[Objective]To investigate the role of CT measurement of distal femur rotational angle in total knee arthroplasty. [Methods]From April 1998 to April 2005,eighty-four patients(106 knees)underwent total knee arthroplasty(TKA),including 48 rheumatoid arthritis(RA)knees,and 67 osteoarthritis(OA) knees and one case of pigmented villonodullar synovitis.All the patients in the study were measured by computed tomographic scanning (CT). The examination was positioned in supination,or neutral position of the lower limbs.The distal femur was micro-scanned by 3 mm width.On the screen one line was made between the two hypocondyles of the femur,and another line was made between the medial epicondyle fossa and the external epicondyl fossa of the femur.The angles of the two lines were measured.The bone resection of femur antero-posterior condyle was performed according to the preoperatively measured angles.Six months after operation,the range-of-motion of knee was examined. A control group(49 knees in 40 patients) to the conventional TKA of the 3 degree external rotation bone resection was comparatively studied. All the operations were made by the same surgeon,and all the prostheseswere the type of PFC ( Press Fit Condyle).[Results]The results indicated that the rotational angles of the distal femur were above 3 degrees in north Chinece population with the male of 5.1 degrees (SD 1.7) and female of 5.8 degrees(SD1.5).[Conclusion]The rotational angler of the distal femur are above 3 degrees in north Chinece population. If the bone resection of femur was performed according to the preoperatively measured angles,the postoperative result is more favourable than the conventional bone resection according to the 3 degree external rotation.

BACKGROUND:Corticosteroid-induced osteonecrosis of femoral head is one of the major causes of the loss of hip joint function. More and more studies have shown that corticosteroid-induced osteonecrosis of femoral head may be associated with proliferation ability of bone marrow mesenchymal stem cells.
OBJECTIVE:To detect the proliferation and differentiation ability of bone marrow mesenchymal stem cells isolated from patients with steroid-induced osteonecrosis of femoral head, providing rational evidences for treatment of corticosteroid-induced osteonecrosis of femoral head with the transplantation of autologous bone marrow containing bone marrow mesenchymal stem cells into the necrotic area of femoral head.
METHODS:Bone marrow mesenchymal stem cells from the femoral heads were col ected from patients with corticosteroid-induced osteonecrosis of femoral head, and new femoral neck fractures without osteonecrosis who were scheduled for total hip arthroplasty. In another group, bone marrow mesenchymal stem cells were col ected from ilium bone marrow of the same steroid-induced osteonecrosis of femoral head patients. The femoral neck fracture was defined as fracture without preceding trauma or in response to minimal trauma. Cases with corticoid treatment were excluded from the femur neck fracture patients. Al bone marrow mesenchymal stem cells were divided three groups:femoral neck fracture group;femoral head group of corticosteroid-induced osteonecrosis of femoral head;ilium group of corticosteroid-induced osteonecrosis of femoral head. The bone marrow mesenchymal stem cells were isolated by enzyme digestion or density gradient centrifugation from bone marrow blood of the three detecting area, and then selected by the adhesive method. Passage 3 bone marrow mesenchymal stem cells were selected for experiments.
RESULTS AND CONCLUSION:The results of methyl-thiazolyl-tetrazolium assay indicated that the bone marrow mesenchymal stem cells obtained from the femoral head group showed reduced proliferation ability compared with those obtained from the other two groups. The percentage of bone marrow mesenchymal stem cells was increased at G 0/G 1 , but decreased significantly at S+G 2/M in the femoral head group (P<0.05). The bone marrow mesenchymal stem cells obtained from the ilium group were proliferated best. The decreased proliferation ability of bone marrow mesenchymal stem cells may play a role in the low repair capacity of corticosteroid-induced osteonecrosis of femoral head, and bone marrow mesenchymal stem cells from the ilium of patients with corticosteroid-induced osteonecrosis of femoral head have a better proliferative ability.

Objective To investigate the application value of MR rthrography (MRA) in the diagnosis of acetabular labral tears. Methods Fifteen patients with a high degree of suspected acetabular labral tears received fluoroscope-guided injection of the contrast media into the hip joint ( hip arthrography) and fat-saturated spin-echo T1-weighted images were obtained in the coronal, sagittal, oblique-axial and radial planes. Hip arthroscopy was performed on 12 of them. Results Labral tears which were diagnosed in 11 patients by hip MRA were confirmed at hip arthroscopy. One patient showed no MRA indication of labral tear, also showed normal on arthroscopy. Tear in the anterior-superior quadrant 10 cases of 12 joints ( 12/13), posterior-superior quadrant 1 case of a joint (1/13). In 11 patients who underwent arthroscopy, hip MRA diagnosed 3 (3/13) joints labral tears in coronal planes, 10 (10/13) joints in sagittal planes and 13 (13/13) labral tears in axial-oblique and radial planes. In 15 patients with 20 hip joints, 5 cases 6 joints (6/20) with normal acetabular sublabral sulcus were performed. Conclusions MR arthrography of hip is a reliable method in the diagnosis of acetabular labral tears. Scanning method should be included fat-saturated spin-echo T1-weighted images in sagittal and oblique-axial planes or sagittal plus radial planes. The diagnosis of tor posterior-inferior quadrant should pay attention to the existence of a normal variation.

