Capsular distance in the hip of the healthy child - normal values with sonography and MR imaging.

PURPOSE: To determine the normal values of the anterior and posterior capsular distances of the hip joint in healthy children by means of US, using MR imaging as reference, and to evaluate any possible correlation between age, length, weight and anterior capsular distance (ACD). MATERIAL AND METHODS: In our first study both hips in 14 healthy children (5-18 years old) were examined with US and MR to obtain measurements of the ACD and the posterior capsular distance (PCD). The distance from the anterior or posterior aspect of the femoral neck to the anterior or posterior aspect, respectively, of the outer limit of the capsule was determined. The distances were measured both with the hips in spontaneous external rotation of 10-15 degrees and in internal rotation of 45 degrees. In our second study, both hips in 28 healthy children (3-16 years old) were examined with US to determine the ACD. Age, length and weight were recorded. RESULTS: Study I: There was good correlation between the US and MR measurements in all positions. The ACD measured by US was significantly increased in inward rotation of the hip. Study II: There was no correlation between ACD and age, length or weight. CONCLUSION: The PCD of the hip joint can be accurately measured by US with the hip in internal rotation of 45 degrees. When compared with MR values, the ACD measured by US was dependent on the degree of rotation of the leg and increased significantly in internal rotation. Because the outer limit of the external layer of the joint capsule is sonographically more distinct, we suggest that the capsular distance should be measured from the outer limit of the joint capsule to the anterior or posterior aspect of the femoral neck. The measurement should be made perpendicular to the femoral neck, at the position where the greatest numerical value is obtained.

Cervical spine surgery in rheumatoid arthritis. A Swedish nation-wide registration of 83 patients.

OBJECTIVE: To investigate diagnostic methods, surgical methods and indications, early complications and short term outcome of cervical spine surgery for rheumatoid arthritis (RA). METHODS: A nation-wide registration of rheumatoid cervical spine surgery carried out in Sweden during 1993. RESULTS: Eighty-six (74 primary) procedures in 83 patients were reported from 11 hospitals. Pain was a more common indication for surgery than was neurologic impairment. C1-C2 instability or subluxation was present in 66/82, subaxial subluxations in 27/82 and atlantoaxial impaction in 10/82 procedures (data partly missing in one case). Indications for surgery and preoperative investigations were found to be reasonably uniform, but surgical methods and post-operative care varied between hospitals. Posterior fusion was performed in 76 patients. C1-C2 wiring with bone grafting was the most common procedure followed by occipito-cervical fusion with wires and bone cement. Subaxial cervical decompression without fusion, posterior fusion with onlay graft only, and carbon fiber grafts were used in a small number of patients. Total mortality was 5/83. The early complication rate was low, but 17 patients showed recurrent subluxation at follow-up at median 7 (1-17) months. Seven of them required reoperation in the same segment. CONCLUSION: The variation in treatment policy and number of operated patients in the different hospitals speak in favor for centralization of cervical spine surgery in RA. New methods for C1-C2-fusion need to be evaluated.

Cervical laminectomy without fusion in patients with rheumatoid arthritis.

OBJECT: The authors performed a prospective study to determine whether cervical laminectomy without simultaneous fusion results in spinal instability. METHODS: Because of clinical and radiographic signs of cord compression, 15 patients with rheumatoid arthritis (including one with Bechterew's disease) and severe involvement of the cervical spine underwent decompressive laminectomy without fusion performed on one or more levels. Preoperative flexion-extension radiographs demonstrated dislocation but no signs of instability at the level of cord compression. Clinical and radiological reexamination were performed twice at a median of 15 months (6-24 months) and 43 months (28-72 months) postoperatively. One patient developed severe vertical translocation 28 months after undergoing a C-1 laminectomy, which led to sudden tetraplegia. She required reoperation in which posterior fusion was performed. No signs of additional instability at the operated levels were found in the remaining 14 patients. In three patients increased but stable dislocation was demonstrated. The results of clinical examination were favorable in most patients, with improvement of neurological symptoms and less pain. CONCLUSIONS: The authors conclude that decompressive laminectomy in which the facet joints are preserved can be performed in the rheumatoid arthritis-affected cervical spine in selected patients in whom signs of cord compression are demonstrated, but in whom radiographic and preoperative signs of instability are not. Performing a simultaneous fusion procedure does not always appear necessary. Vertical translocation must be detected early, and if present, a C-1 laminectomy should be followed by occipitocervical fusion.

