Clinical and radiological outcomes between superior capsule reconstruction using allografts or xenografts: a 2-year retrospective comparison study.

BACKGROUND: Treating symptomatic, massive, irreparable rotator cuff tears remains challenging and controversial. Superior capsule reconstruction (SCR) using the tensor fascia lata has shown promising clinical results; however, due to donor site morbidity, interest in SCR using other grafts has increased. Yet, no studies have compared allografts with xenografts. In addition, the clinical results of graft tears remain controversial. This study compared the clinical and radiological outcomes of SCR between those with allografts and xenografts. METHODS: Sixty-seven patients who had undergone SCR with allografts or xenografts between January 2016 and December 2020 were included in this retrospective study. Furthermore, 62 patients were evaluated 2 years postsurgery, with five patients excluded due to loss to follow-up or conversion to reverse shoulder arthroplasty. The Constant, American Shoulder and Elbow Surgeons, and visual analog scale scores, range of motion, and radiological outcomes were evaluated before the surgery and at 6 and 24 months after surgery. RESULTS: The graft tear rate was 23.08% in the allograft group and 42.86% in the xenograft group at 6 months after surgery; at 2 years postsurgery, the gap further widened to 32.43% and 64%, respectively, showing a significant difference. The graft in the allograft group was thicker than that in the xenograft group, and there were significant differences on the humeral side and in the midsubstance area. The allograft group showed significantly better visual analog scale, Constant, and American Shoulder and Elbow Surgeons scores than the xenograft group 2 years postsurgery. However, the difference in clinical outcomes between the two groups did not surpass minimal clinically important differences. CONCLUSION: Although arthroscopic SCR using xenografts had significantly lower clinical outcome than allografts, this difference did not reach minimal clinically important differences. Arthroscopic SCR using xenografts showed higher graft tear rates than allografts. Even with partial tears, better results were obtained if the graft continuity was maintained. Additionally, after surgery, the xenograft showed less thickness than the allograft and resulted in more tears, specifically in the midsubstance area.

Biomechanical Comparison of Fixation Methods for Posterior Wall Fractures of the Acetabulum: Conventional Reconstruction Plate vs. Spring Plate vs. Variable Angle Locking Compression Plate.

Background and Objectives: Acetabular fractures, though infrequent, present considerable challenges in treatment due to their association with high-energy trauma and poor prognoses. Posterior wall fractures, the most common type among them, typically have a more favorable prognosis compared to other types. Anatomical reduction and stable fixation of the posterior wall are crucial for optimal treatment outcomes. This study aimed to biomechanically compare three commonly used fixation methods for posterior wall fractures of the acetabulum-a conventional reconstruction plate, a spring plate, and a 2.7 mm variable angle locking compression plate (VA-LCP). Materials and Methods: The study utilized 6 fresh-frozen cadavers, yielding 12 hemipelvises free from prior trauma or surgery. Three fixation methods were compared using a simple acetabulum posterior wall fracture model. Fixation was performed by an orthopedic specialist, with prebending of plates to minimize errors. Hemipelvises were subjected to quasi-static and cyclic loading tests, measuring fracture gap, stiffness, and displacement under load. Results: It showed no significant differences in fracture gap among the three fixation methods under cyclic loading conditions simulating walking. However, the conventional reconstruction plate exhibited a greater stiffness compared to the spring and variable angle plates. Fatigue analysis revealed no significant differences among the plates, indicating a similar stability throughout cyclic loading. Despite differences in stiffness, all three fixation methods demonstrated adequate stability under loading conditions. Conclusions: While the conventional reconstruction plate demonstrated a superior stiffness, all three fixation methods provided sufficient stability under cyclic loading conditions similar to walking. This suggests that postoperative limitations are unlikely with any of the three methods, provided excessive activities are avoided. Furthermore, the variable angle plate-like the spring plate-offers an appropriate stability for fragment-specific fixation, supporting its use in surgical applications. These findings contribute to understanding the biomechanical performance of different fixation methods for acetabular fractures, facilitating improved surgical outcomes in challenging cases.

Latarjet procedure without capsular repair produces favorable clinical results and avoids limitation in external rotation.

