Pellegrini–Stieda lesion is described as ossification on the origin of medial collateral ligament. We present a case of end-stage knee osteoarthritis with the Pellegrini–Stieda lesion treated by unicompartmental knee arthroplasty (UKA). During the postoperative follow-up, an interesting change occurred such that the ossification lesion disappeared gradually and did not relapse. It is supposed that the disappearance was caused by UKA changing the abnormal biomechanics of the varus osteoarthritic knee.

目的 分析髓芯减压联合自体骨髓单核细胞移植治疗股骨头坏死病例临床失败因素.方法 回顾性分析中日友好医院2011年7月至2012年9月行髓芯减压联合自体骨髓单核细胞移植治疗股骨头坏死的患者38例(50髋),男28例,女10例,平均年龄31.9岁.经5年随访,失随访3例5髋,根据术前影像学资料分别对其行国际骨循环研究会(ARCO)分期和中日友好医院分型,并行Harris评分.术后使用Harris评分对其行临床效果评价,并行影像学检测.数据比较采用Pearson检验.结果 截止到末次随访,随访病例中19髋行关节置换,Harris评分低于70分但未行关节置换3例.其中ARCOⅡ期(4/18,其中ⅡB和ⅡC各2髋),ARCOⅢA(15/24)、ARCOⅢB(3/3)期临床失败率分别为22.2％、62.5％、100.0％,检验值为10.03,似然比值11.54,线性相关卡方值9.81,差异均有统计学意义(P=0.07、0.03、0.02).中日友好医院分型L2型(2/3)、L3型(19/25)、(C+L1)(1/17)型患者临床失败率分别为66.7％、76.0％、5.9％,检验值为20.32,似然比值23.38,线性相关卡方值19.14,差异均有统计学意义(P值均为0.00).分期和分型是术后临床失败的危险因素.术后Harris评分平均为82.21分.结论 本次研究观察结果表明髓芯减压联合自体骨髓单核细胞移植应用于股骨头坏死病例的治疗中,对ARCOⅢ期,中日友好医院L2、L3型(坏死累及外侧柱)患者术后临床失败率较高,适合ARCOⅡ期,中日友好医院分型L1型和C型患者.

Background: Intraoperative periprosthetic femoral fracture(PFF) is a severe complication of primary cementless total hip arthroplasty (THA). An assessment of risk factors would effectively reduce the risk. Objective: The present study aimed to identify the risk factors for intraoperative calcar fracture and evaluate its clinical effects. Methods: In this retrospec-tive analysis, 712 patients (825 hips) who had undergone primary cementless THA from January 2015 to December 2017 were included. And a case-control (1:2) study was designed to identify the potential risk factors. 19 patients (20 hips) intra-operative calcar fractures were observed. A control group of 38 patients (40 hips) without calcar fractures was randomly se-lected. Demographic data, type of implant, proximal femur morphology, preoperative diagnosis and complications were evaluated to determine risk factors for intraoperative calcar fracture. Results: The overall incidence of PFF was 2.42%(20/825). The mean follow-up time was 6.9±3.8 months. No prosthesis loosening and subsidence occurred. There was no statisti-cally significant difference in the age and gender between two groups as well as BMI (P>0.05). The proportions of osteoporo-sis in the PFF group were significantly higher than that in the control group (P=0.001). There was no statistically significant difference in the type of implants between two groups(P=0.138). Developmental dysplasia of the hip(DDH), femoral neck fracture, stovepipe-type proximal femurs and dissection anomaly were risk factors for intraoperative fracture. Conclusions: In the short period, the treatment of detectable calcar fracture was effective(Vancouver A2 type). Preoperative radiographic eval-uations, careful operation and screening for high-risk patients, may be the potential strategies to reduce the incidence of PFF.

