Advanced 3-Dimensional Characterization of Hill-Sachs Lesions in 100 Anterior Shoulder Instability Patients.

PURPOSE: We sought to qualitatively and quantitatively describe characteristics of Hill-Sachs lesions (HSL) in a cohort of anterior shoulder instability patients using advanced 3-dimensional (3-D) modeling software and assess the impact of various HSL parameters on the HSL volume, location, and orientation in patients with anterior shoulder instability. METHODS: A total of 100 recurrent anterior instability patients with evidence of HSL with a mean age of 27.2 years (range = 18 to 43 years) were evaluated. Three-dimensional models of unilateral proximal humeri were reconstructed from CT scans, and the volume, surface area (SA), width, and depth of identified HSLs were quantified along with their location (medial, superior, and inferior extent). Multiple angular orientation measures of HSLs were recorded, including Hill-Sachs rim (HSLr) angle in order to classify the level and location of potential humeral head engagement. Mann-Whitney U test assessed the relationship between measured parameters. RESULTS: By volume, larger HSL had greater humeral head surface area (HH SA) loss (P = .001), HSL width (P = .001), were more medial (P = .015), and more inferior (P = .001). Additionally, more medial lesions had greater HSLr angles (P = 0.001). The mean depth, width, and volume of HSLs were 3.3 mm (range = 1.2-7.1 mm), 16.0 mm (range = 6.2-30.4 mm) and 449.2 mm3 (range = 62.0-1365.6 mm3), respectively. The medial border of the HSL extended to 17.2 ± 4.4 (range = 9.3-28.3 mm) off the most medial edge of the HH cartilage margin (medialization). The mean HSLr was 29.3 ± 10.5°. CONCLUSION: There was a statistically significant association between HSL medialization and HSL volume, position, and orientation. More medialized HSL have larger volume, greater width, more SA loss and higher lesion angles and are more inferior in the humeral head. As it has been established that more medialized lesions have poorer clinical outcomes, this study highlights that HS lesions have varying angles and medialization, which may portend eventual treatment and outcomes. LEVEL OF EVIDENCE: IV, case series.

Limited Predictive Value of the Instability Severity Index Score: Evaluation of 217 Consecutive Cases of Recurrent Anterior Shoulder Instability.

PURPOSE: To review the existing variables and their ability to predict recurrence of shoulder instability as it relates to the Instability Severity Index Score (ISIS), as well as evaluate any other pertinent imaging and patient history variables that may impact risk of recurrent anterior instability after arthroscopic Bankart repair. METHODS: All consecutive patients with recurrent anterior shoulder instability and who had arthroscopic instability repair were identified. Exclusion criteria were prior surgery on the shoulder, posterior or multidirectional instability, instability caused by seizure disorder, or a rotator cuff tear. All ISIS variables were recorded (age <20 years, sport type and level, hyperlaxity, Hill-Sachs on anteroposterior external rotation radiograph, loss of glenoid contour on anteroposterior radiograph), as well as additional variables: (1) number of instability events; (2) total time of instability; (3) glenoid bone loss (GBL) percent; and (4) Hill-Sachs measures (H/L/W/D/Volume). Postoperative outcomes were assessed based on the Western Ontario Shoulder Instability Index (WOSI), Single Assessment Numeric Evaluation (SANE) scores, and American Shoulder and Elbow Surgeons (ASES) scores, and recurrent anterior instability. Regression analysis was used to determine preoperative variables that predicted outcomes and failures. RESULTS: There were 217 consecutive patients (209 male patients [96.5%], 8 female patients [3.5%]) who met the inclusion criteria and were all treated with a primary arthroscopic shoulder stabilization during a 3.5-year period (2007-2011), with a mean follow-up time of 42 months (range, 26-58). The mean age at first instability event was 23.9 years (range, 16-48 years) and the mean cumulative ISIS score for the overall group was 3.6 (range, 1-6). Outcomes were improved from mean preoperative (WOSI = 1,050/2,100; ASES = 61.0; SANE = 52.5) to postoperative (WOSI = 305/2,100; ASES = 93.5; SANE = 95.5). A total of 11.5% (25/217) of patients had evidence of recurrent instability (subluxation or dislocation). Additionally, all 25 patients who failed postoperatively also had consistently inferior ASES, SANE, and WOSI outcome scores when compared with successfully treated patients. Factors associated with failure were GBL greater than 14.5% (P < .001), total time of instability symptoms greater than 3 months (P = .03), Hill-Sachs volume greater than 1.3 cm3 (P = .02), contact sports participation (P = .05), and age 20 years or younger (P < .01). There was no correlation in outcomes with Hill-Sachs on presence of glenoid contour loss on radiograph (P = .07), participation sports, or ISIS (mean = 3.4 success vs 3.9 failure, P > .05). CONCLUSIONS: At a mean follow-up of 42 months was an 11.5% failure rate after arthroscopic Bankart stabilization surgery. This study shows no correlation between treatment outcome and the ISIS measure, given a mean score of 3.4 for the overall cohort with little difference identified in those who failed. However, several important parameters previously unidentified were detected including, GBL greater than 14.5%, Hill-Sachs volume greater than 1.3 cm3, and duration of instability symptoms (>3 months). The ISIS may need to be redesigned to incorporate variables that more accurately portray the actual risk of failure after arthroscopic stabilization, including quantification of both glenoid and humeral head bone loss. LEVEL OF EVIDENCE: III (Retrospective Case Series).

Postoperative Stiffness and Pain After Arthroscopic Labral Stabilization: Consider Anchor Arthropathy.

