Background:A preoperative high-grade pivot-shift phenomenon (2+ and 3+) is often a predictor of inferior knee rotational stability and excessive anterior tibial translation of the lateral compartment (L-ATT) after an anterior cruciate ligament (ACL) injury. Lateral extra-articular tenodesis (LET) has been reported to reduce failure rates and improve knee stability in patients with an ACL injury. However, the effect of LET on knee rotational stability and L-ATT is still not entirely clear in patients with an ACL injury and a high-grade pivot-shift phenomenon. Purpose:To explore the effect of LET on knee rotational stability and L-ATT in patients with an ACL injury and a high-grade pivot-shift phenomenon. Study Design:Cohort study; Level of evidence, 3. Methods:A total of 254 patients who underwent ACL reconstruction (ACLR) between January 2019 and December 2020 were retrospectively reviewed, and 71 patients (43 male and 28 female) with a preoperative high-grade pivot-shift phenomenon were included. Of these, 24 patients who underwent ACLR combined with LET and 47 patients who underwent ACLR alone were categorized as the study and control groups, respectively. Knee stability was evaluated by the KT-1000 arthrometer side-to-side difference and the pivot-shift test, and L-ATT was measured on magnetic resonance imaging. Baseline patient characteristics, preoperative and postoperative knee stability, and preoperative and postoperative L-ATT were compared between the 2 groups. Moreover, the relative risk of a residual pivot-shift phenomenon after ACLR combined with LET versus ACLR alone was calculated. Results:The mean time from injury to surgery in the study group was significantly longer than that in the control group (29.9 ± 54.7 vs 10.1 ± 23.1 months, respectively; P = .035). Other baseline patient characteristics, preoperative knee stability, and preoperative L-ATT showed no significant differences between the groups. At the final follow-up (26.4 ± 4.7 and 28.1 ± 11.0 months for study and control groups, respectively), knee rotational stability (residual pivot-shift phenomenon: 2/24 vs 16/47, respectively; P = .018) and L-ATT (4.6 ± 2.6 vs 6.3 ± 2.6 mm, respectively; P = .010) were superior in the study group compared with the control group. Furthermore, the relative risk of a residual pivot-shift phenomenon was significantly lower in the study group (0.176 [95% CI, 0.037-0.845]; P = .030). Conclusion:ACLR combined with LET was an effective treatment strategy for ACL injuries with a high-grade pivot-shift phenomenon, associated with satisfactory clinical outcomes, significantly improved rotational stability, and reduced L-ATT.

Objective:To evaluate the clinical efficacy of biplane osteotomy in the treatment of malunion of Stephens-Sanders type Ⅱ calcaneal fracture.Methods:A retrospective study was conducted to analyze the clinical data of 31 patients who had been treated by biplane osteotomy at Sports Medicine Center, The First Affiliated Hospital of Army Medical University for malunion of Stephens-Sanders type Ⅱ calcaneal fracture from January 2019 to January 2022. There were 21 males and 10 females, with an age of (41.4±13.9) years and a duration from injury to diagnosis of (12.8±8.9) months. Functional and image scores were compared before surgery, 6 months after surgery, and at the last follow-up. Functional scores included the visual analogue scale (VAS) score, the American Orthopedic Foot and Ankle Society (AOFAS) score, and the pain interference (PI) and physical function (PF) indices in the Patient-Reported Outcomes Measurement Information System (PROMIS). Image scores included the Gissane angle, B?hler's angle, calcaneal pitch angle, length of the calcaneus, absolute foot height, and axial calcaneal width as measured on X-rays.Results:The operation time was (106.6±29.9) minutes for this cohort. All the 31 patients were followed up for (18.4±5.8) months. At 6 months after surgery and the last follow-up, the VAS scores [3 (2, 3), 2 (1, 3)], AOFAS scores [83 (76, 87), 85 (83, 87)], PI scores [(57±9), (48±6)], PF scores [53 (39, 61), 56 (54, 66)], Gissane angles (109.6°±14.1°, 109.3°±14.9°), B?hler angles (26.5°±11.6°, 26.9°±11.8°), calcaneal pitch angles [19.1° (14.5°, 23.9°), 19.9° (14.5°, 23.9°)], absolute foot heights [(76.5±9.6) mm, (76.0±9.9) mm], and axial calcaneal widths [(38.5±4.1) mm, (38.3±4.1) mm] were all significantly improved compared to the preoperative values [5 (4, 6), 62 (56, 67), (62±6), 47 (38, 51), 126.8°±13.1°, 11.8°±10.9°, 13.8° (8.2°, 18.7°), (71.0±9.1) mm, (42.8±5.5) mm] (all P<0.05). However, there was no statistically significant difference in the length of the calcaneus among pre-surgery, 6 months after surgery, and the last follow-up ( P>0.05). Conclusion:Biplane osteotomy is a surgical technique that demonstrates good clinical efficacy in the treatment of malunion of Stephens-Sanders type Ⅱ calcaneal fracture so that it should be promoted in clinic.

