Fate of allogeneic embryonal chick chondrocytes implanted orthotopically, as determined by the host's age.

Chondrocytes derived from chick embryos can be successfully implanted in defects of adult chick articular cartilage surfaces. Such implants thrive in their implantation site and create a new articular surface. The chondrocytes mature and hypertrophy in the orthotopic site without invoking an immune response. Eventually a steady state is reached in which mature chondrocytes resurface the defect while in the deeper areas spongy bone replaces the hypertrophic chondrocytes. Time schedules of these repair events have been studied in hosts of different ages. We compared 4-month-old chicks with 3-year-old chickens. The embryonal chondrocytes implanted in the latter group underwent an accelerated aging process. The defects were completely filled-up after 1 month as compared with 2-3 months in the younger age group. Endochondral ossification in the older group was evident as early as 2 months post implantation and was completed after 6 months. This contrasts with the situation in the younger group where the chondrocytes only began to hypertrophy after 6 months. At this stage endochondral ossification was hardly seen at all. A unique response to the cartilaginous implants is seen in the old group only in the vicinity of the reparative tissue, accumulation of hematopoietic centers. This study seem to indicate that the host's environment affects the "biological clock", i.e. rate and degree of aging of the implanted cells, as well as their matrices.

99mTc-MIBI scintigraphy in musculoskeletal tumors.

UNLABELLED: The aim of this study was to assess the value of 99mTc-hexakis2-methoxyisobutylisonitrile (MIBI) scintigraphy in patients with clinical and radiologic features of primary or metastatic musculoskeletal tumors. METHODS: The scintigraphic findings for 84 patients were compared with the surgical and histologic findings. Each patient underwent three-phase bone scanning with 99mTc-methylene diphosphonate (MDP) and dynamic and static MIBI scintigraphy. The MIBI scans were evaluated by visual and quantitative analysis. The count ratio of the lesion to the adjacent or contralateral normal area (L/N) was calculated from the region of interest drawn on the MIBI scan. The Mann-Whitney test was used to determine the differences between the uptake ratios of malignant and benign lesions. RESULTS: Although increased MDP uptake was not specific for bone malignancy, a significant difference was found between benign tumors (L/N = 1.22 +/- 0.43) and malignant tumors (L/N = 2.25 +/- 1.03) on MIBI scans. Sensitivity and specificity were 81% and 87%, respectively. Forty-six of 53 proven benign lesions did not show significant MIBI uptake. The negative predictive value was 88%. In all seven sites of pathologic fracture, significant uptake was seen. However, three malignant lesions were not detected by MIBI scintigraphy, whereas seven benign lesions showed false-positive results. CONCLUSION: The major diagnostic worth of MIBI scintigraphy is its high negative predictive value. Although not capable of replacing tissue biopsy as a definitive diagnostic modality for musculoskeletal neoplasms, MIBI scintigraphy does appear to have a role in better preoperative assessment and in distinguishing between pathologic and simple fractures.

Intra-articular hyaluronan injections for the treatment of osteoarthritis of the knee: a randomized, double blind, placebo controlled study.

OBJECTIVE: Hyaluronic acid (HA) polymers have been found to be useful as viscosupplements for the treatment of osteoarthritis (OA) in a number of clinical studies. It appears that HA with high molecular weights (HMW) are more effective than low molecular weight HA polymers. METHODS: A single blind, initial randomized study was conducted involving two randomly selected patient groups, which received injections of either placebo or BioHy, a highly purified HMW HA produced by bacterial fermentation. HA was administered intra-articularly and several functional tests, including pain level, stiffness, and physical function, were used to score efficacy at various intervals throughout the study. RESULTS AND CONCLUSION: The results through week 20 indicate that BioHy provides relief for osteoarthritic patients without causing adverse effects, although the study was not sufficiently powered to obtain statistically significant differences between the treatment groups.

Changes in proteoglycans of intervertebral disc in diabetic patients. A possible cause of increased back pain.

