1. A quantitative study of phosphatase distribution in the limb bones of growing rabbits is reported. 2. Alkaline phosphatase is present in high concentrations in areas of deposition of new bone. Both local concentrations and the total alkaline phosphatase content of a bone are found to decrease with age. There is good correlation between total alkaline phosphatase activity and monthly increment of weight. 3. Acid phosphatase is present in these bones in greatly less concentrations than alkaline phosphatase. 4. The acid phosphatase of bone shows nearly full activity in the presence of 0·5 per cent formaldehyde. It can be subdivided into two enzymes with characteristically different distributions by the effect of M/100 tartrate on activity. 5. The formaldehyde-stable and tartrate-stable acid phosphatase of rabbit bone (FTS) has a distribution very similar to that of alkaline phosphatase, though very much less in amount, and, like the latter, declines in activity as the bone matures. 6. Tartrate-inhibited, formaldehyde-stable acid phosphatase (FSTI) is found mainly in red marrow and cancellous bone, and full activity persists in mature bone. This enzyme may be associated with resorption and remodelling of bone, or it may represent residual activity under these conditions of the acid phosphatase of developing erythrocytes in the marrow

The total plasma alkaline phosphatase level has long been recognised as an indicator of osteoblastic activity, but lack of specificity makes it an insensitive index of the progress of disease and the response to treatment. Selective precipitation by wheatgerm lectin allows measurement of the plasma bone-specific alkaline phosphatase. We measured the plasma levels of this isoenzyme in 170 normal Chinese adolescents and adults, in 49 adults with fractures of a long bone, in 15 patients with osteosarcoma and in 38 patients with osteolytic metastases. The enzyme activity was also determined in 39 patients with liver disease. Of the patients with fractures, 94% had increased plasma activity during the healing process. The level was also increased in those with osteosarcoma but not in those with osteolytic bone metastases. There was no significant increase in activity in the patients with liver disease. We conclude that the plasma bone-specific alkaline phosphatase activity is a sensitive and reliable measure of osteoblastic activity

The primary aim of this study was to develop a patient-reported Activity & Participation Questionnaire (the OKS-APQ) to supplement the Oxford knee score, in order to assess higher levels of activity and participation. The generation of items for the questionnaire involved interviews with 26 patients. Psychometric analysis (exploratory and confirmatory factor analysis and Rasch analysis) guided the reduction of items and the generation of a scale within a prospective study of 122 relatively young patients (mean age 61.5 years (42 to 71)) prior to knee replacement. A total of 99, completed pre-operative and six month post-operative assessments (new items, OKS, Short-Form 36 and American Knee Society Score). The eight-item OKS-APQ scale is unidimensional, reliable (Cronbach’s alpha 0.85; intraclass correlation coefficient (ICC) 0.79; or 0.92 when one outlier was excluded), valid (r >  0.5 with related scales) and responsive (effect size 4.16). We recommend that it is used with the OKS with adults of all ages when further detail regarding the levels of activity and participation of a patient is required. Cite this article: Bone Joint J 2014;96-B:332–8

The alkaline phosphatase activity of pre-osseous tibial cartilage of rachitic bone stored in the deep freeze for two weeks at -25 degrees centigrade was only slightly less than that of fresh controls from the same animals. The deep frozen pre-osseous tissue did not calcify in in vitro calcifying media containing either inorganic phosphorus or organic phosphate ester. The fresh controls calcified equally well in both media. In addition, after deep-freeze storage the tissue hydrolysed the organic phosphate to the same degree as did the fresh tissue. Bones heated at 65 degrees centigrade will calcify in vitro after calcium chloride treatment despite the destruction of phosphatase activity. It appears unlikely that a relationship exists between alkaline phosphatase and the minimal system required for calcification of pre-osseous cartilage in vitro. These findings do not exclude the possibility that alkaline phosphatase plays some critical role in vivo