Objective The aim of this study was to discuss whether TKA patients with preexisting radiographic evidence of vascular calcifications had a higher risk of wound ischemic complications. Methods In this retrospective analysis, all patients who had undergone primary TKA in the period 2015 ～ 2016 with intraoperative use of a tourniquet were included. Vascular calcifications seen on the preoperative radiograph were classified as intimal-type and medial-type calcifications and no calcifications. The correlation analysis of perioperative ischemic complications and calcifications was done. Results There are 437 patients with 577 knees were included. Vascular calcifications were seen in 96 knees (medial type: n=74 knees, 64 patients; intimal type: n=22 knees, 20 patients). Major ischemic complications such as arterial thrombosis were not seen. The rate of minor ischemic complications such as poor healing of superficial wound was significantly elevated in patients with intimal-type calcifications (5. 40％) when compared to patients with medial-type calcifications(0％) and those without (1. 25％, P=0. 032). Multiple Logistic regression analysis revealed the factor most associated with the increase risk for ischemic complications was intimal-type calcifications (OR=1. 367, 95％CI: 1. 152-1. 888). Conclusion The rate of minor ischemic complications was obviously elevated in the patient group with intimal artery calcifications. We recommend high alertness to the presence of calcifications on preoperative radiographs. In patients with intimal artery calcifications, standardized application of tourniquet should not be ignored. Intraoperative soft tissue management should be very careful and postoperative vascular status should be monitored closely.

年轻人运动相关的胫骨应力性骨折临床十分常见.在老年人中,这种疾病常见于类风湿性关节炎、Paget病、焦磷酸盐关节病和甲状旁腺功能亢进等群体中,而在老年退变性骨关节炎（osteoarthritis,OA）患者中则十分罕见.对于这类疾病的病因和最佳治疗方案目前尚无定论.本文通过报道1例膝关节骨关节炎合并胫骨近端应力性骨折患者的诊治及文献回顾,对本病的诊断、治疗和预后进行阐述.

[Objective] To evaluate the morbidity,pathology,diagnosis and treatment of multifocal osteonecrosis(MFON) in patients from our center to to facilitate earlier diagnosis and optimize treatment.[Methods] From January 2010 to June 2015,the MRI screening of both shoulders and ankles was taken from the patients with osteonecrosis high risk factors.For patients with symptoms in other joints,especially the hip and knee,MRI was continuously performed on bilateral shoulders and ankles,and also bilateral wrists and elbows when necessary.If patients were found to have shoulder,ankle,wrist or elbow osteonecrosis,MRI was further performed on their hips and knees,and also other joints when necessary.[Results] A total of 1507 patients with osteonecrosis were admitted in our center,but only 48 were diagnozed as having MFON.In other 102 patients with high risk factors,more joints were screened with MRI,which brought more 31 confirmed MFON cases.Finally,the overall diagnostic confirm rate improved by 5.2％ during this period,with statistically significant difference(P ＜ 0.05).[Conclusion] For patients with high-risk factors,MFON should be noticed.It is necessary to screen other joints to avoid miss-diagnosis.Early diagnosis and early treatment are significant to obtain the best clinical results.

Objective To investigate the causes and prevention of intraoperative periprosthetic femoral fractures around the Corail stem associated with primary total hip arthroplasty (THA).Methods A retrospective cohort study was made on 18 patients (18 hips) developing intraoperative periprosthetic femoral fractures around the Corail stem during primary THA between January 2010 and March 2016.There were 7 male and 11 female patients,with the age range of 42-81 years (mean,57.6 years).At the time of diagnosis,six hips presented with inflammatory arthropathy,five avascular necrosis of the femoral head,four developmental dysplasia of hip,and three femoral neck fractures.Local problems were identified in 14 hips (77.8％),principally osteoporosis in 1 1 hips (61％).Fifteen periprosthetic femoral fractures were recognized intraoperatively and were treated with cerclage wires.Three intraoperatively occult fractures were observed on the postoperative radiograph,including one fracture treated non-operatively,one by wire cerclage fixation and one by open reduction internal fixation.Factors related to intraoperative fractures were analyzed.Harris score and Beals and Tower's criteria were used for clinical and radiological assessment respectively.Results Osteoporosis,inflammatory arthropathy,anatomical abnormity of the proximal femur,excessive pursuit of the degree of interference fit between prosthesis and cortical bone,and inappropriate choice of prosthesis size were the main causes of femur fractures during primary THA.Mean follow-up was 32 months.Union was obtained in all patients in a mean of 4.7 months.No prosthesis loosening and infection occurred.Mean Harris hip score was 91.2 points at the final follow-up.Radiological assessment showed excellent results in 16 hips and good results in two hips.Conclusions Rigidity in patient selection and master of surgery techniques are the key to preventing periprosthetic femoral fractures.Once the periprosthetic femoral fractures happens and the type is stable,cerclage wire fixation is a simple and satisfactory technique that is adequate for both implant and fracture stability.