Bioactive factors combined with advanced ACL (Anterior cruciate ligament) primary repair technology have been used to treat ACL repairs. The current review was conducted to identify whether biological enhancement could enable superior clinical outcome, including side-to-side difference, failure rate, reoperation rate and subjective scores. The implementation of ACL primary repair with biological enhancement will provide better clinical outcomes in terms of side-to-side differences, failure rate, reoperation rate and subjective scores than ACL primary repair alone. A systematic literature review was performed following PRISMA guidelines by searching all studies reporting outcomes of arthroscopic primary repair with or without biological augmentation published until April 19, 2020, in Medline, PubMed, Embase and the Cochrane Library. Primary metrics were side-to-side differences, failure rate and reoperation rate, as well as measurements of patient-reported outcomes at the last follow-up. A total of 20 studies were finally included in this work, of which 3 were Grade I (15%), 3 studies were Grade III (15%), and 14 studies were Grade IV (70%) in terms of the level of evidence. There were 729 patients with a mean age of 30 (range: 8–68) years, and the mean follow-up period of which was 38 (range: 3–122) months. At the final follow-up, the postoperative side-to-side differences (the proportion of patients with a side-to-side difference less than 3 mm) and patient-report outcomes were significantly better in the biological enhancement group. Nevertheless, there were no significant differences between the two groups in the rate of surgical failure, the rate of revision, or the positive Lachman test or pivot shift test. Biologically enhanced arthroscopic ACL primary repair was superior to ACL primary repair alone in terms of postoperative side-to-side differences (proportion of patients with a side-to-side difference less than 3 mm) and patient-reported outcomes. Thus, biologically enhanced arthroscopic ACL primary repair can be preferentially recommended over ACL arthroscopic primary repair alone. IV, systematic review.

BACKGROUND:Bioactive factors combined with advanced anterior cruciate ligament (ACL) primary repair technology have been used to treat ACL repairs. The current review was conducted to identify whether biological enhancement could enable superior clinical outcome, including side-to-side difference, failure rate, reoperation rate and subjective scores. HYPOTHESIS:The implementation of ACL primary repair with biological enhancement will provide better clinical outcomes in terms of side-to-side differences, failure rate, reoperation rate and subjective scores than ACL primary repair alone. MATERIALS AND METHODS:A systematic literature review was performed following PRISMA guidelines by searching all studies reporting outcomes of arthroscopic primary repair with or without biological augmentation published until April 19, 2020, in Medline, PubMed, Embase and the Cochrane Library. Primary metrics were side-to-side differences, failure rate and reoperation rate, as well as measurements of patient-reported outcomes at the last follow-up. RESULTS:A total of 20 studies were finally included in this work, of which 3 were Grade I (15%), 3 studies were Grade III (15%), and 14 studies were Grade IV (70%) in terms of the level of evidence. There were 729 patients with a mean age of 30 (range: 8-68) years, and the mean follow-up period of which was 38 (range: 3-122) months. At the final follow-up, the postoperative side-to-side differences (the proportion of patients with a side-to-side difference less than 3mm) and patient-report outcomes were significantly better in the biological enhancement group. Nevertheless, there were no significant differences between the two groups in the rate of surgical failure, the rate of revision, or the positive Lachman test or pivot shift test. CONCLUSION:Biologically enhanced arthroscopic ACL primary repair was superior to ACL primary repair alone in terms of postoperative side-to-side differences (proportion of patients with a side-to-side difference less than 3mm) and patient-reported outcomes. Thus, biologically enhanced arthroscopic ACL primary repair can be preferentially recommended over ACL arthroscopic primary repair alone. LEVEL OF EVIDENCE:IV, systematic review.

To investigate whether the high-grade pivot-shift phenomenon is associated with asymmetry of the lateral and medial compartment anterior tibial translation (L-ATT and M-ATT) and lateral meniscus posterior horn (LMPH) tears in anterior cruciate ligament (ACL) injuries. A retrospective analysis was performed on 192 consecutive patients who had complete ACL injuries between January 2019 and December 2020. Among these, 156 met the inclusion criteria. L-ATT and M-ATT were measured using preoperative weight-bearing magnetic resonance imaging (MRI), and the differences between L-ATT and M-ATT were calculated. Thirty-five patients who demonstrated excessive differences in L-ATT and M-ATT (> 6.0 mm) were regarded as asymmetric (study group), and 36 patients with minimal or no differences in L-ATT and M-ATT (< 3.0 mm) were allocated to the control group. Demographic data, grade of the pivot-shift test, integrality of LMPH, and medial meniscus posterior horn (MMPH) were compared between the groups. Moreover, predictors of high-grade pivot-shift phenomenon, including asymmetry of L-ATT and M-ATT, integrity of LMPH and MMPH, time from injury to surgery, sex, age, and body mass index (BMI) were assessed using multivariable logistic regression analysis. The difference between L-ATT and M-ATT in the study group was significantly higher than that in the control group (mean ± SD: 8.4 ± 2.1 mm vs. 1.5 ± 1.0 mm, P < 0.001). A higher proportion of patients with high-grade pivot-shift phenomenon (2 + and 3 +) and LMPH tears were identified in the study group (high-grade pivot-shift phenomenon: 25/35 vs. 13/36, P = 0.003; LMPH tears: 18/35 vs. 5/36, P = 0.001). Additionally, asymmetry of L-ATT, M-ATT (odds ratio 5.8; 95