PURPOSE: This study aimed at analyzing the range of motion (ROM) and other clinical outcomes in patients with > 20% glenoid bone loss who underwent the Latarjet procedure with or without anterior capsule repair. METHODS: This retrospective study included 47 patients with > 20% glenoid bone loss who underwent the classic Latarjet procedure from 2016 to 2021. Of these, 25 did not undergo capsular repair (no-capsular-repair group; group I) whereas 22 patients did (capsular-repair group; group II). The Rowe score, American Shoulder and Elbow Surgeons score, Visual Analogue Scale, ROM, recurrence, and complications were evaluated before and 3, 6, and 12 months after the surgery. A goniometer was used to measure the forward flexion and external rotation (arm adducted, 90° abducted) of both shoulders. The ROM deficit was measured as the difference from the contralateral healthy shoulder. RESULTS: The external rotation in arm adduction at 3 and 6 months after surgery showed significantly better results in group I than group II(p = 0.002 at 3 months; p = 0.005 at 6 months). The deficit in external rotation with arm adduction was also significantly lower in group I at 3 months (p = 0.001) and 6 months (p = 0.001) after surgery. However, external rotation with arm adduction at 12 months after surgery did not significantly differ between the groups. Moreover, the ROM in external rotation with 90° arm abduction was significantly better in group I than that in group II at 3, 6, and 12 months postoperatively (p = 0.002, p = 0.001, and p = 0.005, respectively). The deficit in external rotation with 90° arm abduction gradually decreased with time after surgery and differed significantly between the groups. However, the difference in deficit between the two groups at 12 months after surgery did not exceed the measurement error. All clinical scores significantly improved after surgery compared to before surgery; however, the improvement did not significantly differ between the two groups. CONCLUSION: The Latarjet procedure without capsular repair showed good laxity restoration and clinical results with less early postoperative external rotation limitation than that achieved by the same procedure with capsular repair. However, external rotation deficit at 1 year after surgery did not show a clinically relevant difference difference between the two groups. LEVEL OF EVIDENCE: Level III.

Effects of neuromuscular electrical muscle stimulation on the deltoid for shoulder function restoration after reverse total shoulder arthroplasty in the early recovery period: a prospective randomized study.

INTRODUCTION: Neuromuscular electrical stimulation (NMES) is a treatment modality that has been used to accelerate the rehabilitation of patients with neurological damage. However, it is unclear whether NMES of the deltoid can lead to the early restoration of shoulder function after reverse total shoulder arthroplasty (RSA). MATERIALS AND METHODS: In this prospective and randomized study, 88 patients who underwent RSA with the same prosthesis design for cuff tear arthropathy or irreparable rotator cuff tear were assessed. The patients were divided into two groups (NMES group and non-NMES group, 44 patients each). For the NMES group, two pads of the NMES device were placed over the middle and posterior deltoid area, and NMES was maintained for 1 month after surgery. Shoulder functional outcomes and deltoid thickness were compared at 3, 6, and 12 months postoperatively. Shoulder functional outcomes were assessed based on the visual analog scale (VAS) for pain, American Shoulder and Elbow Surgeons (ASES), and Constant scores and the range of motion (ROM) and power of the affected shoulder. The thickness of the anterior, middle, and posterior deltoid was measured by ultrasonography. RESULTS: A total of 76 patients (NMES group, 33 patients; non-NMES group, 43 patients) were enrolled in the final analysis. The preoperative demographics and status of the remaining rotator cuff of both groups were not significantly different. At postoperative 3 months, the ROM and power of external rotation of the NMES group were significantly greater than those of the non-NMES group (ROM, 36° ± 14° vs. 29° ± 12°; P = .003; power, 4.8 kg ± 1.8 kg vs. 3.8 kg ± 1.0 kg; P < .002). The ROM of external rotation of the NMES group at postoperative 6 months was also greater than that of the non-NMES group (41° ± 12° vs. 34° ± 11°; P = .013). However, there was no significant difference in the VAS, ASES, and Constant scores at all follow-up points despite gradual improvements until 1 year postoperatively. Serial measurements of the thickness of the anterior, middle, and posterior deltoid of both groups did not show significant differences. CONCLUSIONS: Postoperative NMES of the deltoid after RSA contributed to significantly faster ROM restoration and considerable improvement in the power of external rotation. Therefore, NMES following RSA could lead to the early restoration of external rotation and recovery of deltoid function.

Improved Clinical and Radiologic Outcomes Seen after Superior Capsule Reconstruction using Long Head Biceps Tendon Autograft.

