Operative versus closed treatment of primary dislocation of the patella. Similar 2-year results in 125 randomized patients

To assess whether initial surgery is beneficial for patients with primary dislocation of the patella, we carried out a prospective randomized study. Knee stability was examined under anesthesia, and associated injuries were excluded by diagnostic arthroscopy. 55 patients then had closed treatment and 70 patients were operated on with individually adjusted proximal realignment procedures. Surgery gave no benefit based on 2 years of follow-up. The subjective result was better in the non-operative group in respect of mean Houghston VAS knee score (closed 90, operative 87), but similar in terms of the patient's own overall opinion and mean Lysholm II knee score. Recurrent instability episodes (redislocation or recurrent subluxation) occurred in 20 nonoperated and in 18 operated patients. Of these, 15 and 12, respectively, then suffered redislocations. Function was better after closed treatment. Serious complications occurred after surgery in 4 patients. In conclusion, the recurrence of patellar dislocation may be more frequent than reported, whatever the form of treatment. Routine operative management cannot be recommended for primary dislocation of the patella.

The cartilaginous femoral sulcus in children with patellar dislocation: an ultrasonographic study

One hundred and sixteen knees of 33 patients with patellar dislocation and 25 normal children 12-18 years of age were examined by ultrasonography to measure the cartilaginous sulcus angle on the patellar surface of the femur. In knees with patellar dislocation, the cartilaginous sulcus angle measured between 154 and 195 degrees, exceeding the corresponding values of normal knees (134-153 degrees). In patient knees, the cartilaginous sulcus was also consistently wider than the underlying osseous sulcus. This suggests that in pediatric patients with patellar dislocation, the actual patella-stabilizing ability of the femoral sulcus is weaker than the osseous outline in axial radiographs would lead one to suppose. It would appear also that by measuring the cartilaginous sulcus angle of the femur, a clear distinction can be made between normal knee joints and joints displaying patellar instability.

Intracellular high energy metabolite depletion and cell membrane injury with antioxidant enzymes during oxidant exposure in vitro

We compared oxidant-induced intracellular adenine nucleotide catabolism and cell membrane injury in 4 different human cell types. Responses to oxidant exposure were correlated with endogenous antioxidant enzyme activities in these cells. Blood monocytes, amniotic fibroblasts, umbilical vein endothelial cells in primary culture, and transformed bronchial epithelial cells (BEAS 2B) were exposed to 0.1-5 mM hydrogen peroxide (H2O2) for 4 h. Some experiments were conducted in cells pretreated with 3-amino 1:2,4-triazole (ATZ) to inactivate catalase or with 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU) to inactivate glutathione (GSH) reductase. Depletion of adenine nucleotides and accumulation of their catabolic products (hypoxanthine, xanthine and uric acid) occurred to varying extent, monocytes being the most resistant. There was a mutual relationship between catalase and GSH reductase activities and maintenance of cellular adenine nucleotide levels during H2O2 exposure. GSH reductase inhibition rendered BEAS 2B cells susceptible to lytic injury by H2O2, assessed by release of lactate dehydrogenase and intact nucleotides into the medium, there was no correlation between these markers of such injury and endogenous antioxidant enzymes. We conclude that adenine nucleotide depletion and nucleotide catabolite accumulation relate closely with the antioxidant enzyme activities, whereas the lack of a similar correlation between the enzyme levels and markers of lytic cell injury suggest that intracellular antioxidant enzymes do not protect cells from membrane damage due to extracellular oxidants.

Mitochondrial superoxide dismutase induction does not protect epithelial cells during oxidant exposure in vitro

The significance of manganese superoxide dismutase (MnSOD) induction in cells and tissues during oxidant stress is still poorly understood. In this study, transformed human bronchial epithelial cells (BEAS 2B) were treated with interferon-gamma (IFN-gamma), tumor necrosis factor-alpha (TNF-alpha), or with combination of these cytokines (10 ng/ml concentrations) for 48 or 72 h and exposed to selected oxidants. TNF-alpha and IFN-gamma + TNF-alpha combination resulted in a marked increase of MnSOD protein and MnSOD activity. When cells pretreated with the cytokines were exposed to hyperoxia (95% O2, 72 h), menadione (5-50 microM, 4 h), or H2O2 (0.5 and 5 mM, 4 h), in all cases IFN-gamma and TNF-alpha enhanced oxidant-related cell injury. The effect was most significant with cells pretreated with a combination of IFN-gamma and TNF-alpha. Antioxidant enzymes such as total SOD, glutathione peroxidase, glutathione reductase, and glucose-6-phosphate dehydrogenase did not change significantly during the cytokine treatment. Catalase activity was not changed by IFN-gamma or TNF-alpha but it decreased significantly (34%) in IFN-gamma + TNF-alpha-treated cells. Free radical generation was not changed by these cytokines in acute (30 min) experimental conditions or after 48-h treatment. These results suggest that cytokine-induced MnSOD does not protect bronchial epithelial cells against endogenously or exogenously generated oxidants in vitro. In fact, cells that contained the highest MnSOD activity were the most sensitive to subsequent oxidant damage.

