High diagnostic accuracy of magnetic resonance imaging in detecting subscapularis tendon tears by focusing on the most superior portion of the subscapularis tendon.

PURPOSE: This study aimed to test the hypothesis that identifying the exact location of the most superior portion of the subscapularis tendon using magnetic resonance imaging (MRI) provides high diagnostic accuracy in detecting subscapularis tendon tears. METHODS: This study included 157 patients who underwent primary arthroscopic rotator cuff repair between 2014 and 2017. All patients underwent conventional 1.5-T MRI in our hospital, within 3 months before surgery. We retrospectively compared the diagnosis of subscapularis tendon tears using MRI based on an anatomical concept focusing on the superior-most insertion point of the subscapularis tendon with intraoperative arthroscopic findings. RESULTS: Subscapularis tendon tears were detected in 80 (51.0%) of the 157 patients during arthroscopic evaluation. The overall sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of the MRI examination were 90, 83, 85, 89, and 87%, respectively. With a kappa score of 0.83, the concordance rate between the two raters was almost perfect (95% confidence interval, 0.75-0.92). The sensitivities of the oblique-sagittal and axial sequences were 84 and 79%, respectively. CONCLUSIONS: Preoperative MRI evaluation focusing on the most superior portion of the subscapularis tendon demonstrated high diagnostic accuracy in detecting subscapularis tendon tears. To find the most superior portion of the subscapularis tendon tears, it was essential to check the slice at the level of the lesser tubercle tip and its adjacent slice. In addition, the combined observation of oblique-sagittal and axial sequences helped to detect subscapularis tendon tears with higher sensitivity.

Two-year follow-up after operative treatment of an osseous Bankart lesion with a flap-detached cartilage lesion of the glenoid: A case report.

Glenoid articular cartilage lesion is a rare complication following traumatic anterior dislocation of the shoulder. We report the case of a 14-year-old male rugby player with traumatic anterior shoulder instability, an extensively flapped lesion on the glenoid articular cartilage, and an osseous Bankart lesion. Arthroscopic findings revealed that the glenoid cartilage was flap-detached, extending from the anteroinferior to the center. Repair of the osseous Bankart lesion using suture anchors and resection of the unstable peripheral part of the cartilage was performed arthroscopically. The main region of the injured articular surface was left untouched. During postoperative follow-up, absorption of the glenoid articular surface near the suture anchor holes was identified. Arthroscopic examination three months post-surgery showed that the flap detached lesion of the residual cartilage was stable and appeared adapted on the glenoid surface. The resected area was covered by fibrous tissue. A follow-up computed tomography scan revealed that the osseous lesion was united. The patient returned to his previous sports capacity eight months following the operation. At the 2-year-follow-up, magnetic resonance imaging revealed that the glenoid surface was remodeled to a flattened round shape with no signs of osteoarthritis, exhibiting proper conformity of the joint surfaces to the humeral head. Arthroscopic Bankart repair using suture anchors may cause bone resorption at the glenoid surface, leading to remodeling of the glenoid surface from the damaged glenoid cartilage lesion in young patients.

Anatomic analysis of the whole articular capsule of the shoulder joint, with reference to the capsular attachment and thickness.

BACKGROUND: Although conventional Bankart repair has been the accepted procedure for traumatic anterior glenohumeral instability, the humeral avulsion of the glenohumeral ligament or an elongation of the capsule remains challenging to decide the appropriate treatment. The anatomical knowledge regarding the whole capsule of glenohumeral joint is necessary to accurately treat for the capsular disorders. The aims of the current study were to investigate the anatomical features of capsular attachment and thickness in a whole capsule of glenohumeral joint. METHODS: We used 13 shoulders in the current study. In 9 shoulders, we macroscopically measured the attachment widths of the capsulolabrum complex on the scapular glenoid, and the attachment widths of the capsule on the humerus in reference to the scapular origin of the long head of triceps brachii, and the humeral insertion of the rotator cuff tendons. We additionally used 4 cadaveric shoulders, which were embalmed using Thiel's method, for the analysis of the thickness in a whole capsule by using micro-CT. RESULTS: The glenoidal attachment of the articular capsule appeared to have a consistent width except for the superior part of the origin of the long head of triceps brachii. On the humerus, the articular capsule was widely attached to areas without overlying rotator cuffs, with the widest width (17.3 ± 0.9 mm) attached to the axillary pouch. The inferior part of the capsule, which was consistently thicker than the superior part, continued to the superior part along the glenoid and humeral side edge. CONCLUSIONS: The current study showed that the inferior part of the glenohumeral capsule had a wide humeral attachment from the inferior edge of the subscapularis insertion to the inferior edge of the teres minor insertion via the anatomical neck of the humerus, and the thickness of it was thicker than the superior part of the capsule.