PURPOSE: The objective of this study was to investigate the clinical and radiologic outcomes after superior capsule reconstruction (SCR) with biceps tendon (BT) for irreparable rotator cuff tears. METHODS: The retrospective study period was May 2015 through February 2018. The average follow-up was 32 months (24-48 months) after surgery. Study inclusion criteria included an arthroscopic SCR performed using only our technique and minimum 2-year clinical follow-up by office visit and survey. Exclusion criteria included irreparable subscapularis tear and those patients lost to follow-up. This method enabled SCR by using the extraarticular portion and the intraarticular portion and making it 2 to 3 bundles by moving back and forth in the intraarticular area. Physical examination and functional scoring procedures were performed before surgery and at 3, 6, 12, and 24 months after surgery. Radiography and magnetic resonance imaging (MRI) were performed before surgery, after surgery (only radiography), and at 6 and 24 months after surgery. RESULTS: Fifty-three shoulders involving 45 consecutive patients underwent BT technique for irreparable massive rotator cuff tears. The visual analog scale (VAS), American Shoulder and Elbow Surgeons (ASES), and constant score (CS) showed statistically significant improvement (VAS, 4.1-1.0; ASES, 60.9-82.7; and CS, 64.9-80.0; P < .0001). The shoulder active range of motion improved significantly by 23 for forward elevation (125.3-148.4; P < .0001) and by 12 for external rotation (38.0-50.9, P < .0001). The acromiohumeral distance (AHD) was significantly increased by 2.7 mm (4.4 ± 1.4 mm -> 7.1 ± 1.3 mm). No graft tear was detected in 39 patients (86.7%) during follow-up (24-48 months). CONCLUSIONS: SCR via our technique improved clinical and radiologic outcomes. Thirty-five (77.7%) patients achieved 17-point improvement (the minimally clinically important difference) in the last follow-up of ASES score. Clinical scores and AHD had significantly increased, and good healed rate (86.7%) was observed in MRI. LEVEL OF EVIDENCE: Level IV, retrospective case series.

Early restoration of shoulder function in patients with the Grammont prosthesis compared to lateralized humeral design in reverse shoulder arthroplasty.

BACKGROUND: This study aimed to compare the clinical outcomes and radiographic parameters of patients after reverse shoulder arthroplasty (RSA) between the Grammont prosthesis and lateralized humeral design prosthesis. METHODS: A total of 114 patients who underwent RSA with a lateralized humeral design (group L; 71 shoulders) and medialized humeral design (group M; 43 shoulders) prosthesis for cuff tear arthropathy or irreparable rotator cuff tear were enrolled. Clinical outcomes including visual analog scale (VAS), American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form (ASES), and Constant scores and range of motion (ROM) were serially followed up at postoperative 3, 6, 12, and 24 months. Radiographic parameters were measured to evaluate preoperative and postoperative status. RESULTS: Both prostheses demonstrated similar clinical outcomes and shoulder function preoperatively and at postoperative 2 years (P >.05). However, patients in group M had significantly better postoperative active forward flexion (postoperative 3 months, 115° ± 12° vs. 101° ± 14°; P <.001; 6 months, 125° ± 13° vs. 118° ± 13°; P <.013) and abduction (3 months, 105° ± 12° vs. 98° ± 12°; P = .002); VAS (3 months, 3.1 ± 1.2 vs. 3.7 ± 1.4; P = .031; 6 months, 2.3 ± 1.1 vs. 2.8 ± 1.3; P = .038); ASES (3 months, 64.2 ± 7.0 vs. 60.4 ± 9.2; P = .022; 6 months, 70.6 ± 6.0 vs. 66.6 ± 8.1; P = .007); and Constant scores (6 months, 59.6 ± 6.9 vs. 55.7 ± 9.3; P = .020). Group L showed a significantly lower rate of scapular notching than group M (15.5% vs. 41.8%; P < .001). The position of the proximal humerus in group L was more lateralized and less distalized than in group M after RSA. CONCLUSIONS: RSA with both the Grammont and lateralized humeral design prostheses provided similar shoulder ROM restoration and functional improvements at a minimum of 2 years. However, patients with a humeral lateralized prosthesis showed slower recovery of shoulder function and ROM up to postoperative 6 months despite a lower incidence of scapular notching.

Incidence and risk factors of acromial fracture following reverse total shoulder arthroplasty.

