Introduction: The problems of the differential diagnosis (d.d.) between musculoskeletal infections and tumours are generally uncommon because both pathologies are quite rare. This is not the experience at the G. Pini Orthopaedic Institute where there are two Units specialized on bone infections and bone tumours and their clinicians often consult each other for difficult cases. Material and Methods: On the basis of this experience, the A.A. revised clinical and radiological criteria of d.d. between acute or chronic osteomyelitis and different histotypes of musculoskeletal tumours. In particular they examined the type and the course of the symptoms, the laboratory data, the site of the lesions and the characteristics of the imaging, both for bone damages and for soft tissues invasion. Afterwards they compared this revision whit the experience of the cases consulted each other. Results: D.d. of acute osteomyelitis include Ewing sarcoma, Osteosarcoma and Eosinofilìe granuloma, especially in children; d.d. of chronic and deep lesions (axial skeleton) in adults include lymphoma and metastasis; in the epiphysis d.d. can involve also benign lesions. This work allowed the A.A. to identify some guidelines that they consider suitable. Time, possibilities and limits of the imaging techniques like bone scans, CT and MRI are outlined, likewise time and types of direct examination of the lesions by puncture or biopsy, that was necessary in many cases, are proposed. Conclusions: The A.A. think that these personal guidelines can help them to face easier, in the future, the difficult cases, minimizing both diagnostics and therapeutics delays and mistakes

Aim: The differential diagnosis between chondroma and grade I chondrosarcoma still represents a challenge. There are always cases in which a perfect diagnosis can’t be done for sure. This cases are defined in literature with different synonyms such as: borderline chondrosarcoma, grade 0 chondrosarcoma, atypical enchondroma or in situ chondrosarcoma. Enchondroma are benign lesions that do not require a surgical treatment. Low grade chondrosarcoma is a malignant tumour that can recur and also if in a low percentage of cases can metastasize. Methods: The Authors reviewed 22 cases of chondrosarcoma of the limbs for clinical, radiographycal and histological features. Results: Pain was present in 80% of cases of low grade chondrosarcoma, while was absent in enchondroma. Radiographic analysis was not significative. Bone scan was often positive in low grade chondrosarcoma as in enchondroma. Histology demonstrated a permeative pattern in chondrosarcoma with infiltration of the bone trabeculae. Conclusions: Only the complete evaluation of the patient resulted in a correct diagnosis. Follow-up of patients confirmed our findings

Identification of modalities and procedures to improve the differential diagnosis of septic and aseptic cases in patients with joint-related pain after total hip or knee alloplasty (THA/TKA). A prospective cohort of 147 patients presenting with problems related to previous THA or TKA was included and subjected to a comprehensive diagnostic algorithm. The standard diagnostics were supplemented with novel or improved methods for sampling of clinical specimens, sonication of retrieved implant parts, prolonged and effective culture of microorganisms, and dedicated clinical samples for molecular biological detection and identification of microorganisms. Furthermore, comprehensive pain investigations and nuclear imaging were employed. For each case the clinical management was decided upon in a clinical conference with participation of clinical microbiologist, orthopedics and experts in nuclear imaging. The clinical management of patients was blinded against the molecular biological detection of microorganisms. Patients grouped as follows: 69 aseptic, 19 acute septic, 19 chronic septic, 40 pain/unresolved. Sonication of retrieved implant parts resulted in detection of biofilm not detected by standard specimens, i.e. joint fluid and periprosthetic tissue biopsies. Next generation sequencing detected and identified few infections not detected by culture. Molecular analyses showed more polymicrobial infections than culture. Nuclear imaging was inconclusive with respect to recommendation of changed setup. Analysis of blood based biomarkers is ongoing. Patients with chronic pain are undergoing follow-up. The special emphasis put on detection of infections resulted in detection of infections in joints that otherwise would have been categorized as aseptic loosening. Clinical management for these cases was changed accordingly. The cross-disciplinary clinical conference is considered valuable for clinical management. The clinical relevance of the polymicrobial nature of infections as diagnosed employing next generation sequencing is yet to be established. Long-term follow-up is planned