Objectives. Periprosthetic joint infection following joint arthroplasty surgery is one of the most feared complications. The key to successful revision surgery for periprosthetic joint infections, regardless of treatment strategy, is a thorough deep debridement. In an attempt to limit antimicrobial and disinfectant use, there has been increasing interest in the use of acetic acid as an adjunct to debridement in the management of periprosthetic joint infections. However, its effectiveness in the eradication of established biofilms following clinically relevant treatment times has not been established. Using an in vitro biofilm model, this study aimed to establish the minimum biofilm eradication concentration (MBEC) of acetic acid following a clinically relevant treatment time. Materials and Methods. Using a methicillin-sensitive Staphylococcus aureus (MSSA) reference strain and the dissolvable bead assay, biofilms were challenged by 0% to 20% acetic acid (pH 4.7) for ten minutes, 20 minutes, 180 minutes, and 24 hours. Results. The MBEC of acetic acid was found to be: 15%, 11%, 3.2%, and 0.8% following a ten-minute, 20-minute, 180-minute, and 24-hour treatment, respectively. Conclusion. This study found that the MBEC of acetic acid following a 10- or 20-minute treatment time exceeded its safety threshold, making these concentrations unsuitable as a topical debridement adjunct. However, a clinically acceptable concentration (5%) was still found to eliminate 96.1% of biofilm-associated MSSA following a 20-minute treatment time. Cite this article: S. T. J. Tsang, P. J. Gwynne, M. P. Gallagher, A. H. R. W. Simpson. The biofilm eradication activity of acetic acid in the management of periprosthetic joint infection. Bone Joint Res 2018;7:517–523. DOI: 10.1302/2046-3758.78.BJR-2018-0045.R1

Previous studies have identified clinical and demographic risk factors for recurrence in the treatment of idiopathic clubfoot (congenital talipes equinovarus). Evertor muscle activity is not usually considered amongst them. This study aimed to evaluate whether recurrence could be predicted by demographic, clinical and gait parameters. From a series of 103 children with clubfeet, 67 had completed a follow-up of two years: 41 male and 26 female, 38 with idiopathic and 29 with non-idiopathic deformities. The mean age was 3.2 years (2.1 to 6.3). Primary correction was obtained in all 38 children (100%) with an idiopathic deformity, and in 26 of 29 patients (90%) with a non-idiopathic deformity. Overall, 60 children (90%) complied with the abduction brace regime. At a mean follow-up of 31.4 months (24 to 62), recurrence was noted in six children (15.8%) in the idiopathic and 14 children (48.3%) in the non-idiopathic group. Significant correlation was found between poor evertor activity and recurrence in both groups. No statistically significant relationship was found between the rate of recurrence and the severity of the initial deformity, the age at the time of treatment, the number of casts required or the compliance with the brace. After correction of idiopathic and non-idiopathic clubfoot using the Ponseti method, only poor evertor muscle activity was statistically associated with recurrence. The identification of risk factors for recurrent deformity allows clinicians to anticipate problems and advocate early additional treatment to improve muscle balance around the ankle. Cite this article: Bone Joint J 2014;96-B:1264–8

We investigated whether patients who underwent internal fixation for an isolated acetabular fracture were able to return to their previous sporting activities. We studied 52 consecutive patients with an isolated acetabular fracture who were operated on between January 2001 and December 2002. Their demographic details, fracture type, rehabilitation regime, outcome and complications were documented prospectively as was their level and frequency of participation in sport both before and after surgery. Quality of life was measured using the EuroQol-5D health outcome tool (EQ-5D). There was a significant reduction in level of activity, frequency of participation in sport (both p < 0.001) and EQ-5D scores in patients of all age groups compared to a normal English population (p = 0.001). A total of 22 (42%) were able to return to their previous level of activities: 35 (67%) were able to take part in sport at some level. Of all the parameters analysed, the Matta radiological follow-up criteria were the single best predictor for resumption of sporting activity and frequency of participation

We have investigated the level of physical activity of 49 women between the ages of 15 and 45 years who sustained a fracture of the neck of the femur at between 60 and 70 years of age, and compared this with the level of activity reported by 49 control subjects without fracture, who were matched for age and social status. We found that the patients had been significantly less physically active than the controls, especially as regards household duties and professional working conditions