Lateral meniscus posterior root tear contributes to anterolateral rotational instability and meniscus extrusion in anterior cruciate ligament-injured patients.

PURPOSE: The purposes of this study were to investigate (1) meniscus status and clinical findings in anterior cruciate ligament (ACL)-injured patients to clarify associations between the meniscus posterior root tear (PRT) and knee instability, and (2) magnetic resonance imaging (MRI) findings of the PRT to clarify sensitivity and specificity of MRI and prevalence of meniscus extrusion. METHODS: Three hundred and seventeen patients with primary ACL reconstruction were included. PRTs for both medial and lateral sides were confirmed by reviewing surgical records. Preoperative MRI was reviewed to evaluate sensitivity and specificity of the PRT and meniscus extrusion width (MEW). Clinical information regarding the number of giving-way episodes, preoperative KT-1000 measurements and preoperative pivot shift was also assessed. RESULTS: Thirty-nine patients had a lateral meniscus (LM) PRT, whereas only four patients had a medial meniscus PRT. One hundred and seventeen patients had no meniscus tear (control). Twenty-eight patients (71.8%) showed positive signs of the LMPRT based on at least one view of MR images, with the coronal view showing the highest sensitivity. MEW in the LMPRT group was significantly larger than that in the control group. The preoperative pivot shift test grade in the LMPRT group was significantly greater than that in the control group. There were no significant differences in other parameters. CONCLUSIONS: In ACL-injured patients, the LMPRT was associated with ALRI as well as with meniscus extrusion. The coronal view of MRI was useful in identifying the LMPRT, although its sensitivity was not high. Therefore, surgeons should prepare to repair PRTs at the time of ACL reconstruction regardless of MRI findings, and they should make every effort to repair the LMPRT. LEVEL OF EVIDENCE: III.

Location and thickness of delaminated rotator cuff tears: cross-sectional analysis with surgery record review.

BACKGROUND: To facilitate better treatment, we analyzed morphologic features of delamination from the viewpoint of the location of delamination and the thickness of each layer. MATERIALS AND METHODS: Of 270 shoulders that consecutively underwent arthroscopic rotator cuff repair, 210 were included. During the operation, the surgeon assessed the size of the rotator cuff tear, determined the presence and location of delamination, and compared the thickness between superficial and deep layers if delamination was present. Immediately after the operation, the surgeon wrote down the data in the record form. The authors retrospectively referred to these surgical records to investigate those items. RESULTS: Delamination was found in 111 of 210 shoulders. The overall preoperative Constant score did not significantly differ between the 2 groups. In terms of the location, 7.2% cases had delamination in the anterior part, 74.8% in the posterior part, and 18.0% in both parts (Fleiss κ = 0.9). The larger the rotator cuff tear, the more frequently the delamination was limited to the posterior part (trend P = .001). As for layer thickness comparison, 40.0% of the shoulders with small tears, 38.8% with medium tears, 66.0% with large tears, and 80.0% with massive tears had a thicker deep layer than superficial layer (Fleiss κ = 0.9). The larger the size of the rotator cuff tear, the more frequently the deep layer was thicker than the superficial layer (trend P = .001). CONCLUSIONS: The larger the rotator cuff tear, the more carefully shoulder surgeons should observe and treat the posterior and deep part of delamination.

Osteochondral lesion of lateral tibial plateau with extrusion of lateral meniscus treated with retrograde osteochondral autograft transplantation and arthroscopic centralisation.