We retrospectively reviewed the clinical notes and radiographs of children with proven non-accident injury (NAI) who had sustained long bone fractures between 1997 and 2002, and compared them to the clinical and radiological appearances of 32 osteogenisis imperfecta (OI) patients, seen over the last 20 years, who sustained fractures before the age of one year. In the five-year period, 501 children had NAI. Sexual abuse was involved in 35%, soft tissue injuries in 31%, head injuries in 26% and long bone fractures in 3.6% (18 children). The mean age of these 18 children was 11 months. Six had more than one fracture, and there were 29 fractures (15 femora, five humeri, three elbows, two forearms, two clavicles and two tibiae). Fifty-seven percent of fractures were diaphyseal and 43% were metaphyseal. There were only three metaphyseal buckle or corner lesions (distal femur). In none of these children were there radiological features of osseous fragility, i.e., osteopoenia, anterolateral bowing of the femur and tibia and gracile bones (thin bones with thin cortices). Of the 32 OA patients, 23 were Sillence type I. There was a positive family history in 84% and 95% had blue sclera and Wormian bones. One patient was unclassifiable. All OI patients had fractures in the first year of life, 38% of them occurring perinatally. All had femoral fractures, with or without other fractures, and 90% were diaphyseal. Two or more features of osseous fragility were present in all type-III and 20 type-I patients. Three type-I patients and the unclassifiable patient had osteopoenia only, without bowing or gracile bones. Howeve, three of the four had a positive family history and all had blue sclera and Wormian bones. In all patients, the differential diagnosis between NAI and OI could be made radiologically. The family history, blue sclera and Wormian bones were adjuncts

Giant synovial cyst is commonly seen in association with rheumatoid arthritis. The Baker’s cyst around the knee is the commonest example but it has also been described at the elbow and hip. The possibility of a synovial cyst around the hip is unfamiliar to most clinicians including those who regularly deal with inguinal swellings and those specialising in musculoskeletal conditions. This is often overlooked as a cause of symptoms in inguinal area and lower limb. We present a report on two patients in whom abnormal pulsatile masses in the groin caused diagnostic difficulty. Patients were initially admitted under vascular surgeons with a clinical diagnosis of aneurysm. Ultrasound examination was useful in excluding aneurysm. Detailed clinical examination revealed painful restricted hip movements and an X–ray showed evidence of arthritis in hip joint. CT Scan confirmed it to be a synovial cyst. Computed Arthrotomogram or Arthrography showed communication of the cyst with hip joint. Synovial cysts and iliopsoas bursa enlargement may be more common than previously reported. They may present as a pulsatile mass due to close proximity to femoral vessels and should be considered as a differential diagnosis in patients with unusual inguinal swelling

A retrospective study of 32 patients with primary tumours of the cauda equina is presented. Most of the patients were initially diagnosed as having prolapsed intervertebral discs and treated accordingly. The correct diagnosis was eventually made, usually after a long delay, and confirmed by myelography. Treatment consisted of laminectomy and excision of the tumour. Only one tumour was frankly malignant; all the remaining patients were relieved of their pain and the majority recovered completely. The exceptions were those patients with long-standing neurological deficits; this highlights the importance of early diagnosis and correct treatment before irreparable damage occurs.

Introduction: The incidence of tuberculosis has increased by almost 30% annually in the UK. Orthopaedic surgeons are more likely to encounter patients affected with Mycobacterium tuberculosis [MTB]. We have reviewed the surgical and medical management of cases of MTB infecting prosthetic hip joints in patients without previous tuberculosis.

Report: A 59 year old Caucasian woman presented to us with apparent osteoarthritis hip. X-rays confirmed osteoarthritis but also revealed a lytic lesion in the greater trochanter and erosion of the superior cortex of the femoral neck. The patient had no prior history of exposure to tuberculosis and no evidence of pulmonary or osteoarticular tuberculosis. The patient was investigated preoperatively with blood tests, bone scan, CT scan, CT guided FNAC, and core biopsy. None of these showed any specific diagnostic features. She underwent a total hip replacement and was asymptomatic up to 15 months post-op when she presented with pain in the joint with an abscess over the gluteal region. The abscess was drained and special media culture grew MTB. We used 4-drug therapy for 12 months with retention of the prosthesis and a good functional result.