Aims. The aim of this study was to identify predictors of return to work (RTW) after revision lower limb arthroplasty in patients of working age in the United Kingdom. Patients and Methods. We assessed 55 patients aged ≤ 65 years after revision total hip arthroplasty (THA). There were 43 women and 12 men with a mean age of 54 years (23 to 65). We also reviewed 30 patients after revision total knee arthroplasty (TKA). There were 14 women and 16 men with a mean age of 58 years (48 to 64). Preoperatively, age, gender, body mass index, social deprivation, mode of failure, length of primary implant survival, work status and nature, activity level (University of California, Los Angeles (UCLA) score), and Oxford Hip and Knee Scores were recorded. Postoperatively, RTW status, Oxford Hip and Knee Scores, EuroQol-5D (EQ-5D), UCLA score, and Work, Osteoarthritis and Joint-Replacement Questionnaire (WORQ) scores were obtained. Univariate and multivariate analysis was performed. Results. Overall, 95% (52/55) of patients were working before their revision THA. Afterwards, 33% (17/52) RTW by one year, 48% (25/52) had retired, and 19% (10/52) were receiving welfare benefit. RTW was associated with age, postoperative Oxford Hip Score, early THA failure (less than two years), mode of failure dislocation, and contralateral revision (p < 0.05). No patient returned to work after revision for dislocation. Only age remained a significant factor on multivariate analysis (p = 0.003), with 79% (11/14) of those less than 50 years of age returning to work, compared with 16% (6/38) of those aged fifty years or over. Before revision TKA, 93% (28/30) of patients were working. Postoperatively only 7% (2/28) returned to work by one year, 71% (20/28) had retired, and 21% (6/28) were receiving welfare benefits. UCLA scores improved after 43% of revision THAs and 44% of revision TKAs. Conclusion. After revision THA, age is the most significant predictor of RTW: only 16% of those over 50 years old return to work. Fewer patients return to work after early revision THA and none after revision for dislocation. After revision TKA, patients rarely return to work: none return to heavy or moderate manual work. Cite this article: Bone Joint J 2018;100-B:1043–53

A continuous ambulatory activity monitor allows objective measurement of the amount and intensity of physical activity. We examined the reliability and validity of this device in the assessment of seven aspects of function over a period of 24 hours in 20 patients who had undergone limb salvage or amputation for a tumour in the leg. The test-retest reliability was determined by undertaking identical assessments on two separate days. The measurements were compared with other indicators of functional status and quality of life in order to determine the validity of the monitor. Its reliability was satisfactory, with intraclass correlation coefficients ranging from 0.65 to 0.91. Significant correlations were seen between the ‘time spent walking’ and the Musculoskeletal Tumor Society rating scales and the Rand-36 physical functioning score. There was also a significant association between the ‘movement intensity during walking’ and the Musculoskeletal Tumor Society score. The satisfactory reliability and validity of the monitor shows considerable promise for its use as a device for measuring physical activity objectively in patients after surgery for limb-salvage or an amputation

Experimentally produced fractures in long bones studied by light and electron microscopic histochemistry were found to heal by a process of enchondral calcification. There was intense proliferation in the cells of the cambium layer of the periosteum, with differentiation to chondroblasts and osteoblasts, suggesting that this layer was the primary tissue responsible for development of the callus. Cytoplasmic processes of the hypertrophic chondrocytes appeared to bud and produce matrix vesicles. Alkaline phosphatase activity was detected along the plasma membrane of the hypertrophic chondrocytes and around the matrix vesicles, before any signs of mineral deposition. Calcification took place by deposition of hydroxyapatite crystals in and around these matrix vesicles which frequently showed alkaline phosphatase activity. It is suggested that there is a close functional association between alkaline phosphatase activity and calcification in the process of fracture healing, which is another type of enchondral calcification mediated by matrix vesicles

1. In a previous investigation, approximately 40 per cent of so-called "primary" degenerative disease or osteoarthritis of the hip appeared to have been the result of an abnormal joint mechanism caused by minimal epiphysiolysis in adolescence. Males were affected much more commonly than females. The residual abnormality of this disturbance, recognised radiologically, was termed the "tilt deformity" of the femoral head. 2. Three groups of young adult males, with different athletic backgrounds, have now been examined to assess the incidence of this abnormality and its relationship to athletic regimes. The condition was found to be more common in subjects who had been engaged in more active regimes and was also related statistically to a history of "growing pains". The deformity is compared with the gross disturbance of adolescent epiphysiolysis or slipped epiphysis, which is believed basically to be caused by chronic stress. 3. Degenerative disease of the hip of this type has a geographical and racial distribution corresponding to the degree of interest in and encouragement of competitive athletic activities. Many cases are therefore postulated to be the direct result of a minor and usually asymptomatic disturbance of this type, attributable to excess activity during adolescence

The haematoma occurring at the site of a fracture is known to play an important role in bone healing. We have recently shown the presence of progenitor cells in human fracture haematoma and demonstrated that they have the capacity for multilineage mesenchymal differentiation. There have been many studies which have shown that low-intensity pulsed ultrasound (LIPUS) stimulates the differentiation of a variety of cells, but none has investigated the effects of LIPUS on cells derived from human fracture tissue including human fracture haematoma-derived progenitor cells (HCs). In this in vitro study, we investigated the effects of LIPUS on the osteogenic activity of HCs. Alkaline phosphatase activity, osteocalcin secretion, the expression of osteoblast-related genes and the mineralisation of HCs were shown to be significantly higher when LIPUS had been applied but without a change in the proliferation of the HCs. These findings provide evidence in favour of the use of LIPUS in the treatment of fractures