BACKGROUND: Extrusion of the meniscus has been reported to be correlated with progression of osteoarthritis. In cases with osteochondral lesions after extrusion of the meniscus, meniscal transplantation was the only surgical intervention. Recently, a novel procedure called arthroscopic centralisation has been developed to restore the meniscus function by centralising the midbody of the extruded meniscus onto the rim of the tibial plateau using suture anchors. CASE REPORT: A combination of novel techniques-retrograde osteochondral autograft transplantation to retain hyaline articular cartilage and arthroscopic centralisation to restore residual meniscal function-was used to repair an osteochondral lesion of the lateral tibial plateau possibly caused by extrusion of the lateral meniscus. Good clinical and radiographic outcomes were achieved at the 2-year follow-up. CONCLUSION: A combination of retrograde osteochondral autograft transplantation and arthroscopic centralisation can be a good option to treat the osteochondral lesion of the tibial plateau caused by extrusion of the meniscus.

Video Analysis of Primary Shoulder Dislocations in Rugby Tackles.

BACKGROUND: Characteristics of rugby tackles that lead to primary anterior shoulder dislocation remain unclear. PURPOSE: To clarify the characteristics of tackling that lead to shoulder dislocation and to assess the correlation between the mechanism of injury and morphological damage of the glenoid. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: Eleven elite rugby players who sustained primary anterior shoulder dislocation due to one-on-one tackling between 2001 and 2014 were included. Using an assessment system, the tackler's movement, posture, and shoulder and head position were evaluated in each phase of tackling. Based on 3-dimensional computed tomography, the glenoid of the affected shoulder was classified into 3 types: intact, erosion, and bone defect. Orientation of the glenoid defect and presence of Hill-Sachs lesion were also evaluated. RESULTS: Eleven tackles that led to primary shoulder dislocation were divided into hand, arm, and shoulder tackle types based on the site at which the tackler contacted the ball carrier initially. In hand and arm tackles, the tackler's shoulder joint was forcibly moved to horizontal abduction by the impact of his upper limb, which appeared to result from an inappropriate approach to the ball carrier. In shoulder tackles, the tackler's head was lowered and was in front of the ball carrier at impact. There was no significant correlation between tackle types and the characteristics of bony lesions of the shoulder. CONCLUSION: Although the precise mechanism of primary anterior shoulder dislocation could not be estimated from this single-view analysis, failure of individual tackling leading to injury is not uniform and can be caused by 2 main factors: failure of approach followed by an extended arm position or inappropriate posture of the tackler at impact, such as a lowered head in front of the opponent. These findings indicate that injury mechanisms should be assessed for each type of tackle, as it is unknown whether external force to the glenoid is different in each mechanism during shoulder dislocation.

Centralization of extruded medial meniscus delays cartilage degeneration in rats.

BACKGROUND: Meniscus extrusion often observed in knee osteoarthritis has a strong correlation with the progression of cartilage degeneration and symptom in the patients. We recently reported a novel procedure "arthroscopic centralization" in which the capsule was sutured to the edge of the tibial plateau to reduce meniscus extrusion in the human knee. However, there is no animal model to study the efficacy of this procedure. The purposes of this study were [1] to establish a model of centralization for the extruded medial meniscus in a rat model; and [2] to investigate the chondroprotective effect of this procedure. METHODS: Medial meniscus extrusion was induced by the release of the anterior synovial capsule and the transection of the meniscotibial ligament. Centralization was performed by the pulled-out suture technique. Alternatively, control rats had only the medial meniscus extrusion surgery. Medial meniscus extrusion was evaluated by micro-CT and macroscopic findings. Cartilage degeneration of the medial tibial plateau was evaluated macroscopically and histologically. RESULTS: By micro-CT analysis, the medial meniscus extrusion was significantly improved in the centralization group in comparison to the extrusion group throughout the study. Both macroscopically and histologically, the cartilage lesion of the medial tibial plateau was prevented in the centralization group but was apparent in the control group. CONCLUSIONS: We developed medial meniscus extrusion in a rat model, and centralization of the extruded medial meniscus by the pull-out suture technique improved the medial meniscus extrusion and delayed cartilage degeneration, though the effect was limited. Centralization is a promising treatment to prevent the progression of osteoarthritis.