目的:探究在应用同一种测量方法时,下肢全长侧位X线片及短节段膝关节侧位X线片上胫骨平台后倾角(posterior tibial slope,PTS)测量值的差异.方法:回顾性分析并纳入100例于我科接受了前交叉韧带(anterior cruciate ligament,ACL)重建的患者,应用同一种测量方法分别在下肢全长侧位X线片及短节段膝关节侧位X线片上进行PTS的测量,PTS定义为胫骨轴线的垂线与胫骨平台前后向切线的夹角.然后对测量结果进行对比、分析,此外还计算出两种测量值的绝对值差异及其频数分布.结果:本研究共计纳入100例ACL损伤患者.在下肢全长侧位X线片及短节段膝关节侧位X线片上PTS的测量值分别为15.2° ±3.8°和13.2° ±3.6°,其差异具有统计学意义(P<0.01).此外,50％的患者其在下肢全长及短节段膝关节侧位X线片上PTS的测量差值≥2.0°.结论:PTS测量值的大小会受到测量过程中胫骨轴线长短的显著影响;当评价PTS在ACL损伤、重建后失效中所起的作用时,测量过程中选取的胫骨长度应与测量值大小受到同样程度的重视.

BACKGROUND:Increased posterior tibial slope (PTS) has been reported to be associated with irreducible anterior tibial subluxation in extension after anatomic anterior cruciate ligament (ACL) reconstruction (ACLR), which raises concerns about the greater risk of graft roof impingement (GRI) although the tibial tunnel is positioned anatomically.HYPOTHESIS:Increased PTS would be associated with greater risk of GRI after anatomic ACLR.STUDY DESIGN:Case-control study; Level of evidence, 3.METHODS:Between January 2016 and December 2017, a total of 418 consecutive patients were diagnosed as having noncontact ACL injuries and underwent primary anatomic ACLR. Among them, 26 patients had ≥1 of the following features during the second-look arthroscopy: fractured/guillotined bundles at the tibial insertion or cyclops lesion. These patients were confirmed to have GRI and were allocated to the study group. They were also matched 1:2 to 52 control participants without GRI. PTS was measured on true lateral whole-leg radiographs. Intra-articular ACL graft signal intensity was evaluated on postoperative magnetic resonance imaging scans (mean, 32.8 months; range, 26-38 months) and divided into 3 grades (I, good; II, moderate; III, poor) based on degree of GRI. Moreover, anterior subluxation of the lateral compartment (ASLC) and medial compartment (ASMC) in extension relative to the femoral condyles were measured on postoperative magnetic resonance imaging scans and compared between the groups. In addition, predictors of GRI were evaluated using multivariate logistic regression analysis and included body mass index, PTS, pivot-shift test, KT-1000 side-to-side difference, and concomitant meniscal tears.RESULTS:PTS in the study group was significantly higher than that in control group (mean ± SD, 13.8°± 1.5° vs 9.5°± 1.8°; P < .05). In the study group (n = 26), patients with grade III (poor) graft signal intensity (n = 9) showed significantly higher PTS than those with grade II (moderate; n = 17) (16.4°± 1.7° vs 12.4°± 1.3°; P < .05). Moreover, the mean postoperative ASLC and ASMC in extension were significantly larger in the study group than the control group (ASLC, 4.1 ± 1.3 vs 0.8 ± 0.4 mm; ASMC, 4.3 ± 1.5 vs 0.9 ± 0.3 mm; P < .05). Furthermore, the abnormal degree of PTS (≥12°) was determined to be an independent risk factor associated with GRI after anatomic ACLR (odds ratio, 9.0 [95% CI, 3.7-30.2]; P < .001), whereas body mass index, grade of pivot-shift test, KT-1000 side-to-side difference, and concomitant meniscal tears were not.CONCLUSION:Increased PTS (≥12°) was associated with greater risk of GRI after anatomic ACLR. This may provide additional information for counseling patients with greater risk of GRI.

The purpose of this study was to evaluate the clinical outcomes of de-rotational distal femoral osteotomy (DDFO) in patients who underwent primary medial patellofemoral ligament reconstruction (MPFLR) failure with increased femoral anteversion along with high-grade J sign. Between 2011 and 2019, 14 patients underwent DDFO revision surgery due to failed MPFLR. The pre- and postoperative J sign grade, Caton-Deschamps index (CDI), tibial tuberosity–trochlear groove (TT–TG) distance, femoral anteversion angle (FAA), patellar lateral tilt angle (PLTA), MPFL graft laxity, and patient-reported outcomes (Kujala, Lysholm, Tegner, and International Knee Documentation Committee (IKDC) subjective scores) were collected. The anterior–posterior and proximal–distal distances between the actual point and the Schöttle point were also calculated. Fourteen patients underwent MPFLR revision by DDFO combined with MPFLR. The mean PLTA improved from 40.7° ± 11.9° to 20.5° ± 8.7° (P < 0.001). The mean FAA significantly decreased from 42.7° ± 12.0° to 14.1° ± 5.2° (P < 0.001). The mean patellar laxity index (PLI) decreased from 82.4% preoperatively to 15.1% postoperatively (P < 0.001). None of these patients experienced subluxation or re-dislocation during follow-up of 29.7 ± 5.0 months after revision surgery. Meanwhile, the Tegner score at the last follow-up ranged from 3 to 6, with a median of 5. The Kujala, Lysholm, and IKDC subjective scores showed significant improvements, from a mean of 51.0 ± 6.8 preoperatively to 75.4 ± 5.1 postoperatively (P < 0.001), 49.2 ± 7.9 to 75.2 ± 7.2 (P < 0.001), and 42.9 ± 6.2 to 76.8 ± 6.0 (P < 0.001), respectively. The proportion of patients with a high-grade J sign was significantly lower postoperatively than preoperatively (100% vs. 14%). Four out of 14 patients (29%) showed femoral tunnel mal-positioning. MPFLR revision by DDFO combined with MPFLR achieved favorable clinical outcomes in patients with increased femoral anteversion along with high-grade J sign. IV.