Discussion: Infected total hip replacement presents a management challenge and surgeons should have a high index of suspicion for Tuberculosis in recalcitrant infections where smears from infected joints are negative. The infection of a total hip replacement with MTB in patients without previous tuberculosis is very uncommon. Only 12 cases have been reported in a search of English language literature from 1966–2005.

We have analysed the wide variation in the management of these cases. The majority of authors in our review resected or revised the infected prosthesis. We are of the opinion that if the infection is clinically under control and the prosthesis is stable, medical treatment alone should suffice.

We retrospectively reviewed eight children with idiopathic chondrolysis (IC) of the hip and nine with atrophic tuberculosis (TB) of the hip treated over the 10 years 1990 to 1999. Both conditions present with a stiff hip and radiographic joint space narrowing. Our aim was to delineate clinical, radiological and histological differences between the two conditions, thereby obviating the need for biopsy in IC, which could worsen the prognosis.

In the IC group all patients were girls. Their mean age was 12 years (11.5 to 13). They presented with a flexion abduction and external rotation deformity of the hip. Chest radiographs were normal in all patients, and all except one had an ESR below 20. The Mantoux was negative in six of the eight. Radiographs showed joint space narrowing and osteopoenia, but the subchondral bony line remained present. Four of the eight had a synovial biopsy, which showed non-specific chronic synovitis. The cartilage looked pale and lustreless. In one hip the cartilage was biopsied and showed cartilage necrosis.

In the TB group, five of the nine patients were boys. The mean age was 7 years (5 to 13.5). The only constant hip deformity was flexion. Chest radiographs were normal in all patients. In all patients the ESR was below 20 and the Mantoux was positive. Hip radiographs showed osteopoenia with loss of the subchondral bony line. Peri-articular lytic lesions were present in all patients except one. Histology of synovial biopsy showed caseous necrosis in all hips, and seven of the nine had a positive culture for TB. Macroscopically the cartilage looked normal, and in one hip the cartilage biopsy was histologically normal.

We confirmed that in IC the joint space narrowing is due to cartilage necrosis. We postulate that in atrophic TB the loss of subchondral bone due to subchondral erosion gives the impression of joint space narrowing. We also concluded that IC was a diagnoses per se and not by exclusion, and that biopsy was not required.

1. Mucopolysaccharides were analysed in the urine of thirteen patients with Morquio's syndrome aged between three and fifty-nine years and of fourteen controls of comparable ages.

2. There were no significant qualitative or quantitative differences between patients and controls.

3. The clinical and radiological findings suggested that these patients did not have the "Morquio-Ullrich" form of the disease, which appears on retrospective assessment of case reports to be more uniform and less diffuse than the Morquio-Brailsford form which may include a number of possibly unrelated diseases.

4. Keratosulphate has so far been demonstrated in the urine only of patients with the "Morquio-Ullrich" form of the disease, although the mucopolysaccharide excretion has been investigated in only a few patients with the Morquio-Brailsford form. The normal mucopolysaccharide excretion of the present series of patients suggests that a normal mucopolysaccharide excretion distinguishes the Morquio-Brailsford from the Morquio-Ullrich form, the latter having a number of features overlapping with Hurler's disease, where large amounts of mucopolysaccharide other than keratosulphate are excreted.

5. Both qualitative and quantitative analysis of urinary mucopolysaccharide are thus necessary to distinguish between Hurler's disease, the Morquio-Ullrich form and the Morquio-Brailsford's form of Morquio's syndrome.

Introduction: Hot swollen knee joints are a common presentation in clinical practice. It has wide differential diagnoses, the most serious being septic arthritis. Delayed or inadequate treatment leads to joint damage. Arthroscopic lavage should be planned appropriately after proper clinical assessment and investigation. Other differential diagnoses like crystal arthritis, reactive arthritis, monoarticular inflammatory arthritis should be considered.

