BACKGROUND:It is important to maintain the height of joint line in total knee arthroplasty or renovation. Foreign scholars have reported the parameters of the distance from different landmarks to knee joint line, but there is stil a lack of relevant data for Chinese people. OBJECTIVE:To explore the relationships of the knee anatomic landmarks and joint line in normal Chinese, thereby providing clinical evidence for primary total knee replacement and knee renovation. METHODS:Totaly 746 normal knee joints of 409 healthy volunteers from North China and Southwest China were randomly enroled, including 214 males and 195 females, with a mean age of 37.7 years. CT scan was used to reconstruct the three-dimensional knee joint, and the distance between the anatomic landmarks and the joint line was measured using Mimics software. RESULTS AND CONCLUSION:The distance from the center of femoral medial sulcus to the joint line was (25.72±2.52) mm. The distance from the center of lateral femoral condyle prominence to the joint line was (26.30±2.65) mm. The distance from the adduction muscle tubercle to the joint line was (44.60±4.32) mm. The distance from the peak of the tibial tubercle to the joint line was (21.50±3.57) mm. These parameters in male group were significantly higher than those in female group (P < 0.05). In conclusion, these findings provide anatomic evidence for the recovery of joint line in knee replacement or renovation; the variability of the distance from the center of femoral medial sulcus, lateral femoral condyle prominence and adductor tubercle to the joint line is smaler, and therefore, these landmarks have more reference values in total knee arthroplasty.

Objective: To analyze the clinical effects of reverse shoulder arthroplasty (RSA) for the patients with the cuff tear arthritis(CTA). Methods: A retrospective analysis of 12 patients who had underwent primary RSA for treatment of CTA from January 2012 to June 2017 in Department of Orthopedic, Beijing Chaoyang Hospital, Capital Medical University. There were 8 males and 4 females, aged 69.4 years (range: 64-73 years). The operation was performed in a conventional manner, the subscapularis and biceps tendon were repaired separately.The preoperative and postoperative American shoulder elbow surgeons score and university of California at LosAngeles score of patients were recorded. The complications and the images of radiological examinations were collected. Data were analyzed by paired-samples t-test. Results: At mean follow-up of (34.7±18.1) months (range:3-66 months), the preoperative ASEA score improved from 58.2±8.2 to 92.9±2.9 (t=14.32, P=0.00) and UCLA score improved from 13.2±1.5 to 30.8±1.7(t=23.14, P=0.00). No complications like loosening of prosthesis, superficial wound infection and shoulder dislocation were noted. Conclusion Reverse shoulder arthroplasty have satisfactory effect for the patients with the cuff tear arthritis.

Objective: To discuss the surgical technique of lateral unicondylar knee replacement (UKR) for patients with lateral compartment osteoarthritis and evaluate its recent clinical efficacy. Methods: A retrospective analysis was conducted on 22 cases of lateral compartment osteoarthritis patients receiving lateral UKR at Orthopedic Department, Beijing Chao Yang Hospital, Capital Medical University from January 2016 to January 2019.There were 8 males (8 knees) and 14 females (14 knees), aged 65.7 years(range: 54 to 83 years).All patients completed preoperative imaging examination and excluded extra-articular deformity.Lateral parapelatellar approach was used for the operation and the tibial osteotomy was performed by extramedullary positioning.The residual cartilage of the external condyle was removed by pendulum saw to subchondral bone.Appropriate prosthesis were selected, and the tightness of the gap and the stability of the joints were repeatedly confirmed during the operation.The postoperative complications and the results of physical and imaging examinations were collected.The preoperative and postoperative Oxford knee Score (OKS) and knee society score (KSS) of patients were recorded and compared by paired t test. Results: All patients were followed up for 24.6 months (range: 8 to 40 months).No complications such as incision exudation, skin necrosis and deep venous thrombosis of lower limbs were found after the operation.No cases of prosthesis loosening, excessive wear of pads, dislocation and postoperative infection were found at the last follow-up.The OKS decreased from 46.5±3.1 preoperative to 22.4±3.3 postoperative(t=13.4, P=0.00) and KSS improved from 69.5±8.7 preoperative to 90.2±7.4 postoperative (t=16.9, P=0.00) . Conclusions For the treatment of lateral compartment osteoarthritis, UKR has the advantages of rapid recovery of knee function, less complications and less trauma.The short-term efficacy is satisfactory, but the long-term efficacy remains to be observed.

