Primary tuberculosis of the left greater trochanter of femur:a case report

Zhuang Liang,Bo Dong,Pu-Wei Yuan,Feng Yang,Xun Li,De-Yu Liu,Zhan-Kui Wang,Wu-Lin Kang

1Shaanxi University of Traditional Chinese Medicine,Xianyang 712000,China.2Department of Osteopathy,Affiliated Hospital of Shaanxi University of Traditional Chinese Medicine,Xianyang 712000,China.

Abstract Tuberculosis of the greater trochanter of the femur is caused by mycobacterium tuberculosis directly or indirectly invading the greater trochanter of the femur.The clinical manifestations are intermittent pain on the side,low fever and night sweat all over the body.The patient was admitted to the Affiliated Hospital of Shaanxi University of Traditional Chinese Medicine on May 27,2020 with the chief complaint of"intermittent pain in the left hip for 2 years,aggravated for more than 1 month".The pre-admission examination was diagnosed as a "bone defect of the left femoral greater trochanter to be investigated." After admission,relevant examinations were actively improved,but the diagnosis could not be clearly made.The diagnosis was left with greater trochanter tuberculosis.The case report,draws the following conclusions:the disease is characterized by insidious onset,low incidence and atypical symptoms,which is prone to misdiagnosis and missed diagnosis in clinical practice.Imaging and laboratory tests can provide more diagnostic evidence before diagnosis,but pathological examination is the main basis for diagnosis.In addition,since the symptoms are not obvious and it is difficult to obtain pathological tissues in the early stage,most patients reach the advanced stage of the disease when they are first diagnosed.The diagnosis and treatment thinking of doctors is relatively fixed when they treat patients.This paper aims to improve the understanding and treatment ideas of the clinical characteristics,laboratory and imaging examination of the disease by reporting this case,which is of great significance to the diagnosis and treatment of the disease.

Keywords: femoral greater trochanter;tuberculous;synovial capsule;bone type

Background

Bone tuberculosis is a tuberculosis disease caused by the direct or indirect invasion of bone and joints by Mycobacterium tuberculosis.Local symptoms of the disease are mainly intermittent pain,systemic symptoms of low fever,night sweats.Bone tuberculosis accounts for 25% of all extrapulmonary tuberculosis,and bone tuberculosis mainly occurs at the spinal column,hip joint and greater trochanter of femur[1-2].When the lesion develops to a certain extent,it can affect the femoral head and eventually cause serious tuberculous femoral head,seriously affecting people's quality of life.We can summarize the etiology,pathogenesis,clinical manifestations,laboratory examination and treatment of tuberculosis of the greater trochanter of femur.By reporting this case,we can avoid the delay of pathogenesis,improve the diagnostic efficiency of clinicians,and raise vigilance and diagnosis and treatment thinking for the future diagnosis and treatment of tuberculosis of the greater trochanter of femur.

Clinical data

Ethical approval

The participants signed informed consent form.The study was approved by the hospital's ethics committee (SLPFVBT-LF-YJ-2001)and signed informed consent was provided by patients or their families