PURPOSE: To describe the key clinical, imaging, and arthroscopic characteristics of anchor arthropathy after arthroscopic shoulder stabilization procedures and, secondarily, to define risk factors for the development of anchor-induced arthropathy. METHODS: A total of 23 patients who underwent revision arthroscopic shoulder surgery and were diagnosed with glenohumeral arthropathy were retrospectively identified from prospectively collected data registries between January 2000 and May 2018. Data included initial diagnosis and index procedure performed, presenting arthropathy symptoms including duration, and examination findings before revision surgery. Pre-revision imaging was used to assess presence of glenohumeral osteoarthritis and chondromalacia, anchors/sutures, loose bodies, and labral pathology. The same parameters were recorded intraoperatively during revision surgery. Descriptive statistics were performed for demographic data and means with standard deviations were calculated for continuous data. A McNemar-Bowker test was used to analyze marginal homogeneity between preoperative imaging and intraoperative findings. RESULTS: Mean age at presentation was 33.4 ± 11.7 years (range 16-59, 17 male patients; 6 female patients). More than one half (13/23) developed symptoms within 10 months after index arthroscopic procedure (mean 32.2 ± 59.9 months, range <1 to 165.2 months) with 87% presenting with pain and 100% presenting with loss of motion on examination. Plain radiographs demonstrated humeral osteoarthritis in 57% (13/23) of patients, magnetic resonance imaging (MRI) revealed recurrent labral pathology in 19 of 23 (83%) patients, potential proud implants in 12 of 23 (52%), and loose bodies in 12 of 23 (52%). Intraoperatively, all had evidence of osteoarthritis; 22 of 23 (96%) had prominent implants. Humeral head chondromalacia was present in 21 of 23 patients (91%), the majority of which was linear stripe wear, and 6 of 23 (26%) had severe global glenohumeral osteoarthritis. Statistical analysis revealed a 54.5% (95% confidence interval 0.327-0.749) sensitivity of MRI identification of proud implants with a specificity of 100% (95% confidence interval 0.055-1). The ability of MRI to accurately assess chondromalacia of the humeral head (P = .342) or glenoid (P = .685) was not statistically significant. CONCLUSIONS: Anchor arthropathy is characterized by symptoms of pain and stiffness on examination and in many cases develops early after stabilization surgery (<10 months). Implants were implicated in the majority of cases of humeral head chondromalacia. MRI scans may produce false-negative identification of proud implants and can be a poor predictor of the severity of chondromalacia and intra-articular pathology; thus, a high index of clinical suspicion is necessary in patients with motion loss and pain postoperatively. LEVEL OF EVIDENCE: Level IV, case series.

Anchor Arthropathy of the Shoulder Joint After Instability Repair: Outcomes Improve With Revision Surgery.

PURPOSE: To report clinical and patient-reported outcome measures (PROMs) in patients undergoing revision surgery after diagnosis of anchor-induced arthropathy. METHODS: Patients who underwent revision arthroscopic shoulder surgery and were diagnosed with post-instability glenohumeral arthropathy performed from January 2006 to May 2018 were included in the current study. Patients were excluded if they underwent prior open shoulder procedures, if glenoid bone loss was present, or if prerevision imaging and records were incomplete or not available. Data included initial diagnosis and index procedure performed, presenting arthropathy symptoms including duration, exam findings before revision surgery, and surgical intervention. PROMs were prospectively collected before surgery and at minimum 2-year follow-up. RESULTS: Fourteen patients were included with a mean (± standard deviation) age at presentation of 35.2 ± 12.1 years (range 16 to 59). The follow-up rate was 86%, with a mean follow-up of 3.8 years (range 1.1 to 10.6). Mean time to development of arthropathy symptoms was 48.2 months (range <1 month to 13.8 years), all presenting with pain and decreased range of motion on exam. At time of revision surgery, all patients underwent either open or arthroscopic removal of previous implants, including anchors and suture material. Six patients underwent additional revision stabilization procedures, 1 underwent total shoulder arthroplasty, and 7 underwent arthroscopic intraarticular debridement, capsular release, and chondroplasty with or without microfracture. Pain significantly improved in 79% of patients (P = .05). Significant improvements in all PROMs were observed, including 12-item Short Form (43.8 to 54.8, P < .01); Disabilities of the Arm, Shoulder, and Hand, shortened version (31.8 to 8.4, P < .01); Single Assessment Numeric Evaluation (47.0 to 84.5, P < .05); and American Shoulder and Elbow Surgeons (61.6 to 92.1, P < .01). Average external rotation significantly improved, from 31° ± 22° to 52° ± 24° (P = .02). CONCLUSION: Rapid intervention after diagnosis, through either revision arthroscopic or open debridement and stabilization, can lead to significant improvement in range of motion, pain, and overall patient function and satisfaction. LEVEL OF EVIDENCE: IV, retrospective case series.

Glenoid Track Instability Management Score: Radiographic Modification of the Instability Severity Index Score.