BACKGROUND: The occurrence and related predictors of acromial fracture following reverse total shoulder arthroplasty (RTSA) have not been fully elucidated. The aim of this study was to determine the incidence and risk factors of acromial fractures after RTSA. METHODS: We conducted a multicenter, retrospective case-control study of 787 cases (29 in acromial fracture group and 758 in control group) that underwent RTSA performed by 6 surgeons. The mean duration of follow-up after RTSA was 31.6 ± 21.8 months (range, 12-136 months). Demographic variables (age, sex, arm dominance, body mass index, working status, bone mineral density [BMD]), clinical variables (preoperative diagnosis, previous operation, implant design, preoperative clinical scores, screw size in glenoid fixation, postoperative rehabilitation), and radiographic variables (acromial thickness, critical shoulder angle, deltoid length, humeral offset to lateral acromion) were investigated. To determine risk correlation, univariate analysis and multivariate logistic regression analysis with calculated odds ratios (ORs) were performed. RESULTS: Postoperative acromial fractures occurred in 29 of the 787 shoulders with RTSA (3.7%). Acromial fractures were detected at a mean of 10.0 months (range, 1-66 months) postoperatively. Univariate analysis revealed that the occurrence of an acromial fracture was significantly associated with a previous operation (38% [11 of 29] vs. 21% [156 of 758], P = .025) and BMD (-2.33 vs. -1.74, P = .013). Multivariate logistic regression analysis found that the occurrence of a postoperative acromial fracture was significantly associated with a previous operation (P = .034; OR, 2.91; 95% confidence interval, 1.08-7.84) and deltoid length (P = .004; OR, 1.04; 95% confidence interval, 1.01-1.07). CONCLUSION: Acromial fracture following RTSA is not an uncommon complication, with an overall incidence of 3.7%. A previous operation, increased deltoid length, and low BMD were risk factors of acromial fracture following RTSA.

Three-dimensional in vivo scapular kinematics and scapulohumeral rhythm: a comparison between active and passive motion.

BACKGROUND: The aim of this study was to compare the scapular kinematics and scapulohumeral rhythm of healthy participants during arm elevation and lowering and to find the difference between active motion and passive motion of the shoulder. METHODS: The study examined the shoulders of 10 healthy men (mean age, 23.5 years; age range, 22-28 years). The shoulders of participants were elevated and lowered while fluoroscopic images were taken, and 3-dimensional bone models were created from 2-dimensional to 3-dimensional images using model registration techniques. The Euler angle sequences of the models' scapular kinematics and scapulohumeral rhythm were compared during active and passive shoulder motion. RESULTS: There was a significant statistical difference of upward rotation during arm elevation between active and passive shoulder movements (P = .027). In particular, the upward rotation between 45° and 90° of elevation showed a statistically significant difference (P < .001). When the scapula was tilted posteriorly by active motion, it resulted in a statistically significant difference as there was more tilting in the high-degree range of motions than when it was tilted by passive motion (P < .001). There was no statistically significant difference between the 2 groups in scapular external rotation. However, during arm lowering, scapular kinematics did not show statistically significant difference between active and passive motion. CONCLUSIONS: The scapular kinematics showed statistically significant differences between active and passive motion of upward rotation and posterior tilting of the scapula during arm elevation, but there were none during lowering. In terms of upward rotation, active shoulders rotated more upward during arm elevation.

Sports injury and illness incidence in the PyeongChang 2018 Olympic Winter Games: a prospective study of 2914 athletes from 92 countries.

OBJECTIVE: To describe the incidence of injuries and illnesses sustained during the XXIII Olympic Winter Games, hosted by PyeongChang on 9-25 February 2018. METHODS: We recorded the daily number of athlete injuries and illnesses (1) through the reporting of all National Olympic Committee (NOC) medical teams and (2) in the polyclinic and medical venues by the PyeongChang 2018 medical staff. RESULTS: In total, 2914 athletes (1210 women, 42%; 1704 men, 58%) from 92 NOCs were observed for occurrence of injury and illness. NOC and PyeongChang 2018 medical staff reported 376 injuries and 279 illnesses, equalling 12.6 injuries and 9.4 illnesses per 100 athletes over the 17-day period. Altogether, 12% of the athletes incurred at least one injury and 9% at least one illness. The injury incidence was highest in ski halfpipe (28%), snowboard cross (26%), ski cross (25%), snowboard slopestyle (21%) and aerials (20%), and lowest in Nordic combined, biathlon, snowboard slalom, moguls and cross-country skiing (2%-6%). Of the 376 injuries recorded, 33% and 13% were estimated to lead to ≥1 day and >7 days of absence from sport, respectively. The highest incidences of illness were recorded in biathlon (15%), curling (14%), bobsleigh (14%) and snowboard slalom (13%). Thirty per cent of the illnesses were expected to result in time loss, and 70% affected the respiratory system. Women suffered 61% more illnesses than men. CONCLUSION: Overall, 12% of the athletes incurred at least one injury during the Games and 9% an illness, incidences that are similar to the Olympic Winter Games of 2010 and 2014.

