Preoperative evaluation of femoral and tibial sagittal alignment in robotic-assisted and conventional total knee arthroplasty and consequences for practice.

PURPOSE: Robot-assisted total knee arthroplasty (TKA) was developed to improve the precision and accuracy of implant placement in conventional TKA. However, the angular differences between referenced axes in robot-assisted TKA and conventional TKA remain unclear. The aim of this study was to investigate the angular differences in sagittal alignment between robot-assisted TKA and conventional TKA for both the femur and the tibia and to discuss their clinical implications. METHODS: We conducted a retrospective analysis of data from 100 patients (97 patients) who underwent computed tomography (CT) for Mako TKA. We measured the angle between the robot femoral axis (RFA) and conventional femoral axis (CFA) in the sagittal plane and the angle between the robot tibial axis (RTA) and the conventional tibial axis (CTA). Angles were compared between the sexes. Correlation analysis was conducted between the angles and height. RESULTS: In the sagittal plane, the mean RFA-CFA angle was 2.2° ± 1.6°, and the mean RTA-CTA angle was 2.3° ± 1.6°. There were no significant differences between the two angles among males and females (p > 0.05). There was a correlation between the RFA-CFA angle and RTA-CTA angle (p < 0.001, r = 0.33), and there was a correlation between height and the combination of the RFA-CFA angle and RTA-CTA angle (p = 0.03, r = 0.22). CONCLUSION: There are angular differences between the axes referenced by robot-assisted TKA and those referenced by conventional TKA, which may be influenced by patient height. Correctly understanding these differences is crucial when evaluating the implant position and surgical outcomes after robot-assisted TKA. Furthermore, caution should be taken when assessing the flexion-extension angle of the knee since the angles displayed in the Mako system are different from the angles measured with intramedullary anatomical axes. After all, sagittal alignment principles differ between robot-assisted and conventional TKA; however, further studies are required to determine which principle is more appropriate or to modify these principles.

Minimally invasive small incision surgical technique for unicompartmental knee arthroplasty.

PURPOSE: It is always a challenge for orthopaedic surgeons to minimise surgical incisions while ensuring excellent surgical results. We propose the minimally invasive small incision (MISI) technique and an extramedullary positioning technique in the unicompartmental knee arthroplasty (UKA) surgery. This study aimed to clarify the early postoperative clinical outcomes and component alignment between MISI and conventional minimally invasive surgical (MIS) techniques. METHODS: We prospectively enrolled 60 patients who underwent MISI-UKA and 60 patients who underwent MIS-UKA as controls. Clinical parameters include the time of straight leg raising, postoperative walking time with walker assistance, hospital stay, Numerical Rating Scale (NRS) pain score and Knee Society Score (KSS). The postoperative components and lower extremity alignment were compared between the two groups with radiographic image measurement. RESULTS: The MISI group obtained a smaller incision during knee extension (P < 0.001) but a longer tourniquet usage time than the MIS group. The MISI group lost less blood (P < 0.001). The MISI group achieved straight leg raising and walking with aid earlier after surgery, with a shorter hospital stay than the MIS group (P < 0.001). Range of motion (ROM), NRS and KSS scores revealed no significant difference between the two groups in six months postoperative follow-up (P > 0.05). Radiographic measurement results between the two groups revealed no statistical difference (P > 0.05) CONCLUSION: The MISI-UKA could achieve faster earlier recovery after surgery and shorter hospital stays without compromising the principles of proper prosthesis position and limb alignment compared with the conventional MIS-UKA.

Lateral meniscus with tears or with histologic calcification does not increase the risk of lateral osteoarthritis after medial unicompartmental arthroplasty.