PURPOSE: The purpose of this study is (1) to test the proposed treatment algorithm, the Glenoid Track Instability Management Score (GTIMS), which incorporates the glenoid track concept into the instability severity index score (ISIS), and (2) to compare treatment decision-making using either GTIMS versus ISIS in 2 cohorts of patients with operatively treated anterior instability. METHODS: A multicenter, retrospective review of two consecutive groups consisting of 72 and 189 patients treated according to ISIS and GTIMS, respectively, was conducted. Inclusion criteria for all patients were ≥2 confirmed traumatic anterior shoulder instability events and a physical examination demonstrating a positive anterior apprehension and relocation test. The GTIMS was graded for all 189 patients in the cohort, which uses 3-dimensional computed tomography as the sole radiographic parameter to assess on-track (0 points) versus off-track (4 points) Hill-Sachs lesions. This method differs from ISIS, which uses multiple plain radiographs for the 4-point imaging portion of the score. Outcomes scores were compared within the GTIMS and ISIS groups, as well as between them for overall comparisons based on the Western Ontario Shoulder Instability Index (WOSI), the Single Assessment Numerical Evaluation (SANE) score, and the mean rates of recurrent instability. RESULTS: A total of 261 consecutive patients from 2009 to 2014 who presented with recurrent anterior shoulder instability were treated according to either ISIS (n = 72/261, 27.6%) or GTIMS (n = 189/261, 72.4%). At a mean follow-up time of 33.2 months (range 24-49 months), the overall cohort mean ISIS of 2.9 ± 2.2 (range 0-9) was significantly higher than the mean GTIMS of 1.9 ± 1.9 (range = 0-9, P < .001). Of the 72 ISIS treated patients, 50 (69.4%) had an ISIS score of ≥ 4 and underwent a Latarjet, and the 22 patients (30.6%) with an ISIS score of < 4 underwent an arthroscopic Bankart repair. Based on GTIMS in the 189-patient cohort, using the same cutoff of 4 to indicate the need for a Latarjet, 162 patients were treated with arthroscopic Bankart repair (85.7%) and 27 with Latarjet (14.3%). The overall outcomes improved for patients treated with a Latarjet in both groups (GTIMS WOSI from 1099 [47.7% normal] to 395 [81.3% normal]; GTIMS SANE from 48 to 81; ISIS WOSI from 1050 [50% normal] to 345 [83.4% normal]; ISIS SANE from 50 to 84; P < .01). Similar positive outcomes were seen in patients treated with arthroscopic Bankart repair (GTIMS WOSI from 1062 [49.2% normal] to 402 [80.6% normal]; GTIMS SANE from 49 to 82; ISIS WOSI from 1080 [51.8% normal] to 490 [76.7% normal]; ISIS SANE from 48 to 77; P < .01). Of note, the patients with arthroscopically indicated ISIS had significantly worse outcomes scores than those treated arthroscopically according to GTIMS (P < .01). Of the 189 patients graded with GTIMS, there would have been 33 more Latarjet procedures recommended based on ISIS score. Thus the distribution of procedures based on ISIS versus GTIMS was significantly different (χ2 = 45.950; P < .001), indicating a higher rate of recommending Latarjets when using ISIS versus GTIMS. CONCLUSIONS: When ISIS scoring and plain radiograph parameters only are used, this predicted a 2-fold increase in recommending a Latarjet versus GTIMS scoring criteria, which uses advanced imaging and the on- and off-track principle to more conservatively delineate anterior instability treatment with promising postoperative patient outcomes. Overall, there were minimal differences in outcomes between GTIMS and ISIS Latarjet patients; however, better outcomes were seen in patients indicated for arthroscopic Bankart repair according to GTIMS and on-off track computed tomography scanning indications. LEVEL OF EVIDENCE: II, Prospective Cohort Study.

Characterization of Posterior Glenoid Bone Loss Morphology in Patients With Posterior Shoulder Instability.

PURPOSE: To systemically describe posterior bone defects in the setting of posterior shoulder instability based on several parameters, including surface area, slope and version, defect height from the base of the glenoid, and extent of bone loss at equal intervals along the long axis of the fossa. METHODS: A total of 40 young, active individuals with recurrent posterior shoulder instability and a bony injury confirmed on either computed tomography (n = 18; mean age, 26.3 ± 4.0 years) or magnetic resonance imaging (n = 22; mean age, 20.0 ± 4.9 years) were identified. The posterior glenoid bone defect was characterized using the following measures: (1) percentage of bone loss, (2) glenoid vault version, (3) slope of the posterior defect relative to the glenoid surface, (4) superior-inferior length of the defect, and (5) anterior-posterior width of the defect at 5 intervals along the glenoid fossa. RESULTS: The mean age of the 40 patients was 22.9 ± 5.5 years (range, 14.9-35.5 years). The mean surface area of glenoid bone loss was 9.7% ± 4.7%. Glenoid version measured at 5 equal intervals along the inferior two-thirds of the glenoid was 12.8° ± 4.9°, 11.9° ± 5.0°, 10.1° ± 6.3°, 10.5° ± 6.5°, and 8.7° ± 7.2° from superior to inferior. The mean slope of the posterior defect relative to the glenoid fossa was 26.8° ± 11.5°. The mean superior-inferior height of the bony defect was 21.9 ± 0.4 mm. The anterior-posterior sloped width of the defect at 5 equal intervals along the glenoid fossa was 0.9 ± 1.5 mm, 2.8 ± 2.4 mm, 4.0 ± 1.7 mm, 4.0 ± 2.1 mm, and 2.9 ± 2.6 mm from superior to inferior. Low-grade (<10%) bone loss was diagnosed in most shoulders (23 of 40 evaluated), whereas 15 had moderate bone loss (10% to <20%) and 2 had high-grade bone loss (≥20%). CONCLUSIONS: Posterior glenoid bone loss is characterized by a loss of posterior bony concavity, increased slope from anterior to posterior, and increased posterior version. The most anterior-posterior sloped width was quantified at the third and fourth intervals of 5 equal intervals from superior to inferior. This study highlights that patients with posterior instability have bone loss that is sloped relative to the glenoid fossa and suggests that management must be appropriately tailored given the distinctiveness of posterior bone loss. LEVEL OF EVIDENCE: Level IV, case series.

Outcomes of Primary Biceps Subpectoral Tenodesis in an Active Population: A Prospective Evaluation of 101 Patients.