BACKGROUND:Controversy exists regarding the surgical treatment of recurrent patellar dislocation (RPD) with an increased femoral anteversion angle (FAA). Medial patellofemoral ligament reconstruction (MPFL-R) either alone or combined with derotational distal femoral osteotomy (DDFO) results in favorable clinical outcomes.PURPOSE:To compare the clinical outcomes of MPFL-R versus MPFL-R with DDFO in treating RPD with increased FAA (>30°).STUDY DESIGN:Cohort study; Level of evidence, 3.METHODS:Between January 2014 and December 2017, 126 patients (135 knees) with RPD and increased FAA (>30°) were surgically treated using MPFL-R with or without DDFO and eligible for this retrospective study. These patients were allocated into 2 groups based on whether an additional DDFO was performed: the DDFO group (MPFL-R + DDFO with or without tibial tubercle transfer; n = 66) and the control group (MPFL-R with or without tibial tubercle transfer; n = 69). Pre- and postoperative patellar stability was measured using stress radiography. Patellar maltracking (J-sign) and patient-reported outcomes (Kujala, International Knee Documentation Committee, Lysholm, and Tegner scores) were evaluated and compared between the 2 groups. Subgroup analysis was performed by stratifying the results in terms of the severity of preoperative patellar maltracking (low-grade vs high-grade J-sign).RESULTS:A total of 135 knees (126 patients) with a mean follow-up time of 3.7 ± 1.2 years were evaluated in the present study. The rates of postoperative MPFL residual graft laxity and residual J-sign were significantly lower in the DDFO group than in the control group (6% vs 19%, P = .028; 33% vs 54%, P = .018). The DDFO group had significantly higher Kujala (82.3 vs 76.7; P = .001) and Lysholm (83.7 vs 77.7; P = .034) scores than the control group had postoperatively. For patients with a preoperative high-grade J-sign, further subgroup analysis demonstrated that the DDFO group had a significantly lower rate of MPFL residual graft laxity than the control group had (18% vs 57%; P = .029).CONCLUSION:In this retrospective study, treatment of RPD with increased femoral anteversion using MPFL-R with DDFO yielded more favorable subjective and objective outcomes than did MPFL-R without DDFO, and this circumstance was more remarkable when the patients had a preoperative high-grade J-sign.

Objective:To investigate the short-term clinical outcomes of patients who received combined anterior closing-wedge high tibial osteotomy (ACW-HTO) and anterior cruciate ligament (ACL) reconstruction in treating chronic ACL injury with increased posterior tibial slope (PTS).Methods:From January 2017 to June 2018, a total of 54 patients (46 males and 8 females, mean age 30.8±3.9 years, range from 20 to 42 years) with chronic (time from injury to surgery was more than 6 months) ACL injury and increased PTS (>17°) were retrospectively analyzed. Eighteen of them received combined ACW-HTO and ACL reconstruction (ACW-HTO+ACL reconstruction group), while the remaining 36 received isolated ACL reconstruction (ACL reconstruction group). The demographic data, pre-operative and post-operative anterior tibial translation, pivot-shift result, KT-1000 side-to-side difference, subjective Lysholm score, Tegner activity score, and International Knee Documentation Committee (IKDC) objective grading system were collected and compared between the two groups.Results:There were no significant differences between the two groups in terms of age, sex, body mass index, time from injury to surgery and proportion of patients with concomitant medial or lateral meniscus tear ( P>0.05). At 2-year's follow-up, the anterior tibial translation in the ACW-HTO+ACL reconstruction group was 0.9±0.4 mm, which was significantly smaller than that in the ACL reconstruction group 7.3±1.5 mm ( t=10.049, P<0.001). Moreover, there was significant difference in the pivot-shift result between the two groups (ACW-HTO+ACL reconstruction group: 18 low-grade vs. ACL reconstruction group: 31 low-grade, 5 high-grade) (χ 2=16.071, P<0.001). The KT-1000 side-to-side difference in the ACW-HTO+ACL reconstruction group was 1.5±0.6 mm, which was significantly smaller than that in the ACL reconstruction group 4.4±1.2 mm ( t=13.858, P<0.001). In addition, the subjective Lysholm score in the ACW-HTO+ACL reconstruction group was 93.3±4.3, which was significantly higher than that in the ACL reconstruction group 80.3±6.3 ( t=12.176, P<0.001). The Tegner activity score in the ACW-HTO+ACL reconstruction group was 7.3±0.9, which was significantly higher than that in the ACL reconstruction group 6.8±0.6 ( t=6.356, P=0.043). There was significant difference in terms of the IKDC objective grading system between the two groups (ACW-HTO+ACL reconstruction group: 17 grade A, 1 grade B vs. ACL reconstruction group: 29 grade A, 5 grade B, 2 grade C) (χ 2=12.351, P<0.001). Conclusion:The combined ACW-HTO and ACL reconstruction showed superior short-term knee stability and functional scores compared with the isolated ACL reconstruction in treating chronic ACL injury with increased PTS.