High hydrostatic pressures in traumatic joints require elevated synovial capillary pressure probably associated with arteriolar vasodilatation

Three out of the four Starling pressures were determined at arthroscopy of traumatic effusions of the knee. The range of the joint fluid hydrostatic pressure Pjoint was 5-83 cmH2O (0.5-8.1 kPa, 4-61 mmHg), that of the colloid osmotic pressure difference COPplasma-COPjoint 0-21.7 cmH2O. In 11 of 15 cases the sum Pjoint+COP difference exceeded 32.6 cmH2O (3.19 kPa, 24 mmHg), a high estimate of average capillary pressure at the level of the heart. The number of 'exceeding' cases was 8/15 if only 80% of the COP difference was considered effective. Pjoint and the COP difference oppose filtration of fluid from plasma into joints, indicating that mean capillary pressure, the only Starling pressure not determined, was elevated unless the effusions were being resorbed back into the blood. The findings can be explained by tamponade compensated by arteriolar vasodilatation, suspected to be metabolically mediated.

Acute patellar dislocation in children: incidence and associated osteochondral fractures

In a prospective two-year study on urban (city of Helsinki) Finnish children, 72 acute patellar dislocations were observed. The calculated annual incidence rate was 43/100,000 in children under 16 years. A total of 28 knees (39%) had associated osteochondral fractures. These fractures comprised 15 capsular avulsions of the medial patellar margin and 15 loose intra-articular fragments detached from the patella and/or lateral femoral condyle. The intra-articular fragments were found only after spontaneous relocation of the patella. The femoral fracture constantly involved the edge of the articular surface in the middle third of the condylar arc.

Cytotoxicity of oxidants and asbestos fibers in cultured human mesothelial cells

The authors investigated the mechanisms caused by oxidants (superoxide and hydrogen peroxide) and asbestos (amosite) fibers in human mesothelial cells. Immortalized human pleural mesothelial cells (MET 5A) were exposed in vitro to one of the following: hypoxanthine (100-200 microM) plus xanthine oxidase (10-20 mU/ml) as a superoxide-generating system, H2O2 (50 microM-5 mM); or amosite (1-100 micrograms/cm2). Cellular adenine nucleotide depletion, DNA single strand breaks, extracellular release of nucleotides, and their catabolites and lactate dehydrogenase (LDH) were assessed as markers of cell damage after 4-6 h exposure to the oxidants or fibers. The effect of intracellular antioxidant enzymes and exogenous antioxidants on cell damage were investigated during oxidant and amosite exposure. Superoxide radical and H2O2 exposure resulted in the depletion of adenine nucleotides, accumulation of the products of nucleotide catabolism, induction of DNA single strand breaks, and extracellular LDH release. Amosite exposure did not cause nucleotide depletion or induction of DNA single strand breaks. Inactivation of the intracellular antioxidant enzymes glutathione reductase or catalase augmented cell damage during H2O2 exposure but not during amosite exposure.

Distraction bone healing

Bone formation by distraction was studied using three different experimental models: (1) Physeal distraction of the sheep radius was performed in 20 animals. (2) Distraction after osteotomy of the radius was carried out in 39 sheep. (3) Mandibular distraction after osteotomy was performed in 17 sheep. Formation of the organic matrix and osteogenesis were studied by radiographic, histologic, and biochemical methods as well as by electron microscopy. The mode of osteogenesis was essentially similar in all of these distraction models. Bone formation was preceded by organization of the collagenous matrix in the distraction area. In the beginning of the distraction, the gap was composed of a heterogeneous cell population, with large polymorphic fibroblast-like cells. The cells in the central part differentiated into fibroblasts, which remained functionally active as long as distraction proceeded. During physeal distraction, bone formed from the epiphyseal and metaphyseal sides as well as from the surrounding perichondrium. Also, in osteotomy distraction of both tubular bone and mandible, bone formed centripetally from the osteotomized bone ends toward the center of the gap. The organic matrix was composed almost solely of Type I collagen in the earliest stages, suggesting that the mode of osteogenesis differs from bone repair by fracture callus. The structure of the distracted segment was mainly lamellar trabecular. Corticalization of the lengthened bone segment occurred gradually after several months.