PURPOSE: To evaluate the surgical outcomes of a primary subpectoral biceps tenodesis for long head of the biceps tendon (LHBT) pathology in a large cohort of prospectively, serially collected, patients in a young active population that has known high physical demands and requirements of their shoulder to perform their vocation. METHODS: A retrospective review of prospectively collected data from an active military personnel with a diagnosis of a Type II SLAP tear or biceps tenosynovitis was performed. Outcomes were evaluated at a minimum follow-up time of 18 months based on preoperative and postoperative assessments of the Single Assessment Numeric Evaluation, Western Ontario Rotator Cuff index, biceps position, and return to active duty. Inclusion criteria were (1) SLAP tears on magnetic resonance arthrogram (classified into SLAP group), and (2) no SLAP tear but examination findings of biceps tendonitis (placed in the LHBT tendonitis group). Patients were excluded for full-thickness rotator cuff tears, high-grade partial thickness tears requiring repair, acromioclavicular joint pathology, and labral pathology outside of the SLAP lesion. Patients from both groups subsequently were treated with open, subpectoral tenodesis. RESULTS: Over a 6-year period at a mean follow-up of 2.75 years (range 1.5-5.7 years), 125 active-duty military personnel with mean age of 42.6 years (range 26.3-56.5) were enrolled. A total of 101 of 125 patients (81%) completed study requirements at a mean of 2.75 years (range 1.5-5.7 years). In total, 40 patients were diagnosed with type II SLAP tears (39.6%) and 61 with biceps tendonitis without SLAP tear (60.4%). Following open, subpectoral tenodesis, there was a significant improvement in patient outcomes (Western Ontario Rotator Cuff = 54% preoperative vs 89% postoperative, Single Assessment Numeric Evaluation = 58 preoperative vs 89.5 postoperative, P < .01). In total, 82% of patients returned to full activity at a mean of 4.1 months. The biceps muscle measured relative to the antecubital fossa of operative (mean 3.20 cm) versus nonoperative (3.11 cm) was not clinically different (P = .57). There was an 8% complication rate, including 3 requiring revision, 2 superficial infections, and 3 transient neurapraxias. CONCLUSIONS: Primary subpectoral open biceps tenodesis for SLAP tears or pathology of the LHBT provides significant improvement in shoulder outcomes with a reliable return to activity level with low risk for complications. LEVEL OF EVIDENCE: Level IV (Case series).

Distal Tibia Allograft Glenoid Reconstruction in Recurrent Anterior Shoulder Instability: Clinical and Radiographic Outcomes.

PURPOSE: To assess the clinical and radiographic outcomes of patients with recurrent anterior shoulder instability treated with fresh distal tibia allograft (DTA) glenoid reconstruction. METHODS: Consecutive patients with a minimum 15% anterior glenoid bone loss associated with recurrent anterior instability who underwent stabilization with DTA glenoid reconstruction were retrospectively reviewed. Patients were evaluated with the American Shoulder and Elbow Society score, Western Ontario shoulder instability index, and single numerical assessment evaluation score at a minimum 2 years after surgery. All patients also underwent postoperative imaging evaluation with computed tomography where graft incorporation and allograft angle were measured. Statistical analysis was performed with paired t-tests, with P < .05 considered significant. RESULTS: A total of 27 patients (100% male) with an average age of 31 ± 5 years and an average follow-up of 45 months (range, 30-66) were included. There were significant improvements in preoperative to postoperative American Shoulder and Elbow Society score (63-91, P < .01), Western Ontario shoulder instability index (46% to 11% of normal, P < .01), and single numerical assessment evaluation score (50-90.5, P < .01) outcomes. Analysis of computed tomography data at an average 1.4 years postoperatively (available for 25 patients) showed an allograft healing rate of 89% (range, 80% to 100%), average allograft angle of 14.9° (range, 6.6° to 29.3°), and average allograft lysis of 3% (range, 0% to 25%). Grafts with lesser allograft angles (<15°) were better opposed to the anterior glenoid, showing superior healing and graft incorporation. There were no cases of recurrent instability. CONCLUSIONS: At an average follow-up of 45 months, fresh DTA reconstruction for recurrent anterior shoulder instability results in a clinically stable joint with excellent clinical outcomes and minimal graft resorption. Optimal allograft placement resulted in superior bony incorporation with the native glenoid. LEVEL OF EVIDENCE: Level IV, therapeutic case series.

Traditional Versus Congruent Arc Latarjet Technique: Effect on Surface Area for Union and Bone Width Surrounding Screws.

PURPOSE: To compare the surface area available for bony contact and the width of bone on each side of the Latarjet fixation screws in the traditional Latarjet technique versus the congruent arc modification of the Latarjet technique. METHODS: Computed tomographic scans of 24 shoulders in patients with glenohumeral instability who underwent multiplanar reconstruction measurements with multiple dimensions of the coracoid. The surface area of the coracoid available for bony contact with the anterior glenoid and width of bone on each side of a 3.5-mm screw was compared for the traditional Latarjet technique versus the congruent arc modification. RESULTS: The surface area available for bony contact to the anterior glenoid was 5.65 ± 1.08 cm2 using the traditional Latarjet technique compared with 3.64 ± 0.93 cm2 using the congruent arc modification of the Latarjet technique (P < .001). The mean width of bone on each side of a 3.5-mm screw was 7.1 ± 1.0 mm using the traditional Latarjet technique compared with 4.1 ± 1.0 mm using the congruent arc modification (P < .001). CONCLUSIONS: The traditional Latarjet technique has greater bony contact with the glenoid and greater bone width on each side of the screws compared with the congruent arc modification of the Latarjet technique. This potentially allows for a larger surface for healing in the traditional Latarjet technique. Moreover, because of smaller width of the bone around the screw, the congruent arc modification is potentially less tolerant of screw-positioning error compared with the traditional Latarjet technique. LEVEL OF EVIDENCE: Level III, retrospective comparative study.