This study aimed to compare the difference in posterior tibial slope (PTS) measurements based on the full-length and half-length tibial anatomic axes of the same group of patients. It was hypothesized that the obtained PTS values would be affected by the length of tibia chosen during the measurements. Full-length true lateral tibia radiographs were obtained for each patient who underwent anterior cruciate ligament reconstruction (ACLR) in our department. PTS measurements were obtained by measuring the angle between the full-length or half-length tibial anatomic axis and an average of the lateral and medial tibial plateau. The anatomic axis was defined as the center of the tibial diaphysis. The PTS measurements from the full-length and half-length true lateral tibia radiographs were obtained and compared. Additionally, the absolute difference and the relationship between the two PTS measurements were calculated and analyzed. A total of 200 ACL-injured patients were included in this study. The average PTS values using the anatomic axis were 15.9 ± 3.7° and 14.1 ± 3.7° on full-length and half-length true lateral tibial radiographs. There was a significant difference between the measurements with the full-length and half-length tibial radiographs (P < 0.01). Additionally, 49.5% (n = 99) of patients had ≥ 2.0° differences between the full-length and half-length anatomic axis PTS measurement techniques; meanwhile, a strong and significant linear relationship (r = 0.95; P < 0.001) was identified between the two PTS measurements. There were significant differences and linear relationships between PTS measurements that measured the anatomic axis from full-length and half-length true lateral tibia radiographs. Therefore, the obtained PTS values were strongly associated with the length of tibia chosen during the measurements. Surgeons should pay more attention to the measurement techniques and the tibial length when considering the role of PTS in ACL injury and ACLR failure. Knowledge of the association is very important for calculating potential closing wedge proximal tibial osteotomies to correct excessive PTS in the setting of ACLR failures. IV.

Background: Clinical outcomes of surgical repairs for tears of the lateral meniscus posterior root (LMPR) in patients undergoing anterior cruciate ligament (ACL) reconstruction (ACLR) have not been comprehensively investigated. Purpose: To systematically review the clinical, radiographic, and arthroscopic results of surgical repairs for tears of the LMPR in patients undergoing ACLR. Study Design: Systematic review; Level of evidence, 4. Methods: A systematic electronic search of the PubMed and Embase databases was performed to identify studies reporting clinical, radiographic, or arthroscopic results of surgical repairs for tears of the LMPR in patients undergoing ACLR. Each included study was abstracted regarding study characteristics, patient characteristics, surgical technique, and outcome measures. The methodological quality of the included studies was analyzed according to the Methodological Index for Non-Randomized Studies (MINORS) criteria. Results: Nine studies were included in this systematic review, representing a total of 215 knees in 215 patients. Overall, 123 side-to-side repairs and 89 pullout repairs were performed for tears of the LMPR during ACLR. After a mean follow-up of 33.9 months, significant improvements ( P < .05) were found in the mean Lysholm score (from 58.3 to 91.4) as well as the mean International Knee Documentation Committee subjective score (from 61.1 to 87.2). Weightbearing anteroposterior radiographs of 41 patients showed no significant narrowing of lateral joint space width. On magnetic resonance imaging scans, 31 patients demonstrated no significant progression of chondral lesions, and no significant decreases in meniscal extrusion on coronal planes were reported in another 76 patients. The complete/partial healing was 93.6% on second-look arthroscopy after side-to-side repairs for radial tears of the LMPR. The MINORS value showed a high risk of bias for all 9 studies. Conclusion: Patients with tears of the LMPR associated with ACL injuries achieved favorable functional scores after ACLR and LMPR repairs, and the side-to-side repair for radial tears of the LMPR succeeded in a high meniscal healing rate of >90%. However, the authors of this review were unable to definitively conclude whether LMPR repairs fully restore the hoop stress of the lateral meniscus.

The purpose of this study was to analyse the risk factors associated with residual graft laxity after medial patellofemoral ligament reconstruction (MPFL-R) in patients with recurrent patellar dislocation (RPD). A total of 312 consecutive patients (354 knees) with clinically diagnosed RPD who underwent MPFL-R from 2011 to 2015 were retrospectively analysed. Postoperative MPFL graft stability was assessed with patellofemoral stress radiography, and if the patellar central ridge surpassed the apex of the lateral femoral trochlea, the reconstructed MPFL was defined as having residual graft laxity. Finally, 15 patients who exhibited MPFL residual graft laxity (study group) were matched in a 1:2 fashion to 30 control participants (control group), who showed a normal postoperative patellar stability on stress radiography. Preoperative three-dimensional computed tomography (3D-CT) was used to identify patients with a high-grade J-sign. Femoral tunnel position was assessed using 3D-CT to identify cases with femoral tunnel malposition. Potential predictors of MPFL residual graft laxity, including age, sex, a preoperative high-grade J-sign, femoral tunnel malposition, and several radiological parameters, were assessed by logistic regression analysis. A preoperative high-grade J-sign was identified in 66.7% of the study group, which was significantly higher than that the 13.3% in the control group (P = 0.001). In addition, the presence of a preoperative high-grade J-sign (odds ratio, 11.9 [95% CI, 1.7–82.8]; P = 0.012) and femoral tunnel malposition (odds ratio, 8.2 [95% CI, 1.2–58.0]; P = 0.036) were determined to be independent risk factors associated with residual graft laxity after MPFL-R. The presence of a preoperative high-grade J-sign and femoral tunnel malposition are associated with residual graft laxity after MPFL-R in patients with RPD. These results may provide additional information for counselling patients on residual graft laxity after MPFL-R. Level III.