The acid and alkaline phosphatase activity in fluid aspirated from solitary bone cysts in six patients was measured, and large increases in the concentration of acid phosphatase were found. In some cases this increase was reflected in venous blood concentrations. The significance of these findings for the pathogenesis and the management of solitary bone cyst is discussed

We evaluated the possible induction of a systemic immune response to increase anti-tumour activity by the re-implantation of destructive tumour tissue treated by liquid nitrogen in a murine osteosarcoma (LM8) model. The tumours were randomised to treatment by excision alone or by cryotreatment after excision. Tissue from the tumour was frozen in liquid nitrogen, thawed in distilled water and then re-implanted in the same animal. In addition, some mice received an immunological response modifier of OK-432 after treatment. We measured the levels of interferon-gamma and interleukin-12 cytokines and the cytotoxicity activity of splenocytes against murine LM8 osteosarcoma cells. The number of lung and the size of abdominal metastases were also measured. Re-implantation of tumour tissue after cryotreatment activated immune responses and inhibited metastatic tumour growth. OK-432 synergistically enhanced the anti-tumour effect. Our results suggest that the treatment of malignant bone tumours by reconstruction using autografts containing tumours which have been treated by liquid nitrogen may be of clinical value

Biopsies of lumbar multifidus muscles were obtained at operation on seventeen patients aged from fifteen to fifty-eight with lumbar spinal derangement, and further material was taken from the cadavers of three subjects aged from nineteen to fifty-one. Sections were prepared to show the presence of ATPase activity, so distinguishing Fast from Slow types of muscle fibre. The normal mosaic pattern arising from the intermingling of fibres from Fast and Slow motor units was seen in sections from cadaveric material and from many of the biopsies. With age and limited lumbar flexibility, the Fast fibres became relatively smaller but with increasing variation in size, suggesting a reduced capacity for phasic activity. The presence of positive root signs was associated with a greater proportion of Slow fibres, and in some patients with the occurrence of atrophied Fast fibres, giving rise to differences in the populations of the two fibres in neighbouring fascicles. The results suggest that multifidus adopts an increasingly postural role with advancing age and with disabling lesions of the lumbar spine

The purpose of this study is to investigate the diagnostic value of evoked spinal cord potentials (ESCPs) and choline acetyltransferase (CAT) activity during exploration of injuries to the brachial plexus. We assessed 25 spinal roots in 19 patients. The results of the two investigations were consistent in all except two roots. Although assessment of ESCPs is easy and quick, it mainly records the nerve potentials along the sensory pathway. Although measurement of CAT activity needs a specimen of the nerve and the availability of a radioisotope laboratory, it gives direct information regarding the motor function of ventral spinal roots. These two techniques should be complementary to each other in order to achieve a more accurate diagnosis

We performed a prospective, randomised double-blind study in 24 patients undergoing high tibial osteotomy to evaluate the effectiveness of human recombinant osteogenic protein (OP-1) on a collagen type-I carrier in a critically-sized fibular defect. The study had two phases, each evaluated by clinical, radiological and DEXA methods during the first postoperative year. The first concerned the validation of the model of the fibular defect, using positive (demineralised bone) and negative (untreated) controls. The second phase concerned the osteogenic potential of OP-1 on collagen type-I ν collagen type-I alone. The results of the first phase established the critically-sized nature of the defect. In the untreated group no bony changes were observed while, in the demineralised bone group, formation of new bone was visible from six weeks onwards. The results of the second phase showed no significant formation of new bone in the presence of collagen alone, while in the OP-1 group, all patients except one showed formation of new bone from six weeks onwards. This proved the osteogenic activity of OP-1 in a validated critically-sized human defect

The presence of the connective tissue components fibronectin and the different types of collagen was demonstrated by histological and immunohistological methods in the granulation and scar tissue of a healing injury in rat muscle. The effects of physical activity on granulation tissue production, scar formation and muscle regeneration at various stages of healing were studied. It was shown that immobilisation after injury accelerates granulation tissue production, but if continued too long, leads to contraction of the scar and to poor structural organisation of the components of regenerating muscle and scar tissue. However, a certain period of immobilisation, about five days for rat muscle, is required to allow newly-formed granulation tissue to cover the injured area and to have sufficient tensile strength to withstand subsequent mobilisation. This mobilisation, at the correct interval, seems essential for the quicker resorption of scar tissue and the better structural organisation of the muscle