STUDY DESIGN: Characterization of the analytic profile of proteoglycans in the intervertebral discs at L4-L5 of nondiabetic (n = 5) and diabetic (n = 5) age-matched subjects. The discs used were discarded material from operations. OBJECTIVES: To clarify the reason for the higher risk of disc prolapse in diabetic patients. SUMMARY OF BACKGROUND DATA: The pathogenesis of diabetes results from a combination of neurologic dysfunctions and a yet undefined metabolic failure, which leads to an abnormal proteoglycan profile. METHODS: The following methods were used to determine the proteoglycan profile: the measurement of 35S-sulfate uptake per gram wet tissue into sulfated glycosaminoglycan using fresh tissue explants; extraction of proteoglycans by 4 M guanidinium chloride containing protease inhibitors, with further purification by ultracentrifugation on cesium chloride buoyant density gradient under dissociative conditions; total uronic acid and protein contents in the various gradient fractions; assessing the length of sugar side chains of isolated 35Sulfate-glycosaminoglycan molecules by separation of the glycosaminoglycan molecules on a Sepharose 6B-CL column; and paper chromatography of the final digest products of glycosaminoglycan molecules obtained by chondroitinase ABC, a glycosaminoglycan-degrading enzyme. RESULTS: The findings show that discs from normal nondiabetic subjects have 15 times the rate of 35Sulfate incorporation into glycosaminoglycan molecules than do discs of diabetic patients. The proteoglycans of diabetic patients are banded at a lower buoyant density, indicating a lowered glycosylation rate and a lower number of sugar side chains per core protein. In discs of diabetic patients, there is a slight increase in the chain length of chondroitin sulfate. Further analysis of the glycosaminoglycan chains showed a decreased amount of keratan sulfate, compared with that in nondiabetic subjects. However, the total uronic acid content of the disc tissues and the ratio of uronic acid to protein of each fraction were unchanged in diabetic patients versus that in control subjects. CONCLUSIONS: Discs in patients with diabetes have proteoglycans with lower buoyant density and substantially undersulfated glycosaminoglycan, which with the specific neurologic damage in these patients, might lead to increased susceptibility to disc prolapse.

Abduction-traction injury of the knee.

Disruption of the major ligaments of the knee was seen in six young men, five parachutists and a house painter, after what we have termed abduction-traction injury. This unusual complaint results from the application of a sudden block to the ankle while falling head first, leading to traction and abduction of the knee. All the patients underwent operations, generally with unsatisfactory results. At operation tears of the anterior cruciate ligament, medial collateral ligament and posterior oblique ligament were seen in each case; in four patients the posterior capsule and in three the posterior cruciate ligament also were torn. In one patient the lateral collateral ligament was torn and the lateral meniscotibial ligament was avulsed. The compression component is absent in this type of injury and consequently the menisci and the osteochondral surfaces of the tibia and femur remained intact in each case.

Microbiologic flora contaminating open fractures: its significance in the choice of primary antibiotic agents and the likelihood of deep wound infection.

A clear understanding of the significance of wound contamination as well as knowledge of the microbial flora that could be expected are needed in order to administer a rational and effective antibiotic treatment for open fractures. We have conducted a prospective study of the contaminating microbial flora in 89 open fractures. In addition, two more cultures were taken of all wounds not primarily closed. Wound and fracture healing were followed in all patients. Most fractures were Gustilo grade II (58.4%) caused by work-related accidents. Wound cultures were positive in 83% of all fractures, and a total of 84 strains of bacteria were isolated. In 39.3% of cultures, various species of aerobic Gram-negative rods (most commonly Pseudomaonas aeruginosa) were retrieved, followed by Staphylococcus epidermidis (34.5%) and Staphylococcus aureus (26.1%). Repeat cultures were mostly either negative (59.5%) or grew saprophytic organisms that were usually nonpathogenic (such as various species of saprophytic Bacillus bacteria). The only cases that developed deep wound infection were those where a repeat culture 1 day after debridement grew the same organisms as the initial organisms. We conclude that (a) most open fractures are already contaminated upon the patient's arrival at the emergency department, in many cases by potentially pathogenic staphylococci and Gram-negative organisms; (b) contaminating organisms are community acquired and, as such, are sensitive to most routine antibiotics; and (c) persistence of the same organisms in a repeat culture taken 1 day after debridement signifies technical failure of debridement and a subsequent very high risk of infection. Therefore, achieving adequate wound asepsis immediately following debridement is of the utmost importance.

Patellofemoral pain syndrome: a preliminary model for analysis and interpretation of isokinetic and pain parameters.