Background: The lateral meniscus posterior root (LMPR) lesion further decreases dynamic knee stability after anterior cruciate ligament (ACL) injury owing to the loss of the “wedge effect” maintained by the posterior horn of the lateral meniscus. However, the effect of LMPR lesions on the static tibiofemoral relationship in extension after ACL injuries is not determined. Purpose: To (1) determine the effect of LMPR lesions on anterior tibial subluxation of the lateral compartment (ATSLC) in extension in patients with ACL injuries and to (2) identify the LMPR-related factors associated with excessive ATSLC in extension. Study Design: Cohort study; Level of evidence, 3. Methods: Between January 2015 and December 2017, 405 consecutive patients with diagnosed ACL injuries who underwent primary ACL reconstructions were retrospectively reviewed. Among them, 45 patients with combined ACL injuries and LMPR lesions (ACL+LMPR group) and 51 patients with isolated ACL injuries (ACL group) were identified. Values of ATSLC in extension were measured on preoperative supine magnetic resonance imaging and classified into high grade (≥6 mm) and low grade (<6 mm). The mean ATSLC in extension and the proportion of patients with high-grade ATSLC in extension were compared between the groups by univariate analysis. In the ACL+LMPR group, predictors of high-grade ATSLC in extension—including age, sex, body mass index, affected side, cause of injury, period from injury (<12 or ≥12 weeks), LMPR lesion pattern (radial tear or root avulsion), and meniscofemoral ligament integrity (intact or impaired)—were assessed by univariate analysis and multivariate logistic regression analysis. Results: The mean ATSLC in extension in the ACL+LMPR group was significantly greater than that in the ACL group (5.6 mm vs 3.1 mm; P = .001). The proportion of patients with high-grade ATSLC in extension in the ACL+LMPR group was also significantly larger than that in the ACL group (44.4% vs 15.7%; P = .002). In addition, the root avulsion (instead of radial tear) (odds ratio, 28.750; 95% CI, 2.344-352.549; P = .009) and the period from injury ≥12 weeks (odds ratio, 17.095; 95% CI, 1.207-242.101; P = .036) were determined to be the 2 independent predictors of high-grade ATSLC in extension. However, age, sex, body mass index, affected side, cause of injury, and meniscofemoral ligament integrity were not. Conclusion: After ACL injuries, concomitant LMPR lesion further increased ATSLC in extension. Chronic LMPR avulsion was associated with high-grade ATSLC in extension.

Background: Steep posterior tibial slope (PTS) and excessive anterior tibial translation (ATT) have been identified as important anatomic risk factors for anterior cruciate ligament (ACL) injury, which have raised concerns about clinical outcomes after primary ACL reconstruction (ACLR). Purpose: To investigate anatomic risk factors of primary ACLR failure and to determine the cutoff values of PTS and ATT for predicting primary ACLR failure. Study Design: Case-control study; Level of evidence, 3. Methods: Between November 2015 and May 2017, a total of 215 consecutive patients with clinically diagnosed noncontact ACL injuries who underwent primary anatomic ACLR were retrospectively analyzed. Among them, 25 patients who showed complete discontinuity of ACL fibers on final follow-up magnetic resonance imaging scans were allocated into the failure group (study group). They were matched 1:2 to 50 control participants who showed clear and continuous ACL fibers on magnetic resonance imaging scans (control group). PTS and ATT were measured on preoperative weightbearing whole leg lateral radiographs and compared between the groups. The cutoff values of PTS and ATT for predicting primary ACLR failure were determined by the receiver operating characteristic curve. Moreover, predictors of primary ACLR failure were assessed by multivariate logistic regression analysis, including sex, age, body mass index, concomitant meniscal tears, degree of pivot-shift test, and KT-1000 arthrometer side-to-side difference, PTS, and ATT. Results: PTS and ATT values in the study group were significantly higher than those in the control group (mean ± SD: PTS, 17.2°± 2.2° vs 14.4°± 2.8°; ATT, 8.3 ± 3.4 mm vs 4.1 ± 3.1 mm; P < .001). The cutoff values of PTS and ATT for predicting primary ACLR failure were 17° (sensitivity, 66.7%; specificity, 90.9%) and 6 mm (sensitivity, 87.5%; specificity, 79.5%), respectively. Additionally, PTS ≥17° (odds ratio, 15.6; 95% CI, 2.7-91.5; P = .002) and ATT ≥6 mm (odds ratio, 9.9; 95% CI, 1.9-51.4; P = .006) were determined to be risk factors of primary ACLR failure, whereas sex, age, body mass index, concomitant meniscal tears, degree of the pivot-shift test, and KT-1000 arthrometer side-to-side difference were not. Conclusion: In this study, PTS ≥17° and ATT ≥6 mm, as measured on weightbearing whole leg radiographs, were identified to be predictive risk factors of primary ACLR failure. This study adds to the existing knowledge about potential surgical indications of simultaneous slope-reducing high tibial osteotomy to mitigate the primary ACLR failure rate.