Objective To investigate the clinical diagnosis and the results of arthroscopic treatment for acetabular labrale tears. Methods From November 2008 to December 2009, 21 patients with unilateral acetabular labrale tears underwent hip arthroscopy were entered in the study, including 9 males and 12 females with an average age of 37.1 years. Physical examination, X-ray examination and magnetic resonance arthrography (MRA) were carried out preoperatively to make the definite diagnosis. Of 21 cases, including labrale debridement in 14 cases, labrale debridement plus femoral osteoplasty in 5 cases and labrale repair plus osteoplasty in 2 cases. Patients were followed-up either by telephone inquiring or out-patient interview.The visual analogue scale (VAS) and Harris hip score were recorded before operation and 6 months after operation respectively. Results All 21 patients showed a positive Fadir impingement sign on the affected hips,meanwhile 15 cases showed a positive Fabir impingement sign, and positive McCarthy test was observed in 9cases. X-ray film showed 11 cases have cam type impingement, among which 6 combined with pincer type impingement. Two cases had acetabulum retroversion alone. On MRA images, signals of contrast agent infiltration in anterior superior quadrant which indicated labrale tear were observed among all cases. All labrale tears were confirmed under arthroscopy. All patients were followed up for average 11.6 months (range, 6-19).The symptoms were obviously released after operation. 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 the differences had statistical significance. Conclusion Acetabular labrale injury has a close correlation with femoroacetabular impingement. Impingement test and MRA have a high sensitivity and accuracy on clinical diagnosis of labrale tears. Arthroscopic debridement, repair and osteoplasty for labrale tears give a good early outcomes.

BACKGROUND: The distal femur resection in total knee arthroplasty is commonly made using a fixed angle relative to an intramedullary rod. Does a fixed distal femur resection angle influence radiographic alignment in primary total knee arthroplasty? OBJECTIVE: To research the femoral mechanical-anatomical angle in Chinese and how it affects the femoral component angle and postoperative mechanical alignment for total knee arthroplasty. METHODS: Totally 109 cases (148 knees) underwent primary total knee arthroplasty. One surgeon used a fixed resection angle of 5° (group A; n=56 cases, 76 knees). The second surgeon adjusted the resection angle according to preoperative coronal alignment, using 5° for neutral/mild varus, 6° for more severe varus, 4° for mild valgus and 3° for severe valgus knees (group B; n=53 cases, 72 knees). Preoperative hip-knee-ankle angle, femoral mechanical-anatomical angle, postoperative hip-knee-ankle angle, femoral component angle and tibial component angle were measured from standing hip-knee-ankle angle radiographs. For postoperative hip-knee-ankle angle, 177°-183° were considered as neutral mechanical axis. For femoral and tibial component angles, the target results were 88°-92°.RESULTS AND CONCLUSION: (1) There was no statistically significant difference between groups in postoperative hip-knee-ankle angle (group A: (178.78±3.57)°, group B: (178.23±2.78)°; P=0.302) and good rate of hip-knee-ankle angle (group A: 62%, group B: 65%). (2) The mean femoral mechanical-anatomical angle was (6.70±1.34)°preoperatively. There was no significant difference in the good rate of hip-knee-ankle angle (hip-knee-ankle angle < 7°:69%; hip-knee-ankle angle ≥7°: 55%; P=0.108) postoperatively. There was a statistically significant difference about good rate of femoral component angle between different femoral mechanical-anatomical angle angles (femoral mechanical-anatomical angle < 7°: 76%; femoral mechanical-anatomical angle ≥7°: 39%; P < 0.01). (3) There was a statistically significant correlation between preoperative femoral mechanical-anatomical angle and postoperative hip-knee-ankle angle (r=?0.42, P < 0.01) and postoperative femoral component angle (r=?0.58, P < 0.01). (4) The mean femoral mechanical-anatomical angle was larger than foreign values. When the resection angle less than femoral mechanical-anatomical angle, the femoral component may tend to be varus which could affect the lower extremity mechanical alignment. For the larger femoral mechanical-anatomical angle, we advise to adjust the resection angle according to measured value preoperatively.

This retrospective study was to compare the clinical effects of arthroscopie drilling with arthroscopic microfracture technology on full-thickness chondral defects in 68 patients treated between March 2003 and June 2005. The patients were followed up for an average of (20 ± 5 ) months. Lysholm score and Tegner scale were used to evaluate the efficacy. For the arthrescopic drilling group (n = 15 ) and the microfracture surgery group (n =27) , total effective rates were 12/15 and 85% (23/27), respectively. Our data suggest that those two methods provide simple and effective surgical procedure for the treatment of chondral defects of the knee; the results of arthroscopic microfracture were significantly better than arthroscopic drilling.