PURPOSE: Meniscal tears or histological meniscal calcifications (in the absence of radiological chondrocalcinosis) are frequent in osteoarthritis. Whether lateral meniscal lesions influence clinical outcomes after medial unicompartmental knee arthroplasty (UKA) is unknown. METHODS: We analyzed 130 patients (130 knees) with medial unicompartmental knee arthroplasties between 2005 and 2015. These 130 knees had full articular cartilage thickness in the lateral compartment and no radiological chondrocalcinosis on preoperative radiographs. The lateral meniscus was analyzed with preoperative MRI and a biopsy of the anterior horn at the time of surgery. Synovial fluid was collected and analyzed for calcium pyrophosphate dihydrate crystal deposition (CPPD crystals). Lateral meniscal tears were untreated when detected on MRI or during surgery, with the hypothesis that these tears on the opposite compartment would remain asymptomatic in medial UKA. At average 10-year follow-up, patients were evaluated with clinical and radiographic outcome, with a focus on the risk of joint space narrowing of the lateral femorotibial compartment. RESULTS: CPPD crystals were present in the synovial fluid of 70 knees. Lateral meniscal tears were seen on MRI in 34 (49%) normal meniscuses of the 60 knees without CPPD crystals and in six other knees without histological meniscal calcification despite CPPD crystals. Histological calcification was present on 61 lateral meniscuses with 53 meniscal tears. The results showed no significant differences in the clinical outcomes between knees with lateral meniscal tears or lateral meniscal histological chondrocalcinosis or both lesions and those without these conditions. Additionally, radiographic progression of osteoarthritis in the opposite femorotibial compartment of the knee was not more frequent in patients with these meniscal issues. The ten year cumulative survival rates, measured by the need for total knee arthroplasty, were 91% for knees without meniscal lesions and 92% for knees with these lesions. CONCLUSION: On this basis, treatment of meniscal tears of the lateral compartment and routine aspiration of the knee to assess for birefringent crystals in the planning of medial UKA do not appear necessary.

Subchondral bone cysts regress after correction of malalignment in knee osteoarthritis: comply with Wolff's law.

PURPOSE: The purpose of this study is to discuss the mechanical function of subchondral bone cysts and its relationship with Wolff's law. METHODS: One hundred forty symptomatic knees (120 patients) with osteoarthritis were subjected to MRI before high tibial osteotomy (HTO). Subchondral bone cysts (SBCs) were detected on 72 knees of these 140 knees. SBCs, bone marrow lesion (BML), and hip-knee-ankle (HKA) axis were measured by using validated methods. After HTO, the evolution of cysts was evaluated on MRI performed with a five year follow-up on the 72 knees with pre-operative cysts. RESULTS: At baseline, 70 (97%) of these 72 knees had a BML surrounding the SBCs; the maximum cyst volume was 874 mm3 and the average cyst volume 9. 6 ± 4.1 mm3. In the subregions where cysts were present, adjacent cartilage was still present without full thickness defects. The mean pre-operative hip-knee-ankle angle was 7.3 ± 3 degrees (0° to 14°) of varus and differed significantly (p = 0.01) between the 68 knees without cysts (average 3 ± 2 degrees) and the 72 knees with cysts (average 9.2 ± 4 degrees). Five years after HTO, the number of cysts had decreased, the maximum cyst volume was 532 mm3, and the average cyst volume was 6.3 ± 2.8 mm3. CONCLUSION: Regression of subchondral bone cysts may be related to restoration of an appropriate load at the subchondral bone. With applying poroelasticity to bone mechaincs, this finding may suggest that SBCs and BMLs may be a physiological adaptation to mechanic overload. More basic research is needed to prove this matter.

Cannulated screw fixation versus plate fixation in treating displaced intra-articular calcaneus fractures: a systematic review and meta-analysis.

BACKGROUND: Operative treatment has become the current trend for displaced intra-articular calcaneus fracture (DIACF), while using cannulated screw fixation or plate fixation is still controversial for treating DIACF. The purpose of this meta-analysis is to compare the outcome of the two fixation methods. METHODS: We searched literature comparing cannulated screw fixation and plate fixation from PubMed, Embase, Web of Science, and Cochrane Library. Only randomized controlled trials were included. The outcomes of post-operative function, radiological measurement, time efficiency, and wound complications were pooled in the meta-analysis. RESULT: Seven RCTs with 902 cases of DIACF were included. Pooled results showed the two fixation methods that had similar function satisfactory of AOFAS score (RR = 0.95, 95% CI = [0.83, 1.09], P = 0.47, I2 = 0%) and Maryland Foot score (RR = 0.93, 95% CI = [0.68, 1.28], P = 0.66, I2 = 84%). Compared to plate fixation, cannulated screw fixation had better improvement of Bohler's angle (WMD = 0.56, 95% CI = [0.20, 0.91], P = 0.002, I2 = 34%) and Gissane's angle (WMD = 1.36, 95% CI = [0.56, 2.16], P = 0.0008, I2 = 7%), better recovery of calcaneal height (WMD = 0.49, 95% CI = [0.02, 0.95], P = 0.04, I2 = 6%), shorter time to operation (WMD = - 2.91, 95% CI = [- 4.99, - 0.84], P = 0.006, I2 = 97%), less operation time (WMD = - 21.58, 95% CI = [- 37.31, - 5.85], P = 0.007, I2 = 98%), reduced length of hospital stay (WMD = - 2.00, 95% CI = [- 3.69, - 0.31], P = 0.02, I2 = 97%), and less wound complications (RR = 0.16, 95% CI = [0.08, 0.32], P < 0.00001, I2 = 0%). CONCLUSION: Cannulated screw fixation and plate fixation have similar postoperative functional satisfactory. Cannulated screw fixation is superior to plate fixation in reduction quality, time efficiency, and wound complications.