Multiple treatment strategies have been developed for osteochondral lesions (OCLs) of the talus. The purpose of this retrospective study was to assess retrograde autologous bone marrow cell (BMC) transplantation via core drilling (CD) combined with focused extracorporeal shock wave treatment (ESWT) in undisplaced OCL of the talus. A total of 69 patients with unilateral osteochondral lesions of the talus (Hepple grade I–III) were divided into two groups: 41 patients received combined therapy of ESWT and BMC transplantation (group A), while 28 were administered BMC transplantation alone (group B). The patients were followed up clinically and radiographically for a minimum of 2 years. Mean follow-up was 4.1 ± 2.8 years. AOFAS scores increased more significantly while pain intensity levels decreased in group A after treatment, compared with group B values ( P < 0.001). In MRI follow-up, a more remarkable improvement of OCLs of the talus was observed in group A compared with group B ( P = 0.040). Therefore, the combined technique reported here is a highly effective therapeutic option in OCLs of the talus with intact cartilage. It promotes patient recovery with pain control, and improves clinical outcome for more than 2 years after surgery.

To compare China-Japan Friendship Hospital (CJFH) classification with Japanese Investigation Committee (JIC) classification by observing the regular progressive pattern of nontraumatic osteonecrosis of femoral head (ONFH) to establish the reliable and convenient new classification of ONFH. The coronal section of the femoral head was divided into three pillars (medial, central, and lateral). The midcoronal section of the femoral head on MRI was selected. The CJFH classification of ONFH was established according to the site of necrotic focus in three pillars. Total 153 hips with ONFH were classified according to CJFH and JIC classifications, respectively. The collapse rate was observed and compared between both classifications of ONFH. The CJFH classification for ONFH consists of three types: type M, the medial pillar was involved; type C, the medial and central pillars were involved; and type L, the lateral pillar was involved. According to site of necrosis focus in the lateral pillar, the type L was divided into three types: L1, there pillars were involved, but there still was some normal tissue in lateral pillar; L2, partial central pillar and all lateral pillar were involved; L3, the whole femoral head was involved. The natural history of the ONFH showed the collapse rate of types L2 and L3 in CJFH classification (95.3%) was higher than that (72.3%) of type C2 in JIC classification. The CJFH classification of ONFH based on three pillars is more applicable than JIC classification in predicting collapse of the femoral head.

Background:There are several overlapping characteristics between the lesions within the femoral head and os-teonecrosis of the femoral head (ONFH), especially in their radiological findings. There are few reports on the differential diagnosis of the lesions in the femoral head and ONFH. Objective:To investigate the differential diagnosis process of the le-sions in femoral head and ONFH. Methods:In this retrospective study, 21 patients with the lesion in the femoral head which was inclined to be misdiagnosed as ONFH in our hospital between January 2011 and July 2015 were enrolled. According to the diagnostic criteria and radiological features of ONFH, the characteristics, clinical manifestations and imaging features of the lesion in femoral head were compared with ONFH and summarized one by one. Results:Of the 21 patients, 13 were con-firmed by radiological examinations, 3 by intraoperative frozen pathologies and 5 by postoperative paraffin pathologies. There were 5 patients diagnosed as subchondral insufficiency fracture (SIF), 8 as pigmented villonodular synovitis (PVNS) and 8 as tumor and tumor-like lesion in the femoral head. Conclusions:The detailed analysis of clinical history, manifesta-tions and imaging data as well as the diagnostic criteria of ONFH can improve the diagnostic accuracy of the lesion in the femoral head.

Objective To evaluate the clinical results and radiographic outcomes of porous tantalum implant in the treatment of osteonecrosis of femoral head (ONFH).Methods A total of 101 ONFH patients (117 consecutive hips) treated with porous tantalum implant combined with bone grafting between June 2008 and December 2013 in China-Japan friendship hospital were evaluated.The inclusion criteria: diagnosis of non-traumatic ONFH.The exclusion criteria: surgical contraindication, having received any other type of surgical treatment, and secondary arthritis.According to the classification system of Association Research Circulation Osseous (ARCO), 49 hips were in stageⅡ, and 68 hips were in stageⅢ;as to China-Japan friendship hospital (CJFH) classification, 15 hips were type L1, 59 hips were type L2, 40 hips were type L3, three hips were type C.The data were analyzed using SPSS 19.0 statistical software.The t test or one-way analysis of variance was used to compare pre-and postoperative Harris hip score (HHS) among different groups.A chi-square test or Fisher exact text was performed to compare the rate of radiological progression and conversion to total hip arthroplasty (THA) among different groups.The Cox proportional hazards model were used to analyze the independent factors associated with conversion to THA and radiological failure.Results Ninety patients (104 hips) were available for follow-up with a mean time of (46±21) months.The mean age was (39 ± 8) years.At the last follow-up or before converting to THA, the mean postoperative HHS score for all the hips (69±15) was less than the mean preoperative HHS score (76±13) (t=3.939, P<0.01).Overall 49 hips converted to THA.According to analysis of Cox risky model, age, CJFH type and ARCO stage were independent risk factors for conversion to THA and failure of radiography.Conclusion Porous tantalum implantation is not a viable option for the treatment of ONFH, and the clinical failure is associated with age more than 40 years old, preoperative ARCO Ⅱ stage, and CJFH L3 type;it is necessary to work out strict indications for this procedure.