Evaluation of pivot shift phenomenon while awake and under anaesthesia by different manoeuvres using triaxial accelerometer.

PURPOSE: Evaluating pivot shift phenomenon is difficult due to its subjectivity, wide variation of testing manoeuvres, and difficulty in evaluating patients while awake. The purpose of this study was to evaluate the pivot shift phenomenon using a triaxial accelerometer by two different manoeuvres, the pivot shift test as representative of flexion manoeuvre and N test as a representative of extension manoeuvre, and in two different conditions, awake and under anaesthesia. METHODS: Twenty-nine patients with unilateral anterior cruciate ligament (ACL)-injured knee were included. Pivot shift test and N test were performed for both injured and uninjured legs while awake and under anaesthesia, with the acceleration measurements using a triaxial accelerometer (KiRA). The tests were also subjectively graded on a scale of 0-6 based on the modification of IKDC criteria. RESULTS: Under anaesthesia, acceleration of ACL-injured knees was greater than that of uninjured knees in both pivot shift test (P < 0.001) and N test (P < 0.001) , whereas the acceleration value was greater in the N test. Furthermore, there were significant positive correlations between the acceleration and subjective grading in both tests, whereas the N test was more significant than the pivot shift test. On the other hand, there was no statistical significance in acceleration between ACL-injured and uninjured knees in either test while the patient was awake. CONCLUSION: The triaxial accelerometer was useful to objectively detect and quantitatively evaluate the pivot shift phenomenon by both the pivot shift test and N test under anaesthesia. The acceleration of ACL-injured knees was greater than that of uninjured knees, and the acceleration was correlated with the subjective manual grading, especially in the N test. On the other hand, its use while the patient was awake was likely limited. LEVELS OF EVIDENCE: Diagnostic study of non-consecutive patients without a universally applied gold standard, Level III.

Attachment area of fibres from the horns of lateral meniscus: anatomic study with special reference to the positional relationship of anterior cruciate ligament.

PURPOSE: Although studies support the clinical importance of the fibres from the horns of lateral meniscus (LM), few studies have investigated the detailed anatomy. This anatomic study was conducted to analyse the structural details of LM with special reference to (1) the attachment area of the fibres from the anterior and posterior horns and (2) the positional relationship between these fibres and the anterior cruciate ligament (ACL). METHODS: A total of 24 cadaveric knees were used in the macroscopic investigation, and six knees were used in the histological investigation. Micro-computed tomography analysis was also performed to assess the anatomy of the posteriormost fibre from the posterior horn of LM. RESULTS: Based on the macroscopic investigations, the outer fibres from the anterior horn of LM extended to ACL and seemed to intermingle with ACL fibres. However, the histological investigations showed a distinct border between the fibres and ACL. The inner fibres from the anterior horn of LM attached to the lateral intercondylar tubercle serving as a lateral margin of ACL attachment. Fibres from the posterior horn of LM were separated into anterolateral and posteromedial crura which attached to the posterior aspect of the lateral and medial intercondylar tubercles, respectively. These two crura formed the posterior margin of the ACL attachment, except for the central part of ACL. CONCLUSION: The outer fibres from the anterior horn of LM adjoined ACL. The inner fibres from the anterior horn of LM and two crura from the posterior horn of LM formed the border of the attachment area of ACL. The distinctive fibre anatomy from LM could provide a surgical landmark during arthroscopic surgery.

The Orientation and Variation of the Acromioclavicular Ligament: An Anatomic Study.