General Information

The patient,a 28-year-old male,had "intermittent pain in the left hip for 2 years,aggravated for more than 1 month." he went to the Affiliated Hospital of Shaanxi University of Traditional Chinese Medicine on May 27,2020 for chief complaint.Two years ago,the patient developed intermittent pain and discomfort on the lateral side of the left hip without obvious inducement.The pain was a pain in nature and could be tolerated.The symptoms were significantly aggravated after strenuous activities and could be relieved after rest.In the other hospital (2019-04-26),bilateral hip CT showed abnormal signals in the left femoral trochanter,which was considered as bone island.A small amount of fluid accumulated in both hip cavities.Further magnetic resonance imaging(MRI)examination of the left hip joint is recommended.MRI showed local bone destruction of the left trochanteric with formation of soft tissue mass,and bursitis of the greater trochanteric was considered.No definite diagnosis,no systematic treatment,details unknown.Nearly one month ago,the patient came to our outpatient department for treatment with intermittent pain severity and frequency increasing.DR was performed on the left hip joint (Figure A):The margin of the left greater trochanter of femur was rough,with low-density area visible,and there were no obvious abnormalities;please refer to the clinic.The CT of both hips was further examined.The CT of both hips(Figure B) showed that the shape of the left greater trochanter of femur was irregular,and bone defects could be seen in the bone cortex,with scattered high-density nodules nearby.Considering the possibility of calcification of tendon sheath,please refer to the clinic.MRI examination is recommended after admission.The outpatient was admitted to the hospital with a "bone defect of the left greater trochanter to be examined." Since the onset of the disease,the patient is conscious,spirit can,physical examination cooperation,answer the question,eating and sleeping,urine and feces normal.Previous health.Physical examination:no obvious abnormality was found in each system.Specialist examination:Left limping gait,left hip is normal,though the skin temperature is not high,did not see obvious ecchymosis,local tenderness (+),longitudinal taps the left leg pain (-),limited activity,left (+) "4" experiment,experiment (-) on the right side of the "4" word,the left hip flexion knees experiment (+),double lower extremities isometric,did not see the strength of lower limbs,muscle hypotonia,dorsalis pedis pulses can be,Physiological reflex was present,but pathological reflex was not elicited.After admission (2020-05-29),MRI examination of both hips (Figure B and Cand D) showed that there was a bilateral hip joint corresponding relationship.The synovial membrane of the synovial capsule around the left greater trochanter was thickened,and multiple nodular low-signal shadows were observed in the left greater trochanter,and local bone defects were observed in the left greater trochanter.A small number of long T1 and long T2 signal shadows were observed in bilateral hip sacs.The left external iliac paravascular lymph node is enlarged.Please combine with clinical.Bone scan showed that the radionuclide distribution in the blood flow phase and blood pool of the left greater trochanter was normal,and the delayed phase radionuclide metabolism increased slightly.SPECT/CT fusion image(Figure E) showing bone destruction of the left greater trochanter.Infectious lesions of the left greater trochanter were considered,not excluding tuberculosis.Laboratory examination;White blood cell count (WBC) was 11.56 × 109/L,neutrophil percentage was 79.6%,C-reactive protein(CRP)was 12 mg/L,erythrocyte sedimentation rate(ESR) was 40.00 mm/h;Tuberculosis antibody (TB-Ab):(-);lymphocytotoxicity (LYM) culture+interferon (basal level) 0.12 IU/mL,LYM culture+interferon (stimulation level) 9.86 IU/mL,TBIGRA 9.74 IU/mL,TB positive control 9.9 IU/mL,TB-specific cellular immune response results suggested (+),N-terminal osteocalcin 24.74 ng/mL,β special collagen degradation product:918 pg/mL.According to the patient's medical history,symptoms,signs,imaging and laboratory examination,the diagnosis is still unconfirmed,and surgical exploration is recommended.Preoperative diagnosis was a partial bone defect of left greater trochanter of femur.Preoperative preparation was actively carried out without surgical contraindications.Incision exploration,lesion resection and biopsy were performed on the part of the left greater trochanter bone defect of the patient.Cheese tissue and bursa were collected from the greater trochanter during the operation and sent for disease examination(Figure G and H).(left greater trochanter of femur,synovial membrane) Chronic granulomatous inflammation with extensive coagulative necrosis,acid fast staining (+) (Figure F).,surrounded by multinucleated giant cells;please confirm further in combination with clinical and laboratory examination.Due to the absence of tuberculosis foci in the lung,the tuberculosis bacilli antibody (-) was not typical,and the increase of ESR was tumor,tuberculosis or infection,which was not specific [3].Finally,the patient underwent surgical focus removal+standard treatment with anti-tuberculosis drugs,followed by a follow-up visit 3 months later,and was confirmed to be clinically cured after the blood routine examination,ESR,C-reactive protein and other indicators were reduced to normal in the local hospital.

Figure 1 X-ray,MRI,SPECT/CT,HE,and intraoperative tissue of greater trochanter tuberculosis. (A) preoperative anteroposterior image of the left greater trochanter;(B)cross-sectional MRI of both greater trochanters;(C)sagittal MRI of both greater trochanters;(D)preoperative CT soft tissue window;(E) SPECT fusion graph (F) pathological examination of focal tissue (HE,staining,40×) suggested tuberculosis of the left greater trochanter;(G) intraoperative destruction area of left greater trochanter;(H) removal of white caseous granuloma of left greater trochanter

Discussion

Clinical manifestations and characteristics

Clinical observation found that the spine had the highest incidence of bone tuberculosis,accounting for more than 60%of bone tuberculosis,followed by hip,knee and ankle joints [4].Tuberculosis occurring in the greater trochanter of femur was relatively rare.More than 95% of the tuberculosis foci of the disease are spread through the blood system,and a few are directly spread to the lesion through lymphatic vessels or pleura [5].The chest X-ray of the patient in this case was normal,and tuberculin test(-)and tuberculosis bacillus antibody(-) both ruled out tuberculosis,which could not provide help for diagnosis.Therefore,for primary bone tuberculosis with misleading clinical manifestations and hidden symptoms,imaging and laboratory tests have no specificity,causing certain difficulties in diagnosing othis disease,and only pathological examination is the gold standard[6].When we encounter patients with similar symptoms,imaging,and laboratory tests in the clinic,we need to consider the disease and conduct a histological examination.Avoid delay until advanced abscess and fistula formation are diagnosed.Therefore,this report is published to improve the clinical workers' understanding and diagnosis and treatment thinking of primary focal femoral greater trochanter tuberculosis.Femoral greater trochanter tuberculosis can be divided into bone type and bursa type,and the incidence of bone type is higher than that of bursa type.Bone type can be divided into central type and marginal type.The prevalence of central type was significantly higher than marginal type[7].