Patient-specific instrumentation (PSI) in total ankle arthroplasty: a systematic review.

BACKGROUND: Patient-specific instrument (PSI) may theoretically make total ankle arthroplasty (TAA) more accurate. Several studies have reported the outcomes of PSI TAA. The aim of this study is to systematically review the literature of PSI TAA. METHODS: PubMed, Embase, Web of Science, and Cochrane Library databases were systematically reviewed according to the Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) guidelines for PSI TAA. The quality of the included studies was evaluated according to Methodological Index for Non-Randomized Studies (MINORS). RESULT: Nine articles were ultimately included in the systematic review. The implant position and function outcome of TAA was similar between PSI and SI. Prediction accuracy of implant size remained great difference. PSI can shorten the operative time and fluoroscopy time. The quality of current studies on PSI TAA is insufficient to produce high-level evidence. CONCLUSION: PSI can get similar implant position and clinical outcome in TAA compared to SI, but current evidence is not strong enough to evaluate PSI TAA.

Sensor and machine learning-based assessment of gap balancing in cadaveric unicompartmental knee arthroplasty surgical training.

PURPOSE: The aim of this study was to assess the difference between flexion and extension contact forces-gap balance-after Oxford mobile-bearing medial unicompartmental knee arthroplasty (UKA) performed by surgeons with varying levels of experience. METHODS: Surgeons in a training programme performed UKAs on fresh frozen cadaveric specimens (n = 60). Contact force in the medial compartment of the knee was measured after UKA during extension and flexion using a force sensor, and values were clustered using an unsupervised machine learning (k-means algorithm). Univariate analysis was performed with general linear regression models to identify the explanatory variable. RESULTS: The level of experience was predictive of gap balance; surgeons were clustered into beginner, mid-level and experienced groups. Experienced surgeons' mean difference between flexion and extension contact force was 83 N, which was significantly lower (p < 0.05) than that achieved by mid-level (215 N) or beginner (346 N) surgeons. CONCLUSION: We found that the lowest mean difference between flexion and extension contact force after UKA was 83 N, which was achieved by surgeons with the most experience; this value can be considered the optimal value. Beginner and mid-level surgeons achieved values that were significantly lower. This study also demonstrates that machine learning can be used in combination with sensor technology for improving gap balancing judgement in UKA.

Combined pharmacotherapy for osteonecrosis of the femoral head after severe acute respiratory syndrome and interstitial pneumonia: two and a half to fourteen year follow-up.

PURPOSE: The purpose of this study was to retrospectively analyze the clinical, functional, and radiological outcomes of combined pharmacotherapy to ONFH after high-dose corticosteroid therapy. METHOD: From August 2003 to June 2015, five patients (ten hips) of ONFH in ARCO stage I, after SARS and Interstitial pneumonia, were treated by combined pharmacotherapy. Lipo-prostaglandin E1 10 µg iv Bid × 28 days, enoxaparin 6000 iu H QD × 12 weeks, alendronate sodium tablet 10 mg QD × 1 year. The patients were fully weight-bearing following completion of the follow-up. RESULT: For these five patients (ten hips), Harris score was 100 from the diagnosis to final follow-up time. Radiologic findings show no signs of collapse, necrotic focus was repaired, and ARCO stages were changed from IC into IIB. CONCLUSION: This combined pharmacotherapy has promising treatment results for delaying or preventing collapse of ONFH in ARCO stage I.

Extracorporeal shock wave therapy in the treatment of primary bone marrow edema syndrome of the knee: a prospective randomised controlled study.