Radiographic Analysis of the Hill-Sachs Lesion in Anteroinferior Shoulder Instability After First-Time Dislocations.

PURPOSE: To identify the relation between the Hill-Sachs (H-S) angle and arm position at the time of the initial dislocation, and to see if this correlates with the glenoid track. METHODS: A total of 102 patients (89 male patients, 87.2%), with a mean age of 32 years (range, 17 to 38 years), were divided into 2 groups, abduction (ABD) and adduction (ADD), dependent on the position of the arm at the time of the instability event. All patients were evaluated with bilateral computed tomography scans (3-dimensional) to define the H-S position on the glenoid track and to measure the H-S angle. One-way analysis of variance was used to compare the H-S angle between the 2 groups. RESULTS: Dislocation occurred in ABD in 45 patients (44.1%) and in ADD in 57 (55.9%). The H-S angle was 32.4° ± 4.7° in the ABD group versus 16.1° ± 2.9° in the ADD group. All patients' injuries were "on-track" glenoid injuries in both groups. CONCLUSIONS: This study identified a difference in the H-S angle relative to arm position at the time of initial dislocation. Patients whose injury occurred in the ABD position showed a higher H-S angle, leading to an increased risk of engagement, because the long axis of the H-S lesion is parallel to the glenoid in a position of function. Thus arm position at the time of the initial instability event may be a risk factor for engagement and higher risk of recurrence. LEVEL OF EVIDENCE: Level IV, prognostic case series.

The effect of sagittal rotation of the glenoid on axial glenoid width and glenoid version in computed tomography scan imaging.

BACKGROUND: Computed tomography (CT) scans of the shoulder are often not well aligned to the axis of the scapula and glenoid. The purpose of this paper was to determine the effect of sagittal rotation of the glenoid on axial measurements of anterior-posterior (AP) glenoid width and glenoid version attained by standard CT scan. In addition, we sought to define the angle of rotation required to correct the CT scan to optimal positioning. METHODS: A total of 30 CT scans of the shoulder were reformatted using OsiriX software multiplanar reconstruction. The uncorrected (UNCORR) and corrected (CORR) CT scans were compared for measurements of both (1) axial AP glenoid width and (2) glenoid version at 5 standardized axial cuts. RESULTS: The mean difference in glenoid version was 2.6% (2° ± 0.1°; P = .0222) and the mean difference in AP glenoid width was 5.2% (1.2 ± 0.42 mm; P = .0026) in comparing the CORR and UNCORR scans. The mean angle of correction required to align the sagittal plane was 20.1° of rotation (range, 9°-39°; standard error of mean, 1.2°). CONCLUSION: These findings demonstrate that UNCORR CT scans of the glenohumeral joint do not correct for the sagittal rotation of the glenoid, and this affects the characteristics of the axial images. Failure to align the sagittal image to the 12-o'clock to 6-o'clock axis results in measurement error in both glenoid version and AP glenoid width. Use of UNCORR CT images may have notable implications for decision-making and surgical treatment.

Biceps tenodesis for long head of the biceps after auto-rupture or failed surgical tenotomy: results in an active population.

BACKGROUND: Long head of the biceps (LHB) deformity after surgical tenotomy or auto-rupture may result from attrition or injury. The purpose of this study was to describe the surgical outcomes of biceps tenodesis after failed surgical tenotomy or auto-rupture of the LHB tendon in a population of active patients. METHODS: During a 5-year period, 11 patients with a mean age of 43.3 years (range, 33-56 years) presented with symptoms of biceps cramping with activity (100%), deformity (100%), or pain (36%) at a mean of 8 months (range, 0.5-22 months) from a tenotomy (6 of 11) or an auto-rupture (5 of 11). All patients underwent a mini-open subpectoral biceps tenodesis with interference screw fixation. Patients were independently evaluated by patient-reported outcome measures (Single Assessment Numeric Evaluation [SANE] and Western Ontario Rotator Cuff Index [WORC]) and a biceps position examination. RESULTS: Of the 11 patients, 10 (91%) completed the study requirements at a mean of 2.6 years (range, 1.6-4.2 years). A total of 9 of the 10 patients (90%) returned to full activity. The mean preoperative SANE score was 61.1 (standard deviation [SD], 8.8), and the mean preoperative WORC score was 53.2 (SD, 9.2), which improved postoperatively to a SANE score of 84.2 (SD, 7.1) and a WORC score of 86 (SD, 8.2). There were no differences in LHB muscle position relative to the antecubital fossa (3.17 cm preoperatively to 3.25 cm postoperatively; P = .35). Deformity was resolved in all patients; 9 of 10 patients reported full resolution of cramping, and pain was resolved in 8 of 10. CONCLUSIONS: LHB tenodesis after auto-rupture or surgical tenotomy improved symptoms and allowed predictable return to activity and patient satisfaction. Additional work is necessary to determine the optimal treatment of primary biceps lesions.

Humeral Head Reconstruction With Osteochondral Allograft: Bone Plug Optimization for Hill-Sachs Lesions Using CT-Based Computer Modeling Analysis.