This paper offers a preliminary model for analysis and interpretation of previously collected isokinetic and pain data based on a group of 55 patients who complained of patellofemoral pain syndrome. All patients underwent detailed physical examination, radiography, bone scanning, and CT. In addition the bilateral concentric and eccentric moments of the quadriceps femoris were assessed using the KinCom system. Following each individual exertion, patients rated the pain provoked according to the Borg pain scale. The clinical findings were non-specific and revealed that a large proportion of the patients had patellar malalignment but no particular pathology common to all could be demonstrated. Isokinetic analysis in combination with the subjective pain rating produced a set of parameters - quadriceps strength deficit, torque curve irregularities, and pain rank-which permitted an alternative approach to the findings. This approach can render the evaluation of certain cases of patellofemoral pain more comprehensive as well as assist in rationalizing the treatment of this heterogenous syndrome.

Thigh muscle activity and anterior cruciate ligament insufficiency.

The purpose of this study was to examine the dynamic relationship between the quadriceps femoris and hamstrings in anterior cruciate ligament (ACL) insufficiency. Thirty-five young active patients with an untreated complete tear of the ACL took part in the study. Using a KINCOM isokinetic dynamometer, the dynamic capacity of each muscle group at 30° in concentric and eccentric exertion in both the deficient and sound knee was measured. Findings demonstrated a significant reduction (P<0.05) in the torque produced by the deficient-side quadriceps compared to the sound side but no significant variations in the hamstring torque. Discussion of the findings considers a possible involvement of neurophysiological inhibition of the quadriceps as a cause for the observed weakness.

Concentric and eccentric torque variations of the quadriceps femoris in patellofemoral pain syndrome.

The purpose of this study was to investigate the extent of torque reduction in the quadriceps femoris in subjects complaining of patellofemoral pain syndrome compared to subjects with sound knees. Fifty-five patients (21 women and 34 men) and 30 healthy subjects (15 women and 15 men) took part in this study. Using the KINCOM isokinetic dynamometer, quadriceps torque was assessed at 30°/s, 60°/s, and 120°/s, both in the concentric and eccentric modes. Findings demonstrated a significant (P < 0·01) reduction of between 30% and 40% in the patients when compared with the control group. This reduction was not speed or mode-specific. Men were stronger than women by a margin of 22% and 14% for the concentric and eccentric modes in the control group. Parallel figures for the patellofemoral pain syndrome group were 25% and 17%. Good to high correlations were found between peak and average torque in both groups. There were no significant differences between the muscles referring to the dominant versus the non-dominant legs of the control group.

Inflammatory reactions associated with a calcium sulfate bone substitute.

OBJECTIVES: Loss of bone substance is a major source of disability that often requires grafting. Recently developed synthetic bone grafts have generated a lot of enthusiasm due to the lack of immunological reactions and infectious disease transmission risk. The current work describes some peculiar complications related to the use of calcium sulfate granules. METHODS: 15 implantations of calcium sulfate pellets Osteoset (Wright Medical Technology) were performed following resection of bone tumors at our service during 1999. Clinical or computerized tomography scans were available in all patients. RESULTS: 3 cases were encountered in which a severe inflammatory reaction developed. In one case serous drainage and an allergic reaction obligated graft removal. In another case, inflammation resolved two months following implantation. In the last case, wound breakdown occurred. CONCLUSIONS: A sterile inflammatory response has previously hindered the use of absorbable poly-lactic and poly-glycolic acid rods. Apparently due to rapid graft resorption, the resulting calcium-rich fluid incites inflammation. The single case of an allergic reaction is interesting. An allergy to plaster of Paris is rare and related to minor additives. These were not present in the bone substitute used. Inflammatory complications should be considered when assessing the risk-benefit ratio of using different types of bone replacement materials, and comparing allogeneic grafts to synthetic ones.

Restoration of pinch in ulnar nerve palsy by transfer of split extensor digiti minimi and extensor indicis.

Subcutaneous transfer of the ulnar slip of the extensor digiti minimi (EDM) to the adductor tubercle across the dorsum of the hand restores pinch, and index finger abduction is reproduced by re-routing extensor indicis proprius around the thumb extensor tendons. Six patients with post-traumatic ulnar palsy have been treated by this method with a minimum follow-up period of 40 months. Pinch was improved from an average of 5% to 40-50% of the normal side, and index abduction to 30-40%. There was no donor morbidity.

Medial epicondylectomy in cubital tunnel syndrome: an electrodiagnostic study.