BACKGROUND: The aim of this prospective study was to evaluate the effectiveness of extracorporeal shock wave therapy (ESWT) in normalizing the symptoms and imaging features of primary bone marrow edema syndrome (BMES) of the knee. METHODS: This study compared the outcomes of ESWT (Group A) (n = 20) and intravenously applied prostacyclin and bisphosphonate (Group B) (n = 20) in the treatment of BMES of the knee in our department between 2011 and 2013. The Visual Analog Scale for pain (VAS, 100 mm), the Western Ontario and McMaster University Osteoarthritis Index (WOMAC), the SF-36 scores and MRI scans as well as plain radiographs were obtained before and after therapy between two groups. RESULTS: Compared with Group B, we found greater improvement in VAS, the WOMAC Osteoarthritis Index and SF-36 score at 1, 3 and 6 months post-treatment in Group A (P < 0.05). Furthermore, MRI scans showed a higher incidence of distinct reduction and complete regression of bone marrow edema at 6 months in Group A (95 vs. 65 %; P = 0.018). The MRI at 1 year follow-up showed complete regression in all patients in Group A. However, two cases in Group B continued to normalize over the subsequent follow-up period. CONCLUSIONS: ESWT can produce rapid pain relief and functional improvement. It may be an effective, reliable, and non-invasive technique for rapid treatment of BMES of the knee. TRIAL REGISTRATION: Research Registry UIN 528, September 03, 2015.

Minimally invasive unicompartmental knee arthroplasty in treatment of osteonecrosis versus osteoarthritis: a matched-pair comparison.

This study was conducted to compare the differences of the outcome and surgical technique for minimally invasive unicompartmental knee arthroplasty(UKA) in treatment of osteonecrosis versus osteoarthritis. Twenty-nine spontaneous osteonecrosis of the knee (SONK) cases were reviewed retrospectively. An equal number of patients with osteoarthritis (OA) performed in the same period were selected and matched with respect to age, preoperative range of motion and radiological grade of knee arthrosis. The mean follow up time were 44.14±14.05 and 44.45±14.45 months, respectively. The preoperative hospital for special surgery knee score and visual analogue score were significantly better in group OA than those of group SONK. However, the results were comparable in terms of postoperative pain, knee score, range of motion and axial alignment. From a technical point of view, the osteonecrosis stage and bone defect must be taken into account when using UKA for SONK.

[Risk factors for lateral compartmental cartilage wear in varus knee osteoarthritis].

OBJECTIVE: To analyze the gross features of articular cartilage wear in varus knee osteoarthritis, and discuss the risk factors for lateral compartmental cartilage erosion. METHODS: Data prospectively collected from the dissection of 286 total knee arthroplasties (223 patients) with varus knee osteoarthritis from January 2013 to December 2013 were analyzed. At the operation, the gross assessments of articular cartilage, ligament and meniscus were recorded, and then the slices were evaluated for histologic analysis. Parameters of the patients with lateral compartmental cartilage erosion were compared with those without lateral compartmental cartilage erosion using the univariate analysis. Logistic regression analysis was used to analyze the risk factors associated with lateral compartmental cartilage erosion. RESULTS: There were 223 patients with 286 knees were included,including 37 male patients (47 knees) and 189 female patients (239 knees), with an average age of (66±8) years (range 50-86 years), body mass index (BMI) was (27±5) kg/m2 (18.0-40.0 kg/m2). Varus degree was 8°±4° (1°-34°). Range of motion was 103°±21° (0°-143°), and Hospital for Special Surgery (HSS) score was 53±12 (29-76). Seventy-five knees (60 patients) showed lateral compartmental cartilage wear (26.2%). Environmental factors showed no differences in age, side, gender, BMI, range of motion,and HSS score (P>0.05). Factors significantly increasing the risk of lateral compartmental cartilage wear by univariate analysis included varus degree, activity level, duration of onset, meniscus, Weidow grade, Kellgren-Lawrence grade, collateral ligament and anterior cruciate ligament (P<0.05). Multiple Logistic regression analysis revealed the factors most highly associated with the increase risk for lateral compartmental wear were high activity level (OR=2.843, 95% CI: 1.010-8.002) and longer duration of onset (OR=1.216, 95% CI: 1.115-1.325). However, intact lateral meniscus (OR=0.012, 95% CI: 0.003-0.048) and anterior cruciate ligament (OR=0.406, 95% CI: 0.192-0.857) were associated with the protection of lateral compartmental. CONCLUSIONS: In varus knee osteoarthritis, the wear incidence of lateral compartmental is low. High activity and increased duration of onset are risk factors of lateral compartmental wear, and intact meniscus and anterior cruciate ligament are protective factors.