Background: It has been speculated that the patellar J sign may have a negative effect on the clinical outcomes of patients with recurrent patellar dislocation (RPD). Purpose: To (1) evaluate clinical outcomes, postoperative patellar stability, and patellar maltracking correction in patients with RPD treated with derotational distal femoral osteotomy (DDFO) and combined procedures and (2) investigate the influence of J sign severity on the clinical outcomes. Study Design: Cohort study; Level of evidence, 3. Methods: Between January 2015 and December 2016, a total of 78 patients (81 knees) with RPD, a positive J sign, and an excessive femoral anteversion angle (FAA; ≥30°) were surgically treated with DDFO and combined procedures. J sign severity was graded according to a previously described classification system (grades 1-3). Routine radiography and computed tomography were performed on every patient to evaluate the patellar height, trochlear dysplasia, genu valgum, tibial tuberosity–trochlear groove distance, patellar lateral tilt angle, and patella–trochlear groove distance. The patellar lateral shift distance during stress radiography was measured preoperatively and postoperatively to quantify medial patellofemoral ligament (MPFL) graft laxity under anesthesia, and “MPFL residual graft laxity” was defined as the patellar ridge surpassing the apex of the lateral femoral trochlea. Patients were evaluated using the Kujala, International Knee Documentation Committee (IKDC), and Lysholm scores preoperatively and postoperatively. Patients were allocated into 3 subgroups in terms of the severity of the J sign: low-grade group 1 (grade 1; n = 19), low-grade group 2 (grade 2; n = 16), and high-grade group (grade 3; n = 12). Subgroup analyses were performed to investigate the influence of a high-grade J sign on the clinical outcomes. Results: Among the 78 patients (81 knees), 47 patients (47 knees) met the inclusion criteria. The mean follow-up time was 26.1 ± 1.7 months. The mean preoperative and postoperative FAAs were 36.2°± 5.3° and 10.0°± 2.1°, respectively, with a mean correction angle of 26.2°± 5.9°. At the final follow-up, all patient-reported outcomes improved significantly, and subgroup analyses showed that the high-grade group had significantly lower Kujala scores (75.6 vs 85.3 for low-grade group 1 [ P < .001] and 83.4 for low-grade group 2 [ P = .001]), Lysholm scores (77.6 vs 84.6 for low-grade group 1 [ P = .003]), and IKDC scores (78.6 vs 87.3 for low-grade group 1 [ P = .001] and 84.3 for low-grade group 2 [ P = .033]) than the low-grade groups. The total rate of MPFL residual graft laxity was 8.5% (4/47), and the prevalence of the postoperative residual J sign was 38.3% (18/47). Subgroup analyses showed significant differences between the high-grade group and the 2 low-grade groups with regard to the MPFL residual graft laxity rate (33.3% vs 0.0% for low-grade group 1 [ P = .016] and 0.0% for low-grade group 2 [ P = .024]), residual J sign rate (91.7% vs 15.8% for low-grade group 1 [ P < .001] and 25.0% for low-grade group 2 [ P < .001]), and patellar lateral shift distance (14.2 vs 8.1 mm for low-grade group 1 [ P = .002] and 8.7 mm for low-grade group 2 [ P = .007]). Conclusion: In a group of patients treated for RPD with a positive preoperative J sign and increased FAA (≥30°), patients with a preoperative high-grade J sign had inferior clinical outcomes, more MPFL residual graft laxity, and greater residual patellar maltracking.

Objective:To explore the risk factors of primary anterior cruciate ligament (ACL) reconstruction failure.Methods:From November 2015 to May 2017, a total of 178 consecutive patients with clinically diagnosed non-contact ACL injury were treated and followed-up more than 2 years. Twenty-five patients (post-operative failure group) who underwent completely ruptured ACL graft confirmed by MRI, positive pivot-shift test, more than 5 mm side-to-side difference (SSD) measured by KT-1000 arthrometer, more than 5 mm static anterior tibial translation (ATT) measured on MRI were determined to be ACL reconstruction failure. They were matched in a 1∶2 fashion to 50 non-failure patients (post-operative non-failure group), who showed intact ACL graft 2 years after ACL reconstruction. The sex, age, body mass index (BMI), affected side, meniscal injury side, time from injury to surgery, KT-1000 SSD, pivot shift test under anesthesia, follow-up duration, posterior tibial slope (PTS) and ATT measured on the pre-operative weight-bearing whole leg radiographs between the two groups were compared using univariate analysis. Moreover, the predictors of ACL reconstruction failure were assessed by multivariable conditional Logistic regression analysis.Results:Post-operative failure group had a significantly higher PTS and ATT values than those in the post-operative non-failure group (17.21°±2.20° vs 14.36°±2.72°, t=4.395, P<0.001; 8.29±3.42 mm vs 4.09±3.06 mm, t=5.504, P<0.001). The sex, age, BMI, affected side, meniscal injury side, time from injury to surgery, KT-1000 SSD, pivot shift test under anesthesia, follow-up duration between the two groups showed no significant difference ( P>0.05). Multivariable Logistic regressions indicated that PTS≥17° ( OR=15.62, P=0.002) and ATT≥6 mm ( OR=9.91, P=0.006) were independent risk factors for primary ACL reconstruction failure. However, sex, age, BMI, meniscal lesions, degree of pivot shift test, KT-1000 SSD were not the independent risk factors. Conclusion:PTS≥17° and ATT≥6 mm could increase the risk of primary ACL reconstruction failure.