BACKGROUND: Several biomechanical studies have shown that the acromioclavicular (AC) ligament prevents posterior translation of the clavicle in the horizontal plane. In anatomy textbooks, however, the AC ligament is illustrated as running straight across the AC joint surface. HYPOTHESIS: The AC ligament does not run straight across the joint surface, and the configuration of the AC ligament may vary. STUDY DESIGN: Descriptive laboratory study. METHODS: We used 16 pairs of shoulder girdles in this study. After identifying the AC ligament, we macroscopically investigated the orientation and attachment of the ligament and measured the angle between the ligament and the line perpendicular to the AC joint surface by using a digital goniometer. In addition, the AC joint inclination angle was measured, and the Spearman rank correlation coefficient between the joint inclination and the ligament angle was calculated. Finally, we sought to classify the AC ligament based on its configuration. Of the 16 pairs of specimens, 3 pairs of shoulders were histologically examined. RESULTS: The AC ligament was divided into 2 parts: a bundle at the superoposterior (SP) part and a bundle at the anteroinferior (AI) part of the joint. The well-developed SP bundle was consistent and ran obliquely at an average ± SD 30° ± 6° in relation to the AC joint surface, from the anterior part of the acromion to the posterior part of the distal clavicle. The joint inclination was 70° ± 12°, and a negative moderate correlation was found between the joint inclination and the ligament angle (P = .02, r = -0.46). In comparison, the AI bundle was thin and narrow, and it could be categorized into 3 types according to its various configurations. CONCLUSION: The AC ligament could be separated into the SP bundle and the AI bundle. The SP bundle ran posteriorly toward the distal clavicle from the acromion at an average angle of 30° to the joint surface. CLINICAL RELEVANCE: Anatomic reconstruction, based on the current findings in combination with findings regarding the coracoclavicular ligament, could facilitate improved outcome in the treatment of AC joint disruption.

Dynamic Evaluation of Pivot-Shift Phenomenon in Double-Bundle Anterior Cruciate Ligament Reconstruction Using Triaxial Accelerometer.

PURPOSE: To evaluate the effect of initial graft tension on rotational stability and to determine the minimum required tension (MRT) based on the pivot-shift phenomenon in isolated anteromedial bundle (AMB), isolated posteromedial bundle (PLB), and double-bundle anterior cruciate ligament (ACL) reconstructions using a triaxial accelerometer during surgery. METHODS: Primary double-bundle ACL reconstructions were included. The pivot-shift test and N-test were performed before and during surgery with the acceleration measurements using a triaxial accelerometer. The pivot-shift test was also manually graded. The AMB and PLB were fixed to a graft tensioning system during surgery with the following settings: (1) AMB only (AMB), (2) PLB only (PLB), and (3) AMB and PLB (A+P). The total graft tension was first set at 20 N and then was increased in increments of 10 N until the pivot-shift test became negative, which was defined as the MRT in each setting. RESULTS: Twenty-five patients were evaluated. The MRT in the AMB setting averaged 26 N (range, 20 to 40 N); in the PLB setting, 28 N (range, 20 to 40 N); and in the A+P setting, 24 N (range, 20 to 40 N). The MRT in the A+P setting was significantly smaller than that in the PLB setting (P = .008). The acceleration in the A+P setting was significantly smaller than that in the AMB and PLB settings both in the pivot-shift test (vs AMB: P = .007, vs PLB: P = .011) and in the N-test (vs AMB: P < .001, vs PLB: P < .001). CONCLUSIONS: Double-bundle ACL reconstruction better controlled rotational stability with smaller MRT than isolated PLB reconstruction at the time of surgery. In double-bundle reconstruction, the MRT based on the pivot-shift phenomenon could be larger than previously reported MRT based on anteroposterior laxity. LEVEL OF EVIDENCE: Level IV, therapeutic case series.

Two-Year Outcomes After Arthroscopic Lateral Meniscus Centralization.