Patients and Methods: This retrospective audit involved 44 patients who had arthroscopic knee lavage for suspected septic arthritis from January 2005 to May 2007. Analysis included the aspects of adequate backup supportive evidence for the procedure, the time from diagnosis to operation and postoperative antibiotic regime.

Results: There were 29 males and 15 females with age group ranging from 11 to 91 yrs. Fever was present in 15 patients(34%), preoperative joint aspiration done in 22(50%), peri-operatively pus found in 11(25%). 13 patients(29.5%) had procedure done within 6hrs, causal organism identified in 25%. Follow-up ranged upto 12 months without persistence or reactivation.

Discussion: Arthroscopic lavage is a useful adjunct in treatment of septic arthritis of knees but proper patient selection with systematic approach considering other possible differential diagnoses is important for avoiding unnecessary operations.

Introduction and Objective. Septic arthritis is an acute infective presentation of the joint calling for urgent intervention, thus making the differential diagnosis process difficult. An increase in temperature in the area containing the suspected septic arthritis is one of the clinically important findings. In this study, it was aimed to investigate whether or not the temperature changes obtained through thermal camera can be used as a new additional diagnostic tool in the differential diagnosis of septic arthritis. Materials and Methods. The study was approved by the local ethics committee as a prospective cohort. A total of 49 patients, 15 septic and 34 non-septic ones, both male and female ones from all ages admitted to the emergency room or evaluated with the consultation of another clinics who were also present with a pre-diagnosis of arthritis (septic or non-septic) in the knee (with complaints of redness, swelling, pain, effusion, increased temperature, edema, and inability to walk) were included in the study. The patients with non-joint inflammatory problems and a history of surgery in the same joint were excluded from the study. The temperature increase in the joint area with suspected septic arthritis was observed, and the difference in temperature changes of this suspicious area with the joint area of the contralateral extremity was compared after which the diagnosis of septic arthritis was confirmed by taking culture with routine intra-articular fluid aspiration, which is the gold standard for definitive diagnosis. Results. The mean age of the patients was 39.89 ± 27.65°C. A significant difference was found between the group with and without septit arthritis in terms of ASO, sedimentation, and leukocyte increase in the analysis of joint fluid (p <0.05). When the thermal measurements were compared, the mean temperature was 37.93°C in the septic group, while it was 36.79°C in the non-septic group, which showed a significant difference (p <0.000∗). The mean temperature difference in both joints was 3.40°C in the septic group, while 0.94°C in the non-septic group (p <0.000∗). While the mean temperature was 37.10°C in the group with septit arthritis, it was measured to be 35.89 °C in the group without (p <0.020). A very strong positive correlation was found between the difference between the mean temperatures of both groups and the values of the hottest and coldest temperature points (r = 0.960, r = 0.902). Conclusions. In the diagnosis of septic arthritis, a thermal imager can be used as a non-invasive diagnostic tool. With the help of this device, a quantitative value, in addition to palpation, can be given to the local temperature increase in the joint, which is an important finding in the clinic of septic arthritis. In future studies, specially designed thermal devices developed with special software for septic arthritis can be developed

Abstract. Background. Schwannomas are slow-growing, benign tumours normally originating from the Schwann cells of the nerve sheath. Intraosseous schwannoma accounts for 0.175% of primary bone tumours and extremely rare especially outside the axial skeleton. Monoclonal gammopathy has been associated with soft tissue schwannomas but never with the intraosseous variety. Presenting problem. A 55-year-old woman with a background of monoclonal gammopathy of undetermined significance (MGUS) presented with a 2-year history of right thigh pain. CT scan showed a well defined, lytic lesion with a thin peripheral rim of sclerosis in the midshaft of the femur. MRI displayed a hyperintense, well marginated and homogenous lesion. Definitive diagnosis was made based on the classical histopathological appearance of schwannoma. Clinical management. We managed our patient with local curettage and prophylactic cephalomedullary nailing on the basis of a high mirel score. Discussion. Intraosseous schwannomas are poorly understood but most commonly reported in middle-aged women. Radiologically, their differential diagnosis includes malignant bone tumours, solitary bone cysts, aneurysmal bone cysts and giant cell tumours. As a result, they are usually diagnosed incidentally on histology. Although malignant transformation is possible in soft tissue schwannomas, all intraosseous schwannomas reported to date have been benign. This case demonstrates the importance of suspecting intraosseous schwannoma as a differential diagnosis for lytic bone lesions to avoid the overtreatment of patients. We also highlight monoclonal gammopathy of undetermined significance as a potential risk factor for a poorly understood disease and make recommendations about the appropriate management of these lesions. Declaration of Interest. (b) declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research reported:I declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project