Background: Habitual patellar dislocation in extension (HPD-E) is a distinctive subtype of recurrent patellar dislocation (RPD); HPD-E represents the most severe type of patellar maltracking in RPD. It has been reported that the presence of preoperative patellar maltracking is associated with a worse clinical outcome after medial patellofemoral ligament (MPFL) reconstruction (MPFL-R). Purpose: To describe the radiological characteristics of HPD-E and to compare clinical outcomes after MPFL-R among patients with and without preoperative HPD-E. Study Design: Cohort study; Level of evidence, 3. Methods: From January 2012 to December 2015, a total of 230 consecutive patients (246 knees) with RPD were treated with MPFL-R alone or combined with tibial tubercle osteotomy. Among them, 28 patients diagnosed with HPD-E by preoperative 3-dimensional computed tomography (CT; HPD-E group) were matched in a 1:1 fashion to 28 control participants who did not show HPD-E (control group). Routine radiography and CT were performed to evaluate patellar height, trochlear dysplasia, tibial tubercle–trochlear groove distance, and torsional deformities. The mean patellar laxity index and lateral patellar translation assessed with stress radiography were measured preoperatively and postoperatively to quantify MPFL laxity. At minimum 2-year follow-up, patient-reported outcomes (Kujala, Lysholm, and Tegner scores), patellar maltracking, and redislocation rates were compared between the HPD-E and control groups. Results: The radiological characteristics of the HPD-E group were as follows: 89% (25/28) of patients had severe trochlear dysplasia (Dejour type B or D), and the mean femoral anteversion angle was 35.5° ± 4.7°. At the final follow-up, the HPD-E group had a significantly lower Kujala score (76.2 vs 84.5, respectively; P = .001), Lysholm score (75.4 vs 86.6, respectively; P < .001), and Tegner score (4.1 vs 5.8, respectively; P = .021) compared with the control group. The postoperative patellar laxity index (43% vs 19%, respectively; P < .001) and redislocation rate (25% vs 0%, respectively; P = .01) were significantly higher in the HPD-E group than in the control group. Conclusion: Preoperative 3-dimensional CT is a reliable method of identfying patients with HPD-E. Treatment of HPD-E by MPFL-R alone or combined with tibial tubercle osteotomy resulted in a higher redislocation rate, more severe MPFL residual laxity, and lower patient-reported outcome scores compared with patients without HPD-E who underwent MPFL-R.

Objective:To evaluate the clinical, radiological and arthroscopic outcomes after surgical repair for chronic lateral meniscus posterior root (LMPR) avulsion combined with anterior cruciate ligament (ACL) reconstruction.Methods:From July 2015 to June 2017, a total of 33 patients who underwent transtibial pull-out suture repair for chronic LMPR avulsion combined with anatomic single-bundle ACL reconstruction with hamstring graft were retrospectively reviewed. There were 30 males and 3 females with an average age of 27.7±7.5 years (range 17-45 years) and a mean BMI of 25.2±3.7 kg/m 2 (range 19.4-36.7 kg/m 2). All patients were available for at least two years of follow-up. A second-look arthroscopy was performed to evaluate the healing status of the repaired meniscus. Subjective knee function was assessed through Lysholm and Tegner scores. Objective knee stability was evaluated using KT-1000 arthrometer side-to-side difference (SSD) and pivot shift test under anesthesia. The tibiofemoral relationship was evaluated by anterior tibial subluxation (ATS) measured on axial MRI. Between patients with preoperative ATS ≥6 mm (18 patients in the ATS positive group) and <6 mm (15 patients in the ATS negative group), the postoperative ATS and the reduction of ATS was also compared. Results:After a mean follow-up of 27.5±4.0 months (range 24-39 months), the LMPR avulsion completely healed in 23 (70%) cases, partially healed in 9 (27%) cases, failed to heal in 1 (3%) case on second-look arthroscopy. The Lysholm score was increased from 60.4±13.6 to 82.7±11.1 at 1 year and to 91.4±9.1 at 2 years operatively ( F=155.996, P<0.001). The Tegner score was increased from 3(2, 5) to 4(3, 5) at 1 year and 6(4, 6) at 2 years postoperatively (χ 2=47.791, P<0.001). The KT-1000 SSD was decreased from 9.1±3.3 mm to 2.0±1.7 mm ( t=11.197, P<0.001). The result of pivot shift test was also improved (10 grade I, 20 grade II, 3 grade III, preoperatively vs 30 grade 0, 3 grade I, postoperatively, U=5.161, P<0.001). The ATS was reduced from 5.7±3.9 mm to 3.5±3.2 mm ( t=3.530, P=0.001). However, there was no statistically significant decrease in the ATS of the ATS negative group ( t=0.400, P=0.695). The ATS of the ATS positive group was reduced from 8.7±1.8 mm to 5.0±3.3 mm ( t=4.765, P<0.001), and the ATS reduction of the ATS positive group was greater than that of the ATS negative group (3.7±3.3 mm vs 0.3±2.8 mm, t=3.115, P=0.004). Conclusion:In patients undergoing ACL reconstruction, the transtibial pull-out suture repair for chronic LMPR avulsion yielded meniscus healing rate of 97% with improved subjective knee function and objective knee stability and better restored the tibiofemoral relationship for patients with excessive ATS.