PURPOSE: To evaluate clinical and radiographic outcomes of arthroscopic centralization for lateral meniscal extrusion. METHODS: Twenty-one patients who underwent arthroscopic centralization of the lateral meniscus were included. In cases with an extruded lateral meniscus (9 patients) or discoid meniscus (12 patients), the capsule at the margin between the midbody of the lateral meniscus and the capsule was sutured to the lateral edge of the lateral tibial plateau and centralized using suture anchors to reduce or prevent meniscal extrusion. Clinical outcomes included clinical examination findings, Lysholm score, Knee Injury and Osteoarthritis Outcome Score, and subjective rating scales regarding patient satisfaction and sports performance level. Radiographic outcomes included meniscal extrusion width (MEW) on magnetic resonance imaging and lateral joint space width on a standing 45° flexion posteroanterior view. All clinical and radiographic outcomes were reported pre-operatively and at 2 years post-operatively, whereas MEW was reported at 1 year; outcomes were compared with baseline. RESULTS: Clinical outcomes were significantly improved at 2 years postoperatively compared with baseline: Lysholm score (97 v 69, P < .0001) and all subscores of the Knee Injury and Osteoarthritis Outcome Score except activities of daily living (pain, 89 v 72, P = .0010; symptoms, 91 v 74, P = .0002; activities of daily living, 94 v 89, P = .091; sport and recreational function, 79 v 42, P = .0028; and quality of life, 78 v 46, P = .0029). Patient satisfaction (84 v 22, P < .0001) and sports performance level (82 v 15, P < .0001) were also improved. At 1 year, MEW was significantly reduced compared with baseline for both the extrusion group (1.0 mm v 5.0 mm, P < .0001) and the discoid group (0.3 mm v 1.6 mm, P = .047). Lateral joint space width increased at 2 years in the extrusion group (5.6 mm v 4.8 mm, P = .041) and was maintained in the discoid group (5.5 mm v 5.4 mm). CONCLUSIONS: Arthroscopic centralization of the lateral meniscus improved clinical and radiographic outcomes for meniscal extrusion as well as for discoid menisci at 2-year follow-up. LEVEL OF EVIDENCE: Level IV, therapeutic case series.

Repair of Rotator Cuff Tear With Delamination: Independent Repairs of the Infraspinatus and Articular Capsule.

We propose a technique to repair delamination, which often occurs during rotator cuff repair surgery. We have reported that the infraspinatus occupies most of the greater tuberosity with the articular capsule attached to a very wide area, and that the superficial layer is mainly composed of the infraspinatus, and the deep layer is mainly composed of the articular capsule. To repair such delamination with consideration of the detailed anatomy, we developed the following repair method with independent repair of the superficial layer (infraspinatus) and the deep layer (articular capsule): (1) the deep layer is pulled laterally and joined to the medial margin of the greater tuberosity using 4 simple sutures from 2 anchors; (2) the paired limbs (same color) of 4 knots are passed over the posterior leaf of the superficial layer at intervals; (3) a push-in anchor loaded with 1 thread each of 4 knots is placed on the anterolateral corner of the greater tuberosity to pull the superficial layer anterolaterally; (4) another push-in anchor (remaining threads) is pushed on the posterior corner of the greater tuberosity. We believe that this technique can recover the function of both the articular capsule and rotator cuff, thereby facilitating better treatment outcomes after surgery.

Effect of Initial Graft Tension on Knee Stability and Graft Tension Pattern in Double-Bundle Anterior Cruciate Ligament Reconstruction.

PURPOSE: To determine the initial minimal tension for restoring knee stability during double-bundle anterior cruciate ligament (ACL) reconstruction in vivo. METHODS: Patients who underwent primary double-bundle ACL reconstruction with an autologous semitendinosus tendon during 2012 were included. The bundles were fixed to a graft-tensioning system during surgery. Initial graft tensions were set to the following tensions per 6 mm in graft diameter: (1) 30 N, (2) 25 N, and (3) 20 N. Bundle tension was recorded during knee flexion-extension and in response to anterior or rotatory loads. In addition, anterior knee laxity was measured with the KT-1000 arthrometer (MEDmetric, San Diego, CA), and the pivot-shift test was evaluated. RESULTS: Sixty patients were evaluated. The tension curves of both bundles among different initial tension settings were significantly different (P < .0001), with the tension in the 30-N setting being highest and that in the 20-N setting being lowest. The tension in both bundles showed reciprocal pattern during flexion-extension (P = .019). The tension of the posterolateral bundle graft was significantly lower than that of the anteromedial bundle graft in response to the anterior load at all settings (P = .0017, P = .0019, and P = .0021 at 30° in the 30-N, 25-N, and 20-N settings, respectively, and P < .0001 at 90° at all settings), whereas the tensions in both bundles in response to rotatory loads were equivalent. Two cases showed a grade 1 pivot shift in the 20-N setting, whereas no case showed a positive pivot shift in the other settings. KT measurements in the 30-N and 25-N settings showed no difference. CONCLUSIONS: In double-bundle ACL reconstruction, initial tension could be set as low as 25 N; however, initial tension of 20 N is not recommended because it might result in residual pivot shift in some cases, although the pivot-shift difference was not significant. LEVEL OF EVIDENCE: Level IV, therapeutic case series.