Collagen synthesis and mineralization in the early phase of distraction bone healing

Corticotomy of the distal radius followed by gradual distraction by external fixation was performed on three sheep. Collagen synthesis and mineral deposition were analysed from sequential biopsies obtained from the center of the distraction area during the first 4 weeks of distraction. The whole distraction area was rapidly filled with organic matrix the amount of which, due to fluctuation in its nonprotein component, initially decreased from 88 to 66% of the level in control bone but gained its initial level in 4 weeks. Total protein in the matrix represented 70% of that in the control bone during the 4-week follow up period while the proportion of collagen of the total protein increased from 53 to 88%, a level comparable with the unoperated bone. Determination of the type of fibrillar collagen by characterization of their cyanogen bromide peptides showed that in the distraction area production of type II collagen does not occur but the heteropolymer type I (alpha 1(I)2 alpha 2(I)1) collagen represents almost totally the collagen synthesized. Deposition of mineral into the distraction gap was detectable already after 2 weeks and increased rapidly after 3 weeks of distraction. The results suggest that unlike in other processes, e.g., direct osteonal and callus-type bone repair, in distraction bone healing gradual distraction of osteotomized bone leads directly to synthesis of mature fibrous organic matrix of bone followed by its rapid mineralization.

Leg lengthening by osteotomy and gradual distraction: an experimental study

Osteotomy and gradual distraction of the distal radius was performed on 12 sheep. After 3-6 weeks of daily distraction by external fixation, lengthening of 0.5-1.8 cm was achieved. Three weeks after distraction was begun, striae of new bone, organized in the direction of the distraction, were noted radiologically. The bony consolidation developed from the osteotomized bone ends to the center of the distraction area. Medullary structures also contributed to bone formation in the distraction area. Collagen bundles, organized in the direction of distraction, formed a template for the developing bone. The medullary canal remodeled 16 weeks after the operation. Solid bone formed after the distraction procedure with no additional bone transplantation.

Experimental lengthening of tibial diaphysis: gap healing with or without gradual distraction

Stepwise distraction of the rabbit tibia after a transverse diaphyseal osteotomy was performed in an external fixator. The goal was to clarify the fine-structural parameters of long-bone lengthening. The tibias were vertically cut and studied 5 weeks after the osteotomy, and the specimens with an initial gap without further lengthening were compared with those with a gap and stepwise distraction. The role of periosteal bone induction was essential for the ossification of a growing gap, whereas the ossification of a simple gap proceeded equally by the endosteal and periosteal routes. The distraction resulted in vertical organization of the premature callus tissue at the proximal pole of the distracted gap, while the distal part of the gap area was deficiently filled by endosteal bone but preliminary fixed by a bridge of periosteal callus tissue.

Fracture repair during external fixation. Torsion tests of rabbit osteotomies

Bone repair was studied in the rabbit tibiofibular bone after a midshaft transverse osteotomy stabilized by external fixation and heavy compression. Both subendosteal and subperiosteal callus formation with concomitant contact healing were observed within 3 weeks, and were further succeeded by subendosteal resorption and increased porosis resulting in atrophy of the cortical bone. Subjected to the torsion test, the bones exhibited restoration of strength within 3 weeks, with maximal energy absorption and elasticity at 6 weeks. The failure of the osteotomy in the torsion test, with radiographic visibility of the osteotomy, characterized the soft-tissue type of behavior of the bones. Hard-tissue like behaviour of the bones with resistance to torsion at the osteotomy site and radiographic obliteration of the osteotomy line occurred by 12 weeks, indicating complete union of the osteotomy. Our experiments demonstrate that elastic external fixation is preferable to the rigid compression plate.

