Objective To compare the clinical outcomes of patients who underwent remnant-preserved anterior cruciate ligament (ACL) reconstruction with those who underwent conventional ACL reconstruction (ACLR).Methods From January 2010 to October 2012,93 eligible patients suffered from ACL injuries were randomly allocated into remnant-preserved group (ACLR with remnant preservation;n=48;Male/Female=34/14;Left/Right=25/23) and conventional group (ACLR without remnant preservation;n=45;Male/Female=33/12;Left/Right=22/23).The mean age of patients,time from injury to surgery,rates of combined meniscal injuries,and medial collateral ligament injury all showed no significant difference between the two groups preoperatively.All the patients underwent ACL reconstruction using 4-strand hamstring autografts.The postoperative assessments included knee functional scales (IKDC grade classification and Lysholm score),stability examinations (Lachman,pivot-shift,and KT-1000 arthometer),proprioceptive evaluations,and second-look arthroscopy.Results The average follow-up time was 25.4 months for the remnant-preserved group and 25.2 months for the conventional group.For IKDC grade classification,there were 32 patients with grade A,9 with grade B,1 with grade C in remnant-preserved group,whereas 30 with grade A,8 with grade B,2 with grade C in conventional group,which showed no significant difference between the two groups.Moreover,the Lysholm score (95.9±5.2 vs.95.4±1.7),Lachman test,pivot-shift test,KT-1000 arthometer (1.1±1.2 mm vs.1.2±0.9 mm),proprioceptive evaluations (joint position sense:3.6°± 1.8° vs.3.9°±2.2°) all showed no significant differences between the two groups.Additionally,the synovial coverage of grafted tendon under second-look arthroscopy was categorized as grade A in 11,grade B in 6,grade C in 2,grade D in 2 in remnant-preserved group,whereas grade A in 10,grade B in 5,grade C in 2,and grade D in 2 in conventional group,which still showed no significant difference.Conclusion In terms of the knee functional scales,stability examinations,joint position sense and graft synovial coverage,remnant-preserved ACLR group showed no superiority to the conventional ACLR group.

Objective To investigate the clinical outcome of dual?plane high tibial osteotomy to treat posterolateral corner injuries combined with varus and/or hyperextension deformity. Methods From October 2008 to March 2014, there were 12 patients (13 knees) undergoing high tibial osteotomy. All the patients were double or triple varus knee combined with posterior cruciate ligament and posterolateral corner (PLC) injuries. During the surgery, the weight bearing line of lower extremity was set to 62%position of the tibial plateau on the coronal plane. The tibial slope was increased to diminish the hyperextension on the sagit?tal plane. Full?length weight bearing X?ray was used to evaluate the position of weight bearing line, femoral?tibial angle and tibial slope pre? and post?operatively. The stress radiograph was used to evaluate the posterior and posterolateral stability. The Op?ti_knee gait analysis system was used to evaluate the varus of angle during weight bearing stage. Results The weight bearing line was corrected from 19.6%±19.1% preoperatively to 42.6%±17.9% postoperatively (t=-4.178, P=0.002). The femoral?tibial angle was 172.8°±4.2° preoperatively and improved to 178.1°±4.2° postoperatively (t=-4.520, P=0.001). The tibial slope was increased from 10.2° ± 5.3° preoperatively to 18.4° ± 6.3° postoperatively (t=-5.735, P=0.000). The tibial posterior translation was decreased from 11.4±5.3 mm preoperatively to 8.1±6.9 mm postoperatively (t=2.415, P=0.042) in 9 patients. The separa?tion of lateral compartment was decreased from 16.3 ± 6.5 mm preoperatively to 14.2 ± 4.9 mm postoperatively (t=3.194, P=0.019). Gait analysis was performed in 7 patients and showed that the varus was improved from 3.0° ± 2.6° preoperatively to-2.7°±2.5° postoperatively during weight bearing stage (t=-8.500,P=0.014). Eight patients had sufficient improvement in knee function so that a subsequent posterolateral corner reconstruction was not necessary. Conclusion The dual?plane medial open wedge high tibial osteotomy can improve the alignment of lower extremity and the stability of knee joint, and 67%patients do not need a staged PLC and posterior cruciate ligament reconstruction.

