Minimally invasive unicompartmental knee arthroplasty for spontaneous osteonecrosis of the knee.

OBJECTIVE: To explore the outcome and surgical technique of minimally invasive unicompartmental knee arthroplasty (UKA) for spontaneous osteonecrosis of the knee. METHODS: Twenty-seven patients with medial compartmental spontaneous osteonecrosis treated by minimally invasive Oxford phase 3 UKA from January 2009 to June 2013 were reviewed retrospectively. Twelve subjects were men and 15 women, with an average age of 64.6 ± 8.6 years (52-82 years). At the time of diagnosis, 11 patients had with grade III necrosis and 16 grade IV according to Mont's classification. Pain, range of motion (ROM) and Hospital for Special Surgery (HSS) knee scores were evaluated before and after UKA. Pre-and postoperative alignment of the lower limbs was measured and compared. Postoperative radiographic assessments were made according to the guidelines proposed by the Oxford group at the final follow-up. RESULTS: All patients were followed for a mean time of 27.8 ± 15.9 months (6-59 months). There were no serious adverse events, such as infection, bearing dislocation, aseptic loosening, pulmonary embolism, deep venous thrombosis, cardio-cerebral vascular incident or psychological problems. One revision was required for unrelated causes (fracture of tibia plateau) 3 years after arthroplasty. One femoral component was tilted with a postoperative radiographic angle >10°. One radiolucent line was observed in a patient with spontaneous osteonecrosis of the knee. The two patients with implant failure had no symptoms at last follow-up. Visual analogue scale scores decreased from 6.9 ± 0.9 to 2.0 ± 1.1 (t = 19.27, P = 0.00). Pain was relieved in 96.3% of subjects (26/27). The mean post-operative ROM and femorotibial angle were 125.7° ± 9.6° and 177.7° ± 3.1°, respectively. HSS scores increased from 61.3 ± 9.7 to 93.0 ± 4.8 (t = 14.46, P = 0.00). Of the 27 patients, 26 (96.3%) were satisfied with the outcome of this surgical procedure. CONCLUSION: Minimally invasive UKA is an effective means of managing spontaneous osteonecrosis of the knee. The short-term outcome of UKA is encouraging.

Salidroside stimulates osteoblast differentiation through BMP signaling pathway.

Salidroside (SAL) is one of main active components of Rhodiola rosea L. and possesses diverse pharmacological effects. However, the direct role of SAL in bone metabolism remains elusive. In this study, effects of SAL on osteoblast differentiation of murine pluripotent mesenchymal cell line C3H10T1/2 and osteoblastic cell line MC3T3-E1 were examined. We first identified SAL as a potential BMP2 activator in a cell-based screening assay. SAL (0.5-10 µM) could slightly promote the proliferation and greatly increase the alkaline phosphatase (ALP) activity in both cells. Furthermore, SAL increased the mRNA expressions of osteoblast marker genes in either C3H10T1/2 or MC3T3-E1 cells after treatment for different time. Moreover, the mineralization of C3H10T1/2 cells assayed by Alizarin red S staining was dose-dependently increased by SAL. Mechanistically, SAL increased the mRNA level of genes involved in the regulation of BMP signaling pathway, including BMP2, BMP6 and BMP7 and enhanced the phosphorylation of Smad1/5/8 and ERK1/2. The osteogenic effect of SAL was abolished by BMP antagonist noggin or by BMP receptor kinase inhibitor dorsomorphin. Further in vivo study demonstrated that SAL reversed bone loss in ovariectomized rats. Collectively, our findings indicate that SAL regulates bone metabolism through BMP signaling pathway.

Clinical diagnosis and arthroscopic treatment of acetabular labral tears.