Pin-hole changes after external fixation of tubular bone

K-wire-pin-induced changes in cortical bone were studied in the intact rabbit tibiofibular bone. Using a bilateral external fixator two pairs of pins were applied under compression (10 kp), under distraction (10 kp), and in a neutralization sense. After defined intervals the pin-holes were investigated macroscopically and radiologically. Reactive and resorptive changes were present in 101 of 576 (17.5%) pin-holes, infection in 13 (2.3%) pin-holes. Changes were significantly more frequent in the distal pin-holes. The appearance of the pin-holes was not influenced by the type of external fixation used nor did the occurrence depend on the duration of metal implantation.

Blood flow in rabbit osteotomies studied with radioactive microspheres

Arterial embolisation with radio-active microspheres was used to measure the proportion of cardiac output to the skeleton and the tibiofibular bone both in unoperated rabbits and in rabbits after tibial osteotomy and subsequent external fixation. The mean uptake of the intact tibiofibula was 0.11 per cent of the cardiac output and, correspondingly, 0.21 per cent after the osteotomy. Maximal uptake occurred 18 days after the operation which was accompanied by a slight decrease in overall skeletal circulation.

Total rupture of pectoralis major muscle in athletes

Total rupture of the pectoralis major muscle is rare. It may follow a severe trauma or strenuous athletic exercise or performance. Five cases of total rupture of the pectoralis major muscle treated in athletes are reported. Two of them had made an extremely exerted effort in weight lifting, one was injured during a parachute landing, one was tackled in an ice hockey match, and one injured his pectoralis major muscle while pushing himself up from a swimming pool. In two cases the diagnosis was made early and in three cases 2-4 months after the injury. All of the patients were male and were treated successfully with surgery. Later they were able to exercise their sports. The weight lifters did not go on with competitive sports.

Experimental epiphyseal separation by torsional force

Separation of the proximal tibial epiphysis from the metaphysis by torsional force was experimentally studied using cadaver bone preparations from 19 adolescent sheep. The energy needed to displace the epiphysis increased in correlation with an increase in the age of the animal. The separated epiphyseal and metaphyseal surfaces were examined using scanning electron microscopy. In the younger animals the separation line passed through the area of hypertrophied chondrocytes. In the animals more near skeletal maturity the separation occurred in a more sinuous fashion and also through spongious bone.

Articular cartilage after meniscectomy. Rabbit knees studied with the scanning electron microscope

Ten rabbits had a medial meniscectomy in both knees. The articular surface was studied with a scanning electron microscope 2, 4 or 12 weeks after the operation. Three sham operated and two unoperated rabbits served as controls. Progressive articular cartilage damage was observed on the weight-bearing areas of the medial condyles. The findings are compatible with clinical observations after meniscectomy; they confirm that meniscectomy is not a harmless operation.

Changes in erythrocyte sedimentation rate and C-reactive protein after total hip arthroplasty

Uncomplicated total hip arthroplasty (THA) was performed in 40 osteoarthritic patients, and changes in erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) levels were registered. The follow-up period was one year. Preoperative ESR appeared to be slightly elevated, and CRP levels were normal, with no exceptions. A postoperative maximum ESR of 64 mm/hour was reached six days after surgery. A slow decrease followed, but ESR remained slightly elevated one year later. The changes in CRP were more rapid; a maximum of 134 mg/l was registered on the second day after surgery, and the values were consistently normalized three weeks after surgery. Thus, uneventful recovery after THA seems to be indicated by a normalizing CRP, regardless of ESR values.

Fever, C-reactive protein, and erythrocyte sedimentation rate in monitoring recovery from septic arthritis: a preliminary study

Body temperature, C-reactive protein (CRP), and erythrocyte sedimentation rate (ESR) were measured sequentially in nine children less than 11 years old during their recovery from culture-positive septic arthritis (SA). The measurements were compared with those of two other children who recovered without antibiotic therapy. A clinical investigation carried out several months after discharge suggested permanent recovery in all cases, including the spontaneously recovered patients. Defervescence and normalization of the primarily elevated CRP and ESR values occurred in a similar manner in both groups. On average, fever lasted 5 days, CRP level decreased below 20 mg/L in 7 days, and ESR reached a value of less than or equal to 20-25 mm/h in 22 days. The normalization time of ESR differed highly significantly (p less than 0.001) both from the duration of fever and from the normalization time of CRP level. Because CRP behaved in a similar manner in both the medicated and the nonmedicated groups, its normalization suggests true extinction of the active inflammatory process. If so, CRP level may be of benefit in monitoring the duration of antibiotic therapy for SA, but the hypothesis has to be confirmed in a larger clinical trial.

