 per cent were improved, 11 per cent unchanged and 7 per cent felt that the condition had deteriorated. Non-union occurred in nine patients, but among these three were free of pain, four were better and two were worse than before operation. The results do not seem to be correlated with age, sex, duration of pain before operation, degree of slipping in spondylolisthesis or the length of time out of work before surgery. It is concluded that this method may be worth continuing, but the patients should be selected with care.

Replacement with the Christiansen endoprosthesis in acute femoral neck fractures. A 5 year follow-up study.

Patients with acute femoral neck fractures, treated with prosthetic replacement (Christiansen's trunnion bearing endoprosthesis), were followed up at 15 months and again at 67 months postoperatively, and the results of the two examinations have been compared. The patients' personal opinion of the results of the operation did not change between the time of the first and second follow-up examinations. However, the objective results showed a deterioration in function (according to Stinchfield's hip assessment scheme) with increasing follow-up time. This deterioration in rating was mostly caused by reduced walking ability. X-ray study of the hips showed an increasing frequency of acetabular protrusion, and settling and loosening of the prosthetic stem. No clear correlation between X-ray findings and clinical results could be found. We conclude that the serviceability of the prosthetic operation is apparently good despite the objective evidence of progressive deterioration both in the grading of the results and in the X-ray findings.

Internal fixation of fractures of the neck of the femur using von Bahr screws and allowing immediated weight bearing: a prospective clinical study.

This article presents the results of von Bahr screw fixation in 103 patients, allowing immediate weight bearing. After a follow-up period of 1 year, a failure rate of 18% was recorded. Analysis of the series shows that the failures are due to inadequate reduction of the displacement during operation, especially when the head is in varus, and to bad positions of the screw. The high failure rate was not related to the initial displacement of the fracture.

Interaction between acute gastric ulcer and epinephrine-induced mucosal erosions in the rat: the significance of gastric acid secretion.

Gastric mucosal erosions were produced in rats by pyloric occlusion and intraperitoneal injection of epinephrine. Gastric ulcer was induced by application of acetic acid to a limited area of the stomach. pH, total amount of acid and volume of gastric juice were determined 5 h after pyloric occlusion. The presence of an acute acetic acid ulcer partly inhibited the development of mucosal erosions induced by pyloric occlusion and epinephrine. The gastric ulcer was associated with decreased acid secretion. A positive correlation was obtained between the degree of mucosal erosions and the total amount of acid in the stomach.