OBJECTIVE: To investigate the clinical diagnosis and arthroscopic treatment of acetabular labral tears. METHODS: Twenty-one patients with unilateral acetabular labral tears hospitalized from November 2008 to December 2009 were included in this retrospective study. A definitive diagnosis was made preoperatively on the basis of physical examination, plain radiography and magnetic resonance arthrography (MRA). All cases were treated with arthroscopic surgeries: labral debridement (14 cases), labral debridement plus femoral osteoplasty (5 cases), and labral repair plus osteoplasty (2 cases). All patients were followed-up and the results evaluated using the visual analogue scale (VAS) and Harris hip score. RESULTS: A positive flexion, abduction and internal rotation (FADIR) impingement sign was found in all 21 affected hips, a positive flexion, abduction and external rotation (FABER) impingement sign in 15, and a positive McCarthy test in 9. Plain radiography showed 11 cases had cam type impingement, in 6 of whom it was combined with pincer type impingement; and 2 cases had acetabular retroversion alone. Labral tears were observed on MRA in all cases and were all confirmed by arthroscopy. All patients were followed up for an average of 11.6 months (range, 6 to 19 months). The VAS decreased from (5.3 ± 1.3) preoperatively to (1.4 ± 0.9) 6 months postoperatively. The mean Harris hip score improved from (63 ± 9) preoperatively to (84 ± 10) 6 months postoperatively. All these differences were statistically significant. CONCLUSIONS: Acetabular labral injury is closely correlated with femoro-acetabular impingement. Impingement tests and MRA have high sensitivity and accuracy in clinical diagnosis of labral tears. Arthroscopic debridement, repair and osteoplasty for labral tears results in a good early outcome.

Treatment of nontraumatic osteonecrosis of the femoral head with the implantation of core decompression and concentrated autologous bone marrow containing mononuclear cells.

BACKGROUND: Since self-limited repair ability of the necrotic lesion may be a cause for failure of the technique, the possibility has been raised that bone marrow mononuclear cells (BMMCs) containing BMSCs implanted into a necrotic lesion of the femoral head with core decompression (CD) may be of benefit in the treatment of this condition. For this reason, we studied the implantation of the concentrated autologous bone marrow containing mononuclear cells in necrotic lesion of the femoral head to determine the effect of the method. METHODS: The study included 45 patients (59 hips, 9 females, 36 males; mean age 37.5 years, range 16-56 years) with stages I-IIIA nontraumatic avascular necrosis of the femoral head according to the system of the Association Research Circulation Osseous. Concentrated bone marrow (30-50 ml) containing mononuclear cells has been gained from autologous bone marrow (100-180 ml) obtained from the iliac crest of patient with the cell processor system. Concentrated bone marrow was injected through a CD channel into the femoral head. The outcome was determined by the changes in the Harris hip score, by progression in radiographic stages, and by the need for hip replacement. The mean follow-up was 27.6 months (range 12-40 months). RESULTS: Pre- and post-operative evaluations showed that the mean Harris hip score increased from 71 to 83. Clinically, the overall success is 79.7%, and hip replacement was done in 7 of the 59 hips (11.9%). Radiologically, 14 of the 59 hips exhibited femoral head collapse or narrowing of the coxofemoral joint space, and the overall failure rate is 23.7%. The number of BMMCs increased from 12.2 +/- 3.2 x 10(6)/ml to 35.2 +/- 12 x 10(6)/ml between pre-concentration and post-concentration. CONCLUSION: The concentrated autologous bone marrow containing mononuclear cells implantation relieves hip pain, prevents the progression of osteonecrosis. Therefore, it may be the treatment of choice particularly in stages I-II nontraumatic osteonecrosis of the femoral head.

Treatment of nontraumatic osteonecrosis of the femoral head using bone impaction grafting through a femoral neck window.