Evaluation of three-dimensional in vivo scapular kinematics and scapulohumeral rhythm between shoulders with a clavicle hook plate and contralateral healthy shoulders.

PURPOSE: Acromioclavicular-coracoclavicular ligament injury occurs frequently, and the clavicle hook plate technique is an easy-to-use treatment method. However, complications such as subacromial impingement syndrome, synovitis, erosion, osteolysis, post-operative pain, and post-operative limitations in range of motion have been reported. We aimed to evaluate the use of the clavicle hook plate in the shoulder joints and to compare in vivo three-dimensional (3D) scapular kinematics and scapulohumeral rhythm between the shoulders with a clavicle hook plate and contralateral normal shoulder joints. METHODS: Ten male patients (aged 40.5 ± 14.4 years) who underwent clavicle hook plate fixation for an acromioclavicular-coracoclavicular ligament injury were selected. Computed tomography and fluoroscopy were conducted on both the shoulder joints, and 3D models were created. Using a 3D-2D model-image registration technique, we determined the 3D coordinates of the scapula, and we measured the scapular kinematics and scapulohumeral rhythm. RESULTS: The values for upward rotation, posterior tilt, and external rotation in the two groups increased in proportion with humeral elevation, showing significant differences between the two groups (p < 0.05). Overall, the value in the clavicle hook plate group (group H) was smaller than that in the control group (group C) by 23.5% (6.7°) of upward rotation and 64.8% (18.9°) of posterior tilt. However, the external rotation in group H was greater than that in group C by 32.3% (2.3°). In overall value, there was a significant difference not in upward rotation and external rotation, but in posterior tilt. During humeral elevation, the overall changes in scapulohumeral rhythm were 4.65 ± 2.45 in group H and 3.8 ± 0.8 in group C, and statistical differences were not detected between the two groups. CONCLUSIONS: Clavicle hook plate fixation changes the scapular kinematics and scapulohumeral rhythm; thus, when clavicle hook plate fixation is complete, the implant should be promptly removed.

Which additional augmented fixation procedure decreases surgical failure after proximal humeral fracture with medial comminution: fibular allograft or inferomedial screws?

BACKGROUND: The purpose of this study was to compare clinical and radiologic results between treatment with locking plate fixation and fibular allograft augmentation (FA) and treatment with locking plate fixation and additional inferomedial screws (IMSs) in 3- or 4-part proximal humeral fractures with medial comminution in geriatric patients. METHODS: We enrolled 164 patients with 3- or 4-part proximal humeral fractures with medial comminution who were treated with locking plates. The patients were divided into 2 groups according to additional augmented fixation procedures. The IMS group was composed of patients treated with additional IMSs (80 patients), whereas the FA group was treated with an additional fibular allograft (84 patients). On the basis of fracture classification, the IMS group was subdivided into those with 3-part fractures (52 patients) and those with 4-part fractures (28 patients) and the FA group was subdivided into those with 3-part fractures (55 patients) and those with 4-part fractures (29 patients). Clinical and radiographic results were compared and analyzed. RESULTS: In patients with 3-part fractures, no differences in clinical outcomes were found regardless of additional procedures. However, the FA group showed superior clinical outcomes in patients with 4-part fractures (P = .038 for Constant score and P = .045 for visual analog scale score). The postoperative neck-shaft angle was maintained in the FA group compared with the IMS group with both fracture types at the last follow-up (P = .048 for IMS vs FA with 3-part fractures and P = .023 for IMS vs FA with 4-part fractures). The number of complications was significantly higher in the IMS group (5.5%) than in the FA group (1.2%) (P = .001). CONCLUSION: An FA technique is considered a primary additional procedure for medial support in patients with 4-part proximal humeral fractures involving medial metaphyseal comminution when treated with locking plate fixation.