Aims. Tenosynovial giant cell tumour (TGCT) is one of the most common soft-tissue tumours of the foot and ankle and can behave in a locally aggressive manner. Tumour control can be difficult, despite the various methods of treatment available. Since treatment guidelines are lacking, the aim of this study was to review the multidisciplinary management by presenting the largest series of TGCT of the foot and ankle to date from two specialized sarcoma centres. Methods. The Oxford Tumour Registry and the Leiden University Medical Centre Sarcoma Registry were retrospectively reviewed for patients with histologically proven foot and ankle TGCT diagnosed between January 2002 and August 2019. Results. A total of 84 patients were included. There were 39 men and 45 women with a mean age at primary treatment of 38.3 years (9 to 72). The median follow-up was 46.5 months (interquartile range (IQR) 21.3 to 82.3). Localized-type TGCT (n = 15) predominantly affected forefoot, whereas diffuse-type TGCT (Dt-TGCT) (n = 9) tended to panarticular involvement. TGCT was not included in the radiological differential diagnosis in 20% (n = 15/75). Most patients had open rather than arthroscopic surgery (76 vs 17). The highest recurrence rates were seen with Dt-TGCT (61%; n = 23/38), panarticular involvement (83%; n = 5/8), and after arthroscopy (47%; n = 8/17). Three (4%) fusions were carried out for osteochondral destruction by Dt-TGCT. There were 14 (16%) patients with Dt-TGCT who underwent systemic treatment, mostly in refractory cases (79%; n = 11). TGCT initially decreased or stabilized in 12 patients (86%), but progressed in five (36%) during follow-up; all five underwent subsequent surgery. Side effects were reported in 12 patients (86%). Conclusion. We recommend open surgical excision as the primary treatment for TGCT of the foot and ankle, particularly in patients with Dt-TGCT with extra-articular involvement. Severe osteochondral destruction may justify salvage procedures, although these are not often undertaken. Systemic treatment is indicated for unresectable or refractory cases. However, side effects are commonly experienced, and relapses may occur once treatment has ceased. Cite this article: Bone Joint J 2021;103-B(4):788–794

Aim. Improving the quality of clinical and radiologic differential diagnosis of intramedullary tumours of long bones. Methods. A database includes clinical and radiologic (X-ray, CT and MRI methods) signs of 106 patients with osteosarcoma (n = 44), chondrosarcoma (n = 31) and giant cell tumour (n = 31). Multivariate analysis of clinical and radiologic characteristics and developing informative set of criteria (decision rule) for the differential diagnosis of osteosarcoma, chondrosarcoma and giant cell tumour were provided with program «ASTA». Results. Before examination in Blokhin Oncology Research Centre in 70% of the osteosarcomas and chondrosarcomas and 60% of GCTs the size of the tumour was more than 8 cm. The reason of the late patients' admission to a specialized medical department is inaccurate diagnosis of these tumours. In our study diagnostic accuracy of the differential diagnosis of osteosarcoma, chondrosarcoma and GCT was 89% in case if the decision rules were based on 14 the most informative clinical and X-ray features, 84% if based on 14 clinical and CT features and 88% if based on 9 MRI features. The comparative analysis revealed a high accuracy in determination of these tumours by using decision rules developed on the basis of multivariate analysis of clinical and X-ray criteria. Conclusion. The comparative accuracy of the developed differential diagnostic criteria (decision rules) of clinical and X-ray, clinical and CT and MRI features proved high informative of each method. The diagnostic accuracy of clinical and X-ray decision rule (89%) exceeded the diagnostic accuracy of radiologist's examination before (62%) and after (83%) admission to Oncology Centre. It proves the necessity for further development and practical application of diagnostic expert systems