OP-1 for cervical spine fusion: bridging bone in only 1 of 4 rheumatoid patients but prednisolone did not inhibit bone induction in rats.

We used OP-1 (also called BMP-7) on a collagen type-1 carrier in atlanto-axial posterior fusions to promote bony healing after wire fixation. 4 patients who had instability between the atlas and axis due to rheumatoid disease received the implants. The patients were examined with conventional radiography postoperatively at 2, 6 and 10 months. In 3 patients, no new bone formation was detectable. In 1 patient, new bone bridged the fusion site at 6 months. 3 patients were on chronic steroid treatment, including the patient in whom bone formation was detected. To determine whether steroid treatment could be responsible for the low rate of bone induction, 24 rats each received OP-1 implants in an abdominal muscle pouch. They were divided into 3 groups receiving saline, 0.1 or 1.0 mg/kg BW of prednisolone daily until they were killed 3 weeks postoperatively. Specimens were decalcified for histology and the amount of calcium in the decalcifying solution was measured. All groups showed ossicles induced by OP-1, and no effect of prednisolone was detected. Thus the failures in the patients may have causes other than prednisolone treatment.

Interposition arthroplasty of the elbow with rheumatoid arthritis.

Radiographic bone loss and clinical outcome were evaluated at a median of 6 years after interposition arthroplasty was performed in 35 elbows with rheumatoid arthritis. Seven early postoperative complications, two major and five minor, occurred. Three elbows subsequently required total elbow replacement. Clinical results were good in terms of pain relief but only fair in terms of joint mobility and stability. Radiographic elbow destruction progressed to a higher Larsen stage in half of the elbows. Measurements revealed humeral bone loss in two thirds of the elbows and ulnar bone loss in one third. In comparison with total elbow replacement, the long-term results of interposition arthroplasty were found to be inferior, with a total elbow replacement being required in one tenth of the elbows in the long term. In addition, bone loss often became extensive, making reoperation difficult or impossible. The authors recommend total elbow replacement as the first choice in the surgical treatment of the painful elbow with rheumatoid arthritis and cartilage destruction.

Short-term complications of the lateral approach for non-constrained elbow replacement. Follow-up of 50 rheumatoid elbows.

We reviewed 50 capitellocondylar elbow replacements performed by the lateral approach in 42 rheumatoid patients, at a median follow-up of three years. There were two major and 17 minor complications; 18 were early and one was late. Eight elbows required reoperation: soft-tissue surgery was performed in seven and prosthesis removal in one because of a deep infection. There were few problems of instability, but one patient sustained a traumatic dislocation which was stabilised after ligament reconstruction. Wound healing was delayed in two of five elbows which had been immobilised postoperatively for only five days, but healing was rapid in 45 elbows immobilised for 12 days. There was transient ulnar-nerve palsy postoperatively in 11 patients, with permanent palsy in three. All elbows were painfree or only slightly painful at follow-up; 49 were stable and 43 had a range of motion sufficient for activities of daily living. Radiological loosening of the humeral component was suspected in one asymptomatic elbow. The lateral approach is recommended for use with the capitellocondylar type of prosthesis in rheumatoid elbows with reasonably well-preserved bone stock.

Intraoperative monitoring of ulnar nerve function during replacement of the rheumatoid elbow via the lateral approach.

Neurography of the ulnar nerve was performed pre-, intra- and postoperatively in 8 arms of 7 patients with rheumatoid arthritis operated on with total elbow replacement via the lateral approach. Ulnar nerve decompression was performed in 4 elbows before implantation. A reduction in the amplitude of compound muscle action potential (CMAP) recorded from the abductor digiti minimi on stimulation of the ulnar nerve in the axilla, was observed during elbow dislocation at surgery in all patients, in 5 cases transiently and in 3 cases until the end of surgery. The ulnar nerve had been decompressed in all patients with lasting amplitude reduction. One of them had a mild sensory ulnar nerve palsy, while the other 2 had normal nerve function at the postoperative clinical examination. All 3 had a reduction in the amplitude of compound sensory nerve action potential (SNAP) and 2 of them also in CMAP amplitude at the postoperative neurographic examination. In patients with transient reduction during surgery, the CMAP amplitude quickly normalized on relocation of the elbow and both the SNAP and the CMAP were preserved at the postoperative neurographic examination. The authors conclude that dislocation of the laterally approached elbow carries a risk of ulnar nerve injury, which is not prevented by decompression of the ulnar nerve, but frequent relocation of the elbow during surgery seems important. It is suggested that the ulnar nerve should not be decompressed routinely, and that the dislocated elbow should be frequently relocated.