Nontraumatic osteonecrosis of the femoral head (non-ONFH) is a disorder that can lead to femoral head collapse and the need for total hip replacement. Various head-preserving procedures have been used for this disease to avert the need for total hip replacement. These include various vascularised and nonvascularised bone grafting procedures. We examined the effect of bone-grafting through a window at the femoral head-neck junction known as the "light bulb" approach for the treatment of osteonecrosis of the femoral head with a combination of demineralised bone matrix (DBM) and auto-iliac bone. The study included 110 patients (138 hips; 41 females, 69 males; mean age 32.36 years, range 17-54 years) with stage IIA-IIIA nontraumatic avascular necrosis of the femoral head according to the system of the ARCO (Association Research Circulation Osseous). The bone grafting procedure is called "light bulb" procedure in which the diseased bone was replaced by a bone graft substitute (combination of DBM and auto-iliac bone).The outcome was determined by the changes in the Harris hip score, by progression in radiographic stages, and by the need for hip replacement. The mean follow-up was 25.37 months (range 7-42 months). All data were processed by a statistics analysis including Cox risk model analysis and Kaplan-Meier survival analysis. Pre- and postoperative evaluations showed that the mean Harris hip score increased from 62 to 79. Clinically, 94 of 138 hips (68%) were successful at the latest follow-up, and radiological improvement was noted in 100% of patients in stage IIA, 76.67% of patients in stage IIB and 50.96% of patients in stage IIC and IIIA cases. Excellent and good results according to the Harris score were obtained in 100% of cases in stage IIA, 93.33% in stage IIB and 59.62% in stages IIIA and IIC stage, with a survivorship of 85% in stages IIA and IIB and 60% in stage IIIA and IIC cases. Cox risk model analysis showed that the clinical success rate correlated with both pre-operation stage and the necrotic area of the femoral head. The complications included ectopic ossification, lateral femoral cutaneous nerve lesion and joint infection. This procedure may be effective at avoiding or forestalling the need for total hip replacement in young patients with early to intermediate stages of osteonecrosis of the femoral head. Therefore, it may be the treatment of choice particularly in nontraumatic osteonecrosis of the femoral head of pre-collapse stage with small and middle area (<30%, or the depth of collapse <2 mm).

Lesion size changes in osteonecrosis of the femoral head: a long-term prospective study using MRI.

Osteonecrosis of the femoral head (ONFH) is one of the intractable diseases. It is controversial whether the lesion size assessed by magnetic resonance imaging (MRI) can change over time without any operative treatment. In this study, we used MRI to observe the lesion size changes of ONFH induced by corticosteroid administration in severe acute respiratory syndrome (SARS) patients. The study included 51 SARS patients (84 hips) with early-stage ONFH who did not receive any operative treatment and were diagnosed by MRI. All of the patients underwent MRI follow-ups. Each patient was evaluated on the basis of the lesion volume on MRI at every follow-up for further comparisons. At the first MRI scan, the mean lesion volume was 10.12 +/- 8.05 cm(3) (range: 0.39-41.62 cm(3)). At the mid-term follow-up (2.5 years), the mean lesion volume was 7.82 +/- 7.59 cm(3) (range: 0.11-39.65 cm(3)). At the final follow-up (five years), complete regression of the lesion was observed in six hips, and the mean lesion volume was 5.67 +/- 6.58 cm(3) (range: 0.00-31.47 cm(3)). Overall, the lesion volume was reduced by >15% in 80 hips, and only four hips with relatively larger lesion volumes showed no apparent reductions. The reduction in lesion size of ONFH observed on MRI is a slow, discontinuous and time-dependent process.

Decreased proliferation of mesenchymal stem cells in corticosteroid-induced osteonecrosis of femoral head.

The ability of self-repair in patients with corticosteroid-induced osteonecrosis of the femoral head is limited, and it has been suggested the cause is likely relevant to the poor proliferation activity of mesenchymal stem cells in the femoral head region. This study measured the number and proliferation activity of human mesenchymal stem cells in patients both with and without corticosteroid-induced osteonecrosis of the femoral head. Bone marrow was collected from the proximal femur in patients with steroid-induced osteonecrosis of the femoral head (osteonecrosis group, n=18) and patients with new femoral neck fractures without osteonecrosis (control group, n=11). Mesenchymal stem cells were isolated by density gradient centrifugation, and then selected by the adhesive method. The MTT reduction assay method was used to evaluate the level of proliferation. Cells from osteonecrosis patients showed reduced proliferation ability compared with the control patients. The percentage of cells in the S+G2/M phase was decreased significantly (P<.01) in the osteonecrosis group. The decreased proliferation ability of mesenchymal stem cells may play a role in the low repair capacity of steroid-induced osteonecrosis of femoral head. The altered function of mesenchymal stem cells may be responsible for the pathogenesis and progression of osteonecrosis.

[Hematological changes and related gene mutation of post-severe acute respiratory syndrome patients with osteonecrosis].