Evaluation of a behind-remnant approach for femoral tunnel creation in remnant-preserving double-bundle anterior cruciate ligament reconstruction - Comparison with a standard approach.

PURPOSE: To evaluate a novel approach for femoral tunnel creation, a behind-remnant approach, in remnant-preserving double-bundle anterior cruciate ligament (ACL) reconstruction through comparison with a standard approach. METHODS: Sixty patients who underwent remnant-preserving double-bundle ACL reconstruction were included. Thirty patients with a standard approach were classified as the standard group, and 30 patients with a behind-remnant approach as the behind-remnant (BR) group. The anteromedial bundle (AMB) and posterolateral bundle (PLB) were provisionally fixed at 20° and 45° of flexion to a graft tensioning system during surgery. Bundle tension was recorded during knee flexion-extension and in response to anterior or rotatory loads. Femoral tunnel positions were then assessed using the quadrant method. RESULTS: During flexion-extension, the BR group showed equivalent tension curves between AMB and PLB, while the standard group showed reciprocal tension curves. The tension on the PLB was lower than the AMB in response to anterior or rotatory loads in the BR group, while the AMB and PLB shared equivalent loads in the standard group. Tunnel position of the AMB in the BR group was lower and deeper, with smaller variances, than that in the standard group. Tunnel position of the PLB in the BR group was lower than that in the standard group. CONCLUSIONS: In remnant-preserving double-bundle ACL reconstruction, a behind-remnant approach can be achieved without any removal of the remnant tissue, and could create a deeper and lower AMB tunnel and a lower PLB tunnel with higher reproducibility, showing equivalent tension curves between the AMB and PLB.

Effect of posterolateral bundle graft fixation angles on clinical outcomes in double-bundle anterior cruciate ligament reconstruction: a randomized controlled trial.

BACKGROUND: In double-bundle (DB) anterior cruciate ligament (ACL) reconstruction, no consensus exists on an optimal setting for the posterolateral bundle (PLB) graft fixation angles. HYPOTHESIS: Different PLB fixation angles would affect clinical outcomes in DB ACL reconstruction. STUDY DESIGN: Randomized controlled trial; Level of evidence, 1. METHODS: This study prospectively included 90 patients who underwent primary DB ACL reconstruction with an autologous semitendinosus tendon. The PLB fixation angles were randomly set as follows: 0° of flexion (P0; n=30), 20° (P20; n=30), and 45° (P45; n=30). In all groups, the anteromedial bundle was fixed at 20° of flexion. The following evaluation methods were used at the preoperative period and at 3, 6, and 9 months and 1 and 2 years after the surgery: clinical examination, KT-1000 arthrometer measurement, muscle strength, Tegner score, Lysholm score, and subjective rating scale regarding patient satisfaction and sports performance levels. Graft retear, contralateral ACL tear, and additional meniscus surgery were also recorded. RESULTS: Seventy-five patients (P0, n=25; P20, n=26; P45, n=24) who were followed for 2 years were evaluated. Preoperatively, there were no differences among the groups. Postoperatively, pivot-shift test results in the P0 and P20 groups were better than those in the P45 group (P0, n=23 graded negative and 2 graded 1+; P20, n=23 and 2; P45, n=15 and 7, respectively; P0 vs P45: P=.038 and P20 vs P45: P=.038). Average KT-1000 arthrometer laxity measurements were better in the P20 group than in the P45 group (P0, 0.4 mm; P20, 0.3 mm; P45, 1.3 mm; P20 vs P45: P=.048), and there were more patients with graft failure (KT-1000 measurement, ≥4 mm) in the P45 group (n=3) than the P0 and P20 groups (each, n=0). There were no significant differences in range of motion, other laxity tests, muscle strength, Tegner score, Lysholm score, subjective rating scale, or additional surgery. CONCLUSION: In DB ACL reconstruction, when the anteromedial bundle was fixed at 20° of flexion, fixation of the PLB at 45° was worse than fixation at 0° and 20° with respect to anterior and rotational stability during the 2-year follow-up. KT-1000 arthrometer measurements and pivot-shift test results were significantly worse, and there were more patients with graft failure in the P45 group. There were no differences among groups in other findings.