Effects of short malunion of the clavicle on in vivo scapular kinematics.

BACKGROUND: Short malunion of the clavicle after fracture can change scapular kinematics and alter clinical outcome. However, the effects of malunion on kinematics and outcomes remains poorly understood because there have been no in vivo studies measuring changes during active motion with malunion. This study aimed to measure and to compare in vivo 3-dimensional (3D) scapular kinematics between normal shoulders and shoulders with short malunion using 3D-2-dimensional model image registration techniques. METHODS: Fifteen patients with clavicle fracture who had been treated conservatively were enrolled in this study. In these patients, the angle of scapular upward rotation, posterior tilting, and external rotation were compared between shoulders with short malunion and contralateral, normal shoulders. A 3D-2-dimensional model image registration technique was used to determine the 3D orientation of the scapula. RESULTS: Scapular upward rotation increased following increase of the arm elevation angle and also showed a significant difference by arm elevation in both groups (P = .04). Posterior tilting of the scapula gradually increased as the arm abduction angle increased, and this varied significantly between groups (P = .01). Shoulders with short malunion also showed a more internally rotated position than the contralateral, normal shoulders between 100° and the maximum abduction angle (P = .04). CONCLUSION: Our results suggest that clavicle shortening of >10% greatly affects scapular kinematics in vivo. Further studies will be needed to determine the clinical implications of short malunion of the clavicle.

Reverse shoulder arthroplasty for four-part proximal humerus fracture in elderly patients: can a healed tuberosity improve the functional outcomes?

BACKGROUND: The purpose of this study was to investigate whether healed tuberosities yield better rotational range of motion (ROM) and functional outcomes compared with unhealed tuberosities after reverse shoulder arthroplasty in elderly patients with comminuted proximal humerus fractures. METHODS: This study included 38 patients who underwent reverse arthroplasty because of 4-part proximal humerus fractures; 14 patients had healed tuberosities (group A) and 24 patients had unhealed tuberosities (group B). Functional assessments included visual analog scale pain score, American Shoulder and Elbow Surgeons score, Constant score, and active ROM. RESULTS: There were no significant differences in the patients' demographics between the 2 groups. At final follow-up, no significant differences were found between groups in visual analog scale score (group A, 1.4; group B, 1.6; P = .647), American Shoulder and Elbow Surgeons score (74.3 and 70.7; P = .231), and Constant score (67.9 and 63.9; P = .228) and ROM with forward flexion and internal rotation. However, in external rotation, there was a significant difference between groups (29° and 10° in external rotation with the elbow at the side [P < .001]; 25° and 7° in external rotation with shoulder abduction [P < .001]). CONCLUSION: After reverse shoulder arthroplasty for 4-part proximal humerus fracture, tuberosities were healed in an anatomic position in 37% of patients. However, there were no significant differences in functional outcomes and ROM between the 2 groups, with the exception of external rotation, which was better in the healed tuberosity group. Therefore, tuberosity healing is not a prerequisite for satisfactory outcomes after reverse shoulder arthroplasty for 4-part proximal humerus fractures in elderly patients.

Effect of glenohumeral position on contact pressure between the capsulolabral complex and the glenoid in free ALPSA and Bankart lesions.

PURPOSE: Anterior shoulder dislocation is a common injury, but the optimal management of dislocation remains controversial. We hypothesized that reducing the shoulder in externally rotated position would aid the reduction in capsulolabral lesions. Thus, in this study, contact pressure between the capsulolabral lesion and the glenoid in free ALPSA and Bankart lesions was measured using a cadaver model. METHODS: In 10 specimens, the humerus was externally rotated by abduction on the coronal plane to measure the contact pressure between the capsulolabral complex and glenoid in free ALPSA and Bankart lesions using a Tekscan pressure system. Stability of the joint was confirmed using the Vicon motion analysis system. RESULTS: In the normal shoulder joint, the peak pressure between the subscapularis muscle and the anterior capsule according to the location of the glenohumeral joint decreased to 83.4 ± 21.2 kPa in the 0° abduction and -30° external rotation positions and showed a 300.7 ± 42.9 kPa peak value in the 60° abduction and 60° external rotation positions. In both free ALPSA and Bankart lesions, the lowest pressure between the labral lesion and the glenoid was measured at 0° abduction and -30° external rotation, and the highest pressure was recorded at 60° external rotation and 60° abduction. CONCLUSION: The contact pressure between the capsulolabral complex and the glenoid significantly increased when the abduction and external rotation angles were increased. Based on our results, the conservative management in free ALPSA lesions would respond better than Bankart lesions. IRB OR ETHICAL COMMITTEE APPROVAL: YWMR-12-0-038.