Objective To investigate the effects of excessive pre?operative anterior tibial translation (ATT) on post?opera?tive knee stability after anterior cruciate ligament (ACL) reconstruction. Methods From January 2016 to December 2016, a total of 348 patients with noncontact ACL injuries who underwent primary anatomic single?bundle ACL reconstruction were retrospec?tively analyzed. The hamstring autograft was used as the grafted tendon. The ATT relative to the lateral femoral condyle was mea?sured on pre?operative magnetic resonance imaging (MRI) scans. Among them, twenty patients (ATT positive group) who demon?strated>10 mm ATT distance were matched in a 1∶2 fashion to 40 control participants (ATT negative group) with<3 mm ATT dis?tance. All patients were followed for at least 2 years. The post?operative clinical outcomes, including the ATT distance, the KT?1000 side?to?side difference, and the pivot?shift tests were compared between the two groups. Results The ATT distance of the ATT positive group was 13.5±1.3 mm, which was significantly larger than that of the ATT negative group (2.5±1.4 mm) (t=45.435, P=0.013) pre?operatively. At 2?year follow?up, the ATT distance of the ATT positive group was 9.7±1.8 mm, which was significant?ly larger than that of the ATT negative group (0.9±1.6 mm) (t=49.655, P=0.011). Moreover, the KT?1000 side?to?side difference of the ATT positive group was 4.4±1.5 mm, which was also significantly larger than that of the ATT negative group (0.8±1.1 mm) (t=38.945, P=0.014). There was significantly difference in the pivot?shift test between the two groups (ATT positive group: 1 grade 0, 18 grade I, 1 grade II vs. ATT negative group: 39 grade 0, 1 grade I) (χ2=40.521, P=0.012). Conclusion Excessive ATT could not be completely restored to normal after isolated anatomic single?bundle ACL reconstruction. Compared to the ATT negative group, the ATT positive group has inferior knee stability at 2?year follow?up.

Objective To identify the incidence of the anteromedial impingement fracture of tibial plateau in the posterolateral corner injuries,and to confirm the relationship between the extent of the anteromedial tibial impingement fracture and the severity of the posterolateral instability of the knee joint.Methods The radiographic images of the posterolateral corner injuries were reviewed retrospectively to identify the incidence of the anteromedial impingement fracture of the tibial plateau.A matched group of the posterolateral corner injury patients without the anteromedial impingement fracture was compared with the anteromedial impingement fracture group for the posterior instability and varus instability.And the anteromedial impingement fracture group was subdivided into a marginal fracture group and a compression fracture group based on the size of the fracture,and the posterior instability and medial instability were compared between the two groups.Results From January 2007 to January 2017,there were 266 patients with posterolateral corner injuries admitted,with 19 (7.1％) combined with the anteromedial impingement fractures of the tibial plateau.The posterior instability was significantly severer in the fracture group than the control group (P=0.030),while there were no significant differences in the varus instability between them (P=0.800).Similarly,the posterior instability was significantly severer in the marginal group compared to the compression group (P=0.026),but without significant differences in the varus instability (P=0.397).However,the compression fracture group had a higher risk to have neurovascular injuries (of the popliteal artery and the common peroneal nerve) compared with the marginal fracture group.Conclusion The incidence of the anteromedial impingement fracture of the tibial plateau in posterolateral corner injuries was 7.1％.The anteromedial impingement fracture of the tibial plateau may indicate more severe posterior instability,and a compression fracture may suggest more severe posterior instability compared with the marginal fracture.If there is a compression type fracture,the neurovascular status must be carefully evaluated in addition to the examination of the posterolateral and posterior instability.

Objective To evaluate the clinical outcome of tibial tubercle proximalization in the treatment of patients with severe habitual dislocation of patella (HDP).Methods Among 51 HDP patients treated surgically in our hospital between April 2010 and 2014,28 were eligible for retrospective evaluation.All patients underwent tibial tubercle proximalization and lateral structure release.Additional surgeries included medial patellofemoral ligament (MPFL)reconstruction and tibial tubercle medialization.Radiological and subjective evaluations were performed at 4th and 8th weeks after the operation,as well as 1 year and every year afterwards.Results Twenty-eight patients,with an average age of (27.2 ± 9.4)(ranging from 18 to 39)were followed up for a minimum of 2 years,the mean follow-up period being (26.4 ± 5.8)months (ranging from 24 to 36).It was found 17.2％ (5/29) patients of quadriceps weakness,6.9％ (2/29)of patellofemoral pain and 6.9％ (2/29)of stiffness.No redislocation was reported.Significant improvement was observed in all subjective evaluation scores.Conclusions For patients with severe HDP,tibial tubercle proximalization can achieve satisfactory results.