OBJECTIVE: To investigate the hematological changes and related gene mutation of post-severe acute respiratory syndrome (SARS) patients with osteonecrosis so as to find the sensitive molecular symbols for early screening of the high risk populations. METHODS: Fast peripheral venous blood samples were collected from 61 post-SARS patients with osteonecrosis, 25 males and 36 females, aged 30.4 (20 - 60), and 52 sex and age-matched healthy persons as controls. ELISA was used to detect the coagulation and fibrinolysis indicators: activated partial thromboplastin time (APTT), protein C (PC), antithrombin III (AT-III), plasminogen activator inhibitor (PAI), activated protein C resistance (APC-R), plasminogen (PLG), von Willebrand factor (VWF), D-dimer (D-D), and fibrinogen (Fib). Real-time PCR was used to detect the mutation of factor V G1601A (FV Leiden) and prothrombin G20210A. RESULTS: The levels of PC, AT-III, and PLG of the osteonecrosis group were 85% +/- 34%, 84 +/- 29%, and 69 +/- 23%, significantly lower than that of the control group (109% +/- 20%, 104% +/- 14%, and 94% +/- 15% respectively, all P < 0.01). PAI of the osteonecrosis group was 16 U/ml +/- 14 U/ml, significantly higher than that of the control group (8.0 U/ml +/- 4.3 U/ml, P < 0.01). The percentage of patients with abnormal indicators was 99.5% (54/61) in the osteonecrosis group, significantly higher than that of the control group (36.5%, 19/52, P < 0.01). The percentage of patients with 3 or more abnormal indicators was 72.1% (44/61) in the osteonecrosis group, significantly higher than that of the control group (17.3%, 9/52, P < 0.01). No mutations of F V Leiden and prothrombin G20210A was found in both groups. CONCLUSION: Trends of hypercoagulation and hypofibrinolysis exist in the post-SARS patients with osteonecrosis. APTT, PC, AT-III, and PLG can be used as sensitive indicator for screening high risk populations of osteonecrosis.

Changes in coagulation and fibrinolysis of post-SARS osteonecrosis in a Chinese population.

The purpose of this study was to detect changes in coagulation and fibrinolysis of post-severe acute respiratory syndrome (SARS) Chinese patients with osteonecrosis, investigate the aetiology of post-SARS osteonecrosis (ON), and select the sensitive molecular markers for identifying the susceptible population. For this study, blood samples were collected from 88 patients with post-SARS ON and 52 healthy people. Activated partial thromboplastin time (APTT), protein C (PC), antithrombin III (AT-III), plasminogen activator inhibitor (PAI), activated protein C resistance (APC-R), plasminogen (PLG), von Willebrand's factor(vWF), D-dimer (D-D), fibrinogen (Fib), and homocysteine (HCY) were examined by enzyme-linked immunosorbent assay (ELISA). We noted that blood agents of patients with ON changed obviously. APTT, PC, AT-III, PAI, APC-R, and PLG were significantly different between the two groups. Hypercoagulation and hypofibrinolysis were found in patients with post-SARS ON. Therefore, these examinations can be used to screen a population susceptible to ON. Measurements of APTT, PC, AT-III, PAI, APC-R, and PLG are sensitive blood tests for screening purposes.

[Clinical research of correlation between osteonecrosis and steroid].

OBJECTIVE: To explore the correlation between the dosage of corticosteroid, time of onset and incidence of osteonecrosis (ON) in patients with SARS. METHODS: From July 2003 to January 2004, general survey carried out for ON in 551 patients with SARS. Five hundred and fifty-one patients except 12 were administrated by corticosteroid from 80 mg to 30 000 mg. The age of patients was (33 +/- 9) years old ranging from 19 to 59 years old. One hundred and thirty-one were male, and four hundred and twenty were female. MRI and X-ray film were taken in all patients including both hips, knees, shoulders, ankles and wrists. CT scan was taken in partial patients. Common classification system were used for staging of hip (ARCO), knee (Lotka) and shoulder (Cruess). Independent test, rank-sum test and multiple factor logistic regression analysis were used for statistical analysis. RESULTS: No osteonecrosis was detected in 12 patients without corticosteroid. Osteonecrosis was detected in 176 patients (32.7 percent) among 539 patients. There were ON of femoral head in 130 cases (210 hips), ON of knee in 98 cases (130 knees), ON of humeral head in 21 cases (36 shoulders), ON of talus and calcaneus in 16 cases (26 ankles), ON of scaphoid and lunate in 11 cases (17 wrists), ON of patella in 3 cases (4 patella), ON of ilium in 1 case and bone infarction (femur, tibia) in 18 cases. One hundred and nineteen cases (195 hips) with ONFH were in stage I (IA 45 hips, IB 77 hips, IC 73 hips). Eleven cases (15 hips) were in stage II. All osteonecrosis of the knee and humoral head was stage I. Thirty-four patients with ON had one joint affected, 45 patients had 2 joints, 93 patients had more than 3 joints. The dosage of corticosteroid was (5842 +/- 4988) mg in ON group and (2719 +/- 2571) mg in non-ON group (P < 0.0001). The duration of steroid was (38 +/- 17) d in ON group and (27 +/- 15) d in non-ON group (P < 0.01). The dosage of pulse treatment was (340 +/- 207) mg/d in ON group and (211 +/- 160) mg/d in non-ON group (P < 0.01). The duration of pulse treatment was (28 +/- 13) d in ON group and (18 +/- 11) d in non-ON group (P < 0.01). All patients with ON were detected within 6 months from administration. CONCLUSION: About one-third patients with SARS who were treated with a high dose of corticosteroid occurred osteonecrosis. ON is frequently multiple focuses. The actual time of onset of ON is early of steroid used. MRI is golden standard for early diagnosis of ON. The patients who were treated with a high dose of corticosteroid should be inspected initially by MRI.