Relationship between the extent of labral lesions and the frequency of glenohumeral dislocation in shoulder instability.

PURPOSE: This study aimed to evaluate the relationship between the extent of the labral lesion and the frequency of glenohumeral dislocation in patients with shoulder instability. METHODS: Ninety-three patients, who underwent surgical treatment at our clinic for chronic anterior shoulder dislocation, were selected and divided into 3 groups (group I: only Bankart lesion; group II: Bankart and SLAP lesions; group III: circumferential-labral lesion). The pre-operative frequency of dislocation, intraoperative findings, operation time, post-operative clinical score, and range of motion 2 years after surgery were analysed and compared among the 3 groups. RESULTS: The time interval from the initial dislocation to operation was significantly shorter in group III than in groups I and II (P = 0.034 and P = 0.046, respectively). The median number of preoperative dislocations was also significantly less in group III than in groups I and II (P = 0.025 and P = 0.044, respectively). In all groups, the clinical scores (Constant, Rowe, and visual analogue scale) improved significantly post-operatively, and there were no significant differences in the scores between the different groups. All patients returned to work, and most patients returned to their preoperative sports activity levels. CONCLUSION: The extent of the labral lesion is not always related to the number of dislocations; therefore, treatment should not be based on this. LEVEL OF EVIDENCE: Retrospective comparative study, Level III.

Ganglion cyst of the spinoglenoid notch: comparison between SLAP repair alone and SLAP repair with cyst decompression.

BACKGROUND: Some authors have described the ganglion cyst of the spinoglenoidal notch as related to repetitive overhead activities and labral tear caused by trauma, while others have explained lesions of the capsulolabral complex and ganglion cysts to have separate pathologies. The purpose of this study is to compare clinical and radiological outcomes between 2 groups: 1 with superior labrum anterior and posterior (SLAP) repair only and the other with SLAP repair and cyst decompression prospectively. MATERIALS AND METHODS: From August 2000 to March 2007, 28 patients matching the inclusion criteria were selected for the study. They were divided into 2 groups: 1 who received SLAP repair and the other with concomitant SLAP repair and cyst decompression. A visual analogue scale (VAS) and Rowe and Constant scores were used to make evaluation. Preoperative magnetic resonance images (MRIs) of 2 patient groups were compared with 2 follow-up MRIs taken 3 months after the operation and at final follow-up. RESULTS: Mean VAS and Constant and Rowe scores in groups I and II improved significantly from mean preoperative score compared to last follow-up score; however, there was no statistically significant difference between the 2 groups (P > .05). Preoperative MRI and arthroscopy revealed type II SLAP lesions and a type V lesion, respectively, as accompanying lesions in 24 cases. CONCLUSION: The hypothesis stating 1-way valve mechanism of SLAP lesion as an initial cause of ganglion cysts has been proved indirectly in this study. Furthermore, direct decompression of the cyst does not lead to different results.

Arthroscopic repair for combined Bankart and superior labral anterior posterior lesions: a comparative study between primary and recurrent anterior dislocation in the shoulder.

PURPOSE: The purpose of this study was to compare clinical outcomes between a primary dislocation group (group P) and a recurrent dislocation group (group R) with combined lesion of Bankart and type II SLAP lesions (type V SLAP lesion) and to evaluate incidence of type V SLAP lesion. In addition, the authors evaluated clinical outcomes of these patients by dividing two groups according to the sequence for Bankart and SLAP lesion suture. METHODS: From May 2000 to May 2005, 310 patients who gave informed consent, underwent the diagnostic arthroscopy and magnetic resonance arthrography (MRA). One hundred and ten patients met the following criteria: (1) post-traumatic primary or recurrent anterior shoulder instability, (2) a normal contralateral shoulder, (3) a type V SLAP lesion, and (4) minimum follow-up of two years. Group P included 42 patients, and group R, 68 patients. Among all patients, 58 patients who had Bankart lesions sutured first were included in group B, and 52 who had their SLAP lesions sutured beforehand, group S. Visual analogue scale, range of motion, Rowe and Constant score were used to compare results between group P and group R, also group B and group S. RESULTS: The incidence rates of type V SLAP lesion were 42.8% in group P and 32.0% in group R. The overall treatment results in our study were good. Even if the difference between the two groups was statistically insignificant, group P showed greater recovery of range of motion than group R in external rotation. No significant difference was found between the two different operative methods according to suture sequence. CONCLUSION: The incidence rates of type V SLAP lesion were 42.8% in the primary dislocation group and 32.0% in the recurrent dislocation group. The overall treatment results in our study were good. Although there was no statistical significance in surgical time between the two groups, when both SLAP and Bankart lesions are present, the Bankart lesion must be sutured first to reduce surgical time.