The deformation of external fixation devices during loading

The stability of four different types of external fixation devices was studied when they were subjected to torsion, bending and deformation under axial compression. The most stable fixation was achieved when the bone ends were in contact. The frames were weakest when the stress was applied at right angles to the plane of the frame. All four had adequate stability for fracture healing.

Biochemical changes in bone grafts stabilized with rigid plates. I. Cancellous grafts

The effect of rigid plate fixation on the chemical composition of cancellous interposition grafts was studied in rabbit-fibular bones. The concentrations of hexosamines and, to a lesser degree, of hydroxyproline and nitrogen, were high in the graft for the first 6 weeks, decreased from weeks 6 to 12, but remained higher than the corresponding values for the controls throughout the experiment (52 weeks). The ratio of hexosamines to hydroxyproline was highest for the graft at 3 weeks, indicating formation of cartilage and osteoid. The initially low calcium concentration of the graft increased by 35 per cent from weeks 1 to 6, decreased from weeks 6 to 12, and remained below normal thereafter in comparison with corresponding values for the cortical host bone. The ratio of calcium to hydroxyproline increased throughout the experiment, reflecting maturation of the graft to lamellar bone. Thus, biochemically the early incorporation of rigidly fixed cancellous interposition grafts resembles the healing of unimmobilized fractures by callus formation.

Classification of ankle fractures in children

The roentgenograms of 310 children treated for ankle fractures were evaluated for grouping according to the classifications of Ashhurst-Bromer-Weber, Lauge-Hansen, and Salter-Harris. The mean age of the children at the time of injury was 11.1 years (range 2-14 years). Two hundred twenty-one (71.3%) children had malleolar fractures, 71 (22.9%) had tibial epiphyseal fractures, and 18 (5.8%) had syndesmotic lesions. The age distribution of fractures was typical: malleolar fractures predominated among the younger children, epiphyseal fractures among the older. Only the oldest children had avulsion fractures of the syndesmosis. Grouping of the fractures according to Lauge-Hansen and Ashhurst-Bromer-Weber, classifications suited to adults was largely unsuccessful. Epiphyseal fractures, moreover, were easily classified according to Salter-Harris. In spite of their complexity, ankle fractures in children can be roughly divided into avulsional and epiphyseal fractures. Adequately reduced avulsional fractures can be expected to heal well; epiphyseal fractures, however, may five rise to late complications. We propose, therefore, that ankle fractures in children be classified on the basis of roentgenological findings with respect primarily to epiphyseal lesions as well as on an additional simple grouping as to risk for clinical purposes: Group I, low risk, avulsional fractures and epiphyseal separations; Group II, high risk, fractures through the epiphyseal plate.

Meniscectomy in children

The results of 42 meniscectomies in 41 children were evaluated 1 to 13 years (mean 5.6 years) after the operation. At the follow-up 11 patients (12 operated knees) had complaints. In four of these patients, all having had removel of the lateral meniscus, roentgenological examination revealed degenerative changes. The results of the clinical and roentgenological follow-up examination showed that insufficiently rigorous appraisal of the indications for surgery had led, in some cases, to unnecessary meniscectomies. The results of operations had not always been satisfactory. The reliability of arthrographic findings alone as an indication for surgery are discussed and the indications for operative treatment are presented.

Medial dislocation of the tendon of the long head of the biceps brachii

Medial displacement of the long tendon of the biceps brachii muscle is a rare condition associated with degenerative or traumatic ruptures of the rotator cuff. This condition was recorded in nine shoulders during 45 reconstructive procedures on the rotator cuff. Five of the displacements were complete, leaving the tendon medially displaced in a fascial sling; four were incomplete, allowing a to-and-fro medial displacement of the tendon out of the intertubercular groove. Anatomical dissections on eight shoulders showed that the coracohumeral ligament is the key ligament which keeps the biceps tendon aligned in the sulcus: transection of the medial part of the ligament allows the tendon to be medially displaced. There was no pathognomonic clinical sign of the luxation or subluxation. Since abnormal movement of the tendon in the sulcus may be an important cause of shoulder pain, the condition should be carefully looked for during reconstructive procedures on the rotator cuff. Tenodesis of the displaced tendon is recommended, either as the sole procedure or in combination with other reconstructive measures.