Prospective analysis of 27 medial epicondylectomies in 22 patients with McGowan grade I ulnar neuropathy demonstrated an improvement in clinical symptoms. In all patients a N.C.V. study, in which compression of the ulnar nerve at the cubital tunnel was evident, has been a prerequisite for operation. Conduction velocity across the cubital tunnel averaged 48% of normal (26.4 +/- 8.7 metres per second) preoperatively and increased to 85% of normal (46.7 +/- 9.7 metres per second) postoperatively. A preoperative N.C.V. study allows the achievement of a high success rate, especially in the less well clinically defined group of patients with grade I neuropathy (subjective complaints without any objective signs of muscle atrophy). Medial epicondylectomy is safe and predictable in the treatment of cubital tunnel syndrome.

Knee joint position sense following reconstruction of the anterior cruciate ligament.

The purpose of this study was to examine whether there was any deterioration in knee static position sense following reconstruction of the anterior cruciate ligament (ACL) due to its complete tear. Twenty-five subjects took part in four different modes of proprioceptive testing in both legs. No significant differences were demonstrated between the operated and normal knees. It is suggested that the role of ACL in knee static position sense is secondary and that this function is likely to be controlled entirely by knee musculatureJ Orthop Sports Phys Ther 1988;10(4):117-120.

Autologous chondrocyte transplantation for reconstruction of isolated joint defects: the Assaf Harofeh experience.

BACKGROUND: Articular cartilage is incapable of undergoing self-repair since chondrocytes lose their mitotic ability as early as the first year of life. Defects in articular cartilage, especially in weight-bearing joints, will predictably deteriorate toward osteoarthritis. No method has been found to prevent this deterioration. Drilling of the subchondral bone can lead to fibrocartilage formation and temporary repair that slowly degrades. Animal experiments indicate that introducing proliferating chondrocytes such as cultured articular chondrocytes can reliably reconstruct joint defects. OBJECTIVES: To describe our clinical experience in culturing and transplanting autologous chondrocytes. METHODS: Biopsies were obtained from 10 patients, aged 18-45, undergoing a routine arthroscopy in which a cartilage defect was identified with indications for cartilage transplantation. The biopsies were further processed to establish chondrocyte cultures. ACT was performed in 8 of the 10 patients because of persistent symptoms for at least 2 months post-arthroscopy. All patients (6 men and 2 women) had a grade IV cartilage defect in the medial or lateral femoral condyle, and three had a defect in the trochlear region as well. Biopsies were removed from the lateral rim of the superior aspect of the femur, and cells were cultured in a clean room. Following a 2 order of magnitude expansion, cells were implanted under a periosteal flap. RESULTS: The eight patients implanted with autologous cells were followed for 6 months to 5 years (average 1 year). Complaints of giving-way, effusion and joint locking resolved in all patients, and pain as assessed by the visual analogue score was reduced by an average of 50%. Follow-up magnetic resonance imaging studies in all patients revealed that the defects were filled with tissue having similar signal characteristics to cartilage. CONCLUSIONS: Chondrocyte implantation is a procedure capable of restoring normal articular cartilage in cases with isolated joint defects. Pain can be predictably reduced, while joint locking and effusion are eliminated. The effect on osteoarthritis progression in humans has not yet been elucidated.

Mesenchymal cells and growth factors in bunions.

Bunion formation in adults is an example of bone growth that occurs after physis closure. Bone is laid down secondary to mechanical irritation caused by foot deformity. It is a mechanism of ectopic bone formation unrelated to physeal growth. In this article, bone formation is analyzed using immunohistochemical and cell culture techniques. Using markers specific for mesenchymal cells (collagen type IIa and fibroblast growth factor receptor 3), a cell population is defined in the soft tissues that overlie the bunion and is isolated from explant cultures. The cells do not produce bone matrix in culture, and they do not express osteoblast-related antigens. Stimulation of the cells by fibroblast growth factor (FGF) 2 leads to rapid cell proliferation and phenotype change. The cells start to form humps and at the same time express alkaline phosphatase and collagen type I. Expression of collagen type IIa and fibroblast growth factor receptor 3 ceases. These series of experiments indicate that a specific population of mesenchymal cells occurs in the soft tissues that overlie the bunion. This population is capable of bone formation when stimulated by FGF, a common mediator of inflammatory processes. Thus, FGF stimulation of mesenchymal cells in soft tissues that overlie the head of the first metatarsal is a potential link between the biomechanical forces that cause hallux valgus and bunion formation.