Mid- to long-term results of single-bundle versus double-bundle anterior cruciate ligament reconstruction: randomized controlled trial.

PURPOSE: To evaluate the mid-to long-term results of a randomized controlled trial of single-bundle (SB) versus double-bundle (DB) anterior cruciate ligament (ACL) reconstruction using a semitendinosus tendon. METHODS: Seventy-eight patients who underwent primary ACL reconstruction with an autologous semitendinosus tendon were prospectively randomized into 2 groups: SB reconstruction (n = 39) and DB reconstruction (n = 39). In both groups, grafts were fixed at 30° of flexion with a total tension of 80 N. The following evaluation methods were used: clinical examination, KT-1000 arthrometer (MEDmetric, San Diego, CA) measurement, muscle strength, Tegner activity score, Lysholm score, subjective rating scale regarding patient satisfaction and sports performance level, graft retear, contralateral ACL tear, and additional meniscus surgery. RESULTS: Fifty-three patients (25 in SB group and 28 in DB group) who were followed up for a minimum of 3 years (mean, 69 months; range, 36 to 140 months) were evaluated. Preoperatively, there were no differences between the groups. Postoperatively, the Lachman and pivot-shift test results were better in the DB group (P = .024 and P < .0001, respectively). KT measurements were better in the DB group (mean, 1.4 mm v 2.7 mm; P = .0023). The Tegner score was also better in the DB group (P = .033). There were no significant differences in range of motion, muscle strength, Lysholm score, subjective rating scale, graft retear, and secondary meniscal tear. CONCLUSIONS: In ACL reconstruction using the transtibial approach, DB reconstruction was significantly better than SB reconstruction regarding anterior and rotational stability during the 3- to 12-year follow-up. The results of KT measurements and the Lachman and pivot-shift tests were significantly better in the DB group, whereas there was no difference in the anterior drawer test results. The Tegner score was also better in the DB group; however, there were no differences in the other subjective findings. LEVEL OF EVIDENCE: Level II, lesser-quality prospective randomized trial.

The anatomic relationship between the morphology of the greater tubercle of the humerus and the insertion of the infraspinatus tendon.

BACKGROUND: The objective of this study was to evaluate the topographic relationship between the morphology of the greater tubercle and the insertion of the tendon of the infraspinatus. MATERIALS AND METHODS: First, we defined an impression of the greater tubercle, which has not been recognized in classic textbooks, as the "lateral impression" and then measured the dimensions of the "lateral impression" of the greater tubercle in 71 samples of dry bone of humeri. Next, we examined 16 cadaveric humeri with rotator cuff tendons by micro-computed tomography to analyze the positional relationship between the lateral impression and the infraspinatus tendon. RESULTS: In all samples of dry bones, the lateral impression could be identified as a triangle shape. The lateral impression was composed of the border with the highest impression (mean, 6.3 mm), the border with the middle impression (mean, 5.0 mm), and the border with the lateral wall of the greater tubercle (mean, 8.5 mm). In all samples of humeri with rotator cuffs, we could confirm the lateral impression, and the border between the highest impression and the lateral impression corresponded to the anterior border of the insertion of the infraspinatus tendon. CONCLUSION: We propose a new anatomic concept of the lateral impression that could enable the precise diagnosis of and facilitate repair techniques for infraspinatus tear, according to specific anatomic characteristics, by applying 3-dimensional computed tomography assessment preoperatively.