Objective To quantify the patellar mal-tracking combined with J-sign using the computed tomography (CT).Method Fifty-three adult patients diagnosed as recurrent patellar dislocation (RPD) were chosen.According to their patellar tracking during knee active flexion and extension,they were divided into group A(with positive J-sign) and group B(with negative J-sign).The CT examinations were performed in all patients at 0°extension of the knee and the patella bisect offset index (BOI),patella troehlear-groove distance (PTG) and patella lateral tilt (PLT) were measured in the axial position and compared.The receiver operating characteristic analysis (ROC) curve was used to analyse the accuracy and stability of the three J-sign parameters.Results In all the 53 patients,thirty-seven(69.8％) knees were of positive J-sign,while the rest 16 were of negative J-sign.The mean values of CT parameters BOI,PTG and PLT in group A were significantly larger than those of group B.Moreover,the area under the curve for BOI,PTG and PLT were 0.906,0.883 and 0.833 respectively.The sensitivity and specificity of BOI were 83.3％ and 87.5％,while the predicting cut-off value was 97.5％.Conclusion In all the 53 recurrent patella instability patients,the morbidity of patella proximal mal-trackingis 69.8％.The CT parameter BOI can be used to quantify the J-Sign into positive and negative groups.

Objectives To evaluate the clinical outcome of lateral structure release in the treatment of patients with mild or moderate habitual dislocation of patella(HDP).Methods From 51 HDP patients undergoing surgical treatment between April 2010 and 2014,23 patients were chosen and given the lateral structure release,including isolated lateral retinaculum release (LRR) and LRR combined with vastus lateralis oblique(VLO) lengthening.Other auxiliary surgeries included medial patellofemoral ligament(MPFL) reconstruction and tibial tubercle medialization.Radiological,objective and subjective evaluations were performed at 4 and 8 weeks,as well as and 1 year after the surgery and every year afterwards.Results There were 21 patients followed for a minimum of 2 years.Their average age was 25.0 + 7.4 years (ranging from 17 to 38 years old),and the mean follow-up period was 30.5 ± 5.8months(ranging from 24 to 36 months).Isolated LRR was performed in 42.9％(9/21) of the patients,and LRR combined with VLO lengthening was performed in 57.1％(12/21) of them.No redislocation was reported.Significant improvement was observed in the subjective evaluation score.Conclusions For patients with mild to moderate HDP,lateral structure release can achieve satisfactory results.

Purpose To determine the incidence,degree and radiographic characteristics of knee Jsign in recurrent patella dislocation patients.Method It was a retrospective review of a consecutive series of 59 recurrent patella dislocation patients.The knee J-sign was classified into negative (-),positive one degree(mild,l+)and positive two degree(gross,2+)based on the severity of patellar lateral translation at the extreme extension of knees with quadriceps contracted actively.The computed tomography(CT)examination at 0° extension of the knee was performed to quantify the degree of patellar lateral translation and tilt,with three CT parameters measured and calculated in axial slices:patella bisect offset index (BOI),patella trochlear-groove (PTG) distance and patella lateral tilt (PLT) angle.Results In all the 59 patients,72.9％(43/59)showed positive J-sign,27.1％(16/59)of positive one degree(1+) and 45.8％(27/59)of positive two degree(2+).All the three CT parameters increased with the severity of Jsign(P＜0.05).Conclusion Among 59 recurrent patella dislocation patients,we have found 72.9％ of positive knee J-sign.The severity of J-sign has a positive correlation with the degree of patellar lateral translation and tilt.