Background: Engaging Hill-Sachs lesions (HSLs) pose a significant risk for failure of surgical repair of recurrent anterior shoulder instability. Reconstruction with fresh osteochondral allograft (OCA) has been proposed as a treatment for large HSLs. Purpose: To determine the optimal characteristics of talus OCA bone plugs in a computer-simulated HSL model. Study Design: Descriptive laboratory study; Level of evidence, 6. Methods: Included were 132 patients with recurrent anterior instability with visible HSLs; patients who had multidirectional instability or previous shoulder surgery were excluded. Three-dimensional computed tomography models were constructed, and a custom computer optimization algorithm was generated to maximize bone plug surface area at the most superior apex (superiorization) and minimize its position relative to the most medial margin of the HSL defect (medialization). The optimal number, diameter, medialization, and superiorization of the bone plug(s) were reported. Percentages of restored glenoid track width and conversion from off- to on-track HSLs after bone plug optimization were calculated. Results: A total of 86 patients were included in the final analysis. Off-track lesions made up 19.7% of HSLs and, of these, the mean bone plug size was 9.9 ± 1.4 mm, with 2.2 mm ± 1.7 mm of medialization and 3.3 mm ± 2.9 mm of superiorization. The optimization identified 21% of HSLs requiring 1 bone plug, 65% requiring 2 plugs, and 14% requiring 3 plugs, with a mean overall coverage of 60%. The mean width of the restored HSLs was 68%, and all off-track HSLs (n = 17) were restored to on-track. A Jenks natural-breaks analysis calculated 3 ideal bone plug diameters of 8 mm (small), 10.4 mm (medium), and 12 mm (large) in order to convert this group of HSLs to on-track. Conclusion: Using a custom computer algorithm, we have demonstrated the optimal talus OCA bone plug diameters for reconstructing HSLs to successfully restore the HSL track and, on average, 60% of the HSL surface area and 68% of the HSL width. Clinical Relevance: Reconstructing HSLs with talus OCA is a promising treatment option with excellent fit and restoration of HSLs. This study will help guide surgeons to optimize OCA bone plugs from the humeral head, femoral head, and talus for varying sizes of HSLs.

Glenoid Bone Loss Directly Affects Hill-Sachs Morphology: An Advanced 3-Dimensional Analysis.

BACKGROUND: While the glenoid track concept presents a useful prediction for recurrent glenohumeral instability, little is known about the humeral head bony architecture as it relates to glenoid erosion in the setting of bipolar bone loss. PURPOSE: To (1) qualitatively and quantitatively analyze the interplay between glenoid bone loss (GBL) and Hill-Sachs lesions (HSLs) in a cohort of patients with anterior instability using 3-dimensional imaging software and (2) assess the relationships between GBL and HSL characteristics. STUDY DESIGN: Cross-sectional study; Level of evidence, 3. METHODS: Patients were identified who had anterior shoulder instability with a minimum 5% GBL and evidence of HSL confirmed on computed tomography. Unilateral 3-dimensional models of the ipsilateral proximal humeral head and en face sagittal oblique view of the glenoid were reconstructed using MIMICS software (Materialise NV). GBL surface area, width, defect length, and glenoid track width were quantified. The volume, surface area, width, and depth of identified HSLs were quantified with their location (medial, superior, and inferior extent) on the humeral head. Severity of GBL was defined as percentage glenoid bone surface area loss and categorized as low grade (5%-10%), moderate grade (>10% to 20%), high grade (>20% to 30%), and extensive (>30%). Analysis of variance was then computed to determine significance (P < .05) between severity of GBL and associated HSL parameters. RESULTS: In total, 100 patients met inclusion criteria (mean age, 27.9 years; range, 18-43 years), which included 58 right shoulders and 42 left shoulders (84 male, 16 female). Among groups, there were 32 patients with low-grade GBL (mean GBL = 6.1%), 38 with moderate grade (mean GBL = 16.2%), 17 with high grade (mean GBL = 23.7%), and 13 with extensive (mean GBL = 34.0%), with an overall mean GBL of 18.1% (range, 5%-39%). Patients with 5%-10% GBL had significantly narrower HSLs (average and maximum width; P < .03) and deeper HSLs (average depth; P = .002) as compared with all other GBL groups, while greater GBL was associated with wider and shallower HSLs. GBL width, percentage width loss, defect length, and glenoid track width all significantly differed across the 4 GBL groups (P < .05). CONCLUSION: HSLs had significantly different morphological characteristics depending on the severity of GBL, indicating that GBL was directly related to the characteristics of HSLs. Patients presenting with smaller glenoid defects had significantly narrower and deeper HSLs with less humeral head surface area loss, while greater GBL was associated with wider and shallower HSLs.

Anterior and posterior glenoid bone loss in patients receiving surgery for glenohumeral instability is not the same: a comparative 3-dimensional imaging analysis.

Background: Anterior and posterior glenoid bone loss morphology have both been individually and morphologically described in previous studies. While there exists substantial literature on anterior bone loss, and emerging evidence describing posterior bone loss, a direct comparison between the two is lacking in the current literature. The purpose of this study is to quantitatively compare the anatomic and morphological differences in glenoid bone loss (GBL) in operative patients with anterior versus posterior glenohumeral instability. Methods: All patients over a 3-year period indicated for operative stabilization with posterior glenohumeral instability and suspected glenoid bone loss who underwent a computed tomography (CT) scan were reviewed. Included patients were then singularly matched by gender, laterality, and age (±3 years) to a collection of patients who presented for operative stabilization of anterior glenohumeral instability. GBL parameters were assessed based on the following characterizing measurements: (1) percentage of GBL, (2) glenoid vault version, (3) slope of the glenoid defect relative to the glenoid surface, (4) superior-inferior defect height, and (5) anterior-posterior defect width. Results: Sixty patients (30 anterior GBL, 30 posterior GBL) were included in the final analysis (60 males), with a mean age of 28.8 ± 8.15 years (range 16.0 to 51.0 years). Patients with anterior instability presented with higher GBL (24.94% ± 7.69 vs. 9.22% ± 5.58, P < .001), greater superior-inferior defect height (23.89 ± 4.21 mm vs. 21.88 ± 3.42 mm, P = .047), and steeper slope of glenoid defect (58.80° ± 11.86 vs. 38.59° ± 14.30, P < .001), while patients with posterior instability had greater retroversion (1.53° ± 4.04 vs. 7.59° ± 7.71, P < .001). Additionally, the anterior instability cohort had significantly more patients with moderate- to high-grade glenoid bone loss (n = 30) than patients with posterior instability (n = 11) (P < .001). Conclusion: Anterior instability presents with a steeper slope of glenoid defect, higher percentage GBL, and greater superior-inferior defect height, whereas posterior instability presents with greater retroversion. This underscores the finding that anterior and posterior instability bone loss are not the same morphologically, and this should be considered in the operative treatment of glenohumeral instability.