[Transtrochateric rotational osteotomy for osteonecrosis of the femoral head].

OBJECTIVE: To explore the indications, operative technique and clinical results of the transtrochanteric rotational osteotomy (TRO) for osteonecrosis of the femoral head (ONFH). METHODS: Nineteen patients (23 hips) with ONFH underwent TRO from October 1992 to May 2001 were reviewed. There were 14 males and 5 females. The age was ranging from 22 to 43 years old with an average age of 33.4 years old. The etiology were as followed: alcoholism 10 cases (12 hips); steroid 6 cases (7 hips); trauma 2 cases (2 hips); caisson disease 1 case (2 hips). Ficat stage: II 8 cases 8 hips; III 11 cases 15 hips. Harris hip score 46 to 74 with mean score 56 preoperatively. In order to determine the location and extent of osteonecrosis, A-P view and accurate lateral view (the film should be placed parallel to the femoral neck with the hip in precisely 90 degrees and flexion 45 degrees of abduction and neutral rotation) were taken in both hips preoperatively. The surgical technique described by Sugioka were used in all patients. RESULTS: Seventeen patients (19 hips) were followed up ranging from 18 to 11 years with mean 54 months. The Harris hip score was from 55 to 94 with mean 80.5. Fourteen hips score more than 80 and good to excellent rate was 73.2%. Harris score were less than 79 in 5 cases and 4 hips of these 5 hips were revised by total hip arthroplasty. The rotation angle was from 55 degrees to 80 degrees with mean 60 degrees . COMPLICATIONS: The circumflex femoral medial artery injury was found in 1 hip; subtrochanteric fracture was found in 2 hips and 1 osteotomy site nonunion occurred. CONCLUSION: TRO can be used to treat ONFH. The indications include: (1) younger patients (less than 45 years old). (2) Ficat stage II and III with more than one third intact articular surface of the femoral head. The better results could be obtained using posterior rotation and lager rotational angle. The Sugioka osteotomy should be used carefully because of its complicated surgical technique.

[Vascularized iliac bone grafting for avascular necrosis of the femoral head].

OBJECTIVE: To evaluate the indications for vascularized iliac bone grafting in the treatment of osteonecrosis of the femoral head and operative results. METHODS: From October 1993 to August 2000, Twenty-six hips of 18 patients with osteonecrosis of the femoral head underwent vascularized iliac bone grafting. Clinical evaluation was made according to Harris Hip Score and ARCO staging system. RESULTS: Twenty-three hips of 16 patients were followed up for 31.5 months (6 - 74 months) on average. The mean Harris hip score was 76 patients (mean 61.7). Thirteen hips (medial 8 hips, central 3 hips, lateral 2 hips) were graded > 80 points by Harris hip score were. The incidence of radiographic collapse 20% was (medial), 40% (central) and 75% (lateral) respectively. CONCLUSIONS: Vascularized iliac bone grafting is effective for the treatment of osteonecrosis of the femoral head in short and middle term. We recommend this procedure for the patients with ONFH in ARCO stage I, stage IIA, IIB medial and central, and stage IIC medial.