Laboratory examination of the greater trochanter

Although the current gold standard for diagnosis of tuberculosis of the greater trochanter of the femur is etiological examination,the use of other imaging and laboratory tests can help improve the diagnosis rate.Etiological testing requires invasive specimen removal,so most patients cannot accept this test method.At present,clinical laboratory examination methods for bone tuberculosis include T-SPOT test (TB),tuberculin test purified protein derivative(PPD),tuberculosis IgG antibody test,Mycobacterium sputum tuberculosis PCR test Nucleic acid amplification of mycobacterium tuberculosis,anti-tuberculosis antibody (TB-Ab) test and nucleic acid amplification test [8] (Xpert MTB/RIF) and other detection methods.Tuberculosis infection T-SPOT assay (T-SPOT.TB) is a new mycobacterium tuberculosis detection method,mainly has the advantages of specificity,high sensitivity,this experiment through the detection of ESAT-6 and CFP-10 antigens stimulate T cells to release interferon γ to determine whether there is tuberculosis infection.This experiment has been approved by the United States Food and Drug Administration (FDA)and other health institutions around the world and used in clinical practice [6].A study by Lee et al.suggested that the sensitivity and specificity of T-SPOT.TB for the diagnosis of tuberculosis was 96.6%and 84.6%,respectively.Miao Biaolie et al.[8]found that T-SPOT and TB had higher sensitivity and specificity than Xpert MTB/RIF.Ma Ke et al.[10] found that tuberculin test had a diagnostic sensitivity of 46.81% and a specificity of 98%,while T-SPOT.TB had a diagnostic sensitivity of 93.62% and a specificity of 100%,indicating that T-SPOT.TB was significantly better than tuberculin test (P＞0.05).Miao Biaolie[8]found that T-SPOT.TB has a sensitivity of 86.54%and specificity of 92.8.

Imaging examination of the greater trochanter of femur

Ultrasound is sensitive to periarticular abscesses,sinus tract and synovial membrane [11].X-ray examination of bone tuberculosis has been reported with no abnormal appearance 3 months after the onset of the disease,so regular review is important.CT has more advantages than X-ray to observe the range and degree of bone destruction,which can clearly show the range and degree of bone destruction,and judge whether there is cold abscess and dead bone formation.At present,MRI is the most commonly used examination method for soft tissue examination,which shows a relatively uniform low signal on T1-weighted images and high signal on T2-weighted images,with varying ranges.An enhanced scan shows abnormal enhancement around abscess.Liu Xin et al.[12] found that MR has a certain diagnostic value for both bone tuberculosis and bone tumor,but has a higher diagnostic value for bone tumor.When bone tuberculosis is examined by SPTCT,the local lesion is granulomatous inflammation,and the activated macrophages and epithelial cells in the granuloma have increased expression of hexokinase and glucose metabolism,so they can concentrate in the lesion nonspecifically,and the degree of concentration is related to the activity of the lesion [13,14].At present,the use of imaging examination to diagnose bone tuberculosis is still a difficult problem [15].

Treatment

Great trochanter tuberculosis is generally divided into conservative treatment and surgical treatment.When there is no obvious bone lesion,patients can be treated with non-surgical treatment,including rest,nutrition,general supportive therapy,anti-tuberculous drugs,local aspiration and injection of anti-tuberculous drugs.Conservative treatment was rifampicin,isoniazid,ethambutol and pyrazinamide according to the guidelines.When there is a dead bone lesion,surgical treatment of tuberculous greater trochanter is generally effective because of its superficial location.The surgical incision is made about 5 cm in length at the center of the affected side of the greater trochanter,which can be a straight incision or an arc incision to expose the greater trochanter of femur.For the removal of the bursa tuberculosis lesion,complete removal of the lesion bursa should be paid attention to during the operation.And carefully look for the posterior or anterior minor lesion bursa and the drainage abscess in the muscle space connected with the main lesion bursa,which should be removed together and not omitted.Attention should be paid to the removal of the posterior bursa,and the adhesion between the posterior bursa and the surrounding tissues should be carefully separated to avoid damage to the sciatic nerve and hip vessels.For mild lesions and localized lesions,necrotic lesions,cheese,granulation,dead bone,etc.in the cavity should be removed and scratched as far as possible until normal bone appears.Studies have found that [16] it is better to use antibiotics (isoniazid +streptomycin) and bone cement in a ratio of 1:10 to fill the defect bone cavity and smear evenly.Serious for long duration time,pathological changes,the greater trochanter bone lesion completely uprooted,with strong for big rotor lateral cortical bone defect,but the bone cavity respectively in the direction of the femoral neck and distal femur are "eight" glyph into two ordinary cancellous screw and then injecting bone cement,to further stabilize the proximal femoral wall to prevent fracture,postoperative general fields activity after a week.The study found that patients with higher recurrence rate had a high incidence of disease due to incomplete removal of surgical lesions,which must be completely removed.