Occipito-cervical fixation in rheumatoid arthritis--an analysis of surgical risk factors in 163 patients.

163 patients with rheumatoid arthritis (RA) and atlanto-axial subluxation treated by posterior occipito-cervical fixation (OCF) over a period of twenty-one years (November 1970-January 1991) were followed. Common complaints prior to surgery were occipital headache, neck pain, radicular pain and myelopathy. The mean age at time of surgery was 61 years. The mean follow-up time was 54 months. Clinical improvement was obtained in 88% of the patients, whereas 7% were unchanged and 5% had progressive symptoms in spite of surgery. There was no pre-operative or immediate postoperative mortality. In 79 patients, one or more potential surgical risk factors were identified. Twenty-four reoperations were performed in the neck. The most common cause for reoperation was mechanical failure due to wire-break or spinous process fracture. Wound infection in the neck was recorded in 16 patients. Five were deep and required removal of the fixation material. Following OCF, new or progressive subaxial subluxation (SAS) led to further surgery in 4%. The study offers support for the beneficial effect of OCF in rheumatoid AAS. We conclude that, in spite of a number of identified risk factors, OCF with the Brattström-Granholm technique remains a safe and effective method for stabilization of upper cervical subluxations in RA.

Bovine bone grafting in occipito-cervical fusion for atlanto-axial instability in rheumatoid arthritis.

Bovine bone chips (Surgibone) were used in occipito-cervical fusion in nine patients with atlanto-axial instability due to rheumatoid arthritis. The patients were examined with CT 12-15 months after surgery. Graft resorbtion was observed in one patient. The other 8 patients showed preserved grafts, in most cases the grafts appeared to be in contact with the underlying bone. One patient was revised, and at the grafted site a bony bridge was found. In conclusion, the use of bovine chips in posterior occipito-cervical fusion will not lead to predictable bone union. However, there seem to be exceptions to that rule.

Technetium-99m-nanocolloid scintigraphy in orthopedic infections: a comparison with indium-111-labeled leukocytes.

Twenty-three patients with clinically suspected acute or chronic osteomyelitis and 21 patients with suspected joint prosthetic infection underwent scintigraphy using both 99mTc-nanocolloid and 111In-labeled leukocytes. The scintigrams of the two tracers were blindly interpreted by three independent observers. Their evaluations showed high correspondence. Patients were classified as having no infection, probable infection or proven infection according to specific criteria which included results of bacteriological cultures and histopathological examinations. For proven and probable infection taken together, the sensitivity with 99mTc-nanocolloid was 94%, the specificity 84% and the accuracy 87%, compared with 75%, 90% and 85% with 111In-labeled leukocytes. We conclude that 99mTc-nanocolloid scintigraphy is at least equivalent with 111In-leucocyte scintigraphy, and its additional advantages are shorter examination time, less complexity and better radiation dosimetry.

Comparison of talonavicular dowel arthrodesis utilizing autogenous bone versus defatted bank bone.

A simple dowel arthrodesis of the talonavicular joint in an early stage of destruction can reduce pain and prevent the development of valgus deformity in the rheumatoid hindfoot. Previously, we used autogenous dowels made from the iliac crest. In order to facilitate the operation and to get a better fitting dowel, we tried defatted cancellous allograft dowels from which marrow tissue had been removed. The dowels were prepared from femoral heads in our surgical bone bank. At operation, the dowels were embedded in fresh marrow aspirate from the iliac crest and the arthrodeses were stabilized with a staple. Results were evaluated by clinical examination and radiography. The results of four patients were compared with an earlier study of eight patients using autogenous dowels taken from the iliac crest. With both techniques, the patients were relieved of pain in the talonavicular joint, but some had pain from other hindfoot joints. With autogenous dowels, all eight patients healed with radiographic bony union, but with allogenous dowels, the four patients developed fibrotic nonunion. The results indicate that talonavicular arthrodesis should be made using only autologous dowels.

Metal backing improves the survival of surface replacement of the hip.

Nineteen patients with juvenile chronic arthritis underwent 29 resurfacing hip arthroplasties. In 22 the original all-plastic Wagner acetabular component was used and in 7 the metal-backed Wagner-Tillmann component. After a mean of 11 (range 8-13) years 19 of the Wagner acetabular components had been revised and another 2 showed radiographic loosening. After a mean of 7 (range 5-9) years no metal-backed acetabular cup had been revised and only 1 was definitely loose.