How to Fashion the Bone Block for Reconstruction of the Glenoid in Anterior and Posterior Instability.

BACKGROUND: Glenoid restoration techniques to address glenohumeral instability-induced anterior and posterior glenoid bone loss (AGBL and PGBL) often require reconstruction, but best-fit bone block (BFBB) modeling has not been developed. PURPOSE: To provide glenoid bony reconstruction models for anterior and posterior instability of the shoulder using a bone loss instability cohort with high-fidelity 3-dimensional (3D) imaging. STUDY DESIGN: Cross-sectional study; Level of evidence, 3. METHODS: We reviewed consecutive patients indicated for operative stabilization who had posterior glenohumeral instability and suspected GBL who underwent 2-dimensional (2D) computed tomography (CT). Patients were matched by sex, laterality, and age to patients who underwent operative stabilization of anterior glenohumeral instability. Mimics software was used to convert all 2D CT scans into 3D models of the scapula. A BFBB model was designed to digitally reconstruct GBL and was used to predict the amount, anatomic configuration, and fixation configuration of bony reconstruction required in AGBL and PGBL. RESULTS: The study included 30 patients with posterior instability and 30 patients with anterior instability; the participants' mean ± SD age was 28.8 ± 8.15 years (range, 16.0-51.0 years). Mean surface area of AGBL was 24.9% ± 7.7% (range, 14.7%-39.1%). Mean BFBB dimensions to reconstruct the anterior glenoid were determined to be a superior-inferior length of 23.9 ± 4.2 mm, anterior-posterior width of 6.4 ± 2.4 mm, and height of 1 cm. Mean angle of AGBL bone block interface relative to glenoid to reconstruct the native concavity was 79.4°± 5.9°. For PGBL, the mean surface area was 9.2% ± 5.6% (range, 3.0%-26.3%). Mean BFBB dimensions to reconstruct the posterior glenoid were a superior-inferior length of 21.9 ± 3.4 mm, width of 4.5 ± 2.3 mm, and height of 1 cm. The mean angle of PGBL bone block interface relative to the glenoid to reconstruct the native concavity was 38.6°± 14.3°. Orientation relative to the vertical glenoid axis was 77.2°± 13.8° in anterior reconstructions versus 105.9°± 10.9° in posterior reconstructions. CONCLUSION: Patients with anterior instability required a more rectangular BFBB with a bone block-glenoid interface angle of 79°, whereas patients with posterior instability required a more trapezoidal, obtusely oriented BFBB with a bone block-glenoid interface angle of 39°. BFBBs for either AGBL or PGBL can be effectively designed, and their size and/or shape can be predicted based on approximate percentage of GBL.

Commercial 3-dimensional imaging programs are not created equal: version and inclination measurement positions vary among preoperative planning software.

Background: Variability exists between total shoulder arthroplasty preoperative planning software (PPS) systems for glenoid angular measurements. The purpose of this study is to locate the region on the glenoid at which inclination and version are measured on the PPS modalities of Blueprint and VIP. Methods: Preoperative computed tomography scans of 30 consecutive patients undergoing primary arthroplasty were analyzed using two PPS systems (VIP and Blueprint) to independently obtain glenoid version and inclination measurements through their respective protocols. Three-dimensional equivalent images were independently analyzed utilizing open-source OsiriX DICOM software by two board-certified orthopedic sports medicine surgeons measuring glenoid version and inclination along ten equal intervals of the glenoid from superior to inferior and anterior to posterior. Manual version and inclination measurements were compared to both the VIP and the Blueprint measurements, and variances were analyzed by calculating root mean square error (RMSE). The closest interval (1, 2, 3, 4, 5, 6, 7, 8, 9, 10) to the VIP and Blueprint measurement was identified for both version and inclination to determine the region of the glenoid both software programs obtained their measurements. Results: Mean glenoid retroversion manually measured using OsiriX was 13.5° compared with 15.1° recorded by Blueprint (P = .516) and 12.2° by VIP (P = .621). Mean inclination using OsiriX was 5.5°, compared with 7.1° (P = .314) and 9.0° (P = .024) recorded by Blueprint and VIP, respectively. RMSE for version between Osirix and VIP was 4.65°, for Osirix and Blueprint was 4.44°, and for VIP and Blueprint was 4.45°. RMSE for inclination between Osirix and VIP was 6.43°, for Osirix and Blueprint was 5.25°, and for VIP and Blueprint was 5.13°. For version, VIP measurements most frequently aligned with the inferior quadrant of the glenoid (n = 13) with a median interval of 7, while Blueprint aligned with the superior quadrant of the glenoid (n = 13) with a median interval of 4. Inclination measurements aligned with the posterior quadrant of the glenoid for both VIP (n = 19) and Blueprint (n = 15) with a median interval of 8. Conclusion: PPS systems for shoulder arthroplasty vary in the region of the glenoid for which version and inclination are measured, which may affect the absolute values generated. Location of version measurement was different among the two commercial software programs, with VIP corresponding closest to the most inferior region of the glenoid, while Blueprint to the most superior one. Further research should assist in determining the version and inclination variations among commercial planning software.