Objective To explore the regular progressive pattern of nontraumatic osteonecrosis of the femoral head (ONFH) in order to establish the reliable and convenient new classification of ONFH.Methods The coronal section of the femoral head was divided into three pillars (medial,central and lateral).The mid-coronal section of the femoral head on MRI was selected.The China-Japan Friendship Hospital (CJFH)classification of ONFH was established according to the site of necrotic focus in three pillars.A total of 153hips with ONFH were classified according to CJFH classification and Japanese Investigation Committee (JIC)classification,respectively.The collapse rate was observed and compared between both classifications of ONFH.Results The CJFH classification for ONFH consists of 3 types:type A,the medial pillar was involved; type B,the medial and central pillars were involved; type C,the lateral pillar was involved.According to site of necrosis focus in the lateral pillar,the type C was divided into 3 types:C1,there pillars were involved but there still was some normal tissue in lateral pillar;,C2,partial central pillar and all lateral pillar were involved; C3,the whole femoral head was involved.The natural history of the ONFH showed the collapse rate of type C2 and C3 in CJFH classification (95.3％) was higher than that (72.3％) of type C2 in JIC classification.Conclusion The CJFH classification of ONFH based on three pillars is more sensitive than JIC classification in predicting collapse of the femoral head.Moreover,the CJFH classification is convenient to use.

Objective To evaluate the efficacy of locking compression plate (LCP) and retrograde intramedullary nail (RIMN) in the treatment of periprosthetic fractures after total knee arthroplasty (TKA),providing reference for surgeons to select the fixation approach.Methods Cochrane Library,PubMed,Embase,Medline,Wanfang database,VIP Database for Chinese Technical Periodicals,and China National Knowledge Infrastructure (CNKI) were searched to identify the retrospective comparison studies (RCS) which compared the clinical outcomes of LCP and RIMN for patients with periprosthetic supracondylar fractures of the distal femur after TKA.The quality of included literatures was evaluated by Newcastle-Ottawa scale(NOS).Meta-analysis was performed using Revman 5.3 software to compare the operation time,Knee society score (KSS),fracture healing time,nonunion rate,reoperation rate,and incidence of complications between the two groups.Results Ten retrospective comparison studies involving 487 patients were identified including LCP group (296 cases) and RIMN group (191 cases).The meta analysis results showed that no significant differences were found in the operation time (MD =10.89,95％ CI-9.56-31.33,P ＞ 0.05),KSS (MD =1.11,95％ CI-8.88-11.10,P =0.83),fracture healing time (MD =0.00,95％ CI-1.51-1.51,P ＞0.05),nonunion rate (OR =0.71,95％ CI 0.38-1.31,P ＞ 0.05),reoperation rate (OR =0.65,95％ CI 0.22-1.91,P ＞ 0.05),and complication incidence rate (0R=0.69,95％CI0.38-1.26,P＞0.05) between these two groups.Conclusions There are no significant differences in the operation time,KSS,fracture healing time,nonunion rate,reoperation rate,and complications between LCP and RIMN groups.LCP and RIMN have similar clinical outcomes in treating periprosthetic supracondylar femoral fracture following TKA.

OBJECTIVETo analyze the gross features of articular cartilage wear in varus knee osteoarthritis, and discuss the risk factors for lateral compartmental cartilage erosion.

METHODSData 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.

RESULTSThere 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.

CONCLUSIONSIn 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.

Aged ; Aged, 80 and over ; Anterior Cruciate Ligament ; Arthroplasty, Replacement, Knee ; Body Mass Index ; Cartilage, Articular ; pathology ; Female ; Humans ; Knee Joint ; Male ; Menisci, Tibial ; Middle Aged ; Osteoarthritis, Knee ; pathology ; Prospective Studies ; Range of Motion, Articular ; Risk Factors

BACKGROUND:Zinc-based alloy medical implant materials have excellent mechanical properties,complete degradability and good biocompatibility,and are mainly used in orthopedic implants,cardiovascular stents,bile duct stents,tracheal stents,nerve catheters,etc. OBJECTIVE:To review the research progress of biodegradable zinc-based alloys in bone defect repair and prospect the promising research direction and achievements of zinc-based materials. METHODS:After searching PubMed,Web of Science,WanFang Data,and CNKI databases from the establishment of the database to June 2023,various relevant articles on biodegradable zinc-based alloys for bone implant material research were collected.The basic characteristics of biodegradable zinc based alloys were summarized,and the role of zinc-based alloys in promoting bone tissue repair was sorted and summarized.The current research hotspots and shortcomings were discussed. RESULTS AND CONCLUSION:(1)Zinc-based alloys have good biocompatibility.Using zinc-based alloys as the matrix material,with the help of scaffold structure construction technology and coating optimization process,the bone conductivity of zinc-based alloys will be effectively improved,and their degradation products will have efficient bone induction to regulate the gene expression of osteoblasts and osteoclasts,thereby promoting the repair and reconstruction of bone defects.(2)However,in the research on optimizing zinc-based alloys,the coating process is relatively insufficient,and additive loading technology is still lacking.(3)Zinc-based alloys have excellent mechanical and biological properties.Through special processes,their bone conductivity and osteoinductivity can be increased to effectively improve their ability to promote bone repair and reconstruction,and it is expected to further achieve the development of personalized transplant materials.Further research and development are needed to optimize the integration of coating and additive loading technologies into zinc-based alloys.