Biomechanical study of Proximal humeral fracture fixation: Locking plate with medial support screw vs. locking plate with intramedullary fibular graft.

BACKGROUND: The purpose of this study was to evaluate the biomechanical properties of two different fixation constructs in varus collapse proximal humerus fracture, locking plate with medial support screw and locking plate with intramedullary fibular graft. METHODS: We used 8 pairs of undamaged fresh-frozen humen cadaveric humeri and fibula from patients ranging in age from 62 to 81 years. We simulated a proximal humerus fracture with medial comminution using wedge shaped osteotomy. One group was fixed with locking plate with medial support screws, the other group with locking plate with intramedullary fibular graft. Biomechanical test was carried out using servohydraulic material testing system. We measured displacement of specimens under cyclic load test, maximum failure load, initial stiffness, and mode of failure under increasing load test. FINDINGS: Under cyclic loading, the displacement of the specimen was significantly less in the locking plate with fibular strut graft group than in the locking plate with medial support screws group. (p = 0.012) Under increasing load test, the Locking plate with fibular strut graft group showed higher values in both maximum failure load and initial stiffness than the Locking plate with medial support screws group, and this was statistically significant. (p = 0.012, p = 0.001). INTERPRETATION: In biomechanical study, the locking plate with fibular strut graft showed significantly better results in all of the maximum failure load, initial stiffness, and gap depletion compared to the locking plate with medial support screws. LEVEL OF EVIDENCE: Level IV.

High Risk of Hip and Spinal Fractures after Distal Radius Fracture: A Longitudinal Follow-Up Study Using a National Sample Cohort.

The purpose of the present study was to estimate the risk of hip and spinal fracture after distal radius fracture. Data from the Korean National Health Insurance Service-National Sample Cohort were collected between 2002 and 2013. A total of 8013 distal radius fracture participants who were 50 years of age or older were selected. The distal radius fracture participants were matched for age, sex, income, region of residence, and past medical history in a 1:4 ratio with control participants. In the subgroup analysis, participants were stratified according to age group (50-59, 60-69, or ≥70 years) and sex (male or female). Distal radius fracture patients had a 1.51-fold and 1.40-fold higher incidence of hip fracture and spinal fracture in the adjusted models, respectively. Among males, patients of all ages had a significantly higher incidence of hip fracture, and those who were 50 to 69 years of age had a significantly higher incidence of spinal fracture. Among females, those older than 70 years had a significantly higher incidence of hip fracture, and patients of all ages had a significantly higher incidence of spinal fracture. Previous distal radius fracture has a significant impact on the risk of subsequent hip and spinal fractures.

Radiocapitellar joint pressures following transradial amputation increase during elbow motion.

This study aimed to compare the contact area, mean pressure, and peak pressure of the radiocapitellar joint (RCJ) in the upper limb after transradial amputation with those of the normal upper limb during elbow flexion and forearm rotation. Testing was performed using ten fresh-frozen upper limbs, and the transradial amputation was performed 5 cm proximal to the radial styloid process. The specimens were connected to a custom-designed apparatus for testing. A pressure sensor was inserted into the RCJ. The biomechanical indices of the RCJ were measured during elbow flexion and forearm rotation in all specimens. There was no significant difference in the contact area between the normal and transradial amputated upper limbs. However, in the upper limbs after transradial amputation, the mean pressure was higher than that in the normal upper limbs at all positions of elbow flexion and forearm rotation. The peak pressure was significantly higher in the upper limbs after transradial amputation than in the normal upper limbs, and was especially increased during pronation at 45° of elbow flexion. In conclusion, these results could cause cartilage erosion in the RCJ of transradial amputees. Thus, methods to reduce the pressure of the RCJ should be considered when a myoelectric prosthesis is developed.