Our objective was to study the incidence, etiology, and diagnosis of multifocal osteonecrosis (MFON) and its treatment options to facilitate an earlier diagnosis and to optimize treatment. A radiological investigation was performed in osteonecrosis patients with a high risk of MFON for a more accurate diagnosis between January 2010 and June 2015. For patients with osteonecrosis of both the hip and knee joints or for patients with a history of corticosteroid use or alcohol abuse who had osteonecrosis of one or more joints in the shoulder, ankle, wrist or elbow, magnetic resonance imaging (MRI) was also performed on other joints, regardless of whether these joints were symptomatic. Furthermore, we performed a radiological screening of 102 patients who had a negative diagnosis of MFON but were at a high risk; among them, another 31 MFON cases were successfully identified (30.4%). Thus, the incidence of MFON during the study period increased from 3.1% to 5.2%. Patients diagnosed with osteonecrosis and who are at a high risk of MFON should have their other joints radiologically examined when necessary. This will reduce missed diagnosis of MFON and facilitate an earlier diagnosis and treatment to achieve an optimal outcome.

Objective: To retrospectively analyze the clinical efficacy of a modified light bulb operation for the treatment of femoral head osteonecrosis. Methods: A total of 38 patients (59 hips) were treated with this procedure between June 2004 and June 2005, and were followed up for over 10 years. They were classified into ARCO stage II (23 hips), stage IIIa (29 hips) and stage IIIb (7 hips); and into the China- Japan Friendship Hospital (CJFH) type C (3 hips), type L1 (7 hips), type L2 (19 hips) and type L3 (30 hips). In the operation, a bone window was made at the femoral head-neck junction. Autologous cancellous bone harvested around the window was mixed with recombinant human bone morphogenetic protein-2 (rh-BMP2), implanted to the subchondral bone and impacted. The cavity was filled with tricalcium phosphate porous bioceramic (Bio- TCP). The Harris hip score was used to evaluate the postoperative improvement of hip function. Excellent, good, fair, and poor results were defined as Harris hip scores of 90-100, 80-89, 70-79 and below 70, respectively. Harris hip scores ＞ 70 were defined as clinical successful. The radiographic follow-up was evaluated by X-ray and CT scan before and 3, 6, 12 months and every year after the treatment. No presences of collapse, crescent sign or narrower joint space were defined as radiographic successful results. Results: Six patients (9 hips) were lost in the follow-up. Of the rest, excellent, good, fair and poor functions were obtained in 30, 6, 5 and 9 hips, respectively. All the failed cases had total hip replacement. The average preoperative Harris hip score of all hips was 60.2 points. The average postoperative Harris hip score was 87.3 points at 10 years after the surgery, with an increase of 27.1 points (p ＜ 0.001). The radiological results were successful in 76% of the hips with preserved spherity of the femoral head and incorporation of the grafts in the femoral heads could be found. Conclusion: (1) The modified lightbulb operation used local cancellous grafts from the femoral head and expanded its volume with Bio-TCP and rhBMP-2. An overall 82% clinical successful rate and 76% radiographic successful rate was achieved with a mean follow-up of 10 years. (2) The operation did not need other autologous grafts to avoid donor site morbidity and was technically easy to perform. Grafts supporting to the lateral column in the necrotic area were found to be the most important determinant to prevent subsequent collapse of the femoral head.