Good results of circumferential spine fusion in smokers, using autograft and allograft.

We have examined the rates of anterior interbody fusion of lumbar spine segments following fusion with a fresh frozen femoral head allograft in 25 heavy smoking patients. They were all stabilized both anteriorly and posteriorly. The indications for surgery were: degenerative disc disease, degenerative spondylolisthesis and nonunion following previous posterolateral fusion of lumbar spine segments. Only patients who had fusion of one or two lumbar segments were included. They all were stabilized posteriorly with pedicle screws and autogenic iliac bone graft. The fusion was assessed at least one year after surgery according to plan X-rays as "Solid", "Questionable" or "Failure". One patient was found at follow up not fused, in another one the fusion was "questionable" and all the other 23 patients had an anterior solid fusion. Clinically, 84% of the patients had the same or improved work status as before surgery and 68% acknowledged that they were satisfied with the surgical results. No major complications were recorded and the average length of hospitalization was 10.3 days.

Hartshill spinal fixation in vertebral metastasis.

Spinal fusion by Hartshill rectangle frame was used in 10 patients with spinal cord compression secondary to vertebral metastasis in the thoracic and lumbar spine, occupying mainly the posterior elements. All patients presented with pain, bone collapse, and neurologic deficit. The procedure is built on a system of sublaminar wires passed under two to three lamina above and below the decompressed area and tightened to a prebent metal frame. This procedure was relatively simple, and the immediate stabilization achieved in our patients was good. All patients experienced immediate pain relief. While only two patients were able to walk before surgery, seven were able to do so at follow-up. During a follow-up period of at least 2 years in two patients, or until death in the other eight patients, one patient had a broken wire that did not affect the correction achieved at surgery. Partial loss of correction in the sagittal plane was found in two patients who had metastasis in the lumbar spine and in another patient who had metastasis in the ninth thoracic vertebra.

The treatment of carpal tunnel syndrome caused by hypertrophied lumbrical muscles. Case reports.

Three cases of manual workers suffering from carpal tunnel syndrome caused by a hypertrophied lumbrical muscle are presented. Results of auxiliary diagnostic tests are presented and the differential diagnosis is discussed. We conclude that release of the transverse carpal ligament should be accompanied by release or excision of the muscle belly to obtain permanent cure.

Transient bone oedema of the tibia mimicking a tumorous process.

The authors describe a distinct clinical entity consisting of bony tenderness, increased isotope uptake along the metaphyses and/or diaphyses and magnetic resonance changes simulating a bone marrow-replacing lesion. Bone biopsies indicate the presence of bone marrow fibrosis and some new bone formation. Nine such cases were prospectively evaluated according to a standardized protocol including clinical examination, x-rays, bone scan and CT scan as well as MRI scans including contrast medium injection. All patients presented with tibial tenderness. In one case the bone was noticeably thicker as compared to the other side. The ages ranged from 6 years to 64 years and 6 of the patients were female. Xrays were normal in 6/9 patients; the rest had minimal periosteal reaction, and mild intramedullary sclerosis. Uniform imaging findings were longitudinal increased uptake along the metadiaphysis of the tibia on bone scans, and increased bone marrow density on CAT scans without a fracture line. A magnetic resonance study indicated bone marrow replacement as demonstrated by an area of low signal intensity on T1-weighted images and high signal intensity on T2-weighted images. Some enhancement of signal was observed following gadolinium injection. This clinical entity, which the authors attribute to be a medullary stress reaction, is self-limited, and pain resolves within 3 months. However the radiographic changes appear to be permanent. A biopsy is not required provided no cortical penetration or soft tissue mass is demonstrated by MRI scan.

[Delayed diagnosis of posterior dislocation of the shoulder].

Posterior dislocation of the shoulder is rare. It may follow trauma, electroconvulsive treatment or an epileptic attack. Correct diagnosis may be delayed, as there is no obvious deformity in the shoulder region and the arm is held in a natural sling position. AP X-ray of the shoulder shows only a few minor signs. A high index of suspicion, proper physical examination, and oblique X-ray views lead to correct diagnosis. Closed reduction is possible if the dislocation is of less than 3 weeks duration. Open reduction is indicated in young patients, and in older patients when there is disability.