Objective To investigate the clinical and MRI outcomes of the arthroscopic rotator cuff repair for massive ro tator cuff tear at minimum 2 years after surgery.Methods From October,2010 to March,2013,data of 79 shoulders in 77 patients with massive rotator cuff tear who were treated with arthroscopic rotator cuff repair were retrospectively analyzed.There were 42 male (44 shoulders) and 35 female (35 shoulders).The average age before surgery was 57.4 years (43.1-80.4 years).There were 64 right shoulders and 15 left shoulders.The dominate side were involved in 70 cases.A trauma history was documented in 52 shoulders.The symptoms persisted less than 3 months in 42 shoulders,between 3 and 6 months in 11 shoulders,between 6 and 12 months in 11 shoulders and more than 1 year in 15 shoulders.No revision case was included.The clinical results (range of motion,forward elevation strength,external rotation strength and American Shoulder & Elbow Surgeons (ASES) score and MRI results were collected.Results All 77 cases were followed up more than 2 years.The forward elevation (156.9°±20.0° to 103.2°± 54.5°),external rotation (40.6°±15.5° to 32.0°±21.4°),internal rotation (L1 to ~),forward elevation strength (9.7±4.7 lb to 4.6±4.9 lb),external rotation strength (11.1±5.1 lb to 8.3±5.4 lb) and ASES score (82.7±14.6 to 45.2± 17.4) were all improved significantly at the latest follow-up.During the surgery,complete repair were achieved in 68 shoulders.The forward elevation (146.4°±31.4° to 110.0°±56.7°),external rotation (45.0°± 14.8° to 34.1°±20.8°) and ASES score (78.6± 14.9 to 54.5± 13.9) were all improved signifi cantly at the latest follow-up in patients with partial repair during the surgery.But the forward elevation strength (10.5±4.9 lb to 6.2±3.2 lb) and external rotation strength (11.5±5.1 lb to 8.3±3.8 lb) were significantly better improved in patients who had complete repair.In 68 shoulders with complete repair during the surgery,20 shoulders were found to have rotator cuff re-tear.The retear rate was 29.4％.But none of the patient with postoperative re-tear received revision surgery.The forward elevation (152.0± 23.3 to 103.5±60.5),forward elevation strength (8.5±4.7 lb to 5.0±4.7 lb) and ASES score (76.9±16.5 to 40.8±18.6) were all improved significantly at the latest follow-up in patients with postoperative re-tear of the rotator cuff tendon.But the forward elevation (161.4°± 13.4° to 152.0°±23.3°),forward elevation strength (11.3±4.7 lb to 8.5±4.7 lb),external rotation strength (12.4±4.8 lb to 9.6±5.3 lb) and ASES score (86.0±13.0 to 76.9±16.5) were significantly better in patients with complete healed rotator cuff tendon comparing with the re-tear group.Conclusion The rotator cuff repair can significantly improve the shoulder function of massive rotator cuff tear even when the rotator cuff tendon can only be partially repaired or re-tear after the surgery.The shoulder function is significantly better in patients with complete healed rotator cuff tendon comparing with the partial repair group and the re-tear group.

Objective To investigate the incidence of concomitant anterolateral ligament (ALL) abnormality by magnetic resonance imaging (MRI) on patients with high-grade pivot-shift after anterior cruciate ligament (ACL) injuries.Methods From January 2016 to June 2016,one hundred and sixty-four consecutive patients with acute ACL injury were retrospectively reviewed.All patients underwent comprehensive pre-operative physical examinations and MRI scans.Sixty-eight patients with acute ACL injury who showed high-grade (grade Ⅱ and Ⅲ) pivot-shift phenomenon were enrolled in the high-grade pivot-shift group.They were matched in a 1:1 fashion to another 68 ACL-injured participants who showed low-grade (grade 0 and Ⅰ) pivot-shift phenomenon during the same study period.The grade of ALL injury was divided into grade Ⅰ (sprain),grade Ⅱ (partial tear) and grade Ⅲ (complete tear),and they were further compared between the high-grade pivot-shift group and the low-grade pivot-shift group on the coronal view of their T2WI MRI scans.Results The mean age of the patients in all groups was 29.3 years old.There were 43 male and 25 female patients in each group.There were no significant differences in terms of the time from injury to surgery,the body mass index and the KT-1000 side-to-side difference.Overall,there were 105 patients (77.2％,105/136) showed abnormal signal of the anterolateral ligament on MRI scans.The incidence of concomitant ALL injury in the high-grade pivot-shift group (94.1％,64/68) was significantly higher than that in the low-grade pivot-shift group (60.3％,41/68,x2=10.786,P=0.013).Specifically,there were 15,19 and 30 patients who showed grade Ⅰ,Ⅱ and Ⅲ ALL abnormality in high-grade pivot-shift group.However,there were only 29,8 and 4 patients who showed grade Ⅰ,Ⅱ and Ⅲ ALL abnormality in low-grade pivot-shift group.The incidence of patients who showed grade Ⅱ/Ⅲ MRI evidence of concomitant ALL injury was 76.6％ (49/64) in the high-grade pivot-shift group,which was also significantly higher than that in the low-grade pivot-shift group (29.3％,12/41,x2=18.452,P=0.009).Conclusion In the present study,77.2％ of the patients who showed high-grade pivot-shift demonstrated combined ALL injury on the MRI scan.In addition,patients in the high-grade pivot-shift group showed significantly higher incidence of combined ALL MRI abnormality compared with those in the low-grade pivot-shift group.The high-grade pivot-shift phenomenon might be caused by combined ACL and ALL injury.