OBJECTIVE:To analyze the effectiveness of bone grafting through windowing at the femoral head-neck junction for the treatment of osteonecrosis with the segmental collapse of the femoral head.METHODS:The clinical data were retrospectively analyzed from 106 patients (131 hips) with osteonecrosis with the segmental collapse of the femoral head who underwent bone grafting through windowing at the femoral head-neck junction between March 2011 and December 2013. There were 78 males and 28 females, with an average age of 31.3 years (range, 17-43 years). The body mass index ranged from 16.5 to 36.5 (mean, 24.2). There were 53 cases of corticosteroid-induced osteonecrosis of the femoral head (ONFH), 18 cases of alcohol-induced ONFH, and 35 cases of idiopathic ONFH. According to Association Research Circulation Osseous (ARCO) classification system, 105 hips were rated as stage IIIa, and 26 hips as stage IIIb; according to the China-Japan Friendship Hospital (CJFH) classification system, 41 hips were classified as C+L1 type, 13 hips as L2 type, and 77 hips as L3 type. Harris score was used for the effectiveness evaluation. The clinical failure cases were defined as patients who need total hip arthroplasty, or had a Harris score of less than 70 points. The Cox risk model analysis and Kaplan-Meier survival curves were used for multivariate analysis and univariate analysis.RESULTS:The average follow-up period was 27.9 months (range, 4-51 months). Solid fusions of bone graft were observed at 1.0-1.5 years after operation. The Harris score at last follow-up was 81.41 ±11.93, showing significant difference when compared with preoperative score (63.24 ± 9.98) (t = 13.710, P = 0.000). The results were excellent in 5 hips, good in 41 hips, fair in 57 hips, and poor in 28 hips, with an excellent and good rate of 35.1%. Thirty-three hips were classified as clinical failure. A progressive collapse of the femoral head was observed in 22 hips. The single factor analysis showed that preoperative ARCO stage, preoperative CJFH type, and preoperative Harris hip score were risk factors for clinical failure (P<0.05). The Cox risk model showed that ARCO stage IIIb was independent risk factor for clinical failure (P < 0.05). The Kaplan- Meier survival curves showed that ARCO stage IIIa patients had a better effectiveness than ARCO stage IIIb patients.CONCLUSION:Bone grafting through windowing at the femoral head-neck junction has a good effectiveness in patients at ARCO stage IIIa, while patients at ARCO stage IIIb and patients of CJFH types L2 and L3 have high clinical failure rates.

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.

Background The acetabular teardrop is often used to guide acetabular component placement in total hip arthroplasty (THA). Placing the lower acetabular component aspect at the same level as the lower teardrop edge was assumed to restore the hip center of rotation. Here we radiographically analyzed the relationship between cup center and normal contralateral acetabulum center height on unilateral THA using this placement method.Methods A total of 106 unilateral THA cases with normal contralateral acetabula were reviewed and the vertical and horizontal distances in relation to the lower acetabular teardrop edge from both hip joint centers, cup inclination, and anteversion were measured radiographically. The paired t-test was used to compare left and right hip center heights. Scatter plots and Pearson's correlation coefficients were used to evaluate differences in hip center heights, cup anteversion, inclination angles, and medialized cup center distance compared to the contralateral hip joint.Results Cup center height was significantly greater (P<0.01) than contralateral hip joint center height (93.4% in the 0-5 mm range, 6.6% >5 mm). There was a weak correlation between hip center height difference and inclination (r=0.376, P<0.01) and between difference and anteversion (r=0.310, P<0.01) but no correlation between difference and outer cup diameter (r=0.184, P=0.058) or difference and medialized cup center distance (r=-0.098, P=0.318).Conclusions Although this method did not exactly replicate anatomic hip center height, the clinical significance of cup center height and anatomic hip center height differences is negligible. This acetabular component placement method has high simplicity, reliability, and stability.

The purpose of this study was to compare the clinical outcomes of impacted bone graft with or without recombinant human bone morphogenetic protein-2 (rhBMP-2) for osteonecrosis of the femoral head (ONFH). 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 ONFH with a combination of artificial bone (Novobone) mixed with or without rhBMP-2. A total of 42 patients (72 hips) were followed-up from 5 to 7.67 years (average of 6.1 years). The patients with and without BMP were the first group (IBG+rhBMP-2) and the second group (IBG), respectively. The clinical effectiveness was evaluated by Harris hip score (HHS). The radiographic follow-up was evaluated by pre-and postoperative X-ray and CT scan. Excellent, good, and fair functions were obtained in 36, 12, and 7 hips, respectively. The survival rate was 81.8% and 71.8% in the first and second group, respectively. However, the survival rate was 90.3% in ARCO stage IIb, c, and only 34.6% in ARCO stage IIIa(P<0.05). It was concluded that good and excellent mid-term follow-up could be achieved in selected patients with ONFH treated with impacted bone graft operation. The rhBMP-2 might improve the clinical efficacy and quality of bone repair.