Objective To compare the anatomical differences of tibia osteotomy between Han and Uygur populations and to analysis their compatibility with imported prosthesis component.Methods Two hundred patients (400 knees) were selected from the outpatients and healthy volunteers of the non-knee joint disease from September 1,2012 to December 1,2014,with 86 men (172 knees) and 114 women (228 knees).The average age is 44.64-10.8 years (range 21-68 years old).According to the populations,the subjects were divided into Han group and Uygur group.Furthermore,each group was divided into male subgroup and female subgroup.A full-length CT scan of the lower limb was conducted to reconstruct the knee joint in the workstation.The tibial osteotomy was simulated in total knee arthroplasty.The transverse diameter of the tibial cross section,the longitudinal depth of the medial platform and the depth of the lateral platform were measured.The front and back diameter and aspect ratio of the osteotomy were calculated.There parameters were compared between the Han and Uygur groups.Five mm tolerance range method was used to analysis the cover rate of the following three kinds of commercially imported prosthesis,namely Depuy,Link and Zimmer.Results The mean value of the tibial cross section were 72.3±4.3 mm,50.7±3.1 mm,47.8±3.0 mm,49.3±2.9 mm and 0.682±0.021 in Han group,while those were 74.5±4.8 mm,51.4±3.0 mm,48.6±2.8 mm,50.0±2.9 mm and 0.672±0.020 in Uygur group,respectively.Except the aspect ratio,the average value of each parameter in Uygur group was greater than that in the Han group with statistically significant differences between the two populations.The cover rate of the three kinds of prosthesis tibial component were 53.0％,37.0％ and 40.0％ for Han group,but 61.0％,43.0％ and 42.5％ for Uygur group.Depuy prosthesis was fit for the Uygur population better.Conclusion The geometry and anatomy of proximal tibia in Chinese showed significant difference between Han and Uygur populations.The mean covering rates of the imported tibial components were low in the dimensions of the resected surface.We can improve the prosthesis and the matching degree by adjusting the parameters or increasing the model set.

Objective: To evaluate clinical treatment efficacy of double-row fixation with bridging suture anchors for chronic, severe patellar tendinopathy. Methods: A retrospective study of 18 patients suffered from severe patellar tendinopathy and underwent surgical treatment during January 2009 and June 2014 at Department of Orthopedic, Beijing Chao Yang Hospital, Capital Medical University was conducted. All patients had received conservative therapy for more than 6 months(range: 6-30 months) but the effect was unsatisfactory. There were 10 males (12 knees) and 8 females (12 knees)with age of 47.2 years(range: 32-63 years). Seven cases on the left and 17 cases on the right. The surgical treatment included a midline incision at patellar tendon, complete debridement, and double-row fixation with bridging suture anchors. Visual analogue scale(VAS), Lysholm score were collected preoperatively and postoperatively, and compared by paired-t test. The postoperative complications was recorded. Results: All patients were followed up for 35.7 months (range:24-64 months) without any dropout.VAS decreased from 7.5±1.6 preoperative to 1.4±1.0 (t=4.45, P=0.00) postoperative, Lysholm score increased from 48.3±5.2 to 89.6±5.4 (t=-4.88,P=0.00).The Lysholm score was excellent in 3 cases and good in 15 cases.No patellar tendon rupture or suture fixation failure was recorded during the follow-up period. Conclusions The effect of double-row fixation with bridging suture anchors is satisfactory with few postoperative complications.It can not only improve clinical symptoms of patients, but also restore knee joint function.