Objectives. Prosthetic joint infection (PJI) diagnosis is a major challenge in orthopaedics, and no reliable parameters have been established for accurate, preoperative predictions in the differential diagnosis of aseptic loosening or PJI. This study surveyed factors in synovial fluid (SF) for improving PJI diagnosis. Methods. We enrolled 48 patients (including 39 PJI and nine aseptic loosening cases) who required knee/hip revision surgery between January 2016 and December 2017. The PJI diagnosis was established according to the Musculoskeletal Infection Society (MSIS) criteria. SF was used to survey factors by protein array and enzyme-linked immunosorbent assay to compare protein expression patterns in SF among three groups (aseptic loosening and first- and second-stage surgery). We compared routine clinical test data, such as C-reactive protein level and leucocyte number, with potential biomarker data to assess the diagnostic ability for PJI within the same patient groups. Results. Cut-off values of 1473 pg/ml, 359 pg/ml, and 8.45 pg/ml were established for interleukin (IL)-16, IL-18, and cysteine-rich with EGF-like domains 2 (CRELD2), respectively. Receiver operating characteristic curve analysis showed that these factors exhibited an accuracy of 1 as predictors of PJI. These factors represent potential biomarkers for decisions associated with prosthesis reimplantation based on their ability to return to baseline values following the completion of debridement. Conclusion. IL-16, IL-18, and CRELD2 were found to be potential biomarkers for PJI diagnosis, with SF tests outperforming blood tests in accuracy. These factors could be useful for assessing successful debridement based on their ability to return to baseline values following the completion of debridement. Cite this article: M-F. Chen, C-H. Chang, L-Y. Yang, P-H. Hsieh, H-N. Shih, S. W. N. Ueng, Y. Chang. Synovial fluid interleukin-16, interleukin-18, and CRELD2 as novel biomarkers of prosthetic joint infections. Bone Joint Res 2019;8:179–188. DOI: 10.1302/2046-3758.84.BJR-2018-0291.R1

Multifocal osteolytic lesions of the skeletal system are a challenge regarding diagnosis especially when multi-nucleated giant cells which are not specific for a tumour entity are found in the histological specimen. Therefore multiple differential diagnosis have to be considered such as metastases, primary malignant bone tumours, multicentric giant cell tumour of bone and brown tumours of primary hyperparathyroidism. A 49 year old woman underwent medical investigation in an external surgical department due to right hip pain after a fall. The radiologic skeletal status surprised with multiple osteolytic pelvic lesions and one tumour in the left scapula and first histological diagnosis described a giant cell tumour of bone with malignant aspects. After confirmation of this diagnosis by a second histopathological inquiry accomplished by a bone tumor specialist the patient was transferred to our tumour centre. To exclude the differential diagnosis of brown tumours a close look on the parathormon level was done which revealed an exorbitantly high serum amount of 922.7 pg/ml (normal 15–65 pg/ml). Further examination confirmed a parathyroid adenoma. After its extirpation serum levels of parathormon decreased and two months after therapy with high dose calcium substitution radiologic controls show a decline of osteolysis with bone consolidation. Brown tumours of hyperparathyroidism have always to be considered as a rare differential diagnosis of multiple giant cell containing tumours. The disease cannot be distinguished by the histological pattern but can very easily be excluded by normal parathormon levels. First step of therapy in brown tumours should be surgical extirpation of parathyroid adenomas or carcinomas followed by an endocrinological regime. Only failure of this treatment requires further surgical stabilisation of the bone lesions

The challenges faced by hip surgeons have changed over the last decade. Historically, fixation, polyethylene wear, osteolysis, loosening and failure to osseointegrate dominated the discussions at hip surgery meetings. With the introduction of highly crosslinked polyethylene, wear and osteolysis are currently not significant issues. Improved surgical technique has resulted in a high rate of osseointegration and once fixed, loosening of cementless components is rare. In this session, we will focus on issues that orthopaedic surgeons performing hip surgery routinely face including bearing couples in the young active patient, implant choices in the dysplastic hip and osteoporotic femur, evaluation and management of the unstable hip and differential diagnosis of the painful THR