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.

BACKGROUND:It is a clinical difficult in the treatment of osteonecrosis with joint preservation, and to solve this problem, a variety of bone graft substitutes are at the exploration stage. OBJECTIVE:To evaluate the clinical outcome of lightbulb operation with porous bioceramic β-tricalcium phosphate in a consecutive series of patients with osteonecrosis of the femoral head. METHODS:From January to December 2008, 58 patients (88 hips) who had undergone lightbulb operation with porous bioceramic β-tricalcium phosphate were involved in this study. Al patients were evaluated both clinicaly and radiographicaly at postoperative 3, 6, 12 months and annualy. Functional improvement was assessed with the Harris hip score. RESULTS AND CONCLUSION: Among these patients, 56 patients (85 hips) were folowed up for 2-5 years. According to the ARCO staging system, there were 27 hips of stage II, 40 hips of stage IIIa, 18 hips of IIIb. According to the hospital’s classification, type C was in 4 hips, L1 in 15 hips, L2 in 28 hips, and L3 in 38 hips. According to the Harris hip score system, excelent outcome was in 55 hips, good in 12 hips, fair in 5 hips and poor in 13 hips. Nine of 11 patients who failed to preserve their own joints were subjected to hip replacement. The&nbsp mean preoperative and postoperative Harris scores were 61.2 and 85.3, respectively, with a mean improvement of 24.1 points (P < 0.001). All hips were radiologically stable, with no progress of osteonecrosis, and bone density in the bone graft area increased obviously. The replacement time of porous bioceramic β-tricalcium phosphate was 1-1.5 years. These findings suggest that the porous bioceramic β-tricalcium phosphate provides an option to treat osteonecrosis of the femoral head with satisfactory clinical outcomes, and profits the repair and reconstruction of femoral head osteonecrosis. When in the lateral column of femoral head, the porous bioceramic β-tricalcium phosphate can play a supporting role in the lateral column of the necrotic area, and further prevent collapse, which is suitable for patients with osteonecrosis of the femoral head, especially for those with joint preservation.

Background The incidence of total hip replacement in the younger and more active patients is ever increasing. The ceramic-on-ceramic (COC) bearing was developed to reduce wear debris-induced osteolysis and loosening and to improve the longevity of hip arthroplasties. Few studies have reported the clinical results and complications of the new zirconia-toughened ceramic total hip arthroplasty (THA). Methods A consecutive series of 132 young patients (177 hips) that underwent primary cementless THAs between January 2010 and December 2012 were included in this study. These arthroplasties all had fourth-generation COC bearings performed through a posterolateral approach. The average age was (41.8±8.3) years (ranging from 22 to 55 years), and the mean follow-up period was (24.5±9.4) months (ranging from 12 to 47 months). The results were evaluated both clinically and radiographically. Harris hip score (HHS) was determined before surgery and at the time of each follow-up. Presence of postoperative groin or thigh pain and squeaking were recorded. Other complications such as dislocations, periprosthetic fractures, and ceramic components fractures were diagnosed and treated in emergency. Results The average HHSs improved from preoperative 60.3±10.7 (ranging from 29 to 76) to 91.0±5.1 (ranging from 74 to 100) at the final follow-up ( t =45.064, P <0.05), and 97.7% of cases were scored as excellent and good results. At the last follow-up, incidental inguinal pain was found in three hips (1.7%) and thigh pain in 11 hips (6.2%). Radiographs showed a high rate of new bone formation around the acetabular and stem components. No obvious osteolysis or prosthesis loosening was detected. Complications occurred in six hips (3.4%): posterior dislocation in two hips (1.1%), periprosthetic femoral fracture in one hip (0.6%), asymptomatic squeaking in two hips (1.1%), and ceramic liner fracture in one hip (0.6%). Conclusions The fourth-generation COC THA showed excellent clinical results in younger active patients with no osteolysis-related prosthesis failure at a short-term follow-up study. Surgeons should still be aware of the potential risks of complications such as dislocation, periprosthetic fracture, squeaking, and ceramic components fracture.