Risk Factors for Recurrence After Arthroscopic Instability Repair-The Importance of Glenoid Bone Loss >15%, Patient Age, and Duration of Symptoms: A Matched Cohort Analysis.

BACKGROUND: Glenoid bone loss (GBL) has been implicated as a risk factor for failure of arthroscopic anterior glenohumeral instability repair. Although certain amounts of GBL are associated with higher recurrence rates, there are limited studies on successes versus failures in these cohorts. PURPOSE: To compare the outcomes of arthroscopic Bankart repair in patients with and without GBL to determine a threshold percentage of GBL that predicts success. STUDY DESIGN: Cohort study; Level of evidence, 2. METHODS: All consecutive patients who underwent arthroscopic Bankart repair for anterior shoulder instability between 2004 and 2013 were prospectively enrolled. Patients with ≤25% GBL were included. Patients with no GBL were grouped and compared with those having 5% to 25% GBL. Outcomes included Single Assessment Numerical Evaluation, Western Ontario Shoulder Index, and American Shoulder and Elbow Surgeons scores, with evidence of recurrent instability. Patients with and without GBL were statistically compared with respect to outcomes and recurrence rates. RESULTS: Of 434 eligible patients, the cases of 405 (45 female, 360 male; mean age, 27.5 years [range, 18-47 years]) were followed for a mean 61 months (range, 48-96 months). There were 189 (46.6%) with no GBL and 216 (53.3%) with GBL; the mean GBL of the latter cohort was 15% (range, 5%-25%). The mean duration of instability symptoms was 7.9 months (range, 1-21 months) and was significantly longer in the GBL group (P < .05). The mean recurrence rate was 14.8%, which was significantly greater in patients presenting with GBL versus those with none (48/216 [22.2%] vs 12/189 [6.3%]; P < .01). Within the GBL group, GBL ≥15%, duration of symptoms >5 months, and younger age (<20 years) were independent risk factors for failure (P < .01). Patients with any GBL had >4-times greater odds of recurrence after arthroscopic stabilization (odds ratio, 4.21; 95% CI, 2.16-8.21). Moreover, patients presenting for arthroscopic Bankart repair with GBL ≥15% had nearly 3-times greater odds of recurrent instability. CONCLUSION: GBL ≥15% in an active patient population portends to increased odds of recurrent instability events and inferior clinical outcomes after arthroscopic Bankart repair. Furthermore, nonmodifiable risk factors, such as age (<20 years) and duration of symptoms before presentation (>5 months), significantly affect risk of recurrence and should be key factors when counseling patients on risk of failure and determining the ideal procedure for the individual patient.

Terminal Sterilization of Anterior Cruciate Ligament (ACL) Allografts: A Systematic Review of Outcomes.

INTRODUCTION: Anterior cruciate ligament (ACL) injuries are common and reconstruction can be completed with either autograft or allograft tissue. However, there is concern about an increased failure rate with allograft tissue. The purpose of this study was to systematically review the available evidence to determine the effect of irradiation and level of dose on the failure rates of allograft in ACL reconstruction. METHODS: A literature search was performed using PubMed, Scopus, and Web of Science from January 2000 to September 2013. Inclusion criteria consisted of the following: (1) primary, unilateral, single-bundle allograft ACL procedure, (2) studies with data documenting graft type and terminal sterilization technique, (3) subjective assessments of outcome, and (4) objective assessments of outcome. Studies without reported subjective and objective outcomes and those pertaining to revision ACL reconstruction were excluded. Failures were defined and compared between irradiated and non-irradiated grafts, as well as between grafts irradiated with 1.2 - 1.8 Mrad and those with 2.0 - 2.5 Mrad. RESULTS: Of the 242 articles identified via initial search, 17 studies met the final inclusion criteria. A total of 1,090 patients were evaluated in this study, all having undergone unilateral primary ACL reconstruction with allograft tissue with 155 failures. The failure rate between non-irradiated (98/687, 14.7%) and irradiated (57/408, 14.0%) was not statistically significant (p = 0.86). Grafts in the high-dose irradiation group (27/135, 20.0%) had a statistically significant higher (p < 0.001) rate of failure than those in the low-dose irradiation group (30/273, 10.6%). CONCLUSION: The irradiation of an allograft increases the risk of failure after an ACL reconstruction but the use of lower doses of radiation decreases that risk.

Distal Clavicular Augmentation with Acromioclavicular and Coracoclavicular Ligament Reconstruction in the Setting of Iatrogenic Induced Acromioclavicular Instability.

Although chronic pain and dysfunction of the acromioclavicular (AC) joint can reliably be treated with distal clavicle excision, disruption of the local stabilizing ligamentous structures may result in iatrogenic instability of the joint. Iatrogenic AC joint instability is a rare condition caused by over resection of the distal clavicle with unintended injury to the stabilizing ligaments in the treatment of AC joint pain. Addressing postresection instability can prove to be difficult because most reconstruction techniques are intended for patients with traumatic AC joint instability with the goal of creating an anatomically stable joint. However, in the setting of iatrogenic instability, the decreased bone stock of the distal clavicle results in instability of the AC joint, especially in the horizontal plane, and may cause these techniques to fail. Thus, operative management must aim to correct both the osseous and ligamentous deficits responsible for the genesis of this instability. In this Technical Note, we describe bony augmentation of the distal clavicle with an iliac crest bone autograft for chronic iatrogenic acromioclavicular joint instability with concomitant reconstruction of the AC and coracoclavicular ligaments.