[Treatment of patellofemoral osteoarthritis with patello-femoral joint arthroplasty].

OBJECTIVE: To study the outcome and surgical technique of patello-femoral joint arthroplasty (PFJ) for osteoarthritis of the knee. METHODS: From January 2010 to June 2012, 17 patients (24 knees) with patello-femoral compartmental osteoarthritis treated by PFJ were reviewed retrospectively. There were 2 male patients (4 knees) and 15 female patients (15 knees), with an average age of (64 ± 9) years (52-77 years) . The mean body mass index was (24 ± 3) kg/m² (18.0-30.1 kg/m²) . Patients were asked to return for follow-up examinations at 3, 6 months and at every year after PFJ. The range of motion (ROM), visual analogue scale(VAS), Hospital for Special Surgery score (HSS score) , Feller patella score, quadriceps muscle strength were evaluated before and after PFJ. The paired sample t-test and one-way analysis of variance (ANOVA) with replicate measures were used to determine whether there were statistically significant differences between the mean data. RESULTS: All of the patients were followed up for 18-47 months, with a mean time of (29 ± 10) months, 75.0% patients were satisfied with the outcome of this surgical procedure 1 year postoperative, and 87.5% were satisfied 2 years postoperative. HSS score was increased from 61 ± 11 to 90 ± 6 at the final follow-up (t = 12.24, P = 0.000). VAS score was reduced from 6.7 ± 1.0 to 2.4 ± 1.0 (t = 15.84, P = 0.000). The mean post-operative ROM of the knees was 126° ± 7° (t = 3.25, P = 0.003). Feller patella scores were 18.0 ± 3.2 before operation, and 18.5 ± 4.5, 19.7 ± 3.4, 24.0 ± 3.8, 26.0 ± 3.3, 26.6 ± 2.5 at 3, 6, 12, 24 months after operation, final follow-up, respectively. Quadriceps muscle strength were 3.9 ± 0.5 before operation, and 3.7 ± 0.5, 3.9 ± 0.5, 4.2 ± 0.5, 4.3 ± 0.5, 4.3 ± 0.5 at 3, 6, 12, 24 months after operation, final follow-up, respectively. Repeated measures ANOVA found significant time effects for Feller patella scores (F = 38.97, P = 0.000) and quadriceps muscle (F = 6.89, P = 0.000). Feller patella scores and quadriceps muscle strength were low at 3, 6 months after operation, with no significant differences compared with pre-operation data (P > 0.05). The improvements of Feller patella scores and quadriceps muscle strength after 6 months were of significant difference compared with pre-operation and postoperative 6 months data (t = 5.65-10.65 and t = 2.18-2.73, P < 0.05) . Three knee reported continuing pains with quadriceps muscle strength less than 4 level. CONCLUSIONS: PFJ is an effective method for patello-femoral compartmental osteoarthritis with less trauma. The early term outcome of PFJ is encouraging. Quadriceps muscle strength should be enhanced.

Alterations of the Subchondral Bone in Osteoarthritis: Complying with Wolff's Law.

Osteoarthritis (OA) is a whole joint disease that is significantly related to abnormal mechanical loads. Subchondral bone alterations, during the evolution course of OA, are considered a reflection of the adaptation of the bone tissue to mechanical loads. However, some of these alterations are taken as a detriment and paradoxical. What are these structure, composition, and mechanical property alterations or mechanical functions for are not quite clear. In this review, we discuss the possibility that these alterations are used for maintaining the joint function. With taking excessive load as a risk factor and under conditions of articular cartilage gradually lose its thickness and its function of evenly distributing the load on the subchondral bone plate, and applying Poroelasticity to bone mechanics; moreover, Boussinesq's pressure bulb theory and bone optimal design principles are utilized. We found that each subchondral bone alteration has its unique mechanical function in resisting loads and maintaining the joint function, and these alterations comply with both bone optimal design principles and Wolff's law within a proper range.

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.

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).

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.

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.

[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.

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.