Surface replacement of the humeral head in the rheumatoid shoulder.

The clinical results obtained an average of 4.2 years after resurfacing of the humeral head in 72 rheumatoid shoulders showed 94% of the patients being pleased regarding pain relief and 82% reporting improved shoulder mobility. Shoulder function was significantly improved. The radiographs were analyzed regarding the position of the humeral head resurfacing cup, proximal migration of the humerus, and glenoid attrition during the follow-up period. Change of the distance between the superior margin of the cup and the greater tuberosity and/or change of inclination of the prosthesis were regarded as signs of prosthetic loosening. With that definition, 25% of the cups were found to be loose at follow-up. Prosthetic loosening, however, had no bearing on the clinical result. Also, no relationship was found between the position of the cup and the clinical outcome. Neither progressive proximal migration of the humerus in 38% of the shoulders nor central attrition of the glenoid in 22% of the shoulders showed any relationship to gain of mobility, pain relief, or functional ability.

Hyperthermia during occipito-cervical fusion with acrylic cement. Epidural thermometry in 23 cases.

In 22 patients, 23 posterior occipito-cervical fusions using acrylic cement were studied; 18 had seropositive rheumatoid arthritis and 4 traumatic atlanto-axial instability. The mean age was 60 (39-75) years. During the curing of the cement, epidural temperature measurements were performed over the cerebellum and between the foramen magnum and C1. Temperatures up to 69 degrees C were recorded. Cooling with profuse surface irrigation using normal saline solution or precooled 8 degrees C fluid did not influence the maximal temperatures recorded under the cement. Even though no gross neurological damage was noted, the epidural temperatures in occipito-cervical fusion with acrylic cement can be of sufficient degree to be hazardous; surface irrigation does not seem to be an effective way to reduce this risk.

Talonavicular arthrodesis in the rheumatoid foot.

Arthrodesis of the talonavicular joint with a cylindrical dowel was performed in 19 feet in 17 rheumatoid patients with arthritic destruction of the talonavicular joint, but without fixed hindfoot deformity. Osseous union was achieved in 12 feet, but all patients experienced pain relief and no foot showed progressive valgus deformity of the hindfoot during follow-up. Staple fixation seemed to promote osseous union. The procedure, easy to perform and requiring only 6 weeks of immobilization, may, in the absence of fixed hindfoot deformity, supersede triple arthrodesis in rheumatoid patients with hindfoot arthritis.

Severe aseptic synovitis of the knee after biodegradable internal fixation. A case report.

Biodegradable rods made of polyglycolide (Dexon, Biofix) or lactide-glycolide copolymer (Vicryl) have been used for the past 5 years for internal fixation of a variety of fractures and osteotomies (Böstman et al. 1989, 1990b). Experience from using such rods for fixation of intraarticular osteochondral lesions seems to be less extensive. We report a case of severe synovial reaction to biodegradable rods used for fixation of osteochondritis dissecans of the knee and discuss possible reasons for the increased risk of foreign-body reactions when these rods are used intraarticularly.

MR imaging of the knee in acute rheumatoid arthritis: synovial uptake of gadolinium-DOTA.

In patients with rheumatoid arthritis, the presence of acute synovial inflammation is an indication of the activity of the disease. It is an important finding because it often influences therapeutic decisions. However, acute synovitis may be difficult to detect by clinical examination, especially if a joint effusion also is present. As gadolinium tetra-azacyclododecane tetraacetic acid (Gd-DOTA) can be expected to accumulate in areas of acute inflammation, we studied the value of Gd-DOTA-enhanced MR to determine the presence of acute synovitis. Nine patients with current knee symptoms underwent MR examination of the knee. Short and long TR/TE MR images were obtained with a 0.3-T magnet before and immediately after IV administration of Gd-DOTA. A 15-min delayed short TR/TE image also was obtained. Of eight patients with moderate to severe clinical evidence of acute synovitis, six had marked increase and two had moderate increase in signal intensity from synovial tissue on the short TR/TE image obtained immediately after administration of contrast material. In the ninth patient, who had minimal synovitis clinically, the signal from the synovium did not change after administration of contrast material. No difference was seen between the enhancement pattern on the immediate and the 15-min delayed images. These results suggest that Gd-DOTA is taken up by inflamed synovium and that Gd-DOTA-enhanced MR scans may be useful in detecting acute synovitis in patients with rheumatoid arthritis.